blob: ddddf651266baa461915fb6c02b023b6dff57a7e [file] [log] [blame]
/*
* Driver for the Conexant CX25821 PCIe bridge
*
* Copyright (C) 2009 Conexant Systems Inc.
* Authors <hiep.huynh@conexant.com>, <shu.lin@conexant.com>
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
*
* GNU General Public License for more details.
*
* 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 "cx25821-video.h"
#include "cx25821-audio-upstream.h"
#include <linux/fs.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/syscalls.h>
#include <linux/file.h>
#include <linux/fcntl.h>
#include <linux/delay.h>
#include <asm/uaccess.h>
MODULE_DESCRIPTION("v4l2 driver module for cx25821 based TV cards");
MODULE_AUTHOR("Hiep Huynh <hiep.huynh@conexant.com>");
MODULE_LICENSE("GPL");
static int _intr_msk =
FLD_AUD_SRC_RISCI1 | FLD_AUD_SRC_OF | FLD_AUD_SRC_SYNC |
FLD_AUD_SRC_OPC_ERR;
int cx25821_sram_channel_setup_upstream_audio(struct cx25821_dev *dev,
struct sram_channel *ch,
unsigned int bpl, u32 risc)
{
unsigned int i, lines;
u32 cdt;
if (ch->cmds_start == 0) {
cx_write(ch->ptr1_reg, 0);
cx_write(ch->ptr2_reg, 0);
cx_write(ch->cnt2_reg, 0);
cx_write(ch->cnt1_reg, 0);
return 0;
}
bpl = (bpl + 7) & ~7; /* alignment */
cdt = ch->cdt;
lines = ch->fifo_size / bpl;
if (lines > 3) {
lines = 3;
}
BUG_ON(lines < 2);
/* write CDT */
for (i = 0; i < lines; i++) {
cx_write(cdt + 16 * i, ch->fifo_start + bpl * i);
cx_write(cdt + 16 * i + 4, 0);
cx_write(cdt + 16 * i + 8, 0);
cx_write(cdt + 16 * i + 12, 0);
}
/* write CMDS */
cx_write(ch->cmds_start + 0, risc);
cx_write(ch->cmds_start + 4, 0);
cx_write(ch->cmds_start + 8, cdt);
cx_write(ch->cmds_start + 12, AUDIO_CDT_SIZE_QW);
cx_write(ch->cmds_start + 16, ch->ctrl_start);
//IQ size
cx_write(ch->cmds_start + 20, AUDIO_IQ_SIZE_DW);
for (i = 24; i < 80; i += 4)
cx_write(ch->cmds_start + i, 0);
/* fill registers */
cx_write(ch->ptr1_reg, ch->fifo_start);
cx_write(ch->ptr2_reg, cdt);
cx_write(ch->cnt2_reg, AUDIO_CDT_SIZE_QW);
cx_write(ch->cnt1_reg, AUDIO_CLUSTER_SIZE_QW - 1);
return 0;
}
static __le32 *cx25821_risc_field_upstream_audio(struct cx25821_dev *dev,
__le32 * rp,
dma_addr_t databuf_phys_addr,
unsigned int bpl,
int fifo_enable)
{
unsigned int line;
struct sram_channel *sram_ch =
&dev->sram_channels[dev->_audio_upstream_channel_select];
int offset = 0;
/* scan lines */
for (line = 0; line < LINES_PER_AUDIO_BUFFER; line++) {
*(rp++) = cpu_to_le32(RISC_READ | RISC_SOL | RISC_EOL | bpl);
*(rp++) = cpu_to_le32(databuf_phys_addr + offset);
*(rp++) = cpu_to_le32(0); /* bits 63-32 */
// Check if we need to enable the FIFO after the first 3 lines
// For the upstream audio channel, the risc engine will enable the FIFO.
