Function | File |
---|---|
driver | sound/soc/codecs/ad193x.c |
include | sound/soc/codecs/ad193x.h |
Unlike PCI or USB devices, SPI devices are not enumerated at the hardware level. Instead, the software must know which devices are connected on each SPI bus segment, and what slave selects these devices are using. For this reason, the kernel code must instantiate SPI devices explicitly. The most common method is to declare the SPI devices by bus number.
This method is appropriate when the SPI bus is a system bus, as in many embedded systems, wherein each SPI bus has a number which is known in advance. It is thus possible to pre-declare the SPI devices that inhabit this bus. This is done with an array of struct spi_board_info, which is registered by calling spi_register_board_info().
For more information see: Documentation/spi/spi-summary.rst
You need to set the modalias of your SPI info according to your codec. Valid values are “ad1935” and “ad1937”, You'll also have to adjust bus_num and chip_select according to your board setup.
static struct spi_board_info board_spi_board_info[] __initdata = { [--snip--] { .modalias = "ad1936", .max_speed_hz = 3125000, /* max spi clock (SCK) speed in HZ */ .bus_num = 0, .chip_select = 4, /* CS, change it for your board */ .mode = SPI_MODE_3, }, [--snip--] };
static int __init board_init(void) { [--snip--] spi_register_board_info(board_spi_board_info, ARRAY_SIZE(board_spi_board_info)); [--snip--] return 0; } arch_initcall(board_init);
Name | Description |
---|---|
DAC1OUT | DAC Channel1 Output |
DAC2OUT | DAC Channel2 Output |
DAC3OUT | DAC Channel3 Output |
DAC4OUT | DAC Channel4 Output |
ADC1IN | ADC Channel1 Input |
ADC2IN | ADC Channel2 Input |
Name | Description |
---|---|
ADC High Pass Filter Switch | Enable/Disable ADC high-pass filter |
Playback Deemphasis | Select playback de-emphasis. Possible Values: “None”, “48kHz”, “44.1kHz”, “32kHz” |
DAC1 Volume | DAC Channel 1 volume |
DAC2 Volume | DAC Channel 2 volume |
DAC3 Volume | DAC Channel 3 volume |
DAC4 Volume | DAC Channel 4 volume |
DAC1 Switch | Mute/Unmute DAC Channel 1 |
DAC2 Switch | Mute/Unmute DAC Channel 2 |
DAC3 Switch | Mute/Unmute DAC Channel 3 |
DAC4 Switch | Mute/Unmute DAC Channel 4 |
ADC1 Switch | Mute/Unmute ADC Channel1 |
ADC2 Switch | Mute/Unmute ADC Channel2 |
DAI name |
---|
“ad193x-hifi” |
Name | Supported by driver | Description |
---|---|---|
SND_SOC_DAIFMT_I2S | yes | I2S mode |
SND_SOC_DAIFMT_RIGHT_J | no | Right Justified mode |
SND_SOC_DAIFMT_LEFT_J | no | Left Justified mode |
SND_SOC_DAIFMT_DSP_A | yes | data MSB after FRM LRC |
SND_SOC_DAIFMT_DSP_B | no | data MSB during FRM LRC |
SND_SOC_DAIFMT_AC97 | no | AC97 mode |
SND_SOC_DAIFMT_PDM | no | Pulse density modulation |
SND_SOC_DAIFMT_NB_NF | yes | Normal bit- and frameclock |
SND_SOC_DAIFMT_NB_IF | yes | Normal bitclock, inverted frameclock |
SND_SOC_DAIFMT_IB_NF | yes | Inverted frameclock, normal bitclock |
SND_SOC_DAIFMT_IB_IF | yes | Inverted bit- and frameclock |
SND_SOC_DAIFMT_CBM_CFM | yes | Codec bit- and frameclock master |
SND_SOC_DAIFMT_CBS_CFM | yes | Codec bitclock slave, frameclock master |
SND_SOC_DAIFMT_CBM_CFS | yes | Codec bitclock master, frameclock slave |
SND_SOC_DAIFMT_CBS_CFS | yes | Codec bit- and frameclock slave |
static int bf5xx_ad193x_hw_params(struct snd_pcm_substream *substream, struct snd_pcm_hw_params *params) { struct snd_soc_pcm_runtime *rtd = substream->private_data; struct snd_soc_dai *cpu_dai = rtd->cpu_dai; struct snd_soc_dai *codec_dai = rtd->codec_dai; int ret; /* set cpu DAI configuration */ ret = snd_soc_dai_set_fmt(cpu_dai, SND_SOC_DAIFMT_DSP_A | SND_SOC_DAIFMT_IB_IF | SND_SOC_DAIFMT_CBM_CFM); if (ret < 0) return ret; /* set codec DAI configuration */ ret = snd_soc_dai_set_fmt(codec_dai, SND_SOC_DAIFMT_DSP_A | SND_SOC_DAIFMT_IB_IF | SND_SOC_DAIFMT_CBM_CFM); if (ret < 0) return ret; return 0; } static struct snd_soc_ops bf5xx_ad193x_ops = { .hw_params = bf5xx_ad193x_hw_params, }; static struct snd_soc_dai_link bf5xx_ad193x_dai = { .name = "ad193x", .stream_name = "AD193X", .cpu_dai_name = "bfin-tdm.0", .codec_dai_name = "ad193x-hifi", .platform_name = "bfin-tdm-pcm-audio", .codec_name = "spi0.4", .ops = &bf5xx_ad193x_ops, };
To add support for the built-in codec AD193X of BF5XX to the kernel build system, a few things must be enabled properly for things to work.The configuration is as following:
Linux Kernel Configuration Device Drivers ---> Sound ---> <M> Sound card support Advanced Linux Sound Architecture ---> <M> Advanced Linux Sound Architecture < > Sequencer support <M> OSS Mixer API <M> OSS PCM (digital audio) API <M> ALSA for SoC audio support ---> <M> SoC I2S(TDM mode) Audio for the ADI BF5xx chip <M> SoC AD193X Audio support for BF5xx
Doing this will create modules (outside the kernel). The modules will be inserted automatically when it is needed. You can also build sound driver into kernel.