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 <drivers/ti/uart/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: r0 - console base address 34 * r1 - Uart clock in Hz 35 * r2 - Baud rate 36 * Out: return 1 on success, 0 on error 37 * Clobber list : r1, r2, r3 38 * ----------------------------------------------- 39 */ 40func console_16550_core_init 41 /* Check the input base address */ 42 cmp r0, #0 43 beq init_fail 44 /* Check baud rate and uart clock for sanity */ 45 cmp r1, #0 46 beq init_fail 47 cmp r2, #0 48 beq init_fail 49 50 /* Program the baudrate */ 51 /* Divisor = Uart clock / (16 * baudrate) */ 52 lsl r2, r2, #4 53 udiv r2, r1, r2 54 and r1, r2, #0xff /* w1 = DLL */ 55 lsr r2, r2, #8 56 and r2, r2, #0xff /* w2 = DLLM */ 57 ldr r3, [r0, #UARTLCR] 58 orr r3, r3, #UARTLCR_DLAB 59 str r3, [r0, #UARTLCR] /* enable DLL, DLLM programming */ 60 str r1, [r0, #UARTDLL] /* program DLL */ 61 str r2, [r0, #UARTDLLM] /* program DLLM */ 62 mov r2, #~UARTLCR_DLAB 63 and r3, r3, r2 64 str r3, [r0, #UARTLCR] /* disable DLL, DLLM programming */ 65 66 /* 8n1 */ 67 mov r3, #3 68 str r3, [r0, #UARTLCR] 69 /* no interrupt */ 70 mov r3, #0 71 str r3, [r0, #UARTIER] 72#ifdef TI_16550_MDR_QUIRK 73 /* UART must be enabled on some platforms via the MDR register */ 74 str r3, [r0, #UARTMDR1] 75#endif /* TI_16550_MDR_QUIRK */ 76 /* enable fifo, DMA */ 77 mov r3, #(UARTFCR_FIFOEN | UARTFCR_DMAEN) 78 str r3, [r0, #UARTFCR] 79 /* DTR + RTS */ 80 mov r3, #3 81 str r3, [r0, #UARTMCR] 82 mov r0, #1 83 bx lr 84init_fail: 85 mov r0, #0 86 bx lr 87endfunc console_16550_core_init 88 89 .globl console_16550_register 90 91 /* ------------------------------------------------------- 92 * int console_stm32_register(uintptr_t baseaddr, 93 * uint32_t clock, uint32_t baud, 94 * struct console_stm32 *console); 95 * Function to initialize and register a new STM32 96 * console. Storage passed in for the console struct 97 * *must* be persistent (i.e. not from the stack). 98 * In: r0 - UART register base address 99 * r1 - UART clock in Hz 100 * r2 - Baud rate 101 * r3 - pointer to empty console_stm32 struct 102 * Out: return 1 on success, 0 on error 103 * Clobber list : r0, r1, r2 104 * ------------------------------------------------------- 105 */ 106func console_16550_register 107 push {r4, lr} 108 mov r4, r3 109 cmp r4, #0 110 beq register_fail 111 str r0, [r4, #CONSOLE_T_16550_BASE] 112 113 bl console_16550_core_init 114 cmp r0, #0 115 beq register_fail 116 117 mov r0, r4 118 pop {r4, lr} 119 finish_console_register 16550 putc=1, getc=1, flush=1 120 121register_fail: 122 pop {r4, pc} 123endfunc console_16550_register 124 125 /* -------------------------------------------------------- 126 * int console_16550_core_putc(int c, uintptr_t base_addr) 127 * Function to output a character over the console. It 128 * returns the character printed on success or -1 on error. 129 * In : r0 - character to be printed 130 * r1 - console base address 131 * Out : return -1 on error else return character. 132 * Clobber list : r2 133 * -------------------------------------------------------- 134 */ 135func console_16550_core_putc 136#if ENABLE_ASSERTIONS 137 cmp r1, #0 138 ASM_ASSERT(ne) 139#endif /* ENABLE_ASSERTIONS */ 140 141 /* Prepend '\r' to '\n' */ 142 cmp r0, #0xA 143 bne 2f 144 /* Check if the transmit FIFO is full */ 1451: ldr r2, [r1, #UARTLSR] 146 and r2, r2, #(UARTLSR_TEMT | UARTLSR_THRE) 147 cmp r2, #(UARTLSR_TEMT | UARTLSR_THRE) 148 bne 1b 149 mov r2, #0xD /* '\r' */ 150 str r2, [r1, #UARTTX] 151 152 /* Check if the transmit FIFO is full */ 1532: ldr r2, [r1, #UARTLSR] 154 and r2, r2, #(UARTLSR_TEMT | UARTLSR_THRE) 155 cmp r2, #(UARTLSR_TEMT | UARTLSR_THRE) 156 bne 2b 157 str r0, [r1, #UARTTX] 158 bx lr 159endfunc console_16550_core_putc 160 161 /* -------------------------------------------------------- 162 * int console_16550_putc(int c, console_16550_t *console) 163 * Function to output a character over the console. It 164 * returns the character printed on success or -1 on error. 