init android origin source code

1 files changed, 1064 insertions, 0 deletions

diff --git a/ANDROID_3.4.5/sound/aoa/soundbus/i2sbus/pcm.c b/ANDROID_3.4.5/sound/aoa/soundbus/i2sbus/pcm.c
new file mode 100644
index 00000000..19491ed9
--- /dev/null
+++ b/ANDROID_3.4.5/sound/aoa/soundbus/i2sbus/pcm.c
@@ -0,0 +1,1064 @@
+/*
+ * i2sbus driver -- pcm routines
+ *
+ * Copyright 2006 Johannes Berg <johannes@sipsolutions.net>
+ *
+ * GPL v2, can be found in COPYING.
+ */
+
+#include <asm/io.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <sound/core.h>
+#include <asm/macio.h>
+#include <linux/pci.h>
+#include <linux/module.h>
+#include "../soundbus.h"
+#include "i2sbus.h"
+
+static inline void get_pcm_info(struct i2sbus_dev *i2sdev, int in,
+				struct pcm_info **pi, struct pcm_info **other)
+{
+	if (in) {
+		if (pi)
+			*pi = &i2sdev->in;
+		if (other)
+			*other = &i2sdev->out;
+	} else {
+		if (pi)
+			*pi = &i2sdev->out;
+		if (other)
+			*other = &i2sdev->in;
+	}
+}
+
+static int clock_and_divisors(int mclk, int sclk, int rate, int *out)
+{
+	/* sclk must be derived from mclk! */
+	if (mclk % sclk)
+		return -1;
+	/* derive sclk register value */
+	if (i2s_sf_sclkdiv(mclk / sclk, out))
+		return -1;
+
+	if (I2S_CLOCK_SPEED_18MHz % (rate * mclk) == 0) {
+		if (!i2s_sf_mclkdiv(I2S_CLOCK_SPEED_18MHz / (rate * mclk), out)) {
+			*out |= I2S_SF_CLOCK_SOURCE_18MHz;
+			return 0;
+		}
+	}
+	if (I2S_CLOCK_SPEED_45MHz % (rate * mclk) == 0) {
+		if (!i2s_sf_mclkdiv(I2S_CLOCK_SPEED_45MHz / (rate * mclk), out)) {
+			*out |= I2S_SF_CLOCK_SOURCE_45MHz;
+			return 0;
+		}
+	}
+	if (I2S_CLOCK_SPEED_49MHz % (rate * mclk) == 0) {
+		if (!i2s_sf_mclkdiv(I2S_CLOCK_SPEED_49MHz / (rate * mclk), out)) {
+			*out |= I2S_SF_CLOCK_SOURCE_49MHz;
+			return 0;
+		}
+	}
+	return -1;
+}
+
+#define CHECK_RATE(rate)						\
+	do { if (rates & SNDRV_PCM_RATE_ ##rate) {			\
+		int dummy;						\
+		if (clock_and_divisors(sysclock_factor,			\
+				       bus_factor, rate, &dummy))	\
+			rates &= ~SNDRV_PCM_RATE_ ##rate;		\
+	} } while (0)
+
+static int i2sbus_pcm_open(struct i2sbus_dev *i2sdev, int in)
+{
+	struct pcm_info *pi, *other;
+	struct soundbus_dev *sdev;
+	int masks_inited = 0, err;
+	struct codec_info_item *cii, *rev;
+	struct snd_pcm_hardware *hw;
+	u64 formats = 0;
+	unsigned int rates = 0;
+	struct transfer_info v;
+	int result = 0;
+	int bus_factor = 0, sysclock_factor = 0;
+	int found_this;
+
+	mutex_lock(&i2sdev->lock);
+
+	get_pcm_info(i2sdev, in, &pi, &other);
+
+	hw = &pi->substream->runtime->hw;
+	sdev = &i2sdev->sound;
+
+	if (pi->active) {
+		/* alsa messed up */
+		result = -EBUSY;
+		goto out_unlock;
+	}
+
+	/* we now need to assign the hw */
+	list_for_each_entry(cii, &sdev->codec_list, list) {
+		struct transfer_info *ti = cii->codec->transfers;
+		bus_factor = cii->codec->bus_factor;
+		sysclock_factor = cii->codec->sysclock_factor;
+		while (ti->formats && ti->rates) {
+			v = *ti;
+			if (ti->transfer_in == in
+			    && cii->codec->usable(cii, ti, &v)) {
+				if (masks_inited) {
+					formats &= v.formats;
+					rates &= v.rates;
+				} else {
+					formats = v.formats;
+					rates = v.rates;
+					masks_inited = 1;
+				}
+			}
+			ti++;
+		}
+	}
+	if (!masks_inited || !bus_factor || !sysclock_factor) {
+		result = -ENODEV;
+		goto out_unlock;
+	}
+	/* bus dependent stuff */
+	hw->info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
+		   SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_RESUME |
+		   SNDRV_PCM_INFO_JOINT_DUPLEX;
+
+	CHECK_RATE(5512);
+	CHECK_RATE(8000);
+	CHECK_RATE(11025);
+	CHECK_RATE(16000);
+	CHECK_RATE(22050);
+	CHECK_RATE(32000);
+	CHECK_RATE(44100);
+	CHECK_RATE(48000);
+	CHECK_RATE(64000);
+	CHECK_RATE(88200);
+	CHECK_RATE(96000);
+	CHECK_RATE(176400);
+	CHECK_RATE(192000);
+	hw->rates = rates;
+
+	/* well. the codec might want 24 bits only, and we'll
+	 * ever only transfer 24 bits, but they are top-aligned!
