// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2012, Analog Devices Inc.
* Author: Lars-Peter Clausen <[email protected]>
*
* Based on:
* imx-pcm-dma-mx2.c, Copyright 2009 Sascha Hauer <[email protected]>
* mxs-pcm.c, Copyright (C) 2011 Freescale Semiconductor, Inc.
* ep93xx-pcm.c, Copyright (C) 2006 Lennert Buytenhek <[email protected]>
* Copyright (C) 2006 Applied Data Systems
*/
#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 <sound/dmaengine_pcm.h>
struct dmaengine_pcm_runtime_data {
struct dma_chan *dma_chan;
dma_cookie_t cookie;
unsigned int pos;
};
static inline struct dmaengine_pcm_runtime_data *substream_to_prtd(
const struct snd_pcm_substream *substream)
{
return substream->runtime->private_data;
}
struct dma_chan *snd_dmaengine_pcm_get_chan(struct snd_pcm_substream *substream)
{
struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
return prtd->dma_chan;
}
EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_get_chan);
/**
* snd_hwparams_to_dma_slave_config - Convert hw_params to dma_slave_config
* @substream: PCM substream
* @params: hw_params
* @slave_config: DMA slave config
*
* This function can be used to initialize a dma_slave_config from a substream
* and hw_params in a dmaengine based PCM driver implementation.
*
* Return: zero if successful, or a negative error code
*/
int snd_hwparams_to_dma_slave_config(const struct snd_pcm_substream *substream,
const struct snd_pcm_hw_params *params,
struct dma_slave_config *slave_config)
{
enum dma_slave_buswidth buswidth;
int bits;
bits = params_physical_width(params);
if (bits < 8 || bits > 64)
return -EINVAL;
else if (bits == 8)
buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE;
else if (bits == 16)
buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
else if (bits == 24)
buswidth = DMA_SLAVE_BUSWIDTH_3_BYTES;
else if (bits <= 32)
buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES;
else
buswidth = DMA_SLAVE_BUSWIDTH_8_BYTES;
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
slave_config->direction = DMA_MEM_TO_DEV;
slave_config->dst_addr_width = buswidth;
} else {
slave_config->direction = DMA_DEV_TO_MEM;
slave_config->src_addr_width = buswidth;
}
slave_config->device_fc = false;
return 0;
}
EXPORT_SYMBOL_GPL(snd_hwparams_to_dma_slave_config);
/**
* snd_dmaengine_pcm_set_config_from_dai_data() - Initializes a dma slave config
* using DAI DMA data.
* @substream: PCM substream
* @dma_data: DAI DMA data
* @slave_config: DMA slave configuration
*
* Initializes the {dst,src}_addr, {dst,src}_maxburst, {dst,src}_addr_width
* fields of the DMA slave config from the same fields of the DAI DMA
* data struct. The src and dst fields will be initialized depending on the
* direction of the substream. If the substream is a playback stream the dst
* fields will be initialized, if it is a capture stream the src fields will be
* initialized. The {dst,src}_addr_width field will only be initialized if the
* SND_DMAENGINE_PCM_DAI_FLAG_PACK flag is set or if the addr_width field of
* the DAI DMA data struct is not equal to DMA_SLAVE_BUSWIDTH_UNDEFINED. If
* both conditions are met the latter takes priority.
*/
void snd_dmaengine_pcm_set_config_from_dai_data(
const struct snd_pcm_substream *substream,
const struct snd_dmaengine_dai_dma_data *dma_data,
struct dma_slave_config *slave_config)
{
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
slave_config->dst_addr = dma_data->addr;
slave_config->dst_maxburst = dma_data->maxburst;
if (dma_data->flags & SND_DMAENGINE_PCM_DAI_FLAG_PACK)
slave_config->dst_addr_width =
DMA_SLAVE_BUSWIDTH_UNDEFINED;
if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED)
slave_config->dst_addr_width = dma_data->addr_width;
} else {
slave_config->src_addr = dma_data->addr;
slave_config->src_maxburst = dma_data->maxburst;
if (dma_data->flags & SND_DMAENGINE_PCM_DAI_FLAG_PACK)
slave_config->src_addr_width =
DMA_SLAVE_BUSWIDTH_UNDEFINED;
if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED)
slave_config->src_addr_width = dma_data->addr_width;
}
slave_config->peripheral_config = dma_data->peripheral_config;
slave_config->peripheral_size = dma_data->peripheral_size;
}
EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_set_config_from_dai_data);
static void dmaengine_pcm_dma_complete(void *arg)
{
unsigned int new_pos;
struct snd_pcm_substream *substream = arg;
struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
new_pos = prtd->pos + snd_pcm_lib_period_bytes(substream);
if (new_pos >= snd_pcm_lib_buffer_bytes(substream))
new_pos = 0;
prtd->pos = new_pos;
snd_pcm_period_elapsed(substream);
}
static int dmaengine_pcm_prepare_and_submit(struct snd_pcm_substream *substream)
{
struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
struct dma_chan *chan = prtd->dma_chan;
struct dma_async_tx_descriptor *desc;
enum dma_transfer_direction direction;
unsigned long flags = DMA_CTRL_ACK;
direction = snd_pcm_substream_to_dma_direction(substream);
if (!substream->runtime->no_period_wakeup)
flags |= DMA_PREP_INTERRUPT;
prtd->pos = 0;
desc = dmaengine_prep_dma_cyclic(chan,
substream->runtime->dma_addr,
snd_pcm_lib_buffer_bytes(substream),
snd_pcm_lib_period_bytes(substream), direction, flags);
if (!desc)
return -ENOMEM;
desc->callback = dmaengine_pcm_dma_complete;
desc->callback_param = substream;
prtd->cookie = dmaengine_submit(desc);
return 0;
}
/**
* snd_dmaengine_pcm_trigger - dmaengine based PCM trigger implementation
* @substream: PCM substream
* @cmd: Trigger command
*
* This function can be used as the PCM trigger callback for dmaengine based PCM
* driver implementations.
