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* [PATCH v15 0/6] usb: misc: Add onboard_usb_hub driver
@ 2021-07-27  0:41 Matthias Kaehlcke
  2021-07-27  0:41 ` [PATCH v15 1/6] " Matthias Kaehlcke
                   ` (7 more replies)
  0 siblings, 8 replies; 15+ messages in thread
From: Matthias Kaehlcke @ 2021-07-27  0:41 UTC (permalink / raw)
  To: Greg Kroah-Hartman, Alan Stern, Rob Herring, Frank Rowand,
	Mathias Nyman, Felipe Balbi
  Cc: Bastien Nocera, Peter Chen, devicetree, Michal Simek,
	linux-kernel, Douglas Anderson, Krzysztof Kozlowski, linux-usb,
	Ravi Chandra Sadineni, Stephen Boyd, Matthias Kaehlcke,
	Al Cooper, Andrey Zhizhikin, Andy Gross, Aswath Govindraju,
	Bjorn Andersson, Catalin Marinas, Dmitry Baryshkov,
	Dmitry Osipenko, Enric Balletbo i Serra, Fabio Estevam,
	Guido Günther, Jagan Teki, Nishanth Menon, Pawel Laszczak,
	Roger Quadros, Shawn Guo, Vinod Koul, Will Deacon,
	linux-arm-kernel, linux-arm-msm

This series adds:
- the onboard_usb_hub_driver
- glue in the xhci-plat driver to create and destroy the
  onboard_usb_hub platform devices if needed
- a device tree binding for the Realtek RTS5411 USB hub controller
- device tree changes that add RTS5411 entries for the QCA SC7180
  based boards trogdor and lazor
- a couple of stubs for platform device functions to avoid
  unresolved symbols with certain kernel configs

The main issue the driver addresses is that a USB hub needs to be
powered before it can be discovered. For discrete onboard hubs (an
example for such a hub is the Realtek RTS5411) this is often solved
by supplying the hub with an 'always-on' regulator, which is kind
of a hack. Some onboard hubs may require further initialization
steps, like changing the state of a GPIO or enabling a clock, which
requires even more hacks. This driver creates a platform device
representing the hub which performs the necessary initialization.
Currently it only supports switching on a single regulator, support
for multiple regulators or other actions can be added as needed.
Different initialization sequences can be supported based on the
compatible string.

Besides performing the initialization the driver can be configured
to power the hub off during system suspend. This can help to extend
battery life on battery powered devices which have no requirements
to keep the hub powered during suspend. The driver can also be
configured to leave the hub powered when a wakeup capable USB device
is connected when suspending, and power it off otherwise.

Changes in v15:
- adjusted dependencies of USB_DWC3_CORE to make sure it can only
  be enabled when at least one of USB_DWC3_HOST, USB_DWC3_GADGET
  or USB_DWC3_DUAL_ROLE is selectable

Changes in v14:
- rebased on top of v5.14-rc1
- dropped DT binding patch which landed in v5.13

Changes in v13:
- added patch "usb: Specify dependency on USB_XHCI_PLATFORM with
  'depends on'" to the series to avoid Kconfig conflicts
- added patch "arm64: defconfig: Explicitly enable USB_XHCI_PLATFORM"
  to the series to keep effective defconfig unchanged

Changes in v12:
- onboard_hub driver: use IS_ENABLED(CONFIG_USB_ONBOARD_HUB_MODULE)
  in onboard_hub.h to also check for the driver built as module
- onboard_hub_driver: include onboard_hub.h again to make sure there
  are prototype declarations for the public functions

Changes in v11:
- support multiple onboard hubs connected to the same parent
- don't include ‘onboard_hub.h’ from the onboard hub driver

Changes in v10:
- always use of_is_onboard_usb_hub() stub unless ONBOARD_USB_HUB=y/m
- keep 'regulator-boot-on' property for pp3300_hub

Changes in v9:
- added dependency on ONBOARD_USB_HUB (or !!ONBOARD_USB_HUB) to
  USB_PLATFORM_XHCI

Changes in v7:
- updated DT binding
- series rebased on qcom/arm64-for-5.13

Changes in v6:
- updated summary

Changes in v5:
- cover letter added

Matthias Kaehlcke (6):
  usb: misc: Add onboard_usb_hub driver
  of/platform: Add stubs for of_platform_device_create/destroy()
  arm64: defconfig: Explicitly enable USB_XHCI_PLATFORM
  usb: Specify dependencies on USB_XHCI_PLATFORM with 'depends on'
  usb: host: xhci-plat: Create platform device for onboard hubs in
    probe()
  arm64: dts: qcom: sc7180-trogdor: Add nodes for onboard USB hub

 .../sysfs-bus-platform-onboard-usb-hub        |   8 +
 MAINTAINERS                                   |   7 +
 .../boot/dts/qcom/sc7180-trogdor-lazor-r0.dts |  19 +-
 .../boot/dts/qcom/sc7180-trogdor-lazor-r1.dts |  12 +-
 .../arm64/boot/dts/qcom/sc7180-trogdor-r1.dts |  19 +-
 arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi  |  19 +-
 arch/arm64/configs/defconfig                  |   1 +
 drivers/usb/cdns3/Kconfig                     |   2 +-
 drivers/usb/dwc3/Kconfig                      |   5 +-
 drivers/usb/host/Kconfig                      |   5 +-
 drivers/usb/host/xhci-plat.c                  |   6 +
 drivers/usb/host/xhci.h                       |   2 +
 drivers/usb/misc/Kconfig                      |  17 +
 drivers/usb/misc/Makefile                     |   1 +
 drivers/usb/misc/onboard_usb_hub.c            | 497 ++++++++++++++++++
 include/linux/of_platform.h                   |  22 +-
 include/linux/usb/onboard_hub.h               |  18 +
 17 files changed, 621 insertions(+), 39 deletions(-)
 create mode 100644 Documentation/ABI/testing/sysfs-bus-platform-onboard-usb-hub
 create mode 100644 drivers/usb/misc/onboard_usb_hub.c
 create mode 100644 include/linux/usb/onboard_hub.h

-- 
2.32.0.432.gabb21c7263-goog


^ permalink raw reply	[flat|nested] 15+ messages in thread

* [PATCH v15 1/6] usb: misc: Add onboard_usb_hub driver
  2021-07-27  0:41 [PATCH v15 0/6] usb: misc: Add onboard_usb_hub driver Matthias Kaehlcke
@ 2021-07-27  0:41 ` Matthias Kaehlcke
  2021-07-27  0:41 ` [PATCH v15 2/6] of/platform: Add stubs for of_platform_device_create/destroy() Matthias Kaehlcke
                   ` (6 subsequent siblings)
  7 siblings, 0 replies; 15+ messages in thread
From: Matthias Kaehlcke @ 2021-07-27  0:41 UTC (permalink / raw)
  To: Greg Kroah-Hartman, Alan Stern, Rob Herring, Frank Rowand,
	Mathias Nyman, Felipe Balbi
  Cc: Bastien Nocera, Peter Chen, devicetree, Michal Simek,
	linux-kernel, Douglas Anderson, Krzysztof Kozlowski, linux-usb,
	Ravi Chandra Sadineni, Stephen Boyd, Matthias Kaehlcke,
	Al Cooper

The main issue this driver addresses is that a USB hub needs to be
powered before it can be discovered. For discrete onboard hubs (an
example for such a hub is the Realtek RTS5411) this is often solved
by supplying the hub with an 'always-on' regulator, which is kind
of a hack. Some onboard hubs may require further initialization
steps, like changing the state of a GPIO or enabling a clock, which
requires even more hacks. This driver creates a platform device
representing the hub which performs the necessary initialization.
Currently it only supports switching on a single regulator, support
for multiple regulators or other actions can be added as needed.
Different initialization sequences can be supported based on the
compatible string.

Besides performing the initialization the driver can be configured
to power the hub off during system suspend. This can help to extend
battery life on battery powered devices which have no requirements
to keep the hub powered during suspend. The driver can also be
configured to leave the hub powered when a wakeup capable USB device
is connected when suspending, and power it off otherwise.

Technically the driver consists of two drivers, the platform driver
described above and a very thin USB driver that subclasses the
generic driver. The purpose of this driver is to provide the platform
driver with the USB devices corresponding to the hub(s) (a hub
controller may provide multiple 'logical' hubs, e.g. one to support
USB 2.0 and another for USB 3.x).

Note: the current series only supports hubs connected directly to
a root hub (through xhci-plat), support for other configurations
could be added if needed.

Co-developed-by: Ravi Chandra Sadineni <ravisadineni@chromium.org>
Signed-off-by: Ravi Chandra Sadineni <ravisadineni@chromium.org>
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
---

Changes in v15:
- none

Changes in v14:
- none

Changes in v13:
- none

Changes in v12:
- use IS_ENABLED(CONFIG_USB_ONBOARD_HUB_MODULE) in onboard_hub.h to
  also check for the driver built as module
- include onboard_hub.h again from the driver to make sure there are
  prototype declarations for the public functions
- remove indentation from label in onboard_hub_create_pdevs()

Changes in v11:
- added onboard_hub_create/destroy_pdevs() helpers, to support multiple onboard
  hubs connected to the same parent hub
- don't include ‘onboard_hub.h’ from the onboard hub driver
- updated commit message
- added ‘Acked-by' from Alan

Changes in v10:
- always use of_is_onboard_usb_hub() stub unless ONBOARD_USB_HUB=y/m

Changes in v9:
- none

Changes in v8:
- none

Changes in v7:
- don't declare stub for of_is_onboard_usb_hub() when
  CONFIG_COMPILE_TEST is defined

Changes in v6:
- use 'companion-hub' to locate the platform device, instead of
  scanning through the nodes of the parent
- added ABI documentation for 'always_powered_in_suspend'
- sysfs_emit() instead of sprintf() in always_powered_in_suspend_show()
- register sysfs attribute through driver.dev_groups
- evaluate return value of driver_attach() in _probe()
- use dev_warn() instead of WARN_ON() in _probe()
- include 'onboard_hub.h'

Changes in v5:
- the platform device is now instantiated from the same DT node
  as the 'primary' USB hub device
  - use the USB compatible strings for the platform device
  - refactored _find_onboard_hub() to search the parents child
    nodes for a platform device with a matching compatible string
  - added exported function of_is_onboard_usb_hub() to allow other
    drivers (like xhci_plat) to check if one of their child DT nodes
    is a supported hub
- use late suspend to make sure info about wakeup enabled descendants
  is updated
- call driver_attach() for the USB driver in onboard_hub_probe() to
  make sure the driver is re-attached after the device_release_driver()
  calls in onboard_hub_remove()
- renamed sysfs attribute 'power_off_in_suspend' to
  'always_powered_in_suspend'
- added sysfs symlinks between platform device and USB devices
- marked 'onboard_hub_pm_ops' as __maybe_unused
- removed 'realtek' compatible string which is not needed at this
  point
- fix log for regulator_disable() failure

Changes in v4:
- updated Kconfig documentation
- changed the loop in onboard_hub_remove() to release the hub lock
  before unbinding the USB device and make self deadlock prevention
  less clunky
- fixed return value in onboard_hub_usbdev_probe()
- added entry to MAINTAINERS file

Changes in v3:
- updated the commit message
- updated description in Kconfig
- remove include of 'core/usb.h'
- use 'is_powered_on' flag instead of 'has_wakeup_capable_descendants'
- added 'going_away' flag to struct onboard_hub
  - don't allow adding new USB devices when the platform device is going away
  - don't bother with deleting the list item in onboard_hub_remove_usbdev()
    when the platform device is going away
- don't assume in onboard_hub_suspend() that all USB hub devices are
  connected to the same controller
- removed unnecessary devm_kfree() from onboard_hub_remove_usbdev()
- fixed error handling in onboard_hub_remove_usbdev()
- use kstrtobool() instead of strtobool() in power_off_in_suspend_store()
- unbind USB devices in onboard_hub_remove() to avoid dangling references
  to the platform device
- moved put_device() for platform device to _find_onboard_hub()
- changed return value of onboard_hub_remove_usbdev() to void
- evaluate return value of onboard_hub_add_usbdev()
- register 'power_off_in_suspend' as managed device attribute
- use USB_DEVICE macro instead manual initialization
- add unwinding to onboard_hub_init()
- updated MODULE_DESCRIPTION
- use module_init() instead of device_initcall()

Changes in v2:
- check wakeup enabled state of the USB controller instead of
  using 'wakeup-source' property
- use sysfs attribute instead of DT property to determine if
  the hub should be powered off at all during system suspend
- added missing brace in onboard_hub_suspend()
- updated commit message
- use pm_ptr for pm_ops as suggested by Alan

Changes in v1:
- renamed the driver to 'onboard_usb_hub'
- single file for platform and USB driver
- USB hub devices register with the platform device
  - the DT includes a phandle of the platform device
- the platform device now controls when power is turned off
- the USB driver became a very thin subclass of the generic USB
  driver
- enabled autosuspend support

 .../sysfs-bus-platform-onboard-usb-hub        |   8 +
 MAINTAINERS                                   |   7 +
 drivers/usb/misc/Kconfig                      |  17 +
 drivers/usb/misc/Makefile                     |   1 +
 drivers/usb/misc/onboard_usb_hub.c            | 497 ++++++++++++++++++
 include/linux/usb/onboard_hub.h               |  18 +
 6 files changed, 548 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-bus-platform-onboard-usb-hub
 create mode 100644 drivers/usb/misc/onboard_usb_hub.c
 create mode 100644 include/linux/usb/onboard_hub.h

diff --git a/Documentation/ABI/testing/sysfs-bus-platform-onboard-usb-hub b/Documentation/ABI/testing/sysfs-bus-platform-onboard-usb-hub
new file mode 100644
index 000000000000..e981d83648e6
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-platform-onboard-usb-hub
@@ -0,0 +1,8 @@
+What:		/sys/bus/platform/devices/<dev>/always_powered_in_suspend
+Date:		March 2021
+KernelVersion:	5.13
+Contact:	Matthias Kaehlcke <matthias@kaehlcke.net>
+		linux-usb@vger.kernel.org
+Description:
+		(RW) Controls whether the USB hub remains always powered
+		during system suspend or not.
\ No newline at end of file
diff --git a/MAINTAINERS b/MAINTAINERS
index a61f4f3b78a9..b19b990a07c7 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -13796,6 +13796,13 @@ S:	Maintained
 T:	git git://linuxtv.org/media_tree.git
 F:	drivers/media/i2c/ov9734.c
 
