ASoC: fsl_asrc: Add ASRC ASoC CPU DAI and platform drivers

The Asynchronous Sample Rate Converter (ASRC) converts the sampling rate of a
signal associated with an input clock into a signal associated with a different
output clock. The driver currently works as a Front End of DPCM with other Back
Ends DAI links such as ESAI<->CS42888 and SSI<->WM8962 and SAI. It converts the
original sample rate to a common rate supported by Back Ends for playback while
converts the common rate of Back Ends to a desired rate for capture. It has 3
pairs to support three different substreams within totally 10 channels.

Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Reviewed-by: Varka Bhadram <varkabhadram@gmail.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

1 files changed, 386 insertions, 0 deletions

diff --git a/sound/soc/fsl/fsl_asrc_dma.c b/sound/soc/fsl/fsl_asrc_dma.c
new file mode 100644
index 0000000..5b1e73e
--- /dev/null
+++ b/sound/soc/fsl/fsl_asrc_dma.c
@@ -0,0 +1,386 @@
+/*
+ * Freescale ASRC ALSA SoC Platform (DMA) driver
+ *
+ * Copyright (C) 2014 Freescale Semiconductor, Inc.
+ *
+ * Author: Nicolin Chen <nicoleotsuka@gmail.com>
+ *
+ * This file is licensed under the terms of the GNU General Public License
+ * version 2. This program is licensed "as is" without any warranty of any
+ * kind, whether express or implied.
+ */
+
+#include <linux/dma-mapping.h>
+#include <linux/module.h>
+#include <linux/platform_data/dma-imx.h>
+#include <sound/dmaengine_pcm.h>
+#include <sound/pcm_params.h>
+
+#include "fsl_asrc.h"
+
+#define FSL_ASRC_DMABUF_SIZE	(256 * 1024)
+
+static struct snd_pcm_hardware snd_imx_hardware = {
+	.info = SNDRV_PCM_INFO_INTERLEAVED |
+		SNDRV_PCM_INFO_BLOCK_TRANSFER |
+		SNDRV_PCM_INFO_MMAP |
+		SNDRV_PCM_INFO_MMAP_VALID |
+		SNDRV_PCM_INFO_PAUSE |
+		SNDRV_PCM_INFO_RESUME,
+	.buffer_bytes_max = FSL_ASRC_DMABUF_SIZE,
+	.period_bytes_min = 128,
+	.period_bytes_max = 65535, /* Limited by SDMA engine */
+	.periods_min = 2,
+	.periods_max = 255,
+	.fifo_size = 0,
+};
+
+static bool filter(struct dma_chan *chan, void *param)
+{
+	if (!imx_dma_is_general_purpose(chan))
+		return false;
+
+	chan->private = param;
+
+	return true;
+}
+
+static void fsl_asrc_dma_complete(void *arg)
+{
+	struct snd_pcm_substream *substream = arg;
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct fsl_asrc_pair *pair = runtime->private_data;
+
+	pair->pos += snd_pcm_lib_period_bytes(substream);
+	if (pair->pos >= snd_pcm_lib_buffer_bytes(substream))
+		pair->pos = 0;
+
+	snd_pcm_period_elapsed(substream);
+}
+
+static int fsl_asrc_dma_prepare_and_submit(struct snd_pcm_substream *substream)
+{
+	u8 dir = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ? OUT : IN;
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct fsl_asrc_pair *pair = runtime->private_data;
+	struct device *dev = rtd->platform->dev;
+	unsigned long flags = DMA_CTRL_ACK;
+
+	/* Prepare and submit Front-End DMA channel */
+	if (!substream->runtime->no_period_wakeup)
+		flags |= DMA_PREP_INTERRUPT;
+
+	pair->pos = 0;
+	pair->desc[!dir] = dmaengine_prep_dma_cyclic(
+			pair->dma_chan[!dir], runtime->dma_addr,
+			snd_pcm_lib_buffer_bytes(substream),
+			snd_pcm_lib_period_bytes(substream),
+			dir == OUT ? DMA_TO_DEVICE : DMA_FROM_DEVICE, flags);
+	if (!pair->desc[!dir]) {
+		dev_err(dev, "failed to prepare slave DMA for Front-End\n");
+		return -ENOMEM;
+	}
+
+	pair->desc[!dir]->callback = fsl_asrc_dma_complete;
+	pair->desc[!dir]->callback_param = substream;
+
+	dmaengine_submit(pair->desc[!dir]);
+
+	/* Prepare and submit Back-End DMA channel */
+	pair->desc[dir] = dmaengine_prep_dma_cyclic(
+			pair->dma_chan[dir], 0xffff, 64, 64, DMA_DEV_TO_DEV, 0);
+	if (!pair->desc[dir]) {
+		dev_err(dev, "failed to prepare slave DMA for Back-End\n");
+		return -ENOMEM;
+	}
+
+	dmaengine_submit(pair->desc[dir]);
+
+	return 0;
+}
+
+static int fsl_asrc_dma_trigger(struct snd_pcm_substream *substream, int cmd)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct fsl_asrc_pair *pair = runtime->private_data;
