1/* 2 * Copyright (C) 2016 Marvell International Ltd. 3 * 4 * SPDX-License-Identifier: BSD-3-Clause 5 * https://spdx.org/licenses 6 */ 7 8#include <arch.h> 9#include <asm_macros.S> 10#include <console_macros.S> 11#include <drivers/marvell/uart/a3700_console.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_a3700_core_putc 18 .globl console_a3700_core_init 19 .globl console_a3700_core_getc 20 .globl console_a3700_core_flush 21 22 .globl console_a3700_putc 23 .globl console_a3700_getc 24 .globl console_a3700_flush 25 26 /* ----------------------------------------------- 27 * int console_a3700_core_init(unsigned long 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 37 * Clobber list : x1, x2, x3 38 * ----------------------------------------------- 39 */ 40func console_a3700_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 = Round(Uartclock / (16 * baudrate)) */ 49 lsl w2, w2, #4 50 add w1, w1, w2, lsr #1 51 udiv w2, w1, w2 52 and w2, w2, #0x3ff 53 54 ldr w3, [x0, #UART_BAUD_REG] 55 bic w3, w3, 0x3ff 56 orr w3, w3, w2 57 str w3, [x0, #UART_BAUD_REG]/* set baud rate divisor */ 58 59 /* Set UART to default 16X scheme */ 60 mov w3, #0 61 str w3, [x0, #UART_POSSR_REG] 62 63 /* 64 * Wait for the TX (THR and TSR) to be empty. If wait for 3ms, the TX FIFO is 65 * still not empty, TX FIFO will reset by all means. 66 */ 67 mov w1, #30 /* max time out 30 * 100 us */ 682: 69 /* Check whether TX (THR and TSR) is empty */ 70 ldr w3, [x0, #UART_STATUS_REG] 71 and w3, w3, #UARTLSR_TXEMPTY 72 cmp w3, #0 73 b.ne 4f 74 75 /* Delay */ 76 mov w2, #60000 /* 60000 cycles of below 3 instructions on 1200 MHz CPU ~~ 100 us */ 773: 78 sub w2, w2, #1 79 cmp w2, #0 80 b.ne 3b 81 82 /* Check whether wait timeout expired */ 83 sub w1, w1, #1 84 cmp w1, #0 85 b.ne 2b 86 874: 88 /* Reset FIFO */ 89 mov w3, #UART_CTRL_RXFIFO_RESET 90 orr w3, w3, #UART_CTRL_TXFIFO_RESET 91 str w3, [x0, #UART_CTRL_REG] 92 93 /* Delay */ 94 mov w2, #2000 951: 96 sub w2, w2, #1 97 cmp w2, #0 98 b.ne 1b 99 100 /* No Parity, 1 Stop */ 101 mov w3, #0 102 str w3, [x0, #UART_CTRL_REG] 103 104 mov w0, #1 105 ret 106init_fail: 107 mov w0, #0 108 ret 109endfunc console_a3700_core_init 110 111 .globl console_a3700_register 112 113 /* ----------------------------------------------- 114 * int console_a3700_register(console_t *console, 115 uintptr_t base, uint32_t clk, uint32_t baud) 116 * Function to initialize and register a new a3700 117 * console. Storage passed in for the console struct 118 * *must* be persistent (i.e. not from the stack). 119 * In: x0 - UART register base address 120 * w1 - UART clock in Hz 121 * w2 - Baud rate 122 * x3 - pointer to empty console_t struct 123 * Out: return 1 on success, 0 on error 124 * Clobber list : x0, x1, x2, x6, x7, x14 125 * ----------------------------------------------- 126 */ 127func console_a3700_register 128 mov x7, x30 129 mov x6, x3 130 cbz x6, register_fail 131 str x0, [x6, #CONSOLE_T_BASE] 132 133 bl console_a3700_core_init 134 cbz x0, register_fail 135 136 mov x0, x6 137 mov x30, x7 138 finish_console_register a3700, putc=1, getc=1, flush=1 139 140register_fail: 141 ret x7 142endfunc console_a3700_register 143 144 /* -------------------------------------------------------- 145 * int console_a3700_core_putc(int c, unsigned int base_addr) 146 * Function to output a character over the console. It 147 * returns the character printed on success or -1 on error. 148 * In : w0 - character to be printed 149 * x1 - console base address 150 * Out : return -1 on error else return character. 