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	Signed-off-by: Vikas Manocha <vikas.manocha@st.com> Reviewed-by: Simon Glass <sjg@chromium.org>
		
			
				
	
	
		
			140 lines
		
	
	
		
			3.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			140 lines
		
	
	
		
			3.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * (C) Copyright 2016
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|  * Vikas Manocha, <vikas.manocha@st.com>
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|  *
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|  * SPDX-License-Identifier:	GPL-2.0+
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|  */
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| 
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| #include <common.h>
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| #include <clk.h>
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| #include <dm.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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| #include <dm/platform_data/serial_stm32x7.h>
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| #include "serial_stm32x7.h"
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| 
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| DECLARE_GLOBAL_DATA_PTR;
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| 
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| static int stm32_serial_setbrg(struct udevice *dev, int baudrate)
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| {
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| 	struct stm32x7_serial_platdata *plat = dev->platdata;
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| 	struct stm32_usart *const usart = plat->base;
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| 	u32  clock, int_div, frac_div, tmp;
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| 
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| 	if (((u32)usart & STM32_BUS_MASK) == APB1_PERIPH_BASE)
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| 		clock = clock_get(CLOCK_APB1);
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| 	else if (((u32)usart & STM32_BUS_MASK) == APB2_PERIPH_BASE)
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| 		clock = clock_get(CLOCK_APB2);
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| 	else
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| 		return -EINVAL;
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| 
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| 	int_div = (25 * clock) / (4 * 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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| 
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| 	return 0;
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| }
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| 
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| static int stm32_serial_getc(struct udevice *dev)
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| {
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| 	struct stm32x7_serial_platdata *plat = dev->platdata;
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| 	struct stm32_usart *const usart = plat->base;
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| 
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| 	if ((readl(&usart->sr) & USART_SR_FLAG_RXNE) == 0)
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| 		return -EAGAIN;
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| 
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| 	return readl(&usart->rd_dr);
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| }
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| 
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| static int stm32_serial_putc(struct udevice *dev, const char c)
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| {
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| 	struct stm32x7_serial_platdata *plat = dev->platdata;
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| 	struct stm32_usart *const usart = plat->base;
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| 
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| 	if ((readl(&usart->sr) & USART_SR_FLAG_TXE) == 0)
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| 		return -EAGAIN;
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| 
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| 	writel(c, &usart->tx_dr);
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| 
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| 	return 0;
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| }
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| 
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| static int stm32_serial_pending(struct udevice *dev, bool input)
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| {
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| 	struct stm32x7_serial_platdata *plat = dev->platdata;
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| 	struct stm32_usart *const usart = plat->base;
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| 
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| 	if (input)
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| 		return readl(&usart->sr) & USART_SR_FLAG_RXNE ? 1 : 0;
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| 	else
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| 		return readl(&usart->sr) & USART_SR_FLAG_TXE ? 0 : 1;
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| }
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| 
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| static int stm32_serial_probe(struct udevice *dev)
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| {
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| 	struct stm32x7_serial_platdata *plat = dev->platdata;
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| 	struct stm32_usart *const usart = plat->base;
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| 
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| #ifdef CONFIG_CLK
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| 	int ret;
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| 	struct clk clk;
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| 
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| 	ret = clk_get_by_index(dev, 0, &clk);
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| 	if (ret < 0)
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| 		return ret;
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| 
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| 	ret = clk_enable(&clk);
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| 	if (ret) {
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| 		dev_err(dev, "failed to enable clock\n");
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| 		return ret;
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| 	}
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| #endif
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| 
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| 	setbits_le32(&usart->cr1, USART_CR1_RE | USART_CR1_TE | USART_CR1_UE);
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| 
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| 	return 0;
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| }
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| 
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| #if CONFIG_IS_ENABLED(OF_CONTROL)
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| static const struct udevice_id stm32_serial_id[] = {
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| 	{.compatible = "st,stm32-usart"},
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| 	{.compatible = "st,stm32-uart"},
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| 	{}
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| };
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| 
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| static int stm32_serial_ofdata_to_platdata(struct udevice *dev)
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| {
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| 	struct stm32x7_serial_platdata *plat = dev_get_platdata(dev);
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| 	fdt_addr_t addr;
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| 
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| 	addr = dev_get_addr(dev);
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| 	if (addr == FDT_ADDR_T_NONE)
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| 		return -EINVAL;
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| 
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| 	plat->base = (struct stm32_usart *)addr;
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| 
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| 	return 0;
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| }
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| #endif
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| 
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| static const struct dm_serial_ops stm32_serial_ops = {
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| 	.putc = stm32_serial_putc,
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| 	.pending = stm32_serial_pending,
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| 	.getc = stm32_serial_getc,
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| 	.setbrg = stm32_serial_setbrg,
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| };
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| 
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| U_BOOT_DRIVER(serial_stm32) = {
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| 	.name = "serial_stm32x7",
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| 	.id = UCLASS_SERIAL,
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| 	.of_match = of_match_ptr(stm32_serial_id),
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| 	.ofdata_to_platdata = of_match_ptr(stm32_serial_ofdata_to_platdata),
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| 	.platdata_auto_alloc_size = sizeof(struct stm32x7_serial_platdata),
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| 	.ops = &stm32_serial_ops,
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| 	.probe = stm32_serial_probe,
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| 	.flags = DM_FLAG_PRE_RELOC,
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| };
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