xref: /linux/drivers/power/reset/as3722-poweroff.c (revision e7d759f31ca295d589f7420719c311870bb3166f)
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 
16 struct as3722_poweroff {
17 	struct device *dev;
18 	struct as3722 *as3722;
19 };
20 
21 static struct as3722_poweroff *as3722_pm_poweroff;
22 
23 static 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 
39 static 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 
64 static 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 
71 static 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 
79 module_platform_driver(as3722_poweroff_driver);
80 
81 MODULE_DESCRIPTION("Power off driver for ams AS3722 PMIC Device");
82 MODULE_ALIAS("platform:as3722-power-off");
83 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
84