ASoC: sti: unip reader tdm mode

Here are the changes to enable reader 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.
- 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/uniperif_reader.c

@@ -73,55 +73,10 @@ static irqreturn_t uni_reader_irq_handler(int irq, void *dev_id)
 	return ret;
 }
 
-static int uni_reader_prepare(struct snd_pcm_substream *substream,
-			      struct snd_soc_dai *dai)
+static int uni_reader_prepare_pcm(struct snd_pcm_runtime *runtime,
+				  struct uniperif *reader)
 {
-	struct sti_uniperiph_data *priv = snd_soc_dai_get_drvdata(dai);
-	struct uniperif *reader = priv->dai_data.uni;
-	struct snd_pcm_runtime *runtime = substream->runtime;
-	int transfer_size, trigger_limit;
 	int slot_width;
-	int count = 10;
-
-	/* The reader should be stopped */
-	if (reader->state != UNIPERIF_STATE_STOPPED) {
-		dev_err(reader->dev, "%s: invalid reader state %d", __func__,
-			reader->state);
-		return -EINVAL;
-	}
-
-	/* Calculate transfer size (in fifo cells and bytes) for frame count */
-	transfer_size = runtime->channels * UNIPERIF_FIFO_FRAMES;
-
-	/* Calculate number of empty cells available before asserting DREQ */
-	if (reader->ver < SND_ST_UNIPERIF_VERSION_UNI_PLR_TOP_1_0)
-		trigger_limit = UNIPERIF_FIFO_SIZE - transfer_size;
-	else
-		/*
-		 * Since SND_ST_UNIPERIF_VERSION_UNI_PLR_TOP_1_0
-		 * FDMA_TRIGGER_LIMIT also controls when the state switches
-		 * from OFF or STANDBY to AUDIO DATA.
-		 */
-		trigger_limit = transfer_size;
-
-	/* Trigger limit must be an even number */
-	if ((!trigger_limit % 2) ||
-	    (trigger_limit != 1 && transfer_size % 2) ||
-	    (trigger_limit > UNIPERIF_CONFIG_DMA_TRIG_LIMIT_MASK(reader))) {
-		dev_err(reader->dev, "invalid trigger limit %d", trigger_limit);
-		return -EINVAL;
-	}
-
-	SET_UNIPERIF_CONFIG_DMA_TRIG_LIMIT(reader, trigger_limit);
-
-	switch (reader->daifmt & SND_SOC_DAIFMT_INV_MASK) {
-	case SND_SOC_DAIFMT_IB_IF:
-	case SND_SOC_DAIFMT_NB_IF:
-		SET_UNIPERIF_I2S_FMT_LR_POL_HIG(reader);
-		break;
-	default:
-		SET_UNIPERIF_I2S_FMT_LR_POL_LOW(reader);
-	}
 
 	/* Force slot width to 32 in I2S mode */
 	if ((reader->daifmt & SND_SOC_DAIFMT_FORMAT_MASK)
@@ -173,6 +128,109 @@ static int uni_reader_prepare(struct snd_pcm_substream *substream,
 		return -EINVAL;
 	}
 
