Re: [alsa-devel] [PATCH 2/4] drm: bridge: dw-hdmi: Report connector status using callback

From: Jonas Karlman
Date: Fri Jul 05 2019 - 01:46:16 EST


On 2019-07-05 06:26, Cheng-Yi Chiang wrote:
> Allow codec driver register callback function for plug event.
>
> The callback registration flow:
> dw-hdmi <--- hw-hdmi-i2s-audio <--- hdmi-codec
>
> dw-hdmi-i2s-audio implements hook_plugged_cb op
> so codec driver can register the callback.
>
> dw-hdmi implements set_plugged_cb op so platform device can register the
> callback.
>
> When connector plug/unplug event happens, report this event using the
> callback.
>
> Make sure that audio and drm are using the single source of truth for
> connector status.

I have a similar notification need for making a snd_ctl_notify() call from hdmi-codec when ELD changes,
see [1] for work in progress patches (part of a dw-hdmi multi-channel lpcm series I am preparing).

Any suggestions on how to handle a ELD change notification?
Should I use a similar pattern as in this series?
(I lost track of the hdmi-notifier/drm_audio_component discussion)

[1] https://github.com/Kwiboo/linux-rockchip/compare/54b40fdd264c7ed96017271eb6524cca4ff755ab...9c17284e8a8657e8b1da53a1c7ff056cbd8ce43c

Best regards,
Jonas

>
> Signed-off-by: Cheng-Yi Chiang <cychiang@xxxxxxxxxxxx>
> ---
> .../gpu/drm/bridge/synopsys/dw-hdmi-audio.h | 3 ++
> .../drm/bridge/synopsys/dw-hdmi-i2s-audio.c | 10 ++++++
> drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 34 ++++++++++++++++++-
> 3 files changed, 46 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-audio.h b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-audio.h
> index 63b5756f463b..f523c590984e 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-audio.h
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-audio.h
> @@ -2,6 +2,8 @@
> #ifndef DW_HDMI_AUDIO_H
> #define DW_HDMI_AUDIO_H
>
> +#include <sound/hdmi-codec.h>
> +
> struct dw_hdmi;
>
> struct dw_hdmi_audio_data {
> @@ -17,6 +19,7 @@ struct dw_hdmi_i2s_audio_data {
>
> void (*write)(struct dw_hdmi *hdmi, u8 val, int offset);
> u8 (*read)(struct dw_hdmi *hdmi, int offset);
> + int (*set_plugged_cb)(struct dw_hdmi *hdmi, hdmi_codec_plugged_cb fn);
> };
>
> #endif
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-i2s-audio.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-i2s-audio.c
> index 5cbb71a866d5..7b93cf05c985 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-i2s-audio.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-i2s-audio.c
> @@ -104,10 +104,20 @@ static int dw_hdmi_i2s_get_dai_id(struct snd_soc_component *component,
> return -EINVAL;
> }
>
> +static int dw_hdmi_i2s_hook_plugged_cb(struct device *dev, void *data,
> + hdmi_codec_plugged_cb fn)
> +{
> + struct dw_hdmi_i2s_audio_data *audio = data;
> + struct dw_hdmi *hdmi = audio->hdmi;
> +
> + return audio->set_plugged_cb(hdmi, fn);
> +}
> +
> static struct hdmi_codec_ops dw_hdmi_i2s_ops = {
> .hw_params = dw_hdmi_i2s_hw_params,
> .audio_shutdown = dw_hdmi_i2s_audio_shutdown,
> .get_dai_id = dw_hdmi_i2s_get_dai_id,
> + .hook_plugged_cb = dw_hdmi_i2s_hook_plugged_cb,
> };
>
> static int snd_dw_hdmi_probe(struct platform_device *pdev)
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> index 045b1b13fd0e..c69a399fc7ca 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> @@ -26,6 +26,8 @@
> #include <drm/drm_probe_helper.h>
> #include <drm/bridge/dw_hdmi.h>
>
> +#include <sound/hdmi-codec.h>
> +
> #include <uapi/linux/media-bus-format.h>
> #include <uapi/linux/videodev2.h>
>
> @@ -185,6 +187,9 @@ struct dw_hdmi {
> void (*disable_audio)(struct dw_hdmi *hdmi);
>
> struct cec_notifier *cec_notifier;
> +
> + hdmi_codec_plugged_cb plugged_cb;
> + enum drm_connector_status last_connector_result;
> };
>
> #define HDMI_IH_PHY_STAT0_RX_SENSE \
> @@ -209,6 +214,17 @@ static inline u8 hdmi_readb(struct dw_hdmi *hdmi, int offset)
> return val;
> }
>
> +static int hdmi_set_plugged_cb(struct dw_hdmi *hdmi, hdmi_codec_plugged_cb fn)
> +{
> + mutex_lock(&hdmi->mutex);
> + hdmi->plugged_cb = fn;
> + if (hdmi->audio && !IS_ERR(hdmi->audio))
> + fn(hdmi->audio,
> + hdmi->last_connector_result == connector_status_connected);
> + mutex_unlock(&hdmi->mutex);
> + return 0;
> +}
> +
> static void hdmi_modb(struct dw_hdmi *hdmi, u8 data, u8 mask, unsigned reg)
> {
> regmap_update_bits(hdmi->regm, reg << hdmi->reg_shift, mask, data);
> @@ -2044,6 +2060,7 @@ dw_hdmi_connector_detect(struct drm_connector *connector, bool force)
> {
> struct dw_hdmi *hdmi = container_of(connector, struct dw_hdmi,
> connector);
> + enum drm_connector_status result;
>
> mutex_lock(&hdmi->mutex);
> hdmi->force = DRM_FORCE_UNSPECIFIED;
> @@ -2051,7 +2068,20 @@ dw_hdmi_connector_detect(struct drm_connector *connector, bool force)
> dw_hdmi_update_phy_mask(hdmi);
> mutex_unlock(&hdmi->mutex);
>
> - return hdmi->phy.ops->read_hpd(hdmi, hdmi->phy.data);
> + result = hdmi->phy.ops->read_hpd(hdmi, hdmi->phy.data);
> +
> + mutex_lock(&hdmi->mutex);
> + if (result != hdmi->last_connector_result) {
> + dev_dbg(hdmi->dev, "read_hpd result: %d", result);
> + if (hdmi->plugged_cb && hdmi->audio && !IS_ERR(hdmi->audio)) {
> + hdmi->plugged_cb(hdmi->audio,
> + result == connector_status_connected);
> + hdmi->last_connector_result = result;
> + }
> + }
> + mutex_unlock(&hdmi->mutex);
> +
> + return result;
> }
>
> static int dw_hdmi_connector_get_modes(struct drm_connector *connector)
> @@ -2460,6 +2490,7 @@ __dw_hdmi_probe(struct platform_device *pdev,
> hdmi->rxsense = true;
> hdmi->phy_mask = (u8)~(HDMI_PHY_HPD | HDMI_PHY_RX_SENSE);
> hdmi->mc_clkdis = 0x7f;
> + hdmi->last_connector_result = connector_status_disconnected;
>
> mutex_init(&hdmi->mutex);
> mutex_init(&hdmi->audio_mutex);
> @@ -2653,6 +2684,7 @@ __dw_hdmi_probe(struct platform_device *pdev,
> audio.hdmi = hdmi;
> audio.write = hdmi_writeb;
> audio.read = hdmi_readb;
> + audio.set_plugged_cb = hdmi_set_plugged_cb;
> hdmi->enable_audio = dw_hdmi_i2s_audio_enable;
> hdmi->disable_audio = dw_hdmi_i2s_audio_disable;
>