[ALSA] ASoC AT91RM92000 I2S support

This patch adds I2S support to the Atmel AT91RM9200 CPU.
Features:-
o Playback/Capture supported.
o 16 Bit data size.
o 8k - 48k sample rates.
o ssc0, ssc1 and ssc2 supported as I2S ports.

Signed-off-by: Frank Mandarino <fmandarino@endrelia.com>
Signed-off-by: Liam Girdwood <liam.girdwood@wolfsonmicro.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>

1 files changed, 688 insertions, 0 deletions

diff --git a/sound/soc/at91/at91rm9200-i2s.c b/sound/soc/at91/at91rm9200-i2s.c
new file mode 100644
index 000000000000..a74c5d85589b
--- /dev/null
+++ b/sound/soc/at91/at91rm9200-i2s.c
@@ -0,0 +1,688 @@
+/*
+ * at91rm9200-i2s.c  --  ALSA Soc Audio Layer Platform driver and DMA engine
+ *
+ * Author: Frank Mandarino <fmandarino@endrelia.com>
+ *         Endrelia Technologies Inc.
+ *
+ * Based on pxa2xx Platform drivers by
+ * Liam Girdwood <liam.girdwood@wolfsonmicro.com>
+ *
+ *  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.
+ *
+ *  Revision history
+ *     3rd Mar 2006   Initial version.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/device.h>
+#include <linux/delay.h>
+#include <linux/clk.h>
+#include <sound/driver.h>
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/initval.h>
+#include <sound/soc.h>
+
+#include <asm/arch/at91rm9200.h>
+#include <asm/arch/at91rm9200_ssc.h>
+#include <asm/arch/at91rm9200_pdc.h>
+#include <asm/arch/hardware.h>
+
+#include "at91rm9200-pcm.h"
+
+#if 0
+#define	DBG(x...)	printk(KERN_DEBUG "at91rm9200-i2s:" x)
+#else
+#define	DBG(x...)
+#endif
+
+#define AT91RM9200_I2S_DAIFMT \
+	(SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_CBS_CFS | SND_SOC_DAIFMT_NB_NF)
+
+#define AT91RM9200_I2S_DIR \
+	(SND_SOC_DAIDIR_PLAYBACK | SND_SOC_DAIDIR_CAPTURE)
+
+/* priv is (SSC_CMR.DIV << 16 | SSC_TCMR.PERIOD ) */
+static struct snd_soc_dai_mode at91rm9200_i2s[] = {
+
+	/* 8k: BCLK = (MCLK/10) = (60MHz/50) = 1.2MHz */
+	{ AT91RM9200_I2S_DAIFMT, SND_SOC_DAITDM_LRDW(0,0),
+		SNDRV_PCM_FMTBIT_S16_LE, SNDRV_PCM_RATE_8000, AT91RM9200_I2S_DIR,
+		SND_SOC_DAI_BFS_DIV, 1500, SND_SOC_FSBD(10), (25 << 16 | 74) },
+
+	/* 16k: BCLK = (MCLK/3) ~= (60MHz/14) = 4.285714MHz */
+	{ AT91RM9200_I2S_DAIFMT, SND_SOC_DAITDM_LRDW(0,0),
+		SNDRV_PCM_FMTBIT_S16_LE, SNDRV_PCM_RATE_16000, AT91RM9200_I2S_DIR,
+		SND_SOC_DAI_BFS_DIV, 750, SND_SOC_FSBD(3) , (7 << 16 | 133) },
+
+	/* 24k: BCLK = (MCLK/10) = (60MHz/50) = 1.2MHz */
+	{ AT91RM9200_I2S_DAIFMT, SND_SOC_DAITDM_LRDW(0,0),
+		SNDRV_PCM_FMTBIT_S16_LE, SNDRV_PCM_RATE_22050, AT91RM9200_I2S_DIR,
+		SND_SOC_DAI_BFS_DIV, 500, SND_SOC_FSBD(10), (25 << 16 | 24) },
+
+	/* 48kHz: BCLK = (MCLK/5) ~= (60MHz/26) = 2.3076923MHz */
+	{ AT91RM9200_I2S_DAIFMT, SND_SOC_DAITDM_LRDW(0,0),
+		SNDRV_PCM_FMTBIT_S16_LE, SNDRV_PCM_RATE_48000, AT91RM9200_I2S_DIR,
+		SND_SOC_DAI_BFS_DIV, 250, SND_SOC_FSBD(5), (13 << 16 | 23) },
+};
+
+
+/*
+ * SSC registers required by the PCM DMA engine.
