[PATCH RFT V2 3/3] iio: mxs-lradc: implement suspend/resume support
Marek Vasut
marex at denx.de
Fri Apr 22 08:47:13 PDT 2016
On 04/22/2016 03:57 PM, Stefan Wahren wrote:
> Hi Marek,
>
> Am 21.04.2016 um 22:45 schrieb Marek Vasut:
>> On 04/21/2016 10:11 PM, 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 <stefan.wahren at i2se.com>
>>> ---
>>> 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;
>> Can lradc->ts_input contain some non-valid pointer ? You should make
>> sure it's either inited to NULL or valid pointer, which I'm not sure
>> you do.
>
> the whole content of lradc get initialized with zero by
> devm_iio_device_alloc.
Ah, good.
> Or do you mean the error case that input registration failed and a
> suspend occur (if it's possible)|?
No, you cannot get suspend call before you registered the device.
> Stefan
>
> |
>>
>>> + 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;
>>> +
>>> + mxs_lradc_hw_stop(lradc);
>>> +
>>> + clk_disable_unprepare(lradc->clk);
>>> +
>>> + return ret;
>>> +}
>>> +
>>> +static int __maybe_unused mxs_lradc_resume(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;
>>> +
>>> + ret = clk_prepare_enable(lradc->clk);
>>> + if (ret)
>>> + return ret;
>>> +
>>> + mxs_lradc_hw_init(lradc);
>>> +
>>> + if (input) {
>>> + mutex_lock(&input->mutex);
>>> +
>>> + /* Disable touchscreen wakeup irq */
>>> + if (input->users && device_may_wakeup(dev))
>>> + ret = disable_irq_wake(lradc->irq[0]);
>>> + else
>>> + mxs_lradc_enable_touch_detection(lradc);
>>> +
>>> + mutex_unlock(&input->mutex);
>>> + }
>>> +
>>> + return ret;
>>> +}
>>> +
>>> +static SIMPLE_DEV_PM_OPS(mxs_lradc_pm_ops, mxs_lradc_suspend, mxs_lradc_resume);
>>> +
>>> static struct platform_driver mxs_lradc_driver = {
>>> .driver = {
>>> .name = DRIVER_NAME,
>>> .of_match_table = mxs_lradc_dt_ids,
>>> + .pm = &mxs_lradc_pm_ops,
>>> },
>>> .probe = mxs_lradc_probe,
>>> .remove = mxs_lradc_remove,
>>>
>> Looks OK otherwise:
>>
>> Reviewed-by: Marek Vasut <marex at denx.de>
>>
>
>
--
Best regards,
Marek Vasut
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