Signed-off-by: Kamil Lulko <rev13@wp.pl> Reviewed-by: Tom Rini <trini@konsulko.com>master
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/*
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* (C) Copyright 2015 |
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* Kamil Lulko, <rev13@wp.pl> |
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* |
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* SPDX-License-Identifier: GPL-2.0+ |
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*/ |
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#include <common.h> |
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#include <asm/io.h> |
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#include <serial.h> |
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#include <asm/arch/stm32.h> |
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#define STM32_USART1_BASE (STM32_APB2PERIPH_BASE + 0x1000) |
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#define RCC_APB2ENR_USART1EN (1 << 4) |
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#define USART_BASE STM32_USART1_BASE |
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#define RCC_USART_ENABLE RCC_APB2ENR_USART1EN |
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struct stm32_serial { |
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u32 sr; |
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u32 dr; |
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u32 brr; |
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u32 cr1; |
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u32 cr2; |
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u32 cr3; |
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u32 gtpr; |
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}; |
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#define USART_CR1_RE (1 << 2) |
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#define USART_CR1_TE (1 << 3) |
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#define USART_CR1_UE (1 << 13) |
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#define USART_SR_FLAG_RXNE (1 << 5) |
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#define USART_SR_FLAG_TXE (1 << 7) |
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#define USART_BRR_F_MASK 0xF |
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#define USART_BRR_M_SHIFT 4 |
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#define USART_BRR_M_MASK 0xFFF0 |
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DECLARE_GLOBAL_DATA_PTR; |
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static void stm32_serial_setbrg(void) |
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{ |
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serial_init(); |
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} |
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static int stm32_serial_init(void) |
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{ |
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struct stm32_serial *usart = (struct stm32_serial *)USART_BASE; |
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u32 clock, int_div, frac_div, tmp; |
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if ((USART_BASE & STM32_BUS_MASK) == STM32_APB1PERIPH_BASE) { |
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setbits_le32(&STM32_RCC->apb1enr, RCC_USART_ENABLE); |
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clock = clock_get(CLOCK_APB1); |
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} else if ((USART_BASE & STM32_BUS_MASK) == STM32_APB2PERIPH_BASE) { |
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setbits_le32(&STM32_RCC->apb2enr, RCC_USART_ENABLE); |
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clock = clock_get(CLOCK_APB2); |
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} else { |
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return -1; |
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} |
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int_div = (25 * clock) / (4 * gd->baudrate); |
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tmp = ((int_div / 100) << USART_BRR_M_SHIFT) & USART_BRR_M_MASK; |
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frac_div = int_div - (100 * (tmp >> USART_BRR_M_SHIFT)); |
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tmp |= (((frac_div * 16) + 50) / 100) & USART_BRR_F_MASK; |
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writel(tmp, &usart->brr); |
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setbits_le32(&usart->cr1, USART_CR1_RE | USART_CR1_TE | USART_CR1_UE); |
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return 0; |
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} |
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static int stm32_serial_getc(void) |
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{ |
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struct stm32_serial *usart = (struct stm32_serial *)USART_BASE; |
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while ((readl(&usart->sr) & USART_SR_FLAG_RXNE) == 0) |
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; |
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return readl(&usart->dr); |
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} |
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static void stm32_serial_putc(const char c) |
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{ |
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struct stm32_serial *usart = (struct stm32_serial *)USART_BASE; |
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while ((readl(&usart->sr) & USART_SR_FLAG_TXE) == 0) |
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; |
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writel(c, &usart->dr); |
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} |
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static int stm32_serial_tstc(void) |
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{ |
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struct stm32_serial *usart = (struct stm32_serial *)USART_BASE; |
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u8 ret; |
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ret = readl(&usart->sr) & USART_SR_FLAG_RXNE; |
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return ret; |
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} |
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static struct serial_device stm32_serial_drv = { |
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.name = "stm32_serial", |
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.start = stm32_serial_init, |
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.stop = NULL, |
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.setbrg = stm32_serial_setbrg, |
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.putc = stm32_serial_putc, |
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.puts = default_serial_puts, |
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.getc = stm32_serial_getc, |
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.tstc = stm32_serial_tstc, |
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}; |
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void stm32_serial_initialize(void) |
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{ |
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serial_register(&stm32_serial_drv); |
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} |
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__weak struct serial_device *default_serial_console(void) |
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{ |
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return &stm32_serial_drv; |
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} |
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