modbus: move MODBUS over serial line code to own file (3ddb47cc) · Commits · Wenxi XU / zephyr

subsys/modbus/CMakeLists.txt

+1 −0

Original line number	Diff line number	Diff line
		@@ -8,6 +8,7 @@ if(CONFIG_MODBUS)

		zephyr_library_sources(
		modbus_core.c
		modbus_serial.c
		)

		zephyr_library_sources_ifdef(

subsys/modbus/modbus_core.c

+32 −537

Original line number	Diff line number	Diff line
		/*
		* Copyright (c) 2020 PHYTEC Messtechnik GmbH
		* Copyright (c) 2021 Nordic Semiconductor ASA
		*
		* SPDX-License-Identifier: Apache-2.0
		*/

		/*
		* This file is based on mb.c and mb_util.c from uC/Modbus Stack.
		*
		* uC/Modbus
		* The Embedded Modbus Stack
		*
		* Copyright 2003-2020 Silicon Laboratories Inc. www.silabs.com
		*
		* SPDX-License-Identifier: APACHE-2.0
		*
		* This software is subject to an open source license and is distributed by
		* Silicon Laboratories Inc. pursuant to the terms of the Apache License,
		* Version 2.0 available at www.apache.org/licenses/LICENSE-2.0.
		*/

		#include <logging/log.h>
		LOG_MODULE_REGISTER(modbus, CONFIG_MODBUS_LOG_LEVEL);

		@@ -59,512 +45,61 @@ static struct modbus_context mb_ctx_tbl[] = {
		DT_INST_FOREACH_STATUS_OKAY(MODBUS_DT_GET_DEV)
		};

		static void mb_tx_enable(struct modbus_context *ctx)
		{
		if (ctx->de != NULL) {
		gpio_pin_set(ctx->de->dev, ctx->de->pin, 1);
		}

		uart_irq_tx_enable(ctx->dev);
		}

		static void mb_tx_disable(struct modbus_context *ctx)
		{
		uart_irq_tx_disable(ctx->dev);
		if (ctx->de != NULL) {
		gpio_pin_set(ctx->de->dev, ctx->de->pin, 0);
		}
		}

		static void mb_rx_enable(struct modbus_context *ctx)
		{
		if (ctx->re != NULL) {
		gpio_pin_set(ctx->re->dev, ctx->re->pin, 1);
		}

		uart_irq_rx_enable(ctx->dev);
		}

		static void mb_rx_disable(struct modbus_context *ctx)
		static void modbus_rx_handler(struct k_work *item)
		{
		uart_irq_rx_disable(ctx->dev);
		if (ctx->re != NULL) {
		gpio_pin_set(ctx->re->dev, ctx->re->pin, 0);
		}
		}

		#ifdef CONFIG_MODBUS_ASCII_MODE
		/* The function calculates an 8-bit Longitudinal Redundancy Check. */
		static uint8_t mb_ascii_get_lrc(uint8_t *src, size_t length)
		{
		uint8_t lrc = 0;
		uint8_t tmp;
		uint8_t *pblock = src;

		while (length-- > 0) {
		/* Add the data byte to LRC, increment data pointer. */
		if (hex2bin(pblock, 2, &tmp, sizeof(tmp)) != sizeof(tmp)) {
		return 0;
		}

		lrc += tmp;
		pblock += 2;
		}

		/* Two complement the binary sum */
		lrc = ~lrc + 1;

		return lrc;
		}

		/* Parses and converts an ASCII mode frame into a Modbus RTU frame. */
		static int mb_rx_ascii_frame(struct modbus_context *ctx)
		{
		uint8_t *pmsg;
		uint8_t *prx_data;
		uint16_t rx_size;
		uint8_t frame_lrc;
		uint8_t calc_lrc;

		rx_size = ctx->uart_buf_ctr;
		prx_data = &ctx->rx_frame.data[0];

		if (!(rx_size & 0x01)) {
		LOG_WRN("Message should have an odd number of bytes");
		return -EMSGSIZE;
		}

		if (rx_size < MODBUS_ASCII_MIN_MSG_SIZE) {
		LOG_WRN("Frame length error");
		return -EMSGSIZE;
		}

		if ((ctx->uart_buf[0] != MODBUS_ASCII_START_FRAME_CHAR) \|\|
		(ctx->uart_buf[rx_size - 2] != MODBUS_ASCII_END_FRAME_CHAR1) \|\|
		(ctx->uart_buf[rx_size - 1] != MODBUS_ASCII_END_FRAME_CHAR2)) {
		LOG_WRN("Frame character error");
		return -EMSGSIZE;
		}

