Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 1300 insertions, 0 deletions

diff --git a/drivers/ieee1394/amdtp.c b/drivers/ieee1394/amdtp.c
new file mode 100644
index 000000000000..84ae027b021a
--- /dev/null
+++ b/drivers/ieee1394/amdtp.c
@@ -0,0 +1,1300 @@
+/* -*- c-basic-offset: 8 -*-
+ *
+ * amdtp.c - Audio and Music Data Transmission Protocol Driver
+ * Copyright (C) 2001 Kristian Høgsberg
+ *
+ * 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.
+ */
+
+/* OVERVIEW
+ * --------
+ *
+ * The AMDTP driver is designed to expose the IEEE1394 bus as a
+ * regular OSS soundcard, i.e. you can link /dev/dsp to /dev/amdtp and
+ * then your favourite MP3 player, game or whatever sound program will
+ * output to an IEEE1394 isochronous channel.  The signal destination
+ * could be a set of IEEE1394 loudspeakers (if and when such things
+ * become available) or an amplifier with IEEE1394 input (like the
+ * Sony STR-LSA1).  The driver only handles the actual streaming, some
+ * connection management is also required for this to actually work.
+ * That is outside the scope of this driver, and furthermore it is not
+ * really standardized yet.
+ *
+ * The Audio and Music Data Tranmission Protocol is available at
+ *
+ *     http://www.1394ta.org/Download/Technology/Specifications/2001/AM20Final-jf2.pdf
+ *
+ *
+ * TODO
+ * ----
+ *
+ * - We should be able to change input sample format between LE/BE, as
+ *   we already shift the bytes around when we construct the iso
+ *   packets.
+ *
+ * - Fix DMA stop after bus reset!
+ *
+ * - Clean up iso context handling in ohci1394.
+ *
+ *
+ * MAYBE TODO
+ * ----------
+ *
+ * - Receive data for local playback or recording.  Playback requires
+ *   soft syncing with the sound card.
+ *
+ * - Signal processing, i.e. receive packets, do some processing, and
+ *   transmit them again using the same packet structure and timestamps
+ *   offset by processing time.
+ *
+ * - Maybe make an ALSA interface, that is, create a file_ops
+ *   implementation that recognizes ALSA ioctls and uses defaults for
+ *   things that can't be controlled through ALSA (iso channel).
+ *
+ *   Changes:
+ *
+ * - Audit copy_from_user in amdtp_write.
+ *                           Daniele Bellucci <bellucda@tiscali.it>
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/list.h>
+#include <linux/sched.h>
+#include <linux/types.h>
+#include <linux/fs.h>
+#include <linux/ioctl.h>
+#include <linux/wait.h>
+#include <linux/pci.h>
+#include <linux/interrupt.h>
+#include <linux/poll.h>
+#include <linux/ioctl32.h>
+#include <linux/compat.h>
+#include <linux/cdev.h>
+#include <asm/uaccess.h>
+#include <asm/atomic.h>
+
+#include "hosts.h"
+#include "highlevel.h"
+#include "ieee1394.h"
+#include "ieee1394_core.h"
+#include "ohci1394.h"
+
+#include "amdtp.h"
+#include "cmp.h"
+
+#define FMT_AMDTP 0x10
+#define FDF_AM824 0x00
+#define FDF_SFC_32KHZ   0x00
+#define FDF_SFC_44K1HZ  0x01
+#define FDF_SFC_48KHZ   0x02
+#define FDF_SFC_88K2HZ  0x03
+#define FDF_SFC_96KHZ   0x04
+#define FDF_SFC_176K4HZ 0x05
+#define FDF_SFC_192KHZ  0x06
+
+struct descriptor_block {
+	struct output_more_immediate {
+		u32 control;
+		u32 pad0;
+		u32 skip;
+		u32 pad1;
+		u32 header[4];
+	} header_desc;
+
+	struct output_last {
+		u32 control;
+		u32 data_address;
+		u32 branch;
+		u32 status;
+	} payload_desc;
+};
+
+struct packet {
+	struct descriptor_block *db;
+	dma_addr_t db_bus;
+	struct iso_packet *payload;
+	dma_addr_t payload_bus;
+};
+
+#include <asm/byteorder.h>
+
+#if defined __BIG_ENDIAN_BITFIELD
+
+struct iso_packet {
+	/* First quadlet */
+	unsigned int dbs      : 8;
+	unsigned int eoh0     : 2;
+	unsigned int sid      : 6;
+
+	unsigned int dbc      : 8;
+	unsigned int fn       : 2;
+	unsigned int qpc      : 3;
+	unsigned int sph      : 1;
+	unsigned int reserved : 2;
+
+	/* Second quadlet */
+	unsigned int fdf      : 8;
+	unsigned int eoh1     : 2;
+	unsigned int fmt      : 6;
+
+	unsigned int syt      : 16;
+
+        quadlet_t data[0];
+};
+
+#elif defined __LITTLE_ENDIAN_BITFIELD
+
+struct iso_packet {
+	/* First quadlet */
+	unsigned int sid      : 6;
+	unsigned int eoh0     : 2;
+	unsigned int dbs      : 8;
+
+	unsigned int reserved : 2;
+	unsigned int sph      : 1;
+	unsigned int qpc      : 3;
+	unsigned int fn       : 2;
+	unsigned int dbc      : 8;
+
+	/* Second quadlet */
+	unsigned int fmt      : 6;
+	unsigned int eoh1     : 2;
+	unsigned int fdf      : 8;
+
+	unsigned int syt      : 16;
+
+	quadlet_t data[0];
+};
+
+#else
+
+#error Unknown bitfield type
+
+#endif
+
+struct fraction {
+	int integer;
+	int numerator;
+	int denominator;
+};
+
+#define PACKET_LIST_SIZE 256
+#define MAX_PACKET_LISTS 4
+
+struct packet_list {
+	struct list_head link;
+	int last_cycle_count;
+	struct packet packets[PACKET_LIST_SIZE];
+};
+
+#define BUFFER_SIZE 128
+
+/* This implements a circular buffer for incoming samples. */
+
+struct buffer {
+	size_t head, tail, length, size;
+	unsigned char data[0];
+};
+
+struct stream {
+	int iso_channel;
+	int format;
+	int rate;
+	int dimension;
+	int fdf;
+	int mode;
+	int sample_format;
+	struct cmp_pcr *opcr;
+
+	/* Input samples are copied here. */
+	struct buffer *input;
+
+	/* ISO Packer state */
+	unsigned char dbc;
+	struct packet_list *current_packet_list;
+	int current_packet;
+	struct fraction ready_samples, samples_per_cycle;
+
+	/* We use these to generate control bits when we are packing
+	 * iec958 data.
