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