1 /* 2 * Copyright (c) 2023 Institute of Parallel And Distributed Systems (IPADS), Shanghai Jiao Tong University (SJTU) 3 * Licensed under the Mulan PSL v2. 4 * You can use this software according to the terms and conditions of the Mulan PSL v2. 5 * You may obtain a copy of Mulan PSL v2 at: 6 * http://license.coscl.org.cn/MulanPSL2 7 * THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND, EITHER EXPRESS OR 8 * IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT, MERCHANTABILITY OR FIT FOR A PARTICULAR 9 * PURPOSE. 10 * See the Mulan PSL v2 for more details. 11 */ 12 13 #include <machine.h> 14 #include <common/types.h> 15 #include <arch/mmu.h> 16 #include <arch/tools.h> 17 18 /* uart register defines */ 19 #define UART_RHR 0x0 20 #define UART_THR 0x0 21 #define UART_IER 0x4 22 #define UART_ISR 0x8 23 #define UART_FCR 0x8 24 #define UART_LCR 0xc 25 #define UART_MCR 0x10 26 #define UART_LSR 0x14 27 #define UART_MSR 0x18 28 #define UART_SPR 0x1c 29 30 /* uart status register bits */ 31 #define LSR_TEMT 0x40 /* Transmitter empty */ 32 #define LSR_THRE 0x20 /* Transmit-hold-register empty */ 33 #define LSR_EMPTY (LSR_TEMT | LSR_THRE) 34 #define LSR_DR 0x01 /* DATA Ready */ 35 serial8250_uart_flush(vaddr_t base)36static void serial8250_uart_flush(vaddr_t base) 37 { 38 u32 state; 39 40 /* Wait until transmit FIFO is empty */ 41 do { 42 state = get32(base + UART_LSR); 43 } while ((state & LSR_EMPTY) != LSR_EMPTY); 44 } 45 serial8250_uart_send(vaddr_t base,int c)46static void serial8250_uart_send(vaddr_t base, int c) 47 { 48 serial8250_uart_flush(base); 49 put32(base + UART_THR, c); 50 } 51 uart_init(void)52void uart_init(void) 53 { 54 /* Do nothing */ 55 } 56 uart_send(int c)57void uart_send(int c) 58 { 59 vaddr_t base = phys_to_virt(get_uart_base()); 60 61 serial8250_uart_send(base, c); 62 } 63 uart_recv(void)64u32 uart_recv(void) 65 { 66 return 0; 67 } 68 nb_uart_recv(void)69u32 nb_uart_recv(void) 70 { 71 return 0; 72 } 73