LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Piyush Mehta <piyush.mehta@xilinx.com>
To: <arnd@arndb.de>, <zou_wei@huawei.com>,
	<gregkh@linuxfoundation.org>, <linus.walleij@linaro.org>,
	<michal.simek@xilinx.com>, <wendy.liang@xilinx.com>,
	<iwamatsu@nigauri.org>, <bgolaszewski@baylibre.com>,
	<robh+dt@kernel.org>, <rajan.vaja@xilinx.com>
Cc: <linux-gpio@vger.kernel.org>, <devicetree@vger.kernel.org>,
	<git@xilinx.com>, <sgoud@xilinx.com>,
	<linux-arm-kernel@lists.infradead.org>,
	<linux-kernel@vger.kernel.org>,
	Piyush Mehta <piyush.mehta@xilinx.com>
Subject: [PATCH V3 3/3] gpio: modepin: Add driver support for modepin GPIO controller
Date: Wed, 18 Aug 2021 13:40:18 +0530	[thread overview]
Message-ID: <20210818081018.2620544-4-piyush.mehta@xilinx.com> (raw)
In-Reply-To: <20210818081018.2620544-1-piyush.mehta@xilinx.com>

This patch adds driver support for the zynqmp modepin GPIO controller.
GPIO modepin driver set and get the value and status of the PS_MODE pin,
based on device-tree pin configuration. These four mode pins are
configurable as input/output. The mode pin has a control register, which
have lower four-bits [0:3] are configurable as input/output, next four-bits
can be used for reading the data  as input[4:7], and next setting the
output pin state output[8:11].

Signed-off-by: Piyush Mehta <piyush.mehta@xilinx.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
---
Changes in v2:
- Modepin driver- Addressed review comments:
  - Update APIs
  - Removed unwanted variables
  - Handle return path for probe function

Review Comments:
https://lore.kernel.org/linux-arm-kernel/20210615080553.2021061-2-piyush.mehta@xilinx.com/T/#m276c8a5c52f8dc1ed1cd91a2d660f78d498e4ae5

Changes in v3:
- Addressed Linus and Arnd review comments:
  - Update probe function return value
  - Remove unnecessary print and header file
  - Update error message for set value method

Review Comments:
https://lore.kernel.org/linux-arm-kernel/20210805174219.3000667-4-piyush.mehta@xilinx.com/T/#m70acd39653033e32458633e21a2e6d21afdd16e6
---
 drivers/gpio/Kconfig               |  12 +++
 drivers/gpio/Makefile              |   1 +
 drivers/gpio/gpio-zynqmp-modepin.c | 153 +++++++++++++++++++++++++++++++++++++
 3 files changed, 166 insertions(+)
 create mode 100644 drivers/gpio/gpio-zynqmp-modepin.c

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index fab5710..90a3a3d 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -755,6 +755,18 @@ config GPIO_ZYNQ
 	help
 	  Say yes here to support Xilinx Zynq GPIO controller.
 
