ASoC: sti: Add CPU DAI driver for capture

Add code to manage Uniperipheral reader IP instances.
These DAIs are dedicated to capture and support I2S and IEC modes.
Signed-off-by: NArnaud Pouliquen <arnaud.pouliquen@st.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

sound/soc/sti/uniperif.h

@@ -1212,4 +1212,7 @@ int uni_player_init(struct platform_device *pdev,
 		    struct uniperif *uni_player);
 int uni_player_resume(struct uniperif *player);
 
+/* uniperiph reader */
+int uni_reader_init(struct platform_device *pdev,
+		    struct uniperif *uni_reader);
 #endif

sound/soc/sti/uniperif_reader.c

+/*
+ * Copyright (C) STMicroelectronics SA 2015
+ * Authors: Arnaud Pouliquen <arnaud.pouliquen@st.com>
+ *          for STMicroelectronics.
+ * License terms:  GNU General Public License (GPL), version 2
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+
+#include <sound/soc.h>
+
+#include "uniperif.h"
+
+/*
+ * Note: snd_pcm_hardware is linked to DMA controller but is declared here to
+ * integrate unireader capability in term of rate and supported channels
+ */
+const struct snd_pcm_hardware uni_reader_pcm_hw = {
+	.info = SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER |
+		SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_MMAP |
+		SNDRV_PCM_INFO_MMAP_VALID,
+	.formats = SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_S16_LE,
+
+	.rates = SNDRV_PCM_RATE_CONTINUOUS,
+	.rate_min = 8000,
+	.rate_max = 96000,
+
+	.channels_min = 2,
+	.channels_max = 8,
+
+	.periods_min = 2,
+	.periods_max = 48,
+
+	.period_bytes_min = 128,
+	.period_bytes_max = 64 * PAGE_SIZE,
+	.buffer_bytes_max = 256 * PAGE_SIZE
+};
+
+/*
+ * uni_reader_irq_handler
+ * In case of error audio stream is stopped; stop action is protected via PCM
+ * stream lock  to avoid race condition with trigger callback.
+ */
+static irqreturn_t uni_reader_irq_handler(int irq, void *dev_id)
+{
+	irqreturn_t ret = IRQ_NONE;
+	struct uniperif *reader = dev_id;
+	unsigned int status;
+
+	if (reader->state == UNIPERIF_STATE_STOPPED) {
+		/* Unexpected IRQ: do nothing */
+		dev_warn(reader->dev, "unexpected IRQ ");
+		return IRQ_HANDLED;
+	}
+
+	/* Get interrupt status & clear them immediately */
+	status = GET_UNIPERIF_ITS(reader);
+	SET_UNIPERIF_ITS_BCLR(reader, status);
+
+	/* Check for fifo overflow error */
+	if (unlikely(status & UNIPERIF_ITS_FIFO_ERROR_MASK(reader))) {
+		dev_err(reader->dev, "FIFO error detected");
+
+		snd_pcm_stream_lock(reader->substream);
+		snd_pcm_stop(reader->substream, SNDRV_PCM_STATE_XRUN);
+		snd_pcm_stream_unlock(reader->substream);
+
+		return IRQ_HANDLED;
+	}
+
+	return ret;
+}
+
+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;
+	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)
+		== 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;
+		}
+	}
+
+	/* Number of bits per subframe (i.e one channel sample) on input. */
+	switch (slot_width) {
+	case 32:
+		SET_UNIPERIF_I2S_FMT_NBIT_32(reader);
+		SET_UNIPERIF_I2S_FMT_DATA_SIZE_32(reader);
+		break;
+	case 16:
+		SET_UNIPERIF_I2S_FMT_NBIT_16(reader);
+		SET_UNIPERIF_I2S_FMT_DATA_SIZE_16(reader);
+		break;
+	default:
+		dev_err(reader->dev, "subframe format not supported");
+		return -EINVAL;
+	}
+
+	/* Configure data memory format */
+	switch (runtime->format) {
+	case SNDRV_PCM_FORMAT_S16_LE:
+		/* One data word contains two samples */
+		SET_UNIPERIF_CONFIG_MEM_FMT_16_16(reader);
+		break;
+
+	case SNDRV_PCM_FORMAT_S32_LE:
+		/*
+		 * Actually "16 bits/0 bits" means "32/28/24/20/18/16 bits
+		 * on the MSB then zeros (if less than 32 bytes)"...
+		 */
+		SET_UNIPERIF_CONFIG_MEM_FMT_16_0(reader);
+		break;
+
+	default:
+		dev_err(reader->dev, "format not supported");
+		return -EINVAL;
+	}
+
+	switch (reader->daifmt & SND_SOC_DAIFMT_FORMAT_MASK) {
+	case SND_SOC_DAIFMT_I2S:
+		SET_UNIPERIF_I2S_FMT_ALIGN_LEFT(reader);
+		SET_UNIPERIF_I2S_FMT_PADDING_I2S_MODE(reader);
+		break;
+	case SND_SOC_DAIFMT_LEFT_J:
+		SET_UNIPERIF_I2S_FMT_ALIGN_LEFT(reader);
+		SET_UNIPERIF_I2S_FMT_PADDING_SONY_MODE(reader);
+		break;
+	case SND_SOC_DAIFMT_RIGHT_J:
