1 /**
2  * CPCAP Power Button Input Driver
3  *
4  * Copyright (C) 2017 Sebastian Reichel <sre@kernel.org>
5  *
6  * This file is subject to the terms and conditions of the GNU General
7  * Public License. See the file "COPYING" in the main directory of this
8  * archive for more details.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  */
15 
16 #include <linux/module.h>
17 #include <linux/init.h>
18 #include <linux/kernel.h>
19 #include <linux/errno.h>
20 #include <linux/input.h>
21 #include <linux/interrupt.h>
22 #include <linux/regmap.h>
23 #include <linux/of.h>
24 #include <linux/platform_device.h>
25 #include <linux/mfd/motorola-cpcap.h>
26 
27 #define CPCAP_IRQ_ON 23
28 #define CPCAP_IRQ_ON_BITMASK (1 << (CPCAP_IRQ_ON % 16))
29 
30 struct cpcap_power_button {
31 	struct regmap *regmap;
32 	struct input_dev *idev;
33 	struct device *dev;
34 };
35 
36 static irqreturn_t powerbutton_irq(int irq, void *_button)
37 {
38 	struct cpcap_power_button *button = _button;
39 	int val;
40 
41 	val = cpcap_sense_virq(button->regmap, irq);
42 	if (val < 0) {
43 		dev_err(button->dev, "irq read failed: %d", val);
44 		return IRQ_HANDLED;
45 	}
46 
47 	pm_wakeup_event(button->dev, 0);
48 	input_report_key(button->idev, KEY_POWER, val);
49 	input_sync(button->idev);
50 
51 	return IRQ_HANDLED;
52 }
53 
54 static int cpcap_power_button_probe(struct platform_device *pdev)
55 {
56 	struct cpcap_power_button *button;
57 	int irq;
58 	int err;
59 
60 	irq = platform_get_irq(pdev, 0);
61 	if (irq < 0)
62 		return irq;
63 
64 	button = devm_kmalloc(&pdev->dev, sizeof(*button), GFP_KERNEL);
65 	if (!button)
66 		return -ENOMEM;
67 
68 	button->idev = devm_input_allocate_device(&pdev->dev);
69 	if (!button->idev)
70 		return -ENOMEM;
71 
72 	button->regmap = dev_get_regmap(pdev->dev.parent, NULL);
73 	if (!button->regmap)
74 		return -ENODEV;
75 
76 	button->dev = &pdev->dev;
77 
78 	button->idev->name = "cpcap-pwrbutton";
79 	button->idev->phys = "cpcap-pwrbutton/input0";
80 	input_set_capability(button->idev, EV_KEY, KEY_POWER);
81 
82 	err = devm_request_threaded_irq(&pdev->dev, irq, NULL,
83 		powerbutton_irq, IRQF_ONESHOT, "cpcap_pwrbutton", button);
84 	if (err < 0) {
85 		dev_err(&pdev->dev, "IRQ request failed: %d\n", err);
86 		return err;
87 	}
88 
89 	err = input_register_device(button->idev);
90 	if (err) {
91 		dev_err(&pdev->dev, "Input register failed: %d\n", err);
92 		return err;
93 	}
94 
95 	device_init_wakeup(&pdev->dev, true);
96 
97 	return 0;
98 }
99 
100 #ifdef CONFIG_OF
101 static const struct of_device_id cpcap_pwrbutton_dt_match_table[] = {
102 	{ .compatible = "motorola,cpcap-pwrbutton" },
103 	{},
104 };
105 MODULE_DEVICE_TABLE(of, cpcap_pwrbutton_dt_match_table);
106 #endif
107 
108 static struct platform_driver cpcap_power_button_driver = {
109 	.probe		= cpcap_power_button_probe,
110 	.driver		= {
111 		.name	= "cpcap-pwrbutton",
112 		.of_match_table = of_match_ptr(cpcap_pwrbutton_dt_match_table),
113 	},
114 };
115 module_platform_driver(cpcap_power_button_driver);
116 
117 MODULE_ALIAS("platform:cpcap-pwrbutton");
118 MODULE_DESCRIPTION("CPCAP Power Button");
119 MODULE_LICENSE("GPL");
120 MODULE_AUTHOR("Sebastian Reichel <sre@kernel.org>");
121