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// SPDX-License-Identifier: GPL-2.0+
//
// Copyright (C) 2013, Analog Devices Inc.
// Author: Lars-Peter Clausen <lars@metafoo.de>
#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>
static unsigned int prealloc_buffer_size_kbytes = 512;
module_param(prealloc_buffer_size_kbytes, uint, 0444);
MODULE_PARM_DESC(prealloc_buffer_size_kbytes, "Preallocate DMA buffer size (KB).");
/*
* The platforms dmaengine driver does not support reporting the amount of
* bytes that are still left to transfer.
*/
#define SND_DMAENGINE_PCM_FLAG_NO_RESIDUE BIT(31)
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_pcm_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 = asoc_substream_to_rtd(substream);
struct snd_dmaengine_dai_dma_data *dma_data;
int ret;
if (rtd->dai_link->num_cpus > 1) {
dev_err(rtd->dev,
"%s doesn't support Multi CPU yet\n", __func__);
return -EINVAL;
}
dma_data = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), 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_soc_component *component,
struct snd_pcm_substream *substream,
struct snd_pcm_hw_params *params)
{
struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
struct dma_chan *chan = snd_dmaengine_pcm_get_chan(substream);
struct dma_slave_config slave_config;
int ret;
if (!pcm->config->prepare_slave_config)
return 0;
memset(&slave_config, 0, sizeof(slave_config));
ret = pcm->config->prepare_slave_config(substream, params, &slave_config);
if (ret)
return ret;
return dmaengine_slave_config(chan, &slave_config);
}
static int
dmaengine_pcm_set_runtime_hwparams(struct snd_soc_component *component,
struct snd_pcm_substream *substream)
{
struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
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 snd_pcm_hardware hw;
if (rtd->dai_link->num_cpus > 1) {
dev_err(rtd->dev,
"%s doesn't support Multi CPU yet\n", __func__);
return -EINVAL;
}
if (pcm->config->pcm_hardware)
return snd_soc_set_runtime_hwparams(substream,
pcm->config->pcm_hardware);
dma_data = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), 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 = dma_data->maxburst * DMA_SLAVE_BUSWIDTH_8_BYTES;
if (!hw.period_bytes_min)
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;
/**
* FIXME: Remove the return value check to align with the code
* before adding snd_dmaengine_pcm_refine_runtime_hwparams
* function.
*/
snd_dmaengine_pcm_refine_runtime_hwparams(substream,
dma_data,
&hw,
chan);
return snd_soc_set_runtime_hwparams(substream, &hw);
}
static int dmaengine_pcm_open(struct snd_soc_component *component,
struct snd_pcm_substream *substream)
{
struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
struct dma_chan *chan = pcm->chan[substream->stream];
int ret;
ret = dmaengine_pcm_set_runtime_hwparams(component, substream);
if (ret)
return ret;
return snd_dmaengine_pcm_open(substream, chan);
}
static int dmaengine_pcm_close(struct snd_soc_component *component,
struct snd_pcm_substream *substream)
{
return snd_dmaengine_pcm_close(substream);
}
static int dmaengine_pcm_trigger(struct snd_soc_component *component,
struct snd_pcm_substream *substream, int cmd)
{
return snd_dmaengine_pcm_trigger(substream, cmd);
}
static struct dma_chan *dmaengine_pcm_compat_request_channel(
struct snd_soc_component *component,
struct snd_soc_pcm_runtime *rtd,
struct snd_pcm_substream *substream)
{
struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
struct snd_dmaengine_dai_dma_data *dma_data;
if (rtd->dai_link->num_cpus > 1) {
dev_err(rtd->dev,
"%s doesn't support Multi CPU yet\n", __func__);
return NULL;
}
dma_data = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), substream);
if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) && pcm->chan[0])
return pcm->chan[0];
if (pcm->config->compat_request_channel)
return pcm->config->compat_request_channel(rtd, substream);
return snd_dmaengine_pcm_request_channel(pcm->config->compat_filter_fn,
dma_data->filter_data);
}
static bool dmaengine_pcm_can_report_residue(struct device *dev,
struct dma_chan *chan)
{
struct dma_slave_caps dma_caps;
int ret;
ret = dma_get_slave_caps(chan, &dma_caps);
if (ret != 0) {
dev_warn(dev, "Failed to get DMA channel capabilities, falling back to period counting: %d\n",
ret);
return false;
}
if (dma_caps.residue_granularity == DMA_RESIDUE_GRANULARITY_DESCRIPTOR)
return false;
return true;
}
static int dmaengine_pcm_new(struct snd_soc_component *component,
struct snd_soc_pcm_runtime *rtd)
{
struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
const struct snd_dmaengine_pcm_config *config = pcm->config;
struct device *dev = component->dev;
size_t prealloc_buffer_size;
size_t max_buffer_size;
unsigned int i;
if (config->prealloc_buffer_size)
prealloc_buffer_size = config->prealloc_buffer_size;
else
prealloc_buffer_size = prealloc_buffer_size_kbytes * 1024;
if (config->pcm_hardware && config->pcm_hardware->buffer_bytes_max)
