diff options
Diffstat (limited to 'drivers/arm/pl011/aarch64/pl011_console.S')
| -rw-r--r-- | drivers/arm/pl011/aarch64/pl011_console.S | 247 |
1 files changed, 247 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 0000000..861d2ed --- /dev/null +++ b/drivers/arm/pl011/aarch64/pl011_console.S @@ -0,0 +1,247 @@ +/* + * Copyright (c) 2013-2020, ARM Limited and Contributors. All rights reserved. + * + * SPDX-License-Identifier: BSD-3-Clause + */ +#include <arch.h> +#include <asm_macros.S> +#include <assert_macros.S> +#include <console_macros.S> +#include <drivers/arm/pl011.h> + + /* + * "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=1, 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 |