if (fifo_enable && line == 2) {
*(rp++) = RISC_WRITECR;
*(rp++) = sram_ch->dma_ctl;
*(rp++) = sram_ch->fld_aud_fifo_en;
*(rp++) = 0x00000020;
}
offset += AUDIO_LINE_SIZE;
}
return rp;
}
int cx25821_risc_buffer_upstream_audio(struct cx25821_dev *dev,
struct pci_dev *pci,
unsigned int bpl, unsigned int lines)
{
__le32 *rp;
int fifo_enable = 0;
int frame = 0, i = 0;
int frame_size = AUDIO_DATA_BUF_SZ;
int databuf_offset = 0;
int risc_flag = RISC_CNT_INC;
dma_addr_t risc_phys_jump_addr;
/* Virtual address of Risc buffer program */
rp = dev->_risc_virt_addr;
/* sync instruction */
*(rp++) = cpu_to_le32(RISC_RESYNC | AUDIO_SYNC_LINE);
for (frame = 0; frame < NUM_AUDIO_FRAMES; frame++) {
databuf_offset = frame_size * frame;
if (frame == 0) {
fifo_enable = 1;
risc_flag = RISC_CNT_RESET;
} else {
fifo_enable = 0;
risc_flag = RISC_CNT_INC;
}
//Calculate physical jump address
if ((frame + 1) == NUM_AUDIO_FRAMES) {
risc_phys_jump_addr =
dev->_risc_phys_start_addr +
RISC_SYNC_INSTRUCTION_SIZE;
} else {
risc_phys_jump_addr =
dev->_risc_phys_start_addr +
RISC_SYNC_INSTRUCTION_SIZE +
AUDIO_RISC_DMA_BUF_SIZE * (frame + 1);
}
rp = cx25821_risc_field_upstream_audio(dev, rp,
dev->
_audiodata_buf_phys_addr
+ databuf_offset, bpl,
fifo_enable);
if (USE_RISC_NOOP_AUDIO) {
for (i = 0; i < NUM_NO_OPS; i++) {
*(rp++) = cpu_to_le32(RISC_NOOP);
}
}
// Loop to (Nth)FrameRISC or to Start of Risc program & generate IRQ
*(rp++) = cpu_to_le32(RISC_JUMP | RISC_IRQ1 | risc_flag);
*(rp++) = cpu_to_le32(risc_phys_jump_addr);
*(rp++) = cpu_to_le32(0);
//Recalculate virtual address based on frame index
rp = dev->_risc_virt_addr + RISC_SYNC_INSTRUCTION_SIZE / 4 +
(AUDIO_RISC_DMA_BUF_SIZE * (frame + 1) / 4);
}
return 0;
}
void cx25821_free_memory_audio(struct cx25821_dev *dev)
{
if (dev->_risc_virt_addr) {
pci_free_consistent(dev->pci, dev->_audiorisc_size,
dev->_risc_virt_addr, dev->_risc_phys_addr);
dev->_risc_virt_addr = NULL;
}
if (dev->_audiodata_buf_virt_addr) {
pci_free_consistent(dev->pci, dev->_audiodata_buf_size,
dev->_audiodata_buf_virt_addr,
dev->_audiodata_buf_phys_addr);
dev->_audiodata_buf_virt_addr = NULL;
}
}
void cx25821_stop_upstream_audio(struct cx25821_dev *dev)
{
struct sram_channel *sram_ch =
&dev->sram_channels[AUDIO_UPSTREAM_SRAM_CHANNEL_B];
u32 tmp = 0;
if (!dev->_audio_is_running) {
printk
("cx25821: No audio file is currently running so return!\n");
return;
}
//Disable RISC interrupts
cx_write(sram_ch->int_msk, 0);
//Turn OFF risc and fifo enable in AUD_DMA_CNTRL
tmp = cx_read(sram_ch->dma_ctl);
cx_write(sram_ch->dma_ctl,
tmp & ~(sram_ch->fld_aud_fifo_en | sram_ch->fld_aud_risc_en));
//Clear data buffer memory
if (dev->_audiodata_buf_virt_addr)
memset(dev->_audiodata_buf_virt_addr, 0,
dev->_audiodata_buf_size);
dev->_audio_is_running = 0;
dev->_is_first_audio_frame = 0;
dev->_audioframe_count = 0;
dev->_audiofile_status = END_OF_FILE;
if (dev->_irq_audio_queues) {
kfree(dev->_irq_audio_queues);
dev->_irq_audio_queues = NULL;
}
if (dev->_audiofilename != NULL)
kfree(dev->_audiofilename);
}
void cx25821_free_mem_upstream_audio(struct cx25821_dev *dev)
{
if (dev->_audio_is_running) {
cx25821_stop_upstream_audio(dev);
}
cx25821_free_memory_audio(dev);
