ASoC: sti: unip player tdm mode

here are the changes to enable player tdm mode:
- When TDM_ENABLE is set to 1, the i2s format should be automatically
configured. Unfortunately this is not the case (HW bug). Then, we shall
force DATA_SIZE setting.
- Compute the transfer size for tdm mode: transfer size = user frame size
- Manage tdm slots configuration given in DT.
- Don't use mclk-fs when unip in tdm mode; use tdm slot config to compute
frame size and to set mclk rate.
- Refine the hw param (channels & format) according to tdm slot config.

Signed-off-by: Moise Gergaud <moise.gergaud@st.com>
Acked-by: Arnaud Pouliquen <arnaud.pouliquen@st.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/sti/sti_uniperif.c

@@ -181,10 +181,16 @@ int sti_uniperiph_dai_hw_params(struct snd_pcm_substream *substream,
 				struct snd_pcm_hw_params *params,
 				struct snd_soc_dai *dai)
 {
+	struct sti_uniperiph_data *priv = snd_soc_dai_get_drvdata(dai);
+	struct uniperif *uni = priv->dai_data.uni;
 	struct snd_dmaengine_dai_dma_data *dma_data;
 	int transfer_size;
 
-	transfer_size = params_channels(params) * UNIPERIF_FIFO_FRAMES;
+	if (uni->info->type == SND_ST_UNIPERIF_TYPE_TDM)
+		/* transfer size = user frame size (in 32-bits FIFO cell) */
+		transfer_size = snd_soc_params_to_frame_size(params) / 32;
+	else
+		transfer_size = params_channels(params) * UNIPERIF_FIFO_FRAMES;
 
 	dma_data = snd_soc_dai_get_dma_data(dai, substream);
 	dma_data->maxburst = transfer_size;

sound/soc/sti/uniperif.h

@@ -1389,6 +1389,17 @@ int sti_uniperiph_dai_hw_params(struct snd_pcm_substream *substream,
 				struct snd_pcm_hw_params *params,
 				struct snd_soc_dai *dai);
 
+static inline int sti_uniperiph_get_user_frame_size(
+	struct snd_pcm_runtime *runtime)
+{
+	return (runtime->channels * snd_pcm_format_width(runtime->format) / 8);
+}
+
+static inline int sti_uniperiph_get_unip_tdm_frame_size(struct uniperif *uni)
+{
+	return (uni->tdm_slot.slots * uni->tdm_slot.slot_width / 8);
+}
+
 int sti_uniperiph_set_tdm_slot(struct snd_soc_dai *dai, unsigned int tx_mask,
 			       unsigned int rx_mask, int slots,
 			       int slot_width);

sound/soc/sti/uniperif_player.c

@@ -435,18 +435,11 @@ static int uni_player_prepare_pcm(struct uniperif *player,
 
 	/* Force slot width to 32 in I2S mode (HW constraint) */
 	if ((player->daifmt & SND_SOC_DAIFMT_FORMAT_MASK) ==
-		SND_SOC_DAIFMT_I2S) {
+		SND_SOC_DAIFMT_I2S)
 		slot_width = 32;
-	} else {
-		switch (runtime->format) {
-		case SNDRV_PCM_FORMAT_S16_LE:
-			slot_width = 16;
-			break;
-		default:
-			slot_width = 32;
-			break;
-		}
-	}
+	else
+		slot_width = snd_pcm_format_width(runtime->format);
+
 	output_frame_size = slot_width * runtime->channels;
 
 	clk_div = player->mclk / runtime->rate;
@@ -521,7 +514,6 @@ static int uni_player_prepare_pcm(struct uniperif *player,
 	SET_UNIPERIF_CONFIG_ONE_BIT_AUD_DISABLE(player);
 
 	SET_UNIPERIF_I2S_FMT_ORDER_MSB(player);
-	SET_UNIPERIF_I2S_FMT_SCLK_EDGE_FALLING(player);
 
