1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * ON pin driver for Dialog DA9052 PMICs
4 *
5 * Copyright(c) 2012 Dialog Semiconductor Ltd.
6 *
7 * Author: David Dajun Chen <dchen@diasemi.com>
8 */
9
10#include <linux/input.h>
11#include <linux/module.h>
12#include <linux/platform_device.h>
13#include <linux/workqueue.h>
14
15#include <linux/mfd/da9052/da9052.h>
16#include <linux/mfd/da9052/reg.h>
17
18struct da9052_onkey {
19	struct da9052 *da9052;
20	struct input_dev *input;
21	struct delayed_work work;
22};
23
24static void da9052_onkey_query(struct da9052_onkey *onkey)
25{
26	int ret;
27
28	ret = da9052_reg_read(onkey->da9052, DA9052_STATUS_A_REG);
29	if (ret < 0) {
30		dev_err(onkey->da9052->dev,
31			"Failed to read onkey event err=%d\n", ret);
32	} else {
33		/*
34		 * Since interrupt for deassertion of ONKEY pin is not
35		 * generated, onkey event state determines the onkey
36		 * button state.
37		 */
38		bool pressed = !(ret & DA9052_STATUSA_NONKEY);
39
40		input_report_key(onkey->input, KEY_POWER, pressed);
41		input_sync(onkey->input);
42
43		/*
44		 * Interrupt is generated only when the ONKEY pin
45		 * is asserted.  Hence the deassertion of the pin
46		 * is simulated through work queue.
47		 */
48		if (pressed)
49			schedule_delayed_work(&onkey->work,
50						msecs_to_jiffies(50));
51	}
52}
53
54static void da9052_onkey_work(struct work_struct *work)
55{
56	struct da9052_onkey *onkey = container_of(work, struct da9052_onkey,
57						  work.work);
58
59	da9052_onkey_query(onkey);
60}
61
62static irqreturn_t da9052_onkey_irq(int irq, void *data)
63{
64	struct da9052_onkey *onkey = data;
65
66	da9052_onkey_query(onkey);
67
68	return IRQ_HANDLED;
69}
70
71static int da9052_onkey_probe(struct platform_device *pdev)
72{
73	struct da9052 *da9052 = dev_get_drvdata(pdev->dev.parent);
74	struct da9052_onkey *onkey;
75	struct input_dev *input_dev;
76	int error;
77
78	if (!da9052) {
79		dev_err(&pdev->dev, "Failed to get the driver's data\n");
80		return -EINVAL;
81	}
82
83	onkey = kzalloc(sizeof(*onkey), GFP_KERNEL);
84	input_dev = input_allocate_device();
85	if (!onkey || !input_dev) {
86		dev_err(&pdev->dev, "Failed to allocate memory\n");
87		error = -ENOMEM;
88		goto err_free_mem;
89	}
90
91	onkey->input = input_dev;
92	onkey->da9052 = da9052;
93	INIT_DELAYED_WORK(&onkey->work, da9052_onkey_work);
94
95	input_dev->name = "da9052-onkey";
96	input_dev->phys = "da9052-onkey/input0";
97	input_dev->dev.parent = &pdev->dev;
98
99	input_dev->evbit[0] = BIT_MASK(EV_KEY);
100	__set_bit(KEY_POWER, input_dev->keybit);
101
102	error = da9052_request_irq(onkey->da9052, DA9052_IRQ_NONKEY, "ONKEY",
103			    da9052_onkey_irq, onkey);
104	if (error < 0) {
105		dev_err(onkey->da9052->dev,
106			"Failed to register ONKEY IRQ: %d\n", error);
107		goto err_free_mem;
108	}
109
110	error = input_register_device(onkey->input);
111	if (error) {
112		dev_err(&pdev->dev, "Unable to register input device, %d\n",
113			error);
114		goto err_free_irq;
115	}
116
117	platform_set_drvdata(pdev, onkey);
118	return 0;
119
120err_free_irq:
121	da9052_free_irq(onkey->da9052, DA9052_IRQ_NONKEY, onkey);
122	cancel_delayed_work_sync(&onkey->work);
123err_free_mem:
124	input_free_device(input_dev);
125	kfree(onkey);
126
127	return error;
128}
129
130static void da9052_onkey_remove(struct platform_device *pdev)
131{
132	struct da9052_onkey *onkey = platform_get_drvdata(pdev);
133
134	da9052_free_irq(onkey->da9052, DA9052_IRQ_NONKEY, onkey);
135	cancel_delayed_work_sync(&onkey->work);
136
137	input_unregister_device(onkey->input);
138	kfree(onkey);
139}
140
141static struct platform_driver da9052_onkey_driver = {
142	.probe	= da9052_onkey_probe,
143	.remove_new = da9052_onkey_remove,
144	.driver = {
145		.name	= "da9052-onkey",
146	},
147};
148module_platform_driver(da9052_onkey_driver);
149
150MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
151MODULE_DESCRIPTION("Onkey driver for DA9052");
152MODULE_LICENSE("GPL");
153MODULE_ALIAS("platform:da9052-onkey");
154