1/*
2 * MAXIM MAX77693 Haptic device driver
3 *
4 * Copyright (C) 2014 Samsung Electronics
5 * Jaewon Kim <jaewon02.kim@samsung.com>
6 *
7 * This program is not provided / owned by Maxim Integrated Products.
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 */
14
15#include <linux/err.h>
16#include <linux/init.h>
17#include <linux/i2c.h>
18#include <linux/regmap.h>
19#include <linux/input.h>
20#include <linux/module.h>
21#include <linux/platform_device.h>
22#include <linux/pwm.h>
23#include <linux/slab.h>
24#include <linux/workqueue.h>
25#include <linux/regulator/consumer.h>
26#include <linux/mfd/max77693.h>
27#include <linux/mfd/max77693-private.h>
28
29#define MAX_MAGNITUDE_SHIFT	16
30
31enum max77693_haptic_motor_type {
32	MAX77693_HAPTIC_ERM = 0,
33	MAX77693_HAPTIC_LRA,
34};
35
36enum max77693_haptic_pulse_mode {
37	MAX77693_HAPTIC_EXTERNAL_MODE = 0,
38	MAX77693_HAPTIC_INTERNAL_MODE,
39};
40
41enum max77693_haptic_pwm_divisor {
42	MAX77693_HAPTIC_PWM_DIVISOR_32 = 0,
43	MAX77693_HAPTIC_PWM_DIVISOR_64,
44	MAX77693_HAPTIC_PWM_DIVISOR_128,
45	MAX77693_HAPTIC_PWM_DIVISOR_256,
46};
47
48struct max77693_haptic {
49	struct regmap *regmap_pmic;
50	struct regmap *regmap_haptic;
51	struct device *dev;
52	struct input_dev *input_dev;
53	struct pwm_device *pwm_dev;
54	struct regulator *motor_reg;
55
56	bool enabled;
57	bool suspend_state;
58	unsigned int magnitude;
59	unsigned int pwm_duty;
60	enum max77693_haptic_motor_type type;
61	enum max77693_haptic_pulse_mode mode;
62	enum max77693_haptic_pwm_divisor pwm_divisor;
63
64	struct work_struct work;
65};
66
67static int max77693_haptic_set_duty_cycle(struct max77693_haptic *haptic)
68{
69	int delta = (haptic->pwm_dev->period + haptic->pwm_duty) / 2;
70	int error;
71
72	error = pwm_config(haptic->pwm_dev, delta, haptic->pwm_dev->period);
73	if (error) {
74		dev_err(haptic->dev, "failed to configure pwm: %d\n", error);
75		return error;
76	}
77
78	return 0;
79}
80
81static int max77693_haptic_configure(struct max77693_haptic *haptic,
82				     bool enable)
83{
84	unsigned int value;
85	int error;
86
87	value = ((haptic->type << MAX77693_CONFIG2_MODE) |
88		(enable << MAX77693_CONFIG2_MEN) |
89		(haptic->mode << MAX77693_CONFIG2_HTYP) |
90		(haptic->pwm_divisor));
91
92	error = regmap_write(haptic->regmap_haptic,
93			     MAX77693_HAPTIC_REG_CONFIG2, value);
94	if (error) {
95		dev_err(haptic->dev,
96			"failed to update haptic config: %d\n", error);
97		return error;
98	}
99
100	return 0;
101}
102
103static int max77693_haptic_lowsys(struct max77693_haptic *haptic, bool enable)
104{
105	int error;
106
107	error = regmap_update_bits(haptic->regmap_pmic,
108				   MAX77693_PMIC_REG_LSCNFG,
109				   MAX77693_PMIC_LOW_SYS_MASK,
110				   enable << MAX77693_PMIC_LOW_SYS_SHIFT);
111	if (error) {
112		dev_err(haptic->dev, "cannot update pmic regmap: %d\n", error);
113		return error;
114	}
115
116	return 0;
117}
118
119static void max77693_haptic_enable(struct max77693_haptic *haptic)
120{
121	int error;
122
123	if (haptic->enabled)
124		return;
125
126	error = pwm_enable(haptic->pwm_dev);
127	if (error) {
128		dev_err(haptic->dev,
