forked from Minki/linux
341 lines
8.3 KiB
C
341 lines
8.3 KiB
C
/*
|
|
* Generic i2c interface for ALSA
|
|
*
|
|
* (c) 1998 Gerd Knorr <kraxel@cs.tu-berlin.de>
|
|
* Modified for the ALSA driver by Jaroslav Kysela <perex@suse.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@suse.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;
|
|
init_MUTEX(&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;
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
int snd_i2c_sendbytes(struct snd_i2c_device *device, unsigned char *bytes, int count)
|
|
{
|
|
return device->bus->ops->sendbytes(device, bytes, count);
|
|
}
|
|
|
|
|
|
int snd_i2c_readbytes(struct snd_i2c_device *device, unsigned char *bytes, int count)
|
|
{
|
|
return device->bus->ops->readbytes(device, bytes, count);
|
|
}
|
|
|
|
int snd_i2c_probeaddr(struct snd_i2c_bus *bus, unsigned short addr)
|
|
{
|
|
return bus->ops->probeaddr(bus, addr);
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
}
|
|
|
|
EXPORT_SYMBOL(snd_i2c_bus_create);
|
|
EXPORT_SYMBOL(snd_i2c_device_create);
|
|
EXPORT_SYMBOL(snd_i2c_device_free);
|
|
EXPORT_SYMBOL(snd_i2c_sendbytes);
|
|
EXPORT_SYMBOL(snd_i2c_readbytes);
|
|
EXPORT_SYMBOL(snd_i2c_probeaddr);
|
|
|
|
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)
|