kernel_optimize_test/drivers/i2c/algos/i2c-algo-ite.c
Jean Delvare c7a46533ff [PATCH] I2C: Kill i2c_algorithm.id (5/7)
Merge the algorithm id part (16 upper bits) of the i2c adapters ids
into the definition of the adapters ids directly. After that, we don't
need to OR both ids together for each i2c_adapter structure.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-09-05 09:14:31 -07:00

809 lines
20 KiB
C

/*
-------------------------------------------------------------------------
i2c-algo-ite.c i2c driver algorithms for ITE adapters
Hai-Pao Fan, MontaVista Software, Inc.
hpfan@mvista.com or source@mvista.com
Copyright 2000 MontaVista Software Inc.
---------------------------------------------------------------------------
This file was highly leveraged from i2c-algo-pcf.c, which was created
by Simon G. Vogl and Hans Berglund:
Copyright (C) 1995-1997 Simon G. Vogl
1998-2000 Hans Berglund
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. */
/* ------------------------------------------------------------------------- */
/* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and
Frodo Looijaard <frodol@dds.nl> ,and also from Martin Bailey
<mbailey@littlefeet-inc.com> */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <asm/uaccess.h>
#include <linux/ioport.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/i2c.h>
#include <linux/i2c-algo-ite.h>
#include "i2c-algo-ite.h"
#define PM_DSR IT8172_PCI_IO_BASE + IT_PM_DSR
#define PM_IBSR IT8172_PCI_IO_BASE + IT_PM_DSR + 0x04
#define GPIO_CCR IT8172_PCI_IO_BASE + IT_GPCCR
#define DEB2(x) if (i2c_debug>=2) x
#define DEB3(x) if (i2c_debug>=3) x /* print several statistical values*/
#define DEF_TIMEOUT 16
/* module parameters:
*/
static int i2c_debug;
static int iic_test; /* see if the line-setting functions work */
/* --- setting states on the bus with the right timing: --------------- */
#define get_clock(adap) adap->getclock(adap->data)
#define iic_outw(adap, reg, val) adap->setiic(adap->data, reg, val)
#define iic_inw(adap, reg) adap->getiic(adap->data, reg)
/* --- other auxiliary functions -------------------------------------- */
static void iic_start(struct i2c_algo_iic_data *adap)
{
iic_outw(adap,ITE_I2CHCR,ITE_CMD);
}
static void iic_stop(struct i2c_algo_iic_data *adap)
{
iic_outw(adap,ITE_I2CHCR,0);
iic_outw(adap,ITE_I2CHSR,ITE_I2CHSR_TDI);
}
static void iic_reset(struct i2c_algo_iic_data *adap)
{
iic_outw(adap, PM_IBSR, iic_inw(adap, PM_IBSR) | 0x80);
}
static int wait_for_bb(struct i2c_algo_iic_data *adap)
{
int timeout = DEF_TIMEOUT;
short status;
status = iic_inw(adap, ITE_I2CHSR);
#ifndef STUB_I2C
while (timeout-- && (status & ITE_I2CHSR_HB)) {
udelay(1000); /* How much is this? */
status = iic_inw(adap, ITE_I2CHSR);
}
#endif
if (timeout<=0) {
printk(KERN_ERR "Timeout, host is busy\n");
iic_reset(adap);
}
return(timeout<=0);
}
/* After we issue a transaction on the IIC bus, this function
* is called. It puts this process to sleep until we get an interrupt from
* from the controller telling us that the transaction we requested in complete.
