sound/i2c/i2c.c - kernel/msm - Gitiles

 /*
  *   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)
	/*
	* 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)