1/*
  2 *  PWM vibrator driver
  3 *
  4 *  Copyright (C) 2017 Collabora Ltd.
  5 *
  6 *  Based on previous work from:
  7 *  Copyright (C) 2012 Dmitry Torokhov <dmitry.torokhov@gmail.com>
  8 *
  9 *  Based on PWM beeper driver:
 10 *  Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
 11 *
 12 *  This program is free software; you can redistribute it and/or modify it
 13 *  under  the terms of the GNU General  Public License as published by the
 14 *  Free Software Foundation;  either version 2 of the License, or (at your
 15 *  option) any later version.
 16 */
 17
 18#include <linux/input.h>
 19#include <linux/kernel.h>
 20#include <linux/module.h>
 21#include <linux/of_device.h>
 22#include <linux/platform_device.h>
 23#include <linux/property.h>
 24#include <linux/pwm.h>
 25#include <linux/regulator/consumer.h>
 26#include <linux/slab.h>
 27
 28struct pwm_vibrator {
 29	struct input_dev *input;
 30	struct pwm_device *pwm;
 31	struct pwm_device *pwm_dir;
 32	struct regulator *vcc;
 33
 34	struct work_struct play_work;
 35	u16 level;
 36	u32 direction_duty_cycle;
 37};
 38
 39static int pwm_vibrator_start(struct pwm_vibrator *vibrator)
 40{
 41	struct device *pdev = vibrator->input->dev.parent;
 42	struct pwm_state state;
 43	int err;
 44
 45	err = regulator_enable(vibrator->vcc);
 46	if (err) {
 47		dev_err(pdev, "failed to enable regulator: %d", err);
 48		return err;
 49	}
 50
 51	pwm_get_state(vibrator->pwm, &state);
 52	pwm_set_relative_duty_cycle(&state, vibrator->level, 0xffff);
 53	state.enabled = true;
 54
 55	err = pwm_apply_state(vibrator->pwm, &state);
 56	if (err) {
 57		dev_err(pdev, "failed to apply pwm state: %d", err);
 58		return err;
 59	}
 60
 61	if (vibrator->pwm_dir) {
 62		pwm_get_state(vibrator->pwm_dir, &state);
 63		state.duty_cycle = vibrator->direction_duty_cycle;
 64		state.enabled = true;
 65
 66		err = pwm_apply_state(vibrator->pwm_dir, &state);
 67		if (err) {
 68			dev_err(pdev, "failed to apply dir-pwm state: %d", err);
 69			pwm_disable(vibrator->pwm);
 70			return err;
 71		}
 72	}
 73
 74	return 0;
 75}
 76
 77static void pwm_vibrator_stop(struct pwm_vibrator *vibrator)
 78{
 79	regulator_disable(vibrator->vcc);
 80
 81	if (vibrator->pwm_dir)
 82		pwm_disable(vibrator->pwm_dir);
 83	pwm_disable(vibrator->pwm);
 84}
 85
 86static void pwm_vibrator_play_work(struct work_struct *work)
 87{
 88	struct pwm_vibrator *vibrator = container_of(work,
 89					struct pwm_vibrator, play_work);
 90
 91	if (vibrator->level)
 92		pwm_vibrator_start(vibrator);
 93	else
 94		pwm_vibrator_stop(vibrator);
 95}
 96
 97static int pwm_vibrator_play_effect(struct input_dev *dev, void *data,
 98				    struct ff_effect *effect)
 99{
100	struct pwm_vibrator *vibrator = input_get_drvdata(dev);
101
102	vibrator->level = effect->u.rumble.strong_magnitude;
103	if (!vibrator->level)
104		vibrator->level = effect->u.rumble.weak_magnitude;
105
106	schedule_work(&vibrator->play_work);
107
108	return 0;
109}
110
111static void pwm_vibrator_close(struct input_dev *input)
112{
113	struct pwm_vibrator *vibrator = input_get_drvdata(input);
114
115	cancel_work_sync(&vibrator->play_work);
116	pwm_vibrator_stop(vibrator);
117}
118
119static int pwm_vibrator_probe(struct platform_device *pdev)
120{
121	struct pwm_vibrator *vibrator;
122	struct pwm_state state;
123	int err;
124
125	vibrator = devm_kzalloc(&pdev->dev, sizeof(*vibrator), GFP_KERNEL);
126	if (!vibrator)
127		return -ENOMEM;
128
129	vibrator->input = devm_input_allocate_device(&pdev->dev);
130	if (!vibrator->input)
131		return -ENOMEM;
132
133	vibrator->vcc = devm_regulator_get(&pdev->dev, "vcc");
134	err = PTR_ERR_OR_ZERO(vibrator->vcc);