*/
static int wait_for_pin(struct i2c_algo_iic_data *adap, short *status) {
int timeout = DEF_TIMEOUT;
timeout = wait_for_bb(adap);
if (timeout) {
DEB2(printk("Timeout waiting for host not busy\n");)
return -EIO;
}
timeout = DEF_TIMEOUT;
*status = iic_inw(adap, ITE_I2CHSR);
#ifndef STUB_I2C
while (timeout-- && !(*status & ITE_I2CHSR_TDI)) {
adap->waitforpin();
*status = iic_inw(adap, ITE_I2CHSR);
}
#endif
if (timeout <= 0)
return(-1);
else
return(0);
}
static int wait_for_fe(struct i2c_algo_iic_data *adap, short *status)
{
int timeout = DEF_TIMEOUT;
*status = iic_inw(adap, ITE_I2CFSR);
#ifndef STUB_I2C
while (timeout-- && (*status & ITE_I2CFSR_FE)) {
udelay(1000);
iic_inw(adap, ITE_I2CFSR);
}
#endif
if (timeout <= 0)
return(-1);
else
return(0);
}
static int iic_init (struct i2c_algo_iic_data *adap)
{
short i;
/* Clear bit 7 to set I2C to normal operation mode */
i=iic_inw(adap, PM_DSR)& 0xff7f;
iic_outw(adap, PM_DSR, i);
/* set IT_GPCCR port C bit 2&3 as function 2 */
i = iic_inw(adap, GPIO_CCR) & 0xfc0f;
iic_outw(adap,GPIO_CCR,i);
/* Clear slave address/sub-address */
iic_outw(adap,ITE_I2CSAR, 0);
iic_outw(adap,ITE_I2CSSAR, 0);
/* Set clock counter register */
iic_outw(adap,ITE_I2CCKCNT, get_clock(adap));
/* Set START/reSTART/STOP time registers */
iic_outw(adap,ITE_I2CSHDR, 0x0a);
iic_outw(adap,ITE_I2CRSUR, 0x0a);
iic_outw(adap,ITE_I2CPSUR, 0x0a);
/* Enable interrupts on completing the current transaction */
iic_outw(adap,ITE_I2CHCR, ITE_I2CHCR_IE | ITE_I2CHCR_HCE);
/* Clear transfer count */
iic_outw(adap,ITE_I2CFBCR, 0x0);
DEB2(printk("iic_init: Initialized IIC on ITE 0x%x\n",
iic_inw(adap, ITE_I2CHSR)));
return 0;
}
/*
* Sanity check for the adapter hardware - check the reaction of
* the bus lines only if it seems to be idle.
*/
static int test_bus(struct i2c_algo_iic_data *adap, char *name) {
#if 0
int scl,sda;
sda=getsda(adap);
if (adap->getscl==NULL) {
printk("test_bus: Warning: Adapter can't read from clock line - skipping test.\n");
return 0;
}
scl=getscl(adap);
printk("test_bus: Adapter: %s scl: %d sda: %d -- testing...\n",
name,getscl(adap),getsda(adap));
if (!scl || !sda ) {
printk("test_bus: %s seems to be busy.\n",adap->name);
goto bailout;
}
sdalo(adap);
printk("test_bus:1 scl: %d sda: %d\n", getscl(adap),
getsda(adap));
if ( 0 != getsda(adap) ) {
printk("test_bus: %s SDA stuck high!\n",name);
sdahi(adap);
goto bailout;
}
if ( 0 == getscl(adap) ) {
printk("test_bus: %s SCL unexpected low while pulling SDA low!\n",
name);
goto bailout;
}
sdahi(adap);
printk("test_bus:2 scl: %d sda: %d\n", getscl(adap),
getsda(adap));
if ( 0 == getsda(adap) ) {
printk("test_bus: %s SDA stuck low!\n",name);
sdahi(adap);
goto bailout;
}
if ( 0 == getscl(adap) ) {
printk("test_bus: %s SCL unexpected low while SDA high!\n",
adap->name);
goto bailout;
}
scllo(adap);
printk("test_bus:3 scl: %d sda: %d\n", getscl(adap),
getsda(adap));
if ( 0 != getscl(adap) ) {
sclhi(adap);
goto bailout;
}
if ( 0 == getsda(adap) ) {
printk("test_bus: %s SDA unexpected low while pulling SCL low!\n",
name);
goto bailout;
}
sclhi(adap);
printk("test_bus:4 scl: %d sda: %d\n", getscl(adap),
getsda(adap));
