serial_stm32x7.c
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/*
* (C) Copyright 2016
* Vikas Manocha, <vikas.manocha@st.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <dm.h>
#include <asm/io.h>
#include <serial.h>
#include <dm/platform_data/serial_stm32x7.h>
#include "serial_stm32x7.h"
DECLARE_GLOBAL_DATA_PTR;
static int stm32_serial_setbrg(struct udevice *dev, int baudrate)
{
struct stm32x7_serial_platdata *plat = dev->platdata;
struct stm32_usart *const usart = plat->base;
writel(plat->clock/baudrate, &usart->brr);
return 0;
}
static int stm32_serial_getc(struct udevice *dev)
{
struct stm32x7_serial_platdata *plat = dev->platdata;
struct stm32_usart *const usart = plat->base;
if ((readl(&usart->sr) & USART_SR_FLAG_RXNE) == 0)
return -EAGAIN;
return readl(&usart->rd_dr);
}
static int stm32_serial_putc(struct udevice *dev, const char c)
{
struct stm32x7_serial_platdata *plat = dev->platdata;
struct stm32_usart *const usart = plat->base;
if ((readl(&usart->sr) & USART_SR_FLAG_TXE) == 0)
return -EAGAIN;
writel(c, &usart->tx_dr);
return 0;
}
static int stm32_serial_pending(struct udevice *dev, bool input)
{
struct stm32x7_serial_platdata *plat = dev->platdata;
struct stm32_usart *const usart = plat->base;
if (input)
return readl(&usart->sr) & USART_SR_FLAG_RXNE ? 1 : 0;
else
return readl(&usart->sr) & USART_SR_FLAG_TXE ? 0 : 1;
}
static int stm32_serial_probe(struct udevice *dev)
{
struct stm32x7_serial_platdata *plat = dev->platdata;
struct stm32_usart *const usart = plat->base;
setbits_le32(&usart->cr1, USART_CR1_RE | USART_CR1_TE | USART_CR1_UE);
return 0;
}
static const struct dm_serial_ops stm32_serial_ops = {
.putc = stm32_serial_putc,
.pending = stm32_serial_pending,
.getc = stm32_serial_getc,
.setbrg = stm32_serial_setbrg,
};
U_BOOT_DRIVER(serial_stm32) = {
.name = "serial_stm32x7",
.id = UCLASS_SERIAL,
.ops = &stm32_serial_ops,
.probe = stm32_serial_probe,
.flags = DM_FLAG_PRE_RELOC,
};