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Date: Tue, 27 Sep 2016 13:48:34 +0800
From: Peter Chen <hzpeterchen@...il.com>
To: Roger Quadros <rogerq@...com>
Cc: cw00.choi@...sung.com, balbi@...nel.org, myungjoo.ham@...sung.com,
grygorii.strashko@...com, linux-kernel@...r.kernel.org,
linux-usb@...r.kernel.org
Subject: Re: [PATCH] extcon: usb-gpio: Add VBUS detection support
On Tue, Sep 20, 2016 at 05:53:55PM +0300, Roger Quadros wrote:
> Driver can now work with both ID and VBUS pins or either one of
> them.
>
> There can be the following 3 cases
>
> 1) Both ID and VBUS GPIOs are available:
>
> ID = LOW -> USB_HOST active, USB inactive
> ID = HIGH -> USB_HOST inactive, USB state is same as VBUS.
>
> 2) Only ID GPIO is available:
>
> ID = LOW -> USB_HOST active, USB inactive
> ID = HIGH -> USB_HOST inactive, USB active
>
> 3) Only VBUS GPIO is available:
>
> VBUS = LOW -> USB_HOST inactive, USB inactive
> VBUS = HIGH -> USB_HOST inactive, USB active
>
> Signed-off-by: Roger Quadros <rogerq@...com>
> ---
> .../devicetree/bindings/extcon/extcon-usb-gpio.txt | 3 +
> drivers/extcon/extcon-usb-gpio.c | 169 ++++++++++++++++-----
> 2 files changed, 132 insertions(+), 40 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/extcon/extcon-usb-gpio.txt b/Documentation/devicetree/bindings/extcon/extcon-usb-gpio.txt
> index af0b903..dfc14f7 100644
> --- a/Documentation/devicetree/bindings/extcon/extcon-usb-gpio.txt
> +++ b/Documentation/devicetree/bindings/extcon/extcon-usb-gpio.txt
> @@ -5,7 +5,10 @@ connected to a GPIO pin.
>
> Required properties:
> - compatible: Should be "linux,extcon-usb-gpio"
> +
> +Either one of id-gpio or vbus-gpio must be present. Both can be present as well.
> - id-gpio: gpio for USB ID pin. See gpio binding.
> +- vbus-gpio: gpio for USB VBUS pin.
>
> Example: Examples of extcon-usb-gpio node in dra7-evm.dts as listed below:
> extcon_usb1 {
> diff --git a/drivers/extcon/extcon-usb-gpio.c b/drivers/extcon/extcon-usb-gpio.c
> index a27d350..d589c5f 100644
> --- a/drivers/extcon/extcon-usb-gpio.c
> +++ b/drivers/extcon/extcon-usb-gpio.c
> @@ -24,7 +24,6 @@
> #include <linux/module.h>
> #include <linux/of_gpio.h>
> #include <linux/platform_device.h>
> -#include <linux/pm_wakeirq.h>
> #include <linux/slab.h>
> #include <linux/workqueue.h>
> #include <linux/acpi.h>
> @@ -36,7 +35,9 @@ struct usb_extcon_info {
> struct extcon_dev *edev;
>
> struct gpio_desc *id_gpiod;
> + struct gpio_desc *vbus_gpiod;
> int id_irq;
> + int vbus_irq;
>
> unsigned long debounce_jiffies;
> struct delayed_work wq_detcable;
> @@ -48,31 +49,47 @@ static const unsigned int usb_extcon_cable[] = {
> EXTCON_NONE,
> };
>
> +/*
> + * "USB" = VBUS and "USB-HOST" = !ID, so we have:
> + * Both "USB" and "USB-HOST" can't be set as active at the
> + * same time so if "USB-HOST" is active (i.e. ID is 0) we keep "USB" inactive
> + * even if VBUS is on.
> + *
> + * State | ID | VBUS
> + * ----------------------------------------
> + * [1] USB | H | H
> + * [2] none | H | L
> + * [3] USB-HOST | L | H
> + * [4] USB-HOST | L | L
> + *
> + * In case we have only one of these signals:
> + * - VBUS only - we want to distinguish between [1] and [2], so ID is always 1.