+ONBOARD USB HUB DRIVER
+M:	Matthias Kaehlcke <mka@chromium.org>
+L:	linux-usb@vger.kernel.org
+S:	Maintained
+F:	Documentation/devicetree/bindings/usb/onboard_usb_hub.yaml
+F:	drivers/usb/misc/onboard_usb_hub.c
+
 ONENAND FLASH DRIVER
 M:	Kyungmin Park <kyungmin.park@samsung.com>
 L:	linux-mtd@lists.infradead.org
diff --git a/drivers/usb/misc/Kconfig b/drivers/usb/misc/Kconfig
index 8f1144359012..f534269fbb20 100644
--- a/drivers/usb/misc/Kconfig
+++ b/drivers/usb/misc/Kconfig
@@ -284,3 +284,20 @@ config BRCM_USB_PINMAP
 	  This option enables support for remapping some USB external
 	  signals, which are typically on dedicated pins on the chip,
 	  to any gpio.
+
+config USB_ONBOARD_HUB
+	tristate "Onboard USB hub support"
+	depends on OF || COMPILE_TEST
+	help
+	  Say Y here if you want to support discrete onboard USB hubs that
+	  don't require an additional control bus for initialization, but
+	  need some nontrivial form of initialization, such as enabling a
+	  power regulator. An example for such a hub is the Realtek
+	  RTS5411.
+
+	  The driver can be configured to turn off the power of the hub
+	  during system suspend. This may reduce power consumption while
+	  the system is suspended.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called onboard_usb_hub.
diff --git a/drivers/usb/misc/Makefile b/drivers/usb/misc/Makefile
index 5f4e598573ab..2c5aec6f1b26 100644
--- a/drivers/usb/misc/Makefile
+++ b/drivers/usb/misc/Makefile
@@ -32,3 +32,4 @@ obj-$(CONFIG_USB_CHAOSKEY)		+= chaoskey.o
 obj-$(CONFIG_USB_SISUSBVGA)		+= sisusbvga/
 obj-$(CONFIG_USB_LINK_LAYER_TEST)	+= lvstest.o
 obj-$(CONFIG_BRCM_USB_PINMAP)		+= brcmstb-usb-pinmap.o
+obj-$(CONFIG_USB_ONBOARD_HUB)		+= onboard_usb_hub.o
diff --git a/drivers/usb/misc/onboard_usb_hub.c b/drivers/usb/misc/onboard_usb_hub.c
new file mode 100644
index 000000000000..ed1f5424ea5f
--- /dev/null
+++ b/drivers/usb/misc/onboard_usb_hub.c
@@ -0,0 +1,497 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  Driver for onboard USB hubs
+ *
+ * Copyright (c) 2020, Google LLC
+ */
+
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+#include <linux/suspend.h>
+#include <linux/sysfs.h>
+#include <linux/usb.h>
+#include <linux/usb/hcd.h>
+#include <linux/usb/of.h>
+#include <linux/usb/onboard_hub.h>
+
+static struct usb_device_driver onboard_hub_usbdev_driver;
+
+/************************** Platform driver **************************/
+
+struct udev_node {
+	struct usb_device *udev;
+	struct list_head list;
+};
+
+struct onboard_hub {
+	struct regulator *vdd;
+	struct device *dev;
+	bool always_powered_in_suspend;
+	bool is_powered_on;
+	bool going_away;
+	struct list_head udev_list;
+	struct mutex lock;
+};
+
+static int onboard_hub_power_on(struct onboard_hub *hub)
+{
+	int err;
+
+	err = regulator_enable(hub->vdd);
+	if (err) {
+		dev_err(hub->dev, "failed to enable regulator: %d\n", err);
+		return err;
+	}
+
+	hub->is_powered_on = true;
+
+	return 0;
+}
+
+static int onboard_hub_power_off(struct onboard_hub *hub)
+{
+	int err;
+
+	err = regulator_disable(hub->vdd);
+	if (err) {
+		dev_err(hub->dev, "failed to disable regulator: %d\n", err);
+		return err;
+	}
+
+	hub->is_powered_on = false;
+
+	return 0;
+}
+
+static int __maybe_unused onboard_hub_suspend(struct device *dev)
+{
+	struct onboard_hub *hub = dev_get_drvdata(dev);
+	struct udev_node *node;
+	bool power_off;
+	int rc = 0;
+
+	if (hub->always_powered_in_suspend)
+		return 0;
+
+	power_off = true;
+
+	mutex_lock(&hub->lock);
+
+	list_for_each_entry(node, &hub->udev_list, list) {
+		if (!device_may_wakeup(node->udev->bus->controller))
+			continue;
+
+		if (usb_wakeup_enabled_descendants(node->udev)) {
+			power_off = false;
+			break;
+		}
+	}
+
+	mutex_unlock(&hub->lock);
+
+	if (power_off)
+		rc = onboard_hub_power_off(hub);
+
+	return rc;
+}
+
+static int __maybe_unused onboard_hub_resume(struct device *dev)
+{
+	struct onboard_hub *hub = dev_get_drvdata(dev);
+	int rc = 0;
+
+	if (!hub->is_powered_on)
+		rc = onboard_hub_power_on(hub);
+
+	return rc;
+}
+
+static int onboard_hub_add_usbdev(struct onboard_hub *hub, struct usb_device *udev)
+{
+	struct udev_node *node;
+	char link_name[64];
+	int ret = 0;
+
+	mutex_lock(&hub->lock);
+
+	if (hub->going_away) {
+		ret = -EINVAL;
+		goto unlock;
+	}
+
+	node = devm_kzalloc(hub->dev, sizeof(*node), GFP_KERNEL);
+	if (!node) {
+		ret = -ENOMEM;
+		goto unlock;
+	}
+
+	node->udev = udev;
+
+	list_add(&node->list, &hub->udev_list);
+
+	snprintf(link_name, sizeof(link_name), "usb_dev.%s", dev_name(&udev->dev));
+	WARN_ON(sysfs_create_link(&hub->dev->kobj, &udev->dev.kobj, link_name));
+
+unlock:
+	mutex_unlock(&hub->lock);
+
+	return ret;
+}
+
+static void onboard_hub_remove_usbdev(struct onboard_hub *hub, struct usb_device *udev)
+{
+	struct udev_node *node;
+	char link_name[64];
+
+	snprintf(link_name, sizeof(link_name), "usb_dev.%s", dev_name(&udev->dev));
+	sysfs_remove_link(&hub->dev->kobj, link_name);
+
+	mutex_lock(&hub->lock);
+
+	list_for_each_entry(node, &hub->udev_list, list) {
+		if (node->udev == udev) {
+			list_del(&node->list);
+			break;
+		}
+	}
+
+	mutex_unlock(&hub->lock);
+}
+
+static ssize_t always_powered_in_suspend_show(struct device *dev, struct device_attribute *attr,
+			   char *buf)
+{
+	struct onboard_hub *hub = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%d\n", hub->always_powered_in_suspend);
+}
+
+static ssize_t always_powered_in_suspend_store(struct device *dev, struct device_attribute *attr,
+			    const char *buf, size_t count)
+{
+	struct onboard_hub *hub = dev_get_drvdata(dev);
+	bool val;
+	int ret;
+
+	ret = kstrtobool(buf, &val);
+	if (ret < 0)
+		return ret;
+
+	hub->always_powered_in_suspend = val;
+
+	return count;
+}
+static DEVICE_ATTR_RW(always_powered_in_suspend);
+
+static struct attribute *onboard_hub_attrs[] = {
+	&dev_attr_always_powered_in_suspend.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(onboard_hub);
+
+static int onboard_hub_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct onboard_hub *hub;
+	int err;
+
+	hub = devm_kzalloc(dev, sizeof(*hub), GFP_KERNEL);
+	if (!hub)
+		return -ENOMEM;
+
+	hub->vdd = devm_regulator_get(dev, "vdd");
+	if (IS_ERR(hub->vdd))
+		return PTR_ERR(hub->vdd);
+
+	hub->dev = dev;
+	mutex_init(&hub->lock);
+	INIT_LIST_HEAD(&hub->udev_list);
+
+	dev_set_drvdata(dev, hub);
+
+	err = onboard_hub_power_on(hub);
+	if (err)
+		return err;
+
+	/*
+	 * The USB driver might have been detached from the USB devices by
+	 * onboard_hub_remove(), make sure to re-attach it if needed.
+	 */
+	err = driver_attach(&onboard_hub_usbdev_driver.drvwrap.driver);
+	if (err) {
+		onboard_hub_power_off(hub);
+		return err;
+	}
+
+	return 0;
+}
+
+static int onboard_hub_remove(struct platform_device *pdev)
+{
+	struct onboard_hub *hub = dev_get_drvdata(&pdev->dev);
+	struct udev_node *node;
+	struct usb_device *udev;
+
+	hub->going_away = true;
+
+	mutex_lock(&hub->lock);
+
+	/* unbind the USB devices to avoid dangling references to this device */
+	while (!list_empty(&hub->udev_list)) {
+		node = list_first_entry(&hub->udev_list, struct udev_node, list);
+		udev = node->udev;
+
+		/*
+		 * Unbinding the driver will call onboard_hub_remove_usbdev(),
+		 * which acquires hub->lock.  We must release the lock first.
+		 */
+		get_device(&udev->dev);
+		mutex_unlock(&hub->lock);
+		device_release_driver(&udev->dev);
+		put_device(&udev->dev);
+		mutex_lock(&hub->lock);
+	}
+
+	mutex_unlock(&hub->lock);
+
+	return onboard_hub_power_off(hub);
+}
+
+static const struct of_device_id onboard_hub_match[] = {
+	{ .compatible = "usbbda,411" },
+	{ .compatible = "usbbda,5411" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, onboard_hub_match);
+
+static bool of_is_onboard_usb_hub(const struct device_node *np)
+{
+	return !!of_match_node(onboard_hub_match, np);
+}
+
+static const struct dev_pm_ops __maybe_unused onboard_hub_pm_ops = {
+	SET_LATE_SYSTEM_SLEEP_PM_OPS(onboard_hub_suspend, onboard_hub_resume)
+};
+
+static struct platform_driver onboard_hub_driver = {
+	.probe = onboard_hub_probe,
+	.remove = onboard_hub_remove,
+
+	.driver = {
+		.name = "onboard-usb-hub",
+		.of_match_table = onboard_hub_match,
+		.pm = pm_ptr(&onboard_hub_pm_ops),
+		.dev_groups = onboard_hub_groups,
+	},
+};
+
+/************************** USB driver **************************/
+
+#define VENDOR_ID_REALTEK	0x0bda
+
+/*
+ * Returns the onboard_hub platform device that is associated with the USB
+ * device passed as parameter.
+ */
+static struct onboard_hub *_find_onboard_hub(struct device *dev)
+{
+	struct platform_device *pdev;
+	struct device_node *np;
+	phandle ph;
+
+	pdev = of_find_device_by_node(dev->of_node);
+	if (!pdev) {
+		if (of_property_read_u32(dev->of_node, "companion-hub", &ph)) {
+			dev_err(dev, "failed to read 'companion-hub' property\n");
+			return ERR_PTR(-EINVAL);
+		}
+
+		np = of_find_node_by_phandle(ph);
+		if (!np) {
+			dev_err(dev, "failed to find device node for companion hub\n");
+			return ERR_PTR(-EINVAL);
+		}
+
+		pdev = of_find_device_by_node(np);
+		of_node_put(np);
+
+		if (!pdev)
+			return ERR_PTR(-EPROBE_DEFER);
+	}
+
+	put_device(&pdev->dev);
+
+	return dev_get_drvdata(&pdev->dev);
+}
+
+static int onboard_hub_usbdev_probe(struct usb_device *udev)
+{
+	struct device *dev = &udev->dev;
+	struct onboard_hub *hub;
+	int err;
+
+	/* ignore supported hubs without device tree node */
+	if (!dev->of_node)
+		return -ENODEV;
+
+	hub = _find_onboard_hub(dev);
+	if (IS_ERR(hub))
+		return PTR_ERR(hub);
+
+	dev_set_drvdata(dev, hub);
+
+	err = onboard_hub_add_usbdev(hub, udev);
+	if (err)
+		return err;
+
+	err = sysfs_create_link(&udev->dev.kobj, &hub->dev->kobj, "onboard_hub_dev");
+	if (err)
+		dev_warn(&udev->dev, "failed to create symlink to platform device: %d\n", err);
+
+	return 0;
+}
+
+static void onboard_hub_usbdev_disconnect(struct usb_device *udev)
+{
+	struct onboard_hub *hub = dev_get_drvdata(&udev->dev);
+
+	sysfs_remove_link(&udev->dev.kobj, "onboard_hub_dev");
+
+	onboard_hub_remove_usbdev(hub, udev);
+}
+
+static const struct usb_device_id onboard_hub_id_table[] = {
+	{ USB_DEVICE(VENDOR_ID_REALTEK, 0x0411) }, /* RTS5411 USB 3.0 */
+	{ USB_DEVICE(VENDOR_ID_REALTEK, 0x5411) }, /* RTS5411 USB 2.0 */
+	{},
+};
+
+MODULE_DEVICE_TABLE(usb, onboard_hub_id_table);
+
+static struct usb_device_driver onboard_hub_usbdev_driver = {
+
+	.name = "onboard-usb-hub",
+	.probe = onboard_hub_usbdev_probe,
+	.disconnect = onboard_hub_usbdev_disconnect,
+	.generic_subclass = 1,
+	.supports_autosuspend =	1,
+	.id_table = onboard_hub_id_table,
+};
+
+/*** Helpers for creating/destroying platform devices for onboard hubs ***/
+
+struct pdev_list_entry {
+	struct platform_device *pdev;
+	struct list_head node;
+};
+
+/*
+ * Creates a platform device for each supported onboard hub that is connected to
+ * the given parent hub. To keep track of the platform devices they are added to
+ * a list that is owned by the parent hub.
+ */
+void onboard_hub_create_pdevs(struct usb_device *parent_hub, struct list_head *pdev_list)
+{
+	int i;
+	phandle ph;
+	struct device_node *np, *npc;
+	struct platform_device *pdev;
+	struct pdev_list_entry *pdle;
+
+	for (i = 1; i <= parent_hub->maxchild; i++) {
+		np = usb_of_get_device_node(parent_hub, i);
+		if (!np)
+			continue;
+
+		if (!of_is_onboard_usb_hub(np))
+			goto node_put;
+
+		if (of_property_read_u32(np, "companion-hub", &ph))
+			goto node_put;
+
+		npc = of_find_node_by_phandle(ph);
+		if (!npc)
+			goto node_put;
+
+		pdev = of_find_device_by_node(npc);
+		of_node_put(npc);
+
+		if (pdev) {
+			/* the companion hub already has a platform device, nothing to do here */
+			put_device(&pdev->dev);
+			goto node_put;
+		}
+
+		pdev = of_platform_device_create(np, NULL, &parent_hub->dev);
+		if (pdev) {
+			pdle = kzalloc(sizeof(*pdle), GFP_KERNEL);
+			if (!pdle)
+				goto node_put;
+
+			INIT_LIST_HEAD(&pdle->node);
+
+			pdle->pdev = pdev;
+			list_add(&pdle->node, pdev_list);
+		} else {
+			dev_err(&parent_hub->dev,
+				"failed to create platform device for onboard hub '%s'\n",
+				of_node_full_name(np));
+		}
+
+node_put:
+		of_node_put(np);
+	}
+}
+EXPORT_SYMBOL_GPL(onboard_hub_create_pdevs);
+
+/*
+ * Destroys the platform devices in the given list and frees the memory associated
+ * with the list entry.
+ */
+void onboard_hub_destroy_pdevs(struct list_head *pdev_list)
+{
+	struct pdev_list_entry *pdle, *tmp;
+
+	list_for_each_entry_safe(pdle, tmp, pdev_list, node) {
+		of_platform_device_destroy(&pdle->pdev->dev, NULL);
+		kfree(pdle);
+	}
+}
+EXPORT_SYMBOL_GPL(onboard_hub_destroy_pdevs);
+
+/************************** Driver (de)registration **************************/
+
+static int __init onboard_hub_init(void)
+{
+	int ret;
+
+	ret = platform_driver_register(&onboard_hub_driver);
+	if (ret)
+		return ret;
+
+	ret = usb_register_device_driver(&onboard_hub_usbdev_driver, THIS_MODULE);
+	if (ret)
+		platform_driver_unregister(&onboard_hub_driver);
+
+	return ret;
+}
+module_init(onboard_hub_init);
+
+static void __exit onboard_hub_exit(void)
+{
+	usb_deregister_device_driver(&onboard_hub_usbdev_driver);
+	platform_driver_unregister(&onboard_hub_driver);
+}
+module_exit(onboard_hub_exit);
+
+MODULE_AUTHOR("Matthias Kaehlcke <mka@chromium.org>");
+MODULE_DESCRIPTION("Driver for discrete onboard USB hubs");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/usb/onboard_hub.h b/include/linux/usb/onboard_hub.h
new file mode 100644
index 000000000000..d9373230556e
--- /dev/null
+++ b/include/linux/usb/onboard_hub.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __LINUX_USB_ONBOARD_HUB_H
+#define __LINUX_USB_ONBOARD_HUB_H
+
+struct usb_device;
+struct list_head;
+
+#if IS_ENABLED(CONFIG_USB_ONBOARD_HUB)
+void onboard_hub_create_pdevs(struct usb_device *parent_hub, struct list_head *pdev_list);
+void onboard_hub_destroy_pdevs(struct list_head *pdev_list);
+#else
+static inline void onboard_hub_create_pdevs(struct usb_device *parent_hub,
+					    struct list_head *pdev_list) {}
+static inline void onboard_hub_destroy_pdevs(struct list_head *pdev_list) {}
+#endif
+
+#endif /* __LINUX_USB_ONBOARD_HUB_H */
-- 
2.32.0.432.gabb21c7263-goog


