linux-kernel - Re: [PATCH 1/2] input: touchscreen: pixcir_i2c_ts: Add support for optional wakeup interrupt

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Message-ID: <55AC7DA1.9050002@ti.com>
Date:	Mon, 20 Jul 2015 10:18:33 +0530
From:	Vignesh R <vigneshr@...com>
To:	Dmitry Torokhov <dmitry.torokhov@...il.com>
CC:	Tony Lindgren <tony@...mide.com>,
	Benoit Cousson <bcousson@...libre.com>,
	Rob Herring <robh+dt@...nel.org>,
	Pawel Moll <pawel.moll@....com>,
	Mark Rutland <mark.rutland@....com>,
	Ian Campbell <ijc+devicetree@...lion.org.uk>,
	Kumar Gala <galak@...eaurora.org>,
	Russell King <linux@....linux.org.uk>,
	"Quadros, Roger" <rogerq@...com>,
	Henrik Rydberg <rydberg@...math.org>,
	Frodo Lai <frodo.lai@...il.com>,
	Jingoo Han <jg1.han@...sung.com>,
	"linux-omap@...r.kernel.org" <linux-omap@...r.kernel.org>,
	"devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"linux-input@...r.kernel.org" <linux-input@...r.kernel.org>
Subject: Re: [PATCH 1/2] input: touchscreen: pixcir_i2c_ts: Add support for
 optional wakeup interrupt

Hi Dmitry,

On 7/18/2015 3:21 AM, Dmitry Torokhov wrote:
> 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 <vigneshr@...com>
>> ---
>>  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()?
>

Ok.

>> +	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().
> 

Yes, I will do this in v2.

>> +
>>  	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.
> 

AFAICU, wakeup flag is deleted when struct device is deleted, hence,
device_init_wakeup() call may not be required in .remove(). But,
dev_pm_clear_wake_irq() can be moved to driver core.

Regards
Vignesh
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