+	 * So for alsa, we claim that we're doing full 32 bit
+	 * while in reality we'll ignore the lower 8 bits of
+	 * that when doing playback (they're transferred as 0
+	 * as far as I know, no codecs we have are 32-bit capable
+	 * so I can't really test) and when doing recording we'll
+	 * always have those lower 8 bits recorded as 0 */
+	if (formats & SNDRV_PCM_FMTBIT_S24_BE)
+		formats |= SNDRV_PCM_FMTBIT_S32_BE;
+	if (formats & SNDRV_PCM_FMTBIT_U24_BE)
+		formats |= SNDRV_PCM_FMTBIT_U32_BE;
+	/* now mask off what we can support. I suppose we could
+	 * also support S24_3LE and some similar formats, but I
+	 * doubt there's a codec that would be able to use that,
+	 * so we don't support it here. */
+	hw->formats = formats & (SNDRV_PCM_FMTBIT_S16_BE |
+				 SNDRV_PCM_FMTBIT_U16_BE |
+				 SNDRV_PCM_FMTBIT_S32_BE |
+				 SNDRV_PCM_FMTBIT_U32_BE);
+
+	/* we need to set the highest and lowest rate possible.
+	 * These are the highest and lowest rates alsa can
+	 * support properly in its bitfield.
+	 * Below, we'll use that to restrict to the rate
+	 * currently in use (if any). */
+	hw->rate_min = 5512;
+	hw->rate_max = 192000;
+	/* if the other stream is active, then we can only
+	 * support what it is currently using.
+	 * FIXME: I lied. This comment is wrong. We can support
+	 * anything that works with the same serial format, ie.
+	 * when recording 24 bit sound we can well play 16 bit
+	 * sound at the same time iff using the same transfer mode.
+	 */
+	if (other->active) {
+		/* FIXME: is this guaranteed by the alsa api? */
+		hw->formats &= (1ULL << i2sdev->format);
+		/* see above, restrict rates to the one we already have */
+		hw->rate_min = i2sdev->rate;
+		hw->rate_max = i2sdev->rate;
+	}
+
+	hw->channels_min = 2;
+	hw->channels_max = 2;
+	/* these are somewhat arbitrary */
+	hw->buffer_bytes_max = 131072;
+	hw->period_bytes_min = 256;
+	hw->period_bytes_max = 16384;
+	hw->periods_min = 3;
+	hw->periods_max = MAX_DBDMA_COMMANDS;
+	err = snd_pcm_hw_constraint_integer(pi->substream->runtime,
+					    SNDRV_PCM_HW_PARAM_PERIODS);
+	if (err < 0) {
+		result = err;
+		goto out_unlock;
+	}
+	list_for_each_entry(cii, &sdev->codec_list, list) {
+		if (cii->codec->open) {
+			err = cii->codec->open(cii, pi->substream);
+			if (err) {
+				result = err;
+				/* unwind */
+				found_this = 0;
+				list_for_each_entry_reverse(rev,
+				    &sdev->codec_list, list) {
+					if (found_this && rev->codec->close) {
+						rev->codec->close(rev,
+								pi->substream);
+					}
+					if (rev == cii)
+						found_this = 1;
+				}
+				goto out_unlock;
+			}
+		}
+	}
+
+ out_unlock:
+	mutex_unlock(&i2sdev->lock);
+	return result;
+}
+
+#undef CHECK_RATE
+
+static int i2sbus_pcm_close(struct i2sbus_dev *i2sdev, int in)
+{
+	struct codec_info_item *cii;
+	struct pcm_info *pi;
+	int err = 0, tmp;
+
+	mutex_lock(&i2sdev->lock);
+
+	get_pcm_info(i2sdev, in, &pi, NULL);
+
+	list_for_each_entry(cii, &i2sdev->sound.codec_list, list) {
+		if (cii->codec->close) {
+			tmp = cii->codec->close(cii, pi->substream);
+			if (tmp)
+				err = tmp;
+		}
+	}
+
+	pi->substream = NULL;
+	pi->active = 0;
+	mutex_unlock(&i2sdev->lock);
+	return err;
+}
+
+static void i2sbus_wait_for_stop(struct i2sbus_dev *i2sdev,
+				 struct pcm_info *pi)
+{
+	unsigned long flags;
+	struct completion done;
+	long timeout;
+
+	spin_lock_irqsave(&i2sdev->low_lock, flags);
+	if (pi->dbdma_ring.stopping) {
+		init_completion(&done);
+		pi->stop_completion = &done;
+		spin_unlock_irqrestore(&i2sdev->low_lock, flags);
+		timeout = wait_for_completion_timeout(&done, HZ);
