1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * ON pin driver for Dialog DA9055 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 
14 #include <linux/mfd/da9055/core.h>
15 #include <linux/mfd/da9055/reg.h>
16 
17 struct da9055_onkey {
18 	struct da9055 *da9055;
19 	struct input_dev *input;
20 	struct delayed_work work;
21 };
22 
23 static void da9055_onkey_query(struct da9055_onkey *onkey)
24 {
25 	int key_stat;
26 
27 	key_stat = da9055_reg_read(onkey->da9055, DA9055_REG_STATUS_A);
28 	if (key_stat < 0) {
29 		dev_err(onkey->da9055->dev,
30 			"Failed to read onkey event %d\n", key_stat);
31 	} else {
32 		key_stat &= DA9055_NOKEY_STS;
33 		/*
34 		 * Onkey status bit is cleared when onkey button is released.
35 		 */
36 		if (!key_stat) {
37 			input_report_key(onkey->input, KEY_POWER, 0);
38 			input_sync(onkey->input);
39 		}
40 	}
41 
42 	/*
43 	 * Interrupt is generated only when the ONKEY pin is asserted.
44 	 * Hence the deassertion of the pin is simulated through work queue.
45 	 */
46 	if (key_stat)
47 		schedule_delayed_work(&onkey->work, msecs_to_jiffies(10));
48 
49 }
50 
51 static void da9055_onkey_work(struct work_struct *work)
52 {
53 	struct da9055_onkey *onkey = container_of(work, struct da9055_onkey,
54 						  work.work);
55 
56 	da9055_onkey_query(onkey);
57 }
58 
59 static irqreturn_t da9055_onkey_irq(int irq, void *data)
60 {
61 	struct da9055_onkey *onkey = data;
62 
63 	input_report_key(onkey->input, KEY_POWER, 1);
64 	input_sync(onkey->input);
65 
66 	da9055_onkey_query(onkey);
67 
68 	return IRQ_HANDLED;
69 }
70 
71 static int da9055_onkey_probe(struct platform_device *pdev)
72 {
73 	struct da9055 *da9055 = dev_get_drvdata(pdev->dev.parent);
74 	struct da9055_onkey *onkey;
75 	struct input_dev *input_dev;
76 	int irq, err;
77 
78 	irq = platform_get_irq_byname(pdev, "ONKEY");
79 	if (irq < 0) {
80 		dev_err(&pdev->dev,
81 			"Failed to get an IRQ for input device, %d\n", irq);
82 		return -EINVAL;
83 	}
84 
85 	onkey = devm_kzalloc(&pdev->dev, sizeof(*onkey), GFP_KERNEL);
86 	if (!onkey) {
87 		dev_err(&pdev->dev, "Failed to allocate memory\n");
88 		return -ENOMEM;
89 	}
90 
91 	input_dev = input_allocate_device();
92 	if (!input_dev) {
93 		dev_err(&pdev->dev, "Failed to allocate memory\n");
94 		return -ENOMEM;
95 	}
96 
97 	onkey->input = input_dev;
98 	onkey->da9055 = da9055;
99 	input_dev->name = "da9055-onkey";
100 	input_dev->phys = "da9055-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 	INIT_DELAYED_WORK(&onkey->work, da9055_onkey_work);
107 
108 	err = request_threaded_irq(irq, NULL, da9055_onkey_irq,
109 				   IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
110 				   "ONKEY", onkey);
111 	if (err < 0) {
112 		dev_err(&pdev->dev,
113 			"Failed to register ONKEY IRQ %d, error = %d\n",
114 			irq, err);
115 		goto err_free_input;
116 	}
117 
118 	err = input_register_device(input_dev);
119 	if (err) {
120 		dev_err(&pdev->dev, "Unable to register input device, %d\n",
121 			err);
122 		goto err_free_irq;
123 	}
124 
125 	platform_set_drvdata(pdev, onkey);
126 
127 	return 0;
128 
129 err_free_irq:
130 	free_irq(irq, onkey);
131 	cancel_delayed_work_sync(&onkey->work);
132 err_free_input:
133 	input_free_device(input_dev);
134 
135 	return err;
136 }
137 
138 static int da9055_onkey_remove(struct platform_device *pdev)
139 {
140 	struct da9055_onkey *onkey = platform_get_drvdata(pdev);
141 	int irq = platform_get_irq_byname(pdev, "ONKEY");
142 
143 	irq = regmap_irq_get_virq(onkey->da9055->irq_data, irq);
144 	free_irq(irq, onkey);
145 	cancel_delayed_work_sync(&onkey->work);
146 	input_unregister_device(onkey->input);
147 
148 	return 0;
149 }
150 
151 static struct platform_driver da9055_onkey_driver = {
152 	.probe	= da9055_onkey_probe,
153 	.remove	= da9055_onkey_remove,
154 	.driver = {
155 		.name	= "da9055-onkey",
156 	},
157 };
158 
159 module_platform_driver(da9055_onkey_driver);
160 
161 MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
162 MODULE_DESCRIPTION("Onkey driver for DA9055");
163 MODULE_LICENSE("GPL");
164 MODULE_ALIAS("platform:da9055-onkey");
165