+	 */
+	int iec958_frame_count;
+	int iec958_rate_code;
+
+	/* The cycle_count and cycle_offset fields are used for the
+	 * synchronization timestamps (syt) in the cip header.  They
+	 * are incremented by at least a cycle every time we put a
+	 * time stamp in a packet.  As we don't time stamp all
+	 * packages, cycle_count isn't updated in every cycle, and
+	 * sometimes it's incremented by 2.  Thus, we have
+	 * cycle_count2, which is simply incremented by one with each
+	 * packet, so we can compare it to the transmission time
+	 * written back in the dma programs.
+	 */
+	atomic_t cycle_count, cycle_count2;
+	struct fraction cycle_offset, ticks_per_syt_offset;
+	int syt_interval;
+	int stale_count;
+
+	/* Theses fields control the sample output to the DMA engine.
+	 * The dma_packet_lists list holds packet lists currently
+	 * queued for dma; the head of the list is currently being
+	 * processed.  The last program in a packet list generates an
+	 * interrupt, which removes the head from dma_packet_lists and
+	 * puts it back on the free list.
+	 */
+	struct list_head dma_packet_lists;
+	struct list_head free_packet_lists;
+        wait_queue_head_t packet_list_wait;
+	spinlock_t packet_list_lock;
+	struct ohci1394_iso_tasklet iso_tasklet;
+	struct pci_pool *descriptor_pool, *packet_pool;
+
+	/* Streams at a host controller are chained through this field. */
+	struct list_head link;
+	struct amdtp_host *host;
+};
+
+struct amdtp_host {
+	struct hpsb_host *host;
+	struct ti_ohci *ohci;
+	struct list_head stream_list;
+	spinlock_t stream_list_lock;
+};
+
+static struct hpsb_highlevel amdtp_highlevel;
+
+
+/* FIXME: This doesn't belong here... */
+
+#define OHCI1394_CONTEXT_CYCLE_MATCH 0x80000000
+#define OHCI1394_CONTEXT_RUN         0x00008000
+#define OHCI1394_CONTEXT_WAKE        0x00001000
+#define OHCI1394_CONTEXT_DEAD        0x00000800
+#define OHCI1394_CONTEXT_ACTIVE      0x00000400
+
+static void ohci1394_start_it_ctx(struct ti_ohci *ohci, int ctx,
+			   dma_addr_t first_cmd, int z, int cycle_match)
+{
+	reg_write(ohci, OHCI1394_IsoXmitIntMaskSet, 1 << ctx);
+	reg_write(ohci, OHCI1394_IsoXmitCommandPtr + ctx * 16, first_cmd | z);
+	reg_write(ohci, OHCI1394_IsoXmitContextControlClear + ctx * 16, ~0);
+	wmb();
+	reg_write(ohci, OHCI1394_IsoXmitContextControlSet + ctx * 16,
+		  OHCI1394_CONTEXT_CYCLE_MATCH | (cycle_match << 16) |
+		  OHCI1394_CONTEXT_RUN);
+}
+
+static void ohci1394_wake_it_ctx(struct ti_ohci *ohci, int ctx)
+{
+	reg_write(ohci, OHCI1394_IsoXmitContextControlSet + ctx * 16,
+		  OHCI1394_CONTEXT_WAKE);
+}
+
+static void ohci1394_stop_it_ctx(struct ti_ohci *ohci, int ctx, int synchronous)
+{
+	u32 control;
+	int wait;
+
+	reg_write(ohci, OHCI1394_IsoXmitIntMaskClear, 1 << ctx);
+	reg_write(ohci, OHCI1394_IsoXmitContextControlClear + ctx * 16,
+		  OHCI1394_CONTEXT_RUN);
+	wmb();
+
+	if (synchronous) {
+		for (wait = 0; wait < 5; wait++) {
+			control = reg_read(ohci, OHCI1394_IsoXmitContextControlSet + ctx * 16);
+			if ((control & OHCI1394_CONTEXT_ACTIVE) == 0)
+				break;
+
+			set_current_state(TASK_INTERRUPTIBLE);
+			schedule_timeout(1);
+		}
+	}
+}
+
+/* Note: we can test if free_packet_lists is empty without aquiring
+ * the packet_list_lock.  The interrupt handler only adds to the free
+ * list, there is no race condition between testing the list non-empty
+ * and acquiring the lock.
