1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Regulator haptic driver
4  *
5  * Copyright (c) 2014 Samsung Electronics Co., Ltd.
6  * Author: Jaewon Kim <jaewon02.kim@samsung.com>
7  * Author: Hyunhee Kim <hyunhee.kim@samsung.com>
8  */
9 
10 #include <linux/input.h>
11 #include <linux/module.h>
12 #include <linux/of.h>
13 #include <linux/platform_data/regulator-haptic.h>
14 #include <linux/platform_device.h>
15 #include <linux/regulator/consumer.h>
16 #include <linux/slab.h>
17 
18 #define MAX_MAGNITUDE_SHIFT	16
19 
20 struct regulator_haptic {
21 	struct device *dev;
22 	struct input_dev *input_dev;
23 	struct regulator *regulator;
24 
25 	struct work_struct work;
26 	struct mutex mutex;
27 
28 	bool active;
29 	bool suspended;
30 
31 	unsigned int max_volt;
32 	unsigned int min_volt;
33 	unsigned int magnitude;
34 };
35 
36 static int regulator_haptic_toggle(struct regulator_haptic *haptic, bool on)
37 {
38 	int error;
39 
40 	if (haptic->active != on) {
41 
42 		error = on ? regulator_enable(haptic->regulator) :
43 			     regulator_disable(haptic->regulator);
44 		if (error) {
45 			dev_err(haptic->dev,
46 				"failed to switch regulator %s: %d\n",
47 				on ? "on" : "off", error);
48 			return error;
49 		}
50 
51 		haptic->active = on;
52 	}
53 
54 	return 0;
55 }
56 
57 static int regulator_haptic_set_voltage(struct regulator_haptic *haptic,
58 					 unsigned int magnitude)
59 {
60 	u64 volt_mag_multi;
61 	unsigned int intensity;
62 	int error;
63 
64 	volt_mag_multi = (u64)(haptic->max_volt - haptic->min_volt) * magnitude;
65 	intensity = (unsigned int)(volt_mag_multi >> MAX_MAGNITUDE_SHIFT);
66 
67 	error = regulator_set_voltage(haptic->regulator,
68 				      intensity + haptic->min_volt,
69 				      haptic->max_volt);
70 	if (error) {
71 		dev_err(haptic->dev, "cannot set regulator voltage to %d: %d\n",
72 			intensity + haptic->min_volt, error);
73 		return error;
74 	}
75 
76 	regulator_haptic_toggle(haptic, !!magnitude);
77 
78 	return 0;
79 }
80 
81 static void regulator_haptic_work(struct work_struct *work)
82 {
83 	struct regulator_haptic *haptic = container_of(work,
84 					struct regulator_haptic, work);
85 
86 	mutex_lock(&haptic->mutex);
87 
88 	if (!haptic->suspended)
89 		regulator_haptic_set_voltage(haptic, haptic->magnitude);
90 
91 	mutex_unlock(&haptic->mutex);
92 }
93 
94 static int regulator_haptic_play_effect(struct input_dev *input, void *data,
95 					struct ff_effect *effect)
96 {
97 	struct regulator_haptic *haptic = input_get_drvdata(input);
98 
99 	haptic->magnitude = effect->u.rumble.strong_magnitude;
100 	if (!haptic->magnitude)
101 		haptic->magnitude = effect->u.rumble.weak_magnitude;
102 
103 	schedule_work(&haptic->work);
104 
105 	return 0;
106 }
107 
108 static void regulator_haptic_close(struct input_dev *input)
109 {
110 	struct regulator_haptic *haptic = input_get_drvdata(input);
111 
112 	cancel_work_sync(&haptic->work);
113 	regulator_haptic_set_voltage(haptic, 0);
114 }
115 
116 static int __maybe_unused
117 regulator_haptic_parse_dt(struct device *dev, struct regulator_haptic *haptic)
118 {
119 	struct device_node *node;
120 	int error;
121 
122 	node = dev->of_node;
123 	if(!node) {
124 		dev_err(dev, "Missing device tree data\n");
125 		return -EINVAL;
126 	}
127 
128 	error = of_property_read_u32(node, "max-microvolt", &haptic->max_volt);
129 	if (error) {
130 		dev_err(dev, "cannot parse max-microvolt\n");
131 		return error;
132 	}
133 
134 	error = of_property_read_u32(node, "min-microvolt", &haptic->min_volt);
135 	if (error) {
136 		dev_err(dev, "cannot parse min-microvolt\n");
137 		return error;
138 	}
139 
140 	return 0;
141 }
142 
143 static int regulator_haptic_probe(struct platform_device *pdev)
