[deliverable/linux.git] / sound / firewire / amdtp.c

/*
 * Audio and Music Data Transmission Protocol (IEC 61883-6) streams
 * with Common Isochronous Packet (IEC 61883-1) headers
 *
 * Copyright (c) Clemens Ladisch <clemens@ladisch.de>
 * Licensed under the terms of the GNU General Public License, version 2.
 */

#include <linux/device.h>
#include <linux/err.h>
#include <linux/firewire.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <sound/pcm.h>
#include "amdtp.h"

#define TICKS_PER_CYCLE		3072
#define CYCLES_PER_SECOND	8000
#define TICKS_PER_SECOND	(TICKS_PER_CYCLE * CYCLES_PER_SECOND)

#define TRANSFER_DELAY_TICKS	0x2e00 /* 479.17 µs */

#define TAG_CIP			1

#define CIP_EOH			(1u << 31)
#define CIP_FMT_AM		(0x10 << 24)
#define AMDTP_FDF_AM824		(0 << 19)
#define AMDTP_FDF_SFC_SHIFT	16

/* TODO: make these configurable */
#define INTERRUPT_INTERVAL	16
#define QUEUE_LENGTH		48

static void pcm_period_tasklet(unsigned long data);

/**
 * amdtp_out_stream_init - initialize an AMDTP output stream structure
 * @s: the AMDTP output stream to initialize
 * @unit: the target of the stream
 * @flags: the packet transmission method to use
 */
int amdtp_out_stream_init(struct amdtp_out_stream *s, struct fw_unit *unit,
			  enum cip_out_flags flags)
{
	if (flags != CIP_NONBLOCKING)
		return -EINVAL;

	s->unit = fw_unit_get(unit);
	s->flags = flags;
	s->context = ERR_PTR(-1);
	mutex_init(&s->mutex);
	tasklet_init(&s->period_tasklet, pcm_period_tasklet, (unsigned long)s);
	s->packet_index = 0;

	return 0;
}
EXPORT_SYMBOL(amdtp_out_stream_init);

/**
 * amdtp_out_stream_destroy - free stream resources
 * @s: the AMDTP output stream to destroy
 */
void amdtp_out_stream_destroy(struct amdtp_out_stream *s)
{
	WARN_ON(!IS_ERR(s->context));
	mutex_destroy(&s->mutex);
	fw_unit_put(s->unit);
}
EXPORT_SYMBOL(amdtp_out_stream_destroy);

/**
 * amdtp_out_stream_set_rate - set the sample rate
 * @s: the AMDTP output stream to configure
 * @rate: the sample rate
 *
 * The sample rate must be set before the stream is started, and must not be
 * changed while the stream is running.
 */
void amdtp_out_stream_set_rate(struct amdtp_out_stream *s, unsigned int rate)
{
	static const struct {
		unsigned int rate;
		unsigned int syt_interval;
	} rate_info[] = {
		[CIP_SFC_32000]  = {  32000,  8, },
		[CIP_SFC_44100]  = {  44100,  8, },
		[CIP_SFC_48000]  = {  48000,  8, },
		[CIP_SFC_88200]  = {  88200, 16, },
		[CIP_SFC_96000]  = {  96000, 16, },
		[CIP_SFC_176400] = { 176400, 32, },
		[CIP_SFC_192000] = { 192000, 32, },
	};
	unsigned int sfc;

	if (WARN_ON(!IS_ERR(s->context)))
		return;

	for (sfc = 0; sfc < ARRAY_SIZE(rate_info); ++sfc)
		if (rate_info[sfc].rate == rate) {
			s->sfc = sfc;
			s->syt_interval = rate_info[sfc].syt_interval;
			return;
		}
	WARN_ON(1);
}
EXPORT_SYMBOL(amdtp_out_stream_set_rate);

/**
 * amdtp_out_stream_get_max_payload - get the stream's packet size
 * @s: the AMDTP output stream
 *
 * This function must not be called before the stream has been configured
 * with amdtp_out_stream_set_hw_params(), amdtp_out_stream_set_pcm(), and
 * amdtp_out_stream_set_midi().
 */
unsigned int amdtp_out_stream_get_max_payload(struct amdtp_out_stream *s)
{
	static const unsigned int max_data_blocks[] = {
		[CIP_SFC_32000]  =  4,
		[CIP_SFC_44100]  =  6,
		[CIP_SFC_48000]  =  6,
		[CIP_SFC_88200]  = 12,
		[CIP_SFC_96000]  = 12,
		[CIP_SFC_176400] = 23,
		[CIP_SFC_192000] = 24,
	};

	s->data_block_quadlets = s->pcm_channels;
	s->data_block_quadlets += DIV_ROUND_UP(s->midi_ports, 8);

	return 8 + max_data_blocks[s->sfc] * 4 * s->data_block_quadlets;
}
EXPORT_SYMBOL(amdtp_out_stream_get_max_payload);

static void amdtp_write_s16(struct amdtp_out_stream *s,
			    struct snd_pcm_substream *pcm,
			    __be32 *buffer, unsigned int frames);
static void amdtp_write_s32(struct amdtp_out_stream *s,
			    struct snd_pcm_substream *pcm,
			    __be32 *buffer, unsigned int frames);

/**
 * amdtp_out_stream_set_pcm_format - set the PCM format
 * @s: the AMDTP output stream to configure
 * @format: the format of the ALSA PCM device
 *
 * The sample format must be set before the stream is started, and must not be
 * changed while the stream is running.
 */
void amdtp_out_stream_set_pcm_format(struct amdtp_out_stream *s,
				     snd_pcm_format_t format)
{
	if (WARN_ON(!IS_ERR(s->context)))
		return;

	switch (format) {
	default:
		WARN_ON(1);
		/* fall through */
	case SNDRV_PCM_FORMAT_S16:
		s->transfer_samples = amdtp_write_s16;
		break;
	case SNDRV_PCM_FORMAT_S32:
		s->transfer_samples = amdtp_write_s32;
		break;
	}
}
EXPORT_SYMBOL(amdtp_out_stream_set_pcm_format);

