1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  *  GPIO vibrator driver
4  *
5  *  Copyright (C) 2019 Luca Weiss <luca@z3ntu.xyz>
6  *
7  *  Based on PWM vibrator driver:
8  *  Copyright (C) 2017 Collabora Ltd.
9  *
10  *  Based on previous work from:
11  *  Copyright (C) 2012 Dmitry Torokhov <dmitry.torokhov@gmail.com>
12  *
13  *  Based on PWM beeper driver:
14  *  Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
15  */
16 
17 #include <linux/gpio/consumer.h>
18 #include <linux/input.h>
19 #include <linux/kernel.h>
20 #include <linux/module.h>
21 #include <linux/of_device.h>
22 #include <linux/platform_device.h>
23 #include <linux/property.h>
24 #include <linux/regulator/consumer.h>
25 #include <linux/slab.h>
26 
27 struct gpio_vibrator {
28 	struct input_dev *input;
29 	struct gpio_desc *gpio;
30 	struct regulator *vcc;
31 
32 	struct work_struct play_work;
33 	bool running;
34 	bool vcc_on;
35 };
36 
gpio_vibrator_start(struct gpio_vibrator * vibrator)37 static int gpio_vibrator_start(struct gpio_vibrator *vibrator)
38 {
39 	struct device *pdev = vibrator->input->dev.parent;
40 	int err;
41 
42 	if (!vibrator->vcc_on) {
43 		err = regulator_enable(vibrator->vcc);
44 		if (err) {
45 			dev_err(pdev, "failed to enable regulator: %d\n", err);
46 			return err;
47 		}
48 		vibrator->vcc_on = true;
49 	}
50 
51 	gpiod_set_value_cansleep(vibrator->gpio, 1);
52 
53 	return 0;
54 }
55 
gpio_vibrator_stop(struct gpio_vibrator * vibrator)56 static void gpio_vibrator_stop(struct gpio_vibrator *vibrator)
57 {
58 	gpiod_set_value_cansleep(vibrator->gpio, 0);
59 
60 	if (vibrator->vcc_on) {
61 		regulator_disable(vibrator->vcc);
62 		vibrator->vcc_on = false;
63 	}
64 }
65 
gpio_vibrator_play_work(struct work_struct * work)66 static void gpio_vibrator_play_work(struct work_struct *work)
67 {
68 	struct gpio_vibrator *vibrator =
69 		container_of(work, struct gpio_vibrator, play_work);
70 
71 	if (vibrator->running)
72 		gpio_vibrator_start(vibrator);
73 	else
74 		gpio_vibrator_stop(vibrator);
75 }
76 
gpio_vibrator_play_effect(struct input_dev * dev,void * data,struct ff_effect * effect)77 static int gpio_vibrator_play_effect(struct input_dev *dev, void *data,
78 				     struct ff_effect *effect)
79 {
80 	struct gpio_vibrator *vibrator = input_get_drvdata(dev);
81 	int level;
82 
83 	level = effect->u.rumble.strong_magnitude;
84 	if (!level)
85 		level = effect->u.rumble.weak_magnitude;
86 
87 	vibrator->running = level;
88 	schedule_work(&vibrator->play_work);
89 
90 	return 0;
91 }
92 
gpio_vibrator_close(struct input_dev * input)93 static void gpio_vibrator_close(struct input_dev *input)
94 {
95 	struct gpio_vibrator *vibrator = input_get_drvdata(input);
96 
97 	cancel_work_sync(&vibrator->play_work);
98 	gpio_vibrator_stop(vibrator);
99 	vibrator->running = false;
100 }
101 
gpio_vibrator_probe(struct platform_device * pdev)102 static int gpio_vibrator_probe(struct platform_device *pdev)
103 {
104 	struct gpio_vibrator *vibrator;
105 	int err;
106 
107 	vibrator = devm_kzalloc(&pdev->dev, sizeof(*vibrator), GFP_KERNEL);
