[GitHub/mt8127/android_kernel_alcatel_ttab.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 <sound/driver.h>
#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;

	snd_assert(bus != NULL, 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;
	snd_assert(bus != NULL, 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
	23	#include <sound/driver.h>
	24	#include <linux/init.h>
	25	#include <linux/slab.h>
	26	#include <linux/string.h>
	27	#include <linux/errno.h>
	28	#include <sound/core.h>
	29	#include <sound/i2c.h>
	30
c1017a4c	31	MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
1da177e4 LT	32	MODULE_DESCRIPTION("Generic i2c interface for ALSA");
	33	MODULE_LICENSE("GPL");
	34
97f02e05 TI	35	static int snd_i2c_bit_sendbytes(struct snd_i2c_device *device,
	36	unsigned char *bytes, int count);
	37	static int snd_i2c_bit_readbytes(struct snd_i2c_device *device,
	38	unsigned char *bytes, int count);
	39	static int snd_i2c_bit_probeaddr(struct snd_i2c_bus *bus,
	40	unsigned short addr);
	41
	42	static struct snd_i2c_ops snd_i2c_bit_ops = {
1da177e4 LT	43	.sendbytes = snd_i2c_bit_sendbytes,
	44	.readbytes = snd_i2c_bit_readbytes,
	45	.probeaddr = snd_i2c_bit_probeaddr,
	46	};
	47
97f02e05	48	static int snd_i2c_bus_free(struct snd_i2c_bus *bus)
1da177e4	49	{
97f02e05 TI	50	struct snd_i2c_bus *slave;
97f02e05 TI	51	struct snd_i2c_device *device;
1da177e4 LT	52
	53	snd_assert(bus != NULL, return -EINVAL);
	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
	116	*rdevice = NULL;
	117	snd_assert(bus != NULL, return -EINVAL);
561b220a	118	device = kzalloc(sizeof(*device), GFP_KERNEL);
1da177e4 LT	119	if (device == NULL)
	120	return -ENOMEM;
	121	device->addr = addr;
	122	strlcpy(device->name, name, sizeof(device->name));
	123	list_add_tail(&device->list, &bus->devices);
	124	device->bus = bus;
	125	*rdevice = device;
	126	return 0;
	127	}
	128
57c65c11 TI	129	EXPORT_SYMBOL(snd_i2c_device_create);
57c65c11 TI	130
97f02e05	131	int snd_i2c_device_free(struct snd_i2c_device *device)
1da177e4 LT	132	{
	133	if (device->bus)
	134	list_del(&device->list);
	135	if (device->private_free)
	136	device->private_free(device);
	137	kfree(device);
	138	return 0;
	139	}
	140
57c65c11 TI	141	EXPORT_SYMBOL(snd_i2c_device_free);
57c65c11 TI	142
97f02e05	143	int snd_i2c_sendbytes(struct snd_i2c_device device, unsigned char bytes, int count)
1da177e4 LT	144	{
	145	return device->bus->ops->sendbytes(device, bytes, count);
	146	}
	147
57c65c11	148	EXPORT_SYMBOL(snd_i2c_sendbytes);
1da177e4	149
97f02e05	150	int snd_i2c_readbytes(struct snd_i2c_device device, unsigned char bytes, int count)
1da177e4 LT	151	{
	152	return device->bus->ops->readbytes(device, bytes, count);
	153	}
	154
