u-boot/cpu/mpc5xxx/i2c.c
wdenk 531716e171 * Patch by David Müller, 13 Sep 2003:
various changes to VCMA9 board specific files

* Add I2C support for MGT5100 / MPC5200
2003-09-13 19:01:12 +00:00

338 lines
6.9 KiB
C

/*
* (C) Copyright 2003
* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
*
* See file CREDITS for list of people who contributed to this
* project.
*
* 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 <common.h>
#ifdef CONFIG_HARD_I2C
#include <mpc5xxx.h>
#include <i2c.h>
#ifdef CFG_I2C_MODULE
#define I2C_BASE MPC5XXX_I2C2
#else
#define I2C_BASE MPC5XXX_I2C1
#endif
#define I2C_TIMEOUT 100
#define I2C_RETRIES 3
static int mpc_reg_in (volatile u32 *reg);
static void mpc_reg_out (volatile u32 *reg, int val, int mask);
static int wait_for_bb (void);
static int wait_for_pin (int *status);
static int do_address (uchar chip, char rdwr_flag);
static int send_bytes (uchar chip, char *buf, int len);
static int receive_bytes (uchar chip, char *buf, int len);
static int mpc_reg_in(volatile u32 *reg)
{
return *reg >> 24;
__asm__ __volatile__ ("eieio");
}
static void mpc_reg_out(volatile u32 *reg, int val, int mask)
{
int tmp;
if (!mask) {
*reg = val << 24;
} else {
tmp = mpc_reg_in(reg);
*reg = ((tmp & ~mask) | (val & mask)) << 24;
}
__asm__ __volatile__ ("eieio");
return;
}
static int wait_for_bb(void)
{
struct mpc5xxx_i2c *regs = (struct mpc5xxx_i2c *)I2C_BASE;
int timeout = I2C_TIMEOUT;
int status;
status = mpc_reg_in(&regs->msr);
while (timeout-- && (status & I2C_BB)) {
#if 1
volatile int temp;
mpc_reg_out(&regs->mcr, I2C_STA, I2C_STA);
temp = mpc_reg_in(&regs->mdr);
mpc_reg_out(&regs->mcr, 0, I2C_STA);
mpc_reg_out(&regs->mcr, 0, 0);
mpc_reg_out(&regs->mcr, I2C_EN, 0);
#endif
udelay(1000);
status = mpc_reg_in(&regs->msr);
}
return (status & I2C_BB);
}
static int wait_for_pin(int *status)
{
struct mpc5xxx_i2c *regs = (struct mpc5xxx_i2c *)I2C_BASE;
int timeout = I2C_TIMEOUT;
*status = mpc_reg_in(&regs->msr);
while (timeout-- && !(*status & I2C_IF)) {
udelay(1000);
*status = mpc_reg_in(&regs->msr);
}
if (!(*status & I2C_IF)) {
return -1;
}
mpc_reg_out(&regs->msr, 0, I2C_IF);
return 0;
}
static int do_address(uchar chip, char rdwr_flag)
{
struct mpc5xxx_i2c *regs = (struct mpc5xxx_i2c *)I2C_BASE;
int status;
chip <<= 1;
if (rdwr_flag) {
chip |= 1;
}
mpc_reg_out(&regs->mcr, I2C_TX, I2C_TX);
mpc_reg_out(&regs->mdr, chip, 0);
if (wait_for_pin(&status)) {
return -2;
}
if (status & I2C_RXAK) {
return -3;
}
return 0;
}
static int send_bytes(uchar chip, char *buf, int len)
{
struct mpc5xxx_i2c *regs = (struct mpc5xxx_i2c *)I2C_BASE;
int wrcount;
int status;
for (wrcount = 0; wrcount < len; ++wrcount) {
mpc_reg_out(&regs->mdr, buf[wrcount], 0);
if (wait_for_pin(&status)) {
break;
}
if (status & I2C_RXAK) {
break;
}
}
return !(wrcount == len);
}
static int receive_bytes(uchar chip, char *buf, int len)
{
struct mpc5xxx_i2c *regs = (struct mpc5xxx_i2c *)I2C_BASE;
int dummy = 1;
