[linux-block.git] / sound / i2c / i2c.c

/*
 *   Generic i2c interface for ALSA
 *
 *   (c) 1998 Gerd Knorr <kraxel@cs.tu-berlin.de>
 *   Modified for the ALSA driver by Jaroslav Kysela <perex@perex.cz>
 *
 *   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
 *
 */

#include <linux/init.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <sound/core.h>
#include <sound/i2c.h>

MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
MODULE_DESCRIPTION("Generic i2c interface for ALSA");
MODULE_LICENSE("GPL");

static int snd_i2c_bit_sendbytes(struct snd_i2c_device *device,
				 unsigned char *bytes, int count);
static int snd_i2c_bit_readbytes(struct snd_i2c_device *device,
				 unsigned char *bytes, int count);
static int snd_i2c_bit_probeaddr(struct snd_i2c_bus *bus,
				 unsigned short addr);

static struct snd_i2c_ops snd_i2c_bit_ops = {
	.sendbytes = snd_i2c_bit_sendbytes,
	.readbytes = snd_i2c_bit_readbytes,
	.probeaddr = snd_i2c_bit_probeaddr,
};

static int snd_i2c_bus_free(struct snd_i2c_bus *bus)
{
	struct snd_i2c_bus *slave;
	struct snd_i2c_device *device;

	if (snd_BUG_ON(!bus))
		return -EINVAL;
	while (!list_empty(&bus->devices)) {
		device = snd_i2c_device(bus->devices.next);
		snd_i2c_device_free(device);
	}
	if (bus->master)
		list_del(&bus->buses);
	else {
		while (!list_empty(&bus->buses)) {
			slave = snd_i2c_slave_bus(bus->buses.next);
			snd_device_free(bus->card, slave);
		}
	}
	if (bus->private_free)
		bus->private_free(bus);
	kfree(bus);
	return 0;
}

static int snd_i2c_bus_dev_free(struct snd_device *device)
{
	struct snd_i2c_bus *bus = device->device_data;
	return snd_i2c_bus_free(bus);
}

int snd_i2c_bus_create(struct snd_card *card, const char *name,
		       struct snd_i2c_bus *master, struct snd_i2c_bus **ri2c)
{
	struct snd_i2c_bus *bus;
	int err;
	static struct snd_device_ops ops = {
		.dev_free =	snd_i2c_bus_dev_free,
	};

	*ri2c = NULL;
	bus = kzalloc(sizeof(*bus), GFP_KERNEL);
	if (bus == NULL)
		return -ENOMEM;
	mutex_init(&bus->lock_mutex);
	INIT_LIST_HEAD(&bus->devices);
	INIT_LIST_HEAD(&bus->buses);
	bus->card = card;
	bus->ops = &snd_i2c_bit_ops;
	if (master) {
		list_add_tail(&bus->buses, &master->buses);
		bus->master = master;
	}
	strlcpy(bus->name, name, sizeof(bus->name));
	if ((err = snd_device_new(card, SNDRV_DEV_BUS, bus, &ops)) < 0) {
		snd_i2c_bus_free(bus);
		return err;
	}
	*ri2c = bus;
	return 0;
}

EXPORT_SYMBOL(snd_i2c_bus_create);

int snd_i2c_device_create(struct snd_i2c_bus *bus, const char *name,
			  unsigned char addr, struct snd_i2c_device **rdevice)
{
	struct snd_i2c_device *device;

	*rdevice = NULL;
	if (snd_BUG_ON(!bus))
		return -EINVAL;
	device = kzalloc(sizeof(*device), GFP_KERNEL);
	if (device == NULL)
		return -ENOMEM;
	device->addr = addr;
	strlcpy(device->name, name, sizeof(device->name));
	list_add_tail(&device->list, &bus->devices);
	device->bus = bus;
	*rdevice = device;
	return 0;
}

EXPORT_SYMBOL(snd_i2c_device_create);

int snd_i2c_device_free(struct snd_i2c_device *device)
{
	if (device->bus)
		list_del(&device->list);
	if (device->private_free)
		device->private_free(device);
	kfree(device);
	return 0;
}

EXPORT_SYMBOL(snd_i2c_device_free);

int snd_i2c_sendbytes(struct snd_i2c_device *device, unsigned char *bytes, int count)
{
	return device->bus->ops->sendbytes(device, bytes, count);
}

