staging: iio: adt7316: fix handling of dac high resolution option

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>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/staging/iio/addac/adt7316.c b/drivers/staging/iio/addac/adt7316.c
index e17c1cb12c947ec3b81d018239d7144aa6b6c8be..80cc3420036b14a89a2ec5591380cb259c3fc59b 100644 (file)
--- 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)