^ permalink raw reply	[flat|nested] 15+ messages in thread

* [PATCH v15 2/6] of/platform: Add stubs for of_platform_device_create/destroy()
  2021-07-27  0:41 [PATCH v15 0/6] usb: misc: Add onboard_usb_hub driver Matthias Kaehlcke
  2021-07-27  0:41 ` [PATCH v15 1/6] " Matthias Kaehlcke
@ 2021-07-27  0:41 ` Matthias Kaehlcke
  2021-07-27  0:41 ` [PATCH v15 3/6] arm64: defconfig: Explicitly enable USB_XHCI_PLATFORM Matthias Kaehlcke
                   ` (5 subsequent siblings)
  7 siblings, 0 replies; 15+ messages in thread
From: Matthias Kaehlcke @ 2021-07-27  0:41 UTC (permalink / raw)
  To: Greg Kroah-Hartman, Alan Stern, Rob Herring, Frank Rowand,
	Mathias Nyman, Felipe Balbi
  Cc: Bastien Nocera, Peter Chen, devicetree, Michal Simek,
	linux-kernel, Douglas Anderson, Krzysztof Kozlowski, linux-usb,
	Ravi Chandra Sadineni, Stephen Boyd, Matthias Kaehlcke,
	Rob Herring

Code for platform_device_create() and of_platform_device_destroy() is
only generated if CONFIG_OF_ADDRESS=y. Add stubs to avoid unresolved
symbols when CONFIG_OF_ADDRESS is not set.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Acked-by: Rob Herring <robh@kernel.org>
---

Changes in v15:
- none

Changes in v14:
- none

Changes in v13:
- none

Changes in v12:
- none

Changes in v11:
- none

Changes in v10:
- none

Changes in v9:
- added Rob's 'Acked-by' tag

Changes in v8:
- fixed C&P error in commit message

Changes in v7:
- none

Changes in v6:
- patch added to the series

 include/linux/of_platform.h | 22 ++++++++++++++++++----
 1 file changed, 18 insertions(+), 4 deletions(-)

diff --git a/include/linux/of_platform.h b/include/linux/of_platform.h
index 84a966623e78..d15b6cd5e1c3 100644
--- a/include/linux/of_platform.h
+++ b/include/linux/of_platform.h
@@ -61,16 +61,18 @@ static inline struct platform_device *of_find_device_by_node(struct device_node
 }
 #endif
 
+extern int of_platform_bus_probe(struct device_node *root,
+				 const struct of_device_id *matches,
+				 struct device *parent);
+
+#ifdef CONFIG_OF_ADDRESS
 /* Platform devices and busses creation */
 extern struct platform_device *of_platform_device_create(struct device_node *np,
 						   const char *bus_id,
 						   struct device *parent);
 
 extern int of_platform_device_destroy(struct device *dev, void *data);
-extern int of_platform_bus_probe(struct device_node *root,
-				 const struct of_device_id *matches,
-				 struct device *parent);
-#ifdef CONFIG_OF_ADDRESS
+
 extern int of_platform_populate(struct device_node *root,
 				const struct of_device_id *matches,
 				const struct of_dev_auxdata *lookup,
@@ -84,6 +86,18 @@ extern int devm_of_platform_populate(struct device *dev);
 
 extern void devm_of_platform_depopulate(struct device *dev);
 #else
+/* Platform devices and busses creation */
+static inline struct platform_device *of_platform_device_create(struct device_node *np,
+								const char *bus_id,
+								struct device *parent)
+{
+	return NULL;
+}
+static inline int of_platform_device_destroy(struct device *dev, void *data)
+{
+	return -ENODEV;
+}
+
 static inline int of_platform_populate(struct device_node *root,
 					const struct of_device_id *matches,
 					const struct of_dev_auxdata *lookup,
-- 
2.32.0.432.gabb21c7263-goog


^ permalink raw reply	[flat|nested] 15+ messages in thread

* [PATCH v15 3/6] arm64: defconfig: Explicitly enable USB_XHCI_PLATFORM
  2021-07-27  0:41 [PATCH v15 0/6] usb: misc: Add onboard_usb_hub driver Matthias Kaehlcke
  2021-07-27  0:41 ` [PATCH v15 1/6] " Matthias Kaehlcke
  2021-07-27  0:41 ` [PATCH v15 2/6] of/platform: Add stubs for of_platform_device_create/destroy() Matthias Kaehlcke
@ 2021-07-27  0:41 ` Matthias Kaehlcke
  2021-07-27  0:41 ` [PATCH v15 4/6] usb: Specify dependencies on USB_XHCI_PLATFORM with 'depends on' Matthias Kaehlcke
                   ` (4 subsequent siblings)
  7 siblings, 0 replies; 15+ messages in thread
From: Matthias Kaehlcke @ 2021-07-27  0:41 UTC (permalink / raw)
  To: Greg Kroah-Hartman, Alan Stern, Rob Herring, Frank Rowand,
	Mathias Nyman, Felipe Balbi
  Cc: Bastien Nocera, Peter Chen, devicetree, Michal Simek,
	linux-kernel, Douglas Anderson, Krzysztof Kozlowski, linux-usb,
	Ravi Chandra Sadineni, Stephen Boyd, Matthias Kaehlcke,
	Andrey Zhizhikin, Bjorn Andersson, Catalin Marinas,
	Dmitry Baryshkov, Enric Balletbo i Serra, Guido Günther,
	Jagan Teki, Nishanth Menon, Shawn Guo, Vinod Koul, Will Deacon,
	linux-arm-kernel

The dependency of USB_DWC3 on USB_XHCI_PLATFORM is being changed
from 'select' to 'depends on' by another patch. The defconfig selects
USB_DWC3 and implicitly USB_DWC3_DUAL_ROLE, to keep this unchanged
USB_XHCI_PLATFORM now needs to be selected explicitly.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
---

Changes in v15:
- none

Changes in v14:
- rebased on v5.14-rc1 (with the rest of the series)
- added 'Reviewed-by' tag from Doug

Changes in v13:
- patch added to the series

 arch/arm64/configs/defconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/configs/defconfig b/arch/arm64/configs/defconfig
index f423d08b9a71..b243bd11a4ed 100644
--- a/arch/arm64/configs/defconfig
+++ b/arch/arm64/configs/defconfig
@@ -802,6 +802,7 @@ CONFIG_USB_OTG=y
 CONFIG_USB_XHCI_HCD=y
 CONFIG_USB_XHCI_PCI=m
 CONFIG_USB_XHCI_PCI_RENESAS=m
+CONFIG_USB_XHCI_PLATFORM=y
 CONFIG_USB_XHCI_TEGRA=y
 CONFIG_USB_EHCI_HCD=y
 CONFIG_USB_EHCI_EXYNOS=y
-- 
2.32.0.432.gabb21c7263-goog


^ permalink raw reply	[flat|nested] 15+ messages in thread

* [PATCH v15 4/6] usb: Specify dependencies on USB_XHCI_PLATFORM with 'depends on'
  2021-07-27  0:41 [PATCH v15 0/6] usb: misc: Add onboard_usb_hub driver Matthias Kaehlcke
                   ` (2 preceding siblings ...)
  2021-07-27  0:41 ` [PATCH v15 3/6] arm64: defconfig: Explicitly enable USB_XHCI_PLATFORM Matthias Kaehlcke
@ 2021-07-27  0:41 ` Matthias Kaehlcke
  2021-07-27  0:41 ` [PATCH v15 5/6] usb: host: xhci-plat: Create platform device for onboard hubs in probe() Matthias Kaehlcke
                   ` (3 subsequent siblings)
  7 siblings, 0 replies; 15+ messages in thread
From: Matthias Kaehlcke @ 2021-07-27  0:41 UTC (permalink / raw)
  To: Greg Kroah-Hartman, Alan Stern, Rob Herring, Frank Rowand,
	Mathias Nyman, Felipe Balbi
  Cc: Bastien Nocera, Peter Chen, devicetree, Michal Simek,
	linux-kernel, Douglas Anderson, Krzysztof Kozlowski, linux-usb,
	Ravi Chandra Sadineni, Stephen Boyd, Matthias Kaehlcke,
	Aswath Govindraju, Dmitry Osipenko, Fabio Estevam,
	Pawel Laszczak, Roger Quadros

Some USB controller drivers that depend on the xhci-plat driver
specify this dependency using 'select' in Kconfig. This is not
recommended for symbols that have other dependencies as it may
lead to invalid configurations. Use 'depends on' to specify the
dependency instead of 'select'.

For dwc3 specify the dependency on USB_XHCI_PLATFORM in
USB_DWC3_HOST and USB_DWC3_DUAL_ROLE. Also adjust the
dependencies of USB_DWC3_CORE to make sure that at least one
of USB_DWC3_HOST, USB_DWC3_GADGET or USB_DWC3_DUAL_ROLE can be
selected.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
---

Changes in v15:
- adjusted dependencies of USB_DWC3_CORE to make sure it can only
  be enabled when at least one of USB_DWC3_HOST, USB_DWC3_GADGET
  or USB_DWC3_DUAL_ROLE is selectable
- updated commit message

Changes in v14:
- none

Changes in v13:
- patch added to the series

 drivers/usb/cdns3/Kconfig | 2 +-
 drivers/usb/dwc3/Kconfig  | 5 +++--
 drivers/usb/host/Kconfig  | 4 ++--
 3 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/usb/cdns3/Kconfig b/drivers/usb/cdns3/Kconfig
index b98ca0a1352a..07e12f786d48 100644
--- a/drivers/usb/cdns3/Kconfig
+++ b/drivers/usb/cdns3/Kconfig
@@ -1,7 +1,7 @@
 config USB_CDNS_SUPPORT
 	tristate "Cadence USB Support"
 	depends on USB_SUPPORT && (USB || USB_GADGET) && HAS_DMA
-	select USB_XHCI_PLATFORM if USB_XHCI_HCD
+	depends on !USB_XHCI_HCD || USB_XHCI_PLATFORM
 	select USB_ROLE_SWITCH
 	help
 	  Say Y here if your system has a Cadence USBSS or USBSSP
diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
index 66b1454c4db2..870f2251350a 100644
--- a/drivers/usb/dwc3/Kconfig
+++ b/drivers/usb/dwc3/Kconfig
@@ -2,8 +2,7 @@
 
 config USB_DWC3
 	tristate "DesignWare USB3 DRD Core Support"
-	depends on (USB || USB_GADGET) && HAS_DMA
-	select USB_XHCI_PLATFORM if USB_XHCI_HCD
+	depends on ((USB && USB_XHCI_PLATFORM) || USB_GADGET) && HAS_DMA
 	select USB_ROLE_SWITCH if USB_DWC3_DUAL_ROLE
 	help
 	  Say Y or M here if your system has a Dual Role SuperSpeed
@@ -30,6 +29,7 @@ choice
 config USB_DWC3_HOST
 	bool "Host only mode"
 	depends on USB=y || USB=USB_DWC3
+	depends on USB_XHCI_PLATFORM
 	help
 	  Select this when you want to use DWC3 in host mode only,
 	  thereby the gadget feature will be regressed.
@@ -44,6 +44,7 @@ config USB_DWC3_GADGET
 config USB_DWC3_DUAL_ROLE
 	bool "Dual Role mode"
 	depends on ((USB=y || USB=USB_DWC3) && (USB_GADGET=y || USB_GADGET=USB_DWC3))
+	depends on USB_XHCI_PLATFORM
 	depends on (EXTCON=y || EXTCON=USB_DWC3)
 	help
 	  This is the default mode of working of DWC3 controller where
diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
index df9428f1dc5e..518c2312ef0c 100644
--- a/drivers/usb/host/Kconfig
+++ b/drivers/usb/host/Kconfig
@@ -80,7 +80,7 @@ config USB_XHCI_MTK
 
 config USB_XHCI_MVEBU
 	tristate "xHCI support for Marvell Armada 375/38x/37xx"
-	select USB_XHCI_PLATFORM
+	depends on USB_XHCI_PLATFORM
 	depends on HAS_IOMEM
 	depends on ARCH_MVEBU || COMPILE_TEST
 	help
@@ -112,9 +112,9 @@ config USB_EHCI_BRCMSTB
 config USB_BRCMSTB
 	tristate "Broadcom STB USB support"
 	depends on (ARCH_BRCMSTB && PHY_BRCM_USB) || COMPILE_TEST
+	depends on !USB_XHCI_HCD || USB_XHCI_PLATFORM
 	select USB_OHCI_HCD_PLATFORM if USB_OHCI_HCD
 	select USB_EHCI_BRCMSTB if USB_EHCI_HCD
-	select USB_XHCI_PLATFORM if USB_XHCI_HCD
 	help
 	  Enables support for XHCI, EHCI and OHCI host controllers
 	  found in Broadcom STB SoC's.
-- 
2.32.0.432.gabb21c7263-goog


^ permalink raw reply	[flat|nested] 15+ messages in thread

* [PATCH v15 5/6] usb: host: xhci-plat: Create platform device for onboard hubs in probe()
  2021-07-27  0:41 [PATCH v15 0/6] usb: misc: Add onboard_usb_hub driver Matthias Kaehlcke
                   ` (3 preceding siblings ...)
  2021-07-27  0:41 ` [PATCH v15 4/6] usb: Specify dependencies on USB_XHCI_PLATFORM with 'depends on' Matthias Kaehlcke
@ 2021-07-27  0:41 ` Matthias Kaehlcke
  2021-07-27  0:41 ` [PATCH v15 6/6] arm64: dts: qcom: sc7180-trogdor: Add nodes for onboard USB hub Matthias Kaehlcke
                   ` (2 subsequent siblings)
  7 siblings, 0 replies; 15+ messages in thread
From: Matthias Kaehlcke @ 2021-07-27  0:41 UTC (permalink / raw)
  To: Greg Kroah-Hartman, Alan Stern, Rob Herring, Frank Rowand,
	Mathias Nyman, Felipe Balbi
  Cc: Bastien Nocera, Peter Chen, devicetree, Michal Simek,
	linux-kernel, Douglas Anderson, Krzysztof Kozlowski, linux-usb,
	Ravi Chandra Sadineni, Stephen Boyd, Matthias Kaehlcke,
	Dmitry Osipenko, Fabio Estevam

Call onboard_hub_create/destroy_pdevs() from  _probe()/_remove()
to create/destroy platform devices for onboard USB hubs that may
be connected to the root hub of the controller. These functions
are a NOP unless CONFIG_USB_ONBOARD_HUB=y/m.

