1. 根目录:
2. sound
3. soc
4. omap
5. omap3beagle.c

/*
 * omap3beagle.c  --  SoC audio for OMAP3 Beagle
 *
 * Author: Steve Sakoman <steve@sakoman.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 *
 */

#include <linux/clk.h>
#include <linux/platform_device.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/soc.h>

#include <asm/mach-types.h>
#include <mach/hardware.h>
#include <mach/gpio.h>
#include <plat/mcbsp.h>

#include "omap-mcbsp.h"
#include "omap-pcm.h"

static int omap3beagle_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 *codec_dai = rtd->codec_dai;
	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
	unsigned int fmt;
	int ret;

	switch (params_channels(params)) {
	case 2: /* Stereo I2S mode */
		fmt =	SND_SOC_DAIFMT_I2S |
			SND_SOC_DAIFMT_NB_NF |
			SND_SOC_DAIFMT_CBM_CFM;
		break;
	case 4: /* Four channel TDM mode */
		fmt =	SND_SOC_DAIFMT_DSP_A |
			SND_SOC_DAIFMT_IB_NF |
			SND_SOC_DAIFMT_CBM_CFM;
		break;
	default:
		return -EINVAL;
	}

	/* Set codec DAI configuration */
	ret = snd_soc_dai_set_fmt(codec_dai, fmt);
	if (ret < 0) {
		printk(KERN_ERR "can't set codec DAI configuration\n");
		return ret;
	}

	/* Set cpu DAI configuration */
	ret = snd_soc_dai_set_fmt(cpu_dai, fmt);
	if (ret < 0) {
		printk(KERN_ERR "can't set cpu DAI configuration\n");
		return ret;
	}

	/* Set the codec system clock for DAC and ADC */
	ret = snd_soc_dai_set_sysclk(codec_dai, 0, 26000000,
				     SND_SOC_CLOCK_IN);
	if (ret < 0) {
		printk(KERN_ERR "can't set codec system clock\n");
		return ret;
	}

	return 0;
}

static struct snd_soc_ops omap3beagle_ops = {
	.hw_params = omap3beagle_hw_params,
};

/* Digital audio interface glue - connects codec <--> CPU */
static struct snd_soc_dai_link omap3beagle_dai = {
	.name = "TWL4030",
	.stream_name = "TWL4030",
	.cpu_dai_name = "omap-mcbsp-dai.1",
	.platform_name = "omap-pcm-audio",
	.codec_dai_name = "twl4030-hifi",
	.codec_name = "twl4030-codec",
	.ops = &omap3beagle_ops,
};

/* Audio machine driver */
static struct snd_soc_card snd_soc_omap3beagle = {
	.name = "omap3beagle",
	.owner = THIS_MODULE,
	.dai_link = &omap3beagle_dai,
	.num_links = 1,
};

static struct platform_device *omap3beagle_snd_device;

static int __init omap3beagle_soc_init(void)
{
	int ret;

	if (!(machine_is_omap3_beagle() || machine_is_devkit8000()))
		return -ENODEV;
	pr_info("OMAP3 Beagle/Devkit8000 SoC init\n");

	omap3beagle_snd_device = platform_device_alloc("soc-audio", -1);
	if (!omap3beagle_snd_device) {
		printk(KERN_ERR "Platform device allocation failed\n");
		return -ENOMEM;
	}

	platform_set_drvdata(omap3beagle_snd_device, &snd_soc_omap3beagle);

	ret = platform_device_add(omap3beagle_snd_device);
	if (ret)
		goto err1;

	return 0;

err1:
	printk(KERN_ERR "Unable to add platform device\n");
	platform_device_put(omap3beagle_snd_device);

	return ret;
}

static void __exit omap3beagle_soc_exit(void)
{
	platform_device_unregister(omap3beagle_snd_device);
}

module_init(omap3beagle_soc_init);
module_exit(omap3beagle_soc_exit);

MODULE_AUTHOR("Steve Sakoman <steve@sakoman.com>");
MODULE_DESCRIPTION("ALSA SoC OMAP3 Beagle");
MODULE_LICENSE("GPL");