max_buffer_size = config->pcm_hardware->buffer_bytes_max;
else
max_buffer_size = SIZE_MAX;
for_each_pcm_streams(i) {
struct snd_pcm_substream *substream = rtd->pcm->streams[i].substream;
if (!substream)
continue;
if (!pcm->chan[i] && config->chan_names[i])
pcm->chan[i] = dma_request_slave_channel(dev,
config->chan_names[i]);
if (!pcm->chan[i] && (pcm->flags & SND_DMAENGINE_PCM_FLAG_COMPAT)) {
pcm->chan[i] = dmaengine_pcm_compat_request_channel(
component, rtd, substream);
}
if (!pcm->chan[i]) {
dev_err(component->dev,
"Missing dma channel for stream: %d\n", i);
return -EINVAL;
}
snd_pcm_set_managed_buffer(substream,
SNDRV_DMA_TYPE_DEV_IRAM,
dmaengine_dma_dev(pcm, substream),
prealloc_buffer_size,
max_buffer_size);
if (!dmaengine_pcm_can_report_residue(dev, pcm->chan[i]))
pcm->flags |= SND_DMAENGINE_PCM_FLAG_NO_RESIDUE;
if (rtd->pcm->streams[i].pcm->name[0] == '\0') {
strscpy_pad(rtd->pcm->streams[i].pcm->name,
rtd->pcm->streams[i].pcm->id,
sizeof(rtd->pcm->streams[i].pcm->name));
}
}
return 0;
}
static snd_pcm_uframes_t dmaengine_pcm_pointer(
struct snd_soc_component *component,
struct snd_pcm_substream *substream)
{
struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
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 int dmaengine_copy(struct snd_soc_component *component,
struct snd_pcm_substream *substream,
int channel, unsigned long hwoff,
struct iov_iter *iter, unsigned long bytes)
{
struct snd_pcm_runtime *runtime = substream->runtime;
struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
int (*process)(struct snd_pcm_substream *substream,
int channel, unsigned long hwoff,
unsigned long bytes) = pcm->config->process;
bool is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
void *dma_ptr = runtime->dma_area + hwoff +
channel * (runtime->dma_bytes / runtime->channels);
if (is_playback)
if (copy_from_iter(dma_ptr, bytes, iter) != bytes)
return -EFAULT;
if (process) {
int ret = process(substream, channel, hwoff, bytes);
if (ret < 0)
return ret;
}
if (!is_playback)
if (copy_to_iter(dma_ptr, bytes, iter) != bytes)
return -EFAULT;
return 0;
}
static const struct snd_soc_component_driver dmaengine_pcm_component = {
.name = SND_DMAENGINE_PCM_DRV_NAME,
.probe_order = SND_SOC_COMP_ORDER_LATE,
.open = dmaengine_pcm_open,
.close = dmaengine_pcm_close,
.hw_params = dmaengine_pcm_hw_params,
.trigger = dmaengine_pcm_trigger,
.pointer = dmaengine_pcm_pointer,
.pcm_construct = dmaengine_pcm_new,
};
static const struct snd_soc_component_driver dmaengine_pcm_component_process = {
.name = SND_DMAENGINE_PCM_DRV_NAME,
.probe_order = SND_SOC_COMP_ORDER_LATE,
.open = dmaengine_pcm_open,
.close = dmaengine_pcm_close,
.hw_params = dmaengine_pcm_hw_params,
.trigger = dmaengine_pcm_trigger,
.pointer = dmaengine_pcm_pointer,
.copy = dmaengine_copy,
.pcm_construct = 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) || (!dev->of_node &&
!(config->dma_dev && config->dma_dev->of_node)))
return 0;
if (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_each_pcm_streams(i) {
if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
name = "rx-tx";
else
name = dmaengine_pcm_dma_channel_names[i];
if (config->chan_names[i])
name = config->chan_names[i];
chan = dma_request_chan(dev, name);
if (IS_ERR(chan)) {
/*
* Only report probe deferral errors, channels
* might not be present for devices that
* support only TX or only RX.
*/
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_each_pcm_streams(i) {
if (!pcm->chan[i])
continue;
dma_release_channel(pcm->chan[i]);
if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
break;
}
}
static const struct snd_dmaengine_pcm_config snd_dmaengine_pcm_default_config = {
.prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config,
};
/**
* 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)
{
const struct snd_soc_component_driver *driver;
struct dmaengine_pcm *pcm;
int ret;
pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
if (!pcm)
return -ENOMEM;
#ifdef CONFIG_DEBUG_FS
pcm->component.debugfs_prefix = "dma";
#endif
if (!config)
config = &snd_dmaengine_pcm_default_config;
pcm->config = config;
pcm->flags = flags;
ret = dmaengine_pcm_request_chan_of(pcm, dev, config);
if (ret)
goto err_free_dma;
if (config->process)
driver = &dmaengine_pcm_component_process;
else
driver = &dmaengine_pcm_component;
ret = snd_soc_component_initialize(&pcm->component, driver, dev);
if (ret)
goto err_free_dma;
ret = snd_soc_add_component(&pcm->component, NULL, 0);
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_component *component;
struct dmaengine_pcm *pcm;
component = snd_soc_lookup_component(dev, SND_DMAENGINE_PCM_DRV_NAME);
if (!component)
return;
pcm = soc_component_to_pcm(component);
snd_soc_unregister_component_by_driver(dev, component->driver);
dmaengine_pcm_release_chan(pcm);
kfree(pcm);
}
EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_unregister);
MODULE_LICENSE("GPL");