PCM3168A是一款四通道模拟输入和输出的音频编解码器，支持I2S和SPI接口。以下是一份基于SPI接口的PCM3168A初始化及应用的使用例程。这个例程假设你已经配置好了SPI接口。
1. 初始化SPI接口：
首先，你需要初始化SPI接口。这通常涉及到设置SPI的时钟速率、CPOL、CPHA等参数。以下是一个示例代码：
```c
#include
#include
static struct spi_device *pcm3168_spi;
static int __init pcm3168_init(void)
{
struct spi_master *master;
struct spi_board_info info;
int ret;
master = spi_busnum_to_master(0);
if (!master) {
printk(KERN_ERR "PCM3168: No SPI master foundn");
return -ENODEV;
}
memset(&info, 0, sizeof(info));
info.modalias = "pcm3168";
info.bus_num = 0;
info.chip_select = 0;
info.max_speed_hz = 1000000; // 1 MHz
info.mode = SPI_MODE_0;
pcm3168_spi = spi_new_device(master, &info);
if (!pcm3168_spi) {
printk(KERN_ERR "PCM3168: Failed to add devicen");
return -ENODEV;
}
ret = spi_setup(pcm3168_spi);
if (ret < 0) {
printk(KERN_ERR "PCM3168: Failed to setup SPI devicen");
return ret;
}
return 0;
}
static void __exit pcm3168_exit(void)
{
spi_unregister_device(pcm3168_spi);
}
module_init(pcm3168_init);
module_exit(pcm3168_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Your Name");
MODULE_DESCRIPTION("PCM3168A SPI driver");
```
2. 初始化PCM3168A：
接下来，你需要初始化PCM3168A。这通常涉及到发送一些初始化命令，以配置音频格式、采样率等参数。以下是一个示例代码：
```c
#include
#include
#define PCM3168_REG_FORMAT_CONTROL 0x00
#define PCM3168_REG_POWER_CONTROL 0x02
#define PCM3168_REG_FILTER_CONTROL 0x04
#define PCM3168_REG_CLOCK_CONTROL 0x06
#define PCM3168_REG_INTERFACE_CONTROL 0x08
#define PCM3168_REG_MISC_CONTROL 0x0A
static int pcm3168_write_reg(struct spi_device *spi, u8 reg, u16 value)
{
u8 buf[3] = {reg, value & 0xFF, (value >> 8) & 0xFF};
return spi_write(spi, buf, sizeof(buf));
}
static int pcm3168_init_device(struct spi_device *spi)
{
int ret;
// Set audio format to 24-bit I2S
ret = pcm3168_write_reg(spi, PCM3168_REG_FORMAT_CONTROL, 0x0000);
if (ret < 0) {
return ret;
}
// Enable all channels
ret = pcm3168_write_reg(spi, PCM3168_REG_POWER_CONTROL, 0x0F0F);
if (ret < 0) {
return ret;
}
// Configure filter settings
ret = pcm3168_write_reg(spi, PCM3168_REG_FILTER_CONTROL, 0x0000);
if (ret < 0) {
return ret;
}
// Configure clock settings
ret = pcm3168_write_reg(spi, PCM3168_REG_CLOCK_CONTROL, 0x0000);
if (ret < 0) {
return ret;
}
// Configure interface settings
ret = pcm3168_write_reg(spi, PCM3168_REG_INTERFACE_CONTROL, 0x0000);
if (ret < 0) {
return ret;
}
// Configure miscellaneous settings
ret = pcm3168_write_reg(spi, PCM3168_REG_MISC_CONTROL, 0x0000);
if (ret < 0) {
return ret;
}
return 0;
}
```
3. 配置PCM3168A时隙：
PCM3168A的时隙配置取决于你的音频格式和采样率。通常，你需要根据这些参数计算时隙大小。以下是一个示例代码：
```c
static int pcm3168_config_tsi(struct spi_device *spi, int sample_rate, int bits_per_sample)
{
int ret;
u16 format_control;
// Calculate format control value based on sample rate and bits per sample
format_control = (sample_rate == 48000) ?