/**
 * amdtp_out_stream_pcm_prepare - prepare PCM device for running
 * @s: the AMDTP output stream
 *
 * This function should be called from the PCM device's .prepare callback.
 */
void amdtp_out_stream_pcm_prepare(struct amdtp_out_stream *s)
{
	tasklet_kill(&s->period_tasklet);
	s->pcm_buffer_pointer = 0;
	s->pcm_period_pointer = 0;
}
EXPORT_SYMBOL(amdtp_out_stream_pcm_prepare);

static unsigned int calculate_data_blocks(struct amdtp_out_stream *s)
{
	unsigned int phase, data_blocks;

	if (!cip_sfc_is_base_44100(s->sfc)) {
		/* Sample_rate / 8000 is an integer, and precomputed. */
		data_blocks = s->data_block_state;
	} else {
		phase = s->data_block_state;

		/*
		 * This calculates the number of data blocks per packet so that
		 * 1) the overall rate is correct and exactly synchronized to
		 *    the bus clock, and
		 * 2) packets with a rounded-up number of blocks occur as early
		 *    as possible in the sequence (to prevent underruns of the
		 *    device's buffer).
		 */
		if (s->sfc == CIP_SFC_44100)
			/* 6 6 5 6 5 6 5 ... */
			data_blocks = 5 + ((phase & 1) ^
					   (phase == 0 || phase >= 40));
		else
			/* 12 11 11 11 11 ... or 23 22 22 22 22 ... */
			data_blocks = 11 * (s->sfc >> 1) + (phase == 0);
		if (++phase >= (80 >> (s->sfc >> 1)))
			phase = 0;
		s->data_block_state = phase;
	}

	return data_blocks;
}

static unsigned int calculate_syt(struct amdtp_out_stream *s,
				  unsigned int cycle)
{
	unsigned int syt_offset, phase, index, syt;

	if (s->last_syt_offset < TICKS_PER_CYCLE) {
		if (!cip_sfc_is_base_44100(s->sfc))
			syt_offset = s->last_syt_offset + s->syt_offset_state;
		else {
		/*
		 * The time, in ticks, of the n'th SYT_INTERVAL sample is:
		 *   n * SYT_INTERVAL * 24576000 / sample_rate
		 * Modulo TICKS_PER_CYCLE, the difference between successive
		 * elements is about 1386.23.  Rounding the results of this
		 * formula to the SYT precision results in a sequence of
		 * differences that begins with:
		 *   1386 1386 1387 1386 1386 1386 1387 1386 1386 1386 1387 ...
		 * This code generates _exactly_ the same sequence.
		 */
			phase = s->syt_offset_state;
			index = phase % 13;
			syt_offset = s->last_syt_offset;
			syt_offset += 1386 + ((index && !(index & 3)) ||
					      phase == 146);
			if (++phase >= 147)
				phase = 0;
			s->syt_offset_state = phase;
		}
	} else
		syt_offset = s->last_syt_offset - TICKS_PER_CYCLE;
	s->last_syt_offset = syt_offset;

	if (syt_offset < TICKS_PER_CYCLE) {
		syt_offset += TRANSFER_DELAY_TICKS - TICKS_PER_CYCLE;
		syt = (cycle + syt_offset / TICKS_PER_CYCLE) << 12;
		syt += syt_offset % TICKS_PER_CYCLE;

		return syt & 0xffff;
	} else {
		return 0xffff; /* no info */
	}
}

static void amdtp_write_s32(struct amdtp_out_stream *s,
			    struct snd_pcm_substream *pcm,
			    __be32 *buffer, unsigned int frames)
{
	struct snd_pcm_runtime *runtime = pcm->runtime;
	unsigned int channels, remaining_frames, frame_step, i, c;
	const u32 *src;

	channels = s->pcm_channels;
	src = (void *)runtime->dma_area +
			s->pcm_buffer_pointer * (runtime->frame_bits / 8);
	remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
	frame_step = s->data_block_quadlets - channels;

	for (i = 0; i < frames; ++i) {
		for (c = 0; c < channels; ++c) {
			*buffer = cpu_to_be32((*src >> 8) | 0x40000000);
			src++;
			buffer++;
		}
		buffer += frame_step;
		if (--remaining_frames == 0)
			src = (void *)runtime->dma_area;
	}
}

static void amdtp_write_s16(struct amdtp_out_stream *s,
			    struct snd_pcm_substream *pcm,
			    __be32 *buffer, unsigned int frames)
{
	struct snd_pcm_runtime *runtime = pcm->runtime;
	unsigned int channels, remaining_frames, frame_step, i, c;
	const u16 *src;

	channels = s->pcm_channels;
	src = (void *)runtime->dma_area +
			s->pcm_buffer_pointer * (runtime->frame_bits / 8);
	remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
	frame_step = s->data_block_quadlets - channels;

	for (i = 0; i < frames; ++i) {
		for (c = 0; c < channels; ++c) {
			*buffer = cpu_to_be32((*src << 8) | 0x40000000);
			src++;
			buffer++;
		}
		buffer += frame_step;
		if (--remaining_frames == 0)
			src = (void *)runtime->dma_area;
	}
}

static void amdtp_fill_pcm_silence(struct amdtp_out_stream *s,
				   __be32 *buffer, unsigned int frames)
{
	unsigned int i, c;

