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/* Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
/* I2C cross-platform code for Chrome EC */
#include "clock.h"
#include "console.h"
#include "host_command.h"
#include "i2c.h"
#include "system.h"
#include "task.h"
#include "util.h"
#include "watchdog.h"
extern const struct i2c_port_t i2c_ports[I2C_PORTS_USED];
static struct mutex port_mutex[I2C_PORT_COUNT];
void i2c_lock(int port, int lock)
{
if (lock) {
#ifdef CHIP_stm32
/* Don't allow deep sleep when I2C port is locked */
disable_sleep(SLEEP_MASK_I2C);
#endif
mutex_lock(port_mutex + port);
} else {
mutex_unlock(port_mutex + port);
#ifdef CHIP_stm32
/* Allow deep sleep again after I2C port is unlocked */
enable_sleep(SLEEP_MASK_I2C);
#endif
}
}
int i2c_read16(int port, int slave_addr, int offset, int *data)
{
int rv;
uint8_t reg, buf[2];
reg = offset & 0xff;
/* I2C read 16-bit word: transmit 8-bit offset, and read 16bits */
i2c_lock(port, 1);
rv = i2c_xfer(port, slave_addr, ®, 1, buf, 2, I2C_XFER_SINGLE);
i2c_lock(port, 0);
if (rv)
return rv;
if (slave_addr & I2C_FLAG_BIG_ENDIAN)
*data = ((int)buf[0] << 8) | buf[1];
else
*data = ((int)buf[1] << 8) | buf[0];
return EC_SUCCESS;
}
int i2c_write16(int port, int slave_addr, int offset, int data)
{
int rv;
uint8_t buf[3];
buf[0] = offset & 0xff;
if (slave_addr & I2C_FLAG_BIG_ENDIAN) {
buf[1] = (data >> 8) & 0xff;
buf[2] = data & 0xff;
} else {
buf[1] = data & 0xff;
buf[2] = (data >> 8) & 0xff;
}
i2c_lock(port, 1);
rv = i2c_xfer(port, slave_addr, buf, 3, NULL, 0, I2C_XFER_SINGLE);
i2c_lock(port, 0);
return rv;
}
int i2c_read8(int port, int slave_addr, int offset, int *data)
{
int rv;
/* We use buf[1] here so it's aligned for DMA on STM32 */
uint8_t reg, buf[1];
reg = offset;
i2c_lock(port, 1);
rv = i2c_xfer(port, slave_addr, ®, 1, buf, 1, I2C_XFER_SINGLE);
i2c_lock(port, 0);
if (!rv)
*data = buf[0];
return rv;
}
int i2c_write8(int port, int slave_addr, int offset, int data)
{
int rv;
uint8_t buf[2];
buf[0] = offset;
buf[1] = data;
i2c_lock(port, 1);
rv = i2c_xfer(port, slave_addr, buf, 2, 0, 0, I2C_XFER_SINGLE);
i2c_lock(port, 0);
return rv;
}
/*****************************************************************************/
/* Host commands */
/* TODO: replace with single I2C passthru command */
static int i2c_command_read(struct host_cmd_handler_args *args)
{
const struct ec_params_i2c_read *p = args->params;
struct ec_response_i2c_read *r = args->response;
int data, rv = -1;
if (system_is_locked())
return EC_RES_ACCESS_DENIED;
if (p->read_size == 16)
rv = i2c_read16(p->port, p->addr, p->offset, &data);
else if (p->read_size == 8)
rv = i2c_read8(p->port, p->addr, p->offset, &data);
if (rv)
return EC_RES_ERROR;
r->data = data;
args->response_size = sizeof(*r);
return EC_RES_SUCCESS;
}
DECLARE_HOST_COMMAND(EC_CMD_I2C_READ, i2c_command_read, EC_VER_MASK(0));
static int i2c_command_write(struct host_cmd_handler_args *args)
{
const struct ec_params_i2c_write *p = args->params;
int rv = -1;
if (system_is_locked())
return EC_RES_ACCESS_DENIED;
if (p->write_size == 16)
rv = i2c_write16(p->port, p->addr, p->offset, p->data);
else if (p->write_size == 8)
rv = i2c_write8(p->port, p->addr, p->offset, p->data);
if (rv)
return EC_RES_ERROR;
return EC_RES_SUCCESS;
}
DECLARE_HOST_COMMAND(EC_CMD_I2C_WRITE, i2c_command_write, EC_VER_MASK(0));
/*****************************************************************************/
/* Console commands */
static void scan_bus(int port, const char *desc)
{
int a;
uint8_t tmp;
ccprintf("Scanning %d %s", port, desc);
/* Don't scan a busy port, since reads will just fail / time out */
a = i2c_get_line_levels(port);
if (a != I2C_LINE_IDLE) {
ccprintf(": port busy (SDA=%d, SCL=%d)\n",
(a & I2C_LINE_SDA_HIGH) ? 1 : 0,
(a & I2C_LINE_SCL_HIGH) ? 1 : 0);
return;
}
i2c_lock(port, 1);
for (a = 0; a < 0x100; a += 2) {
watchdog_reload(); /* Otherwise a full scan trips watchdog */
ccputs(".");
#if defined(CHIP_VARIANT_stm32f100) || defined(CHIP_VARIANT_stm32f10x)
/*
* Hope that address 0 exists, because the i2c_xfer()
* implementation on STM32 can't read a byte without writing
* one first.
*
* TODO: remove when that limitation is fixed.
*/
tmp = 0;
if (!i2c_xfer(port, a, &tmp, 1, &tmp, 1, I2C_XFER_SINGLE))
#else
/* Do a single read */
if (!i2c_xfer(port, a, NULL, 0, &tmp, 1, I2C_XFER_SINGLE))
#endif
ccprintf("\n 0x%02x", a);
}
i2c_lock(port, 0);
ccputs("\n");
}
static int command_scan(int argc, char **argv)
{
int i;
for (i = 0; i < I2C_PORTS_USED; i++)
scan_bus(i2c_ports[i].port, i2c_ports[i].name);
return EC_SUCCESS;
}
DECLARE_CONSOLE_COMMAND(i2cscan, command_scan,
NULL,
"Scan I2C ports for devices",
NULL);
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