1/* 2 * Copyright (c) 2015-2017, ARM Limited and Contributors. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions are met: 6 * 7 * Redistributions of source code must retain the above copyright notice, this 8 * list of conditions and the following disclaimer. 9 * 10 * Redistributions in binary form must reproduce the above copyright notice, 11 * this list of conditions and the following disclaimer in the documentation 12 * and/or other materials provided with the distribution. 13 * 14 * Neither the name of ARM nor the names of its contributors may be used 15 * to endorse or promote products derived from this software without specific 16 * prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 19 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE 22 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 28 * POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31#include <arch.h> 32#include <asm_macros.S> 33#include <uart_16550.h> 34 35 .globl console_core_init 36 .globl console_core_putc 37 .globl console_core_getc 38 .globl console_core_flush 39 40 /* ----------------------------------------------- 41 * int console_core_init(unsigned long base_addr, 42 * unsigned int uart_clk, unsigned int baud_rate) 43 * Function to initialize the console without a 44 * C Runtime to print debug information. This 45 * function will be accessed by console_init and 46 * crash reporting. 47 * In: x0 - console base address 48 * w1 - Uart clock in Hz 49 * w2 - Baud rate 50 * Out: return 1 on success 51 * Clobber list : x1, x2, x3 52 * ----------------------------------------------- 53 */ 54func console_core_init 55 /* Check the input base address */ 56 cbz x0, init_fail 57 /* Check baud rate and uart clock for sanity */ 58 cbz w1, init_fail 59 cbz w2, init_fail 60 61 /* Program the baudrate */ 62 /* Divisor = Uart clock / (16 * baudrate) */ 63 lsl w2, w2, #4 64 udiv w2, w1, w2 65 and w1, w2, #0xff /* w1 = DLL */ 66 lsr w2, w2, #8 67 and w2, w2, #0xff /* w2 = DLLM */ 68 ldr w3, [x0, #UARTLCR] 69 orr w3, w3, #UARTLCR_DLAB 70 str w3, [x0, #UARTLCR] /* enable DLL, DLLM programming */ 71 str w1, [x0, #UARTDLL] /* program DLL */ 72 str w2, [x0, #UARTDLLM] /* program DLLM */ 73 mov w2, #~UARTLCR_DLAB 74 and w3, w3, w2 75 str w3, [x0, #UARTLCR] /* disable DLL, DLLM programming */ 76 77 /* 8n1 */ 78 mov w3, #3 79 str w3, [x0, #UARTLCR] 80 /* no interrupt */ 81 mov w3, #0 82 str w3, [x0, #UARTIER] 83 /* enable fifo, DMA */ 84 mov w3, #(UARTFCR_FIFOEN | UARTFCR_DMAEN) 85 str w3, [x0, #UARTFCR] 86 /* DTR + RTS */ 87 mov w3, #3 88 str w3, [x0, #UARTMCR] 89 mov w0, #1 90init_fail: 91 ret 92endfunc console_core_init 93 94 /* -------------------------------------------------------- 95 * int console_core_putc(int c, unsigned int base_addr) 96 * Function to output a character over the console. It 97 * returns the character printed on success or -1 on error. 98 * In : w0 - character to be printed 99 * x1 - console base address 100 * Out : return -1 on error else return character. 101 * Clobber list : x2 102 * -------------------------------------------------------- 103 */ 104func console_core_putc 105 /* Check the input parameter */ 106 cbz x1, putc_error 107 108 /* Prepend '\r' to '\n' */ 109 cmp w0, #0xA 110 b.ne 2f 111 /* Check if the transmit FIFO is full */ 1121: ldr w2, [x1, #UARTLSR] 113 and w2, w2, #(UARTLSR_TEMT | UARTLSR_THRE) 114 cmp w2, #(UARTLSR_TEMT | UARTLSR_THRE) 115 b.ne 1b 116 mov w2, #0xD /* '\r' */ 117 str w2, [x1, #UARTTX] 118 ldr w2, [x1, #UARTFCR] 119 orr w2, w2, #UARTFCR_TXCLR 120 str w2, [x1, #UARTFCR] 121 122 /* Check if the transmit FIFO is full */ 1232: ldr w2, [x1, #UARTLSR] 124 and w2, w2, #(UARTLSR_TEMT | UARTLSR_THRE) 125 cmp w2, #(UARTLSR_TEMT | UARTLSR_THRE) 126 b.ne 2b 127 str w0, [x1, #UARTTX] 128 ldr w2, [x1, #UARTFCR] 129 orr w2, w2, #UARTFCR_TXCLR 130 str w2, [x1, #UARTFCR] 131 ret 132putc_error: 133 mov w0, #-1 134 ret 135endfunc console_core_putc 136 137 /* --------------------------------------------- 138 * int console_core_getc(void) 139 * Function to get a character from the console. 140 * It returns the character grabbed on success 141 * or -1 on error. 142 * In : w0 - console base address 143 * Out : return -1 on error else return character. 144 * Clobber list : x0, x1 145 * --------------------------------------------- 146 */ 147func console_core_getc 148 /* Check if the receive FIFO is empty */ 1491: ldr w1, [x0, #UARTLSR] 150 tbz w1, #UARTLSR_RDR_BIT, 1b 151 ldr w0, [x0, #UARTRX] 152 ret 153getc_error: 154 mov w0, #-1 155 ret 156endfunc console_core_getc 157 158 /* --------------------------------------------- 159 * int console_core_flush(uintptr_t base_addr) 160 * Function to force a write of all buffered 161 * data that hasn't been output. 162 * In : x0 - console base address 163 * Out : return -1 on error else return 0. 164 * Clobber list : x0, x1 165 * --------------------------------------------- 166 */ 167func console_core_flush 168 /* Placeholder */ 169 mov w0, #0 170 ret 171endfunc console_core_flush 172