+ */
+static struct at91rm9200_ssc_regs ssc_reg[3] = {
+	{
+	.cr	= (void __iomem *) (AT91_VA_BASE_SSC0 + AT91_SSC_CR),
+	.ier	= (void __iomem *) (AT91_VA_BASE_SSC0 + AT91_SSC_IER),
+	.idr	= (void __iomem *) (AT91_VA_BASE_SSC0 + AT91_SSC_IDR),
+	},
+	{
+	.cr	= (void __iomem *) (AT91_VA_BASE_SSC1 + AT91_SSC_CR),
+	.ier	= (void __iomem *) (AT91_VA_BASE_SSC1 + AT91_SSC_IER),
+	.idr	= (void __iomem *) (AT91_VA_BASE_SSC1 + AT91_SSC_IDR),
+	},
+	{
+	.cr	= (void __iomem *) (AT91_VA_BASE_SSC2 + AT91_SSC_CR),
+	.ier	= (void __iomem *) (AT91_VA_BASE_SSC2 + AT91_SSC_IER),
+	.idr	= (void __iomem *) (AT91_VA_BASE_SSC2 + AT91_SSC_IDR),
+	},
+};
+
+static struct at91rm9200_pdc_regs pdc_tx_reg[3] = {
+	{
+	.xpr	= (void __iomem *) (AT91_VA_BASE_SSC0 + AT91_PDC_TPR),
+	.xcr	= (void __iomem *) (AT91_VA_BASE_SSC0 + AT91_PDC_TCR),
+	.xnpr	= (void __iomem *) (AT91_VA_BASE_SSC0 + AT91_PDC_TNPR),
+	.xncr	= (void __iomem *) (AT91_VA_BASE_SSC0 + AT91_PDC_TNCR),
+	.ptcr	= (void __iomem *) (AT91_VA_BASE_SSC0 + AT91_PDC_PTCR),
+	},
+	{
+	.xpr	= (void __iomem *) (AT91_VA_BASE_SSC1 + AT91_PDC_TPR),
+	.xcr	= (void __iomem *) (AT91_VA_BASE_SSC1 + AT91_PDC_TCR),
+	.xnpr	= (void __iomem *) (AT91_VA_BASE_SSC1 + AT91_PDC_TNPR),
+	.xncr	= (void __iomem *) (AT91_VA_BASE_SSC1 + AT91_PDC_TNCR),
+	.ptcr	= (void __iomem *) (AT91_VA_BASE_SSC1 + AT91_PDC_PTCR),
+	},
+	{
+	.xpr	= (void __iomem *) (AT91_VA_BASE_SSC2 + AT91_PDC_TPR),
+	.xcr	= (void __iomem *) (AT91_VA_BASE_SSC2 + AT91_PDC_TCR),
+	.xnpr	= (void __iomem *) (AT91_VA_BASE_SSC2 + AT91_PDC_TNPR),
+	.xncr	= (void __iomem *) (AT91_VA_BASE_SSC2 + AT91_PDC_TNCR),
+	.ptcr	= (void __iomem *) (AT91_VA_BASE_SSC2 + AT91_PDC_PTCR),
+	},
+};
+
+static struct at91rm9200_pdc_regs pdc_rx_reg[3] = {
+	{
+	.xpr	= (void __iomem *) (AT91_VA_BASE_SSC0 + AT91_PDC_RPR),
+	.xcr	= (void __iomem *) (AT91_VA_BASE_SSC0 + AT91_PDC_RCR),
+	.xnpr	= (void __iomem *) (AT91_VA_BASE_SSC0 + AT91_PDC_RNPR),
+	.xncr	= (void __iomem *) (AT91_VA_BASE_SSC0 + AT91_PDC_RNCR),
+	.ptcr	= (void __iomem *) (AT91_VA_BASE_SSC0 + AT91_PDC_PTCR),
+	},
+	{
+	.xpr	= (void __iomem *) (AT91_VA_BASE_SSC1 + AT91_PDC_RPR),
+	.xcr	= (void __iomem *) (AT91_VA_BASE_SSC1 + AT91_PDC_RCR),
+	.xnpr	= (void __iomem *) (AT91_VA_BASE_SSC1 + AT91_PDC_RNPR),
+	.xncr	= (void __iomem *) (AT91_VA_BASE_SSC1 + AT91_PDC_RNCR),
+	.ptcr	= (void __iomem *) (AT91_VA_BASE_SSC1 + AT91_PDC_PTCR),
+	},
+	{
+	.xpr	= (void __iomem *) (AT91_VA_BASE_SSC2 + AT91_PDC_RPR),
+	.xcr	= (void __iomem *) (AT91_VA_BASE_SSC2 + AT91_PDC_RCR),
+	.xnpr	= (void __iomem *) (AT91_VA_BASE_SSC2 + AT91_PDC_RNPR),
+	.xncr	= (void __iomem *) (AT91_VA_BASE_SSC2 + AT91_PDC_RNCR),
+	.ptcr	= (void __iomem *) (AT91_VA_BASE_SSC2 + AT91_PDC_PTCR),
+	},
+};
+
+/*
+ * SSC & PDC status bits for transmit and receive.
