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 
18 struct da9052_onkey {
19 	struct da9052 *da9052;
20 	struct input_dev *input;
21 	struct delayed_work work;
22 };
23 
24 static 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 
54 static 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 
62 static 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 
71 static 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 
120 err_free_irq:
121 	da9052_free_irq(onkey->da9052, DA9052_IRQ_NONKEY, onkey);
122 	cancel_delayed_work_sync(&onkey->work);
123 err_free_mem:
124 	input_free_device(input_dev);
125 	kfree(onkey);
126 
127 	return error;
128 }
129 
130 static int 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 	return 0;
141 }
142 
143 static struct platform_driver da9052_onkey_driver = {
144 	.probe	= da9052_onkey_probe,
145 	.remove	= da9052_onkey_remove,
146 	.driver = {
147 		.name	= "da9052-onkey",
148 	},
149 };
150 module_platform_driver(da9052_onkey_driver);
151 
152 MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
153 MODULE_DESCRIPTION("Onkey driver for DA9052");
154 MODULE_LICENSE("GPL");
155 MODULE_ALIAS("platform:da9052-onkey");
156