Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Reset driver for Axxia devices
 *
 * Copyright (C) 2014 LSI
 */
#include <linux/init.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/notifier.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/reboot.h>
#include <linux/regmap.h>
 
#define SC_CRIT_WRITE_KEY	0x1000
#define SC_LATCH_ON_RESET	0x1004
#define SC_RESET_CONTROL	0x1008
#define   RSTCTL_RST_ZERO	(1<<3)
#define   RSTCTL_RST_FAB	(1<<2)
#define   RSTCTL_RST_CHIP	(1<<1)
#define   RSTCTL_RST_SYS	(1<<0)
#define SC_EFUSE_INT_STATUS	0x180c
#define   EFUSE_READ_DONE	(1<<31)
 
static struct regmap *syscon;
 
static int axxia_restart_handler(struct notifier_block *this,
<------><------><------><------> unsigned long mode, void *cmd)
{
<------>/* Access Key (0xab) */
<------>regmap_write(syscon, SC_CRIT_WRITE_KEY, 0xab);
<------>/* Select internal boot from 0xffff0000 */
<------>regmap_write(syscon, SC_LATCH_ON_RESET, 0x00000040);
<------>/* Assert ResetReadDone (to avoid hanging in boot ROM) */
<------>regmap_write(syscon, SC_EFUSE_INT_STATUS, EFUSE_READ_DONE);
<------>/* Assert chip reset */
<------>regmap_update_bits(syscon, SC_RESET_CONTROL,
<------><------><------>   RSTCTL_RST_CHIP, RSTCTL_RST_CHIP);
 
<------>return NOTIFY_DONE;
}
 
static struct notifier_block axxia_restart_nb = {
<------>.notifier_call = axxia_restart_handler,
<------>.priority = 128,
};
 
static int axxia_reset_probe(struct platform_device *pdev)
{
<------>struct device *dev = &pdev->dev;
<------>int err;
 
<------>syscon = syscon_regmap_lookup_by_phandle(dev->of_node, "syscon");
<------>if (IS_ERR(syscon)) {
<------><------>pr_err("%pOFn: syscon lookup failed\n", dev->of_node);
<------><------>return PTR_ERR(syscon);
<------>}
 
<------>err = register_restart_handler(&axxia_restart_nb);
<------>if (err)
<------><------>dev_err(dev, "cannot register restart handler (err=%d)\n", err);
 
<------>return err;
}
 
static const struct of_device_id of_axxia_reset_match[] = {
<------>{ .compatible = "lsi,axm55xx-reset", },
<------>{},
};
MODULE_DEVICE_TABLE(of, of_axxia_reset_match);
 
static struct platform_driver axxia_reset_driver = {
<------>.probe = axxia_reset_probe,
<------>.driver = {
<------><------>.name = "axxia-reset",
<------><------>.of_match_table = of_match_ptr(of_axxia_reset_match),
<------>},
};
 
static int __init axxia_reset_init(void)
{
<------>return platform_driver_register(&axxia_reset_driver);
}
device_initcall(axxia_reset_init);