+ */
+static struct at91rm9200_ssc_mask ssc_tx_mask = {
+	.ssc_enable	= AT91_SSC_TXEN,
+	.ssc_disable	= AT91_SSC_TXDIS,
+	.ssc_endx	= AT91_SSC_ENDTX,
+	.ssc_endbuf	= AT91_SSC_TXBUFE,
+	.pdc_enable	= AT91_PDC_TXTEN,
+	.pdc_disable	= AT91_PDC_TXTDIS,
+};
+
+static struct at91rm9200_ssc_mask ssc_rx_mask = {
+	.ssc_enable	= AT91_SSC_RXEN,
+	.ssc_disable	= AT91_SSC_RXDIS,
+	.ssc_endx	= AT91_SSC_ENDRX,
+	.ssc_endbuf	= AT91_SSC_RXBUFF,
+	.pdc_enable	= AT91_PDC_RXTEN,
+	.pdc_disable	= AT91_PDC_RXTDIS,
+};
+
+/*
+ * A MUTEX is used to protect an SSC initialzed flag which allows
+ * the substream hw_params() call to initialize the SSC only if
+ * there are no other substreams open.  If there are other
+ * substreams open, the hw_param() call can only check that
+ * it is using the same format and rate.
+ */
+static DECLARE_MUTEX(ssc0_mutex);
+static DECLARE_MUTEX(ssc1_mutex);
+static DECLARE_MUTEX(ssc2_mutex);
+
+/*
+ * DMA parameters.
+ */
+static at91rm9200_pcm_dma_params_t ssc_dma_params[3][2] = {
+	{{
+	.name		= "SSC0/I2S PCM Stereo out",
+	.ssc		= &ssc_reg[0],
+	.pdc		= &pdc_tx_reg[0],
+	.mask		= &ssc_tx_mask,
+	},
+	{
+	.name		= "SSC0/I2S PCM Stereo in",
+	.ssc		= &ssc_reg[0],
+	.pdc		= &pdc_rx_reg[0],
+	.mask		= &ssc_rx_mask,
+	}},
+	{{
+	.name		= "SSC1/I2S PCM Stereo out",
+	.ssc		= &ssc_reg[1],
+	.pdc		= &pdc_tx_reg[1],
+	.mask		= &ssc_tx_mask,
+	},
+	{
+	.name		= "SSC1/I2S PCM Stereo in",
+	.ssc		= &ssc_reg[1],
+	.pdc		= &pdc_rx_reg[1],
+	.mask		= &ssc_rx_mask,
+	}},
+	{{
+	.name		= "SSC2/I2S PCM Stereo out",
+	.ssc		= &ssc_reg[2],
+	.pdc		= &pdc_tx_reg[2],
+	.mask		= &ssc_tx_mask,
+	},
+	{
+	.name		= "SSC1/I2S PCM Stereo in",
+	.ssc		= &ssc_reg[2],
+	.pdc		= &pdc_rx_reg[2],
+	.mask		= &ssc_rx_mask,
+	}},
+};
+
+
+struct at91rm9200_ssc_state {
+	u32	ssc_cmr;
+	u32	ssc_rcmr;
+	u32	ssc_rfmr;
+	u32	ssc_tcmr;
+	u32	ssc_tfmr;
+	u32	ssc_sr;
+	u32	ssc_imr;
+};
+
+static struct at91rm9200_ssc_info {
+	char		*name;
+	void __iomem    *ssc_base;
+	u32		pid;
+	spinlock_t 	lock;		/* lock for dir_mask */
+	int		dir_mask;	/* 0=unused, 1=playback, 2=capture */
+	struct semaphore *mutex;
+	int		initialized;
+	int		pcmfmt;
+	int		rate;
+	at91rm9200_pcm_dma_params_t *dma_params[2];
+	struct at91rm9200_ssc_state ssc_state;
+
+} ssc_info[3] = {
+	{
+	.name		= "ssc0",
+	.ssc_base	= (void __iomem *) AT91_VA_BASE_SSC0,
+	.pid		= AT91_ID_SSC0,
+	.lock		= SPIN_LOCK_UNLOCKED,
+	.dir_mask	= 0,
+	.mutex		= &ssc0_mutex,
+	.initialized	= 0,
+	},
+	{
+	.name		= "ssc1",
+	.ssc_base	= (void __iomem *) AT91_VA_BASE_SSC1,
+	.pid		= AT91_ID_SSC1,
+	.lock		= SPIN_LOCK_UNLOCKED,
+	.dir_mask	= 0,
+	.mutex		= &ssc1_mutex,
+	.initialized	= 0,
+	},
+	{
+	.name		= "ssc2",
