| #pragma once |
| |
| /*! \file soft_uart.h |
| * Software UART implementation. */ |
| /* |
| * (C) 2022 by Harald Welte <laforge@gnumonks.org> |
| * (C) 2023 by sysmocom - s.f.m.c. GmbH <info@sysmocom.de> |
| * |
| * All Rights Reserved |
| * |
| * SPDX-License-Identifier: GPL-2.0+ |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| */ |
| |
| #include <stdint.h> |
| #include <stdbool.h> |
| |
| #include <osmocom/core/bits.h> |
| #include <osmocom/core/msgb.h> |
| |
| /*! Parity mode. |
| * https://en.wikipedia.org/wiki/Parity_bit */ |
| enum osmo_soft_uart_parity_mode { |
| OSMO_SUART_PARITY_NONE, /*!< No parity bit */ |
| OSMO_SUART_PARITY_EVEN, /*!< Even parity */ |
| OSMO_SUART_PARITY_ODD, /*!< Odd parity */ |
| OSMO_SUART_PARITY_MARK, /*!< Always 1 */ |
| OSMO_SUART_PARITY_SPACE, /*!< Always 0 */ |
| _OSMO_SUART_PARITY_NUM |
| }; |
| |
| /*! Flags passed to the application. */ |
| enum osmo_soft_uart_flags { |
| OSMO_SUART_F_FRAMING_ERROR = (1 << 0), /*!< Framing error occurred */ |
| OSMO_SUART_F_PARITY_ERROR = (1 << 1), /*!< Parity error occurred */ |
| OSMO_SUART_F_BREAK = (1 << 2), /*!< Break condition (not implemented) */ |
| }; |
| |
| /*! Modem status "line" flags. |
| * https://en.wikipedia.org/wiki/RS-232#Data_and_control_signals */ |
| enum osmo_soft_uart_status { |
| OSMO_SUART_STATUS_F_DTR = (1 << 0), /*!< Data Terminal Ready */ |
| OSMO_SUART_STATUS_F_DCD = (1 << 1), /*!< Data Carrier Detect */ |
| OSMO_SUART_STATUS_F_DSR = (1 << 2), /*!< Data Set Ready */ |
| OSMO_SUART_STATUS_F_RI = (1 << 3), /*!< Ring Indicator */ |
| OSMO_SUART_STATUS_F_RTS_RTR = (1 << 4), /*!< Request To Send or Ready To Receive */ |
| OSMO_SUART_STATUS_F_CTS = (1 << 5), /*!< Clear To Send */ |
| }; |
| |
| /*! Flow control mode. |
| * https://en.wikipedia.org/wiki/Flow_control_(data)#Hardware_flow_control */ |
| enum osmo_soft_uart_flow_ctrl_mode { |
| /*! No flow control */ |
| OSMO_SUART_FLOW_CTRL_NONE, |
| /*! DTR/DSR flow control: Tx if DSR is active and drop DTR if cannot Rx anymore. */ |
| OSMO_SUART_FLOW_CTRL_DTR_DSR, |
| /*! RTS/CTS flow control: Tx if CTS is active and drop RTS if cannot Rx anymore. |
| * The technically correct name would be RTR/CTS, because the RTS signal actually |
| * indicates readiness to *receive* data (Ready To Receive), and not really used |
| * to request a transmission (Request To Send) nowadays. Alternatively, the RTS |
| * signal can be interpreted as "Request To Send to me". */ |
| OSMO_SUART_FLOW_CTRL_RTS_CTS, |
| }; |
| |
| /*! Configuration for a soft-UART. */ |
| struct osmo_soft_uart_cfg { |
| /*! Number of data bits (typically 5, 6, 7 or 8). */ |
| uint8_t num_data_bits; |
| /*! Number of stop bits (typically 1 or 2). */ |
| uint8_t num_stop_bits; |
| /*! Parity mode (none, even, odd, space, mark). */ |
| enum osmo_soft_uart_parity_mode parity_mode; |
| /*! Size of the receive buffer; UART will buffer up to that number |
| * of characters before calling the receive call-back. */ |
| unsigned int rx_buf_size; |
| /*! Receive timeout; UART will flush the receive buffer via the receive call-back |
| * after indicated number of milliseconds, even if it is not full yet. */ |
| unsigned int rx_timeout_ms; |
| |
| /*! Opaque application-private data; passed to call-backs. */ |
| void *priv; |
| |
| /*! Receive call-back of the application. |
| * |
| * Called if at least one of the following conditions is met: |
| * a) rx_buf_size characters were received (Rx buffer is full); |
| * b) rx_timeout_ms expired and Rx buffer is not empty; |
| * c) a parity or framing error is occurred. |
| * |
| * \param[in] priv opaque application-private data. |
| * \param[in] rx_data msgb holding the received data. |
| * Must be free()ed by the application. |
| * \param[in] flags bit-mask of OSMO_SUART_F_*. */ |
| void (*rx_cb)(void *priv, struct msgb *rx_data, unsigned int flags); |
| |
| /*! Transmit call-back of the application. |
| * |
| * The implementation is expected to provide at most tx_data->data_len |
| * characters (the actual amount is determined by the number of requested |
| * bits and the effective UART configuration). |
| * |
| * \param[in] priv opaque application-private data. |
| * \param[inout] tx_data msgb for writing to be transmitted data. */ |
| void (*tx_cb)(void *priv, struct msgb *tx_data); |
| |
| /*! Modem status line change call-back. |
| * \param[in] priv opaque application-private data. |
| * \param[in] status updated status; bit-mask of OSMO_SUART_STATUS_F_*. */ |
| void (*status_change_cb)(void *priv, unsigned int status); |
| |
| /*! "Hardware" flow control mode. */ |
| enum osmo_soft_uart_flow_ctrl_mode flow_ctrl_mode; |
| }; |
| |
| extern const struct osmo_soft_uart_cfg osmo_soft_uart_default_cfg; |
| |
| struct osmo_soft_uart; |
| |
| struct osmo_soft_uart *osmo_soft_uart_alloc(void *ctx, const char *name, |
| const struct osmo_soft_uart_cfg *cfg); |
| void osmo_soft_uart_free(struct osmo_soft_uart *suart); |
| int osmo_soft_uart_configure(struct osmo_soft_uart *suart, const struct osmo_soft_uart_cfg *cfg); |
| |
| const char *osmo_soft_uart_get_name(const struct osmo_soft_uart *suart); |
| void osmo_soft_uart_set_name(struct osmo_soft_uart *suart, const char *name); |
| |
| int osmo_soft_uart_set_rx(struct osmo_soft_uart *suart, bool enable); |
| int osmo_soft_uart_set_tx(struct osmo_soft_uart *suart, bool enable); |
| |
| int osmo_soft_uart_rx_ubits(struct osmo_soft_uart *suart, const ubit_t *ubits, size_t n_ubits); |
| int osmo_soft_uart_tx_ubits(struct osmo_soft_uart *suart, ubit_t *ubits, size_t n_ubits); |
| |
| unsigned int osmo_soft_uart_get_status(const struct osmo_soft_uart *suart); |
| int osmo_soft_uart_set_status(struct osmo_soft_uart *suart, unsigned int status); |
| void osmo_soft_uart_set_status_line(struct osmo_soft_uart *suart, |
| enum osmo_soft_uart_status line, |
| bool active); |
| |
| void osmo_soft_uart_flush_rx(struct osmo_soft_uart *suart); |