[mirror_ubuntu-bionic-kernel.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/module.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 const 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));
	err = snd_device_new(card, SNDRV_DEV_BUS, bus, &ops);
	if (err < 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)));
	err = snd_i2c_bit_ack(bus);
	if (err < 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);
	err = snd_i2c_bit_sendbyte(bus, device->addr << 1);
	if (err < 0) {
		snd_i2c_bit_hw_stop(bus);
		return err;
	}
	while (count-- > 0) {
		err = snd_i2c_bit_sendbyte(bus, *bytes++);
		if (err < 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);
	err = snd_i2c_bit_sendbyte(bus, (device->addr << 1) | 1);
	if (err < 0) {
		snd_i2c_bit_hw_stop(bus);
		return err;
	}
	while (count-- > 0) {
		err = snd_i2c_bit_readbyte(bus, count == 0);
		if (err < 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>
1da177e4 LT	24	#include <linux/slab.h>
da155d5b	25	#include <linux/module.h>
1da177e4 LT	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
5df29bca	42	static const 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	52
5e246b85 TI	53	if (snd_BUG_ON(!bus))
5e246b85 TI	54	return -EINVAL;
1da177e4 LT	55	while (!list_empty(&bus->devices)) {
	56	device = snd_i2c_device(bus->devices.next);
	57	snd_i2c_device_free(device);
	58	}
	59	if (bus->master)
	60	list_del(&bus->buses);
	61	else {
	62	while (!list_empty(&bus->buses)) {
	63	slave = snd_i2c_slave_bus(bus->buses.next);
	64	snd_device_free(bus->card, slave);
	65	}
	66	}
	67	if (bus->private_free)
	68	bus->private_free(bus);
	69	kfree(bus);
	70	return 0;
	71	}
	72
97f02e05	73	static int snd_i2c_bus_dev_free(struct snd_device *device)
1da177e4	74	{
97f02e05	75	struct snd_i2c_bus *bus = device->device_data;
1da177e4 LT	76	return snd_i2c_bus_free(bus);
	77	}
	78
97f02e05 TI	79	int snd_i2c_bus_create(struct snd_card card, const char name,
97f02e05 TI	80	struct snd_i2c_bus master, struct snd_i2c_bus *ri2c)
1da177e4	81	{
97f02e05	82	struct snd_i2c_bus *bus;
1da177e4	83	int err;
97f02e05	84	static struct snd_device_ops ops = {
1da177e4 LT	85	.dev_free = snd_i2c_bus_dev_free,
	86	};
	87
	88	*ri2c = NULL;
561b220a	89	bus = kzalloc(sizeof(*bus), GFP_KERNEL);
1da177e4 LT	90	if (bus == NULL)
1da177e4 LT	91	return -ENOMEM;
ef9f0a42	92	mutex_init(&bus->lock_mutex);
1da177e4 LT	93	INIT_LIST_HEAD(&bus->devices);
	94	INIT_LIST_HEAD(&bus->buses);
	95	bus->card = card;
	96	bus->ops = &snd_i2c_bit_ops;
	97	if (master) {
	98	list_add_tail(&bus->buses, &master->buses);
	99	bus->master = master;
	100	}
	101	strlcpy(bus->name, name, sizeof(bus->name));
1cff399e BW	102	err = snd_device_new(card, SNDRV_DEV_BUS, bus, &ops);
1cff399e BW	103	if (err < 0) {
1da177e4 LT	104	snd_i2c_bus_free(bus);
	105	return err;
	106	}
	107	*ri2c = bus;
	108	return 0;
	109	}
	110
57c65c11 TI	111	EXPORT_SYMBOL(snd_i2c_bus_create);
57c65c11 TI	112
97f02e05 TI	113	int snd_i2c_device_create(struct snd_i2c_bus bus, const char name,
97f02e05 TI	114	unsigned char addr, struct snd_i2c_device **rdevice)
1da177e4	115	{
97f02e05	116	struct snd_i2c_device *device;
1da177e4 LT	117
1da177e4 LT	118	*rdevice = NULL;
5e246b85 TI	119	if (snd_BUG_ON(!bus))
5e246b85 TI	120	return -EINVAL;
561b220a	121	device = kzalloc(sizeof(*device), GFP_KERNEL);
1da177e4 LT	122	if (device == NULL)
	123	return -ENOMEM;
