1// SPDX-License-Identifier: GPL-2.0-only
 2/*
 3 * Power off driver for ams AS3722 device.
 4 *
 5 * Copyright (c) 2013, NVIDIA CORPORATION.  All rights reserved.
 6 *
 7 * Author: Laxman Dewangan <ldewangan@nvidia.com>
 8 */
 9
10#include <linux/mfd/as3722.h>
11#include <linux/module.h>
12#include <linux/of.h>
13#include <linux/platform_device.h>
14#include <linux/slab.h>
15
16struct as3722_poweroff {
17	struct device *dev;
18	struct as3722 *as3722;
19};
20
21static struct as3722_poweroff *as3722_pm_poweroff;
22
23static void as3722_pm_power_off(void)
24{
25	int ret;
26
27	if (!as3722_pm_poweroff) {
28		pr_err("AS3722 poweroff is not initialised\n");
29		return;
30	}
31
32	ret = as3722_update_bits(as3722_pm_poweroff->as3722,
33		AS3722_RESET_CONTROL_REG, AS3722_POWER_OFF, AS3722_POWER_OFF);
34	if (ret < 0)
35		dev_err(as3722_pm_poweroff->dev,
36			"RESET_CONTROL_REG update failed, %d\n", ret);
37}
38
39static int as3722_poweroff_probe(struct platform_device *pdev)
40{
41	struct as3722_poweroff *as3722_poweroff;
42	struct device_node *np = pdev->dev.parent->of_node;
43
44	if (!np)
45		return -EINVAL;
46
47	if (!of_property_read_bool(np, "ams,system-power-controller"))
48		return 0;
49
50	as3722_poweroff = devm_kzalloc(&pdev->dev, sizeof(*as3722_poweroff),
51				GFP_KERNEL);
52	if (!as3722_poweroff)
53		return -ENOMEM;
54
55	as3722_poweroff->as3722 = dev_get_drvdata(pdev->dev.parent);
56	as3722_poweroff->dev = &pdev->dev;
57	as3722_pm_poweroff = as3722_poweroff;
58	if (!pm_power_off)
59		pm_power_off = as3722_pm_power_off;
60
61	return 0;
62}
63
64static void as3722_poweroff_remove(struct platform_device *pdev)
65{
66	if (pm_power_off == as3722_pm_power_off)
67		pm_power_off = NULL;
68	as3722_pm_poweroff = NULL;
69}
70
71static struct platform_driver as3722_poweroff_driver = {
72	.driver = {
73		.name = "as3722-power-off",
74	},
75	.probe = as3722_poweroff_probe,
76	.remove_new = as3722_poweroff_remove,
77};
78
79module_platform_driver(as3722_poweroff_driver);
80
81MODULE_DESCRIPTION("Power off driver for ams AS3722 PMIC Device");
82MODULE_ALIAS("platform:as3722-power-off");
83MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");