brcm-kona-reset.c
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/*
* Copyright (C) 2016 Broadcom
*
* 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 version 2.
*
* This program is distributed "as is" WITHOUT ANY WARRANTY of any
* kind, whether express or implied; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/io.h>
#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <linux/reboot.h>
#define RSTMGR_REG_WR_ACCESS_OFFSET 0
#define RSTMGR_REG_CHIP_SOFT_RST_OFFSET 4
#define RSTMGR_WR_PASSWORD 0xa5a5
#define RSTMGR_WR_PASSWORD_SHIFT 8
#define RSTMGR_WR_ACCESS_ENABLE 1
static void __iomem *kona_reset_base;
static int kona_reset_handler(struct notifier_block *this,
unsigned long mode, void *cmd)
{
/*
* A soft reset is triggered by writing a 0 to bit 0 of the soft reset
* register. To write to that register we must first write the password
* and the enable bit in the write access enable register.
*/
writel((RSTMGR_WR_PASSWORD << RSTMGR_WR_PASSWORD_SHIFT) |
RSTMGR_WR_ACCESS_ENABLE,
kona_reset_base + RSTMGR_REG_WR_ACCESS_OFFSET);
writel(0, kona_reset_base + RSTMGR_REG_CHIP_SOFT_RST_OFFSET);
return NOTIFY_DONE;
}
static struct notifier_block kona_reset_nb = {
.notifier_call = kona_reset_handler,
.priority = 128,
};
static int kona_reset_probe(struct platform_device *pdev)
{
struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
kona_reset_base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(kona_reset_base))
return PTR_ERR(kona_reset_base);
return register_restart_handler(&kona_reset_nb);
}
static const struct of_device_id of_match[] = {
{ .compatible = "brcm,bcm21664-resetmgr" },
{},
};
static struct platform_driver bcm_kona_reset_driver = {
.probe = kona_reset_probe,
.driver = {
.name = "brcm-kona-reset",
.of_match_table = of_match,
},
};
builtin_platform_driver(bcm_kona_reset_driver);