diff options
Diffstat (limited to 'drivers/cadence/uart/aarch64/cdns_console.S')
| -rw-r--r-- | drivers/cadence/uart/aarch64/cdns_console.S | 220 |
1 files changed, 220 insertions, 0 deletions
diff --git a/drivers/cadence/uart/aarch64/cdns_console.S b/drivers/cadence/uart/aarch64/cdns_console.S new file mode 100644 index 0000000..4c1a80e --- /dev/null +++ b/drivers/cadence/uart/aarch64/cdns_console.S @@ -0,0 +1,220 @@ +/* + * Copyright (c) 2016-2020, 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/cadence/cdns_uart.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_cdns_core_init + .globl console_cdns_core_putc + .globl console_cdns_core_getc + .globl console_cdns_core_flush + + .globl console_cdns_putc + .globl console_cdns_getc + .globl console_cdns_flush + + /* ----------------------------------------------- + * int console_cdns_core_init(uintptr_t base_addr) + * Function to initialize the console without a + * C Runtime to print debug information. This + * function will be accessed by console_init and + * crash reporting. + * We assume that the bootloader already set up + * the HW (baud, ...) and only enable the trans- + * mitter and receiver here. + * In: x0 - console base address + * Out: return 1 on success else 0 on error + * Clobber list : x1, x2, x3 + * ----------------------------------------------- + */ +func console_cdns_core_init + /* Check the input base address */ + cbz x0, core_init_fail + + /* RX/TX enabled & reset */ + mov w3, #(R_UART_CR_TX_EN | R_UART_CR_RX_EN | R_UART_CR_TXRST | R_UART_CR_RXRST) + str w3, [x0, #R_UART_CR] + + mov w0, #1 + ret +core_init_fail: + mov w0, wzr + ret +endfunc console_cdns_core_init + + .globl console_cdns_register + + /* ----------------------------------------------- + * int console_cdns_register(uintptr_t baseaddr, + * uint32_t clock, uint32_t baud, + * console_t *console); + * Function to initialize and register a new CDNS + * 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_cdns_register + mov x7, x30 + mov x6, x3 + cbz x6, register_fail + str x0, [x6, #CONSOLE_T_BASE] + + bl console_cdns_core_init + cbz x0, register_fail + + mov x0, x6 + mov x30, x7 + finish_console_register cdns putc=1, getc=1, flush=1 + +register_fail: + ret x7 +endfunc console_cdns_register + + /* -------------------------------------------------------- + * int console_cdns_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_cdns_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 empty */ + ldr w2, [x1, #R_UART_SR] + tbz w2, #UART_SR_INTR_TEMPTY_BIT, 1b + mov w2, #0xD + str w2, [x1, #R_UART_TX] +2: + /* Check if the transmit FIFO is empty */ + ldr w2, [x1, #R_UART_SR] + tbz w2, #UART_SR_INTR_TEMPTY_BIT, 2b + str w0, [x1, #R_UART_TX] + ret +endfunc console_cdns_core_putc + + /* -------------------------------------------------------- + * int console_cdns_putc(int c, console_t *cdns) + * 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_cdns_putc +#if ENABLE_ASSERTIONS + cmp x1, #0 + ASM_ASSERT(ne) +#endif /* ENABLE_ASSERTIONS */ + ldr x1, [x1, #CONSOLE_T_BASE] + b console_cdns_core_putc +endfunc console_cdns_putc + + /* --------------------------------------------- + * int console_cdns_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_cdns_core_getc +#if ENABLE_ASSERTIONS + cmp x0, #0 + ASM_ASSERT(ne) +#endif /* ENABLE_ASSERTIONS */ + + /* Check if the receive FIFO is empty */ + ldr w1, [x0, #R_UART_SR] + tbnz w1, #UART_SR_INTR_REMPTY_BIT, no_char + ldr w1, [x0, #R_UART_RX] + mov w0, w1 + ret +no_char: + mov w0, #ERROR_NO_PENDING_CHAR + ret +endfunc console_cdns_core_getc + + /* --------------------------------------------- + * int console_cdns_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_cdns_getc +#if ENABLE_ASSERTIONS + cmp x0, #0 + ASM_ASSERT(ne) +#endif /* ENABLE_ASSERTIONS */ + ldr x0, [x0, #CONSOLE_T_BASE] + b console_cdns_core_getc +endfunc console_cdns_getc + + /* --------------------------------------------- + * void console_cdns_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_cdns_core_flush +#if ENABLE_ASSERTIONS + cmp x0, #0 + ASM_ASSERT(ne) +#endif /* ENABLE_ASSERTIONS */ + /* Placeholder */ + ret +endfunc console_cdns_core_flush + + /* --------------------------------------------- + * void console_cdns_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_cdns_flush +#if ENABLE_ASSERTIONS + cmp x0, #0 + ASM_ASSERT(ne) +#endif /* ENABLE_ASSERTIONS */ + ldr x0, [x0, #CONSOLE_T_BASE] + b console_cdns_core_flush +endfunc console_cdns_flush |