blob: 331d5e3263ac94146f8333f2d544ceb3197c84a7 [file] [log] [blame] [edit]
/*
* Copyright (c), 2023 Basalte bv
*
* SPDX-License-Identifier: Apache-2.0
*/
#define DT_DRV_COMPAT nxp_sc18im704_i2c
#include <errno.h>
#include <zephyr/kernel.h>
#include <zephyr/device.h>
#include <zephyr/init.h>
#include <zephyr/drivers/gpio.h>
#include <zephyr/drivers/i2c.h>
#include <zephyr/drivers/uart.h>
#include <zephyr/logging/log.h>
LOG_MODULE_REGISTER(i2c_sc18im, CONFIG_I2C_LOG_LEVEL);
#include "i2c_sc18im704.h"
struct i2c_sc18im_config {
const struct device *bus;
uint32_t bus_speed;
const struct gpio_dt_spec reset_gpios;
};
struct i2c_sc18im_data {
struct k_mutex lock;
uint32_t i2c_config;
};
int sc18im704_claim(const struct device *dev)
{
struct i2c_sc18im_data *data = dev->data;
return k_mutex_lock(&data->lock, K_FOREVER);
}
int sc18im704_release(const struct device *dev)
{
struct i2c_sc18im_data *data = dev->data;
return k_mutex_unlock(&data->lock);
}
int sc18im704_transfer(const struct device *dev,
const uint8_t *tx_data, uint8_t tx_len,
uint8_t *rx_data, uint8_t rx_len)
{
const struct i2c_sc18im_config *cfg = dev->config;
struct i2c_sc18im_data *data = dev->data;
int ret = 0;
ret = k_mutex_lock(&data->lock, K_FOREVER);
if (ret < 0) {
return ret;
}
if (tx_data != NULL) {
for (uint8_t i = 0; i < tx_len; ++i) {
uart_poll_out(cfg->bus, tx_data[i]);
}
}
if (rx_data != NULL) {
uint64_t end;
for (uint8_t i = 0; i < rx_len && ret == 0; ++i) {
/* Make sure we don't wait forever */
end = sys_clock_timeout_end_calc(K_SECONDS(1));
do {
ret = uart_poll_in(cfg->bus, &rx_data[i]);
} while (ret == -1 && end > k_uptime_ticks());
}
/* -1 indicates we timed out */
ret = ret == -1 ? -EAGAIN : ret;
if (ret < 0) {
LOG_ERR("Failed to read data (%d)", ret);
}
}
k_mutex_unlock(&data->lock);
return ret;
}
static int i2c_sc18im_configure(const struct device *dev, uint32_t config)
{
struct i2c_sc18im_data *data = dev->data;
if (!(I2C_MODE_CONTROLLER & config)) {
return -EINVAL;
}
if (I2C_ADDR_10_BITS & config) {
return -EINVAL;
}
if (I2C_SPEED_GET(config) != I2C_SPEED_GET(data->i2c_config)) {
uint8_t buf[] = {
SC18IM704_CMD_WRITE_REG,
SC18IM704_REG_I2C_CLK_L,
0,
SC18IM704_CMD_STOP,
};
int ret;
/* CLK value is calculated as 15000000 / (8 * freq), see datasheet */
switch (I2C_SPEED_GET(config)) {
case I2C_SPEED_STANDARD:
buf[2] = 0x13; /* 99 kHz */
break;
case I2C_SPEED_FAST:
buf[2] = 0x05; /* 375 kHz */
break;
default:
return -EINVAL;
}
ret = sc18im704_transfer(dev, buf, sizeof(buf), NULL, 0);
if (ret < 0) {
LOG_ERR("Failed to set I2C speed (%d)", ret);
return -EIO;
}
}
data->i2c_config = config;
return 0;
}
static int i2c_sc18im_get_config(const struct device *dev, uint32_t *config)
{
struct i2c_sc18im_data *data = dev->data;
*config = data->i2c_config;
return 0;
}
static int i2c_sc18im_transfer_msg(const struct device *dev,
struct i2c_msg *msg,
uint16_t addr)
{
uint8_t start[] = {
SC18IM704_CMD_I2C_START,
0x00,
0x00,
};
uint8_t stop = SC18IM704_CMD_STOP;
int ret;
if (msg->flags & I2C_MSG_ADDR_10_BITS || msg->len > UINT8_MAX) {
return -EINVAL;
}
start[1] = addr | (msg->flags & I2C_MSG_RW_MASK);
start[2] = msg->len;
ret = sc18im704_transfer(dev, start, sizeof(start), NULL, 0);
if (ret < 0) {
return ret;
}
if (msg->flags & I2C_MSG_READ) {
/* Send the stop character before reading */
ret = sc18im704_transfer(dev, &stop, 1, msg->buf, msg->len);
if (ret < 0) {
return ret;
}
} else {
ret = sc18im704_transfer(dev, msg->buf, msg->len, NULL, 0);
if (ret < 0) {
return ret;
}
