From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762434AbbA3ODt (ORCPT ); Fri, 30 Jan 2015 09:03:49 -0500 Received: from bear.ext.ti.com ([192.94.94.41]:37988 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1762376AbbA3ODq (ORCPT ); Fri, 30 Jan 2015 09:03:46 -0500 Message-ID: <54CB8F3A.7020903@ti.com> Date: Fri, 30 Jan 2015 16:03:38 +0200 From: Roger Quadros User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 MIME-Version: 1.0 To: Chanwoo Choi CC: , , , , , , , , Subject: Re: [PATCH v3 1/7] extcon: usb-gpio: Introduce gpio usb extcon driver References: <1422274532-9488-1-git-send-email-rogerq@ti.com> <1422274532-9488-2-git-send-email-rogerq@ti.com> <54C8D2F4.9050404@ti.com> <54CACC28.3050306@samsung.com> In-Reply-To: <54CACC28.3050306@samsung.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 30/01/15 02:11, Chanwoo Choi wrote: > Hi Roger, > > On 01/28/2015 09:15 PM, Roger Quadros wrote: >> This driver observes the USB ID pin connected over a GPIO and >> updates the USB cable extcon states accordingly. >> >> The existing GPIO extcon driver is not suitable for this purpose >> as it needs to be taught to understand USB cable states and it >> can't handle more than one cable per instance. >> >> For the USB case we need to handle 2 cable states. >> 1) USB (attach/detach) >> 2) USB-Host (attach/detach) >> >> This driver can be easily updated in the future to handle VBUS >> events in case it happens to be available on GPIO for any platform. >> >> Signed-off-by: Roger Quadros >> --- >> v3: >> - removed IRQF_NO_SUSPEND flag. Added IRQF_TRIGGER_RISING and >> IRQF_TRIGGER_FALLING >> - Added disable_irq() to suspend() and enable_irq() to resume() >> >> .../devicetree/bindings/extcon/extcon-usb-gpio.txt | 18 ++ >> drivers/extcon/Kconfig | 7 + >> drivers/extcon/Makefile | 1 + >> drivers/extcon/extcon-usb-gpio.c | 233 +++++++++++++++++++++ >> 4 files changed, 259 insertions(+) >> create mode 100644 Documentation/devicetree/bindings/extcon/extcon-usb-gpio.txt >> create mode 100644 drivers/extcon/extcon-usb-gpio.c >> >> diff --git a/Documentation/devicetree/bindings/extcon/extcon-usb-gpio.txt b/Documentation/devicetree/bindings/extcon/extcon-usb-gpio.txt >> new file mode 100644 >> index 0000000..85fe6b0 >> --- /dev/null >> +++ b/Documentation/devicetree/bindings/extcon/extcon-usb-gpio.txt >> @@ -0,0 +1,18 @@ >> +USB GPIO Extcon device >> + >> +This is a virtual device used to generate USB cable states from the USB ID pin >> +connected to a GPIO pin. >> + >> +Required properties: >> +- compatible: Should be "linux,extcon-usb-gpio" >> +- id-gpio: gpio for USB ID pin. See gpio binding. >> + >> +Example: >> + extcon_usb1 { >> + compatible = "linux,extcon-usb-gpio"; >> + id-gpio = <&gpio6 1 GPIO_ACTIVE_HIGH>; >> + } >> + >> + &omap_dwc3_1 { >> + extcon = <&extcon_usb1>; >> + }; >> diff --git a/drivers/extcon/Kconfig b/drivers/extcon/Kconfig >> index 6a1f7de..fd11536 100644 >> --- a/drivers/extcon/Kconfig >> +++ b/drivers/extcon/Kconfig >> @@ -93,4 +93,11 @@ config EXTCON_SM5502 >> Silicon Mitus SM5502. The SM5502 is a USB port accessory >> detector and switch. >> >> +config EXTCON_USB_GPIO >> + tristate "USB GPIO extcon support" >> + select GPIOLIB >> + help >> + Say Y here to enable GPIO based USB cable detection extcon support. >> + Used typically if GPIO is used for USB ID pin detection. >> + >> endif # MULTISTATE_SWITCH >> diff --git a/drivers/extcon/Makefile b/drivers/extcon/Makefile >> index 0370b42..6a08a98 100644 >> --- a/drivers/extcon/Makefile >> +++ b/drivers/extcon/Makefile >> @@ -12,3 +12,4 @@ obj-$(CONFIG_EXTCON_MAX8997) += extcon-max8997.o >> obj-$(CONFIG_EXTCON_PALMAS) += extcon-palmas.o >> obj-$(CONFIG_EXTCON_RT8973A) += extcon-rt8973a.o >> obj-$(CONFIG_EXTCON_SM5502) += extcon-sm5502.o >> +obj-$(CONFIG_EXTCON_USB_GPIO) += extcon-usb-gpio.o >> diff --git a/drivers/extcon/extcon-usb-gpio.c b/drivers/extcon/extcon-usb-gpio.c >> new file mode 100644 >> index 0000000..99a58b2 >> --- /dev/null >> +++ b/drivers/extcon/extcon-usb-gpio.c >> @@ -0,0 +1,233 @@ >> +/** >> + * drivers/extcon/extcon-usb-gpio.c - USB GPIO extcon driver >> + * >> + * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com >> + * Author: Roger Quadros >> + * >> + * This program is free software; you can redistribute it and/or modify >> + * it under the terms of the GNU General Public License version 2 as >> + * published by the Free Software Foundation. >> + * >> + * This program is distributed in the hope that it will be useful, >> + * but WITHOUT ANY WARRANTY; without even the implied warranty of >> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the >> + * GNU General Public License for more details. >> + */ >> + >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> + >> +#define USB_GPIO_DEBOUNCE_MS 20 /* ms */ >> + >> +struct usb_extcon_info { >> + struct device *dev; >> + struct extcon_dev *edev; >> + >> + struct gpio_desc *id_gpiod; >> + int id_irq; >> + bool id_irqwake; /* ID wakeup enabled flag */ >> + >> + unsigned long debounce_jiffies; >> + struct delayed_work wq_detcable; >> +}; >> + >> +/* List of detectable cables */ >> +enum { >> + EXTCON_CABLE_USB = 0, >> + EXTCON_CABLE_USB_HOST, >> + >> + EXTCON_CABLE_END, >> +}; >> + >> +static const char *usb_extcon_cable[] = { >> + [EXTCON_CABLE_USB] = "USB", >> + [EXTCON_CABLE_USB_HOST] = "USB-Host", > > I'll use the defined name for extcon cable name as soon because > it has potential isseu about the conflict of extcon cable name between subsystems. > So, I recommend to use a captical letter as "USB-HOST" instead of "USB-Host". > If other extcon driver don't use the captical letter, I'll fix it. Did you see patch 2 in this series? In that I had fixed all instances to use "USB-Host" based on http://lxr.free-electrons.com/source/drivers/extcon/extcon-class.c#L45 What do you suggest? Skip patch 2 and convert all "USB-Host" to "USB-HOST"? cheers, -roger