4  * SPDX-License-Identifier: Apache-2.0
10  * @brief 1-Wire Bus Master driver using Zephyr serial interface.
12  * This driver implements the 1-Wire interface using an uart.
15  * presence detection as suggested for normal speed operating mode in:
16 …* https://www.analog.com/en/resources/technical-articles/using-a-uart-to-implement-a-1wire-bus-mas…
17  * For overdrive speed communication baudrates of 1 MBd and 115.2 kBd
34 /* Standard speed signal parameters:
43  * Overdrive speed signal parameters:
54 	/** UART device used for 1-Wire communication */
66  * Concurrently transmits and receives one 1-Wire bit
72 	const struct w1_serial_config *cfg = dev->config;  in serial_tx_rx()
81 		while (uart_poll_in(cfg->uart_dev, &dummy) == 0) {  in serial_tx_rx()
85 		uart_poll_out(cfg->uart_dev, tx_data[i]);  in serial_tx_rx()
89 			ret = uart_poll_in(cfg->uart_dev, &rx_data[i]);  in serial_tx_rx()
96 /* Concurretly tranmits and receives one 1-Wire byte */
115 		return -EIO;  in serial_tx_rx_byte()
121 		 * rx-byte different from 0xFF indicates that a slave has  in serial_tx_rx_byte()
132 	const struct w1_serial_config *cfg = dev->config;  in w1_serial_reset_bus()
133 	struct w1_serial_data *data = dev->data;  in w1_serial_reset_bus()
134 	uint8_t reset_byte = data->overdrive_active ?  in w1_serial_reset_bus()
137 	 * adjust timeout accordingly, also valid for overdrive speed.  in w1_serial_reset_bus()
141 	data->uart_cfg.baudrate = data->overdrive_active ?  in w1_serial_reset_bus()
143 	if (uart_configure(cfg->uart_dev, &data->uart_cfg) != 0) {  in w1_serial_reset_bus()
145 		return -EIO;  in w1_serial_reset_bus()
150 		return -EIO;  in w1_serial_reset_bus()
153 	data->uart_cfg.baudrate = data->overdrive_active ?  in w1_serial_reset_bus()
155 	if (uart_configure(cfg->uart_dev, &data->uart_cfg) != 0) {  in w1_serial_reset_bus()
157 		return -EIO;  in w1_serial_reset_bus()
173 		return -EIO;  in w1_serial_read_bit()
187 		return -EIO;  in w1_serial_write_bit()
198 		return -EIO;  in w1_serial_read_byte()
214 	const struct w1_serial_config *cfg = dev->config;  in w1_serial_configure()
215 	struct w1_serial_data *data = dev->data;  in w1_serial_configure()
222 		if (temp == data->overdrive_active) {  in w1_serial_configure()
226 		data->overdrive_active = temp;  in w1_serial_configure()
227 		data->uart_cfg.baudrate = data->overdrive_active ?  in w1_serial_configure()
229 		if (uart_configure(cfg->uart_dev, &data->uart_cfg) != 0) {  in w1_serial_configure()
231 			ret = -EIO;  in w1_serial_configure()
235 		ret = -ENOTSUP;  in w1_serial_configure()
242 	const struct w1_serial_config *cfg = dev->config;  in w1_serial_init()
243 	struct w1_serial_data *data = dev->data;  in w1_serial_init()
245 	if (!device_is_ready(cfg->uart_dev)) {  in w1_serial_init()
247 		return -ENODEV;  in w1_serial_init()
250 	data->uart_cfg.baudrate = W1_SERIAL_STD_DATA_BAUD;  in w1_serial_init()
251 	data->uart_cfg.parity = UART_CFG_PARITY_NONE;  in w1_serial_init()
252 	data->uart_cfg.data_bits = UART_CFG_DATA_BITS_8;  in w1_serial_init()
253 	data->uart_cfg.stop_bits = UART_CFG_STOP_BITS_1;  in w1_serial_init()
254 	data->uart_cfg.flow_ctrl = UART_CFG_FLOW_CTRL_NONE;  in w1_serial_init()
256 	if (uart_configure(cfg->uart_dev, &data->uart_cfg) != 0) {  in w1_serial_init()
258 		return -EINVAL;  in w1_serial_init()
261 	data->overdrive_active = false;  in w1_serial_init()
263 	LOG_DBG("w1-serial initialized, with %d slave devices",  in w1_serial_init()
264 		cfg->master_config.slave_count);  in w1_serial_init()