if (msg->flags & I2C_MSG_STOP) {
ret = sc18im704_transfer(dev, &stop, 1, NULL, 0);
if (ret < 0) {
return ret;
}
}
}
return 0;
}
static int i2c_sc18im_transfer(const struct device *dev,
struct i2c_msg *msgs,
uint8_t num_msgs, uint16_t addr)
{
int ret;
if (num_msgs == 0) {
return 0;
}
ret = sc18im704_claim(dev);
if (ret < 0) {
LOG_ERR("Failed to claim I2C bridge (%d)", ret);
return ret;
}
for (uint8_t i = 0; i < num_msgs && ret == 0; ++i) {
ret = i2c_sc18im_transfer_msg(dev, &msgs[i], addr);
}
#ifdef CONFIG_I2C_SC18IM704_VERIFY
if (ret == 0) {
uint8_t buf[] = {
SC18IM704_CMD_READ_REG,
SC18IM704_REG_I2C_STAT,
SC18IM704_CMD_STOP,
};
uint8_t data;
ret = sc18im704_transfer(dev, buf, sizeof(buf), &data, 1);
if (ret == 0 && data != SC18IM704_I2C_STAT_OK) {
ret = -EIO;
}
}
#endif /* CONFIG_I2C_SC18IM704_VERIFY */
sc18im704_release(dev);
return ret;
}
static int i2c_sc18im_init(const struct device *dev)
{
const struct i2c_sc18im_config *cfg = dev->config;
struct i2c_sc18im_data *data = dev->data;
int ret;
/* The device baudrate after reset is 9600 */
struct uart_config uart_cfg = {
.baudrate = 9600,
.parity = UART_CFG_PARITY_NONE,
.stop_bits = UART_CFG_STOP_BITS_1,
.data_bits = UART_CFG_DATA_BITS_8,
.flow_ctrl = UART_CFG_FLOW_CTRL_NONE,
};
k_mutex_init(&data->lock);
if (!device_is_ready(cfg->bus)) {
LOG_ERR("UART bus not ready");
return -ENODEV;
}
ret = uart_configure(cfg->bus, &uart_cfg);
if (ret < 0) {
LOG_ERR("Failed to configure UART (%d)", ret);
return ret;
}
if (cfg->reset_gpios.port) {
uint8_t buf[2];
if (!device_is_ready(cfg->reset_gpios.port)) {
LOG_ERR("Reset GPIO device not ready");
return -ENODEV;
}
ret = gpio_pin_configure_dt(&cfg->reset_gpios, GPIO_OUTPUT_ACTIVE);
if (ret < 0) {
LOG_ERR("Failed to configure reset GPIO (%d)", ret);
return ret;
}
ret = gpio_pin_set_dt(&cfg->reset_gpios, 0);
if (ret < 0) {
LOG_ERR("Failed to set reset GPIO (%d)", ret);
return ret;
}
/* The device sends "OK" */
ret = sc18im704_transfer(dev, NULL, 0, buf, sizeof(buf));
if (ret < 0) {
LOG_ERR("Failed to get OK (%d)", ret);
return ret;
}
}
if (cfg->bus_speed != 9600) {
uint16_t brg = (7372800 / cfg->bus_speed) - 16;
uint8_t buf[] = {
SC18IM704_CMD_WRITE_REG,
SC18IM704_REG_BRG0,
brg & 0xff,
SC18IM704_REG_BRG1,
brg >> 8,
SC18IM704_CMD_STOP,
};
ret = sc18im704_transfer(dev, buf, sizeof(buf), NULL, 0);
if (ret < 0) {
LOG_ERR("Failed to set baudrate (%d)", ret);
return ret;
}
/* Make sure UART buffer is sent */
k_msleep(1);
/* Re-configure the UART controller with the new baudrate */
uart_cfg.baudrate = cfg->bus_speed;
ret = uart_configure(cfg->bus, &uart_cfg);
if (ret < 0) {
LOG_ERR("Failed to re-configure UART (%d)", ret);
return ret;
}
}
return 0;
}
static const struct i2c_driver_api i2c_sc18im_driver_api = {
.configure = i2c_sc18im_configure,
.get_config = i2c_sc18im_get_config,
.transfer = i2c_sc18im_transfer,
};
#define I2C_SC18IM_DEFINE(n) \
\
static const struct i2c_sc18im_config i2c_sc18im_config_##n = { \
.bus = DEVICE_DT_GET(DT_BUS(DT_INST_PARENT(n))), \
.bus_speed = DT_PROP_OR(DT_INST_PARENT(n), target_speed, 9600), \
.reset_gpios = GPIO_DT_SPEC_GET_OR(DT_INST_PARENT(n), reset_gpios, {0}), \
}; \
static struct i2c_sc18im_data i2c_sc18im_data_##n = { \
.i2c_config = I2C_MODE_CONTROLLER | (I2C_SPEED_STANDARD << I2C_SPEED_SHIFT), \
}; \
\
DEVICE_DT_INST_DEFINE(n, i2c_sc18im_init, NULL, \
&i2c_sc18im_data_##n, &i2c_sc18im_config_##n, \
POST_KERNEL, CONFIG_I2C_SC18IM704_INIT_PRIORITY, \
&i2c_sc18im_driver_api);
DT_INST_FOREACH_STATUS_OKAY(I2C_SC18IM_DEFINE)