Re: [PATCH v4 1/2] extcon: palmas: Support GPIO based USB ID detection

[Roger Quadros <rogerq@ti.com>]

Hi Lee / Samuel,

On 03/08/15 17:40, Roger Quadros wrote:
> Some palmas based chip variants do not have OTG based ID logic.
> For these variants we rely on GPIO based USB ID detection.
> 
> These chips do have VBUS comparator for VBUS detection so we
> continue to use the old way of detecting VBUS.
> 
> Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
> Signed-off-by: Roger Quadros <rogerq@ti.com>

It seems the extcon maintainer Chanwoo needs either of your Ack
to accept this patch.

Can you please take a look and Ack if OK? Thanks.

cheers,
-roger

> ---
> v4: updated gpio debounce logic to use delayed_workqueue.
> 
>  .../devicetree/bindings/extcon/extcon-palmas.txt   |   5 +-
>  drivers/extcon/extcon-palmas.c                     | 129 ++++++++++++++++++---
>  drivers/extcon/extcon-usb-gpio.c                   |   1 +
>  include/linux/mfd/palmas.h                         |   7 ++
>  4 files changed, 126 insertions(+), 16 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/extcon/extcon-palmas.txt b/Documentation/devicetree/bindings/extcon/extcon-palmas.txt
> index 45414bb..f61d5af 100644
> --- a/Documentation/devicetree/bindings/extcon/extcon-palmas.txt
> +++ b/Documentation/devicetree/bindings/extcon/extcon-palmas.txt
> @@ -10,8 +10,11 @@ Required Properties:
>  
>  Optional Properties:
>   - ti,wakeup : To enable the wakeup comparator in probe
> - - ti,enable-id-detection: Perform ID detection.
> + - ti,enable-id-detection: Perform ID detection. If id-gpio is specified
> +		it performs id-detection using GPIO else using OTG core.
>   - ti,enable-vbus-detection: Perform VBUS detection.
> + - id-gpio: gpio for GPIO ID detection. See gpio binding.
> + - debounce-delay-ms: debounce delay for GPIO ID pin in milliseconds.
>  
>  palmas-usb {
>         compatible = "ti,twl6035-usb", "ti,palmas-usb";
> diff --git a/drivers/extcon/extcon-palmas.c b/drivers/extcon/extcon-palmas.c
> index 8933e7e..662e917 100644
> --- a/drivers/extcon/extcon-palmas.c
> +++ b/drivers/extcon/extcon-palmas.c
> @@ -28,6 +28,10 @@
>  #include <linux/mfd/palmas.h>
>  #include <linux/of.h>
>  #include <linux/of_platform.h>
> +#include <linux/of_gpio.h>
> +#include <linux/workqueue.h>
> +
> +#define USB_GPIO_DEBOUNCE_MS	20	/* ms */
>  
>  static const unsigned int palmas_extcon_cable[] = {
>  	EXTCON_USB,
> @@ -118,19 +122,54 @@ static irqreturn_t palmas_id_irq_handler(int irq, void *_palmas_usb)
>  	return IRQ_HANDLED;
>  }
>  
> +static void palmas_gpio_id_detect(struct work_struct *work)
> +{
> +	int id;
> +	struct palmas_usb *palmas_usb = container_of(to_delayed_work(work),
> +						     struct palmas_usb,
> +						     wq_detectid);
> +	struct extcon_dev *edev = palmas_usb->edev;
> +
> +	if (!palmas_usb->id_gpiod)
> +		return;
> +
> +	id = gpiod_get_value_cansleep(palmas_usb->id_gpiod);
> +
> +	if (id) {
> +		extcon_set_cable_state_(edev, EXTCON_USB_HOST, false);
> +		dev_info(palmas_usb->dev, "USB-HOST cable is detached\n");
> +	} else {
> +		extcon_set_cable_state_(edev, EXTCON_USB_HOST, true);
> +		dev_info(palmas_usb->dev, "USB-HOST cable is attached\n");
> +	}
> +}
> +
> +static irqreturn_t palmas_gpio_id_irq_handler(int irq, void *_palmas_usb)
> +{
> +	struct palmas_usb *palmas_usb = _palmas_usb;
> +
> +	queue_delayed_work(system_power_efficient_wq, &palmas_usb->wq_detectid,
> +			   palmas_usb->sw_debounce_jiffies);
> +
> +	return IRQ_HANDLED;
> +}
> +
