[ALSA] ARM AACI primecell driver

ARM,/arm/Makefile,ARM AACI PL041 driver
Add support for the ARM AACI Primecell, which provides an AC'97
based interface.  This driver only provides playback support.

This has been extensively tested with an LM4549 AC'97 codec.

Signed-off-by: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 968 insertions, 0 deletions

diff --git a/sound/arm/aaci.c b/sound/arm/aaci.c
new file mode 100644
index 000000000000..08cc3ddca96f
--- /dev/null
+++ b/sound/arm/aaci.c
@@ -0,0 +1,968 @@
+/*
+ *  linux/sound/arm/aaci.c - ARM PrimeCell AACI PL041 driver
+ *
+ *  Copyright (C) 2003 Deep Blue Solutions Ltd, All Rights Reserved.
+ *
+ * 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.
+ *
+ *  Documentation: ARM DDI 0173B
+ */
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/ioport.h>
+#include <linux/device.h>
+#include <linux/spinlock.h>
+#include <linux/interrupt.h>
+#include <linux/err.h>
+
+#include <asm/io.h>
+#include <asm/irq.h>
+#include <asm/hardware/amba.h>
+
+#include <sound/driver.h>
+#include <sound/core.h>
+#include <sound/initval.h>
+#include <sound/ac97_codec.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+
+#include "aaci.h"
+#include "devdma.h"
+
+#define DRIVER_NAME	"aaci-pl041"
+
+/*
+ * PM support is not complete.  Turn it off.
+ */
+#undef CONFIG_PM
+
+static void aaci_ac97_select_codec(struct aaci *aaci, ac97_t *ac97)
+{
+	u32 v, maincr = aaci->maincr | MAINCR_SCRA(ac97->num);
+
+	/*
+	 * Ensure that the slot 1/2 RX registers are empty.
+	 */
+	v = readl(aaci->base + AACI_SLFR);
+	if (v & SLFR_2RXV)
+		readl(aaci->base + AACI_SL2RX);
+	if (v & SLFR_1RXV)
+		readl(aaci->base + AACI_SL1RX);
+
+	writel(maincr, aaci->base + AACI_MAINCR);
+}
+
+/*
+ * P29:
+ *  The recommended use of programming the external codec through slot 1
+ *  and slot 2 data is to use the channels during setup routines and the
+ *  slot register at any other time.  The data written into slot 1, slot 2
+ *  and slot 12 registers is transmitted only when their corresponding
+ *  SI1TxEn, SI2TxEn and SI12TxEn bits are set in the AACI_MAINCR
+ *  register.
+ */
+static void aaci_ac97_write(ac97_t *ac97, unsigned short reg, unsigned short val)
+{
+	struct aaci *aaci = ac97->private_data;
+	u32 v;
+
+	if (ac97->num >= 4)
+		return;
+
+	down(&aaci->ac97_sem);
+
+	aaci_ac97_select_codec(aaci, ac97);
+
+	/*
+	 * P54: You must ensure that AACI_SL2TX is always written
+	 * to, if required, before data is written to AACI_SL1TX.
+	 */
+	writel(val << 4, aaci->base + AACI_SL2TX);
+	writel(reg << 12, aaci->base + AACI_SL1TX);
+
+	/*
+	 * Wait for the transmission of both slots to complete.
+	 */
+	do {
+		v = readl(aaci->base + AACI_SLFR);
+	} while (v & (SLFR_1TXB|SLFR_2TXB));
+
+	up(&aaci->ac97_sem);
+}
+
+/*
+ * Read an AC'97 register.
+ */
+static unsigned short aaci_ac97_read(ac97_t *ac97, unsigned short reg)
+{
+	struct aaci *aaci = ac97->private_data;
+	u32 v;
+
+	if (ac97->num >= 4)
+		return ~0;
+
+	down(&aaci->ac97_sem);
+
+	aaci_ac97_select_codec(aaci, ac97);
+
+	/*
+	 * Write the register address to slot 1.
+	 */
+	writel((reg << 12) | (1 << 19), aaci->base + AACI_SL1TX);
+
+	/*
+	 * Wait for the transmission to complete.
