107 lines
2.0 KiB
C
107 lines
2.0 KiB
C
|
// SPDX-License-Identifier: GPL-2.0-only
|
||
|
|
#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 <asm/system_misc.h>
|
||
|
|
|
||
|
|
#include "regs-ost.h"
|
||
|
|
#include "reset.h"
|
||
|
|
#include "smemc.h"
|
||
|
|
|
||
|
|
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 */
|
||
|
|
writel_relaxed(OWER_WME, OWER);
|
||
|
|
writel_relaxed(OSSR_M3, OSSR);
|
||
|
|
/* ... in 100 ms */
|
||
|
|
writel_relaxed(readl_relaxed(OSCR) + 368640, OSMR3);
|
||
|
|
/*
|
||
|
|
* SDRAM hangs on watchdog reset on Marvell PXA270 (erratum 71)
|
||
|
|
* we put SDRAM into self-refresh to prevent that
|
||
|
|
*/
|
||
|
|
while (1)
|
||
|
|
writel_relaxed(MDREFR_SLFRSH, MDREFR);
|
||
|
|
}
|
||
|
|
|
||
|
|
void pxa_restart(enum reboot_mode mode, const char *cmd)
|
||
|
|
{
|
||
|
|
local_irq_disable();
|
||
|
|
local_fiq_disable();
|
||
|
|
|
||
|
|
clear_reset_status(RESET_STATUS_ALL);
|
||
|
|
|
||
|
|
switch (mode) {
|
||
|
|
case REBOOT_SOFT:
|
||
|
|
/* Jump into ROM at address 0 */
|
||
|
|
soft_restart(0);
|
||
|
|
break;
|
||
|
|
case REBOOT_GPIO:
|
||
|
|
do_gpio_reset();
|
||
|
|
break;
|
||
|
|
case REBOOT_HARD:
|
||
|
|
default:
|
||
|
|
do_hw_reset();
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
}
|