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#include <console_macros.S> 11#include <uart_16550.h> 12 13 /* 14 * "core" functions are low-level implementations that don't require 15 * writable memory and are thus safe to call in BL1 crash context. 16 */ 17 .globl console_16550_core_init 18 .globl console_16550_core_putc 19 .globl console_16550_core_getc 20 .globl console_16550_core_flush 21 22 .globl console_16550_putc 23 .globl console_16550_getc 24 .globl console_16550_flush 25 26 /* ----------------------------------------------- 27 * int console_16550_core_init(uintptr_t base_addr, 28 * unsigned int uart_clk, unsigned int baud_rate) 29 * Function to initialize the console without a 30 * C Runtime to print debug information. This 31 * function will be accessed by console_init and 32 * crash reporting. 33 * In: x0 - console base address 34 * w1 - Uart clock in Hz 35 * w2 - Baud rate 36 * Out: return 1 on success, 0 on error 37 * Clobber list : x1, x2, x3 38 * ----------------------------------------------- 39 */ 40func console_16550_core_init 41 /* Check the input base address */ 42 cbz x0, init_fail 43 /* Check baud rate and uart clock for sanity */ 44 cbz w1, init_fail 45 cbz w2, init_fail 46 47 /* Program the baudrate */ 48 /* Divisor = Uart clock / (16 * baudrate) */ 49 lsl w2, w2, #4 50 udiv w2, w1, w2 51 and w1, w2, #0xff /* w1 = DLL */ 52 lsr w2, w2, #8 53 and w2, w2, #0xff /* w2 = DLLM */ 54 ldr w3, [x0, #UARTLCR] 55 orr w3, w3, #UARTLCR_DLAB 56 str w3, [x0, #UARTLCR] /* enable DLL, DLLM programming */ 57 str w1, [x0, #UARTDLL] /* program DLL */ 58 str w2, [x0, #UARTDLLM] /* program DLLM */ 59 mov w2, #~UARTLCR_DLAB 60 and w3, w3, w2 61 str w3, [x0, #UARTLCR] /* disable DLL, DLLM programming */ 62 63 /* 8n1 */ 64 mov w3, #3 65 str w3, [x0, #UARTLCR] 66 /* no interrupt */ 67 mov w3, #0 68 str w3, [x0, #UARTIER] 69#ifdef TI_16550_MDR_QUIRK 70 /* UART must be enabled on some platforms via the MDR register */ 71 str w3, [x0, #UARTMDR1] 72#endif /* TI_16550_MDR_QUIRK */ 73 /* enable fifo, DMA */ 74 mov w3, #(UARTFCR_FIFOEN | UARTFCR_DMAEN) 75 str w3, [x0, #UARTFCR] 76 /* DTR + RTS */ 77 mov w3, #3 78 str w3, [x0, #UARTMCR] 79 mov w0, #1 80 ret 81init_fail: 82 mov w0, #0 83 ret 84endfunc console_16550_core_init 85 86#if MULTI_CONSOLE_API 87 .globl console_16550_register 88 89 /* ----------------------------------------------- 90 * int console_16550_register(console_16550_t *console, 91 uintptr_t base, uint32_t clk, uint32_t baud) 92 * Function to initialize and register a new 16550 93 * console. Storage passed in for the console struct 94 * *must* be persistent (i.e. not from the stack). 95 * In: x0 - UART register base address 96 * w1 - UART clock in Hz 97 * w2 - Baud rate 98 * x3 - pointer to empty console_16550_t struct 99 * Out: return 1 on success, 0 on error 100 * Clobber list : x0, x1, x2, x6, x7, x14 101 * ----------------------------------------------- 102 */ 103func console_16550_register 104 mov x7, x30 105 mov x6, x3 106 cbz x6, register_fail 107 str x0, [x6, #CONSOLE_T_16550_BASE] 108 109 bl console_16550_core_init 110 cbz x0, register_fail 111 112 mov x0, x6 113 mov x30, x7 114 finish_console_register 16550 115 116register_fail: 117 ret x7 118endfunc console_16550_register 119#else 120 .globl console_core_init 121 .globl console_core_putc 122 .globl console_core_getc 123 .globl console_core_flush 124 .equ console_core_init,console_16550_core_init 125 .equ console_core_putc,console_16550_core_putc 126 .equ console_core_getc,console_16550_core_getc 127 .equ console_core_flush,console_16550_core_flush 128#endif 129 130 /* -------------------------------------------------------- 131 * int console_16550_core_putc(int c, uintptr_t base_addr) 132 * Function to output a character over the console. It 133 * returns the character printed on success or -1 on error. 134 * In : w0 - character to be printed 135 * x1 - console base address 136 * Out : return -1 on error else return character. 