Also add a field to struct xhci_hcd to keep track of the onboard hub
platform devices that are owned by the xHCI.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
---

Changes in v15:
- none

Changes in v14:
- none

Changes in v13:
- added comment for 'depends on USB_ONBOARD_HUB || !USB_ONBOARD_HUB'
  construct

Changes in v12:
- none

Changes in v11:
- use onboard_hub_create/destroy_pdevs() to support multiple onboard
  hubs that are connected to the same root hub
- moved field/list to keep track of platform devices from struct
  usb_hcd to struct xhci_hcd
- updated commit message

Changes in v10:
- none

Changes in v9:
- added dependency on USB_ONBOARD_HUB (or !!USB_ONBOARD_HUB) to
  USB_XHCI_PLATFORM

Changes in v8:
- none

Changes in v7:
- none

Changes in v6:
- none

Changes in v5:
- patch added to the series

 drivers/usb/host/Kconfig     | 1 +
 drivers/usb/host/xhci-plat.c | 6 ++++++
 drivers/usb/host/xhci.h      | 2 ++
 3 files changed, 9 insertions(+)

diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
index 518c2312ef0c..099e9615919c 100644
--- a/drivers/usb/host/Kconfig
+++ b/drivers/usb/host/Kconfig
@@ -54,6 +54,7 @@ config USB_XHCI_PCI_RENESAS
 config USB_XHCI_PLATFORM
 	tristate "Generic xHCI driver for a platform device"
 	select USB_XHCI_RCAR if ARCH_RENESAS
+	depends on USB_ONBOARD_HUB || !USB_ONBOARD_HUB # if USB_ONBOARD_HUB=m, this can't be 'y'
 	help
 	  Adds an xHCI host driver for a generic platform device, which
 	  provides a memory space and an irq.
diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
index c1edcc9b13ce..ee98a3671619 100644
--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -15,6 +15,7 @@
 #include <linux/of.h>
 #include <linux/of_device.h>
 #include <linux/platform_device.h>
+#include <linux/usb/onboard_hub.h>
 #include <linux/usb/phy.h>
 #include <linux/slab.h>
 #include <linux/acpi.h>
@@ -374,6 +375,9 @@ static int xhci_plat_probe(struct platform_device *pdev)
 	 */
 	pm_runtime_forbid(&pdev->dev);
 
+	INIT_LIST_HEAD(&xhci->onboard_hub_devs);
+	onboard_hub_create_pdevs(hcd->self.root_hub, &xhci->onboard_hub_devs);
+
 	return 0;
 
 
@@ -420,6 +424,8 @@ static int xhci_plat_remove(struct platform_device *dev)
 	usb_remove_hcd(hcd);
 	usb_put_hcd(shared_hcd);
 
+	onboard_hub_destroy_pdevs(&xhci->onboard_hub_devs);
+
 	clk_disable_unprepare(clk);
 	clk_disable_unprepare(reg_clk);
 	usb_put_hcd(hcd);
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 3c7d281672ae..5ba01d5ccab8 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1923,6 +1923,8 @@ struct xhci_hcd {
 	struct dentry		*debugfs_slots;
 	struct list_head	regset_list;
 
+	struct list_head	onboard_hub_devs;
+
 	void			*dbc;
 	/* platform-specific data -- must come last */
 	unsigned long		priv[] __aligned(sizeof(s64));
-- 
2.32.0.432.gabb21c7263-goog


^ permalink raw reply	[flat|nested] 15+ messages in thread

* [PATCH v15 6/6] arm64: dts: qcom: sc7180-trogdor: Add nodes for onboard USB hub
  2021-07-27  0:41 [PATCH v15 0/6] usb: misc: Add onboard_usb_hub driver Matthias Kaehlcke
                   ` (4 preceding siblings ...)
  2021-07-27  0:41 ` [PATCH v15 5/6] usb: host: xhci-plat: Create platform device for onboard hubs in probe() Matthias Kaehlcke
@ 2021-07-27  0:41 ` Matthias Kaehlcke
  2021-08-09 15:49 ` [PATCH v15 0/6] usb: misc: Add onboard_usb_hub driver Matthias Kaehlcke
  2021-10-19 16:24 ` Dmitry Baryshkov
  7 siblings, 0 replies; 15+ messages in thread
From: Matthias Kaehlcke @ 2021-07-27  0:41 UTC (permalink / raw)
  To: Greg Kroah-Hartman, Alan Stern, Rob Herring, Frank Rowand,
	Mathias Nyman, Felipe Balbi
  Cc: Bastien Nocera, Peter Chen, devicetree, Michal Simek,
	linux-kernel, Douglas Anderson, Krzysztof Kozlowski, linux-usb,
	Ravi Chandra Sadineni, Stephen Boyd, Matthias Kaehlcke,
	Andy Gross, Bjorn Andersson, linux-arm-msm

Add nodes for the onboard USB hub on trogdor devices. Remove the
'always-on' property from the hub regulator, since the regulator
is now managed by the onboard_usb_hub driver.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
---

Changes in v15:
- none

Changes in v14:
- none

Changes in v13:
- none

Changes in v12:
- none

Changes in v11:
- rebased on qcom/arm64-for-5.14 (with the rest of the series)

Changes in v10:
- keep 'regulator-boot-on' property
- updated commit message

Changes in v9:
- none

Changes in v8:
- none

Changes in v7:
- rebased on qcom/arm64-for-5.13 (with the rest of the series)

Changes in v6:
- added 'companion-hub' entry to both USB devices
- added 'vdd-supply' also to hub@2

Changes in v5:
- patch added to the series

 .../boot/dts/qcom/sc7180-trogdor-lazor-r0.dts | 19 ++++++++-----------
 .../boot/dts/qcom/sc7180-trogdor-lazor-r1.dts | 12 +++++-------
 .../arm64/boot/dts/qcom/sc7180-trogdor-r1.dts | 19 ++++++++-----------
 arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi  | 19 ++++++++++++++++++-
 4 files changed, 39 insertions(+), 30 deletions(-)

diff --git a/arch/arm64/boot/dts/qcom/sc7180-trogdor-lazor-r0.dts b/arch/arm64/boot/dts/qcom/sc7180-trogdor-lazor-r0.dts
index 30e3e769d2b4..5fb8e12af1a0 100644
--- a/arch/arm64/boot/dts/qcom/sc7180-trogdor-lazor-r0.dts
+++ b/arch/arm64/boot/dts/qcom/sc7180-trogdor-lazor-r0.dts
@@ -14,17 +14,6 @@ / {
 	compatible = "google,lazor-rev0", "qcom,sc7180";
 };
 
-&pp3300_hub {
-	/* pp3300_l7c is used to power the USB hub */
-	/delete-property/regulator-always-on;
-	/delete-property/regulator-boot-on;
-};
-
-&pp3300_l7c {
-	regulator-always-on;
-	regulator-boot-on;
-};
-
 &sn65dsi86_out {
 	/*
 	 * Lane 0 was incorrectly mapped on the cable, but we've now decided
@@ -33,3 +22,11 @@ &sn65dsi86_out {
 	 */
 	lane-polarities = <1 0>;
 };
+
+&usb_hub_2_0 {
+	 vdd-supply = <&pp3300_l7c>;
+};
+
+&usb_hub_3_0 {
+	 vdd-supply = <&pp3300_l7c>;
+};
diff --git a/arch/arm64/boot/dts/qcom/sc7180-trogdor-lazor-r1.dts b/arch/arm64/boot/dts/qcom/sc7180-trogdor-lazor-r1.dts
index c2ef06367baf..1dae714250f5 100644
--- a/arch/arm64/boot/dts/qcom/sc7180-trogdor-lazor-r1.dts
+++ b/arch/arm64/boot/dts/qcom/sc7180-trogdor-lazor-r1.dts
@@ -14,13 +14,11 @@ / {
 	compatible = "google,lazor-rev1", "google,lazor-rev2", "qcom,sc7180";
 };
 
-&pp3300_hub {
-	/* pp3300_l7c is used to power the USB hub */
-	/delete-property/regulator-always-on;
-	/delete-property/regulator-boot-on;
+
+&usb_hub_2_0 {
+	 vdd-supply = <&pp3300_l7c>;
 };
 
-&pp3300_l7c {
-	regulator-always-on;
-	regulator-boot-on;
+&usb_hub_3_0 {
+	 vdd-supply = <&pp3300_l7c>;
 };
diff --git a/arch/arm64/boot/dts/qcom/sc7180-trogdor-r1.dts b/arch/arm64/boot/dts/qcom/sc7180-trogdor-r1.dts
index 2b522f9e0d8f..2f5263e3d1b9 100644
--- a/arch/arm64/boot/dts/qcom/sc7180-trogdor-r1.dts
+++ b/arch/arm64/boot/dts/qcom/sc7180-trogdor-r1.dts
@@ -42,17 +42,6 @@ &panel {
 	compatible = "auo,b116xa01";
 };
 
-&pp3300_hub {
-	/* pp3300_l7c is used to power the USB hub */
-	/delete-property/regulator-always-on;
-	/delete-property/regulator-boot-on;
-};
-
-&pp3300_l7c {
-	regulator-always-on;
-	regulator-boot-on;
-};
-
 &sdhc_2 {
 	status = "okay";
 };
@@ -61,6 +50,14 @@ &trackpad {
 	interrupts = <58 IRQ_TYPE_EDGE_FALLING>;
 };
 
+&usb_hub_2_0 {
+	 vdd-supply = <&pp3300_l7c>;
+};
+
+&usb_hub_3_0 {
+	 vdd-supply = <&pp3300_l7c>;
+};
+
 /* PINCTRL - modifications to sc7180-trogdor.dtsi */
 
 &trackpad_int_1v8_odl {
diff --git a/arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi b/arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi
index 77ae7561d436..f89c6a7045e5 100644
--- a/arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi
+++ b/arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi
@@ -202,7 +202,6 @@ pp3300_hub: pp3300-hub {
 		pinctrl-names = "default";
 		pinctrl-0 = <&en_pp3300_hub>;
 
-		regulator-always-on;
 		regulator-boot-on;
 
 		vin-supply = <&pp3300_a>;
@@ -898,6 +897,24 @@ &usb_1 {
 
 &usb_1_dwc3 {
 	dr_mode = "host";
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	/* 2.0 hub on port 1 */
+	usb_hub_2_0: hub@1 {
+		compatible = "usbbda,5411";
+		reg = <1>;
+		vdd-supply = <&pp3300_hub>;
+		companion-hub = <&usb_hub_3_0>;
+	};
+
+	/* 3.0 hub on port 2 */
+	usb_hub_3_0: hub@2 {
+		compatible = "usbbda,411";
+		reg = <2>;
+		vdd-supply = <&pp3300_hub>;
+		companion-hub = <&usb_hub_2_0>;
+	};
 };
 
 &usb_1_hsphy {
-- 
2.32.0.432.gabb21c7263-goog


^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [PATCH v15 0/6] usb: misc: Add onboard_usb_hub driver
  2021-07-27  0:41 [PATCH v15 0/6] usb: misc: Add onboard_usb_hub driver Matthias Kaehlcke
                   ` (5 preceding siblings ...)
  2021-07-27  0:41 ` [PATCH v15 6/6] arm64: dts: qcom: sc7180-trogdor: Add nodes for onboard USB hub Matthias Kaehlcke
@ 2021-08-09 15:49 ` Matthias Kaehlcke
  2021-08-11 12:38   ` Roger Quadros
  2021-10-19 16:24 ` Dmitry Baryshkov
  7 siblings, 1 reply; 15+ messages in thread
From: Matthias Kaehlcke @ 2021-08-09 15:49 UTC (permalink / raw)
  To: Greg Kroah-Hartman, Alan Stern, Rob Herring, Frank Rowand,
	Mathias Nyman, Felipe Balbi
  Cc: Bastien Nocera, Peter Chen, devicetree, Michal Simek,
	linux-kernel, Douglas Anderson, Krzysztof Kozlowski, linux-usb,
	Ravi Chandra Sadineni, Stephen Boyd, Al Cooper, Andrey Zhizhikin,
	Andy Gross, Aswath Govindraju, Bjorn Andersson, Catalin Marinas,
	Dmitry Baryshkov, Dmitry Osipenko, Enric Balletbo i Serra,
	Fabio Estevam, Guido Günther, Jagan Teki, Nishanth Menon,
	Pawel Laszczak, Roger Quadros, Shawn Guo, Vinod Koul,
	Will Deacon, linux-arm-kernel, linux-arm-msm

Hi Greg,

Just wanted to check if this series is still on your radar. Is
there anything that blocks it from landing (further ACKs, ...)?

Thanks

Matthias

On Mon, Jul 26, 2021 at 05:41:12PM -0700, Matthias Kaehlcke wrote:
> This series adds:
> - the onboard_usb_hub_driver
> - glue in the xhci-plat driver to create and destroy the
>   onboard_usb_hub platform devices if needed
> - a device tree binding for the Realtek RTS5411 USB hub controller
> - device tree changes that add RTS5411 entries for the QCA SC7180
>   based boards trogdor and lazor
> - a couple of stubs for platform device functions to avoid
>   unresolved symbols with certain kernel configs
> 
> The main issue the driver addresses is that a USB hub needs to be
> powered before it can be discovered. For discrete onboard hubs (an
> example for such a hub is the Realtek RTS5411) this is often solved
> by supplying the hub with an 'always-on' regulator, which is kind
> of a hack. Some onboard hubs may require further initialization
> steps, like changing the state of a GPIO or enabling a clock, which
> requires even more hacks. This driver creates a platform device
> representing the hub which performs the necessary initialization.
> Currently it only supports switching on a single regulator, support
> for multiple regulators or other actions can be added as needed.
> Different initialization sequences can be supported based on the
> compatible string.
> 
> Besides performing the initialization the driver can be configured
> to power the hub off during system suspend. This can help to extend
> battery life on battery powered devices which have no requirements
> to keep the hub powered during suspend. The driver can also be
> configured to leave the hub powered when a wakeup capable USB device
> is connected when suspending, and power it off otherwise.
> 
> Changes in v15:
> - adjusted dependencies of USB_DWC3_CORE to make sure it can only
>   be enabled when at least one of USB_DWC3_HOST, USB_DWC3_GADGET
>   or USB_DWC3_DUAL_ROLE is selectable
> 
> Changes in v14:
> - rebased on top of v5.14-rc1
> - dropped DT binding patch which landed in v5.13
> 
> Changes in v13:
> - added patch "usb: Specify dependency on USB_XHCI_PLATFORM with
>   'depends on'" to the series to avoid Kconfig conflicts
> - added patch "arm64: defconfig: Explicitly enable USB_XHCI_PLATFORM"
>   to the series to keep effective defconfig unchanged
> 
> Changes in v12:
> - onboard_hub driver: use IS_ENABLED(CONFIG_USB_ONBOARD_HUB_MODULE)
>   in onboard_hub.h to also check for the driver built as module
> - onboard_hub_driver: include onboard_hub.h again to make sure there
>   are prototype declarations for the public functions
> 
> Changes in v11:
> - support multiple onboard hubs connected to the same parent
> - don't include ‘onboard_hub.h’ from the onboard hub driver
> 
> Changes in v10:
> - always use of_is_onboard_usb_hub() stub unless ONBOARD_USB_HUB=y/m
> - keep 'regulator-boot-on' property for pp3300_hub
> 
> Changes in v9:
> - added dependency on ONBOARD_USB_HUB (or !!ONBOARD_USB_HUB) to
>   USB_PLATFORM_XHCI
> 
> Changes in v7:
> - updated DT binding
> - series rebased on qcom/arm64-for-5.13
> 
> Changes in v6:
> - updated summary
> 
> Changes in v5:
> - cover letter added
> 
> Matthias Kaehlcke (6):
>   usb: misc: Add onboard_usb_hub driver
>   of/platform: Add stubs for of_platform_device_create/destroy()
>   arm64: defconfig: Explicitly enable USB_XHCI_PLATFORM
>   usb: Specify dependencies on USB_XHCI_PLATFORM with 'depends on'
>   usb: host: xhci-plat: Create platform device for onboard hubs in
>     probe()
>   arm64: dts: qcom: sc7180-trogdor: Add nodes for onboard USB hub
> 
>  .../sysfs-bus-platform-onboard-usb-hub        |   8 +
>  MAINTAINERS                                   |   7 +
>  .../boot/dts/qcom/sc7180-trogdor-lazor-r0.dts |  19 +-
>  .../boot/dts/qcom/sc7180-trogdor-lazor-r1.dts |  12 +-
>  .../arm64/boot/dts/qcom/sc7180-trogdor-r1.dts |  19 +-
>  arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi  |  19 +-
>  arch/arm64/configs/defconfig                  |   1 +
>  drivers/usb/cdns3/Kconfig                     |   2 +-
>  drivers/usb/dwc3/Kconfig                      |   5 +-
>  drivers/usb/host/Kconfig                      |   5 +-
>  drivers/usb/host/xhci-plat.c                  |   6 +
>  drivers/usb/host/xhci.h                       |   2 +
>  drivers/usb/misc/Kconfig                      |  17 +
>  drivers/usb/misc/Makefile                     |   1 +
>  drivers/usb/misc/onboard_usb_hub.c            | 497 ++++++++++++++++++
>  include/linux/of_platform.h                   |  22 +-
>  include/linux/usb/onboard_hub.h               |  18 +
>  17 files changed, 621 insertions(+), 39 deletions(-)
>  create mode 100644 Documentation/ABI/testing/sysfs-bus-platform-onboard-usb-hub
>  create mode 100644 drivers/usb/misc/onboard_usb_hub.c
>  create mode 100644 include/linux/usb/onboard_hub.h
> 
> -- 
> 2.32.0.432.gabb21c7263-goog
> 