+	 */
+	do {
+		v = readl(aaci->base + AACI_SLFR);
+	} while (v & SLFR_1TXB);
+
+	/*
+	 * Give the AC'97 codec more than enough time
+	 * to respond. (42us = ~2 frames at 48kHz.)
+	 */
+	udelay(42);
+
+	/*
+	 * Wait for slot 2 to indicate data.
+	 */
+	do {
+		cond_resched();
+		v = readl(aaci->base + AACI_SLFR) & (SLFR_1RXV|SLFR_2RXV);
+	} while (v != (SLFR_1RXV|SLFR_2RXV));
+
+	v = readl(aaci->base + AACI_SL1RX) >> 12;
+	if (v == reg) {
+		v = readl(aaci->base + AACI_SL2RX) >> 4;
+	} else {
+		dev_err(&aaci->dev->dev,
+			"wrong ac97 register read back (%x != %x)\n",
+			v, reg);
+		v = ~0;
+	}
+
+	up(&aaci->ac97_sem);
+	return v;
+}
+
+static inline void aaci_chan_wait_ready(struct aaci_runtime *aacirun)
+{
+	u32 val;
+	int timeout = 5000;
+
+	do {
+		val = readl(aacirun->base + AACI_SR);
+	} while (val & (SR_TXB|SR_RXB) && timeout--);
+}
+
+
+
+/*
+ * Interrupt support.
+ */
+static void aaci_fifo_irq(struct aaci *aaci, u32 mask)
+{
+	if (mask & ISR_URINTR) {
+		writel(ICLR_TXUEC1, aaci->base + AACI_INTCLR);
+	}
+
+	if (mask & ISR_TXINTR) {
+		struct aaci_runtime *aacirun = &aaci->playback;
+		void *ptr;
+
+		if (!aacirun->substream || !aacirun->start) {
+			dev_warn(&aaci->dev->dev, "TX interrupt???");
+			writel(0, aacirun->base + AACI_IE);
+			return;
+		}
+
+		ptr = aacirun->ptr;
+		do {
+			unsigned int len = aacirun->fifosz;
+			u32 val;
+
+			if (aacirun->bytes <= 0) {
+				aacirun->bytes += aacirun->period;
+				aacirun->ptr = ptr;
+				spin_unlock(&aaci->lock);
+				snd_pcm_period_elapsed(aacirun->substream);
+				spin_lock(&aaci->lock);
+			}
+			if (!(aacirun->cr & TXCR_TXEN))
+				break;
+
+			val = readl(aacirun->base + AACI_SR);
+			if (!(val & SR_TXHE))
+				break;
+			if (!(val & SR_TXFE))
+				len >>= 1;
+
+			aacirun->bytes -= len;
+
+			/* writing 16 bytes at a time */
+			for ( ; len > 0; len -= 16) {
+				asm(
+					"ldmia	%0!, {r0, r1, r2, r3}\n\t"
+					"stmia	%1, {r0, r1, r2, r3}"
+					: "+r" (ptr)
+					: "r" (aacirun->fifo)
+					: "r0", "r1", "r2", "r3", "cc");
+
+				if (ptr >= aacirun->end)
+					ptr = aacirun->start;
+			}
+		} while (1);
+
+		aacirun->ptr = ptr;
+	}
+}
+
+static irqreturn_t aaci_irq(int irq, void *devid, struct pt_regs *regs)
+{
+	struct aaci *aaci = devid;
+	u32 mask;
+	int i;
+
+	spin_lock(&aaci->lock);
+	mask = readl(aaci->base + AACI_ALLINTS);
+	if (mask) {
+		u32 m = mask;
+		for (i = 0; i < 4; i++, m >>= 7) {
+			if (m & 0x7f) {
+				aaci_fifo_irq(aaci, m);
+			}
+		}
+	}
+	spin_unlock(&aaci->lock);
+
+	return mask ? IRQ_HANDLED : IRQ_NONE;
+}
+
+
+
+/*
+ * ALSA support.
