[alsa-devel] [PATCH v5 6/6] drm/bridge: sii902x: Implement HDMI audio support

Andrzej Hajda a.hajda at samsung.com
Fri Apr 12 14:30:34 CEST 2019


On 12.04.2019 13:53, Jyri Sarha wrote:
> On 12/04/2019 11:52, Andrzej Hajda wrote:
>> On 22.03.2019 09:06, Jyri Sarha wrote:
>>> Implement HDMI audio support by using ASoC HDMI codec. The commit
>>> implements the necessary callbacks and configuration for the HDMI
>>> codec and registers a virtual platform device for the codec to attach.
>>>
>>> Signed-off-by: Jyri Sarha <jsarha at ti.com>
>>> ---
>>>  drivers/gpu/drm/bridge/sii902x.c | 459 ++++++++++++++++++++++++++++++-
>>>  1 file changed, 453 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/bridge/sii902x.c b/drivers/gpu/drm/bridge/sii902x.c
>>> index 358cf81c5ea4..cb12e264111d 100644
>>> --- a/drivers/gpu/drm/bridge/sii902x.c
>>> +++ b/drivers/gpu/drm/bridge/sii902x.c
>>> @@ -27,12 +27,15 @@
>>>  #include <linux/i2c.h>
>>>  #include <linux/module.h>
>>>  #include <linux/regmap.h>
>>> +#include <linux/clk.h>
>>>  
>>>  #include <drm/drmP.h>
>>>  #include <drm/drm_atomic_helper.h>
>>>  #include <drm/drm_crtc_helper.h>
>>>  #include <drm/drm_edid.h>
>>>  
>>> +#include <sound/hdmi-codec.h>
>>> +
>>>  #define SII902X_TPI_VIDEO_DATA			0x0
>>>  
>>>  #define SII902X_TPI_PIXEL_REPETITION		0x8
>>> @@ -74,6 +77,77 @@
>>>  #define SII902X_AVI_POWER_STATE_MSK		GENMASK(1, 0)
>>>  #define SII902X_AVI_POWER_STATE_D(l)		((l) & SII902X_AVI_POWER_STATE_MSK)
>>>  
>>> +/* Audio  */
>>> +#define SII902X_TPI_I2S_ENABLE_MAPPING_REG	0x1f
>>> +#define SII902X_TPI_I2S_CONFIG_FIFO0			(0 << 0)
>>> +#define SII902X_TPI_I2S_CONFIG_FIFO1			(1 << 0)
>>> +#define SII902X_TPI_I2S_CONFIG_FIFO2			(2 << 0)
>>> +#define SII902X_TPI_I2S_CONFIG_FIFO3			(3 << 0)
>>> +#define SII902X_TPI_I2S_LEFT_RIGHT_SWAP			(1 << 2)
>>> +#define SII902X_TPI_I2S_AUTO_DOWNSAMPLE			(1 << 3)
>>> +#define SII902X_TPI_I2S_SELECT_SD0			(0 << 4)
>>> +#define SII902X_TPI_I2S_SELECT_SD1			(1 << 4)
>>> +#define SII902X_TPI_I2S_SELECT_SD2			(2 << 4)
>>> +#define SII902X_TPI_I2S_SELECT_SD3			(3 << 4)
>>> +#define SII902X_TPI_I2S_FIFO_ENABLE			(1 << 7)
>>> +
>>> +#define SII902X_TPI_I2S_INPUT_CONFIG_REG	0x20
>>> +#define SII902X_TPI_I2S_FIRST_BIT_SHIFT_YES		(0 << 0)
>>> +#define SII902X_TPI_I2S_FIRST_BIT_SHIFT_NO		(1 << 0)
>>> +#define SII902X_TPI_I2S_SD_DIRECTION_MSB_FIRST		(0 << 1)
>>> +#define SII902X_TPI_I2S_SD_DIRECTION_LSB_FIRST		(1 << 1)
>>> +#define SII902X_TPI_I2S_SD_JUSTIFY_LEFT			(0 << 2)
>>> +#define SII902X_TPI_I2S_SD_JUSTIFY_RIGHT		(1 << 2)
>>> +#define SII902X_TPI_I2S_WS_POLARITY_LOW			(0 << 3)
>>> +#define SII902X_TPI_I2S_WS_POLARITY_HIGH		(1 << 3)
>>> +#define SII902X_TPI_I2S_MCLK_MULTIPLIER_128		(0 << 4)
>>> +#define SII902X_TPI_I2S_MCLK_MULTIPLIER_256		(1 << 4)
>>> +#define SII902X_TPI_I2S_MCLK_MULTIPLIER_384		(2 << 4)
>>> +#define SII902X_TPI_I2S_MCLK_MULTIPLIER_512		(3 << 4)
>>> +#define SII902X_TPI_I2S_MCLK_MULTIPLIER_768		(4 << 4)
>>> +#define SII902X_TPI_I2S_MCLK_MULTIPLIER_1024		(5 << 4)