EXPORT_SYMBOL(snd_i2c_sendbytes);

int snd_i2c_readbytes(struct snd_i2c_device *device, unsigned char *bytes, int count)
{
	return device->bus->ops->readbytes(device, bytes, count);
}

EXPORT_SYMBOL(snd_i2c_readbytes);

int snd_i2c_probeaddr(struct snd_i2c_bus *bus, unsigned short addr)
{
	return bus->ops->probeaddr(bus, addr);
}

EXPORT_SYMBOL(snd_i2c_probeaddr);

/*
 *  bit-operations
 */

static inline void snd_i2c_bit_hw_start(struct snd_i2c_bus *bus)
{
	if (bus->hw_ops.bit->start)
		bus->hw_ops.bit->start(bus);
}

static inline void snd_i2c_bit_hw_stop(struct snd_i2c_bus *bus)
{
	if (bus->hw_ops.bit->stop)
		bus->hw_ops.bit->stop(bus);
}

static void snd_i2c_bit_direction(struct snd_i2c_bus *bus, int clock, int data)
{
	if (bus->hw_ops.bit->direction)
		bus->hw_ops.bit->direction(bus, clock, data);
}

static void snd_i2c_bit_set(struct snd_i2c_bus *bus, int clock, int data)
{
	bus->hw_ops.bit->setlines(bus, clock, data);
}

#if 0
static int snd_i2c_bit_clock(struct snd_i2c_bus *bus)
{
	if (bus->hw_ops.bit->getclock)
		return bus->hw_ops.bit->getclock(bus);
	return -ENXIO;
}
#endif

static int snd_i2c_bit_data(struct snd_i2c_bus *bus, int ack)
{
	return bus->hw_ops.bit->getdata(bus, ack);
}

static void snd_i2c_bit_start(struct snd_i2c_bus *bus)
{
	snd_i2c_bit_hw_start(bus);
	snd_i2c_bit_direction(bus, 1, 1);	/* SCL - wr, SDA - wr */
	snd_i2c_bit_set(bus, 1, 1);
	snd_i2c_bit_set(bus, 1, 0);
	snd_i2c_bit_set(bus, 0, 0);
}

static void snd_i2c_bit_stop(struct snd_i2c_bus *bus)
{
	snd_i2c_bit_set(bus, 0, 0);
	snd_i2c_bit_set(bus, 1, 0);
	snd_i2c_bit_set(bus, 1, 1);
	snd_i2c_bit_hw_stop(bus);
}

static void snd_i2c_bit_send(struct snd_i2c_bus *bus, int data)
{
	snd_i2c_bit_set(bus, 0, data);
	snd_i2c_bit_set(bus, 1, data);
	snd_i2c_bit_set(bus, 0, data);
}

static int snd_i2c_bit_ack(struct snd_i2c_bus *bus)
{
	int ack;

	snd_i2c_bit_set(bus, 0, 1);
	snd_i2c_bit_set(bus, 1, 1);
	snd_i2c_bit_direction(bus, 1, 0);	/* SCL - wr, SDA - rd */
	ack = snd_i2c_bit_data(bus, 1);
	snd_i2c_bit_direction(bus, 1, 1);	/* SCL - wr, SDA - wr */
	snd_i2c_bit_set(bus, 0, 1);
	return ack ? -EIO : 0;
}

static int snd_i2c_bit_sendbyte(struct snd_i2c_bus *bus, unsigned char data)
{
	int i, err;

	for (i = 7; i >= 0; i--)
		snd_i2c_bit_send(bus, !!(data & (1 << i)));
	if ((err = snd_i2c_bit_ack(bus)) < 0)
		return err;
	return 0;
}

static int snd_i2c_bit_readbyte(struct snd_i2c_bus *bus, int last)
{
	int i;
	unsigned char data = 0;

	snd_i2c_bit_set(bus, 0, 1);
	snd_i2c_bit_direction(bus, 1, 0);	/* SCL - wr, SDA - rd */
	for (i = 7; i >= 0; i--) {
		snd_i2c_bit_set(bus, 1, 1);
		if (snd_i2c_bit_data(bus, 0))
			data |= (1 << i);
		snd_i2c_bit_set(bus, 0, 1);
	}
	snd_i2c_bit_direction(bus, 1, 1);	/* SCL - wr, SDA - wr */
	snd_i2c_bit_send(bus, !!last);
	return data;
}