+ */
+
+static struct packet_list *stream_get_free_packet_list(struct stream *s)
+{
+	struct packet_list *pl;
+	unsigned long flags;
+
+	if (list_empty(&s->free_packet_lists))
+		return NULL;
+
+	spin_lock_irqsave(&s->packet_list_lock, flags);
+	pl = list_entry(s->free_packet_lists.next, struct packet_list, link);
+	list_del(&pl->link);
+	spin_unlock_irqrestore(&s->packet_list_lock, flags);
+
+	return pl;
+}
+
+static void stream_start_dma(struct stream *s, struct packet_list *pl)
+{
+	u32 syt_cycle, cycle_count, start_cycle;
+
+	cycle_count = reg_read(s->host->ohci,
+			       OHCI1394_IsochronousCycleTimer) >> 12;
+	syt_cycle = (pl->last_cycle_count - PACKET_LIST_SIZE + 1) & 0x0f;
+
+	/* We program the DMA controller to start transmission at
+	 * least 17 cycles from now - this happens when the lower four
+	 * bits of cycle_count is 0x0f and syt_cycle is 0, in this
+	 * case the start cycle is cycle_count - 15 + 32. */
+	start_cycle = (cycle_count & ~0x0f) + 32 + syt_cycle;
+	if ((start_cycle & 0x1fff) >= 8000)
+		start_cycle = start_cycle - 8000 + 0x2000;
+
+	ohci1394_start_it_ctx(s->host->ohci, s->iso_tasklet.context,
+			      pl->packets[0].db_bus, 3,
+			      start_cycle & 0x7fff);
+}
+
+static void stream_put_dma_packet_list(struct stream *s,
+				       struct packet_list *pl)
+{
+	unsigned long flags;
+	struct packet_list *prev;
+
+	/* Remember the cycle_count used for timestamping the last packet. */
+	pl->last_cycle_count = atomic_read(&s->cycle_count2) - 1;
+	pl->packets[PACKET_LIST_SIZE - 1].db->payload_desc.branch = 0;
+
+	spin_lock_irqsave(&s->packet_list_lock, flags);
+	list_add_tail(&pl->link, &s->dma_packet_lists);
+	spin_unlock_irqrestore(&s->packet_list_lock, flags);
+
+	prev = list_entry(pl->link.prev, struct packet_list, link);
+	if (pl->link.prev != &s->dma_packet_lists) {
+		struct packet *last = &prev->packets[PACKET_LIST_SIZE - 1];
+		last->db->payload_desc.branch = pl->packets[0].db_bus | 3;
+		last->db->header_desc.skip = pl->packets[0].db_bus | 3;
+		ohci1394_wake_it_ctx(s->host->ohci, s->iso_tasklet.context);
+	}
+	else
+		stream_start_dma(s, pl);
+}
+
+static void stream_shift_packet_lists(unsigned long l)
+{
+	struct stream *s = (struct stream *) l;
+	struct packet_list *pl;
+	struct packet *last;
+	int diff;
+
+	if (list_empty(&s->dma_packet_lists)) {
+		HPSB_ERR("empty dma_packet_lists in %s", __FUNCTION__);
+		return;
+	}
+
+	/* Now that we know the list is non-empty, we can get the head
+	 * of the list without locking, because the process context
+	 * only adds to the tail.
+	 */
+	pl = list_entry(s->dma_packet_lists.next, struct packet_list, link);
+	last = &pl->packets[PACKET_LIST_SIZE - 1];
+
+	/* This is weird... if we stop dma processing in the middle of
+	 * a packet list, the dma context immediately generates an
+	 * interrupt if we enable it again later.  This only happens
+	 * when amdtp_release is interrupted while waiting for dma to
+	 * complete, though.  Anyway, we detect this by seeing that
+	 * the status of the dma descriptor that we expected an
+	 * interrupt from is still 0.
+	 */
+	if (last->db->payload_desc.status == 0) {
+		HPSB_INFO("weird interrupt...");
+		return;
+	}
+
+	/* If the last descriptor block does not specify a branch
+	 * address, we have a sample underflow.
+	 */
+	if (last->db->payload_desc.branch == 0)
+		HPSB_INFO("FIXME: sample underflow...");
+
+	/* Here we check when (which cycle) the last packet was sent
+	 * and compare it to what the iso packer was using at the
+	 * time.  If there is a mismatch, we adjust the cycle count in
+	 * the iso packer.  However, there are still up to
+	 * MAX_PACKET_LISTS packet lists queued with bad time stamps,
+	 * so we disable time stamp monitoring for the next
+	 * MAX_PACKET_LISTS packet lists.
+	 */
+	diff = (last->db->payload_desc.status - pl->last_cycle_count) & 0xf;
+	if (diff > 0 && s->stale_count == 0) {
+		atomic_add(diff, &s->cycle_count);
+		atomic_add(diff, &s->cycle_count2);
+		s->stale_count = MAX_PACKET_LISTS;
+	}
+
+	if (s->stale_count > 0)
+		s->stale_count--;
+
+	/* Finally, we move the packet list that was just processed
+	 * back to the free list, and notify any waiters.
+	 */
+	spin_lock(&s->packet_list_lock);
+	list_del(&pl->link);
+	list_add_tail(&pl->link, &s->free_packet_lists);
+	spin_unlock(&s->packet_list_lock);
+
+	wake_up_interruptible(&s->packet_list_wait);
+}
+
+static struct packet *stream_current_packet(struct stream *s)
+{
+	if (s->current_packet_list == NULL &&
+	    (s->current_packet_list = stream_get_free_packet_list(s)) == NULL)
+		return NULL;
+
+	return &s->current_packet_list->packets[s->current_packet];
+}
+
+static void stream_queue_packet(struct stream *s)
+{
+	s->current_packet++;
+	if (s->current_packet == PACKET_LIST_SIZE) {
+		stream_put_dma_packet_list(s, s->current_packet_list);
+		s->current_packet_list = NULL;
+		s->current_packet = 0;
+	}
+}
+
+/* Integer fractional math.  When we transmit a 44k1Hz signal we must
+ * send 5 41/80 samples per isochronous cycle, as these occur 8000
+ * times a second.  Of course, we must send an integral number of
+ * samples in a packet, so we use the integer math to alternate
+ * between sending 5 and 6 samples per packet.