+		spin_lock_irqsave(&i2sdev->low_lock, flags);
+		pi->stop_completion = NULL;
+		if (timeout == 0) {
+			/* timeout expired, stop dbdma forcefully */
+			printk(KERN_ERR "i2sbus_wait_for_stop: timed out\n");
+			/* make sure RUN, PAUSE and S0 bits are cleared */
+			out_le32(&pi->dbdma->control, (RUN | PAUSE | 1) << 16);
+			pi->dbdma_ring.stopping = 0;
+			timeout = 10;
+			while (in_le32(&pi->dbdma->status) & ACTIVE) {
+				if (--timeout <= 0)
+					break;
+				udelay(1);
+			}
+		}
+	}
+	spin_unlock_irqrestore(&i2sdev->low_lock, flags);
+}
+
+#ifdef CONFIG_PM
+void i2sbus_wait_for_stop_both(struct i2sbus_dev *i2sdev)
+{
+	struct pcm_info *pi;
+
+	get_pcm_info(i2sdev, 0, &pi, NULL);
+	i2sbus_wait_for_stop(i2sdev, pi);
+	get_pcm_info(i2sdev, 1, &pi, NULL);
+	i2sbus_wait_for_stop(i2sdev, pi);
+}
+#endif
+
+static int i2sbus_hw_params(struct snd_pcm_substream *substream,
+			    struct snd_pcm_hw_params *params)
+{
+	return snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(params));
+}
+
+static inline int i2sbus_hw_free(struct snd_pcm_substream *substream, int in)
+{
+	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
+	struct pcm_info *pi;
+
+	get_pcm_info(i2sdev, in, &pi, NULL);
+	if (pi->dbdma_ring.stopping)
+		i2sbus_wait_for_stop(i2sdev, pi);
+	snd_pcm_lib_free_pages(substream);
+	return 0;
+}
+
+static int i2sbus_playback_hw_free(struct snd_pcm_substream *substream)
+{
+	return i2sbus_hw_free(substream, 0);
+}
+
+static int i2sbus_record_hw_free(struct snd_pcm_substream *substream)
+{
+	return i2sbus_hw_free(substream, 1);
+}
+
+static int i2sbus_pcm_prepare(struct i2sbus_dev *i2sdev, int in)
+{
+	/* whee. Hard work now. The user has selected a bitrate
+	 * and bit format, so now we have to program our
+	 * I2S controller appropriately. */
+	struct snd_pcm_runtime *runtime;
+	struct dbdma_cmd *command;
+	int i, periodsize, nperiods;
+	dma_addr_t offset;
+	struct bus_info bi;
+	struct codec_info_item *cii;
+	int sfr = 0;		/* serial format register */
+	int dws = 0;		/* data word sizes reg */
+	int input_16bit;
+	struct pcm_info *pi, *other;
+	int cnt;
+	int result = 0;
+	unsigned int cmd, stopaddr;
+
+	mutex_lock(&i2sdev->lock);
+
+	get_pcm_info(i2sdev, in, &pi, &other);
+
+	if (pi->dbdma_ring.running) {
+		result = -EBUSY;
+		goto out_unlock;
+	}
+	if (pi->dbdma_ring.stopping)
+		i2sbus_wait_for_stop(i2sdev, pi);
+
+	if (!pi->substream || !pi->substream->runtime) {
+		result = -EINVAL;
+		goto out_unlock;
+	}
+
+	runtime = pi->substream->runtime;
+	pi->active = 1;
+	if (other->active &&
+	    ((i2sdev->format != runtime->format)
+	     || (i2sdev->rate != runtime->rate))) {
+		result = -EINVAL;
+		goto out_unlock;
+	}
+
+	i2sdev->format = runtime->format;
+	i2sdev->rate = runtime->rate;
+
+	periodsize = snd_pcm_lib_period_bytes(pi->substream);
+	nperiods = pi->substream->runtime->periods;
+	pi->current_period = 0;
+
+	/* generate dbdma command ring first */
+	command = pi->dbdma_ring.cmds;
+	memset(command, 0, (nperiods + 2) * sizeof(struct dbdma_cmd));
+
+	/* commands to DMA to/from the ring */
+	/*
+	 * For input, we need to do a graceful stop; if we abort
+	 * the DMA, we end up with leftover bytes that corrupt
+	 * the next recording.  To do this we set the S0 status
+	 * bit and wait for the DMA controller to stop.  Each
+	 * command has a branch condition to
+	 * make it branch to a stop command if S0 is set.
+	 * On input we also need to wait for the S7 bit to be
+	 * set before turning off the DMA controller.
+	 * In fact we do the graceful stop for output as well.
