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/*
* Copyright 2016-2020 NXP
*
* SPDX-License-Identifier: BSD-3-Clause
*
*/
#include <errno.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <common/debug.h>
#include <drivers/delay_timer.h>
#include "i2c.h"
#include <nxp_timer.h>
static uintptr_t g_nxp_i2c_addr;
void i2c_init(uintptr_t nxp_i2c_addr)
{
struct ls_i2c *ccsr_i2c = (void *)nxp_i2c_addr;
g_nxp_i2c_addr = nxp_i2c_addr;
/* Presume workaround for erratum a009203 applied */
i2c_out(&ccsr_i2c->cr, I2C_CR_DIS);
i2c_out(&ccsr_i2c->fd, I2C_FD_CONSERV);
i2c_out(&ccsr_i2c->sr, I2C_SR_RST);
i2c_out(&ccsr_i2c->cr, I2C_CR_EN);
}
static int wait_for_state(struct ls_i2c *ccsr_i2c,
unsigned char state, unsigned char mask)
{
unsigned char sr;
uint64_t start_time = get_timer_val(0);
uint64_t timer;
do {
sr = i2c_in(&ccsr_i2c->sr);
if (sr & I2C_SR_AL) {
i2c_out(&ccsr_i2c->sr, sr);
WARN("I2C arbitration lost\n");
return -EIO;
}
if ((sr & mask) == state) {
return (int)sr;
}
timer = get_timer_val(start_time);
if (timer > I2C_TIMEOUT)
break;
mdelay(1);
} while (1);
WARN("I2C: Timeout waiting for state 0x%x, sr = 0x%x\n", state, sr);
return -ETIMEDOUT;
}
static int tx_byte(struct ls_i2c *ccsr_i2c, unsigned char c)
{
int ret;
i2c_out(&ccsr_i2c->sr, I2C_SR_IF);
i2c_out(&ccsr_i2c->dr, c);
ret = wait_for_state(ccsr_i2c, I2C_SR_IF, I2C_SR_IF);
if (ret < 0) {
WARN("%s: state error\n", __func__);
return ret;
}
if (ret & I2C_SR_RX_NAK) {
WARN("%s: nodev\n", __func__);
return -ENODEV;
}
return 0;
}
static int gen_stop(struct ls_i2c *ccsr_i2c)
{
unsigned char cr;
int ret;
cr = i2c_in(&ccsr_i2c->cr);
cr &= ~(I2C_CR_MA | I2C_CR_TX);
i2c_out(&ccsr_i2c->cr, cr);
ret = wait_for_state(ccsr_i2c, I2C_SR_IDLE, I2C_SR_BB);
if (ret < 0) {
WARN("I2C: Generating stop failed.\n");
}
return ret;
}
static int i2c_write_addr(struct ls_i2c *ccsr_i2c, unsigned char chip,
int addr, int alen)
{
int ret;
unsigned char cr;
if (alen != 1) {
WARN("I2C: Unsupported address len [%d]\n", alen);
return -EIO;
}
if (i2c_in(&ccsr_i2c->ad) == (chip << 1)) {
WARN("I2C: slave address same as self\n");
return -ENODEV;
}
i2c_out(&ccsr_i2c->sr, I2C_SR_IF);
ret = wait_for_state(ccsr_i2c, I2C_SR_IDLE, I2C_SR_BB);
if (ret < 0) {
return ret;
}
cr = i2c_in(&ccsr_i2c->cr);
cr |= I2C_CR_MA;
i2c_out(&ccsr_i2c->cr, cr);
ret = wait_for_state(ccsr_i2c, I2C_SR_BB, I2C_SR_BB);
if (ret < 0) {
return ret;
}
VERBOSE("Before writing chip %d\n", chip);
cr |= I2C_CR_TX | I2C_CR_TX_NAK;
i2c_out(&ccsr_i2c->cr, cr);
ret = tx_byte(ccsr_i2c, chip << 1);
if (ret < 0) {
gen_stop(ccsr_i2c);
return ret;
}
VERBOSE("Before writing addr\n");
while (alen--) {
ret = tx_byte(ccsr_i2c, (addr >> (alen << 3)) & 0xff);
if (ret < 0) {
gen_stop(ccsr_i2c);
return ret;
}
}
return 0;
}
static int read_data(struct ls_i2c *ccsr_i2c, unsigned char chip,
unsigned char *buf, int len)
{
int i;
int ret;
unsigned char cr;
cr = i2c_in(&ccsr_i2c->cr);
cr &= ~(I2C_CR_TX | I2C_CR_TX_NAK);
if (len == 1) {
cr |= I2C_CR_TX_NAK;
}
i2c_out(&ccsr_i2c->cr, cr);
i2c_out(&ccsr_i2c->sr, I2C_SR_IF);
i2c_in(&ccsr_i2c->dr); /* dummy read */
for (i = 0; i < len; i++) {
ret = wait_for_state(ccsr_i2c, I2C_SR_IF, I2C_SR_IF);
if (ret < 0) {
gen_stop(ccsr_i2c);
return ret;
}
if (i == (len - 1)) {
gen_stop(ccsr_i2c);
} else if (i == (len - 2)) {
/* Updating the command to send
* No ACK.
*/
cr = i2c_in(&ccsr_i2c->cr);
cr |= I2C_CR_TX_NAK;
i2c_out(&ccsr_i2c->cr, cr);
}
i2c_out(&ccsr_i2c->sr, I2C_SR_IF);
buf[i] = i2c_in(&ccsr_i2c->dr);
}
return 0;
}
static int write_data(struct ls_i2c *ccsr_i2c, unsigned char chip,
const unsigned char *buf, int len)
{
int i;
int ret;
for (i = 0; i < len; i++) {
ret = tx_byte(ccsr_i2c, buf[i]);
if (ret < 0) {
break;
}
}
ret = gen_stop(ccsr_i2c);
return ret;
}
int i2c_read(unsigned char chip, int addr, int alen,
unsigned char *buf, int len)
{
int ret;
unsigned char cr;
struct ls_i2c *ccsr_i2c = (void *)g_nxp_i2c_addr;
ret = i2c_write_addr(ccsr_i2c, chip, addr, alen);
if (ret < 0) {
gen_stop(ccsr_i2c);
return ret;
}
cr = i2c_in(&ccsr_i2c->cr);
cr |= I2C_CR_RSTA;
i2c_out(&ccsr_i2c->cr, cr);
ret = tx_byte(ccsr_i2c, (chip << 1) | 1);
if (ret < 0) {
gen_stop(ccsr_i2c);
return ret;
}
return read_data(ccsr_i2c, chip, buf, len);
}
int i2c_write(unsigned char chip, int addr, int alen,
const unsigned char *buf, int len)
{
int ret;
struct ls_i2c *ccsr_i2c = (void *)g_nxp_i2c_addr;
ret = i2c_write_addr(ccsr_i2c, chip, addr, alen);
if (ret < 0) {
return ret;
}
return write_data(ccsr_i2c, chip, buf, len);
}
int i2c_probe_chip(unsigned char chip)
{
int ret;
struct ls_i2c *ccsr_i2c = (void *)g_nxp_i2c_addr;
ret = i2c_write_addr(ccsr_i2c, chip, 0, 0);
if (ret < 0) {
WARN("write addr failed\n");
return ret;
}
ret = gen_stop(ccsr_i2c);
if (ret < 0) {
WARN("I2C: Probe not complete.\n");
}
return ret;
}
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