 	/* No iec958 formatting as outputting to DAC  */
 	SET_UNIPERIF_CTRL_SPDIF_FMT_OFF(player);
@@ -529,6 +521,55 @@ static int uni_player_prepare_pcm(struct uniperif *player,
 	return 0;
 }
 
+static int uni_player_prepare_tdm(struct uniperif *player,
+				  struct snd_pcm_runtime *runtime)
+{
+	int tdm_frame_size; /* unip tdm frame size in bytes */
+	int user_frame_size; /* user tdm frame size in bytes */
+	/* default unip TDM_WORD_POS_X_Y */
+	unsigned int word_pos[4] = {
+		0x04060002, 0x0C0E080A, 0x14161012, 0x1C1E181A};
+	int freq, ret;
+
+	tdm_frame_size =
+		sti_uniperiph_get_unip_tdm_frame_size(player);
+	user_frame_size =
+		sti_uniperiph_get_user_frame_size(runtime);
+
+	/* fix 16/0 format */
+	SET_UNIPERIF_CONFIG_MEM_FMT_16_0(player);
+	SET_UNIPERIF_I2S_FMT_DATA_SIZE_32(player);
+
+	/* number of words inserted on the TDM line */
+	SET_UNIPERIF_I2S_FMT_NUM_CH(player, user_frame_size / 4 / 2);
+
+	SET_UNIPERIF_I2S_FMT_ORDER_MSB(player);
+	SET_UNIPERIF_I2S_FMT_ALIGN_LEFT(player);
+
+	/* Enable the tdm functionality */
+	SET_UNIPERIF_TDM_ENABLE_TDM_ENABLE(player);
+
+	/* number of 8 bits timeslots avail in unip tdm frame */
+	SET_UNIPERIF_TDM_FS_REF_DIV_NUM_TIMESLOT(player, tdm_frame_size);
+
+	/* set the timeslot allocation for words in FIFO */
+	sti_uniperiph_get_tdm_word_pos(player, word_pos);
+	SET_UNIPERIF_TDM_WORD_POS(player, 1_2, word_pos[WORD_1_2]);
+	SET_UNIPERIF_TDM_WORD_POS(player, 3_4, word_pos[WORD_3_4]);
+	SET_UNIPERIF_TDM_WORD_POS(player, 5_6, word_pos[WORD_5_6]);
+	SET_UNIPERIF_TDM_WORD_POS(player, 7_8, word_pos[WORD_7_8]);
+
+	/* set unip clk rate (not done vai set_sysclk ops) */
+	freq = runtime->rate * tdm_frame_size * 8;
+	mutex_lock(&player->ctrl_lock);
+	ret = uni_player_clk_set_rate(player, freq);
+	if (!ret)
+		player->mclk = freq;
+	mutex_unlock(&player->ctrl_lock);
+
+	return 0;
+}
+
 /*
  * ALSA uniperipheral iec958 controls
  */
@@ -659,11 +700,29 @@ static int uni_player_startup(struct snd_pcm_substream *substream,
 {
 	struct sti_uniperiph_data *priv = snd_soc_dai_get_drvdata(dai);
 	struct uniperif *player = priv->dai_data.uni;
+	int ret;
+
 	player->substream = substream;
 
 	player->clk_adj = 0;
 
-	return 0;
+	if (!UNIPERIF_TYPE_IS_TDM(player))
+		return 0;
+
+	/* refine hw constraint in tdm mode */
+	ret = snd_pcm_hw_rule_add(substream->runtime, 0,
+				  SNDRV_PCM_HW_PARAM_CHANNELS,
+				  sti_uniperiph_fix_tdm_chan,
+				  player, SNDRV_PCM_HW_PARAM_CHANNELS,
+				  -1);
+	if (ret < 0)
+		return ret;
+
+	return snd_pcm_hw_rule_add(substream->runtime, 0,
+				   SNDRV_PCM_HW_PARAM_FORMAT,
+				   sti_uniperiph_fix_tdm_format,
+				   player, SNDRV_PCM_HW_PARAM_FORMAT,
+				   -1);
 }
 
 static int uni_player_set_sysclk(struct snd_soc_dai *dai, int clk_id,
@@ -673,7 +732,7 @@ static int uni_player_set_sysclk(struct snd_soc_dai *dai, int clk_id,
 	struct uniperif *player = priv->dai_data.uni;
 	int ret;
 