>>> +#define SII902X_TPI_I2S_MCLK_MULTIPLIER_1152		(6 << 4)
>>> +#define SII902X_TPI_I2S_MCLK_MULTIPLIER_192		(7 << 4)
>>> +#define SII902X_TPI_I2S_SCK_EDGE_FALLING		(0 << 7)
>>> +#define SII902X_TPI_I2S_SCK_EDGE_RISING			(1 << 7)
>>> +
>>> +#define SII902X_TPI_I2S_STRM_HDR_BASE	0x21
>>> +#define SII902X_TPI_I2S_STRM_HDR_SIZE	5
>>> +
>>> +#define SII902X_TPI_AUDIO_CONFIG_BYTE2_REG	0x26
>>> +#define SII902X_TPI_AUDIO_CODING_STREAM_HEADER		(0 << 0)
>>> +#define SII902X_TPI_AUDIO_CODING_PCM			(1 << 0)
>>> +#define SII902X_TPI_AUDIO_CODING_AC3			(2 << 0)
>>> +#define SII902X_TPI_AUDIO_CODING_MPEG1			(3 << 0)
>>> +#define SII902X_TPI_AUDIO_CODING_MP3			(4 << 0)
>>> +#define SII902X_TPI_AUDIO_CODING_MPEG2			(5 << 0)
>>> +#define SII902X_TPI_AUDIO_CODING_AAC			(6 << 0)
>>> +#define SII902X_TPI_AUDIO_CODING_DTS			(7 << 0)
>>> +#define SII902X_TPI_AUDIO_CODING_ATRAC			(8 << 0)
>>> +#define SII902X_TPI_AUDIO_MUTE_DISABLE			(0 << 4)
>>> +#define SII902X_TPI_AUDIO_MUTE_ENABLE			(1 << 4)
>>> +#define SII902X_TPI_AUDIO_LAYOUT_2_CHANNELS		(0 << 5)
>>> +#define SII902X_TPI_AUDIO_LAYOUT_8_CHANNELS		(1 << 5)
>>> +#define SII902X_TPI_AUDIO_INTERFACE_DISABLE		(0 << 6)
>>> +#define SII902X_TPI_AUDIO_INTERFACE_SPDIF		(1 << 6)
>>> +#define SII902X_TPI_AUDIO_INTERFACE_I2S			(2 << 6)
>>> +
>>> +#define SII902X_TPI_AUDIO_CONFIG_BYTE3_REG	0x27
>>> +#define SII902X_TPI_AUDIO_FREQ_STREAM			(0 << 3)
>>> +#define SII902X_TPI_AUDIO_FREQ_32KHZ			(1 << 3)
>>> +#define SII902X_TPI_AUDIO_FREQ_44KHZ			(2 << 3)
>>> +#define SII902X_TPI_AUDIO_FREQ_48KHZ			(3 << 3)
>>> +#define SII902X_TPI_AUDIO_FREQ_88KHZ			(4 << 3)
>>> +#define SII902X_TPI_AUDIO_FREQ_96KHZ			(5 << 3)
>>> +#define SII902X_TPI_AUDIO_FREQ_176KHZ			(6 << 3)
>>> +#define SII902X_TPI_AUDIO_FREQ_192KHZ			(7 << 3)
>>> +#define SII902X_TPI_AUDIO_SAMPLE_SIZE_STREAM		(0 << 6)
>>> +#define SII902X_TPI_AUDIO_SAMPLE_SIZE_16		(1 << 6)
>>> +#define SII902X_TPI_AUDIO_SAMPLE_SIZE_20		(2 << 6)
>>> +#define SII902X_TPI_AUDIO_SAMPLE_SIZE_24		(3 << 6)
>>> +
>>> +#define SII902X_TPI_AUDIO_CONFIG_BYTE4_REG	0x28
>>> +
>>>  #define SII902X_INT_ENABLE			0x3c
>>>  #define SII902X_INT_STATUS			0x3d
>>>  #define SII902X_HOTPLUG_EVENT			BIT(0)
>>> @@ -81,6 +155,16 @@
>>>  
>>>  #define SII902X_REG_TPI_RQB			0xc7
>>>  
>>> +/* Indirect internal register access */
>>> +#define SII902X_IND_SET_PAGE			0xbc
>>> +#define SII902X_IND_OFFSET			0xbd
>>> +#define SII902X_IND_VALUE			0xbe
>>> +
>>> +#define SII902X_TPI_MISC_INFOFRAME_BASE		0xbf
>>> +#define SII902X_TPI_MISC_INFOFRAME_END		0xde
>>> +#define SII902X_TPI_MISC_INFOFRAME_SIZE	\
>>> +	(SII902X_TPI_MISC_INFOFRAME_END - SII902X_TPI_MISC_INFOFRAME_BASE)
>>> +
>>>  #define SII902X_I2C_BUS_ACQUISITION_TIMEOUT_MS	500
>>>  
>>>  struct sii902x {
>>> @@ -90,6 +174,16 @@ struct sii902x {
>>>  	struct drm_connector connector;
>>>  	struct gpio_desc *reset_gpio;
>>>  	struct i2c_mux_core *i2cmux;
>>> +	/*
>>> +	 * Mutex protects audio and video functions from interfering
>>> +	 * each other, by keeping their i2c command sequences atomic.
