1 files changed, 466 insertions, 0 deletions
diff --git a/sound/soc/soc-generic-dmaengine-pcm.c b/sound/soc/soc-generic-dmaengine-pcm.c
new file mode 100644
index 000000000..c9917ca5d
--- /dev/null
+++ b/sound/soc/soc-generic-dmaengine-pcm.c
@@ -0,0 +1,466 @@
+/*
+ *  Copyright (C) 2013, Analog Devices Inc.
+ *	Author: Lars-Peter Clausen <lars@metafoo.de>
+ *
+ *  This program is free software; you can redistribute it and/or modify it
+ *  under  the terms of the GNU General  Public License as published by the
+ *  Free Software Foundation;  either version 2 of the License, or (at your
+ *  option) any later version.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/dmaengine.h>
+#include <linux/slab.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+#include <linux/dma-mapping.h>
+#include <linux/of.h>
+
+#include <sound/dmaengine_pcm.h>
+
+struct dmaengine_pcm {
+	struct dma_chan *chan[SNDRV_PCM_STREAM_LAST + 1];
+	const struct snd_dmaengine_pcm_config *config;
+	struct snd_soc_platform platform;
+	unsigned int flags;
+};
+
+static struct dmaengine_pcm *soc_platform_to_pcm(struct snd_soc_platform *p)
+{
+	return container_of(p, struct dmaengine_pcm, platform);
+}
+
+static struct device *dmaengine_dma_dev(struct dmaengine_pcm *pcm,
+	struct snd_pcm_substream *substream)
+{
+	if (!pcm->chan[substream->stream])
+		return NULL;
+
+	return pcm->chan[substream->stream]->device->dev;
+}
+
+/**
+ * snd_dmaengine_pcm_prepare_slave_config() - Generic prepare_slave_config callback
+ * @substream: PCM substream
+ * @params: hw_params
+ * @slave_config: DMA slave config to prepare
+ *
+ * This function can be used as a generic prepare_slave_config callback for
+ * platforms which make use of the snd_dmaengine_dai_dma_data struct for their
+ * DAI DMA data. Internally the function will first call
+ * snd_hwparams_to_dma_slave_config to fill in the slave config based on the
+ * hw_params, followed by snd_dmaengine_set_config_from_dai_data to fill in the
+ * remaining fields based on the DAI DMA data.
+ */
+int snd_dmaengine_pcm_prepare_slave_config(struct snd_pcm_substream *substream,
+	struct snd_pcm_hw_params *params, struct dma_slave_config *slave_config)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct snd_dmaengine_dai_dma_data *dma_data;
+	int ret;
+
+	dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
+
+	ret = snd_hwparams_to_dma_slave_config(substream, params, slave_config);
+	if (ret)
+		return ret;
+
+	snd_dmaengine_pcm_set_config_from_dai_data(substream, dma_data,
+		slave_config);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_prepare_slave_config);
+
+static int dmaengine_pcm_hw_params(struct snd_pcm_substream *substream,
+	struct snd_pcm_hw_params *params)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
+	struct dma_chan *chan = snd_dmaengine_pcm_get_chan(substream);
+	int (*prepare_slave_config)(struct snd_pcm_substream *substream,
+			struct snd_pcm_hw_params *params,
+			struct dma_slave_config *slave_config);
+	struct dma_slave_config slave_config;
+	int ret;
+
+	memset(&slave_config, 0, sizeof(slave_config));
+
+	if (!pcm->config)
+		prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config;
+	else
+		prepare_slave_config = pcm->config->prepare_slave_config;
+
+	if (prepare_slave_config) {
+		ret = prepare_slave_config(substream, params, &slave_config);
+		if (ret)
+			return ret;
+
+		ret = dmaengine_slave_config(chan, &slave_config);
+		if (ret)
+			return ret;
+	}
+
+	return snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(params));
+}
+
