WebSVN - shark - Rev 170 - /shark/trunk/drivers/bttv/i2c-core.c

/* i2c-core.c - a device driver for the iic-bus interface */
/* ------------------------------------------------------------------------- */
/* Copyright (C) 1995-99 Simon G. Vogl

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., 675 Mass Ave, Cambridge, MA 02139, USA. */
/* ------------------------------------------------------------------------- */

/* SHARK version by Giacomo Guidi <giacomo@gandalf.sssup.it> */

#include <stdio.h>
#include <stdlib.h>
#include <stdio.h>

#include <kernel/log.h>
#include <asm/errno.h>

#include "drivers/i2c.h"

#define DEB(x) if (i2c_debug>=1) x;
#define DEB2(x) if (i2c_debug>=2) x;

/* ----- global variables -------------------------------------------------- */

/**** adapter list */
static struct i2c_adapter *adapters[I2C_ADAP_MAX];
static int adap_count;

/**** drivers list */
static struct i2c_driver *drivers[I2C_DRIVER_MAX];
static int driver_count;

/**** debug level */
static int i2c_debug = 0;

#define i2cproc_init() 0
#define i2cproc_cleanup() 0

/* ---------------------------------------------------
* registering functions
* ---------------------------------------------------
*/

/* -----
* i2c_add_adapter is called from within the algorithm layer,
* when a new hw adapter registers. A new device is register to be
* available for clients.
*/
int i2c_add_adapter(struct i2c_adapter *adap)
{
int i,j,res;

for (i = 0; i < I2C_ADAP_MAX; i++)
if (NULL == adapters[i])
break;
if (I2C_ADAP_MAX == i) {
printk(KERN_INFO"i2c-core.o: register_adapter(%s) - enlarge I2C_ADAP_MAX.\n", adap->name);
res = -ENOMEM;
goto ERROR0;
}

adapters[i] = adap;
adap_count++;

/* inform drivers of new adapters */
for (j=0;j<I2C_DRIVER_MAX;j++)
if (drivers[j]!=NULL &&
(drivers[j]->flags&(I2C_DF_NOTIFY|I2C_DF_DUMMY)))
/* We ignore the return code; if it fails, too bad */
drivers[j]->attach_adapter(adap);

printk(KERN_INFO "i2c-core.o: adapter %s registered as adapter %d.\n", adap->name,i);

return 0;

ERROR0:
return res;
}

int i2c_del_adapter(struct i2c_adapter *adap)
{
int i,j,res;

for (i = 0; i < I2C_ADAP_MAX; i++)
if (adap == adapters[i])
break;
if (I2C_ADAP_MAX == i) {
printk(KERN_INFO "i2c-core.o: unregister_adapter adap [%s] not found.\n",
adap->name);
res = -ENODEV;
goto ERROR0;
}

/* DUMMY drivers do not register their clients, so we have to
* use a trick here: we call driver->attach_adapter to
* *detach* it! Of course, each dummy driver should know about
* this or hell will break loose...
*/
for (j = 0; j < I2C_DRIVER_MAX; j++)
if (drivers[j] && (drivers[j]->flags & I2C_DF_DUMMY))
if ((res = drivers[j]->attach_adapter(adap))) {
cprintf("i2c-core.o: can't detach adapter %s "
"while detaching driver %s: driver not "
"detached!",adap->name,drivers[j]->name);
goto ERROR1;
}

/* detach any active clients. This must be done first, because
* it can fail; in which case we give upp. */
for (j=0;j<I2C_CLIENT_MAX;j++) {
struct i2c_client *client = adap->clients[j];
if (client!=NULL)
/* detaching devices is unconditional of the set notify
* flag, as _all_ clients that reside on the adapter
* must be deleted, as this would cause invalid states.
*/
if ((res=client->driver->detach_client(client))) {
cprintf("i2c-core.o: adapter %s not "
"unregistered, because client at "
"address %02x can't be detached. ",
adap->name, client->addr);
goto ERROR0;
}
}

adapters[i] = NULL;
adap_count--;

