First, to achieve machine-driven framework (s3c2440_uda1341.c)
(Reference sound \ soc \ samsung \ s3c24xx_uda134x.c)
1. Assign a registration platform called soc-audio equipment of
2. The device has a private internet data snd_soc_card, which has a snd_soc_dai_link, is used to determine the drive of each part ASOC
static struct snd_soc_ops s3c2440_uda1341_ops = { // .STARTUP = s3c24xx_uda134x_startup, // transplant from the kernel, these functions temporarily masked, and the like when used together with // = s3c24xx_uda134x_shutdown .shutdown, // .hw_params = s3c24xx_uda134x_hw_params, } ; static struct snd_soc_dai_link s3c2440_uda1341_dai_link = { .name = " 100ask_UDA1341 ", .stream_name = " 100ask_UDA1341 ", .codec_name = " UDA1341-codec ", // must be the same name of the driver and codec .codec_dai_name = " UDA1341-IIS ", // and the name of the driver must codec_dai same .cpu_dai_name = " S3C2440-IIS ", the same // name of the driver must cpu_dai .ops = &s3c2440_uda1341_ops, .platform_name = "s3c2440-dma", }; static struct snd_soc_card myalsa_card = { .name = "S3C2440_UDA1341", .owner = THIS_MODULE, .dai_link = &s3c2440_uda1341_dai_link, // snd_soc_dai_link被用来决定ASOC各部分的驱动 .num_links = 1, }; static void asoc_release(struct device * dev) { } static struct platform_device asoc_dev = { .name = "soc-audio", .id = -1, .dev = { .release = asoc_release, }, }; static int s3c2440_uda1341_init ( void ) { platform_set_drvdata (& asoc_dev, & myalsa_card); // This device has a private internet data snd_soc_card platform_device_register (& asoc_dev); // allocate a register called soc-audio equipment platform return 0; }
Second, the realization of the drive frame codec (uda1341.c)
(Reference sound \ soc \ codecs \ uda134x.c)
1. Construct a snd_soc_dai_driver
static const struct snd_soc_dai_ops uda1341_dai_ops = { // .STARTUP = uda134x_startup, // transplant from the kernel, these functions temporarily masked, and the like when used together with // = uda134x_shutdown .shutdown, // .hw_params = uda134x_hw_params, uda134x_mute .digital_mute = //, // .set_sysclk = uda134x_set_dai_sysclk, // .set_fmt = uda134x_set_dai_fmt, }; static struct snd_soc_dai_driver uda1341_dai = { .name = " UDA1341-IIS ", // s3c2440_uda1341_dai_link.codec_dai_name must be consistent and machine-driven / * Capabilities playback * / // respective capture and playback attribute values will be used to call such as soc_pcm_open in runtime-> hw.rate_min = max (codec_dai_drv-> playback.rate_min, cpu_dai_drv->playback.rate_min); .playback = { .stream_name = "Playback", .channels_min = 1, .channels_max = 2, .rates = UDA134X_RATES, .formats = UDA134X_FORMATS, }, /* capture capabilities */ .capture = { .stream_name = "Capture", .channels_min = 1, .channels_max = 2, .rates = UDA134X_RATES, .formats = UDA134X_FORMATS, }, /* pcm operations */ .ops = &uda1341_dai_ops, };
2. Construct a snd_soc_codec_driver
static struct snd_soc_codec_driver soc_codec_dev_uda1341 = { // .PROBE = uda134x_soc_probe, // transplant from the kernel, these functions temporarily masked, and the like when used together with // = uda134x_soc_remove .remove, // .suspend = uda134x_soc_suspend, // = uda134x_soc_resume .resume, // = .reg_cache_size the sizeof (uda134x_reg), // = .reg_word_size the sizeof (U8), // .reg_cache_default = uda134x_reg, // = .reg_cache_step. 1, // = uda134x_read_reg_cache .read, // .write uda134x_write =, // .set_bias_level = uda134x_set_bias_level, };
3. register them (a little trick: because snd_soc_register_codec need to pass device parameters can not be called directly in uda1341_init () in snd_soc_register_codec, and more so around a bend, by registering platform_device, platform_driver, in its probe () function call snd_soc_register_codec)
static struct platform_device uda1341_dev = { .name = " UDA1341-CODEC ", // and the machine must be driven s3c2440_uda1341_dai_link.codec_name consistent .id = -1, .dev = { .release = uda1341_dev_release, }, }; struct platform_driver uda1341_drv = { = uda1341_probe .PROBE, // snd_soc_register_codec calls registered in it and drive codec_dai codec driver . Remove = uda1341_remove, .driver = { .name = " UDA1341-codec ", // must be the same name uda1341_dev } }; static int uda1341_init ( void { ) platform_device_register(&uda1341_dev); platform_driver_register(&uda1341_drv); return 0; } static void uda1341_exit(void) { platform_device_unregister(&uda1341_dev); platform_driver_unregister(&uda1341_drv); } module_init(uda1341_init); module_exit(uda1341_exit); MODULE_LICENSE("GPL");
Third, to achieve cpu_dai driven framework (s3c2440_iis.c)
