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u-boot/arch/powerpc/cpu/mpc512x/i2c.c
Wolfgang Denk 1a4596601f Add GPL-2.0+ SPDX-License-Identifier to source files 
Signed-off-by: Wolfgang Denk <wd@denx.de>
[trini: Fixup common/cmd_io.c]
Signed-off-by: Tom Rini <trini@ti.com>
2013-07-24 09:44:38 -04:00

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/*
* (C) Copyright 2003 - 2009
* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
*
* SPDX-License-Identifier: GPL-2.0+
*
* 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)) {
mpc_reg_out (&regs->mcr, I2C_STA, I2C_STA);
(void)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->arch.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 */
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