		/* Take away for the ':', CR, and LF */
		rx_size -= 3;
		/* Point past the ':' to the address. */
		pmsg = &ctx->uart_buf[1];

		hex2bin(pmsg, 2, &ctx->rx_frame.addr, 1);
		pmsg += 2;
		rx_size -= 2;
		hex2bin(pmsg, 2, &ctx->rx_frame.fc, 1);
		pmsg += 2;
		rx_size -= 2;

		/* Get the data from the message */
		ctx->rx_frame.length = 0;
		while (rx_size > 2) {
		hex2bin(pmsg, 2, prx_data, 1);
		prx_data++;
		pmsg += 2;
		rx_size -= 2;
		/* Increment the number of Modbus packets received */
		ctx->rx_frame.length++;
		}

		/* Extract the message's LRC */
		hex2bin(pmsg, 2, &frame_lrc, 1);
		ctx->rx_frame.crc = frame_lrc;

		/*
		* The LRC is calculated on the ADDR, FC and Data fields,
		* not the ':', CR/LF and LRC placed in the message
		* by the sender. We thus need to subtract 5 'ASCII' characters
		* from the received message to exclude these.
		*/
		calc_lrc = mb_ascii_get_lrc(&ctx->uart_buf[1],
		(ctx->uart_buf_ctr - 5) / 2);

		if (calc_lrc != frame_lrc) {
		LOG_ERR("Calculated LRC does not match received LRC");
		return -EIO;
		}

		return 0;
		}

		static uint8_t mb_bin2hex(uint8_t value, uint8_t pbuf)
		{
		uint8_t u_nibble = (value >> 4) & 0x0F;
		uint8_t l_nibble = value & 0x0F;

		hex2char(u_nibble, pbuf);
		pbuf++;
		hex2char(l_nibble, pbuf);
		pbuf++;

		return pbuf;
		}

		static void mb_tx_ascii_frame(struct modbus_context *ctx)
		{
		uint16_t tx_bytes = 0;
		uint8_t lrc;
		uint8_t *pbuf;

		/* Place the start-of-frame character into output buffer */
		ctx->uart_buf[0] = MODBUS_ASCII_START_FRAME_CHAR;
		tx_bytes = 1;

		pbuf = &ctx->uart_buf[1];
		pbuf = mb_bin2hex(ctx->tx_frame.addr, pbuf);
		tx_bytes += 2;
		pbuf = mb_bin2hex(ctx->tx_frame.fc, pbuf);
		tx_bytes += 2;

		for (int i = 0; i < ctx->tx_frame.length; i++) {
		pbuf = mb_bin2hex(ctx->tx_frame.data[i], pbuf);
		tx_bytes += 2;
		}

		/*
		* Add the LRC checksum in the packet.
		*
		* The LRC is calculated on the ADDR, FC and Data fields,
		* not the ':' which was inserted in the uart_buf[].
		* Thus we subtract 1 ASCII character from the LRC.
		* The LRC and CR/LF bytes are not YET in the .uart_buf[].
		*/
		lrc = mb_ascii_get_lrc(&ctx->uart_buf[1], (tx_bytes - 1) / 2);
		pbuf = mb_bin2hex(lrc, pbuf);
		tx_bytes += 2;

		*pbuf++ = MODBUS_ASCII_END_FRAME_CHAR1;
		*pbuf++ = MODBUS_ASCII_END_FRAME_CHAR2;
		tx_bytes += 2;

		/* Update the total number of bytes to send */
		ctx->uart_buf_ctr = tx_bytes;
		ctx->uart_buf_ptr = &ctx->uart_buf[0];

