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
 20struct 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
 36static 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
 57static 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
 81static 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
 94static 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
108static 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
116static int __maybe_unused
117regulator_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
143static 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
204static int __maybe_unused 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
223static int __maybe_unused 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
242static SIMPLE_DEV_PM_OPS(regulator_haptic_pm_ops,
243		regulator_haptic_suspend, regulator_haptic_resume);
244
245static const struct of_device_id regulator_haptic_dt_match[] = {
246	{ .compatible = "regulator-haptic" },
247	{ /* sentinel */ },
248};
249MODULE_DEVICE_TABLE(of, regulator_haptic_dt_match);
250
251static 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		= &regulator_haptic_pm_ops,
257	},
258};
259module_platform_driver(regulator_haptic_driver);
260
261MODULE_AUTHOR("Jaewon Kim <jaewon02.kim@samsung.com>");
262MODULE_AUTHOR("Hyunhee Kim <hyunhee.kim@samsung.com>");
263MODULE_DESCRIPTION("Regulator haptic driver");
264MODULE_LICENSE("GPL");