+	int ret;
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+	case SNDRV_PCM_TRIGGER_RESUME:
+	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+		ret = fsl_asrc_dma_prepare_and_submit(substream);
+		if (ret)
+			return ret;
+		dma_async_issue_pending(pair->dma_chan[IN]);
+		dma_async_issue_pending(pair->dma_chan[OUT]);
+		break;
+	case SNDRV_PCM_TRIGGER_STOP:
+	case SNDRV_PCM_TRIGGER_SUSPEND:
+	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+		dmaengine_terminate_all(pair->dma_chan[OUT]);
+		dmaengine_terminate_all(pair->dma_chan[IN]);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int fsl_asrc_dma_hw_params(struct snd_pcm_substream *substream,
+				  struct snd_pcm_hw_params *params)
+{
+	enum dma_slave_buswidth buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
+	struct snd_dmaengine_dai_dma_data *dma_params_fe = NULL;
+	struct snd_dmaengine_dai_dma_data *dma_params_be = NULL;
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct fsl_asrc_pair *pair = runtime->private_data;
+	struct fsl_asrc *asrc_priv = pair->asrc_priv;
+	struct dma_slave_config config_fe, config_be;
+	enum asrc_pair_index index = pair->index;
+	struct device *dev = rtd->platform->dev;
+	int stream = substream->stream;
+	struct imx_dma_data *tmp_data;
+	struct snd_soc_dpcm *dpcm;
+	struct dma_chan *tmp_chan;
+	struct device *dev_be;
+	u8 dir = tx ? OUT : IN;
+	dma_cap_mask_t mask;
+	int ret;
+
+	/* Fetch the Back-End dma_data from DPCM */
+	list_for_each_entry(dpcm, &rtd->dpcm[stream].be_clients, list_be) {
+		struct snd_soc_pcm_runtime *be = dpcm->be;
+		struct snd_pcm_substream *substream_be;
+		struct snd_soc_dai *dai = be->cpu_dai;
+
+		if (dpcm->fe != rtd)
+			continue;
+
+		substream_be = snd_soc_dpcm_get_substream(be, stream);
+		dma_params_be = snd_soc_dai_get_dma_data(dai, substream_be);
+		dev_be = dai->dev;
+		break;
+	}
+
+	if (!dma_params_be) {
+		dev_err(dev, "failed to get the substream of Back-End\n");
+		return -EINVAL;
+	}
+
+	/* Override dma_data of the Front-End and config its dmaengine */
+	dma_params_fe = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
+	dma_params_fe->addr = asrc_priv->paddr + REG_ASRDx(!dir, index);
+	dma_params_fe->maxburst = dma_params_be->maxburst;
+
+	pair->dma_chan[!dir] = fsl_asrc_get_dma_channel(pair, !dir);
+	if (!pair->dma_chan[!dir]) {
+		dev_err(dev, "failed to request DMA channel\n");
+		return -EINVAL;
+	}
+
+	memset(&config_fe, 0, sizeof(config_fe));
+	ret = snd_dmaengine_pcm_prepare_slave_config(substream, params, &config_fe);
+	if (ret) {
+		dev_err(dev, "failed to prepare DMA config for Front-End\n");
+		return ret;
+	}
+
+	ret = dmaengine_slave_config(pair->dma_chan[!dir], &config_fe);
+	if (ret) {
+		dev_err(dev, "failed to config DMA channel for Front-End\n");
+		return ret;
+	}
+
+	/* Request and config DMA channel for Back-End */
+	dma_cap_zero(mask);
+	dma_cap_set(DMA_SLAVE, mask);
+	dma_cap_set(DMA_CYCLIC, mask);
+
+	/* Get DMA request of Back-End */
+	tmp_chan = dma_request_slave_channel(dev_be, tx ? "tx" : "rx");
+	tmp_data = tmp_chan->private;
+	pair->dma_data.dma_request = tmp_data->dma_request;
+	dma_release_channel(tmp_chan);
+
+	/* Get DMA request of Front-End */
+	tmp_chan = fsl_asrc_get_dma_channel(pair, dir);
+	tmp_data = tmp_chan->private;
+	pair->dma_data.dma_request2 = tmp_data->dma_request;
+	pair->dma_data.peripheral_type = tmp_data->peripheral_type;
+	pair->dma_data.priority = tmp_data->priority;
+	dma_release_channel(tmp_chan);
+
+	pair->dma_chan[dir] = dma_request_channel(mask, filter, &pair->dma_data);
+	if (!pair->dma_chan[dir]) {
+		dev_err(dev, "failed to request DMA channel for Back-End\n");
+		return -EINVAL;
+	}
+
+	if (asrc_priv->asrc_width == 16)
+		buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
+	else
+		buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES;
+
+	config_be.direction = DMA_DEV_TO_DEV;