>>> +	 */
>>> +	struct mutex mutex;
>>> +	struct sii902x_audio {
>>> +		struct platform_device *pdev;
>>> +		struct clk *mclk;
>>> +		u32 i2s_fifo_sequence[4];
>>> +	} audio;
>>>  };
>>>  
>>>  static int sii902x_read_unlocked(struct i2c_client *i2c, u8 reg, u8 *val)
>>> @@ -161,8 +255,12 @@ sii902x_connector_detect(struct drm_connector *connector, bool force)
>>>  	struct sii902x *sii902x = connector_to_sii902x(connector);
>>>  	unsigned int status;
>>>  
>>> +	mutex_lock(&sii902x->mutex);
>>> +
>>>  	regmap_read(sii902x->regmap, SII902X_INT_STATUS, &status);
>>>  
>>> +	mutex_unlock(&sii902x->mutex);
>>> +
>>
>> regmap uses its own lock so we have here and in other places redundant
>> locks.
>>
>> Probably you should disable regmap locking (config->disable_locking = 1).
>>
> Makes sense. I'll add that.
>
>>>  	return (status & SII902X_PLUGGED_STATUS) ?
>>>  	       connector_status_connected : connector_status_disconnected;
>>>  }
>>> @@ -184,6 +282,8 @@ static int sii902x_get_modes(struct drm_connector *connector)
>>>  	struct edid *edid;
>>>  	int num = 0, ret;
>>>  
>>> +	mutex_lock(&sii902x->mutex);
>>> +
>>>  	edid = drm_get_edid(connector, sii902x->i2cmux->adapter[0]);
>>>  	drm_connector_update_edid_property(connector, edid);
>>>  	if (edid) {
>>> @@ -197,14 +297,19 @@ static int sii902x_get_modes(struct drm_connector *connector)
>>>  	ret = drm_display_info_set_bus_formats(&connector->display_info,
>>>  					       &bus_format, 1);
>>>  	if (ret)
>>> -		return ret;
>>> +		goto error_out;
>>>  
>>>  	ret = regmap_update_bits(sii902x->regmap, SII902X_SYS_CTRL_DATA,
>>>  				 SII902X_SYS_CTRL_OUTPUT_MODE, output_mode);
>>>  	if (ret)
>>> -		return ret;
>>> +		goto error_out;
>>> +
>>> +	ret = num;
>>> +
>>> +error_out:
>>> +	mutex_unlock(&sii902x->mutex);
>>>  
>>> -	return num;
>>> +	return ret;
>>>  }
>>>  
>>>  static enum drm_mode_status sii902x_mode_valid(struct drm_connector *connector,
>>> @@ -224,20 +329,28 @@ static void sii902x_bridge_disable(struct drm_bridge *bridge)
>>>  {
>>>  	struct sii902x *sii902x = bridge_to_sii902x(bridge);
>>>  
>>> +	mutex_lock(&sii902x->mutex);
>>> +
>>>  	regmap_update_bits(sii902x->regmap, SII902X_SYS_CTRL_DATA,
>>>  			   SII902X_SYS_CTRL_PWR_DWN,
>>>  			   SII902X_SYS_CTRL_PWR_DWN);
>>> +
>>> +	mutex_unlock(&sii902x->mutex);
>>>  }
>>>  
>>>  static void sii902x_bridge_enable(struct drm_bridge *bridge)
>>>  {
>>>  	struct sii902x *sii902x = bridge_to_sii902x(bridge);
>>>  
>>> +	mutex_lock(&sii902x->mutex);
>>> +
>>>  	regmap_update_bits(sii902x->regmap, SII902X_PWR_STATE_CTRL,
>>>  			   SII902X_AVI_POWER_STATE_MSK,
>>>  			   SII902X_AVI_POWER_STATE_D(0));
>>>  	regmap_update_bits(sii902x->regmap, SII902X_SYS_CTRL_DATA,
