Commit 9dc515f8 authored by Russell King's avatar Russell King
Browse files

drm: bridge/dw_hdmi-ahb-audio: basic support for multi-channel PCM audio 



Add basic support for multi-channel PCM audio, with fixed speaker
mappings.  This has been tested with an AV receiver, and appears to
work for low sample rates up to 8 channels.

It should be noted that multi-channel mode using the IEC958 alsa-lib
conversion plugin requires correct AES channel status for the AV
receiver to recognise the stream, especially the sample rate bits.
"Not identified" does not work there.

Tested-by: default avatarFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent f5ce4057

drivers/gpu/drm/bridge/dw_hdmi-ahb-audio.c

+57 −2
Original line number Diff line number Diff line
@@ -62,9 +62,14 @@ enum { 
	HDMI_AHB_DMA_CONF0_INCR4 = 0,

	HDMI_AHB_DMA_CONF0_BURST_MODE = BIT(0),

	HDMI_AHB_DMA_MASK_DONE = BIT(7),



	HDMI_REVISION_ID = 0x0001,

	HDMI_IH_AHBDMAAUD_STAT0 = 0x0109,

	HDMI_IH_MUTE_AHBDMAAUD_STAT0 = 0x0189,

	HDMI_FC_AUDICONF2 = 0x1027,

	HDMI_FC_AUDSCONF = 0x1063,

	HDMI_FC_AUDSCONF_LAYOUT1 = 1 << 0,

	HDMI_FC_AUDSCONF_LAYOUT0 = 0 << 0,

	HDMI_AHB_DMA_CONF0 = 0x3600,

	HDMI_AHB_DMA_START = 0x3601,

	HDMI_AHB_DMA_STOP = 0x3602,
@@ -77,6 +82,44 @@ enum { 
	HDMI_AHB_DMA_BUFFPOL = 0x361a,

};



struct dw_hdmi_channel_conf {

	u8 conf1;

	u8 ca;

};



/*

 * The default mapping of ALSA channels to HDMI channels and speaker

 * allocation bits.  Note that we can't do channel remapping here -

 * channels must be in the same order.

 *

 * Mappings for alsa-lib pcm/surround*.conf files:

 *

 *		Front	Sur4.0	Sur4.1	Sur5.0	Sur5.1	Sur7.1

 * Channels	2	4	6	6	6	8

 *

 * Our mapping from ALSA channel to CEA686D speaker name and HDMI channel:

 *

 *				Number of ALSA channels

 * ALSA Channel	2	3	4	5	6	7	8

 * 0		FL:0	=	=	=	=	=	=

 * 1		FR:1	=	=	=	=	=	=

 * 2			FC:3	RL:4	LFE:2	=	=	=

 * 3				RR:5	RL:4	FC:3	=	=

 * 4					RR:5	RL:4	=	=

 * 5						RR:5	=	=

 * 6							RC:6	=

 * 7							RLC/FRC	RLC/FRC

 */

static struct dw_hdmi_channel_conf default_hdmi_channel_config[7] = {

	{ 0x03, 0x00 },	/* FL,FR */

	{ 0x0b, 0x02 },	/* FL,FR,FC */

	{ 0x33, 0x08 },	/* FL,FR,RL,RR */

	{ 0x37, 0x09 },	/* FL,FR,LFE,RL,RR */

	{ 0x3f, 0x0b },	/* FL,FR,LFE,FC,RL,RR */

	{ 0x7f, 0x0f },	/* FL,FR,LFE,FC,RL,RR,RC */

	{ 0xff, 0x13 },	/* FL,FR,LFE,FC,RL,RR,[FR]RC,[FR]LC */

};



struct snd_dw_hdmi {

	struct snd_card *card;

	struct snd_pcm *pcm;
@@ -354,7 +397,7 @@ static int dw_hdmi_prepare(struct snd_pcm_substream *substream) 
{

	struct snd_pcm_runtime *runtime = substream->runtime;

	struct snd_dw_hdmi *dw = substream->private_data;

	u8 threshold, conf0, conf1;

	u8 threshold, conf0, conf1, layout, ca;



	/* Setup as per 3.0.5 FSL 4.1.0 BSP */

	switch (dw->revision) {
@@ -382,11 +425,23 @@ static int dw_hdmi_prepare(struct snd_pcm_substream *substream) 
	runtime->hw.fifo_size = threshold * 32;



	conf0 |= HDMI_AHB_DMA_CONF0_EN_HLOCK;

	conf1 = (1 << runtime->channels) - 1;

	conf1 = default_hdmi_channel_config[runtime->channels - 2].conf1;

	ca = default_hdmi_channel_config[runtime->channels - 2].ca;



	/*

	 * For >2 channel PCM audio, we need to select layout 1

	 * and set an appropriate channel map.

	 */

	if (runtime->channels > 2)

		layout = HDMI_FC_AUDSCONF_LAYOUT1;

	else

		layout = HDMI_FC_AUDSCONF_LAYOUT0;



	writeb_relaxed(threshold, dw->data.base + HDMI_AHB_DMA_THRSLD);

	writeb_relaxed(conf0, dw->data.base + HDMI_AHB_DMA_CONF0);

	writeb_relaxed(conf1, dw->data.base + HDMI_AHB_DMA_CONF1);

	writeb_relaxed(layout, dw->data.base + HDMI_FC_AUDSCONF);

	writeb_relaxed(ca, dw->data.base + HDMI_FC_AUDICONF2);



	switch (runtime->format) {

	case SNDRV_PCM_FORMAT_IEC958_SUBFRAME_LE:

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