	for (i = 0; i < frames; ++i) {
		for (c = 0; c < s->pcm_channels; ++c)
			buffer[c] = cpu_to_be32(0x40000000);
		buffer += s->data_block_quadlets;
	}
}

static void amdtp_fill_midi(struct amdtp_out_stream *s,
			    __be32 *buffer, unsigned int frames)
{
	unsigned int i;

	for (i = 0; i < frames; ++i)
		buffer[s->pcm_channels + i * s->data_block_quadlets] =
						cpu_to_be32(0x80000000);
}

static void queue_out_packet(struct amdtp_out_stream *s, unsigned int cycle)
{
	__be32 *buffer;
	unsigned int index, data_blocks, syt, ptr;
	struct snd_pcm_substream *pcm;
	struct fw_iso_packet packet;
	int err;

	if (s->packet_index < 0)
		return;
	index = s->packet_index;

	data_blocks = calculate_data_blocks(s);
	syt = calculate_syt(s, cycle);

	buffer = s->buffer.packets[index].buffer;
	buffer[0] = cpu_to_be32(ACCESS_ONCE(s->source_node_id_field) |
				(s->data_block_quadlets << 16) |
				s->data_block_counter);
	buffer[1] = cpu_to_be32(CIP_EOH | CIP_FMT_AM | AMDTP_FDF_AM824 |
				(s->sfc << AMDTP_FDF_SFC_SHIFT) | syt);
	buffer += 2;

	pcm = ACCESS_ONCE(s->pcm);
	if (pcm)
		s->transfer_samples(s, pcm, buffer, data_blocks);
	else
		amdtp_fill_pcm_silence(s, buffer, data_blocks);
	if (s->midi_ports)
		amdtp_fill_midi(s, buffer, data_blocks);

	s->data_block_counter = (s->data_block_counter + data_blocks) & 0xff;

	packet.payload_length = 8 + data_blocks * 4 * s->data_block_quadlets;
	packet.interrupt = IS_ALIGNED(index + 1, INTERRUPT_INTERVAL);
	packet.skip = 0;
	packet.tag = TAG_CIP;
	packet.sy = 0;
	packet.header_length = 0;

	err = fw_iso_context_queue(s->context, &packet, &s->buffer.iso_buffer,
				   s->buffer.packets[index].offset);
	if (err < 0) {
		dev_err(&s->unit->device, "queueing error: %d\n", err);
		s->packet_index = -1;
		amdtp_out_stream_pcm_abort(s);
		return;
	}

	if (++index >= QUEUE_LENGTH)
		index = 0;
	s->packet_index = index;

	if (pcm) {
		ptr = s->pcm_buffer_pointer + data_blocks;
		if (ptr >= pcm->runtime->buffer_size)
			ptr -= pcm->runtime->buffer_size;
		ACCESS_ONCE(s->pcm_buffer_pointer) = ptr;

		s->pcm_period_pointer += data_blocks;
		if (s->pcm_period_pointer >= pcm->runtime->period_size) {
			s->pcm_period_pointer -= pcm->runtime->period_size;
			tasklet_hi_schedule(&s->period_tasklet);
		}
	}
}

static void pcm_period_tasklet(unsigned long data)
{
	struct amdtp_out_stream *s = (void *)data;
	struct snd_pcm_substream *pcm = ACCESS_ONCE(s->pcm);

	if (pcm)
		snd_pcm_period_elapsed(pcm);
}

static void out_packet_callback(struct fw_iso_context *context, u32 cycle,
				size_t header_length, void *header, void *data)
{
	struct amdtp_out_stream *s = data;
	unsigned int i, packets = header_length / 4;

	/*
	 * Compute the cycle of the last queued packet.
	 * (We need only the four lowest bits for the SYT, so we can ignore
	 * that bits 0-11 must wrap around at 3072.)
	 */
	cycle += QUEUE_LENGTH - packets;

	for (i = 0; i < packets; ++i)
		queue_out_packet(s, ++cycle);
	fw_iso_context_queue_flush(s->context);
}

static int queue_initial_skip_packets(struct amdtp_out_stream *s)
{
	struct fw_iso_packet skip_packet = {
		.skip = 1,
	};
	unsigned int i;
	int err;

	for (i = 0; i < QUEUE_LENGTH; ++i) {
		skip_packet.interrupt = IS_ALIGNED(s->packet_index + 1,
						   INTERRUPT_INTERVAL);
		err = fw_iso_context_queue(s->context, &skip_packet, NULL, 0);
		if (err < 0)
			return err;
		if (++s->packet_index >= QUEUE_LENGTH)
			s->packet_index = 0;
	}

	return 0;
}

/**
 * amdtp_out_stream_start - start sending packets
 * @s: the AMDTP output stream to start
 * @channel: the isochronous channel on the bus
 * @speed: firewire speed code
 *
 * The stream cannot be started until it has been configured with
 * amdtp_out_stream_set_hw_params(), amdtp_out_stream_set_pcm(), and
 * amdtp_out_stream_set_midi(); and it must be started before any
 * PCM or MIDI device can be started.
 */
int amdtp_out_stream_start(struct amdtp_out_stream *s, int channel, int speed)
{
	static const struct {
		unsigned int data_block;
		unsigned int syt_offset;
	} initial_state[] = {
		[CIP_SFC_32000]  = {  4, 3072 },
		[CIP_SFC_48000]  = {  6, 1024 },
		[CIP_SFC_96000]  = { 12, 1024 },
		[CIP_SFC_192000] = { 24, 1024 },
		[CIP_SFC_44100]  = {  0,   67 },
		[CIP_SFC_88200]  = {  0,   67 },
		[CIP_SFC_176400] = {  0,   67 },
	};
	int err;

	mutex_lock(&s->mutex);