+ */
+
+struct aaci_stream {
+	unsigned char codec_idx;
+	unsigned char rate_idx;
+};
+
+static struct aaci_stream aaci_streams[] = {
+	[ACSTREAM_FRONT] = {
+		.codec_idx	= 0,
+		.rate_idx	= AC97_RATES_FRONT_DAC,
+	},
+	[ACSTREAM_SURROUND] = {
+		.codec_idx	= 0,
+		.rate_idx	= AC97_RATES_SURR_DAC,
+	},
+	[ACSTREAM_LFE] = {
+		.codec_idx	= 0,
+		.rate_idx	= AC97_RATES_LFE_DAC,
+	},
+};
+
+static inline unsigned int aaci_rate_mask(struct aaci *aaci, int streamid)
+{
+	struct aaci_stream *s = aaci_streams + streamid;
+	return aaci->ac97_bus->codec[s->codec_idx]->rates[s->rate_idx];
+}
+
+static unsigned int rate_list[] = {
+	5512, 8000, 11025, 16000, 22050, 32000, 44100,
+	48000, 64000, 88200, 96000, 176400, 192000
+};
+
+/*
+ * Double-rate rule: we can support double rate iff channels == 2
+ *  (unimplemented)
+ */
+static int
+aaci_rule_rate_by_channels(snd_pcm_hw_params_t *p, snd_pcm_hw_rule_t *rule)
+{
+	struct aaci *aaci = rule->private;
+	unsigned int rate_mask = SNDRV_PCM_RATE_8000_48000|SNDRV_PCM_RATE_5512;
+	snd_interval_t *c = hw_param_interval(p, SNDRV_PCM_HW_PARAM_CHANNELS);
+
+	switch (c->max) {
+	case 6:
+		rate_mask &= aaci_rate_mask(aaci, ACSTREAM_LFE);
+	case 4:
+		rate_mask &= aaci_rate_mask(aaci, ACSTREAM_SURROUND);
+	case 2:
+		rate_mask &= aaci_rate_mask(aaci, ACSTREAM_FRONT);
+	}
+
+	return snd_interval_list(hw_param_interval(p, rule->var),
+				 ARRAY_SIZE(rate_list), rate_list,
+				 rate_mask);
+}
+
+static snd_pcm_hardware_t aaci_hw_info = {
+	.info			= SNDRV_PCM_INFO_MMAP |
+				  SNDRV_PCM_INFO_MMAP_VALID |
+				  SNDRV_PCM_INFO_INTERLEAVED |
+				  SNDRV_PCM_INFO_BLOCK_TRANSFER |
+				  SNDRV_PCM_INFO_RESUME,
+
+	/*
+	 * ALSA doesn't support 18-bit or 20-bit packed into 32-bit
+	 * words.  It also doesn't support 12-bit at all.
+	 */
+	.formats		= SNDRV_PCM_FMTBIT_S16_LE,
+
+	/* should this be continuous or knot? */
+	.rates			= SNDRV_PCM_RATE_CONTINUOUS,
+	.rate_max		= 48000,
+	.rate_min		= 4000,
+	.channels_min		= 2,
+	.channels_max		= 6,
+	.buffer_bytes_max	= 64 * 1024,
+	.period_bytes_min	= 256,
+	.period_bytes_max	= PAGE_SIZE,
+	.periods_min		= 4,
+	.periods_max		= PAGE_SIZE / 16,
+};
+
+static int aaci_pcm_open(struct aaci *aaci, snd_pcm_substream_t *substream,
+			 struct aaci_runtime *aacirun)
+{
+	snd_pcm_runtime_t *runtime = substream->runtime;
+	int ret;
+
+	aacirun->substream = substream;
+	runtime->private_data = aacirun;
+	runtime->hw = aaci_hw_info;
+
+	/*
+	 * FIXME: ALSA specifies fifo_size in bytes.  If we're in normal
+	 * mode, each 32-bit word contains one sample.  If we're in
+	 * compact mode, each 32-bit word contains two samples, effectively
+	 * halving the FIFO size.  However, we don't know for sure which
+	 * we'll be using at this point.  We set this to the lower limit.
+	 */
+	runtime->hw.fifo_size = aaci->fifosize * 2;
+
+	/*
+	 * Add rule describing hardware rate dependency
+	 * on the number of channels.
