On 01/04/2013 06:18 PM, Lucas Stach wrote:
> This adds the driver for the Tegra 2x AC97 host controller.
>
> Signed-off-by: Lucas Stach <dev@xxxxxxxxxx>
> diff --git a/Documentation/devicetree/bindings/sound/nvidia,tegra20-ac97.txt b/Documentation/devicetree/bindings/sound/nvidia,tegra20-ac97.txt
> +- nvidia,codec-sync-gpio : The Tegra GPIO controller's phandle and the number
> + of the GPIO corresponding with the AC97 DAP _FS line
> +Example:
If you have to repost for any reason, you probably want a blank line
before the "Example:" line.
> diff --git a/sound/soc/tegra/tegra20_ac97.c b/sound/soc/tegra/tegra20_ac97.c
> +static void tegra20_ac97_codec_warm_reset(struct snd_ac97 *ac97)
> +{
> + u32 readback;
> + unsigned long timeout;
> +
> + /*
> + * although sync line is driven by the DAC pad group warm reset using
> + * the controller cmd is not working, have to toggle sync line
> + * manually.
> + */
> + gpio_request(workdata->sync_gpio, "codec-sync");
> +
> + gpio_direction_output(workdata->sync_gpio, 1);
Would it make sense to just request the GPIO during probe()? Or, is the
sync signal used as part of the AC'97 protocol at other times?
> +static inline void tegra20_ac97_start_playback(struct tegra20_ac97 *ac97)
> +{
> + regmap_update_bits(ac97->regmap, TEGRA20_AC97_FIFO1_SCR,
> + TEGRA20_AC97_FIFO_SCR_PB_QRT_MT_EN,
> + TEGRA20_AC97_FIFO_SCR_PB_QRT_MT_EN);
> +
> + regmap_update_bits(ac97->regmap, TEGRA20_AC97_CTRL,
> + TEGRA20_AC97_CTRL_PCM_DAC_EN |
> + TEGRA20_AC97_CTRL_STM_EN,
> + TEGRA20_AC97_CTRL_PCM_DAC_EN |
> + TEGRA20_AC97_CTRL_STM_EN);
> +}
That sets both PCM_DAC_EN and STM_EN, but ...
> +static inline void tegra20_ac97_stop_playback(struct tegra20_ac97 *ac97)
> +{
> + regmap_update_bits(ac97->regmap, TEGRA20_AC97_FIFO1_SCR,
> + TEGRA20_AC97_FIFO_SCR_PB_QRT_MT_EN, 0);
> +
> + regmap_update_bits(ac97->regmap, TEGRA20_AC97_CTRL,
> + TEGRA20_AC97_CTRL_PCM_DAC_EN, 0);
> +}
... that only clears DAC_EN. Should it clear STM_EN too?
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