[PATCH] ASoC: arizona: Implement TDM support for Arizona devices

[PATCH] ASoC: arizona: Implement TDM support for Arizona devices

[Charles Keepax]

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
---
 include/linux/mfd/arizona/core.h |    3 +
 sound/soc/codecs/arizona.c       |   81 +++++++++++++++++++++++++++++++++++---
 2 files changed, 78 insertions(+), 6 deletions(-)

diff --git a/include/linux/mfd/arizona/core.h b/include/linux/mfd/arizona/core.h
index 5cf8b91..11783b5 100644
--- a/include/linux/mfd/arizona/core.h
+++ b/include/linux/mfd/arizona/core.h
@@ -110,6 +110,9 @@ struct arizona {
 	int clk32k_ref;
 
 	struct snd_soc_dapm_context *dapm;
+
+	int tdm_width[ARIZONA_MAX_AIF];
+	int tdm_slots[ARIZONA_MAX_AIF];
 };
 
 int arizona_clk32k_enable(struct arizona *arizona);
diff --git a/sound/soc/codecs/arizona.c b/sound/soc/codecs/arizona.c
index 29e198f..d98bd77 100644
--- a/sound/soc/codecs/arizona.c
+++ b/sound/soc/codecs/arizona.c
@@ -1185,7 +1185,10 @@ static int arizona_hw_params(struct snd_pcm_substream *substream,
 	int base = dai->driver->base;
 	const int *rates;
 	int i, ret, val;
+	int channels = params_channels(params);
 	int chan_limit = arizona->pdata.max_channels_clocked[dai->id - 1];
+	int tdm_width = arizona->tdm_width[dai->id - 1];
+	int tdm_slots = arizona->tdm_slots[dai->id - 1];
 	int bclk, lrclk, wl, frame, bclk_target;
 
 	if (params_rate(params) % 8000)
@@ -1193,18 +1196,27 @@ static int arizona_hw_params(struct snd_pcm_substream *substream,
 	else
 		rates = &arizona_48k_bclk_rates[0];
 
-	bclk_target = snd_soc_params_to_bclk(params);
-	if (chan_limit && chan_limit < params_channels(params)) {
+	if (tdm_slots) {
+		arizona_aif_dbg(dai, "Configuring for %d %d bit TDM slots\n",
+				tdm_slots, tdm_width);
+		bclk_target = tdm_slots * tdm_width * params_rate(params);
+		channels = tdm_slots;
+	} else {
+		bclk_target = snd_soc_params_to_bclk(params);
+	}
+
+	if (chan_limit && chan_limit < channels) {
 		arizona_aif_dbg(dai, "Limiting to %d channels\n", chan_limit);
-		bclk_target /= params_channels(params);
+		bclk_target /= channels;
 		bclk_target *= chan_limit;
 	}
 
-	/* Force stereo for I2S mode */
+	/* Force multiple of 2 channels for I2S mode */
 	val = snd_soc_read(codec, base + ARIZONA_AIF_FORMAT);
-	if (params_channels(params) == 1 && (val & ARIZONA_AIF1_FMT_MASK)) {
+	if ((channels & 1) && (val & ARIZONA_AIF1_FMT_MASK)) {
 		arizona_aif_dbg(dai, "Forcing stereo mode\n");
-		bclk_target *= 2;
+		bclk_target /= channels;
+		bclk_target *= channels + 1;
 	}
 
 	for (i = 0; i < ARRAY_SIZE(arizona_44k1_bclk_rates); i++) {
@@ -1228,6 +1240,9 @@ static int arizona_hw_params(struct snd_pcm_substream *substream,
 	wl = snd_pcm_format_width(params_format(params));
 	frame = wl << ARIZONA_AIF1TX_WL_SHIFT | wl;
 
+	if (tdm_width && wl != tdm_width)
+		arizona_aif_warn(dai, "Word length not equal to TDM width\n");
+
 	ret = arizona_hw_params_rate(substream, params, dai);
 	if (ret != 0)
 		return ret;
@@ -1324,9 +1339,63 @@ static int arizona_set_tristate(struct snd_soc_dai *dai, int tristate)
 				   ARIZONA_AIF1_TRI, reg);
 }
 
