1/* 2 * Copyright (c) 2018-2020, ARM Limited and Contributors. All rights reserved. 3 * 4 * SPDX-License-Identifier: BSD-3-Clause 5 */ 6 7#include <asm_macros.S> 8#include <assert_macros.S> 9#include <console_macros.S> 10#include <drivers/amlogic/meson_console.h> 11 12 .globl console_meson_register 13 .globl console_meson_init 14 .globl console_meson_putc 15 .globl console_meson_getc 16 .globl console_meson_flush 17 .globl console_meson_core_putc 18 .globl console_meson_core_getc 19 .globl console_meson_core_flush 20 21 /* ----------------------------------------------- 22 * Hardware definitions 23 * ----------------------------------------------- 24 */ 25#define MESON_WFIFO_OFFSET 0x0 26#define MESON_RFIFO_OFFSET 0x4 27#define MESON_CONTROL_OFFSET 0x8 28#define MESON_STATUS_OFFSET 0xC 29#define MESON_MISC_OFFSET 0x10 30#define MESON_REG5_OFFSET 0x14 31 32#define MESON_CONTROL_CLR_ERROR_BIT 24 33#define MESON_CONTROL_RX_RESET_BIT 23 34#define MESON_CONTROL_TX_RESET_BIT 22 35#define MESON_CONTROL_RX_ENABLE_BIT 13 36#define MESON_CONTROL_TX_ENABLE_BIT 12 37 38#define MESON_STATUS_RX_EMPTY_BIT 20 39#define MESON_STATUS_TX_FULL_BIT 21 40#define MESON_STATUS_TX_EMPTY_BIT 22 41 42#define MESON_REG5_USE_XTAL_CLK_BIT 24 43#define MESON_REG5_USE_NEW_RATE_BIT 23 44#define MESON_REG5_NEW_BAUD_RATE_MASK 0x7FFFFF 45 46 /* ----------------------------------------------- 47 * int console_meson_register(uintptr_t base, 48 * uint32_t clk, uint32_t baud, 49 * console_t *console); 50 * Function to initialize and register a new MESON 51 * console. Storage passed in for the console struct 52 * *must* be persistent (i.e. not from the stack). 53 * In: x0 - UART register base address 54 * w1 - UART clock in Hz 55 * w2 - Baud rate 56 * x3 - pointer to empty console_t struct 57 * Out: return 1 on success, 0 on error 58 * Clobber list : x0, x1, x2, x6, x7, x14 59 * ----------------------------------------------- 60 */ 61func console_meson_register 62 mov x7, x30 63 mov x6, x3 64 cbz x6, register_fail 65 str x0, [x6, #CONSOLE_T_BASE] 66 67 bl console_meson_init 68 cbz x0, register_fail 69 70 mov x0, x6 71 mov x30, x7 72 finish_console_register meson putc=1, getc=1, flush=1 73 74register_fail: 75 ret x7 76endfunc console_meson_register 77 78 /* ----------------------------------------------- 79 * int console_meson_init(uintptr_t base_addr, 80 * unsigned int uart_clk, unsigned int baud_rate) 81 * Function to initialize the console without a 82 * C Runtime to print debug information. This 83 * function will be accessed by console_init and 84 * crash reporting. 85 * In: x0 - console base address 86 * w1 - Uart clock in Hz 87 * w2 - Baud rate 88 * Out: return 1 on success else 0 on error 89 * Clobber list : x0-x3 90 * ----------------------------------------------- 91 */ 92func console_meson_init 93 cmp w0, #0 94 beq init_fail 95 mov_imm w3, 24000000 /* TODO: This only works with a 24 MHz clock. */ 96 cmp w1, w3 97 bne init_fail 98 cmp w2, #0 99 beq init_fail 100 /* Set baud rate: value = ((clock / 3) / baudrate) - 1 */ 101 mov w3, #3 102 udiv w3, w1, w3 103 udiv w3, w3, w2 104 sub w3, w3, #1 105 orr w3, w3, #((1 << MESON_REG5_USE_XTAL_CLK_BIT) | \ 106 (1 << MESON_REG5_USE_NEW_RATE_BIT)) 107 str w3, [x0, #MESON_REG5_OFFSET] 108 /* Reset UART and clear error flag */ 109 ldr w3, [x0, #MESON_CONTROL_OFFSET] 110 orr w3, w3, #((1 << MESON_CONTROL_CLR_ERROR_BIT) | \ 111 (1 << MESON_CONTROL_RX_RESET_BIT) | \ 112 (1 << MESON_CONTROL_TX_RESET_BIT)) 113 str w3, [x0, #MESON_CONTROL_OFFSET] 114 bic w3, w3, #((1 << MESON_CONTROL_CLR_ERROR_BIT) | \ 115 (1 << MESON_CONTROL_RX_RESET_BIT) | \ 116 (1 << MESON_CONTROL_TX_RESET_BIT)) 117 str w3, [x0, #MESON_CONTROL_OFFSET] 118 /* Enable transfer and receive FIFO */ 119 orr w3, w3, #((1 << MESON_CONTROL_RX_ENABLE_BIT) | \ 120 (1 << MESON_CONTROL_TX_ENABLE_BIT)) 121 str w3, [x0, #MESON_CONTROL_OFFSET] 122 /* Success */ 123 mov w0, #1 124 ret 125init_fail: 126 mov w0, wzr 127 ret 128endfunc console_meson_init 129 130 /* -------------------------------------------------------- 131 * int console_meson_putc(int c, console_t *console) 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 - pointer to console_t structure 136 * Out : return -1 on error else return character. 