+	 */
+	offset = runtime->dma_addr;
+	cmd = (in? INPUT_MORE: OUTPUT_MORE) | BR_IFSET | INTR_ALWAYS;
+	stopaddr = pi->dbdma_ring.bus_cmd_start +
+		(nperiods + 1) * sizeof(struct dbdma_cmd);
+	for (i = 0; i < nperiods; i++, command++, offset += periodsize) {
+		command->command = cpu_to_le16(cmd);
+		command->cmd_dep = cpu_to_le32(stopaddr);
+		command->phy_addr = cpu_to_le32(offset);
+		command->req_count = cpu_to_le16(periodsize);
+	}
+
+	/* branch back to beginning of ring */
+	command->command = cpu_to_le16(DBDMA_NOP | BR_ALWAYS);
+	command->cmd_dep = cpu_to_le32(pi->dbdma_ring.bus_cmd_start);
+	command++;
+
+	/* set stop command */
+	command->command = cpu_to_le16(DBDMA_STOP);
+
+	/* ok, let's set the serial format and stuff */
+	switch (runtime->format) {
+	/* 16 bit formats */
+	case SNDRV_PCM_FORMAT_S16_BE:
+	case SNDRV_PCM_FORMAT_U16_BE:
+		/* FIXME: if we add different bus factors we need to
+		 * do more here!! */
+		bi.bus_factor = 0;
+		list_for_each_entry(cii, &i2sdev->sound.codec_list, list) {
+			bi.bus_factor = cii->codec->bus_factor;
+			break;
+		}
+		if (!bi.bus_factor) {
+			result = -ENODEV;
+			goto out_unlock;
+		}
+		input_16bit = 1;
+		break;
+	case SNDRV_PCM_FORMAT_S32_BE:
+	case SNDRV_PCM_FORMAT_U32_BE:
+		/* force 64x bus speed, otherwise the data cannot be
+		 * transferred quickly enough! */
+		bi.bus_factor = 64;
+		input_16bit = 0;
+		break;
+	default:
+		result = -EINVAL;
+		goto out_unlock;
+	}
+	/* we assume all sysclocks are the same! */
+	list_for_each_entry(cii, &i2sdev->sound.codec_list, list) {
+		bi.sysclock_factor = cii->codec->sysclock_factor;
+		break;
+	}
+
+	if (clock_and_divisors(bi.sysclock_factor,
+			       bi.bus_factor,
+			       runtime->rate,
+			       &sfr) < 0) {
+		result = -EINVAL;
+		goto out_unlock;
+	}
+	switch (bi.bus_factor) {
+	case 32:
+		sfr |= I2S_SF_SERIAL_FORMAT_I2S_32X;
+		break;
+	case 64:
+		sfr |= I2S_SF_SERIAL_FORMAT_I2S_64X;
+		break;
+	}
+	/* FIXME: THIS ASSUMES MASTER ALL THE TIME */
+	sfr |= I2S_SF_SCLK_MASTER;
+
+	list_for_each_entry(cii, &i2sdev->sound.codec_list, list) {
+		int err = 0;
+		if (cii->codec->prepare)
+			err = cii->codec->prepare(cii, &bi, pi->substream);
+		if (err) {
+			result = err;
+			goto out_unlock;
+		}
+	}
+	/* codecs are fine with it, so set our clocks */
+	if (input_16bit)
+		dws =	(2 << I2S_DWS_NUM_CHANNELS_IN_SHIFT) |
+			(2 << I2S_DWS_NUM_CHANNELS_OUT_SHIFT) |
+			I2S_DWS_DATA_IN_16BIT | I2S_DWS_DATA_OUT_16BIT;
+	else
+		dws =	(2 << I2S_DWS_NUM_CHANNELS_IN_SHIFT) |
+			(2 << I2S_DWS_NUM_CHANNELS_OUT_SHIFT) |
+			I2S_DWS_DATA_IN_24BIT | I2S_DWS_DATA_OUT_24BIT;
+
+	/* early exit if already programmed correctly */
+	/* not locking these is fine since we touch them only in this function */
+	if (in_le32(&i2sdev->intfregs->serial_format) == sfr
+	 && in_le32(&i2sdev->intfregs->data_word_sizes) == dws)
+		goto out_unlock;
+
+	/* let's notify the codecs about clocks going away.
