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/*
* This file is part of the coreboot project.
*
* Copyright (C) 2016 Intel Corporation.
*
* 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; version 2 of the License.
*
* 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.
*/
#include <assert.h>
#include <console/console.h>
#include <delay.h>
#include <device/device.h>
#include <device/i2c.h>
#include <device/pci.h>
#include <device/pci_ids.h>
#include <soc/i2c.h>
#include <soc/ramstage.h>
#include <soc/reg_access.h>
static void i2c_disable(I2C_REGS *regs)
{
uint32_t status;
uint32_t timeout;
/* Disable I2C controller */
regs->ic_enable = 0;
/* Wait for the enable bit to clear */
timeout = 1 * 1000 * 1000;
status = regs->ic_enable_status;
while (status & IC_ENABLE_CONTROLLER) {
udelay(1);
if (--timeout == 0)
die("ERROR - I2C failed to disable!\n");
status = regs->ic_enable_status;
}
/* Clear any pending interrupts */
status = regs->ic_clr_intr;
}
int platform_i2c_transfer(unsigned bus, struct i2c_seg *segments, int count)
{
uint8_t *buffer;
int bytes_transferred;
uint8_t chip;
uint32_t cmd;
int length;
int read_length;
I2C_REGS *regs;
uint32_t status;
uint32_t timeout;
regs = get_i2c_address();
/* Disable the I2C controller to get access to the registers */
i2c_disable(regs);
/* Set the slave address */
ASSERT (count > 0);
ASSERT (segments != NULL);
ASSERT (segments->read == 0);
/* Clear the start and stop detection */
status = regs->ic_clr_start_det;
status = regs->ic_clr_stop_det;
/* Set addressing mode to 7-bit and fast mode */
cmd = regs->ic_con;
cmd &= ~(IC_CON_10B | IC_CON_SPEED);
cmd |= IC_CON_RESTART_EN | IC_CON_7B | IC_CON_SPEED_100_KHz
| IC_CON_MASTER_MODE;
regs->ic_con = cmd;
/* Set the target chip address */
chip = segments->chip;
regs->ic_tar = chip;
/* Enable the I2C controller */
regs->ic_enable = IC_ENABLE_CONTROLLER;
/* Clear the interrupts */
status = regs->ic_clr_rx_under;
status = regs->ic_clr_rx_over;
status = regs->ic_clr_tx_over;
status = regs->ic_clr_tx_abrt;
/* Process each of the segments */
bytes_transferred = 0;
read_length = 0;
buffer = NULL;
while (count-- > 0) {
buffer = segments->buf;
length = segments->len;
ASSERT (buffer != NULL);
ASSERT (length >= 1);
ASSERT (segments->chip = chip);
if (segments->read) {
/* Place read commands into the FIFO */
read_length = length;
while (length > 0) {
/* Send stop bit after last byte */
cmd = IC_DATA_CMD_READ;
if ((count == 0) && (length == 1))
cmd |= IC_DATA_CMD_STOP;
/* Place read command in transmit FIFO */
regs->ic_data_cmd = cmd;
length--;
}
} else {
/* Write the data into the FIFO */
while (length > 0) {
/* End of the transaction? */
cmd = IC_DATA_CMD_WRITE | *buffer++;
if ((count == 0) && (length == 1))
cmd |= IC_DATA_CMD_STOP;
/* Place a data byte into the FIFO */
regs->ic_data_cmd = cmd;
length--;
bytes_transferred++;
}
}
segments++;
}
/* Wait for the end of the transaction */
timeout = 1 * 1000 * 1000;
do {
status = regs->ic_raw_intr_stat;
if (status & IC_INTR_STOP_DET)
break;
if ((status & (IC_INTR_RX_OVER | IC_INTR_RX_UNDER
| IC_INTR_TX_ABRT | IC_INTR_TX_OVER))
|| (timeout == 0)) {
if (timeout == 0)
printk (BIOS_ERR,
"ERROR - I2C stop bit not received!\n");
if (status & IC_INTR_RX_OVER)
printk (BIOS_ERR,
"ERROR - I2C receive overrun!\n");
if (status & IC_INTR_RX_UNDER)
printk (BIOS_ERR,
"ERROR - I2C receive underrun!\n");
if (status & IC_INTR_TX_ABRT)
printk (BIOS_ERR,
"ERROR - I2C transmit abort!\n");
if (status & IC_INTR_TX_OVER)
printk (BIOS_ERR,
"ERROR - I2C transmit overrun!\n");
i2c_disable(regs);
return -1;
}
timeout--;
udelay(1);
} while(1);
/* Finish reading the data bytes */
while (read_length > 0) {
status = regs->ic_status;
*buffer++ = (uint8_t)regs->ic_data_cmd;
read_length--;
bytes_transferred++;
status = regs->ic_status;
}
return bytes_transferred;
}
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