| /* |
| * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved. |
| * |
| * SPDX-License-Identifier: BSD-3-Clause |
| */ |
| |
| #include <arch.h> |
| #include <asm_macros.S> |
| #include <console_macros.S> |
| #include <assert_macros.S> |
| #include "ls_16550.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_ls_16550_core_init |
| .globl console_ls_16550_core_putc |
| .globl console_ls_16550_core_getc |
| |
| .globl console_ls_16550_putc |
| .globl console_ls_16550_getc |
| .globl console_ls_16550_flush |
| |
| /* ----------------------------------------------- |
| * int console_ls_16550_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, 0 on error |
| * Clobber list : x1, x2, x3 |
| * ----------------------------------------------- |
| */ |
| func console_ls_16550_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 = Uart clock / (16 * baudrate) */ |
| lsl w2, w2, #4 |
| udiv w2, w1, w2 |
| and w1, w2, #0xff /* w1 = DLL */ |
| lsr w2, w2, #8 |
| and w2, w2, #0xff /* w2 = DLLM */ |
| ldrb w3, [x0, #UARTLCR] |
| orr w3, w3, #UARTLCR_DLAB |
| strb w3, [x0, #UARTLCR] /* enable DLL, DLLM programming */ |
| strb w1, [x0, #UARTDLL] /* program DLL */ |
| strb w2, [x0, #UARTDLLM] /* program DLLM */ |
| mov w2, #~UARTLCR_DLAB |
| and w3, w3, w2 |
| strb w3, [x0, #UARTLCR] /* disable DLL, DLLM programming */ |
| |
| /* 8n1 */ |
| mov w3, #3 |
| strb w3, [x0, #UARTLCR] |
| /* no interrupt */ |
| mov w3, #0 |
| strb w3, [x0, #UARTIER] |
| /* enable fifo, DMA */ |
| mov w3, #(UARTFCR_FIFOEN |UARTFCR_TXCLR | UARTFCR_RXCLR) |
| strb w3, [x0, #UARTFCR] |
| /* DTR + RTS */ |
| mov w3, #3 |
| str w3, [x0, #UARTMCR] |
| mov w0, #1 |
| ret |
| init_fail: |
| mov w0, #0 |
| ret |
| endfunc console_ls_16550_core_init |
| |
| #if MULTI_CONSOLE_API |
| .globl console_ls_16550_register |
| |
| /* ----------------------------------------------- |
| * int console_ls_16550_register(console_ls_16550_t *console, |
| * uintptr_t base, uint32_t clk, uint32_t baud) |
| * Function to initialize and register a new 16550 |
| * 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_ls_16550_t struct |
| * Out: return 1 on success, 0 on error |
| * Clobber list : x0, x1, x2, x6, x7, x14 |
| * ----------------------------------------------- |
| */ |
| func console_ls_16550_register |
| mov x7, x30 |
| mov x6, x3 |
| cbz x6, register_fail |
| str x0, [x6, #CONSOLE_T_16550_BASE] |
| |
| bl console_ls_16550_core_init |
| cbz x0, register_fail |
| |
| mov x0, x6 |
| mov x30, x7 |
| finish_console_register ls_16550 |
| |
| register_fail: |
| ret x7 |
| endfunc console_ls_16550_register |
| #else |
| .globl console_core_init |
| .globl console_core_putc |
| .globl console_core_getc |
| .globl console_core_flush |
| .equ console_core_init,console_ls_16550_core_init |
| .equ console_core_putc,console_ls_16550_core_putc |
| .equ console_core_getc,console_ls_16550_core_getc |
| .equ console_core_flush,console_ls_16550_core_flush |
| #endif |
| |
| /* -------------------------------------------------------- |
| * int console_ls_16550_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_ls_16550_core_putc |
| #if ENABLE_ASSERTIONS |
| cmp x1, #0 |
| ASM_ASSERT(ne) |