+	 * For now we only do mastering on the i2s cell... */
+	list_for_each_entry(cii, &i2sdev->sound.codec_list, list)
+		if (cii->codec->switch_clock)
+			cii->codec->switch_clock(cii, CLOCK_SWITCH_PREPARE_SLAVE);
+
+	i2sbus_control_enable(i2sdev->control, i2sdev);
+	i2sbus_control_cell(i2sdev->control, i2sdev, 1);
+
+	out_le32(&i2sdev->intfregs->intr_ctl, I2S_PENDING_CLOCKS_STOPPED);
+
+	i2sbus_control_clock(i2sdev->control, i2sdev, 0);
+
+	msleep(1);
+
+	/* wait for clock stopped. This can apparently take a while... */
+	cnt = 100;
+	while (cnt-- &&
+	    !(in_le32(&i2sdev->intfregs->intr_ctl) & I2S_PENDING_CLOCKS_STOPPED)) {
+		msleep(5);
+	}
+	out_le32(&i2sdev->intfregs->intr_ctl, I2S_PENDING_CLOCKS_STOPPED);
+
+	/* not locking these is fine since we touch them only in this function */
+	out_le32(&i2sdev->intfregs->serial_format, sfr);
+	out_le32(&i2sdev->intfregs->data_word_sizes, dws);
+
+        i2sbus_control_enable(i2sdev->control, i2sdev);
+        i2sbus_control_cell(i2sdev->control, i2sdev, 1);
+        i2sbus_control_clock(i2sdev->control, i2sdev, 1);
+	msleep(1);
+
+	list_for_each_entry(cii, &i2sdev->sound.codec_list, list)
+		if (cii->codec->switch_clock)
+			cii->codec->switch_clock(cii, CLOCK_SWITCH_SLAVE);
+
+ out_unlock:
+	mutex_unlock(&i2sdev->lock);
+	return result;
+}
+
+#ifdef CONFIG_PM
+void i2sbus_pcm_prepare_both(struct i2sbus_dev *i2sdev)
+{
+	i2sbus_pcm_prepare(i2sdev, 0);
+	i2sbus_pcm_prepare(i2sdev, 1);
+}
+#endif
+
+static int i2sbus_pcm_trigger(struct i2sbus_dev *i2sdev, int in, int cmd)
+{
+	struct codec_info_item *cii;
+	struct pcm_info *pi;
+	int result = 0;
+	unsigned long flags;
+
+	spin_lock_irqsave(&i2sdev->low_lock, flags);
+
+	get_pcm_info(i2sdev, in, &pi, NULL);
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+	case SNDRV_PCM_TRIGGER_RESUME:
+		if (pi->dbdma_ring.running) {
+			result = -EALREADY;
+			goto out_unlock;
+		}
+		list_for_each_entry(cii, &i2sdev->sound.codec_list, list)
+			if (cii->codec->start)
+				cii->codec->start(cii, pi->substream);
+		pi->dbdma_ring.running = 1;
+
+		if (pi->dbdma_ring.stopping) {
+			/* Clear the S0 bit, then see if we stopped yet */
+			out_le32(&pi->dbdma->control, 1 << 16);
+			if (in_le32(&pi->dbdma->status) & ACTIVE) {
+				/* possible race here? */
+				udelay(10);
+				if (in_le32(&pi->dbdma->status) & ACTIVE) {
+					pi->dbdma_ring.stopping = 0;
+					goto out_unlock; /* keep running */
+				}
+			}
+		}
+
+		/* make sure RUN, PAUSE and S0 bits are cleared */
+		out_le32(&pi->dbdma->control, (RUN | PAUSE | 1) << 16);
+
+		/* set branch condition select register */
+		out_le32(&pi->dbdma->br_sel, (1 << 16) | 1);
+
+		/* write dma command buffer address to the dbdma chip */
+		out_le32(&pi->dbdma->cmdptr, pi->dbdma_ring.bus_cmd_start);
+
+		/* initialize the frame count and current period */
+		pi->current_period = 0;
+		pi->frame_count = in_le32(&i2sdev->intfregs->frame_count);
+
+		/* set the DMA controller running */
+		out_le32(&pi->dbdma->control, (RUN << 16) | RUN);
+
+		/* off you go! */
+		break;
+
+	case SNDRV_PCM_TRIGGER_STOP:
+	case SNDRV_PCM_TRIGGER_SUSPEND:
+		if (!pi->dbdma_ring.running) {
+			result = -EALREADY;
+			goto out_unlock;
+		}
+		pi->dbdma_ring.running = 0;
+
+		/* Set the S0 bit to make the DMA branch to the stop cmd */
+		out_le32(&pi->dbdma->control, (1 << 16) | 1);
+		pi->dbdma_ring.stopping = 1;
+
+		list_for_each_entry(cii, &i2sdev->sound.codec_list, list)
+			if (cii->codec->stop)
+				cii->codec->stop(cii, pi->substream);
+		break;
+	default:
+		result = -EINVAL;
+		goto out_unlock;
+	}
+
+ out_unlock:
+	spin_unlock_irqrestore(&i2sdev->low_lock, flags);
+	return result;
+}
+
+static snd_pcm_uframes_t i2sbus_pcm_pointer(struct i2sbus_dev *i2sdev, int in)
+{
+	struct pcm_info *pi;
+	u32 fc;
+
+	get_pcm_info(i2sdev, in, &pi, NULL);
+
+	fc = in_le32(&i2sdev->intfregs->frame_count);
+	fc = fc - pi->frame_count;
+
+	if (fc >= pi->substream->runtime->buffer_size)
+		fc %= pi->substream->runtime->buffer_size;
+	return fc;
+}
+
+static inline void handle_interrupt(struct i2sbus_dev *i2sdev, int in)
+{
+	struct pcm_info *pi;
+	u32 fc, nframes;
+	u32 status;
+	int timeout, i;
+	int dma_stopped = 0;
+	struct snd_pcm_runtime *runtime;
+
+	spin_lock(&i2sdev->low_lock);
+	get_pcm_info(i2sdev, in, &pi, NULL);
+	if (!pi->dbdma_ring.running && !pi->dbdma_ring.stopping)
+		goto out_unlock;
+
+	i = pi->current_period;
+	runtime = pi->substream->runtime;
+	while (pi->dbdma_ring.cmds[i].xfer_status) {
+		if (le16_to_cpu(pi->dbdma_ring.cmds[i].xfer_status) & BT)
+			/*
+			 * BT is the branch taken bit.  If it took a branch
+			 * it is because we set the S0 bit to make it
+			 * branch to the stop command.
