u-boot/arch/powerpc/cpu/mpc512x/i2c.c
Stefan Roese a47a12becf Move arch/ppc to arch/powerpc
As discussed on the list, move "arch/ppc" to "arch/powerpc" to
better match the Linux directory structure.

Please note that this patch also changes the "ppc" target in
MAKEALL to "powerpc" to match this new infrastructure. But "ppc"
is kept as an alias for now, to not break compatibility with
scripts using this name.

Signed-off-by: Stefan Roese <sr@denx.de>
Acked-by: Wolfgang Denk <wd@denx.de>
Acked-by: Detlev Zundel <dzu@denx.de>
Acked-by: Kim Phillips <kim.phillips@freescale.com>
Cc: Peter Tyser <ptyser@xes-inc.com>
Cc: Anatolij Gustschin <agust@denx.de>
2010-04-21 23:42:38 +02:00

403 lines
8.2 KiB
C

/*
* (C) Copyright 2003 - 2009
* 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
*
* Based on the MPC5xxx code.
*/
#include <common.h>
#include <asm/io.h>
DECLARE_GLOBAL_DATA_PTR;
#ifdef CONFIG_HARD_I2C
#include <i2c.h>
/* by default set I2C bus 0 active */
static unsigned int bus_num __attribute__ ((section (".data"))) = 0;
#define I2C_TIMEOUT 100
#define I2C_RETRIES 3
struct mpc512x_i2c_tap {
int scl2tap;
int tap2tap;
};
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_get_fdr(int);
static int mpc_reg_in (volatile u32 *reg)
{
int ret = in_be32(reg) >> 24;
return ret;
}
static void mpc_reg_out (volatile u32 *reg, int val, int mask)
{
if (!mask) {
out_be32(reg, val << 24);
} else {
clrsetbits_be32(reg, mask << 24, (val & mask) << 24);
}
}
static int wait_for_bb (void)
{
volatile immap_t *im = (immap_t *) CONFIG_SYS_IMMR;
volatile i2c512x_dev_t *regs = &im->i2c.dev[bus_num];
int timeout = I2C_TIMEOUT;
int status;
status = mpc_reg_in (&regs->msr);
while (timeout-- && (status & I2C_BB)) {
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);
udelay (1000);
status = mpc_reg_in (&regs->msr);
}
return (status & I2C_BB);
}
static int wait_for_pin (int *status)
{
volatile immap_t *im = (immap_t *) CONFIG_SYS_IMMR;
volatile i2c512x_dev_t *regs = &im->i2c.dev[bus_num];
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)
{
volatile immap_t *im = (immap_t *) CONFIG_SYS_IMMR;
volatile i2c512x_dev_t *regs = &im->i2c.dev[bus_num];
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)
{
volatile immap_t *im = (immap_t *) CONFIG_SYS_IMMR;
volatile i2c512x_dev_t *regs = &im->i2c.dev[bus_num];
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)
{
volatile immap_t *im = (immap_t *) CONFIG_SYS_IMMR;
volatile i2c512x_dev_t *regs = &im->i2c.dev[bus_num];
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)
{
volatile immap_t *im = (immap_t *) CONFIG_SYS_IMMR;
int i;
for (i = 0; i < I2C_BUS_CNT; i++){
volatile i2c512x_dev_t *regs = &im->i2c.dev[i];
mpc_reg_out (&regs->mcr, 0, 0);
/* Set clock */
mpc_reg_out (&regs->mfdr, mpc_get_fdr (speed), 0);
mpc_reg_out (&regs->madr, saddr << 1, 0);
/* Enable module */
mpc_reg_out (&regs->mcr, I2C_EN, I2C_INIT_MASK);
mpc_reg_out (&regs->msr, 0, I2C_IF);
}
/* Disable interrupts */
out_be32(&im->i2c.icr, 0);
/* Turn off filters */
out_be32(&im->i2c.mifr, 0);
}
static int mpc_get_fdr (int speed)
{
static int fdr = -1;
if (fdr == -1) {
ulong best_speed = 0;
ulong divider;
ulong ips, scl;
ulong bestmatch = 0xffffffffUL;
int best_i = 0, best_j = 0, i, j;
int SCL_Tap[] = { 9, 10, 12, 15, 5, 6, 7, 8};
struct mpc512x_i2c_tap scltap[] = {
{4, 1},
{4, 2},
{6, 4},
{6, 8},
{14, 16},
{30, 32},
{62, 64},
{126, 128}
};
ips = gd->ips_clk;
for (i = 7; i >= 0; i--) {
for (j = 7; j >= 0; j--) {
scl = 2 * (scltap[j].scl2tap +
(SCL_Tap[i] - 1) * scltap[j].tap2tap
+ 2);
if (ips <= speed*scl) {
if ((speed*scl - ips) < bestmatch) {
bestmatch = speed*scl - ips;
best_i = i;
best_j = j;
best_speed = ips/scl;
}
}
}
}
divider = (best_i & 3) | ((best_i & 4) << 3) | (best_j << 2);
if (gd->flags & GD_FLG_RELOC) {
fdr = divider;
} else {
debug("%ld kHz, \n", best_speed / 1000);
return divider;
}
}
return fdr;
}
int i2c_probe (uchar chip)
{
volatile immap_t *im = (immap_t *) CONFIG_SYS_IMMR;
volatile i2c512x_dev_t *regs = &im->i2c.dev[bus_num];
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);
udelay (500);
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)
{
volatile immap_t *im = (immap_t *) CONFIG_SYS_IMMR;
volatile i2c512x_dev_t *regs = &im->i2c.dev[bus_num];
char xaddr[4];
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, (char *)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)
{
volatile immap_t *im = (immap_t *) CONFIG_SYS_IMMR;
volatile i2c512x_dev_t *regs = &im->i2c.dev[bus_num];
char xaddr[4];
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, (char *)buf, len)) {
printf ("i2c_write: send_bytes failed\n");
goto Done;
}
ret = 0;
Done:
mpc_reg_out (&regs->mcr, 0, I2C_STA);
return ret;
}
int i2c_set_bus_num (unsigned int bus)
{
if (bus >= I2C_BUS_CNT) {
return -1;
}
bus_num = bus;
return 0;
}
unsigned int i2c_get_bus_num (void)
{
return bus_num;
}
#endif /* CONFIG_HARD_I2C */