1/*
  2 * MAXIM MAX77693/MAX77843 Haptic device driver
  3 *
  4 * Copyright (C) 2014,2015 Samsung Electronics
  5 * Jaewon Kim <jaewon02.kim@samsung.com>
  6 * Krzysztof Kozlowski <krzk@kernel.org>
  7 *
  8 * This program is not provided / owned by Maxim Integrated Products.
  9 *
 10 * This program is free software; you can redistribute it and/or modify
 11 * it under the terms of the GNU General Public License as published by
 12 * the Free Software Foundation; either version 2 of the License, or
 13 * (at your option) any later version.
 14 */
 15
 16#include <linux/err.h>
 17#include <linux/init.h>
 18#include <linux/i2c.h>
 19#include <linux/regmap.h>
 20#include <linux/input.h>
 21#include <linux/module.h>
 22#include <linux/platform_device.h>
 23#include <linux/pwm.h>
 24#include <linux/slab.h>
 25#include <linux/workqueue.h>
 26#include <linux/regulator/consumer.h>
 27#include <linux/mfd/max77693.h>
 28#include <linux/mfd/max77693-common.h>
 29#include <linux/mfd/max77693-private.h>
 30#include <linux/mfd/max77843-private.h>
 31
 32#define MAX_MAGNITUDE_SHIFT	16
 33
 34enum max77693_haptic_motor_type {
 35	MAX77693_HAPTIC_ERM = 0,
 36	MAX77693_HAPTIC_LRA,
 37};
 38
 39enum max77693_haptic_pulse_mode {
 40	MAX77693_HAPTIC_EXTERNAL_MODE = 0,
 41	MAX77693_HAPTIC_INTERNAL_MODE,
 42};
 43
 44enum max77693_haptic_pwm_divisor {
 45	MAX77693_HAPTIC_PWM_DIVISOR_32 = 0,
 46	MAX77693_HAPTIC_PWM_DIVISOR_64,
 47	MAX77693_HAPTIC_PWM_DIVISOR_128,
 48	MAX77693_HAPTIC_PWM_DIVISOR_256,
 49};
 50
 51struct max77693_haptic {
 52	enum max77693_types dev_type;
 53
 54	struct regmap *regmap_pmic;
 55	struct regmap *regmap_haptic;
 56	struct device *dev;
 57	struct input_dev *input_dev;
 58	struct pwm_device *pwm_dev;
 59	struct regulator *motor_reg;
 60
 61	bool enabled;
 62	bool suspend_state;
 63	unsigned int magnitude;
 64	unsigned int pwm_duty;
 65	enum max77693_haptic_motor_type type;
 66	enum max77693_haptic_pulse_mode mode;
 67
 68	struct work_struct work;
 69};
 70
 71static int max77693_haptic_set_duty_cycle(struct max77693_haptic *haptic)
 72{
 73	struct pwm_args pargs;
 74	int delta;
 75	int error;
 76
 77	pwm_get_args(haptic->pwm_dev, &pargs);
 78	delta = (pargs.period + haptic->pwm_duty) / 2;
 79	error = pwm_config(haptic->pwm_dev, delta, pargs.period);
 80	if (error) {
 81		dev_err(haptic->dev, "failed to configure pwm: %d\n", error);
 82		return error;
 83	}
 84
 85	return 0;
 86}
 87
 88static int max77843_haptic_bias(struct max77693_haptic *haptic, bool on)
 89{
 90	int error;
 91
 92	if (haptic->dev_type != TYPE_MAX77843)
 93		return 0;
 94
 95	error = regmap_update_bits(haptic->regmap_haptic,
 96				   MAX77843_SYS_REG_MAINCTRL1,
 97				   MAX77843_MAINCTRL1_BIASEN_MASK,
 98				   on << MAINCTRL1_BIASEN_SHIFT);
 99	if (error) {
100		dev_err(haptic->dev, "failed to %s bias: %d\n",
101			on ? "enable" : "disable", error);
102		return error;
103	}
104
105	return 0;
106}
107
108static int max77693_haptic_configure(struct max77693_haptic *haptic,
109				     bool enable)
110{
111	unsigned int value, config_reg;
112	int error;
113
114	switch (haptic->dev_type) {
115	case TYPE_MAX77693:
116		value = ((haptic->type << MAX77693_CONFIG2_MODE) |
117			(enable << MAX77693_CONFIG2_MEN) |
118			(haptic->mode << MAX77693_CONFIG2_HTYP) |
119			MAX77693_HAPTIC_PWM_DIVISOR_128);
120		config_reg = MAX77693_HAPTIC_REG_CONFIG2;
121		break;
122	case TYPE_MAX77843:
123		value = (haptic->type << MCONFIG_MODE_SHIFT) |
124			(enable << MCONFIG_MEN_SHIFT) |
125			MAX77693_HAPTIC_PWM_DIVISOR_128;
126		config_reg = MAX77843_HAP_REG_MCONFIG;
127		break;
128	default:
129		return -EINVAL;
130	}
131
132	error = regmap_write(haptic->regmap_haptic,
133			     config_reg, value);
134	if (error) {
135		dev_err(haptic->dev,
136			"failed to update haptic config: %d\n", error);
137		return error;
138	}
139
140	return 0;
141}
142
143static int max77693_haptic_lowsys(struct max77693_haptic *haptic, bool enable)
144{