^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [PATCH v15 0/6] usb: misc: Add onboard_usb_hub driver
  2021-08-09 15:49 ` [PATCH v15 0/6] usb: misc: Add onboard_usb_hub driver Matthias Kaehlcke
@ 2021-08-11 12:38   ` Roger Quadros
  2021-08-11 12:56     ` Roger Quadros
  0 siblings, 1 reply; 15+ messages in thread
From: Roger Quadros @ 2021-08-11 12:38 UTC (permalink / raw)
  To: Matthias Kaehlcke, Greg Kroah-Hartman, Alan Stern, Rob Herring,
	Frank Rowand, Mathias Nyman, Felipe Balbi
  Cc: Bastien Nocera, Peter Chen, devicetree, Michal Simek,
	linux-kernel, Douglas Anderson, Krzysztof Kozlowski, linux-usb,
	Ravi Chandra Sadineni, Stephen Boyd, Al Cooper, Andrey Zhizhikin,
	Andy Gross, Aswath Govindraju, Bjorn Andersson, Catalin Marinas,
	Dmitry Baryshkov, Dmitry Osipenko, Enric Balletbo i Serra,
	Fabio Estevam, Guido Günther, Jagan Teki, Nishanth Menon,
	Pawel Laszczak, Shawn Guo, Vinod Koul, Will Deacon,
	linux-arm-kernel, linux-arm-msm

Hi Matthias,

On 09/08/2021 18:49, Matthias Kaehlcke wrote:
> Hi Greg,
> 
> Just wanted to check if this series is still on your radar. Is
> there anything that blocks it from landing (further ACKs, ...)?
> 
> Thanks
> 
> Matthias
> 
> On Mon, Jul 26, 2021 at 05:41:12PM -0700, Matthias Kaehlcke wrote:
>> This series adds:
>> - the onboard_usb_hub_driver
>> - glue in the xhci-plat driver to create and destroy the
>>   onboard_usb_hub platform devices if needed
>> - a device tree binding for the Realtek RTS5411 USB hub controller
>> - device tree changes that add RTS5411 entries for the QCA SC7180
>>   based boards trogdor and lazor
>> - a couple of stubs for platform device functions to avoid
>>   unresolved symbols with certain kernel configs
>>
>> The main issue the driver addresses is that a USB hub needs to be
>> powered before it can be discovered. For discrete onboard hubs (an
>> example for such a hub is the Realtek RTS5411) this is often solved
>> by supplying the hub with an 'always-on' regulator, which is kind
>> of a hack. Some onboard hubs may require further initialization
>> steps, like changing the state of a GPIO or enabling a clock, which
>> requires even more hacks. This driver creates a platform device
>> representing the hub which performs the necessary initialization.
>> Currently it only supports switching on a single regulator, support
>> for multiple regulators or other actions can be added as needed.
>> Different initialization sequences can be supported based on the
>> compatible string.
>>
>> Besides performing the initialization the driver can be configured
>> to power the hub off during system suspend. This can help to extend
>> battery life on battery powered devices which have no requirements
>> to keep the hub powered during suspend. The driver can also be
>> configured to leave the hub powered when a wakeup capable USB device
>> is connected when suspending, and power it off otherwise.
>>
>> Changes in v15:
>> - adjusted dependencies of USB_DWC3_CORE to make sure it can only
>>   be enabled when at least one of USB_DWC3_HOST, USB_DWC3_GADGET
>>   or USB_DWC3_DUAL_ROLE is selectable
>>
>> Changes in v14:
>> - rebased on top of v5.14-rc1
>> - dropped DT binding patch which landed in v5.13
>>
>> Changes in v13:
>> - added patch "usb: Specify dependency on USB_XHCI_PLATFORM with
>>   'depends on'" to the series to avoid Kconfig conflicts
>> - added patch "arm64: defconfig: Explicitly enable USB_XHCI_PLATFORM"
>>   to the series to keep effective defconfig unchanged
>>
>> Changes in v12:
>> - onboard_hub driver: use IS_ENABLED(CONFIG_USB_ONBOARD_HUB_MODULE)
>>   in onboard_hub.h to also check for the driver built as module
>> - onboard_hub_driver: include onboard_hub.h again to make sure there
>>   are prototype declarations for the public functions
>>
>> Changes in v11:
>> - support multiple onboard hubs connected to the same parent
>> - don't include ‘onboard_hub.h’ from the onboard hub driver
>>
>> Changes in v10:
>> - always use of_is_onboard_usb_hub() stub unless ONBOARD_USB_HUB=y/m
>> - keep 'regulator-boot-on' property for pp3300_hub
>>
>> Changes in v9:
>> - added dependency on ONBOARD_USB_HUB (or !!ONBOARD_USB_HUB) to
>>   USB_PLATFORM_XHCI
>>
>> Changes in v7:
>> - updated DT binding
>> - series rebased on qcom/arm64-for-5.13
>>
>> Changes in v6:
>> - updated summary
>>
>> Changes in v5:
>> - cover letter added
>>
>> Matthias Kaehlcke (6):
>>   usb: misc: Add onboard_usb_hub driver
>>   of/platform: Add stubs for of_platform_device_create/destroy()
>>   arm64: defconfig: Explicitly enable USB_XHCI_PLATFORM
>>   usb: Specify dependencies on USB_XHCI_PLATFORM with 'depends on'
>>   usb: host: xhci-plat: Create platform device for onboard hubs in
>>     probe()
>>   arm64: dts: qcom: sc7180-trogdor: Add nodes for onboard USB hub
>>
>>  .../sysfs-bus-platform-onboard-usb-hub        |   8 +
>>  MAINTAINERS                                   |   7 +
>>  .../boot/dts/qcom/sc7180-trogdor-lazor-r0.dts |  19 +-
>>  .../boot/dts/qcom/sc7180-trogdor-lazor-r1.dts |  12 +-
>>  .../arm64/boot/dts/qcom/sc7180-trogdor-r1.dts |  19 +-
>>  arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi  |  19 +-
>>  arch/arm64/configs/defconfig                  |   1 +
>>  drivers/usb/cdns3/Kconfig                     |   2 +-
>>  drivers/usb/dwc3/Kconfig                      |   5 +-
>>  drivers/usb/host/Kconfig                      |   5 +-

These Kconfig changes are causing the resulting .config to be different.
For example, if I start with omap2plus_defconfig, the resulting .config
before and after your series is different as shown below

:/work/linux$ diff /tmp/.config .config
1902d1901
< # CONFIG_HISI_HIKEY_USB is not set
4992c4991
< CONFIG_USB_XHCI_PLATFORM=m
---
> # CONFIG_USB_XHCI_PLATFORM is not set
5073,5075c5072
< # CONFIG_USB_DWC3_HOST is not set
< # CONFIG_USB_DWC3_GADGET is not set
< CONFIG_USB_DWC3_DUAL_ROLE=y
---
> CONFIG_USB_DWC3_GADGET=y
5173a5171
> # CONFIG_USB_ONBOARD_HUB is not set
5285c5283
< CONFIG_USB_ROLE_SWITCH=m
---
> # CONFIG_USB_ROLE_SWITCH is not set

I would expect the same issues for multi_v7_defconfig and multi_v8_defconfig as well.
I'm ok to update the relevant defconfigs files so that the resulting .config is identical to
before your series. Thanks!

--
cheers,
-roger

^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [PATCH v15 0/6] usb: misc: Add onboard_usb_hub driver
  2021-08-11 12:38   ` Roger Quadros
@ 2021-08-11 12:56     ` Roger Quadros
  2021-08-12 17:08       ` Matthias Kaehlcke
  0 siblings, 1 reply; 15+ messages in thread
From: Roger Quadros @ 2021-08-11 12:56 UTC (permalink / raw)
  To: Matthias Kaehlcke, Greg Kroah-Hartman, Alan Stern, Rob Herring,
	Frank Rowand, Mathias Nyman, Felipe Balbi
  Cc: Bastien Nocera, Peter Chen, devicetree, Michal Simek,
	linux-kernel, Douglas Anderson, Krzysztof Kozlowski, linux-usb,
	Ravi Chandra Sadineni, Stephen Boyd, Al Cooper, Andrey Zhizhikin,
	Andy Gross, Aswath Govindraju, Bjorn Andersson, Catalin Marinas,
	Dmitry Baryshkov, Dmitry Osipenko, Enric Balletbo i Serra,
	Fabio Estevam, Guido Günther, Jagan Teki, Nishanth Menon,
	Pawel Laszczak, Shawn Guo, Vinod Koul, Will Deacon,
	linux-arm-kernel, linux-arm-msm



On 11/08/2021 15:38, Roger Quadros wrote:
> Hi Matthias,
> 
> On 09/08/2021 18:49, Matthias Kaehlcke wrote:
>> Hi Greg,
>>
>> Just wanted to check if this series is still on your radar. Is
>> there anything that blocks it from landing (further ACKs, ...)?
>>
>> Thanks
>>
>> Matthias
>>
>> On Mon, Jul 26, 2021 at 05:41:12PM -0700, Matthias Kaehlcke wrote:
>>> This series adds:
>>> - the onboard_usb_hub_driver
>>> - glue in the xhci-plat driver to create and destroy the
>>>   onboard_usb_hub platform devices if needed
>>> - a device tree binding for the Realtek RTS5411 USB hub controller
>>> - device tree changes that add RTS5411 entries for the QCA SC7180
>>>   based boards trogdor and lazor
>>> - a couple of stubs for platform device functions to avoid
>>>   unresolved symbols with certain kernel configs
>>>
>>> The main issue the driver addresses is that a USB hub needs to be
>>> powered before it can be discovered. For discrete onboard hubs (an
>>> example for such a hub is the Realtek RTS5411) this is often solved
>>> by supplying the hub with an 'always-on' regulator, which is kind
>>> of a hack. Some onboard hubs may require further initialization
>>> steps, like changing the state of a GPIO or enabling a clock, which
>>> requires even more hacks. This driver creates a platform device
>>> representing the hub which performs the necessary initialization.
>>> Currently it only supports switching on a single regulator, support
>>> for multiple regulators or other actions can be added as needed.
>>> Different initialization sequences can be supported based on the
>>> compatible string.
>>>
>>> Besides performing the initialization the driver can be configured
>>> to power the hub off during system suspend. This can help to extend
>>> battery life on battery powered devices which have no requirements
>>> to keep the hub powered during suspend. The driver can also be
>>> configured to leave the hub powered when a wakeup capable USB device
>>> is connected when suspending, and power it off otherwise.
>>>
>>> Changes in v15:
>>> - adjusted dependencies of USB_DWC3_CORE to make sure it can only
>>>   be enabled when at least one of USB_DWC3_HOST, USB_DWC3_GADGET
>>>   or USB_DWC3_DUAL_ROLE is selectable
>>>
>>> Changes in v14:
>>> - rebased on top of v5.14-rc1
>>> - dropped DT binding patch which landed in v5.13
>>>
>>> Changes in v13:
>>> - added patch "usb: Specify dependency on USB_XHCI_PLATFORM with
>>>   'depends on'" to the series to avoid Kconfig conflicts
>>> - added patch "arm64: defconfig: Explicitly enable USB_XHCI_PLATFORM"
>>>   to the series to keep effective defconfig unchanged
>>>
>>> Changes in v12:
>>> - onboard_hub driver: use IS_ENABLED(CONFIG_USB_ONBOARD_HUB_MODULE)
>>>   in onboard_hub.h to also check for the driver built as module
>>> - onboard_hub_driver: include onboard_hub.h again to make sure there
>>>   are prototype declarations for the public functions
>>>
>>> Changes in v11:
>>> - support multiple onboard hubs connected to the same parent
>>> - don't include ‘onboard_hub.h’ from the onboard hub driver
>>>
>>> Changes in v10:
>>> - always use of_is_onboard_usb_hub() stub unless ONBOARD_USB_HUB=y/m
>>> - keep 'regulator-boot-on' property for pp3300_hub
>>>
>>> Changes in v9:
>>> - added dependency on ONBOARD_USB_HUB (or !!ONBOARD_USB_HUB) to
>>>   USB_PLATFORM_XHCI
>>>
>>> Changes in v7:
>>> - updated DT binding
>>> - series rebased on qcom/arm64-for-5.13
>>>
>>> Changes in v6:
>>> - updated summary
>>>
>>> Changes in v5:
>>> - cover letter added
>>>
>>> Matthias Kaehlcke (6):
>>>   usb: misc: Add onboard_usb_hub driver
>>>   of/platform: Add stubs for of_platform_device_create/destroy()
>>>   arm64: defconfig: Explicitly enable USB_XHCI_PLATFORM
>>>   usb: Specify dependencies on USB_XHCI_PLATFORM with 'depends on'
>>>   usb: host: xhci-plat: Create platform device for onboard hubs in
>>>     probe()
>>>   arm64: dts: qcom: sc7180-trogdor: Add nodes for onboard USB hub
>>>
>>>  .../sysfs-bus-platform-onboard-usb-hub        |   8 +
>>>  MAINTAINERS                                   |   7 +
>>>  .../boot/dts/qcom/sc7180-trogdor-lazor-r0.dts |  19 +-
>>>  .../boot/dts/qcom/sc7180-trogdor-lazor-r1.dts |  12 +-
>>>  .../arm64/boot/dts/qcom/sc7180-trogdor-r1.dts |  19 +-
>>>  arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi  |  19 +-
>>>  arch/arm64/configs/defconfig                  |   1 +
>>>  drivers/usb/cdns3/Kconfig                     |   2 +-
>>>  drivers/usb/dwc3/Kconfig                      |   5 +-
>>>  drivers/usb/host/Kconfig                      |   5 +-
> 
> These Kconfig changes are causing the resulting .config to be different.
> For example, if I start with omap2plus_defconfig, the resulting .config
> before and after your series is different as shown below
> 
> :/work/linux$ diff /tmp/.config .config
> 1902d1901
> < # CONFIG_HISI_HIKEY_USB is not set
> 4992c4991
> < CONFIG_USB_XHCI_PLATFORM=m
> ---
>> # CONFIG_USB_XHCI_PLATFORM is not set
> 5073,5075c5072
> < # CONFIG_USB_DWC3_HOST is not set
> < # CONFIG_USB_DWC3_GADGET is not set
> < CONFIG_USB_DWC3_DUAL_ROLE=y
> ---
>> CONFIG_USB_DWC3_GADGET=y
> 5173a5171
>> # CONFIG_USB_ONBOARD_HUB is not set
> 5285c5283
> < CONFIG_USB_ROLE_SWITCH=m
> ---
>> # CONFIG_USB_ROLE_SWITCH is not set
> 
> I would expect the same issues for multi_v7_defconfig and multi_v8_defconfig as well.

