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

[Roger Quadros <rogerq@ti.com>]

Fixed Felipe's id.

On 09/06/16 11:38, Roger Quadros wrote:
> 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 <r.baldyga@samsung.com>
>> Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
>>
>> ---
>>
>> 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
>