216e3b7abb
I want to reuse tosa/spitz gpio_reset code, but my board needs the reset gpio to be driven high during normal operation. Signed-off-by: Daniel Ribeiro <drwyrm@gmail.com> Acked-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com> Signed-off-by: Eric Miao <eric.miao@marvell.com>
102 lines
1.8 KiB
C
102 lines
1.8 KiB
C
/*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*/
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/gpio.h>
|
|
#include <linux/io.h>
|
|
#include <asm/proc-fns.h>
|
|
|
|
#include <mach/regs-ost.h>
|
|
#include <mach/reset.h>
|
|
|
|
unsigned int reset_status;
|
|
EXPORT_SYMBOL(reset_status);
|
|
|
|
static void do_hw_reset(void);
|
|
|
|
static int reset_gpio = -1;
|
|
|
|
int init_gpio_reset(int gpio, int output, int level)
|
|
{
|
|
int rc;
|
|
|
|
rc = gpio_request(gpio, "reset generator");
|
|
if (rc) {
|
|
printk(KERN_ERR "Can't request reset_gpio\n");
|
|
goto out;
|
|
}
|
|
|
|
if (output)
|
|
rc = gpio_direction_output(gpio, level);
|
|
else
|
|
rc = gpio_direction_input(gpio);
|
|
if (rc) {
|
|
printk(KERN_ERR "Can't configure reset_gpio\n");
|
|
gpio_free(gpio);
|
|
goto out;
|
|
}
|
|
|
|
out:
|
|
if (!rc)
|
|
reset_gpio = gpio;
|
|
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
* Trigger GPIO reset.
|
|
* This covers various types of logic connecting gpio pin
|
|
* to RESET pins (nRESET or GPIO_RESET):
|
|
*/
|
|
static void do_gpio_reset(void)
|
|
{
|
|
BUG_ON(reset_gpio == -1);
|
|
|
|
/* drive it low */
|
|
gpio_direction_output(reset_gpio, 0);
|
|
mdelay(2);
|
|
/* rising edge or drive high */
|
|
gpio_set_value(reset_gpio, 1);
|
|
mdelay(2);
|
|
/* falling edge */
|
|
gpio_set_value(reset_gpio, 0);
|
|
|
|
/* give it some time */
|
|
mdelay(10);
|
|
|
|
WARN_ON(1);
|
|
/* fallback */
|
|
do_hw_reset();
|
|
}
|
|
|
|
static void do_hw_reset(void)
|
|
{
|
|
/* Initialize the watchdog and let it fire */
|
|
OWER = OWER_WME;
|
|
OSSR = OSSR_M3;
|
|
OSMR3 = OSCR + 368640; /* ... in 100 ms */
|
|
}
|
|
|
|
void arch_reset(char mode, const char *cmd)
|
|
{
|
|
clear_reset_status(RESET_STATUS_ALL);
|
|
|
|
switch (mode) {
|
|
case 's':
|
|
/* Jump into ROM at address 0 */
|
|
cpu_reset(0);
|
|
break;
|
|
case 'g':
|
|
do_gpio_reset();
|
|
break;
|
|
case 'h':
|
|
default:
|
|
do_hw_reset();
|
|
break;
|
|
}
|
|
}
|
|
|