+ */
+
+static void fraction_init(struct fraction *f, int numerator, int denominator)
+{
+	f->integer = numerator / denominator;
+	f->numerator = numerator % denominator;
+	f->denominator = denominator;
+}
+
+static __inline__ void fraction_add(struct fraction *dst,
+				    struct fraction *src1,
+				    struct fraction *src2)
+{
+	/* assert: src1->denominator == src2->denominator */
+
+	int sum, denom;
+
+	/* We use these two local variables to allow gcc to optimize
+	 * the division and the modulo into only one division. */
+
+	sum = src1->numerator + src2->numerator;
+	denom = src1->denominator;
+	dst->integer = src1->integer + src2->integer + sum / denom;
+	dst->numerator = sum % denom;
+	dst->denominator = denom;
+}
+
+static __inline__ void fraction_sub_int(struct fraction *dst,
+					struct fraction *src, int integer)
+{
+	dst->integer = src->integer - integer;
+	dst->numerator = src->numerator;
+	dst->denominator = src->denominator;
+}
+
+static __inline__ int fraction_floor(struct fraction *frac)
+{
+	return frac->integer;
+}
+
+static __inline__ int fraction_ceil(struct fraction *frac)
+{
+	return frac->integer + (frac->numerator > 0 ? 1 : 0);
+}
+
+static void packet_initialize(struct packet *p, struct packet *next)
+{
+	/* Here we initialize the dma descriptor block for
+	 * transferring one iso packet.  We use two descriptors per
+	 * packet: an OUTPUT_MORE_IMMMEDIATE descriptor for the
+	 * IEEE1394 iso packet header and an OUTPUT_LAST descriptor
+	 * for the payload.
+	 */
+
+	p->db->header_desc.control =
+		DMA_CTL_OUTPUT_MORE | DMA_CTL_IMMEDIATE | 8;
+
+	if (next) {
+		p->db->payload_desc.control =
+			DMA_CTL_OUTPUT_LAST | DMA_CTL_BRANCH;
+		p->db->payload_desc.branch = next->db_bus | 3;
+		p->db->header_desc.skip = next->db_bus | 3;
+	}
+	else {
+		p->db->payload_desc.control =
+			DMA_CTL_OUTPUT_LAST | DMA_CTL_BRANCH |
+			DMA_CTL_UPDATE | DMA_CTL_IRQ;
+		p->db->payload_desc.branch = 0;
+		p->db->header_desc.skip = 0;
+	}
+	p->db->payload_desc.data_address = p->payload_bus;
+	p->db->payload_desc.status = 0;
+}
+
+static struct packet_list *packet_list_alloc(struct stream *s)
+{
+	int i;
+	struct packet_list *pl;
+	struct packet *next;
+
+	pl = kmalloc(sizeof *pl, SLAB_KERNEL);
+	if (pl == NULL)
+		return NULL;
+
+	for (i = 0; i < PACKET_LIST_SIZE; i++) {
+		struct packet *p = &pl->packets[i];
+		p->db = pci_pool_alloc(s->descriptor_pool, SLAB_KERNEL,
+				       &p->db_bus);
+		p->payload = pci_pool_alloc(s->packet_pool, SLAB_KERNEL,
+					    &p->payload_bus);
+	}
+
+	for (i = 0; i < PACKET_LIST_SIZE; i++) {
+		if (i < PACKET_LIST_SIZE - 1)
+			next = &pl->packets[i + 1];
+		else
+			next = NULL;
+		packet_initialize(&pl->packets[i], next);
+	}
+
+	return pl;
+}
+
+static void packet_list_free(struct packet_list *pl, struct stream *s)
+{
+	int i;
+
+	for (i = 0; i < PACKET_LIST_SIZE; i++) {
+		struct packet *p = &pl->packets[i];
+		pci_pool_free(s->descriptor_pool, p->db, p->db_bus);
+		pci_pool_free(s->packet_pool, p->payload, p->payload_bus);
+	}
+	kfree(pl);
+}
+
+static struct buffer *buffer_alloc(int size)
+{
+	struct buffer *b;
+
+	b = kmalloc(sizeof *b + size, SLAB_KERNEL);
+	if (b == NULL)
+		return NULL;
+	b->head = 0;
+	b->tail = 0;
+	b->length = 0;
+	b->size = size;
+
+	return b;
+}
+
+static unsigned char *buffer_get_bytes(struct buffer *buffer, int size)
+{
+	unsigned char *p;
+
+	if (buffer->head + size > buffer->size)
+		BUG();
+
+	p = &buffer->data[buffer->head];
+	buffer->head += size;
+	if (buffer->head == buffer->size)
+		buffer->head = 0;
+	buffer->length -= size;
+
+	return p;
+}
+
+static unsigned char *buffer_put_bytes(struct buffer *buffer,
+				       size_t max, size_t *actual)
+{
+	size_t length;
+	unsigned char *p;
+
+	p = &buffer->data[buffer->tail];
+	length = min(buffer->size - buffer->length, max);
+	if (buffer->tail + length < buffer->size) {
+		*actual = length;
+		buffer->tail += length;
+	}
+	else {
+		*actual = buffer->size - buffer->tail;
+		 buffer->tail = 0;
+	}
+
+	buffer->length += *actual;
+	return p;
+}
+
+static u32 get_iec958_header_bits(struct stream *s, int sub_frame, u32 sample)
+{
+	int csi, parity, shift;
+	int block_start;
+	u32 bits;
+
+	switch (s->iec958_frame_count) {
+	case 1:
