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-rw-r--r--drivers/dma/dmaengine.c35
-rw-r--r--drivers/dma/of-dma.c15
-rw-r--r--include/linux/dmaengine.h8
-rw-r--r--include/sound/dmaengine_pcm.h6
-rw-r--r--sound/soc/soc-generic-dmaengine-pcm.c91
5 files changed, 123 insertions, 32 deletions
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index ea806bdc12e..e17e9b22d85 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -540,6 +540,8 @@ EXPORT_SYMBOL_GPL(dma_get_slave_channel);
* @mask: capabilities that the channel must satisfy
* @fn: optional callback to disposition available channels
* @fn_param: opaque parameter to pass to dma_filter_fn
+ *
+ * Returns pointer to appropriate DMA channel on success or NULL.
*/
struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask,
dma_filter_fn fn, void *fn_param)
@@ -591,18 +593,43 @@ EXPORT_SYMBOL_GPL(__dma_request_channel);
* dma_request_slave_channel - try to allocate an exclusive slave channel
* @dev: pointer to client device structure
* @name: slave channel name
+ *
+ * Returns pointer to appropriate DMA channel on success or an error pointer.
*/
-struct dma_chan *dma_request_slave_channel(struct device *dev, const char *name)
+struct dma_chan *dma_request_slave_channel_reason(struct device *dev,
+ const char *name)
{
+ struct dma_chan *chan;
+
/* If device-tree is present get slave info from here */
if (dev->of_node)
return of_dma_request_slave_channel(dev->of_node, name);
/* If device was enumerated by ACPI get slave info from here */
- if (ACPI_HANDLE(dev))
- return acpi_dma_request_slave_chan_by_name(dev, name);
+ if (ACPI_HANDLE(dev)) {
+ chan = acpi_dma_request_slave_chan_by_name(dev, name);
+ if (chan)
+ return chan;
+ }
- return NULL;
+ return ERR_PTR(-ENODEV);
+}
+EXPORT_SYMBOL_GPL(dma_request_slave_channel_reason);
+
+/**
+ * dma_request_slave_channel - try to allocate an exclusive slave channel
+ * @dev: pointer to client device structure
+ * @name: slave channel name
+ *
+ * Returns pointer to appropriate DMA channel on success or NULL.
+ */
+struct dma_chan *dma_request_slave_channel(struct device *dev,
+ const char *name)
+{
+ struct dma_chan *ch = dma_request_slave_channel_reason(dev, name);
+ if (IS_ERR(ch))
+ return NULL;
+ return ch;
}
EXPORT_SYMBOL_GPL(dma_request_slave_channel);
diff --git a/drivers/dma/of-dma.c b/drivers/dma/of-dma.c
index 0b88dd3d05f..e8fe9dc455f 100644
--- a/drivers/dma/of-dma.c
+++ b/drivers/dma/of-dma.c
@@ -143,7 +143,7 @@ static int of_dma_match_channel(struct device_node *np, const char *name,
* @np: device node to get DMA request from
* @name: name of desired channel
*
- * Returns pointer to appropriate dma channel on success or NULL on error.
+ * Returns pointer to appropriate DMA channel on success or an error pointer.
*/
struct dma_chan *of_dma_request_slave_channel(struct device_node *np,
const char *name)
@@ -152,17 +152,18 @@ struct dma_chan *of_dma_request_slave_channel(struct device_node *np,
struct of_dma *ofdma;
struct dma_chan *chan;
int count, i;
+ int ret_no_channel = -ENODEV;
if (!np || !name) {
pr_err("%s: not enough information provided\n", __func__);
- return NULL;
+ return ERR_PTR(-ENODEV);
}
count = of_property_count_strings(np, "dma-names");
if (count < 0) {
pr_err("%s: dma-names property of node '%s' missing or empty\n",
__func__, np->full_name);
- return NULL;
+ return ERR_PTR(-ENODEV);
}
for (i = 0; i < count; i++) {
@@ -172,10 +173,12 @@ struct dma_chan *of_dma_request_slave_channel(struct device_node *np,
mutex_lock(&of_dma_lock);
ofdma = of_dma_find_controller(&dma_spec);
- if (ofdma)
+ if (ofdma) {
chan = ofdma->of_dma_xlate(&dma_spec, ofdma);
- else
+ } else {
+ ret_no_channel = -EPROBE_DEFER;
chan = NULL;
+ }
mutex_unlock(&of_dma_lock);
@@ -185,7 +188,7 @@ struct dma_chan *of_dma_request_slave_channel(struct device_node *np,
return chan;
}
- return NULL;
+ return ERR_PTR(ret_no_channel);
}
/**
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index 41cf0c39928..ed92b30a02f 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -22,6 +22,7 @@
#define LINUX_DMAENGINE_H
