linux-kernel - Re: [PATCH] rtc: pcf85363: Allow to wake up system without IRQ

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Date:   Thu, 17 Aug 2023 10:17:59 +0200
From:   Alexandre Belloni <alexandre.belloni@...tlin.com>
To:     Mike Looijmans <mike.looijmans@...ic.nl>
Cc:     linux-rtc@...r.kernel.org, Alessandro Zummo <a.zummo@...ertech.it>,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] rtc: pcf85363: Allow to wake up system without IRQ

On 17/08/2023 07:42:25+0200, Mike Looijmans wrote:
> On 16-08-2023 23:40, Alexandre Belloni wrote:
> > Hello Mike,
> > 
> > Sorry for the very late review, there is a small change that is needed:
> 
> Better late than never
> 
> > 
> > On 02/05/2023 07:54:58+0200, Mike Looijmans wrote:
> > > When wakeup-source is set in the devicetree, set up the device for
> > > using the output as interrupt instead of clock. This is similar to
> > > how other RTC devices handle this.
> > > 
> > > This allows the clock chip to turn on the board when wired to do
> > > so in hardware.
> > > 
> > > Signed-off-by: Mike Looijmans <mike.looijmans@...ic.nl>
> > > 
> > > ---
> > > 
> > >   drivers/rtc/rtc-pcf85363.c | 17 ++++++++++-------
> > >   1 file changed, 10 insertions(+), 7 deletions(-)
> > > 
> > > diff --git a/drivers/rtc/rtc-pcf85363.c b/drivers/rtc/rtc-pcf85363.c
> > > index 8958eadf1c3e..b1543bcdc530 100644
> > > --- a/drivers/rtc/rtc-pcf85363.c
> > > +++ b/drivers/rtc/rtc-pcf85363.c
> > > @@ -434,23 +434,26 @@ static int pcf85363_probe(struct i2c_client *client)
> > >   	pcf85363->rtc->range_max = RTC_TIMESTAMP_END_2099;
> > >   	clear_bit(RTC_FEATURE_ALARM, pcf85363->rtc->features);
> > > +	if (client->irq > 0 || device_property_read_bool(&client->dev,
> > > +							 "wakeup-source")) {
> > > +		regmap_write(pcf85363->regmap, CTRL_FLAGS, 0);
> > > +		regmap_update_bits(pcf85363->regmap, CTRL_PIN_IO,
> > > +				   PIN_IO_INTA_OUT, PIN_IO_INTAPM);
> > > +		device_init_wakeup(&client->dev, true);
> > > +		set_bit(RTC_FEATURE_ALARM, pcf85363->rtc->features);
> > 
> > This should not be done when devm_request_threaded_irq fails.
> 
> Yeah, easiest would be to just clear the feature flag when that happens.

My comment was also for device_init_wakeup(&client->dev, true);. I think
the easiest would be to move this block later on and set client->irq to
0 when devm_request_threaded_irq fails.

-- 
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com