		LOG_DBG("Start frame transmission");
		mb_rx_disable(ctx);
		mb_tx_enable(ctx);
		}
		#else
		static int mb_rx_ascii_frame(struct modbus_context *ctx)
		{
		return 0;
		}

		static void mb_tx_ascii_frame(struct modbus_context *ctx)
		{
		}
		#endif

		static uint16_t mb_rtu_crc16(uint8_t *src, size_t length)
		{
		uint16_t crc = 0xFFFF;
		uint8_t shiftctr;
		bool flag;
		uint8_t *pblock = src;

		while (length > 0) {
		length--;
		crc ^= (uint16_t)*pblock++;
		shiftctr = 8;
		do {
		/* Determine if the shift out of rightmost bit is 1 */
		flag = (crc & 0x0001) ? true : false;
		/* Shift CRC to the right one bit. */
		crc >>= 1;
		/*
		* If bit shifted out of rightmost bit was a 1
		* exclusive OR the CRC with the generating polynomial.
		*/
		if (flag == true) {
		crc ^= MODBUS_CRC16_POLY;
		}

		shiftctr--;
		} while (shiftctr > 0);
		}

		return crc;
		}

		/* Copy Modbus RTU frame and check if the CRC is valid. */
		static int mb_rx_rtu_frame(struct modbus_context *ctx)
		{
		uint16_t calc_crc;
		uint16_t crc_idx;
		uint8_t *data_ptr;

		/* Is the message long enough? */
		if ((ctx->uart_buf_ctr < MODBUS_RTU_MIN_MSG_SIZE) \|\|
		(ctx->uart_buf_ctr > CONFIG_MODBUS_BUFFER_SIZE)) {
		LOG_WRN("Frame length error");
		return -EMSGSIZE;
		}

		ctx->rx_frame.addr = ctx->uart_buf[0];
		ctx->rx_frame.fc = ctx->uart_buf[1];
		data_ptr = &ctx->uart_buf[2];
		/* Payload length without node address, function code, and CRC */
		ctx->rx_frame.length = ctx->uart_buf_ctr - 4;
		/* CRC index */
		crc_idx = ctx->uart_buf_ctr - sizeof(uint16_t);

		memcpy(ctx->rx_frame.data, data_ptr, ctx->rx_frame.length);

		ctx->rx_frame.crc = sys_get_le16(&ctx->uart_buf[crc_idx]);
		/* Calculate CRC over address, function code, and payload */
		calc_crc = mb_rtu_crc16(&ctx->uart_buf[0],
		ctx->uart_buf_ctr - sizeof(ctx->rx_frame.crc));

		if (ctx->rx_frame.crc != calc_crc) {
		LOG_WRN("Calculated CRC does not match received CRC");
		return -EIO;
		}

		return 0;
		}

		static void mb_tx_rtu_frame(struct modbus_context *ctx)
		{
		uint16_t tx_bytes = 0;
		uint8_t *data_ptr;

		ctx->uart_buf[0] = ctx->tx_frame.addr;
		ctx->uart_buf[1] = ctx->tx_frame.fc;
		tx_bytes = 2 + ctx->tx_frame.length;
		data_ptr = &ctx->uart_buf[2];

		memcpy(data_ptr, ctx->tx_frame.data, ctx->tx_frame.length);

		ctx->tx_frame.crc = mb_rtu_crc16(&ctx->uart_buf[0],
		ctx->tx_frame.length + 2);
		sys_put_le16(ctx->tx_frame.crc,
		&ctx->uart_buf[ctx->tx_frame.length + 2]);
		tx_bytes += 2;

		ctx->uart_buf_ctr = tx_bytes;
		ctx->uart_buf_ptr = &ctx->uart_buf[0];
		struct modbus_context *ctx;

