1/*
2 * MAXIM MAX77693 Haptic device driver
3 *
4 * Copyright (C) 2015 Samsung Electronics
5 * Author: Jaewon Kim <jaewon02.kim@samsung.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 */
12
13#include <linux/err.h>
14#include <linux/i2c.h>
15#include <linux/init.h>
16#include <linux/input.h>
17#include <linux/mfd/max77843-private.h>
18#include <linux/module.h>
19#include <linux/platform_device.h>
20#include <linux/pwm.h>
21#include <linux/regmap.h>
22#include <linux/regulator/consumer.h>
23#include <linux/slab.h>
24#include <linux/workqueue.h>
25
26#define MAX_MAGNITUDE_SHIFT        16
27
28enum max77843_haptic_motor_type {
29	MAX77843_HAPTIC_ERM = 0,
30	MAX77843_HAPTIC_LRA,
31};
32
33enum max77843_haptic_pwm_divisor {
34	MAX77843_HAPTIC_PWM_DIVISOR_32 = 0,
35	MAX77843_HAPTIC_PWM_DIVISOR_64,
36	MAX77843_HAPTIC_PWM_DIVISOR_128,
37	MAX77843_HAPTIC_PWM_DIVISOR_256,
38};
39
40struct max77843_haptic {
41	struct regmap *regmap_haptic;
42	struct device *dev;
43	struct input_dev *input_dev;
44	struct pwm_device *pwm_dev;
45	struct regulator *motor_reg;
46	struct work_struct work;
47	struct mutex mutex;
48
49	unsigned int magnitude;
50	unsigned int pwm_duty;
51
52	bool active;
53	bool suspended;
54
55	enum max77843_haptic_motor_type type;
56	enum max77843_haptic_pwm_divisor pwm_divisor;
57};
58
59static int max77843_haptic_set_duty_cycle(struct max77843_haptic *haptic)
60{
61	int delta = (haptic->pwm_dev->period + haptic->pwm_duty) / 2;
62	int error;
63
64	error = pwm_config(haptic->pwm_dev, delta, haptic->pwm_dev->period);
65	if (error) {
66		dev_err(haptic->dev, "failed to configure pwm: %d\n", error);
67		return error;
68	}
69
70	return 0;
71}
72
73static int max77843_haptic_bias(struct max77843_haptic *haptic, bool on)
74{
75	int error;
76
77	error = regmap_update_bits(haptic->regmap_haptic,
78				   MAX77843_SYS_REG_MAINCTRL1,
79				   MAX77843_MAINCTRL1_BIASEN_MASK,
80				   on << MAINCTRL1_BIASEN_SHIFT);
81	if (error) {
82		dev_err(haptic->dev, "failed to %s bias: %d\n",
83			on ? "enable" : "disable", error);
84		return error;
85	}
86
87	return 0;
88}
89
90static int max77843_haptic_config(struct max77843_haptic *haptic, bool enable)
91{
92	unsigned int value;
93	int error;
94
95	value = (haptic->type << MCONFIG_MODE_SHIFT) |
96		(enable << MCONFIG_MEN_SHIFT) |
97		(haptic->pwm_divisor << MCONFIG_PDIV_SHIFT);
98
99	error = regmap_write(haptic->regmap_haptic,
100			     MAX77843_HAP_REG_MCONFIG, value);
101	if (error) {
102		dev_err(haptic->dev,
103			"failed to update haptic config: %d\n", error);
104		return error;
105	}
106
107	return 0;
108}
109
110static int max77843_haptic_enable(struct max77843_haptic *haptic)
111{
112	int error;
113
114	if (haptic->active)
115		return 0;
116
117	error = pwm_enable(haptic->pwm_dev);
118	if (error) {
119		dev_err(haptic->dev,
120			"failed to enable pwm device: %d\n", error);
121		return error;
122	}
123
124	error = max77843_haptic_config(haptic, true);
125	if (error)
126		goto err_config;
127
128	haptic->active = true;
129
130	return 0;
131
132err_config:
133	pwm_disable(haptic->pwm_dev);
134
135	return error;
136}
137
138static int max77843_haptic_disable(struct max77843_haptic *haptic)
139{
140	int error;
141
142	if (!haptic->active)
143		return 0;
144
145	error = max77843_haptic_config(haptic, false);
146	if (error)
147		return error;
148
149	pwm_disable(haptic->pwm_dev);
150
151	haptic->active = false;
152
153	return 0;
154}
155
156static void max77843_haptic_play_work(struct work_struct *work)
157{
158	struct max77843_haptic *haptic =
159			container_of(work, struct max77843_haptic, work);
160	int error;
161
162	mutex_lock(&haptic->mutex);
163
164	if (haptic->suspended)
165		goto out_unlock;
166
167	if (haptic->magnitude) {
168		error = max77843_haptic_set_duty_cycle(haptic);
169		if (error) {
170			dev_err(haptic->dev,
171				"failed to set duty cycle: %d\n", error);
172			goto out_unlock;
173		}
174
175		error = max77843_haptic_enable(haptic);
176		if (error)
177			dev_err(haptic->dev,
178				"cannot enable haptic: %d\n", error);
179	} else {
180		error = max77843_haptic_disable(haptic);
181		if (error)
182			dev_err(haptic->dev,
183				"cannot disable haptic: %d\n", error);
184	}
185
186out_unlock:
187	mutex_unlock(&haptic->mutex);
188}
189
190static int max77843_haptic_play_effect(struct input_dev *dev, void *data,
191		struct ff_effect *effect)
192{
193	struct max77843_haptic *haptic = input_get_drvdata(dev);
194	u64 period_mag_multi;
195
196	haptic->magnitude = effect->u.rumble.strong_magnitude;
