TI中文支持网我接的引脚是 MCASP0_AXR0, 现在输出的声音全是沙沙响，但是解码器那边可以识别歌曲的采样频率.
pinmux_config 我总觉得是 punmux_config 那里出了问题，刚接触学习这些，希望指点。
[ 2.034003] line:472 file:drivers/base/platform.c======drv->driver.name: snd-soc-dummy
[ 2.042536] line:472 file:drivers/base/platform.c======drv->driver.name: soc-audio
[ 2.050722] line:472 file:drivers/base/platform.c======drv->driver.name: spdif-dit
[ 2.059062] line:472 file:drivers/base/platform.c======drv->driver.name: davinci-pcm-audio
[ 2.067943] line:472 file:drivers/base/platform.c======drv->driver.name: davinci-mcasp
[ 2.086728] ===========card->name: AM335X EVM SPDIF[ 2.086734] card->dai_link->name: McASP0
[ 2.086738] card->dai_link->stream_name: spdif
[ 2.086742] card->dai_link->codec_dai_name: dit-hifi
[ 2.086746] card->dai_link->codec_name: spdif-dit
[ 2.086750] card->dai_link->platform_name: davinci-pcm-audio
root@am335x-evm:~# aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: SPDIF [AM335X EVM SPDIF], device 0: spdif dit-hifi-0 []
Subdevices: 1/1
Subdevice #0: subdevice #0
========================================================
还有一点，对于 pinmux_config 的原理我不是很懂，有没有什么说明文档吗？
我从 arch/arm/mach-omap2/board-am335xevm.c ——-> setup_pin_mux(struct pinmux_config *pin_mux) ———–>
———>omap_mux_init_signal(const char *muxname, int val)——->omap_mux_get_by_name—-> _omap_mux_get_by_name—-> …..
看的一头雾水，产生了一些疑问，比如：
/* Module pin mux for mcasp0 */
static struct pinmux_config mcasp0_pin_mux[] = {
{"mcasp0_aclkx.mcasp0_aclkx", OMAP_MUX_MODE0 | AM33XX_PIN_INPUT_PULLDOWN},
{"mcasp0_fsx.mcasp0_fsx", OMAP_MUX_MODE0 | AM33XX_PIN_INPUT_PULLDOWN},
{"mcasp0_axr0.mcasp0_axr0", OMAP_MUX_MODE0 | AM33XX_PIN_INPUT_PULLDOWN},
{"mcasp0_ahclkr.mcasp0_axr2", OMAP_MUX_MODE2 | AM33XX_PIN_INPUT_PULLDOWN},
{NULL, 0},
};
像 mcasp0_aclkx.mcasp0_aclkx 是 mode0.muxname 模式？
这两个部分是什么mcasp0_aclkx.mcasp0_aclkx？
比如 {"mcasp0_ahclkr.mcasp0_axr2", OMAP_MUX_MODE2 | AM33XX_PIN_INPUT_PULLDOWN}, 这一行的意思？
读了一下代码,先说说我自己的理解，mcasp0_ahclkr 是模式0 下这个名字对应的 io, mcasp0_axr2 是后面 “OMAP_MUX_MODE2 | AM33XX_PIN_INPUT_PULLDOWN” 这个新
模式对应的名字，整句的意思是将模式0 下这个名字对应的 io,配置为模式 "OMAP_MUX_MODE2 | AM33XX_PIN_INPUT_PULLDOWN"。猜的,望指正^_^
Steven Liu1：
对于pinmux，有一个工具，下载地址和使用方法：http://processors.wiki.ti.com/index.php/Pin_Mux_Utility_for_ARM_MPU_Processors
由于在AM335x上，为了灵活配置，是有引脚复用功能的，比如你上面提到的mcasp0_aclkx，这个管脚，他除了可以配置成mcasp0_aclkx，还可以配成spi1_sclk，mmc0_sdcd, gpio3_14等多种模式，最多有8种，“mcasp0_aclkx.mcasp0_aclkx”，这种表达，点前面的mcasp0_aclkx代表着管脚，每个管脚以模式0的含义来命名，点后面的表示他现在的功能配置，这个定义就是把这个管脚配成mcasp0_aclkx，即配成模式0，所以后面就有 OMAP_MUX_MODE0的参数，其他的一些参数上下拉，input等也是在这个表达式中表示出来。
jing zhu：
回复 Steven Liu1:
请问我直接将 mcasp0_axr0 接到 spdif 的同轴输出, 是不是配置为 模式0 就可以了，还要上下拉什么吗？
jing zhu：
回复 Steven Liu1:
现在的输出是放一首歌，有部分可以一直沙沙响，久不久有点正常的音乐，.接收端识别的采样率一直为44.1k.
