u-boot/drivers/serial/serial_mvebu_a3700.c

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/*
* Copyright (C) 2016 Stefan Roese <sr@denx.de>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <dm.h>
#include <serial.h>
#include <asm/io.h>
struct mvebu_platdata {
void __iomem *base;
};
/*
* Register offset
*/
#define UART_RX_REG 0x00
#define UART_TX_REG 0x04
#define UART_CTRL_REG 0x08
#define UART_STATUS_REG 0x0c
#define UART_BAUD_REG 0x10
#define UART_POSSR_REG 0x14
#define UART_STATUS_RX_RDY 0x10
#define UART_STATUS_TXFIFO_FULL 0x800
#define UART_CTRL_RXFIFO_RESET 0x4000
#define UART_CTRL_TXFIFO_RESET 0x8000
#define CONFIG_UART_BASE_CLOCK 25804800
static int mvebu_serial_putc(struct udevice *dev, const char ch)
{
struct mvebu_platdata *plat = dev_get_platdata(dev);
void __iomem *base = plat->base;
while (readl(base + UART_STATUS_REG) & UART_STATUS_TXFIFO_FULL)
;
writel(ch, base + UART_TX_REG);
return 0;
}
static int mvebu_serial_getc(struct udevice *dev)
{
struct mvebu_platdata *plat = dev_get_platdata(dev);
void __iomem *base = plat->base;
while (!(readl(base + UART_STATUS_REG) & UART_STATUS_RX_RDY))
;
return readl(base + UART_RX_REG) & 0xff;
}
static int mvebu_serial_pending(struct udevice *dev, bool input)
{
struct mvebu_platdata *plat = dev_get_platdata(dev);
void __iomem *base = plat->base;
if (readl(base + UART_STATUS_REG) & UART_STATUS_RX_RDY)
return 1;
return 0;
}
static int mvebu_serial_setbrg(struct udevice *dev, int baudrate)
{
struct mvebu_platdata *plat = dev_get_platdata(dev);
void __iomem *base = plat->base;
/*
* Calculate divider
* baudrate = clock / 16 / divider
*/
writel(CONFIG_UART_BASE_CLOCK / baudrate / 16, base + UART_BAUD_REG);
/*
* Set Programmable Oversampling Stack to 0,
* UART defaults to 16x scheme
*/
writel(0, base + UART_POSSR_REG);
return 0;
}
static int mvebu_serial_probe(struct udevice *dev)
{
struct mvebu_platdata *plat = dev_get_platdata(dev);
void __iomem *base = plat->base;
/* reset FIFOs */
writel(UART_CTRL_RXFIFO_RESET | UART_CTRL_TXFIFO_RESET,
base + UART_CTRL_REG);
/* No Parity, 1 Stop */
writel(0, base + UART_CTRL_REG);
return 0;
}
static int mvebu_serial_ofdata_to_platdata(struct udevice *dev)
{
struct mvebu_platdata *plat = dev_get_platdata(dev);
plat->base = devfdt_get_addr_ptr(dev);
return 0;
}
static const struct dm_serial_ops mvebu_serial_ops = {
.putc = mvebu_serial_putc,
.pending = mvebu_serial_pending,
.getc = mvebu_serial_getc,
.setbrg = mvebu_serial_setbrg,
};
static const struct udevice_id mvebu_serial_ids[] = {
{ .compatible = "marvell,armada-3700-uart" },
{ }
};
U_BOOT_DRIVER(serial_mvebu) = {
.name = "serial_mvebu",
.id = UCLASS_SERIAL,
.of_match = mvebu_serial_ids,
.ofdata_to_platdata = mvebu_serial_ofdata_to_platdata,
.platdata_auto_alloc_size = sizeof(struct mvebu_platdata),
.probe = mvebu_serial_probe,
.ops = &mvebu_serial_ops,
.flags = DM_FLAG_PRE_RELOC,
};
#ifdef CONFIG_DEBUG_MVEBU_A3700_UART
#include <debug_uart.h>
static inline void _debug_uart_init(void)
{
void __iomem *base = (void __iomem *)CONFIG_DEBUG_UART_BASE;
/* reset FIFOs */
writel(UART_CTRL_RXFIFO_RESET | UART_CTRL_TXFIFO_RESET,
base + UART_CTRL_REG);
/* No Parity, 1 Stop */
writel(0, base + UART_CTRL_REG);
/*
* Calculate divider
* baudrate = clock / 16 / divider
*/
writel(CONFIG_UART_BASE_CLOCK / 115200 / 16, base + UART_BAUD_REG);
/*
* Set Programmable Oversampling Stack to 0,
* UART defaults to 16x scheme
*/
writel(0, base + UART_POSSR_REG);
}
static inline void _debug_uart_putc(int ch)
{
void __iomem *base = (void __iomem *)CONFIG_DEBUG_UART_BASE;
while (readl(base + UART_STATUS_REG) & UART_STATUS_TXFIFO_FULL)
;
writel(ch, base + UART_TX_REG);
}
DEBUG_UART_FUNCS
#endif