The .set_sysclk() function in ASoC codec drivers can be used to tell the driver what the frequency of master clock (mclk) is. Some codecs use a divider on this clock to determine the sample rate. The WM8776 is one such codec.
So instead of hard-coding a list of specific sample rates supported, these codec drivers can specify SNDRV_PCM_RATE_CONTINUOUS instead, clamping the range to the absolute limits of the hardware. Then the .hw_params() function can use the mclk rate to determine whether any requested rate is actually supported.
Although the WM8776 driver includes a .set_sysclk function, it was also hard-coding the list of supported sample rates. We change the hard-coded list to a range within the capabilities of the WM8776 itself.
Signed-off-by: Timur Tabi timur@freescale.com --- sound/soc/codecs/wm8776.c | 13 ++++++------- 1 files changed, 6 insertions(+), 7 deletions(-)
diff --git a/sound/soc/codecs/wm8776.c b/sound/soc/codecs/wm8776.c index ad6f0fa..ca8a593 100644 --- a/sound/soc/codecs/wm8776.c +++ b/sound/soc/codecs/wm8776.c @@ -321,11 +321,6 @@ static int wm8776_set_bias_level(struct snd_soc_codec *codec, return 0; }
-#define WM8776_RATES (SNDRV_PCM_RATE_32000 | SNDRV_PCM_RATE_44100 |\ - SNDRV_PCM_RATE_48000 | SNDRV_PCM_RATE_88200 |\ - SNDRV_PCM_RATE_96000) - - #define WM8776_FORMATS (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S20_3LE |\ SNDRV_PCM_FMTBIT_S24_LE | SNDRV_PCM_FMTBIT_S32_LE)
@@ -350,7 +345,9 @@ static struct snd_soc_dai_driver wm8776_dai[] = { .stream_name = "Playback", .channels_min = 2, .channels_max = 2, - .rates = WM8776_RATES, + .rates = SNDRV_PCM_RATE_CONTINUOUS, + .rate_min = 32000, + .rate_max = 192000, .formats = WM8776_FORMATS, }, .ops = &wm8776_dac_ops, @@ -362,7 +359,9 @@ static struct snd_soc_dai_driver wm8776_dai[] = { .stream_name = "Capture", .channels_min = 2, .channels_max = 2, - .rates = WM8776_RATES, + .rates = SNDRV_PCM_RATE_CONTINUOUS, + .rate_min = 32000, + .rate_max = 96000, .formats = WM8776_FORMATS, }, .ops = &wm8776_adc_ops,