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 	uint64_t 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 = (int64_t)(haptic->pwm_dev->period *
209 						haptic->magnitude);
210 	haptic->pwm_duty = (unsigned int)(period_mag_multi >>
211 						MAX_MAGNITUDE_SHIFT);
212 
213 	schedule_work(&haptic->work);
214 
215 	return 0;
216 }
217 
218 static int max77693_haptic_open(struct input_dev *dev)
219 {
220 	struct max77693_haptic *haptic = input_get_drvdata(dev);
221 	int error;
222 
223 	error = regulator_enable(haptic->motor_reg);
224 	if (error) {
225 		dev_err(haptic->dev,
226 			"failed to enable regulator: %d\n", error);
227 		return error;
228 	}
229 
230 	return 0;
231 }
232 
233 static void max77693_haptic_close(struct input_dev *dev)
234 {
235 	struct max77693_haptic *haptic = input_get_drvdata(dev);
236 	int error;
237 
238 	cancel_work_sync(&haptic->work);
239 	max77693_haptic_disable(haptic);
240 
241 	error = regulator_disable(haptic->motor_reg);
242 	if (error)
243 		dev_err(haptic->dev,
244 			"failed to disable regulator: %d\n", error);
245 }
246 
247 static int max77693_haptic_probe(struct platform_device *pdev)
248 {
249 	struct max77693_dev *max77693 = dev_get_drvdata(pdev->dev.parent);
250 	struct max77693_haptic *haptic;
251 	int error;
252 
253 	haptic = devm_kzalloc(&pdev->dev, sizeof(*haptic), GFP_KERNEL);
254 	if (!haptic)
255 		return -ENOMEM;
256 
257 	haptic->regmap_pmic = max77693->regmap;
258 	haptic->regmap_haptic = max77693->regmap_haptic;
259 	haptic->dev = &pdev->dev;
260 	haptic->type = MAX77693_HAPTIC_LRA;
261 	haptic->mode = MAX77693_HAPTIC_EXTERNAL_MODE;
262 	haptic->pwm_divisor = MAX77693_HAPTIC_PWM_DIVISOR_128;
263 	haptic->suspend_state = false;
264 
265 	INIT_WORK(&haptic->work, max77693_haptic_play_work);
266 
267 	/* Get pwm and regulatot for haptic device */
268 	haptic->pwm_dev = devm_pwm_get(&pdev->dev, NULL);
269 	if (IS_ERR(haptic->pwm_dev)) {
270 		dev_err(&pdev->dev, "failed to get pwm device\n");
271 		return PTR_ERR(haptic->pwm_dev);
272 	}
273 
274 	haptic->motor_reg = devm_regulator_get(&pdev->dev, "haptic");
275 	if (IS_ERR(haptic->motor_reg)) {
276 		dev_err(&pdev->dev, "failed to get regulator\n");
277 		return PTR_ERR(haptic->motor_reg);
278 	}
279 
280 	/* Initialize input device for haptic device */
281 	haptic->input_dev = devm_input_allocate_device(&pdev->dev);
282 	if (!haptic->input_dev) {
283 		dev_err(&pdev->dev, "failed to allocate input device\n");
284 		return -ENOMEM;
285 	}
286 
287 	haptic->input_dev->name = "max77693-haptic";
288 	haptic->input_dev->id.version = 1;
289 	haptic->input_dev->dev.parent = &pdev->dev;
290 	haptic->input_dev->open = max77693_haptic_open;
291 	haptic->input_dev->close = max77693_haptic_close;
292 	input_set_drvdata(haptic->input_dev, haptic);
293 	input_set_capability(haptic->input_dev, EV_FF, FF_RUMBLE);
294 
295 	error = input_ff_create_memless(haptic->input_dev, NULL,
296 				max77693_haptic_play_effect);
297 	if (error) {
298 		dev_err(&pdev->dev, "failed to create force-feedback\n");
299 		return error;
300 	}
301 
302 	error = input_register_device(haptic->input_dev);
303 	if (error) {
304 		dev_err(&pdev->dev, "failed to register input device\n");
305 		return error;
306 	}
307 
308 	platform_set_drvdata(pdev, haptic);
309 
310 	return 0;
311 }
312 
313 #ifdef CONFIG_PM_SLEEP
314 static int max77693_haptic_suspend(struct device *dev)
315 {
316 	struct platform_device *pdev = to_platform_device(dev);
317 	struct max77693_haptic *haptic = platform_get_drvdata(pdev);
318 
319 	if (haptic->enabled) {
320 		max77693_haptic_disable(haptic);
321 		haptic->suspend_state = true;
322 	}
323 
324 	return 0;
325 }
326 
327 static int max77693_haptic_resume(struct device *dev)
328 {
329 	struct platform_device *pdev = to_platform_device(dev);
330 	struct max77693_haptic *haptic = platform_get_drvdata(pdev);
331 
332 	if (haptic->suspend_state) {
333 		max77693_haptic_enable(haptic);
334 		haptic->suspend_state = false;
335 	}
336 
337 	return 0;
338 }
339 #endif
340 
341 static SIMPLE_DEV_PM_OPS(max77693_haptic_pm_ops,
342 			 max77693_haptic_suspend, max77693_haptic_resume);
343 
344 static struct platform_driver max77693_haptic_driver = {
345 	.driver		= {
346 		.name	= "max77693-haptic",
347 		.owner	= THIS_MODULE,
348 		.pm	= &max77693_haptic_pm_ops,
349 	},
350 	.probe		= max77693_haptic_probe,
351 };
352 module_platform_driver(max77693_haptic_driver);
353 
354 MODULE_AUTHOR("Jaewon Kim <jaewon02.kim@samsung.com>");
355 MODULE_DESCRIPTION("MAXIM MAX77693 Haptic driver");
356 MODULE_ALIAS("platform:max77693-haptic");
357 MODULE_LICENSE("GPL");
358