Yann Gautier | 4b0c72a | 2018-07-16 10:54:09 +0200 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved. |
| 3 | * |
| 4 | * SPDX-License-Identifier: BSD-3-Clause |
| 5 | */ |
| 6 | #include <asm_macros.S> |
Yann Gautier | 3d48bae | 2018-11-14 18:18:12 +0100 | [diff] [blame^] | 7 | #include <stm32_uart_regs.h> |
Yann Gautier | 4b0c72a | 2018-07-16 10:54:09 +0200 | [diff] [blame] | 8 | |
Yann Gautier | 69035a8 | 2018-07-05 16:48:16 +0200 | [diff] [blame] | 9 | #define USART_TIMEOUT 0x1000 |
| 10 | |
Yann Gautier | 4b0c72a | 2018-07-16 10:54:09 +0200 | [diff] [blame] | 11 | .globl console_core_init |
| 12 | .globl console_core_putc |
| 13 | .globl console_core_getc |
| 14 | .globl console_core_flush |
| 15 | |
| 16 | /* ----------------------------------------------------------------- |
| 17 | * int console_core_init(uintptr_t base_addr, |
| 18 | * unsigned int uart_clk, |
| 19 | * unsigned int baud_rate) |
| 20 | * |
| 21 | * Function to initialize the console without a C Runtime to print |
| 22 | * debug information. This function will be accessed by console_init |
| 23 | * and crash reporting. |
| 24 | * |
| 25 | * In: r0 - console base address |
| 26 | * r1 - Uart clock in Hz |
| 27 | * r2 - Baud rate |
| 28 | * Out: return 1 on success else 0 on error |
| 29 | * Clobber list : r1, r2, r3 |
| 30 | * ----------------------------------------------------------------- |
| 31 | */ |
| 32 | func console_core_init |
Yann Gautier | 69035a8 | 2018-07-05 16:48:16 +0200 | [diff] [blame] | 33 | /* Check the input base address */ |
| 34 | cmp r0, #0 |
| 35 | beq core_init_fail |
| 36 | #if defined(IMAGE_BL2) |
| 37 | /* Check baud rate and uart clock for sanity */ |
| 38 | cmp r1, #0 |
| 39 | beq core_init_fail |
| 40 | cmp r2, #0 |
| 41 | beq core_init_fail |
| 42 | /* Disable UART */ |
| 43 | ldr r3, [r0, #USART_CR1] |
| 44 | bic r3, r3, #USART_CR1_UE |
| 45 | str r3, [r0, #USART_CR1] |
| 46 | /* Configure UART */ |
| 47 | orr r3, r3, #(USART_CR1_TE | USART_CR1_FIFOEN) |
| 48 | str r3, [r0, #USART_CR1] |
| 49 | ldr r3, [r0, #USART_CR2] |
| 50 | bic r3, r3, #USART_CR2_STOP |
| 51 | str r3, [r0, #USART_CR2] |
| 52 | /* Divisor = (Uart clock + (baudrate / 2)) / baudrate */ |
| 53 | lsl r3, r2, #1 |
| 54 | add r3, r1, r3 |
| 55 | udiv r3, r3, r2 |
| 56 | str r3, [r0, #USART_BRR] |
| 57 | /* Enable UART */ |
| 58 | ldr r3, [r0, #USART_CR1] |
| 59 | orr r3, r3, #USART_CR1_UE |
| 60 | str r3, [r0, #USART_CR1] |
| 61 | /* Check TEACK bit */ |
| 62 | mov r2, #USART_TIMEOUT |
| 63 | teack_loop: |
| 64 | subs r2, r2, #1 |
| 65 | beq core_init_fail |
| 66 | ldr r3, [r0, #USART_ISR] |
| 67 | tst r3, #USART_ISR_TEACK |
| 68 | beq teack_loop |
| 69 | #endif /* IMAGE_BL2 */ |
| 70 | mov r0, #1 |
| 71 | bx lr |
| 72 | core_init_fail: |
| 73 | mov r0, #0 |
Yann Gautier | 4b0c72a | 2018-07-16 10:54:09 +0200 | [diff] [blame] | 74 | bx lr |
| 75 | endfunc console_core_init |
| 76 | |
| 77 | /* --------------------------------------------------------------- |
| 78 | * int console_core_putc(int c, uintptr_t base_addr) |
| 79 | * |
| 80 | * Function to output a character over the console. It returns the |