Steven Liu1：
回复 jing zhu:
为啥你觉得是pinmux的问题呢？配置上面的都确认是没问题的？
如果你担心pinmux的问题，在linux console里面通过devmem2 0x44e0990来查看control module里面对mcasp0_aclkx的pingmux的配置，其他的管家都能通过这样的方式来确认。
jing zhu：
回复 Steven Liu1:
sound/soc/davinci/davinci-evm.c 下面是我对这个文件的修改，贴上来看看是不是哪里做的不够？.
==================================================
35 #define AUDIO_FORMAT (SND_SOC_DAIFMT_DSP_B | \ 36 SND_SOC_DAIFMT_CBM_CFM | SND_SOC_DAIFMT_IB_NF)
93 static int evm_spdif_hw_params(struct snd_pcm_substream *substream, 94 struct snd_pcm_hw_params *params) 95 { 96 struct snd_soc_pcm_runtime *rtd = substream->private_data; 97 struct snd_soc_dai *cpu_dai = rtd->cpu_dai; 98 99 /* set cpu DAI configuration */100 return snd_soc_dai_set_fmt(cpu_dai, AUDIO_FORMAT);101 }
111 static struct snd_soc_ops evm_spdif_ops = {112 .hw_params = evm_spdif_hw_params,113 };
==================================================
304 static struct snd_soc_dai_link my_am335x_evm_sk_dai1 = {305 .name = "McASP0",306 .stream_name = "spdif",307 .cpu_dai_name= "davinci-mcasp.0",308 .codec_dai_name = "dit-hifi",309 .codec_name = "spdif-dit",310 .platform_name = "davinci-pcm-audio",311 .ops = &evm_spdif_ops,312 };====================================================
453 static struct snd_soc_card my_am335x_evm_sk_snd_soc_card1 = {454 .name = "AM335X EVM SPDIF",455 .dai_link = &my_am335x_evm_sk_dai1,456 .num_links = 1,457 };====================================================
static struct platform_device *evm_snd_spdif_dit_device;
static struct platform_device *evm_snd_device_1;
static int __init evm_init(void) {
int ret; evm_snd_spdif_dit_device = platform_device_alloc("spdif-dit",-1); if(!evm_snd_spdif_dit_device) return -ENOMEM; ret = platform_device_add(evm_snd_spdif_dit_device); if(ret) goto err1; evm_snd_device_1 = platform_device_alloc("soc-audio", 0); if (!evm_snd_device_1) { ret = -ENOMEM; goto err4; } platform_set_drvdata(evm_snd_device_1, &my_am335x_evm_sk_snd_soc_card1); ret = platform_device_add(evm_snd_device_1); if (ret) { pr_info("line======== %d,platform device add error\n",__LINE__); platform_device_put(evm_snd_device_1); goto err4; }return 0;
……
err1:….
}
jing zhu：
回复 Steven Liu1:
arch/arm/mach-omap2/board-am335xevm.c
＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝
233 static u8 my_am335x_dit_serializer_direction0[] = { 234 TX_MODE, INACTIVE_MODE, INACTIVE_MODE, INACTIVE_MODE, 235 INACTIVE_MODE, INACTIVE_MODE, INACTIVE_MODE, INACTIVE_MODE, 236 INACTIVE_MODE, INACTIVE_MODE, INACTIVE_MODE, INACTIVE_MODE, 237 INACTIVE_MODE, INACTIVE_MODE, INACTIVE_MODE, INACTIVE_MODE, 238 };
255 static struct snd_platform_data my_am335x_evm_snd_data0 = { 256 .tx_dma_offset = 0x46000000, /* McASP0 */ 257 //.rx_dma_offset = 0x46000000, 258 .op_mode = DAVINCI_MCASP_DIT_MODE, 259 .num_serializer = ARRAY_SIZE(my_am335x_dit_serializer_direction0), 260 .tdm_slots = 2, 261 .serial_dir = my_am335x_dit_serializer_direction0, 262 .asp_chan_q = EVENTQ_2, 263 .version = MCASP_VERSION_3, 264 .txnumevt = 1, 265 .rxnumevt = 1, 266 }; 693 /* Module pin mux for mcasp0 （我最迷糊的是这里）*/ 694 static struct pinmux_config my_mcasp0_pin_mux[] = { 695 {"mcasp0_aclkr.mcasp0_axr2", OMAP_MUX_MODE2 | AM33XX_PULL_DISA}, 696 {"mcasp0_ahclkx.mcasp0_ahclkx", OMAP_MUX_MODE0 | AM33XX_PULL_DISA}, 697 {"mcasp0_fsx.mcasp0_fsx", OMAP_MUX_MODE0 | AM33XX_PULL_DISA}, 698 //{"mcasp0_axr0.mcasp0_axr0", OMAP_MUX_MODE0 | AM33XX_PIN_INPUT_PULLDOWN}, 699 {"mcasp0_axr0.mcasp0_axr0", OMAP_MUX_MODE0 | AM33XX_PIN_OUTPUT}, 700 {NULL, 0}, 701 };