+		csi = s->format == AMDTP_FORMAT_IEC958_AC3;
+		break;
+	case 2:
+	case 9:
+		csi = 1;
+		break;
+	case 24 ... 27:
+		csi = (s->iec958_rate_code >> (27 - s->iec958_frame_count)) & 0x01;
+		break;
+	default:
+		csi = 0;
+		break;
+	}
+
+	block_start = (s->iec958_frame_count == 0 && sub_frame == 0);
+
+	/* The parity bit is the xor of the sample bits and the
+	 * channel status info bit. */
+	for (shift = 16, parity = sample ^ csi; shift > 0; shift >>= 1)
+		parity ^= (parity >> shift);
+
+	bits =  (block_start << 5) |		/* Block start bit */
+		((sub_frame == 0) << 4) |	/* Subframe bit */
+		((parity & 1) << 3) |		/* Parity bit */
+		(csi << 2);			/* Channel status info bit */
+
+	return bits;
+}
+
+static u32 get_header_bits(struct stream *s, int sub_frame, u32 sample)
+{
+	switch (s->format) {
+	case AMDTP_FORMAT_IEC958_PCM:
+	case AMDTP_FORMAT_IEC958_AC3:
+		return get_iec958_header_bits(s, sub_frame, sample);
+
+	case AMDTP_FORMAT_RAW:
+		return 0x40;
+
+	default:
+		return 0;
+	}
+}
+
+static void fill_payload_le16(struct stream *s, quadlet_t *data, int nevents)
+{
+	quadlet_t *event, sample, bits;
+	unsigned char *p;
+	int i, j;
+
+	for (i = 0, event = data; i < nevents; i++) {
+
+		for (j = 0; j < s->dimension; j++) {
+			p = buffer_get_bytes(s->input, 2);
+			sample = (p[1] << 16) | (p[0] << 8);
+			bits = get_header_bits(s, j, sample);
+			event[j] = cpu_to_be32((bits << 24) | sample);
+		}
+
+		event += s->dimension;
+		if (++s->iec958_frame_count == 192)
+			s->iec958_frame_count = 0;
+	}
+}
+
+static void fill_packet(struct stream *s, struct packet *packet, int nevents)
+{
+	int syt_index, syt, size;
+	u32 control;
+
+	size = (nevents * s->dimension + 2) * sizeof(quadlet_t);
+
+	/* Update DMA descriptors */
+	packet->db->payload_desc.status = 0;
+	control = packet->db->payload_desc.control & 0xffff0000;
+	packet->db->payload_desc.control = control | size;
+
+	/* Fill IEEE1394 headers */
+	packet->db->header_desc.header[0] =
+		(IEEE1394_SPEED_100 << 16) | (0x01 << 14) |
+		(s->iso_channel << 8) | (TCODE_ISO_DATA << 4);
+	packet->db->header_desc.header[1] = size << 16;
+
+	/* Calculate synchronization timestamp (syt). First we
+	 * determine syt_index, that is, the index in the packet of
+	 * the sample for which the timestamp is valid. */
+	syt_index = (s->syt_interval - s->dbc) & (s->syt_interval - 1);
+	if (syt_index < nevents) {
+		syt = ((atomic_read(&s->cycle_count) << 12) |
+		       s->cycle_offset.integer) & 0xffff;
+		fraction_add(&s->cycle_offset,
+			     &s->cycle_offset, &s->ticks_per_syt_offset);
+
+		/* This next addition should be modulo 8000 (0x1f40),
+		 * but we only use the lower 4 bits of cycle_count, so
+		 * we don't need the modulo. */
+		atomic_add(s->cycle_offset.integer / 3072, &s->cycle_count);
+		s->cycle_offset.integer %= 3072;
+	}
+	else
+		syt = 0xffff;
+
+	atomic_inc(&s->cycle_count2);
+
+	/* Fill cip header */
+	packet->payload->eoh0 = 0;
+	packet->payload->sid = s->host->host->node_id & 0x3f;
+	packet->payload->dbs = s->dimension;
+	packet->payload->fn = 0;
+	packet->payload->qpc = 0;
+	packet->payload->sph = 0;
+	packet->payload->reserved = 0;
+	packet->payload->dbc = s->dbc;
+	packet->payload->eoh1 = 2;
+	packet->payload->fmt = FMT_AMDTP;
+	packet->payload->fdf = s->fdf;
+	packet->payload->syt = cpu_to_be16(syt);
+
+	switch (s->sample_format) {
+	case AMDTP_INPUT_LE16:
+		fill_payload_le16(s, packet->payload->data, nevents);
+		break;
+	}
+
+	s->dbc += nevents;
+}
+
+static void stream_flush(struct stream *s)
+{
+	struct packet *p;
+	int nevents;
+	struct fraction next;
+
+	/* The AMDTP specifies two transmission modes: blocking and
+	 * non-blocking.  In blocking mode you always transfer
+	 * syt_interval or zero samples, whereas in non-blocking mode
+	 * you send as many samples as you have available at transfer
+	 * time.
+	 *
+	 * The fraction samples_per_cycle specifies the number of
+	 * samples that become available per cycle.  We add this to
+	 * the fraction ready_samples, which specifies the number of
+	 * leftover samples from the previous transmission.  The sum,
+	 * stored in the fraction next, specifies the number of
+	 * samples available for transmission, and from this we
+	 * determine the number of samples to actually transmit.
