SSM4329
SSM4329 Sound CODEC Linux Driver.
Supported Devices
Source Code
Status
Files
Function |
File |
|
|---|---|---|
driver |
||
include |
Example device initialization
For compile time configuration, it’s common Linux practice to keep board- and application-specific configuration out of the main driver file, instead putting it into the board support file.
For devices on custom boards, as typical of embedded and SoC-(system-on-chip)
based hardware, Linux uses platform_data to point to board-specific structures
describing devices and how they are connected to the SoC. This can include
available ports, chip variants, preferred modes, default initialization,
additional pin roles, and so on. This shrinks the board-support packages (BSPs)
and minimizes board and application specific #ifdefs in drivers.
Unlike PCI or USB devices, I2C devices are not enumerated at the hardware level. Instead, the software must know which devices are connected on each I2C bus segment, and what address these devices are using. For this reason, the kernel code must instantiate I2C devices explicitly. There are different ways to achieve this, depending on the context and requirements. However the most common method is to declare the I2C devices by bus number.
This method is appropriate when the I2C bus is a system bus, as in many
embedded systems, wherein each I2C bus has a number which is known in advance.
It is thus possible to pre-declare the I2C devices that inhabit this bus. This
is done with an array of struct i2c_board_info, which is registered by
calling i2c_register_board_info().
So, to enable such a driver one need only edit the board support file by adding
an appropriate entry to i2c_board_info.
For more information see: How to instantiate I2C devices
The I2C address of the SSM4329 depends on the setting of the ADDR0 and ADDR1 pins
ADDR0 |
ADDR1 |
I2C Address |
|---|---|---|
0 |
0 |
0x34 |
1 |
0 |
0x35 |
0 |
1 |
0x36 |
1 |
1 |
0x37 |
static struct i2c_board_info __initdata bfin_i2c_board_info[] = {
[--snip--]
{
I2C_BOARD_INFO("ssm4329", 0x34),
},
[--snip--]
}
static int __init stamp_init(void)
{
[--snip--]
i2c_register_board_info(0, bfin_i2c_board_info,
ARRAY_SIZE(bfin_i2c_board_info));
[--snip--]
return 0;
}
arch_initcall(board_init);
Devicetree
i2s: i2c@41600000 {
compatible = "...;
...
#size-cells = <0>;
#address-cells = <1>;
ssm4329: ssm4329@34 {
compatible = "adi,ssm4329";
reg = <0x34>;
gpios = <&gpio 5 0>;
};
};
ASoC DAPM Widgets
Name |
Description |
|---|---|
OUT |
Class-D Amplifier Output |
AIN |
Mono ADC Input |
ALSA Controls
Name |
Description |
|---|---|
DAC Playback Switch |
Mutes/Unmutes the DAC path |
DAC Playback Volume |
Configures the digital Volume of the DAC |
DAC Clip Point Volume |
Configures the cliping point of the DAC |
Interpolator Playback Volume |
Configures the digital Volume of the Interpolator |
Interpolator Clip Point Volume |
Configures the cliping point of the DAC |
ADC Playback Switch |
Mutes/Unmutes the ADC path |
ADC Capture Volume |
Configures the digital Volume of the ADC |
DAC High Pass Filter Switch |
Enables/Disables the High Pass Filter for the DAC |
DAC Low-power Switch |
Enables/Disables Low-power mode for the DAC |
ADC High Pass Filter Switch |
Enables/Disables the High Pass Filter for the ADC |
ADC Low-power Switch |
Enables/Disables Low-power mode for the DAC |
Interpolator Playback Switch |
Mute/Unmutes the Interpolator path |
Low-EMI Mode Playback Switch |
Enables/Disables Low-EMI mode for the Class-D stage |
Amplifier Boost Switch |
Enables/Disables the boost of of the Class-D stage |
DAC Playback Mux |
Selects the audio source for the DAC. Possible values: |
Interpolator Playback Mux |
Selects the audio source for the Interpolator path. Possible values:
|
Serial Port 1 Channel 1 Output Mux |
Selects the audio source for serial port 1 channel 1. Possible values:
|
Serial Port 1 Channel 2 Output Mux |
Selects the audio source for serial port 1 channel 1. Possible values:
|
Serial Port 1 Channel 3 Output Mux |
Selects the audio source for serial port 1 channel 1. Possible values:
|
Serial Port 1 Channel 4 Output Mux |
Selects the audio source for serial port 1 channel 1. Possible values:
|
Serial Port 2 Channel 1 Output Mux |
Selects the audio source for serial port 1 channel 1. Possible values:
|
Serial Port 2 Channel 2 Output Mux |
Selects the audio source for serial port 1 channel 1. Possible values:
|
Serial Port 2 Channel 3 Output Mux |
Selects the audio source for serial port 1 channel 1. Possible values:
|
Serial Port 2 Channel 4 Output Mux |
Selects the audio source for serial port 1 channel 1. Possible values:
|
Input SRC Channel 1 Mux |
Select the audio source for the sample-rate-converter channel 1. Possible
values: |
Input SRC Channel 2 Mux |
Select the audio source for the input sample-rate-converter channel 2.
