path: root/sound/firewire/bebob/bebob_stream.c

/*
 * bebob_stream.c - a part of driver for BeBoB based devices
 *
 * Copyright (c) 2013-2014 Takashi Sakamoto
 *
 * Licensed under the terms of the GNU General Public License, version 2.
 */

#include "./bebob.h"

#define CALLBACK_TIMEOUT	2000
#define FW_ISO_RESOURCE_DELAY	1000

/*
 * NOTE;
 * For BeBoB streams, Both of input and output CMP connection are important.
 *
 * For most devices, each CMP connection starts to transmit/receive a
 * corresponding stream. But for a few devices, both of CMP connection needs
 * to start transmitting stream. An example is 'M-Audio Firewire 410'.
 */

/* 128 is an arbitrary length but it seems to be enough */
#define FORMAT_MAXIMUM_LENGTH 128

const unsigned int snd_bebob_rate_table[SND_BEBOB_STRM_FMT_ENTRIES] = {
	[0] = 32000,
	[1] = 44100,
	[2] = 48000,
	[3] = 88200,
	[4] = 96000,
	[5] = 176400,
	[6] = 192000,
};

/*
 * See: Table 51: Extended Stream Format Info ‘Sampling Frequency’
 * in Additional AVC commands (Nov 2003, BridgeCo)
 */
static const unsigned int bridgeco_freq_table[] = {
	[0] = 0x02,
	[1] = 0x03,
	[2] = 0x04,
	[3] = 0x0a,
	[4] = 0x05,
	[5] = 0x06,
	[6] = 0x07,
};

static int
get_formation_index(unsigned int rate, unsigned int *index)
{
	unsigned int i;

	for (i = 0; i < ARRAY_SIZE(snd_bebob_rate_table); i++) {
		if (snd_bebob_rate_table[i] == rate) {
			*index = i;
			return 0;
		}
	}
	return -EINVAL;
}

int
snd_bebob_stream_get_rate(struct snd_bebob *bebob, unsigned int *curr_rate)
{
	unsigned int tx_rate, rx_rate, trials;
	int err;

	trials = 0;
	do {
		err = avc_general_get_sig_fmt(bebob->unit, &tx_rate,
					      AVC_GENERAL_PLUG_DIR_OUT, 0);
	} while (err == -EAGAIN && ++trials < 3);
	if (err < 0)
		goto end;

	trials = 0;
	do {
		err = avc_general_get_sig_fmt(bebob->unit, &rx_rate,
					      AVC_GENERAL_PLUG_DIR_IN, 0);
	} while (err == -EAGAIN && ++trials < 3);
	if (err < 0)
		goto end;

	*curr_rate = rx_rate;
	if (rx_rate == tx_rate)
		goto end;

	/* synchronize receive stream rate to transmit stream rate */
	err = avc_general_set_sig_fmt(bebob->unit, rx_rate,
				      AVC_GENERAL_PLUG_DIR_IN, 0);
end:
	return err;
}

int
snd_bebob_stream_set_rate(struct snd_bebob *bebob, unsigned int rate)
{
	int err;

	err = avc_general_set_sig_fmt(bebob->unit, rate,
				      AVC_GENERAL_PLUG_DIR_OUT, 0);
	if (err < 0)
		goto end;

	err = avc_general_set_sig_fmt(bebob->unit, rate,
				      AVC_GENERAL_PLUG_DIR_IN, 0);
	if (err < 0)
		goto end;

	/*
	 * Some devices need a bit time for transition.
	 * 300msec is got by some experiments.
	 */
	msleep(300);
end:
	return err;
}

int snd_bebob_stream_get_clock_src(struct snd_bebob *bebob,
				   enum snd_bebob_clock_type *src)
{
	const struct snd_bebob_clock_spec *clk_spec = bebob->spec->clock;
	u8 addr[AVC_BRIDGECO_ADDR_BYTES], input[7];
	unsigned int id;
	enum avc_bridgeco_plug_type type;
	int err = 0;

	/* 1.The device has its own operation to switch source of clock */
	if (clk_spec) {
		err = clk_spec->get(bebob, &id);
		if (err < 0) {
			dev_err(&bebob->unit->device,
				"fail to get clock source: %d\n", err);
			goto end;
		}

		if (id >= clk_spec->num) {
			dev_err(&bebob->unit->device,
				"clock source %d out of range 0..%d\n",
				id, clk_spec->num - 1);
			err = -EIO;
			goto end;
		}

		*src = clk_spec->types[id];
		goto end;
	}

	/*
	 * 2.The device don't support to switch source of clock then assumed
	 *   to use internal clock always
	 */
	if (bebob->sync_input_plug < 0) {
		*src = SND_BEBOB_CLOCK_TYPE_INTERNAL;
		goto end;
	}

	/*
	 * 3.The device supports to switch source of clock by an usual way.
	 *   Let's check input for 'Music Sub Unit Sync Input' plug.
	 */
	avc_bridgeco_fill_msu_addr(addr, AVC_BRIDGECO_PLUG_DIR_IN,
				   bebob->sync_input_plug);
	err = avc_bridgeco_get_plug_input(bebob->unit, addr, input);
	if (err < 0) {
		dev_err(&bebob->unit->device,
			"fail to get an input for MSU in plug %d: %d\n",
			b