zephyr/drivers/w1/w1_ds2485.c

116 lines
3.1 KiB
C

/*
* Copyright (c) 2022 Thomas Stranger
*
* SPDX-License-Identifier: Apache-2.0
*/
#define DT_DRV_COMPAT maxim_ds2485
/**
* @brief Driver for the Analog Devices DS2485 1-Wire Master
*/
#include "w1_ds2477_85_common.h"
#include <zephyr/drivers/i2c.h>
#include <zephyr/drivers/w1.h>
#include <zephyr/kernel.h>
#include <zephyr/logging/log.h>
LOG_MODULE_REGISTER(w1_ds2485, CONFIG_W1_LOG_LEVEL);
/* upper limits; guaranteed over operating temperature range */
#define DS2485_T_OSCWUP_us 1000U
#define DS2485_T_OP_us 400U
#define DS2485_T_SEQ_us 10U
int ds2485_w1_script_cmd(const struct device *dev, int w1_delay_us, uint8_t w1_cmd,
const uint8_t *tx_buf, const uint8_t tx_len,
uint8_t *rx_buf, uint8_t rx_len)
{
const struct w1_ds2477_85_config *cfg = dev->config;
uint8_t i2c_len = 3 + tx_len;
uint8_t tx_bytes[3 + SCRIPT_WR_LEN] = {
CMD_W1_SCRIPT, tx_len + CMD_W1_SCRIPT_LEN, w1_cmd
};
uint8_t rx_bytes[3];
struct i2c_msg rx_msg[2] = {
{
.buf = rx_bytes,
.len = (CMD_W1_SCRIPT_LEN + CMD_OVERHEAD_LEN),
.flags = I2C_MSG_READ,
},
{
.buf = rx_buf,
.len = rx_len,
.flags = (I2C_MSG_READ | I2C_MSG_STOP),
},
};
int ret;
__ASSERT_NO_MSG(tx_len <= SCRIPT_WR_LEN);
memcpy(&tx_bytes[3], tx_buf, tx_len);
ret = i2c_write_dt(&cfg->i2c_spec, tx_bytes, i2c_len);
if (ret < 0) {
return ret;
}
k_usleep(DS2485_T_OP_us + DS2485_T_SEQ_us + w1_delay_us);
ret = i2c_transfer_dt(&cfg->i2c_spec, rx_msg, 2);
if (ret < 0) {
LOG_ERR("scripts_cmd fail: ret: %x", ret);
return ret;
}
if ((rx_bytes[0] != (rx_len + 2)) || (rx_bytes[2] != w1_cmd)) {
LOG_ERR("scripts_cmd fail: response: %x,%x:",
rx_bytes[0], rx_bytes[2]);
return -EIO;
}
return rx_bytes[1];
}
static int w1_ds2485_init(const struct device *dev)
{
const struct w1_ds2477_85_config *cfg = dev->config;
if (!device_is_ready(cfg->i2c_spec.bus)) {
LOG_ERR("%s is not ready", cfg->i2c_spec.bus->name);
return -ENODEV;
}
if (ds2477_85_reset_master(dev)) {
return -EIO;
}
k_usleep(DS2485_T_OSCWUP_us);
return w1_ds2477_85_init(dev);
}
static const struct w1_driver_api w1_ds2485_driver_api = {
.reset_bus = ds2477_85_reset_bus,
.read_bit = ds2477_85_read_bit,
.write_bit = ds2477_85_write_bit,
.read_byte = ds2477_85_read_byte,
.write_byte = ds2477_85_write_byte,
.read_block = ds2477_85_read_block,
.write_block = ds2477_85_write_block,
.configure = ds2477_85_configure,
};
#define W1_DS2485_INIT(inst) \
static const struct w1_ds2477_85_config w1_ds2477_85_cfg_##inst = \
W1_DS2477_85_DT_CONFIG_INST_GET(inst, DS2485_T_OP_us, \
DS2485_T_SEQ_us, \
ds2485_w1_script_cmd); \
\
static struct w1_ds2477_85_data w1_ds2477_85_data_##inst = {}; \
DEVICE_DT_INST_DEFINE(inst, &w1_ds2485_init, NULL, \
&w1_ds2477_85_data_##inst, \
&w1_ds2477_85_cfg_##inst, POST_KERNEL, \
CONFIG_W1_INIT_PRIORITY, &w1_ds2485_driver_api);
DT_INST_FOREACH_STATUS_OKAY(W1_DS2485_INIT)