	124	device->addr = addr;
	125	strlcpy(device->name, name, sizeof(device->name));
	126	list_add_tail(&device->list, &bus->devices);
	127	device->bus = bus;
	128	*rdevice = device;
	129	return 0;
	130	}
	131
57c65c11 TI	132	EXPORT_SYMBOL(snd_i2c_device_create);
57c65c11 TI	133
97f02e05	134	int snd_i2c_device_free(struct snd_i2c_device *device)
1da177e4 LT	135	{
	136	if (device->bus)
	137	list_del(&device->list);
	138	if (device->private_free)
	139	device->private_free(device);
	140	kfree(device);
	141	return 0;
	142	}
	143
57c65c11 TI	144	EXPORT_SYMBOL(snd_i2c_device_free);
57c65c11 TI	145
97f02e05	146	int snd_i2c_sendbytes(struct snd_i2c_device device, unsigned char bytes, int count)
1da177e4 LT	147	{
	148	return device->bus->ops->sendbytes(device, bytes, count);
	149	}
	150
57c65c11	151	EXPORT_SYMBOL(snd_i2c_sendbytes);
1da177e4	152
97f02e05	153	int snd_i2c_readbytes(struct snd_i2c_device device, unsigned char bytes, int count)
1da177e4 LT	154	{
	155	return device->bus->ops->readbytes(device, bytes, count);
	156	}
	157
57c65c11 TI	158	EXPORT_SYMBOL(snd_i2c_readbytes);
57c65c11 TI	159
97f02e05	160	int snd_i2c_probeaddr(struct snd_i2c_bus *bus, unsigned short addr)
1da177e4 LT	161	{
	162	return bus->ops->probeaddr(bus, addr);
	163	}
	164
57c65c11 TI	165	EXPORT_SYMBOL(snd_i2c_probeaddr);
57c65c11 TI	166
1da177e4 LT	167	/*
	168	* bit-operations
	169	*/
	170
97f02e05	171	static inline void snd_i2c_bit_hw_start(struct snd_i2c_bus *bus)
1da177e4 LT	172	{
	173	if (bus->hw_ops.bit->start)
	174	bus->hw_ops.bit->start(bus);
	175	}
	176
97f02e05	177	static inline void snd_i2c_bit_hw_stop(struct snd_i2c_bus *bus)
1da177e4 LT	178	{
	179	if (bus->hw_ops.bit->stop)
	180	bus->hw_ops.bit->stop(bus);
	181	}
	182
97f02e05	183	static void snd_i2c_bit_direction(struct snd_i2c_bus *bus, int clock, int data)
1da177e4 LT	184	{
	185	if (bus->hw_ops.bit->direction)
	186	bus->hw_ops.bit->direction(bus, clock, data);
	187	}
	188
97f02e05	189	static void snd_i2c_bit_set(struct snd_i2c_bus *bus, int clock, int data)
1da177e4 LT	190	{
	191	bus->hw_ops.bit->setlines(bus, clock, data);
	192	}
	193
	194	#if 0
97f02e05	195	static int snd_i2c_bit_clock(struct snd_i2c_bus *bus)
1da177e4 LT	196	{
	197	if (bus->hw_ops.bit->getclock)
	198	return bus->hw_ops.bit->getclock(bus);
	199	return -ENXIO;
	200	}
	201	#endif
	202
97f02e05	203	static int snd_i2c_bit_data(struct snd_i2c_bus *bus, int ack)
1da177e4 LT	204	{
	205	return bus->hw_ops.bit->getdata(bus, ack);
	206	}
	207
97f02e05	208	static void snd_i2c_bit_start(struct snd_i2c_bus *bus)
1da177e4 LT	209	{
	210	snd_i2c_bit_hw_start(bus);
	211	snd_i2c_bit_direction(bus, 1, 1); /* SCL - wr, SDA - wr */
	212	snd_i2c_bit_set(bus, 1, 1);
	213	snd_i2c_bit_set(bus, 1, 0);
	214	snd_i2c_bit_set(bus, 0, 0);
	215	}
	216
97f02e05	217	static void snd_i2c_bit_stop(struct snd_i2c_bus *bus)
1da177e4 LT	218	{
	219	snd_i2c_bit_set(bus, 0, 0);
	220	snd_i2c_bit_set(bus, 1, 0);
	221	snd_i2c_bit_set(bus, 1, 1);
	222	snd_i2c_bit_hw_stop(bus);
	223	}
	224
97f02e05	225	static void snd_i2c_bit_send(struct snd_i2c_bus *bus, int data)
1da177e4 LT	226	{
	227	snd_i2c_bit_set(bus, 0, data);
	228	snd_i2c_bit_set(bus, 1, data);
	229	snd_i2c_bit_set(bus, 0, data);
	230	}
	231
97f02e05	232	static int snd_i2c_bit_ack(struct snd_i2c_bus *bus)
1da177e4 LT	233	{
	234	int ack;
	235
	236	snd_i2c_bit_set(bus, 0, 1);
	237	snd_i2c_bit_set(bus, 1, 1);
