ENGR00172342-2 EDID parse audio data blocks

Add functionality to parse Audio Data Blocks from EDID data to
find out what modes of LPCM are suppored by the HDMI sink device.

The parsed settings are saved in the hdmi mfd.  The HDMI audio driver
will check the settings when the audio stream is opened and will
then apply appropriate constraints.

If we are unable to read from the EDID, then we default to supporting
Basic Audio as defined by the HDMI specification (stereo, 16 bit,
32KHz, 44.1KHz, 48KHz PCM).

Signed-off-by: Alan Tull <r80115@freescale.com>

1 files changed, 127 insertions, 16 deletions

diff --git a/sound/soc/codecs/mxc_hdmi.c b/sound/soc/codecs/mxc_hdmi.c
index c6a6bcbdbfd9..70c9b8c9bfe0 100644
--- a/sound/soc/codecs/mxc_hdmi.c
+++ b/sound/soc/codecs/mxc_hdmi.c
@@ -1,7 +1,7 @@
 /*
  * MXC HDMI ALSA Soc Codec Driver
  *
- * Copyright (C) 2011 Freescale Semiconductor, Inc.
+ * Copyright (C) 2011-2012 Freescale Semiconductor, Inc.
  */
 
 /*
@@ -42,6 +42,7 @@
 #include <mach/hardware.h>
 
 #include <linux/mfd/mxc-hdmi-core.h>
+#include <mach/mxc_edid.h>
 #include <mach/mxc_hdmi.h>
 #include "../imx/imx-hdmi.h"
 
@@ -53,6 +54,16 @@ struct mxc_hdmi_priv {
 	struct clk *iahb_clk;
 };
 
+static struct mxc_edid_cfg edid_cfg;
+
+static unsigned int playback_rates[HDMI_MAX_RATES];
+static unsigned int playback_sample_size[HDMI_MAX_SAMPLE_SIZE];
+static unsigned int playback_channels[HDMI_MAX_CHANNEL_CONSTRAINTS];
+
+static struct snd_pcm_hw_constraint_list playback_constraint_rates;
+static struct snd_pcm_hw_constraint_list playback_constraint_bits;
+static struct snd_pcm_hw_constraint_list playback_constraint_channels;
+
 #ifdef DEBUG
 static void dumpregs(void)
 {
@@ -100,19 +111,126 @@ static void hdmi_set_audio_infoframe(void)
 	hdmi_writeb(0x00, HDMI_FC_AUDICONF2);
 }
 
-static unsigned int hdmi_playback_rates[] = { 32000, 44100, 48000, 88200, 96000 };
-
-static struct snd_pcm_hw_constraint_list playback_rate_constraints = {
-	.count = ARRAY_SIZE(hdmi_playback_rates),
-	.list = hdmi_playback_rates,
-	.mask = 0,
+static int cea_audio_rates[HDMI_MAX_RATES] = {
+	32000,
+	44100,
+	48000,
+	88200,
+	96000,
+	176400,
+	192000,
 };
 
+static void mxc_hdmi_get_playback_rates(void)
+{
+	int i, count = 0;
+	u8 rates;
+
+	/* always assume basic audio support */
+	rates = edid_cfg.sample_rates | 0x7;
+
+	for (i = 0 ; i < HDMI_MAX_RATES ; i++)
+		if ((rates & (1 << i)) != 0)
+			playback_rates[count++] = cea_audio_rates[i];
+
+	playback_constraint_rates.list = playback_rates;
+	playback_constraint_rates.count = count;
+
+#ifdef DEBUG
+	for (i = 0 ; i < playback_constraint_rates.count ; i++)
+		pr_debug("%s: constraint = %d Hz\n", __func__,
+			 playback_rates[i]);
+#endif
+}
+
+static void mxc_hdmi_get_playback_sample_size(void)
+{
+	int i = 0;
+
+	/* always assume basic audio support */
+	playback_sample_size[i++] = 16;
+
+	if (edid_cfg.sample_sizes & 0x2)
+		playback_sample_size[i++] = 20;
+
+	if (edid_cfg.sample_sizes & 0x4)
+		playback_sample_size[i++] = 24;
+
+	playback_constraint_bits.list = playback_sample_size;
+	playback_constraint_bits.count = i;
+
+#ifdef DEBUG
+	for (i = 0 ; i < playback_constraint_bits.count ; i++)
+		pr_debug("%s: constraint = %d bits\n", __func__,
+			 playback_sample_size[i]);
+#endif
+}
+
+static void mxc_hdmi_get_playback_channels(void)
+{
+	int channels = 2, i = 0;
+
+	/* always assume basic audio support */
+	playback_channels[i++] = channels;
+	channels += 2;
+
+	while ((i < HDMI_MAX_CHANNEL_CONSTRAINTS) &&
+		(channels <= edid_cfg.max_channels)) {
+		playback_channels[i++] = channels;
+		channels += 2;
+	}
+
+	playback_constraint_channels.list = playback_channels;
+	playback_constraint_channels.count = i;
+
+#ifdef DEBUG
+	for (i = 0 ; i < playback_constraint_channels.count ; i++)
+		pr_debug("%s: constraint = %d channels\n", __func__,
+			 playback_channels[i]);
+#endif
+}
+
+static int mxc_hdmi_update_constraints(struct mxc_hdmi_priv *priv,
+				       struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	int ret;
+
+	hdmi_get_edid_cfg(&edid_cfg);
+
+	mxc_hdmi_get_playback_rates();
+	ret = snd_pcm_hw_constraint_list(substream->runtime, 0,
+					SNDRV_PCM_HW_PARAM_RATE,
+					&playback_constraint_rates);
+	if (ret < 0)
+		return ret;
+
+	mxc_hdmi_get_playback_sample_size();
+	ret = snd_pcm_hw_constraint_list(substream->runtime, 0,
+					SNDRV_PCM_HW_PARAM_SAMPLE_BITS,
+					&playback_constraint_bits);
+	if (ret < 0)
+		return ret;
+
+	mxc_hdmi_get_playback_channels();
+	ret = snd_pcm_hw_constraint_list(runtime, 0,
+					SNDRV_PCM_HW_PARAM_CHANNELS,
+					&playback_constraint_channels);
+	if (ret < 0)
+		return ret;
+
+	ret = snd_pcm_hw_constraint_integer(substream->runtime,
+			SNDRV_PCM_HW_PARAM_PERIODS);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
 static int mxc_hdmi_codec_startup(struct snd_pcm_substream *substream,
 				  struct snd_soc_dai *dai)
 {
 	struct mxc_hdmi_priv *hdmi_priv = snd_soc_dai_get_drvdata(dai);
-	struct snd_pcm_runtime *runtime = substream->runtime;
 	int ret;
 
 	clk_enable(hdmi_priv->isfr_clk);
@@ -122,14 +240,7 @@ static int mxc_hdmi_codec_startup(struct snd_pcm_substream *substream,
 		(int)clk_get_rate(hdmi_priv->isfr_clk),
 		(int)clk_get_rate(hdmi_priv->iahb_clk));
 
-	ret = snd_pcm_hw_constraint_list(runtime, 0,
-					 SNDRV_PCM_HW_PARAM_RATE,
-					 &playback_rate_constraints);
-	if (ret < 0)
-		return ret;
-
-	ret = snd_pcm_hw_constraint_integer(runtime,
-					SNDRV_PCM_HW_PARAM_PERIODS);
+	ret = mxc_hdmi_update_constraints(hdmi_priv, substream);
 	if (ret < 0)
 		return ret;