xref: /openbmc/linux/drivers/input/misc/pcap_keys.c (revision 9cfc5c90)
1 /*
2  *  Input driver for PCAP events:
3  *   * Power key
4  *   * Headphone button
5  *
6  *  Copyright (c) 2008,2009 Ilya Petrov <ilya.muromec@gmail.com>
7  *
8  *  This program is free software; you can redistribute it and/or modify
9  *  it under the terms of the GNU General Public License version 2 as
10  *  published by the Free Software Foundation.
11  *
12  */
13 
14 #include <linux/module.h>
15 #include <linux/interrupt.h>
16 #include <linux/platform_device.h>
17 #include <linux/input.h>
18 #include <linux/mfd/ezx-pcap.h>
19 #include <linux/slab.h>
20 
21 struct pcap_keys {
22 	struct pcap_chip *pcap;
23 	struct input_dev *input;
24 };
25 
26 /* PCAP2 interrupts us on keypress */
27 static irqreturn_t pcap_keys_handler(int irq, void *_pcap_keys)
28 {
29 	struct pcap_keys *pcap_keys = _pcap_keys;
30 	int pirq = irq_to_pcap(pcap_keys->pcap, irq);
31 	u32 pstat;
32 
33 	ezx_pcap_read(pcap_keys->pcap, PCAP_REG_PSTAT, &pstat);
34 	pstat &= 1 << pirq;
35 
36 	switch (pirq) {
37 	case PCAP_IRQ_ONOFF:
38 		input_report_key(pcap_keys->input, KEY_POWER, !pstat);
39 		break;
40 	case PCAP_IRQ_MIC:
41 		input_report_key(pcap_keys->input, KEY_HP, !pstat);
42 		break;
43 	}
44 
45 	input_sync(pcap_keys->input);
46 
47 	return IRQ_HANDLED;
48 }
49 
50 static int pcap_keys_probe(struct platform_device *pdev)
51 {
52 	int err = -ENOMEM;
53 	struct pcap_keys *pcap_keys;
54 	struct input_dev *input_dev;
55 
56 	pcap_keys = kmalloc(sizeof(struct pcap_keys), GFP_KERNEL);
57 	if (!pcap_keys)
58 		return err;
59 
60 	pcap_keys->pcap = dev_get_drvdata(pdev->dev.parent);
61 
62 	input_dev = input_allocate_device();
63 	if (!input_dev)
64 		goto fail;
65 
66 	pcap_keys->input = input_dev;
67 
68 	platform_set_drvdata(pdev, pcap_keys);
69 	input_dev->name = pdev->name;
70 	input_dev->phys = "pcap-keys/input0";
71 	input_dev->id.bustype = BUS_HOST;
72 	input_dev->dev.parent = &pdev->dev;
73 
74 	__set_bit(EV_KEY, input_dev->evbit);
75 	__set_bit(KEY_POWER, input_dev->keybit);
76 	__set_bit(KEY_HP, input_dev->keybit);
77 
78 	err = input_register_device(input_dev);
79 	if (err)
80 		goto fail_allocate;
81 
82 	err = request_irq(pcap_to_irq(pcap_keys->pcap, PCAP_IRQ_ONOFF),
83 			pcap_keys_handler, 0, "Power key", pcap_keys);
84 	if (err)
85 		goto fail_register;
86 
87 	err = request_irq(pcap_to_irq(pcap_keys->pcap, PCAP_IRQ_MIC),
88 			pcap_keys_handler, 0, "Headphone button", pcap_keys);
89 	if (err)
90 		goto fail_pwrkey;
91 
92 	return 0;
93 
94 fail_pwrkey:
95 	free_irq(pcap_to_irq(pcap_keys->pcap, PCAP_IRQ_ONOFF), pcap_keys);
96 fail_register:
97 	input_unregister_device(input_dev);
98 	goto fail;
99 fail_allocate:
100 	input_free_device(input_dev);
101 fail:
102 	kfree(pcap_keys);
103 	return err;
104 }
105 
106 static int pcap_keys_remove(struct platform_device *pdev)
107 {
108 	struct pcap_keys *pcap_keys = platform_get_drvdata(pdev);
109 
110 	free_irq(pcap_to_irq(pcap_keys->pcap, PCAP_IRQ_ONOFF), pcap_keys);
111 	free_irq(pcap_to_irq(pcap_keys->pcap, PCAP_IRQ_MIC), pcap_keys);
112 
113 	input_unregister_device(pcap_keys->input);
114 	kfree(pcap_keys);
115 
116 	return 0;
117 }
118 
119 static struct platform_driver pcap_keys_device_driver = {
120 	.probe		= pcap_keys_probe,
121 	.remove		= pcap_keys_remove,
122 	.driver		= {
123 		.name	= "pcap-keys",
124 	}
125 };
126 module_platform_driver(pcap_keys_device_driver);
127 
128 MODULE_DESCRIPTION("Motorola PCAP2 input events driver");
129 MODULE_AUTHOR("Ilya Petrov <ilya.muromec@gmail.com>");
130 MODULE_LICENSE("GPL");
131 MODULE_ALIAS("platform:pcap_keys");
132