+	.ssc_base	= (void __iomem *) AT91_VA_BASE_SSC2,
+	.pid		= AT91_ID_SSC2,
+	.lock		= SPIN_LOCK_UNLOCKED,
+	.dir_mask	= 0,
+	.mutex		= &ssc2_mutex,
+	.initialized	= 0,
+	},
+};
+
+
+static int at91rm9200_i2s_interrupt(int irq, void *dev_id,
+	struct pt_regs *regs)
+{
+	struct at91rm9200_ssc_info *ssc_p = dev_id;
+	at91rm9200_pcm_dma_params_t *dma_params;
+	u32 ssc_sr;
+	int i;
+
+	ssc_sr = at91_ssc_read(ssc_p->ssc_base + AT91_SSC_SR)
+			& at91_ssc_read(ssc_p->ssc_base + AT91_SSC_IMR);
+
+	/*
+	 * Loop through the substreams attached to this SSC.  If
+	 * a DMA-related interrupt occurred on that substream, call
+	 * the DMA interrupt handler function, if one has been
+	 * registered in the dma_params structure by the PCM driver.
+	 */
+	for (i = 0; i < ARRAY_SIZE(ssc_p->dma_params); i++) {
+		dma_params = ssc_p->dma_params[i];
+
+		if (dma_params != NULL && dma_params->dma_intr_handler != NULL &&
+			(ssc_sr &
+			(dma_params->mask->ssc_endx | dma_params->mask->ssc_endbuf)))
+
+			dma_params->dma_intr_handler(ssc_sr, dma_params->substream);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int at91rm9200_i2s_startup(struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct at91rm9200_ssc_info *ssc_p = &ssc_info[rtd->cpu_dai->id];
+	int dir_mask;
+
+	DBG("i2s_startup: SSC_SR=0x%08lx\n",
+			at91_ssc_read(ssc_p->ssc_base + AT91_SSC_SR));
+	dir_mask = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ? 0x1 : 0x2;
+
+	spin_lock_irq(&ssc_p->lock);
+	if (ssc_p->dir_mask & dir_mask) {
+		spin_unlock_irq(&ssc_p->lock);
+		return -EBUSY;
+	}
+	ssc_p->dir_mask |= dir_mask;
+	spin_unlock_irq(&ssc_p->lock);
+
+	return 0;
+}
+
+static void at91rm9200_i2s_shutdown(struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct at91rm9200_ssc_info *ssc_p = &ssc_info[rtd->cpu_dai->id];
+	at91rm9200_pcm_dma_params_t *dma_params = rtd->cpu_dai->dma_data;
+	int dir, dir_mask;
+
+	dir = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ? 0 : 1;
+
+	if (dma_params != NULL) {
+		at91_ssc_write(dma_params->ssc->cr, dma_params->mask->ssc_disable);
+		DBG("%s disabled SSC_SR=0x%08lx\n", (dir ? "receive" : "transmit"),
+			at91_ssc_read(ssc_p->ssc_base + AT91_SSC_SR));
+
+		dma_params->substream = NULL;
+		ssc_p->dma_params[dir] = NULL;
+	}
+
+	dir_mask = 1 << dir;
+
+	spin_lock_irq(&ssc_p->lock);
+	ssc_p->dir_mask &= ~dir_mask;
+	if (!ssc_p->dir_mask) {
+		/* Shutdown the SSC clock. */
+		DBG("Stopping pid %d clock\n", ssc_p->pid);
+		at91_sys_write(AT91_PMC_PCDR, ssc_p->pid);
+
+		if (ssc_p->initialized)
+			free_irq(ssc_p->pid, ssc_p);
+
+		/* Reset the SSC */
+		at91_ssc_write(ssc_p->ssc_base + AT91_SSC_CR, AT91_SSC_SWRST);
+
