u-boot/drivers/serial/serial_stm32.c
Tom Rini d024236e5a Remove unnecessary instances of DECLARE_GLOBAL_DATA_PTR
We have a large number of places where while we historically referenced
gd in the code we no longer do, as well as cases where the code added
that line "just in case" during development and never dropped it.

Signed-off-by: Tom Rini <trini@konsulko.com>
2018-04-27 14:54:48 -04:00

157 lines
4.1 KiB
C

/*
* Copyright (C) 2016, STMicroelectronics - All Rights Reserved
* Author(s): Vikas Manocha, <vikas.manocha@st.com> for STMicroelectronics.
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <clk.h>
#include <dm.h>
#include <asm/io.h>
#include <serial.h>
#include <asm/arch/stm32.h>
#include "serial_stm32.h"
static int stm32_serial_setbrg(struct udevice *dev, int baudrate)
{
struct stm32x7_serial_platdata *plat = dev_get_platdata(dev);
bool stm32f4 = plat->uart_info->stm32f4;
fdt_addr_t base = plat->base;
u32 int_div, mantissa, fraction, oversampling;
int_div = DIV_ROUND_CLOSEST(plat->clock_rate, baudrate);
if (int_div < 16) {
oversampling = 8;
setbits_le32(base + CR1_OFFSET(stm32f4), USART_CR1_OVER8);
} else {
oversampling = 16;
clrbits_le32(base + CR1_OFFSET(stm32f4), USART_CR1_OVER8);
}
mantissa = (int_div / oversampling) << USART_BRR_M_SHIFT;
fraction = int_div % oversampling;
writel(mantissa | fraction, base + BRR_OFFSET(stm32f4));
return 0;
}
static int stm32_serial_getc(struct udevice *dev)
{
struct stm32x7_serial_platdata *plat = dev_get_platdata(dev);
bool stm32f4 = plat->uart_info->stm32f4;
fdt_addr_t base = plat->base;
if ((readl(base + ISR_OFFSET(stm32f4)) & USART_SR_FLAG_RXNE) == 0)
return -EAGAIN;
return readl(base + RDR_OFFSET(stm32f4));
}
static int stm32_serial_putc(struct udevice *dev, const char c)
{
struct stm32x7_serial_platdata *plat = dev_get_platdata(dev);
bool stm32f4 = plat->uart_info->stm32f4;
fdt_addr_t base = plat->base;
if ((readl(base + ISR_OFFSET(stm32f4)) & USART_SR_FLAG_TXE) == 0)
return -EAGAIN;
writel(c, base + TDR_OFFSET(stm32f4));
return 0;
}
static int stm32_serial_pending(struct udevice *dev, bool input)
{
struct stm32x7_serial_platdata *plat = dev_get_platdata(dev);
bool stm32f4 = plat->uart_info->stm32f4;
fdt_addr_t base = plat->base;
if (input)
return readl(base + ISR_OFFSET(stm32f4)) &
USART_SR_FLAG_RXNE ? 1 : 0;
else
return readl(base + ISR_OFFSET(stm32f4)) &
USART_SR_FLAG_TXE ? 0 : 1;
}
static int stm32_serial_probe(struct udevice *dev)
{
struct stm32x7_serial_platdata *plat = dev_get_platdata(dev);
struct clk clk;
fdt_addr_t base = plat->base;
int ret;
bool stm32f4;
u8 uart_enable_bit;
plat->uart_info = (struct stm32_uart_info *)dev_get_driver_data(dev);
stm32f4 = plat->uart_info->stm32f4;
uart_enable_bit = plat->uart_info->uart_enable_bit;
ret = clk_get_by_index(dev, 0, &clk);
if (ret < 0)
return ret;
ret = clk_enable(&clk);
if (ret) {
dev_err(dev, "failed to enable clock\n");
return ret;
}
plat->clock_rate = clk_get_rate(&clk);
if (plat->clock_rate < 0) {
clk_disable(&clk);
return plat->clock_rate;
};
/* Disable uart-> disable overrun-> enable uart */
clrbits_le32(base + CR1_OFFSET(stm32f4), USART_CR1_RE | USART_CR1_TE |
BIT(uart_enable_bit));
if (plat->uart_info->has_overrun_disable)
setbits_le32(base + CR3_OFFSET(stm32f4), USART_CR3_OVRDIS);
if (plat->uart_info->has_fifo)
setbits_le32(base + CR1_OFFSET(stm32f4), USART_CR1_FIFOEN);
setbits_le32(base + CR1_OFFSET(stm32f4), USART_CR1_RE | USART_CR1_TE |
BIT(uart_enable_bit));
return 0;
}
static const struct udevice_id stm32_serial_id[] = {
{ .compatible = "st,stm32-uart", .data = (ulong)&stm32f4_info},
{ .compatible = "st,stm32f7-uart", .data = (ulong)&stm32f7_info},
{ .compatible = "st,stm32h7-uart", .data = (ulong)&stm32h7_info},
{}
};
static int stm32_serial_ofdata_to_platdata(struct udevice *dev)
{
struct stm32x7_serial_platdata *plat = dev_get_platdata(dev);
plat->base = devfdt_get_addr(dev);
if (plat->base == FDT_ADDR_T_NONE)
return -EINVAL;
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_stm32",
.id = UCLASS_SERIAL,
.of_match = of_match_ptr(stm32_serial_id),
.ofdata_to_platdata = of_match_ptr(stm32_serial_ofdata_to_platdata),
.platdata_auto_alloc_size = sizeof(struct stm32x7_serial_platdata),
.ops = &stm32_serial_ops,
.probe = stm32_serial_probe,
.flags = DM_FLAG_PRE_RELOC,
};