diff options
Diffstat (limited to 'drivers/arm/pl011/aarch64/pl011_console.S')
| -rw-r--r-- | drivers/arm/pl011/aarch64/pl011_console.S | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/drivers/arm/pl011/aarch64/pl011_console.S b/drivers/arm/pl011/aarch64/pl011_console.S new file mode 100644 index 00000000..8b15d565 --- /dev/null +++ b/drivers/arm/pl011/aarch64/pl011_console.S @@ -0,0 +1,154 @@ +/* + * Copyright (c) 2013-2017, ARM Limited and Contributors. All rights reserved. + * + * SPDX-License-Identifier: BSD-3-Clause + */ +#include <arch.h> +#include <asm_macros.S> +#include <pl011.h> + +/* + * Pull in generic functions to provide backwards compatibility for + * platform makefiles + */ +#include "../../../console/aarch64/console.S" + + + .globl console_core_init + .globl console_core_putc + .globl console_core_getc + .globl console_core_flush + + + /* ----------------------------------------------- + * int console_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_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_core_init + + /* -------------------------------------------------------- + * int console_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_core_putc + /* Check the input parameter */ + cbz x1, putc_error + /* 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 +putc_error: + mov w0, #-1 + ret +endfunc console_core_putc + + /* --------------------------------------------- + * int console_core_getc(uintptr_t base_addr) + * Function to get a character from the console. + * It returns the character grabbed on success + * or -1 on error. + * In : x0 - console base address + * Clobber list : x0, x1 + * --------------------------------------------- + */ +func console_core_getc + cbz x0, getc_error +1: + /* Check if the receive FIFO is empty */ + ldr w1, [x0, #UARTFR] + tbnz w1, #PL011_UARTFR_RXFE_BIT, 1b + ldr w1, [x0, #UARTDR] + mov w0, w1 + ret +getc_error: + mov w0, #-1 + ret +endfunc console_core_getc + + /* --------------------------------------------- + * int console_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 : return -1 on error else return 0. + * Clobber list : x0, x1 + * --------------------------------------------- + */ +func console_core_flush + cbz x0, flush_error + +1: + /* Loop until the transmit FIFO is empty */ + ldr w1, [x0, #UARTFR] + tbnz w1, #PL011_UARTFR_BUSY_BIT, 1b + + mov w0, #0 + ret +flush_error: + mov w0, #-1 + ret +endfunc console_core_flush |