[PATCH] ASoC: cros_ec_codec: Reset I2S RX when probing

[Guenter Roeck]

On Tue, Jan 5, 2021 at 9:06 PM Yu-Hsuan Hsu <yuhsuan at chromium.org> wrote:

> It is not guaranteed that I2S RX is disabled when the kernel booting.
> For example, if the kernel crashes while it is enabled, it will keep
> enabled until the next time EC reboots. Reset I2S RX when probing to
> fix this issue.
>
> Signed-off-by: Yu-Hsuan Hsu <yuhsuan at chromium.org>
> ---
>  include/linux/platform_data/cros_ec_commands.h | 1 +
>  sound/soc/codecs/cros_ec_codec.c               | 7 +++++++
>  2 files changed, 8 insertions(+)
>
> diff --git a/include/linux/platform_data/cros_ec_commands.h
> b/include/linux/platform_data/cros_ec_commands.h
> index 86376779ab31..95889ada83a3 100644
> --- a/include/linux/platform_data/cros_ec_commands.h
> +++ b/include/linux/platform_data/cros_ec_commands.h
> @@ -4600,6 +4600,7 @@ enum ec_codec_i2s_rx_subcmd {
>         EC_CODEC_I2S_RX_SET_SAMPLE_DEPTH = 0x2,
>         EC_CODEC_I2S_RX_SET_DAIFMT = 0x3,
>         EC_CODEC_I2S_RX_SET_BCLK = 0x4,
> +       EC_CODEC_I2S_RX_RESET = 0x5,
>         EC_CODEC_I2S_RX_SUBCMD_COUNT,
>  };
>
>
I would prefer to see a separate patch to sync cros_ec_commands.h with the
version in EC code to reduce future conflicts.

Guenter


> diff --git a/sound/soc/codecs/cros_ec_codec.c
> b/sound/soc/codecs/cros_ec_codec.c
> index f33a2a9654e7..28b3e2c48c86 100644
> --- a/sound/soc/codecs/cros_ec_codec.c
> +++ b/sound/soc/codecs/cros_ec_codec.c
> @@ -1011,6 +1011,13 @@ static int cros_ec_codec_platform_probe(struct
> platform_device *pdev)
>         }
>         priv->ec_capabilities = r.capabilities;
>
> +       /* Reset EC codec i2s rx. */
> +       p.cmd = EC_CODEC_I2S_RX_RESET;
> +       ret = send_ec_host_command(priv->ec_device, EC_CMD_EC_CODEC_I2S_RX,
> +                                  (uint8_t *)&p, sizeof(p), NULL, 0);
> +       if (ret)
> +               dev_warn(dev, "failed to EC_CODEC_I2S_RESET: %d\n", ret);
> +
>         platform_set_drvdata(pdev, priv);
>
>         ret = devm_snd_soc_register_component(dev,
> &i2s_rx_component_driver,
> --
> 2.29.2.729.g45daf8777d-goog
>
>