}
int cx25821_get_audio_data(struct cx25821_dev *dev,
struct sram_channel *sram_ch)
{
struct file *myfile;
int frame_index_temp = dev->_audioframe_index;
int i = 0;
int line_size = AUDIO_LINE_SIZE;
int frame_size = AUDIO_DATA_BUF_SZ;
int frame_offset = frame_size * frame_index_temp;
ssize_t vfs_read_retval = 0;
char mybuf[line_size];
loff_t file_offset = dev->_audioframe_count * frame_size;
loff_t pos;
mm_segment_t old_fs;
if (dev->_audiofile_status == END_OF_FILE)
return 0;
myfile = filp_open(dev->_audiofilename, O_RDONLY | O_LARGEFILE, 0);
if (IS_ERR(myfile)) {
const int open_errno = -PTR_ERR(myfile);
printk("%s(): ERROR opening file(%s) with errno = %d! \n",
__func__, dev->_audiofilename, open_errno);
return PTR_ERR(myfile);
} else {
if (!(myfile->f_op)) {
printk("%s: File has no file operations registered!\n",
__func__);
filp_close(myfile, NULL);
return -EIO;
}
if (!myfile->f_op->read) {
printk("%s: File has no READ operations registered! \n",
__func__);
filp_close(myfile, NULL);
return -EIO;
}
pos = myfile->f_pos;
old_fs = get_fs();
set_fs(KERNEL_DS);
for (i = 0; i < dev->_audio_lines_count; i++) {
pos = file_offset;
vfs_read_retval =
vfs_read(myfile, mybuf, line_size, &pos);
if (vfs_read_retval > 0 && vfs_read_retval == line_size
&& dev->_audiodata_buf_virt_addr != NULL) {
memcpy((void *)(dev->_audiodata_buf_virt_addr +
frame_offset / 4), mybuf,
vfs_read_retval);
}
file_offset += vfs_read_retval;
frame_offset += vfs_read_retval;
if (vfs_read_retval < line_size) {
printk(KERN_INFO
"Done: exit %s() since no more bytes to read from Audio file.\n",
__func__);
break;
}
}
if (i > 0)
dev->_audioframe_count++;
dev->_audiofile_status =
(vfs_read_retval == line_size) ? IN_PROGRESS : END_OF_FILE;
set_fs(old_fs);
filp_close(myfile, NULL);
}
return 0;
}
static void cx25821_audioups_handler(struct work_struct *work)
{
struct cx25821_dev *dev =
container_of(work, struct cx25821_dev, _audio_work_entry);
if (!dev) {
printk("ERROR %s(): since container_of(work_struct) FAILED! \n",
__func__);
return;
}
cx25821_get_audio_data(dev,
&dev->sram_channels[dev->
_audio_upstream_channel_select]);
}
int cx25821_openfile_audio(struct cx25821_dev *dev,
struct sram_channel *sram_ch)
{
struct file *myfile;
int i = 0, j = 0;
int line_size = AUDIO_LINE_SIZE;
ssize_t vfs_read_retval = 0;
char mybuf[line_size];
loff_t pos;
loff_t offset = (unsigned long)0;
mm_segment_t old_fs;
myfile = filp_open(dev->_audiofilename, O_RDONLY | O_LARGEFILE, 0);
if (IS_ERR(myfile)) {
const int open_errno = -PTR_ERR(myfile);
printk("%s(): ERROR opening file(%s) with errno = %d! \n",
__func__, dev->_audiofilename, open_errno);
return PTR_ERR(myfile);
} else {
if (!(myfile->f_op)) {
printk("%s: File has no file operations registered! \n",
__func__);
filp_close(myfile, NULL);
return -EIO;
}
if (!myfile->f_op->read) {
printk("%s: File has no READ operations registered! \n",
__func__);
filp_close(myfile, NULL);
return -EIO;
}
pos = myfile->f_pos;
old_fs = get_fs();
set_fs(KERNEL_DS);
for (j = 0; j < NUM_AUDIO_FRAMES; j++) {
for (i = 0; i < dev->_audio_lines_count; i++) {
pos = offset;
vfs_read_retval =
vfs_read(myfile, mybuf, line_size, &pos);
if (vfs_read_retval > 0
