Subject: [RFC v4 4/7] extcon: usb-gpio: Add support for VBUS detection

From: [email-masked] (Roger Quadros)
Date: Thu, 9 Jun 2016 11:38:26 +0300

Hi,

On 08/06/16 16:48, Krzysztof Kozlowski wrote:
> Add VBUS pin detection support to extcon-usb-gpio driver for boards
> which have both VBUS and ID pins, or only one of them.
> 
> The logic behind reporting USB and USB-HOST extcon cables is not
> affected. The driver however will report extcon changes for USB-VBUS and
> USB-ID.
> 
> Signed-off-by: Robert Baldyga <[email-masked]>
> Signed-off-by: Krzysztof Kozlowski <[email-masked]>
> 
> ---
> 
> Some parts base on old Robert's patchset.
> ---
>  drivers/extcon/extcon-usb-gpio.c | 125 +++++++++++++++++++++++++++++++--------
>  1 file changed, 99 insertions(+), 26 deletions(-)
> 
> diff --git a/drivers/extcon/extcon-usb-gpio.c b/drivers/extcon/extcon-usb-gpio.c
> index a36aab007022..85b8a0ce5731 100644
> --- a/drivers/extcon/extcon-usb-gpio.c
> +++ b/drivers/extcon/extcon-usb-gpio.c
> @@ -35,7 +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;
> @@ -44,6 +46,8 @@ struct usb_extcon_info {
>  static const unsigned int usb_extcon_cable[] = {
>  	EXTCON_USB,
>  	EXTCON_USB_HOST,
> +	EXTCON_USB_ID,
> +	EXTCON_USB_VBUS,
>  	EXTCON_NONE,
>  };
>  
> @@ -55,7 +59,8 @@ static void usb_extcon_detect_cable(struct work_struct *work)
>  						    wq_detcable);
>  
>  	/* check ID and update cable state */
> -	id = gpiod_get_value_cansleep(info->id_gpiod);
> +	id = info->id_gpiod ? gpiod_get_value_cansleep(info->id_gpiod) : 1;
> +
>  	if (id) {
>  		/*
>  		 * ID = 1 means USB HOST cable detached.
> @@ -73,6 +78,14 @@ static void usb_extcon_detect_cable(struct work_struct *work)
>  		extcon_set_cable_state_(info->edev, EXTCON_USB, false);
>  		extcon_set_cable_state_(info->edev, EXTCON_USB_HOST, true);
>  	}
> +
> +	if (info->id_gpiod)
> +		extcon_set_cable_state_(info->edev, EXTCON_USB_ID, id);
> +	if (info->vbus_gpiod) {
> +		int vbus = gpiod_get_value_cansleep(info->vbus_gpiod);
> +
> +		extcon_set_cable_state_(info->edev, EXTCON_USB_VBUS, vbus);
> +	}

What happens if either id_gpiod or vbus_gpiod is present?

As per the DT binding document
"In general we have three cases:
1. If VBUS and ID gpios are present we pass them as is
USB-HOST = !ID, USB = VBUS
2. If only VBUS gpio is present we assume that ID pin is always High.
USB-HOST = false, USB = VBUS.
3. If only ID pin is available we infer the VBUS pin states based on ID.
USB-HOST = !ID, USB = ID"

So do you want to be consistent and infer VBUS and ID states based on the other?

>  }
>  
>  static irqreturn_t usb_irq_handler(int irq, void *dev_id)
> @@ -100,9 +113,11 @@ 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");
> +	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 PTR_ERR(info->id_gpiod);
>  	}
>  
> @@ -118,27 +133,54 @@ 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);
> @@ -166,9 +208,16 @@ 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;
> +		}
>  	}
>  
>  	/*
> @@ -176,8 +225,16 @@ 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;
>  }
>  
> @@ -187,17 +244,33 @@ 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);
> +
>  	if (!device_may_wakeup(dev))
>  		queue_delayed_work(system_power_efficient_wq,
>  				   &info->wq_detcable, 0);
>  
>  	return ret;
> +
> +err:
> +	if (info->id_gpiod)
> +		enable_irq_wake(info->id_irq);
> +	return ret;
>  }
>  #endif
>  
> 

--
cheers,
-roger