144 {
145 	const struct regulator_haptic_data *pdata = dev_get_platdata(&pdev->dev);
146 	struct regulator_haptic *haptic;
147 	struct input_dev *input_dev;
148 	int error;
149 
150 	haptic = devm_kzalloc(&pdev->dev, sizeof(*haptic), GFP_KERNEL);
151 	if (!haptic)
152 		return -ENOMEM;
153 
154 	platform_set_drvdata(pdev, haptic);
155 	haptic->dev = &pdev->dev;
156 	mutex_init(&haptic->mutex);
157 	INIT_WORK(&haptic->work, regulator_haptic_work);
158 
159 	if (pdata) {
160 		haptic->max_volt = pdata->max_volt;
161 		haptic->min_volt = pdata->min_volt;
162 	} else if (IS_ENABLED(CONFIG_OF)) {
163 		error = regulator_haptic_parse_dt(&pdev->dev, haptic);
164 		if (error)
165 			return error;
166 	} else {
167 		dev_err(&pdev->dev, "Missing platform data\n");
168 		return -EINVAL;
169 	}
170 
171 	haptic->regulator = devm_regulator_get_exclusive(&pdev->dev, "haptic");
172 	if (IS_ERR(haptic->regulator)) {
173 		dev_err(&pdev->dev, "failed to get regulator\n");
174 		return PTR_ERR(haptic->regulator);
175 	}
176 
177 	input_dev = devm_input_allocate_device(&pdev->dev);
178 	if (!input_dev)
179 		return	-ENOMEM;
180 
181 	haptic->input_dev = input_dev;
182 	haptic->input_dev->name = "regulator-haptic";
183 	haptic->input_dev->dev.parent = &pdev->dev;
184 	haptic->input_dev->close = regulator_haptic_close;
185 	input_set_drvdata(haptic->input_dev, haptic);
186 	input_set_capability(haptic->input_dev, EV_FF, FF_RUMBLE);
187 
188 	error = input_ff_create_memless(input_dev, NULL,
189 					regulator_haptic_play_effect);
190 	if (error) {
191 		dev_err(&pdev->dev, "failed to create force-feedback\n");
192 		return error;
193 	}
194 
195 	error = input_register_device(haptic->input_dev);
196 	if (error) {
197 		dev_err(&pdev->dev, "failed to register input device\n");
198 		return error;
199 	}
200 
201 	return 0;
202 }
203 
204 static int __maybe_unused regulator_haptic_suspend(struct device *dev)
205 {
206 	struct platform_device *pdev = to_platform_device(dev);
207 	struct regulator_haptic *haptic = platform_get_drvdata(pdev);
208 	int error;
209 
210 	error = mutex_lock_interruptible(&haptic->mutex);
211 	if (error)
212 		return error;
213 
214 	regulator_haptic_set_voltage(haptic, 0);
215 
216 	haptic->suspended = true;
217 
218 	mutex_unlock(&haptic->mutex);
219 
220 	return 0;
221 }
222 
223 static int __maybe_unused regulator_haptic_resume(struct device *dev)
224 {
225 	struct platform_device *pdev = to_platform_device(dev);
226 	struct regulator_haptic *haptic = platform_get_drvdata(pdev);
227 	unsigned int magnitude;
228 
229 	mutex_lock(&haptic->mutex);
230 
231 	haptic->suspended = false;
232 
233 	magnitude = READ_ONCE(haptic->magnitude);
234 	if (magnitude)
235 		regulator_haptic_set_voltage(haptic, magnitude);
236 
237 	mutex_unlock(&haptic->mutex);
238 
239 	return 0;
240 }
241 
242 static SIMPLE_DEV_PM_OPS(regulator_haptic_pm_ops,
243 		regulator_haptic_suspend, regulator_haptic_resume);
244 
245 static const struct of_device_id regulator_haptic_dt_match[] = {
246 	{ .compatible = "regulator-haptic" },
247 	{ /* sentinel */ },
248 };
249 MODULE_DEVICE_TABLE(of, regulator_haptic_dt_match);
250 
251 static struct platform_driver regulator_haptic_driver = {
252 	.probe		= regulator_haptic_probe,
253 	.driver		= {
254 		.name		= "regulator-haptic",
255 		.of_match_table = regulator_haptic_dt_match,
256 		.pm		= &regulator_haptic_pm_ops,
257 	},
258 };
259 module_platform_driver(regulator_haptic_driver);
260 
261 MODULE_AUTHOR("Jaewon Kim <jaewon02.kim@samsung.com>");
262 MODULE_AUTHOR("Hyunhee Kim <hyunhee.kim@samsung.com>");
263 MODULE_DESCRIPTION("Regulator haptic driver");
264 MODULE_LICENSE("GPL");
265