*
* Return: 0 on success, a negative error code otherwise
*/
int snd_dmaengine_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
{
struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
struct snd_pcm_runtime *runtime = substream->runtime;
int ret;
switch (cmd) {
case SNDRV_PCM_TRIGGER_START:
ret = dmaengine_pcm_prepare_and_submit(substream);
if (ret)
return ret;
dma_async_issue_pending(prtd->dma_chan);
break;
case SNDRV_PCM_TRIGGER_RESUME:
case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
dmaengine_resume(prtd->dma_chan);
break;
case SNDRV_PCM_TRIGGER_SUSPEND:
if (runtime->info & SNDRV_PCM_INFO_PAUSE)
dmaengine_pause(prtd->dma_chan);
else
dmaengine_terminate_async(prtd->dma_chan);
break;
case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
dmaengine_pause(prtd->dma_chan);
break;
case SNDRV_PCM_TRIGGER_STOP:
dmaengine_terminate_async(prtd->dma_chan);
break;
default:
return -EINVAL;
}
return 0;
}
EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_trigger);
/**
* snd_dmaengine_pcm_pointer_no_residue - dmaengine based PCM pointer implementation
* @substream: PCM substream
*
* This function is deprecated and should not be used by new drivers, as its
* results may be unreliable.
*
* Return: PCM position in frames
*/
snd_pcm_uframes_t snd_dmaengine_pcm_pointer_no_residue(struct snd_pcm_substream *substream)
{
struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
return bytes_to_frames(substream->runtime, prtd->pos);
}
EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer_no_residue);
/**
* snd_dmaengine_pcm_pointer - dmaengine based PCM pointer implementation
* @substream: PCM substream
*
* This function can be used as the PCM pointer callback for dmaengine based PCM
* driver implementations.
*
* Return: PCM position in frames
*/
snd_pcm_uframes_t snd_dmaengine_pcm_pointer(struct snd_pcm_substream *substream)
{
struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
struct snd_pcm_runtime *runtime = substream->runtime;
struct dma_tx_state state;
enum dma_status status;
unsigned int buf_size;
unsigned int pos = 0;
status = dmaengine_tx_status(prtd->dma_chan, prtd->cookie, &state);
if (status == DMA_IN_PROGRESS || status == DMA_PAUSED) {
buf_size = snd_pcm_lib_buffer_bytes(substream);
if (state.residue > 0 && state.residue <= buf_size)
pos = buf_size - state.residue;
runtime->delay = bytes_to_frames(runtime,
state.in_flight_bytes);
}
return bytes_to_frames(runtime, pos);
}
EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer);
/**
* snd_dmaengine_pcm_request_channel - Request channel for the dmaengine PCM
* @filter_fn: Filter function used to request the DMA channel
* @filter_data: Data passed to the DMA filter function
*
* This function request a DMA channel for usage with dmaengine PCM.
*
* Return: NULL or the requested DMA channel
*/
struct dma_chan *snd_dmaengine_pcm_request_channel(dma_filter_fn filter_fn,
void *filter_data)
{
dma_cap_mask_t mask;
dma_cap_zero(mask);
dma_cap_set(DMA_SLAVE, mask);
dma_cap_set(DMA_CYCLIC, mask);
return dma_request_channel(mask, filter_fn, filter_data);
}
EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_request_channel);
/**
* snd_dmaengine_pcm_open - Open a dmaengine based PCM substream
* @substream: PCM substream
* @chan: DMA channel to use for data transfers
*
* The function should usually be called from the pcm open callback. Note that
* this function will use private_data field of the substream's runtime. So it
* is not available to your pcm driver implementation.
