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Message-ID: <ac15a747-0fc8-c415-00b2-3fe6e0a3d81a@ti.com>
Date:   Fri, 7 Oct 2016 12:18:12 +0300
From:   Roger Quadros <rogerq@...com>
To:     Peter Chen <hzpeterchen@...il.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

Hi Chanwoo,


On 27/09/16 08:48, Peter Chen wrote:
> 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>

Can you please pick this one for v4.9? Thanks.

cheers,
-roger

>> ---
>>  .../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>
> 

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