static int snd_i2c_bit_sendbytes(struct snd_i2c_device *device,
				 unsigned char *bytes, int count)
{
	struct snd_i2c_bus *bus = device->bus;
	int err, res = 0;

	if (device->flags & SND_I2C_DEVICE_ADDRTEN)
		return -EIO;		/* not yet implemented */
	snd_i2c_bit_start(bus);
	if ((err = snd_i2c_bit_sendbyte(bus, device->addr << 1)) < 0) {
		snd_i2c_bit_hw_stop(bus);
		return err;
	}
	while (count-- > 0) {
		if ((err = snd_i2c_bit_sendbyte(bus, *bytes++)) < 0) {
			snd_i2c_bit_hw_stop(bus);
			return err;
		}
		res++;
	}
	snd_i2c_bit_stop(bus);
	return res;
}

static int snd_i2c_bit_readbytes(struct snd_i2c_device *device,
				 unsigned char *bytes, int count)
{
	struct snd_i2c_bus *bus = device->bus;
	int err, res = 0;

	if (device->flags & SND_I2C_DEVICE_ADDRTEN)
		return -EIO;		/* not yet implemented */
	snd_i2c_bit_start(bus);
	if ((err = snd_i2c_bit_sendbyte(bus, (device->addr << 1) | 1)) < 0) {
		snd_i2c_bit_hw_stop(bus);
		return err;
	}
	while (count-- > 0) {
		if ((err = snd_i2c_bit_readbyte(bus, count == 0)) < 0) {
			snd_i2c_bit_hw_stop(bus);
			return err;
		}
		*bytes++ = (unsigned char)err;
		res++;
	}
	snd_i2c_bit_stop(bus);
	return res;
}

static int snd_i2c_bit_probeaddr(struct snd_i2c_bus *bus, unsigned short addr)
{
	int err;

	if (addr & 0x8000)	/* 10-bit address */
		return -EIO;	/* not yet implemented */
	if (addr & 0x7f80)	/* invalid address */
		return -EINVAL;
	snd_i2c_bit_start(bus);
	err = snd_i2c_bit_sendbyte(bus, addr << 1);
	snd_i2c_bit_stop(bus);
	return err;
}