DEB(cprintf("i2c-core.o: adapter unregistered: %s\n",adap->name));

return 0;

ERROR0:
return res;
ERROR1:
return res;
}

/* -----
* What follows is the "upwards" interface: commands for talking to clients,
* which implement the functions to access the physical information of the
* chips.
*/

int i2c_add_driver(struct i2c_driver *driver)
{
int i;
for (i = 0; i < I2C_DRIVER_MAX; i++)
if (NULL == drivers[i])
break;
if (I2C_DRIVER_MAX == i) {
printk(KERN_INFO "i2c-core.o: register_driver(%s) "
"- enlarge I2C_DRIVER_MAX.\n",
driver->name);
return -ENOMEM;
}

drivers[i] = driver;
driver_count++;

DEB(cprintf("i2c-core.o: driver %s registered.\n",driver->name));

/* now look for instances of driver on our adapters
*/
if (driver->flags& (I2C_DF_NOTIFY|I2C_DF_DUMMY)) {
for (i=0;i<I2C_ADAP_MAX;i++)
if (adapters[i]!=NULL)
/* Ignore errors */
driver->attach_adapter(adapters[i]);
}
return 0;
}

int i2c_del_driver(struct i2c_driver *driver)
{
int i,j,k,res;

for (i = 0; i < I2C_DRIVER_MAX; i++)
if (driver == drivers[i])
break;
if (I2C_DRIVER_MAX == i) {
printk(KERN_INFO "i2c-core.o: unregister_driver: "
"[%s] not found\n",
driver->name);
return -ENODEV;
}
/* Have a look at each adapter, if clients of this driver are still
* attached. If so, detach them to be able to kill the driver
* afterwards.
*/
DEB2(cprintf("i2c-core.o: unregister_driver - looking for clients.\n"));
/* removing clients does not depend on the notify flag, else
* invalid operation might (will!) result, when using stale client
* pointers.
*/
for (k=0;k<I2C_ADAP_MAX;k++) {
struct i2c_adapter *adap = adapters[k];
if (adap == NULL) /* skip empty entries. */
continue;
DEB2(cprintf("i2c-core.o: examining adapter %s:\n",
adap->name));
if (driver->flags & I2C_DF_DUMMY) {
/* DUMMY drivers do not register their clients, so we have to
* use a trick here: we call driver->attach_adapter to
* *detach* it! Of course, each dummy driver should know about
* this or hell will break loose...
*/
if ((res = driver->attach_adapter(adap))) {
cprintf("i2c-core.o: while unregistering "
"dummy driver %s, adapter %s could "
"not be detached properly; driver "
"not unloaded!",driver->name,
adap->name);
return res;
}
} else {
for (j=0;j<I2C_CLIENT_MAX;j++) {
struct i2c_client *client = adap->clients[j];
if (client != NULL &&
client->driver == driver) {
DEB2(cprintf("i2c-core.o: "
"detaching client %s:\n",
client->name));
if ((res = driver->
detach_client(client)))
{
cprintf("i2c-core.o: while "
"unregistering driver "
"`%s', the client at "
"address %02x of "
"adapter `%s' could not"
"be detached; driver"
"not unloaded!",
driver->name,
client->addr,
adap->name);
return res;
}
}
}
}
}
drivers[i] = NULL;
driver_count--;

DEB(cprintf("i2c-core.o: driver unregistered: %s\n",driver->name));
return 0;
}

int i2c_check_addr (struct i2c_adapter *adapter, int addr)
{
int i;
for (i = 0; i < I2C_CLIENT_MAX ; i++)
if (adapter->clients[i] && (adapter->clients[i]->addr == addr))
return -EBUSY;
return 0;
}

int i2c_attach_client(struct i2c_client *client)
{
struct i2c_adapter *adapter = client->adapter;
int i;

if (i2c_check_addr(client->adapter,client->addr))
return -EBUSY;

for (i = 0; i < I2C_CLIENT_MAX; i++)
if (NULL == adapter->clients[i])
break;
if (I2C_CLIENT_MAX == i) {
printk(KERN_INFO "i2c-core.o: attach_client(%s) - enlarge I2C_CLIENT_MAX.\n",
client->name);
return -ENOMEM;
}