		LOG_HEXDUMP_DBG(ctx->uart_buf, ctx->uart_buf_ctr, "uart_buf");
		LOG_DBG("Start frame transmission");
		mb_rx_disable(ctx);
		mb_tx_enable(ctx);
		ctx = CONTAINER_OF(item, struct modbus_context, server_work);
		if (ctx == NULL) {
		LOG_ERR("Failed to obtain context pointer?");
		return;
		}

		void mb_tx_frame(struct modbus_context *ctx)
		{
		switch (ctx->mode) {
		case MODBUS_MODE_RTU:
		mb_tx_rtu_frame(ctx);
		break;
		case MODBUS_MODE_ASCII:
		if (IS_ENABLED(CONFIG_MODBUS_ASCII_MODE)) {
		mb_tx_ascii_frame(ctx);
		modbus_serial_rx_disable(ctx);
		ctx->rx_frame_err = modbus_serial_rx_frame(ctx);
		break;
		}
		default:
		LOG_ERR("Unknown MODBUS mode");
		return;
		}
		}

		/*
		* A byte has been received from a serial port. We just store it in the buffer
		* for processing when a complete packet has been received.
		*/
		static void mb_cb_handler_rx(struct modbus_context *ctx)
		{
		if ((ctx->mode == MODBUS_MODE_ASCII) &&
		IS_ENABLED(CONFIG_MODBUS_ASCII_MODE)) {
		uint8_t c;

		if (uart_fifo_read(ctx->dev, &c, 1) != 1) {
		LOG_ERR("Failed to read UART");
		return;
		}

		if (c == MODBUS_ASCII_START_FRAME_CHAR) {
		/* Restart a new frame */
		ctx->uart_buf_ptr = &ctx->uart_buf[0];
		ctx->uart_buf_ctr = 0;
		}

		if (ctx->uart_buf_ctr < CONFIG_MODBUS_BUFFER_SIZE) {
		*ctx->uart_buf_ptr++ = c;
		ctx->uart_buf_ctr++;
		}

		if (c == MODBUS_ASCII_END_FRAME_CHAR2) {
		k_work_submit(&ctx->server_work);
		}

		} else {
		int n;

		/* Restart timer on a new character */
		k_timer_start(&ctx->rtu_timer,
		K_USEC(ctx->rtu_timeout), K_NO_WAIT);

		n = uart_fifo_read(ctx->dev, ctx->uart_buf_ptr,
		(CONFIG_MODBUS_BUFFER_SIZE -
		ctx->uart_buf_ctr));

		ctx->uart_buf_ptr += n;
		ctx->uart_buf_ctr += n;
		}
		}

		static void mb_cb_handler_tx(struct modbus_context *ctx)
		{
		int n;

		if (ctx->uart_buf_ctr > 0) {
		n = uart_fifo_fill(ctx->dev, ctx->uart_buf_ptr,
		ctx->uart_buf_ctr);
		ctx->uart_buf_ctr -= n;
		ctx->uart_buf_ptr += n;
		} else {
		/* Disable transmission */
		ctx->uart_buf_ptr = &ctx->uart_buf[0];
		mb_tx_disable(ctx);
		mb_rx_enable(ctx);
		}
		}

		static void mb_uart_cb_handler(const struct device dev, void app_data)
		{
		struct modbus_context ctx = (struct modbus_context )app_data;

		if (ctx == NULL) {
		LOG_ERR("Modbus hardware is not properly initialized");
		return;
		}

		while (uart_irq_update(ctx->dev) && uart_irq_is_pending(ctx->dev)) {

		if (uart_irq_rx_ready(ctx->dev)) {
		mb_cb_handler_rx(ctx);
		}

		if (uart_irq_tx_ready(ctx->dev)) {
		mb_cb_handler_tx(ctx);
		}
		}
		}

		static void mb_rx_handler(struct k_work *item)
		{
		struct modbus_context *ctx =
		CONTAINER_OF(item, struct modbus_context, server_work);

		if (ctx == NULL) {
		LOG_ERR("Where is my pointer?");
		if (ctx->client == true) {
		k_sem_give(&ctx->client_wait_sem);
		return;
		}

		mb_rx_disable(ctx);
		if (IS_ENABLED(CONFIG_MODBUS_SERVER)) {
		bool respond = mbs_rx_handler(ctx);

		switch (ctx->mode) {
		case MODBUS_MODE_RTU:
		ctx->rx_frame_err = mb_rx_rtu_frame(ctx);
		break;
		case MODBUS_MODE_ASCII:
		if (IS_ENABLED(CONFIG_MODBUS_ASCII_MODE)) {
		ctx->rx_frame_err = mb_rx_ascii_frame(ctx);
		break;
		if (respond == false) {
		LOG_DBG("Server has dropped frame");
		modbus_serial_rx_enable(ctx);
		}
		break;
		default:
		LOG_ERR("Unknown MODBUS mode");
		return;
		}

