Re: [PATCH v2 2/4] staging: iio: adt7316: fix handling of dac high resolution option

[Jonathan Cameron <jic23@kernel.org>]

On Sat, 22 Dec 2018 21:57:41 -0700
Jeremy Fertic <jeremyfertic@gmail.com> wrote:

> The adt7316/7 and adt7516/7 have the option to output voltage proportional
> to temperature on dac a and/or dac b. The default dac resolution in this
> mode is 8 bits with the dac high resolution option enabling 10 bits. None
> of these settings affect dacs c and d. Remove the "1 (12 bits)" output from
> the show function since that is not an option for this mode. Return
> "1 (10 bits)" if the device is one of the above mentioned chips and the dac
> high resolution mode is enabled.
> 
> In the store function, the driver currently allows the user to write to the
> ADT7316_DA_HIGH_RESOLUTION bit regardless of the device in use. Add a check
> to return an error in the case of an adt7318 or adt7519. Remove the else
> statement that clears the ADT7316_DA_HIGH_RESOLUTION bit. Instead, clear it
> before conditionally enabling it, depending on user input. This matches the
> typical pattern in the driver when an attribute is a boolean.
> 
> Fixes: 35f6b6b86ede ("staging: iio: new ADT7316/7/8 and ADT7516/7/9 driver")
> Signed-off-by: Jeremy Fertic <jeremyfertic@gmail.com>
Applied to the togreg branch of iio.git and pushed out as testing for
the autobuilders to play with it.

Thanks,

Jonathan

> ---
>  drivers/staging/iio/addac/adt7316.c | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/staging/iio/addac/adt7316.c b/drivers/staging/iio/addac/adt7316.c
> index e17c1cb12c94..80cc3420036b 100644
> --- a/drivers/staging/iio/addac/adt7316.c
> +++ b/drivers/staging/iio/addac/adt7316.c
> @@ -633,9 +633,7 @@ static ssize_t adt7316_show_da_high_resolution(struct device *dev,
>  	struct adt7316_chip_info *chip = iio_priv(dev_info);
>  
>  	if (chip->config3 & ADT7316_DA_HIGH_RESOLUTION) {
> -		if (chip->id == ID_ADT7316 || chip->id == ID_ADT7516)
> -			return sprintf(buf, "1 (12 bits)\n");
> -		if (chip->id == ID_ADT7317 || chip->id == ID_ADT7517)
> +		if (chip->id != ID_ADT7318 && chip->id != ID_ADT7519)
>  			return sprintf(buf, "1 (10 bits)\n");
>  	}
>  
> @@ -652,10 +650,12 @@ static ssize_t adt7316_store_da_high_resolution(struct device *dev,
>  	u8 config3;
>  	int ret;
>  
> +	if (chip->id == ID_ADT7318 || chip->id == ID_ADT7519)
> +		return -EPERM;
> +
> +	config3 = chip->config3 & (~ADT7316_DA_HIGH_RESOLUTION);
>  	if (buf[0] == '1')
> -		config3 = chip->config3 | ADT7316_DA_HIGH_RESOLUTION;
> -	else
> -		config3 = chip->config3 & (~ADT7316_DA_HIGH_RESOLUTION);
> +		config3 |= ADT7316_DA_HIGH_RESOLUTION;
>  
>  	ret = chip->bus.write(chip->bus.client, ADT7316_CONFIG3, config3);
>  	if (ret)