1/*
2 * ON pin driver for Dialog DA9052 PMICs
3 *
4 * Copyright(c) 2012 Dialog Semiconductor Ltd.
5 *
6 * Author: David Dajun Chen <dchen@diasemi.com>
7 *
8 * This program is free software; you can redistribute  it and/or modify it
9 * under  the terms of  the GNU General  Public License as published by the
10 * Free Software Foundation;  either version 2 of the  License, or (at your
11 * option) any later version.
12 */
13
14#include <linux/input.h>
15#include <linux/module.h>
16#include <linux/platform_device.h>
17#include <linux/workqueue.h>
18
19#include <linux/mfd/da9052/da9052.h>
20#include <linux/mfd/da9052/reg.h>
21
22struct da9052_onkey {
23	struct da9052 *da9052;
24	struct input_dev *input;
25	struct delayed_work work;
26};
27
28static void da9052_onkey_query(struct da9052_onkey *onkey)
29{
30	int ret;
31
32	ret = da9052_reg_read(onkey->da9052, DA9052_STATUS_A_REG);
33	if (ret < 0) {
34		dev_err(onkey->da9052->dev,
35			"Failed to read onkey event err=%d\n", ret);
36	} else {
37		/*
38		 * Since interrupt for deassertion of ONKEY pin is not
39		 * generated, onkey event state determines the onkey
40		 * button state.
41		 */
42		bool pressed = !(ret & DA9052_STATUSA_NONKEY);
43
44		input_report_key(onkey->input, KEY_POWER, pressed);
45		input_sync(onkey->input);
46
47		/*
48		 * Interrupt is generated only when the ONKEY pin
49		 * is asserted.  Hence the deassertion of the pin
50		 * is simulated through work queue.
51		 */
52		if (pressed)
53			schedule_delayed_work(&onkey->work,
54						msecs_to_jiffies(50));
55	}
56}
57
58static void da9052_onkey_work(struct work_struct *work)
59{
60	struct da9052_onkey *onkey = container_of(work, struct da9052_onkey,
61						  work.work);
62
63	da9052_onkey_query(onkey);
64}
65
66static irqreturn_t da9052_onkey_irq(int irq, void *data)
67{
68	struct da9052_onkey *onkey = data;
69
70	da9052_onkey_query(onkey);
71
72	return IRQ_HANDLED;
73}
74
75static int da9052_onkey_probe(struct platform_device *pdev)
76{
77	struct da9052 *da9052 = dev_get_drvdata(pdev->dev.parent);
78	struct da9052_onkey *onkey;
79	struct input_dev *input_dev;
80	int error;
81
82	if (!da9052) {
83		dev_err(&pdev->dev, "Failed to get the driver's data\n");
84		return -EINVAL;
85	}
86
87	onkey = kzalloc(sizeof(*onkey), GFP_KERNEL);
88	input_dev = input_allocate_device();
89	if (!onkey || !input_dev) {
90		dev_err(&pdev->dev, "Failed to allocate memory\n");
91		error = -ENOMEM;
92		goto err_free_mem;
93	}
94
95	onkey->input = input_dev;
96	onkey->da9052 = da9052;
97	INIT_DELAYED_WORK(&onkey->work, da9052_onkey_work);
98
99	input_dev->name = "da9052-onkey";
100	input_dev->phys = "da9052-onkey/input0";
101	input_dev->dev.parent = &pdev->dev;
102
103	input_dev->evbit[0] = BIT_MASK(EV_KEY);
104	__set_bit(KEY_POWER, input_dev->keybit);
105
106	error = da9052_request_irq(onkey->da9052, DA9052_IRQ_NONKEY, "ONKEY",
107			    da9052_onkey_irq, onkey);
108	if (error < 0) {
109		dev_err(onkey->da9052->dev,
110			"Failed to register ONKEY IRQ: %d\n", error);
111		goto err_free_mem;
112	}
113
114	error = input_register_device(onkey->input);
115	if (error) {
116		dev_err(&pdev->dev, "Unable to register input device, %d\n",
117			error);
118		goto err_free_irq;
119	}
120
121	platform_set_drvdata(pdev, onkey);
122	return 0;
123
124err_free_irq:
125	da9052_free_irq(onkey->da9052, DA9052_IRQ_NONKEY, onkey);
126	cancel_delayed_work_sync(&onkey->work);
127err_free_mem:
128	input_free_device(input_dev);
129	kfree(onkey);
130
131	return error;
132}
133
134static int da9052_onkey_remove(struct platform_device *pdev)
135{
136	struct da9052_onkey *onkey = platform_get_drvdata(pdev);
137
138	da9052_free_irq(onkey->da9052, DA9052_IRQ_NONKEY, onkey);
139	cancel_delayed_work_sync(&onkey->work);
140
141	input_unregister_device(onkey->input);
142	kfree(onkey);
143
144	return 0;
145}
146
147static struct platform_driver da9052_onkey_driver = {
148	.probe	= da9052_onkey_probe,
149	.remove	= da9052_onkey_remove,
150	.driver = {
151		.name	= "da9052-onkey",
152	},
153};
154module_platform_driver(da9052_onkey_driver);
155
156MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
157MODULE_DESCRIPTION("Onkey driver for DA9052");
158MODULE_LICENSE("GPL");
159MODULE_ALIAS("platform:da9052-onkey");
160