1// SPDX-License-Identifier: GPL-2.0-or-later
 2/*
 3 * Generic Syscon Poweroff Driver
 4 *
 5 * Copyright (c) 2015, National Instruments Corp.
 6 * Author: Moritz Fischer <moritz.fischer@ettus.com>
 
 
 
 
 
 
 
 
 
 
 7 */
 8
 
 9#include <linux/delay.h>
10#include <linux/io.h>
11#include <linux/notifier.h>
12#include <linux/mfd/syscon.h>
13#include <linux/of.h>
 
14#include <linux/platform_device.h>
15#include <linux/pm.h>
16#include <linux/regmap.h>
17
18static struct regmap *map;
19static u32 offset;
20static u32 value;
21static u32 mask;
22
23static void syscon_poweroff(void)
24{
25	/* Issue the poweroff */
26	regmap_update_bits(map, offset, mask, value);
27
28	mdelay(1000);
29
30	pr_emerg("Unable to poweroff system\n");
31}
32
33static int syscon_poweroff_probe(struct platform_device *pdev)
34{
35	struct device *dev = &pdev->dev;
36	int mask_err, value_err;
37
38	map = syscon_regmap_lookup_by_phandle(dev->of_node, "regmap");
39	if (IS_ERR(map)) {
40		map = syscon_node_to_regmap(dev->parent->of_node);
41		if (IS_ERR(map)) {
42			dev_err(dev, "unable to get syscon");
43			return PTR_ERR(map);
44		}
45	}
46
47	if (of_property_read_u32(dev->of_node, "offset", &offset)) {
48		dev_err(dev, "unable to read 'offset'");
49		return -EINVAL;
50	}
51
52	value_err = of_property_read_u32(dev->of_node, "value", &value);
53	mask_err = of_property_read_u32(dev->of_node, "mask", &mask);
54	if (value_err && mask_err) {
55		dev_err(dev, "unable to read 'value' and 'mask'");
56		return -EINVAL;
57	}
58
59	if (value_err) {
60		/* support old binding */
61		value = mask;
62		mask = 0xFFFFFFFF;
63	} else if (mask_err) {
64		/* support value without mask*/
65		mask = 0xFFFFFFFF;
66	}
67
68	if (pm_power_off) {
69		dev_err(dev, "pm_power_off already claimed for %ps",
70			pm_power_off);
 
 
71		return -EBUSY;
72	}
73
74	pm_power_off = syscon_poweroff;
75
76	return 0;
77}
78
79static void syscon_poweroff_remove(struct platform_device *pdev)
80{
81	if (pm_power_off == syscon_poweroff)
82		pm_power_off = NULL;
 
 
83}
84
85static const struct of_device_id syscon_poweroff_of_match[] = {
86	{ .compatible = "syscon-poweroff" },
87	{}
88};
89
90static struct platform_driver syscon_poweroff_driver = {
91	.probe = syscon_poweroff_probe,
92	.remove_new = syscon_poweroff_remove,
93	.driver = {
94		.name = "syscon-poweroff",
95		.of_match_table = syscon_poweroff_of_match,
96	},
97};
98builtin_platform_driver(syscon_poweroff_driver);
 
 
 
 
 

 
  1/*
  2 * Generic Syscon Poweroff Driver
  3 *
  4 * Copyright (c) 2015, National Instruments Corp.
  5 * Author: Moritz Fischer <moritz.fischer@ettus.com>
  6 *
  7 * This program is free software; you can redistribute it and/or
  8 * modify it under the terms of the GNU General Public License as
  9 * published by the Free Software Foundation; either version 2 of
 10 * the License, or (at your option) any later version.
 11 *
 12 * This program is distributed in the hope that it will be useful,
 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 15 * GNU General Public License for more details.
 16 */
 17
 18#include <linux/kallsyms.h>
 19#include <linux/delay.h>
 20#include <linux/io.h>
 21#include <linux/notifier.h>
 22#include <linux/mfd/syscon.h>
 23#include <linux/of_address.h>
 24#include <linux/of_device.h>
 25#include <linux/platform_device.h>
 26#include <linux/pm.h>
 27#include <linux/regmap.h>
 28
 29static struct regmap *map;
 30static u32 offset;
 
 31static u32 mask;
 32
 33void syscon_poweroff(void)
 34{
 35	/* Issue the poweroff */
 36	regmap_write(map, offset, mask);
 37
 38	mdelay(1000);
 39
 40	pr_emerg("Unable to poweroff system\n");
 41}
 42
 43static int syscon_poweroff_probe(struct platform_device *pdev)
 44{
 45	char symname[KSYM_NAME_LEN];
 
 46
 47	map = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "regmap");
 48	if (IS_ERR(map)) {
 49		dev_err(&pdev->dev, "unable to get syscon");
 50		return PTR_ERR(map);
 
 
 
 51	}
 52
 53	if (of_property_read_u32(pdev->dev.of_node, "offset", &offset)) {
 54		dev_err(&pdev->dev, "unable to read 'offset'");
 55		return -EINVAL;
 56	}
 57
 58	if (of_property_read_u32(pdev->dev.of_node, "mask", &mask)) {
 59		dev_err(&pdev->dev, "unable to read 'mask'");
 
 
 60		return -EINVAL;
 61	}
 62
 
 
 
 
 
 
 
 
 
 63	if (pm_power_off) {
 64		lookup_symbol_name((ulong)pm_power_off, symname);
 65		dev_err(&pdev->dev,
 66		"pm_power_off already claimed %p %s",
 67		pm_power_off, symname);
 68		return -EBUSY;
 69	}
 70
 71	pm_power_off = syscon_poweroff;
 72
 73	return 0;
 74}
 75
 76static int syscon_poweroff_remove(struct platform_device *pdev)
 77{
 78	if (pm_power_off == syscon_poweroff)
 79		pm_power_off = NULL;
 80
 81	return 0;
 82}
 83
 84static const struct of_device_id syscon_poweroff_of_match[] = {
 85	{ .compatible = "syscon-poweroff" },
 86	{}
 87};
 88
 89static struct platform_driver syscon_poweroff_driver = {
 90	.probe = syscon_poweroff_probe,
 91	.remove = syscon_poweroff_remove,
 92	.driver = {
 93		.name = "syscon-poweroff",
 94		.of_match_table = syscon_poweroff_of_match,
 95	},
 96};
 97
 98static int __init syscon_poweroff_register(void)
 99{
100	return platform_driver_register(&syscon_poweroff_driver);
101}
102device_initcall(syscon_poweroff_register);