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/of_device.h>
14 #include <linux/platform_device.h>
15 #include <linux/slab.h>
16 
17 struct as3722_poweroff {
18 	struct device *dev;
19 	struct as3722 *as3722;
20 };
21 
22 static struct as3722_poweroff *as3722_pm_poweroff;
23 
24 static void as3722_pm_power_off(void)
25 {
26 	int ret;
27 
28 	if (!as3722_pm_poweroff) {
29 		pr_err("AS3722 poweroff is not initialised\n");
30 		return;
31 	}
32 
33 	ret = as3722_update_bits(as3722_pm_poweroff->as3722,
34 		AS3722_RESET_CONTROL_REG, AS3722_POWER_OFF, AS3722_POWER_OFF);
35 	if (ret < 0)
36 		dev_err(as3722_pm_poweroff->dev,
37 			"RESET_CONTROL_REG update failed, %d\n", ret);
38 }
39 
40 static int as3722_poweroff_probe(struct platform_device *pdev)
41 {
42 	struct as3722_poweroff *as3722_poweroff;
43 	struct device_node *np = pdev->dev.parent->of_node;
44 
45 	if (!np)
46 		return -EINVAL;
47 
48 	if (!of_property_read_bool(np, "ams,system-power-controller"))
49 		return 0;
50 
51 	as3722_poweroff = devm_kzalloc(&pdev->dev, sizeof(*as3722_poweroff),
52 				GFP_KERNEL);
53 	if (!as3722_poweroff)
54 		return -ENOMEM;
55 
56 	as3722_poweroff->as3722 = dev_get_drvdata(pdev->dev.parent);
57 	as3722_poweroff->dev = &pdev->dev;
58 	as3722_pm_poweroff = as3722_poweroff;
59 	if (!pm_power_off)
60 		pm_power_off = as3722_pm_power_off;
61 
62 	return 0;
63 }
64 
65 static int as3722_poweroff_remove(struct platform_device *pdev)
66 {
67 	if (pm_power_off == as3722_pm_power_off)
68 		pm_power_off = NULL;
69 	as3722_pm_poweroff = NULL;
70 
71 	return 0;
72 }
73 
74 static struct platform_driver as3722_poweroff_driver = {
75 	.driver = {
76 		.name = "as3722-power-off",
77 	},
78 	.probe = as3722_poweroff_probe,
79 	.remove = as3722_poweroff_remove,
80 };
81 
82 module_platform_driver(as3722_poweroff_driver);
83 
84 MODULE_DESCRIPTION("Power off driver for ams AS3722 PMIC Device");
85 MODULE_ALIAS("platform:as3722-power-off");
86 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
87