+		/* Force a re-init on the next hw_params() call. */
+		ssc_p->initialized = 0;
+	}
+	spin_unlock_irq(&ssc_p->lock);
+}
+
+#ifdef CONFIG_PM
+static int at91rm9200_i2s_suspend(struct platform_device *pdev,
+	struct snd_soc_cpu_dai *dai)
+{
+	struct at91rm9200_ssc_info *ssc_p;
+
+	if(!dai->active)
+		return 0;
+
+	ssc_p = &ssc_info[dai->id];
+
+	/* Save the status register before disabling transmit and receive. */
+	ssc_p->state->ssc_sr = at91_ssc_read(ssc_p->ssc_base + AT91_SSC_SR);
+	at91_ssc_write(ssc_p->ssc_base +
+		AT91_SSC_CR, AT91_SSC_TXDIS | AT91_SSC_RXDIS);
+
+	/* Save the current interrupt mask, then disable unmasked interrupts. */
+	ssc_p->state->ssc_imr = at91_ssc_read(ssc_p->ssc_base + AT91_SSC_IMR);
+	at91_ssc_write(ssc_p->ssc_base + AT91_SSC_IDR, ssc_p->state->ssc_imr);
+
+	ssc_p->state->ssc_cmr  = at91_ssc_read(ssc_p->ssc_base + AT91_SSC_CMR);
+	ssc_p->state->ssc_rcmr = at91_ssc_read(ssc_p->ssc_base + AT91_SSC_RCMR);
+	ssc_p->state->ssc_rfmr = at91_ssc_read(ssc_p->ssc_base + AT91_SSC_RCMR);
+	ssc_p->state->ssc_tcmr = at91_ssc_read(ssc_p->ssc_base + AT91_SSC_RCMR);
+	ssc_p->state->ssc_tfmr = at91_ssc_read(ssc_p->ssc_base + AT91_SSC_RCMR);
+
+	return 0;
+}
+
+static int at91rm9200_i2s_resume(struct platform_device *pdev,
+	struct snd_soc_cpu_dai *dai)
+{
+	struct at91rm9200_ssc_info *ssc_p;
+	u32 cr_mask;
+
+	if(!dai->active)
+		return 0;
+
+	ssc_p = &ssc_info[dai->id];
+
+	at91_ssc_write(ssc_p->ssc_base + AT91_SSC_RCMR, ssc_p->state->ssc_tfmr);
+	at91_ssc_write(ssc_p->ssc_base + AT91_SSC_RCMR, ssc_p->state->ssc_tcmr);
+	at91_ssc_write(ssc_p->ssc_base + AT91_SSC_RCMR, ssc_p->state->ssc_rfmr);
+	at91_ssc_write(ssc_p->ssc_base + AT91_SSC_RCMR, ssc_p->state->ssc_rcmr);
+	at91_ssc_write(ssc_p->ssc_base + AT91_SSC_CMR,  ssc_p->state->ssc_cmr);
+
+	at91_ssc_write(ssc_p->ssc_base + AT91_SSC_IER,  ssc_p->state->ssc_imr);
+
+	at91_ssc_write(ssc_p->ssc_base + AT91_SSC_CR,
+		((ssc_p->state->ssc_sr & AT91_SSC_RXENA) ? AT91_SSC_RXEN : 0) |
+		((ssc_p->state->ssc_sr & AT91_SSC_TXENA) ? AT91_SSC_TXEN : 0));
+
+	return 0;
+}
+
+#else
+#define at91rm9200_i2s_suspend	NULL
+#define at91rm9200_i2s_resume	NULL
+#endif
+
+static unsigned int at91rm9200_i2s_config_sysclk(
+	struct snd_soc_cpu_dai *iface, struct snd_soc_clock_info *info,
+	unsigned int clk)
+{
+	/* Currently, there is only support for USB (12Mhz) mode */
+	if (clk != 12000000)
+		return 0;
+	return 12000000;
+}
+
+static int at91rm9200_i2s_hw_params(struct snd_pcm_substream *substream,
+	struct snd_pcm_hw_params *params)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	int id = rtd->cpu_dai->id;
+	struct at91rm9200_ssc_info *ssc_p = &ssc_info[id];
+	at91rm9200_pcm_dma_params_t *dma_params;
