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Date: Thu, 2 Apr 2015 17:02:23 +0300
From: Roger Quadros <rogerq@...com>
To: Robert Baldyga <r.baldyga@...sung.com>, <cw00.choi@...sung.com>
CC: <myungjoo.ham@...sung.com>, <linux-usb@...r.kernel.org>,
<devicetree@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
<m.szyprowski@...sung.com>
Subject: Re: [PATCH v3 2/4] extcon: usb-gpio: add support for VBUS detection
On 02/04/15 16:13, Robert Baldyga wrote:
> This patch adds VBUS pin detection support to extcon-usb-gpio driver.
> It allows to use this driver with boards which have both VBUS and ID
> pins, or only one of them.
>
> Following table of states presents relationship between this signals
> and detected cable type:
>
> State | ID | VBUS
> ----------------------------------------
> [1] USB | H | H
> [2] none | H | L
> [3] USB & 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.
>
> Signed-off-by: Robert Baldyga <r.baldyga@...sung.com>
Acked-by: Roger Quadros <rogerq@...com>
cheers,
-roger
> ---
> drivers/extcon/extcon-usb-gpio.c | 169 +++++++++++++++++++++++++++------------
> 1 file changed, 119 insertions(+), 50 deletions(-)
>
> diff --git a/drivers/extcon/extcon-usb-gpio.c b/drivers/extcon/extcon-usb-gpio.c
> index f6aa99d..baf7add 100644
> --- a/drivers/extcon/extcon-usb-gpio.c
> +++ b/drivers/extcon/extcon-usb-gpio.c
> @@ -32,7 +32,9 @@ 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;
> @@ -52,40 +54,51 @@ static const char *usb_extcon_cable[] = {
> NULL,
> };
>
> +/*
> + * "USB" = VBUS and "USB-HOST" = !ID, so we have:
> + *
> + * State | ID | VBUS
> + * ----------------------------------------
> + * [1] USB | H | H
> + * [2] none | H | L
> + * [3] USB & 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 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_cable_state(info->edev,
> - usb_extcon_cable[EXTCON_CABLE_USB_HOST],
> - false);
> + usb_extcon_cable[EXTCON_CABLE_USB_HOST], false);
> + if (!vbus)
> extcon_set_cable_state(info->edev,
> - usb_extcon_cable[EXTCON_CABLE_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.
> - */
> + usb_extcon_cable[EXTCON_CABLE_USB], false);
> +
> + if (!id)
> extcon_set_cable_state(info->edev,
> - usb_extcon_cable[EXTCON_CABLE_USB],
> - false);
> + usb_extcon_cable[EXTCON_CABLE_USB_HOST], true);
> + if (vbus)
> extcon_set_cable_state(info->edev,
> - usb_extcon_cable[EXTCON_CABLE_USB_HOST],
> - true);
> - }
> + usb_extcon_cable[EXTCON_CABLE_USB], true);
> }
>
> static irqreturn_t usb_irq_handler(int irq, void *dev_id)
> @@ -113,10 +126,12 @@ static int usb_extcon_probe(struct platform_device *pdev)
> return -ENOMEM;
>
> info->dev = dev;
> - info->id_gpiod = devm_gpiod_get(&pdev->dev, "id");
> - 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");
> + info->vbus_gpiod = devm_gpiod_get_optional(&pdev->dev, "vbus");
> +
> + if (!info->id_gpiod && !info->vbus_gpiod) {
> + dev_err(dev, "failed to get gpios\n");
> + return -ENODEV;
> }
>
> info->edev = devm_extcon_dev_allocate(dev, usb_extcon_cable);
> @@ -131,27 +146,51 @@ 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->id_gpiod)
> + gpiod_set_debounce(info->vbus_gpiod, 0);
> + }
> 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);
> @@ -179,9 +218,16 @@ static int usb_extcon_suspend(struct device *dev)
> int ret = 0;
>
> if (device_may_wakeup(dev)) {
> - ret = enable_irq_wake(info->id_irq);
> - if (ret)
> - return ret;
> + 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)
> + goto err;
> + }
> }
>
> /*
> @@ -189,9 +235,17 @@ static int usb_extcon_suspend(struct device *dev)
> * 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;
> +
> +err:
> + if (info->id_gpiod)
> + disable_irq_wake(info->id_irq);
> + return ret;
> }
>
> static int usb_extcon_resume(struct device *dev)
> @@ -200,13 +254,28 @@ static int usb_extcon_resume(struct device *dev)
> int ret = 0;
>
> if (device_may_wakeup(dev)) {
> - ret = disable_irq_wake(info->id_irq);
> - if (ret)
> - return ret;
> + 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)
> + goto err;
> + }
> }
>
> - enable_irq(info->id_irq);
> + if (info->id_gpiod)
> + enable_irq(info->id_irq);
> + if (info->vbus_gpiod)
> + enable_irq(info->vbus_irq);
> +
> + return ret;
>
> +err:
> + if (info->id_gpiod)
> + enable_irq_wake(info->id_irq);
> return ret;
> }
> #endif
>
--
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