Possible values: |
Output SRC Channel 1 Mux |
Selects the audio source for the output sample-rate converter channel 1.
Possible values: |
Output SRC Channel 2 Mux |
Selects the audio source for the output sample-rate converter channel 2.
Possible values: |
SigmaDSP Firmware
In order to use the SigmaDSP core of the SSM4329 you need to provide a firmware file. Please refer to the SigmaDSP Firmware Utility for Linux page on how to generate a firmware file. The firmware file for SSM4329 driver has to be named ssm4329.bin.
PLL configuration
To configure the PLL of the device the snd_soc_codec_set_pll() function can
be used. It should be used to configure the internal PLL correctly depending on
the external clock source and the desired sampling rate. The clk_id
parameter must always be SSM4329_PLL. The source parameter must be one
of the input clock source constants listed below. The freq_in parameter must be
in the range of 8000 to 2700000, this needs to match the frequency of the
selected input clock source. The freq_out parameter should typically be
98304000.
#define SSM4329_PLL 0
#define SSM4329_PLL_SRC_MCLKIN 0
#define SSM4329_PLL_SRC_FSYNC1 1
#define SSM4329_PLL_SRC_BCLK1 2
#define SSM4329_PLL_SRC_FSYNC2 3
#define SSM4329_PLL_SRC_BCLK2 4
DAI configuration
The codec driver registers two DAIs, one for each serial port. The DAIs are named ``ssm4329-sp0`` and ``ssm4329-sp1``.
Supported DAI formats
Name |
Supported by driver |
Description |
|---|---|---|
SND_SOC_DAIFMT_I2S |
yes |
I2S mode |
SND_SOC_DAIFMT_RIGHT_J |
yes |
Right Justified mode |
SND_SOC_DAIFMT_LEFT_J |
yes |
Left Justified mode |
SND_SOC_DAIFMT_DSP_A |
yes |
data MSB after FRM LRC |
SND_SOC_DAIFMT_DSP_B |
yes |
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 |
TDM configuration
If you want to use the SSM4329 in TDM mode you can configure it using snd_soc_dai_set_tdm_slot() from you ASoC board driver.
The following restrictions apply to the parameters of snd_soc_dai_set_tdm_slot().
tx_mask specifies the output channel mapping for the serial port. The first set bit specifies the slot for the first channel, the second set bit the slot for the second channel and so on.
rx_mask specifies the input channel mapping for the serial port. The first set bit specifies the slot for the first channel, the second set bit the slot for the second channel and so on.
slots must be between 1 and 16
width must be either 16, 24, 32
Example:
static int ssm4329_link_init(struct snd_soc_pcm_runtime *rtd)
{
int ret;
ret = snd_soc_dai_set_tdm_slot(rtd->codec_dai, 0x0c, 0x0c, 8, 32);
if (ret < 0)
return ret;
return 0;
}
static struct snd_soc_dai_link ssm4329_dai_link = {
...,
.init = ssm4329_link_init,
};
Example DAI configuration
#include "../codecs/ssm4329.h"
static int ssm4329_zed_init(struct snd_soc_pcm_runtime *rtd)
{
return snd_soc_codec_set_pll(rtd->codec_dai->codec, SSM4329_PLL,
SSM4329_PLL_SRC_MCLKIN, 12288000, 2048 * 48000);
}
static const struct snd_soc_dapm_widget ssm4329_zed_widgets[] = {
SND_SOC_DAPM_SPK("Speaker Out", NULL),
SND_SOC_DAPM_LINEIN("Line In", NULL),
};
static const struct snd_soc_dapm_route ssm4329_zed_routes[] = {
{ "Speaker Out", NULL, "OUT" },
{ "AIN", NULL, "Line In" }
};
static struct snd_soc_dai_link ssm4329_zed_dai_link = {
.name = "ssm4329",
.stream_name = "ssm4329",
.codec_dai_name = "ssm4329-sp1",
.dai_fmt = SND_SOC_DAIFMT_I2S |
SND_SOC_DAIFMT_NB_NF |
SND_SOC_DAIFMT_CBS_CFS,
.init = ssm4329_zed_init,
};
static struct snd_soc_card ssm4329_zed_card = {
.name = "ZED SSM4329",
.owner = THIS_MODULE,
.dai_link = &zed_ssm4329_dai_link,
.num_links = 1,
.dapm_widgets = zed_ssm4329_widgets,
.num_dapm_widgets = ARRAY_SIZE(zed_ssm4329_widgets),
.dapm_routes = zed_ssm4329_routes,
.num_dapm_routes = ARRAY_SIZE(zed_ssm4329_routes),
.fully_routed = true,
};
More information
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