adapter->clients[i] = client;
adapter->client_count++;

if (adapter->client_register)
if (adapter->client_register(client))
cprintf("i2c-core.o: warning: client_register seems "
"to have failed for client %02x at adapter %s\n",
client->addr,adapter->name);
DEB(cprintf("i2c-core.o: client [%s] registered to adapter [%s](pos. %d).\n",
client->name, adapter->name,i));

if(client->flags & I2C_CLIENT_ALLOW_USE)
client->usage_count = 0;

return 0;
}

int i2c_detach_client(struct i2c_client *client)
{
struct i2c_adapter *adapter = client->adapter;
int i,res;

for (i = 0; i < I2C_CLIENT_MAX; i++)
if (client == adapter->clients[i])
break;
if (I2C_CLIENT_MAX == i) {
cprintf("i2c-core.o: unregister_client "
"[%s] not found\n",
client->name);
return -ENODEV;
}

if( (client->flags & I2C_CLIENT_ALLOW_USE) &&
(client->usage_count>0))
return -EBUSY;

if (adapter->client_unregister != NULL)
if ((res = adapter->client_unregister(client))) {
cprintf("i2c-core.o: client_unregister [%s] failed, "
"client not detached",client->name);
return res;
}

adapter->clients[i] = NULL;
adapter->client_count--;

DEB(cprintf("i2c-core.o: client [%s] unregistered.\n",client->name));
return 0;
}

void i2c_inc_use_client(struct i2c_client *client)
{

if (client->driver->inc_use != NULL)
client->driver->inc_use(client);

if (client->adapter->inc_use != NULL)
client->adapter->inc_use(client->adapter);
}

void i2c_dec_use_client(struct i2c_client *client)
{

if (client->driver->dec_use != NULL)
client->driver->dec_use(client);

if (client->adapter->dec_use != NULL)
client->adapter->dec_use(client->adapter);
}

struct i2c_client *i2c_get_client(int driver_id, int adapter_id,
struct i2c_client *prev)
{
int i,j;

/* Will iterate through the list of clients in each adapter of adapters-list
in search for a client that matches the search criteria. driver_id or
adapter_id are ignored if set to 0. If both are ignored this returns
first client found. */

i = j = 0;

/* set starting point */
if(prev)
{
if(!(prev->adapter))
return (struct i2c_client *) -EINVAL;

for(j=0; j < I2C_ADAP_MAX; j++)
if(prev->adapter == adapters[j])
break;

/* invalid starting point? */
if (I2C_ADAP_MAX == j) {
printk(KERN_INFO "i2c-core.o: get_client adapter for client:[%s] not found\n",
prev->name);
return (struct i2c_client *) -ENODEV;
}

for(i=0; i < I2C_CLIENT_MAX; i++)
if(prev == adapters[j]->clients[i])
break;

/* invalid starting point? */
if (I2C_CLIENT_MAX == i) {
printk(KERN_INFO "i2c-core.o: get_client client:[%s] not found\n",
prev->name);
return (struct i2c_client *) -ENODEV;
}

i++; /* start from one after prev */
}

for(; j < I2C_ADAP_MAX; j++)
{
if(!adapters[j])
continue;

if(adapter_id && (adapters[j]->id != adapter_id))
continue;

for(; i < I2C_CLIENT_MAX; i++)
{
if(!adapters[j]->clients[i])
continue;

if(driver_id && (adapters[j]->clients[i]->driver->id != driver_id))
continue;
if(adapters[j]->clients[i]->flags & I2C_CLIENT_ALLOW_USE)
return adapters[j]->clients[i];
}
i = 0;
}

return 0;
}

int i2c_use_client(struct i2c_client *client)
{
if(client->flags & I2C_CLIENT_ALLOW_USE) {
if (client->flags & I2C_CLIENT_ALLOW_MULTIPLE_USE)
client->usage_count++;
else {
if(client->usage_count > 0)
return -EBUSY;
else
client->usage_count++;
}
}