151 * Clobber list : x2 152 * -------------------------------------------------------- 153 */ 154func console_a3700_core_putc 155 /* Check the input parameter */ 156 cbz x1, putc_error 157 158 /* Prepend '\r' to '\n' */ 159 cmp w0, #0xA 160 b.ne 2f 161 /* Check if the transmit FIFO is full */ 1621: ldr w2, [x1, #UART_STATUS_REG] 163 and w2, w2, #UARTLSR_TXFIFOFULL 164 cmp w2, #UARTLSR_TXFIFOFULL 165 b.eq 1b 166 mov w2, #0xD /* '\r' */ 167 str w2, [x1, #UART_TX_REG] 168 169 /* Check if the transmit FIFO is full */ 1702: ldr w2, [x1, #UART_STATUS_REG] 171 and w2, w2, #UARTLSR_TXFIFOFULL 172 cmp w2, #UARTLSR_TXFIFOFULL 173 b.eq 2b 174 str w0, [x1, #UART_TX_REG] 175 ret 176putc_error: 177 mov w0, #-1 178 ret 179endfunc console_a3700_core_putc 180 181 /* -------------------------------------------------------- 182 * int console_a3700_putc(int c, console_t *console) 183 * Function to output a character over the console. It 184 * returns the character printed on success or -1 on error. 185 * In : w0 - character to be printed 186 * x1 - pointer to console_t structure 187 * Out : return -1 on error else return character. 188 * Clobber list : x2 189 * -------------------------------------------------------- 190 */ 191func console_a3700_putc 192 ldr x1, [x1, #CONSOLE_T_BASE] 193 b console_a3700_core_putc 194endfunc console_a3700_putc 195 196 /* --------------------------------------------- 197 * int console_a3700_core_getc(void) 198 * Function to get a character from the console. 199 * It returns the character grabbed on success 200 * or -1 if no character is available. 201 * In : w0 - console base address 202 * Out : w0 - character if available, else -1 203 * Clobber list : x0, x1 204 * --------------------------------------------- 205 */ 206func console_a3700_core_getc 207 /* Check if there is a pending character */ 208 ldr w1, [x0, #UART_STATUS_REG] 209 and w1, w1, #UARTLSR_RXRDY 210 cmp w1, #UARTLSR_RXRDY 211 b.ne getc_no_char 212 ldr w0, [x0, #UART_RX_REG] 213 and w0, w0, #0xff 214 ret 215getc_no_char: 216 mov w0, #ERROR_NO_PENDING_CHAR 217 ret 218endfunc console_a3700_core_getc 219 220 /* --------------------------------------------- 221 * int console_a3700_getc(console_t *console) 222 * Function to get a character from the console. 223 * It returns the character grabbed on success 224 * or -1 on if no character is available. 225 * In : x0 - pointer to console_t structure 226 * Out : w0 - character if available, else -1 227 * Clobber list : x0, x1 228 * --------------------------------------------- 229 */ 230func console_a3700_getc 231 ldr x0, [x0, #CONSOLE_T_BASE] 232 b console_a3700_core_getc 233endfunc console_a3700_getc 234 235 /* --------------------------------------------- 236 * void console_a3700_core_flush(uintptr_t base_addr) 237 * Function to force a write of all buffered 238 * data that hasn't been output. 239 * In : x0 - console base address 240 * Out : void. 241 * Clobber list : x0, x1 242 * --------------------------------------------- 243 */ 244func console_a3700_core_flush 245 /* Wait for the TX (THR and TSR) to be empty */ 2461: ldr w1, [x0, #UART_STATUS_REG] 247 and w1, w1, #UARTLSR_TXEMPTY 248 cmp w1, #UARTLSR_TXEMPTY 249 b.ne 1b 250 ret 251endfunc console_a3700_core_flush 252 253 /* --------------------------------------------- 254 * void console_a3700_flush(console_t *console) 255 * Function to force a write of all buffered 256 * data that hasn't been output. 257 * In : x0 - pointer to console_t structure 258 * Out : void. 259 * Clobber list : x0, x1 260 * --------------------------------------------- 261 */ 262func console_a3700_flush 263 ldr x0, [x0, #CONSOLE_T_BASE] 264 b console_a3700_core_flush 265endfunc console_a3700_flush 266 267