if ( 0 == getscl(adap) ) {
printk("test_bus: %s SCL stuck low!\n",name);
sclhi(adap);
goto bailout;
}
if ( 0 == getsda(adap) ) {
printk("test_bus: %s SDA unexpected low while SCL high!\n",
name);
goto bailout;
}
printk("test_bus: %s passed test.\n",name);
return 0;
bailout:
sdahi(adap);
sclhi(adap);
return -ENODEV;
#endif
return (0);
}
/* ----- Utility functions
*/
/* Verify the device we want to talk to on the IIC bus really exists. */
static inline int try_address(struct i2c_algo_iic_data *adap,
unsigned int addr, int retries)
{
int i, ret = -1;
short status;
for (i=0;i<retries;i++) {
iic_outw(adap, ITE_I2CSAR, addr);
iic_start(adap);
if (wait_for_pin(adap, &status) == 0) {
if ((status & ITE_I2CHSR_DNE) == 0) {
iic_stop(adap);
iic_outw(adap, ITE_I2CFCR, ITE_I2CFCR_FLUSH);
ret=1;
break; /* success! */
}
}
iic_stop(adap);
udelay(adap->udelay);
}
DEB2(if (i) printk("try_address: needed %d retries for 0x%x\n",i,
addr));
return ret;
}
static int iic_sendbytes(struct i2c_adapter *i2c_adap,const char *buf,
int count)
{
struct i2c_algo_iic_data *adap = i2c_adap->algo_data;
int wrcount=0, timeout;
short status;
int loops, remainder, i, j;
union {
char byte[2];
unsigned short word;
} tmp;
iic_outw(adap, ITE_I2CSSAR, (unsigned short)buf[wrcount++]);
count--;
if (count == 0)
return -EIO;
loops = count / 32; /* 32-byte FIFO */
remainder = count % 32;
if(loops) {
for(i=0; i<loops; i++) {
iic_outw(adap, ITE_I2CFBCR, 32);
for(j=0; j<32/2; j++) {
tmp.byte[1] = buf[wrcount++];
tmp.byte[0] = buf[wrcount++];
iic_outw(adap, ITE_I2CFDR, tmp.word);
}
/* status FIFO overrun */
iic_inw(adap, ITE_I2CFSR);
iic_inw(adap, ITE_I2CFBCR);
iic_outw(adap, ITE_I2CHCR, ITE_WRITE); /* Issue WRITE command */
/* Wait for transmission to complete */
timeout = wait_for_pin(adap, &status);
if(timeout) {
iic_stop(adap);
printk("iic_sendbytes: %s write timeout.\n", i2c_adap->name);
return -EREMOTEIO; /* got a better one ?? */
}
if (status & ITE_I2CHSR_DB) {
iic_stop(adap);
printk("iic_sendbytes: %s write error - no ack.\n", i2c_adap->name);
return -EREMOTEIO; /* got a better one ?? */
}
}
}
if(remainder) {
iic_outw(adap, ITE_I2CFBCR, remainder);
for(i=0; i<remainder/2; i++) {
tmp.byte[1] = buf[wrcount++];
tmp.byte[0] = buf[wrcount++];
iic_outw(adap, ITE_I2CFDR, tmp.word);
}
/* status FIFO overrun */
iic_inw(adap, ITE_I2CFSR);
iic_inw(adap, ITE_I2CFBCR);
iic_outw(adap, ITE_I2CHCR, ITE_WRITE); /* Issue WRITE command */
timeout = wait_for_pin(adap, &status);
if(timeout) {
iic_stop(adap);
printk("iic_sendbytes: %s write timeout.\n", i2c_adap->name);
return -EREMOTEIO; /* got a better one ?? */
}
#ifndef STUB_I2C
if (status & ITE_I2CHSR_DB) {
iic_stop(adap);
printk("iic_sendbytes: %s write error - no ack.\n", i2c_adap->name);
return -EREMOTEIO; /* got a better one ?? */
}
#endif
}
iic_stop(adap);
return wrcount;
}
static int iic_readbytes(struct i2c_adapter *i2c_adap, char *buf, int count,
int sread)
{
int rdcount=0, i, timeout;
short status;
struct i2c_algo_iic_data *adap = i2c_adap->algo_data;
int loops, remainder, j;
union {
char byte[2];
unsigned short word;
} tmp;
loops = count / 32; /* 32-byte FIFO */
remainder = count % 32;