>>>  			   SII902X_SYS_CTRL_PWR_DWN, 0);
>>> +
>>> +	mutex_unlock(&sii902x->mutex);
>>>  }
>>>  
>>>  static void sii902x_bridge_mode_set(struct drm_bridge *bridge,
>>> @@ -264,26 +377,31 @@ static void sii902x_bridge_mode_set(struct drm_bridge *bridge,
>>>  	buf[9] = SII902X_TPI_AVI_INPUT_RANGE_AUTO |
>>>  		 SII902X_TPI_AVI_INPUT_COLORSPACE_RGB;
>>>  
>>> +	mutex_lock(&sii902x->mutex);
>>> +
>>>  	ret = regmap_bulk_write(regmap, SII902X_TPI_VIDEO_DATA, buf, 10);
>>>  	if (ret)
>>> -		return;
>>> +		goto out;
>>>  
>>>  	ret = drm_hdmi_avi_infoframe_from_display_mode(&frame, adj, false);
>>>  	if (ret < 0) {
>>>  		DRM_ERROR("couldn't fill AVI infoframe\n");
>>> -		return;
>>> +		goto out;
>>>  	}
>>>  
>>>  	ret = hdmi_avi_infoframe_pack(&frame, buf, sizeof(buf));
>>>  	if (ret < 0) {
>>>  		DRM_ERROR("failed to pack AVI infoframe: %d\n", ret);
>>> -		return;
>>> +		goto out;
>>>  	}
>>>  
>>>  	/* Do not send the infoframe header, but keep the CRC field. */
>>>  	regmap_bulk_write(regmap, SII902X_TPI_AVI_INFOFRAME,
>>>  			  buf + HDMI_INFOFRAME_HEADER_SIZE - 1,
>>>  			  HDMI_AVI_INFOFRAME_SIZE + 1);
>>> +
>>> +out:
>>> +	mutex_unlock(&sii902x->mutex);
>>>  }
>>>  
>>>  static int sii902x_bridge_attach(struct drm_bridge *bridge)
>>> @@ -324,6 +442,330 @@ static const struct drm_bridge_funcs sii902x_bridge_funcs = {
>>>  	.enable = sii902x_bridge_enable,
>>>  };
>>>  
>>> +static int sii902x_mute(struct sii902x *sii902x, bool mute)
>>> +{
>>> +	struct device *dev = &sii902x->i2c->dev;
>>> +	unsigned int val = mute ? SII902X_TPI_AUDIO_MUTE_ENABLE :
>>> +		SII902X_TPI_AUDIO_MUTE_DISABLE;
>>> +
>>> +	dev_dbg(dev, "%s: %s\n", __func__, mute ? "Muted" : "Unmuted");
>>> +
>>> +	return regmap_update_bits(sii902x->regmap,
>>> +				  SII902X_TPI_AUDIO_CONFIG_BYTE2_REG,
>>> +				  SII902X_TPI_AUDIO_MUTE_ENABLE, val);
>>> +}
>>> +
>>> +static const unsigned int sii902x_mclk_div_table[] = {
>>> +	128, 256, 384, 512, 768, 1024, 1152, 192 };
>>> +
>>> +static int sii902x_select_mclk_div(u8 *i2s_config_reg, unsigned int rate,
>>> +				   unsigned int mclk)
>>> +{
>>> +	unsigned int div = mclk / rate;
>>> +	int distance = 100000;
>>> +	u8 i, nearest = 0;
>>> +
>>> +	for (i = 0; i < ARRAY_SIZE(sii902x_mclk_div_table); i++) {
>>> +		unsigned int d = abs(div - sii902x_mclk_div_table[i]);
>>
>> Using unsigned types in this context seems to be asking for troubles.
>>
> Why? Isn't return value of abs() by definition unsigned? Using signed
> integers when comparing absolute distances would seem awkward to me.


(div - sii902x_mclk_div_table[i]) is unsigned, if div is lower, there is overflow, and the value is big int, I suppose this is not what you want.


