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 guard(mutex)(&haptic->mutex);
87
88 if (!haptic->suspended)
89 regulator_haptic_set_voltage(haptic, haptic->magnitude);
90 }
91
regulator_haptic_play_effect(struct input_dev * input,void * data,struct ff_effect * effect)92 static int regulator_haptic_play_effect(struct input_dev *input, void *data,
93 struct ff_effect *effect)
94 {
95 struct regulator_haptic *haptic = input_get_drvdata(input);
96
97 haptic->magnitude = effect->u.rumble.strong_magnitude;
98 if (!haptic->magnitude)
99 haptic->magnitude = effect->u.rumble.weak_magnitude;
100
101 schedule_work(&haptic->work);
102
103 return 0;
104 }
105
regulator_haptic_close(struct input_dev * input)106 static void regulator_haptic_close(struct input_dev *input)
107 {
108 struct regulator_haptic *haptic = input_get_drvdata(input);
109
110 cancel_work_sync(&haptic->work);
111 regulator_haptic_set_voltage(haptic, 0);
112 }
113
114 static int __maybe_unused
regulator_haptic_parse_dt(struct device * dev,struct regulator_haptic * haptic)115 regulator_haptic_parse_dt(struct device *dev, struct regulator_haptic *haptic)
116 {
117 struct device_node *node;
118 int error;
119
120 node = dev->of_node;
121 if(!node) {
122 dev_err(dev, "Missing device tree data\n");
123 return -EINVAL;
124 }
125
126 error = of_property_read_u32(node, "max-microvolt", &haptic->max_volt);
127 if (error) {
128 dev_err(dev, "cannot parse max-microvolt\n");
129 return error;
130 }
131
132 error = of_property_read_u32(node, "min-microvolt", &haptic->min_volt);
133 if (error) {
134 dev_err(dev, "cannot parse min-microvolt\n");
135 return error;
136 }
137
138 return 0;
139 }
140
regulator_haptic_probe(struct platform_device * pdev)141 static int regulator_haptic_probe(struct platform_device *pdev)
142 {
143 const struct regulator_haptic_data *pdata = dev_get_platdata(&pdev->dev);
144 struct regulator_haptic *haptic;
145 struct input_dev *input_dev;
146 int error;
147
148 haptic = devm_kzalloc(&pdev->dev, sizeof(*haptic), GFP_KERNEL);
149 if (!haptic)
150 return -ENOMEM;
151
152 platform_set_drvdata(pdev, haptic);
153 haptic->dev = &pdev->dev;
154 mutex_init(&haptic->mutex);
155 INIT_WORK(&haptic->work, regulator_haptic_work);
156
157 if (pdata) {
158 haptic->max_volt = pdata->max_volt;
159 haptic->min_volt = pdata->min_volt;
160 } else if (IS_ENABLED(CONFIG_OF)) {
161 error = regulator_haptic_parse_dt(&pdev->dev, haptic);
162 if (error)
163 return error;
164 } else {
165 dev_err(&pdev->dev, "Missing platform data\n");
166 return -EINVAL;
167 }
168
169 haptic->regulator = devm_regulator_get_exclusive(&pdev->dev, "haptic");
170 if (IS_ERR(haptic->regulator)) {
171 dev_err(&pdev->dev, "failed to get regulator\n");
172 return PTR_ERR(haptic->regulator);
173 }
174
175 input_dev = devm_input_allocate_device(&pdev->dev);
176 if (!input_dev)
177 return -ENOMEM;
178
179 haptic->input_dev = input_dev;
180 haptic->input_dev->name = "regulator-haptic";
181 haptic->input_dev->dev.parent = &pdev->dev;
182 haptic->input_dev->close = regulator_haptic_close;
183 input_set_drvdata(haptic->input_dev, haptic);
184 input_set_capability(haptic->input_dev, EV_FF, FF_RUMBLE);
185
186 error = input_ff_create_memless(input_dev, NULL,
187 regulator_haptic_play_effect);
188 if (error) {
189 dev_err(&pdev->dev, "failed to create force-feedback\n");
190 return error;
191 }
192
193 error = input_register_device(haptic->input_dev);
194 if (error) {
195 dev_err(&pdev->dev, "failed to register input device\n");
196 return error;
197 }
198
199 return 0;
200 }
201
regulator_haptic_suspend(struct device * dev)202 static int regulator_haptic_suspend(struct device *dev)
203 {
204 struct platform_device *pdev = to_platform_device(dev);
205 struct regulator_haptic *haptic = platform_get_drvdata(pdev);
206
207 scoped_guard(mutex_intr, &haptic->mutex) {
208 regulator_haptic_set_voltage(haptic, 0);
209 haptic->suspended = true;
210
211 return 0;
212 }
213
214 return -EINTR;
215 }
216
regulator_haptic_resume(struct device * dev)217 static int regulator_haptic_resume(struct device *dev)
218 {
219 struct platform_device *pdev = to_platform_device(dev);
220 struct regulator_haptic *haptic = platform_get_drvdata(pdev);
221 unsigned int magnitude;
222
223 guard(mutex)(&haptic->mutex);
224
225 haptic->suspended = false;
226
227 magnitude = READ_ONCE(haptic->magnitude);
228 if (magnitude)
229 regulator_haptic_set_voltage(haptic, magnitude);
230
231 return 0;
232 }
233
234 static DEFINE_SIMPLE_DEV_PM_OPS(regulator_haptic_pm_ops,
235 regulator_haptic_suspend, regulator_haptic_resume);
236
237 static const struct of_device_id regulator_haptic_dt_match[] = {
238 { .compatible = "regulator-haptic" },
239 { /* sentinel */ },
240 };
241 MODULE_DEVICE_TABLE(of, regulator_haptic_dt_match);
242
243 static struct platform_driver regulator_haptic_driver = {
244 .probe = regulator_haptic_probe,
245 .driver = {
246 .name = "regulator-haptic",
247 .of_match_table = regulator_haptic_dt_match,
248 .pm = pm_sleep_ptr(®ulator_haptic_pm_ops),
249 },
250 };
251 module_platform_driver(regulator_haptic_driver);
252
253 MODULE_AUTHOR("Jaewon Kim <jaewon02.kim@samsung.com>");
254 MODULE_AUTHOR("Hyunhee Kim <hyunhee.kim@samsung.com>");
255 MODULE_DESCRIPTION("Regulator haptic driver");
256 MODULE_LICENSE("GPL");
257