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/init.h>
15 #include <linux/input.h>
16 #include <linux/module.h>
17 #include <linux/platform_device.h>
18 
19 #include <linux/mfd/da9055/core.h>
20 #include <linux/mfd/da9055/reg.h>
21 
22 struct da9055_onkey {
23 	struct da9055 *da9055;
24 	struct input_dev *input;
25 	struct delayed_work work;
26 };
27 
28 static void da9055_onkey_query(struct da9055_onkey *onkey)
29 {
30 	int key_stat;
31 
32 	key_stat = da9055_reg_read(onkey->da9055, DA9055_REG_STATUS_A);
33 	if (key_stat < 0) {
34 		dev_err(onkey->da9055->dev,
35 			"Failed to read onkey event %d\n", key_stat);
36 	} else {
37 		key_stat &= DA9055_NOKEY_STS;
38 		/*
39 		 * Onkey status bit is cleared when onkey button is relased.
40 		 */
41 		if (!key_stat) {
42 			input_report_key(onkey->input, KEY_POWER, 0);
43 			input_sync(onkey->input);
44 		}
45 	}
46 
47 	/*
48 	 * Interrupt is generated only when the ONKEY pin is asserted.
49 	 * Hence the deassertion of the pin is simulated through work queue.
50 	 */
51 	if (key_stat)
52 		schedule_delayed_work(&onkey->work, msecs_to_jiffies(10));
53 
54 }
55 
56 static void da9055_onkey_work(struct work_struct *work)
57 {
58 	struct da9055_onkey *onkey = container_of(work, struct da9055_onkey,
59 						  work.work);
60 
61 	da9055_onkey_query(onkey);
62 }
63 
64 static irqreturn_t da9055_onkey_irq(int irq, void *data)
65 {
66 	struct da9055_onkey *onkey = data;
67 
68 	input_report_key(onkey->input, KEY_POWER, 1);
69 	input_sync(onkey->input);
70 
71 	da9055_onkey_query(onkey);
72 
73 	return IRQ_HANDLED;
74 }
75 
76 static int da9055_onkey_probe(struct platform_device *pdev)
77 {
78 	struct da9055 *da9055 = dev_get_drvdata(pdev->dev.parent);
79 	struct da9055_onkey *onkey;
80 	struct input_dev *input_dev;
81 	int irq, err;
82 
83 	irq = platform_get_irq_byname(pdev, "ONKEY");
84 	if (irq < 0) {
85 		dev_err(&pdev->dev,
86 			"Failed to get an IRQ for input device, %d\n", irq);
87 		return -EINVAL;
88 	}
89 
90 	onkey = devm_kzalloc(&pdev->dev, sizeof(*onkey), GFP_KERNEL);
91 	if (!onkey) {
92 		dev_err(&pdev->dev, "Failed to allocate memory\n");
93 		return -ENOMEM;
94 	}
95 
96 	input_dev = input_allocate_device();
97 	if (!input_dev) {
98 		dev_err(&pdev->dev, "Failed to allocate memory\n");
99 		return -ENOMEM;
100 	}
101 
102 	onkey->input = input_dev;
103 	onkey->da9055 = da9055;
104 	input_dev->name = "da9055-onkey";
105 	input_dev->phys = "da9055-onkey/input0";
106 	input_dev->dev.parent = &pdev->dev;
107 
108 	input_dev->evbit[0] = BIT_MASK(EV_KEY);
109 	__set_bit(KEY_POWER, input_dev->keybit);
110 
111 	INIT_DELAYED_WORK(&onkey->work, da9055_onkey_work);
112 
113 	irq = regmap_irq_get_virq(da9055->irq_data, irq);
114 	err = request_threaded_irq(irq, NULL, da9055_onkey_irq,
115 				   IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
116 				   "ONKEY", onkey);
117 	if (err < 0) {
118 		dev_err(&pdev->dev,
119 			"Failed to register ONKEY IRQ %d, error = %d\n",
120 			irq, err);
121 		goto err_free_input;
122 	}
123 
124 	err = input_register_device(input_dev);
125 	if (err) {
126 		dev_err(&pdev->dev, "Unable to register input device, %d\n",
127 			err);
128 		goto err_free_irq;
129 	}
130 
131 	platform_set_drvdata(pdev, onkey);
132 
133 	return 0;
134 
135 err_free_irq:
136 	free_irq(irq, onkey);
137 	cancel_delayed_work_sync(&onkey->work);
138 err_free_input:
139 	input_free_device(input_dev);
140 
141 	return err;
142 }
143 
144 static int da9055_onkey_remove(struct platform_device *pdev)
145 {
146 	struct da9055_onkey *onkey = platform_get_drvdata(pdev);
147 	int irq = platform_get_irq_byname(pdev, "ONKEY");
148 
149 	irq = regmap_irq_get_virq(onkey->da9055->irq_data, irq);
150 	free_irq(irq, onkey);
151 	cancel_delayed_work_sync(&onkey->work);
152 	input_unregister_device(onkey->input);
153 
154 	return 0;
155 }
156 
157 static struct platform_driver da9055_onkey_driver = {
158 	.probe	= da9055_onkey_probe,
159 	.remove	= da9055_onkey_remove,
160 	.driver = {
161 		.name	= "da9055-onkey",
162 		.owner	= THIS_MODULE,
163 	},
164 };
165 
166 module_platform_driver(da9055_onkey_driver);
167 
168 MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
169 MODULE_DESCRIPTION("Onkey driver for DA9055");
170 MODULE_LICENSE("GPL");
171 MODULE_ALIAS("platform:da9055-onkey");
172