	238	snd_i2c_bit_direction(bus, 1, 0); /* SCL - wr, SDA - rd */
	239	ack = snd_i2c_bit_data(bus, 1);
	240	snd_i2c_bit_direction(bus, 1, 1); /* SCL - wr, SDA - wr */
	241	snd_i2c_bit_set(bus, 0, 1);
	242	return ack ? -EIO : 0;
	243	}
	244
97f02e05	245	static int snd_i2c_bit_sendbyte(struct snd_i2c_bus *bus, unsigned char data)
1da177e4 LT	246	{
	247	int i, err;
	248
	249	for (i = 7; i >= 0; i--)
	250	snd_i2c_bit_send(bus, !!(data & (1 << i)));
1cff399e BW	251	err = snd_i2c_bit_ack(bus);
1cff399e BW	252	if (err < 0)
1da177e4 LT	253	return err;
	254	return 0;
	255	}
	256
97f02e05	257	static int snd_i2c_bit_readbyte(struct snd_i2c_bus *bus, int last)
1da177e4 LT	258	{
	259	int i;
	260	unsigned char data = 0;
	261
	262	snd_i2c_bit_set(bus, 0, 1);
	263	snd_i2c_bit_direction(bus, 1, 0); /* SCL - wr, SDA - rd */
	264	for (i = 7; i >= 0; i--) {
	265	snd_i2c_bit_set(bus, 1, 1);
	266	if (snd_i2c_bit_data(bus, 0))
	267	data \|= (1 << i);
	268	snd_i2c_bit_set(bus, 0, 1);
	269	}
	270	snd_i2c_bit_direction(bus, 1, 1); /* SCL - wr, SDA - wr */
	271	snd_i2c_bit_send(bus, !!last);
	272	return data;
	273	}
	274
97f02e05 TI	275	static int snd_i2c_bit_sendbytes(struct snd_i2c_device *device,
97f02e05 TI	276	unsigned char *bytes, int count)
1da177e4	277	{
97f02e05	278	struct snd_i2c_bus *bus = device->bus;
1da177e4 LT	279	int err, res = 0;
	280
	281	if (device->flags & SND_I2C_DEVICE_ADDRTEN)
	282	return -EIO; /* not yet implemented */
	283	snd_i2c_bit_start(bus);
1cff399e BW	284	err = snd_i2c_bit_sendbyte(bus, device->addr << 1);
1cff399e BW	285	if (err < 0) {
1da177e4 LT	286	snd_i2c_bit_hw_stop(bus);
	287	return err;
	288	}
	289	while (count-- > 0) {
1cff399e BW	290	err = snd_i2c_bit_sendbyte(bus, *bytes++);
1cff399e BW	291	if (err < 0) {
1da177e4 LT	292	snd_i2c_bit_hw_stop(bus);
	293	return err;
	294	}
	295	res++;
	296	}
	297	snd_i2c_bit_stop(bus);
	298	return res;
	299	}
	300
97f02e05 TI	301	static int snd_i2c_bit_readbytes(struct snd_i2c_device *device,
97f02e05 TI	302	unsigned char *bytes, int count)
1da177e4	303	{
97f02e05	304	struct snd_i2c_bus *bus = device->bus;
1da177e4 LT	305	int err, res = 0;
	306
	307	if (device->flags & SND_I2C_DEVICE_ADDRTEN)
	308	return -EIO; /* not yet implemented */
	309	snd_i2c_bit_start(bus);
1cff399e BW	310	err = snd_i2c_bit_sendbyte(bus, (device->addr << 1) \| 1);
1cff399e BW	311	if (err < 0) {
1da177e4 LT	312	snd_i2c_bit_hw_stop(bus);
	313	return err;
	314	}
	315	while (count-- > 0) {
1cff399e BW	316	err = snd_i2c_bit_readbyte(bus, count == 0);
1cff399e BW	317	if (err < 0) {
1da177e4 LT	318	snd_i2c_bit_hw_stop(bus);
	319	return err;
	320	}
	321	*bytes++ = (unsigned char)err;
	322	res++;
	323	}
	324	snd_i2c_bit_stop(bus);
	325	return res;
	326	}
	327
97f02e05	328	static int snd_i2c_bit_probeaddr(struct snd_i2c_bus *bus, unsigned short addr)
1da177e4 LT	329	{
	330	int err;
	331
	332	if (addr & 0x8000) /* 10-bit address */
	333	return -EIO; /* not yet implemented */
	334	if (addr & 0x7f80) /* invalid address */
	335	return -EINVAL;
	336	snd_i2c_bit_start(bus);
	337	err = snd_i2c_bit_sendbyte(bus, addr << 1);
	338	snd_i2c_bit_stop(bus);
	339	return err;
	340	}
	341
1da177e4 LT	342
	343	static int __init alsa_i2c_init(void)
	344	{
	345	return 0;
	346	}
	347
	348	static void __exit alsa_i2c_exit(void)
	349	{
	350	}
	351
	352	module_init(alsa_i2c_init)
	353	module_exit(alsa_i2c_exit)