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(uintptr_t baseaddr, 91 * uint32_t clock, uint32_t baud, 92 * console_16550_t *console); 93 * Function to initialize and register a new 16550 94 * console. Storage passed in for the console struct 95 * *must* be persistent (i.e. not from the stack). 96 * In: x0 - UART register base address 97 * w1 - UART clock in Hz 98 * w2 - Baud rate 99 * x3 - pointer to empty console_16550_t struct 100 * Out: return 1 on success, 0 on error 101 * Clobber list : x0, x1, x2, x6, x7, x14 102 * ----------------------------------------------- 103 */ 104func console_16550_register 105 mov x7, x30 106 mov x6, x3 107 cbz x6, register_fail 108 str x0, [x6, #CONSOLE_T_16550_BASE] 109 110 bl console_16550_core_init 111 cbz x0, register_fail 112 113 mov x0, x6 114 mov x30, x7 115 finish_console_register 16550 116 117register_fail: 118 ret x7 119endfunc console_16550_register 120#else 121 .globl console_core_init 122 .globl console_core_putc 123 .globl console_core_getc 124 .globl console_core_flush 125 .equ console_core_init,console_16550_core_init 126 .equ console_core_putc,console_16550_core_putc 127 .equ console_core_getc,console_16550_core_getc 128 .equ console_core_flush,console_16550_core_flush 129#endif 130 131 /* -------------------------------------------------------- 132 * int console_16550_core_putc(int c, uintptr_t base_addr) 133 * Function to output a character over the console. It 134 * returns the character printed on success or -1 on error. 135 * In : w0 - character to be printed 136 * x1 - console base address 137 * Out : return -1 on error else return character. 138 * Clobber list : x2 139 * -------------------------------------------------------- 140 */ 141func console_16550_core_putc 142#if ENABLE_ASSERTIONS 143 cmp x1, #0 144 ASM_ASSERT(ne) 145#endif /* ENABLE_ASSERTIONS */ 146 147 /* Prepend '\r' to '\n' */ 148 cmp w0, #0xA 149 b.ne 2f 150 /* Check if the transmit FIFO is full */ 1511: ldr w2, [x1, #UARTLSR] 152 and w2, w2, #(UARTLSR_TEMT | UARTLSR_THRE) 153 cmp w2, #(UARTLSR_TEMT | UARTLSR_THRE) 154 b.ne 1b 155 mov w2, #0xD /* '\r' */ 156 str w2, [x1, #UARTTX] 157 158 /* Check if the transmit FIFO is full */ 1592: ldr w2, [x1, #UARTLSR] 160 and w2, w2, #(UARTLSR_TEMT | UARTLSR_THRE) 161 cmp w2, #(UARTLSR_TEMT | UARTLSR_THRE) 162 b.ne 2b 163 str w0, [x1, #UARTTX] 164 ret 165endfunc console_16550_core_putc 166 167 /* -------------------------------------------------------- 168 * int console_16550_putc(int c, console_16550_t *console) 169 * Function to output a character over the console. It 170 * returns the character printed on success or -1 on error. 171 * In : w0 - character to be printed 172 * x1 - pointer to console_t structure 173 * Out : return -1 on error else return character. 174 * Clobber list : x2 175 * -------------------------------------------------------- 176 */ 177func console_16550_putc 178#if ENABLE_ASSERTIONS 179 cmp x1, #0 180 ASM_ASSERT(ne) 181#endif /* ENABLE_ASSERTIONS */ 182 ldr x1, [x1, #CONSOLE_T_16550_BASE] 183 b console_16550_core_putc 184endfunc console_16550_putc 185 186 /* --------------------------------------------- 187 * int console_16550_core_getc(uintptr_t base_addr) 188 * Function to get a character from the console. 189 * It returns the character grabbed on success 190 * or -1 on if no character is available. 191 * In : x0 - console base address 192 * Out : w0 - character if available, else -1 193 * Clobber list : x0, x1 194 * --------------------------------------------- 195 */ 196func console_16550_core_getc 197#if ENABLE_ASSERTIONS 198 cmp x0, #0 199 ASM_ASSERT(ne) 200#endif /* ENABLE_ASSERTIONS */ 201 202 /* Check if the receive FIFO is empty */ 2031: ldr w1, [x0, #UARTLSR] 204 tbz w1, #UARTLSR_RDR_BIT, no_char 205 ldr w0, [x0, #UARTRX] 206 ret 207no_char: 208 mov w0, #ERROR_NO_PENDING_CHAR 209 ret 210endfunc console_16550_core_getc 211 212 /* --------------------------------------------- 213 * int console_16550_getc(console_16550_t *console) 214 * Function to get a character from the console. 215 * It returns the character grabbed on success 216 * or -1 on if no character is available. 217 * In : x0 - pointer to console_t stucture 218 * Out : w0 - character if available, else -1 219 * Clobber list : x0, x1 220 * --------------------------------------------- 221 */ 222func console_16550_getc 223#if ENABLE_ASSERTIONS 224 cmp x1, #0 225 ASM_ASSERT(ne) 226#endif /* ENABLE_ASSERTIONS */ 227 ldr x0, [x0, #CONSOLE_T_16550_BASE] 228 b console_16550_core_getc 229endfunc console_16550_getc 230 231 /* --------------------------------------------- 232 * int console_16550_core_flush(uintptr_t base_addr) 233 * Function to force a write of all buffered 234 * data that hasn't been output. 235 * In : x0 - console base address 236 * Out : return -1 on error else return 0. 237 * Clobber list : x0, x1 238 * --------------------------------------------- 239 */ 240func console_16550_core_flush 241#if ENABLE_ASSERTIONS 242 cmp x0, #0 243 ASM_ASSERT(ne) 244#endif /* ENABLE_ASSERTIONS */ 245 246 /* Loop until the transmit FIFO is empty */ 2471: ldr w1, [x0, #UARTLSR] 248 and w1, w1, #(UARTLSR_TEMT | UARTLSR_THRE) 249 cmp w1, #(UARTLSR_TEMT | UARTLSR_THRE) 250 b.ne 1b 251 252 mov w0, #0 253 ret 254endfunc console_16550_core_flush 255 256 /* --------------------------------------------- 257 * int console_16550_flush(console_pl011_t *console) 258 * Function to force a write of all buffered 259 * data that hasn't been output. 260 * In : x0 - pointer to console_t structure 261 * Out : return -1 on error else return 0. 262 * Clobber list : x0, x1 263 * --------------------------------------------- 264 */ 265func console_16550_flush 266#if ENABLE_ASSERTIONS 267 cmp x0, #0 268 ASM_ASSERT(ne) 269#endif /* ENABLE_ASSERTIONS */ 270 ldr x0, [x0, #CONSOLE_T_16550_BASE] 271 b console_16550_core_flush 272endfunc console_16550_flush 273