+	/* Number of channels must be even */
+	if ((runtime->channels % 2) || (runtime->channels < 2) ||
+	    (runtime->channels > 10)) {
+		dev_err(reader->dev, "%s: invalid nb of channels", __func__);
+		return -EINVAL;
+	}
+
+	SET_UNIPERIF_I2S_FMT_NUM_CH(reader, runtime->channels / 2);
+	SET_UNIPERIF_I2S_FMT_ORDER_MSB(reader);
+
+	return 0;
+}
+
+static int uni_reader_prepare_tdm(struct snd_pcm_runtime *runtime,
+				  struct uniperif *reader)
+{
+	int frame_size; /* user tdm frame size in bytes */
+	/* default unip TDM_WORD_POS_X_Y */
+	unsigned int word_pos[4] = {
+		0x04060002, 0x0C0E080A, 0x14161012, 0x1C1E181A};
+
+	frame_size = sti_uniperiph_get_user_frame_size(runtime);
+
+	/* fix 16/0 format */
+	SET_UNIPERIF_CONFIG_MEM_FMT_16_0(reader);
+	SET_UNIPERIF_I2S_FMT_DATA_SIZE_32(reader);
+
+	/* number of words inserted on the TDM line */
+	SET_UNIPERIF_I2S_FMT_NUM_CH(reader, frame_size / 4 / 2);
+
+	SET_UNIPERIF_I2S_FMT_ORDER_MSB(reader);
+	SET_UNIPERIF_I2S_FMT_ALIGN_LEFT(reader);
+	SET_UNIPERIF_TDM_ENABLE_TDM_ENABLE(reader);
+
+	/*
+	 * set the timeslots allocation for words in FIFO
+	 *
+	 * HW bug: (LSB word < MSB word) => this config is not possible
+	 *         So if we want (LSB word < MSB) word, then it shall be
+	 *         handled by user
+	 */
+	sti_uniperiph_get_tdm_word_pos(reader, word_pos);
+	SET_UNIPERIF_TDM_WORD_POS(reader, 1_2, word_pos[WORD_1_2]);
+	SET_UNIPERIF_TDM_WORD_POS(reader, 3_4, word_pos[WORD_3_4]);
+	SET_UNIPERIF_TDM_WORD_POS(reader, 5_6, word_pos[WORD_5_6]);
+	SET_UNIPERIF_TDM_WORD_POS(reader, 7_8, word_pos[WORD_7_8]);
+
+	return 0;
+}
+
+static int uni_reader_prepare(struct snd_pcm_substream *substream,
+			      struct snd_soc_dai *dai)
+{
+	struct sti_uniperiph_data *priv = snd_soc_dai_get_drvdata(dai);
+	struct uniperif *reader = priv->dai_data.uni;
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	int transfer_size, trigger_limit, ret;
+	int count = 10;
+
+	/* The reader should be stopped */
+	if (reader->state != UNIPERIF_STATE_STOPPED) {
+		dev_err(reader->dev, "%s: invalid reader state %d", __func__,
+			reader->state);
+		return -EINVAL;
+	}
+
+	/* Calculate transfer size (in fifo cells and bytes) for frame count */
+	if (reader->info->type == SND_ST_UNIPERIF_TYPE_TDM) {
+		/* transfer size = unip 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 (reader->ver < SND_ST_UNIPERIF_VERSION_UNI_PLR_TOP_1_0)
+		trigger_limit = UNIPERIF_FIFO_SIZE - transfer_size;
+	else
+		/*
+		 * Since SND_ST_UNIPERIF_VERSION_UNI_PLR_TOP_1_0
+		 * FDMA_TRIGGER_LIMIT also controls when the state switches
+		 * from OFF or STANDBY to AUDIO DATA.
+		 */
+		trigger_limit = transfer_size;
+
+	/* Trigger limit must be an even number */
+	if ((!trigger_limit % 2) ||
+	    (trigger_limit != 1 && transfer_size % 2) ||
+	    (trigger_limit > UNIPERIF_CONFIG_DMA_TRIG_LIMIT_MASK(reader))) {
+		dev_err(reader->dev, "invalid trigger limit %d", trigger_limit);
+		return -EINVAL;
+	}
+
+	SET_UNIPERIF_CONFIG_DMA_TRIG_LIMIT(reader, trigger_limit);
+
+	if (UNIPERIF_TYPE_IS_TDM(reader))
+		ret = uni_reader_prepare_tdm(runtime, reader);
+	else
+		ret = uni_reader_prepare_pcm(runtime, reader);
+	if (ret)
+		return ret;
+
 	switch (reader->daifmt & SND_SOC_DAIFMT_FORMAT_MASK) {
 	case SND_SOC_DAIFMT_I2S:
 		SET_UNIPERIF_I2S_FMT_ALIGN_LEFT(reader);
@@ -191,21 +249,26 @@ static int uni_reader_prepare(struct snd_pcm_substream *substream,
 		return -EINVAL;
 	}
 