if(loops) {
for(i=0; i<loops; i++) {
iic_outw(adap, ITE_I2CFBCR, 32);
if (sread)
iic_outw(adap, ITE_I2CHCR, ITE_SREAD);
else
iic_outw(adap, ITE_I2CHCR, ITE_READ); /* Issue READ command */
timeout = wait_for_pin(adap, &status);
if(timeout) {
iic_stop(adap);
printk("iic_readbytes: %s read timeout.\n", i2c_adap->name);
return (-1);
}
#ifndef STUB_I2C
if (status & ITE_I2CHSR_DB) {
iic_stop(adap);
printk("iic_readbytes: %s read error - no ack.\n", i2c_adap->name);
return (-1);
}
#endif
timeout = wait_for_fe(adap, &status);
if(timeout) {
iic_stop(adap);
printk("iic_readbytes: %s FIFO is empty\n", i2c_adap->name);
return (-1);
}
for(j=0; j<32/2; j++) {
tmp.word = iic_inw(adap, ITE_I2CFDR);
buf[rdcount++] = tmp.byte[1];
buf[rdcount++] = tmp.byte[0];
}
/* status FIFO underrun */
iic_inw(adap, ITE_I2CFSR);
}
}
if(remainder) {
remainder=(remainder+1)/2 * 2;
iic_outw(adap, ITE_I2CFBCR, remainder);
if (sread)
iic_outw(adap, ITE_I2CHCR, ITE_SREAD);
else
iic_outw(adap, ITE_I2CHCR, ITE_READ); /* Issue READ command */
timeout = wait_for_pin(adap, &status);
if(timeout) {
iic_stop(adap);
printk("iic_readbytes: %s read timeout.\n", i2c_adap->name);
return (-1);
}
#ifndef STUB_I2C
if (status & ITE_I2CHSR_DB) {
iic_stop(adap);
printk("iic_readbytes: %s read error - no ack.\n", i2c_adap->name);
return (-1);
}
#endif
timeout = wait_for_fe(adap, &status);
if(timeout) {
iic_stop(adap);
printk("iic_readbytes: %s FIFO is empty\n", i2c_adap->name);
return (-1);
}
for(i=0; i<(remainder+1)/2; i++) {
tmp.word = iic_inw(adap, ITE_I2CFDR);
buf[rdcount++] = tmp.byte[1];
buf[rdcount++] = tmp.byte[0];
}
/* status FIFO underrun */
iic_inw(adap, ITE_I2CFSR);
}
iic_stop(adap);
return rdcount;
}
/* This function implements combined transactions. Combined
* transactions consist of combinations of reading and writing blocks of data.
* Each transfer (i.e. a read or a write) is separated by a repeated start
* condition.
*/
#if 0
static int iic_combined_transaction(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num)
{
int i;
struct i2c_msg *pmsg;
int ret;
DEB2(printk("Beginning combined transaction\n"));
for(i=0; i<(num-1); i++) {
pmsg = &msgs[i];
if(pmsg->flags & I2C_M_RD) {
DEB2(printk(" This one is a read\n"));
ret = iic_readbytes(i2c_adap, pmsg->buf, pmsg->len, IIC_COMBINED_XFER);
}
else if(!(pmsg->flags & I2C_M_RD)) {
DEB2(printk("This one is a write\n"));
ret = iic_sendbytes(i2c_adap, pmsg->buf, pmsg->len, IIC_COMBINED_XFER);
}
}
/* Last read or write segment needs to be terminated with a stop */
pmsg = &msgs[i];
if(pmsg->flags & I2C_M_RD) {
DEB2(printk("Doing the last read\n"));
ret = iic_readbytes(i2c_adap, pmsg->buf, pmsg->len, IIC_SINGLE_XFER);
}
else if(!(pmsg->flags & I2C_M_RD)) {
DEB2(printk("Doing the last write\n"));
ret = iic_sendbytes(i2c_adap, pmsg->buf, pmsg->len, IIC_SINGLE_XFER);
}
return ret;
}
#endif
/* Whenever we initiate a transaction, the first byte clocked
* onto the bus after the start condition is the address (7 bit) of the
* device we want to talk to. This function manipulates the address specified
* so that it makes sense to the hardware when written to the IIC peripheral.
