Re: [PATCH v2 1/2] staging: iio: ad7780: check if ad778x before gain update

From: Tomasz Duszynski
Date: Thu Nov 08 2018 - 13:26:51 EST


Hi Giuliano,

Comment inline.

On 11/8/18 2:03 PM, Giuliano Belinassi wrote:
> Only the ad778x have the 'gain' status bit. Check it before updating
> through a new variable is_ad778x in chip_info.
>
> Signed-off-by: Giuliano Belinassi <giuliano.belinassi@xxxxxx>
> ---
> Changes in v2:
> - Squashed is_ad778x declaration commit with the ad778x checkage
> - Changed is_ad778x type to bool
>
> drivers/staging/iio/adc/ad7780.c | 15 +++++++++++----
> 1 file changed, 11 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/staging/iio/adc/ad7780.c b/drivers/staging/iio/adc/ad7780.c
> index 91e016d534ed..9ec2b002539e 100644
> --- a/drivers/staging/iio/adc/ad7780.c
> +++ b/drivers/staging/iio/adc/ad7780.c
> @@ -35,6 +35,7 @@ struct ad7780_chip_info {
> struct iio_chan_spec channel;
> unsigned int pattern_mask;
> unsigned int pattern;
> + bool is_ad778x;
> };
>
> struct ad7780_state {
> @@ -113,10 +114,12 @@ static int ad7780_postprocess_sample(struct ad_sigma_delta *sigma_delta,
> ((raw_sample & chip_info->pattern_mask) != chip_info->pattern))
> return -EIO;
>
> - if (raw_sample & AD7780_GAIN)
> - st->gain = 1;
> - else
> - st->gain = 128;
> + if (chip_info->is_ad778x) {
> + if (raw_sample & AD7780_GAIN)
> + st->gain = 1;
> + else
> + st->gain = 128;
> + }

Just some random though. Instead of introducing extra level of indentation you
can simply check whether is_ad778x is asserted and simply return.

>
> return 0;
> }
> @@ -135,21 +138,25 @@ static const struct ad7780_chip_info ad7780_chip_info_tbl[] = {
> .channel = AD7780_CHANNEL(12, 24),
> .pattern = 0x5,
> .pattern_mask = 0x7,
> + .is_ad778x = false,

Any reason for setting this explicitly? That's going to be false anyway.

> },
> [ID_AD7171] = {
> .channel = AD7780_CHANNEL(16, 24),
> .pattern = 0x5,
> .pattern_mask = 0x7,
> + .is_ad778x = false,
> },
> [ID_AD7780] = {
> .channel = AD7780_CHANNEL(24, 32),
> .pattern = 0x1,
> .pattern_mask = 0x3,
> + .is_ad778x = true,
> },
> [ID_AD7781] = {
> .channel = AD7780_CHANNEL(20, 32),
> .pattern = 0x1,
> .pattern_mask = 0x3,
> + .is_ad778x = true,
> },
> };
>