PCM3168A是一款四通道模拟输入和输出的音频编解码器，支持I2S和SPI接口。以下是一份基于SPI接口的PCM3168A初始化及应用的使用例程。这个例程假设你已经配置好了SPI接口。
1. 初始化SPI接口：
首先，你需要初始化SPI接口。这通常涉及到设置SPI的时钟速率、CPOL、CPHA等参数。以下是一个示例代码：
```c
#include
#include
static struct spi_device *pcm3168_spi;
static int __init pcm3168_init(void)
{
struct spi_master *master;
struct spi_board_info info;
int ret;
master = spi_busnum_to_master(0);
if (!master) {
printk(KERN_ERR "PCM3168: No SPI master foundn");
return -ENODEV;
}
memset(&info, 0, sizeof(info));
info.modalias = "pcm3168";
info.bus_num = 0;
info.chip_select = 0;
info.max_speed_hz = 1000000; // 1 MHz
info.mode = SPI_MODE_0;
pcm3168_spi = spi_new_device(master, &info);
if (!pcm3168_spi) {
printk(KERN_ERR "PCM3168: Failed to add devicen");
return -ENODEV;
}
ret = spi_setup(pcm3168_spi);
if (ret < 0) {
printk(KERN_ERR "PCM3168: Failed to setup SPI devicen");
return ret;
}
return 0;
}
static void __exit pcm3168_exit(void)
{
spi_unregister_device(pcm3168_spi);
}
module_init(pcm3168_init);
module_exit(pcm3168_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Your Name");
MODULE_DESCRIPTION("PCM3168A SPI driver");
```
2. 初始化PCM3168A：
接下来，你需要初始化PCM3168A。这通常涉及到发送一些初始化命令，以配置音频格式、采样率等参数。以下是一个示例代码：
```c
#include
#include
#define PCM3168_REG_FORMAT_CONTROL 0x00
#define PCM3168_REG_POWER_CONTROL 0x02
#define PCM3168_REG_FILTER_CONTROL 0x04
#define PCM3168_REG_CLOCK_CONTROL 0x06
#define PCM3168_REG_INTERFACE_CONTROL 0x08
#define PCM3168_REG_MISC_CONTROL 0x0A
static int pcm3168_write_reg(struct spi_device *spi, u8 reg, u16 value)
{
u8 buf[3] = {reg, value & 0xFF, (value >> 8) & 0xFF};
return spi_write(spi, buf, sizeof(buf));
}
static int pcm3168_init_device(struct spi_device *spi)
{
int ret;
// Set audio format to 24-bit I2S
ret = pcm3168_write_reg(spi, PCM3168_REG_FORMAT_CONTROL, 0x0000);
if (ret < 0) {
return ret;
}
// Enable all channels
ret = pcm3168_write_reg(spi, PCM3168_REG_POWER_CONTROL, 0x0F0F);
if (ret < 0) {
return ret;
}
// Configure filter settings
ret = pcm3168_write_reg(spi, PCM3168_REG_FILTER_CONTROL, 0x0000);
if (ret < 0) {
return ret;
}
// Configure clock settings
ret = pcm3168_write_reg(spi, PCM3168_REG_CLOCK_CONTROL, 0x0000);
if (ret < 0) {
return ret;
}
// Configure interface settings
ret = pcm3168_write_reg(spi, PCM3168_REG_INTERFACE_CONTROL, 0x0000);
if (ret < 0) {
return ret;
}
// Configure miscellaneous settings
ret = pcm3168_write_reg(spi, PCM3168_REG_MISC_CONTROL, 0x0000);
if (ret < 0) {
return ret;
}
return 0;
}
```
3. 配置PCM3168A时隙：
PCM3168A的时隙配置取决于你的音频格式和采样率。通常，你需要根据这些参数计算时隙大小。以下是一个示例代码：
```c
static int pcm3168_config_tsi(struct spi_device *spi, int sample_rate, int bits_per_sample)
{
int ret;
u16 format_control;
// Calculate format control value based on sample rate and bits per sample
format_control = (sample_rate == 48000) ?
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