*
* Note: 10 bit addresses are not supported in this driver, although they are
* supported by the hardware. This functionality needs to be implemented.
*/
static inline int iic_doAddress(struct i2c_algo_iic_data *adap,
struct i2c_msg *msg, int retries)
{
unsigned short flags = msg->flags;
unsigned int addr;
int ret;
/* Ten bit addresses not supported right now */
if ( (flags & I2C_M_TEN) ) {
#if 0
addr = 0xf0 | (( msg->addr >> 7) & 0x03);
DEB2(printk("addr0: %d\n",addr));
ret = try_address(adap, addr, retries);
if (ret!=1) {
printk("iic_doAddress: died at extended address code.\n");
return -EREMOTEIO;
}
iic_outw(adap,msg->addr & 0x7f);
if (ret != 1) {
printk("iic_doAddress: died at 2nd address code.\n");
return -EREMOTEIO;
}
if ( flags & I2C_M_RD ) {
i2c_repstart(adap);
addr |= 0x01;
ret = try_address(adap, addr, retries);
if (ret!=1) {
printk("iic_doAddress: died at extended address code.\n");
return -EREMOTEIO;
}
}
#endif
} else {
addr = ( msg->addr << 1 );
#if 0
if (flags & I2C_M_RD )
addr |= 1;
if (flags & I2C_M_REV_DIR_ADDR )
addr ^= 1;
#endif
if (iic_inw(adap, ITE_I2CSAR) != addr) {
iic_outw(adap, ITE_I2CSAR, addr);
ret = try_address(adap, addr, retries);
if (ret!=1) {
printk("iic_doAddress: died at address code.\n");
return -EREMOTEIO;
}
}
}
return 0;
}
/* Description: Prepares the controller for a transaction (clearing status
* registers, data buffers, etc), and then calls either iic_readbytes or
* iic_sendbytes to do the actual transaction.
*
* still to be done: Before we issue a transaction, we should
* verify that the bus is not busy or in some unknown state.
*/
static int iic_xfer(struct i2c_adapter *i2c_adap,
struct i2c_msg *msgs,
int num)
{
struct i2c_algo_iic_data *adap = i2c_adap->algo_data;
struct i2c_msg *pmsg;
int i = 0;
int ret, timeout;
pmsg = &msgs[i];
if(!pmsg->len) {
DEB2(printk("iic_xfer: read/write length is 0\n");)
return -EIO;
}
if(!(pmsg->flags & I2C_M_RD) && (!(pmsg->len)%2) ) {
DEB2(printk("iic_xfer: write buffer length is not odd\n");)
return -EIO;
}
/* Wait for any pending transfers to complete */
timeout = wait_for_bb(adap);
if (timeout) {
DEB2(printk("iic_xfer: Timeout waiting for host not busy\n");)
return -EIO;
}
/* Flush FIFO */
iic_outw(adap, ITE_I2CFCR, ITE_I2CFCR_FLUSH);
/* Load address */
ret = iic_doAddress(adap, pmsg, i2c_adap->retries);
if (ret)
return -EIO;
#if 0
/* Combined transaction (read and write) */
if(num > 1) {
DEB2(printk("iic_xfer: Call combined transaction\n"));
ret = iic_combined_transaction(i2c_adap, msgs, num);
}
#endif
DEB3(printk("iic_xfer: Msg %d, addr=0x%x, flags=0x%x, len=%d\n",
i, msgs[i].addr, msgs[i].flags, msgs[i].len);)
if(pmsg->flags & I2C_M_RD) /* Read */
ret = iic_readbytes(i2c_adap, pmsg->buf, pmsg->len, 0);
else { /* Write */
udelay(1000);
ret = iic_sendbytes(i2c_adap, pmsg->buf, pmsg->len);
}
if (ret != pmsg->len)
DEB3(printk("iic_xfer: error or fail on read/write %d bytes.\n",ret));
else
DEB3(printk("iic_xfer: read/write %d bytes.\n",ret));
return ret;
}
/* Implements device specific ioctls. Higher level ioctls can
* be found in i2c-core.c and are typical of any i2c controller (specifying
* slave address, timeouts, etc). These ioctls take advantage of any hardware
* features built into the controller for which this algorithm-adapter set
* was written. These ioctls allow you to take control of the data and clock
* lines and set the either high or low,
* similar to a GPIO pin.
