Hello Dmitry!
On Mon, 2021-06-14 at 14:55 -0700, Dmitry Torokhov wrote:
> > Use clk_prepare_enable()/clk_disable_unprepare() in preparation for switch
> > to Common Clock Framework.
>
> Can this be merged standalone?
In principle, yes, but I thought it would be easier if the patches
would go via the same path as CCF conversion.
> > Signed-off-by: Alexander Sverdlin <alexander.sverdlin@xxxxxxxxx>
> > ---
> > drivers/input/keyboard/ep93xx_keypad.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/input/keyboard/ep93xx_keypad.c b/drivers/input/keyboard/ep93xx_keypad.c
> > index c8194333d612..e0e931e796fa 100644
> > --- a/drivers/input/keyboard/ep93xx_keypad.c
> > +++ b/drivers/input/keyboard/ep93xx_keypad.c
> > @@ -157,7 +157,7 @@ static int ep93xx_keypad_open(struct input_dev *pdev)
> >
> > if (!keypad->enabled) {
> > ep93xx_keypad_config(keypad);
> > - clk_enable(keypad->clk);
> > + clk_prepare_enable(keypad->clk);
> > keypad->enabled = true;
> > }
> >
> > @@ -169,7 +169,7 @@ static void ep93xx_keypad_close(struct input_dev *pdev)
> > struct ep93xx_keypad *keypad = input_get_drvdata(pdev);
> >
> > if (keypad->enabled) {
> > - clk_disable(keypad->clk);
> > + clk_disable_unprepare(keypad->clk);
> > keypad->enabled = false;
>
> While we are at it, I wonder about handling suspend/resume. I see that
> we disable the clock even if keyboard is configured as a wakeup source.
> Is it really capable of waking up the system when clock is off?
That what "EP93xx User’s Guide" says:
26.2.4 Low Power Mode
The key scanning block also supports a low power wake-up mode. In this mode, a key press
generates a wake up interrupt. The key scan interrupt should be masked. Because the wake
up interrupt is asynchronous, and depends on external keypad lines which may have a large
capacitance value, glitches may occur on the interrupt when transitioning to low power mode.
After transitioning, all clocks to the key scanning circuitry can be shut down.
--
Alexander Sverdlin.