+	 */
+
+	while (1) {
+		fraction_add(&next, &s->ready_samples, &s->samples_per_cycle);
+		if (s->mode == AMDTP_MODE_BLOCKING) {
+			if (fraction_floor(&next) >= s->syt_interval)
+				nevents = s->syt_interval;
+			else
+				nevents = 0;
+		}
+		else
+			nevents = fraction_floor(&next);
+
+		p = stream_current_packet(s);
+		if (s->input->length < nevents * s->dimension * 2 || p == NULL)
+			break;
+
+		fill_packet(s, p, nevents);
+		stream_queue_packet(s);
+
+		/* Now that we have successfully queued the packet for
+		 * transmission, we update the fraction ready_samples. */
+		fraction_sub_int(&s->ready_samples, &next, nevents);
+	}
+}
+
+static int stream_alloc_packet_lists(struct stream *s)
+{
+	int max_nevents, max_packet_size, i;
+
+	if (s->mode == AMDTP_MODE_BLOCKING)
+		max_nevents = s->syt_interval;
+	else
+		max_nevents = fraction_ceil(&s->samples_per_cycle);
+
+	max_packet_size = max_nevents * s->dimension * 4 + 8;
+	s->packet_pool = pci_pool_create("packet pool", s->host->ohci->dev,
+					 max_packet_size, 0, 0);
+
+	if (s->packet_pool == NULL)
+		return -1;
+
+	INIT_LIST_HEAD(&s->free_packet_lists);
+	INIT_LIST_HEAD(&s->dma_packet_lists);
+	for (i = 0; i < MAX_PACKET_LISTS; i++) {
+		struct packet_list *pl = packet_list_alloc(s);
+		if (pl == NULL)
+			break;
+		list_add_tail(&pl->link, &s->free_packet_lists);
+	}
+
+	return i < MAX_PACKET_LISTS ? -1 : 0;
+}
+
+static void stream_free_packet_lists(struct stream *s)
+{
+	struct packet_list *packet_l, *packet_l_next;
+
+	if (s->current_packet_list != NULL)
+		packet_list_free(s->current_packet_list, s);
+	list_for_each_entry_safe(packet_l, packet_l_next, &s->dma_packet_lists, link)
+		packet_list_free(packet_l, s);
+	list_for_each_entry_safe(packet_l, packet_l_next, &s->free_packet_lists, link)
+		packet_list_free(packet_l, s);
+	if (s->packet_pool != NULL)
+		pci_pool_destroy(s->packet_pool);
+
+	s->current_packet_list = NULL;
+	INIT_LIST_HEAD(&s->free_packet_lists);
+	INIT_LIST_HEAD(&s->dma_packet_lists);
+	s->packet_pool = NULL;
+}
+
+static void plug_update(struct cmp_pcr *plug, void *data)
+{
+	struct stream *s = data;
+
+	HPSB_INFO("plug update: p2p_count=%d, channel=%d",
+		  plug->p2p_count, plug->channel);
+	s->iso_channel = plug->channel;
+	if (plug->p2p_count > 0) {
+		struct packet_list *pl;
+
+		pl = list_entry(s->dma_packet_lists.next, struct packet_list, link);
+		stream_start_dma(s, pl);
+	}
+	else {
+		ohci1394_stop_it_ctx(s->host->ohci, s->iso_tasklet.context, 0);
+	}
+}
+
+static int stream_configure(struct stream *s, int cmd, struct amdtp_ioctl *cfg)
+{
+	const int transfer_delay = 9000;
+
+	if (cfg->format <= AMDTP_FORMAT_IEC958_AC3)
+		s->format = cfg->format;
+	else
+		return -EINVAL;
+
+	switch (cfg->rate) {
+	case 32000:
+		s->syt_interval = 8;
+		s->fdf = FDF_SFC_32KHZ;
+		s->iec958_rate_code = 0x0c;
+		break;
+	case 44100:
+		s->syt_interval = 8;
+		s->fdf = FDF_SFC_44K1HZ;
+		s->iec958_rate_code = 0x00;
+		break;
+	case 48000:
+		s->syt_interval = 8;
+		s->fdf = FDF_SFC_48KHZ;
+		s->iec958_rate_code = 0x04;
+		break;
+	case 88200:
+		s->syt_interval = 16;
+		s->fdf = FDF_SFC_88K2HZ;
+		s->iec958_rate_code = 0x00;
+		break;
+	case 96000:
+		s->syt_interval = 16;
+		s->fdf = FDF_SFC_96KHZ;
+		s->iec958_rate_code = 0x00;
+		break;
+	case 176400:
+		s->syt_interval = 32;
+		s->fdf = FDF_SFC_176K4HZ;
+		s->iec958_rate_code = 0x00;
+		break;
+	case 192000:
+		s->syt_interval = 32;
+		s->fdf = FDF_SFC_192KHZ;
+		s->iec958_rate_code = 0x00;
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	s->rate = cfg->rate;
+	fraction_init(&s->samples_per_cycle, s->rate, 8000);
+	fraction_init(&s->ready_samples, 0, 8000);
+
+	/* The ticks_per_syt_offset is initialized to the number of
+	 * ticks between syt_interval events.  The number of ticks per
+	 * second is 24.576e6, so the number of ticks between
+	 * syt_interval events is 24.576e6 * syt_interval / rate.