-	if (dir == SND_SOC_CLOCK_IN)
+	if (UNIPERIF_TYPE_IS_TDM(player) || (dir == SND_SOC_CLOCK_IN))
 		return 0;
 
 	if (clk_id != 0)
@@ -705,7 +764,13 @@ static int uni_player_prepare(struct snd_pcm_substream *substream,
 	}
 
 	/* Calculate transfer size (in fifo cells and bytes) for frame count */
-	transfer_size = runtime->channels * UNIPERIF_FIFO_FRAMES;
+	if (player->info->type == SND_ST_UNIPERIF_TYPE_TDM) {
+		/* transfer size = user frame size (in 32 bits FIFO cell) */
+		transfer_size =
+			sti_uniperiph_get_user_frame_size(runtime) / 4;
+	} else {
+		transfer_size = runtime->channels * UNIPERIF_FIFO_FRAMES;
+	}
 
 	/* Calculate number of empty cells available before asserting DREQ */
 	if (player->ver < SND_ST_UNIPERIF_VERSION_UNI_PLR_TOP_1_0) {
@@ -739,6 +804,9 @@ static int uni_player_prepare(struct snd_pcm_substream *substream,
 	case SND_ST_UNIPERIF_TYPE_SPDIF:
 		ret = uni_player_prepare_iec958(player, runtime);
 		break;
+	case SND_ST_UNIPERIF_TYPE_TDM:
+		ret = uni_player_prepare_tdm(player, runtime);
+		break;
 	default:
 		dev_err(player->dev, "invalid player type");
 		return -EINVAL;
@@ -1008,6 +1076,8 @@ static int uni_player_parse_dt(struct platform_device *pdev,
 		info->type = SND_ST_UNIPERIF_TYPE_PCM;
 	else if (strcasecmp(mode, "spdif") == 0)
 		info->type = SND_ST_UNIPERIF_TYPE_SPDIF;
+	else if (strcasecmp(mode, "tdm") == 0)
+		info->type = SND_ST_UNIPERIF_TYPE_TDM;
 	else
 		info->type = SND_ST_UNIPERIF_TYPE_NONE;
 
@@ -1028,7 +1098,8 @@ static const struct snd_soc_dai_ops uni_player_dai_ops = {
 		.trigger = uni_player_trigger,
 		.hw_params = sti_uniperiph_dai_hw_params,
 		.set_fmt = sti_uniperiph_dai_set_fmt,
-		.set_sysclk = uni_player_set_sysclk
+		.set_sysclk = uni_player_set_sysclk,
+		.set_tdm_slot = sti_uniperiph_set_tdm_slot
 };
 
 int uni_player_init(struct platform_device *pdev,
@@ -1038,7 +1109,6 @@ int uni_player_init(struct platform_device *pdev,
 
 	player->dev = &pdev->dev;
 	player->state = UNIPERIF_STATE_STOPPED;
-	player->hw = &uni_player_pcm_hw;
 	player->dai_ops = &uni_player_dai_ops;
 
 	ret = uni_player_parse_dt(pdev, player);
@@ -1048,6 +1118,11 @@ int uni_player_init(struct platform_device *pdev,
 		return ret;
 	}
 
+	if (UNIPERIF_TYPE_IS_TDM(player))
+		player->hw = &uni_tdm_hw;
+	else
+		player->hw = &uni_player_pcm_hw;
+
 	/* Get uniperif resource */
 	player->clk = of_clk_get(pdev->dev.of_node, 0);
 	if (IS_ERR(player->clk))