Re: [PATCH 2/4] staging: iio: ad7150: use FIELD_GET and GENMASK

[Alexandru Ardelean]

On Sat, May 4, 2019 at 1:25 AM Melissa Wen <melissa.srw@xxxxxxxxx> wrote:
>
> Use the bitfield macro FIELD_GET, and GENMASK to do the shift and mask in
> one go. This makes the code more readable than explicit masking followed
> by a shift.
>

This looks neat.
I'd have to remember to ack it from my work email.

One minor comment inline, which would be the object of a new patch.

> Signed-off-by: Melissa Wen <melissa.srw@xxxxxxxxx>
> ---
>  drivers/staging/iio/cdc/ad7150.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/staging/iio/cdc/ad7150.c b/drivers/staging/iio/cdc/ad7150.c
> index 24601ba7db88..4ba46fb6ac02 100644
> --- a/drivers/staging/iio/cdc/ad7150.c
> +++ b/drivers/staging/iio/cdc/ad7150.c
> @@ -5,6 +5,7 @@
>   * Copyright 2010-2011 Analog Devices Inc.
>   */
>
> +#include <linux/bitfield.h>
>  #include <linux/interrupt.h>
>  #include <linux/device.h>
>  #include <linux/kernel.h>
> @@ -44,6 +45,9 @@
>  #define AD7150_SN0_REG                         0x16
>  #define AD7150_ID_REG                          0x17
>
> +/* AD7150 masks */
> +#define AD7150_THRESHTYPE_MSK                  GENMASK(6, 5)
> +
>  /**
>   * struct ad7150_chip_info - instance specific chip data
>   * @client: i2c client for this device
> @@ -136,7 +140,7 @@ static int ad7150_read_event_config(struct iio_dev *indio_dev,
>         if (ret < 0)
>                 return ret;
>
> -       threshtype = (ret >> 5) & 0x03;
> +       threshtype = FIELD_GET(AD7150_THRESHTYPE_MSK, ret);
>         adaptive = !!(ret & 0x80);

Why not also do something similar for the `adaptive` value ?

>
>         switch (type) {
> --
> 2.20.1
>