>
>>> +
>>> +		if (d >= distance)
>>> +			continue;
>>> +
>>> +		nearest = i;
>>> +		distance = d;
>>> +		if (d == 0)
>>> +			break;
>>> +	}
>>> +
>>> +	*i2s_config_reg |= nearest << 4;
>>> +
>>> +	if (distance != 0)
>>> +		return sii902x_mclk_div_table[nearest];
>>> +
>>> +	return 0;
>>
>> ret value is inconsistent, 0 in case of exact match, closest value
>> otherwise, code will be cleaner if you return always closest match.
>>
> Then I do not have the information to print a warning if an exact match
> was not found. The return value is only used in that warning message,
> the register configuration value is always delivered trough
> *i2s_config_reg. I do not see any inconsistency here.

You have it:

+    ret = sii902x_select_mclk_div(&i2s_config_reg, params->sample_rate,
+                      mclk_rate);
+    if (mclk_rate / ret != params->sample_rate)
+        dev_dbg(dev, "Inaccurate reference clock (%ld/%d != %u)\n",
+            mclk_rate, ret, params->sample_rate);
+

or to avoid division: if (mclk_rate != ret * params->sample_rate) ...


But this is not something I would die for, it just hurts my teeth :)


>
>>> +}
>>> +
>>> +static const struct sii902x_sample_freq {
>>> +	u32 freq;
>>> +	u8 val;
>>> +} sii902x_sample_freq[] = {
>>> +	{ .freq = 32000,	.val = SII902X_TPI_AUDIO_FREQ_32KHZ },
>>> +	{ .freq = 44000,	.val = SII902X_TPI_AUDIO_FREQ_44KHZ },
>>> +	{ .freq = 48000,	.val = SII902X_TPI_AUDIO_FREQ_48KHZ },
>>> +	{ .freq = 88000,	.val = SII902X_TPI_AUDIO_FREQ_88KHZ },
>>> +	{ .freq = 96000,	.val = SII902X_TPI_AUDIO_FREQ_96KHZ },
>>> +	{ .freq = 176000,	.val = SII902X_TPI_AUDIO_FREQ_176KHZ },
>>> +	{ .freq = 192000,	.val = SII902X_TPI_AUDIO_FREQ_192KHZ },
>>> +};
>>> +
>>> +static int sii902x_audio_hw_params(struct device *dev, void *data,
>>> +				   struct hdmi_codec_daifmt *daifmt,
>>> +				   struct hdmi_codec_params *params)
>>> +{
>>> +	struct sii902x *sii902x = dev_get_drvdata(dev);
>>> +	u8 i2s_config_reg = SII902X_TPI_I2S_SD_DIRECTION_MSB_FIRST;
>>> +	u8 config_byte2_reg = (SII902X_TPI_AUDIO_INTERFACE_I2S |
>>> +			       SII902X_TPI_AUDIO_MUTE_ENABLE |
>>> +			       SII902X_TPI_AUDIO_CODING_PCM);
>>> +	u8 config_byte3_reg = 0;
>>> +	u8 infoframe_buf[HDMI_INFOFRAME_SIZE(AUDIO)];
>>> +	unsigned long mclk_rate;
>>> +	int i, ret;
>>> +
>>> +	if (daifmt->bit_clk_master || daifmt->frame_clk_master) {
>>> +		dev_dbg(dev, "%s: I2S master mode not supported\n", __func__);
>>> +		return -EINVAL;
>>> +	}
>>> +
>>> +	switch (daifmt->fmt) {
>>> +	case HDMI_I2S:
>>> +		i2s_config_reg |= SII902X_TPI_I2S_FIRST_BIT_SHIFT_YES |
>>> +			SII902X_TPI_I2S_SD_JUSTIFY_LEFT;
>>> +		break;
>>> +	case HDMI_RIGHT_J:
>>> +		i2s_config_reg |= SII902X_TPI_I2S_SD_JUSTIFY_RIGHT;
>>> +		break;
>>> +	case HDMI_LEFT_J:
>>> +		i2s_config_reg |= SII902X_TPI_I2S_SD_JUSTIFY_LEFT;
>>> +		break;
>>> +	default:
>>> +		dev_dbg(dev, "%s: Unsupported i2s format %u\n", __func__,
>>> +			daifmt->fmt);
>>> +		return -EINVAL;
>>> +	}
>>> +
>>> +	if (daifmt->bit_clk_inv)
>>> +		i2s_config_reg |= SII902X_TPI_I2S_SCK_EDGE_FALLING;
>>> +	else
>>> +		i2s_config_reg |= SII902X_TPI_I2S_SCK_EDGE_RISING;
>>> +
>>> +	if (daifmt->frame_clk_inv)
>>> +		i2s_config_reg |= SII902X_TPI_I2S_WS_POLARITY_LOW;
>>> +	else
>>> +		i2s_config_reg |= SII902X_TPI_I2S_WS_POLARITY_HIGH;