-	SET_UNIPERIF_I2S_FMT_ORDER_MSB(reader);
-
-	/* Data clocking (changing) on the rising edge */
-	SET_UNIPERIF_I2S_FMT_SCLK_EDGE_RISING(reader);
-
-	/* Number of channels must be even */
-
-	if ((runtime->channels % 2) || (runtime->channels < 2) ||
-	    (runtime->channels > 10)) {
-		dev_err(reader->dev, "%s: invalid nb of channels", __func__);
-		return -EINVAL;
+	/* Data clocking (changing) on the rising/falling edge */
+	switch (reader->daifmt & SND_SOC_DAIFMT_INV_MASK) {
+	case SND_SOC_DAIFMT_NB_NF:
+		SET_UNIPERIF_I2S_FMT_LR_POL_LOW(reader);
+		SET_UNIPERIF_I2S_FMT_SCLK_EDGE_RISING(reader);
+		break;
+	case SND_SOC_DAIFMT_NB_IF:
+		SET_UNIPERIF_I2S_FMT_LR_POL_HIG(reader);
+		SET_UNIPERIF_I2S_FMT_SCLK_EDGE_RISING(reader);
+		break;
+	case SND_SOC_DAIFMT_IB_NF:
+		SET_UNIPERIF_I2S_FMT_LR_POL_LOW(reader);
+		SET_UNIPERIF_I2S_FMT_SCLK_EDGE_FALLING(reader);
+		break;
+	case SND_SOC_DAIFMT_IB_IF:
+		SET_UNIPERIF_I2S_FMT_LR_POL_HIG(reader);
+		SET_UNIPERIF_I2S_FMT_SCLK_EDGE_FALLING(reader);
+		break;
 	}
 
-	SET_UNIPERIF_I2S_FMT_NUM_CH(reader, runtime->channels / 2);
-
 	/* Clear any pending interrupts */
 	SET_UNIPERIF_ITS_BCLR(reader, GET_UNIPERIF_ITS(reader));
 
@@ -293,6 +356,32 @@ static int  uni_reader_trigger(struct snd_pcm_substream *substream,
 	}
 }
 
+static int uni_reader_startup(struct snd_pcm_substream *substream,
+			      struct snd_soc_dai *dai)
+{
+	struct sti_uniperiph_data *priv = snd_soc_dai_get_drvdata(dai);
+	struct uniperif *reader = priv->dai_data.uni;
+	int ret;
+
+	if (!UNIPERIF_TYPE_IS_TDM(reader))
+		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,
+				  reader, 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,
+				   reader, SNDRV_PCM_HW_PARAM_FORMAT,
+				   -1);
+}
+
 static void uni_reader_shutdown(struct snd_pcm_substream *substream,
 				struct snd_soc_dai *dai)
 {
@@ -310,6 +399,7 @@ static int uni_reader_parse_dt(struct platform_device *pdev,
 {
 	struct uniperif_info *info;
 	struct device_node *node = pdev->dev.of_node;
+	const char *mode;
 
 	/* Allocate memory for the info structure */
 	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
@@ -322,6 +412,17 @@ static int uni_reader_parse_dt(struct platform_device *pdev,
 		return -EINVAL;
 	}
 
+	/* Read the device mode property */
+	if (of_property_read_string(node, "st,mode", &mode)) {
+		dev_err(&pdev->dev, "uniperipheral mode not defined");
+		return -EINVAL;
+	}
+
+	if (strcasecmp(mode, "tdm") == 0)
+		info->type = SND_ST_UNIPERIF_TYPE_TDM;
+	else
+		info->type = SND_ST_UNIPERIF_TYPE_PCM;
+
 	/* Save the info structure */
 	reader->info = info;
 
@@ -329,11 +430,13 @@ static int uni_reader_parse_dt(struct platform_device *pdev,
 }
 
 static const struct snd_soc_dai_ops uni_reader_dai_ops = {
+		.startup = uni_reader_startup,
 		.shutdown = uni_reader_shutdown,
 		.prepare = uni_reader_prepare,
 		.trigger = uni_reader_trigger,
 		.hw_params = sti_uniperiph_dai_hw_params,
 		.set_fmt = sti_uniperiph_dai_set_fmt,
+		.set_tdm_slot = sti_uniperiph_set_tdm_slot
 };
 
 int uni_reader_init(struct platform_device *pdev,
@@ -343,7 +446,6 @@ int uni_reader_init(struct platform_device *pdev,
 
 	reader->dev = &pdev->dev;
 	reader->state = UNIPERIF_STATE_STOPPED;
-	reader->hw = &uni_reader_pcm_hw;
 	reader->dai_ops = &uni_reader_dai_ops;
 
 	ret = uni_reader_parse_dt(pdev, reader);
@@ -352,6 +454,11 @@ int uni_reader_init(struct platform_device *pdev,
 		return ret;
 	}
 
+	if (UNIPERIF_TYPE_IS_TDM(reader))
+		reader->hw = &uni_tdm_hw;
+	else
+		reader->hw = &uni_reader_pcm_hw;
+
 	ret = devm_request_irq(&pdev->dev, reader->irq,
 			       uni_reader_irq_handler, IRQF_SHARED,
 			       dev_name(&pdev->dev), reader);