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 
31 enum max77693_haptic_motor_type {
32 	MAX77693_HAPTIC_ERM = 0,
33 	MAX77693_HAPTIC_LRA,
34 };
35 
36 enum max77693_haptic_pulse_mode {
37 	MAX77693_HAPTIC_EXTERNAL_MODE = 0,
38 	MAX77693_HAPTIC_INTERNAL_MODE,
39 };
40 
41 enum 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 
48 struct 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 
67 static 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 
81 static 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 
103 static 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 
119 static 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 
145 err_enable_config:
146 	max77693_haptic_lowsys(haptic, false);
147 err_enable_lowsys:
148 	pwm_disable(haptic->pwm_dev);
149 }
150 
151 static 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 
171 err_disable_lowsys:
172 	max77693_haptic_configure(haptic, true);
173 }
174 
175 static 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 
193 static 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 
217 static 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 
232 static 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 
246 static 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 
312 static 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 
325 static 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 
338 static SIMPLE_DEV_PM_OPS(max77693_haptic_pm_ops,
339 			 max77693_haptic_suspend, max77693_haptic_resume);
340 
341 static 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 };
348 module_platform_driver(max77693_haptic_driver);
349 
350 MODULE_AUTHOR("Jaewon Kim <jaewon02.kim@samsung.com>");
351 MODULE_DESCRIPTION("MAXIM MAX77693 Haptic driver");
352 MODULE_ALIAS("platform:max77693-haptic");
353 MODULE_LICENSE("GPL");
354