[PATCH] input: sun4i-lradc-keys: Add wakup support

[Ondrej Jirman]

Allow the driver to wakeup the system on key press.

Signed-off-by: Ondrej Jirman <meg...@megous.com>
---
drivers/input/keyboard/sun4i-lradc-keys.c | 22 ++++++++++++++++++----
1 file changed, 18 insertions(+), 4 deletions(-)

diff --git a/drivers/input/keyboard/sun4i-lradc-keys.c b/drivers/input/keyboard/sun4i-lradc-keys.c
index 4a796bed48ac..bba679d7b54b 100644
--- a/drivers/input/keyboard/sun4i-lradc-keys.c
+++ b/drivers/input/keyboard/sun4i-lradc-keys.c
@@ -22,6 +22,8 @@
#include <linux/module.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
+#include <linux/pm_wakeirq.h>
+#include <linux/pm_wakeup.h>
#include <linux/regulator/consumer.h>
#include <linux/slab.h>

@@ -226,8 +228,7 @@ static int sun4i_lradc_probe(struct platform_device *pdev)
{
struct sun4i_lradc_data *lradc;
struct device *dev = &pdev->dev;
- int i;
- int error;
+ int i, error, irq;

lradc = devm_kzalloc(dev, sizeof(struct sun4i_lradc_data), GFP_KERNEL);
if (!lradc)
@@ -272,8 +273,13 @@ static int sun4i_lradc_probe(struct platform_device *pdev)
if (IS_ERR(lradc->base))
return PTR_ERR(lradc->base);

- error = devm_request_irq(dev, platform_get_irq(pdev, 0),
- sun4i_lradc_irq, 0,
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0) {
+ dev_err(&pdev->dev, "Failed to get IRQ\n");
+ return irq;
+ }
+
+ error = devm_request_irq(dev, irq, sun4i_lradc_irq, 0,
"sun4i-a10-lradc-keys", lradc);
if (error)
return error;
@@ -282,6 +288,14 @@ static int sun4i_lradc_probe(struct platform_device *pdev)
if (error)
return error;

+ device_init_wakeup(dev, true);
+
+ error = dev_pm_set_wake_irq(dev, irq);
+ if (error) {
+ dev_err(dev, "Could not set wake IRQ\n");
+ return error;
+ }
+
return 0;
}

--
2.23.0

[Dmitry Torokhov]

Hi Ondrej,

I do not think we want to do this unconditionally. Can we maybe key off
"wakeup-source" device property.

> +
> + error = dev_pm_set_wake_irq(dev, irq);
> + if (error) {
> + dev_err(dev, "Could not set wake IRQ\n");
> + return error;
> + }
> +

I wonder if we could teach platform driver core to handle this for us.

Thanks.

--
Dmitry

[Ondřej Jirman]

Hello Dmitry,

Sure thing.

> > +
> > + error = dev_pm_set_wake_irq(dev, irq);
> > + if (error) {
> > + dev_err(dev, "Could not set wake IRQ\n");
> > + return error;
> > + }
> > +
>
> I wonder if we could teach platform driver core to handle this for us.

Not sure, some drivers do enable/disable wake_irq by hand in suspend/resume
callbacks, so it would probably need to be opt-in somehow. I guess calling the
function like this is one way to make it opt-in.

The other way may be by passing a flag somewhere, like to
request_threaded_irq. Did you have something more concrete in mind?

regards,
o.

> Thanks.
>
> --
> Dmitry

[Dmitry Torokhov]

I think it is perfectly fine to continue using enable_irq_wake and
disable_irq_wake from the driver while marking irq as being wake irq
form the core.

Thanks.

--
Dmitry

[Ondřej Jirman]

I see, it looks like irq_set_irq_wake will track the calls via wake_depth

https://elixir.bootlin.com/linux/latest/source/kernel/irq/manage.c#L714

But all irqs are not necessarily wake irqs, no? So it still may need to be
opt-in somehow.

Anyway, I'm no PM expert. I started looking at PM code about two weeks ago, and
I really don't feel like I can contribute much to these kinds of decisions with
my current level of understanding, right now.

regards,
o.

> Thanks.
>
> --
> Dmitry
>

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[Dmitry Torokhov]

On Tue, Oct 29, 2019 at 02:45:59AM +0100, Ondřej Jirman wrote:
> On Mon, Oct 28, 2019 at 05:12:50PM -0700, Dmitry Torokhov wrote:
> > On Tue, Oct 29, 2019 at 12:56:26AM +0100, Ondřej Jirman wrote:
> > > On Mon, Oct 28, 2019 at 04:38:28PM -0700, Dmitry Torokhov wrote:
> > > > > +
> > > > > + error = dev_pm_set_wake_irq(dev, irq);
> > > > > + if (error) {
> > > > > + dev_err(dev, "Could not set wake IRQ\n");
> > > > > + return error;
> > > > > + }
> > > > > +
> > > >
> > > > I wonder if we could teach platform driver core to handle this for us.
> > >
> > > Not sure, some drivers do enable/disable wake_irq by hand in suspend/resume
> > > callbacks, so it would probably need to be opt-in somehow. I guess calling the
> > > function like this is one way to make it opt-in.
> > >
> > > The other way may be by passing a flag somewhere, like to
> > > request_threaded_irq. Did you have something more concrete in mind?
> >
> > I think it is perfectly fine to continue using enable_irq_wake and
> > disable_irq_wake from the driver while marking irq as being wake irq
> > form the core.
>
> I see, it looks like irq_set_irq_wake will track the calls via wake_depth
>
> https://elixir.bootlin.com/linux/latest/source/kernel/irq/manage.c#L714
>
> But all irqs are not necessarily wake irqs, no? So it still may need to be
> opt-in somehow.

I thought we'd do that for IRQ named "wakeirq" or the very first IRQ if
there is no named IRQ, and when we have the "wakeup-source" property,
similarly to what we do in I2C bus.

Thanks.

--
Dmitry

[Ondřej Jirman]

I see. I've looked at drivers using dev_pm_set_wake_irq and
dev_pm_set_dedicated_wake_irq and not many platform drivers would potentially
benefit (~25 out of 2300), of those only some use OF and are platform
drivers, maybe 15-20:

https://elixir.bootlin.com/linux/latest/ident/dev_pm_set_wake_irq
https://elixir.bootlin.com/linux/latest/ident/dev_pm_set_dedicated_wake_irq

I don't think it's worth it.

regards,
o.

> Thanks.
>
> --
> Dmitry
>

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