1/*
2 * ON pin driver for Dialog DA9055 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
18#include <linux/mfd/da9055/core.h>
19#include <linux/mfd/da9055/reg.h>
20
21struct da9055_onkey {
22	struct da9055 *da9055;
23	struct input_dev *input;
24	struct delayed_work work;
25};
26
27static void da9055_onkey_query(struct da9055_onkey *onkey)
28{
29	int key_stat;
30
31	key_stat = da9055_reg_read(onkey->da9055, DA9055_REG_STATUS_A);
32	if (key_stat < 0) {
33		dev_err(onkey->da9055->dev,
34			"Failed to read onkey event %d\n", key_stat);
35	} else {
36		key_stat &= DA9055_NOKEY_STS;
37		/*
38		 * Onkey status bit is cleared when onkey button is released.
39		 */
40		if (!key_stat) {
41			input_report_key(onkey->input, KEY_POWER, 0);
42			input_sync(onkey->input);
43		}
44	}
45
46	/*
47	 * Interrupt is generated only when the ONKEY pin is asserted.
48	 * Hence the deassertion of the pin is simulated through work queue.
49	 */
50	if (key_stat)
51		schedule_delayed_work(&onkey->work, msecs_to_jiffies(10));
52
53}
54
55static void da9055_onkey_work(struct work_struct *work)
56{
57	struct da9055_onkey *onkey = container_of(work, struct da9055_onkey,
58						  work.work);
59
60	da9055_onkey_query(onkey);
61}
62
63static irqreturn_t da9055_onkey_irq(int irq, void *data)
64{
65	struct da9055_onkey *onkey = data;
66
67	input_report_key(onkey->input, KEY_POWER, 1);
68	input_sync(onkey->input);
69
70	da9055_onkey_query(onkey);
71
72	return IRQ_HANDLED;
73}
74
75static int da9055_onkey_probe(struct platform_device *pdev)
76{
77	struct da9055 *da9055 = dev_get_drvdata(pdev->dev.parent);
78	struct da9055_onkey *onkey;
79	struct input_dev *input_dev;
80	int irq, err;
81
82	irq = platform_get_irq_byname(pdev, "ONKEY");
83	if (irq < 0) {
84		dev_err(&pdev->dev,
85			"Failed to get an IRQ for input device, %d\n", irq);
86		return -EINVAL;
87	}
88
89	onkey = devm_kzalloc(&pdev->dev, sizeof(*onkey), GFP_KERNEL);
90	if (!onkey) {
91		dev_err(&pdev->dev, "Failed to allocate memory\n");
92		return -ENOMEM;
93	}
94
95	input_dev = input_allocate_device();
96	if (!input_dev) {
97		dev_err(&pdev->dev, "Failed to allocate memory\n");
98		return -ENOMEM;
99	}
100
101	onkey->input = input_dev;
102	onkey->da9055 = da9055;
103	input_dev->name = "da9055-onkey";
104	input_dev->phys = "da9055-onkey/input0";
105	input_dev->dev.parent = &pdev->dev;
106
107	input_dev->evbit[0] = BIT_MASK(EV_KEY);
108	__set_bit(KEY_POWER, input_dev->keybit);
109
110	INIT_DELAYED_WORK(&onkey->work, da9055_onkey_work);
111
112	err = request_threaded_irq(irq, NULL, da9055_onkey_irq,
113				   IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
114				   "ONKEY", onkey);
115	if (err < 0) {
116		dev_err(&pdev->dev,
117			"Failed to register ONKEY IRQ %d, error = %d\n",
118			irq, err);
119		goto err_free_input;
120	}
121
122	err = input_register_device(input_dev);
123	if (err) {
124		dev_err(&pdev->dev, "Unable to register input device, %d\n",
125			err);
126		goto err_free_irq;
127	}
128
129	platform_set_drvdata(pdev, onkey);
130
131	return 0;
132
133err_free_irq:
134	free_irq(irq, onkey);
135	cancel_delayed_work_sync(&onkey->work);
136err_free_input:
137	input_free_device(input_dev);
138
139	return err;
140}
141
142static int da9055_onkey_remove(struct platform_device *pdev)
143{
144	struct da9055_onkey *onkey = platform_get_drvdata(pdev);
145	int irq = platform_get_irq_byname(pdev, "ONKEY");
146
147	irq = regmap_irq_get_virq(onkey->da9055->irq_data, irq);
148	free_irq(irq, onkey);
149	cancel_delayed_work_sync(&onkey->work);
150	input_unregister_device(onkey->input);
151
152	return 0;
153}
154
155static struct platform_driver da9055_onkey_driver = {
156	.probe	= da9055_onkey_probe,
157	.remove	= da9055_onkey_remove,
158	.driver = {
159		.name	= "da9055-onkey",
160	},
161};
162
163module_platform_driver(da9055_onkey_driver);
164
165MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
166MODULE_DESCRIPTION("Onkey driver for DA9055");
167MODULE_LICENSE("GPL");
168MODULE_ALIAS("platform:da9055-onkey");
169