135	if (err) {
136		if (err != -EPROBE_DEFER)
137			dev_err(&pdev->dev, "Failed to request regulator: %d",
138				err);
139		return err;
140	}
141
142	vibrator->pwm = devm_pwm_get(&pdev->dev, "enable");
143	err = PTR_ERR_OR_ZERO(vibrator->pwm);
144	if (err) {
145		if (err != -EPROBE_DEFER)
146			dev_err(&pdev->dev, "Failed to request main pwm: %d",
147				err);
148		return err;
149	}
150
151	INIT_WORK(&vibrator->play_work, pwm_vibrator_play_work);
152
153	/* Sync up PWM state and ensure it is off. */
154	pwm_init_state(vibrator->pwm, &state);
155	state.enabled = false;
156	err = pwm_apply_state(vibrator->pwm, &state);
157	if (err) {
158		dev_err(&pdev->dev, "failed to apply initial PWM state: %d",
159			err);
160		return err;
161	}
162
163	vibrator->pwm_dir = devm_pwm_get(&pdev->dev, "direction");
164	err = PTR_ERR_OR_ZERO(vibrator->pwm_dir);
165	switch (err) {
166	case 0:
167		/* Sync up PWM state and ensure it is off. */
168		pwm_init_state(vibrator->pwm_dir, &state);
169		state.enabled = false;
170		err = pwm_apply_state(vibrator->pwm_dir, &state);
171		if (err) {
172			dev_err(&pdev->dev, "failed to apply initial PWM state: %d",
173				err);
174			return err;
175		}
176
177		vibrator->direction_duty_cycle =
178			pwm_get_period(vibrator->pwm_dir) / 2;
179		device_property_read_u32(&pdev->dev, "direction-duty-cycle-ns",
180					 &vibrator->direction_duty_cycle);
181		break;
182
183	case -ENODATA:
184		/* Direction PWM is optional */
185		vibrator->pwm_dir = NULL;
186		break;
187
188	default:
189		dev_err(&pdev->dev, "Failed to request direction pwm: %d", err);
190		/* Fall through */
191
192	case -EPROBE_DEFER:
193		return err;
194	}
195
196	vibrator->input->name = "pwm-vibrator";
197	vibrator->input->id.bustype = BUS_HOST;
198	vibrator->input->dev.parent = &pdev->dev;
199	vibrator->input->close = pwm_vibrator_close;
200
201	input_set_drvdata(vibrator->input, vibrator);
202	input_set_capability(vibrator->input, EV_FF, FF_RUMBLE);
203
204	err = input_ff_create_memless(vibrator->input, NULL,
205				      pwm_vibrator_play_effect);
206	if (err) {
207		dev_err(&pdev->dev, "Couldn't create FF dev: %d", err);
208		return err;
209	}
210
211	err = input_register_device(vibrator->input);
212	if (err) {
213		dev_err(&pdev->dev, "Couldn't register input dev: %d", err);
214		return err;
215	}
216
217	platform_set_drvdata(pdev, vibrator);
218
219	return 0;
220}
221
222static int __maybe_unused pwm_vibrator_suspend(struct device *dev)
223{
224	struct pwm_vibrator *vibrator = dev_get_drvdata(dev);
225
226	cancel_work_sync(&vibrator->play_work);
227	if (vibrator->level)
228		pwm_vibrator_stop(vibrator);
229
230	return 0;
231}
232
233static int __maybe_unused pwm_vibrator_resume(struct device *dev)
234{
235	struct pwm_vibrator *vibrator = dev_get_drvdata(dev);
236
237	if (vibrator->level)
238		pwm_vibrator_start(vibrator);
239
240	return 0;
241}
242
243static SIMPLE_DEV_PM_OPS(pwm_vibrator_pm_ops,
244			 pwm_vibrator_suspend, pwm_vibrator_resume);
245
246#ifdef CONFIG_OF
247static const struct of_device_id pwm_vibra_dt_match_table[] = {
248	{ .compatible = "pwm-vibrator" },
249	{},
250};
251MODULE_DEVICE_TABLE(of, pwm_vibra_dt_match_table);
252#endif
253
254static struct platform_driver pwm_vibrator_driver = {
255	.probe	= pwm_vibrator_probe,
256	.driver	= {
257		.name	= "pwm-vibrator",
258		.pm	= &pwm_vibrator_pm_ops,
259		.of_match_table = of_match_ptr(pwm_vibra_dt_match_table),
260	},
261};
262module_platform_driver(pwm_vibrator_driver);
263
264MODULE_AUTHOR("Sebastian Reichel <sre@kernel.org>");
265MODULE_DESCRIPTION("PWM vibrator driver");
266MODULE_LICENSE("GPL");
267MODULE_ALIAS("platform:pwm-vibrator");