+	unsigned int pcmfmt, rate;
+	int dir, channels, bits;
+	struct clk *mck_clk;
+	unsigned long bclk;
+	u32 div, period, tfmr, rfmr, tcmr, rcmr;
+	int ret;
+
+	/*
+	 * Currently, there is only one set of dma params for
+	 * each direction.  If more are added, this code will
+	 * have to be changed to select the proper set.
+	 */
+	dir = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ? 0 : 1;
+
+	dma_params = &ssc_dma_params[id][dir];
+	dma_params->substream = substream;
+
+	ssc_p->dma_params[dir] = dma_params;
+	rtd->cpu_dai->dma_data = dma_params;
+
+	rate = params_rate(params);
+	channels = params_channels(params);
+
+	pcmfmt = rtd->cpu_dai->dai_runtime.pcmfmt;
+	switch (pcmfmt) {
+		case SNDRV_PCM_FMTBIT_S16_LE:
+			/* likely this is all we'll ever support, but ... */
+			bits = 16;
+			dma_params->pdc_xfer_size = 2;
+			break;
+		default:
+			printk(KERN_WARNING "at91rm9200-i2s: unsupported format %x\n",
+				pcmfmt);
+			return -EINVAL;
+	}
+
+	/* Don't allow both SSC substreams to initialize at the same time. */
+	down(ssc_p->mutex);
+
+	/*
+	 * If this SSC is alreadly initialized, then this substream must use
+	 * the same format and rate.
+	 */
+	if (ssc_p->initialized) {
+		if (pcmfmt != ssc_p->pcmfmt || rate != ssc_p->rate) {
+			printk(KERN_WARNING "at91rm9200-i2s: "
+				"incompatible substream in other direction\n");
+			up(ssc_p->mutex);
+			return -EINVAL;
+		}
+	} else {
+		/* Enable PMC peripheral clock for this SSC */
+		DBG("Starting pid %d clock\n", ssc_p->pid);
+		at91_sys_write(AT91_PMC_PCER, 1<<ssc_p->pid);
+
+		/* Reset the SSC */
+		at91_ssc_write(ssc_p->ssc_base + AT91_SSC_CR, AT91_SSC_SWRST);
+
+		at91_ssc_write(ssc_p->ssc_base + AT91_PDC_RPR, 0);
+		at91_ssc_write(ssc_p->ssc_base + AT91_PDC_RCR, 0);
+		at91_ssc_write(ssc_p->ssc_base + AT91_PDC_RNPR, 0);
+		at91_ssc_write(ssc_p->ssc_base + AT91_PDC_RNCR, 0);
+		at91_ssc_write(ssc_p->ssc_base + AT91_PDC_TPR, 0);
+		at91_ssc_write(ssc_p->ssc_base + AT91_PDC_TCR, 0);
+		at91_ssc_write(ssc_p->ssc_base + AT91_PDC_TNPR, 0);
+		at91_ssc_write(ssc_p->ssc_base + AT91_PDC_TNCR, 0);
+
+		mck_clk = clk_get(NULL, "mck");
+
+		div = rtd->cpu_dai->dai_runtime.priv >> 16;
+		period = rtd->cpu_dai->dai_runtime.priv & 0xffff;
+		bclk = 60000000 / (2 * div);
+
+		DBG("mck %ld fsbd %d bfs %d bfs_real %d bclk %ld div %d period %d\n",
+			clk_get_rate(mck_clk),
+			SND_SOC_FSBD(6),
+			rtd->cpu_dai->dai_runtime.bfs,
+			SND_SOC_FSBD_REAL(rtd->cpu_dai->dai_runtime.bfs),
+			bclk,
+			div,
+			period);
+
+		clk_put(mck_clk);
+
+		at91_ssc_write(ssc_p->ssc_base + AT91_SSC_CMR, div);
+
+		/*
+		 * Setup the TFMR and RFMR for the proper data format.