145	int error;
146
147	if (haptic->dev_type != TYPE_MAX77693)
148		return 0;
149
150	error = regmap_update_bits(haptic->regmap_pmic,
151				   MAX77693_PMIC_REG_LSCNFG,
152				   MAX77693_PMIC_LOW_SYS_MASK,
153				   enable << MAX77693_PMIC_LOW_SYS_SHIFT);
154	if (error) {
155		dev_err(haptic->dev, "cannot update pmic regmap: %d\n", error);
156		return error;
157	}
158
159	return 0;
160}
161
162static void max77693_haptic_enable(struct max77693_haptic *haptic)
163{
164	int error;
165
166	if (haptic->enabled)
167		return;
168
169	error = pwm_enable(haptic->pwm_dev);
170	if (error) {
171		dev_err(haptic->dev,
172			"failed to enable haptic pwm device: %d\n", error);
173		return;
174	}
175
176	error = max77693_haptic_lowsys(haptic, true);
177	if (error)
178		goto err_enable_lowsys;
179
180	error = max77693_haptic_configure(haptic, true);
181	if (error)
182		goto err_enable_config;
183
184	haptic->enabled = true;
185
186	return;
187
188err_enable_config:
189	max77693_haptic_lowsys(haptic, false);
190err_enable_lowsys:
191	pwm_disable(haptic->pwm_dev);
192}
193
194static void max77693_haptic_disable(struct max77693_haptic *haptic)
195{
196	int error;
197
198	if (!haptic->enabled)
199		return;
200
201	error = max77693_haptic_configure(haptic, false);
202	if (error)
203		return;
204
205	error = max77693_haptic_lowsys(haptic, false);
206	if (error)
207		goto err_disable_lowsys;
208
209	pwm_disable(haptic->pwm_dev);
210	haptic->enabled = false;
211
212	return;
213
214err_disable_lowsys:
215	max77693_haptic_configure(haptic, true);
216}
217
218static void max77693_haptic_play_work(struct work_struct *work)
219{
220	struct max77693_haptic *haptic =
221			container_of(work, struct max77693_haptic, work);
222	int error;
223
224	error = max77693_haptic_set_duty_cycle(haptic);
225	if (error) {
226		dev_err(haptic->dev, "failed to set duty cycle: %d\n", error);
227		return;
228	}
229
230	if (haptic->magnitude)
231		max77693_haptic_enable(haptic);
232	else
233		max77693_haptic_disable(haptic);
234}
235
236static int max77693_haptic_play_effect(struct input_dev *dev, void *data,
237				       struct ff_effect *effect)
238{
239	struct max77693_haptic *haptic = input_get_drvdata(dev);
240	struct pwm_args pargs;
241	u64 period_mag_multi;
242
243	haptic->magnitude = effect->u.rumble.strong_magnitude;
244	if (!haptic->magnitude)
245		haptic->magnitude = effect->u.rumble.weak_magnitude;
246
247	/*
248	 * The magnitude comes from force-feedback interface.
249	 * The formula to convert magnitude to pwm_duty as follows:
250	 * - pwm_duty = (magnitude * pwm_period) / MAX_MAGNITUDE(0xFFFF)
251	 */
252	pwm_get_args(haptic->pwm_dev, &pargs);
253	period_mag_multi = (u64)pargs.period * haptic->magnitude;
254	haptic->pwm_duty = (unsigned int)(period_mag_multi >>
255						MAX_MAGNITUDE_SHIFT);
256
257	schedule_work(&haptic->work);
258
259	return 0;
260}
261
262static int max77693_haptic_open(struct input_dev *dev)
263{
264	struct max77693_haptic *haptic = input_get_drvdata(dev);
265	int error;
266
267	error = max77843_haptic_bias(haptic, true);
268	if (error)
269		return error;
270
271	error = regulator_enable(haptic->motor_reg);
272	if (error) {
273		dev_err(haptic->dev,
274			"failed to enable regulator: %d\n", error);
275		return error;
276	}
277
278	return 0;
279}
280
281static void max77693_haptic_close(struct input_dev *dev)
282{
283	struct max77693_haptic *haptic = input_get_drvdata(dev);
284	int error;
285
286	cancel_work_sync(&haptic->work);
287	max77693_haptic_disable(haptic);
288
289	error = regulator_disable(haptic->motor_reg);
290	if (error)
291		dev_err(haptic->dev,
292			"failed to disable regulator: %d\n", error);
293
294	max77843_haptic_bias(haptic, false);
295}
296
297static int max77693_haptic_probe(struct platform_device *pdev)
298{
299	struct max77693_dev *max77693 = dev_get_drvdata(pdev->dev.parent);
300	struct max77693_haptic *haptic;
301	int error;
302
303	haptic = devm_kzalloc(&pdev->dev, sizeof(*haptic), GFP_KERNEL);
