| /* |
| * Copyright (C) 2023, STMicroelectronics - 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: 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_stm32_core_init |
| /* Check the input base address */ |
| cbz x0, core_init_fail |
| #if !defined(IMAGE_BL2) |
| #if STM32MP_RECONFIGURE_CONSOLE |
| /* UART clock rate is set to 0 in BL32, skip init in that case */ |
| cbz x1, 1f |
| #else /* STM32MP_RECONFIGURE_CONSOLE */ |
| /* Skip UART initialization if it is already enabled */ |
| ldr w3, [x0, #USART_CR1] |
| tst w3, #USART_CR1_UE |
| b.ne 1f |
| #endif /* STM32MP_RECONFIGURE_CONSOLE */ |
| #endif /* IMAGE_BL2 */ |
| /* Check baud rate and uart clock for sanity */ |
| cbz w1, core_init_fail |
| cbz w2, core_init_fail |
| /* Disable UART */ |
| ldr w3, [x0, #USART_CR1] |
| mov w4, #USART_CR1_UE |
| bic w3, w3, w4 |
| str w3, [x0, #USART_CR1] |
| /* Configure UART */ |
| mov w4, #(USART_CR1_TE) |
| orr w4, w4, #(USART_CR1_FIFOEN) |
| orr w3, w3, w4 |
| str w3, [x0, #USART_CR1] |
| ldr w3, [x0, #USART_CR2] |
| mov w4, #USART_CR2_STOP |
| bic w3, w3, w4 |
| str w3, [x0, #USART_CR2] |
| /* Divisor = (Uart clock + (baudrate / 2)) / baudrate */ |
| lsr w3, w2, #1 |
| add w3, w1, w3 |
| udiv w3, w3, w2 |
| cmp w3, #16 |
| b.hi 2f |
| /* Oversampling 8 */ |
| /* Divisor = (2 * Uart clock + (baudrate / 2)) / baudrate */ |
| lsr w3, w2, #1 |
| add w3, w3, w1, lsl #1 |
| udiv w3, w3, w2 |
| and w1, w3, #USART_BRR_DIV_FRACTION |
| lsr w1, w1, #1 |
| bic w3, w3, #USART_BRR_DIV_FRACTION |
| orr w3, w3, w1 |
| ldr w1, [x0, #USART_CR1] |
| orr w1, w1, #USART_CR1_OVER8 |
| str w1, [x0, #USART_CR1] |
| 2: |
| str w3, [x0, #USART_BRR] |
| /* Enable UART */ |
| ldr w3, [x0, #USART_CR1] |
| mov w4, #USART_CR1_UE |
| orr w3, w3, w4 |
| str w3, [x0, #USART_CR1] |
| /* Check TEACK bit */ |
| mov w2, #USART_TIMEOUT |
| teack_loop: |
| subs w2, w2, #1 |
| beq core_init_fail |
| ldr w3, [x0, #USART_ISR] |
| tst w3, #USART_ISR_TEACK |
| beq teack_loop |
| 1: |
| mov w0, #1 |
| ret |
| core_init_fail: |
| mov w0, wzr |
| ret |
| endfunc console_stm32_core_init |
| |
| .globl console_stm32_register |
| |
| /* ------------------------------------------------------- |
| * int console_stm32_register(uintptr_t baseaddr, |
| * uint32_t clock, uint32_t baud, |
| * console_t *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: 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_stm32_register |
| mov x7, x30 |
| mov x6, x3 |
| cbz x6, register_fail |
| str x0, [x6, #CONSOLE_T_BASE] |
| |
| bl console_stm32_core_init |
| cbz x0, register_fail |
| |
| mov x0, x6 |
| mov x30, x7 |
| finish_console_register stm32 putc=1, getc=0, flush=1 |
| |
| register_fail: |
| ret x7 |
| endfunc console_stm32_register |
| |
| /* -------------------------------------------------------- |
| * int console_stm32_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_stm32_core_putc |
| #if ENABLE_ASSERTIONS |
| cmp x1, #0 |
| ASM_ASSERT(ne) |
| #endif /* ENABLE_ASSERTIONS */ |
| |
| /* Check Transmit Data Register Empty */ |
| txe_loop: |
| ldr w2, [x1, #USART_ISR] |
| tst w2, #USART_ISR_TXE |
| beq txe_loop |
| str w0, [x1, #USART_TDR] |
| /* Check transmit complete flag */ |
| tc_loop: |
| ldr w2, [x1, #USART_ISR] |
| tst w2, #USART_ISR_TC |
| beq tc_loop |
| ret |
| endfunc console_stm32_core_putc |
| |
| /* -------------------------------------------------------- |
| * int console_stm32_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_stm32_putc |
| #if ENABLE_ASSERTIONS |
| cmp x1, #0 |
| ASM_ASSERT(ne) |
| #endif /* ENABLE_ASSERTIONS */ |
| ldr x1, [x1, #CONSOLE_T_BASE] |
| b console_stm32_core_putc |
| endfunc console_stm32_putc |
| |
| /* --------------------------------------------- |
| * int console_stm32_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_stm32_core_getc |
| /* Not supported */ |
| mov w0, #-1 |
| ret |
| endfunc console_stm32_core_getc |
| |
| /* --------------------------------------------- |
| * int console_stm32_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_stm32_core_flush |
| #if ENABLE_ASSERTIONS |
| cmp x0, #0 |
| ASM_ASSERT(ne) |
| #endif /* ENABLE_ASSERTIONS */ |
| /* Check Transmit Data Register Empty */ |
| txe_loop_3: |
| ldr w1, [x0, #USART_ISR] |
| tst w1, #USART_ISR_TXE |
| beq txe_loop_3 |
| mov w0, #0 |
| ret |
| endfunc console_stm32_core_flush |
| |
| /* --------------------------------------------- |
| * int console_stm32_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 : return -1 on error else return 0. |
| * Clobber list : x0, x1 |
| * --------------------------------------------- |
| */ |
| func console_stm32_flush |
| #if ENABLE_ASSERTIONS |
| cmp x0, #0 |
| ASM_ASSERT(ne) |
| #endif /* ENABLE_ASSERTIONS */ |
| ldr x0, [x0, #CONSOLE_T_BASE] |
| b console_stm32_core_flush |
| endfunc console_stm32_flush |