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 #include <machine.h> 13 #include <common/types.h> 14 #include <arch/mmu.h> 15 #include <arch/tools.h> 16 17 /* uart register defines */ 18 #define UART_RHR 0x0 19 #define UART_THR 0x0 20 #define UART_IER 0x4 21 #define UART_ISR 0x8 22 #define UART_FCR 0x8 23 #define UART_LCR 0xc 24 #define UART_MCR 0x10 25 #define UART_LSR 0x14 26 #define UART_MSR 0x18 27 #define UART_SPR 0x1c 28 29 /* uart status register bits */ 30 #define LSR_TEMT 0x40 /* Transmitter empty */ 31 #define LSR_THRE 0x20 /* Transmit-hold-register empty */ 32 #define LSR_EMPTY (LSR_TEMT | LSR_THRE) 33 #define LSR_DR 0x01 /* DATA Ready */ 34 serial8250_uart_flush(vaddr_t base)35static void serial8250_uart_flush(vaddr_t base) 36 { 37 u32 state; 38 39 /* Wait until transmit FIFO is empty */ 40 do { 41 state = get32(base + UART_LSR); 42 } while ((state & LSR_EMPTY) != LSR_EMPTY); 43 } 44 serial8250_uart_send(vaddr_t base,int c)45static void serial8250_uart_send(vaddr_t base, int c) 46 { 47 serial8250_uart_flush(base); 48 put32(base + UART_THR, c); 49 } 50 uart_init(void)51void uart_init(void) 52 { 53 /* Do nothing */ 54 } 55 uart_send(int c)56void uart_send(int c) 57 { 58 vaddr_t base = phys_to_virt(get_uart_base()); 59 60 serial8250_uart_send(base, c); 61 } 62 uart_recv(void)63u32 uart_recv(void) 64 { 65 return 0; 66 } 67 nb_uart_recv(void)68u32 nb_uart_recv(void) 69 { 70 return 0; 71 } 72