+	 */
+	ret = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
+				  aaci_rule_rate_by_channels, aaci,
+				  SNDRV_PCM_HW_PARAM_CHANNELS,
+				  SNDRV_PCM_HW_PARAM_RATE, -1);
+	if (ret)
+		goto out;
+
+	ret = request_irq(aaci->dev->irq[0], aaci_irq, SA_SHIRQ|SA_INTERRUPT,
+			  DRIVER_NAME, aaci);
+	if (ret)
+		goto out;
+
+	return 0;
+
+ out:
+	return ret;
+}
+
+
+/*
+ * Common ALSA stuff
+ */
+static int aaci_pcm_close(snd_pcm_substream_t *substream)
+{
+	struct aaci *aaci = substream->private_data;
+	struct aaci_runtime *aacirun = substream->runtime->private_data;
+
+	WARN_ON(aacirun->cr & TXCR_TXEN);
+
+	aacirun->substream = NULL;
+	free_irq(aaci->dev->irq[0], aaci);
+
+	return 0;
+}
+
+static int aaci_pcm_hw_free(snd_pcm_substream_t *substream)
+{
+	struct aaci_runtime *aacirun = substream->runtime->private_data;
+
+	/*
+	 * This must not be called with the device enabled.
+	 */
+	WARN_ON(aacirun->cr & TXCR_TXEN);
+
+	if (aacirun->pcm_open)
+		snd_ac97_pcm_close(aacirun->pcm);
+	aacirun->pcm_open = 0;
+
+	/*
+	 * Clear out the DMA and any allocated buffers.
+	 */
+	devdma_hw_free(NULL, substream);
+
+	return 0;
+}
+
+static int aaci_pcm_hw_params(snd_pcm_substream_t *substream,
+			      struct aaci_runtime *aacirun,
+			      snd_pcm_hw_params_t *params)
+{
+	int err;
+
+	aaci_pcm_hw_free(substream);
+
+	err = devdma_hw_alloc(NULL, substream,
+			      params_buffer_bytes(params));
+	if (err < 0)
+		goto out;
+
+	err = snd_ac97_pcm_open(aacirun->pcm, params_rate(params),
+				params_channels(params),
+				aacirun->pcm->r[0].slots);
+	if (err)
+		goto out;
+
+	aacirun->pcm_open = 1;
+
+ out:
+	return err;
+}
+
+static int aaci_pcm_prepare(snd_pcm_substream_t *substream)
+{
+	snd_pcm_runtime_t *runtime = substream->runtime;
+	struct aaci_runtime *aacirun = runtime->private_data;
+
+	aacirun->start	= (void *)runtime->dma_area;
+	aacirun->end	= aacirun->start + runtime->dma_bytes;
+	aacirun->ptr	= aacirun->start;
+	aacirun->period	=
+	aacirun->bytes	= frames_to_bytes(runtime, runtime->period_size);
+
+	return 0;
+}
+
+static snd_pcm_uframes_t aaci_pcm_pointer(snd_pcm_substream_t *substream)
+{
+	snd_pcm_runtime_t *runtime = substream->runtime;
+	struct aaci_runtime *aacirun = runtime->private_data;
+	ssize_t bytes = aacirun->ptr - aacirun->start;
+
+	return bytes_to_frames(runtime, bytes);
+}
+
+static int aaci_pcm_mmap(snd_pcm_substream_t *substream, struct vm_area_struct *vma)
+{
+	return devdma_mmap(NULL, substream, vma);
+}
+
+
+/*
+ * Playback specific ALSA stuff
+ */
+static const u32 channels_to_txmask[] = {
+	[2] = TXCR_TX3 | TXCR_TX4,
+	[4] = TXCR_TX3 | TXCR_TX4 | TXCR_TX7 | TXCR_TX8,
+	[6] = TXCR_TX3 | TXCR_TX4 | TXCR_TX7 | TXCR_TX8 | TXCR_TX6 | TXCR_TX9,
+};
+
+/*
+ * We can support two and four channel audio.  Unfortunately
+ * six channel audio requires a non-standard channel ordering:
+ *   2 -> FL(3), FR(4)
+ *   4 -> FL(3), FR(4), SL(7), SR(8)
+ *   6 -> FL(3), FR(4), SL(7), SR(8), C(6), LFE(9) (required)
+ *        FL(3), FR(4), C(6), SL(7), SR(8), LFE(9) (actual)
+ * This requires an ALSA configuration file to correct.