+	 */
+	fraction_init(&s->ticks_per_syt_offset,
+		      24576000 * s->syt_interval, s->rate);
+	fraction_init(&s->cycle_offset, (transfer_delay % 3072) * s->rate, s->rate);
+	atomic_set(&s->cycle_count, transfer_delay / 3072);
+	atomic_set(&s->cycle_count2, 0);
+
+	s->mode = cfg->mode;
+	s->sample_format = AMDTP_INPUT_LE16;
+
+	/* When using the AM824 raw subformat we can stream signals of
+	 * any dimension.  The IEC958 subformat, however, only
+	 * supports 2 channels.
+	 */
+	if (s->format == AMDTP_FORMAT_RAW || cfg->dimension == 2)
+		s->dimension = cfg->dimension;
+	else
+		return -EINVAL;
+
+	if (s->opcr != NULL) {
+		cmp_unregister_opcr(s->host->host, s->opcr);
+		s->opcr = NULL;
+	}
+
+	switch(cmd) {
+	case AMDTP_IOC_PLUG:
+		s->opcr = cmp_register_opcr(s->host->host, cfg->u.plug,
+					   /*payload*/ 12, plug_update, s);
+		if (s->opcr == NULL)
+			return -EINVAL;
+		s->iso_channel = s->opcr->channel;
+		break;
+
+	case AMDTP_IOC_CHANNEL:
+		if (cfg->u.channel >= 0 && cfg->u.channel < 64)
+			s->iso_channel = cfg->u.channel;
+		else
+			return -EINVAL;
+		break;
+	}
+
+	/* The ioctl settings were all valid, so we realloc the packet
+	 * lists to make sure the packet size is big enough.
+	 */
+	if (s->packet_pool != NULL)
+		stream_free_packet_lists(s);
+
+	if (stream_alloc_packet_lists(s) < 0) {
+		stream_free_packet_lists(s);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static struct stream *stream_alloc(struct amdtp_host *host)
+{
+	struct stream *s;
+	unsigned long flags;
+
+        s = kmalloc(sizeof(struct stream), SLAB_KERNEL);
+        if (s == NULL)
+                return NULL;
+
+        memset(s, 0, sizeof(struct stream));
+	s->host = host;
+
+	s->input = buffer_alloc(BUFFER_SIZE);
+	if (s->input == NULL) {
+		kfree(s);
+		return NULL;
+	}
+
+	s->descriptor_pool = pci_pool_create("descriptor pool", host->ohci->dev,
+					     sizeof(struct descriptor_block),
+					     16, 0);
+
+	if (s->descriptor_pool == NULL) {
+		kfree(s->input);
+		kfree(s);
+		return NULL;
+	}
+
+	INIT_LIST_HEAD(&s->free_packet_lists);
+	INIT_LIST_HEAD(&s->dma_packet_lists);
+
+        init_waitqueue_head(&s->packet_list_wait);
+        spin_lock_init(&s->packet_list_lock);
+
+	ohci1394_init_iso_tasklet(&s->iso_tasklet, OHCI_ISO_TRANSMIT,
+				  stream_shift_packet_lists,
+				  (unsigned long) s);
+
+	if (ohci1394_register_iso_tasklet(host->ohci, &s->iso_tasklet) < 0) {
+		pci_pool_destroy(s->descriptor_pool);
+		kfree(s->input);
+		kfree(s);
+		return NULL;
+	}
+
+	spin_lock_irqsave(&host->stream_list_lock, flags);
+	list_add_tail(&s->link, &host->stream_list);
+	spin_unlock_irqrestore(&host->stream_list_lock, flags);
+
+	return s;
+}
+
+static void stream_free(struct stream *s)
+{
+	unsigned long flags;
+
+	/* Stop the DMA.  We wait for the dma packet list to become
+	 * empty and let the dma controller run out of programs.  This
+	 * seems to be more reliable than stopping it directly, since
+	 * that sometimes generates an it transmit interrupt if we
+	 * later re-enable the context.
+	 */
+	wait_event_interruptible(s->packet_list_wait,
+				 list_empty(&s->dma_packet_lists));
+
+	ohci1394_stop_it_ctx(s->host->ohci, s->iso_tasklet.context, 1);
+	ohci1394_unregister_iso_tasklet(s->host->ohci, &s->iso_tasklet);
+
+	if (s->opcr != NULL)
+		cmp_unregister_opcr(s->host->host, s->opcr);
+
+	spin_lock_irqsave(&s->host->stream_list_lock, flags);
+	list_del(&s->link);
+	spin_unlock_irqrestore(&s->host->stream_list_lock, flags);
+
+	kfree(s->input);
+
+	stream_free_packet_lists(s);
+	pci_pool_destroy(s->descriptor_pool);
+
+	kfree(s);
+}
+
+/* File operations */
+
+static ssize_t amdtp_write(struct file *file, const char __user *buffer, size_t count,
+			   loff_t *offset_is_ignored)
+{
+	struct stream *s = file->private_data;
+	unsigned char *p;
+	int i;
+	size_t length;
+
+	if (s->packet_pool == NULL)
+		return -EBADFD;
+
+	/* Fill the circular buffer from the input buffer and call the
+	 * iso packer when the buffer is full.  The iso packer may
+	 * leave bytes in the buffer for two reasons: either the
+	 * remaining bytes wasn't enough to build a new packet, or
+	 * there were no free packet lists.  In the first case we
+	 * re-fill the buffer and call the iso packer again or return
+	 * if we used all the data from userspace.  In the second
+	 * case, the wait_event_interruptible will block until the irq
+	 * handler frees a packet list.