		ctx->uart_buf_ctr = 0;
		ctx->uart_buf_ptr = &ctx->uart_buf[0];

		if (ctx->client == true) {
		k_sem_give(&ctx->client_wait_sem);
		} else if (IS_ENABLED(CONFIG_MODBUS_SERVER)) {
		if (mbs_rx_handler(ctx) == false) {
		/* Server does not send response, re-enable RX */
		mb_rx_enable(ctx);
		}
		}
		break;
		}

		/* This function is called when the RTU framing timer expires. */
		static void mb_rtu_tmr_handler(struct k_timer *t_id)
		{
		struct modbus_context *ctx;

		ctx = (struct modbus_context *)k_timer_user_data_get(t_id);

		if (ctx == NULL) {
		LOG_ERR("Failed to get Modbus context");
		return;
		}

		k_work_submit(&ctx->server_work);
		}

		static int mb_configure_uart(struct modbus_context *ctx,
		uint32_t baudrate,
		enum uart_config_parity parity)
		void mb_tx_frame(struct modbus_context *ctx)
		{
		const uint32_t if_delay_max = 3500000;
		const uint32_t numof_bits = 11;
		struct uart_config uart_cfg;

		ctx->dev = device_get_binding(ctx->dev_name);
		if (ctx->dev == NULL) {
		LOG_ERR("Failed to get UART device %s",
		log_strdup(ctx->dev_name));
		return -ENODEV;
		}

		uart_cfg.baudrate = baudrate,
		uart_cfg.flow_ctrl = UART_CFG_FLOW_CTRL_NONE;

		if (ctx->mode == MODBUS_MODE_ASCII) {
		uart_cfg.data_bits = UART_CFG_DATA_BITS_7;
		} else {
		uart_cfg.data_bits = UART_CFG_DATA_BITS_8;
		switch (ctx->mode) {
		case MODBUS_MODE_RTU:
		case MODBUS_MODE_ASCII:
		if (modbus_serial_tx_frame(ctx)) {
		LOG_ERR("Unsupported MODBUS serial mode");
		}

		switch (parity) {
		case UART_CFG_PARITY_ODD:
		case UART_CFG_PARITY_EVEN:
		uart_cfg.parity = parity;
		uart_cfg.stop_bits = UART_CFG_STOP_BITS_1;
		break;
		case UART_CFG_PARITY_NONE:
		/* Use of no parity requires 2 stop bits */
		uart_cfg.parity = parity;
		uart_cfg.stop_bits = UART_CFG_STOP_BITS_2;
		break;
		default:
		return -EINVAL;
		}

		if (uart_configure(ctx->dev, &uart_cfg) != 0) {
		LOG_ERR("Failed to configure UART");
		return -EINVAL;
		}

		uart_irq_callback_user_data_set(ctx->dev, mb_uart_cb_handler, ctx);
		mb_rx_enable(ctx);

		if (baudrate <= 38400) {
		ctx->rtu_timeout = (numof_bits * if_delay_max) / baudrate;
		} else {
		ctx->rtu_timeout = (numof_bits * if_delay_max) / 38400;
		LOG_ERR("Unknown MODBUS mode");
		}

		LOG_INF("RTU timeout %u us", ctx->rtu_timeout);

		return 0;
		}

		struct modbus_context *mb_get_context(const uint8_t iface)
		@@ -586,36 +121,6 @@ struct modbus_context *mb_get_context(const uint8_t iface)
		return ctx;
		}

		static int mb_configure_gpio(struct modbus_context *ctx)
		{
		if (ctx->de != NULL) {
		ctx->de->dev = device_get_binding(ctx->de->name);
		if (ctx->de->dev == NULL) {
		return -ENODEV;
		}

		if (gpio_pin_configure(ctx->de->dev, ctx->de->pin,
		GPIO_OUTPUT_INACTIVE \| ctx->de->flags)) {
		return -EIO;
		}
		}


