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/*
* Generic i2c interface for linux
*
* (c) 1998 Gerd Knorr <kraxel@cs.tu-berlin.de>
*
*/
#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/delay.h>
#include <linux/locks.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/i2c-old.h>
#define REGPRINT(x) if (verbose) (x)
#define I2C_DEBUG(x) if (i2c_debug) (x)
static int scan = 0;
static int verbose = 0;
static int i2c_debug = 0;
#if LINUX_VERSION_CODE >= 0x020117
MODULE_PARM(scan,"i");
MODULE_PARM(verbose,"i");
MODULE_PARM(i2c_debug,"i");
#endif
/* ----------------------------------------------------------------------- */
static struct i2c_bus *busses[I2C_BUS_MAX];
static struct i2c_driver *drivers[I2C_DRIVER_MAX];
static int bus_count = 0, driver_count = 0;
#ifdef CONFIG_VIDEO_BUZ
extern int saa7111_init(void);
extern int saa7185_init(void);
#endif
#ifdef CONFIG_VIDEO_LML33
extern int bt819_init(void);
extern int bt856_init(void);
#endif
int i2c_init(void)
{
printk(KERN_INFO "i2c: initialized%s\n",
scan ? " (i2c bus scan enabled)" : "");
/* anything to do here ? */
#ifdef CONFIG_VIDEO_BUZ
saa7111_init();
saa7185_init();
#endif
#ifdef CONFIG_VIDEO_LML33
bt819_init();
bt856_init();
#endif
return 0;
}
/* ----------------------------------------------------------------------- */
static void i2c_attach_device(struct i2c_bus *bus, struct i2c_driver *driver)
{
struct i2c_device *device;
int i,j,ack=1;
unsigned char addr;
LOCK_FLAGS;
/* probe for device */
LOCK_I2C_BUS(bus);
for (addr = driver->addr_l; addr <= driver->addr_h; addr += 2)
{
i2c_start(bus);
ack = i2c_sendbyte(bus,addr,0);
i2c_stop(bus);
if (!ack)
break;
}
UNLOCK_I2C_BUS(bus);
if (ack)
return;
/* got answer */
for (i = 0; i < I2C_DEVICE_MAX; i++)
if (NULL == driver->devices[i])
break;
if (I2C_DEVICE_MAX == i)
return;
for (j = 0; j < I2C_DEVICE_MAX; j++)
if (NULL == bus->devices[j])
break;
if (I2C_DEVICE_MAX == j)
return;
if (NULL == (device = kmalloc(sizeof(struct i2c_device),GFP_KERNEL)))
return;
device->bus = bus;
device->driver = driver;
device->addr = addr;
/* Attach */
if (driver->attach(device)!=0)
{
kfree(device);
return;
}
driver->devices[i] = device;
driver->devcount++;
bus->devices[j] = device;
bus->devcount++;
if (bus->attach_inform)
bus->attach_inform(bus,driver->id);
REGPRINT(printk("i2c: device attached: %s (addr=0x%02x, bus=%s, driver=%s)\n",device->name,addr,bus->name,driver->name));
}
static void i2c_detach_device(struct i2c_device *device)
{
int i;
if (device->bus->detach_inform)
device->bus->detach_inform(device->bus,device->driver->id);
device->driver->detach(device);
for (i = 0; i < I2C_DEVICE_MAX; i++)
if (device == device->driver->devices[i])
break;
if (I2C_DEVICE_MAX == i)
{
printk(KERN_WARNING "i2c: detach_device #1: device not found: %s\n",
device->name);
return;
}
device->driver->devices[i] = NULL;
device->driver->devcount--;
for (i = 0; i < I2C_DEVICE_MAX; i++)
if (device == device->bus->devices[i])