| 81 | * character printed on success or -1 on error. |
| 82 | * |
| 83 | * In : r0 - character to be printed |
| 84 | * r1 - console base address |
| 85 | * Out : return -1 on error else return character. |
| 86 | * Clobber list : r2 |
| 87 | * --------------------------------------------------------------- |
| 88 | */ |
| 89 | func console_core_putc |
Yann Gautier | 69035a8 | 2018-07-05 16:48:16 +0200 | [diff] [blame] | 90 | /* Check the input parameter */ |
| 91 | cmp r1, #0 |
| 92 | beq putc_error |
| 93 | /* Prepend '\r' to '\n' */ |
| 94 | cmp r0, #0xA |
| 95 | bne 2f |
| 96 | 1: |
| 97 | /* Check Transmit Data Register Empty */ |
| 98 | txe_loop_1: |
| 99 | ldr r2, [r1, #USART_ISR] |
| 100 | tst r2, #USART_ISR_TXE |
| 101 | beq txe_loop_1 |
| 102 | mov r2, #0xD |
| 103 | str r2, [r1, #USART_TDR] |
| 104 | /* Check transmit complete flag */ |
| 105 | tc_loop_1: |
| 106 | ldr r2, [r1, #USART_ISR] |
| 107 | tst r2, #USART_ISR_TC |
| 108 | beq tc_loop_1 |
| 109 | 2: |
| 110 | /* Check Transmit Data Register Empty */ |
| 111 | txe_loop_2: |
| 112 | ldr r2, [r1, #USART_ISR] |
| 113 | tst r2, #USART_ISR_TXE |
| 114 | beq txe_loop_2 |
| 115 | str r0, [r1, #USART_TDR] |
| 116 | /* Check transmit complete flag */ |
| 117 | tc_loop_2: |
| 118 | ldr r2, [r1, #USART_ISR] |
| 119 | tst r2, #USART_ISR_TC |
| 120 | beq tc_loop_2 |
| 121 | bx lr |
| 122 | putc_error: |
| 123 | mov r0, #-1 |
Yann Gautier | 4b0c72a | 2018-07-16 10:54:09 +0200 | [diff] [blame] | 124 | bx lr |
| 125 | endfunc console_core_putc |
| 126 | |
| 127 | /* ----------------------------------------------------------- |
| 128 | * int console_core_getc(uintptr_t base_addr) |
| 129 | * |
| 130 | * Function to get a character from the console. |
| 131 | * It returns the character grabbed on success or -1 on error. |
| 132 | * |
| 133 | * In : r0 - console base address |
| 134 | * Out : return -1. |
| 135 | * Clobber list : r0, r1 |
| 136 | * ----------------------------------------------------------- |
| 137 | */ |
| 138 | func console_core_getc |
| 139 | /* Not supported */ |
| 140 | mov r0, #-1 |
| 141 | bx lr |
| 142 | endfunc console_core_getc |
| 143 | |
| 144 | /* --------------------------------------------------------------- |
| 145 | * int console_core_flush(uintptr_t base_addr) |
| 146 | * |
| 147 | * Function to force a write of all buffered data that hasn't been |
| 148 | * output. |
| 149 | * |
| 150 | * In : r0 - console base address |
| 151 | * Out : return -1 on error else return 0. |
| 152 | * Clobber list : r0, r1 |
| 153 | * --------------------------------------------------------------- |
| 154 | */ |
| 155 | func console_core_flush |
Yann Gautier | 69035a8 | 2018-07-05 16:48:16 +0200 | [diff] [blame] | 156 | cmp r0, #0 |
| 157 | beq flush_error |
| 158 | /* Check Transmit Data Register Empty */ |
| 159 | txe_loop_3: |
| 160 | ldr r1, [r0, #USART_ISR] |
| 161 | tst r1, #USART_ISR_TXE |
| 162 | beq txe_loop_3 |
| 163 | mov r0, #0 |
| 164 | bx lr |
| 165 | flush_error: |
| 166 | mov r0, #-1 |
Yann Gautier | 4b0c72a | 2018-07-16 10:54:09 +0200 | [diff] [blame] | 167 | bx lr |
| 168 | endfunc console_core_flush |