*/
static int algo_control(struct i2c_adapter *adapter,
unsigned int cmd, unsigned long arg)
{
struct i2c_algo_iic_data *adap = adapter->algo_data;
struct i2c_iic_msg s_msg;
char *buf;
int ret;
if (cmd == I2C_SREAD) {
if(copy_from_user(&s_msg, (struct i2c_iic_msg *)arg,
sizeof(struct i2c_iic_msg)))
return -EFAULT;
buf = kmalloc(s_msg.len, GFP_KERNEL);
if (buf== NULL)
return -ENOMEM;
/* Flush FIFO */
iic_outw(adap, ITE_I2CFCR, ITE_I2CFCR_FLUSH);
/* Load address */
iic_outw(adap, ITE_I2CSAR,s_msg.addr<<1);
iic_outw(adap, ITE_I2CSSAR,s_msg.waddr & 0xff);
ret = iic_readbytes(adapter, buf, s_msg.len, 1);
if (ret>=0) {
if(copy_to_user( s_msg.buf, buf, s_msg.len) )
ret = -EFAULT;
}
kfree(buf);
}
return 0;
}
static u32 iic_func(struct i2c_adapter *adap)
{
return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR |
I2C_FUNC_PROTOCOL_MANGLING;
}
/* -----exported algorithm data: ------------------------------------- */
static struct i2c_algorithm iic_algo = {
.master_xfer = iic_xfer,
.algo_control = algo_control, /* ioctl */
.functionality = iic_func,
};
/*
* registering functions to load algorithms at runtime
*/
int i2c_iic_add_bus(struct i2c_adapter *adap)
{
struct i2c_algo_iic_data *iic_adap = adap->algo_data;
if (iic_test) {
int ret = test_bus(iic_adap, adap->name);
if (ret<0)
return -ENODEV;
}
DEB2(printk("i2c-algo-ite: hw routines for %s registered.\n",
adap->name));
/* register new adapter to i2c module... */
adap->algo = &iic_algo;
adap->timeout = 100; /* default values, should */
adap->retries = 3; /* be replaced by defines */
adap->flags = 0;
i2c_add_adapter(adap);
iic_init(iic_adap);
return 0;
}
int i2c_iic_del_bus(struct i2c_adapter *adap)
{
int res;
if ((res = i2c_del_adapter(adap)) < 0)
return res;
DEB2(printk("i2c-algo-ite: adapter unregistered: %s\n",adap->name));
return 0;
}
int __init i2c_algo_iic_init (void)
{
printk(KERN_INFO "ITE iic (i2c) algorithm module\n");
return 0;
}
void i2c_algo_iic_exit(void)
{
return;
}
EXPORT_SYMBOL(i2c_iic_add_bus);
EXPORT_SYMBOL(i2c_iic_del_bus);
/* The MODULE_* macros resolve to nothing if MODULES is not defined
* when this file is compiled.
*/
MODULE_AUTHOR("MontaVista Software <www.mvista.com>");
MODULE_DESCRIPTION("ITE iic algorithm");
MODULE_LICENSE("GPL");
module_param(iic_test, bool, 0);
module_param(i2c_debug, int, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(iic_test, "Test if the I2C bus is available");
MODULE_PARM_DESC(i2c_debug,
"debug level - 0 off; 1 normal; 2,3 more verbose; 9 iic-protocol");
/* This function resolves to init_module (the function invoked when a module
* is loaded via insmod) when this file is compiled with MODULES defined.
* Otherwise (i.e. if you want this driver statically linked to the kernel),
* a pointer to this function is stored in a table and called
* during the initialization of the kernel (in do_basic_setup in /init/main.c)
*
* All this functionality is complements of the macros defined in linux/init.h
*/
module_init(i2c_algo_iic_init);
/* If MODULES is defined when this file is compiled, then this function will
* resolved to cleanup_module.
*/
module_exit(i2c_algo_iic_exit);