> + * - ID only - we want to distinguish between [1] and [4], so VBUS = ID.
> +*/
> static void usb_extcon_detect_cable(struct work_struct *work)
> {
> - int id;
> + int id, vbus;
> struct usb_extcon_info *info = container_of(to_delayed_work(work),
> struct usb_extcon_info,
> wq_detcable);
>
> - /* check ID and update cable state */
> - id = gpiod_get_value_cansleep(info->id_gpiod);
> - if (id) {
> - /*
> - * ID = 1 means USB HOST cable detached.
> - * As we don't have event for USB peripheral cable attached,
> - * we simulate USB peripheral attach here.
> - */
> + /* check ID and VBUS and update cable state */
> + id = info->id_gpiod ?
> + gpiod_get_value_cansleep(info->id_gpiod) : 1;
> + vbus = info->vbus_gpiod ?
> + gpiod_get_value_cansleep(info->vbus_gpiod) : id;
> +
> + /* at first we clean states which are no longer active */
> + if (id)
> extcon_set_state_sync(info->edev, EXTCON_USB_HOST, false);
> - extcon_set_state_sync(info->edev, EXTCON_USB, true);
> - } else {
> - /*
> - * ID = 0 means USB HOST cable attached.
> - * As we don't have event for USB peripheral cable detached,
> - * we simulate USB peripheral detach here.
> - */
> + if (!vbus)
> extcon_set_state_sync(info->edev, EXTCON_USB, false);
> +
> + if (!id) {
> extcon_set_state_sync(info->edev, EXTCON_USB_HOST, true);
> + } else {
> + if (vbus)
> + extcon_set_state_sync(info->edev, EXTCON_USB, true);
> }
> }
>
> @@ -101,12 +118,21 @@ static int usb_extcon_probe(struct platform_device *pdev)
> return -ENOMEM;
>
> info->dev = dev;
> - info->id_gpiod = devm_gpiod_get(&pdev->dev, "id", GPIOD_IN);
> - if (IS_ERR(info->id_gpiod)) {
> - dev_err(dev, "failed to get ID GPIO\n");
> - return PTR_ERR(info->id_gpiod);
> + info->id_gpiod = devm_gpiod_get_optional(&pdev->dev, "id", GPIOD_IN);
> + info->vbus_gpiod = devm_gpiod_get_optional(&pdev->dev, "vbus",
> + GPIOD_IN);
> +
> + if (!info->id_gpiod && !info->vbus_gpiod) {
> + dev_err(dev, "failed to get gpios\n");
> + return -ENODEV;
> }
>
> + if (IS_ERR(info->id_gpiod))
> + return PTR_ERR(info->id_gpiod);
> +
> + if (IS_ERR(info->vbus_gpiod))
> + return PTR_ERR(info->vbus_gpiod);
> +
> info->edev = devm_extcon_dev_allocate(dev, usb_extcon_cable);
> if (IS_ERR(info->edev)) {
> dev_err(dev, "failed to allocate extcon device\n");
> @@ -119,32 +145,56 @@ static int usb_extcon_probe(struct platform_device *pdev)
> return ret;
> }
>
> - ret = gpiod_set_debounce(info->id_gpiod,
> - USB_GPIO_DEBOUNCE_MS * 1000);
> + if (info->id_gpiod)
> + ret = gpiod_set_debounce(info->id_gpiod,
> + USB_GPIO_DEBOUNCE_MS * 1000);
> + if (!ret && info->vbus_gpiod)
> + ret = gpiod_set_debounce(info->vbus_gpiod,
> + USB_GPIO_DEBOUNCE_MS * 1000);
> +
> if (ret < 0)
> info->debounce_jiffies = msecs_to_jiffies(USB_GPIO_DEBOUNCE_MS);
>
> INIT_DELAYED_WORK(&info->wq_detcable, usb_extcon_detect_cable);
>
> - info->id_irq = gpiod_to_irq(info->id_gpiod);
> - if (info->id_irq < 0) {
> - dev_err(dev, "failed to get ID IRQ\n");
> - return info->id_irq;
> + if (info->id_gpiod) {
> + info->id_irq = gpiod_to_irq(info->id_gpiod);
> + if (info->id_irq < 0) {
> + dev_err(dev, "failed to get ID IRQ\n");
> + return info->id_irq;
> + }
> +
> + ret = devm_request_threaded_irq(dev, info->id_irq, NULL,
