Re: [PATCH 1/3] leds: pca9532: Use PWM1 for hardware blinking

[Bastien Curutchet]

Hi Lee,

Thank you for the feedback, I'll send a V2 iteration that corrects all 
the points you mentioned.

Best regards,
Bastien

On 5/31/24 16:55, Lee Jones wrote:
> On Mon, 27 May 2024, Bastien Curutchet wrote:
>
> > PSC0/PWM0 are used by all leds for brightness and blinking. This causes
>
> LEDs everywhere please.
>
> > conflicts when you set a brightness of a new led while an other one is
> > already using PWM0 for blinking.
> >
> > Use PSC1/PWM1 for blinking.
> > Check that no other led is already blinking with a different PSC1/PWM1
> > configuration to avoid conflict.
> >
> > Signed-off-by: Bastien Curutchet <bastien.curutchet@xxxxxxxxxxx>
> > ---
> >   drivers/leds/leds-pca9532.c | 49 ++++++++++++++++++++++++++++++-------
> >   1 file changed, 40 insertions(+), 9 deletions(-)
> >
> > diff --git a/drivers/leds/leds-pca9532.c b/drivers/leds/leds-pca9532.c
> > index bf8bb8fc007c..c210608ad336 100644
> > --- a/drivers/leds/leds-pca9532.c
> > +++ b/drivers/leds/leds-pca9532.c
> > @@ -191,29 +191,60 @@ static int pca9532_set_brightness(struct led_classdev *led_cdev,
> >   	return err;
> >   }
> >   
> > +static int pca9532_update_hw_blink(struct pca9532_led *led,
> > +				   unsigned long delay_on, unsigned long delay_off)
> > +{
> > +	struct pca9532_data *data = i2c_get_clientdata(led->client);
> > +	unsigned int psc;
> > +	int i;
> > +
> > +	/* Look for others leds that already use PWM1 */
> > +	for (i = 0; i < data->chip_info->num_leds; i++) {
> > +		struct pca9532_led *other = &data->leds[i];
> > +
> > +		if (other == led)
> > +			continue;
>
> Don't bunch things up please - new line here.
>
> > +		if (other->state == PCA9532_PWM1) {
> > +			if (other->ldev.blink_delay_on != delay_on ||
> > +			    other->ldev.blink_delay_off != delay_off) {
> > +				dev_dbg(&led->client->dev,
> > +					"HW can handle only one blink configuration at a time\n");
> > +				return -EINVAL;
> > +			}
> > +		}
> > +	}
> > +
> > +	psc = ((delay_on + delay_off) * 152 - 1) / 1000;
>
> What are these funny magic numbers?  Define them please.
>
> > +	if (psc > 255) {
>
> And this.
>
> > +		dev_dbg(&led->client->dev, "Blink period too long to be handled by hardware\n");
>
> If you're returning an error, this should be dev_err().
>
> > +		return -EINVAL;
> > +	}
> > +
> > +	data->psc[1] = psc;
>
> Can we define these indexes please?
>
> > +	data->pwm[1] = (delay_on * 255) / (delay_on + delay_off);
> > +
> > +	return pca9532_setpwm(data->client, 1);
> > +}
> > +
> >   static int pca9532_set_blink(struct led_classdev *led_cdev,
> >   	unsigned long *delay_on, unsigned long *delay_off)
> >   {
> >   	struct pca9532_led *led = ldev_to_led(led_cdev);
> >   	struct i2c_client *client = led->client;
> > -	int psc;
> > -	int err = 0;
> > +	struct pca9532_data *data = i2c_get_clientdata(client);
>
> Did you build this with W=1?  This looks unused.
>
> > +	int err;
> >   
> >   	if (*delay_on == 0 && *delay_off == 0) {
> >   		/* led subsystem ask us for a blink rate */
> >   		*delay_on = 1000;
> >   		*delay_off = 1000;
> >   	}
> > -	if (*delay_on != *delay_off || *delay_on > 1690 || *delay_on < 6)
> > -		return -EINVAL;
> >   
> > -	/* Thecus specific: only use PSC/PWM 0 */
> > -	psc = (*delay_on * 152-1)/1000;
> > -	err = pca9532_calcpwm(client, 0, psc, led_cdev->brightness);
> > +	led->state = PCA9532_PWM1;
> > +	err = pca9532_update_hw_blink(led, *delay_on, *delay_off);
> >   	if (err)
> >   		return err;
> > -	if (led->state == PCA9532_PWM0)
> > -		pca9532_setpwm(led->client, 0);
> > +
> >   	pca9532_setled(led);
> >   
> >   	return 0;
> > --
> > 2.44.0