[alsa-devel] SOC_VALUE_ENUM usages in cs42l52 & cs42l73 drivers

[Takashi Iwai]

Hi,

as I audited through ASoC codec drivers recently, I noticed that
cs42l52 and cs42l73 drivers have some strange SOC_VALUE_ENUM usages.

For example, cs42l52.c has the following code snippet:

static const char * const left_swap_text[] = {
	"Left", "LR 2", "Right"};
....
static const unsigned int swap_values[] = { 0, 1, 3 };

static const struct soc_enum adca_swap_enum =
	SOC_VALUE_ENUM_SINGLE(CS42L52_ADC_PCM_MIXER, 2, 1,
			      ARRAY_SIZE(left_swap_text),
			      left_swap_text,
			      swap_values);

Note that the third argument of SOC_VALUE_ENUM_SINGLE() is the mask
bits.  Passing 1 means only the least bit is evaluated no matter what
value is assigned while swap_values can be 0, 1 or 3.
I suppose here meant 3, but would like to know how the code is
supposed to work.  There are three value-enum definitions in
cs42l52.c, and all pass 1 there.

Similarly, cs42l73.c has four definitions, but with different masks:

	SOC_VALUE_ENUM_SINGLE(CS42L73_MMIXCTL, 6, 1, ...
	SOC_VALUE_ENUM_SINGLE(CS42L73_MMIXCTL, 4, 3, ...
	SOC_VALUE_ENUM_SINGLE(CS42L73_MMIXCTL, 2, 5, ...
	SOC_VALUE_ENUM_SINGLE(CS42L73_MMIXCTL, 0, 7, ...

while values can be either 0, 1 or 2.  Something really fishy here.


thanks,

Takashi