break;
if (I2C_DEVICE_MAX == i)
{
printk(KERN_WARNING "i2c: detach_device #2: device not found: %s\n",
device->name);
return;
}
device->bus->devices[i] = NULL;
device->bus->devcount--;
REGPRINT(printk("i2c: device detached: %s (addr=0x%02x, bus=%s, driver=%s)\n",device->name,device->addr,device->bus->name,device->driver->name));
kfree(device);
}
/* ----------------------------------------------------------------------- */
int i2c_register_bus(struct i2c_bus *bus)
{
int i,ack;
LOCK_FLAGS;
memset(bus->devices,0,sizeof(bus->devices));
bus->devcount = 0;
for (i = 0; i < I2C_BUS_MAX; i++)
if (NULL == busses[i])
break;
if (I2C_BUS_MAX == i)
return -ENOMEM;
busses[i] = bus;
bus_count++;
REGPRINT(printk("i2c: bus registered: %s\n",bus->name));
MOD_INC_USE_COUNT;
if (scan)
{
/* scan whole i2c bus */
LOCK_I2C_BUS(bus);
for (i = 0; i < 256; i+=2)
{
i2c_start(bus);
ack = i2c_sendbyte(bus,i,0);
i2c_stop(bus);
if (!ack)
{
printk(KERN_INFO "i2c: scanning bus %s: found device at addr=0x%02x\n",
bus->name,i);
}
}
UNLOCK_I2C_BUS(bus);
}
/* probe available drivers */
for (i = 0; i < I2C_DRIVER_MAX; i++)
if (drivers[i])
i2c_attach_device(bus,drivers[i]);
return 0;
}
int i2c_unregister_bus(struct i2c_bus *bus)
{
int i;
/* detach devices */
for (i = 0; i < I2C_DEVICE_MAX; i++)
if (bus->devices[i])
i2c_detach_device(bus->devices[i]);
for (i = 0; i < I2C_BUS_MAX; i++)
if (bus == busses[i])
break;
if (I2C_BUS_MAX == i)
{
printk(KERN_WARNING "i2c: unregister_bus #1: bus not found: %s\n",
bus->name);
return -ENODEV;
}
MOD_DEC_USE_COUNT;
busses[i] = NULL;
bus_count--;
REGPRINT(printk("i2c: bus unregistered: %s\n",bus->name));
return 0;
}
/* ----------------------------------------------------------------------- */
int i2c_register_driver(struct i2c_driver *driver)
{
int i;
memset(driver->devices,0,sizeof(driver->devices));
driver->devcount = 0;
for (i = 0; i < I2C_DRIVER_MAX; i++)
if (NULL == drivers[i])
break;
if (I2C_DRIVER_MAX == i)
return -ENOMEM;
drivers[i] = driver;
driver_count++;
MOD_INC_USE_COUNT;
REGPRINT(printk("i2c: driver registered: %s\n",driver->name));
/* Probe available busses */
for (i = 0; i < I2C_BUS_MAX; i++)
if (busses[i])
i2c_attach_device(busses[i],driver);
return 0;
}
int i2c_unregister_driver(struct i2c_driver *driver)
{
int i;
/* detach devices */
for (i = 0; i < I2C_DEVICE_MAX; i++)
if (driver->devices[i])
i2c_detach_device(driver->devices[i]);
for (i = 0; i < I2C_DRIVER_MAX; i++)
if (driver == drivers[i])
break;
if (I2C_DRIVER_MAX == i)
{
printk(KERN_WARNING "i2c: unregister_driver: driver not found: %s\n",
driver->name);
return -ENODEV;
}
MOD_DEC_USE_COUNT;
drivers[i] = NULL;
driver_count--;
REGPRINT(printk("i2c: driver unregistered: %s\n",driver->name));
return 0;
}
/* ----------------------------------------------------------------------- */
int i2c_control_device(struct i2c_bus *bus, int id,
unsigned int cmd, void *arg)
{
int i;
for (i = 0; i < I2C_DEVICE_MAX; i++)
