ASoC: Add audio support for the Atmel AT91SAM9G20ek board(uing wolfson 8731).

Add audio support for the Atmel AT91SAM9G20ek board(uing wolfson 8731).
It is based on the former eti_b1_wm8731.c file, using the atmel scc API.
Signed-off-by: Sedji Gaouaou <sedji.gaouaou@atmel.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/atmel/sam9g20_wm8731.c

+/*
+ * sam9g20_wm8731  --  SoC audio for AT91SAM9G20-based
+ * 			ATMEL AT91SAM9G20ek board.
+ *
+ *  Copyright (C) 2005 SAN People
+ *  Copyright (C) 2008 Atmel
+ *
+ * Authors: Sedji Gaouaou <sedji.gaouaou@atmel.com>
+ *
+ * Based on ati_b1_wm8731.c by:
+ * Frank Mandarino <fmandarino@endrelia.com>
+ * Copyright 2006 Endrelia Technologies Inc.
+ * Based on corgi.c by:
+ * Copyright 2005 Wolfson Microelectronics PLC.
+ * Copyright 2005 Openedhand Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/version.h>
+#include <linux/kernel.h>
+#include <linux/clk.h>
+#include <linux/timer.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+
+#include <linux/atmel-ssc.h>
+
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+#include <sound/soc-dapm.h>
+
+#include <mach/hardware.h>
+#include <mach/gpio.h>
+
+#include "../codecs/wm8731.h"
+#include "atmel-pcm.h"
+#include "atmel_ssc_dai.h"
+
+
+static int at91sam9g20ek_startup(struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *rtd = snd_pcm_substream_chip(substream);
+	struct snd_soc_dai *codec_dai = rtd->dai->codec_dai;
+	int ret;
+
+	/* codec system clock is supplied by PCK0, set to 12MHz */
+	ret = snd_soc_dai_set_sysclk(codec_dai, WM8731_SYSCLK,
+		12000000, SND_SOC_CLOCK_IN);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static void at91sam9g20ek_shutdown(struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *rtd = snd_pcm_substream_chip(substream);
+
+	dev_dbg(rtd->socdev->dev, "shutdown");
+}
+
+static int at91sam9g20ek_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->dai->codec_dai;
+	struct snd_soc_dai *cpu_dai = rtd->dai->cpu_dai;
+	struct atmel_ssc_info *ssc_p = cpu_dai->private_data;
+	struct ssc_device *ssc = ssc_p->ssc;
+	int ret;
+
+	unsigned int rate;
+	int cmr_div, period;
+
+	if (ssc == NULL) {
+		printk(KERN_INFO "at91sam9g20ek_hw_params: ssc is NULL!\n");
+		return -EINVAL;
+	}
+
+	/* set codec DAI configuration */
+	ret = snd_soc_dai_set_fmt(codec_dai, SND_SOC_DAIFMT_I2S |
+		SND_SOC_DAIFMT_NB_NF | SND_SOC_DAIFMT_CBS_CFS);
+	if (ret < 0)
+		return ret;
+
+	/* set cpu DAI configuration */
+	ret = snd_soc_dai_set_fmt(cpu_dai, SND_SOC_DAIFMT_I2S |
+		SND_SOC_DAIFMT_NB_NF | SND_SOC_DAIFMT_CBS_CFS);
+	if (ret < 0)
+		return ret;
+
+	/*
+	 * The SSC clock dividers depend on the sample rate.  The CMR.DIV
+	 * field divides the system master clock MCK to drive the SSC TK
+	 * signal which provides the codec BCLK.  The TCMR.PERIOD and
+	 * RCMR.PERIOD fields further divide the BCLK signal to drive
+	 * the SSC TF and RF signals which provide the codec DACLRC and
+	 * ADCLRC clocks.
+	 *
+	 * The dividers were determined through trial and error, where a
+	 * CMR.DIV value is chosen such that the resulting BCLK value is
+	 * divisible, or almost divisible, by (2 * sample rate), and then
+	 * the TCMR.PERIOD or RCMR.PERIOD is BCLK / (2 * sample rate) - 1.