>>> +
>>> +	if (params->channels > 2)
>>> +		config_byte2_reg |= SII902X_TPI_AUDIO_LAYOUT_8_CHANNELS;
>>> +	else
>>> +		config_byte2_reg |= SII902X_TPI_AUDIO_LAYOUT_2_CHANNELS;
>>> +
>>> +	switch (params->sample_width) {
>>> +	case 16:
>>> +		config_byte3_reg |= SII902X_TPI_AUDIO_SAMPLE_SIZE_16;
>>> +		break;
>>> +	case 20:
>>> +		config_byte3_reg |= SII902X_TPI_AUDIO_SAMPLE_SIZE_20;
>>> +		break;
>>> +	case 24:
>>> +	case 32:
>>> +		config_byte3_reg |= SII902X_TPI_AUDIO_SAMPLE_SIZE_24;
>>> +		break;
>>> +	default:
>>> +		dev_err(dev, "%s: Unsupported sample width %u\n", __func__,
>>> +			params->sample_width);
>>> +		return -EINVAL;
>>> +	}
>>> +
>>> +	for (i = 0; i < ARRAY_SIZE(sii902x_sample_freq); i++) {
>>> +		if (params->sample_rate == sii902x_sample_freq[i].freq) {
>>> +			config_byte3_reg |= sii902x_sample_freq[i].val;
>>> +			break;
>>> +		}
>>> +	}
>>> +
>>> +	ret = clk_prepare_enable(sii902x->audio.mclk);
>>> +	if (ret) {
>>> +		dev_err(dev, "Enabling mclk failed: %d\n", ret);
>>> +		return ret;
>>> +	}
>>> +
>>> +	mclk_rate = clk_get_rate(sii902x->audio.mclk);
>>> +
>>> +	ret = sii902x_select_mclk_div(&i2s_config_reg, params->sample_rate,
>>> +				      mclk_rate);
>>> +	if (ret)
>>> +		dev_dbg(dev, "Inaccurate reference clock (%ld/%d != %u)\n",
>>> +			mclk_rate, ret, params->sample_rate);
>>> +
>>> +	mutex_lock(&sii902x->mutex);
>>> +
>>> +	ret = regmap_write(sii902x->regmap,
>>> +			   SII902X_TPI_AUDIO_CONFIG_BYTE2_REG,
>>> +			   config_byte2_reg);
>>> +	if (ret < 0)
>>> +		goto out;
>>> +
>>> +	ret = regmap_write(sii902x->regmap, SII902X_TPI_I2S_INPUT_CONFIG_REG,
>>> +			   i2s_config_reg);
>>> +	if (ret)
>>> +		goto out;
>>> +
>>> +	for (i = 0; sii902x->audio.i2s_fifo_sequence[i] &&
>>> +		     i < ARRAY_SIZE(sii902x->audio.i2s_fifo_sequence); i++)
>>> +		regmap_write(sii902x->regmap,
>>> +			     SII902X_TPI_I2S_ENABLE_MAPPING_REG,
>>> +			     sii902x->audio.i2s_fifo_sequence[i]);
>>> +
>>> +	ret = regmap_write(sii902x->regmap, SII902X_TPI_AUDIO_CONFIG_BYTE3_REG,
>>> +			   config_byte3_reg);
>>> +	if (ret)
>>> +		goto out;
>>> +
>>> +	ret = regmap_bulk_write(sii902x->regmap, SII902X_TPI_I2S_STRM_HDR_BASE,
>>> +				params->iec.status,
>>> +				min((size_t) SII902X_TPI_I2S_STRM_HDR_SIZE,
>>> +				    sizeof(params->iec.status)));
>>> +	if (ret)
>>> +		goto out;
>>> +
>>> +	ret = hdmi_audio_infoframe_pack(&params->cea, infoframe_buf,
>>> +					sizeof(infoframe_buf));
>>> +	if (ret < 0) {
>>> +		dev_err(dev, "%s: Failed to pack audio infoframe: %d\n",
>>> +			__func__, ret);
>>> +		goto out;
>>> +	}
>>> +
>>> +	ret = regmap_bulk_write(sii902x->regmap,
>>> +				SII902X_TPI_MISC_INFOFRAME_BASE,
>>> +				infoframe_buf,
>>> +				min(ret, SII902X_TPI_MISC_INFOFRAME_SIZE));
>>> +	if (ret)
>>> +		goto out;
>>> +
>>> +	/* Decode Level 0 Packets */
>>> +	ret = regmap_write(sii902x->regmap, SII902X_IND_SET_PAGE, 0x02);
>>> +	if (ret)
>>> +		goto out;
>>> +
>>> +	ret = regmap_write(sii902x->regmap, SII902X_IND_OFFSET, 0x24);
>>> +	if (ret)
>>> +		goto out;
>>> +
>>> +	ret = regmap_write(sii902x->regmap, SII902X_IND_VALUE, 0x02);
>>> +	if (ret)
>>> +		goto out;
>>> +
>>> +	dev_dbg(dev, "%s: hdmi audio enabled\n", __func__);
>>> +out:
>>> +	mutex_unlock(&sii902x->mutex);
>>> +
>>> +	if (ret) {