Sorry I meant defconfig for arm64, not multi_v8_defconfig.

I checked that for arm64 defconfig it is ok.

> I'm ok to update the relevant defconfigs files so that the resulting .config is identical to
> before your series. Thanks!

With the below patch you can fix it for omap2plus_defconfig and multi_v7_defconfig.

diff --git a/arch/arm/configs/multi_v7_defconfig b/arch/arm/configs/multi_v7_defconfig
index d9abaae118dd..8c175ab37377 100644
--- a/arch/arm/configs/multi_v7_defconfig
+++ b/arch/arm/configs/multi_v7_defconfig
@@ -787,6 +787,7 @@ CONFIG_SND_AUDIO_GRAPH_CARD=m
 CONFIG_USB=y
 CONFIG_USB_OTG=y
 CONFIG_USB_XHCI_HCD=y
+CONFIG_USB_XHCI_PLATFORM=y
 CONFIG_USB_XHCI_MVEBU=y
 CONFIG_USB_XHCI_TEGRA=m
 CONFIG_USB_EHCI_HCD=y
diff --git a/arch/arm/configs/omap2plus_defconfig b/arch/arm/configs/omap2plus_defconfig
index 2ac2418084ab..a015fb04fa25 100644
--- a/arch/arm/configs/omap2plus_defconfig
+++ b/arch/arm/configs/omap2plus_defconfig
@@ -562,6 +562,7 @@ CONFIG_USB=m
 CONFIG_USB_ANNOUNCE_NEW_DEVICES=y
 CONFIG_USB_MON=m
 CONFIG_USB_XHCI_HCD=m
+CONFIG_USB_XHCI_PLATFORM=m
 CONFIG_USB_EHCI_HCD=m
 CONFIG_USB_OHCI_HCD=m
 CONFIG_USB_ACM=m

--
cheers,
-roger

^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [PATCH v15 0/6] usb: misc: Add onboard_usb_hub driver
  2021-08-11 12:56     ` Roger Quadros
@ 2021-08-12 17:08       ` Matthias Kaehlcke
  2021-08-13  6:35         ` Roger Quadros
  0 siblings, 1 reply; 15+ messages in thread
From: Matthias Kaehlcke @ 2021-08-12 17:08 UTC (permalink / raw)
  To: Roger Quadros
  Cc: Greg Kroah-Hartman, Alan Stern, Rob Herring, Frank Rowand,
	Mathias Nyman, Felipe Balbi, Bastien Nocera, Peter Chen,
	devicetree, Michal Simek, linux-kernel, Douglas Anderson,
	Krzysztof Kozlowski, linux-usb, Ravi Chandra Sadineni,
	Stephen Boyd, Al Cooper, Andrey Zhizhikin, Andy Gross,
	Aswath Govindraju, Bjorn Andersson, Catalin Marinas,
	Dmitry Baryshkov, Dmitry Osipenko, Enric Balletbo i Serra,
	Fabio Estevam, Guido Günther, Jagan Teki, Nishanth Menon,
	Pawel Laszczak, Shawn Guo, Vinod Koul, Will Deacon,
	linux-arm-kernel, linux-arm-msm

Hi Roger,

On Wed, Aug 11, 2021 at 03:56:15PM +0300, Roger Quadros wrote:
> 
> 
> On 11/08/2021 15:38, Roger Quadros wrote:
> > Hi Matthias,
> > 
> > On 09/08/2021 18:49, Matthias Kaehlcke wrote:
> >> Hi Greg,
> >>
> >> Just wanted to check if this series is still on your radar. Is
> >> there anything that blocks it from landing (further ACKs, ...)?
> >>
> >> Thanks
> >>
> >> Matthias
> >>
> >> On Mon, Jul 26, 2021 at 05:41:12PM -0700, Matthias Kaehlcke wrote:
> >>> This series adds:
> >>> - the onboard_usb_hub_driver
> >>> - glue in the xhci-plat driver to create and destroy the
> >>>   onboard_usb_hub platform devices if needed
> >>> - a device tree binding for the Realtek RTS5411 USB hub controller
> >>> - device tree changes that add RTS5411 entries for the QCA SC7180
> >>>   based boards trogdor and lazor
> >>> - a couple of stubs for platform device functions to avoid
> >>>   unresolved symbols with certain kernel configs
> >>>
> >>> The main issue the driver addresses is that a USB hub needs to be
> >>> powered before it can be discovered. For discrete onboard hubs (an
> >>> example for such a hub is the Realtek RTS5411) this is often solved
> >>> by supplying the hub with an 'always-on' regulator, which is kind
> >>> of a hack. Some onboard hubs may require further initialization
> >>> steps, like changing the state of a GPIO or enabling a clock, which
> >>> requires even more hacks. This driver creates a platform device
> >>> representing the hub which performs the necessary initialization.
> >>> Currently it only supports switching on a single regulator, support
> >>> for multiple regulators or other actions can be added as needed.
> >>> Different initialization sequences can be supported based on the
> >>> compatible string.
> >>>
> >>> Besides performing the initialization the driver can be configured
> >>> to power the hub off during system suspend. This can help to extend
> >>> battery life on battery powered devices which have no requirements
> >>> to keep the hub powered during suspend. The driver can also be
> >>> configured to leave the hub powered when a wakeup capable USB device
> >>> is connected when suspending, and power it off otherwise.
> >>>
> >>> Changes in v15:
> >>> - adjusted dependencies of USB_DWC3_CORE to make sure it can only
> >>>   be enabled when at least one of USB_DWC3_HOST, USB_DWC3_GADGET
> >>>   or USB_DWC3_DUAL_ROLE is selectable
> >>>
> >>> Changes in v14:
> >>> - rebased on top of v5.14-rc1
> >>> - dropped DT binding patch which landed in v5.13
> >>>
> >>> Changes in v13:
> >>> - added patch "usb: Specify dependency on USB_XHCI_PLATFORM with
> >>>   'depends on'" to the series to avoid Kconfig conflicts
> >>> - added patch "arm64: defconfig: Explicitly enable USB_XHCI_PLATFORM"
> >>>   to the series to keep effective defconfig unchanged
> >>>
> >>> Changes in v12:
> >>> - onboard_hub driver: use IS_ENABLED(CONFIG_USB_ONBOARD_HUB_MODULE)
> >>>   in onboard_hub.h to also check for the driver built as module
> >>> - onboard_hub_driver: include onboard_hub.h again to make sure there
> >>>   are prototype declarations for the public functions
> >>>
> >>> Changes in v11:
> >>> - support multiple onboard hubs connected to the same parent
> >>> - don't include ‘onboard_hub.h’ from the onboard hub driver
> >>>
> >>> Changes in v10:
> >>> - always use of_is_onboard_usb_hub() stub unless ONBOARD_USB_HUB=y/m
> >>> - keep 'regulator-boot-on' property for pp3300_hub
> >>>
> >>> Changes in v9:
> >>> - added dependency on ONBOARD_USB_HUB (or !!ONBOARD_USB_HUB) to
> >>>   USB_PLATFORM_XHCI
> >>>
> >>> Changes in v7:
> >>> - updated DT binding
> >>> - series rebased on qcom/arm64-for-5.13
> >>>
> >>> Changes in v6:
> >>> - updated summary
> >>>
> >>> Changes in v5:
> >>> - cover letter added
> >>>
> >>> Matthias Kaehlcke (6):
> >>>   usb: misc: Add onboard_usb_hub driver
> >>>   of/platform: Add stubs for of_platform_device_create/destroy()
> >>>   arm64: defconfig: Explicitly enable USB_XHCI_PLATFORM
> >>>   usb: Specify dependencies on USB_XHCI_PLATFORM with 'depends on'
> >>>   usb: host: xhci-plat: Create platform device for onboard hubs in
> >>>     probe()
> >>>   arm64: dts: qcom: sc7180-trogdor: Add nodes for onboard USB hub
> >>>
> >>>  .../sysfs-bus-platform-onboard-usb-hub        |   8 +
> >>>  MAINTAINERS                                   |   7 +
> >>>  .../boot/dts/qcom/sc7180-trogdor-lazor-r0.dts |  19 +-
> >>>  .../boot/dts/qcom/sc7180-trogdor-lazor-r1.dts |  12 +-
> >>>  .../arm64/boot/dts/qcom/sc7180-trogdor-r1.dts |  19 +-
> >>>  arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi  |  19 +-
> >>>  arch/arm64/configs/defconfig                  |   1 +
> >>>  drivers/usb/cdns3/Kconfig                     |   2 +-
> >>>  drivers/usb/dwc3/Kconfig                      |   5 +-
> >>>  drivers/usb/host/Kconfig                      |   5 +-
> > 
> > These Kconfig changes are causing the resulting .config to be different.
> > For example, if I start with omap2plus_defconfig, the resulting .config
> > before and after your series is different as shown below
> > 
> > :/work/linux$ diff /tmp/.config .config
> > 1902d1901
> > < # CONFIG_HISI_HIKEY_USB is not set
> > 4992c4991
> > < CONFIG_USB_XHCI_PLATFORM=m
> > ---
> >> # CONFIG_USB_XHCI_PLATFORM is not set
> > 5073,5075c5072
> > < # CONFIG_USB_DWC3_HOST is not set
> > < # CONFIG_USB_DWC3_GADGET is not set
> > < CONFIG_USB_DWC3_DUAL_ROLE=y
> > ---
> >> CONFIG_USB_DWC3_GADGET=y
> > 5173a5171
> >> # CONFIG_USB_ONBOARD_HUB is not set
> > 5285c5283
> > < CONFIG_USB_ROLE_SWITCH=m
> > ---
> >> # CONFIG_USB_ROLE_SWITCH is not set
> > 
> > I would expect the same issues for multi_v7_defconfig and multi_v8_defconfig as well.
> 
> Sorry I meant defconfig for arm64, not multi_v8_defconfig.
> 
> I checked that for arm64 defconfig it is ok.
> 
> > I'm ok to update the relevant defconfigs files so that the resulting .config is identical to
> > before your series. Thanks!
> 
> With the below patch you can fix it for omap2plus_defconfig and multi_v7_defconfig.
> 
> diff --git a/arch/arm/configs/multi_v7_defconfig b/arch/arm/configs/multi_v7_defconfig
> index d9abaae118dd..8c175ab37377 100644
> --- a/arch/arm/configs/multi_v7_defconfig
> +++ b/arch/arm/configs/multi_v7_defconfig
> @@ -787,6 +787,7 @@ CONFIG_SND_AUDIO_GRAPH_CARD=m
>  CONFIG_USB=y
>  CONFIG_USB_OTG=y
>  CONFIG_USB_XHCI_HCD=y
> +CONFIG_USB_XHCI_PLATFORM=y
>  CONFIG_USB_XHCI_MVEBU=y
>  CONFIG_USB_XHCI_TEGRA=m
>  CONFIG_USB_EHCI_HCD=y
> diff --git a/arch/arm/configs/omap2plus_defconfig b/arch/arm/configs/omap2plus_defconfig
> index 2ac2418084ab..a015fb04fa25 100644
> --- a/arch/arm/configs/omap2plus_defconfig
> +++ b/arch/arm/configs/omap2plus_defconfig
> @@ -562,6 +562,7 @@ CONFIG_USB=m
>  CONFIG_USB_ANNOUNCE_NEW_DEVICES=y
>  CONFIG_USB_MON=m
>  CONFIG_USB_XHCI_HCD=m
> +CONFIG_USB_XHCI_PLATFORM=m
>  CONFIG_USB_EHCI_HCD=m
>  CONFIG_USB_OHCI_HCD=m
>  CONFIG_USB_ACM=m

Thanks for testing!

I completely forgot that arm32 has all these different defconfigs.

While trying to adjust qcom_defconfig I came across something that confuses
me. The original defconfig results in:

# CONFIG_USB_XHCI_HCD is not set
CONFIG_USB_DWC3_DUAL_ROLE=y

My assumption was that xHCI support is need for dwc3 dual mode (which is
made explicit by https://lore.kernel.org/patchwork/patch/1468240/), is
that incorrect? Maybe without xHCI support the controller can still
operate in USB 2.0 dual role mode?

