/* * Copyright (C) 2016 Marvell International Ltd. * * SPDX-License-Identifier: BSD-3-Clause * https://spdx.org/licenses */ #include #include #include #include /* * "core" functions are low-level implementations that don't require * writable memory and are thus safe to call in BL1 crash context. */ .globl console_a3700_core_putc .globl console_a3700_core_init .globl console_a3700_core_getc .globl console_a3700_core_flush .globl console_a3700_putc .globl console_a3700_getc .globl console_a3700_flush /* ----------------------------------------------- * int console_a3700_core_init(unsigned long 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 * Clobber list : x1, x2, x3 * ----------------------------------------------- */ func console_a3700_core_init /* Check the input base address */ cbz x0, init_fail /* Check baud rate and uart clock for sanity */ cbz w1, init_fail cbz w2, init_fail /* Program the baudrate */ /* Divisor = Round(Uartclock / (16 * baudrate)) */ lsl w2, w2, #4 add w1, w1, w2, lsr #1 udiv w2, w1, w2 and w2, w2, #0x3ff ldr w3, [x0, #UART_BAUD_REG] bic w3, w3, 0x3ff orr w3, w3, w2 str w3, [x0, #UART_BAUD_REG]/* set baud rate divisor */ /* Set UART to default 16X scheme */ mov w3, #0 str w3, [x0, #UART_POSSR_REG] /* * Wait for the TX (THR and TSR) to be empty. If wait for 3ms, the TX FIFO is * still not empty, TX FIFO will reset by all means. */ mov w1, #30 /* max time out 30 * 100 us */ 2: /* Check whether TX (THR and TSR) is empty */ ldr w3, [x0, #UART_STATUS_REG] and w3, w3, #UARTLSR_TXEMPTY cmp w3, #0 b.ne 4f /* Delay */ mov w2, #60000 /* 60000 cycles of below 3 instructions on 1200 MHz CPU ~~ 100 us */ 3: sub w2, w2, #1 cmp w2, #0 b.ne 3b /* Check whether wait timeout expired */ sub w1, w1, #1 cmp w1, #0 b.ne 2b 4: /* Reset FIFO */ mov w3, #UART_CTRL_RXFIFO_RESET orr w3, w3, #UART_CTRL_TXFIFO_RESET str w3, [x0, #UART_CTRL_REG] /* Delay */ mov w2, #2000 1: sub w2, w2, #1 cmp w2, #0 b.ne 1b /* No Parity, 1 Stop */ mov w3, #0 str w3, [x0, #UART_CTRL_REG] mov w0, #1 ret init_fail: mov w0, #0 ret endfunc console_a3700_core_init .globl console_a3700_register /* ----------------------------------------------- * int console_a3700_register(console_t *console, uintptr_t base, uint32_t clk, uint32_t baud) * Function to initialize and register a new a3700 * 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_a3700_register mov x7, x30 mov x6, x3 cbz x6, register_fail str x0, [x6, #CONSOLE_T_BASE] bl console_a3700_core_init cbz x0, register_fail mov x0, x6 mov x30, x7 finish_console_register a3700, putc=1, getc=1, flush=1 register_fail: ret x7 endfunc console_a3700_register /* -------------------------------------------------------- * int console_a3700_core_putc(int c, unsigned int 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_a3700_core_putc /* Check the input parameter */ cbz x1, putc_error /* Prepend '\r' to '\n' */ cmp w0, #0xA b.ne 2f /* Check if the transmit FIFO is full */ 1: ldr w2, [x1, #UART_STATUS_REG] and w2, w2, #UARTLSR_TXFIFOFULL cmp w2, #UARTLSR_TXFIFOFULL b.eq 1b mov w2, #0xD /* '\r' */ str w2, [x1, #UART_TX_REG] /* Check if the transmit FIFO is full */ 2: ldr w2, [x1, #UART_STATUS_REG] and w2, w2, #UARTLSR_TXFIFOFULL cmp w2, #UARTLSR_TXFIFOFULL b.eq 2b str w0, [x1, #UART_TX_REG] ret putc_error: mov w0, #-1 ret endfunc console_a3700_core_putc /* -------------------------------------------------------- * int console_a3700_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_a3700_putc ldr x1, [x1, #CONSOLE_T_BASE] b console_a3700_core_putc endfunc console_a3700_putc /* --------------------------------------------- * int console_a3700_core_getc(void) * Function to get a character from the console. * It returns the character grabbed on success * or -1 if no character is available. * In : w0 - console base address * Out : w0 - character if available, else -1 * Clobber list : x0, x1 * --------------------------------------------- */ func console_a3700_core_getc /* Check if there is a pending character */ ldr w1, [x0, #UART_STATUS_REG] and w1, w1, #UARTLSR_RXRDY cmp w1, #UARTLSR_RXRDY b.ne getc_no_char ldr w0, [x0, #UART_RX_REG] and w0, w0, #0xff ret getc_no_char: mov w0, #ERROR_NO_PENDING_CHAR ret endfunc console_a3700_core_getc /* --------------------------------------------- * int console_a3700_getc(console_t *console) * Function to get a character from the console. * It returns the character grabbed on success * or -1 on 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_a3700_getc ldr x0, [x0, #CONSOLE_T_BASE] b console_a3700_core_getc endfunc console_a3700_getc /* --------------------------------------------- * void console_a3700_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_a3700_core_flush /* Wait for the TX (THR and TSR) to be empty */ 1: ldr w1, [x0, #UART_STATUS_REG] and w1, w1, #UARTLSR_TXEMPTY cmp w1, #UARTLSR_TXEMPTY b.ne 1b ret endfunc console_a3700_core_flush /* --------------------------------------------- * void console_a3700_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_a3700_flush ldr x0, [x0, #CONSOLE_T_BASE] b console_a3700_core_flush endfunc console_a3700_flush