1/* 2 * Copyright (c) 2015-2018, ARM Limited and Contributors. All rights reserved. 3 * 4 * SPDX-License-Identifier: BSD-3-Clause 5 */ 6 7#include <arch.h> 8#include <asm_macros.S> 9#include <assert_macros.S> 10#define USE_FINISH_CONSOLE_REG_2 11#include <console_macros.S> 12#include <drivers/ti/uart/uart_16550.h> 13 14 /* 15 * "core" functions are low-level implementations that don't require 16 * writable memory and are thus safe to call in BL1 crash context. 17 */ 18 .globl console_16550_core_init 19 .globl console_16550_core_putc 20 .globl console_16550_core_getc 21 .globl console_16550_core_flush 22 23 .globl console_16550_putc 24 .globl console_16550_getc 25 .globl console_16550_flush 26 27 /* ----------------------------------------------- 28 * int console_16550_core_init(uintptr_t base_addr, 29 * unsigned int uart_clk, unsigned int baud_rate) 30 * Function to initialize the console without a 31 * C Runtime to print debug information. This 32 * function will be accessed by console_init and 33 * crash reporting. 34 * In: x0 - console base address 35 * w1 - Uart clock in Hz 36 * w2 - Baud rate 37 * Out: return 1 on success, 0 on error 38 * Clobber list : x1, x2, x3 39 * ----------------------------------------------- 40 */ 41func console_16550_core_init 42 /* Check the input base address */ 43 cbz x0, init_fail 44 /* Check baud rate and uart clock for sanity */ 45 cbz w1, init_fail 46 cbz w2, init_fail 47 48 /* Program the baudrate */ 49 /* Divisor = Uart clock / (16 * baudrate) */ 50 lsl w2, w2, #4 51 udiv w2, w1, w2 52 and w1, w2, #0xff /* w1 = DLL */ 53 lsr w2, w2, #8 54 and w2, w2, #0xff /* w2 = DLLM */ 55 ldr w3, [x0, #UARTLCR] 56 orr w3, w3, #UARTLCR_DLAB 57 str w3, [x0, #UARTLCR] /* enable DLL, DLLM programming */ 58 str w1, [x0, #UARTDLL] /* program DLL */ 59 str w2, [x0, #UARTDLLM] /* program DLLM */ 60 mov w2, #~UARTLCR_DLAB 61 and w3, w3, w2 62 str w3, [x0, #UARTLCR] /* disable DLL, DLLM programming */ 63 64 /* 8n1 */ 65 mov w3, #3 66 str w3, [x0, #UARTLCR] 67 /* no interrupt */ 68 mov w3, #0 69 str w3, [x0, #UARTIER] 70#ifdef TI_16550_MDR_QUIRK 71 /* UART must be enabled on some platforms via the MDR register */ 72 str w3, [x0, #UARTMDR1] 73#endif /* TI_16550_MDR_QUIRK */ 74 /* enable fifo, DMA */ 75 mov w3, #(UARTFCR_FIFOEN | UARTFCR_DMAEN) 76 str w3, [x0, #UARTFCR] 77 /* DTR + RTS */ 78 mov w3, #3 79 str w3, [x0, #UARTMCR] 80 mov w0, #1 81 ret 82init_fail: 83 mov w0, #0 84 ret 85endfunc console_16550_core_init 86 87#if MULTI_CONSOLE_API 88 .globl console_16550_register 89 90 /* ----------------------------------------------- 91 * int console_16550_register(uintptr_t baseaddr, 92 * uint32_t clock, uint32_t baud, 93 * console_16550_t *console); 94 * Function to initialize and register a new 16550 95 * console. Storage passed in for the console struct 96 * *must* be persistent (i.e. not from the stack). 97 * In: x0 - UART register base address 98 * w1 - UART clock in Hz 99 * w2 - Baud rate 100 * x3 - pointer to empty console_16550_t struct 101 * Out: return 1 on success, 0 on error 102 * Clobber list : x0, x1, x2, x6, x7, x14 103 * ----------------------------------------------- 104 */ 105func console_16550_register 106 mov x7, x30 107 mov x6, x3 108 cbz x6, register_fail 109 str x0, [x6, #CONSOLE_T_16550_BASE] 110 111 bl console_16550_core_init 112 cbz x0, register_fail 113 114 mov x0, x6 115 mov x30, x7 116 finish_console_register 16550 putc=1, getc=1, flush=1 117 118register_fail: 119 ret x7 120endfunc console_16550_register 121#else 122 .globl console_core_init 123 .globl console_core_putc 124 .globl console_core_getc 125 .globl console_core_flush 126 .equ console_core_init,console_16550_core_init 127 .equ console_core_putc,console_16550_core_putc 128 .equ console_core_getc,console_16550_core_getc 129 .equ console_core_flush,console_16550_core_flush 130#endif 131 132 /* -------------------------------------------------------- 133 * int console_16550_core_putc(int c, uintptr_t base_addr) 134 * Function to output a character over the console. It 135 * returns the character printed on success or -1 on error. 136 * In : w0 - character to be printed 137 * x1 - console base address 138 * Out : return -1 on error else return character. 