| /* |
| * Copyright (c) 2018-2019, ARM Limited and Contributors. All rights reserved. |
| * |
| * SPDX-License-Identifier: BSD-3-Clause |
| */ |
| #include <asm_macros.S> |
| #include <assert_macros.S> |
| #include <console_macros.S> |
| #include <drivers/st/stm32_console.h> |
| #include <drivers/st/stm32_uart_regs.h> |
| |
| #define USART_TIMEOUT 0x1000 |
| |
| /* |
| * "core" functions are low-level implementations that don't require |
| * writeable memory and are thus safe to call in BL1 crash context. |
| */ |
| .globl console_stm32_core_init |
| .globl console_stm32_core_putc |
| .globl console_stm32_core_getc |
| .globl console_stm32_core_flush |
| |
| .globl console_stm32_putc |
| .globl console_stm32_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: r0 - console base address |
| * r1 - Uart clock in Hz |
| * r2 - Baud rate |
| * Out: return 1 on success else 0 on error |
| * Clobber list : r1, r2, r3 |
| * ----------------------------------------------------------------- |
| */ |
| func console_stm32_core_init |
| /* Check the input base address */ |
| cmp r0, #0 |
| beq core_init_fail |
| #if defined(IMAGE_BL2) |
| /* Check baud rate and uart clock for sanity */ |
| cmp r1, #0 |
| beq core_init_fail |
| cmp r2, #0 |
| beq core_init_fail |
| /* Disable UART */ |
| ldr r3, [r0, #USART_CR1] |
| bic r3, r3, #USART_CR1_UE |
| str r3, [r0, #USART_CR1] |
| /* Configure UART */ |
| orr r3, r3, #(USART_CR1_TE | USART_CR1_FIFOEN) |
| str r3, [r0, #USART_CR1] |
| ldr r3, [r0, #USART_CR2] |
| bic r3, r3, #USART_CR2_STOP |
| str r3, [r0, #USART_CR2] |
| /* Divisor = (Uart clock + (baudrate / 2)) / baudrate */ |
| lsl r3, r2, #1 |
| add r3, r1, r3 |
| udiv r3, r3, r2 |
| str r3, [r0, #USART_BRR] |
| /* Enable UART */ |
| ldr r3, [r0, #USART_CR1] |
| orr r3, r3, #USART_CR1_UE |
| str r3, [r0, #USART_CR1] |
| /* Check TEACK bit */ |
| mov r2, #USART_TIMEOUT |
| teack_loop: |
| subs r2, r2, #1 |
| beq core_init_fail |
| ldr r3, [r0, #USART_ISR] |
| tst r3, #USART_ISR_TEACK |
| beq teack_loop |
| #endif /* IMAGE_BL2 */ |
| mov r0, #1 |
| bx lr |
| core_init_fail: |
| mov r0, #0 |
| bx lr |
| endfunc console_stm32_core_init |
| |
| .globl console_stm32_register |
| |
| /* ------------------------------------------------------- |
| * int console_stm32_register(uintptr_t baseaddr, |
| * uint32_t clock, uint32_t baud, |
| * struct console_stm32 *console); |
| * Function to initialize and register a new STM32 |
| * console. Storage passed in for the console struct |
| * *must* be persistent (i.e. not from the stack). |
| * In: r0 - UART register base address |
| * r1 - UART clock in Hz |
| * r2 - Baud rate |
| * r3 - pointer to empty console_stm32 struct |
| * Out: return 1 on success, 0 on error |
| * Clobber list : r0, r1, r2 |
| * ------------------------------------------------------- |
| */ |
| func console_stm32_register |
| push {r4, lr} |
| mov r4, r3 |
| cmp r4, #0 |
| beq register_fail |
| str r0, [r4, #CONSOLE_T_STM32_BASE] |
| |
| bl console_stm32_core_init |
| cmp r0, #0 |
| beq register_fail |
| |
| mov r0, r4 |
| pop {r4, lr} |
| finish_console_register stm32 putc=1, getc=0, flush=1 |
| |
| register_fail: |
| pop {r4, pc} |
| endfunc console_stm32_register |
| |
| /* --------------------------------------------------------------- |
| * 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 : r0 - character to be printed |
| * r1 - console base address |
| * Out : return -1 on error else return character. |
| * Clobber list : r2 |
| * --------------------------------------------------------------- |
| */ |
| func console_stm32_core_putc |
| /* Check the input parameter */ |
| cmp r1, #0 |
| beq putc_error |
| |
| /* Check Transmit Data Register Empty */ |
| txe_loop: |
| ldr r2, [r1, #USART_ISR] |
| tst r2, #USART_ISR_TXE |
| beq txe_loop |
| str r0, [r1, #USART_TDR] |
| /* Check transmit complete flag */ |
| tc_loop: |
| ldr r2, [r1, #USART_ISR] |
| tst r2, #USART_ISR_TC |
| beq tc_loop |
| bx lr |
| putc_error: |
| mov r0, #-1 |
| bx lr |
| endfunc console_stm32_core_putc |
| |
| /* ------------------------------------------------------------ |
| * int console_stm32_putc(int c, struct console_stm32 *console) |
| * Function to output a character over the console. It |
| * returns the character printed on success or -1 on error. |
| * In: r0 - character to be printed |
| * r1 - pointer to console_t structure |
| * Out : return -1 on error else return character. |
| * Clobber list: r2 |
| * ------------------------------------------------------------ |
| */ |
| func console_stm32_putc |
| #if ENABLE_ASSERTIONS |
| cmp r1, #0 |
| ASM_ASSERT(ne) |
| #endif /* ENABLE_ASSERTIONS */ |
| ldr r1, [r1, #CONSOLE_T_STM32_BASE] |
| b console_stm32_core_putc |
| endfunc console_stm32_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 : r0 - console base address |
| * Out : return -1. |
| * Clobber list : r0, r1 |
| * ----------------------------------------------------------- |
| */ |
| func console_stm32_core_getc |
| /* Not supported */ |
| mov r0, #-1 |
| bx lr |
| endfunc console_stm32_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 : r0 - console base address |
| * Out : return -1 on error else return 0. |
| * Clobber list : r0, r1 |
| * --------------------------------------------------------------- |
| */ |
| func console_stm32_core_flush |
| cmp r0, #0 |
| beq flush_error |
| /* Check Transmit Data Register Empty */ |
| txe_loop_3: |
| ldr r1, [r0, #USART_ISR] |
| tst r1, #USART_ISR_TXE |
| beq txe_loop_3 |
| mov r0, #0 |
| bx lr |
| flush_error: |
| mov r0, #-1 |
| bx lr |
| endfunc console_stm32_core_flush |
| |
| /* ------------------------------------------------------ |
| * int console_stm32_flush(struct console_stm32 *console) |
| * Function to force a write of all buffered |
| * data that hasn't been output. |
| * In : r0 - pointer to console_t structure |
| * Out : return -1 on error else return 0. |
| * Clobber list: r0, r1 |
| * ------------------------------------------------------ |
| */ |
| func console_stm32_flush |
| #if ENABLE_ASSERTIONS |
| cmp r0, #0 |
| ASM_ASSERT(ne) |
| #endif /* ENABLE_ASSERTIONS */ |
| ldr r0, [r0, #CONSOLE_T_STM32_BASE] |
| b console_stm32_core_flush |
| endfunc console_stm32_flush |