(Reference sound \ soc \ samsung \ s3c24xx-i2s.c)
static const struct snd_soc_dai_ops s3c2440_i2s_dai_ops = { //.trigger = s3c24xx_i2s_trigger, // transplant from the kernel, these functions temporarily masked, and the like when used together with // = s3c24xx_i2s_hw_params .hw_params, // .set_fmt = s3c24xx_i2s_set_fmt, s3c24xx_i2s_set_clkdiv .set_clkdiv = //, // .set_sysclk = s3c24xx_i2s_set_syscl }; #define S3C24XX_I2S_RATES \ (SNDRV_PCM_RATE_8000 | SNDRV_PCM_RATE_11025 | SNDRV_PCM_RATE_16000 | \ SNDRV_PCM_RATE_22050 | SNDRV_PCM_RATE_32000 | SNDRV_PCM_RATE_44100 | \ SNDRV_PCM_RATE_48000 | SNDRV_PCM_RATE_88200 | SNDRV_PCM_RATE_96000) static struct snd_soc_dai_driver s3c2440_i2s_dai = { // no name, in fact, name copy snd_soc_register_dai () will s3c2440_iis_dev in to dai-> name // .PROBE = s3c24xx_i2s_probe, // from the kernel transplant, temporarily block out the functions, such as when used together
// .suspend = s3c24xx_i2s_suspend, // .resume = s3c24xx_i2s_resum .playback = { .channels_min = 2, .channels_max = 2, .rates = S3C24XX_I2S_RATES, .formats = SNDRV_PCM_FMTBIT_S8 | SNDRV_PCM_FMTBIT_S16_LE,}, .capture = { .channels_min = 2, .channels_max = 2, .rates = S3C24XX_I2S_RATES, .formats = SNDRV_PCM_FMTBIT_S8 | SNDRV_PCM_FMTBIT_S16_LE,}, .ops = &s3c2440_i2s_dai_ops, };
2. Sign it
static int s3c2440_iis_probe(struct platform_device *pdev) { return snd_soc_register_dai(&pdev->dev, &s3c2440_i2s_dai); } static int s3c2440_iis_remove(struct platform_device *pdev) { snd_soc_unregister_dai(&pdev->dev); return 0; } static void s3c2440_iis_release(struct device * dev) { } static struct platform_device s3c2440_iis_dev = { .name = "s3c2440-iis", //必须和machine驱动的s3c2440_uda1341_dai_link.cpu_dai_name一致 .id = -1, .dev = { .release = s3c2440_iis_release, }, }; struct platform_driver s3c2440_iis_drv = { .probe = s3c2440_iis_probe, .remove = s3c2440_iis_remove, .driver = { .name = "s3c2440-iis", //必须和s3c2440_iis_dev的name一致 } }; static int s3c2440_iis_init(void) { platform_device_register(&s3c2440_iis_dev); platform_driver_register(&s3c2440_iis_drv); return 0; } static void s3c2440_iis_exit(void) { struct clk *clk; platform_device_unregister(&s3c2440_iis_dev); platform_driver_unregister(&s3c2440_iis_drv); } static void s3c2440_iis_exit(void) { platform_device_unregister(&s3c2440_iis_dev); platform_driver_unregister(&s3c2440_iis_drv); } module_init(s3c2440_iis_init); module_exit(s3c2440_iis_exit); MODULE_LICENSE("GPL");
Attaining driven platform frame (s3c2440_dma.c)
( Reference sound \ soc \ samsung \ dma.c)
1. Construct a snd_soc_platform_driver
static struct snd_pcm_ops dma_ops = { // .Open = dma_open, // transplant from the kernel, these functions temporarily masked, and the like when used together with // = .close dma_close, // .ioctl = snd_pcm_lib_ioctl, / / = dma_hw_params .hw_params, // .hw_free = dma_hw_free, // = the .Prepare dma_prepare, // = .trigger dma_trigger, // .pointer = dma_pointer, // .mmap = dma_mmap, }; static struct snd_soc_platform_driver s3c2440_dma_platform = { . = & s3c2440_dma_ops OPS, // .pcm_new = dma_new, // transplant from the kernel, these functions temporarily masked, and the like when used together with // = dma_free_dma_buffer .pcm_free };
static int s3c2440_dma_probe(struct platform_device *pdev) { return snd_soc_register_platform(&pdev->dev, &s3c2440_dma_platform); } static int s3c2440_dma_remove(struct platform_device *pdev) { snd_soc_unregister_platform(&pdev->dev); return 0; } static void s3c2440_dma_release(struct device * dev) { } static struct platform_device s3c2440_dma_dev = { .name = "s3c2440-dma", // and the machine must be driven s3c2440_uda1341_dai_link platform_name consistent .id = -1, .dev = { .release = s3c2440_dma_release, }, }; struct platform_driver s3c2440_dma_drv = { .PROBE = s3c2440_dma_probe, . Remove = s3c2440_dma_remove, .driver = { . = name " S3C2440-DMA ", // must be the same name s3c2440_dma_dev } }; static int s3c2440_dma_init ( void ) { dma_regs = ioremap (DMA2_BASE_ADDR, the sizeof ( struct s3c_dma_regs)); platform_device_register (& s3c2440_dma_dev); platform_driver_register(&s3c2440_dma_drv); return 0; } static void s3c2440_dma_exit(void) { platform_device_unregister(&s3c2440_dma_dev); platform_driver_unregister(&s3c2440_dma_drv); iounmap(dma_regs); } module_init(s3c2440_dma_init); module_exit(s3c2440_dma_exit); MODULE_LICENSE("GPL");
V. References
Framework Lesson 2 1.1_17 _ALSA sound 08_ write it from scratch: 1. Wei Dongshan embedded Linux video tutorial _3 of the project combat the ALSA sound card
2. DroidPhone "Linux ALSA sound drivers."