	if (WARN_ON(!IS_ERR(s->context) ||
		    (!s->pcm_channels && !s->midi_ports))) {
		err = -EBADFD;
		goto err_unlock;
	}

	s->data_block_state = initial_state[s->sfc].data_block;
	s->syt_offset_state = initial_state[s->sfc].syt_offset;
	s->last_syt_offset = TICKS_PER_CYCLE;

	err = iso_packets_buffer_init(&s->buffer, s->unit, QUEUE_LENGTH,
				      amdtp_out_stream_get_max_payload(s),
				      DMA_TO_DEVICE);
	if (err < 0)
		goto err_unlock;

	s->context = fw_iso_context_create(fw_parent_device(s->unit)->card,
					   FW_ISO_CONTEXT_TRANSMIT,
					   channel, speed, 0,
					   out_packet_callback, s);
	if (IS_ERR(s->context)) {
		err = PTR_ERR(s->context);
		if (err == -EBUSY)
			dev_err(&s->unit->device,
				"no free output stream on this controller\n");
		goto err_buffer;
	}

	amdtp_out_stream_update(s);

	s->packet_index = 0;
	s->data_block_counter = 0;
	err = queue_initial_skip_packets(s);
	if (err < 0)
		goto err_context;

	err = fw_iso_context_start(s->context, -1, 0, 0);
	if (err < 0)
		goto err_context;

	mutex_unlock(&s->mutex);

	return 0;

err_context:
	fw_iso_context_destroy(s->context);
	s->context = ERR_PTR(-1);
err_buffer:
	iso_packets_buffer_destroy(&s->buffer, s->unit);
err_unlock:
	mutex_unlock(&s->mutex);

	return err;
}
EXPORT_SYMBOL(amdtp_out_stream_start);

/**
 * amdtp_out_stream_update - update the stream after a bus reset
 * @s: the AMDTP output stream
 */
void amdtp_out_stream_update(struct amdtp_out_stream *s)
{
	ACCESS_ONCE(s->source_node_id_field) =
		(fw_parent_device(s->unit)->card->node_id & 0x3f) << 24;
}
EXPORT_SYMBOL(amdtp_out_stream_update);

/**
 * amdtp_out_stream_stop - stop sending packets
 * @s: the AMDTP output stream to stop
 *
 * All PCM and MIDI devices of the stream must be stopped before the stream
 * itself can be stopped.
 */
void amdtp_out_stream_stop(struct amdtp_out_stream *s)
{
	mutex_lock(&s->mutex);

	if (IS_ERR(s->context)) {
		mutex_unlock(&s->mutex);
		return;
	}

	tasklet_kill(&s->period_tasklet);
	fw_iso_context_stop(s->context);
	fw_iso_context_destroy(s->context);
	s->context = ERR_PTR(-1);
	iso_packets_buffer_destroy(&s->buffer, s->unit);

	mutex_unlock(&s->mutex);
}
EXPORT_SYMBOL(amdtp_out_stream_stop);

/**
 * amdtp_out_stream_pcm_abort - abort the running PCM device
 * @s: the AMDTP stream about to be stopped
 *
 * If the isochronous stream needs to be stopped asynchronously, call this
 * function first to stop the PCM device.
 */
void amdtp_out_stream_pcm_abort(struct amdtp_out_stream *s)
{
	struct snd_pcm_substream *pcm;