+	 */
+
+	for (i = 0; i < count; i += length) {
+		p = buffer_put_bytes(s->input, count - i, &length);
+		if (copy_from_user(p, buffer + i, length))
+			return -EFAULT;
+		if (s->input->length < s->input->size)
+			continue;
+
+		stream_flush(s);
+
+		if (s->current_packet_list != NULL)
+			continue;
+
+		if (file->f_flags & O_NONBLOCK)
+			return i + length > 0 ? i + length : -EAGAIN;
+
+		if (wait_event_interruptible(s->packet_list_wait,
+					     !list_empty(&s->free_packet_lists)))
+			return -EINTR;
+	}
+
+	return count;
+}
+
+static long amdtp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	struct stream *s = file->private_data;
+	struct amdtp_ioctl cfg;
+	int err;
+	lock_kernel();
+	switch(cmd)
+	{
+	case AMDTP_IOC_PLUG:
+	case AMDTP_IOC_CHANNEL:
+		if (copy_from_user(&cfg, (struct amdtp_ioctl __user *) arg, sizeof cfg))
+			err = -EFAULT;
+		else
+			err = stream_configure(s, cmd, &cfg);
+		break;
+
+	default:
+		err = -EINVAL;
+		break;
+	}
+	unlock_kernel();
+	return err;
+}
+
+static unsigned int amdtp_poll(struct file *file, poll_table *pt)
+{
+	struct stream *s = file->private_data;
+
+	poll_wait(file, &s->packet_list_wait, pt);
+
+	if (!list_empty(&s->free_packet_lists))
+		return POLLOUT | POLLWRNORM;
+	else
+		return 0;
+}
+
+static int amdtp_open(struct inode *inode, struct file *file)
+{
+	struct amdtp_host *host;
+	int i = ieee1394_file_to_instance(file);
+
+	host = hpsb_get_hostinfo_bykey(&amdtp_highlevel, i);
+	if (host == NULL)
+		return -ENODEV;
+
+	file->private_data = stream_alloc(host);
+	if (file->private_data == NULL)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static int amdtp_release(struct inode *inode, struct file *file)
+{
+	struct stream *s = file->private_data;
+
+	stream_free(s);
+
+	return 0;
+}
+
+static struct cdev amdtp_cdev;
+static struct file_operations amdtp_fops =
+{
+	.owner =	THIS_MODULE,
+	.write =	amdtp_write,
+	.poll =		amdtp_poll,
+	.unlocked_ioctl = amdtp_ioctl,
+	.compat_ioctl = amdtp_ioctl, /* All amdtp ioctls are compatible */
+	.open =		amdtp_open,
+	.release =	amdtp_release
+};
+
+/* IEEE1394 Subsystem functions */
+
+static void amdtp_add_host(struct hpsb_host *host)
+{
+	struct amdtp_host *ah;
+	int minor;
+
+	if (strcmp(host->driver->name, OHCI1394_DRIVER_NAME) != 0)
+		return;
+
+	ah = hpsb_create_hostinfo(&amdtp_highlevel, host, sizeof(*ah));
+	if (!ah) {
+		HPSB_ERR("amdtp: Unable able to alloc hostinfo");
+		return;
+	}
+
+	ah->host = host;
+	ah->ohci = host->hostdata;
+
+	hpsb_set_hostinfo_key(&amdtp_highlevel, host, ah->host->id);
+
+	minor = IEEE1394_MINOR_BLOCK_AMDTP * 16 + ah->host->id;
+
+	INIT_LIST_HEAD(&ah->stream_list);
+	spin_lock_init(&ah->stream_list_lock);
+
+	devfs_mk_cdev(MKDEV(IEEE1394_MAJOR, minor),
+			S_IFCHR|S_IRUSR|S_IWUSR, "amdtp/%d", ah->host->id);
+}
+
+static void amdtp_remove_host(struct hpsb_host *host)
+{
+	struct amdtp_host *ah = hpsb_get_hostinfo(&amdtp_highlevel, host);
+
+	if (ah)
+		devfs_remove("amdtp/%d", ah->host->id);
+
+	return;
+}
+
+static struct hpsb_highlevel amdtp_highlevel = {
+	.name =		"amdtp",
+	.add_host =	amdtp_add_host,
+	.remove_host =	amdtp_remove_host,
+};
+
+/* Module interface */
+
+MODULE_AUTHOR("Kristian Hogsberg <hogsberg@users.sf.net>");
+MODULE_DESCRIPTION("Driver for Audio & Music Data Transmission Protocol "
+		   "on OHCI boards.");
+MODULE_SUPPORTED_DEVICE("amdtp");
+MODULE_LICENSE("GPL");
+
+static int __init amdtp_init_module (void)
+{
+	cdev_init(&amdtp_cdev, &amdtp_fops);
+	amdtp_cdev.owner = THIS_MODULE;
+	kobject_set_name(&amdtp_cdev.kobj, "amdtp");
+	if (cdev_add(&amdtp_cdev, IEEE1394_AMDTP_DEV, 16)) {
+		HPSB_ERR("amdtp: unable to add char device");
+ 		return -EIO;
+ 	}
+
+	devfs_mk_dir("amdtp");
+
+	hpsb_register_highlevel(&amdtp_highlevel);
+
+	HPSB_INFO("Loaded AMDTP driver");
+
+	return 0;
+}
+
+static void __exit amdtp_exit_module (void)
+{
+        hpsb_unregister_highlevel(&amdtp_highlevel);
+	devfs_remove("amdtp");
+	cdev_del(&amdtp_cdev);
+
+	HPSB_INFO("Unloaded AMDTP driver");
+}
+
+module_init(amdtp_init_module);
+module_exit(amdtp_exit_module);
+MODULE_ALIAS_CHARDEV(IEEE1394_MAJOR, IEEE1394_MINOR_BLOCK_AMDTP * 16);