+	 */
+	rate = params_rate(params);
+
+	switch (rate) {
+	case 8000:
+		cmr_div = 55;	/* BCLK = 133MHz/(2*55) = 1.209MHz */
+		period = 74;	/* LRC = BCLK/(2*(74+1)) ~= 8060,6Hz */
+		break;
+	case 11025:
+		cmr_div = 67;	/* BCLK = 133MHz/(2*60) = 1.108MHz */
+		period = 45;	/* LRC = BCLK/(2*(49+1)) = 11083,3Hz */
+		break;
+	case 16000:
+		cmr_div = 63;	/* BCLK = 133MHz/(2*63) = 1.055MHz */
+		period = 32;	/* LRC = BCLK/(2*(32+1)) = 15993,2Hz */
+		break;
+	case 22050:
+		cmr_div = 52;	/* BCLK = 133MHz/(2*52) = 1.278MHz */
+		period = 28;	/* LRC = BCLK/(2*(28+1)) = 22049Hz */
+		break;
+	case 32000:
+		cmr_div = 66;	/* BCLK = 133MHz/(2*66) = 1.007MHz */
+		period = 15;	/* LRC = BCLK/(2*(15+1)) = 31486,742Hz */
+		break;
+	case 44100:
+		cmr_div = 29;	/* BCLK = 133MHz/(2*29) = 2.293MHz */
+		period = 25;	/* LRC = BCLK/(2*(25+1)) = 44098Hz */
+		break;
+	case 48000:
+		cmr_div = 33;	/* BCLK = 133MHz/(2*33) = 2.015MHz */
+		period = 20;	/* LRC = BCLK/(2*(20+1)) = 47979,79Hz */
+		break;
+	case 88200:
+		cmr_div = 29;	/* BCLK = 133MHz/(2*29) = 2.293MHz */
+		period = 12;	/* LRC = BCLK/(2*(12+1)) = 88196Hz */
+		break;
+	case 96000:
+		cmr_div = 23;	/* BCLK = 133MHz/(2*23) = 2.891MHz */
+		period = 14;	/* LRC = BCLK/(2*(14+1)) = 96376Hz */
+		break;
+	default:
+		printk(KERN_WARNING "unsupported rate %d"
+				" on at91sam9g20ek board\n", rate);
+		return -EINVAL;
+	}
+
+	/* set the MCK divider for BCLK */
+	ret = snd_soc_dai_set_clkdiv(cpu_dai, ATMEL_SSC_CMR_DIV, cmr_div);
+	if (ret < 0)
+		return ret;
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		/* set the BCLK divider for DACLRC */
+		ret = snd_soc_dai_set_clkdiv(cpu_dai,
+						ATMEL_SSC_TCMR_PERIOD, period);
+	} else {
+		/* set the BCLK divider for ADCLRC */
+		ret = snd_soc_dai_set_clkdiv(cpu_dai,
+						ATMEL_SSC_RCMR_PERIOD, period);
+	}
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static struct snd_soc_ops at91sam9g20ek_ops = {
+	.startup = at91sam9g20ek_startup,
+	.hw_params = at91sam9g20ek_hw_params,
+	.shutdown = at91sam9g20ek_shutdown,
+};
+
+
+static const struct snd_soc_dapm_widget at91sam9g20ek_dapm_widgets[] = {
+	SND_SOC_DAPM_MIC("Int Mic", NULL),
+	SND_SOC_DAPM_SPK("Ext Spk", NULL),
+};
+
+static const struct snd_soc_dapm_route intercon[] = {
+
+	/* speaker connected to LHPOUT */
+	{"Ext Spk", NULL, "LHPOUT"},
+
+	/* mic is connected to Mic Jack, with WM8731 Mic Bias */
+	{"MICIN", NULL, "Mic Bias"},
+	{"Mic Bias", NULL, "Int Mic"},
+};
+
+/*
+ * Logic for a wm8731 as connected on a at91sam9g20ek board.