108 	if (!vibrator)
109 		return -ENOMEM;
110 
111 	vibrator->input = devm_input_allocate_device(&pdev->dev);
112 	if (!vibrator->input)
113 		return -ENOMEM;
114 
115 	vibrator->vcc = devm_regulator_get(&pdev->dev, "vcc");
116 	err = PTR_ERR_OR_ZERO(vibrator->vcc);
117 	if (err) {
118 		if (err != -EPROBE_DEFER)
119 			dev_err(&pdev->dev, "Failed to request regulator: %d\n",
120 				err);
121 		return err;
122 	}
123 
124 	vibrator->gpio = devm_gpiod_get(&pdev->dev, "enable", GPIOD_OUT_LOW);
125 	err = PTR_ERR_OR_ZERO(vibrator->gpio);
126 	if (err) {
127 		if (err != -EPROBE_DEFER)
128 			dev_err(&pdev->dev, "Failed to request main gpio: %d\n",
129 				err);
130 		return err;
131 	}
132 
133 	INIT_WORK(&vibrator->play_work, gpio_vibrator_play_work);
134 
135 	vibrator->input->name = "gpio-vibrator";
136 	vibrator->input->id.bustype = BUS_HOST;
137 	vibrator->input->close = gpio_vibrator_close;
138 
139 	input_set_drvdata(vibrator->input, vibrator);
140 	input_set_capability(vibrator->input, EV_FF, FF_RUMBLE);
141 
142 	err = input_ff_create_memless(vibrator->input, NULL,
143 				      gpio_vibrator_play_effect);
144 	if (err) {
145 		dev_err(&pdev->dev, "Couldn't create FF dev: %d\n", err);
146 		return err;
147 	}
148 
149 	err = input_register_device(vibrator->input);
150 	if (err) {
151 		dev_err(&pdev->dev, "Couldn't register input dev: %d\n", err);
152 		return err;
153 	}
154 
155 	platform_set_drvdata(pdev, vibrator);
156 
157 	return 0;
158 }
159 
gpio_vibrator_suspend(struct device * dev)160 static int __maybe_unused gpio_vibrator_suspend(struct device *dev)
161 {
162 	struct platform_device *pdev = to_platform_device(dev);
163 	struct gpio_vibrator *vibrator = platform_get_drvdata(pdev);
164 
165 	cancel_work_sync(&vibrator->play_work);
166 	if (vibrator->running)
167 		gpio_vibrator_stop(vibrator);
168 
169 	return 0;
170 }
171 
gpio_vibrator_resume(struct device * dev)172 static int __maybe_unused gpio_vibrator_resume(struct device *dev)
173 {
174 	struct platform_device *pdev = to_platform_device(dev);
175 	struct gpio_vibrator *vibrator = platform_get_drvdata(pdev);
176 
177 	if (vibrator->running)
178 		gpio_vibrator_start(vibrator);
179 
180 	return 0;
181 }
182 
183 static SIMPLE_DEV_PM_OPS(gpio_vibrator_pm_ops,
184 			 gpio_vibrator_suspend, gpio_vibrator_resume);
185 
186 #ifdef CONFIG_OF
187 static const struct of_device_id gpio_vibra_dt_match_table[] = {
188 	{ .compatible = "gpio-vibrator" },
189 	{}
190 };
191 MODULE_DEVICE_TABLE(of, gpio_vibra_dt_match_table);
192 #endif
193 
194 static struct platform_driver gpio_vibrator_driver = {
195 	.probe	= gpio_vibrator_probe,
196 	.driver	= {
197 		.name	= "gpio-vibrator",
198 		.pm	= &gpio_vibrator_pm_ops,
199 		.of_match_table = of_match_ptr(gpio_vibra_dt_match_table),
200 	},
201 };
202 module_platform_driver(gpio_vibrator_driver);
203 
204 MODULE_AUTHOR("Luca Weiss <luca@z3ntu.xy>");
205 MODULE_DESCRIPTION("GPIO vibrator driver");
206 MODULE_LICENSE("GPL");
207 MODULE_ALIAS("platform:gpio-vibrator");
208