i2c_inc_use_client(client);

return 0;
}

int i2c_release_client(struct i2c_client *client)
{
if(client->flags & I2C_CLIENT_ALLOW_USE) {
if(client->usage_count>0)
client->usage_count--;
else
{
cprintf("i2c-core.o: dec_use_client used one too many times\n");
return -EPERM;
}
}

i2c_dec_use_client(client);

return 0;
}

/* ----------------------------------------------------
* the functional interface to the i2c busses.
* ----------------------------------------------------
*/

int i2c_transfer(struct i2c_adapter * adap, struct i2c_msg msgs[],int num)
{
int ret;

if (adap->algo->master_xfer) {
DEB2(cprintf("i2c-core.o: master_xfer: %s with %d msgs.\n",
adap->name,num));

ret = adap->algo->master_xfer(adap,msgs,num);

return ret;
} else {
printk(KERN_INFO "i2c-core.o: I2C adapter %04x: I2C level transfers not supported\n",
adap->id);
return -ENOSYS;
}
}

int i2c_master_send(struct i2c_client *client,const char *buf ,int count)
{
int ret;
struct i2c_adapter *adap=client->adapter;
struct i2c_msg msg;

if (client->adapter->algo->master_xfer) {
msg.addr = client->addr;
msg.flags = client->flags & I2C_M_TEN;
msg.len = count;
(const char *)msg.buf = buf;

DEB2(cprintf("i2c-core.o: master_send: writing %d bytes on %s.\n",
count,client->adapter->name));

ret = adap->algo->master_xfer(adap,&msg,1);

/* if everything went ok (i.e. 1 msg transmitted), return #bytes
* transmitted, else error code.
*/
return (ret == 1 )? count : ret;
} else {
printk(KERN_INFO "i2c-core.o: I2C adapter %04x: I2C level transfers not supported\n",
client->adapter->id);
return -ENOSYS;
}
}

int i2c_master_recv(struct i2c_client *client, char *buf ,int count)
{
struct i2c_adapter *adap=client->adapter;
struct i2c_msg msg;
int ret;
if (client->adapter->algo->master_xfer) {
msg.addr = client->addr;
msg.flags = client->flags & I2C_M_TEN;
msg.flags |= I2C_M_RD;
msg.len = count;
msg.buf = buf;

DEB2(cprintf("i2c-core.o: master_recv: reading %d bytes on %s.\n",
count,client->adapter->name));

ret = adap->algo->master_xfer(adap,&msg,1);

DEB2(cprintf("i2c-core.o: master_recv: return:%d (count:%d, addr:0x%02x)\n",
ret, count, client->addr));

/* if everything went ok (i.e. 1 msg transmitted), return #bytes
* transmitted, else error code.
*/
return (ret == 1 )? count : ret;
} else {
printk(KERN_INFO "i2c-core.o: I2C adapter %04x: I2C level transfers not supported\n",
client->adapter->id);
return -ENOSYS;
}
}

int i2c_control(struct i2c_client *client,
unsigned int cmd, unsigned long arg)
{
int ret = 0;
struct i2c_adapter *adap = client->adapter;

DEB2(cprintf("i2c-core.o: i2c ioctl, cmd: 0x%x, arg: %#lx\n", cmd, arg));
switch ( cmd ) {
case I2C_RETRIES:
adap->retries = arg;
break;
case I2C_TIMEOUT:
adap->timeout = arg;
break;
default:
if (adap->algo->algo_control!=NULL)
ret = adap->algo->algo_control(adap,cmd,arg);
}
return ret;
}

/* ----------------------------------------------------
* the i2c address scanning function
* Will not work for 10-bit addresses!
* ----------------------------------------------------
*/
int i2c_probe(struct i2c_adapter *adapter,
struct i2c_client_address_data *address_data,
i2c_client_found_addr_proc *found_proc)
{
int addr,i,found,err;
int adap_id = i2c_adapter_id(adapter);

