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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* TI DaVinci serial driver
*
* Copyright (C) 2006 Texas Instruments.
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/serial_8250.h>
#include <linux/serial_reg.h>
#include <linux/platform_device.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <linux/io.h>
#include "serial.h"
#include "cputype.h"
static inline void serial_write_reg(struct plat_serial8250_port *p, int offset,
int value)
{
offset <<= p->regshift;
WARN_ONCE(!p->membase, "unmapped write: uart[%d]\n", offset);
__raw_writel(value, p->membase + offset);
}
static void __init davinci_serial_reset(struct plat_serial8250_port *p)
{
unsigned int pwremu = 0;
serial_write_reg(p, UART_IER, 0); /* disable all interrupts */
/* reset both transmitter and receiver: bits 14,13 = UTRST, URRST */
serial_write_reg(p, UART_DAVINCI_PWREMU, pwremu);
mdelay(10);
pwremu |= (0x3 << 13);
pwremu |= 0x1;
serial_write_reg(p, UART_DAVINCI_PWREMU, pwremu);
if (cpu_is_davinci_dm646x())
serial_write_reg(p, UART_DM646X_SCR,
UART_DM646X_SCR_TX_WATERMARK);
}
int __init davinci_serial_init(struct platform_device *serial_dev)
{
int i, ret = 0;
struct device *dev;
struct plat_serial8250_port *p;
struct clk *clk;
/*
* Make sure the serial ports are muxed on at this point.
* You have to mux them off in device drivers later on if not needed.
*/
for (i = 0; serial_dev[i].dev.platform_data != NULL; i++) {
dev = &serial_dev[i].dev;
p = dev->platform_data;
ret = platform_device_register(&serial_dev[i]);
if (ret)
continue;
clk = clk_get(dev, NULL);
if (IS_ERR(clk)) {
pr_err("%s:%d: failed to get UART%d clock\n",
__func__, __LINE__, i);
continue;
}
clk_prepare_enable(clk);
p->uartclk = clk_get_rate(clk);
if (!p->membase && p->mapbase) {
p->membase = ioremap(p->mapbase, SZ_4K);
if (p->membase)
p->flags &= ~UPF_IOREMAP;
else
pr_err("uart regs ioremap failed\n");
}
if (p->membase && p->type != PORT_AR7)
davinci_serial_reset(p);
}
return ret;
}
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