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/*
* This file is part of the coreboot project.
*
* Copyright 2013 Google Inc.
*
* 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.
*
* 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <arch/io.h>
#include <console/console.h>
#include <device/i2c.h>
#include <stdlib.h>
#include <string.h>
#include <soc/addressmap.h>
#include "i2c.h"
static int tegra_i2c_send_recv(struct tegra_i2c_regs *regs, int read,
uint32_t *headers, int header_words,
uint8_t *data, int data_len)
{
while (data_len) {
uint32_t status = read32(®s->fifo_status);
int tx_empty =
status & TEGRA_I2C_FIFO_STATUS_TX_FIFO_EMPTY_CNT_MASK;
tx_empty >>= TEGRA_I2C_FIFO_STATUS_TX_FIFO_EMPTY_CNT_SHIFT;
int rx_full =
status & TEGRA_I2C_FIFO_STATUS_RX_FIFO_FULL_CNT_MASK;
rx_full >>= TEGRA_I2C_FIFO_STATUS_RX_FIFO_FULL_CNT_SHIFT;
while (header_words && tx_empty) {
write32(*headers++, ®s->tx_packet_fifo);
header_words--;
tx_empty--;
}
if (!header_words) {
if (read) {
while (data_len && rx_full) {
uint32_t word = read32(®s->rx_fifo);
int todo = MIN(data_len, sizeof(word));
memcpy(data, &word, todo);
data_len -= todo;
data += sizeof(word);
rx_full--;
}
} else {
while (data_len && tx_empty) {
uint32_t word;
int todo = MIN(data_len, sizeof(word));
memcpy(&word, data, todo);
write32(word, ®s->tx_packet_fifo);
data_len -= todo;
data += sizeof(word);
tx_empty--;
}
}
}
uint32_t transfer_status =
read32(®s->packet_transfer_status);
if (transfer_status & TEGRA_I2C_PKT_STATUS_NOACK_ADDR_MASK) {
printk(BIOS_ERR,
"%s: The address was not acknowledged.\n",
__func__);
return -1;
} else if (transfer_status &
TEGRA_I2C_PKT_STATUS_NOACK_DATA_MASK) {
printk(BIOS_ERR,
"%s: The data was not acknowledged.\n",
__func__);
return -1;
} else if (transfer_status &
TEGRA_I2C_PKT_STATUS_ARB_LOST_MASK) {
printk(BIOS_ERR,
"%s: Lost arbitration.\n",
__func__);
return -1;
}
}
return 0;
}
static int tegra_i2c_request(int bus, unsigned chip, int cont, int restart,
int read, void *data, int data_len)
{
struct tegra_i2c_regs * const regs = tegra_i2c_bases[bus];
uint32_t headers[3];
if (restart && cont) {
printk(BIOS_ERR, "%s: Repeat start and continue xfer are "
"mutually exclusive.\n", __func__);
return -1;
}
headers[0] = (0 << IOHEADER_WORD0_PROTHDRSZ_SHIFT) |
(1 << IOHEADER_WORD0_PKTID_SHIFT) |
(bus << IOHEADER_WORD0_CONTROLLER_ID_SHIFT) |
IOHEADER_WORD0_PROTOCOL_I2C |
IOHEADER_WORD0_PKTTYPE_REQUEST;
headers[1] = (data_len - 1) << IOHEADER_WORD1_PAYLOADSIZE_SHIFT;
uint32_t slave_addr = (chip << 1) | (read ? 1 : 0);
headers[2] = IOHEADER_I2C_REQ_ADDRESS_MODE_7BIT |
(slave_addr << IOHEADER_I2C_REQ_SLAVE_ADDR_SHIFT);
if (read)
headers[2] |= IOHEADER_I2C_REQ_READ_WRITE_READ;
else
headers[2] |= IOHEADER_I2C_REQ_READ_WRITE_WRITE;
if (restart)
headers[2] |= IOHEADER_I2C_REQ_REPEAT_START_STOP_START;
if (cont)
headers[2] |= IOHEADER_I2C_REQ_CONTINUE_XFER_MASK;
return tegra_i2c_send_recv(regs, read, headers, ARRAY_SIZE(headers),
data, data_len);
}
static int i2c_readwrite(unsigned bus, unsigned chip, unsigned addr,
unsigned alen, uint8_t *buf, unsigned len, int read)
{
const uint32_t max_payload =
(IOHEADER_WORD1_PAYLOADSIZE_MASK + 1) >>
IOHEADER_WORD1_PAYLOADSIZE_SHIFT;
uint8_t abuf[sizeof(addr)];
int i;
for (i = 0; i < alen; i++)
abuf[i] = addr >> ((alen - i - 1) * 8);
if (tegra_i2c_request(bus, chip, !read, 0, 0, abuf, alen))
return -1;
while (len) {
int todo = MIN(len, max_payload);
int cont = (todo < len);
if (tegra_i2c_request(bus, chip, cont, 0, read, buf, todo)) {
// We should reset the controller here.
return -1;
}
len -= todo;
buf += todo;
}
return 0;
}
int i2c_read(unsigned bus, unsigned chip, unsigned addr,
unsigned alen, uint8_t *buf, unsigned len)
{
return i2c_readwrite(bus, chip, addr, alen, buf, len, 1);
}
int i2c_write(unsigned bus, unsigned chip, unsigned addr,
unsigned alen, const uint8_t *buf, unsigned len)
{
return i2c_readwrite(bus, chip, addr, alen, (void *)buf, len, 0);
}
void i2c_init(unsigned bus)
{
struct tegra_i2c_regs * const regs = tegra_i2c_bases[bus];
write32(TEGRA_I2C_CNFG_PACKET_MODE_EN_MASK, ®s->cnfg);
}
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