regulator-haptic.c

  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#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 <jaewon02.kim@samsung.com>");
255MODULE_AUTHOR("Hyunhee Kim <hyunhee.kim@samsung.com>");
256MODULE_DESCRIPTION("Regulator haptic driver");
257MODULE_LICENSE("GPL");