		if (ctx->re != NULL) {
		ctx->re->dev = device_get_binding(ctx->re->name);
		if (ctx->re->dev == NULL) {
		return -ENODEV;
		}

		if (gpio_pin_configure(ctx->re->dev, ctx->re->pin,
		GPIO_OUTPUT_INACTIVE \| ctx->re->flags)) {
		return -EIO;
		}
		}

		return 0;
		}

		static struct modbus_context *mb_cfg_iface(const uint8_t iface,
		const uint8_t node_addr,
		const uint32_t baud,
		@@ -648,7 +153,6 @@ static struct modbus_context *mb_cfg_iface(const uint8_t iface,
		ctx->rxwait_to = rx_timeout;
		ctx->node_addr = node_addr;
		ctx->client = client;
		ctx->mode = ascii_mode ? MODBUS_MODE_ASCII : MODBUS_MODE_RTU;
		ctx->mbs_user_cb = NULL;
		k_mutex_init(&ctx->iface_lock);

		@@ -656,23 +160,17 @@ static struct modbus_context *mb_cfg_iface(const uint8_t iface,
		ctx->uart_buf_ptr = &ctx->uart_buf[0];

		k_sem_init(&ctx->client_wait_sem, 0, 1);
		k_work_init(&ctx->server_work, mb_rx_handler);
		k_work_init(&ctx->server_work, modbus_rx_handler);

		if (IS_ENABLED(CONFIG_MODBUS_FC08_DIAGNOSTIC)) {
		mbs_reset_statistics(ctx);
		}

		if (mb_configure_gpio(ctx) != 0) {
		return NULL;
		}

		if (mb_configure_uart(ctx, baud, parity) != 0) {
		LOG_ERR("Failed to configure UART");
		if (modbus_serial_init(ctx, baud, parity, ascii_mode) != 0) {
		LOG_ERR("Failed to init MODBUS over serial line");
		return NULL;
		}

		k_timer_init(&ctx->rtu_timer, mb_rtu_tmr_handler, NULL);
		k_timer_user_data_set(&ctx->rtu_timer, ctx);
		LOG_DBG("Modbus interface %s initialized", ctx->iface_name);

		return ctx;
		@@ -751,10 +249,7 @@ int modbus_disable(const uint8_t iface)

		ctx = &mb_ctx_tbl[iface];

		mb_tx_disable(ctx);
		mb_rx_disable(ctx);
		k_timer_stop(&ctx->rtu_timer);

		modbus_serial_disable(ctx);
		ctx->rxwait_to = 0;
		ctx->node_addr = 0;
		ctx->mode = MODBUS_MODE_RTU;

subsys/modbus/modbus_internal.h

+11 −2

Original line number	Diff line number	Diff line
		@@ -135,7 +135,7 @@ struct modbus_context {
		/* Number of bytes received or to send */
		uint16_t uart_buf_ctr;
		/* Records error from frame reception, e.g. CRC error */
		uint16_t rx_frame_err;
		int rx_frame_err;

		#ifdef CONFIG_MODBUS_FC08_DIAGNOSTIC
		uint16_t mbs_msg_ctr;
		@@ -152,10 +152,19 @@ struct modbus_context {
		};

		struct modbus_context *mb_get_context(const uint8_t iface);
		int mb_rx_frame(struct modbus_context *ctx);
		void mb_tx_frame(struct modbus_context *ctx);

		bool mbs_rx_handler(struct modbus_context *ctx);
		void mbs_reset_statistics(struct modbus_context *pch);

		void modbus_serial_rx_disable(struct modbus_context *ctx);
		void modbus_serial_rx_enable(struct modbus_context *ctx);
		int modbus_serial_rx_frame(struct modbus_context *ctx);
		int modbus_serial_tx_frame(struct modbus_context *ctx);
		int modbus_serial_init(struct modbus_context *ctx,
		uint32_t baudrate,
		enum uart_config_parity parity,
		const bool ascii_mode);
		void modbus_serial_disable(struct modbus_context *ctx);

		#endif /* ZEPHYR_INCLUDE_MODBUS_INTERNAL_H_ */

subsys/modbus/modbus_serial.c

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+581 −0

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