1/*
2 * Regulator haptic driver
3 *
4 * Copyright (c) 2014 Samsung Electronics Co., Ltd.
5 * Author: Jaewon Kim <jaewon02.kim@samsung.com>
6 * Author: Hyunhee Kim <hyunhee.kim@samsung.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12
13#include <linux/input.h>
14#include <linux/module.h>
15#include <linux/of.h>
16#include <linux/platform_data/regulator-haptic.h>
17#include <linux/platform_device.h>
18#include <linux/regulator/consumer.h>
19#include <linux/slab.h>
20
21#define MAX_MAGNITUDE_SHIFT 16
22
23struct regulator_haptic {
24 struct device *dev;
25 struct input_dev *input_dev;
26 struct regulator *regulator;
27
28 struct work_struct work;
29 struct mutex mutex;
30
31 bool active;
32 bool suspended;
33
34 unsigned int max_volt;
35 unsigned int min_volt;
36 unsigned int magnitude;
37};
38
39static int regulator_haptic_toggle(struct regulator_haptic *haptic, bool on)
40{
41 int error;
42
43 if (haptic->active != on) {
44
45 error = on ? regulator_enable(haptic->regulator) :
46 regulator_disable(haptic->regulator);
47 if (error) {
48 dev_err(haptic->dev,
49 "failed to switch regulator %s: %d\n",
50 on ? "on" : "off", error);
51 return error;
52 }
53
54 haptic->active = on;
55 }
56
57 return 0;
58}
59
60static int regulator_haptic_set_voltage(struct regulator_haptic *haptic,
61 unsigned int magnitude)
62{
63 u64 volt_mag_multi;
64 unsigned int intensity;
65 int error;
66
67 volt_mag_multi = (u64)(haptic->max_volt - haptic->min_volt) * magnitude;
68 intensity = (unsigned int)(volt_mag_multi >> MAX_MAGNITUDE_SHIFT);
69
70 error = regulator_set_voltage(haptic->regulator,
71 intensity + haptic->min_volt,
72 haptic->max_volt);
73 if (error) {
74 dev_err(haptic->dev, "cannot set regulator voltage to %d: %d\n",
75 intensity + haptic->min_volt, error);
76 return error;
77 }
78
79 regulator_haptic_toggle(haptic, !!magnitude);
80
81 return 0;
82}
83
84static void regulator_haptic_work(struct work_struct *work)
85{
86 struct regulator_haptic *haptic = container_of(work,
87 struct regulator_haptic, work);
88
89 mutex_lock(&haptic->mutex);
90
91 if (!haptic->suspended)
92 regulator_haptic_set_voltage(haptic, haptic->magnitude);
93
94 mutex_unlock(&haptic->mutex);
95}
96
97static int regulator_haptic_play_effect(struct input_dev *input, void *data,
98 struct ff_effect *effect)
99{
100 struct regulator_haptic *haptic = input_get_drvdata(input);
101
102 haptic->magnitude = effect->u.rumble.strong_magnitude;
103 if (!haptic->magnitude)
104 haptic->magnitude = effect->u.rumble.weak_magnitude;
105
106 schedule_work(&haptic->work);
107
108 return 0;
109}
110
111static void regulator_haptic_close(struct input_dev *input)
112{
113 struct regulator_haptic *haptic = input_get_drvdata(input);
114
115 cancel_work_sync(&haptic->work);
116 regulator_haptic_set_voltage(haptic, 0);
117}
118
119static int __maybe_unused
120regulator_haptic_parse_dt(struct device *dev, struct regulator_haptic *haptic)
121{
122 struct device_node *node;
123 int error;
124
125 node = dev->of_node;
126 if(!node) {
127 dev_err(dev, "Missing device tree data\n");
128 return -EINVAL;
129 }
130
131 error = of_property_read_u32(node, "max-microvolt", &haptic->max_volt);
132 if (error) {
133 dev_err(dev, "cannot parse max-microvolt\n");
134 return error;
135 }
136
137 error = of_property_read_u32(node, "min-microvolt", &haptic->min_volt);
138 if (error) {
139 dev_err(dev, "cannot parse min-microvolt\n");
140 return error;
141 }
142
143 return 0;
144}
145
146static int regulator_haptic_probe(struct platform_device *pdev)
