[alsa-devel] [PATCH v3] drm: bridge/dw_hdmi: add audio sample channel status setting

[Neil Armstrong]

On 11/09/2019 10:26, Cheng-Yi Chiang wrote:
> From: Yakir Yang <ykk at rock-chips.com>
> 
> When transmitting IEC60985 linear PCM audio, we configure the
> Aduio Sample Channel Status information in the IEC60958 frame.
> The status bit is already available in iec.status of hdmi_codec_params.
> 
> This fix the issue that audio does not come out on some monitors
> (e.g. LG 22CV241)
> 
> Note that these registers are only for interfaces:
> I2S audio interface, General Purpose Audio (GPA), or AHB audio DMA
> (AHBAUDDMA).
> For S/PDIF interface this information comes from the stream.
> 
> Currently this function dw_hdmi_set_channel_status is only called
> from dw-hdmi-i2s-audio in I2S setup.
> 
> Signed-off-by: Yakir Yang <ykk at rock-chips.com>
> Signed-off-by: Cheng-Yi Chiang <cychiang at chromium.org>
> ---
> 
> Change from v2 to v3:
> 1. Reuse what is already set in iec.status in hw_param.
> 2. Remove all useless definition of registers and values.
> 3. Note that the original sampling frequency is not written to
>    the channel status as we reuse create_iec958_consumer in pcm_iec958.c.
>    Without that it can still play audio fine.
> 
>  .../drm/bridge/synopsys/dw-hdmi-i2s-audio.c   |  1 +
>  drivers/gpu/drm/bridge/synopsys/dw-hdmi.c     | 20 +++++++++++++++++++
>  drivers/gpu/drm/bridge/synopsys/dw-hdmi.h     |  2 ++
>  include/drm/bridge/dw_hdmi.h                  |  1 +
>  4 files changed, 24 insertions(+)
> 
> 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 34d8e837555f..20f4f92dd866 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-i2s-audio.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-i2s-audio.c
> @@ -102,6 +102,7 @@ static int dw_hdmi_i2s_hw_params(struct device *dev, void *data,
>  	}
>  
>  	dw_hdmi_set_sample_rate(hdmi, hparms->sample_rate);
> +	dw_hdmi_set_channel_status(hdmi, hparms->iec.status);
>  	dw_hdmi_set_channel_count(hdmi, hparms->channels);
>  	dw_hdmi_set_channel_allocation(hdmi, hparms->cea.channel_allocation);
>  
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> index bd65d0479683..aa7efd4da1c8 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> @@ -582,6 +582,26 @@ static unsigned int hdmi_compute_n(unsigned int freq, unsigned long pixel_clk)
>  	return n;
>  }
>  
> +/*
> + * When transmitting IEC60958 linear PCM audio, these registers allow to
> + * configure the channel status information of all the channel status
> + * bits in the IEC60958 frame. For the moment this configuration is only
> + * used when the I2S audio interface, General Purpose Audio (GPA),
> + * or AHB audio DMA (AHBAUDDMA) interface is active
> + * (for S/PDIF interface this information comes from the stream).
> + */
> +void dw_hdmi_set_channel_status(struct dw_hdmi *hdmi,
> +				u8 *channel_status)
> +{
> +	/*
> +	 * Set channel status register for frequency and word length.
> +	 * Use default values for other registers.
> +	 */
> +	hdmi_writeb(hdmi, channel_status[3], HDMI_FC_AUDSCHNLS7);
> +	hdmi_writeb(hdmi, channel_status[4], HDMI_FC_AUDSCHNLS8);
> +}
> +EXPORT_SYMBOL_GPL(dw_hdmi_set_channel_status);
> +
>  static void hdmi_set_clk_regenerator(struct dw_hdmi *hdmi,
>  	unsigned long pixel_clk, unsigned int sample_rate)
>  {
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.h b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.h
> index 6988f12d89d9..fcff5059db24 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.h
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.h
> @@ -158,6 +158,8 @@
>  #define HDMI_FC_SPDDEVICEINF                    0x1062
>  #define HDMI_FC_AUDSCONF                        0x1063
>  #define HDMI_FC_AUDSSTAT                        0x1064
> +#define HDMI_FC_AUDSCHNLS7                      0x106e
> +#define HDMI_FC_AUDSCHNLS8                      0x106f
>  #define HDMI_FC_DATACH0FILL                     0x1070
>  #define HDMI_FC_DATACH1FILL                     0x1071
>  #define HDMI_FC_DATACH2FILL                     0x1072
> diff --git a/include/drm/bridge/dw_hdmi.h b/include/drm/bridge/dw_hdmi.h
> index cf528c289857..4b3e863c4f8a 100644
> --- a/include/drm/bridge/dw_hdmi.h
> +++ b/include/drm/bridge/dw_hdmi.h
> @@ -156,6 +156,7 @@ void dw_hdmi_setup_rx_sense(struct dw_hdmi *hdmi, bool hpd, bool rx_sense);
>  
>  void dw_hdmi_set_sample_rate(struct dw_hdmi *hdmi, unsigned int rate);
>  void dw_hdmi_set_channel_count(struct dw_hdmi *hdmi, unsigned int cnt);
> +void dw_hdmi_set_channel_status(struct dw_hdmi *hdmi, u8 *channel_status);
>  void dw_hdmi_set_channel_allocation(struct dw_hdmi *hdmi, unsigned int ca);
>  void dw_hdmi_audio_enable(struct dw_hdmi *hdmi);
>  void dw_hdmi_audio_disable(struct dw_hdmi *hdmi);
> 

Looks fine for me:
Reviewed-by: Neil Armstrong <narmstrong at baylibre.com>

Jonas ? Jernej ? Russell ?

If it's ok for you I'll apply it.

Neil