57c65c11 TI	155	EXPORT_SYMBOL(snd_i2c_readbytes);
57c65c11 TI	156
97f02e05	157	int snd_i2c_probeaddr(struct snd_i2c_bus *bus, unsigned short addr)
1da177e4 LT	158	{
	159	return bus->ops->probeaddr(bus, addr);
	160	}
	161
57c65c11 TI	162	EXPORT_SYMBOL(snd_i2c_probeaddr);
57c65c11 TI	163
1da177e4 LT	164	/*
	165	* bit-operations
	166	*/
	167
97f02e05	168	static inline void snd_i2c_bit_hw_start(struct snd_i2c_bus *bus)
1da177e4 LT	169	{
	170	if (bus->hw_ops.bit->start)
	171	bus->hw_ops.bit->start(bus);
	172	}
	173
97f02e05	174	static inline void snd_i2c_bit_hw_stop(struct snd_i2c_bus *bus)
1da177e4 LT	175	{
	176	if (bus->hw_ops.bit->stop)
	177	bus->hw_ops.bit->stop(bus);
	178	}
	179
97f02e05	180	static void snd_i2c_bit_direction(struct snd_i2c_bus *bus, int clock, int data)
1da177e4 LT	181	{
	182	if (bus->hw_ops.bit->direction)
	183	bus->hw_ops.bit->direction(bus, clock, data);
	184	}
	185
97f02e05	186	static void snd_i2c_bit_set(struct snd_i2c_bus *bus, int clock, int data)
1da177e4 LT	187	{
	188	bus->hw_ops.bit->setlines(bus, clock, data);
	189	}
	190
	191	#if 0
97f02e05	192	static int snd_i2c_bit_clock(struct snd_i2c_bus *bus)
1da177e4 LT	193	{
	194	if (bus->hw_ops.bit->getclock)
	195	return bus->hw_ops.bit->getclock(bus);
	196	return -ENXIO;
	197	}
	198	#endif
	199
97f02e05	200	static int snd_i2c_bit_data(struct snd_i2c_bus *bus, int ack)
1da177e4 LT	201	{
	202	return bus->hw_ops.bit->getdata(bus, ack);
	203	}
	204
97f02e05	205	static void snd_i2c_bit_start(struct snd_i2c_bus *bus)
1da177e4 LT	206	{
	207	snd_i2c_bit_hw_start(bus);
	208	snd_i2c_bit_direction(bus, 1, 1); /* SCL - wr, SDA - wr */
	209	snd_i2c_bit_set(bus, 1, 1);
	210	snd_i2c_bit_set(bus, 1, 0);
	211	snd_i2c_bit_set(bus, 0, 0);
	212	}
	213
97f02e05	214	static void snd_i2c_bit_stop(struct snd_i2c_bus *bus)
1da177e4 LT	215	{
	216	snd_i2c_bit_set(bus, 0, 0);
	217	snd_i2c_bit_set(bus, 1, 0);
	218	snd_i2c_bit_set(bus, 1, 1);
	219	snd_i2c_bit_hw_stop(bus);
	220	}
	221
97f02e05	222	static void snd_i2c_bit_send(struct snd_i2c_bus *bus, int data)
1da177e4 LT	223	{
	224	snd_i2c_bit_set(bus, 0, data);
	225	snd_i2c_bit_set(bus, 1, data);
	226	snd_i2c_bit_set(bus, 0, data);
	227	}
	228
97f02e05	229	static int snd_i2c_bit_ack(struct snd_i2c_bus *bus)
1da177e4 LT	230	{
	231	int ack;
	232
	233	snd_i2c_bit_set(bus, 0, 1);
	234	snd_i2c_bit_set(bus, 1, 1);
	235	snd_i2c_bit_direction(bus, 1, 0); /* SCL - wr, SDA - rd */
	236	ack = snd_i2c_bit_data(bus, 1);
	237	snd_i2c_bit_direction(bus, 1, 1); /* SCL - wr, SDA - wr */
	238	snd_i2c_bit_set(bus, 0, 1);
	239	return ack ? -EIO : 0;
	240	}
	241
97f02e05	242	static int snd_i2c_bit_sendbyte(struct snd_i2c_bus *bus, unsigned char data)
1da177e4 LT	243	{
	244	int i, err;
	245
	246	for (i = 7; i >= 0; i--)