/* Forget it if we can't probe using SMBUS_QUICK */
if (! i2c_check_functionality(adapter,I2C_FUNC_SMBUS_QUICK))
return -1;

for (addr = 0x00; addr <= 0x7f; addr++) {

/* Skip if already in use */
if (i2c_check_addr(adapter,addr))
continue;

/* If it is in one of the force entries, we don't do any detection
at all */
found = 0;

for (i = 0; !found && (address_data->force[i] != I2C_CLIENT_END); i += 3) {
if (((adap_id == address_data->force[i]) ||
(address_data->force[i] == ANY_I2C_BUS)) &&
(addr == address_data->force[i+1])) {
DEB2(cprintf("i2c-core.o: found force parameter for adapter %d, addr %04x\n",
adap_id,addr));
if ((err = found_proc(adapter,addr,0,0)))
return err;
found = 1;
}
}
if (found)
continue;

/* If this address is in one of the ignores, we can forget about
it right now */
for (i = 0;
!found && (address_data->ignore[i] != I2C_CLIENT_END);
i += 2) {
if (((adap_id == address_data->ignore[i]) ||
((address_data->ignore[i] == ANY_I2C_BUS))) &&
(addr == address_data->ignore[i+1])) {
DEB2(cprintf("i2c-core.o: found ignore parameter for adapter %d, "
"addr %04x\n", adap_id ,addr));
found = 1;
}
}
for (i = 0;
!found && (address_data->ignore_range[i] != I2C_CLIENT_END);
i += 3) {
if (((adap_id == address_data->ignore_range[i]) ||
((address_data->ignore_range[i]==ANY_I2C_BUS))) &&
(addr >= address_data->ignore_range[i+1]) &&
(addr <= address_data->ignore_range[i+2])) {
DEB2(cprintf("i2c-core.o: found ignore_range parameter for adapter %d, "
"addr %04x\n", adap_id,addr));
found = 1;
}
}
if (found)
continue;

/* Now, we will do a detection, but only if it is in the normal or
probe entries */
for (i = 0;
!found && (address_data->normal_i2c[i] != I2C_CLIENT_END);
i += 1) {
if (addr == address_data->normal_i2c[i]) {
found = 1;
DEB2(cprintf("i2c-core.o: found normal i2c entry for adapter %d, "
"addr %02x", adap_id,addr));
}
}

for (i = 0;
!found && (address_data->normal_i2c_range[i] != I2C_CLIENT_END);
i += 2) {
if ((addr >= address_data->normal_i2c_range[i]) &&
(addr <= address_data->normal_i2c_range[i+1])) {
found = 1;
DEB2(cprintf("i2c-core.o: found normal i2c_range entry for adapter %d, "
"addr %04x\n", adap_id,addr));
}
}

for (i = 0;
!found && (address_data->probe[i] != I2C_CLIENT_END);
i += 2) {
if (((adap_id == address_data->probe[i]) ||
((address_data->probe[i] == ANY_I2C_BUS))) &&
(addr == address_data->probe[i+1])) {
found = 1;
DEB2(cprintf("i2c-core.o: found probe parameter for adapter %d, "
"addr %04x\n", adap_id,addr));
}
}
for (i = 0;
!found && (address_data->probe_range[i] != I2C_CLIENT_END);
i += 3) {
if (((adap_id == address_data->probe_range[i]) ||
(address_data->probe_range[i] == ANY_I2C_BUS)) &&
(addr >= address_data->probe_range[i+1]) &&
(addr <= address_data->probe_range[i+2])) {
found = 1;
DEB2(cprintf("i2c-core.o: found probe_range parameter for adapter %d, "
"addr %04x\n", adap_id,addr));
}
}
if (!found)
continue;

/* OK, so we really should examine this address. First check
whether there is some client here at all! */
if (i2c_smbus_xfer(adapter,addr,0,0,0,I2C_SMBUS_QUICK,NULL) >= 0)
if ((err = found_proc(adapter,addr,0,-1)))
return err;
}
return 0;
}

/*
* return id number for a specific adapter
*/
int i2c_adapter_id(struct i2c_adapter *adap)
{
int i;
for (i = 0; i < I2C_ADAP_MAX; i++)
if (adap == adapters[i])
return i;
return -1;
}

