On Wed, 18 Aug 2021 13:11:30 +0200
Miquel Raynal <miquel.raynal@xxxxxxxxxxx> wrote:
> There are two ways to physically trigger a conversion:
> - A falling edge on the cnvst pin
> - A write operation on the conversion register
>
> Let's create a helper for this.
>
> Signed-off-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
Trivial comments inline.
Thanks,
Jonathan
> ---
> drivers/iio/adc/max1027.c | 52 ++++++++++++++++++++++++++-------------
> 1 file changed, 35 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/iio/adc/max1027.c b/drivers/iio/adc/max1027.c
> index a6ebc951c09a..59914fcfd320 100644
> --- a/drivers/iio/adc/max1027.c
> +++ b/drivers/iio/adc/max1027.c
> @@ -232,10 +232,37 @@ struct max1027_state {
> struct iio_trigger *trig;
> __be16 *buffer;
> struct mutex lock;
> -
Avoid white space changes in a patch doing something else.
In this case, I'd imagine the reg had a blank line before it to more
strongly indicate the cacheline_aligned nature meaning there would be
a bit of padding inserted here.
> + bool cnvst_trigger;
I'd expect a cnvst_trigger named variable to be a pointer to the trigger. Perhaps
call it use_cnvst_trigger or something like that?
> u8 reg ____cacheline_aligned;
> };
>
> +static int max1027_configure_trigger(struct iio_dev *indio_dev)
> +{
> + struct max1027_state *st = iio_priv(indio_dev);
> + int ret;
> +
> + st->reg = MAX1027_SETUP_REG | MAX1027_REF_MODE2;
> +
> + /*
> + * Start acquisition on:
> + * MODE0: external hardware trigger wired to the cnvst input pin
> + * MODE2: conversion register write
> + */
> + if (st->cnvst_trigger)
> + st->reg |= MAX1027_CKS_MODE0;
> + else
> + st->reg |= MAX1027_CKS_MODE2;
> +
> + ret = spi_write(st->spi, &st->reg, 1);
> + if (ret < 0) {
> + dev_err(&indio_dev->dev,
> + "Failed to configure register (%d)\n", ret);
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> static int max1027_read_single_value(struct iio_dev *indio_dev,
> struct iio_chan_spec const *chan,
> int *val)
> @@ -248,14 +275,9 @@ static int max1027_read_single_value(struct iio_dev *indio_dev,
> return -EBUSY;
> }
>
> - /* Start acquisition on conversion register write */
> - st->reg = MAX1027_SETUP_REG | MAX1027_REF_MODE2 | MAX1027_CKS_MODE2;
> - ret = spi_write(st->spi, &st->reg, 1);
> - if (ret < 0) {
> - dev_err(&indio_dev->dev,
> - "Failed to configure setup register\n");
> + ret = max1027_configure_trigger(indio_dev);
> + if (ret)
> return ret;
> - }
>
> /* Configure conversion register with the requested chan */
> st->reg = MAX1027_CONV_REG | MAX1027_CHAN(chan->channel) |
> @@ -363,12 +385,10 @@ static int max1027_set_cnvst_trigger_state(struct iio_trigger *trig, bool state)
> if (bitmap_empty(indio_dev->active_scan_mask, indio_dev->masklength))
> return -EINVAL;
>
> + st->cnvst_trigger = state;
> if (state) {
> - /* Start acquisition on cnvst */
> - st->reg = MAX1027_SETUP_REG | MAX1027_CKS_MODE0 |
> - MAX1027_REF_MODE2;
> - ret = spi_write(st->spi, &st->reg, 1);
> - if (ret < 0)
> + ret = max1027_configure_trigger(indio_dev);
> + if (ret)
> return ret;
>
> /*
> @@ -382,10 +402,8 @@ static int max1027_set_cnvst_trigger_state(struct iio_trigger *trig, bool state)
> return ret;
> } else {
> /* Start acquisition on conversion register write */
> - st->reg = MAX1027_SETUP_REG | MAX1027_CKS_MODE2 |
> - MAX1027_REF_MODE2;
> - ret = spi_write(st->spi, &st->reg, 1);
> - if (ret < 0)
> + ret = max1027_configure_trigger(indio_dev);
> + if (ret)
> return ret;
> }
>