+static void arizona_set_channels_to_mask(struct snd_soc_dai *dai,
+					 unsigned int base,
+					 int channels, unsigned int mask)
+{
+	struct snd_soc_codec *codec = dai->codec;
+	struct arizona_priv *priv = snd_soc_codec_get_drvdata(codec);
+	struct arizona *arizona = priv->arizona;
+	int slot, i;
+
+	for (i = 0; i < channels; ++i) {
+		slot = ffs(mask) - 1;
+		if (slot < 0)
+			return;
+
+		regmap_write(arizona->regmap, base + i, slot);
+
+		mask &= ~(1 << slot);
+	}
+
+	if (mask)
+		arizona_aif_warn(dai, "Too many channels in TDM mask\n");
+}
+
+static int arizona_set_tdm_slot(struct snd_soc_dai *dai, unsigned int tx_mask,
+				unsigned int rx_mask, int slots, int slot_width)
+{
+	struct snd_soc_codec *codec = dai->codec;
+	struct arizona_priv *priv = snd_soc_codec_get_drvdata(codec);
+	struct arizona *arizona = priv->arizona;
+	int base = dai->driver->base;
+	int rx_max_chan = dai->driver->playback.channels_max;
+	int tx_max_chan = dai->driver->capture.channels_max;
+
+	/* Only support TDM for the physical AIFs */
+	if (dai->id > ARIZONA_MAX_AIF)
+		return -ENOTSUPP;
+
+	if (slots == 0) {
+		tx_mask = (1 << tx_max_chan) - 1;
+		rx_mask = (1 << rx_max_chan) - 1;
+	}
+
+	arizona_set_channels_to_mask(dai, base + ARIZONA_AIF_FRAME_CTRL_3,
+				     tx_max_chan, tx_mask);
+	arizona_set_channels_to_mask(dai, base + ARIZONA_AIF_FRAME_CTRL_11,
+				     rx_max_chan, rx_mask);
+
+	arizona->tdm_width[dai->id - 1] = slot_width;
+	arizona->tdm_slots[dai->id - 1] = slots;
+
+	return 0;
+}
+
 const struct snd_soc_dai_ops arizona_dai_ops = {
 	.startup = arizona_startup,
 	.set_fmt = arizona_set_fmt,
+	.set_tdm_slot = arizona_set_tdm_slot,
 	.hw_params = arizona_hw_params,
 	.set_sysclk = arizona_dai_set_sysclk,
 	.set_tristate = arizona_set_tristate,
-- 
1.7.2.5

Re: [PATCH] ASoC: arizona: Implement TDM support for Arizona devices

[Mark Brown]

[-- Attachment #1.1: Type: text/plain, Size: 432 bytes --]

On Tue, Jun 03, 2014 at 08:06:10PM +0100, Charles Keepax wrote:

> +	if (tdm_width && wl != tdm_width)
> +		arizona_aif_warn(dai, "Word length not equal to TDM width\n");
> +

Is it a problem to have say 16 bit words in a 32 bit TDM slot?  One of
the reasons this stuff sometimes gets used is to help out the other
connected device if it's having trouble configuring the "natural" clock
rates.  Ignoring LSBs shouldn't be an issue.

[-- Attachment #1.2: Digital signature --]
[-- Type: application/pgp-signature, Size: 836 bytes --]

[-- Attachment #2: Type: text/plain, Size: 0 bytes --]

Re: [PATCH] ASoC: arizona: Implement TDM support for Arizona devices

[Charles Keepax]

On Tue, Jun 03, 2014 at 11:06:07PM +0100, Mark Brown wrote:
> On Tue, Jun 03, 2014 at 08:06:10PM +0100, Charles Keepax wrote:
> 
> > +	if (tdm_width && wl != tdm_width)
> > +		arizona_aif_warn(dai, "Word length not equal to TDM width\n");
> > +
> 
> Is it a problem to have say 16 bit words in a 32 bit TDM slot?  One of
> the reasons this stuff sometimes gets used is to help out the other
> connected device if it's having trouble configuring the "natural" clock
> rates.  Ignoring LSBs shouldn't be an issue.

A good point I will respin and take this out.

Thanks,
Charles