1 /*
2  * Power off driver for ams AS3722 device.
3  *
4  * Copyright (c) 2013, NVIDIA CORPORATION.  All rights reserved.
5  *
6  * Author: Laxman Dewangan <ldewangan@nvidia.com>
7  *
8  * This program is free software; you can redistribute it and/or modify it
9  * under the terms and conditions of the GNU General Public License,
10  * version 2, as published by the Free Software Foundation.
11  *
12  * This program is distributed in the hope it will be useful, but WITHOUT
13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
15  * more details.
16  */
17 
18 #include <linux/mfd/as3722.h>
19 #include <linux/module.h>
20 #include <linux/of.h>
21 #include <linux/of_device.h>
22 #include <linux/platform_device.h>
23 #include <linux/slab.h>
24 
25 struct as3722_poweroff {
26 	struct device *dev;
27 	struct as3722 *as3722;
28 };
29 
30 static struct as3722_poweroff *as3722_pm_poweroff;
31 
32 static void as3722_pm_power_off(void)
33 {
34 	int ret;
35 
36 	if (!as3722_pm_poweroff) {
37 		pr_err("AS3722 poweroff is not initialised\n");
38 		return;
39 	}
40 
41 	ret = as3722_update_bits(as3722_pm_poweroff->as3722,
42 		AS3722_RESET_CONTROL_REG, AS3722_POWER_OFF, AS3722_POWER_OFF);
43 	if (ret < 0)
44 		dev_err(as3722_pm_poweroff->dev,
45 			"RESET_CONTROL_REG update failed, %d\n", ret);
46 }
47 
48 static int as3722_poweroff_probe(struct platform_device *pdev)
49 {
50 	struct as3722_poweroff *as3722_poweroff;
51 	struct device_node *np = pdev->dev.parent->of_node;
52 
53 	if (!np)
54 		return -EINVAL;
55 
56 	if (!of_property_read_bool(np, "ams,system-power-controller"))
57 		return 0;
58 
59 	as3722_poweroff = devm_kzalloc(&pdev->dev, sizeof(*as3722_poweroff),
60 				GFP_KERNEL);
61 	if (!as3722_poweroff)
62 		return -ENOMEM;
63 
64 	as3722_poweroff->as3722 = dev_get_drvdata(pdev->dev.parent);
65 	as3722_poweroff->dev = &pdev->dev;
66 	as3722_pm_poweroff = as3722_poweroff;
67 	if (!pm_power_off)
68 		pm_power_off = as3722_pm_power_off;
69 
70 	return 0;
71 }
72 
73 static int as3722_poweroff_remove(struct platform_device *pdev)
74 {
75 	if (pm_power_off == as3722_pm_power_off)
76 		pm_power_off = NULL;
77 	as3722_pm_poweroff = NULL;
78 
79 	return 0;
80 }
81 
82 static struct platform_driver as3722_poweroff_driver = {
83 	.driver = {
84 		.name = "as3722-power-off",
85 	},
86 	.probe = as3722_poweroff_probe,
87 	.remove = as3722_poweroff_remove,
88 };
89 
90 module_platform_driver(as3722_poweroff_driver);
91 
92 MODULE_DESCRIPTION("Power off driver for ams AS3722 PMIC Device");
93 MODULE_ALIAS("platform:as3722-power-off");
94 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
95 MODULE_LICENSE("GPL v2");
96