Initial Release

src/host/hardware_uart/CMakeLists.txt

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+pico_simple_hardware_target(uart)

src/host/hardware_uart/include/hardware/uart.h

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+/*
+ * Copyright (c) 2020 Raspberry Pi (Trading) Ltd.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef _HARDWARE_UART_H
+#define _HARDWARE_UART_H
+
+#include "pico.h"
+
+#ifndef PARAM_ASSERTIONS_ENABLED_UART
+#define PARAM_ASSERTIONS_ENABLED_UART 0
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct uart_inst uart_inst_t;
+
+extern uart_inst_t * const uart0;
+extern uart_inst_t * const uart1;
+#define uart_default uart0
+
+typedef enum {
+    UART_PARITY_NONE,
+    UART_PARITY_EVEN,
+    UART_PARITY_ODD
+} uart_parity_t;
+
+// ----------------------------------------------------------------------------
+// Setup
+
+// Put the UART into a known state, and enable it. Must be called before other
+// functions.
+uint uart_init(uart_inst_t *uart, uint baudrate);
+
+// Disable the UART if it is no longer used. Must be reinitialised before
+// being used again.
+void uart_deinit(uart_inst_t *uart);
+
+// Set baud rate as close as possible to requested, and return actual rate.
+uint uart_set_baudrate(uart_inst_t *uart, uint baudrate);
+
+// cts: enable flow control of TX by clear-to-send input
+// rts: enable assertion of request-to-send output by RX flow control
+void uart_set_hw_flow(uart_inst_t *uart, bool cts, bool rts);
+
+// Configure how the UART serialises and deserialises data on the wire
+void uart_set_format(uart_inst_t *uart, uint data_bits, uint stop_bits, uart_parity_t parity);
+
+// Enable the UART's interrupt output. Need to install an interrupt handler first.
+void uart_set_irq_enables(uart_inst_t *uart, bool rx_has_data, bool tx_needs_data);
+
+// ----------------------------------------------------------------------------
+// Generic input/output
+
+// If returns 0, no space is available in the UART to write more data.
+// If returns nonzero, at least that many bytes can be written without blocking.
+size_t uart_is_writable(uart_inst_t *uart);
+
+// If returns 0, no data is available to be read from UART.
+// If returns nonzero, at least that many bytes can be written without blocking.
+size_t uart_is_readable(uart_inst_t *uart);
+
+// Write len bytes directly from src to the UART
+void uart_write_blocking(uart_inst_t *uart, const uint8_t *src, size_t len);
+
+// Read len bytes directly from the UART to dst
+void uart_read_blocking(uart_inst_t *uart, uint8_t *dst, size_t len);
+
+// ----------------------------------------------------------------------------
+// UART-specific operations and aliases
+
+void uart_putc(uart_inst_t *uart, char c);
+
+void uart_puts(uart_inst_t *uart, const char *s);
+
+char uart_getc(uart_inst_t *uart);
+
+// en: assert break condition (TX held low) if true. Clear break condition if false.
+void uart_set_break(uart_inst_t *uart, bool en);
+
+void uart_default_tx_wait_blocking();
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

src/host/hardware_uart/uart.c

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+/*
+ * Copyright (c) 2020 Raspberry Pi (Trading) Ltd.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <stdio.h>
+#include "hardware/uart.h"
+
+#if defined(__unix) || defined(__APPLE__)
+#define _XOPEN_SOURCE 600 /* for ONLCR */
+#define __BSD_VISIBLE 1 /* for ONLCR in *BSD */
+
+#include <unistd.h>
+#include <termios.h>
+#include <fcntl.h>
+#include <stdlib.h>
+
+#ifndef FNONBLOCK
+#define FNONBLOCK O_NONBLOCK
+#endif
+
+struct termios _tty;
+static tcflag_t _res_oflg = 0;
+static tcflag_t _res_lflg = 0;
+
+void _resetty(void) {
+    if (!isatty(STDIN_FILENO))
+        return;
+
+    /* reset tty: */
+    _tty.c_oflag = _res_oflg;
+    _tty.c_lflag = _res_lflg;
+    tcsetattr(STDIN_FILENO, TCSADRAIN, &_tty);
+}
+
+void _inittty(void) {
+    if (!isatty(STDIN_FILENO))
+        return;
+
+    /* save tty: */
+    tcgetattr(STDIN_FILENO, &_tty);
+    _res_oflg = _tty.c_oflag;
+    _res_lflg = _tty.c_lflag;
+
+    /* set raw: */
+    _tty.c_lflag &= ~(ICANON | ICRNL);// | ISIG);
+    //_tty.c_oflag &= ~ONLCR;
+    tcsetattr(STDIN_FILENO, TCSANOW, &_tty);
+
+    fcntl(STDIN_FILENO, F_SETFL, FNONBLOCK);
+    atexit(_resetty);
+}
+
+#else
+void _inittty() {}
+#endif
+
+typedef struct {
+    bool dummy;
+} uart_hw_t;
+
+uart_inst_t *const uart0;
+uart_inst_t *const uart1;
+
+static int _nextchar = EOF;
+
+static bool _peekchar() {
+    if (_nextchar == EOF) {
+        _nextchar = getchar();
+    }
+    return _nextchar != EOF;
+}
+
+uint uart_init(uart_inst_t *uart, uint baud_rate) {
+    _inittty();
+    return baud_rate;
+}
+
+size_t uart_is_writable(uart_inst_t *uart) {
+    return 1;
+}
+
+// If returns 0, no data is available to be read from UART.
+// If returns nonzero, at least that many bytes can be written without blocking.
+size_t uart_is_readable(uart_inst_t *uart) {
+    return _peekchar() ? 1 : 0;
+}
+
+// Write len bytes directly from src to the UART
+//void uart_write_blocking(uart_inst_t uart, const uint8_t *src, size_t len);
+
+// Read len bytes directly from the UART to dst
+//void uart_read_blocking(uart_inst_t uart, uint8_t *dst, size_t len);
+
+// ----------------------------------------------------------------------------
+// UART-specific operations and aliases
+
+void uart_putc(uart_inst_t *uart, char c) {
+    putchar(c);
+}
+
+void uart_puts(uart_inst_t *uart, const char *s) {
+    puts(s);
+}
+
+char uart_getc(uart_inst_t *uart) {
+    while (!_peekchar()) {
+        tight_loop_contents();
+    }
+    char rc = (char) _nextchar;
+    _nextchar = EOF;
+    return rc;
+}
+
+void uart_default_tx_wait_blocking() {
+
+}