*
* Return: 0 on success, a negative error code otherwise
*/
int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream,
struct dma_chan *chan)
{
struct dmaengine_pcm_runtime_data *prtd;
int ret;
if (!chan)
return -ENXIO;
ret = snd_pcm_hw_constraint_integer(substream->runtime,
SNDRV_PCM_HW_PARAM_PERIODS);
if (ret < 0)
return ret;
prtd = kzalloc(sizeof(*prtd), GFP_KERNEL);
if (!prtd)
return -ENOMEM;
prtd->dma_chan = chan;
substream->runtime->private_data = prtd;
return 0;
}
EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open);
/**
* snd_dmaengine_pcm_open_request_chan - Open a dmaengine based PCM substream and request channel
* @substream: PCM substream
* @filter_fn: Filter function used to request the DMA channel
* @filter_data: Data passed to the DMA filter function
*
* This function will request a DMA channel using the passed filter function and
* data. The function should usually be called from the pcm open callback. Note
* that this function will use private_data field of the substream's runtime. So
* it is not available to your pcm driver implementation.
*
* Return: 0 on success, a negative error code otherwise
*/
int snd_dmaengine_pcm_open_request_chan(struct snd_pcm_substream *substream,
dma_filter_fn filter_fn, void *filter_data)
{
return snd_dmaengine_pcm_open(substream,
snd_dmaengine_pcm_request_channel(filter_fn, filter_data));
}
EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open_request_chan);
int snd_dmaengine_pcm_sync_stop(struct snd_pcm_substream *substream)
{
struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
struct dma_tx_state state;
enum dma_status status;
status = dmaengine_tx_status(prtd->dma_chan, prtd->cookie, &state);
if (status != DMA_PAUSED)
dmaengine_synchronize(prtd->dma_chan);
return 0;
}
EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_sync_stop);
static void __snd_dmaengine_pcm_close(struct snd_pcm_substream *substream,
bool release_channel)
{
struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
struct dma_tx_state state;
enum dma_status status;
status = dmaengine_tx_status(prtd->dma_chan, prtd->cookie, &state);
if (status == DMA_PAUSED)
dmaengine_terminate_async(prtd->dma_chan);
dmaengine_synchronize(prtd->dma_chan);
if (release_channel)
dma_release_channel(prtd->dma_chan);
kfree(prtd);
}
/**
* snd_dmaengine_pcm_close - Close a dmaengine based PCM substream
* @substream: PCM substream
*
* Return: 0 on success, a negative error code otherwise
*/
int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream)
{
__snd_dmaengine_pcm_close(substream, false);
return 0;
}
EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close);
/**
* snd_dmaengine_pcm_close_release_chan - Close a dmaengine based PCM
* substream and release channel
* @substream: PCM substream
*
* Releases the DMA channel associated with the PCM substream.
*
* Return: zero if successful, or a negative error code
*/
int snd_dmaengine_pcm_close_release_chan(struct snd_pcm_substream *substream)
{
__snd_dmaengine_pcm_close(substream, true);
return 0;
}
EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close_release_chan);
/**
* snd_dmaengine_pcm_refine_runtime_hwparams - Refine runtime hw params
* @substream: PCM substream
* @dma_data: DAI DMA data
* @hw: PCM hw params
* @chan: DMA channel to use for data transfers
*
* This function will query DMA capability, then refine the pcm hardware
* parameters.
*
* Return: 0 on success, a negative error code otherwise
*/
int snd_dmaengine_pcm_refine_runtime_hwparams(
struct snd_pcm_substream *substream,
struct snd_dmaengine_dai_dma_data *dma_data,
struct snd_pcm_hardware *hw,
struct dma_chan *chan)
{
struct dma_slave_caps dma_caps;
u32 addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
snd_pcm_format_t i;
int ret = 0;
if (!hw || !chan || !dma_data)
return -EINVAL;
ret = dma_get_slave_caps(chan, &dma_caps);
if (ret == 0) {
if (dma_caps.cmd_pause && dma_caps.cmd_resume)
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;
}
/*
* If SND_DMAENGINE_PCM_DAI_FLAG_PACK is set keep
* hw.formats set to 0, meaning no restrictions are in place.
* In this case it's the responsibility of the DAI driver to
* provide the supported format information.
*/
if (!(dma_data->flags & SND_DMAENGINE_PCM_DAI_FLAG_PACK))
/*
* 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.
*/
pcm_for_each_format(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 |= pcm_format_to_bits(i);
break;
default:
/* Unsupported types */
break;
}
}
return ret;
}
EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_refine_runtime_hwparams);
MODULE_DESCRIPTION("PCM dmaengine helper APIs");
MODULE_LICENSE("GPL");
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