Re: [alsa-devel] [PATCH] ASoC: wm8804: Allow fine-grained controlof the PLL generation

From: Charles Keepax
Date: Thu Jan 09 2014 - 09:27:54 EST


On Wed, Jan 08, 2014 at 10:36:53PM +0100, Daniel Matuschek wrote:
> Signed-off-by: Daniel Matuschek <daniel@xxxxxxxxxxxxx>
>

<snip>

> pll_div->freqmode = post_table[i].freqmode;
> - pll_div->mclkdiv = post_table[i].mclkdiv;
> - target *= post_table[i].div;
> - break;
> + if ((mclk_div == WM8804_MCLKDIV_DONTCARE) ||
> + ((post_table[i].mclkdiv == 1) &&
> + (mclk_div == WM8804_MCLKDIV_1)) ||
> + ((post_table[i].mclkdiv == 0) &&
> + (mclk_div == WM8804_MCLKDIV_0))) {

Would probably be nicer to update the post_table to use the new
defines and directly compare.

> + pll_div->mclkdiv = post_table[i].mclkdiv;
> + target *= post_table[i].div;
> + break;
> + }
> }
> }
>
> @@ -388,7 +396,7 @@ static int wm8804_set_pll(struct snd_soc_dai *dai, int pll_id,
> int ret;
> struct pll_div pll_div;
>
> - ret = pll_factors(&pll_div, freq_out, freq_in);
> + ret = pll_factors(&pll_div, freq_out, freq_in, pll_id);

This does feel like a slight abuse of pll_id, it feels to me that
using the set_clkdiv callback would be a little more natural from
a user perspective.

> if (ret)
> return ret;
>
> diff --git a/sound/soc/codecs/wm8804.h b/sound/soc/codecs/wm8804.h
> index 8ec14f5..0365177 100644
> --- a/sound/soc/codecs/wm8804.h
> +++ b/sound/soc/codecs/wm8804.h
> @@ -58,4 +58,11 @@
>
> #define WM8804_CLKOUT_DIV 1
>
> +#define WM8804_MCLKDIV_DONTCARE 0
> +#define WM8804_MCLKDIV_0 1
> +#define WM8804_MCLKDIV_1 2
> +#define WM8804_PLL_MCLKDIV_DONTCARE WM8804_MCLKDIV_DONTCARE
> +#define WM8804_PLL_MCLKDIV_0 WM8804_MCLKDIV_0
> +#define WM8804_PLL_MCLKDIV_1 WM8804_MCLKDIV_1

Do we really need two copies of these?

Thanks,
Charles
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