1/* 2 * Copyright (c) 2015-2016, 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 39 /* ----------------------------------------------- 40 * int console_core_init(unsigned long base_addr, 41 * unsigned int uart_clk, unsigned int baud_rate) 42 * Function to initialize the console without a 43 * C Runtime to print debug information. This 44 * function will be accessed by console_init and 45 * crash reporting. 46 * In: x0 - console base address 47 * w1 - Uart clock in Hz 48 * w2 - Baud rate 49 * Out: return 1 on success 50 * Clobber list : x1, x2, x3 51 * ----------------------------------------------- 52 */ 53func console_core_init 54 /* Check the input base address */ 55 cbz x0, init_fail 56 /* Check baud rate and uart clock for sanity */ 57 cbz w1, init_fail 58 cbz w2, init_fail 59 60 /* Program the baudrate */ 61 /* Divisor = Uart clock / (16 * baudrate) */ 62 lsl w2, w2, #4 63 udiv w2, w1, w2 64 and w1, w2, #0xff /* w1 = DLL */ 65 lsr w2, w2, #8 66 and w2, w2, #0xff /* w2 = DLLM */ 67 ldr w3, [x0, #UARTLCR] 68 orr w3, w3, #UARTLCR_DLAB 69 str w3, [x0, #UARTLCR] /* enable DLL, DLLM programming */ 70 str w1, [x0, #UARTDLL] /* program DLL */ 71 str w2, [x0, #UARTDLLM] /* program DLLM */ 72 mov w2, #~UARTLCR_DLAB 73 and w3, w3, w2 74 str w3, [x0, #UARTLCR] /* disable DLL, DLLM programming */ 75 76 /* 8n1 */ 77 mov w3, #3 78 str w3, [x0, #UARTLCR] 79 /* no interrupt */ 80 mov w3, #0 81 str w3, [x0, #UARTIER] 82 /* enable fifo, DMA */ 83 mov w3, #(UARTFCR_FIFOEN | UARTFCR_DMAEN) 84 str w3, [x0, #UARTFCR] 85 /* DTR + RTS */ 86 mov w3, #3 87 str w3, [x0, #UARTMCR] 88 mov w0, #1 89init_fail: 90 ret 91endfunc console_core_init 92 93 /* -------------------------------------------------------- 94 * int console_core_putc(int c, unsigned int base_addr) 95 * Function to output a character over the console. It 96 * returns the character printed on success or -1 on error. 97 * In : w0 - character to be printed 98 * x1 - console base address 99 * Out : return -1 on error else return character. 100 * Clobber list : x2 101 * -------------------------------------------------------- 102 */ 103func console_core_putc 104 /* Check the input parameter */ 105 cbz x1, putc_error 106 107 /* Prepend '\r' to '\n' */ 108 cmp w0, #0xA 109 b.ne 2f 110 /* Check if the transmit FIFO is full */ 1111: ldr w2, [x1, #UARTLSR] 112 and w2, w2, #(UARTLSR_TEMT | UARTLSR_THRE) 113 cmp w2, #(UARTLSR_TEMT | UARTLSR_THRE) 114 b.ne 1b 115 mov w2, #0xD /* '\r' */ 116 str w2, [x1, #UARTTX] 117 ldr w2, [x1, #UARTFCR] 118 orr w2, w2, #UARTFCR_TXCLR 119 str w2, [x1, #UARTFCR] 120 121 /* Check if the transmit FIFO is full */ 1222: ldr w2, [x1, #UARTLSR] 123 and w2, w2, #(UARTLSR_TEMT | UARTLSR_THRE) 124 cmp w2, #(UARTLSR_TEMT | UARTLSR_THRE) 125 b.ne 2b 126 str w0, [x1, #UARTTX] 127 ldr w2, [x1, #UARTFCR] 128 orr w2, w2, #UARTFCR_TXCLR 129 str w2, [x1, #UARTFCR] 130 ret 131putc_error: 132 mov w0, #-1 133 ret 134endfunc console_core_putc 135 136 /* --------------------------------------------- 137 * int console_core_getc(void) 138 * Function to get a character from the console. 139 * It returns the character grabbed on success 140 * or -1 on error. 141 * In : w0 - console base address 142 * Out : return -1 on error else return character. 143 * Clobber list : x0, x1 144 * --------------------------------------------- 145 */ 146func console_core_getc 147 /* Check if the receive FIFO is empty */ 1481: ldr w1, [x0, #UARTLSR] 149 tbz w1, #UARTLSR_RDR_BIT, 1b 150 ldr w0, [x0, #UARTRX] 151 ret 152getc_error: 153 mov w0, #-1 154 ret 155endfunc console_core_getc 156