129			"failed to enable haptic pwm device: %d\n", error);
130		return;
131	}
132
133	error = max77693_haptic_lowsys(haptic, true);
134	if (error)
135		goto err_enable_lowsys;
136
137	error = max77693_haptic_configure(haptic, true);
138	if (error)
139		goto err_enable_config;
140
141	haptic->enabled = true;
142
143	return;
144
145err_enable_config:
146	max77693_haptic_lowsys(haptic, false);
147err_enable_lowsys:
148	pwm_disable(haptic->pwm_dev);
149}
150
151static void max77693_haptic_disable(struct max77693_haptic *haptic)
152{
153	int error;
154
155	if (!haptic->enabled)
156		return;
157
158	error = max77693_haptic_configure(haptic, false);
159	if (error)
160		return;
161
162	error = max77693_haptic_lowsys(haptic, false);
163	if (error)
164		goto err_disable_lowsys;
165
166	pwm_disable(haptic->pwm_dev);
167	haptic->enabled = false;
168
169	return;
170
171err_disable_lowsys:
172	max77693_haptic_configure(haptic, true);
173}
174
175static void max77693_haptic_play_work(struct work_struct *work)
176{
177	struct max77693_haptic *haptic =
178			container_of(work, struct max77693_haptic, work);
179	int error;
180
181	error = max77693_haptic_set_duty_cycle(haptic);
182	if (error) {
183		dev_err(haptic->dev, "failed to set duty cycle: %d\n", error);
184		return;
185	}
186
187	if (haptic->magnitude)
188		max77693_haptic_enable(haptic);
189	else
190		max77693_haptic_disable(haptic);
191}
192
193static int max77693_haptic_play_effect(struct input_dev *dev, void *data,
194				       struct ff_effect *effect)
195{
196	struct max77693_haptic *haptic = input_get_drvdata(dev);
197	u64 period_mag_multi;
198
199	haptic->magnitude = effect->u.rumble.strong_magnitude;
200	if (!haptic->magnitude)
201		haptic->magnitude = effect->u.rumble.weak_magnitude;
202
203	/*
204	 * The magnitude comes from force-feedback interface.
205	 * The formula to convert magnitude to pwm_duty as follows:
206	 * - pwm_duty = (magnitude * pwm_period) / MAX_MAGNITUDE(0xFFFF)
207	 */
208	period_mag_multi = (u64)haptic->pwm_dev->period * haptic->magnitude;
209	haptic->pwm_duty = (unsigned int)(period_mag_multi >>
210						MAX_MAGNITUDE_SHIFT);
211
212	schedule_work(&haptic->work);
213
214	return 0;
215}
216
217static int max77693_haptic_open(struct input_dev *dev)
218{
219	struct max77693_haptic *haptic = input_get_drvdata(dev);
220	int error;
221
222	error = regulator_enable(haptic->motor_reg);
223	if (error) {
224		dev_err(haptic->dev,
225			"failed to enable regulator: %d\n", error);
226		return error;
227	}
228
229	return 0;
230}
231
232static void max77693_haptic_close(struct input_dev *dev)
233{
234	struct max77693_haptic *haptic = input_get_drvdata(dev);
235	int error;
236
237	cancel_work_sync(&haptic->work);
238	max77693_haptic_disable(haptic);
239
240	error = regulator_disable(haptic->motor_reg);
241	if (error)
242		dev_err(haptic->dev,
243			"failed to disable regulator: %d\n", error);
244}
245
246static int max77693_haptic_probe(struct platform_device *pdev)
247{
248	struct max77693_dev *max77693 = dev_get_drvdata(pdev->dev.parent);
249	struct max77693_haptic *haptic;
250	int error;
251
252	haptic = devm_kzalloc(&pdev->dev, sizeof(*haptic), GFP_KERNEL);