+static int dmaengine_pcm_set_runtime_hwparams(struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
+	struct device *dma_dev = dmaengine_dma_dev(pcm, substream);
+	struct dma_chan *chan = pcm->chan[substream->stream];
+	struct snd_dmaengine_dai_dma_data *dma_data;
+	struct dma_slave_caps dma_caps;
+	struct snd_pcm_hardware hw;
+	u32 addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
+			  BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
+			  BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
+	int i, ret;
+
+	if (pcm->config && pcm->config->pcm_hardware)
+		return snd_soc_set_runtime_hwparams(substream,
+				pcm->config->pcm_hardware);
+
+	dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
+
+	memset(&hw, 0, sizeof(hw));
+	hw.info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
+			SNDRV_PCM_INFO_INTERLEAVED;
+	hw.periods_min = 2;
+	hw.periods_max = UINT_MAX;
+	hw.period_bytes_min = 256;
+	hw.period_bytes_max = dma_get_max_seg_size(dma_dev);
+	hw.buffer_bytes_max = SIZE_MAX;
+	hw.fifo_size = dma_data->fifo_size;
+
+	if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE)
+		hw.info |= SNDRV_PCM_INFO_BATCH;
+
+	ret = dma_get_slave_caps(chan, &dma_caps);
+	if (ret == 0) {
+		if (dma_caps.cmd_pause)
+			hw.info |= SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_RESUME;
+		if (dma_caps.residue_granularity <= DMA_RESIDUE_GRANULARITY_SEGMENT)
+			hw.info |= SNDRV_PCM_INFO_BATCH;
+
+		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+			addr_widths = dma_caps.dst_addr_widths;
+		else
+			addr_widths = dma_caps.src_addr_widths;
+	}
+
+	/*
+	 * Prepare formats mask for valid/allowed sample types. If the dma does
+	 * not have support for the given physical word size, it needs to be
+	 * masked out so user space can not use the format which produces
+	 * corrupted audio.
+	 * In case the dma driver does not implement the slave_caps the default
+	 * assumption is that it supports 1, 2 and 4 bytes widths.
+	 */
+	for (i = 0; i <= SNDRV_PCM_FORMAT_LAST; i++) {
+		int bits = snd_pcm_format_physical_width(i);
+
+		/* Enable only samples with DMA supported physical widths */
+		switch (bits) {
+		case 8:
+		case 16:
+		case 24:
+		case 32:
+		case 64:
+			if (addr_widths & (1 << (bits / 8)))
+				hw.formats |= (1LL << i);
+			break;
+		default:
+			/* Unsupported types */
+			break;
+		}
+	}
+
+	return snd_soc_set_runtime_hwparams(substream, &hw);
+}
+
+static int dmaengine_pcm_open(struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
+	struct dma_chan *chan = pcm->chan[substream->stream];
+	int ret;
+
+	ret = dmaengine_pcm_set_runtime_hwparams(substream);
+	if (ret)
+		return ret;
+
+	return snd_dmaengine_pcm_open(substream, chan);
+}
+
+static struct dma_chan *dmaengine_pcm_compat_request_channel(
+	struct snd_soc_pcm_runtime *rtd,
+	struct snd_pcm_substream *substream)
+{
+	struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
+	struct snd_dmaengine_dai_dma_data *dma_data;
+	dma_filter_fn fn = NULL;
+
+	dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
+
+	if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) && pcm->chan[0])
+		return pcm->chan[0];
+
+	if (pcm->config && pcm->config->compat_request_channel)
+		return pcm->config->compat_request_channel(rtd, substream);
+
+	if (pcm->config)
+		fn = pcm->config->compat_filter_fn;
+
+	return snd_dmaengine_pcm_request_channel(fn, dma_data->filter_data);
+}
+
+static bool dmaengine_pcm_can_report_residue(struct dma_chan *chan)
+{
+	struct dma_slave_caps dma_caps;
+	int ret;
+
+	ret = dma_get_slave_caps(chan, &dma_caps);
+	if (ret != 0)