304	if (!haptic)
305		return -ENOMEM;
306
307	haptic->regmap_pmic = max77693->regmap;
308	haptic->dev = &pdev->dev;
309	haptic->type = MAX77693_HAPTIC_LRA;
310	haptic->mode = MAX77693_HAPTIC_EXTERNAL_MODE;
311	haptic->suspend_state = false;
312
313	/* Variant-specific init */
314	haptic->dev_type = platform_get_device_id(pdev)->driver_data;
315	switch (haptic->dev_type) {
316	case TYPE_MAX77693:
317		haptic->regmap_haptic = max77693->regmap_haptic;
318		break;
319	case TYPE_MAX77843:
320		haptic->regmap_haptic = max77693->regmap;
321		break;
322	default:
323		dev_err(&pdev->dev, "unsupported device type: %u\n",
324			haptic->dev_type);
325		return -EINVAL;
326	}
327
328	INIT_WORK(&haptic->work, max77693_haptic_play_work);
329
330	/* Get pwm and regulatot for haptic device */
331	haptic->pwm_dev = devm_pwm_get(&pdev->dev, NULL);
332	if (IS_ERR(haptic->pwm_dev)) {
333		dev_err(&pdev->dev, "failed to get pwm device\n");
334		return PTR_ERR(haptic->pwm_dev);
335	}
336
337	/*
338	 * FIXME: pwm_apply_args() should be removed when switching to the
339	 * atomic PWM API.
340	 */
341	pwm_apply_args(haptic->pwm_dev);
342
343	haptic->motor_reg = devm_regulator_get(&pdev->dev, "haptic");
344	if (IS_ERR(haptic->motor_reg)) {
345		dev_err(&pdev->dev, "failed to get regulator\n");
346		return PTR_ERR(haptic->motor_reg);
347	}
348
349	/* Initialize input device for haptic device */
350	haptic->input_dev = devm_input_allocate_device(&pdev->dev);
351	if (!haptic->input_dev) {
352		dev_err(&pdev->dev, "failed to allocate input device\n");
353		return -ENOMEM;
354	}
355
356	haptic->input_dev->name = "max77693-haptic";
357	haptic->input_dev->id.version = 1;
358	haptic->input_dev->dev.parent = &pdev->dev;
359	haptic->input_dev->open = max77693_haptic_open;
360	haptic->input_dev->close = max77693_haptic_close;
361	input_set_drvdata(haptic->input_dev, haptic);
362	input_set_capability(haptic->input_dev, EV_FF, FF_RUMBLE);
363
364	error = input_ff_create_memless(haptic->input_dev, NULL,
365				max77693_haptic_play_effect);
366	if (error) {
367		dev_err(&pdev->dev, "failed to create force-feedback\n");
368		return error;
369	}
370
371	error = input_register_device(haptic->input_dev);
372	if (error) {
373		dev_err(&pdev->dev, "failed to register input device\n");
374		return error;
375	}
376
377	platform_set_drvdata(pdev, haptic);
378
379	return 0;
380}
381
382static int __maybe_unused max77693_haptic_suspend(struct device *dev)
383{
384	struct platform_device *pdev = to_platform_device(dev);
385	struct max77693_haptic *haptic = platform_get_drvdata(pdev);
386
387	if (haptic->enabled) {
388		max77693_haptic_disable(haptic);
389		haptic->suspend_state = true;
390	}
391
392	return 0;
393}
394
395static int __maybe_unused max77693_haptic_resume(struct device *dev)
396{
397	struct platform_device *pdev = to_platform_device(dev);
398	struct max77693_haptic *haptic = platform_get_drvdata(pdev);
399
400	if (haptic->suspend_state) {
401		max77693_haptic_enable(haptic);
402		haptic->suspend_state = false;
403	}
404
405	return 0;
406}
407
408static SIMPLE_DEV_PM_OPS(max77693_haptic_pm_ops,
409			 max77693_haptic_suspend, max77693_haptic_resume);
410
411static const struct platform_device_id max77693_haptic_id[] = {
412	{ "max77693-haptic", TYPE_MAX77693 },
413	{ "max77843-haptic", TYPE_MAX77843 },
414	{},
415};
416MODULE_DEVICE_TABLE(platform, max77693_haptic_id);
417
418static struct platform_driver max77693_haptic_driver = {
419	.driver		= {
420		.name	= "max77693-haptic",
421		.pm	= &max77693_haptic_pm_ops,
422	},
423	.probe		= max77693_haptic_probe,
424	.id_table	= max77693_haptic_id,
425};
426module_platform_driver(max77693_haptic_driver);
427
428MODULE_AUTHOR("Jaewon Kim <jaewon02.kim@samsung.com>");
429MODULE_AUTHOR("Krzysztof Kozlowski <krzk@kernel.org>");
430MODULE_DESCRIPTION("MAXIM 77693/77843 Haptic driver");
431MODULE_ALIAS("platform:max77693-haptic");
432MODULE_LICENSE("GPL");