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 
22 struct da9052_onkey {
23 	struct da9052 *da9052;
24 	struct input_dev *input;
25 	struct delayed_work work;
26 };
27 
28 static 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 
58 static 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 
66 static 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 
75 static 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 
124 err_free_irq:
125 	da9052_free_irq(onkey->da9052, DA9052_IRQ_NONKEY, onkey);
126 	cancel_delayed_work_sync(&onkey->work);
127 err_free_mem:
128 	input_free_device(input_dev);
129 	kfree(onkey);
130 
131 	return error;
132 }
133 
134 static 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 
147 static struct platform_driver da9052_onkey_driver = {
148 	.probe	= da9052_onkey_probe,
149 	.remove	= da9052_onkey_remove,
150 	.driver = {
151 		.name	= "da9052-onkey",
152 	},
153 };
154 module_platform_driver(da9052_onkey_driver);
155 
156 MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
157 MODULE_DESCRIPTION("Onkey driver for DA9052");
158 MODULE_LICENSE("GPL");
159 MODULE_ALIAS("platform:da9052-onkey");
160