&& vfs_read_retval == line_size
&& dev->_audiodata_buf_virt_addr != NULL) {
memcpy((void *)(dev->
_audiodata_buf_virt_addr
+ offset / 4), mybuf,
vfs_read_retval);
}
offset += vfs_read_retval;
if (vfs_read_retval < line_size) {
printk(KERN_INFO
"Done: exit %s() since no more bytes to read from Audio file.\n",
__func__);
break;
}
}
if (i > 0) {
dev->_audioframe_count++;
}
if (vfs_read_retval < line_size) {
break;
}
}
dev->_audiofile_status =
(vfs_read_retval == line_size) ? IN_PROGRESS : END_OF_FILE;
set_fs(old_fs);
myfile->f_pos = 0;
filp_close(myfile, NULL);
}
return 0;
}
static int cx25821_audio_upstream_buffer_prepare(struct cx25821_dev *dev,
struct sram_channel *sram_ch,
int bpl)
{
int ret = 0;
dma_addr_t dma_addr;
dma_addr_t data_dma_addr;
cx25821_free_memory_audio(dev);
dev->_risc_virt_addr =
pci_alloc_consistent(dev->pci, dev->audio_upstream_riscbuf_size,
&dma_addr);
dev->_risc_virt_start_addr = dev->_risc_virt_addr;
dev->_risc_phys_start_addr = dma_addr;
dev->_risc_phys_addr = dma_addr;
dev->_audiorisc_size = dev->audio_upstream_riscbuf_size;
if (!dev->_risc_virt_addr) {
printk
("cx25821 ERROR: pci_alloc_consistent() FAILED to allocate memory for RISC program! Returning.\n");
return -ENOMEM;
}
//Clear out memory at address
memset(dev->_risc_virt_addr, 0, dev->_audiorisc_size);
//For Audio Data buffer allocation
dev->_audiodata_buf_virt_addr =
pci_alloc_consistent(dev->pci, dev->audio_upstream_databuf_size,
&data_dma_addr);
dev->_audiodata_buf_phys_addr = data_dma_addr;
dev->_audiodata_buf_size = dev->audio_upstream_databuf_size;
if (!dev->_audiodata_buf_virt_addr) {
printk
("cx25821 ERROR: pci_alloc_consistent() FAILED to allocate memory for data buffer! Returning. \n");
return -ENOMEM;
}
//Clear out memory at address
memset(dev->_audiodata_buf_virt_addr, 0, dev->_audiodata_buf_size);
ret = cx25821_openfile_audio(dev, sram_ch);
if (ret < 0)
return ret;
//Creating RISC programs
ret =
cx25821_risc_buffer_upstream_audio(dev, dev->pci, bpl,
dev->_audio_lines_count);
if (ret < 0) {
printk(KERN_DEBUG
"cx25821 ERROR creating audio upstream RISC programs! \n");
goto error;
}
return 0;
error:
return ret;
}
int cx25821_audio_upstream_irq(struct cx25821_dev *dev, int chan_num,
u32 status)
{
int i = 0;
u32 int_msk_tmp;
struct sram_channel *channel = &dev->sram_channels[chan_num];
dma_addr_t risc_phys_jump_addr;
__le32 *rp;
if (status & FLD_AUD_SRC_RISCI1) {
//Get interrupt_index of the program that interrupted
u32 prog_cnt = cx_read(channel->gpcnt);
//Since we've identified our IRQ, clear our bits from the interrupt mask and interrupt status registers
cx_write(channel->int_msk, 0);
cx_write(channel->int_stat, cx_read(channel->int_stat));
spin_lock(&dev->slock);
while (prog_cnt != dev->_last_index_irq) {
//Update _last_index_irq
if (dev->_last_index_irq < (NUMBER_OF_PROGRAMS - 1)) {
dev->_last_index_irq++;
} else {
dev->_last_index_irq = 0;
}
dev->_audioframe_index = dev->_last_index_irq;
queue_work(dev->_irq_audio_queues,
&dev->_audio_work_entry);
}
if (dev->_is_first_audio_frame) {
dev->_is_first_audio_frame = 0;
if (dev->_risc_virt_start_addr != NULL) {
risc_phys_jump_addr =
dev->_risc_phys_start_addr +
RISC_SYNC_INSTRUCTION_SIZE +
AUDIO_RISC_DMA_BUF_SIZE;