	pcm = ACCESS_ONCE(s->pcm);
	if (pcm) {
		snd_pcm_stream_lock_irq(pcm);
		if (snd_pcm_running(pcm))
			snd_pcm_stop(pcm, SNDRV_PCM_STATE_XRUN);
		snd_pcm_stream_unlock_irq(pcm);
	}
}
EXPORT_SYMBOL(amdtp_out_stream_pcm_abort);
Commit	Line	Data
31ef9134 CL	1	/*
	2	* Audio and Music Data Transmission Protocol (IEC 61883-6) streams
	3	* with Common Isochronous Packet (IEC 61883-1) headers
	4	*
	5	* Copyright (c) Clemens Ladisch <clemens@ladisch.de>
	6	* Licensed under the terms of the GNU General Public License, version 2.
	7	*/
	8
	9	#include <linux/device.h>
	10	#include <linux/err.h>
	11	#include <linux/firewire.h>
	12	#include <linux/module.h>
	13	#include <linux/slab.h>
	14	#include <sound/pcm.h>
	15	#include "amdtp.h"
	16
	17	#define TICKS_PER_CYCLE 3072
	18	#define CYCLES_PER_SECOND 8000
	19	#define TICKS_PER_SECOND (TICKS_PER_CYCLE * CYCLES_PER_SECOND)
	20
	21	#define TRANSFER_DELAY_TICKS 0x2e00 /* 479.17 µs */
	22
	23	#define TAG_CIP 1
	24
	25	#define CIP_EOH (1u << 31)
	26	#define CIP_FMT_AM (0x10 << 24)
	27	#define AMDTP_FDF_AM824 (0 << 19)
	28	#define AMDTP_FDF_SFC_SHIFT 16
	29
	30	/* TODO: make these configurable */
	31	#define INTERRUPT_INTERVAL 16
	32	#define QUEUE_LENGTH 48
	33
76fb8789 CL	34	static void pcm_period_tasklet(unsigned long data);
76fb8789 CL	35
31ef9134 CL	36	/**
	37	* amdtp_out_stream_init - initialize an AMDTP output stream structure
	38	* @s: the AMDTP output stream to initialize
	39	* @unit: the target of the stream
	40	* @flags: the packet transmission method to use
	41	*/
	42	int amdtp_out_stream_init(struct amdtp_out_stream s, struct fw_unit unit,
	43	enum cip_out_flags flags)
	44	{
	45	if (flags != CIP_NONBLOCKING)
	46	return -EINVAL;
	47
	48	s->unit = fw_unit_get(unit);
	49	s->flags = flags;
	50	s->context = ERR_PTR(-1);
	51	mutex_init(&s->mutex);
76fb8789	52	tasklet_init(&s->period_tasklet, pcm_period_tasklet, (unsigned long)s);
ec00f5e4	53	s->packet_index = 0;
31ef9134 CL	54
	55	return 0;
	56	}
	57	EXPORT_SYMBOL(amdtp_out_stream_init);
	58
	59	/**
	60	* amdtp_out_stream_destroy - free stream resources
	61	* @s: the AMDTP output stream to destroy
	62	*/
	63	void amdtp_out_stream_destroy(struct amdtp_out_stream *s)
	64	{
	65	WARN_ON(!IS_ERR(s->context));
	66	mutex_destroy(&s->mutex);
	67	fw_unit_put(s->unit);
	68	}
	69	EXPORT_SYMBOL(amdtp_out_stream_destroy);
	70
	71	/**
	72	* amdtp_out_stream_set_rate - set the sample rate
	73	* @s: the AMDTP output stream to configure
	74	* @rate: the sample rate
	75	*
	76	* The sample rate must be set before the stream is started, and must not be
	77	* changed while the stream is running.
	78	*/
	79	void amdtp_out_stream_set_rate(struct amdtp_out_stream *s, unsigned int rate)
	80	{
	81	static const struct {
	82	unsigned int rate;
	83	unsigned int syt_interval;
	84	} rate_info[] = {
	85	[CIP_SFC_32000] = { 32000, 8, },
	86	[CIP_SFC_44100] = { 44100, 8, },
	87	[CIP_SFC_48000] = { 48000, 8, },
	88	[CIP_SFC_88200] = { 88200, 16, },
	89	[CIP_SFC_96000] = { 96000, 16, },
	90	[CIP_SFC_176400] = { 176400, 32, },
	91	[CIP_SFC_192000] = { 192000, 32, },
	92	};
	93	unsigned int sfc;
	94
	95	if (WARN_ON(!IS_ERR(s->context)))
	96	return;
	97
	98	for (sfc = 0; sfc < ARRAY_SIZE(rate_info); ++sfc)
	99	if (rate_info[sfc].rate == rate) {
	100	s->sfc = sfc;
	101	s->syt_interval = rate_info[sfc].syt_interval;
	102	return;
	103	}
	104	WARN_ON(1);
	105	}
	106	EXPORT_SYMBOL(amdtp_out_stream_set_rate);
	107
	108	/**
	109	* amdtp_out_stream_get_max_payload - get the stream's packet size
	110	* @s: the AMDTP output stream
	111	*
	112	* This function must not be called before the stream has been configured
	113	* with amdtp_out_stream_set_hw_params(), amdtp_out_stream_set_pcm(), and
	114	* amdtp_out_stream_set_midi().
	115	*/
	116	unsigned int amdtp_out_stream_get_max_payload(struct amdtp_out_stream *s)
	117	{
118	static const unsigned int max_data_blocks[] = {
119	[CIP_SFC_32000] = 4,
120	[CIP_SFC_44100] = 6,
121	[CIP_SFC_48000] = 6,
122	[CIP_SFC_88200] = 12,
123	[CIP_SFC_96000] = 12,
124	[CIP_SFC_176400] = 23,
125	[CIP_SFC_192000] = 24,
126	};
127
128	s->data_block_quadlets = s->pcm_channels;
129	s->data_block_quadlets += DIV_ROUND_UP(s->midi_ports, 8);
130
131	return 8 + max_data_blocks[s->sfc] * 4 * s->data_block_quadlets;
132	}
133	EXPORT_SYMBOL(amdtp_out_stream_get_max_payload);
134
135	static void amdtp_write_s16(struct amdtp_out_stream *s,
136	struct snd_pcm_substream *pcm,
137	__be32 *buffer, unsigned int frames);
138	static void amdtp_write_s32(struct amdtp_out_stream *s,
139	struct snd_pcm_substream *pcm,
140	__be32 *buffer, unsigned int frames);
141
142	/**