+		SET_UNIPERIF_I2S_FMT_ALIGN_RIGHT(reader);
+		SET_UNIPERIF_I2S_FMT_PADDING_SONY_MODE(reader);
+		break;
+	default:
+		dev_err(reader->dev, "format not supported");
+		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;
+	}
+
+	SET_UNIPERIF_I2S_FMT_NUM_CH(reader, runtime->channels / 2);
+
+	/* Clear any pending interrupts */
+	SET_UNIPERIF_ITS_BCLR(reader, GET_UNIPERIF_ITS(reader));
+
+	SET_UNIPERIF_I2S_FMT_NO_OF_SAMPLES_TO_READ(reader, 0);
+
+	/* Set the interrupt mask */
+	SET_UNIPERIF_ITM_BSET_DMA_ERROR(reader);
+	SET_UNIPERIF_ITM_BSET_FIFO_ERROR(reader);
+	SET_UNIPERIF_ITM_BSET_MEM_BLK_READ(reader);
+
+	/* Enable underflow recovery interrupts */
+	if (reader->info->underflow_enabled) {
+		SET_UNIPERIF_ITM_BSET_UNDERFLOW_REC_DONE(reader);
+		SET_UNIPERIF_ITM_BSET_UNDERFLOW_REC_FAILED(reader);
+	}
+
+	/* Reset uniperipheral reader */
+	SET_UNIPERIF_SOFT_RST_SOFT_RST(reader);
+
+	while (GET_UNIPERIF_SOFT_RST_SOFT_RST(reader)) {
+		udelay(5);
+		count--;
+	}
+	if (!count) {
+		dev_err(reader->dev, "Failed to reset uniperif");
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static int uni_reader_start(struct uniperif *reader)
+{
+	/* The reader should be stopped */
+	if (reader->state != UNIPERIF_STATE_STOPPED) {
+		dev_err(reader->dev, "%s: invalid reader state", __func__);
+		return -EINVAL;
+	}
+
+	/* Enable reader interrupts (and clear possible stalled ones) */
+	SET_UNIPERIF_ITS_BCLR_FIFO_ERROR(reader);
+	SET_UNIPERIF_ITM_BSET_FIFO_ERROR(reader);
+
+	/* Launch the reader */
+	SET_UNIPERIF_CTRL_OPERATION_PCM_DATA(reader);
+
+	/* Update state to started */
+	reader->state = UNIPERIF_STATE_STARTED;
+	return 0;
+}
+
+static int uni_reader_stop(struct uniperif *reader)
+{
+	/* The reader should not be in stopped state */
+	if (reader->state == UNIPERIF_STATE_STOPPED) {
+		dev_err(reader->dev, "%s: invalid reader state", __func__);
+		return -EINVAL;
+	}
+
+	/* Turn the reader off */
+	SET_UNIPERIF_CTRL_OPERATION_OFF(reader);
+
+	/* Disable interrupts */
+	SET_UNIPERIF_ITM_BCLR(reader, GET_UNIPERIF_ITM(reader));
+
+	/* Update state to stopped and return */
+	reader->state = UNIPERIF_STATE_STOPPED;
+
+	return 0;
+}
+
+static int  uni_reader_trigger(struct snd_pcm_substream *substream,
+			       int cmd, struct snd_soc_dai *dai)
+{
+	struct sti_uniperiph_data *priv = snd_soc_dai_get_drvdata(dai);
+	struct uniperif *reader = priv->dai_data.uni;
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+		return  uni_reader_start(reader);
+	case SNDRV_PCM_TRIGGER_STOP:
+		return  uni_reader_stop(reader);
+	default:
+		return -EINVAL;
+	}
+}
+
+static void uni_reader_shutdown(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;
+
+	if (reader->state != UNIPERIF_STATE_STOPPED) {
+		/* Stop the reader */
+		uni_reader_stop(reader);
+	}
+}
+
+static int uni_reader_parse_dt(struct platform_device *pdev,
+			       struct uniperif *reader)
+{
+	struct uniperif_info *info;
+	struct device_node *node = pdev->dev.of_node;
+
+	/* Allocate memory for the info structure */
+	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	of_property_read_u32(node, "version", &reader->ver);
+
+	/* Save the info structure */
+	reader->info = info;
+
+	return 0;
+}
+
+const struct snd_soc_dai_ops uni_reader_dai_ops = {
+		.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,
+};
+
+int uni_reader_init(struct platform_device *pdev,
+		    struct uniperif *reader)
+{
+	int ret = 0;
+
+	reader->dev = &pdev->dev;
+	reader->state = UNIPERIF_STATE_STOPPED;
+	reader->hw = &uni_reader_pcm_hw;
+	reader->dai_ops = &uni_reader_dai_ops;
+
+	dev_err(reader->dev, "%s: enter\n", __func__);
+	ret = uni_reader_parse_dt(pdev, reader);
+	if (ret < 0) {
+		dev_err(reader->dev, "Failed to parse DeviceTree");
+		return ret;
+	}
+
+	ret = devm_request_irq(&pdev->dev, reader->irq,
+			       uni_reader_irq_handler, IRQF_SHARED,
+			       dev_name(&pdev->dev), reader);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "Failed to request IRQ");
+		return -EBUSY;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(uni_reader_init);