+		 */
+		tfmr =
+		  (( AT91_SSC_FSEDGE_POSITIVE	     ) & AT91_SSC_FSEDGE)
+		| (( 0				<< 23) & AT91_SSC_FSDEN)
+		| (( AT91_SSC_FSOS_NEGATIVE	     ) & AT91_SSC_FSOS)
+		| (((bits - 1)			<< 16) & AT91_SSC_FSLEN)
+		| (((channels - 1)		<<  8) & AT91_SSC_DATNB)
+		| (( 1				<<  7) & AT91_SSC_MSBF)
+		| (( 0				<<  5) & AT91_SSC_DATDEF)
+		| (((bits - 1)			<<  0) & AT91_SSC_DATALEN);
+		DBG("SSC_TFMR=0x%08x\n", tfmr);
+		at91_ssc_write(ssc_p->ssc_base + AT91_SSC_TFMR, tfmr);
+
+		rfmr =
+		  (( AT91_SSC_FSEDGE_POSITIVE	     ) & AT91_SSC_FSEDGE)
+		| (( AT91_SSC_FSOS_NONE		     ) & AT91_SSC_FSOS)
+		| (( 0				<< 16) & AT91_SSC_FSLEN)
+		| (((channels - 1)		<<  8) & AT91_SSC_DATNB)
+		| (( 1				<<  7) & AT91_SSC_MSBF)
+		| (( 0				<<  5) & AT91_SSC_LOOP)
+		| (((bits - 1)			<<  0) & AT91_SSC_DATALEN);
+
+		DBG("SSC_RFMR=0x%08x\n", rfmr);
+		at91_ssc_write(ssc_p->ssc_base + AT91_SSC_RFMR, rfmr);
+
+		/*
+		 * Setup the TCMR and RCMR to generate the proper BCLK
+		 * and LRC signals.
+		 */
+		tcmr =
+		  (( period			<< 24) & AT91_SSC_PERIOD)
+		| (( 1				<< 16) & AT91_SSC_STTDLY)
+		| (( AT91_SSC_START_FALLING_RF       ) & AT91_SSC_START)
+		| (( AT91_SSC_CKI_FALLING	     ) & AT91_SSC_CKI)
+		| (( AT91_SSC_CKO_CONTINUOUS	     ) & AT91_SSC_CKO)
+		| (( AT91_SSC_CKS_DIV		     ) & AT91_SSC_CKS);
+
+		DBG("SSC_TCMR=0x%08x\n", tcmr);
+		at91_ssc_write(ssc_p->ssc_base + AT91_SSC_TCMR, tcmr);
+
+		rcmr =
+		  (( 0				<< 24) & AT91_SSC_PERIOD)
+		| (( 1				<< 16) & AT91_SSC_STTDLY)
+		| (( AT91_SSC_START_TX_RX	     ) & AT91_SSC_START)
+		| (( AT91_SSC_CK_RISING		     ) & AT91_SSC_CKI)
+		| (( AT91_SSC_CKO_NONE		     ) & AT91_SSC_CKO)
+		| (( AT91_SSC_CKS_CLOCK		     ) & AT91_SSC_CKS);
+
+		DBG("SSC_RCMR=0x%08x\n", rcmr);
+		at91_ssc_write(ssc_p->ssc_base + AT91_SSC_RCMR, rcmr);
+
+		if ((ret = request_irq(ssc_p->pid, at91rm9200_i2s_interrupt,
+					0, ssc_p->name, ssc_p)) < 0) {
+			printk(KERN_WARNING "at91rm9200-i2s: request_irq failure\n");
+			return ret;
+		}
+
+		/*
+		 * Save the current substream parameters in order to check
+		 * that the substream in the opposite direction uses the
+		 * same parameters.