+ */
+static unsigned int channel_list[] = { 2, 4, 6 };
+
+static int
+aaci_rule_channels(snd_pcm_hw_params_t *p, snd_pcm_hw_rule_t *rule)
+{
+	struct aaci *aaci = rule->private;
+	unsigned int chan_mask = 1 << 0, slots;
+
+	/*
+	 * pcms[0] is the our 5.1 PCM instance.
+	 */
+	slots = aaci->ac97_bus->pcms[0].r[0].slots;
+	if (slots & (1 << AC97_SLOT_PCM_SLEFT)) {
+		chan_mask |= 1 << 1;
+		if (slots & (1 << AC97_SLOT_LFE))
+			chan_mask |= 1 << 2;
+	}
+
+	return snd_interval_list(hw_param_interval(p, rule->var),
+				 ARRAY_SIZE(channel_list), channel_list,
+				 chan_mask);
+}
+
+static int aaci_pcm_playback_open(snd_pcm_substream_t *substream)
+{
+	struct aaci *aaci = substream->private_data;
+	int ret;
+
+	/*
+	 * Add rule describing channel dependency.
+	 */
+	ret = snd_pcm_hw_rule_add(substream->runtime, 0,
+				  SNDRV_PCM_HW_PARAM_CHANNELS,
+				  aaci_rule_channels, aaci,
+				  SNDRV_PCM_HW_PARAM_CHANNELS, -1);
+	if (ret)
+		return ret;
+
+	return aaci_pcm_open(aaci, substream, &aaci->playback);
+}
+
+static int aaci_pcm_playback_hw_params(snd_pcm_substream_t *substream,
+				       snd_pcm_hw_params_t *params)
+{
+	struct aaci *aaci = substream->private_data;
+	struct aaci_runtime *aacirun = substream->runtime->private_data;
+	unsigned int channels = params_channels(params);
+	int ret;
+
+	WARN_ON(channels >= ARRAY_SIZE(channels_to_txmask) ||
+		!channels_to_txmask[channels]);
+
+	ret = aaci_pcm_hw_params(substream, aacirun, params);
+
+	/*
+	 * Enable FIFO, compact mode, 16 bits per sample.
+	 * FIXME: double rate slots?
+	 */
+	if (ret >= 0) {
+		aacirun->cr = TXCR_FEN | TXCR_COMPACT | TXCR_TSZ16;
+		aacirun->cr |= channels_to_txmask[channels];
+
+		aacirun->fifosz	= aaci->fifosize * 4;
+		if (aacirun->cr & TXCR_COMPACT)
+			aacirun->fifosz >>= 1;
+	}
+	return ret;
+}
+
+static void aaci_pcm_playback_stop(struct aaci_runtime *aacirun)
+{
+	u32 ie;
+
+	ie = readl(aacirun->base + AACI_IE);
+	ie &= ~(IE_URIE|IE_TXIE);
+	writel(ie, aacirun->base + AACI_IE);
+	aacirun->cr &= ~TXCR_TXEN;
+	aaci_chan_wait_ready(aacirun);
+	writel(aacirun->cr, aacirun->base + AACI_TXCR);
+}
+
+static void aaci_pcm_playback_start(struct aaci_runtime *aacirun)
+{
+	u32 ie;
+
+	aaci_chan_wait_ready(aacirun);
+	aacirun->cr |= TXCR_TXEN;
+
+	ie = readl(aacirun->base + AACI_IE);
+	ie |= IE_URIE | IE_TXIE;
+	writel(ie, aacirun->base + AACI_IE);
+	writel(aacirun->cr, aacirun->base + AACI_TXCR);
+}
+
+static int aaci_pcm_playback_trigger(snd_pcm_substream_t *substream, int cmd)
+{
+	struct aaci *aaci = substream->private_data;
+	struct aaci_runtime *aacirun = substream->runtime->private_data;
+	unsigned long flags;
+	int ret = 0;
+
+	spin_lock_irqsave(&aaci->lock, flags);
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+		aaci_pcm_playback_start(aacirun);
+		break;
+
+	case SNDRV_PCM_TRIGGER_RESUME:
+		aaci_pcm_playback_start(aacirun);
+		break;
+
+	case SNDRV_PCM_TRIGGER_STOP:
