Re: [PATCH v5 4/8] iio: adc: ad7606: Add PWM support for conversion trigger

[Jonathan Cameron]

On Tue, 15 Oct 2024 13:56:17 +0000
Guillaume Stols <gstols@xxxxxxxxxxxx> wrote:

> Until now, the conversion were triggered by setting high the GPIO
> connected to the convst pin. This commit gives the possibility to
> connect the convst pin to a PWM.
> Connecting a PWM allows to have a better control on the samplerate,
> but it must be handled with care, as it is completely decorrelated of
> the driver's busy pin handling.
> Hence it is not recommended to be used "as is" but must be exploited
> in conjunction with IIO backend, and for now only a mock functionality
> is enabled, i.e PWM never swings, but is used as a GPIO, i.e duty_cycle
> == period equals high state, duty_cycle == 0 equals low state.
> 
> This mock functionality will be disabled after the IIO backend usecase
> is introduced.
> 
> Signed-off-by: Guillaume Stols <gstols@xxxxxxxxxxxx>
Trivial fix needed so this builds.

>  static int ad7606_read_samples(struct ad7606_state *st)
>  {
>  	unsigned int num = st->chip_info->num_channels - 1;
> @@ -324,7 +393,13 @@ static irqreturn_t ad7606_trigger_handler(int irq, void *p)
>  error_ret:
>  	iio_trigger_notify_done(indio_dev->trig);
>  	/* The rising edge of the CONVST signal starts a new conversion. */
> -	gpiod_set_value(st->gpio_convst, 1);
> +	if (st->gpio_convst) {
> +		gpiod_set_value(st->gpio_convst, 1);
> +	} else {
> +		ret = ad7606_pwm_set_high(st)
Missing ;

> +		if (ret < 0)
> +			dev_err(st->dev, "Could not set PWM to high.");
> +	}