+ */
+static int at91sam9g20ek_wm8731_init(struct snd_soc_codec *codec)
+{
+	printk(KERN_DEBUG
+			"at91sam9g20ek_wm8731 "
+			": at91sam9g20ek_wm8731_init() called\n");
+
+	/* Add specific widgets */
+	snd_soc_dapm_new_controls(codec, at91sam9g20ek_dapm_widgets,
+				  ARRAY_SIZE(at91sam9g20ek_dapm_widgets));
+	/* Set up specific audio path interconnects */
+	snd_soc_dapm_add_routes(codec, intercon, ARRAY_SIZE(intercon));
+
+	/* not connected */
+	snd_soc_dapm_disable_pin(codec, "RLINEIN");
+	snd_soc_dapm_disable_pin(codec, "LLINEIN");
+
+	/* always connected */
+	snd_soc_dapm_enable_pin(codec, "Int Mic");
+	snd_soc_dapm_enable_pin(codec, "Ext Spk");
+
+	snd_soc_dapm_sync(codec);
+
+	return 0;
+}
+
+static struct snd_soc_dai_link at91sam9g20ek_dai = {
+	.name = "WM8731",
+	.stream_name = "WM8731 PCM",
+	.cpu_dai = &atmel_ssc_dai[0],
+	.codec_dai = &wm8731_dai,
+	.init = at91sam9g20ek_wm8731_init,
+	.ops = &at91sam9g20ek_ops,
+};
+
+static struct snd_soc_machine snd_soc_machine_at91sam9g20ek = {
+	.name = "WM8731",
+	.dai_link = &at91sam9g20ek_dai,
+	.num_links = 1,
+};
+
+static struct wm8731_setup_data at91sam9g20ek_wm8731_setup = {
+	.i2c_bus = 0,
+	.i2c_address = 0x1b,
+};
+
+static struct snd_soc_device at91sam9g20ek_snd_devdata = {
+	.machine = &snd_soc_machine_at91sam9g20ek,
+	.platform = &atmel_soc_platform,
+	.codec_dev = &soc_codec_dev_wm8731,
+	.codec_data = &at91sam9g20ek_wm8731_setup,
+};
+
+static struct platform_device *at91sam9g20ek_snd_device;
+
+static int __init at91sam9g20ek_init(void)
+{
+	struct atmel_ssc_info *ssc_p = at91sam9g20ek_dai.cpu_dai->private_data;
+	struct ssc_device *ssc = NULL;
+	int ret;
+
+	/*
+	 * Request SSC device
+	 */
+	ssc = ssc_request(0);
+	if (IS_ERR(ssc)) {
+		ret = PTR_ERR(ssc);
+		ssc = NULL;
+		goto err_ssc;
+	}
+	ssc_p->ssc = ssc;
+
+	at91sam9g20ek_snd_device = platform_device_alloc("soc-audio", -1);
+	if (!at91sam9g20ek_snd_device) {
+		printk(KERN_DEBUG
+				"platform device allocation failed\n");
+		ret = -ENOMEM;
+	}
+
+	platform_set_drvdata(at91sam9g20ek_snd_device,
+			&at91sam9g20ek_snd_devdata);
+	at91sam9g20ek_snd_devdata.dev = &at91sam9g20ek_snd_device->dev;
+
+	ret = platform_device_add(at91sam9g20ek_snd_device);
+	if (ret) {
+		printk(KERN_DEBUG
+				"platform device allocation failed\n");
+		platform_device_put(at91sam9g20ek_snd_device);
+	}
+
+	return ret;
+
+err_ssc:
+	return ret;
+}
+
+static void __exit at91sam9g20ek_exit(void)
+{
+	struct atmel_ssc_info *ssc_p = at91sam9g20ek_dai.cpu_dai->private_data;
+	struct ssc_device *ssc;
+
+	if (ssc_p != NULL) {
+		ssc = ssc_p->ssc;
+		if (ssc != NULL)
+			ssc_free(ssc);
+		ssc_p->ssc = NULL;
+	}
+
+	platform_device_unregister(at91sam9g20ek_snd_device);
+	at91sam9g20ek_snd_device = NULL;
+}
+
+module_init(at91sam9g20ek_init);
+module_exit(at91sam9g20ek_exit);
+
+/* Module information */
+MODULE_AUTHOR("Sedji Gaouaou <sedji.gaouaou@atmel.com>");
+MODULE_DESCRIPTION("ALSA SoC AT91SAM9G20EK_WM8731");
+MODULE_LICENSE("GPL");