/* The SMBus parts */

extern s32 i2c_smbus_write_quick(struct i2c_client * client, u8 value)
{
return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
value,0,I2C_SMBUS_QUICK,NULL);
}

extern s32 i2c_smbus_read_byte(struct i2c_client * client)
{
union i2c_smbus_data data;
if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
I2C_SMBUS_READ,0,I2C_SMBUS_BYTE, &data))
return -1;
else
return 0x0FF & data.byte;
}

extern s32 i2c_smbus_write_byte(struct i2c_client * client, u8 value)
{
return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
I2C_SMBUS_WRITE,value, I2C_SMBUS_BYTE,NULL);
}

extern s32 i2c_smbus_read_byte_data(struct i2c_client * client, u8 command)
{
union i2c_smbus_data data;
if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
I2C_SMBUS_READ,command, I2C_SMBUS_BYTE_DATA,&data))
return -1;
else
return 0x0FF & data.byte;
}

extern s32 i2c_smbus_write_byte_data(struct i2c_client * client, u8 command,
u8 value)
{
union i2c_smbus_data data;
data.byte = value;
return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
I2C_SMBUS_WRITE,command,
I2C_SMBUS_BYTE_DATA,&data);
}

extern s32 i2c_smbus_read_word_data(struct i2c_client * client, u8 command)
{
union i2c_smbus_data data;
if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
I2C_SMBUS_READ,command, I2C_SMBUS_WORD_DATA, &data))
return -1;
else
return 0x0FFFF & data.word;
}

extern s32 i2c_smbus_write_word_data(struct i2c_client * client,
u8 command, u16 value)
{
union i2c_smbus_data data;
data.word = value;
return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
I2C_SMBUS_WRITE,command,
I2C_SMBUS_WORD_DATA,&data);
}

extern s32 i2c_smbus_process_call(struct i2c_client * client,
u8 command, u16 value)
{
union i2c_smbus_data data;
data.word = value;
if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
I2C_SMBUS_WRITE,command,
I2C_SMBUS_PROC_CALL, &data))
return -1;
else
return 0x0FFFF & data.word;
}

/* Returns the number of read bytes */
extern s32 i2c_smbus_read_block_data(struct i2c_client * client,
u8 command, u8 *values)
{
union i2c_smbus_data data;
int i;
if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
I2C_SMBUS_READ,command,
I2C_SMBUS_BLOCK_DATA,&data))
return -1;
else {
for (i = 1; i <= data.block[0]; i++)
values[i-1] = data.block[i];
return data.block[0];
}
}

extern s32 i2c_smbus_write_block_data(struct i2c_client * client,
u8 command, u8 length, u8 *values)
{
union i2c_smbus_data data;
int i;
if (length > 32)
length = 32;
for (i = 1; i <= length; i++)
data.block[i] = values[i-1];
data.block[0] = length;
return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
I2C_SMBUS_WRITE,command,
I2C_SMBUS_BLOCK_DATA,&data);
}

extern s32 i2c_smbus_write_i2c_block_data(struct i2c_client * client,
u8 command, u8 length, u8 *values)
{
union i2c_smbus_data data;
int i;
if (length > 32)
length = 32;
for (i = 1; i <= length; i++)
data.block[i] = values[i-1];
data.block[0] = length;
return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
I2C_SMBUS_WRITE,command,
I2C_SMBUS_I2C_BLOCK_DATA,&data);
}