^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [PATCH v15 0/6] usb: misc: Add onboard_usb_hub driver
  2021-08-12 17:08       ` Matthias Kaehlcke
@ 2021-08-13  6:35         ` Roger Quadros
  2021-08-13 18:33           ` Matthias Kaehlcke
  0 siblings, 1 reply; 15+ messages in thread
From: Roger Quadros @ 2021-08-13  6:35 UTC (permalink / raw)
  To: Matthias Kaehlcke
  Cc: Greg Kroah-Hartman, Alan Stern, Rob Herring, Frank Rowand,
	Mathias Nyman, Felipe Balbi, Bastien Nocera, Peter Chen,
	devicetree, Michal Simek, linux-kernel, Douglas Anderson,
	Krzysztof Kozlowski, linux-usb, Ravi Chandra Sadineni,
	Stephen Boyd, Al Cooper, Andrey Zhizhikin, Andy Gross,
	Aswath Govindraju, Bjorn Andersson, Catalin Marinas,
	Dmitry Baryshkov, Dmitry Osipenko, Enric Balletbo i Serra,
	Fabio Estevam, Guido Günther, Jagan Teki, Nishanth Menon,
	Pawel Laszczak, Shawn Guo, Vinod Koul, Will Deacon,
	linux-arm-kernel, linux-arm-msm

Hi Matthias,

On 12/08/2021 20:08, Matthias Kaehlcke wrote:
> Hi Roger,
> 
> On Wed, Aug 11, 2021 at 03:56:15PM +0300, Roger Quadros wrote:
>>
>>
>> On 11/08/2021 15:38, Roger Quadros wrote:
>>> Hi Matthias,
>>>
>>> On 09/08/2021 18:49, Matthias Kaehlcke wrote:
>>>> Hi Greg,
>>>>
>>>> Just wanted to check if this series is still on your radar. Is
>>>> there anything that blocks it from landing (further ACKs, ...)?
>>>>
>>>> Thanks
>>>>
>>>> Matthias
>>>>
>>>> On Mon, Jul 26, 2021 at 05:41:12PM -0700, Matthias Kaehlcke wrote:
>>>>> This series adds:
>>>>> - the onboard_usb_hub_driver
>>>>> - glue in the xhci-plat driver to create and destroy the
>>>>>   onboard_usb_hub platform devices if needed
>>>>> - a device tree binding for the Realtek RTS5411 USB hub controller
>>>>> - device tree changes that add RTS5411 entries for the QCA SC7180
>>>>>   based boards trogdor and lazor
>>>>> - a couple of stubs for platform device functions to avoid
>>>>>   unresolved symbols with certain kernel configs
>>>>>
>>>>> The main issue the driver addresses is that a USB hub needs to be
>>>>> powered before it can be discovered. For discrete onboard hubs (an
>>>>> example for such a hub is the Realtek RTS5411) this is often solved
>>>>> by supplying the hub with an 'always-on' regulator, which is kind
>>>>> of a hack. Some onboard hubs may require further initialization
>>>>> steps, like changing the state of a GPIO or enabling a clock, which
>>>>> requires even more hacks. This driver creates a platform device
>>>>> representing the hub which performs the necessary initialization.
>>>>> Currently it only supports switching on a single regulator, support
>>>>> for multiple regulators or other actions can be added as needed.
>>>>> Different initialization sequences can be supported based on the
>>>>> compatible string.
>>>>>
>>>>> Besides performing the initialization the driver can be configured
>>>>> to power the hub off during system suspend. This can help to extend
>>>>> battery life on battery powered devices which have no requirements
>>>>> to keep the hub powered during suspend. The driver can also be
>>>>> configured to leave the hub powered when a wakeup capable USB device
>>>>> is connected when suspending, and power it off otherwise.
>>>>>
>>>>> Changes in v15:
>>>>> - adjusted dependencies of USB_DWC3_CORE to make sure it can only
>>>>>   be enabled when at least one of USB_DWC3_HOST, USB_DWC3_GADGET
>>>>>   or USB_DWC3_DUAL_ROLE is selectable
>>>>>
>>>>> Changes in v14:
>>>>> - rebased on top of v5.14-rc1
>>>>> - dropped DT binding patch which landed in v5.13
>>>>>
>>>>> Changes in v13:
>>>>> - added patch "usb: Specify dependency on USB_XHCI_PLATFORM with
>>>>>   'depends on'" to the series to avoid Kconfig conflicts
>>>>> - added patch "arm64: defconfig: Explicitly enable USB_XHCI_PLATFORM"
>>>>>   to the series to keep effective defconfig unchanged
>>>>>
>>>>> Changes in v12:
>>>>> - onboard_hub driver: use IS_ENABLED(CONFIG_USB_ONBOARD_HUB_MODULE)
>>>>>   in onboard_hub.h to also check for the driver built as module
>>>>> - onboard_hub_driver: include onboard_hub.h again to make sure there
>>>>>   are prototype declarations for the public functions
>>>>>
>>>>> Changes in v11:
>>>>> - support multiple onboard hubs connected to the same parent
>>>>> - don't include ‘onboard_hub.h’ from the onboard hub driver
>>>>>
>>>>> Changes in v10:
>>>>> - always use of_is_onboard_usb_hub() stub unless ONBOARD_USB_HUB=y/m
>>>>> - keep 'regulator-boot-on' property for pp3300_hub
>>>>>
>>>>> Changes in v9:
>>>>> - added dependency on ONBOARD_USB_HUB (or !!ONBOARD_USB_HUB) to
>>>>>   USB_PLATFORM_XHCI
>>>>>
>>>>> Changes in v7:
>>>>> - updated DT binding
>>>>> - series rebased on qcom/arm64-for-5.13
>>>>>
>>>>> Changes in v6:
>>>>> - updated summary
>>>>>
>>>>> Changes in v5:
>>>>> - cover letter added
>>>>>
>>>>> Matthias Kaehlcke (6):
>>>>>   usb: misc: Add onboard_usb_hub driver
>>>>>   of/platform: Add stubs for of_platform_device_create/destroy()
>>>>>   arm64: defconfig: Explicitly enable USB_XHCI_PLATFORM
>>>>>   usb: Specify dependencies on USB_XHCI_PLATFORM with 'depends on'
>>>>>   usb: host: xhci-plat: Create platform device for onboard hubs in
>>>>>     probe()
>>>>>   arm64: dts: qcom: sc7180-trogdor: Add nodes for onboard USB hub
>>>>>
>>>>>  .../sysfs-bus-platform-onboard-usb-hub        |   8 +
>>>>>  MAINTAINERS                                   |   7 +
>>>>>  .../boot/dts/qcom/sc7180-trogdor-lazor-r0.dts |  19 +-
>>>>>  .../boot/dts/qcom/sc7180-trogdor-lazor-r1.dts |  12 +-
>>>>>  .../arm64/boot/dts/qcom/sc7180-trogdor-r1.dts |  19 +-
>>>>>  arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi  |  19 +-
>>>>>  arch/arm64/configs/defconfig                  |   1 +
>>>>>  drivers/usb/cdns3/Kconfig                     |   2 +-
>>>>>  drivers/usb/dwc3/Kconfig                      |   5 +-
>>>>>  drivers/usb/host/Kconfig                      |   5 +-
>>>
>>> These Kconfig changes are causing the resulting .config to be different.
>>> For example, if I start with omap2plus_defconfig, the resulting .config
>>> before and after your series is different as shown below
>>>
>>> :/work/linux$ diff /tmp/.config .config
>>> 1902d1901
>>> < # CONFIG_HISI_HIKEY_USB is not set
>>> 4992c4991
>>> < CONFIG_USB_XHCI_PLATFORM=m
>>> ---
>>>> # CONFIG_USB_XHCI_PLATFORM is not set
>>> 5073,5075c5072
>>> < # CONFIG_USB_DWC3_HOST is not set
>>> < # CONFIG_USB_DWC3_GADGET is not set
>>> < CONFIG_USB_DWC3_DUAL_ROLE=y
>>> ---
>>>> CONFIG_USB_DWC3_GADGET=y
>>> 5173a5171
>>>> # CONFIG_USB_ONBOARD_HUB is not set
>>> 5285c5283
>>> < CONFIG_USB_ROLE_SWITCH=m
>>> ---
>>>> # CONFIG_USB_ROLE_SWITCH is not set
>>>
>>> I would expect the same issues for multi_v7_defconfig and multi_v8_defconfig as well.
>>
>> Sorry I meant defconfig for arm64, not multi_v8_defconfig.
>>
>> I checked that for arm64 defconfig it is ok.
>>
>>> I'm ok to update the relevant defconfigs files so that the resulting .config is identical to
>>> before your series. Thanks!
>>
>> With the below patch you can fix it for omap2plus_defconfig and multi_v7_defconfig.
>>
>> diff --git a/arch/arm/configs/multi_v7_defconfig b/arch/arm/configs/multi_v7_defconfig
>> index d9abaae118dd..8c175ab37377 100644
>> --- a/arch/arm/configs/multi_v7_defconfig
>> +++ b/arch/arm/configs/multi_v7_defconfig
>> @@ -787,6 +787,7 @@ CONFIG_SND_AUDIO_GRAPH_CARD=m
>>  CONFIG_USB=y
>>  CONFIG_USB_OTG=y
>>  CONFIG_USB_XHCI_HCD=y
>> +CONFIG_USB_XHCI_PLATFORM=y
>>  CONFIG_USB_XHCI_MVEBU=y
>>  CONFIG_USB_XHCI_TEGRA=m
>>  CONFIG_USB_EHCI_HCD=y
>> diff --git a/arch/arm/configs/omap2plus_defconfig b/arch/arm/configs/omap2plus_defconfig
>> index 2ac2418084ab..a015fb04fa25 100644
>> --- a/arch/arm/configs/omap2plus_defconfig
>> +++ b/arch/arm/configs/omap2plus_defconfig
>> @@ -562,6 +562,7 @@ CONFIG_USB=m
>>  CONFIG_USB_ANNOUNCE_NEW_DEVICES=y
>>  CONFIG_USB_MON=m
>>  CONFIG_USB_XHCI_HCD=m
>> +CONFIG_USB_XHCI_PLATFORM=m
>>  CONFIG_USB_EHCI_HCD=m
>>  CONFIG_USB_OHCI_HCD=m
>>  CONFIG_USB_ACM=m
> 
> Thanks for testing!
> 
> I completely forgot that arm32 has all these different defconfigs.
> 
> While trying to adjust qcom_defconfig I came across something that confuses
> me. The original defconfig results in:
> 
> # CONFIG_USB_XHCI_HCD is not set
> CONFIG_USB_DWC3_DUAL_ROLE=y

The original Kconfig was:

> config USB_DWC3_DUAL_ROLE
>         bool "Dual Role mode"
>         depends on ((USB=y || USB=USB_DWC3) && (USB_GADGET=y || USB_GADGET=USB_DWC3))
>         depends on (EXTCON=y || EXTCON=USB_DWC3)

Which means USB_DWC3_DUAL_ROLE can be enabled even without CONFIG_USB_XHCI_HCD.

All the dual role code does is add/remove the host/gadget controller platform devices.
It doesn't care whether there is a driver for it or not.
i.e. there is no build dependency on CONFIG_USB_XHCI_HCD.

> 
> My assumption was that xHCI support is need for dwc3 dual mode (which is
> made explicit by https://lore.kernel.org/patchwork/patch/1468240/), is
> that incorrect? Maybe without xHCI support the controller can still
> operate in USB 2.0 dual role mode?
> 

Without xHCI support the host functionality will not work at all on dwc3 dual role.
So I think your Kconfig changes for USB_DWC3_DUAL_ROLE to depend on USB_XHCI_PLATFORM
are correct.

cheers,
-roger

^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [PATCH v15 0/6] usb: misc: Add onboard_usb_hub driver
  2021-08-13  6:35         ` Roger Quadros
@ 2021-08-13 18:33           ` Matthias Kaehlcke
  0 siblings, 0 replies; 15+ messages in thread
From: Matthias Kaehlcke @ 2021-08-13 18:33 UTC (permalink / raw)
  To: Roger Quadros
  Cc: Greg Kroah-Hartman, Alan Stern, Rob Herring, Frank Rowand,
	Mathias Nyman, Felipe Balbi, Bastien Nocera, Peter Chen,
	devicetree, Michal Simek, linux-kernel, Douglas Anderson,
	Krzysztof Kozlowski, linux-usb, Ravi Chandra Sadineni,
	Stephen Boyd, Al Cooper, Andrey Zhizhikin, Andy Gross,
	Aswath Govindraju, Bjorn Andersson, Catalin Marinas,
	Dmitry Baryshkov, Dmitry Osipenko, Enric Balletbo i Serra,
	Fabio Estevam, Guido Günther, Jagan Teki, Nishanth Menon,
	Pawel Laszczak, Shawn Guo, Vinod Koul, Will Deacon,
	linux-arm-kernel, linux-arm-msm

