Subject: [PATCH RFT V2 3/3] iio: mxs-lradc: implement suspend/resume support

From: [email-masked] (Stefan Wahren)
Date: Fri, 22 Apr 2016 15:32:44 +0200

Hi Dmitry,

Am 21.04.2016 um 23:08 schrieb Dmitry Torokhov:
> On Thu, Apr 21, 2016 at 08:11:18PM +0000, Stefan Wahren wrote:
>> This patch implements suspend/resume support for mxs-lradc.
>> It's possible to use the touchscreen as wakeup source.
>>
>> Signed-off-by: Stefan Wahren <[email-masked]>
>> ---
>>  drivers/iio/adc/mxs-lradc.c |   61 +++++++++++++++++++++++++++++++++++++++++++
>>  1 file changed, 61 insertions(+)
>>
>> diff --git a/drivers/iio/adc/mxs-lradc.c b/drivers/iio/adc/mxs-lradc.c
>> index cfc558f..6bd387f 100644
>> --- a/drivers/iio/adc/mxs-lradc.c
>> +++ b/drivers/iio/adc/mxs-lradc.c
>> @@ -29,6 +29,7 @@
>>  #include <linux/of.h>
>>  #include <linux/of_device.h>
>>  #include <linux/platform_device.h>
>> +#include <linux/pm.h>
>>  #include <linux/slab.h>
>>  #include <linux/stmp_device.h>
>>  #include <linux/sysfs.h>
>> @@ -1745,10 +1746,70 @@ static int mxs_lradc_remove(struct platform_device *pdev)
>>  	return 0;
>>  }
>>  
>> +static int __maybe_unused mxs_lradc_suspend(struct device *dev)
>> +{
>> +	struct iio_dev *iio = dev_get_drvdata(dev);
>> +	struct mxs_lradc *lradc = iio_priv(iio);
>> +	struct input_dev *input = lradc->ts_input;
>> +	int ret = 0;
>> +
>> +	if (input) {
>> +		mutex_lock(&input->mutex);
>> +
>> +		/* Enable touchscreen wakeup irq */
>> +		if (input->users && device_may_wakeup(dev))
>> +			ret = enable_irq_wake(lradc->irq[0]);
>> +		else
>> +			mxs_lradc_disable_ts(lradc);
>> +
>> +		mutex_unlock(&input->mutex);
>> +	}
>> +
>> +	if (ret)
>> +		return ret;
> I'd rather we had it right after we do:
>
> 			ret = enable_irq_wake(lradc->irq[0]);

but we must unlock the mutex first before return. An option would be to
place the return inside the input branch.

Stefan