137 * Clobber list : x2 138 * -------------------------------------------------------- 139 */ 140func console_16550_core_putc 141#if ENABLE_ASSERTIONS 142 cmp x1, #0 143 ASM_ASSERT(ne) 144#endif /* ENABLE_ASSERTIONS */ 145 146 /* Prepend '\r' to '\n' */ 147 cmp w0, #0xA 148 b.ne 2f 149 /* Check if the transmit FIFO is full */ 1501: ldr w2, [x1, #UARTLSR] 151 and w2, w2, #(UARTLSR_TEMT | UARTLSR_THRE) 152 cmp w2, #(UARTLSR_TEMT | UARTLSR_THRE) 153 b.ne 1b 154 mov w2, #0xD /* '\r' */ 155 str w2, [x1, #UARTTX] 156 157 /* Check if the transmit FIFO is full */ 1582: ldr w2, [x1, #UARTLSR] 159 and w2, w2, #(UARTLSR_TEMT | UARTLSR_THRE) 160 cmp w2, #(UARTLSR_TEMT | UARTLSR_THRE) 161 b.ne 2b 162 str w0, [x1, #UARTTX] 163 ret 164endfunc console_16550_core_putc 165 166 /* -------------------------------------------------------- 167 * int console_16550_putc(int c, console_16550_t *console) 168 * Function to output a character over the console. It 169 * returns the character printed on success or -1 on error. 170 * In : w0 - character to be printed 171 * x1 - pointer to console_t structure 172 * Out : return -1 on error else return character. 173 * Clobber list : x2 174 * -------------------------------------------------------- 175 */ 176func console_16550_putc 177#if ENABLE_ASSERTIONS 178 cmp x1, #0 179 ASM_ASSERT(ne) 180#endif /* ENABLE_ASSERTIONS */ 181 ldr x1, [x1, #CONSOLE_T_16550_BASE] 182 b console_16550_core_putc 183endfunc console_16550_putc 184 185 /* --------------------------------------------- 186 * int console_16550_core_getc(uintptr_t base_addr) 187 * Function to get a character from the console. 188 * It returns the character grabbed on success 189 * or -1 on if no character is available. 190 * In : x0 - console base address 191 * Out : w0 - character if available, else -1 192 * Clobber list : x0, x1 193 * --------------------------------------------- 194 */ 195func console_16550_core_getc 196#if ENABLE_ASSERTIONS 197 cmp x0, #0 198 ASM_ASSERT(ne) 199#endif /* ENABLE_ASSERTIONS */ 200 201 /* Check if the receive FIFO is empty */ 2021: ldr w1, [x0, #UARTLSR] 203 tbz w1, #UARTLSR_RDR_BIT, no_char 204 ldr w0, [x0, #UARTRX] 205 ret 206no_char: 207 mov w0, #ERROR_NO_PENDING_CHAR 208 ret 209endfunc console_16550_core_getc 210 211 /* --------------------------------------------- 212 * int console_16550_getc(console_16550_t *console) 213 * Function to get a character from the console. 214 * It returns the character grabbed on success 215 * or -1 on if no character is available. 216 * In : x0 - pointer to console_t stucture 217 * Out : w0 - character if available, else -1 218 * Clobber list : x0, x1 219 * --------------------------------------------- 220 */ 221func console_16550_getc 222#if ENABLE_ASSERTIONS 223 cmp x1, #0 224 ASM_ASSERT(ne) 225#endif /* ENABLE_ASSERTIONS */ 226 ldr x0, [x0, #CONSOLE_T_16550_BASE] 227 b console_16550_core_getc 228endfunc console_16550_getc 229 230 /* --------------------------------------------- 231 * int console_16550_core_flush(uintptr_t base_addr) 232 * Function to force a write of all buffered 233 * data that hasn't been output. 234 * In : x0 - console base address 235 * Out : return -1 on error else return 0. 236 * Clobber list : x0, x1 237 * --------------------------------------------- 238 */ 239func console_16550_core_flush 240#if ENABLE_ASSERTIONS 241 cmp x0, #0 242 ASM_ASSERT(ne) 243#endif /* ENABLE_ASSERTIONS */ 244 245 /* Loop until the transmit FIFO is empty */ 2461: ldr w1, [x0, #UARTLSR] 247 and w1, w1, #(UARTLSR_TEMT | UARTLSR_THRE) 248 cmp w1, #(UARTLSR_TEMT | UARTLSR_THRE) 249 b.ne 1b 250 251 mov w0, #0 252 ret 253endfunc console_16550_core_flush 254 255 /* --------------------------------------------- 256 * int console_16550_flush(console_pl011_t *console) 257 * Function to force a write of all buffered 258 * data that hasn't been output. 259 * In : x0 - pointer to console_t structure 260 * Out : return -1 on error else return 0. 261 * Clobber list : x0, x1 262 * --------------------------------------------- 263 */ 264func console_16550_flush 265#if ENABLE_ASSERTIONS 266 cmp x0, #0 267 ASM_ASSERT(ne) 268#endif /* ENABLE_ASSERTIONS */ 269 ldr x0, [x0, #CONSOLE_T_16550_BASE] 270 b console_16550_core_flush 271endfunc console_16550_flush 272