+			 */
+			dma_stopped = 1;
+		pi->dbdma_ring.cmds[i].xfer_status = 0;
+
+		if (++i >= runtime->periods) {
+			i = 0;
+			pi->frame_count += runtime->buffer_size;
+		}
+		pi->current_period = i;
+
+		/*
+		 * Check the frame count.  The DMA tends to get a bit
+		 * ahead of the frame counter, which confuses the core.
+		 */
+		fc = in_le32(&i2sdev->intfregs->frame_count);
+		nframes = i * runtime->period_size;
+		if (fc < pi->frame_count + nframes)
+			pi->frame_count = fc - nframes;
+	}
+
+	if (dma_stopped) {
+		timeout = 1000;
+		for (;;) {
+			status = in_le32(&pi->dbdma->status);
+			if (!(status & ACTIVE) && (!in || (status & 0x80)))
+				break;
+			if (--timeout <= 0) {
+				printk(KERN_ERR "i2sbus: timed out "
+				       "waiting for DMA to stop!\n");
+				break;
+			}
+			udelay(1);
+		}
+
+		/* Turn off DMA controller, clear S0 bit */
+		out_le32(&pi->dbdma->control, (RUN | PAUSE | 1) << 16);
+
+		pi->dbdma_ring.stopping = 0;
+		if (pi->stop_completion)
+			complete(pi->stop_completion);
+	}
+
+	if (!pi->dbdma_ring.running)
+		goto out_unlock;
+	spin_unlock(&i2sdev->low_lock);
+	/* may call _trigger again, hence needs to be unlocked */
+	snd_pcm_period_elapsed(pi->substream);
+	return;
+
+ out_unlock:
+	spin_unlock(&i2sdev->low_lock);
+}
+
+irqreturn_t i2sbus_tx_intr(int irq, void *devid)
+{
+	handle_interrupt((struct i2sbus_dev *)devid, 0);
+	return IRQ_HANDLED;
+}
+
+irqreturn_t i2sbus_rx_intr(int irq, void *devid)
+{
+	handle_interrupt((struct i2sbus_dev *)devid, 1);
+	return IRQ_HANDLED;
+}
+
+static int i2sbus_playback_open(struct snd_pcm_substream *substream)
+{
+	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
+
+	if (!i2sdev)
+		return -EINVAL;
+	i2sdev->out.substream = substream;
+	return i2sbus_pcm_open(i2sdev, 0);
+}
+
+static int i2sbus_playback_close(struct snd_pcm_substream *substream)
+{
+	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
+	int err;
+
+	if (!i2sdev)
+		return -EINVAL;
+	if (i2sdev->out.substream != substream)
+		return -EINVAL;
+	err = i2sbus_pcm_close(i2sdev, 0);
+	if (!err)
+		i2sdev->out.substream = NULL;
+	return err;
+}
+
+static int i2sbus_playback_prepare(struct snd_pcm_substream *substream)
+{
+	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
+
+	if (!i2sdev)
+		return -EINVAL;
+	if (i2sdev->out.substream != substream)
+		return -EINVAL;
+	return i2sbus_pcm_prepare(i2sdev, 0);
+}
+
+static int i2sbus_playback_trigger(struct snd_pcm_substream *substream, int cmd)
+{
+	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
+
+	if (!i2sdev)
+		return -EINVAL;
+	if (i2sdev->out.substream != substream)
+		return -EINVAL;
+	return i2sbus_pcm_trigger(i2sdev, 0, cmd);
+}
+
+static snd_pcm_uframes_t i2sbus_playback_pointer(struct snd_pcm_substream
+						 *substream)
+{
+	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
+
+	if (!i2sdev)
+		return -EINVAL;
+	if (i2sdev->out.substream != substream)
+		return 0;
+	return i2sbus_pcm_pointer(i2sdev, 0);
+}
+
+static struct snd_pcm_ops i2sbus_playback_ops = {
+	.open =		i2sbus_playback_open,
+	.close =	i2sbus_playback_close,
+	.ioctl =	snd_pcm_lib_ioctl,
+	.hw_params =	i2sbus_hw_params,
+	.hw_free =	i2sbus_playback_hw_free,
+	.prepare =	i2sbus_playback_prepare,
+	.trigger =	i2sbus_playback_trigger,
+	.pointer =	i2sbus_playback_pointer,
+};
+
+static int i2sbus_record_open(struct snd_pcm_substream *substream)
+{
+	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
+
+	if (!i2sdev)
+		return -EINVAL;
+	i2sdev->in.substream = substream;
+	return i2sbus_pcm_open(i2sdev, 1);
