/* * Copyright (c) 2013-2020, ARM Limited and Contributors. All rights reserved. * * SPDX-License-Identifier: BSD-3-Clause */ #include #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_pl011_core_init .globl console_pl011_core_putc .globl console_pl011_core_getc .globl console_pl011_core_flush .globl console_pl011_putc .globl console_pl011_getc .globl console_pl011_flush /* ----------------------------------------------- * int console_pl011_core_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 : x1, x2, x3, x4 * ----------------------------------------------- */ func console_pl011_core_init /* Check the input base address */ cbz x0, core_init_fail #if !PL011_GENERIC_UART /* Check baud rate and uart clock for sanity */ cbz w1, core_init_fail cbz w2, core_init_fail /* Disable uart before programming */ ldr w3, [x0, #UARTCR] mov w4, #PL011_UARTCR_UARTEN bic w3, w3, w4 str w3, [x0, #UARTCR] /* Program the baudrate */ /* Divisor = (Uart clock * 4) / baudrate */ lsl w1, w1, #2 udiv w2, w1, w2 /* IBRD = Divisor >> 6 */ lsr w1, w2, #6 /* Write the IBRD */ str w1, [x0, #UARTIBRD] /* FBRD = Divisor & 0x3F */ and w1, w2, #0x3f /* Write the FBRD */ str w1, [x0, #UARTFBRD] mov w1, #PL011_LINE_CONTROL str w1, [x0, #UARTLCR_H] /* Clear any pending errors */ str wzr, [x0, #UARTECR] /* Enable tx, rx, and uart overall */ mov w1, #(PL011_UARTCR_RXE | PL011_UARTCR_TXE | PL011_UARTCR_UARTEN) str w1, [x0, #UARTCR] #endif mov w0, #1 ret core_init_fail: mov w0, wzr ret endfunc console_pl011_core_init .globl console_pl011_register /* ----------------------------------------------- * int console_pl011_register(uintptr_t baseaddr, * uint32_t clock, uint32_t baud, * console_t *console); * Function to initialize and register a new PL011 * 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_pl011_register mov x7, x30 mov x6, x3 cbz x6, register_fail str x0, [x6, #CONSOLE_T_BASE] bl console_pl011_core_init cbz x0, register_fail mov x0, x6 mov x30, x7 finish_console_register pl011 putc=1, getc=ENABLE_CONSOLE_GETC, flush=1 register_fail: ret x7 endfunc console_pl011_register /* -------------------------------------------------------- * int console_pl011_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_pl011_core_putc #if ENABLE_ASSERTIONS cmp x1, #0 ASM_ASSERT(ne) #endif /* ENABLE_ASSERTIONS */ /* Prepend '\r' to '\n' */ cmp w0, #0xA b.ne 2f 1: /* Check if the transmit FIFO is full */ ldr w2, [x1, #UARTFR] tbnz w2, #PL011_UARTFR_TXFF_BIT, 1b mov w2, #0xD str w2, [x1, #UARTDR] 2: /* Check if the transmit FIFO is full */ ldr w2, [x1, #UARTFR] tbnz w2, #PL011_UARTFR_TXFF_BIT, 2b str w0, [x1, #UARTDR] ret endfunc console_pl011_core_putc /* -------------------------------------------------------- * int console_pl011_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_pl011_putc #if ENABLE_ASSERTIONS cmp x1, #0 ASM_ASSERT(ne) #endif /* ENABLE_ASSERTIONS */ ldr x1, [x1, #CONSOLE_T_BASE] b console_pl011_core_putc endfunc console_pl011_putc /* --------------------------------------------- * int console_pl011_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_pl011_core_getc #if ENABLE_ASSERTIONS cmp x0, #0 ASM_ASSERT(ne) #endif /* ENABLE_ASSERTIONS */ /* Check if the receive FIFO is empty */ ldr w1, [x0, #UARTFR] tbnz w1, #PL011_UARTFR_RXFE_BIT, no_char ldr w1, [x0, #UARTDR] mov w0, w1 ret no_char: mov w0, #ERROR_NO_PENDING_CHAR ret endfunc console_pl011_core_getc /* --------------------------------------------- * int console_pl011_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_pl011_getc #if ENABLE_ASSERTIONS cmp x0, #0 ASM_ASSERT(ne) #endif /* ENABLE_ASSERTIONS */ ldr x0, [x0, #CONSOLE_T_BASE] b console_pl011_core_getc endfunc console_pl011_getc /* --------------------------------------------- * void console_pl011_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_pl011_core_flush #if ENABLE_ASSERTIONS cmp x0, #0 ASM_ASSERT(ne) #endif /* ENABLE_ASSERTIONS */ 1: /* Loop until the transmit FIFO is empty */ ldr w1, [x0, #UARTFR] tbnz w1, #PL011_UARTFR_BUSY_BIT, 1b ret endfunc console_pl011_core_flush /* --------------------------------------------- * void console_pl011_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_pl011_flush #if ENABLE_ASSERTIONS cmp x0, #0 ASM_ASSERT(ne) #endif /* ENABLE_ASSERTIONS */ ldr x0, [x0, #CONSOLE_T_BASE] b console_pl011_core_flush endfunc console_pl011_flush