+		aaci_pcm_playback_stop(aacirun);
+		break;
+
+	case SNDRV_PCM_TRIGGER_SUSPEND:
+		aaci_pcm_playback_stop(aacirun);
+		break;
+
+	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+		break;
+
+	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+		break;
+
+	default:
+		ret = -EINVAL;
+	}
+	spin_unlock_irqrestore(&aaci->lock, flags);
+
+	return ret;
+}
+
+static snd_pcm_ops_t aaci_playback_ops = {
+	.open		= aaci_pcm_playback_open,
+	.close		= aaci_pcm_close,
+	.ioctl		= snd_pcm_lib_ioctl,
+	.hw_params	= aaci_pcm_playback_hw_params,
+	.hw_free	= aaci_pcm_hw_free,
+	.prepare	= aaci_pcm_prepare,
+	.trigger	= aaci_pcm_playback_trigger,
+	.pointer	= aaci_pcm_pointer,
+	.mmap		= aaci_pcm_mmap,
+};
+
+
+
+/*
+ * Power Management.
+ */
+#ifdef CONFIG_PM
+static int aaci_do_suspend(snd_card_t *card, unsigned int state)
+{
+	struct aaci *aaci = card->private_data;
+	if (aaci->card->power_state != SNDRV_CTL_POWER_D3cold) {
+		snd_pcm_suspend_all(aaci->pcm);
+		snd_power_change_state(aaci->card, SNDRV_CTL_POWER_D3cold);
+	}
+	return 0;
+}
+
+static int aaci_do_resume(snd_card_t *card, unsigned int state)
+{
+	struct aaci *aaci = card->private_data;
+	if (aaci->card->power_state != SNDRV_CTL_POWER_D0) {
+		snd_power_change_state(aaci->card, SNDRV_CTL_POWER_D0);
+	}
+	return 0;
+}
+
+static int aaci_suspend(struct amba_device *dev, u32 state)
+{
+	snd_card_t *card = amba_get_drvdata(dev);
+	return card ? aaci_do_suspend(card) : 0;
+}
+
+static int aaci_resume(struct amba_device *dev)
+{
+	snd_card_t *card = amba_get_drvdata(dev);
+	return card ? aaci_do_resume(card) : 0;
+}
+#else
+#define aaci_do_suspend		NULL
+#define aaci_do_resume		NULL
+#define aaci_suspend		NULL
+#define aaci_resume		NULL
+#endif
+
+
+static struct ac97_pcm ac97_defs[] __devinitdata = {
+	[0] = {		/* Front PCM */
+		.exclusive = 1,
+		.r = {
+			[0] = {
+				.slots	= (1 << AC97_SLOT_PCM_LEFT) |
+					  (1 << AC97_SLOT_PCM_RIGHT) |
+					  (1 << AC97_SLOT_PCM_CENTER) |
+					  (1 << AC97_SLOT_PCM_SLEFT) |
+					  (1 << AC97_SLOT_PCM_SRIGHT) |
+					  (1 << AC97_SLOT_LFE),
+			},
+		},
+	},
+	[1] = {	/* PCM in */
+		.stream = 1,
+		.exclusive = 1,
+		.r = {
+			[0] = {
+				.slots	= (1 << AC97_SLOT_PCM_LEFT) |
+					  (1 << AC97_SLOT_PCM_RIGHT),
+			},
+		},
+	},
+	[2] = {	/* Mic in */
+		.stream = 1,
+		.exclusive = 1,
+		.r = {
+			[0] = {
+				.slots	= (1 << AC97_SLOT_MIC),
+			},
+		},
+	}
+};
+
+static ac97_bus_ops_t aaci_bus_ops = {
+	.write	= aaci_ac97_write,
+	.read	= aaci_ac97_read,
+};
+
+static int __devinit aaci_probe_ac97(struct aaci *aaci)
+{
+	ac97_template_t ac97_template;
+	ac97_bus_t *ac97_bus;
+	ac97_t *ac97;
+	int ret;
+
+	/*
+	 * Assert AACIRESET for 2us
+	 */
+	writel(0, aaci->base + AACI_RESET);
+	udelay(2);
+	writel(RESET_NRST, aaci->base + AACI_RESET);
+
+	/*
+	 * Give the AC'97 codec more than enough time
+	 * to wake up. (42us = ~2 frames at 48kHz.)