rp = cx25821_risc_field_upstream_audio(dev,
dev->
_risc_virt_start_addr
+ 1,
dev->
_audiodata_buf_phys_addr,
AUDIO_LINE_SIZE,
FIFO_DISABLE);
if (USE_RISC_NOOP_AUDIO) {
for (i = 0; i < NUM_NO_OPS; i++) {
*(rp++) =
cpu_to_le32(RISC_NOOP);
}
}
// Jump to 2nd Audio Frame
*(rp++) =
cpu_to_le32(RISC_JUMP | RISC_IRQ1 |
RISC_CNT_RESET);
*(rp++) = cpu_to_le32(risc_phys_jump_addr);
*(rp++) = cpu_to_le32(0);
}
}
spin_unlock(&dev->slock);
} else {
if (status & FLD_AUD_SRC_OF)
printk("%s: Audio Received Overflow Error Interrupt!\n",
__func__);
if (status & FLD_AUD_SRC_SYNC)
printk("%s: Audio Received Sync Error Interrupt!\n",
__func__);
if (status & FLD_AUD_SRC_OPC_ERR)
printk("%s: Audio Received OpCode Error Interrupt!\n",
__func__);
// Read and write back the interrupt status register to clear our bits
cx_write(channel->int_stat, cx_read(channel->int_stat));
}
if (dev->_audiofile_status == END_OF_FILE) {
printk("cx25821: EOF Channel Audio Framecount = %d\n",
dev->_audioframe_count);
return -1;
}
//ElSE, set the interrupt mask register, re-enable irq.
int_msk_tmp = cx_read(channel->int_msk);
cx_write(channel->int_msk, int_msk_tmp |= _intr_msk);
return 0;
}
static irqreturn_t cx25821_upstream_irq_audio(int irq, void *dev_id)
{
struct cx25821_dev *dev = dev_id;
u32 msk_stat, audio_status;
int handled = 0;
struct sram_channel *sram_ch;
if (!dev)
return -1;
sram_ch = &dev->sram_channels[dev->_audio_upstream_channel_select];
msk_stat = cx_read(sram_ch->int_mstat);
audio_status = cx_read(sram_ch->int_stat);
// Only deal with our interrupt
if (audio_status) {
handled =
cx25821_audio_upstream_irq(dev,
dev->
_audio_upstream_channel_select,
audio_status);
}
if (handled < 0) {
cx25821_stop_upstream_audio(dev);
} else {
handled += handled;
}
return IRQ_RETVAL(handled);
}
static void cx25821_wait_fifo_enable(struct cx25821_dev *dev,
struct sram_channel *sram_ch)
{
int count = 0;
u32 tmp;
do {
//Wait 10 microsecond before checking to see if the FIFO is turned ON.
udelay(10);
tmp = cx_read(sram_ch->dma_ctl);
if (count++ > 1000) //10 millisecond timeout
{
printk
("cx25821 ERROR: %s() fifo is NOT turned on. Timeout!\n",
__func__);
return;
}
} while (!(tmp & sram_ch->fld_aud_fifo_en));
}
int cx25821_start_audio_dma_upstream(struct cx25821_dev *dev,
struct sram_channel *sram_ch)
{
u32 tmp = 0;
int err = 0;
// Set the physical start address of the RISC program in the initial program counter(IPC) member of the CMDS.
cx_write(sram_ch->cmds_start + 0, dev->_risc_phys_addr);
cx_write(sram_ch->cmds_start + 4, 0); /* Risc IPC High 64 bits 63-32 */
/* reset counter */
cx_write(sram_ch->gpcnt_ctl, 3);
//Set the line length (It looks like we do not need to set the line length)
cx_write(sram_ch->aud_length, AUDIO_LINE_SIZE & FLD_AUD_DST_LN_LNGTH);
//Set the input mode to 16-bit
tmp = cx_read(sram_ch->aud_cfg);
tmp |=
FLD_AUD_SRC_ENABLE | FLD_AUD_DST_PK_MODE | FLD_AUD_CLK_ENABLE |
FLD_AUD_MASTER_MODE | FLD_AUD_CLK_SELECT_PLL_D | FLD_AUD_SONY_MODE;
cx_write(sram_ch->aud_cfg, tmp);
// Read and write back the interrupt status register to clear it
tmp = cx_read(sram_ch->int_stat);
cx_write(sram_ch->int_stat, tmp);
// Clear our bits from the interrupt status register.