>  static void palmas_enable_irq(struct palmas_usb *palmas_usb)
>  {
>  	palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
>  		PALMAS_USB_VBUS_CTRL_SET,
>  		PALMAS_USB_VBUS_CTRL_SET_VBUS_ACT_COMP);
>  
> -	palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
> -		PALMAS_USB_ID_CTRL_SET, PALMAS_USB_ID_CTRL_SET_ID_ACT_COMP);
> +	if (palmas_usb->enable_id_detection) {
> +		palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
> +			     PALMAS_USB_ID_CTRL_SET,
> +			     PALMAS_USB_ID_CTRL_SET_ID_ACT_COMP);
>  
> -	palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
> -		PALMAS_USB_ID_INT_EN_HI_SET,
> -		PALMAS_USB_ID_INT_EN_HI_SET_ID_GND |
> -		PALMAS_USB_ID_INT_EN_HI_SET_ID_FLOAT);
> +		palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
> +			     PALMAS_USB_ID_INT_EN_HI_SET,
> +			     PALMAS_USB_ID_INT_EN_HI_SET_ID_GND |
> +			     PALMAS_USB_ID_INT_EN_HI_SET_ID_FLOAT);
> +	}
>  
>  	if (palmas_usb->enable_vbus_detection)
>  		palmas_vbus_irq_handler(palmas_usb->vbus_irq, palmas_usb);
> @@ -169,20 +208,36 @@ static int palmas_usb_probe(struct platform_device *pdev)
>  			palmas_usb->wakeup = pdata->wakeup;
>  	}
>  
> +	palmas_usb->id_gpiod = devm_gpiod_get_optional(&pdev->dev, "id");
> +	if (IS_ERR(palmas_usb->id_gpiod)) {
> +		dev_err(&pdev->dev, "failed to get id gpio\n");
> +		return PTR_ERR(palmas_usb->id_gpiod);
> +	}
> +
> +	if (palmas_usb->enable_id_detection && palmas_usb->id_gpiod) {
> +		palmas_usb->enable_id_detection = false;
> +		palmas_usb->enable_gpio_id_detection = true;
> +	}
> +
> +	if (palmas_usb->enable_gpio_id_detection) {
> +		u32 debounce;
> +
> +		if (of_property_read_u32(node, "debounce-delay-ms", &debounce))
> +			debounce = USB_GPIO_DEBOUNCE_MS;
> +
> +		status = gpiod_set_debounce(palmas_usb->id_gpiod,
> +					    debounce * 1000);
> +		if (status < 0)
> +			palmas_usb->sw_debounce_jiffies = msecs_to_jiffies(debounce);
> +	}
> +
> +	INIT_DELAYED_WORK(&palmas_usb->wq_detectid, palmas_gpio_id_detect);
> +
>  	palmas->usb = palmas_usb;
>  	palmas_usb->palmas = palmas;
>  
>  	palmas_usb->dev	 = &pdev->dev;
>  
> -	palmas_usb->id_otg_irq = regmap_irq_get_virq(palmas->irq_data,
> -						PALMAS_ID_OTG_IRQ);
> -	palmas_usb->id_irq = regmap_irq_get_virq(palmas->irq_data,
> -						PALMAS_ID_IRQ);
> -	palmas_usb->vbus_otg_irq = regmap_irq_get_virq(palmas->irq_data,
> -						PALMAS_VBUS_OTG_IRQ);
> -	palmas_usb->vbus_irq = regmap_irq_get_virq(palmas->irq_data,
> -						PALMAS_VBUS_IRQ);
> -
>  	palmas_usb_wakeup(palmas, palmas_usb->wakeup);
>  
>  	platform_set_drvdata(pdev, palmas_usb);
> @@ -201,6 +256,10 @@ static int palmas_usb_probe(struct platform_device *pdev)
>  	}
>  
>  	if (palmas_usb->enable_id_detection) {
> +		palmas_usb->id_otg_irq = regmap_irq_get_virq(palmas->irq_data,
> +							     PALMAS_ID_OTG_IRQ);
> +		palmas_usb->id_irq = regmap_irq_get_virq(palmas->irq_data,
> +							 PALMAS_ID_IRQ);
>  		status = devm_request_threaded_irq(palmas_usb->dev,
>  				palmas_usb->id_irq,
>  				NULL, palmas_id_irq_handler,
> @@ -212,9 +271,33 @@ static int palmas_usb_probe(struct platform_device *pdev)
>  					palmas_usb->id_irq, status);
>  			return status;
>  		}
> +	} else if (palmas_usb->enable_gpio_id_detection) {
> +		palmas_usb->gpio_id_irq = gpiod_to_irq(palmas_usb->id_gpiod);
> +		if (palmas_usb->gpio_id_irq < 0) {
> +			dev_err(&pdev->dev, "failed to get id irq\n");
> +			return palmas_usb->gpio_id_irq;
> +		}
> +		status = devm_request_threaded_irq(&pdev->dev,
> +						   palmas_usb->gpio_id_irq,
