[PATCH v2 2/3] drm/mediatek: support HDMI jack status reporting

[CK Hu]

Hi, Tzung-Bi:

On Thu, 2020-02-06 at 11:17 +0800, Tzung-Bi Shih wrote:
> 1.
> Provides a callback (i.e. mtk_hdmi_audio_hook_plugged_cb) to hdmi-codec.
> When ASoC machine driver calls hdmi_codec_set_jack_detect(), the
> callback will be invoked to save plugged_cb and codec_dev parameters.
> 
> +---------+  set_jack_  +------------+ plugged_cb  +----------+
> | machine | ----------> | hdmi-codec | ----------> | mtk-hdmi |
> +---------+  detect()   +------------+ codec_dev   +----------+
> 
> 2.
> When there is any jack status changes, mtk-hdmi will call the
> plugged_cb() to notify hdmi-codec.  And then hdmi-codec will call
> snd_soc_jack_report().
> 
> +----------+ plugged_cb  +------------+
> | mtk-hdmi | ----------> | hdmi-codec | -> snd_soc_jack_report()
> +----------+ codec_dev   +------------+
>              connector_status
> 
> Signed-off-by: Tzung-Bi Shih <tzungbi at google.com>
> ---
>  drivers/gpu/drm/mediatek/mtk_hdmi.c | 34 ++++++++++++++++++++++++++---
>  1 file changed, 31 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_hdmi.c b/drivers/gpu/drm/mediatek/mtk_hdmi.c
> index 23c2b0e8693d..fccdd975947d 100644
> --- a/drivers/gpu/drm/mediatek/mtk_hdmi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_hdmi.c
> @@ -169,6 +169,8 @@ struct mtk_hdmi {
>  	bool audio_enable;
>  	bool powered;
>  	bool enabled;
> +	hdmi_codec_plugged_cb plugged_cb;
> +	struct device *codec_dev;
>  };
>  
>  static inline struct mtk_hdmi *hdmi_ctx_from_bridge(struct drm_bridge *b)
> @@ -1194,13 +1196,23 @@ static void mtk_hdmi_clk_disable_audio(struct mtk_hdmi *hdmi)
>  	clk_disable_unprepare(hdmi->clk[MTK_HDMI_CLK_AUD_SPDIF]);
>  }
>  
> +static enum drm_connector_status
> +mtk_hdmi_update_plugged_status(struct mtk_hdmi *hdmi)
> +{
> +	bool connected = mtk_cec_hpd_high(hdmi->cec_dev);
> +
> +	if (hdmi->plugged_cb && hdmi->codec_dev)
> +		hdmi->plugged_cb(hdmi->codec_dev, connected);
> +
> +	return connected ?
> +	       connector_status_connected : connector_status_disconnected;
> +}
> +
>  static enum drm_connector_status hdmi_conn_detect(struct drm_connector *conn,
>  						  bool force)
>  {
>  	struct mtk_hdmi *hdmi = hdmi_ctx_from_conn(conn);
> -
> -	return mtk_cec_hpd_high(hdmi->cec_dev) ?
> -	       connector_status_connected : connector_status_disconnected;
> +	return mtk_hdmi_update_plugged_status(hdmi);
>  }
>  
>  static void hdmi_conn_destroy(struct drm_connector *conn)
> @@ -1648,20 +1660,36 @@ static int mtk_hdmi_audio_get_eld(struct device *dev, void *data, uint8_t *buf,
>  	return 0;
>  }
>  
> +static int mtk_hdmi_audio_hook_plugged_cb(struct device *dev, void *data,
> +					  hdmi_codec_plugged_cb fn,
> +					  struct device *codec_dev)
> +{
> +	struct mtk_hdmi *hdmi = data;
> +
> +	hdmi->plugged_cb = fn;
> +	hdmi->codec_dev = codec_dev;
> +	mtk_hdmi_update_plugged_status(hdmi);

I think hdmi_conn_detect() and mtk_hdmi_audio_hook_plugged_cb() would be
called in different thread. So it's necessary to use a mutex to protect
this.

Regards,
CK

> +
> +	return 0;
> +}
> +
>  static const struct hdmi_codec_ops mtk_hdmi_audio_codec_ops = {
>  	.hw_params = mtk_hdmi_audio_hw_params,
>  	.audio_startup = mtk_hdmi_audio_startup,
>  	.audio_shutdown = mtk_hdmi_audio_shutdown,
>  	.digital_mute = mtk_hdmi_audio_digital_mute,
>  	.get_eld = mtk_hdmi_audio_get_eld,
> +	.hook_plugged_cb = mtk_hdmi_audio_hook_plugged_cb,
>  };
>  
>  static int mtk_hdmi_register_audio_driver(struct device *dev)
>  {
> +	struct mtk_hdmi *hdmi = dev_get_drvdata(dev);
>  	struct hdmi_codec_pdata codec_data = {
>  		.ops = &mtk_hdmi_audio_codec_ops,
>  		.max_i2s_channels = 2,
>  		.i2s = 1,
> +		.data = hdmi,
>  	};
>  	struct platform_device *pdev;
>