143	* amdtp_out_stream_set_pcm_format - set the PCM format
144	* @s: the AMDTP output stream to configure
145	* @format: the format of the ALSA PCM device
146	*
147	* The sample format must be set before the stream is started, and must not be
148	* changed while the stream is running.
149	*/
150	void amdtp_out_stream_set_pcm_format(struct amdtp_out_stream *s,
151	snd_pcm_format_t format)
152	{
153	if (WARN_ON(!IS_ERR(s->context)))
154	return;
155
156	switch (format) {
157	default:
158	WARN_ON(1);
159	/* fall through */
160	case SNDRV_PCM_FORMAT_S16:
161	s->transfer_samples = amdtp_write_s16;
162	break;
163	case SNDRV_PCM_FORMAT_S32:
164	s->transfer_samples = amdtp_write_s32;
165	break;
166	}
167	}
168	EXPORT_SYMBOL(amdtp_out_stream_set_pcm_format);
169
76fb8789 CL	170	/**
	171	* amdtp_out_stream_pcm_prepare - prepare PCM device for running
	172	* @s: the AMDTP output stream
	173	*
	174	* This function should be called from the PCM device's .prepare callback.
	175	*/
	176	void amdtp_out_stream_pcm_prepare(struct amdtp_out_stream *s)
	177	{
	178	tasklet_kill(&s->period_tasklet);
	179	s->pcm_buffer_pointer = 0;
	180	s->pcm_period_pointer = 0;
	181	}
	182	EXPORT_SYMBOL(amdtp_out_stream_pcm_prepare);
	183
31ef9134 CL	184	static unsigned int calculate_data_blocks(struct amdtp_out_stream *s)
	185	{
	186	unsigned int phase, data_blocks;
	187
	188	if (!cip_sfc_is_base_44100(s->sfc)) {
	189	/* Sample_rate / 8000 is an integer, and precomputed. */
	190	data_blocks = s->data_block_state;
	191	} else {
	192	phase = s->data_block_state;
	193
	194	/*
	195	* This calculates the number of data blocks per packet so that
	196	* 1) the overall rate is correct and exactly synchronized to
	197	* the bus clock, and
	198	* 2) packets with a rounded-up number of blocks occur as early
	199	* as possible in the sequence (to prevent underruns of the
	200	* device's buffer).
	201	*/
	202	if (s->sfc == CIP_SFC_44100)
	203	/* 6 6 5 6 5 6 5 ... */
	204	data_blocks = 5 + ((phase & 1) ^
	205	(phase == 0 \|\| phase >= 40));
	206	else
	207	/* 12 11 11 11 11 ... or 23 22 22 22 22 ... */
	208	data_blocks = 11 * (s->sfc >> 1) + (phase == 0);
	209	if (++phase >= (80 >> (s->sfc >> 1)))
	210	phase = 0;
	211	s->data_block_state = phase;
	212	}
	213
	214	return data_blocks;
	215	}
	216
	217	static unsigned int calculate_syt(struct amdtp_out_stream *s,
	218	unsigned int cycle)
	219	{
	220	unsigned int syt_offset, phase, index, syt;
	221
	222	if (s->last_syt_offset < TICKS_PER_CYCLE) {
	223	if (!cip_sfc_is_base_44100(s->sfc))
	224	syt_offset = s->last_syt_offset + s->syt_offset_state;
	225	else {
	226	/*
	227	* The time, in ticks, of the n'th SYT_INTERVAL sample is:
	228	* n * SYT_INTERVAL * 24576000 / sample_rate
	229	* Modulo TICKS_PER_CYCLE, the difference between successive
	230	* elements is about 1386.23. Rounding the results of this
	231	* formula to the SYT precision results in a sequence of
	232	* differences that begins with:
	233	* 1386 1386 1387 1386 1386 1386 1387 1386 1386 1386 1387 ...
	234	* This code generates _exactly_ the same sequence.
	235	*/
	236	phase = s->syt_offset_state;
	237	index = phase % 13;
	238	syt_offset = s->last_syt_offset;
	239	syt_offset += 1386 + ((index && !(index & 3)) \|\|
	240	phase == 146);
	241	if (++phase >= 147)
	242	phase = 0;
	243	s->syt_offset_state = phase;
	244	}
	245	} else
	246	syt_offset = s->last_syt_offset - TICKS_PER_CYCLE;
	247	s->last_syt_offset = syt_offset;
248
be454366 CL	249	if (syt_offset < TICKS_PER_CYCLE) {
	250	syt_offset += TRANSFER_DELAY_TICKS - TICKS_PER_CYCLE;
	251	syt = (cycle + syt_offset / TICKS_PER_CYCLE) << 12;
	252	syt += syt_offset % TICKS_PER_CYCLE;
31ef9134	253
be454366 CL	254	return syt & 0xffff;
	255	} else {
	256	return 0xffff; /* no info */
	257	}
31ef9134 CL	258	}
	259
	260	static void amdtp_write_s32(struct amdtp_out_stream *s,
	261	struct snd_pcm_substream *pcm,
	262	__be32 *buffer, unsigned int frames)
	263	{
	264	struct snd_pcm_runtime *runtime = pcm->runtime;
	265	unsigned int channels, remaining_frames, frame_step, i, c;
	266	const u32 *src;
	267
	268	channels = s->pcm_channels;
	269	src = (void *)runtime->dma_area +
	270	s->pcm_buffer_pointer * (runtime->frame_bits / 8);
	271	remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
	272	frame_step = s->data_block_quadlets - channels;
	273
	274	for (i = 0; i < frames; ++i) {
	275	for (c = 0; c < channels; ++c) {
	276	buffer = cpu_to_be32((src >> 8) \| 0x40000000);
	277	src++;
	278	buffer++;
	279	}
	280	buffer += frame_step;
	281	if (--remaining_frames == 0)
	282	src = (void *)runtime->dma_area;
	283	}
	284	}
	285
	286	static void amdtp_write_s16(struct amdtp_out_stream *s,