> +						   NULL,
> +						   palmas_gpio_id_irq_handler,
> +						   IRQF_TRIGGER_RISING |
> +						   IRQF_TRIGGER_FALLING |
> +						   IRQF_ONESHOT,
> +						   "palmas_usb_id",
> +						   palmas_usb);
> +		if (status < 0) {
> +			dev_err(&pdev->dev,
> +				"failed to request handler for id irq\n");
> +			return status;
> +		}
>  	}
>  
>  	if (palmas_usb->enable_vbus_detection) {
> +		palmas_usb->vbus_otg_irq = regmap_irq_get_virq(palmas->irq_data,
> +						       PALMAS_VBUS_OTG_IRQ);
> +		palmas_usb->vbus_irq = regmap_irq_get_virq(palmas->irq_data,
> +							   PALMAS_VBUS_IRQ);
>  		status = devm_request_threaded_irq(palmas_usb->dev,
>  				palmas_usb->vbus_irq, NULL,
>  				palmas_vbus_irq_handler,
> @@ -229,10 +312,21 @@ static int palmas_usb_probe(struct platform_device *pdev)
>  	}
>  
>  	palmas_enable_irq(palmas_usb);
> +	/* perform initial detection */
> +	palmas_gpio_id_detect(&palmas_usb->wq_detectid.work);
>  	device_set_wakeup_capable(&pdev->dev, true);
>  	return 0;
>  }
>  
> +static int palmas_usb_remove(struct platform_device *pdev)
> +{
> +	struct palmas_usb *palmas_usb = platform_get_drvdata(pdev);
> +
> +	cancel_delayed_work_sync(&palmas_usb->wq_detectid);
> +
> +	return 0;
> +}
> +
>  #ifdef CONFIG_PM_SLEEP
>  static int palmas_usb_suspend(struct device *dev)
>  {
> @@ -243,6 +337,8 @@ static int palmas_usb_suspend(struct device *dev)
>  			enable_irq_wake(palmas_usb->vbus_irq);
>  		if (palmas_usb->enable_id_detection)
>  			enable_irq_wake(palmas_usb->id_irq);
> +		if (palmas_usb->enable_gpio_id_detection)
> +			enable_irq_wake(palmas_usb->gpio_id_irq);
>  	}
>  	return 0;
>  }
> @@ -256,6 +352,8 @@ static int palmas_usb_resume(struct device *dev)
>  			disable_irq_wake(palmas_usb->vbus_irq);
>  		if (palmas_usb->enable_id_detection)
>  			disable_irq_wake(palmas_usb->id_irq);
> +		if (palmas_usb->enable_gpio_id_detection)
> +			disable_irq_wake(palmas_usb->gpio_id_irq);
>  	}
>  	return 0;
>  };
> @@ -273,6 +371,7 @@ static const struct of_device_id of_palmas_match_tbl[] = {
>  
>  static struct platform_driver palmas_usb_driver = {
>  	.probe = palmas_usb_probe,
> +	.remove = palmas_usb_remove,
>  	.driver = {
>  		.name = "palmas-usb",
>  		.of_match_table = of_palmas_match_tbl,
> diff --git a/drivers/extcon/extcon-usb-gpio.c b/drivers/extcon/extcon-usb-gpio.c
> index a2a4453..2b2fecf 100644
> --- a/drivers/extcon/extcon-usb-gpio.c
> +++ b/drivers/extcon/extcon-usb-gpio.c
> @@ -15,6 +15,7 @@
>   */
>  
>  #include <linux/extcon.h>
> +#include <linux/gpio.h>
>  #include <linux/gpio/consumer.h>
>  #include <linux/init.h>
>  #include <linux/interrupt.h>
> diff --git a/include/linux/mfd/palmas.h b/include/linux/mfd/palmas.h
> index bb270bd..13e1d96 100644
> --- a/include/linux/mfd/palmas.h
> +++ b/include/linux/mfd/palmas.h
> @@ -21,6 +21,7 @@
>  #include <linux/regmap.h>
>  #include <linux/regulator/driver.h>
>  #include <linux/extcon.h>
> +#include <linux/of_gpio.h>
>  #include <linux/usb/phy_companion.h>
>  
>  #define PALMAS_NUM_CLIENTS		3
> @@ -551,10 +552,16 @@ struct palmas_usb {
>  	int vbus_otg_irq;
>  	int vbus_irq;
>  
> +	int gpio_id_irq;
> +	struct gpio_desc *id_gpiod;
> +	unsigned long sw_debounce_jiffies;
> +	struct delayed_work wq_detectid;
> +
>  	enum palmas_usb_state linkstat;
>  	int wakeup;
>  	bool enable_vbus_detection;
>  	bool enable_id_detection;
> +	bool enable_gpio_id_detection;
>  };
>  
>  #define comparator_to_palmas(x) container_of((x), struct palmas_usb, comparator)
>