Kristofer Jonsson | 43ce491 | 2020-11-20 09:42:53 +0100 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2019-2020 Arm Limited. All rights reserved. |
| 3 | * |
| 4 | * SPDX-License-Identifier: Apache-2.0 |
| 5 | * |
| 6 | * Licensed under the Apache License, Version 2.0 (the License); you may |
| 7 | * not use this file except in compliance with the License. |
| 8 | * You may obtain a copy of the License at |
| 9 | * |
| 10 | * www.apache.org/licenses/LICENSE-2.0 |
| 11 | * |
| 12 | * Unless required by applicable law or agreed to in writing, software |
| 13 | * distributed under the License is distributed on an AS IS BASIS, WITHOUT |
| 14 | * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 15 | * See the License for the specific language governing permissions and |
| 16 | * limitations under the License. |
| 17 | */ |
| 18 | |
| 19 | #include "uart.h" |
| 20 | #include "uart_config.h" |
| 21 | #include <stdint.h> |
| 22 | #include <stdio.h> |
| 23 | |
| 24 | #define CNTLQ 0x11 |
| 25 | #define CNTLS 0x13 |
| 26 | #define DEL 0x7F |
| 27 | #define BACKSPACE 0x08 |
| 28 | #define CR 0x0D |
| 29 | #define LF 0x0A |
| 30 | #define ESC 0x1B |
| 31 | |
| 32 | /*------------- Universal Asynchronous Receiver Transmitter (UART) -----------*/ |
| 33 | |
| 34 | #define __IO volatile |
| 35 | #define __I volatile const |
| 36 | #define __O volatile |
| 37 | |
| 38 | typedef struct { |
| 39 | __IO uint32_t DATA; /* Offset: 0x000 (R/W) Data Register */ |
| 40 | __IO uint32_t STATE; /* Offset: 0x004 (R/W) Status Register */ |
| 41 | __IO uint32_t CTRL; /* Offset: 0x008 (R/W) Control Register */ |
| 42 | union { |
| 43 | __I uint32_t INTSTATUS; /* Offset: 0x00C (R/ ) Interrupt Status Register */ |
| 44 | __O uint32_t INTCLEAR; /* Offset: 0x00C ( /W) Interrupt Clear Register */ |
| 45 | }; |
| 46 | __IO uint32_t BAUDDIV; /* Offset: 0x010 (R/W) Baudrate Divider Register */ |
| 47 | } CMSDK_UART_TypeDef; |
| 48 | |
| 49 | #define CMSDK_UART0_BASE UART0_BASE |
| 50 | #define CMSDK_UART0 ((CMSDK_UART_TypeDef *)CMSDK_UART0_BASE) |
| 51 | #define CMSDK_UART0_BAUDRATE UART0_BAUDRATE |
| 52 | |
| 53 | void uart_init(void) { |
| 54 | // SystemCoreClock / 9600 |
| 55 | CMSDK_UART0->BAUDDIV = SYSTEM_CORE_CLOCK / CMSDK_UART0_BAUDRATE; |
| 56 | |
| 57 | CMSDK_UART0->CTRL = ((1ul << 0) | /* TX enable */ |
| 58 | (1ul << 1)); /* RX enable */ |
| 59 | } |
| 60 | |
| 61 | // Output a character |
| 62 | unsigned char uart_putc(unsigned char my_ch) { |
| 63 | while ((CMSDK_UART0->STATE & 1)) |
| 64 | ; // Wait if Transmit Holding register is full |
| 65 | |
| 66 | if (my_ch == '\n') { |
| 67 | CMSDK_UART0->DATA = '\r'; |
| 68 | while ((CMSDK_UART0->STATE & 1)) |
| 69 | ; // Wait if Transmit Holding register is full |
| 70 | } |
| 71 | |
| 72 | CMSDK_UART0->DATA = my_ch; // write to transmit holding register |
| 73 | |
| 74 | return (my_ch); |
| 75 | } |
| 76 | |
| 77 | // Get a character |
| 78 | unsigned char uart_getc(void) { |
| 79 | unsigned char my_ch; |
| 80 | // unsigned int cnt; |
| 81 | |
| 82 | while ((CMSDK_UART0->STATE & 2) == 0) // Wait if Receive Holding register is empty |
| 83 | { |
| 84 | #if 0 |
| 85 | cnt = MPS3_FPGAIO->CLK100HZ / 50; |
| 86 | if (cnt & 0x8) |
| 87 | MPS3_FPGAIO->LED = 0x01 << (cnt & 0x7); |
| 88 | else |
| 89 | MPS3_FPGAIO->LED = 0x80 >> (cnt & 0x7); |
| 90 | #endif |
| 91 | } |
| 92 | |
| 93 | my_ch = CMSDK_UART0->DATA; |
| 94 | |
| 95 | // Convert CR to LF |
| 96 | if (my_ch == '\r') |
| 97 | my_ch = '\n'; |
| 98 | |
| 99 | return (my_ch); |
| 100 | } |
| 101 | |
| 102 | // Get line from terminal |
| 103 | unsigned int uart_getline(char *lp, unsigned int len) { |
| 104 | unsigned int cnt = 0; |
| 105 | char c; |
| 106 | |
| 107 | do { |
| 108 | c = uart_getc(); |
| 109 | switch (c) { |
| 110 | case CNTLQ: /* ignore Control S/Q */ |
| 111 | case CNTLS: |
| 112 | break; |
| 113 | case BACKSPACE: |
| 114 | case DEL: |
| 115 | if (cnt == 0) { |
| 116 | break; |
| 117 | } |
| 118 | cnt--; /* decrement count */ |
| 119 | lp--; /* and line pointer */ |
| 120 | uart_putc(0x08); /* echo backspace */ |
| 121 | uart_putc(' '); |
| 122 | uart_putc(0x08); |
| 123 | fflush(stdout); |
| 124 | break; |
| 125 | case ESC: |
| 126 | case 0: |
| 127 | *lp = 0; /* ESC - stop editing line */ |
| 128 | return 0; |
| 129 | case CR: /* CR - done, stop editing line */ |
| 130 | *lp = c; |
| 131 | lp++; /* increment line pointer */ |
| 132 | cnt++; /* and count */ |
| 133 | c = LF; |
| 134 | default: |
| 135 | uart_putc(*lp = c); /* echo and store character */ |
| 136 | fflush(stdout); |
| 137 | lp++; /* increment line pointer */ |
| 138 | cnt++; /* and count */ |
| 139 | break; |
| 140 | } |
| 141 | } while (cnt < len - 2 && c != LF); /* check limit and CR */ |
| 142 | *lp = 0; /* mark end of string */ |
| 143 | return 1; |
| 144 | } |