/* Simulate a SMBus command using the i2c protocol
No checking of parameters is done! */
static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr,
unsigned short flags,
char read_write, u8 command, int size,
union i2c_smbus_data * data)
{
/* So we need to generate a series of msgs. In the case of writing, we
need to use only one message; when reading, we need two. We initialize
most things with sane defaults, to keep the code below somewhat
simpler. */
unsigned char msgbuf0[34];
unsigned char msgbuf1[34];
int num = read_write == I2C_SMBUS_READ?2:1;
struct i2c_msg msg[2] = { { addr, flags, 1, msgbuf0 },
{ addr, flags | I2C_M_RD, 0, msgbuf1 }
};
int i;

msgbuf0[0] = command;
switch(size) {
case I2C_SMBUS_QUICK:
msg[0].len = 0;
/* Special case: The read/write field is used as data */
msg[0].flags = flags | (read_write==I2C_SMBUS_READ)?I2C_M_RD:0;
num = 1;
break;
case I2C_SMBUS_BYTE:
if (read_write == I2C_SMBUS_READ) {
/* Special case: only a read! */
msg[0].flags = I2C_M_RD | flags;
num = 1;
}
break;
case I2C_SMBUS_BYTE_DATA:
if (read_write == I2C_SMBUS_READ)
msg[1].len = 1;
else {
msg[0].len = 2;
msgbuf0[1] = data->byte;
}
break;
case I2C_SMBUS_WORD_DATA:
if (read_write == I2C_SMBUS_READ)
msg[1].len = 2;
else {
msg[0].len=3;
msgbuf0[1] = data->word & 0xff;
msgbuf0[2] = (data->word >> 8) & 0xff;
}
break;
case I2C_SMBUS_PROC_CALL:
num = 2; /* Special case */
msg[0].len = 3;
msg[1].len = 2;
msgbuf0[1] = data->word & 0xff;
msgbuf0[2] = (data->word >> 8) & 0xff;
break;
case I2C_SMBUS_BLOCK_DATA:
if (read_write == I2C_SMBUS_READ) {
cprintf("i2c-core.o: Block read not supported under "
"I2C emulation!\n");
return -1;
} else {
msg[0].len = data->block[0] + 2;
if (msg[0].len > 34) {
cprintf("i2c-core.o: smbus_access called with "
"invalid block write size (%d)\n",
msg[0].len);
return -1;
}
for (i = 1; i <= msg[0].len; i++)
msgbuf0[i] = data->block[i-1];
}
break;
default:
cprintf("i2c-core.o: smbus_access called with invalid size (%d)\n",
size);
return -1;
}

if (i2c_transfer(adapter, msg, num) < 0)
return -1;

if (read_write == I2C_SMBUS_READ)
switch(size) {
case I2C_SMBUS_BYTE:
data->byte = msgbuf0[0];
break;
case I2C_SMBUS_BYTE_DATA:
data->byte = msgbuf1[0];
break;
case I2C_SMBUS_WORD_DATA:
case I2C_SMBUS_PROC_CALL:
data->word = msgbuf1[0] | (msgbuf1[1] << 8);
break;
}
return 0;
}

s32 i2c_smbus_xfer(struct i2c_adapter * adapter, u16 addr, unsigned short flags,
char read_write, u8 command, int size,
union i2c_smbus_data * data)
{
s32 res;
flags = flags & I2C_M_TEN;
if (adapter->algo->smbus_xfer) {
res = adapter->algo->smbus_xfer(adapter,addr,flags,read_write,
command,size,data);
} else
res = i2c_smbus_xfer_emulated(adapter,addr,flags,read_write,
command,size,data);
return res;
}

/* You should always define `functionality'; the 'else' is just for
backward compatibility. */
u32 i2c_get_functionality (struct i2c_adapter *adap)
{
if (adap->algo->functionality)
return adap->algo->functionality(adap);
else
return 0xffffffff;
}

int i2c_check_functionality (struct i2c_adapter *adap, u32 func)
{
u32 adap_func = i2c_get_functionality (adap);
return (func & adap_func) == func;
}

static int i2c_init(void)
{
printk(KERN_INFO "i2c-core.o: i2c core module\n");
memset(adapters,0,sizeof(adapters));
memset(drivers,0,sizeof(drivers));
adap_count=0;
driver_count=0;

return 0;
}

extern void i2c_algo_bit_init(void);

int i2c_init_all(void)
{
/* --------------------- global ----- */
i2c_init();

i2c_algo_bit_init();

return 0;
}

Subversion Repositories shark

(root)/shark/trunk/drivers/bttv/i2c-core.c @ 181 - Rev 170