summaryrefslogtreecommitdiff
path: root/sound/soc/soc-generic-dmaengine-pcm.c
diff options
context:
space:
mode:
Diffstat (limited to 'sound/soc/soc-generic-dmaengine-pcm.c')
-rw-r--r--sound/soc/soc-generic-dmaengine-pcm.c241
1 files changed, 241 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 000000000000..acfc92698995
--- /dev/null
+++ b/sound/soc/soc-generic-dmaengine-pcm.c
@@ -0,0 +1,241 @@
+/*
+ * 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 <linux/of_dma.h>
+
+#include <sound/dmaengine_pcm.h>
+
+struct dmaengine_pcm {
+ struct dma_chan *chan[SNDRV_PCM_STREAM_CAPTURE + 1];
+ const struct snd_dmaengine_pcm_config *config;
+ struct snd_soc_platform platform;
+};
+
+static struct dmaengine_pcm *soc_platform_to_pcm(struct snd_soc_platform *p)
+{
+ return container_of(p, struct dmaengine_pcm, platform);
+}
+
+/**
+ * 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);
+ struct dma_slave_config slave_config;
+ int ret;
+
+ if (pcm->config->prepare_slave_config) {
+ ret = pcm->config->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_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 = snd_soc_set_runtime_hwparams(substream,
+ pcm->config->pcm_hardware);
+ if (ret)
+ return ret;
+
+ return snd_dmaengine_pcm_open(substream, chan);
+}
+
+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;
+}
+
+static void dmaengine_pcm_free(struct snd_pcm *pcm)
+{
+ snd_pcm_lib_preallocate_free_for_all(pcm);
+}
+
+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 snd_pcm_substream *substream;
+ unsigned int i;
+ int ret;
+
+ for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) {
+ substream = rtd->pcm->streams[i].substream;
+ if (!substream)
+ continue;
+
+ if (!pcm->chan[i]) {
+ dev_err(rtd->platform->dev,
+ "Missing dma channel for stream: %d\n", i);
+ ret = -EINVAL;
+ goto err_free;
+ }
+
+ ret = snd_pcm_lib_preallocate_pages(substream,
+ SNDRV_DMA_TYPE_DEV,
+ dmaengine_dma_dev(pcm, substream),
+ config->prealloc_buffer_size,
+ config->pcm_hardware->buffer_bytes_max);
+ if (ret)
+ goto err_free;
+ }
+
+ return 0;
+
+err_free:
+ dmaengine_pcm_free(rtd->pcm);
+ return ret;
+}
+
+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 = snd_dmaengine_pcm_pointer,
+};
+
+static const struct snd_soc_platform_driver dmaengine_pcm_platform = {
+ .ops = &dmaengine_pcm_ops,
+ .pcm_new = dmaengine_pcm_new,
+ .pcm_free = dmaengine_pcm_free,
+};
+
+static const char * const dmaengine_pcm_dma_channel_names[] = {
+ [SNDRV_PCM_STREAM_PLAYBACK] = "tx",
+ [SNDRV_PCM_STREAM_CAPTURE] = "rx",
+};
+
+/**
+ * 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;
+ unsigned int i;
+
+ if (!dev->of_node)
+ return -EINVAL;
+
+ pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
+ if (!pcm)
+ return -ENOMEM;
+
+ pcm->config = config;
+
+ for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) {
+ pcm->chan[i] = of_dma_request_slave_channel(dev->of_node,
+ dmaengine_pcm_dma_channel_names[i]);
+ }
+
+ return snd_soc_add_platform(dev, &pcm->platform,
+ &dmaengine_pcm_platform);
+}
+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;
+ unsigned int i;
+
+ platform = snd_soc_lookup_platform(dev);
+ if (!platform)
+ return;
+
+ pcm = soc_platform_to_pcm(platform);
+
+ for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) {
+ if (pcm->chan[i])
+ dma_release_channel(pcm->chan[i]);
+ }
+
+ snd_soc_remove_platform(platform);
+ kfree(pcm);
+}
+EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_unregister);
+
+MODULE_LICENSE("GPL");