+}
+
+static int i2sbus_record_close(struct snd_pcm_substream *substream)
+{
+	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
+	int err;
+
+	if (!i2sdev)
+		return -EINVAL;
+	if (i2sdev->in.substream != substream)
+		return -EINVAL;
+	err = i2sbus_pcm_close(i2sdev, 1);
+	if (!err)
+		i2sdev->in.substream = NULL;
+	return err;
+}
+
+static int i2sbus_record_prepare(struct snd_pcm_substream *substream)
+{
+	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
+
+	if (!i2sdev)
+		return -EINVAL;
+	if (i2sdev->in.substream != substream)
+		return -EINVAL;
+	return i2sbus_pcm_prepare(i2sdev, 1);
+}
+
+static int i2sbus_record_trigger(struct snd_pcm_substream *substream, int cmd)
+{
+	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
+
+	if (!i2sdev)
+		return -EINVAL;
+	if (i2sdev->in.substream != substream)
+		return -EINVAL;
+	return i2sbus_pcm_trigger(i2sdev, 1, cmd);
+}
+
+static snd_pcm_uframes_t i2sbus_record_pointer(struct snd_pcm_substream
+					       *substream)
+{
+	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
+
+	if (!i2sdev)
+		return -EINVAL;
+	if (i2sdev->in.substream != substream)
+		return 0;
+	return i2sbus_pcm_pointer(i2sdev, 1);
+}
+
+static struct snd_pcm_ops i2sbus_record_ops = {
+	.open =		i2sbus_record_open,
+	.close =	i2sbus_record_close,
+	.ioctl =	snd_pcm_lib_ioctl,
+	.hw_params =	i2sbus_hw_params,
+	.hw_free =	i2sbus_record_hw_free,
+	.prepare =	i2sbus_record_prepare,
+	.trigger =	i2sbus_record_trigger,
+	.pointer =	i2sbus_record_pointer,
+};
+
+static void i2sbus_private_free(struct snd_pcm *pcm)
+{
+	struct i2sbus_dev *i2sdev = snd_pcm_chip(pcm);
+	struct codec_info_item *p, *tmp;
+
+	i2sdev->sound.pcm = NULL;
+	i2sdev->out.created = 0;
+	i2sdev->in.created = 0;
+	list_for_each_entry_safe(p, tmp, &i2sdev->sound.codec_list, list) {
+		printk(KERN_ERR "i2sbus: a codec didn't unregister!\n");
+		list_del(&p->list);
+		module_put(p->codec->owner);
+		kfree(p);
+	}
+	soundbus_dev_put(&i2sdev->sound);
+	module_put(THIS_MODULE);
+}
+
+int
+i2sbus_attach_codec(struct soundbus_dev *dev, struct snd_card *card,
+		    struct codec_info *ci, void *data)
+{
+	int err, in = 0, out = 0;
+	struct transfer_info *tmp;
+	struct i2sbus_dev *i2sdev = soundbus_dev_to_i2sbus_dev(dev);
+	struct codec_info_item *cii;
+
+	if (!dev->pcmname || dev->pcmid == -1) {
+		printk(KERN_ERR "i2sbus: pcm name and id must be set!\n");
+		return -EINVAL;
+	}
+
+	list_for_each_entry(cii, &dev->codec_list, list) {
+		if (cii->codec_data == data)
+			return -EALREADY;
+	}
+
+	if (!ci->transfers || !ci->transfers->formats
+	    || !ci->transfers->rates || !ci->usable)
+		return -EINVAL;
+
+	/* we currently code the i2s transfer on the clock, and support only
+	 * 32 and 64 */
+	if (ci->bus_factor != 32 && ci->bus_factor != 64)
+		return -EINVAL;
+
+	/* If you want to fix this, you need to keep track of what transport infos
+	 * are to be used, which codecs they belong to, and then fix all the
+	 * sysclock/busclock stuff above to depend on which is usable */
+	list_for_each_entry(cii, &dev->codec_list, list) {
+		if (cii->codec->sysclock_factor != ci->sysclock_factor) {
+			printk(KERN_DEBUG
+			       "cannot yet handle multiple different sysclocks!\n");
+			return -EINVAL;
+		}
+		if (cii->codec->bus_factor != ci->bus_factor) {
+			printk(KERN_DEBUG
+			       "cannot yet handle multiple different bus clocks!\n");
+			return -EINVAL;
+		}
+	}
+
+	tmp = ci->transfers;
+	while (tmp->formats && tmp->rates) {
+		if (tmp->transfer_in)
+			in = 1;
+		else
+			out = 1;
+		tmp++;
+	}