+config GPIO_ZYNQMP_MODEPIN
+	tristate "ZynqMP ps-mode pin gpio configuration driver"
+	depends on ZYNQMP_FIRMWARE
+	default ZYNQMP_FIRMWARE
+	help
+	  Say yes here to support the ZynqMP ps-mode pin gpio configuration
+	  driver.
+
+	  This ps-mode pin gpio driver is based on GPIO framework, PS_MODE
+	  is 4-bits boot mode pins. It sets and gets the status of
+	  the ps-mode pin. Every pin can be configured as input/output.
+
 config GPIO_LOONGSON1
 	tristate "Loongson1 GPIO support"
 	depends on MACH_LOONGSON32
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 32a3265..978dc4595 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -183,3 +183,4 @@ obj-$(CONFIG_GPIO_XRA1403)		+= gpio-xra1403.o
 obj-$(CONFIG_GPIO_XTENSA)		+= gpio-xtensa.o
 obj-$(CONFIG_GPIO_ZEVIO)		+= gpio-zevio.o
 obj-$(CONFIG_GPIO_ZYNQ)			+= gpio-zynq.o
+obj-$(CONFIG_GPIO_ZYNQMP_MODEPIN)	+= gpio-zynqmp-modepin.o
diff --git a/drivers/gpio/gpio-zynqmp-modepin.c b/drivers/gpio/gpio-zynqmp-modepin.c
new file mode 100644
index 0000000..d52e391
--- /dev/null
+++ b/drivers/gpio/gpio-zynqmp-modepin.c
@@ -0,0 +1,153 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for the ps-mode pin configuration.
+ *
+ * Copyright (c) 2021 Xilinx, Inc.
+ */
+
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/gpio/driver.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/firmware/xlnx-zynqmp.h>
+
+/* 4-bit boot mode pins */
+#define MODE_PINS			4
+
+/**
+ * modepin_gpio_get_value - Get the state of the specified pin of GPIO device
+ * @chip:	gpio_chip instance to be worked on
+ * @pin:	gpio pin number within the device
+ *
+ * This function reads the state of the specified pin of the GPIO device.
+ *
+ * Return: 0 if the pin is low, 1 if pin is high, -EINVAL wrong pin configured
+ *         or error value.
+ */
+static int modepin_gpio_get_value(struct gpio_chip *chip, unsigned int pin)
+{
+	u32 regval = 0;
+	int ret;
+
+	ret = zynqmp_pm_bootmode_read(&regval);
+	if (ret)
+		return ret;
+
+	return !!(regval & BIT(pin + 8));
+}
+
+/**
+ * modepin_gpio_set_value - Modify the state of the pin with specified value
+ * @chip:	gpio_chip instance to be worked on
+ * @pin:	gpio pin number within the device
+ * @state:	value used to modify the state of the specified pin
+ *
+ * This function reads the state of the specified pin of the GPIO device, mask
+ * with the capture state of GPIO pin, and update pin of GPIO device.
+ *
+ * Return:	None.
+ */
+static void modepin_gpio_set_value(struct gpio_chip *chip, unsigned int pin,
+				   int state)
+{
+	u32 bootpin_val = 0;
+	int ret;
+
+	zynqmp_pm_bootmode_read(&bootpin_val);
+
+	if (state)
+		bootpin_val |= BIT(pin + 8);
+	else
+		bootpin_val &= ~BIT(pin + 8);
+
+	/* Configure bootpin value */
+	ret = zynqmp_pm_bootmode_write(bootpin_val);
+	if (ret)
+		pr_err("modepin: set value error %d for pin %d\n", ret, pin);
+}
+
+/**
+ * modepin_gpio_dir_in - Set the direction of the specified GPIO pin as input
+ * @chip:	gpio_chip instance to be worked on
+ * @pin:	gpio pin number within the device
+ *
+ * Return: 0 always
+ */
+static int modepin_gpio_dir_in(struct gpio_chip *chip, unsigned int pin)
+{
+	return 0;
+}
+
+/**
+ * modepin_gpio_dir_out - Set the direction of the specified GPIO pin as output
+ * @chip:	gpio_chip instance to be worked on
+ * @pin:	gpio pin number within the device
+ * @state:	value to be written to specified pin
+ *
+ * Return: 0 always
+ */
+static int modepin_gpio_dir_out(struct gpio_chip *chip, unsigned int pin,
+				int state)
+{
+	return 0;
+}
+
+/**
+ * modepin_gpio_probe - Initialization method for modepin_gpio
+ * @pdev:		platform device instance
+ *
+ * Return: 0 on success, negative error otherwise.
+ */
+static int modepin_gpio_probe(struct platform_device *pdev)
+{
+	struct gpio_chip *chip;
+	int status;
+
+	chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
+	if (!chip)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, chip);
+
+	/* configure the gpio chip */
+	chip->base = -1;
+	chip->ngpio = MODE_PINS;
+	chip->owner = THIS_MODULE;
+	chip->parent = &pdev->dev;
+	chip->get = modepin_gpio_get_value;
+	chip->set = modepin_gpio_set_value;
+	chip->direction_input = modepin_gpio_dir_in;
+	chip->direction_output = modepin_gpio_dir_out;
+	chip->label = dev_name(&pdev->dev);
+
+	/* modepin gpio registration */
+	status = devm_gpiochip_add_data(&pdev->dev, chip, chip);
+	if (status)
+		return dev_err_probe(&pdev->dev, status,
+			      "Failed to add GPIO chip\n");
+
+	return status;
+}
+
+static const struct of_device_id modepin_platform_id[] = {
+	{ .compatible = "xlnx,zynqmp-gpio-modepin", },
+	{ }
+};
+
+static struct platform_driver modepin_platform_driver = {
+	.driver = {
+		.name = "modepin-gpio",
+		.of_match_table = modepin_platform_id,
+	},
+	.probe = modepin_gpio_probe,
+};
+
+module_platform_driver(modepin_platform_driver);
+
+MODULE_AUTHOR("Piyush Mehta <piyush.mehta@xilinx.com>");
+MODULE_DESCRIPTION("ZynqMP Boot PS_MODE Configuration");
+MODULE_LICENSE("GPL v2");
-- 
2.7.4


  parent reply	other threads:[~2021-08-18  8:11 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-18  8:10 [PATCH V3 0/3] " Piyush Mehta
2021-08-18  8:10 ` [PATCH V3 1/3] firmware: zynqmp: Add MMIO read and write support for PS_MODE pin Piyush Mehta
2021-08-18  8:10 ` [PATCH V3 2/3] dt-bindings: gpio: zynqmp: Add binding documentation for modepin Piyush Mehta
2021-08-18  9:00   ` Ahmad Fatoum
2021-08-18  9:38     ` Michal Simek
2021-08-18  9:55       ` Ahmad Fatoum
2021-08-18 10:01         ` Michal Simek
2021-08-23 18:09   ` Rob Herring
2021-08-18  8:10 ` Piyush Mehta [this message]
2021-08-18  8:52   ` [PATCH V3 3/3] gpio: modepin: Add driver support for modepin GPIO controller Ahmad Fatoum
2021-08-18 10:09     ` Piyush Mehta
2021-08-18 13:05       ` Ahmad Fatoum
2021-08-23  8:02   ` Bartosz Golaszewski
2021-08-23  8:14     ` Michal Simek
2021-09-22 10:18       ` Bartosz Golaszewski
2021-09-22 10:21         ` Bartosz Golaszewski
2021-09-22 10:23           ` Michal Simek

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210818081018.2620544-4-piyush.mehta@xilinx.com \
    --to=piyush.mehta@xilinx.com \
    --cc=arnd@arndb.de \
    --cc=bgolaszewski@baylibre.com \
    --cc=devicetree@vger.kernel.org \
    --cc=git@xilinx.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=iwamatsu@nigauri.org \
    --cc=linus.walleij@linaro.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-gpio@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=michal.simek@xilinx.com \
    --cc=rajan.vaja@xilinx.com \
    --cc=robh+dt@kernel.org \
    --cc=sgoud@xilinx.com \
    --cc=wendy.liang@xilinx.com \
    --cc=zou_wei@huawei.com \
    --subject='Re: [PATCH V3 3/3] gpio: modepin: Add driver support for modepin GPIO controller' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).