147{
148 const struct regulator_haptic_data *pdata = dev_get_platdata(&pdev->dev);
149 struct regulator_haptic *haptic;
150 struct input_dev *input_dev;
151 int error;
152
153 haptic = devm_kzalloc(&pdev->dev, sizeof(*haptic), GFP_KERNEL);
154 if (!haptic)
155 return -ENOMEM;
156
157 platform_set_drvdata(pdev, haptic);
158 haptic->dev = &pdev->dev;
159 mutex_init(&haptic->mutex);
160 INIT_WORK(&haptic->work, regulator_haptic_work);
161
162 if (pdata) {
163 haptic->max_volt = pdata->max_volt;
164 haptic->min_volt = pdata->min_volt;
165 } else if (IS_ENABLED(CONFIG_OF)) {
166 error = regulator_haptic_parse_dt(&pdev->dev, haptic);
167 if (error)
168 return error;
169 } else {
170 dev_err(&pdev->dev, "Missing platform data\n");
171 return -EINVAL;
172 }
173
174 haptic->regulator = devm_regulator_get_exclusive(&pdev->dev, "haptic");
175 if (IS_ERR(haptic->regulator)) {
176 dev_err(&pdev->dev, "failed to get regulator\n");
177 return PTR_ERR(haptic->regulator);
178 }
179
180 input_dev = devm_input_allocate_device(&pdev->dev);
181 if (!input_dev)
182 return -ENOMEM;
183
184 haptic->input_dev = input_dev;
185 haptic->input_dev->name = "regulator-haptic";
186 haptic->input_dev->dev.parent = &pdev->dev;
187 haptic->input_dev->close = regulator_haptic_close;
188 input_set_drvdata(haptic->input_dev, haptic);
189 input_set_capability(haptic->input_dev, EV_FF, FF_RUMBLE);
190
191 error = input_ff_create_memless(input_dev, NULL,
192 regulator_haptic_play_effect);
193 if (error) {
194 dev_err(&pdev->dev, "failed to create force-feedback\n");
195 return error;
196 }
197
198 error = input_register_device(haptic->input_dev);
199 if (error) {
200 dev_err(&pdev->dev, "failed to register input device\n");
201 return error;
202 }
203
204 return 0;
205}
206
207static int __maybe_unused regulator_haptic_suspend(struct device *dev)
208{
209 struct platform_device *pdev = to_platform_device(dev);
210 struct regulator_haptic *haptic = platform_get_drvdata(pdev);
211 int error;
212
213 error = mutex_lock_interruptible(&haptic->mutex);
214 if (error)
215 return error;
216
217 regulator_haptic_set_voltage(haptic, 0);
218
219 haptic->suspended = true;
220
221 mutex_unlock(&haptic->mutex);
222
223 return 0;
224}
225
226static int __maybe_unused regulator_haptic_resume(struct device *dev)
227{
228 struct platform_device *pdev = to_platform_device(dev);
229 struct regulator_haptic *haptic = platform_get_drvdata(pdev);
230 unsigned int magnitude;
231
232 mutex_lock(&haptic->mutex);
233
234 haptic->suspended = false;
235
236 magnitude = READ_ONCE(haptic->magnitude);
237 if (magnitude)
238 regulator_haptic_set_voltage(haptic, magnitude);
239
240 mutex_unlock(&haptic->mutex);
241
242 return 0;
243}
244
245static SIMPLE_DEV_PM_OPS(regulator_haptic_pm_ops,
246 regulator_haptic_suspend, regulator_haptic_resume);
247
248static const struct of_device_id regulator_haptic_dt_match[] = {
249 { .compatible = "regulator-haptic" },
250 { /* sentinel */ },
251};
252MODULE_DEVICE_TABLE(of, regulator_haptic_dt_match);
253
254static struct platform_driver regulator_haptic_driver = {
255 .probe = regulator_haptic_probe,
256 .driver = {
257 .name = "regulator-haptic",
258 .of_match_table = regulator_haptic_dt_match,
259 .pm = &regulator_haptic_pm_ops,
260 },
261};
262module_platform_driver(regulator_haptic_driver);
263
264MODULE_AUTHOR("Jaewon Kim <jaewon02.kim@samsung.com>");
265MODULE_AUTHOR("Hyunhee Kim <hyunhee.kim@samsung.com>");
266MODULE_DESCRIPTION("Regulator haptic driver");
267MODULE_LICENSE("GPL");
268