#include <linux/device.h>
+#include <linux/err.h>
#include <linux/uio.h>
#include <linux/bug.h>
#include <linux/scatterlist.h>
@@ -1040,6 +1041,8 @@ enum dma_status dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx);
void dma_issue_pending_all(void);
struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask,
dma_filter_fn fn, void *fn_param);
+struct dma_chan *dma_request_slave_channel_reason(struct device *dev,
+ const char *name);
struct dma_chan *dma_request_slave_channel(struct device *dev, const char *name);
void dma_release_channel(struct dma_chan *chan);
#else
@@ -1063,6 +1066,11 @@ static inline struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask,
{
return NULL;
}
+static inline struct dma_chan *dma_request_slave_channel_reason(
+ struct device *dev, const char *name)
+{
+ return ERR_PTR(-ENODEV);
+}
static inline struct dma_chan *dma_request_slave_channel(struct device *dev,
const char *name)
{
diff --git a/include/sound/dmaengine_pcm.h b/include/sound/dmaengine_pcm.h
index 4ef986cab18..eb73a3a39ec 100644
--- a/include/sound/dmaengine_pcm.h
+++ b/include/sound/dmaengine_pcm.h
@@ -114,6 +114,10 @@ void snd_dmaengine_pcm_set_config_from_dai_data(
* @compat_filter_fn: Will be used as the filter function when requesting a
* channel for platforms which do not use devicetree. The filter parameter
* will be the DAI's DMA data.
+ * @dma_dev: If set, request DMA channel on this device rather than the DAI
+ * device.
+ * @chan_names: If set, these custom DMA channel names will be requested at
+ * registration time.
* @pcm_hardware: snd_pcm_hardware struct to be used for the PCM.
* @prealloc_buffer_size: Size of the preallocated audio buffer.
*
@@ -130,6 +134,8 @@ struct snd_dmaengine_pcm_config {
struct snd_soc_pcm_runtime *rtd,
struct snd_pcm_substream *substream);
dma_filter_fn compat_filter_fn;
+ struct device *dma_dev;
+ const char *chan_names[SNDRV_PCM_STREAM_LAST + 1];
const struct snd_pcm_hardware *pcm_hardware;
unsigned int prealloc_buffer_size;
diff --git a/sound/soc/soc-generic-dmaengine-pcm.c b/sound/soc/soc-generic-dmaengine-pcm.c
index 87e86357124..2a6c569d991 100644
--- a/sound/soc/soc-generic-dmaengine-pcm.c
+++ b/sound/soc/soc-generic-dmaengine-pcm.c
@@ -287,24 +287,67 @@ static const char * const dmaengine_pcm_dma_channel_names[] = {
[SNDRV_PCM_STREAM_CAPTURE] = "rx",
};
-static void dmaengine_pcm_request_chan_of(struct dmaengine_pcm *pcm,
- struct device *dev)
+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;
+ 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;
+ }
- if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) {
- pcm->chan[0] = dma_request_slave_channel(dev, "rx-tx");
- pcm->chan[1] = pcm->chan[0];
- } else {
- for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) {
- pcm->chan[i] = dma_request_slave_channel(dev,
- dmaengine_pcm_dma_channel_names[i]);
+ 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;
}
}
@@ -318,6 +361,7 @@ 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)
@@ -326,14 +370,25 @@ int snd_dmaengine_pcm_register(struct device *dev,
pcm->config = config;
pcm->flags = flags;
- dmaengine_pcm_request_chan_of(pcm, dev);
+ ret = dmaengine_pcm_request_chan_of(pcm, dev, config);
+ if (ret)
+ goto err_free_dma;
if (flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE)
- return snd_soc_add_platform(dev, &pcm->platform,
+ ret = snd_soc_add_platform(dev, &pcm->platform,
&dmaengine_no_residue_pcm_platform);
else
- return snd_soc_add_platform(dev, &pcm->platform,
+ 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);
@@ -348,7 +403,6 @@ 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)
@@ -356,15 +410,8 @@ void snd_dmaengine_pcm_unregister(struct device *dev)
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]);
- if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
- break;
- }
- }
-
snd_soc_remove_platform(platform);
+ dmaengine_pcm_release_chan(pcm);
kfree(pcm);
}
EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_unregister);
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2025-08-09 11:03:19 +0000