Re: [RFC PATCH] drm: msm: Add ASoC generic hdmi audio codec support.

[Jyri Sarha <jsarha@ti.com>]

On 06/03/16 16:56, Srinivas Kandagatla wrote:
> This patch adds support to generic audio codec via
> ASoC hdmi-codec infrastucture which is merged recently.
> 

I know nothing about msm HW, but from the hdmi-codec point of view this
looks like a correct usage. However, the hdmi-codec could probably do
more to connect the hdmi audio infoframe's channel allocation field and
ALSA's channel mapping API together.

There looks to be a bug in selecting 44100 sample rate bellow.

BR,
Jyri

> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
> ---
>  drivers/gpu/drm/msm/Kconfig     |   1 +
>  drivers/gpu/drm/msm/hdmi/hdmi.c | 120 +++++++++++++++++++++++++++++++++++++++-
>  drivers/gpu/drm/msm/hdmi/hdmi.h |  14 +++++
>  3 files changed, 134 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/msm/Kconfig b/drivers/gpu/drm/msm/Kconfig
> index 167a497..7c7a031 100644
> --- a/drivers/gpu/drm/msm/Kconfig
> +++ b/drivers/gpu/drm/msm/Kconfig
> @@ -10,6 +10,7 @@ config DRM_MSM
>  	select SHMEM
>  	select TMPFS
>  	select QCOM_SCM
> +	select SND_SOC_HDMI_CODEC if SND_SOC
>  	default y
>  	help
>  	  DRM/KMS driver for MSM/snapdragon.
> diff --git a/drivers/gpu/drm/msm/hdmi/hdmi.c b/drivers/gpu/drm/msm/hdmi/hdmi.c
> index 51b9ea5..3281496 100644
> --- a/drivers/gpu/drm/msm/hdmi/hdmi.c
> +++ b/drivers/gpu/drm/msm/hdmi/hdmi.c
> @@ -19,6 +19,7 @@
>  #include <linux/of_irq.h>
>  #include <linux/of_gpio.h>
>  
> +#include <sound/hdmi-codec.h>
>  #include "hdmi.h"
>  
>  void msm_hdmi_set_mode(struct hdmi *hdmi, bool power_on)
> @@ -434,6 +435,114 @@ static int msm_hdmi_get_gpio(struct device_node *of_node, const char *name)
>  	return gpio;
>  }
>  
> +/*
> + * HDMI audio codec callbacks
> + */
> +static int msm_hdmi_audio_hw_params(struct device *dev,
> +				    struct hdmi_codec_daifmt *daifmt,
> +				    struct hdmi_codec_params *params)
> +{
> +	struct hdmi *hdmi = dev_get_drvdata(dev);
> +	unsigned int chan;
> +	unsigned int channel_allocation = 0;
> +	unsigned int rate;
> +	unsigned int level_shift  = 0; /* 0dB */
> +	bool down_mix = false;
> +
> +	dev_dbg(dev, "%u Hz, %d bit, %d channels\n", params->sample_rate,
> +		 params->sample_width, params->cea.channels);
> +
> +	switch (params->cea.channels) {
> +	case 2:
> +		/* FR and FL speakers */
> +		channel_allocation  = 0;
> +		chan = MSM_HDMI_AUDIO_CHANNEL_2;
> +		break;
> +	case 4:
> +		/* FC, LFE, FR and FL speakers */
> +		channel_allocation  = 0x3;
> +		chan = MSM_HDMI_AUDIO_CHANNEL_4;
> +		break;
> +	case 6:
> +		/* RR, RL, FC, LFE, FR and FL speakers */
> +		channel_allocation  = 0x0B;
> +		chan = MSM_HDMI_AUDIO_CHANNEL_6;
> +		break;
> +	case 8:
> +		/* FRC, FLC, RR, RL, FC, LFE, FR and FL speakers */
> +		channel_allocation  = 0x1F; 
> +		chan = MSM_HDMI_AUDIO_CHANNEL_8;
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	switch (params->sample_rate) {
> +	case 32000:
> +		rate = HDMI_SAMPLE_RATE_32KHZ;
> +		break;
> +	case 44100:
> +		rate = HDMI_SAMPLE_RATE_48KHZ;
> +		break;

This looks like a bug...