cx_write(sram_ch->int_stat, _intr_msk);
//Set the interrupt mask register, enable irq.
cx_set(PCI_INT_MSK, cx_read(PCI_INT_MSK) | (1 << sram_ch->irq_bit));
tmp = cx_read(sram_ch->int_msk);
cx_write(sram_ch->int_msk, tmp |= _intr_msk);
err =
request_irq(dev->pci->irq, cx25821_upstream_irq_audio,
IRQF_SHARED | IRQF_DISABLED, dev->name, dev);
if (err < 0) {
printk(KERN_ERR "%s: can't get upstream IRQ %d\n", dev->name,
dev->pci->irq);
goto fail_irq;
}
// Start the DMA engine
tmp = cx_read(sram_ch->dma_ctl);
cx_set(sram_ch->dma_ctl, tmp | sram_ch->fld_aud_risc_en);
dev->_audio_is_running = 1;
dev->_is_first_audio_frame = 1;
// The fifo_en bit turns on by the first Risc program
cx25821_wait_fifo_enable(dev, sram_ch);
return 0;
fail_irq:
cx25821_dev_unregister(dev);
return err;
}
int cx25821_audio_upstream_init(struct cx25821_dev *dev, int channel_select)
{
struct sram_channel *sram_ch;
int retval = 0;
int err = 0;
int str_length = 0;
if (dev->_audio_is_running) {
printk("Audio Channel is still running so return!\n");
return 0;
}
dev->_audio_upstream_channel_select = channel_select;
sram_ch = &dev->sram_channels[channel_select];
//Work queue
INIT_WORK(&dev->_audio_work_entry, cx25821_audioups_handler);
dev->_irq_audio_queues =
create_singlethread_workqueue("cx25821_audioworkqueue");
if (!dev->_irq_audio_queues) {
printk
("cx25821 ERROR: create_singlethread_workqueue() for Audio FAILED!\n");
return -ENOMEM;
}
dev->_last_index_irq = 0;
dev->_audio_is_running = 0;
dev->_audioframe_count = 0;
dev->_audiofile_status = RESET_STATUS;
dev->_audio_lines_count = LINES_PER_AUDIO_BUFFER;
_line_size = AUDIO_LINE_SIZE;
if (dev->input_audiofilename) {
str_length = strlen(dev->input_audiofilename);
dev->_audiofilename =
(char *)kmalloc(str_length + 1, GFP_KERNEL);
if (!dev->_audiofilename)
goto error;
memcpy(dev->_audiofilename, dev->input_audiofilename,
str_length + 1);
//Default if filename is empty string
if (strcmp(dev->input_audiofilename, "") == 0) {
dev->_audiofilename = "/root/audioGOOD.wav";
}
} else {
str_length = strlen(_defaultAudioName);
dev->_audiofilename =
(char *)kmalloc(str_length + 1, GFP_KERNEL);
if (!dev->_audiofilename)
goto error;
memcpy(dev->_audiofilename, _defaultAudioName, str_length + 1);
}
retval =
cx25821_sram_channel_setup_upstream_audio(dev, sram_ch, _line_size,
0);
dev->audio_upstream_riscbuf_size =
AUDIO_RISC_DMA_BUF_SIZE * NUM_AUDIO_PROGS +
RISC_SYNC_INSTRUCTION_SIZE;
dev->audio_upstream_databuf_size = AUDIO_DATA_BUF_SZ * NUM_AUDIO_PROGS;
//Allocating buffers and prepare RISC program
retval =
cx25821_audio_upstream_buffer_prepare(dev, sram_ch, _line_size);
if (retval < 0) {
printk(KERN_ERR
"%s: Failed to set up Audio upstream buffers!\n",
dev->name);
goto error;
}
//Start RISC engine
cx25821_start_audio_dma_upstream(dev, sram_ch);
return 0;
error:
cx25821_dev_unregister(dev);
return err;
}