1 /*
2 * Copyright (c) 2020-2021 Huawei Device Co., Ltd.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
14 */
15
16 #include "uart.h"
17
18 #include "los_arch_interrupt.h"
19 #include "los_interrupt.h"
20 #include "riscv_hal.h"
21
22 #ifdef __cplusplus
23 #if __cplusplus
24 extern "C" {
25 #endif
26 #endif
27
UartPutc(INT32 c,VOID * file)28 INT32 UartPutc(INT32 c, VOID *file)
29 {
30 (VOID) file;
31 /* wait for Transmit Holding Empty to be set in LSR */
32 while ((ReadUartReg(UART_LSR_OFFSET) & UART_LSR_THRE) == 0) {
33 ;
34 }
35 WriteUartReg(UART_THR_OFFSET, (UINT8)c);
36 return c;
37 }
38
UartGetc(VOID)39 INT32 UartGetc(VOID)
40 {
41 if (ReadUartReg(UART_LSR_OFFSET) & UART_LSR_DR) {
42 return ReadUartReg(UART_RHR_OFFSET);
43 } else {
44 return 0;
45 }
46 }
47
UartOut(INT32 c,VOID * file)48 INT32 UartOut(INT32 c, VOID *file)
49 {
50 (VOID) file;
51 return UartGetc();
52 }
53
UartInit(VOID)54 VOID UartInit(VOID)
55 {
56 /* Disable all interrupts */
57 WriteUartReg(UART_IER_OFFSET, 0x00);
58
59 /* special mode to set baud rate */
60 WriteUartReg(UART_LCR_OFFSET, UART_LCR_DLAB);
61
62 /* Set divisor low byte, LSB for baud rate of 38.4K */
63 WriteUartReg(UART_DLL_OFFSET, 0x03);
64
65 /* Set divisor high byte, LSB for baud rate of 38.4K */
66 WriteUartReg(UART_DLM_OFFSET, 0x00);
67
68 /* leave set-baud mode, and set word length to 8 bits, no parity */
69 WriteUartReg(UART_LCR_OFFSET, UART_LCR_8N1);
70
71 /* reset and enable FIFOs */
72 WriteUartReg(UART_FCR_OFFSET, UART_FCR_FIFO_EN | UART_FCR_RXSR | UART_FCR_TXSR);
73 }
74
UartReceiveHandler(VOID)75 VOID UartReceiveHandler(VOID)
76 {
77 if (ReadUartReg(UART_LSR_OFFSET) & UART_LSR_DR) {
78 (void)LOS_EventWrite(&g_shellInputEvent, 0x1);
79 }
80 return;
81 }
82
Uart0RxIrqRegister(VOID)83 VOID Uart0RxIrqRegister(VOID)
84 {
85 WriteUartReg(UART_IER_OFFSET, ReadUartReg(UART_IER_OFFSET) | UART_IER_RDI);
86 uint32_t ret = LOS_HwiCreate(RISCV_UART0_Rx_IRQn, OS_HWI_PRIO_HIGHEST, 0, (HWI_PROC_FUNC)UartReceiveHandler, 0);
87 if (ret != LOS_OK) {
88 return;
89 }
90 HalIrqEnable(RISCV_UART0_Rx_IRQn);
91 }
92
93 #ifdef __cplusplus
94 #if __cplusplus
95 }
96 #endif /* __cplusplus */
97 #endif /* __cplusplus */
98