1 /* 2 * Copyright (c) 2016-2017, ARM Limited and Contributors. All rights reserved. 3 * 4 * SPDX-License-Identifier: BSD-3-Clause 5 */ 6 #include <arch.h> 7 #include <asm_macros.S> 8 #include <cadence/cdns_uart.h> 9 10 .globl console_core_init 11 .globl console_core_putc 12 .globl console_core_getc 13 .globl console_core_flush 14 15 /* ----------------------------------------------- 16 * int console_core_init(unsigned long base_addr, 17 * unsigned int uart_clk, unsigned int baud_rate) 18 * Function to initialize the console without a 19 * C Runtime to print debug information. This 20 * function will be accessed by console_init and 21 * crash reporting. 22 * We assume that the bootloader already set up 23 * the HW (baud, ...) and only enable the trans- 24 * mitter and receiver here. 25 * In: x0 - console base address 26 * w1 - Uart clock in Hz 27 * w2 - Baud rate 28 * Out: return 1 on success else 0 on error 29 * Clobber list : x1, x2, x3 30 * ----------------------------------------------- 31 */ 32 func console_core_init 33 /* Check the input base address */ 34 cbz x0, core_init_fail 35 /* Check baud rate and uart clock for sanity */ 36 cbz w1, core_init_fail 37 cbz w2, core_init_fail 38 39 /* RX/TX enabled & reset */ 40 mov w3, #(R_UART_CR_TX_EN | R_UART_CR_RX_EN | R_UART_CR_TXRST | R_UART_CR_RXRST) 41 str w3, [x0, #R_UART_CR] 42 43 mov w0, #1 44 ret 45 core_init_fail: 46 mov w0, wzr 47 ret 48 endfunc console_core_init 49 50 /* -------------------------------------------------------- 51 * int console_core_putc(int c, unsigned long base_addr) 52 * Function to output a character over the console. It 53 * returns the character printed on success or -1 on error. 54 * In : w0 - character to be printed 55 * x1 - console base address 56 * Out : return -1 on error else return character. 57 * Clobber list : x2 58 * -------------------------------------------------------- 59 */ 60 func console_core_putc 61 /* Check the input parameter */ 62 cbz x1, putc_error 63 /* Prepend '\r' to '\n' */ 64 cmp w0, #0xA 65 b.ne 2f 66 1: 67 /* Check if the transmit FIFO is full */ 68 ldr w2, [x1, #R_UART_SR] 69 tbnz w2, #UART_SR_INTR_TFUL_BIT, 1b 70 mov w2, #0xD 71 str w2, [x1, #R_UART_TX] 72 2: 73 /* Check if the transmit FIFO is full */ 74 ldr w2, [x1, #R_UART_SR] 75 tbnz w2, #UART_SR_INTR_TFUL_BIT, 2b 76 str w0, [x1, #R_UART_TX] 77 ret 78 putc_error: 79 mov w0, #-1 80 ret 81 endfunc console_core_putc 82 83 /* --------------------------------------------- 84 * int console_core_getc(unsigned long base_addr) 85 * Function to get a character from the console. 86 * It returns the character grabbed on success 87 * or -1 on error. 88 * In : x0 - console base address 89 * Clobber list : x0, x1 90 * --------------------------------------------- 91 */ 92 func console_core_getc 93 cbz x0, getc_error 94 1: 95 /* Check if the receive FIFO is empty */ 96 ldr w1, [x0, #R_UART_SR] 97 tbnz w1, #UART_SR_INTR_REMPTY_BIT, 1b 98 ldr w1, [x0, #R_UART_RX] 99 mov w0, w1 100 ret 101 getc_error: 102 mov w0, #-1 103 ret 104 endfunc console_core_getc 105 106 /* --------------------------------------------- 107 * int console_core_flush(uintptr_t base_addr) 108 * Function to force a write of all buffered 109 * data that hasn't been output. 110 * In : x0 - console base address 111 * Out : return -1 on error else return 0. 112 * Clobber list : x0, x1 113 * --------------------------------------------- 114 */ 115 func console_core_flush 116 /* Placeholder */ 117 mov w0, #0 118 ret 119 endfunc console_core_flush 120