static int __init alsa_i2c_init(void)
{
	return 0;
}

static void __exit alsa_i2c_exit(void)
{
}

module_init(alsa_i2c_init)
module_exit(alsa_i2c_exit)
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Generic i2c interface for ALSA
	3	*
	4	* (c) 1998 Gerd Knorr <kraxel@cs.tu-berlin.de>
c1017a4c	5	* Modified for the ALSA driver by Jaroslav Kysela <perex@perex.cz>
1da177e4 LT	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License as published by
	9	* the Free Software Foundation; either version 2 of the License, or
	10	* (at your option) any later version.
	11	*
	12	* This program is distributed in the hope that it will be useful,
	13	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	* GNU General Public License for more details.
	16	*
	17	* You should have received a copy of the GNU General Public License
	18	* along with this program; if not, write to the Free Software
	19	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	20	*
	21	*/
	22
1da177e4 LT	23	#include <linux/init.h>
	24	#include <linux/slab.h>
	25	#include <linux/string.h>
	26	#include <linux/errno.h>
	27	#include <sound/core.h>
	28	#include <sound/i2c.h>
	29
c1017a4c	30	MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
1da177e4 LT	31	MODULE_DESCRIPTION("Generic i2c interface for ALSA");
	32	MODULE_LICENSE("GPL");
	33
97f02e05 TI	34	static int snd_i2c_bit_sendbytes(struct snd_i2c_device *device,
	35	unsigned char *bytes, int count);
	36	static int snd_i2c_bit_readbytes(struct snd_i2c_device *device,
	37	unsigned char *bytes, int count);
	38	static int snd_i2c_bit_probeaddr(struct snd_i2c_bus *bus,
	39	unsigned short addr);
	40
	41	static struct snd_i2c_ops snd_i2c_bit_ops = {
1da177e4 LT	42	.sendbytes = snd_i2c_bit_sendbytes,
	43	.readbytes = snd_i2c_bit_readbytes,
	44	.probeaddr = snd_i2c_bit_probeaddr,
	45	};
	46
97f02e05	47	static int snd_i2c_bus_free(struct snd_i2c_bus *bus)
1da177e4	48	{
97f02e05 TI	49	struct snd_i2c_bus *slave;
97f02e05 TI	50	struct snd_i2c_device *device;
1da177e4	51
5e246b85 TI	52	if (snd_BUG_ON(!bus))
5e246b85 TI	53	return -EINVAL;
1da177e4 LT	54	while (!list_empty(&bus->devices)) {
	55	device = snd_i2c_device(bus->devices.next);
	56	snd_i2c_device_free(device);
	57	}
	58	if (bus->master)
	59	list_del(&bus->buses);
	60	else {
	61	while (!list_empty(&bus->buses)) {
	62	slave = snd_i2c_slave_bus(bus->buses.next);
	63	snd_device_free(bus->card, slave);
	64	}
	65	}
	66	if (bus->private_free)
	67	bus->private_free(bus);
	68	kfree(bus);
	69	return 0;
	70	}
	71
97f02e05	72	static int snd_i2c_bus_dev_free(struct snd_device *device)
1da177e4	73	{
97f02e05	74	struct snd_i2c_bus *bus = device->device_data;
1da177e4 LT	75	return snd_i2c_bus_free(bus);
	76	}
	77
97f02e05 TI	78	int snd_i2c_bus_create(struct snd_card card, const char name,
97f02e05 TI	79	struct snd_i2c_bus master, struct snd_i2c_bus *ri2c)
1da177e4	80	{
97f02e05	81	struct snd_i2c_bus *bus;
1da177e4	82	int err;
97f02e05	83	static struct snd_device_ops ops = {
1da177e4 LT	84	.dev_free = snd_i2c_bus_dev_free,
	85	};
	86
	87	*ri2c = NULL;
561b220a	88	bus = kzalloc(sizeof(*bus), GFP_KERNEL);
1da177e4 LT	89	if (bus == NULL)
1da177e4 LT	90	return -ENOMEM;
ef9f0a42	91	mutex_init(&bus->lock_mutex);
1da177e4 LT	92	INIT_LIST_HEAD(&bus->devices);
	93	INIT_LIST_HEAD(&bus->buses);
	94	bus->card = card;
	95	bus->ops = &snd_i2c_bit_ops;
	96	if (master) {
	97	list_add_tail(&bus->buses, &master->buses);
	98	bus->master = master;
	99	}
	100	strlcpy(bus->name, name, sizeof(bus->name));
	101	if ((err = snd_device_new(card, SNDRV_DEV_BUS, bus, &ops)) < 0) {
