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/init.h>
15 #include <linux/input.h>
16 #include <linux/module.h>
17 #include <linux/platform_device.h>
18 #include <linux/workqueue.h>
19 
20 #include <linux/mfd/da9052/da9052.h>
21 #include <linux/mfd/da9052/reg.h>
22 
23 struct da9052_onkey {
24 	struct da9052 *da9052;
25 	struct input_dev *input;
26 	struct delayed_work work;
27 	unsigned int irq;
28 };
29 
30 static void da9052_onkey_query(struct da9052_onkey *onkey)
31 {
32 	int key_stat;
33 
34 	key_stat = da9052_reg_read(onkey->da9052, DA9052_EVENT_B_REG);
35 	if (key_stat < 0) {
36 		dev_err(onkey->da9052->dev,
37 			"Failed to read onkey event %d\n", key_stat);
38 	} else {
39 		/*
40 		 * Since interrupt for deassertion of ONKEY pin is not
41 		 * generated, onkey event state determines the onkey
42 		 * button state.
43 		 */
44 		key_stat &= DA9052_EVENTB_ENONKEY;
45 		input_report_key(onkey->input, KEY_POWER, key_stat);
46 		input_sync(onkey->input);
47 	}
48 
49 	/*
50 	 * Interrupt is generated only when the ONKEY pin is asserted.
51 	 * Hence the deassertion of the pin is simulated through work queue.
52 	 */
53 	if (key_stat)
54 		schedule_delayed_work(&onkey->work, msecs_to_jiffies(50));
55 }
56 
57 static void da9052_onkey_work(struct work_struct *work)
58 {
59 	struct da9052_onkey *onkey = container_of(work, struct da9052_onkey,
60 						  work.work);
61 
62 	da9052_onkey_query(onkey);
63 }
64 
65 static irqreturn_t da9052_onkey_irq(int irq, void *data)
66 {
67 	struct da9052_onkey *onkey = data;
68 
69 	da9052_onkey_query(onkey);
70 
71 	return IRQ_HANDLED;
72 }
73 
74 static int da9052_onkey_probe(struct platform_device *pdev)
75 {
76 	struct da9052 *da9052 = dev_get_drvdata(pdev->dev.parent);
77 	struct da9052_onkey *onkey;
78 	struct input_dev *input_dev;
79 	int irq;
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 	irq = platform_get_irq_byname(pdev, "ONKEY");
88 	if (irq < 0) {
89 		dev_err(&pdev->dev,
90 			"Failed to get an IRQ for input device, %d\n", irq);
91 		return -EINVAL;
92 	}
93 
94 	onkey = kzalloc(sizeof(*onkey), GFP_KERNEL);
95 	input_dev = input_allocate_device();
96 	if (!onkey || !input_dev) {
97 		dev_err(&pdev->dev, "Failed to allocate memory\n");
98 		error = -ENOMEM;
99 		goto err_free_mem;
100 	}
101 
102 	onkey->input = input_dev;
103 	onkey->da9052 = da9052;
104 	onkey->irq = irq;
105 	INIT_DELAYED_WORK(&onkey->work, da9052_onkey_work);
106 
107 	input_dev->name = "da9052-onkey";
108 	input_dev->phys = "da9052-onkey/input0";
109 	input_dev->dev.parent = &pdev->dev;
110 
111 	input_dev->evbit[0] = BIT_MASK(EV_KEY);
112 	__set_bit(KEY_POWER, input_dev->keybit);
113 
114 	error = request_threaded_irq(onkey->irq, NULL, da9052_onkey_irq,
115 				     IRQF_TRIGGER_LOW | IRQF_ONESHOT,
116 				     "ONKEY", onkey);
117 	if (error < 0) {
118 		dev_err(onkey->da9052->dev,
119 			"Failed to register ONKEY IRQ %d, error = %d\n",
120 			onkey->irq, error);
121 		goto err_free_mem;
122 	}
123 
124 	error = input_register_device(onkey->input);
125 	if (error) {
126 		dev_err(&pdev->dev, "Unable to register input device, %d\n",
127 			error);
128 		goto err_free_irq;
129 	}
130 
131 	platform_set_drvdata(pdev, onkey);
132 	return 0;
133 
134 err_free_irq:
135 	free_irq(onkey->irq, onkey);
136 	cancel_delayed_work_sync(&onkey->work);
137 err_free_mem:
138 	input_free_device(input_dev);
139 	kfree(onkey);
140 
141 	return error;
142 }
143 
144 static int da9052_onkey_remove(struct platform_device *pdev)
145 {
146 	struct da9052_onkey *onkey = platform_get_drvdata(pdev);
147 
148 	free_irq(onkey->irq, onkey);
149 	cancel_delayed_work_sync(&onkey->work);
150 
151 	input_unregister_device(onkey->input);
152 	kfree(onkey);
153 
154 	return 0;
155 }
156 
157 static struct platform_driver da9052_onkey_driver = {
158 	.probe	= da9052_onkey_probe,
159 	.remove	= da9052_onkey_remove,
160 	.driver = {
161 		.name	= "da9052-onkey",
162 		.owner	= THIS_MODULE,
163 	},
164 };
165 module_platform_driver(da9052_onkey_driver);
166 
167 MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
168 MODULE_DESCRIPTION("Onkey driver for DA9052");
169 MODULE_LICENSE("GPL");
170 MODULE_ALIAS("platform:da9052-onkey");
171