/* * Copyright (c) 2018-2020, ARM Limited and Contributors. All rights reserved. * * SPDX-License-Identifier: BSD-3-Clause */ #include #include #include #include .globl console_meson_register .globl console_meson_init .globl console_meson_putc .globl console_meson_getc .globl console_meson_flush .globl console_meson_core_putc .globl console_meson_core_getc .globl console_meson_core_flush /* ----------------------------------------------- * Hardware definitions * ----------------------------------------------- */ #define MESON_WFIFO_OFFSET 0x0 #define MESON_RFIFO_OFFSET 0x4 #define MESON_CONTROL_OFFSET 0x8 #define MESON_STATUS_OFFSET 0xC #define MESON_MISC_OFFSET 0x10 #define MESON_REG5_OFFSET 0x14 #define MESON_CONTROL_CLR_ERROR_BIT 24 #define MESON_CONTROL_RX_RESET_BIT 23 #define MESON_CONTROL_TX_RESET_BIT 22 #define MESON_CONTROL_RX_ENABLE_BIT 13 #define MESON_CONTROL_TX_ENABLE_BIT 12 #define MESON_STATUS_RX_EMPTY_BIT 20 #define MESON_STATUS_TX_FULL_BIT 21 #define MESON_STATUS_TX_EMPTY_BIT 22 #define MESON_REG5_USE_XTAL_CLK_BIT 24 #define MESON_REG5_USE_NEW_RATE_BIT 23 #define MESON_REG5_NEW_BAUD_RATE_MASK 0x7FFFFF /* ----------------------------------------------- * int console_meson_register(uintptr_t base, * uint32_t clk, uint32_t baud, * console_t *console); * Function to initialize and register a new MESON * console. Storage passed in for the console struct * *must* be persistent (i.e. not from the stack). * In: x0 - UART register base address * w1 - UART clock in Hz * w2 - Baud rate * x3 - pointer to empty console_t struct * Out: return 1 on success, 0 on error * Clobber list : x0, x1, x2, x6, x7, x14 * ----------------------------------------------- */ func console_meson_register mov x7, x30 mov x6, x3 cbz x6, register_fail str x0, [x6, #CONSOLE_T_BASE] bl console_meson_init cbz x0, register_fail mov x0, x6 mov x30, x7 finish_console_register meson putc=1, getc=ENABLE_CONSOLE_GETC, flush=1 register_fail: ret x7 endfunc console_meson_register /* ----------------------------------------------- * int console_meson_init(uintptr_t base_addr, * unsigned int uart_clk, unsigned int baud_rate) * Function to initialize the console without a * C Runtime to print debug information. This * function will be accessed by console_init and * crash reporting. * In: x0 - console base address * w1 - Uart clock in Hz * w2 - Baud rate * Out: return 1 on success else 0 on error * Clobber list : x0-x3 * ----------------------------------------------- */ func console_meson_init cmp w0, #0 beq init_fail mov_imm w3, 24000000 /* TODO: This only works with a 24 MHz clock. */ cmp w1, w3 bne init_fail cmp w2, #0 beq init_fail /* Set baud rate: value = ((clock / 3) / baudrate) - 1 */ mov w3, #3 udiv w3, w1, w3 udiv w3, w3, w2 sub w3, w3, #1 orr w3, w3, #((1 << MESON_REG5_USE_XTAL_CLK_BIT) | \ (1 << MESON_REG5_USE_NEW_RATE_BIT)) str w3, [x0, #MESON_REG5_OFFSET] /* Reset UART and clear error flag */ ldr w3, [x0, #MESON_CONTROL_OFFSET] orr w3, w3, #((1 << MESON_CONTROL_CLR_ERROR_BIT) | \ (1 << MESON_CONTROL_RX_RESET_BIT) | \ (1 << MESON_CONTROL_TX_RESET_BIT)) str w3, [x0, #MESON_CONTROL_OFFSET] bic w3, w3, #((1 << MESON_CONTROL_CLR_ERROR_BIT) | \ (1 << MESON_CONTROL_RX_RESET_BIT) | \ (1 << MESON_CONTROL_TX_RESET_BIT)) str w3, [x0, #MESON_CONTROL_OFFSET] /* Enable transfer and receive FIFO */ orr w3, w3, #((1 << MESON_CONTROL_RX_ENABLE_BIT) | \ (1 << MESON_CONTROL_TX_ENABLE_BIT)) str w3, [x0, #MESON_CONTROL_OFFSET] /* Success */ mov w0, #1 ret init_fail: mov w0, wzr ret endfunc console_meson_init /* -------------------------------------------------------- * int console_meson_putc(int c, console_t *console) * Function to output a character over the console. It * returns the character printed