	287	struct snd_pcm_substream *pcm,
	288	__be32 *buffer, unsigned int frames)
	289	{
	290	struct snd_pcm_runtime *runtime = pcm->runtime;
	291	unsigned int channels, remaining_frames, frame_step, i, c;
	292	const u16 *src;
	293
	294	channels = s->pcm_channels;
	295	src = (void *)runtime->dma_area +
	296	s->pcm_buffer_pointer * (runtime->frame_bits / 8);
	297	remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
	298	frame_step = s->data_block_quadlets - channels;
	299
	300	for (i = 0; i < frames; ++i) {
	301	for (c = 0; c < channels; ++c) {
	302	buffer = cpu_to_be32((src << 8) \| 0x40000000);
	303	src++;
	304	buffer++;
	305	}
	306	buffer += frame_step;
	307	if (--remaining_frames == 0)
	308	src = (void *)runtime->dma_area;
	309	}
	310	}
	311
	312	static void amdtp_fill_pcm_silence(struct amdtp_out_stream *s,
	313	__be32 *buffer, unsigned int frames)
	314	{
	315	unsigned int i, c;
	316
	317	for (i = 0; i < frames; ++i) {
	318	for (c = 0; c < s->pcm_channels; ++c)
	319	buffer[c] = cpu_to_be32(0x40000000);
	320	buffer += s->data_block_quadlets;
	321	}
322	}
323
324	static void amdtp_fill_midi(struct amdtp_out_stream *s,
325	__be32 *buffer, unsigned int frames)
326	{
327	unsigned int i;
328
329	for (i = 0; i < frames; ++i)
330	buffer[s->pcm_channels + i * s->data_block_quadlets] =
331	cpu_to_be32(0x80000000);
332	}
333
334	static void queue_out_packet(struct amdtp_out_stream *s, unsigned int cycle)
335	{
336	__be32 *buffer;
ec00f5e4	337	unsigned int index, data_blocks, syt, ptr;
31ef9134 CL	338	struct snd_pcm_substream *pcm;
	339	struct fw_iso_packet packet;
	340	int err;
	341
ec00f5e4 CL	342	if (s->packet_index < 0)
	343	return;
	344	index = s->packet_index;
	345
31ef9134 CL	346	data_blocks = calculate_data_blocks(s);
	347	syt = calculate_syt(s, cycle);
	348
ec00f5e4	349	buffer = s->buffer.packets[index].buffer;
31ef9134 CL	350	buffer[0] = cpu_to_be32(ACCESS_ONCE(s->source_node_id_field) \|
	351	(s->data_block_quadlets << 16) \|
	352	s->data_block_counter);
	353	buffer[1] = cpu_to_be32(CIP_EOH \| CIP_FMT_AM \| AMDTP_FDF_AM824 \|
	354	(s->sfc << AMDTP_FDF_SFC_SHIFT) \| syt);
	355	buffer += 2;
	356
	357	pcm = ACCESS_ONCE(s->pcm);
	358	if (pcm)
	359	s->transfer_samples(s, pcm, buffer, data_blocks);
	360	else
	361	amdtp_fill_pcm_silence(s, buffer, data_blocks);
	362	if (s->midi_ports)
	363	amdtp_fill_midi(s, buffer, data_blocks);
	364
	365	s->data_block_counter = (s->data_block_counter + data_blocks) & 0xff;
	366
	367	packet.payload_length = 8 + data_blocks * 4 * s->data_block_quadlets;
ec00f5e4	368	packet.interrupt = IS_ALIGNED(index + 1, INTERRUPT_INTERVAL);
31ef9134 CL	369	packet.skip = 0;
	370	packet.tag = TAG_CIP;
	371	packet.sy = 0;
	372	packet.header_length = 0;
	373
	374	err = fw_iso_context_queue(s->context, &packet, &s->buffer.iso_buffer,
ec00f5e4 CL	375	s->buffer.packets[index].offset);
ec00f5e4 CL	376	if (err < 0) {
31ef9134	377	dev_err(&s->unit->device, "queueing error: %d\n", err);
ec00f5e4 CL	378	s->packet_index = -1;
	379	amdtp_out_stream_pcm_abort(s);
	380	return;
	381	}
31ef9134	382
ec00f5e4 CL	383	if (++index >= QUEUE_LENGTH)
	384	index = 0;
	385	s->packet_index = index;
31ef9134 CL	386
	387	if (pcm) {
	388	ptr = s->pcm_buffer_pointer + data_blocks;
	389	if (ptr >= pcm->runtime->buffer_size)
	390	ptr -= pcm->runtime->buffer_size;
	391	ACCESS_ONCE(s->pcm_buffer_pointer) = ptr;
	392
	393	s->pcm_period_pointer += data_blocks;
	394	if (s->pcm_period_pointer >= pcm->runtime->period_size) {
	395	s->pcm_period_pointer -= pcm->runtime->period_size;
76fb8789	396	tasklet_hi_schedule(&s->period_tasklet);
31ef9134 CL	397	}
	398	}
	399	}
	400
76fb8789 CL	401	static void pcm_period_tasklet(unsigned long data)
	402	{
	403	struct amdtp_out_stream s = (void )data;
	404	struct snd_pcm_substream *pcm = ACCESS_ONCE(s->pcm);
	405
	406	if (pcm)
	407	snd_pcm_period_elapsed(pcm);
	408	}
	409
31ef9134 CL	410	static void out_packet_callback(struct fw_iso_context *context, u32 cycle,
	411	size_t header_length, void header, void data)
	412	{
	413	struct amdtp_out_stream *s = data;
	414	unsigned int i, packets = header_length / 4;
	415
	416	/*
	417	* Compute the cycle of the last queued packet.
	418	* (We need only the four lowest bits for the SYT, so we can ignore
	419	* that bits 0-11 must wrap around at 3072.)
	420	*/
	421	cycle += QUEUE_LENGTH - packets;
	422
	423	for (i = 0; i < packets; ++i)
	424	queue_out_packet(s, ++cycle);
13882a82	425	fw_iso_context_queue_flush(s->context);
31ef9134 CL	426	}
	427
	428	static int queue_initial_skip_packets(struct amdtp_out_stream *s)
	429	{
	430	struct fw_iso_packet skip_packet = {
	431	.skip = 1,
	432	};