+		return true;
+
+	if (dma_caps.residue_granularity == DMA_RESIDUE_GRANULARITY_DESCRIPTOR)
+		return false;
+
+	return true;
+}
+
+static int dmaengine_pcm_new(struct snd_soc_pcm_runtime *rtd)
+{
+	struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
+	const struct snd_dmaengine_pcm_config *config = pcm->config;
+	struct device *dev = rtd->platform->dev;
+	struct snd_dmaengine_dai_dma_data *dma_data;
+	struct snd_pcm_substream *substream;
+	size_t prealloc_buffer_size;
+	size_t max_buffer_size;
+	unsigned int i;
+	int ret;
+
+	if (config && config->prealloc_buffer_size) {
+		prealloc_buffer_size = config->prealloc_buffer_size;
+		max_buffer_size = config->pcm_hardware->buffer_bytes_max;
+	} else {
+		prealloc_buffer_size = 512 * 1024;
+		max_buffer_size = SIZE_MAX;
+	}
+
+
+	for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) {
+		substream = rtd->pcm->streams[i].substream;
+		if (!substream)
+			continue;
+
+		dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
+
+		if (!pcm->chan[i] &&
+		    (pcm->flags & SND_DMAENGINE_PCM_FLAG_CUSTOM_CHANNEL_NAME))
+			pcm->chan[i] = dma_request_slave_channel(dev,
+				dma_data->chan_name);
+
+		if (!pcm->chan[i] && (pcm->flags & SND_DMAENGINE_PCM_FLAG_COMPAT)) {
+			pcm->chan[i] = dmaengine_pcm_compat_request_channel(rtd,
+				substream);
+		}
+
+		if (!pcm->chan[i]) {
+			dev_err(rtd->platform->dev,
+				"Missing dma channel for stream: %d\n", i);
+			return -EINVAL;
+		}
+
+		ret = snd_pcm_lib_preallocate_pages(substream,
+				SNDRV_DMA_TYPE_DEV_IRAM,
+				dmaengine_dma_dev(pcm, substream),
+				prealloc_buffer_size,
+				max_buffer_size);
+		if (ret)
+			return ret;
+
+		/*
+		 * This will only return false if we know for sure that at least
+		 * one channel does not support residue reporting. If the DMA
+		 * driver does not implement the slave_caps API we rely having
+		 * the NO_RESIDUE flag set manually in case residue reporting is
+		 * not supported.
+		 */
+		if (!dmaengine_pcm_can_report_residue(pcm->chan[i]))
+			pcm->flags |= SND_DMAENGINE_PCM_FLAG_NO_RESIDUE;
+	}
+
+	return 0;
+}
+
+static snd_pcm_uframes_t dmaengine_pcm_pointer(
+	struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
+
+	if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE)
+		return snd_dmaengine_pcm_pointer_no_residue(substream);
+	else
+		return snd_dmaengine_pcm_pointer(substream);
+}
+
+static const struct snd_pcm_ops dmaengine_pcm_ops = {
+	.open		= dmaengine_pcm_open,
+	.close		= snd_dmaengine_pcm_close,
+	.ioctl		= snd_pcm_lib_ioctl,
+	.hw_params	= dmaengine_pcm_hw_params,
+	.hw_free	= snd_pcm_lib_free_pages,
+	.trigger	= snd_dmaengine_pcm_trigger,
+	.pointer	= dmaengine_pcm_pointer,
+};
+
+static const struct snd_soc_platform_driver dmaengine_pcm_platform = {
+	.component_driver = {
+		.probe_order = SND_SOC_COMP_ORDER_LATE,
+	},
+	.ops		= &dmaengine_pcm_ops,
+	.pcm_new	= dmaengine_pcm_new,
+};
+
+static const char * const dmaengine_pcm_dma_channel_names[] = {
+	[SNDRV_PCM_STREAM_PLAYBACK] = "tx",
+	[SNDRV_PCM_STREAM_CAPTURE] = "rx",
+};
+
+static int dmaengine_pcm_request_chan_of(struct dmaengine_pcm *pcm,
+	struct device *dev, const struct snd_dmaengine_pcm_config *config)
+{
+	unsigned int i;
+	const char *name;
+	struct dma_chan *chan;
+
+	if ((pcm->flags & (SND_DMAENGINE_PCM_FLAG_NO_DT |
+			   SND_DMAENGINE_PCM_FLAG_CUSTOM_CHANNEL_NAME)) ||
+	    !dev->of_node)
+		return 0;
+
+	if (config && config->dma_dev) {
+		/*
+		 * If this warning is seen, it probably means that your Linux
+		 * device structure does not match your HW device structure.
