linux-kernel - RE: [RESEND] input: keyboard: imx: make sure keyboard can always wake up system

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Date:   Thu, 9 May 2019 01:41:09 +0000
From:   Anson Huang <anson.huang@....com>
To:     "dmitry.torokhov@...il.com" <dmitry.torokhov@...il.com>,
        "shawnguo@...nel.org" <shawnguo@...nel.org>,
        "s.hauer@...gutronix.de" <s.hauer@...gutronix.de>,
        "kernel@...gutronix.de" <kernel@...gutronix.de>,
        "festevam@...il.com" <festevam@...il.com>,
        "linux-input@...r.kernel.org" <linux-input@...r.kernel.org>,
        "linux-arm-kernel@...ts.infradead.org" 
        <linux-arm-kernel@...ts.infradead.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
CC:     dl-linux-imx <linux-imx@....com>
Subject: RE: [RESEND] input: keyboard: imx: make sure keyboard can always wake
 up system

Ping...

> -----Original Message-----
> From: Anson Huang
> Sent: Thursday, April 25, 2019 9:50 AM
> To: dmitry.torokhov@...il.com; shawnguo@...nel.org;
> s.hauer@...gutronix.de; kernel@...gutronix.de; festevam@...il.com;
> linux-input@...r.kernel.org; linux-arm-kernel@...ts.infradead.org; linux-
> kernel@...r.kernel.org
> Cc: dl-linux-imx <linux-imx@....com>
> Subject: RE: [RESEND] input: keyboard: imx: make sure keyboard can always
> wake up system
> 
> Gentle ping...
> 
> > -----Original Message-----
> > From: Anson Huang
> > Sent: Thursday, April 4, 2019 9:40 AM
> > To: dmitry.torokhov@...il.com; shawnguo@...nel.org;
> > s.hauer@...gutronix.de; kernel@...gutronix.de; festevam@...il.com;
> > linux-input@...r.kernel.org; linux-arm-kernel@...ts.infradead.org;
> > linux- kernel@...r.kernel.org
> > Cc: dl-linux-imx <linux-imx@....com>
> > Subject: [RESEND] input: keyboard: imx: make sure keyboard can always
> > wake up system
> >
> > There are several scenarios that keyboard can NOT wake up system from
> > suspend, e.g., if a keyboard is depressed between system device
> > suspend phase and device noirq suspend phase, the keyboard ISR will be
> > called and both keyboard depress and release interrupts will be
> > disabled, then keyboard will no longer be able to wake up system.
> > Another scenario would be, if a keyboard is kept depressed, and then
> > system goes into suspend, the expected behavior would be when keyboard
> > is released, system will be waked up, but current implementation can
> > NOT achieve that, because both depress and release interrupts are
> > disabled in ISR, and the event check is still in progress.
> >
> > To fix these issues, need to make sure keyboard's depress or release
> > interrupt is enabled after noirq device suspend phase, this patch
> > moves the suspend/resume callback to noirq suspend/resume phase, and
> > enable the corresponding interrupt according to current keyboard status.
> >
> > Signed-off-by: Anson Huang <Anson.Huang@....com>
> > ---
> >  drivers/input/keyboard/imx_keypad.c | 18 ++++++++++++++----
> >  1 file changed, 14 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/input/keyboard/imx_keypad.c
> > b/drivers/input/keyboard/imx_keypad.c
> > index cf08f4a..97500a2 100644
> > --- a/drivers/input/keyboard/imx_keypad.c
> > +++ b/drivers/input/keyboard/imx_keypad.c
> > @@ -524,11 +524,12 @@ static int imx_keypad_probe(struct
> > platform_device *pdev)
> >  	return 0;
> >  }
> >
> > -static int __maybe_unused imx_kbd_suspend(struct device *dev)
> > +static int __maybe_unused imx_kbd_noirq_suspend(struct device *dev)
> >  {
> >  	struct platform_device *pdev = to_platform_device(dev);
> >  	struct imx_keypad *kbd = platform_get_drvdata(pdev);
> >  	struct input_dev *input_dev = kbd->input_dev;
> > +	unsigned short reg_val = readw(kbd->mmio_base + KPSR);
> >
> >  	/* imx kbd can wake up system even clock is disabled */
> >  	mutex_lock(&input_dev->mutex);
> > @@ -538,13 +539,20 @@ static int __maybe_unused
> imx_kbd_suspend(struct
> > device *dev)
> >
> >  	mutex_unlock(&input_dev->mutex);
> >
> > -	if (device_may_wakeup(&pdev->dev))
> > +	if (device_may_wakeup(&pdev->dev)) {
> > +		if (reg_val & KBD_STAT_KPKD)
> > +			reg_val |= KBD_STAT_KRIE;
> > +		if (reg_val & KBD_STAT_KPKR)
> > +			reg_val |= KBD_STAT_KDIE;
> > +		writew(reg_val, kbd->mmio_base + KPSR);
> > +
> >  		enable_irq_wake(kbd->irq);
> > +	}
> >
> >  	return 0;
> >  }
> >
> > -static int __maybe_unused imx_kbd_resume(struct device *dev)
> > +static int __maybe_unused imx_kbd_noirq_resume(struct device *dev)
> >  {
> >  	struct platform_device *pdev = to_platform_device(dev);
> >  	struct imx_keypad *kbd = platform_get_drvdata(pdev); @@ -568,7
> > +576,9 @@ static int __maybe_unused imx_kbd_resume(struct device
> *dev)
> >  	return ret;
> >  }
> >
> > -static SIMPLE_DEV_PM_OPS(imx_kbd_pm_ops, imx_kbd_suspend,
> > imx_kbd_resume);
> > +static const struct dev_pm_ops imx_kbd_pm_ops = {
> > +	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(imx_kbd_noirq_suspend,
> > +imx_kbd_noirq_resume) };
> >
> >  static struct platform_driver imx_keypad_driver = {
> >  	.driver		= {
> > --
> > 2.7.4