linux/drivers/power/reset/brcmstb-reboot.c

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/*
* Copyright (C) 2013 Broadcom Corporation
*
* 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/bitops.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/jiffies.h>
#include <linux/notifier.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/printk.h>
#include <linux/reboot.h>
#include <linux/regmap.h>
#include <linux/smp.h>
#include <linux/mfd/syscon.h>
#define RESET_SOURCE_ENABLE_REG 1
#define SW_MASTER_RESET_REG 2
static struct regmap *regmap;
static u32 rst_src_en;
static u32 sw_mstr_rst;
struct reset_reg_mask {
u32 rst_src_en_mask;
u32 sw_mstr_rst_mask;
};
static const struct reset_reg_mask *reset_masks;
static int brcmstb_restart_handler(struct notifier_block *this,
unsigned long mode, void *cmd)
{
int rc;
u32 tmp;
rc = regmap_write(regmap, rst_src_en, reset_masks->rst_src_en_mask);
if (rc) {
pr_err("failed to write rst_src_en (%d)\n", rc);
return NOTIFY_DONE;
}
rc = regmap_read(regmap, rst_src_en, &tmp);
if (rc) {
pr_err("failed to read rst_src_en (%d)\n", rc);
return NOTIFY_DONE;
}
rc = regmap_write(regmap, sw_mstr_rst, reset_masks->sw_mstr_rst_mask);
if (rc) {
pr_err("failed to write sw_mstr_rst (%d)\n", rc);
return NOTIFY_DONE;
}
rc = regmap_read(regmap, sw_mstr_rst, &tmp);
if (rc) {
pr_err("failed to read sw_mstr_rst (%d)\n", rc);
return NOTIFY_DONE;
}
while (1)
;
return NOTIFY_DONE;
}
static struct notifier_block brcmstb_restart_nb = {
.notifier_call = brcmstb_restart_handler,
.priority = 128,
};
static const struct reset_reg_mask reset_bits_40nm = {
.rst_src_en_mask = BIT(0),
.sw_mstr_rst_mask = BIT(0),
};
static const struct of_device_id of_match[] = {
{ .compatible = "brcm,brcmstb-reboot", .data = &reset_bits_40nm },
{},
};
static int brcmstb_reboot_probe(struct platform_device *pdev)
{
int rc;
struct device_node *np = pdev->dev.of_node;
const struct of_device_id *of_id;
of_id = of_match_node(of_match, np);
if (!of_id) {
pr_err("failed to look up compatible string\n");
return -EINVAL;
}
reset_masks = of_id->data;
regmap = syscon_regmap_lookup_by_phandle(np, "syscon");
if (IS_ERR(regmap)) {
pr_err("failed to get syscon phandle\n");
return -EINVAL;
}
rc = of_property_read_u32_index(np, "syscon", RESET_SOURCE_ENABLE_REG,
&rst_src_en);
if (rc) {
pr_err("can't get rst_src_en offset (%d)\n", rc);
return -EINVAL;
}
rc = of_property_read_u32_index(np, "syscon", SW_MASTER_RESET_REG,
&sw_mstr_rst);
if (rc) {
pr_err("can't get sw_mstr_rst offset (%d)\n", rc);
return -EINVAL;
}
rc = register_restart_handler(&brcmstb_restart_nb);
if (rc)
dev_err(&pdev->dev,
"cannot register restart handler (err=%d)\n", rc);
return rc;
}
static struct platform_driver brcmstb_reboot_driver = {
.probe = brcmstb_reboot_probe,
.driver = {
.name = "brcmstb-reboot",
.of_match_table = of_match,
},
};
static int __init brcmstb_reboot_init(void)
{
return platform_driver_probe(&brcmstb_reboot_driver,
brcmstb_reboot_probe);
}
subsys_initcall(brcmstb_reboot_init);