1// SPDX-License-Identifier: GPL-2.0-only
 2/*
 3 * Reset driver for Axxia devices
 4 *
 5 * Copyright (C) 2014 LSI
 6 */
 7#include <linux/init.h>
 8#include <linux/err.h>
 9#include <linux/io.h>
10#include <linux/kernel.h>
11#include <linux/mfd/syscon.h>
12#include <linux/module.h>
13#include <linux/notifier.h>
14#include <linux/of.h>
15#include <linux/platform_device.h>
16#include <linux/reboot.h>
17#include <linux/regmap.h>
18
19#define SC_CRIT_WRITE_KEY	0x1000
20#define SC_LATCH_ON_RESET	0x1004
21#define SC_RESET_CONTROL	0x1008
22#define   RSTCTL_RST_ZERO	(1<<3)
23#define   RSTCTL_RST_FAB	(1<<2)
24#define   RSTCTL_RST_CHIP	(1<<1)
25#define   RSTCTL_RST_SYS	(1<<0)
26#define SC_EFUSE_INT_STATUS	0x180c
27#define   EFUSE_READ_DONE	(1<<31)
28
29static struct regmap *syscon;
30
31static int axxia_restart_handler(struct notifier_block *this,
32				 unsigned long mode, void *cmd)
33{
34	/* Access Key (0xab) */
35	regmap_write(syscon, SC_CRIT_WRITE_KEY, 0xab);
36	/* Select internal boot from 0xffff0000 */
37	regmap_write(syscon, SC_LATCH_ON_RESET, 0x00000040);
38	/* Assert ResetReadDone (to avoid hanging in boot ROM) */
39	regmap_write(syscon, SC_EFUSE_INT_STATUS, EFUSE_READ_DONE);
40	/* Assert chip reset */
41	regmap_update_bits(syscon, SC_RESET_CONTROL,
42			   RSTCTL_RST_CHIP, RSTCTL_RST_CHIP);
43
44	return NOTIFY_DONE;
45}
46
47static struct notifier_block axxia_restart_nb = {
48	.notifier_call = axxia_restart_handler,
49	.priority = 128,
50};
51
52static int axxia_reset_probe(struct platform_device *pdev)
53{
54	struct device *dev = &pdev->dev;
55	int err;
56
57	syscon = syscon_regmap_lookup_by_phandle(dev->of_node, "syscon");
58	if (IS_ERR(syscon)) {
59		pr_err("%pOFn: syscon lookup failed\n", dev->of_node);
60		return PTR_ERR(syscon);
61	}
62
63	err = register_restart_handler(&axxia_restart_nb);
64	if (err)
65		dev_err(dev, "cannot register restart handler (err=%d)\n", err);
66
67	return err;
68}
69
70static const struct of_device_id of_axxia_reset_match[] = {
71	{ .compatible = "lsi,axm55xx-reset", },
72	{},
73};
74MODULE_DEVICE_TABLE(of, of_axxia_reset_match);
75
76static struct platform_driver axxia_reset_driver = {
77	.probe = axxia_reset_probe,
78	.driver = {
79		.name = "axxia-reset",
80		.of_match_table = of_match_ptr(of_axxia_reset_match),
81	},
82};
83builtin_platform_driver(axxia_reset_driver);
 
 
 
 
 

 1// SPDX-License-Identifier: GPL-2.0-only
 2/*
 3 * Reset driver for Axxia devices
 4 *
 5 * Copyright (C) 2014 LSI
 6 */
 7#include <linux/init.h>
 8#include <linux/err.h>
 9#include <linux/io.h>
10#include <linux/kernel.h>
11#include <linux/mfd/syscon.h>
12#include <linux/module.h>
13#include <linux/notifier.h>
14#include <linux/of.h>
15#include <linux/platform_device.h>
16#include <linux/reboot.h>
17#include <linux/regmap.h>
18
19#define SC_CRIT_WRITE_KEY	0x1000
20#define SC_LATCH_ON_RESET	0x1004
21#define SC_RESET_CONTROL	0x1008
22#define   RSTCTL_RST_ZERO	(1<<3)
23#define   RSTCTL_RST_FAB	(1<<2)
24#define   RSTCTL_RST_CHIP	(1<<1)
25#define   RSTCTL_RST_SYS	(1<<0)
26#define SC_EFUSE_INT_STATUS	0x180c
27#define   EFUSE_READ_DONE	(1<<31)
28
29static struct regmap *syscon;
30
31static int axxia_restart_handler(struct notifier_block *this,
32				 unsigned long mode, void *cmd)
33{
34	/* Access Key (0xab) */
35	regmap_write(syscon, SC_CRIT_WRITE_KEY, 0xab);
36	/* Select internal boot from 0xffff0000 */
37	regmap_write(syscon, SC_LATCH_ON_RESET, 0x00000040);
38	/* Assert ResetReadDone (to avoid hanging in boot ROM) */
39	regmap_write(syscon, SC_EFUSE_INT_STATUS, EFUSE_READ_DONE);
40	/* Assert chip reset */
41	regmap_update_bits(syscon, SC_RESET_CONTROL,
42			   RSTCTL_RST_CHIP, RSTCTL_RST_CHIP);
43
44	return NOTIFY_DONE;
45}
46
47static struct notifier_block axxia_restart_nb = {
48	.notifier_call = axxia_restart_handler,
49	.priority = 128,
50};
51
52static int axxia_reset_probe(struct platform_device *pdev)
53{
54	struct device *dev = &pdev->dev;
55	int err;
56
57	syscon = syscon_regmap_lookup_by_phandle(dev->of_node, "syscon");
58	if (IS_ERR(syscon)) {
59		pr_err("%pOFn: syscon lookup failed\n", dev->of_node);
60		return PTR_ERR(syscon);
61	}
62
63	err = register_restart_handler(&axxia_restart_nb);
64	if (err)
65		dev_err(dev, "cannot register restart handler (err=%d)\n", err);
66
67	return err;
68}
69
70static const struct of_device_id of_axxia_reset_match[] = {
71	{ .compatible = "lsi,axm55xx-reset", },
72	{},
73};
74MODULE_DEVICE_TABLE(of, of_axxia_reset_match);
75
76static struct platform_driver axxia_reset_driver = {
77	.probe = axxia_reset_probe,
78	.driver = {
79		.name = "axxia-reset",
80		.of_match_table = of_match_ptr(of_axxia_reset_match),
81	},
82};
83
84static int __init axxia_reset_init(void)
85{
86	return platform_driver_register(&axxia_reset_driver);
87}
88device_initcall(axxia_reset_init);