Re: [PATCH 3/3] stagging:iio:meter: Add ade7854_write_raw function

Jonathan Cameron
2018-04-21T17:26:08Z

On Sat, 21 Apr 2018 08:56:19 -0300
Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com> wrote:

> This patch adds the ade7854_write_raw() function which is responsible
> for handling the write operation for registers: AIGAIN, BIGAIN, CIGAIN,
> NIGAIN, AVGAIN, BVGAIN, and CVGAIN. Finally, this patch completely
> removes the old ABI used for handling the registers mentioned above.
>
> Signed-off-by: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>
The baby steps approach here is good, but with all 3 patches as one it
would have been a lot easier to follow.

This is almost fine except for the issue I had with how the channels
were defined in the first place.

Also a question about scales inline...

> ---
> drivers/staging/iio/meter/ade7854.c | 60 ++++++++++++-----------------
> 1 file changed, 25 insertions(+), 35 deletions(-)
>
> diff --git a/drivers/staging/iio/meter/ade7854.c b/drivers/staging/iio/meter/ade7854.c
> index 242ecde75900..df19c8b4b5d7 100644
> --- a/drivers/staging/iio/meter/ade7854.c
> +++ b/drivers/staging/iio/meter/ade7854.c
> @@ -228,34 +228,6 @@ static int ade7854_reset(struct device *dev)
> return st->write_reg(dev, ADE7854_CONFIG, val, 16);
> }
>
> -static IIO_DEV_ATTR_AIGAIN(0644,
> - NULL,
> - ade7854_write_24bit,
> - ADE7854_AIGAIN);
> -static IIO_DEV_ATTR_BIGAIN(0644,
> - NULL,
> - ade7854_write_24bit,
> - ADE7854_BIGAIN);
> -static IIO_DEV_ATTR_CIGAIN(0644,
> - NULL,
> - ade7854_write_24bit,
> - ADE7854_CIGAIN);
> -static IIO_DEV_ATTR_NIGAIN(0644,
> - NULL,
> - ade7854_write_24bit,
> - ADE7854_NIGAIN);
> -static IIO_DEV_ATTR_AVGAIN(0644,
> - NULL,
> - ade7854_write_24bit,
> - ADE7854_AVGAIN);
> -static IIO_DEV_ATTR_BVGAIN(0644,
> - NULL,
> - ade7854_write_24bit,
> - ADE7854_BVGAIN);
> -static IIO_DEV_ATTR_CVGAIN(0644,
> - NULL,
> - ade7854_write_24bit,
> - ADE7854_CVGAIN);
> static IIO_DEV_ATTR_APPARENT_POWER_A_GAIN(0644,
> ade7854_read_24bit,
> ade7854_write_24bit,
> @@ -497,6 +469,30 @@ static int ade7854_read_raw(struct iio_dev *indio_dev,
> return -EINVAL;
> }
>
> +static int ade7854_write_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + int val, int val2, long mask)
> +{
> + struct ade7854_state *st = iio_priv(indio_dev);
> + int ret;
> +
> + if (mask != IIO_CHAN_INFO_SCALE)
> + return -EINVAL;
> +
> + switch (chan->type) {
> + case IIO_CURRENT:
> + case IIO_VOLTAGE:
Probably need some range checking to make sure we have a sane value.

Also, I'm curious about units here.

you are using CHAN_INFO_SCALE which would mean this is linked to
the _RAW value (the actual reading of the channel) by _RAW*_SCALE = value in
defined base units for the channel type. So I'd expect to see some
code here doing a conversion to the internal format for the device.

I wouldn't expect to see a value from userspace written unconverted
into the register.

(I missed this in the previous patch - sorry).

Jonathan

> + ret = st->write_reg(&indio_dev->dev, chan->address, val, 24);
> + if (ret < 0)
> + return ret;
> + return 0;
> + default:
> + break;
> + }
> +
> + return -EINVAL;
> +}
> +
> static int ade7854_initial_setup(struct iio_dev *indio_dev)
> {
> int ret;
> @@ -521,13 +517,6 @@ static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("8000");
> static IIO_CONST_ATTR(name, "ade7854");
>
> static struct attribute *ade7854_attributes[] = {
> - &iio_dev_attr_aigain.dev_attr.attr,
> - &iio_dev_attr_bigain.dev_attr.attr,
> - &iio_dev_attr_cigain.dev_attr.attr,
> - &iio_dev_attr_nigain.dev_attr.attr,
> - &iio_dev_attr_avgain.dev_attr.attr,
> - &iio_dev_attr_bvgain.dev_attr.attr,
> - &iio_dev_attr_cvgain.dev_attr.attr,
> &iio_dev_attr_linecyc.dev_attr.attr,
> &iio_dev_attr_sagcyc.dev_attr.attr,
> &iio_dev_attr_cfcyc.dev_attr.attr,
> @@ -599,6 +588,7 @@ static const struct attribute_group ade7854_attribute_group = {
> static const struct iio_info ade7854_info = {
> .attrs = &ade7854_attribute_group,
> .read_raw = &ade7854_read_raw,
> + .write_raw = &ade7854_write_raw,
> };
>
> int ade7854_probe(struct iio_dev *indio_dev, struct device *dev)