197	if (!haptic->magnitude)
198		haptic->magnitude = effect->u.rumble.weak_magnitude;
199
200	period_mag_multi = (u64)haptic->pwm_dev->period * haptic->magnitude;
201	haptic->pwm_duty = (unsigned int)(period_mag_multi >>
202						MAX_MAGNITUDE_SHIFT);
203
204	schedule_work(&haptic->work);
205
206	return 0;
207}
208
209static int max77843_haptic_open(struct input_dev *dev)
210{
211	struct max77843_haptic *haptic = input_get_drvdata(dev);
212	int error;
213
214	error = max77843_haptic_bias(haptic, true);
215	if (error)
216		return error;
217
218	error = regulator_enable(haptic->motor_reg);
219	if (error) {
220		dev_err(haptic->dev,
221			"failed to enable regulator: %d\n", error);
222		return error;
223	}
224
225	return 0;
226}
227
228static void max77843_haptic_close(struct input_dev *dev)
229{
230	struct max77843_haptic *haptic = input_get_drvdata(dev);
231	int error;
232
233	cancel_work_sync(&haptic->work);
234	max77843_haptic_disable(haptic);
235
236	error = regulator_disable(haptic->motor_reg);
237	if (error)
238		dev_err(haptic->dev,
239			"failed to disable regulator: %d\n", error);
240
241	max77843_haptic_bias(haptic, false);
242}
243
244static int max77843_haptic_probe(struct platform_device *pdev)
245{
246	struct max77843 *max77843 = dev_get_drvdata(pdev->dev.parent);
247	struct max77843_haptic *haptic;
248	int error;
249
250	haptic = devm_kzalloc(&pdev->dev, sizeof(*haptic), GFP_KERNEL);
251	if (!haptic)
252		return -ENOMEM;
253
254	haptic->regmap_haptic = max77843->regmap;
255	haptic->dev = &pdev->dev;
256	haptic->type = MAX77843_HAPTIC_LRA;
257	haptic->pwm_divisor = MAX77843_HAPTIC_PWM_DIVISOR_128;
258
259	INIT_WORK(&haptic->work, max77843_haptic_play_work);
260	mutex_init(&haptic->mutex);
261
262	haptic->pwm_dev = devm_pwm_get(&pdev->dev, NULL);
263	if (IS_ERR(haptic->pwm_dev)) {
264		dev_err(&pdev->dev, "failed to get pwm device\n");
265		return PTR_ERR(haptic->pwm_dev);
266	}
267
268	haptic->motor_reg = devm_regulator_get_exclusive(&pdev->dev, "haptic");
269	if (IS_ERR(haptic->motor_reg)) {
270		dev_err(&pdev->dev, "failed to get regulator\n");
271		return PTR_ERR(haptic->motor_reg);
272	}
273
274	haptic->input_dev = devm_input_allocate_device(&pdev->dev);
275	if (!haptic->input_dev) {
276		dev_err(&pdev->dev, "failed to allocate input device\n");
277		return -ENOMEM;
278	}
279
280	haptic->input_dev->name = "max77843-haptic";
281	haptic->input_dev->id.version = 1;
282	haptic->input_dev->dev.parent = &pdev->dev;
283	haptic->input_dev->open = max77843_haptic_open;
284	haptic->input_dev->close = max77843_haptic_close;
285	input_set_drvdata(haptic->input_dev, haptic);
286	input_set_capability(haptic->input_dev, EV_FF, FF_RUMBLE);
287
288	error = input_ff_create_memless(haptic->input_dev, NULL,
289			max77843_haptic_play_effect);
290	if (error) {
291		dev_err(&pdev->dev, "failed to create force-feedback\n");
292		return error;
293	}
294
295	error = input_register_device(haptic->input_dev);
296	if (error) {
297		dev_err(&pdev->dev, "failed to register input device\n");
298		return error;
299	}
300
301	platform_set_drvdata(pdev, haptic);
302
303	return 0;
304}
305
306static int __maybe_unused max77843_haptic_suspend(struct device *dev)
307{
308	struct platform_device *pdev = to_platform_device(dev);
309	struct max77843_haptic *haptic = platform_get_drvdata(pdev);
310	int error;
311
312	error = mutex_lock_interruptible(&haptic->mutex);
313	if (error)
314		return error;
315
316	max77843_haptic_disable(haptic);
317
318	haptic->suspended = true;
319
320	mutex_unlock(&haptic->mutex);
321
322	return 0;
323}
324
325static int __maybe_unused max77843_haptic_resume(struct device *dev)
326{
327	struct platform_device *pdev = to_platform_device(dev);
328	struct max77843_haptic *haptic = platform_get_drvdata(pdev);
329	unsigned int magnitude;
330
331	mutex_lock(&haptic->mutex);
332
333	haptic->suspended = false;
334
335	magnitude = ACCESS_ONCE(haptic->magnitude);
336	if (magnitude)
337		max77843_haptic_enable(haptic);
338
339	mutex_unlock(&haptic->mutex);
340
341	return 0;
342}
343
344static SIMPLE_DEV_PM_OPS(max77843_haptic_pm_ops,
345		max77843_haptic_suspend, max77843_haptic_resume);
346
347static struct platform_driver max77843_haptic_driver = {
348	.driver		= {
349		.name	= "max77843-haptic",
350		.pm	= &max77843_haptic_pm_ops,
351	},
352	.probe		= max77843_haptic_probe,
353};
354module_platform_driver(max77843_haptic_driver);
355
356MODULE_AUTHOR("Jaewon Kim <jaewon02.kim@samsung.com>");
357MODULE_DESCRIPTION("MAXIM MAX77843 Haptic driver");
358MODULE_LICENSE("GPL");
359