	433	unsigned int i;
	434	int err;
	435
	436	for (i = 0; i < QUEUE_LENGTH; ++i) {
ec00f5e4	437	skip_packet.interrupt = IS_ALIGNED(s->packet_index + 1,
31ef9134 CL	438	INTERRUPT_INTERVAL);
	439	err = fw_iso_context_queue(s->context, &skip_packet, NULL, 0);
	440	if (err < 0)
	441	return err;
ec00f5e4 CL	442	if (++s->packet_index >= QUEUE_LENGTH)
ec00f5e4 CL	443	s->packet_index = 0;
31ef9134 CL	444	}
	445
	446	return 0;
	447	}
	448
	449	/**
	450	* amdtp_out_stream_start - start sending packets
	451	* @s: the AMDTP output stream to start
	452	* @channel: the isochronous channel on the bus
	453	* @speed: firewire speed code
	454	*
	455	* The stream cannot be started until it has been configured with
	456	* amdtp_out_stream_set_hw_params(), amdtp_out_stream_set_pcm(), and
	457	* amdtp_out_stream_set_midi(); and it must be started before any
	458	* PCM or MIDI device can be started.
	459	*/
	460	int amdtp_out_stream_start(struct amdtp_out_stream *s, int channel, int speed)
	461	{
	462	static const struct {
	463	unsigned int data_block;
	464	unsigned int syt_offset;
	465	} initial_state[] = {
	466	[CIP_SFC_32000] = { 4, 3072 },
	467	[CIP_SFC_48000] = { 6, 1024 },
	468	[CIP_SFC_96000] = { 12, 1024 },
	469	[CIP_SFC_192000] = { 24, 1024 },
	470	[CIP_SFC_44100] = { 0, 67 },
	471	[CIP_SFC_88200] = { 0, 67 },
	472	[CIP_SFC_176400] = { 0, 67 },
	473	};
	474	int err;
	475
	476	mutex_lock(&s->mutex);
	477
	478	if (WARN_ON(!IS_ERR(s->context) \|\|
	479	(!s->pcm_channels && !s->midi_ports))) {
	480	err = -EBADFD;
	481	goto err_unlock;
	482	}
	483
	484	s->data_block_state = initial_state[s->sfc].data_block;
	485	s->syt_offset_state = initial_state[s->sfc].syt_offset;
	486	s->last_syt_offset = TICKS_PER_CYCLE;
	487
	488	err = iso_packets_buffer_init(&s->buffer, s->unit, QUEUE_LENGTH,
	489	amdtp_out_stream_get_max_payload(s),
	490	DMA_TO_DEVICE);
	491	if (err < 0)
	492	goto err_unlock;
	493
	494	s->context = fw_iso_context_create(fw_parent_device(s->unit)->card,
	495	FW_ISO_CONTEXT_TRANSMIT,
	496	channel, speed, 0,
	497	out_packet_callback, s);
	498	if (IS_ERR(s->context)) {
	499	err = PTR_ERR(s->context);
	500	if (err == -EBUSY)
	501	dev_err(&s->unit->device,
	502	"no free output stream on this controller\n");
	503	goto err_buffer;
	504	}
	505
	506	amdtp_out_stream_update(s);
	507
ec00f5e4	508	s->packet_index = 0;
31ef9134 CL	509	s->data_block_counter = 0;
	510	err = queue_initial_skip_packets(s);
	511	if (err < 0)
	512	goto err_context;
	513
	514	err = fw_iso_context_start(s->context, -1, 0, 0);
	515	if (err < 0)
	516	goto err_context;
	517
	518	mutex_unlock(&s->mutex);
	519
	520	return 0;
	521
	522	err_context:
	523	fw_iso_context_destroy(s->context);
	524	s->context = ERR_PTR(-1);
	525	err_buffer:
	526	iso_packets_buffer_destroy(&s->buffer, s->unit);
	527	err_unlock:
	528	mutex_unlock(&s->mutex);
	529
	530	return err;
	531	}
	532	EXPORT_SYMBOL(amdtp_out_stream_start);
	533
	534	/**
	535	* amdtp_out_stream_update - update the stream after a bus reset
	536	* @s: the AMDTP output stream
	537	*/
	538	void amdtp_out_stream_update(struct amdtp_out_stream *s)
	539	{
	540	ACCESS_ONCE(s->source_node_id_field) =
	541	(fw_parent_device(s->unit)->card->node_id & 0x3f) << 24;
	542	}
	543	EXPORT_SYMBOL(amdtp_out_stream_update);
	544
	545	/**
	546	* amdtp_out_stream_stop - stop sending packets
	547	* @s: the AMDTP output stream to stop
	548	*
	549	* All PCM and MIDI devices of the stream must be stopped before the stream
	550	* itself can be stopped.
	551	*/
	552	void amdtp_out_stream_stop(struct amdtp_out_stream *s)
	553	{
	554	mutex_lock(&s->mutex);
	555
	556	if (IS_ERR(s->context)) {
	557	mutex_unlock(&s->mutex);
	558	return;
	559	}
	560
76fb8789	561	tasklet_kill(&s->period_tasklet);
31ef9134 CL	562	fw_iso_context_stop(s->context);
	563	fw_iso_context_destroy(s->context);
	564	s->context = ERR_PTR(-1);
	565	iso_packets_buffer_destroy(&s->buffer, s->unit);
	566
	567	mutex_unlock(&s->mutex);
	568	}
	569	EXPORT_SYMBOL(amdtp_out_stream_stop);
	570
	571	/**
	572	* amdtp_out_stream_pcm_abort - abort the running PCM device
	573	* @s: the AMDTP stream about to be stopped
	574	*
	575	* If the isochronous stream needs to be stopped asynchronously, call this
	576	* function first to stop the PCM device.
	577	*/
	578	void amdtp_out_stream_pcm_abort(struct amdtp_out_stream *s)
	579	{
	580	struct snd_pcm_substream *pcm;
	581
	582	pcm = ACCESS_ONCE(s->pcm);
	583	if (pcm) {
	584	snd_pcm_stream_lock_irq(pcm);
	585	if (snd_pcm_running(pcm))
	586	snd_pcm_stop(pcm, SNDRV_PCM_STATE_XRUN);
	587	snd_pcm_stream_unlock_irq(pcm);
	588	}
	589	}
	590	EXPORT_SYMBOL(amdtp_out_stream_pcm_abort);