linux-kernel - Re: [PATCH 5/5] Input: tca6416-keypad - switch to using input core's polling features

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Message-ID: <ZMAno7jWmlBZpAO/@google.com>
Date:   Tue, 25 Jul 2023 12:50:59 -0700
From:   Dmitry Torokhov <dmitry.torokhov@...il.com>
To:     Silvan Jegen <s.jegen@...il.com>
Cc:     linux-input@...r.kernel.org, Yangtao Li <frank.li@...o.com>,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH 5/5] Input: tca6416-keypad - switch to using input core's
 polling features

On Tue, Jul 25, 2023 at 09:43:12PM +0200, Silvan Jegen wrote:
> Hi
> 
> Just one question below.
> 
> Dmitry Torokhov <dmitry.torokhov@...il.com> wrote:
> > Instead of rolling custom polling implementation use input core
> > facilities.
> > 
> > Signed-off-by: Dmitry Torokhov <dmitry.torokhov@...il.com>
> > ---
> >  drivers/input/keyboard/tca6416-keypad.c | 46 ++++++++++---------------
> >  1 file changed, 19 insertions(+), 27 deletions(-)
> > 
> > diff --git a/drivers/input/keyboard/tca6416-keypad.c b/drivers/input/keyboard/tca6416-keypad.c
> > index ff665319791e..ebc8b9561266 100644
> > --- a/drivers/input/keyboard/tca6416-keypad.c
> > +++ b/drivers/input/keyboard/tca6416-keypad.c
> > @@ -24,6 +24,8 @@
> >  #define TCA6416_INVERT         2
> >  #define TCA6416_DIRECTION      3
> >  
> > +#define TCA6416_POLL_INTERVAL	100 /* msec */
> > +
> >  static const struct i2c_device_id tca6416_id[] = {
> >  	{ "tca6416-keys", 16, },
> >  	{ "tca6408-keys", 8, },
> > @@ -43,7 +45,6 @@ struct tca6416_keypad_chip {
> >  
> >  	struct i2c_client *client;
> >  	struct input_dev *input;
> > -	struct delayed_work dwork;
> >  	int io_size;
> >  	int irqnum;
> >  	u16 pinmask;
> > @@ -85,9 +86,9 @@ static int tca6416_read_reg(struct tca6416_keypad_chip *chip, int reg, u16 *val)
> >  	return 0;
> >  }
> >  
> > -static void tca6416_keys_scan(struct tca6416_keypad_chip *chip)
> > +static void tca6416_keys_scan(struct input_dev *input)
> >  {
> > -	struct input_dev *input = chip->input;
> > +	struct tca6416_keypad_chip *chip = input_get_drvdata(input);
> >  	u16 reg_val, val;
> >  	int error, i, pin_index;
> >  
> > @@ -122,33 +123,20 @@ static void tca6416_keys_scan(struct tca6416_keypad_chip *chip)
> >   */
> >  static irqreturn_t tca6416_keys_isr(int irq, void *dev_id)
> >  {
> > -	struct tca6416_keypad_chip *chip = dev_id;
> > -
> > -	tca6416_keys_scan(chip);
> > +	tca6416_keys_scan(dev_id);
> >  
> >  	return IRQ_HANDLED;
> >  }
> >  
> > -static void tca6416_keys_work_func(struct work_struct *work)
> > -{
> > -	struct tca6416_keypad_chip *chip =
> > -		container_of(work, struct tca6416_keypad_chip, dwork.work);
> > -
> > -	tca6416_keys_scan(chip);
> > -	schedule_delayed_work(&chip->dwork, msecs_to_jiffies(100));
> > -}
> > -
> >  static int tca6416_keys_open(struct input_dev *dev)
> >  {
> >  	struct tca6416_keypad_chip *chip = input_get_drvdata(dev);
> >  
> > -	/* Get initial device state in case it has switches */
> > -	tca6416_keys_scan(chip);
> > -
> > -	if (chip->use_polling)
> > -		schedule_delayed_work(&chip->dwork, msecs_to_jiffies(100));
> > -	else
> > +	if (!chip->use_polling) {
> > +		/* Get initial device state in case it has switches */
> > +		tca6416_keys_scan(dev);
> >  		enable_irq(chip->client->irq);
> > +	}
> >  
> >  	return 0;
> >  }
> > @@ -157,9 +145,7 @@ static void tca6416_keys_close(struct input_dev *dev)
> >  {
> >  	struct tca6416_keypad_chip *chip = input_get_drvdata(dev);
> >  
> > -	if (chip->use_polling)
> > -		cancel_delayed_work_sync(&chip->dwork);
> > -	else
> > +	if (!chip->use_polling)
> >  		disable_irq(chip->client->irq);
> >  }
> >  
> > @@ -232,8 +218,6 @@ static int tca6416_keypad_probe(struct i2c_client *client)
> >  	chip->pinmask = pdata->pinmask;
> >  	chip->use_polling = pdata->use_polling;
> >  
> > -	INIT_DELAYED_WORK(&chip->dwork, tca6416_keys_work_func);
> > -
> >  	input->phys = "tca6416-keys/input0";
> >  	input->name = client->name;
> >  
> > @@ -268,12 +252,20 @@ static int tca6416_keypad_probe(struct i2c_client *client)
> >  		return error;
> >  
> >  	if (!chip->use_polling) {
> 
> Sorry for my ignorant question but it seems counterituitive that we set
> up polling when chip->use_polling is false. Is this intended?

Nope, this is my brain fart. Thanks for noticing! I'll fix up the
condition before committing...

Thanks.

-- 
Dmitry