+	 */
+	udelay(42);
+
+	ret = snd_ac97_bus(aaci->card, 0, &aaci_bus_ops, aaci, &ac97_bus);
+	if (ret)
+		goto out;
+
+	ac97_bus->clock = 48000;
+	aaci->ac97_bus = ac97_bus;
+
+	memset(&ac97_template, 0, sizeof(ac97_template_t));
+	ac97_template.private_data = aaci;
+	ac97_template.num = 0;
+	ac97_template.scaps = AC97_SCAP_SKIP_MODEM;
+
+	ret = snd_ac97_mixer(ac97_bus, &ac97_template, &ac97);
+	if (ret)
+		goto out;
+
+	/*
+	 * Disable AC97 PC Beep input on audio codecs.
+	 */
+	if (ac97_is_audio(ac97))
+		snd_ac97_write_cache(ac97, AC97_PC_BEEP, 0x801e);
+
+	ret = snd_ac97_pcm_assign(ac97_bus, ARRAY_SIZE(ac97_defs), ac97_defs);
+	if (ret)
+		goto out;
+
+	aaci->playback.pcm = &ac97_bus->pcms[0];
+
+ out:
+	return ret;
+}
+
+static void aaci_free_card(snd_card_t *card)
+{
+	struct aaci *aaci = card->private_data;
+	if (aaci->base)
+		iounmap(aaci->base);
+}
+
+static struct aaci * __devinit aaci_init_card(struct amba_device *dev)
+{
+	struct aaci *aaci;
+	snd_card_t *card;
+
+	card = snd_card_new(SNDRV_DEFAULT_IDX1, SNDRV_DEFAULT_STR1,
+			    THIS_MODULE, sizeof(struct aaci));
+	if (card == NULL)
+		return ERR_PTR(-ENOMEM);
+
+	card->private_free = aaci_free_card;
+	snd_card_set_pm_callback(card, aaci_do_suspend, aaci_do_resume, NULL);
+
+	strlcpy(card->driver, DRIVER_NAME, sizeof(card->driver));
+	strlcpy(card->shortname, "ARM AC'97 Interface", sizeof(card->shortname));
+	snprintf(card->longname, sizeof(card->longname),
+		 "%s at 0x%08lx, irq %d",
+		 card->shortname, dev->res.start, dev->irq[0]);
+
+	aaci = card->private_data;
+	init_MUTEX(&aaci->ac97_sem);
+	spin_lock_init(&aaci->lock);
+	aaci->card = card;
+	aaci->dev = dev;
+
+	/* Set MAINCR to allow slot 1 and 2 data IO */
+	aaci->maincr = MAINCR_IE | MAINCR_SL1RXEN | MAINCR_SL1TXEN |
+		       MAINCR_SL2RXEN | MAINCR_SL2TXEN;
+
+	return aaci;
+}
+
+static int __devinit aaci_init_pcm(struct aaci *aaci)
+{
+	snd_pcm_t *pcm;
+	int ret;
+
+	ret = snd_pcm_new(aaci->card, "AACI AC'97", 0, 1, 0, &pcm);
+	if (ret == 0) {
+		aaci->pcm = pcm;
+		pcm->private_data = aaci;
+		pcm->info_flags = 0;
+
+		strlcpy(pcm->name, DRIVER_NAME, sizeof(pcm->name));
+
+		snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &aaci_playback_ops);
+	}
+
+	return ret;
+}
+
+static unsigned int __devinit aaci_size_fifo(struct aaci *aaci)
+{
+	void *base = aaci->base + AACI_CSCH1;
+	int i;
+
+	writel(TXCR_FEN | TXCR_TSZ16 | TXCR_TXEN, base + AACI_TXCR);
+
+	for (i = 0; !(readl(base + AACI_SR) & SR_TXFF) && i < 4096; i++)
+		writel(0, aaci->base + AACI_DR1);
+
+	writel(0, base + AACI_TXCR);
+
+	/*
+	 * Re-initialise the AACI after the FIFO depth test, to
+	 * ensure that the FIFOs are empty.  Unfortunately, merely
+	 * disabling the channel doesn't clear the FIFO.
