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// 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"
#include "generic.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;
}
}
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