Subject: [PATCH 1/2] input: touchscreen: pixcir_i2c_ts: Add support for optional wakeup interrupt

From: [email-masked] (Dmitry Torokhov)
Date: Fri, 17 Jul 2015 14:51:22 -0700

Hi Vignesh,

On Fri, Jul 17, 2015 at 12:10:40PM +0530, Vignesh R wrote:
> On am437x-gp-evm, pixcir touchscreen can wake the system from low power
> state by generating wake-up interrupt via pinctrl and IO daisy chain.
> Add support for optional wakeup interrupt source by regsitering to
> automated wake IRQ framework introduced by commit 4990d4fe327b ("PM /
> Wakeirq: Add automated device wake IRQ handling").
> This is similar in approach to commit 2a0b965cfb6e ("serial: omap: Add
> support for optional wake-up")
> 
> Signed-off-by: Vignesh R <[email-masked]>
> ---
>  drivers/input/touchscreen/pixcir_i2c_ts.c | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
> 
> diff --git a/drivers/input/touchscreen/pixcir_i2c_ts.c b/drivers/input/touchscreen/pixcir_i2c_ts.c
> index 8f3e243a62bf..f7c602027fbd 100644
> --- a/drivers/input/touchscreen/pixcir_i2c_ts.c
> +++ b/drivers/input/touchscreen/pixcir_i2c_ts.c
> @@ -29,6 +29,8 @@
>  #include <linux/of.h>
>  #include <linux/of_gpio.h>
>  #include <linux/of_device.h>
> +#include <linux/of_irq.h>
> +#include <linux/pm_wakeirq.h>
>  
>  #define PIXCIR_MAX_SLOTS       5 /* Max fingers supported by driver */
>  
> @@ -38,6 +40,7 @@ struct pixcir_i2c_ts_data {
>  	const struct pixcir_ts_platform_data *pdata;
>  	bool running;
>  	int max_fingers;	/* Max fingers supported in this instance */
> +	int wakeirq;
>  };
>  
>  struct pixcir_touch {
> @@ -564,11 +567,22 @@ static int pixcir_i2c_ts_probe(struct i2c_client *client,
>  	i2c_set_clientdata(client, tsdata);
>  	device_init_wakeup(&client->dev, 1);
>  
> +	/* Register wakeirq, if available */
> +	tsdata->wakeirq = of_irq_get(dev->of_node, 1);

Can we put this in platform data and parse in pixcir_parse_dt() please?
Also, why not of_irq_get_byname()?

> +	if (tsdata->wakeirq) {
> +		error = dev_pm_set_dedicated_wake_irq(dev,
> +						      tsdata->wakeirq);
> +		if (error)
> +			dev_dbg(dev, "unable to get wakeirq %d\n",
> +				error);
> +	}

Shouldn't his actually be:

	error = tsdata->wakeirq ?
		dev_pm_set_dedicated_wake_irq(dev, tsdata->wakeirq) :
		dev_pm_set_wake_irq(dev, client->irq);
	if (error) {
		...
	}

and then we can get rid of enable_irq_wake()/disable_irq_wake() in
pixcir_i2c_ts_suspend() and pixcir_i2c_ts_resume().

> +
>  	return 0;
>  }
>  
>  static int pixcir_i2c_ts_remove(struct i2c_client *client)
>  {
> +	dev_pm_clear_wake_irq(&client->dev);
>  	device_init_wakeup(&client->dev, 0);

I wonder if driver core should be responsible for clearing wake irq and
also for clearing wakeup flag.

Thanks.

-- 
Dmitry