#pragma once /*! \file soft_uart.h * Software UART implementation. */ /* * (C) 2022 by Harald Welte * (C) 2023 by sysmocom - s.f.m.c. GmbH * * 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 #include #include #include /*! 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);