int rdcount = 0;
int status;
int i;
mpc_reg_out(&regs->mcr, 0, I2C_TX);
for (i = 0; i < len; ++i) {
buf[rdcount] = mpc_reg_in(&regs->mdr);
if (dummy) {
dummy = 0;
} else {
rdcount++;
}
if (wait_for_pin(&status)) {
return -4;
}
}
mpc_reg_out(&regs->mcr, I2C_TXAK, I2C_TXAK);
buf[rdcount++] = mpc_reg_in(&regs->mdr);
if (wait_for_pin(&status)) {
return -5;
}
mpc_reg_out(&regs->mcr, 0, I2C_TXAK);
return 0;
}
/**************** I2C API ****************/
void i2c_init(int speed, int saddr)
{
struct mpc5xxx_i2c *regs = (struct mpc5xxx_i2c *)I2C_BASE;
mpc_reg_out(&regs->mcr, 0, 0);
mpc_reg_out(&regs->madr, saddr << 1, 0);
/* Set clock
*/
mpc_reg_out(&regs->mfdr, speed, 0);
/* Enable module
*/
mpc_reg_out(&regs->mcr, I2C_EN, I2C_INIT_MASK);
mpc_reg_out(&regs->msr, 0, I2C_IF);
return;
}
int i2c_probe(uchar chip)
{
struct mpc5xxx_i2c *regs = (struct mpc5xxx_i2c *)I2C_BASE;
int i;
for (i = 0; i < I2C_RETRIES; i++) {
mpc_reg_out(&regs->mcr, I2C_STA, I2C_STA);
if (! do_address(chip, 0)) {
mpc_reg_out(&regs->mcr, 0, I2C_STA);
break;
}
mpc_reg_out(&regs->mcr, 0, I2C_STA);
udelay(500);
}
return (i == I2C_RETRIES);
}
int i2c_read(uchar chip, uint addr, int alen, uchar *buf, int len)
{
uchar xaddr[4];
struct mpc5xxx_i2c * regs = (struct mpc5xxx_i2c *)I2C_BASE;
int ret = -1;
xaddr[0] = (addr >> 24) & 0xFF;
xaddr[1] = (addr >> 16) & 0xFF;
xaddr[2] = (addr >> 8) & 0xFF;
xaddr[3] = addr & 0xFF;
if (wait_for_bb()) {
printf("i2c_read: bus is busy\n");
goto Done;
}
mpc_reg_out(&regs->mcr, I2C_STA, I2C_STA);
if (do_address(chip, 0)) {
printf("i2c_read: failed to address chip\n");
goto Done;
}
if (send_bytes(chip, &xaddr[4-alen], alen)) {
printf("i2c_read: send_bytes failed\n");
goto Done;
}
mpc_reg_out(&regs->mcr, I2C_RSTA, I2C_RSTA);
if (do_address(chip, 1)) {
printf("i2c_read: failed to address chip\n");
goto Done;
}
if (receive_bytes(chip, buf, len)) {
printf("i2c_read: receive_bytes failed\n");
goto Done;
}
ret = 0;
Done:
mpc_reg_out(&regs->mcr, 0, I2C_STA);
return ret;
}
int i2c_write(uchar chip, uint addr, int alen, uchar *buf, int len)
{
uchar xaddr[4];
struct mpc5xxx_i2c *regs = (struct mpc5xxx_i2c *)I2C_BASE;
int ret = -1;
xaddr[0] = (addr >> 24) & 0xFF;
xaddr[1] = (addr >> 16) & 0xFF;
xaddr[2] = (addr >> 8) & 0xFF;
xaddr[3] = addr & 0xFF;
if (wait_for_bb()) {
printf("i2c_write: bus is busy\n");
goto Done;
}
mpc_reg_out(&regs->mcr, I2C_STA, I2C_STA);
if (do_address(chip, 0)) {
printf("i2c_write: failed to address chip\n");
goto Done;
}
if (send_bytes(chip, &xaddr[4-alen], alen)) {
printf("i2c_write: send_bytes failed\n");
goto Done;
}
if (send_bytes(chip, buf, len)) {
printf("i2c_write: send_bytes failed\n");
goto Done;
}
ret = 0;
Done:
mpc_reg_out(&regs->mcr, 0, I2C_STA);
return ret;
}
uchar i2c_reg_read(uchar chip, uchar reg)
{
char buf;
i2c_read(chip, reg, 1, &buf, 1);
return buf;
}
void i2c_reg_write(uchar chip, uchar reg, uchar val)
{
i2c_write(chip, reg, 1, &val, 1);
return;
}
#endif /* CONFIG_HARD_I2C */