1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Generic Syscon Poweroff Driver
5 * Copyright (c) 2015, National Instruments Corp.
6 * Author: Moritz Fischer <moritz.fischer@ettus.com>
9 #include <linux/delay.h>
11 #include <linux/notifier.h>
12 #include <linux/mfd/syscon.h>
14 #include <linux/platform_device.h>
16 #include <linux/regmap.h>
18 static struct regmap
*map
;
23 static void syscon_poweroff(void)
25 /* Issue the poweroff */
26 regmap_update_bits(map
, offset
, mask
, value
);
30 pr_emerg("Unable to poweroff system\n");
33 static int syscon_poweroff_probe(struct platform_device
*pdev
)
35 int mask_err
, value_err
;
37 map
= syscon_regmap_lookup_by_phandle(pdev
->dev
.of_node
, "regmap");
39 dev_err(&pdev
->dev
, "unable to get syscon");
43 if (of_property_read_u32(pdev
->dev
.of_node
, "offset", &offset
)) {
44 dev_err(&pdev
->dev
, "unable to read 'offset'");
48 value_err
= of_property_read_u32(pdev
->dev
.of_node
, "value", &value
);
49 mask_err
= of_property_read_u32(pdev
->dev
.of_node
, "mask", &mask
);
50 if (value_err
&& mask_err
) {
51 dev_err(&pdev
->dev
, "unable to read 'value' and 'mask'");
56 /* support old binding */
59 } else if (mask_err
) {
60 /* support value without mask*/
65 dev_err(&pdev
->dev
, "pm_power_off already claimed for %ps",
70 pm_power_off
= syscon_poweroff
;
75 static int syscon_poweroff_remove(struct platform_device
*pdev
)
77 if (pm_power_off
== syscon_poweroff
)
83 static const struct of_device_id syscon_poweroff_of_match
[] = {
84 { .compatible
= "syscon-poweroff" },
88 static struct platform_driver syscon_poweroff_driver
= {
89 .probe
= syscon_poweroff_probe
,
90 .remove
= syscon_poweroff_remove
,
92 .name
= "syscon-poweroff",
93 .of_match_table
= syscon_poweroff_of_match
,
97 static int __init
syscon_poweroff_register(void)
99 return platform_driver_register(&syscon_poweroff_driver
);
101 device_initcall(syscon_poweroff_register
);