1857 /* Setup McASP 0 */1858 static void my_mcasp0_init(int evm_id, int profile)1859 {1860 /* Configure McASP */1861 pr_info("line: %d file: %s setup_pin_mux\n",__LINE__,__FILE__);1862 setup_pin_mux(my_mcasp0_pin_mux);1863 1864 pr_info("line: %d file: %s am335x_register_mcasp(&my_am335x_evm_snd_data0, 0)\n",__LINE__,__FILE_ _);1865 am335x_register_mcasp(&my_am335x_evm_snd_data0, 0);1866 1867 return;1868 }
2516 static struct evm_dev_cfg evm_chipsee_bbbexp_dev_cfg[] = {2517 {mii1_init, DEV_ON_BASEBOARD, PROFILE_ALL},2518 {usb0_init, DEV_ON_BASEBOARD, PROFILE_ALL},2519 {usb1_init, DEV_ON_BASEBOARD, PROFILE_ALL},2520 {mmc0_init, DEV_ON_BASEBOARD, PROFILE_ALL},2521 {lcdc_init, DEV_ON_BASEBOARD, PROFILE_ALL},2522 {i2c1_init, DEV_ON_BASEBOARD, PROFILE_ALL},2523 {cap_tsc_init, DEV_ON_BASEBOARD, PROFILE_ALL},2524 {mfd_tscadc_init, DEV_ON_BASEBOARD, PROFILE_ALL},2525 //{mcasp0_init, DEV_ON_BASEBOARD, PROFILE_ALL},2526 {my_mcasp0_init, DEV_ON_BASEBOARD, PROFILE_ALL},2527 {chipsee_gpio_led_init, DEV_ON_BASEBOARD, PROFILE_ALL},2528 {chipsee_buzz_init, DEV_ON_BASEBOARD, PROFILE_ALL},2529 {chipsee_backlight_init, DEV_ON_BASEBOARD, PROFILE_ALL},2530 {chipsee_hmi_audio_init, DEV_ON_BASEBOARD, PROFILE_ALL},2531 {d_can_init, DEV_ON_BASEBOARD, PROFILE_ALL},2532 {uart1_init, DEV_ON_BASEBOARD, PROFILE_ALL},2533 {uart2_init, DEV_ON_BASEBOARD, PROFILE_ALL},2534 {uart4_init, DEV_ON_BASEBOARD, PROFILE_ALL},2535 {NULL, 0, 0},2536 };2636 /* Setup Chipsee Beaglebone Black Expansion */2637 static void setup_chipsee_bbbexp(void)2638 {2639 pr_info("The board is a Chipsee Beaglebone Black Expansion.\n");2640 2641 am335x_mmc[0].gpio_wp = -EINVAL;2642 2643 _configure_device(CHIPSEE_BBBEXP, evm_chipsee_bbbexp_dev_cfg, PROFILE_NONE);2644 2645 am33xx_cpsw_init(AM33XX_CPSW_MODE_MII, NULL, NULL);2646 /* Atheros Tx Clk delay Phy fixup */2647 phy_register_fixup_for_uid(AM335X_EVM_PHY_ID, AM335X_EVM_PHY_MASK,2648 am33xx_evm_tx_clk_dly_phy_fixup);2649 }2677 static void am335x_evm_setup(struct memory_accessor *mem_acc, void *context)2678 {2679 /* Chipsee Beaglebone Black Expansion */2680 setup_chipsee_bbbexp();2681 return;2682 }2692 static struct at24_platform_data am335x_baseboard_eeprom_info = {2693 .byte_len = (256*1024) / 8,2694 .page_size = 64,2695 .flags = AT24_FLAG_ADDR16,2696 .setup = am335x_evm_setup,2697 .context = (void *)NULL,2698 };
Jian Zhou：
回复 jing zhu:
请问你用的是哪家的audio codec？我们demo板上的用的是AIC3106，如果codec不一样需要在ALSA的架构下增加驱动程序
jing zhu：
回复 Jian Zhou:
我直接将引脚接到外面功放的 spdif 输入端口了.
Jian Zhou：
回复 jing zhu:
我们MCASP的引脚出来要接个音频codec(或者简单的DA)，然后在接到功放才对啊。
SPDIF是个纯粹的功放么？
jing zhu：
回复 Jian Zhou:
那边有DA的，播放音乐时，可以间隔听到点音乐声，但多数都是沙沙响，而且在 alsa 库里设置别的采样率，那边ＤＡ依然显示 44.1k, 不知道是不是驱动有问题