if (bus->devices[i] && bus->devices[i]->driver->id == id)
break;
if (i == I2C_DEVICE_MAX)
return -ENODEV;
if (NULL == bus->devices[i]->driver->command)
return -ENODEV;
return bus->devices[i]->driver->command(bus->devices[i],cmd,arg);
}
/* ----------------------------------------------------------------------- */
#define I2C_SET(bus,ctrl,data) (bus->i2c_setlines(bus,ctrl,data))
#define I2C_GET(bus) (bus->i2c_getdataline(bus))
void i2c_start(struct i2c_bus *bus)
{
I2C_SET(bus,0,1);
I2C_SET(bus,1,1);
I2C_SET(bus,1,0);
I2C_SET(bus,0,0);
I2C_DEBUG(printk("%s: < ",bus->name));
}
void i2c_stop(struct i2c_bus *bus)
{
I2C_SET(bus,0,0);
I2C_SET(bus,1,0);
I2C_SET(bus,1,1);
I2C_DEBUG(printk(">\n"));
}
void i2c_one(struct i2c_bus *bus)
{
I2C_SET(bus,0,1);
I2C_SET(bus,1,1);
I2C_SET(bus,0,1);
}
void i2c_zero(struct i2c_bus *bus)
{
I2C_SET(bus,0,0);
I2C_SET(bus,1,0);
I2C_SET(bus,0,0);
}
int i2c_ack(struct i2c_bus *bus)
{
int ack;
I2C_SET(bus,0,1);
I2C_SET(bus,1,1);
ack = I2C_GET(bus);
I2C_SET(bus,0,1);
return ack;
}
int i2c_sendbyte(struct i2c_bus *bus,unsigned char data,int wait_for_ack)
{
int i, ack;
I2C_SET(bus,0,0);
for (i=7; i>=0; i--)
(data&(1<<i)) ? i2c_one(bus) : i2c_zero(bus);
if (wait_for_ack)
udelay(wait_for_ack);
ack=i2c_ack(bus);
I2C_DEBUG(printk("%02x%c ",(int)data,ack?'-':'+'));
return ack;
}
unsigned char i2c_readbyte(struct i2c_bus *bus,int last)
{
int i;
unsigned char data=0;
I2C_SET(bus,0,1);
for (i=7; i>=0; i--)
{
I2C_SET(bus,1,1);
if (I2C_GET(bus))
data |= (1<<i);
I2C_SET(bus,0,1);
}
last ? i2c_one(bus) : i2c_zero(bus);
I2C_DEBUG(printk("=%02x%c ",(int)data,last?'-':'+'));
return data;
}
/* ----------------------------------------------------------------------- */
int i2c_read(struct i2c_bus *bus, unsigned char addr)
{
int ret;
if (bus->i2c_read)
return bus->i2c_read(bus, addr);
i2c_start(bus);
i2c_sendbyte(bus,addr,0);
ret = i2c_readbyte(bus,1);
i2c_stop(bus);
return ret;
}
int i2c_write(struct i2c_bus *bus, unsigned char addr,
unsigned char data1, unsigned char data2, int both)
{
int ack;
if (bus->i2c_write)
return bus->i2c_write(bus, addr, data1, data2, both);
i2c_start(bus);
i2c_sendbyte(bus,addr,0);
ack = i2c_sendbyte(bus,data1,0);
if (both)
ack = i2c_sendbyte(bus,data2,0);
i2c_stop(bus);
return ack ? -1 : 0 ;
}
/* ----------------------------------------------------------------------- */
#ifdef MODULE
#if LINUX_VERSION_CODE >= 0x020100
EXPORT_SYMBOL(i2c_register_bus);
EXPORT_SYMBOL(i2c_unregister_bus);
EXPORT_SYMBOL(i2c_register_driver);
EXPORT_SYMBOL(i2c_unregister_driver);
EXPORT_SYMBOL(i2c_control_device);
EXPORT_SYMBOL(i2c_start);
EXPORT_SYMBOL(i2c_stop);
EXPORT_SYMBOL(i2c_one);
EXPORT_SYMBOL(i2c_zero);
EXPORT_SYMBOL(i2c_ack);
EXPORT_SYMBOL(i2c_sendbyte);
EXPORT_SYMBOL(i2c_readbyte);
EXPORT_SYMBOL(i2c_read);
EXPORT_SYMBOL(i2c_write);
#endif
int init_module(void)
{
return i2c_init();
}
void cleanup_module(void)
{
}
#endif
MODULE_LICENSE("GPL");
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