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
regulator_haptic_toggle(struct regulator_haptic * haptic,bool on)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
regulator_haptic_set_voltage(struct regulator_haptic * haptic,unsigned int magnitude)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
regulator_haptic_work(struct work_struct * work)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
regulator_haptic_play_effect(struct input_dev * input,void * data,struct ff_effect * effect)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
regulator_haptic_close(struct input_dev * input)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
regulator_haptic_parse_dt(struct device * dev,struct regulator_haptic * haptic)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
regulator_haptic_probe(struct platform_device * pdev)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
regulator_haptic_suspend(struct device * dev)204 static int 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
regulator_haptic_resume(struct device * dev)223 static int 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 DEFINE_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 = pm_sleep_ptr(®ulator_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