165 * In : r0 - character to be printed 166 * r1 - pointer to console_t structure 167 * Out : return -1 on error else return character. 168 * Clobber list : r2 169 * -------------------------------------------------------- 170 */ 171func console_16550_putc 172#if ENABLE_ASSERTIONS 173 cmp r1, #0 174 ASM_ASSERT(ne) 175#endif /* ENABLE_ASSERTIONS */ 176 ldr r1, [r1, #CONSOLE_T_16550_BASE] 177 b console_16550_core_putc 178endfunc console_16550_putc 179 180 /* --------------------------------------------- 181 * int console_16550_core_getc(uintptr_t base_addr) 182 * Function to get a character from the console. 183 * It returns the character grabbed on success 184 * or -1 on if no character is available. 185 * In : r0 - console base address 186 * Clobber list : r0, r1 187 * --------------------------------------------- 188 */ 189func console_16550_core_getc 190#if ENABLE_ASSERTIONS 191 cmp r0, #0 192 ASM_ASSERT(ne) 193#endif /* ENABLE_ASSERTIONS */ 194 195 /* Check if the receive FIFO is empty */ 1961: ldr r1, [r0, #UARTLSR] 197 tst r1, #UARTLSR_RDR_BIT 198 beq no_char 199 ldr r1, [r0, #UARTRX] 200 mov r0, r1 201 bx lr 202no_char: 203 mov r0, #ERROR_NO_PENDING_CHAR 204 bx lr 205endfunc console_16550_core_getc 206 207 /* --------------------------------------------- 208 * int console_16550_getc(console_16550_t *console) 209 * Function to get a character from the console. 210 * It returns the character grabbed on success 211 * or -1 on if no character is available. 212 * In : r0 - pointer to console_t stucture 213 * Out : r0 - character if available, else -1 214 * Clobber list : r0, r1 215 * --------------------------------------------- 216 */ 217func console_16550_getc 218#if ENABLE_ASSERTIONS 219 cmp r0, #0 220 ASM_ASSERT(ne) 221#endif /* ENABLE_ASSERTIONS */ 222 ldr r0, [r0, #CONSOLE_T_16550_BASE] 223 b console_16550_core_getc 224endfunc console_16550_getc 225 226 /* --------------------------------------------- 227 * int console_16550_core_flush(uintptr_t base_addr) 228 * Function to force a write of all buffered 229 * data that hasn't been output. 230 * In : r0 - console base address 231 * Out : return -1 on error else return 0. 232 * Clobber list : r0, r1 233 * --------------------------------------------- 234 */ 235func console_16550_core_flush 236#if ENABLE_ASSERTIONS 237 cmp r0, #0 238 ASM_ASSERT(ne) 239#endif /* ENABLE_ASSERTIONS */ 240 241 /* Loop until the transmit FIFO is empty */ 2421: ldr r1, [r0, #UARTLSR] 243 and r1, r1, #(UARTLSR_TEMT | UARTLSR_THRE) 244 cmp r1, #(UARTLSR_TEMT | UARTLSR_THRE) 245 bne 1b 246 247 mov r0, #0 248 bx lr 249endfunc console_16550_core_flush 250 251 /* --------------------------------------------- 252 * int console_16550_flush(console_pl011_t *console) 253 * Function to force a write of all buffered 254 * data that hasn't been output. 255 * In : r0 - pointer to console_t structure 256 * Out : return -1 on error else return 0. 257 * Clobber list : r0, r1 258 * --------------------------------------------- 259 */ 260func console_16550_flush 261#if ENABLE_ASSERTIONS 262 cmp r0, #0 263 ASM_ASSERT(ne) 264#endif /* ENABLE_ASSERTIONS */ 265 ldr r0, [r0, #CONSOLE_T_16550_BASE] 266 b console_16550_core_flush 267endfunc console_16550_flush 268