+	config_be.src_addr_width = buswidth;
+	config_be.src_maxburst = dma_params_be->maxburst;
+	config_be.dst_addr_width = buswidth;
+	config_be.dst_maxburst = dma_params_be->maxburst;
+
+	if (tx) {
+		config_be.src_addr = asrc_priv->paddr + REG_ASRDO(index);
+		config_be.dst_addr = dma_params_be->addr;
+	} else {
+		config_be.dst_addr = asrc_priv->paddr + REG_ASRDI(index);
+		config_be.src_addr = dma_params_be->addr;
+	}
+
+	ret = dmaengine_slave_config(pair->dma_chan[dir], &config_be);
+	if (ret) {
+		dev_err(dev, "failed to config DMA channel for Back-End\n");
+		return ret;
+	}
+
+	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
+
+	return 0;
+}
+
+static int fsl_asrc_dma_hw_free(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct fsl_asrc_pair *pair = runtime->private_data;
+
+	snd_pcm_set_runtime_buffer(substream, NULL);
+
+	if (pair->dma_chan[IN])
+		dma_release_channel(pair->dma_chan[IN]);
+
+	if (pair->dma_chan[OUT])
+		dma_release_channel(pair->dma_chan[OUT]);
+
+	pair->dma_chan[IN] = NULL;
+	pair->dma_chan[OUT] = NULL;
+
+	return 0;
+}
+
+static int fsl_asrc_dma_startup(struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct device *dev = rtd->platform->dev;
+	struct fsl_asrc *asrc_priv = dev_get_drvdata(dev);
+	struct fsl_asrc_pair *pair;
+
+	pair = kzalloc(sizeof(struct fsl_asrc_pair), GFP_KERNEL);
+	if (!pair) {
+		dev_err(dev, "failed to allocate pair\n");
+		return -ENOMEM;
+	}
+
+	pair->asrc_priv = asrc_priv;
+
+	runtime->private_data = pair;
+
+	snd_pcm_hw_constraint_integer(substream->runtime,
+				      SNDRV_PCM_HW_PARAM_PERIODS);
+	snd_soc_set_runtime_hwparams(substream, &snd_imx_hardware);
+
+	return 0;
+}
+
+static int fsl_asrc_dma_shutdown(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct fsl_asrc_pair *pair = runtime->private_data;
+	struct fsl_asrc *asrc_priv = pair->asrc_priv;
+
+	if (pair && asrc_priv->pair[pair->index] == pair)
+		asrc_priv->pair[pair->index] = NULL;
+
+	kfree(pair);
+
+	return 0;
+}
+
+static snd_pcm_uframes_t fsl_asrc_dma_pcm_pointer(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct fsl_asrc_pair *pair = runtime->private_data;
+
+	return bytes_to_frames(substream->runtime, pair->pos);
+}
+
+static struct snd_pcm_ops fsl_asrc_dma_pcm_ops = {
+	.ioctl		= snd_pcm_lib_ioctl,
+	.hw_params	= fsl_asrc_dma_hw_params,
+	.hw_free	= fsl_asrc_dma_hw_free,
+	.trigger	= fsl_asrc_dma_trigger,
+	.open		= fsl_asrc_dma_startup,
+	.close		= fsl_asrc_dma_shutdown,
+	.pointer	= fsl_asrc_dma_pcm_pointer,
+};
+
+static int fsl_asrc_dma_pcm_new(struct snd_soc_pcm_runtime *rtd)
+{
+	struct snd_card *card = rtd->card->snd_card;
+	struct snd_pcm_substream *substream;
+	struct snd_pcm *pcm = rtd->pcm;
+	int ret, i;
+
+	ret = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32));
+	if (ret) {
+		dev_err(card->dev, "failed to set DMA mask\n");
+		return ret;
+	}
+
+	for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_LAST; i++) {
+		substream = pcm->streams[i].substream;
+		if (!substream)
+			continue;
+
+		ret = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, pcm->card->dev,
+				FSL_ASRC_DMABUF_SIZE, &substream->dma_buffer);
+		if (ret) {
+			dev_err(card->dev, "failed to allocate DMA buffer\n");
+			goto err;
+		}
+	}
+
+	return 0;
+
+err:
+	if (--i == 0 && pcm->streams[i].substream)
+		snd_dma_free_pages(&pcm->streams[i].substream->dma_buffer);
+
+	return ret;
+}
+
+static void fsl_asrc_dma_pcm_free(struct snd_pcm *pcm)
+{
+	struct snd_pcm_substream *substream;
+	int i;
+
+	for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_LAST; i++) {
+		substream = pcm->streams[i].substream;
+		if (!substream)
+			continue;
+
+		snd_dma_free_pages(&substream->dma_buffer);
+		substream->dma_buffer.area = NULL;
+		substream->dma_buffer.addr = 0;
+	}
+}
+
+struct snd_soc_platform_driver fsl_asrc_platform = {
+	.ops		= &fsl_asrc_dma_pcm_ops,
+	.pcm_new	= fsl_asrc_dma_pcm_new,
+	.pcm_free	= fsl_asrc_dma_pcm_free,
+};
+EXPORT_SYMBOL_GPL(fsl_asrc_platform);