116 lines
3.1 KiB
C
116 lines
3.1 KiB
C
/*
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* Copyright (c) 2022 Thomas Stranger
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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#define DT_DRV_COMPAT maxim_ds2485
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/**
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* @brief Driver for the Maxim ds2485 1-Wire Master
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*/
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#include "w1_ds2477_85_common.h"
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#include <zephyr/drivers/i2c.h>
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#include <zephyr/drivers/w1.h>
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#include <zephyr/kernel.h>
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#include <zephyr/logging/log.h>
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LOG_MODULE_REGISTER(w1_ds2485, CONFIG_W1_LOG_LEVEL);
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/* upper limits; guaranteed over operating temperature range */
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#define DS2485_T_OSCWUP_us 1000U
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#define DS2485_T_OP_us 400U
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#define DS2485_T_SEQ_us 10U
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int ds2485_w1_script_cmd(const struct device *dev, int w1_delay_us, uint8_t w1_cmd,
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const uint8_t *tx_buf, const uint8_t tx_len,
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uint8_t *rx_buf, uint8_t rx_len)
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{
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const struct w1_ds2477_85_config *cfg = dev->config;
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uint8_t i2c_len = 3 + tx_len;
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uint8_t tx_bytes[3 + SCRIPT_WR_LEN] = {
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CMD_W1_SCRIPT, tx_len + CMD_W1_SCRIPT_LEN, w1_cmd
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};
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uint8_t rx_bytes[3];
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struct i2c_msg rx_msg[2] = {
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{
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.buf = rx_bytes,
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.len = (CMD_W1_SCRIPT_LEN + CMD_OVERHEAD_LEN),
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.flags = I2C_MSG_READ,
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},
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{
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.buf = rx_buf,
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.len = rx_len,
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.flags = (I2C_MSG_READ | I2C_MSG_STOP),
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},
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};
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int ret;
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__ASSERT_NO_MSG(tx_len <= SCRIPT_WR_LEN);
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memcpy(&tx_bytes[3], tx_buf, tx_len);
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ret = i2c_write_dt(&cfg->i2c_spec, tx_bytes, i2c_len);
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if (ret < 0) {
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return ret;
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}
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k_usleep(DS2485_T_OP_us + DS2485_T_SEQ_us + w1_delay_us);
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ret = i2c_transfer_dt(&cfg->i2c_spec, rx_msg, 2);
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if (ret < 0) {
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LOG_ERR("scripts_cmd fail: ret: %x", ret);
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return ret;
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}
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if ((rx_bytes[0] != (rx_len + 2)) || (rx_bytes[2] != w1_cmd)) {
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LOG_ERR("scripts_cmd fail: response: %x,%x:",
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rx_bytes[0], rx_bytes[2]);
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return -EIO;
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}
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return rx_bytes[1];
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}
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static int w1_ds2485_init(const struct device *dev)
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{
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const struct w1_ds2477_85_config *cfg = dev->config;
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if (!device_is_ready(cfg->i2c_spec.bus)) {
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LOG_ERR("%s is not ready", cfg->i2c_spec.bus->name);
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return -ENODEV;
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}
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if (ds2477_85_reset_master(dev)) {
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return -EIO;
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}
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k_usleep(DS2485_T_OSCWUP_us);
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return w1_ds2477_85_init(dev);
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}
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static const struct w1_driver_api w1_ds2485_driver_api = {
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.reset_bus = ds2477_85_reset_bus,
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.read_bit = ds2477_85_read_bit,
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.write_bit = ds2477_85_write_bit,
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.read_byte = ds2477_85_read_byte,
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.write_byte = ds2477_85_write_byte,
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.read_block = ds2477_85_read_block,
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.write_block = ds2477_85_write_block,
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.configure = ds2477_85_configure,
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};
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#define W1_DS2485_INIT(inst) \
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static const struct w1_ds2477_85_config w1_ds2477_85_cfg_##inst = \
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W1_DS2477_85_DT_CONFIG_INST_GET(inst, DS2485_T_OP_us, \
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DS2485_T_SEQ_us, \
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ds2485_w1_script_cmd); \
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\
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static struct w1_ds2477_85_data w1_ds2477_85_data_##inst = {}; \
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DEVICE_DT_INST_DEFINE(inst, &w1_ds2485_init, NULL, \
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&w1_ds2477_85_data_##inst, \
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&w1_ds2477_85_cfg_##inst, POST_KERNEL, \
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CONFIG_W1_INIT_PRIORITY, &w1_ds2485_driver_api);
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DT_INST_FOREACH_STATUS_OKAY(W1_DS2485_INIT)
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