>>> +		clk_disable_unprepare(sii902x->audio.mclk);
>>> +		dev_err(dev, "%s: hdmi audio enable failed: %d\n", __func__,
>>> +			ret);
>>> +	}
>>> +
>>> +	return ret;
>>> +}
>>> +
>>> +static void sii902x_audio_shutdown(struct device *dev, void *data)
>>> +{
>>> +	struct sii902x *sii902x = dev_get_drvdata(dev);
>>> +
>>> +	mutex_lock(&sii902x->mutex);
>>> +
>>> +	regmap_write(sii902x->regmap, SII902X_TPI_AUDIO_CONFIG_BYTE2_REG,
>>> +		     SII902X_TPI_AUDIO_INTERFACE_DISABLE);
>>> +
>>> +	mutex_unlock(&sii902x->mutex);
>>> +
>>> +	clk_disable_unprepare(sii902x->audio.mclk);
>>> +}
>>> +
>>> +int sii902x_audio_digital_mute(struct device *dev, void *data, bool enable)
>>> +{
>>> +	struct sii902x *sii902x = dev_get_drvdata(dev);
>>> +
>>> +	mutex_lock(&sii902x->mutex);
>>> +
>>> +	sii902x_mute(sii902x, enable);
>>> +
>>> +	mutex_unlock(&sii902x->mutex);
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static int sii902x_audio_get_eld(struct device *dev, void *data,
>>> +				 uint8_t *buf, size_t len)
>>> +{
>>> +	struct sii902x *sii902x = dev_get_drvdata(dev);
>>> +
>>> +	mutex_lock(&sii902x->mutex);
>>> +
>>> +	memcpy(buf, sii902x->connector.eld,
>>> +	       min(sizeof(sii902x->connector.eld), len));
>>
>> I am not familiar with audio stuff, so forgive my ignorance :)
>>
>> What happens when this or other audio callbacks is called:
>>
>> 1. before sth is plugged in connector.
>>> 2. after unplug.
>> 3. plug/un-plug happens between these calls.
>>
> The audio side calls this at the time of audio playback request. If
> there is no valid eld at that time, the playback request fails. The eld
> is only used at the playback start time, never after it.
>
> When an audio playback is running it we do not do anything to until the
> playback is stopped. E.g. if plug/un-plug happens we just keep playing
> with the original configuration (my first version had an abort call back
> to abort playback in unplug event, but that was refused in the reviews).
>
> If the cable is never plugged again, or the new display does not have
> audio support, the i2s just keeps banging the bits to dev null and audio
> data keeps drainging away. When cable is again plugged to audio capable
> display, it continues playing there (and it never stopped in between.
>
> This comes closest to already established behaviour with already
> existing HDMI audio implementations. This is also usually the preferred
> behavior, because resebles how video stream playback behaves.
>
> I know very well that this is not the perfect solution. The perfect
> solution would have the abort callback there, and some mechanism above
> that to deal with the audio playback being aborted and the device
> becoming available again. This would require co-operation from
> userspace. However, the world is not ready and this is a best effort
> implementation.


OK, thanks for explanation.


>
>> Also I do not see hotplug/unplug notification mechanism to audio
>> subsystem. It looks suspicious.
>>
> Yes, as mentioned above, I had it in my first version of hdmi-codec, but
> it was never accepted to mainline. However, in practice this has not
> been a problem. The HDMI audio implementation on the encoder chips I
> have seen is usually quite independent from the video side workings.
