Re: [PATCH v3 1/2] input: touchscreen: pixcir_i2c_ts: Add support for optional wakeup interrupt

From: Dmitry Torokhov
Date: Mon Jul 27 2015 - 17:20:52 EST


On Mon, Jul 27, 2015 at 04:49:22PM +0530, Vignesh R wrote:
>
>
> On 07/27/2015 04:19 PM, Roger Quadros wrote:
> > Hi,
> >
> > On 23/07/15 17:54, 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@xxxxxx>
> >> ---
> >>
> >> v3:
> >> * handle error code returned by of_irq_get_byname()
> >>
> >> v2:
> >> * use of_irq_get_byname()
> >> * remove enable/disable_wake_irq()
> >>
> >> drivers/input/touchscreen/pixcir_i2c_ts.c | 22 ++++++++++++++++++----
> >> include/linux/input/pixcir_ts.h | 1 +
> >> 2 files changed, 19 insertions(+), 4 deletions(-)
> >>
> >> diff --git a/drivers/input/touchscreen/pixcir_i2c_ts.c b/drivers/input/touchscreen/pixcir_i2c_ts.c
> >> index 8f3e243a62bf..3a4ab358bf52 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 */
> >>
> >> @@ -364,8 +366,6 @@ static int __maybe_unused pixcir_i2c_ts_suspend(struct device *dev)
> >> goto unlock;
> >> }
> >> }
> >> -
> >> - enable_irq_wake(client->irq);
> >> } else if (input->users) {
> >> ret = pixcir_stop(ts);
> >> }
> >> @@ -386,8 +386,6 @@ static int __maybe_unused pixcir_i2c_ts_resume(struct device *dev)
> >> mutex_lock(&input->mutex);
> >>
> >> if (device_may_wakeup(&client->dev)) {
> >> - disable_irq_wake(client->irq);
> >> -
> >> if (!input->users) {
> >> ret = pixcir_stop(ts);
> >> if (ret) {
> >> @@ -445,6 +443,13 @@ static struct pixcir_ts_platform_data *pixcir_parse_dt(struct device *dev)
> >> dev_dbg(dev, "%s: x %d, y %d, gpio %d\n", __func__,
> >> pdata->x_max + 1, pdata->y_max + 1, pdata->gpio_attb);
> >>
> >> + pdata->wakeirq = of_irq_get_byname(dev->of_node, "wakeup");
> >> + if (pdata->wakeirq < 0 && pdata->wakeirq != -ENODATA &&
> >> + pdata->wakeirq != -EINVAL) {
> >> + dev_err(dev, "Failed to get wakeirq\n");
> >> + return ERR_PTR(pdata->wakeirq);
> >> + }
> >> +
> >> return pdata;
> >> }
> >> #else
> >> @@ -564,11 +569,20 @@ static int pixcir_i2c_ts_probe(struct i2c_client *client,
> >> i2c_set_clientdata(client, tsdata);
> >> device_init_wakeup(&client->dev, 1);
> >>
> >> + /* Register wakeirq */
> >> + error = (pdata->wakeirq > 0) ?
> >> + dev_pm_set_dedicated_wake_irq(dev, pdata->wakeirq) :
> >> + dev_pm_set_wake_irq(dev, client->irq);
> >
> > Can 0 be a valid wakeirq or client->irq?
> > If yes then this logic is broken.
> >
>
> AFAIK, IRQ 0 is always assigned to system timer interrupt (cannot find
> reliable source to quote).
>
> > I would set wakeirq to -EINVAL or something if it is not available
> > during probe and check for that condition.
> >
>
> Not sure, if I understand you correctly
> pdata->wakeirq will have -ENODATA or -EINVAL(as returned by
> of_irq_get_byname()), if wakeirq is not available. Do you want me to
> check for these two conditions specifically rather than
> (pdata->wakeirq > 0) ?

0 is not really valid general IRQ number; I2C for example sets
client->irq to 0 when there is no IRQ.

BTW, what do you think about my patch pushing this into i2c core? Could
you try and see if it works for you?

Thanks.

--
Dmitry
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/