+		 */
+		ssc_p->pcmfmt = pcmfmt;
+		ssc_p->rate = rate;
+		ssc_p->initialized = 1;
+
+		DBG("hw_params: SSC initialized\n");
+	}
+
+	up(ssc_p->mutex);
+
+	return 0;
+}
+
+
+static int at91rm9200_i2s_prepare(struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	at91rm9200_pcm_dma_params_t *dma_params = rtd->cpu_dai->dma_data;
+
+	at91_ssc_write(dma_params->ssc->cr, dma_params->mask->ssc_enable);
+
+	DBG("%s enabled SSC_SR=0x%08lx\n",
+	substream->stream == SNDRV_PCM_STREAM_PLAYBACK ? "transmit" : "receive",
+	at91_ssc_read(ssc_info[rtd->cpu_dai->id].ssc_base + AT91_SSC_SR));
+	return 0;
+}
+
+
+struct snd_soc_cpu_dai at91rm9200_i2s_dai[] = {
+	{	.name = "at91rm9200-ssc0/i2s",
+		.id = 0,
+		.type = SND_SOC_DAI_I2S,
+		.suspend = at91rm9200_i2s_suspend,
+		.resume = at91rm9200_i2s_resume,
+		.config_sysclk = at91rm9200_i2s_config_sysclk,
+		.playback = {
+			.channels_min = 1,
+			.channels_max = 2,},
+		.capture = {
+			.channels_min = 1,
+			.channels_max = 2,},
+		.ops = {
+			.startup = at91rm9200_i2s_startup,
+			.shutdown = at91rm9200_i2s_shutdown,
+			.prepare = at91rm9200_i2s_prepare,
+			.hw_params = at91rm9200_i2s_hw_params,},
+		.caps = {
+			.mode = &at91rm9200_i2s[0],
+			.num_modes = ARRAY_SIZE(at91rm9200_i2s),},
+	},
+	{	.name = "at91rm9200-ssc1/i2s",
+		.id = 1,
+		.type = SND_SOC_DAI_I2S,
+		.suspend = at91rm9200_i2s_suspend,
+		.resume = at91rm9200_i2s_resume,
+		.config_sysclk = at91rm9200_i2s_config_sysclk,
+		.playback = {
+			.channels_min = 1,
+			.channels_max = 2,},
+		.capture = {
+			.channels_min = 1,
+			.channels_max = 2,},
+		.ops = {
+			.startup = at91rm9200_i2s_startup,
+			.shutdown = at91rm9200_i2s_shutdown,
+			.prepare = at91rm9200_i2s_prepare,
+			.hw_params = at91rm9200_i2s_hw_params,},
+		.caps = {
+			.mode = &at91rm9200_i2s[0],
+			.num_modes = ARRAY_SIZE(at91rm9200_i2s),},
+	},
+	{	.name = "at91rm9200-ssc2/i2s",
+		.id = 2,
+		.type = SND_SOC_DAI_I2S,
+		.suspend = at91rm9200_i2s_suspend,
+		.resume = at91rm9200_i2s_resume,
+		.config_sysclk = at91rm9200_i2s_config_sysclk,
+		.playback = {
+			.channels_min = 1,
+			.channels_max = 2,},
+		.capture = {
+			.channels_min = 1,
+			.channels_max = 2,},
+		.ops = {
+			.startup = at91rm9200_i2s_startup,
+			.shutdown = at91rm9200_i2s_shutdown,
+			.prepare = at91rm9200_i2s_prepare,
+			.hw_params = at91rm9200_i2s_hw_params,},
+		.caps = {
+			.mode = &at91rm9200_i2s[0],
+			.num_modes = ARRAY_SIZE(at91rm9200_i2s),},
+	},
+};
+
+EXPORT_SYMBOL_GPL(at91rm9200_i2s_dai);
+
+/* Module information */
+MODULE_AUTHOR("Frank Mandarino, fmandarino@endrelia.com, www.endrelia.com");
+MODULE_DESCRIPTION("AT91RM9200 I2S ASoC Interface");
+MODULE_LICENSE("GPL");