+		 * It would be best to refactor the Linux device structure to
+		 * correctly match the HW structure.
+		 */
+		dev_warn(dev, "DMA channels sourced from device %s",
+			 dev_name(config->dma_dev));
+		dev = config->dma_dev;
+	}
+
+	for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE;
+	     i++) {
+		if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
+			name = "rx-tx";
+		else
+			name = dmaengine_pcm_dma_channel_names[i];
+		if (config && config->chan_names[i])
+			name = config->chan_names[i];
+		chan = dma_request_slave_channel_reason(dev, name);
+		if (IS_ERR(chan)) {
+			if (PTR_ERR(chan) == -EPROBE_DEFER)
+				return -EPROBE_DEFER;
+			pcm->chan[i] = NULL;
+		} else {
+			pcm->chan[i] = chan;
+		}
+		if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
+			break;
+	}
+
+	if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
+		pcm->chan[1] = pcm->chan[0];
+
+	return 0;
+}
+
+static void dmaengine_pcm_release_chan(struct dmaengine_pcm *pcm)
+{
+	unsigned int i;
+
+	for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE;
+	     i++) {
+		if (!pcm->chan[i])
+			continue;
+		dma_release_channel(pcm->chan[i]);
+		if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
+			break;
+	}
+}
+
+/**
+ * snd_dmaengine_pcm_register - Register a dmaengine based PCM device
+ * @dev: The parent device for the PCM device
+ * @config: Platform specific PCM configuration
+ * @flags: Platform specific quirks
+ */
+int snd_dmaengine_pcm_register(struct device *dev,
+	const struct snd_dmaengine_pcm_config *config, unsigned int flags)
+{
+	struct dmaengine_pcm *pcm;
+	int ret;
+
+	pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
+	if (!pcm)
+		return -ENOMEM;
+
+	pcm->config = config;
+	pcm->flags = flags;
+
+	ret = dmaengine_pcm_request_chan_of(pcm, dev, config);
+	if (ret)
+		goto err_free_dma;
+
+	ret = snd_soc_add_platform(dev, &pcm->platform,
+		&dmaengine_pcm_platform);
+	if (ret)
+		goto err_free_dma;
+
+	return 0;
+
+err_free_dma:
+	dmaengine_pcm_release_chan(pcm);
+	kfree(pcm);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_register);
+
+/**
+ * snd_dmaengine_pcm_unregister - Removes a dmaengine based PCM device
+ * @dev: Parent device the PCM was register with
+ *
+ * Removes a dmaengine based PCM device previously registered with
+ * snd_dmaengine_pcm_register.
+ */
+void snd_dmaengine_pcm_unregister(struct device *dev)
+{
+	struct snd_soc_platform *platform;
+	struct dmaengine_pcm *pcm;
+
+	platform = snd_soc_lookup_platform(dev);
+	if (!platform)
+		return;
+
+	pcm = soc_platform_to_pcm(platform);
+
+	snd_soc_remove_platform(platform);
+	dmaengine_pcm_release_chan(pcm);
+	kfree(pcm);
+}
+EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_unregister);
+
+MODULE_LICENSE("GPL");