on success or -1 on error. * In : w0 - character to be printed * x1 - pointer to console_t structure * Out : return -1 on error else return character. * Clobber list : x2 * -------------------------------------------------------- */ func console_meson_putc #if ENABLE_ASSERTIONS cmp x1, #0 ASM_ASSERT(ne) #endif /* ENABLE_ASSERTIONS */ ldr x1, [x1, #CONSOLE_T_BASE] b console_meson_core_putc endfunc console_meson_putc /* -------------------------------------------------------- * int console_meson_core_putc(int c, uintptr_t base_addr) * Function to output a character over the console. It * returns the character printed on success or -1 on error. * In : w0 - character to be printed * x1 - console base address * Out : return -1 on error else return character. * Clobber list : x2 * -------------------------------------------------------- */ func console_meson_core_putc #if ENABLE_ASSERTIONS cmp x1, #0 ASM_ASSERT(ne) #endif /* Prepend '\r' to '\n' */ cmp w0, #0xA b.ne 2f /* Wait until the transmit FIFO isn't full */ 1: ldr w2, [x1, #MESON_STATUS_OFFSET] tbnz w2, #MESON_STATUS_TX_FULL_BIT, 1b /* Write '\r' if needed */ mov w2, #0xD str w2, [x1, #MESON_WFIFO_OFFSET] /* Wait until the transmit FIFO isn't full */ 2: ldr w2, [x1, #MESON_STATUS_OFFSET] tbnz w2, #MESON_STATUS_TX_FULL_BIT, 2b /* Write input character */ str w0, [x1, #MESON_WFIFO_OFFSET] ret endfunc console_meson_core_putc /* --------------------------------------------- * int console_meson_getc(console_t *console) * Function to get a character from the console. * It returns the character grabbed on success * or -1 if no character is available. * In : x0 - pointer to console_t structure * Out: w0 - character if available, else -1 * Clobber list : x0, x1 * --------------------------------------------- */ func console_meson_getc #if ENABLE_ASSERTIONS cmp x0, #0 ASM_ASSERT(ne) #endif /* ENABLE_ASSERTIONS */ ldr x0, [x0, #CONSOLE_T_BASE] b console_meson_core_getc endfunc console_meson_getc /* --------------------------------------------- * int console_meson_core_getc(uintptr_t base_addr) * Function to get a character from the console. * It returns the character grabbed on success * or -1 if no character is available. * In : x0 - console base address * Out: w0 - character if available, else -1 * Clobber list : x0, x1 * --------------------------------------------- */ func console_meson_core_getc #if ENABLE_ASSERTIONS cmp x0, #0 ASM_ASSERT(ne) #endif /* Is the receive FIFO empty? */ ldr w1, [x0, #MESON_STATUS_OFFSET] tbnz w1, #MESON_STATUS_RX_EMPTY_BIT, 1f /* Read one character from the RX FIFO */ ldr w0, [x0, #MESON_RFIFO_OFFSET] ret 1: mov w0, #ERROR_NO_PENDING_CHAR ret endfunc console_meson_core_getc /* --------------------------------------------- * void console_meson_flush(console_t *console) * Function to force a write of all buffered * data that hasn't been output. * In : x0 - pointer to console_t structure * Out : void. * Clobber list : x0, x1 * --------------------------------------------- */ func console_meson_flush #if ENABLE_ASSERTIONS cmp x0, #0 ASM_ASSERT(ne) #endif /* ENABLE_ASSERTIONS */ ldr x0, [x0, #CONSOLE_T_BASE] b console_meson_core_flush endfunc console_meson_flush /* --------------------------------------------- * void console_meson_core_flush(uintptr_t base_addr) * Function to force a write of all buffered * data that hasn't been output. * In : x0 - console base address * Out : void. * Clobber list : x0, x1 * --------------------------------------------- */ func console_meson_core_flush #if ENABLE_ASSERTIONS cmp x0, #0 ASM_ASSERT(ne) #endif /* Wait until the transmit FIFO is empty */ 1: ldr w1, [x0, #MESON_STATUS_OFFSET] tbz w1, #MESON_STATUS_TX_EMPTY_BIT, 1b ret endfunc console_meson_core_flush