Re: [PATCH v6 6/6] drivers:iio:dac:ad5766.c: Add trigger buffer

[Jonathan Cameron <jic23@kernel.org>]

On Thu, 7 Oct 2021 08:00:37 +0000
Mihail Chindris <mihail.chindris@analog.com> wrote:

> This chip is able to generate waveform and using an
> with the output trigger buffer will be easy to generate one.
> 
> Signed-off-by: Mihail Chindris <mihail.chindris@analog.com>
> Reviewed-by: Alexandru Ardelean <ardeleanalex@gmail.com>

Rest of series applied to the togreg branch of iio.git, initially pushed out as
testing for 0-day to poke at it.

Thanks,

Jonathan

> ---
>  drivers/iio/dac/ad5766.c | 42 ++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 42 insertions(+)
> 
> diff --git a/drivers/iio/dac/ad5766.c b/drivers/iio/dac/ad5766.c
> index dafda84fdea3..b0d220c3a126 100644
> --- a/drivers/iio/dac/ad5766.c
> +++ b/drivers/iio/dac/ad5766.c
> @@ -5,10 +5,13 @@
>   * Copyright 2019-2020 Analog Devices Inc.
>   */
>  #include <linux/bitfield.h>
> +#include <linux/bitops.h>
>  #include <linux/delay.h>
>  #include <linux/device.h>
>  #include <linux/gpio/consumer.h>
>  #include <linux/iio/iio.h>
> +#include <linux/iio/triggered_buffer.h>
> +#include <linux/iio/trigger_consumer.h>
>  #include <linux/module.h>
>  #include <linux/spi/spi.h>
>  #include <asm/unaligned.h>
> @@ -455,6 +458,7 @@ static const struct iio_chan_spec_ext_info ad5766_ext_info[] = {
>  	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),			\
>  	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |		\
>  		BIT(IIO_CHAN_INFO_SCALE),				\
> +	.scan_index = (_chan),						\
>  	.scan_type = {							\
>  		.sign = 'u',						\
>  		.realbits = (_bits),					\
> @@ -576,6 +580,35 @@ static int ad5766_default_setup(struct ad5766_state *st)
>  	return  __ad5766_spi_write(st, AD5766_CMD_SPAN_REG, st->crt_range);
>  }
>  
> +static irqreturn_t ad5766_trigger_handler(int irq, void *p)
> +{
> +	struct iio_poll_func *pf = p;
> +	struct iio_dev *indio_dev = pf->indio_dev;
> +	struct iio_buffer *buffer = indio_dev->buffer;
> +	struct ad5766_state *st = iio_priv(indio_dev);
> +	int ret, ch, i;
> +	u16 data[ARRAY_SIZE(ad5766_channels)];
> +
> +	ret = iio_pop_from_buffer(buffer, data);
> +	if (ret)
> +		goto done;
> +
> +	i = 0;
> +	mutex_lock(&st->lock);
> +	for_each_set_bit(ch, indio_dev->active_scan_mask,
> +			 st->chip_info->num_channels - 1)
> +		__ad5766_spi_write(st, AD5766_CMD_WR_IN_REG(ch), data[i++]);
> +
> +	__ad5766_spi_write(st, AD5766_CMD_SW_LDAC,
> +			   *indio_dev->active_scan_mask);
> +	mutex_unlock(&st->lock);
> +
> +done:
> +	iio_trigger_notify_done(indio_dev->trig);
> +
> +	return IRQ_HANDLED;
> +}
> +
>  static int ad5766_probe(struct spi_device *spi)
>  {
>  	enum ad5766_type type;
> @@ -609,6 +642,15 @@ static int ad5766_probe(struct spi_device *spi)
>  	if (ret)
>  		return ret;
>  
> +	/* Configure trigger buffer */
> +	ret = devm_iio_triggered_buffer_setup_ext(&spi->dev, indio_dev, NULL,
> +						  ad5766_trigger_handler,
> +						  IIO_BUFFER_DIRECTION_OUT,
> +						  NULL,
> +						  NULL);
> +	if (ret)
> +		return ret;
> +
>  	return devm_iio_device_register(&spi->dev, indio_dev);
>  }
>