	247	snd_i2c_bit_send(bus, !!(data & (1 << i)));
	248	if ((err = snd_i2c_bit_ack(bus)) < 0)
	249	return err;
	250	return 0;
	251	}
	252
97f02e05	253	static int snd_i2c_bit_readbyte(struct snd_i2c_bus *bus, int last)
1da177e4 LT	254	{
	255	int i;
	256	unsigned char data = 0;
	257
	258	snd_i2c_bit_set(bus, 0, 1);
	259	snd_i2c_bit_direction(bus, 1, 0); /* SCL - wr, SDA - rd */
	260	for (i = 7; i >= 0; i--) {
	261	snd_i2c_bit_set(bus, 1, 1);
	262	if (snd_i2c_bit_data(bus, 0))
	263	data \|= (1 << i);
	264	snd_i2c_bit_set(bus, 0, 1);
	265	}
	266	snd_i2c_bit_direction(bus, 1, 1); /* SCL - wr, SDA - wr */
	267	snd_i2c_bit_send(bus, !!last);
	268	return data;
	269	}
	270
97f02e05 TI	271	static int snd_i2c_bit_sendbytes(struct snd_i2c_device *device,
97f02e05 TI	272	unsigned char *bytes, int count)
1da177e4	273	{
97f02e05	274	struct snd_i2c_bus *bus = device->bus;
1da177e4 LT	275	int err, res = 0;
	276
	277	if (device->flags & SND_I2C_DEVICE_ADDRTEN)
	278	return -EIO; /* not yet implemented */
	279	snd_i2c_bit_start(bus);
	280	if ((err = snd_i2c_bit_sendbyte(bus, device->addr << 1)) < 0) {
	281	snd_i2c_bit_hw_stop(bus);
	282	return err;
	283	}
	284	while (count-- > 0) {
	285	if ((err = snd_i2c_bit_sendbyte(bus, *bytes++)) < 0) {
	286	snd_i2c_bit_hw_stop(bus);
	287	return err;
	288	}
	289	res++;
	290	}
	291	snd_i2c_bit_stop(bus);
	292	return res;
	293	}
	294
97f02e05 TI	295	static int snd_i2c_bit_readbytes(struct snd_i2c_device *device,
97f02e05 TI	296	unsigned char *bytes, int count)
1da177e4	297	{
97f02e05	298	struct snd_i2c_bus *bus = device->bus;
1da177e4 LT	299	int err, res = 0;
	300
	301	if (device->flags & SND_I2C_DEVICE_ADDRTEN)
	302	return -EIO; /* not yet implemented */
	303	snd_i2c_bit_start(bus);
	304	if ((err = snd_i2c_bit_sendbyte(bus, (device->addr << 1) \| 1)) < 0) {
	305	snd_i2c_bit_hw_stop(bus);
	306	return err;
	307	}
	308	while (count-- > 0) {
	309	if ((err = snd_i2c_bit_readbyte(bus, count == 0)) < 0) {
	310	snd_i2c_bit_hw_stop(bus);
	311	return err;
	312	}
	313	*bytes++ = (unsigned char)err;
	314	res++;
	315	}
	316	snd_i2c_bit_stop(bus);
	317	return res;
	318	}
	319
97f02e05	320	static int snd_i2c_bit_probeaddr(struct snd_i2c_bus *bus, unsigned short addr)
1da177e4 LT	321	{
	322	int err;
	323
	324	if (addr & 0x8000) /* 10-bit address */
	325	return -EIO; /* not yet implemented */
	326	if (addr & 0x7f80) /* invalid address */
	327	return -EINVAL;
	328	snd_i2c_bit_start(bus);
	329	err = snd_i2c_bit_sendbyte(bus, addr << 1);
	330	snd_i2c_bit_stop(bus);
	331	return err;
	332	}
	333
1da177e4 LT	334
	335	static int __init alsa_i2c_init(void)
	336	{
	337	return 0;
	338	}
	339
	340	static void __exit alsa_i2c_exit(void)
	341	{
	342	}
	343
	344	module_init(alsa_i2c_init)
	345	module_exit(alsa_i2c_exit)