| /* |
| * Copyright (c) 2019-2021 Arm Limited. All rights reserved. |
| * |
| * SPDX-License-Identifier: Apache-2.0 |
| * |
| * Licensed under the Apache License, Version 2.0 (the License); you may |
| * not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an AS IS BASIS, WITHOUT |
| * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| /* Basic CMSDK APB UART driver */ |
| |
| #include "uart_config.h" |
| #include "uart_stdout.h" |
| #include <stdint.h> |
| #include <stdio.h> |
| |
| #define CNTLQ 0x11 |
| #define CNTLS 0x13 |
| #define DEL 0x7F |
| #define BACKSPACE 0x08 |
| #define CR 0x0D |
| #define LF 0x0A |
| #define ESC 0x1B |
| |
| #define __IO volatile |
| #define __I volatile const |
| #define __O volatile |
| |
| typedef struct { |
| __IO uint32_t DATA; /* Offset: 0x000 (R/W) Data Register */ |
| __IO uint32_t STATE; /* Offset: 0x004 (R/W) Status Register */ |
| __IO uint32_t CTRL; /* Offset: 0x008 (R/W) Control Register */ |
| union { |
| __I uint32_t INTSTATUS; /* Offset: 0x00C (R/ ) Interrupt Status Register */ |
| __O uint32_t INTCLEAR; /* Offset: 0x00C ( /W) Interrupt Clear Register */ |
| }; |
| __IO uint32_t BAUDDIV; /* Offset: 0x010 (R/W) Baudrate Divider Register */ |
| } CMSDK_UART_TypeDef; |
| |
| #define CMSDK_UART0_BASE UART0_BASE |
| #define CMSDK_UART0 ((CMSDK_UART_TypeDef *)CMSDK_UART0_BASE) |
| #define CMSDK_UART0_BAUDRATE UART0_BAUDRATE |
| |
| void UartStdOutInit(void) { |
| CMSDK_UART0->BAUDDIV = SYSTEM_CORE_CLOCK / CMSDK_UART0_BAUDRATE; |
| |
| CMSDK_UART0->CTRL = ((1ul << 0) | /* TX enable */ |
| (1ul << 1)); /* RX enable */ |
| } |
| |
| // Output a character |
| unsigned char UartPutc(unsigned char my_ch) { |
| while ((CMSDK_UART0->STATE & 1)) |
| ; // Wait if Transmit Holding register is full |
| |
| if (my_ch == '\n') { |
| CMSDK_UART0->DATA = '\r'; |
| while ((CMSDK_UART0->STATE & 1)) |
| ; // Wait if Transmit Holding register is full |
| } |
| |
| CMSDK_UART0->DATA = my_ch; // write to transmit holding register |
| |
| return (my_ch); |
| } |
| |
| // Get a character |
| unsigned char UartGetc(void) { |
| unsigned char my_ch; |
| // unsigned int cnt; |
| |
| while ((CMSDK_UART0->STATE & 2) == 0) // Wait if Receive Holding register is empty |
| ; |
| |
| my_ch = CMSDK_UART0->DATA; |
| |
| // Convert CR to LF |
| if (my_ch == '\r') |
| my_ch = '\n'; |
| |
| return (my_ch); |
| } |
| |
| // Get line from terminal |
| unsigned int GetLine(char *lp, unsigned int len) { |
| unsigned int cnt = 0; |
| char c; |
| |
| do { |
| c = UartGetc(); |
| switch (c) { |
| case CNTLQ: /* ignore Control S/Q */ |
| case CNTLS: |
| break; |
| case BACKSPACE: |
| case DEL: |
| if (cnt == 0) { |
| break; |
| } |
| cnt--; /* decrement count */ |
| lp--; /* and line pointer */ |
| UartPutc(0x08); /* echo backspace */ |
| UartPutc(' '); |
| UartPutc(0x08); |
| fflush(stdout); |
| break; |
| case ESC: |
| case 0: |
| *lp = 0; /* ESC - stop editing line */ |
| return 0; |
| case CR: /* CR - done, stop editing line */ |
| *lp = c; |
| lp++; /* increment line pointer */ |
| cnt++; /* and count */ |
| c = LF; |
| /* fall through */ |
| default: |
| UartPutc(*lp = c); /* echo and store character */ |
| fflush(stdout); |
| lp++; /* increment line pointer */ |
| cnt++; /* and count */ |
| break; |
| } |
| } while (cnt < len - 2 && c != LF); /* check limit and CR */ |
| *lp = 0; /* mark end of string */ |
| return 1; |
| } |