> +	case 48000:
> +		rate = HDMI_SAMPLE_RATE_48KHZ;
> +		break;
> +	case 88200:
> +		rate = HDMI_SAMPLE_RATE_88_2KHZ;
> +		break;
> +	case 96000:
> +		rate = HDMI_SAMPLE_RATE_96KHZ;
> +		break;
> +	case 176400:
> +		rate = HDMI_SAMPLE_RATE_176_4KHZ;
> +		break;
> +	case 192000:
> +		rate = HDMI_SAMPLE_RATE_192KHZ;
> +		break;
> +	default:
> +		dev_err(dev, "rate[%d] not supported!\n",
> +			params->sample_rate);
> +		return -EINVAL;
> +	}
> +
> +	msm_hdmi_audio_set_sample_rate(hdmi, rate);
> +	msm_hdmi_audio_info_setup(hdmi, 1, chan, channel_allocation,
> +			      level_shift, down_mix);
> +
> +	return 0;
> +}
> +
> +static void msm_hdmi_audio_shutdown(struct device *dev)
> +{
> +	struct hdmi *hdmi = dev_get_drvdata(dev);
> +
> +	msm_hdmi_audio_info_setup(hdmi, 0, 0, 0, 0, 0);
> +}
> +
> +static const struct hdmi_codec_ops msm_hdmi_audio_codec_ops = {
> +	.hw_params = msm_hdmi_audio_hw_params, 
> +	.audio_shutdown = msm_hdmi_audio_shutdown,
> +};
> +
> +static struct hdmi_codec_pdata codec_data = {
> +	.ops = &msm_hdmi_audio_codec_ops,
> +	.max_i2s_channels = 8,
> +	.i2s = 1,
> +};
> +
> +static int msm_hdmi_register_audio_driver(struct hdmi *hdmi, struct device *dev)
> +{
> +	hdmi->audio_pdev = platform_device_register_data(dev,
> +							 HDMI_CODEC_DRV_NAME,
> +							 PLATFORM_DEVID_AUTO,
> +							 &codec_data,
> +							 sizeof(codec_data));
> +	if (IS_ERR(hdmi->audio_pdev))
> +		return PTR_ERR(hdmi->audio_pdev);
> +
> +	return 0;
> +}
> +
>  static int msm_hdmi_bind(struct device *dev, struct device *master, void *data)
>  {
>  	struct drm_device *drm = dev_get_drvdata(master);
> @@ -441,7 +550,7 @@ static int msm_hdmi_bind(struct device *dev, struct device *master, void *data)
>  	static struct hdmi_platform_config *hdmi_cfg;
>  	struct hdmi *hdmi;
>  	struct device_node *of_node = dev->of_node;
> -	int i;
> +	int i, err;
>  
>  	hdmi_cfg = (struct hdmi_platform_config *)
>  			of_device_get_match_data(dev);
> @@ -468,6 +577,12 @@ static int msm_hdmi_bind(struct device *dev, struct device *master, void *data)
>  		return PTR_ERR(hdmi);
>  	priv->hdmi = hdmi;
>  
> +	err = msm_hdmi_register_audio_driver(hdmi, dev);
> +	if (err) {
> +		DRM_ERROR("Failed to attach an audio codec %d\n", err);
> +		hdmi->audio_pdev = NULL;
> +	}
> +
>  	return 0;
>  }
>  
> @@ -477,6 +592,9 @@ static void msm_hdmi_unbind(struct device *dev, struct device *master,
>  	struct drm_device *drm = dev_get_drvdata(master);
>  	struct msm_drm_private *priv = drm->dev_private;
>  	if (priv->hdmi) {
> +		if (priv->hdmi->audio_pdev)
> +			platform_device_unregister(priv->hdmi->audio_pdev);
> +
>  		msm_hdmi_destroy(priv->hdmi);
>  		priv->hdmi = NULL;
>  	}
> diff --git a/drivers/gpu/drm/msm/hdmi/hdmi.h b/drivers/gpu/drm/msm/hdmi/hdmi.h
> index bc7ba0b..accc9a6 100644
> --- a/drivers/gpu/drm/msm/hdmi/hdmi.h
> +++ b/drivers/gpu/drm/msm/hdmi/hdmi.h
> @@ -50,6 +50,7 @@ struct hdmi_hdcp_ctrl;
>  struct hdmi {
>  	struct drm_device *dev;
>  	struct platform_device *pdev;
> +	struct platform_device *audio_pdev;
>  
>  	const struct hdmi_platform_config *config;
>  
> @@ -210,6 +211,19 @@ static inline int msm_hdmi_pll_8996_init(struct platform_device *pdev)
>  /*
>   * audio:
>   */
> +/* Supported HDMI Audio channels and rates */
> +#define	MSM_HDMI_AUDIO_CHANNEL_2	0
> +#define	MSM_HDMI_AUDIO_CHANNEL_4	1
> +#define	MSM_HDMI_AUDIO_CHANNEL_6	2
> +#define	MSM_HDMI_AUDIO_CHANNEL_8	3
> +
> +#define	HDMI_SAMPLE_RATE_32KHZ		0
> +#define	HDMI_SAMPLE_RATE_44_1KHZ	1
> +#define	HDMI_SAMPLE_RATE_48KHZ		2
> +#define	HDMI_SAMPLE_RATE_88_2KHZ	3
> +#define	HDMI_SAMPLE_RATE_96KHZ		4
> +#define	HDMI_SAMPLE_RATE_176_4KHZ	5
> +#define	HDMI_SAMPLE_RATE_192KHZ		6
>  
>  int msm_hdmi_audio_update(struct hdmi *hdmi);
>  int msm_hdmi_audio_info_setup(struct hdmi *hdmi, bool enabled,
>