mirror of https://gitee.com/openkylin/linux.git
107 lines
2.7 KiB
C
107 lines
2.7 KiB
C
/*
|
|
* TI DaVinci serial driver
|
|
*
|
|
* Copyright (C) 2006 Texas Instruments.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
|
|
*
|
|
*/
|
|
|
|
#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 <mach/serial.h>
|
|
#include <mach/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;
|
|
}
|