| #endif /* ENABLE_ASSERTIONS */ |
| |
| /* Prepend '\r' to '\n' */ |
| cmp w0, #0xA //'\n' |
| b.ne 2f |
| /* Check if the transmit FIFO is full */ |
| 1: ldrb w2, [x1, #UARTLSR] |
| and w2, w2, #UARTLSR_THRE /* #(UARTLSR_TEMT | UARTLSR_THRE)*/ |
| cmp w2, #(UARTLSR_THRE) |
| b.ne 1b |
| mov w2, #0xD /* '\r' */ |
| strb w2, [x1, #UARTTX] |
| ldrb w2, [x1, #UARTFCR] |
| orr w2, w2, #UARTFCR_TXCLR |
| |
| /* Check if the transmit FIFO is full */ |
| 2: ldrb w2, [x1, #UARTLSR] |
| and w2, w2, #(UARTLSR_THRE) |
| cmp w2, #(UARTLSR_THRE) |
| b.ne 2b |
| strb w0, [x1, #UARTTX] |
| ret |
| endfunc console_ls_16550_core_putc |
| |
| /* -------------------------------------------------------- |
| * int console_16550_putc(int c, console_ls_16550_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_ls_16550_putc |
| #if ENABLE_ASSERTIONS |
| cmp x1, #0 |
| ASM_ASSERT(ne) |
| #endif /* ENABLE_ASSERTIONS */ |
| ldr x1, [x1, #CONSOLE_T_16550_BASE] |
| b console_ls_16550_core_putc |
| endfunc console_ls_16550_putc |
| |
| /* --------------------------------------------- |
| * int console_ls_16550_core_getc(uintptr_t base_addr) |
| * 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 - console base address |
| * Out : w0 - character if available, else -1 |
| * Clobber list : x0, x1 |
| * --------------------------------------------- |
| */ |
| func console_ls_16550_core_getc |
| #if ENABLE_ASSERTIONS |
| cmp x0, #0 |
| ASM_ASSERT(ne) |
| #endif /* ENABLE_ASSERTIONS */ |
| |
| /* Check if the receive FIFO is empty */ |
| 1: ldrb w1, [x0, #UARTLSR] |
| tbz w1, #UARTLSR_RDR, 1b |
| ldrb w0, [x0, #UARTRX] |
| ret |
| no_char: |
| mov w0, #ERROR_NO_PENDING_CHAR |
| ret |
| endfunc console_ls_16550_core_getc |
| |
| /* --------------------------------------------- |
| * int console_ls_16550_getc(console_ls_16550_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_ls_16550_getc |
| #if ENABLE_ASSERTIONS |
| cmp x1, #0 |
| ASM_ASSERT(ne) |
| #endif /* ENABLE_ASSERTIONS */ |
| ldr x0, [x0, #CONSOLE_T_16550_BASE] |
| b console_ls_16550_core_getc |
| endfunc console_ls_16550_getc |
| |
| /* --------------------------------------------- |
| * int console_ls_16550_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_ls_16550_core_flush |
| #if ENABLE_ASSERTIONS |
| cmp x0, #0 |
| ASM_ASSERT(ne) |
| #endif /* ENABLE_ASSERTIONS */ |
| |
| /* Loop until the transmit FIFO is empty */ |
| 1: ldrb w1, [x0, #UARTLSR] |
| and w1, w1, #(UARTLSR_TEMT | UARTLSR_THRE) |
| cmp w1, #(UARTLSR_TEMT | UARTLSR_THRE) |
| b.ne 1b |
| |
| mov w0, #0 |
| ret |
| endfunc console_ls_16550_core_flush |
| |
| /* --------------------------------------------- |
| * int console_ls_16550_flush(console_ls_16550_t *console) |
| * Function to force a write of all buffered |
| * data that hasn't been output. |
| * In : x0 - pointer to console_t structure |
| * Out : return -1 on error else return 0. |
| * Clobber list : x0, x1 |
| * --------------------------------------------- |
| */ |
| func console_ls_16550_flush |
| #if ENABLE_ASSERTIONS |
| cmp x0, #0 |
| ASM_ASSERT(ne) |
| #endif /* ENABLE_ASSERTIONS */ |
| ldr x0, [x0, #CONSOLE_T_16550_BASE] |
| b console_ls_16550_core_flush |
| endfunc console_ls_16550_flush |
