Messages in this thread | | | Subject | Re: [PATCH 1/2] ASoC: Add driver for PROTO Audio CODEC (with a WM8731) | From | Codrin Ciubotariu <> | Date | Wed, 29 Aug 2018 18:20:59 +0300 |
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On 29.08.2018 17:53, Mark Brown wrote: > On Wed, Aug 29, 2018 at 05:47:26PM +0300, Codrin Ciubotariu wrote: > >> +static const unsigned int wm8731_rates_12288000[] = { >> + 8000, 32000, 48000, 96000, >> +}; >> + >> +static struct snd_pcm_hw_constraint_list wm8731_constraints_12288000 = { >> + .list = wm8731_rates_12288000, >> + .count = ARRAY_SIZE(wm8731_rates_12288000), >> +}; >> + >> +static int snd_proto_startup(struct snd_pcm_substream *substream) >> +{ >> + /* Setup constraints, because there is a 12.288 MHz XTAL on the board */ >> + snd_pcm_hw_constraint_list(substream->runtime, 0, >> + SNDRV_PCM_HW_PARAM_RATE, >> + &wm8731_constraints_12288000); >> + return 0; >> +} > > This bit is better added to the CODEC driver since it'll apply to any > system where there's this clock rate (someone else could come in and add > other rates, no need to do that yourself though it'd be nice of course).
I could do it.
> > That also has the nice bonus that with that I think you'd be able to use > the graph card rather than a custom driver?
The main reason for adding a custom driver and not using graph/simple card is the snd_soc_dai_set_sysclk(codec_dai, WM8731_SYSCLK_XTAL, XTAL_RATE, SND_SOC_CLOCK_IN) call. This enables the oscillator found in the wm8731 codec. Since WM8731_SYSCLK_XTAL is not 0, we can't use system-clock-frequency DT property to set it.
Best regards, Codrin
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