+
+	cii = kzalloc(sizeof(struct codec_info_item), GFP_KERNEL);
+	if (!cii) {
+		printk(KERN_DEBUG "i2sbus: failed to allocate cii\n");
+		return -ENOMEM;
+	}
+
+	/* use the private data to point to the codec info */
+	cii->sdev = soundbus_dev_get(dev);
+	cii->codec = ci;
+	cii->codec_data = data;
+
+	if (!cii->sdev) {
+		printk(KERN_DEBUG
+		       "i2sbus: failed to get soundbus dev reference\n");
+		err = -ENODEV;
+		goto out_free_cii;
+	}
+
+	if (!try_module_get(THIS_MODULE)) {
+		printk(KERN_DEBUG "i2sbus: failed to get module reference!\n");
+		err = -EBUSY;
+		goto out_put_sdev;
+	}
+
+	if (!try_module_get(ci->owner)) {
+		printk(KERN_DEBUG
+		       "i2sbus: failed to get module reference to codec owner!\n");
+		err = -EBUSY;
+		goto out_put_this_module;
+	}
+
+	if (!dev->pcm) {
+		err = snd_pcm_new(card, dev->pcmname, dev->pcmid, 0, 0,
+				  &dev->pcm);
+		if (err) {
+			printk(KERN_DEBUG "i2sbus: failed to create pcm\n");
+			goto out_put_ci_module;
+		}
+		dev->pcm->dev = &dev->ofdev.dev;
+	}
+
+	/* ALSA yet again sucks.
+	 * If it is ever fixed, remove this line. See below. */
+	out = in = 1;
+
+	if (!i2sdev->out.created && out) {
+		if (dev->pcm->card != card) {
+			/* eh? */
+			printk(KERN_ERR
+			       "Can't attach same bus to different cards!\n");
+			err = -EINVAL;
+			goto out_put_ci_module;
+		}
+		err = snd_pcm_new_stream(dev->pcm, SNDRV_PCM_STREAM_PLAYBACK, 1);
+		if (err)
+			goto out_put_ci_module;
+		snd_pcm_set_ops(dev->pcm, SNDRV_PCM_STREAM_PLAYBACK,
+				&i2sbus_playback_ops);
+		i2sdev->out.created = 1;
+	}
+
+	if (!i2sdev->in.created && in) {
+		if (dev->pcm->card != card) {
+			printk(KERN_ERR
+			       "Can't attach same bus to different cards!\n");
+			err = -EINVAL;
+			goto out_put_ci_module;
+		}
+		err = snd_pcm_new_stream(dev->pcm, SNDRV_PCM_STREAM_CAPTURE, 1);
+		if (err)
+			goto out_put_ci_module;
+		snd_pcm_set_ops(dev->pcm, SNDRV_PCM_STREAM_CAPTURE,
+				&i2sbus_record_ops);
+		i2sdev->in.created = 1;
+	}
+
+	/* so we have to register the pcm after adding any substream
+	 * to it because alsa doesn't create the devices for the
+	 * substreams when we add them later.
+	 * Therefore, force in and out on both busses (above) and
+	 * register the pcm now instead of just after creating it.
+	 */
+	err = snd_device_register(card, dev->pcm);
+	if (err) {
+		printk(KERN_ERR "i2sbus: error registering new pcm\n");
+		goto out_put_ci_module;
+	}
+	/* no errors any more, so let's add this to our list */
+	list_add(&cii->list, &dev->codec_list);
+
+	dev->pcm->private_data = i2sdev;
+	dev->pcm->private_free = i2sbus_private_free;
+
+	/* well, we really should support scatter/gather DMA */
+	snd_pcm_lib_preallocate_pages_for_all(
+		dev->pcm, SNDRV_DMA_TYPE_DEV,
+		snd_dma_pci_data(macio_get_pci_dev(i2sdev->macio)),
+		64 * 1024, 64 * 1024);
+
+	return 0;
+ out_put_ci_module:
+	module_put(ci->owner);
+ out_put_this_module:
+	module_put(THIS_MODULE);
+ out_put_sdev:
+	soundbus_dev_put(dev);
+ out_free_cii:
+	kfree(cii);
+	return err;
+}
+
+void i2sbus_detach_codec(struct soundbus_dev *dev, void *data)
+{
+	struct codec_info_item *cii = NULL, *i;
+
+	list_for_each_entry(i, &dev->codec_list, list) {
+		if (i->codec_data == data) {
+			cii = i;
+			break;
+		}
+	}
+	if (cii) {
+		list_del(&cii->list);
+		module_put(cii->codec->owner);
+		kfree(cii);
+	}
+	/* no more codecs, but still a pcm? */
+	if (list_empty(&dev->codec_list) && dev->pcm) {
+		/* the actual cleanup is done by the callback above! */
+		snd_device_free(dev->pcm->card, dev->pcm);
+	}
+}