253	if (!haptic)
254		return -ENOMEM;
255
256	haptic->regmap_pmic = max77693->regmap;
257	haptic->regmap_haptic = max77693->regmap_haptic;
258	haptic->dev = &pdev->dev;
259	haptic->type = MAX77693_HAPTIC_LRA;
260	haptic->mode = MAX77693_HAPTIC_EXTERNAL_MODE;
261	haptic->pwm_divisor = MAX77693_HAPTIC_PWM_DIVISOR_128;
262	haptic->suspend_state = false;
263
264	INIT_WORK(&haptic->work, max77693_haptic_play_work);
265
266	/* Get pwm and regulatot for haptic device */
267	haptic->pwm_dev = devm_pwm_get(&pdev->dev, NULL);
268	if (IS_ERR(haptic->pwm_dev)) {
269		dev_err(&pdev->dev, "failed to get pwm device\n");
270		return PTR_ERR(haptic->pwm_dev);
271	}
272
273	haptic->motor_reg = devm_regulator_get(&pdev->dev, "haptic");
274	if (IS_ERR(haptic->motor_reg)) {
275		dev_err(&pdev->dev, "failed to get regulator\n");
276		return PTR_ERR(haptic->motor_reg);
277	}
278
279	/* Initialize input device for haptic device */
280	haptic->input_dev = devm_input_allocate_device(&pdev->dev);
281	if (!haptic->input_dev) {
282		dev_err(&pdev->dev, "failed to allocate input device\n");
283		return -ENOMEM;
284	}
285
286	haptic->input_dev->name = "max77693-haptic";
287	haptic->input_dev->id.version = 1;
288	haptic->input_dev->dev.parent = &pdev->dev;
289	haptic->input_dev->open = max77693_haptic_open;
290	haptic->input_dev->close = max77693_haptic_close;
291	input_set_drvdata(haptic->input_dev, haptic);
292	input_set_capability(haptic->input_dev, EV_FF, FF_RUMBLE);
293
294	error = input_ff_create_memless(haptic->input_dev, NULL,
295				max77693_haptic_play_effect);
296	if (error) {
297		dev_err(&pdev->dev, "failed to create force-feedback\n");
298		return error;
299	}
300
301	error = input_register_device(haptic->input_dev);
302	if (error) {
303		dev_err(&pdev->dev, "failed to register input device\n");
304		return error;
305	}
306
307	platform_set_drvdata(pdev, haptic);
308
309	return 0;
310}
311
312static int __maybe_unused max77693_haptic_suspend(struct device *dev)
313{
314	struct platform_device *pdev = to_platform_device(dev);
315	struct max77693_haptic *haptic = platform_get_drvdata(pdev);
316
317	if (haptic->enabled) {
318		max77693_haptic_disable(haptic);
319		haptic->suspend_state = true;
320	}
321
322	return 0;
323}
324
325static int __maybe_unused max77693_haptic_resume(struct device *dev)
326{
327	struct platform_device *pdev = to_platform_device(dev);
328	struct max77693_haptic *haptic = platform_get_drvdata(pdev);
329
330	if (haptic->suspend_state) {
331		max77693_haptic_enable(haptic);
332		haptic->suspend_state = false;
333	}
334
335	return 0;
336}
337
338static SIMPLE_DEV_PM_OPS(max77693_haptic_pm_ops,
339			 max77693_haptic_suspend, max77693_haptic_resume);
340
341static struct platform_driver max77693_haptic_driver = {
342	.driver		= {
343		.name	= "max77693-haptic",
344		.pm	= &max77693_haptic_pm_ops,
345	},
346	.probe		= max77693_haptic_probe,
347};
348module_platform_driver(max77693_haptic_driver);
349
350MODULE_AUTHOR("Jaewon Kim <jaewon02.kim@samsung.com>");
351MODULE_DESCRIPTION("MAXIM MAX77693 Haptic driver");
352MODULE_ALIAS("platform:max77693-haptic");
353MODULE_LICENSE("GPL");
354