	102	snd_i2c_bus_free(bus);
	103	return err;
	104	}
	105	*ri2c = bus;
	106	return 0;
	107	}
	108
57c65c11 TI	109	EXPORT_SYMBOL(snd_i2c_bus_create);
57c65c11 TI	110
97f02e05 TI	111	int snd_i2c_device_create(struct snd_i2c_bus bus, const char name,
97f02e05 TI	112	unsigned char addr, struct snd_i2c_device **rdevice)
1da177e4	113	{
97f02e05	114	struct snd_i2c_device *device;
1da177e4 LT	115
1da177e4 LT	116	*rdevice = NULL;
5e246b85 TI	117	if (snd_BUG_ON(!bus))
5e246b85 TI	118	return -EINVAL;
561b220a	119	device = kzalloc(sizeof(*device), GFP_KERNEL);
1da177e4 LT	120	if (device == NULL)
	121	return -ENOMEM;
	122	device->addr = addr;
	123	strlcpy(device->name, name, sizeof(device->name));
	124	list_add_tail(&device->list, &bus->devices);
	125	device->bus = bus;
	126	*rdevice = device;
	127	return 0;
	128	}
	129
57c65c11 TI	130	EXPORT_SYMBOL(snd_i2c_device_create);
57c65c11 TI	131
97f02e05	132	int snd_i2c_device_free(struct snd_i2c_device *device)
1da177e4 LT	133	{
	134	if (device->bus)
	135	list_del(&device->list);
	136	if (device->private_free)
	137	device->private_free(device);
	138	kfree(device);
	139	return 0;
	140	}
	141
57c65c11 TI	142	EXPORT_SYMBOL(snd_i2c_device_free);
57c65c11 TI	143
97f02e05	144	int snd_i2c_sendbytes(struct snd_i2c_device device, unsigned char bytes, int count)
1da177e4 LT	145	{
	146	return device->bus->ops->sendbytes(device, bytes, count);
	147	}
	148
57c65c11	149	EXPORT_SYMBOL(snd_i2c_sendbytes);
1da177e4	150
97f02e05	151	int snd_i2c_readbytes(struct snd_i2c_device device, unsigned char bytes, int count)
1da177e4 LT	152	{
	153	return device->bus->ops->readbytes(device, bytes, count);
	154	}
	155
57c65c11 TI	156	EXPORT_SYMBOL(snd_i2c_readbytes);
57c65c11 TI	157
97f02e05	158	int snd_i2c_probeaddr(struct snd_i2c_bus *bus, unsigned short addr)
1da177e4 LT	159	{
	160	return bus->ops->probeaddr(bus, addr);
	161	}
	162
57c65c11 TI	163	EXPORT_SYMBOL(snd_i2c_probeaddr);
57c65c11 TI	164
1da177e4 LT	165	/*
	166	* bit-operations
	167	*/
	168
97f02e05	169	static inline void snd_i2c_bit_hw_start(struct snd_i2c_bus *bus)
1da177e4 LT	170	{
	171	if (bus->hw_ops.bit->start)
	172	bus->hw_ops.bit->start(bus);
	173	}
	174
97f02e05	175	static inline void snd_i2c_bit_hw_stop(struct snd_i2c_bus *bus)
1da177e4 LT	176	{
	177	if (bus->hw_ops.bit->stop)
	178	bus->hw_ops.bit->stop(bus);
	179	}
	180
97f02e05	181	static void snd_i2c_bit_direction(struct snd_i2c_bus *bus, int clock, int data)
1da177e4 LT	182	{
	183	if (bus->hw_ops.bit->direction)
	184	bus->hw_ops.bit->direction(bus, clock, data);
	185	}
	186
97f02e05	187	static void snd_i2c_bit_set(struct snd_i2c_bus *bus, int clock, int data)
1da177e4 LT	188	{
	189	bus->hw_ops.bit->setlines(bus, clock, data);
	190	}
	191
	192	#if 0
97f02e05	193	static int snd_i2c_bit_clock(struct snd_i2c_bus *bus)
1da177e4 LT	194	{
	195	if (bus->hw_ops.bit->getclock)
	196	return bus->hw_ops.bit->getclock(bus);
	197	return -ENXIO;
	198	}
	199	#endif
	200
97f02e05	201	static int snd_i2c_bit_data(struct snd_i2c_bus *bus, int ack)
1da177e4 LT	202	{
	203	return bus->hw_ops.bit->getdata(bus, ack);
	204	}
	205
97f02e05	206	static void snd_i2c_bit_start(struct snd_i2c_bus *bus)
1da177e4 LT	207	{
	208	snd_i2c_bit_hw_start(bus);
	209	snd_i2c_bit_direction(bus, 1, 1); /* SCL - wr, SDA - wr */
	210	snd_i2c_bit_set(bus, 1, 1);
	211	snd_i2c_bit_set(bus, 1, 0);
	212	snd_i2c_bit_set(bus, 0, 0);
	213	}
	214
97f02e05	215	static void snd_i2c_bit_stop(struct snd_i2c_bus *bus)
1da177e4 LT	216	{
	217	snd_i2c_bit_set(bus, 0, 0);
	218	snd_i2c_bit_set(bus, 1, 0);
	219	snd_i2c_bit_set(bus, 1, 1);