+	 */
+	writel(aaci->maincr & ~MAINCR_IE, aaci->base + AACI_MAINCR);
+	writel(aaci->maincr, aaci->base + AACI_MAINCR);
+
+	/*
+	 * If we hit 4096, we failed.  Go back to the specified
+	 * fifo depth.
+	 */
+	if (i == 4096)
+		i = 8;
+
+	return i;
+}
+
+static int __devinit aaci_probe(struct amba_device *dev, void *id)
+{
+	struct aaci *aaci;
+	int ret, i;
+
+	ret = amba_request_regions(dev, NULL);
+	if (ret)
+		return ret;
+
+	aaci = aaci_init_card(dev);
+	if (IS_ERR(aaci)) {
+		ret = PTR_ERR(aaci);
+		goto out;
+	}
+
+	aaci->base = ioremap(dev->res.start, SZ_4K);
+	if (!aaci->base) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	/*
+	 * Playback uses AACI channel 0
+	 */
+	aaci->playback.base = aaci->base + AACI_CSCH1;
+	aaci->playback.fifo = aaci->base + AACI_DR1;
+
+	for (i = 0; i < 4; i++) {
+		void *base = aaci->base + i * 0x14;
+
+		writel(0, base + AACI_IE);
+		writel(0, base + AACI_TXCR);
+		writel(0, base + AACI_RXCR);
+	}
+
+	writel(0x1fff, aaci->base + AACI_INTCLR);
+	writel(aaci->maincr, aaci->base + AACI_MAINCR);
+
+	/*
+	 * Size the FIFOs.
+	 */
+	aaci->fifosize = aaci_size_fifo(aaci);
+
+	ret = aaci_probe_ac97(aaci);
+	if (ret)
+		goto out;
+
+	ret = aaci_init_pcm(aaci);
+	if (ret)
+		goto out;
+
+	ret = snd_card_register(aaci->card);
+	if (ret == 0) {
+		dev_info(&dev->dev, "%s, fifo %d\n", aaci->card->longname,
+			aaci->fifosize);
+		amba_set_drvdata(dev, aaci->card);
+		return ret;
+	}
+
+ out:
+	if (aaci)
+		snd_card_free(aaci->card);
+	amba_release_regions(dev);
+	return ret;
+}
+
+static int __devexit aaci_remove(struct amba_device *dev)
+{
+	snd_card_t *card = amba_get_drvdata(dev);
+
+	amba_set_drvdata(dev, NULL);
+
+	if (card) {
+		struct aaci *aaci = card->private_data;
+		writel(0, aaci->base + AACI_MAINCR);
+
+		snd_card_free(card);
+		amba_release_regions(dev);
+	}
+
+	return 0;
+}
+
+static struct amba_id aaci_ids[] = {
+	{
+		.id	= 0x00041041,
+		.mask	= 0x000fffff,
+	},
+	{ 0, 0 },
+};
+
+static struct amba_driver aaci_driver = {
+	.drv		= {
+		.name	= DRIVER_NAME,
+	},
+	.probe		= aaci_probe,
+	.remove		= __devexit_p(aaci_remove),
+	.suspend	= aaci_suspend,
+	.resume		= aaci_resume,
+	.id_table	= aaci_ids,
+};
+
+static int __init aaci_init(void)
+{
+	return amba_driver_register(&aaci_driver);
+}
+
+static void __exit aaci_exit(void)
+{
+	amba_driver_unregister(&aaci_driver);
+}
+
+module_init(aaci_init);
+module_exit(aaci_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("ARM PrimeCell PL041 Advanced Audio CODEC Interface driver");