/*
-------------------------------------------------------------------------
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;
iic_init(iic_adap);
return i2c_add_adapter(adap);
}
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);