137 * Clobber list : x2 138 * -------------------------------------------------------- 139 */ 140func console_meson_putc 141#if ENABLE_ASSERTIONS 142 cmp x1, #0 143 ASM_ASSERT(ne) 144#endif /* ENABLE_ASSERTIONS */ 145 ldr x1, [x1, #CONSOLE_T_BASE] 146 b console_meson_core_putc 147endfunc console_meson_putc 148 149 /* -------------------------------------------------------- 150 * int console_meson_core_putc(int c, uintptr_t base_addr) 151 * Function to output a character over the console. It 152 * returns the character printed on success or -1 on error. 153 * In : w0 - character to be printed 154 * x1 - console base address 155 * Out : return -1 on error else return character. 156 * Clobber list : x2 157 * -------------------------------------------------------- 158 */ 159func console_meson_core_putc 160#if ENABLE_ASSERTIONS 161 cmp x1, #0 162 ASM_ASSERT(ne) 163#endif 164 /* Prepend '\r' to '\n' */ 165 cmp w0, #0xA 166 b.ne 2f 167 /* Wait until the transmit FIFO isn't full */ 1681: ldr w2, [x1, #MESON_STATUS_OFFSET] 169 tbnz w2, #MESON_STATUS_TX_FULL_BIT, 1b 170 /* Write '\r' if needed */ 171 mov w2, #0xD 172 str w2, [x1, #MESON_WFIFO_OFFSET] 173 /* Wait until the transmit FIFO isn't full */ 1742: ldr w2, [x1, #MESON_STATUS_OFFSET] 175 tbnz w2, #MESON_STATUS_TX_FULL_BIT, 2b 176 /* Write input character */ 177 str w0, [x1, #MESON_WFIFO_OFFSET] 178 ret 179endfunc console_meson_core_putc 180 181 /* --------------------------------------------- 182 * int console_meson_getc(console_t *console) 183 * Function to get a character from the console. 184 * It returns the character grabbed on success 185 * or -1 if no character is available. 186 * In : x0 - pointer to console_t structure 187 * Out: w0 - character if available, else -1 188 * Clobber list : x0, x1 189 * --------------------------------------------- 190 */ 191func console_meson_getc 192#if ENABLE_ASSERTIONS 193 cmp x0, #0 194 ASM_ASSERT(ne) 195#endif /* ENABLE_ASSERTIONS */ 196 ldr x0, [x0, #CONSOLE_T_BASE] 197 b console_meson_core_getc 198endfunc console_meson_getc 199 200 /* --------------------------------------------- 201 * int console_meson_core_getc(uintptr_t base_addr) 202 * Function to get a character from the console. 203 * It returns the character grabbed on success 204 * or -1 if no character is available. 205 * In : x0 - console base address 206 * Out: w0 - character if available, else -1 207 * Clobber list : x0, x1 208 * --------------------------------------------- 209 */ 210func console_meson_core_getc 211#if ENABLE_ASSERTIONS 212 cmp x0, #0 213 ASM_ASSERT(ne) 214#endif 215 /* Is the receive FIFO empty? */ 216 ldr w1, [x0, #MESON_STATUS_OFFSET] 217 tbnz w1, #MESON_STATUS_RX_EMPTY_BIT, 1f 218 /* Read one character from the RX FIFO */ 219 ldr w0, [x0, #MESON_RFIFO_OFFSET] 220 ret 2211: 222 mov w0, #ERROR_NO_PENDING_CHAR 223 ret 224endfunc console_meson_core_getc 225 226 /* --------------------------------------------- 227 * void console_meson_flush(console_t *console) 228 * Function to force a write of all buffered 229 * data that hasn't been output. 230 * In : x0 - pointer to console_t structure 231 * Out : void. 232 * Clobber list : x0, x1 233 * --------------------------------------------- 234 */ 235func console_meson_flush 236#if ENABLE_ASSERTIONS 237 cmp x0, #0 238 ASM_ASSERT(ne) 239#endif /* ENABLE_ASSERTIONS */ 240 ldr x0, [x0, #CONSOLE_T_BASE] 241 b console_meson_core_flush 242endfunc console_meson_flush 243 244 /* --------------------------------------------- 245 * void console_meson_core_flush(uintptr_t base_addr) 246 * Function to force a write of all buffered 247 * data that hasn't been output. 248 * In : x0 - console base address 249 * Out : void. 250 * Clobber list : x0, x1 251 * --------------------------------------------- 252 */ 253func console_meson_core_flush 254#if ENABLE_ASSERTIONS 255 cmp x0, #0 256 ASM_ASSERT(ne) 257#endif 258 /* Wait until the transmit FIFO is empty */ 2591: ldr w1, [x0, #MESON_STATUS_OFFSET] 260 tbz w1, #MESON_STATUS_TX_EMPTY_BIT, 1b 261 ret 262endfunc console_meson_core_flush 263