On Fri, Aug 13, 2021 at 09:35:53AM +0300, Roger Quadros wrote:
> Hi Matthias,
> 
> On 12/08/2021 20:08, Matthias Kaehlcke wrote:
> > Hi Roger,
> > 
> > On Wed, Aug 11, 2021 at 03:56:15PM +0300, Roger Quadros wrote:
> >>
> >>
> >> On 11/08/2021 15:38, Roger Quadros wrote:
> >>> Hi Matthias,
> >>>
> >>> On 09/08/2021 18:49, Matthias Kaehlcke wrote:
> >>>> Hi Greg,
> >>>>
> >>>> Just wanted to check if this series is still on your radar. Is
> >>>> there anything that blocks it from landing (further ACKs, ...)?
> >>>>
> >>>> Thanks
> >>>>
> >>>> Matthias
> >>>>
> >>>> On Mon, Jul 26, 2021 at 05:41:12PM -0700, Matthias Kaehlcke wrote:
> >>>>> This series adds:
> >>>>> - the onboard_usb_hub_driver
> >>>>> - glue in the xhci-plat driver to create and destroy the
> >>>>>   onboard_usb_hub platform devices if needed
> >>>>> - a device tree binding for the Realtek RTS5411 USB hub controller
> >>>>> - device tree changes that add RTS5411 entries for the QCA SC7180
> >>>>>   based boards trogdor and lazor
> >>>>> - a couple of stubs for platform device functions to avoid
> >>>>>   unresolved symbols with certain kernel configs
> >>>>>
> >>>>> The main issue the driver addresses is that a USB hub needs to be
> >>>>> powered before it can be discovered. For discrete onboard hubs (an
> >>>>> example for such a hub is the Realtek RTS5411) this is often solved
> >>>>> by supplying the hub with an 'always-on' regulator, which is kind
> >>>>> of a hack. Some onboard hubs may require further initialization
> >>>>> steps, like changing the state of a GPIO or enabling a clock, which
> >>>>> requires even more hacks. This driver creates a platform device
> >>>>> representing the hub which performs the necessary initialization.
> >>>>> Currently it only supports switching on a single regulator, support
> >>>>> for multiple regulators or other actions can be added as needed.
> >>>>> Different initialization sequences can be supported based on the
> >>>>> compatible string.
> >>>>>
> >>>>> Besides performing the initialization the driver can be configured
> >>>>> to power the hub off during system suspend. This can help to extend
> >>>>> battery life on battery powered devices which have no requirements
> >>>>> to keep the hub powered during suspend. The driver can also be
> >>>>> configured to leave the hub powered when a wakeup capable USB device
> >>>>> is connected when suspending, and power it off otherwise.
> >>>>>
> >>>>> Changes in v15:
> >>>>> - adjusted dependencies of USB_DWC3_CORE to make sure it can only
> >>>>>   be enabled when at least one of USB_DWC3_HOST, USB_DWC3_GADGET
> >>>>>   or USB_DWC3_DUAL_ROLE is selectable
> >>>>>
> >>>>> Changes in v14:
> >>>>> - rebased on top of v5.14-rc1
> >>>>> - dropped DT binding patch which landed in v5.13
> >>>>>
> >>>>> Changes in v13:
> >>>>> - added patch "usb: Specify dependency on USB_XHCI_PLATFORM with
> >>>>>   'depends on'" to the series to avoid Kconfig conflicts
> >>>>> - added patch "arm64: defconfig: Explicitly enable USB_XHCI_PLATFORM"
> >>>>>   to the series to keep effective defconfig unchanged
> >>>>>
> >>>>> Changes in v12:
> >>>>> - onboard_hub driver: use IS_ENABLED(CONFIG_USB_ONBOARD_HUB_MODULE)
> >>>>>   in onboard_hub.h to also check for the driver built as module
> >>>>> - onboard_hub_driver: include onboard_hub.h again to make sure there
> >>>>>   are prototype declarations for the public functions
> >>>>>
> >>>>> Changes in v11:
> >>>>> - support multiple onboard hubs connected to the same parent
> >>>>> - don't include ‘onboard_hub.h’ from the onboard hub driver
> >>>>>
> >>>>> Changes in v10:
> >>>>> - always use of_is_onboard_usb_hub() stub unless ONBOARD_USB_HUB=y/m
> >>>>> - keep 'regulator-boot-on' property for pp3300_hub
> >>>>>
> >>>>> Changes in v9:
> >>>>> - added dependency on ONBOARD_USB_HUB (or !!ONBOARD_USB_HUB) to
> >>>>>   USB_PLATFORM_XHCI
> >>>>>
> >>>>> Changes in v7:
> >>>>> - updated DT binding
> >>>>> - series rebased on qcom/arm64-for-5.13
> >>>>>
> >>>>> Changes in v6:
> >>>>> - updated summary
> >>>>>
> >>>>> Changes in v5:
> >>>>> - cover letter added
> >>>>>
> >>>>> Matthias Kaehlcke (6):
> >>>>>   usb: misc: Add onboard_usb_hub driver
> >>>>>   of/platform: Add stubs for of_platform_device_create/destroy()
> >>>>>   arm64: defconfig: Explicitly enable USB_XHCI_PLATFORM
> >>>>>   usb: Specify dependencies on USB_XHCI_PLATFORM with 'depends on'
> >>>>>   usb: host: xhci-plat: Create platform device for onboard hubs in
> >>>>>     probe()
> >>>>>   arm64: dts: qcom: sc7180-trogdor: Add nodes for onboard USB hub
> >>>>>
> >>>>>  .../sysfs-bus-platform-onboard-usb-hub        |   8 +
> >>>>>  MAINTAINERS                                   |   7 +
> >>>>>  .../boot/dts/qcom/sc7180-trogdor-lazor-r0.dts |  19 +-
> >>>>>  .../boot/dts/qcom/sc7180-trogdor-lazor-r1.dts |  12 +-
> >>>>>  .../arm64/boot/dts/qcom/sc7180-trogdor-r1.dts |  19 +-
> >>>>>  arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi  |  19 +-
> >>>>>  arch/arm64/configs/defconfig                  |   1 +
> >>>>>  drivers/usb/cdns3/Kconfig                     |   2 +-
> >>>>>  drivers/usb/dwc3/Kconfig                      |   5 +-
> >>>>>  drivers/usb/host/Kconfig                      |   5 +-
> >>>
> >>> These Kconfig changes are causing the resulting .config to be different.
> >>> For example, if I start with omap2plus_defconfig, the resulting .config
> >>> before and after your series is different as shown below
> >>>
> >>> :/work/linux$ diff /tmp/.config .config
> >>> 1902d1901
> >>> < # CONFIG_HISI_HIKEY_USB is not set
> >>> 4992c4991
> >>> < CONFIG_USB_XHCI_PLATFORM=m
> >>> ---
> >>>> # CONFIG_USB_XHCI_PLATFORM is not set
> >>> 5073,5075c5072
> >>> < # CONFIG_USB_DWC3_HOST is not set
> >>> < # CONFIG_USB_DWC3_GADGET is not set
> >>> < CONFIG_USB_DWC3_DUAL_ROLE=y
> >>> ---
> >>>> CONFIG_USB_DWC3_GADGET=y
> >>> 5173a5171
> >>>> # CONFIG_USB_ONBOARD_HUB is not set
> >>> 5285c5283
> >>> < CONFIG_USB_ROLE_SWITCH=m
> >>> ---
> >>>> # CONFIG_USB_ROLE_SWITCH is not set
> >>>
> >>> I would expect the same issues for multi_v7_defconfig and multi_v8_defconfig as well.
> >>
> >> Sorry I meant defconfig for arm64, not multi_v8_defconfig.
> >>
> >> I checked that for arm64 defconfig it is ok.
> >>
> >>> I'm ok to update the relevant defconfigs files so that the resulting .config is identical to
> >>> before your series. Thanks!
> >>
> >> With the below patch you can fix it for omap2plus_defconfig and multi_v7_defconfig.
> >>
> >> diff --git a/arch/arm/configs/multi_v7_defconfig b/arch/arm/configs/multi_v7_defconfig
> >> index d9abaae118dd..8c175ab37377 100644
> >> --- a/arch/arm/configs/multi_v7_defconfig
> >> +++ b/arch/arm/configs/multi_v7_defconfig
> >> @@ -787,6 +787,7 @@ CONFIG_SND_AUDIO_GRAPH_CARD=m
> >>  CONFIG_USB=y
> >>  CONFIG_USB_OTG=y
> >>  CONFIG_USB_XHCI_HCD=y
> >> +CONFIG_USB_XHCI_PLATFORM=y
> >>  CONFIG_USB_XHCI_MVEBU=y
> >>  CONFIG_USB_XHCI_TEGRA=m
> >>  CONFIG_USB_EHCI_HCD=y
> >> diff --git a/arch/arm/configs/omap2plus_defconfig b/arch/arm/configs/omap2plus_defconfig
> >> index 2ac2418084ab..a015fb04fa25 100644
> >> --- a/arch/arm/configs/omap2plus_defconfig
> >> +++ b/arch/arm/configs/omap2plus_defconfig
> >> @@ -562,6 +562,7 @@ CONFIG_USB=m
> >>  CONFIG_USB_ANNOUNCE_NEW_DEVICES=y
> >>  CONFIG_USB_MON=m
> >>  CONFIG_USB_XHCI_HCD=m
> >> +CONFIG_USB_XHCI_PLATFORM=m
> >>  CONFIG_USB_EHCI_HCD=m
> >>  CONFIG_USB_OHCI_HCD=m
> >>  CONFIG_USB_ACM=m
> > 
> > Thanks for testing!
> > 
> > I completely forgot that arm32 has all these different defconfigs.
> > 
> > While trying to adjust qcom_defconfig I came across something that confuses
> > me. The original defconfig results in:
> > 
> > # CONFIG_USB_XHCI_HCD is not set
> > CONFIG_USB_DWC3_DUAL_ROLE=y
> 
> The original Kconfig was:
> 
> > config USB_DWC3_DUAL_ROLE
> >         bool "Dual Role mode"
> >         depends on ((USB=y || USB=USB_DWC3) && (USB_GADGET=y || USB_GADGET=USB_DWC3))
> >         depends on (EXTCON=y || EXTCON=USB_DWC3)
> 
> Which means USB_DWC3_DUAL_ROLE can be enabled even without CONFIG_USB_XHCI_HCD.
> 
> All the dual role code does is add/remove the host/gadget controller platform devices.
> It doesn't care whether there is a driver for it or not.
> i.e. there is no build dependency on CONFIG_USB_XHCI_HCD.
> 
> > 
> > My assumption was that xHCI support is need for dwc3 dual mode (which is
> > made explicit by https://lore.kernel.org/patchwork/patch/1468240/), is
> > that incorrect? Maybe without xHCI support the controller can still
> > operate in USB 2.0 dual role mode?
> > 
> 
> Without xHCI support the host functionality will not work at all on dwc3 dual role.
> So I think your Kconfig changes for USB_DWC3_DUAL_ROLE to depend on USB_XHCI_PLATFORM
> are correct.

Thanks for the clarification!

^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [PATCH v15 0/6] usb: misc: Add onboard_usb_hub driver
  2021-07-27  0:41 [PATCH v15 0/6] usb: misc: Add onboard_usb_hub driver Matthias Kaehlcke
                   ` (6 preceding siblings ...)
  2021-08-09 15:49 ` [PATCH v15 0/6] usb: misc: Add onboard_usb_hub driver Matthias Kaehlcke
@ 2021-10-19 16:24 ` Dmitry Baryshkov
  2021-10-19 22:54   ` Matthias Kaehlcke
  7 siblings, 1 reply; 15+ messages in thread
From: Dmitry Baryshkov @ 2021-10-19 16:24 UTC (permalink / raw)
  To: Matthias Kaehlcke
  Cc: Greg Kroah-Hartman, Alan Stern, Rob Herring, Frank Rowand,
	Mathias Nyman, Felipe Balbi, Bastien Nocera, Peter Chen,
	open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS,
	Michal Simek, open list, Douglas Anderson, Krzysztof Kozlowski,
	linux-usb, Ravi Chandra Sadineni, Stephen Boyd, Al Cooper,
	Andrey Zhizhikin, Andy Gross, Aswath Govindraju, Bjorn Andersson,
	Catalin Marinas, Dmitry Osipenko, Enric Balletbo i Serra,
	Fabio Estevam, Guido Günther, Jagan Teki, Nishanth Menon,
	Pawel Laszczak, Roger Quadros, Shawn Guo, Vinod Koul,
	Will Deacon, Linux ARM, open list:DRM DRIVER FOR MSM ADRENO GPU

On Tue, 27 Jul 2021 at 03:41, Matthias Kaehlcke <mka@chromium.org> wrote:
>
> This series adds:
> - the onboard_usb_hub_driver
> - glue in the xhci-plat driver to create and destroy the
>   onboard_usb_hub platform devices if needed
> - a device tree binding for the Realtek RTS5411 USB hub controller
> - device tree changes that add RTS5411 entries for the QCA SC7180
>   based boards trogdor and lazor
> - a couple of stubs for platform device functions to avoid
>   unresolved symbols with certain kernel configs
>
> The main issue the driver addresses is that a USB hub needs to be
> powered before it can be discovered. For discrete onboard hubs (an
> example for such a hub is the Realtek RTS5411) this is often solved
> by supplying the hub with an 'always-on' regulator, which is kind
> of a hack. Some onboard hubs may require further initialization
> steps, like changing the state of a GPIO or enabling a clock, which
> requires even more hacks. This driver creates a platform device
> representing the hub which performs the necessary initialization.
> Currently it only supports switching on a single regulator, support
> for multiple regulators or other actions can be added as needed.
> Different initialization sequences can be supported based on the
> compatible string.

I have the feeling that you might want to check if you can use pwrseq
subsystem being proposed at
https://lore.kernel.org/linux-arm-msm/20211006035407.1147909-1-dmitry.baryshkov@linaro.org/.
It has been created for exactly the same reason of handling complex
power up/down requirements in a bus-neutral way. So instead of
creating an onboard-usb-hub, you might want to populate the hub node
with the reference to pwrseq device and make usb core call into
pwrseq. How does that sound to you?

>
> Besides performing the initialization the driver can be configured
> to power the hub off during system suspend. This can help to extend
> battery life on battery powered devices which have no requirements
> to keep the hub powered during suspend. The driver can also be
> configured to leave the hub powered when a wakeup capable USB device
> is connected when suspending, and power it off otherwise.


-- 
With best wishes
Dmitry

^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [PATCH v15 0/6] usb: misc: Add onboard_usb_hub driver
  2021-10-19 16:24 ` Dmitry Baryshkov
@ 2021-10-19 22:54   ` Matthias Kaehlcke
  0 siblings, 0 replies; 15+ messages in thread
From: Matthias Kaehlcke @ 2021-10-19 22:54 UTC (permalink / raw)
  To: Dmitry Baryshkov
  Cc: Greg Kroah-Hartman, Alan Stern, Rob Herring, Frank Rowand,
	Mathias Nyman, Felipe Balbi, Bastien Nocera, Peter Chen,
	open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS,
	Michal Simek, open list, Douglas Anderson, Krzysztof Kozlowski,
	linux-usb, Ravi Chandra Sadineni, Stephen Boyd, Al Cooper,
	Andrey Zhizhikin, Andy Gross, Aswath Govindraju, Bjorn Andersson,
	Catalin Marinas, Dmitry Osipenko, Enric Balletbo i Serra,
	Fabio Estevam, Guido Günther, Jagan Teki, Nishanth Menon,
	Pawel Laszczak, Roger Quadros, Shawn Guo, Vinod Koul,
	Will Deacon, Linux ARM, open list:DRM DRIVER FOR MSM ADRENO GPU

Hi Dmitry,

On Tue, Oct 19, 2021 at 07:24:41PM +0300, Dmitry Baryshkov wrote:
> On Tue, 27 Jul 2021 at 03:41, Matthias Kaehlcke <mka@chromium.org> wrote:
> >
> > This series adds:
> > - the onboard_usb_hub_driver
> > - glue in the xhci-plat driver to create and destroy the
> >   onboard_usb_hub platform devices if needed
> > - a device tree binding for the Realtek RTS5411 USB hub controller
> > - device tree changes that add RTS5411 entries for the QCA SC7180
> >   based boards trogdor and lazor
> > - a couple of stubs for platform device functions to avoid
> >   unresolved symbols with certain kernel configs
> >
> > The main issue the driver addresses is that a USB hub needs to be
> > powered before it can be discovered. For discrete onboard hubs (an
> > example for such a hub is the Realtek RTS5411) this is often solved
> > by supplying the hub with an 'always-on' regulator, which is kind
> > of a hack. Some onboard hubs may require further initialization
> > steps, like changing the state of a GPIO or enabling a clock, which
> > requires even more hacks. This driver creates a platform device
> > representing the hub which performs the necessary initialization.
> > Currently it only supports switching on a single regulator, support
> > for multiple regulators or other actions can be added as needed.
> > Different initialization sequences can be supported based on the
> > compatible string.
> 
> I have the feeling that you might want to check if you can use pwrseq
> subsystem being proposed at
> https://lore.kernel.org/linux-arm-msm/20211006035407.1147909-1-dmitry.baryshkov@linaro.org/.
> It has been created for exactly the same reason of handling complex
> power up/down requirements in a bus-neutral way. So instead of
> creating an onboard-usb-hub, you might want to populate the hub node
> with the reference to pwrseq device and make usb core call into
> pwrseq. How does that sound to you?

Thanks for the pointer, it's good to see another attempt to sort out
power sequencing.

The pwrseq framework could potentially be used by the onboard_usb_hub
driver, but it probably can't replace it completely. Besides powering
the USB hub on before enumeration the driver also can optionally power
it off during system suspend when no wakeup capable USB devices are
connected, which can result in signifcant power savings on battery
powered devices. For this the driver needs knowledge about the USB
(hub) devices that are provided by a hub chip. That part is probably
best implemented by a driver under drivers/usb/.

It might be an option to have the USB core and the onboard_usb_hub
driver use the pwrseq framework, though we'd have to ensure that it
isn't a problem that the USB core turns power on (before
enumeration) and the onboard_usb_hub driver turns it off during
system suspend (and on again on resume).

^ permalink raw reply	[flat|nested] 15+ messages in thread

end of thread, other threads:[~2021-10-19 22:54 UTC | newest]

Thread overview: 15+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-07-27  0:41 [PATCH v15 0/6] usb: misc: Add onboard_usb_hub driver Matthias Kaehlcke
2021-07-27  0:41 ` [PATCH v15 1/6] " Matthias Kaehlcke
2021-07-27  0:41 ` [PATCH v15 2/6] of/platform: Add stubs for of_platform_device_create/destroy() Matthias Kaehlcke
2021-07-27  0:41 ` [PATCH v15 3/6] arm64: defconfig: Explicitly enable USB_XHCI_PLATFORM Matthias Kaehlcke
2021-07-27  0:41 ` [PATCH v15 4/6] usb: Specify dependencies on USB_XHCI_PLATFORM with 'depends on' Matthias Kaehlcke
2021-07-27  0:41 ` [PATCH v15 5/6] usb: host: xhci-plat: Create platform device for onboard hubs in probe() Matthias Kaehlcke
2021-07-27  0:41 ` [PATCH v15 6/6] arm64: dts: qcom: sc7180-trogdor: Add nodes for onboard USB hub Matthias Kaehlcke
2021-08-09 15:49 ` [PATCH v15 0/6] usb: misc: Add onboard_usb_hub driver Matthias Kaehlcke
2021-08-11 12:38   ` Roger Quadros
2021-08-11 12:56     ` Roger Quadros
2021-08-12 17:08       ` Matthias Kaehlcke
2021-08-13  6:35         ` Roger Quadros
2021-08-13 18:33           ` Matthias Kaehlcke
2021-10-19 16:24 ` Dmitry Baryshkov
2021-10-19 22:54   ` Matthias Kaehlcke

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