> + usb_irq_handler,
> + IRQF_TRIGGER_RISING |
> + IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
> + pdev->name, info);
> + if (ret < 0) {
> + dev_err(dev, "failed to request handler for ID IRQ\n");
> + return ret;
> + }
> }
>
> - ret = devm_request_threaded_irq(dev, info->id_irq, NULL,
> - usb_irq_handler,
> - IRQF_TRIGGER_RISING |
> - IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
> - pdev->name, info);
> - if (ret < 0) {
> - dev_err(dev, "failed to request handler for ID IRQ\n");
> - return ret;
> + if (info->vbus_gpiod) {
> + info->vbus_irq = gpiod_to_irq(info->vbus_gpiod);
> + if (info->vbus_irq < 0) {
> + dev_err(dev, "failed to get VBUS IRQ\n");
> + return info->vbus_irq;
> + }
> +
> + ret = devm_request_threaded_irq(dev, info->vbus_irq, NULL,
> + usb_irq_handler,
> + IRQF_TRIGGER_RISING |
> + IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
> + pdev->name, info);
> + if (ret < 0) {
> + dev_err(dev, "failed to request handler for VBUS IRQ\n");
> + return ret;
> + }
> }
>
> platform_set_drvdata(pdev, info);
> device_init_wakeup(dev, true);
> - dev_pm_set_wake_irq(dev, info->id_irq);
>
> /* Perform initial detection */
> usb_extcon_detect_cable(&info->wq_detcable.work);
> @@ -157,8 +207,6 @@ static int usb_extcon_remove(struct platform_device *pdev)
> struct usb_extcon_info *info = platform_get_drvdata(pdev);
>
> cancel_delayed_work_sync(&info->wq_detcable);
> -
> - dev_pm_clear_wake_irq(&pdev->dev);
> device_init_wakeup(&pdev->dev, false);
>
> return 0;
> @@ -170,12 +218,32 @@ static int usb_extcon_suspend(struct device *dev)
> struct usb_extcon_info *info = dev_get_drvdata(dev);
> int ret = 0;
>
> + if (device_may_wakeup(dev)) {
> + if (info->id_gpiod) {
> + ret = enable_irq_wake(info->id_irq);
> + if (ret)
> + return ret;
> + }
> + if (info->vbus_gpiod) {
> + ret = enable_irq_wake(info->vbus_irq);
> + if (ret) {
> + if (info->id_gpiod)
> + disable_irq_wake(info->id_irq);
> +
> + return ret;
> + }
> + }
> + }
> +
> /*
> * We don't want to process any IRQs after this point
> * as GPIOs used behind I2C subsystem might not be
> * accessible until resume completes. So disable IRQ.
> */
> - disable_irq(info->id_irq);
> + if (info->id_gpiod)
> + disable_irq(info->id_irq);
> + if (info->vbus_gpiod)
> + disable_irq(info->vbus_irq);
>
> return ret;
> }
> @@ -185,7 +253,28 @@ static int usb_extcon_resume(struct device *dev)
> struct usb_extcon_info *info = dev_get_drvdata(dev);
> int ret = 0;
>
> - enable_irq(info->id_irq);
> + if (device_may_wakeup(dev)) {
> + if (info->id_gpiod) {
> + ret = disable_irq_wake(info->id_irq);
> + if (ret)
> + return ret;
> + }
> + if (info->vbus_gpiod) {
> + ret = disable_irq_wake(info->vbus_irq);
> + if (ret) {
> + if (info->id_gpiod)
> + enable_irq_wake(info->id_irq);
> +
> + return ret;
> + }
> + }
> + }
> +
> + if (info->id_gpiod)
> + enable_irq(info->id_irq);
> + if (info->vbus_gpiod)
> + enable_irq(info->vbus_irq);
> +
> if (!device_may_wakeup(dev))
> queue_delayed_work(system_power_efficient_wq,
> &info->wq_detcable, 0);
> --
Reviewed-by: Peter Chen <peter.chen@....com>
--
Best Regards,
Peter Chen
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