139 * Clobber list : x2 140 * -------------------------------------------------------- 141 */ 142func console_16550_core_putc 143#if ENABLE_ASSERTIONS 144 cmp x1, #0 145 ASM_ASSERT(ne) 146#endif /* ENABLE_ASSERTIONS */ 147 148 /* Prepend '\r' to '\n' */ 149 cmp w0, #0xA 150 b.ne 2f 151 /* Check if the transmit FIFO is full */ 1521: ldr w2, [x1, #UARTLSR] 153 and w2, w2, #(UARTLSR_TEMT | UARTLSR_THRE) 154 cmp w2, #(UARTLSR_TEMT | UARTLSR_THRE) 155 b.ne 1b 156 mov w2, #0xD /* '\r' */ 157 str w2, [x1, #UARTTX] 158 159 /* Check if the transmit FIFO is full */ 1602: ldr w2, [x1, #UARTLSR] 161 and w2, w2, #(UARTLSR_TEMT | UARTLSR_THRE) 162 cmp w2, #(UARTLSR_TEMT | UARTLSR_THRE) 163 b.ne 2b 164 str w0, [x1, #UARTTX] 165 ret 166endfunc console_16550_core_putc 167 168 /* -------------------------------------------------------- 169 * int console_16550_putc(int c, console_16550_t *console) 170 * Function to output a character over the console. It 171 * returns the character printed on success or -1 on error. 172 * In : w0 - character to be printed 173 * x1 - pointer to console_t structure 174 * Out : return -1 on error else return character. 175 * Clobber list : x2 176 * -------------------------------------------------------- 177 */ 178func console_16550_putc 179#if ENABLE_ASSERTIONS 180 cmp x1, #0 181 ASM_ASSERT(ne) 182#endif /* ENABLE_ASSERTIONS */ 183 ldr x1, [x1, #CONSOLE_T_16550_BASE] 184 b console_16550_core_putc 185endfunc console_16550_putc 186 187 /* --------------------------------------------- 188 * int console_16550_core_getc(uintptr_t base_addr) 189 * Function to get a character from the console. 190 * It returns the character grabbed on success 191 * or -1 on if no character is available. 192 * In : x0 - console base address 193 * Out : w0 - character if available, else -1 194 * Clobber list : x0, x1 195 * --------------------------------------------- 196 */ 197func console_16550_core_getc 198#if ENABLE_ASSERTIONS 199 cmp x0, #0 200 ASM_ASSERT(ne) 201#endif /* ENABLE_ASSERTIONS */ 202 203 /* Check if the receive FIFO is empty */ 2041: ldr w1, [x0, #UARTLSR] 205 tbz w1, #UARTLSR_RDR_BIT, no_char 206 ldr w0, [x0, #UARTRX] 207 ret 208no_char: 209 mov w0, #ERROR_NO_PENDING_CHAR 210 ret 211endfunc console_16550_core_getc 212 213 /* --------------------------------------------- 214 * int console_16550_getc(console_16550_t *console) 215 * Function to get a character from the console. 216 * It returns the character grabbed on success 217 * or -1 on if no character is available. 218 * In : x0 - pointer to console_t stucture 219 * Out : w0 - character if available, else -1 220 * Clobber list : x0, x1 221 * --------------------------------------------- 222 */ 223func console_16550_getc 224#if ENABLE_ASSERTIONS 225 cmp x1, #0 226 ASM_ASSERT(ne) 227#endif /* ENABLE_ASSERTIONS */ 228 ldr x0, [x0, #CONSOLE_T_16550_BASE] 229 b console_16550_core_getc 230endfunc console_16550_getc 231 232 /* --------------------------------------------- 233 * int console_16550_core_flush(uintptr_t base_addr) 234 * Function to force a write of all buffered 235 * data that hasn't been output. 236 * In : x0 - console base address 237 * Out : return -1 on error else return 0. 238 * Clobber list : x0, x1 239 * --------------------------------------------- 240 */ 241func console_16550_core_flush 242#if ENABLE_ASSERTIONS 243 cmp x0, #0 244 ASM_ASSERT(ne) 245#endif /* ENABLE_ASSERTIONS */ 246 247 /* Loop until the transmit FIFO is empty */ 2481: ldr w1, [x0, #UARTLSR] 249 and w1, w1, #(UARTLSR_TEMT | UARTLSR_THRE) 250 cmp w1, #(UARTLSR_TEMT | UARTLSR_THRE) 251 b.ne 1b 252 253 mov w0, #0 254 ret 255endfunc console_16550_core_flush 256 257 /* --------------------------------------------- 258 * int console_16550_flush(console_pl011_t *console) 259 * Function to force a write of all buffered 260 * data that hasn't been output. 261 * In : x0 - pointer to console_t structure 262 * Out : return -1 on error else return 0. 263 * Clobber list : x0, x1 264 * --------------------------------------------- 265 */ 266func console_16550_flush 267#if ENABLE_ASSERTIONS 268 cmp x0, #0 269 ASM_ASSERT(ne) 270#endif /* ENABLE_ASSERTIONS */ 271 ldr x0, [x0, #CONSOLE_T_16550_BASE] 272 b console_16550_core_flush 273endfunc console_16550_flush 274