>
>> Regards
>>
>> Andrzej
>>
> Thanks,
> Jyri
>
>>
>>> +
>>> +	mutex_unlock(&sii902x->mutex);
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static const struct hdmi_codec_ops sii902x_audio_codec_ops = {
>>> +	.hw_params = sii902x_audio_hw_params,
>>> +	.audio_shutdown = sii902x_audio_shutdown,
>>> +	.digital_mute = sii902x_audio_digital_mute,
>>> +	.get_eld = sii902x_audio_get_eld,
>>> +};
>>> +
>>> +static int sii902x_audio_codec_init(struct sii902x *sii902x,
>>> +				    struct device *dev)
>>> +{
>>> +	static const u8 audio_fifo_id[] = {
>>> +		SII902X_TPI_I2S_CONFIG_FIFO0,
>>> +		SII902X_TPI_I2S_CONFIG_FIFO1,
>>> +		SII902X_TPI_I2S_CONFIG_FIFO2,
>>> +		SII902X_TPI_I2S_CONFIG_FIFO3,
>>> +	};
>>> +	static const u8 i2s_lane_id[] = {
>>> +		SII902X_TPI_I2S_SELECT_SD0,
>>> +		SII902X_TPI_I2S_SELECT_SD1,
>>> +		SII902X_TPI_I2S_SELECT_SD2,
>>> +		SII902X_TPI_I2S_SELECT_SD3,
>>> +	};
>>> +	struct hdmi_codec_pdata codec_data = {
>>> +		.ops = &sii902x_audio_codec_ops,
>>> +		.i2s = 1, /* Only i2s support for now. */
>>> +		.spdif = 0,
>>> +		.max_i2s_channels = 0,
>>> +	};
>>> +	u8 lanes[4];
>>> +	u32 num_lanes, i;
>>> +
>>> +	num_lanes = of_property_read_variable_u8_array(dev->of_node,
>>> +						       "sil,i2s-data-lanes",
>>> +						       lanes, 1,
>>> +						       ARRAY_SIZE(lanes));
>>> +	if (num_lanes < 0) {
>>> +		if (num_lanes == -EINVAL)
>>> +			dev_dbg(dev,
>>> +				"%s: No \"sil,i2s-data-lanes\", no audio\n",
>>> +				__func__);
>>> +		else
>>> +			dev_err(dev,
>>> +				"%s: Error gettin \"sil,i2s-data-lanes\": %d\n",
>>> +				__func__, num_lanes);
>>> +		return 0;
>>> +	}
>>> +	codec_data.max_i2s_channels = 2 * num_lanes;
>>> +
>>> +	for (i = 0; i < num_lanes; i++)
>>> +		sii902x->audio.i2s_fifo_sequence[i] |= audio_fifo_id[i] |
>>> +			i2s_lane_id[lanes[i]] |	SII902X_TPI_I2S_FIFO_ENABLE;
>>> +
>>> +	if (IS_ERR(sii902x->audio.mclk)) {
>>> +		dev_err(dev, "%s: No clock (audio mclk) found: %ld\n",
>>> +			__func__, PTR_ERR(sii902x->audio.mclk));
>>> +		return 0;
>>> +	}
>>> +
>>> +	sii902x->audio.pdev = platform_device_register_data(
>>> +		dev, HDMI_CODEC_DRV_NAME, PLATFORM_DEVID_AUTO,
>>> +		&codec_data, sizeof(codec_data));
>>> +
>>> +	return PTR_ERR_OR_ZERO(sii902x->audio.pdev);
>>> +}
>>> +
>>>  static const struct regmap_range sii902x_volatile_ranges[] = {
>>>  	{ .range_min = 0, .range_max = 0xff },
>>>  };
>>> @@ -336,6 +778,7 @@ static const struct regmap_access_table sii902x_volatile_table = {
>>>  static const struct regmap_config sii902x_regmap_config = {
>>>  	.reg_bits = 8,
>>>  	.val_bits = 8,
>>> +	.max_register = SII902X_TPI_MISC_INFOFRAME_END,
>>>  	.volatile_table = &sii902x_volatile_table,
>>>  	.cache_type = REGCACHE_NONE,
>>>  };
>>> @@ -508,6 +951,8 @@ static int sii902x_probe(struct i2c_client *client,
>>>  		return PTR_ERR(sii902x->reset_gpio);
>>>  	}
>>>  
>>> +	mutex_init(&sii902x->mutex);
>>> +
>>>  	sii902x_reset(sii902x);
>>>  
>>>  	ret = regmap_write(sii902x->regmap, SII902X_REG_TPI_RQB, 0x0);
>>> @@ -548,6 +993,8 @@ static int sii902x_probe(struct i2c_client *client,
>>>  	sii902x->bridge.timings = &default_sii902x_timings;
>>>  	drm_bridge_add(&sii902x->bridge);
>>>  
>>> +	sii902x_audio_codec_init(sii902x, dev);
>>> +
>>>  	i2c_set_clientdata(client, sii902x);
>>>  
>>>  	sii902x->i2cmux = i2c_mux_alloc(client->adapter, dev,
>>
>



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