mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-05 01:54:09 +08:00
76d57ce6ef
Provide an API to initialize a UART clock. Refactor existing davinci_serial_init() to separate out the part which enables the clock. This will later be used to help DA850 DT boot support. Signed-off-by: Sekhar Nori <nsekhar@ti.com>
131 lines
3.4 KiB
C
131 lines
3.4 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 unsigned int serial_read_reg(struct plat_serial8250_port *up,
|
|
int offset)
|
|
{
|
|
offset <<= up->regshift;
|
|
|
|
WARN_ONCE(!up->membase, "unmapped read: uart[%d]\n", offset);
|
|
|
|
return (unsigned int)__raw_readl(up->membase + offset);
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
/* Enable UART clock and obtain its rate */
|
|
int __init davinci_serial_setup_clk(unsigned instance, unsigned int *rate)
|
|
{
|
|
char name[16];
|
|
struct clk *clk;
|
|
struct davinci_soc_info *soc_info = &davinci_soc_info;
|
|
struct device *dev = &soc_info->serial_dev->dev;
|
|
|
|
sprintf(name, "uart%d", instance);
|
|
clk = clk_get(dev, name);
|
|
if (IS_ERR(clk)) {
|
|
pr_err("%s:%d: failed to get UART%d clock\n",
|
|
__func__, __LINE__, instance);
|
|
return PTR_ERR(clk);
|
|
}
|
|
|
|
clk_prepare_enable(clk);
|
|
|
|
if (rate)
|
|
*rate = clk_get_rate(clk);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int __init davinci_serial_init(struct davinci_uart_config *info)
|
|
{
|
|
int i, ret;
|
|
struct davinci_soc_info *soc_info = &davinci_soc_info;
|
|
struct device *dev = &soc_info->serial_dev->dev;
|
|
struct plat_serial8250_port *p = dev->platform_data;
|
|
|
|
/*
|
|
* 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; p->flags; i++, p++) {
|
|
if (!(info->enabled_uarts & (1 << i)))
|
|
continue;
|
|
|
|
ret = davinci_serial_setup_clk(i, &p->uartclk);
|
|
if (ret)
|
|
continue;
|
|
|
|
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 platform_device_register(soc_info->serial_dev);
|
|
}
|