linux/drivers/power/reset/arm-versatile-reboot.c

112 lines
2.8 KiB
C

/*
* Copyright (C) 2014 Linaro Ltd.
*
* Author: Linus Walleij <linus.walleij@linaro.org>
*
* 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/init.h>
#include <linux/mfd/syscon.h>
#include <linux/reboot.h>
#include <linux/regmap.h>
#include <linux/of.h>
#include <asm/system_misc.h>
#define REALVIEW_SYS_LOCK_OFFSET 0x20
#define REALVIEW_SYS_LOCK_VAL 0xA05F
#define REALVIEW_SYS_RESETCTL_OFFSET 0x40
/*
* We detect the different syscon types from the compatible strings.
*/
enum versatile_reboot {
REALVIEW_REBOOT_EB,
REALVIEW_REBOOT_PB1176,
REALVIEW_REBOOT_PB11MP,
REALVIEW_REBOOT_PBA8,
REALVIEW_REBOOT_PBX,
};
/* Pointer to the system controller */
static struct regmap *syscon_regmap;
static enum versatile_reboot versatile_reboot_type;
static const struct of_device_id versatile_reboot_of_match[] = {
{
.compatible = "arm,realview-eb-syscon",
.data = (void *)REALVIEW_REBOOT_EB,
},
{
.compatible = "arm,realview-pb1176-syscon",
.data = (void *)REALVIEW_REBOOT_PB1176,
},
{
.compatible = "arm,realview-pb11mp-syscon",
.data = (void *)REALVIEW_REBOOT_PB11MP,
},
{
.compatible = "arm,realview-pba8-syscon",
.data = (void *)REALVIEW_REBOOT_PBA8,
},
{
.compatible = "arm,realview-pbx-syscon",
.data = (void *)REALVIEW_REBOOT_PBX,
},
};
static void versatile_reboot(enum reboot_mode mode, const char *cmd)
{
/* Unlock the reset register */
regmap_write(syscon_regmap, REALVIEW_SYS_LOCK_OFFSET,
REALVIEW_SYS_LOCK_VAL);
/* Then hit reset on the different machines */
switch (versatile_reboot_type) {
case REALVIEW_REBOOT_EB:
regmap_write(syscon_regmap,
REALVIEW_SYS_RESETCTL_OFFSET, 0x0008);
break;
case REALVIEW_REBOOT_PB1176:
regmap_write(syscon_regmap,
REALVIEW_SYS_RESETCTL_OFFSET, 0x0100);
break;
case REALVIEW_REBOOT_PB11MP:
case REALVIEW_REBOOT_PBA8:
regmap_write(syscon_regmap, REALVIEW_SYS_RESETCTL_OFFSET,
0x0000);
regmap_write(syscon_regmap, REALVIEW_SYS_RESETCTL_OFFSET,
0x0004);
break;
case REALVIEW_REBOOT_PBX:
regmap_write(syscon_regmap, REALVIEW_SYS_RESETCTL_OFFSET,
0x00f0);
regmap_write(syscon_regmap, REALVIEW_SYS_RESETCTL_OFFSET,
0x00f4);
break;
}
dsb();
}
static int __init versatile_reboot_probe(void)
{
const struct of_device_id *reboot_id;
struct device_node *np;
np = of_find_matching_node_and_match(NULL, versatile_reboot_of_match,
&reboot_id);
if (!np)
return -ENODEV;
versatile_reboot_type = (enum versatile_reboot)reboot_id->data;
syscon_regmap = syscon_node_to_regmap(np);
if (IS_ERR(syscon_regmap))
return PTR_ERR(syscon_regmap);
arm_pm_restart = versatile_reboot;
pr_info("versatile reboot driver registered\n");
return 0;
}
device_initcall(versatile_reboot_probe);