diff options
Diffstat (limited to 'drivers/uart/src/uart_cmsdk_apb.c')
-rw-r--r-- | drivers/uart/src/uart_cmsdk_apb.c | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/drivers/uart/src/uart_cmsdk_apb.c b/drivers/uart/src/uart_cmsdk_apb.c new file mode 100644 index 0000000..2c644bb --- /dev/null +++ b/drivers/uart/src/uart_cmsdk_apb.c @@ -0,0 +1,136 @@ +/* + * 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; +} |