	220	snd_i2c_bit_hw_stop(bus);
	221	}
	222
97f02e05	223	static void snd_i2c_bit_send(struct snd_i2c_bus *bus, int data)
1da177e4 LT	224	{
	225	snd_i2c_bit_set(bus, 0, data);
	226	snd_i2c_bit_set(bus, 1, data);
	227	snd_i2c_bit_set(bus, 0, data);
	228	}
	229
97f02e05	230	static int snd_i2c_bit_ack(struct snd_i2c_bus *bus)
1da177e4 LT	231	{
	232	int ack;
	233
	234	snd_i2c_bit_set(bus, 0, 1);
	235	snd_i2c_bit_set(bus, 1, 1);
	236	snd_i2c_bit_direction(bus, 1, 0); /* SCL - wr, SDA - rd */
	237	ack = snd_i2c_bit_data(bus, 1);
	238	snd_i2c_bit_direction(bus, 1, 1); /* SCL - wr, SDA - wr */
	239	snd_i2c_bit_set(bus, 0, 1);
	240	return ack ? -EIO : 0;
	241	}
	242
97f02e05	243	static int snd_i2c_bit_sendbyte(struct snd_i2c_bus *bus, unsigned char data)
1da177e4 LT	244	{
	245	int i, err;
	246
	247	for (i = 7; i >= 0; i--)
	248	snd_i2c_bit_send(bus, !!(data & (1 << i)));
	249	if ((err = snd_i2c_bit_ack(bus)) < 0)
	250	return err;
	251	return 0;
	252	}
	253
97f02e05	254	static int snd_i2c_bit_readbyte(struct snd_i2c_bus *bus, int last)
1da177e4 LT	255	{
	256	int i;
	257	unsigned char data = 0;
	258
	259	snd_i2c_bit_set(bus, 0, 1);
	260	snd_i2c_bit_direction(bus, 1, 0); /* SCL - wr, SDA - rd */
	261	for (i = 7; i >= 0; i--) {
	262	snd_i2c_bit_set(bus, 1, 1);
	263	if (snd_i2c_bit_data(bus, 0))
	264	data \|= (1 << i);
	265	snd_i2c_bit_set(bus, 0, 1);
	266	}
	267	snd_i2c_bit_direction(bus, 1, 1); /* SCL - wr, SDA - wr */
	268	snd_i2c_bit_send(bus, !!last);
	269	return data;
	270	}
	271
97f02e05 TI	272	static int snd_i2c_bit_sendbytes(struct snd_i2c_device *device,
97f02e05 TI	273	unsigned char *bytes, int count)
1da177e4	274	{
97f02e05	275	struct snd_i2c_bus *bus = device->bus;
1da177e4 LT	276	int err, res = 0;
	277
	278	if (device->flags & SND_I2C_DEVICE_ADDRTEN)
	279	return -EIO; /* not yet implemented */
	280	snd_i2c_bit_start(bus);
	281	if ((err = snd_i2c_bit_sendbyte(bus, device->addr << 1)) < 0) {
	282	snd_i2c_bit_hw_stop(bus);
	283	return err;
	284	}
	285	while (count-- > 0) {
	286	if ((err = snd_i2c_bit_sendbyte(bus, *bytes++)) < 0) {
	287	snd_i2c_bit_hw_stop(bus);
	288	return err;
	289	}
	290	res++;
	291	}
	292	snd_i2c_bit_stop(bus);
	293	return res;
	294	}
	295
97f02e05 TI	296	static int snd_i2c_bit_readbytes(struct snd_i2c_device *device,
97f02e05 TI	297	unsigned char *bytes, int count)
1da177e4	298	{
97f02e05	299	struct snd_i2c_bus *bus = device->bus;
1da177e4 LT	300	int err, res = 0;
	301
	302	if (device->flags & SND_I2C_DEVICE_ADDRTEN)
	303	return -EIO; /* not yet implemented */
	304	snd_i2c_bit_start(bus);
	305	if ((err = snd_i2c_bit_sendbyte(bus, (device->addr << 1) \| 1)) < 0) {
	306	snd_i2c_bit_hw_stop(bus);
	307	return err;
	308	}
	309	while (count-- > 0) {
	310	if ((err = snd_i2c_bit_readbyte(bus, count == 0)) < 0) {
	311	snd_i2c_bit_hw_stop(bus);
	312	return err;
	313	}
	314	*bytes++ = (unsigned char)err;
	315	res++;
	316	}
	317	snd_i2c_bit_stop(bus);
	318	return res;
	319	}
	320
97f02e05	321	static int snd_i2c_bit_probeaddr(struct snd_i2c_bus *bus, unsigned short addr)
1da177e4 LT	322	{
	323	int err;
	324
	325	if (addr & 0x8000) /* 10-bit address */
	326	return -EIO; /* not yet implemented */
	327	if (addr & 0x7f80) /* invalid address */
	328	return -EINVAL;
	329	snd_i2c_bit_start(bus);
	330	err = snd_i2c_bit_sendbyte(bus, addr << 1);
	331	snd_i2c_bit_stop(bus);
	332	return err;
	333	}
	334
1da177e4 LT	335
	336	static int __init alsa_i2c_init(void)
	337	{
	338	return 0;
	339	}
	340
	341	static void __exit alsa_i2c_exit(void)
	342	{
	343	}
	344
	345	module_init(alsa_i2c_init)
	346	module_exit(alsa_i2c_exit)