Re: [alsa-devel] [PATCH v3] ASoC: Add support for NAU8825 codec to ASoC

From: Liam Girdwood
Date: Mon Jul 13 2015 - 05:23:19 EST


On Mon, 2015-07-13 at 15:33 +0800, Chih-Chiang Chang wrote:
> +static void set_sys_clk(struct snd_soc_codec *codec, int sys_clk)
> +{
> + struct nau8825_priv *nau8825 = snd_soc_codec_get_drvdata(codec);
> +
> + pr_debug("%s :: sys_clk=%x\n", __func__, sys_clk);
> + switch (sys_clk) {
> + case NAU8825_INTERNALCLOCK:
> + regmap_update_bits(nau8825->regmap, NAU8825_CLK_DIVIDER,
> + NAU8825_SYSCLK_EN_MASK, NAU8825_SYSCLK_DIS);
> + regmap_update_bits(nau8825->regmap, NAU8825_FLL_6,
> + NAU8825_DCO_EN_MASK, NAU8825_DCO_EN);
> + regmap_update_bits(nau8825->regmap, NAU8825_CLK_DIVIDER,
> + NAU8825_SYSCLK_EN_MASK, NAU8825_SYSCLK_EN);
> + break;
> + case NAU8825_MCLK:
> + default:
> + regmap_update_bits(nau8825->regmap, NAU8825_FLL_6,
> + NAU8825_DCO_EN_MASK, NAU8825_DCO_DIS);
> + regmap_update_bits(nau8825->regmap, NAU8825_I2S_PCM_CTRL_2,
> + NAU8825_I2S_MS_MASK, NAU8825_I2S_MS_SLAVE);
> + /* FLL clock source from MCLK */
> + regmap_update_bits(nau8825->regmap, NAU8825_CLK_DIVIDER,
> + NAU8825_SYSCLK_EN_MASK, NAU8825_SYSCLK_DIS);
> + mdelay(2);

Probably best to sleep here rather than block, especially if this code
will be used in init/PM sequences.

Btw, is there anyway to check whether the FLL actually achieves lock
after the 2ms ?

> + regmap_update_bits(nau8825->regmap, NAU8825_CLK_DIVIDER,
> + NAU8825_SYSCLK_EN_MASK, NAU8825_SYSCLK_EN);
> + break;
> + }
> +}
> +

Thanks

Liam


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