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 bool vcc_on;
38};
39
40static int pwm_vibrator_start(struct pwm_vibrator *vibrator)
41{
42 struct device *pdev = vibrator->input->dev.parent;
43 struct pwm_state state;
44 int err;
45
46 if (!vibrator->vcc_on) {
47 err = regulator_enable(vibrator->vcc);
48 if (err) {
49 dev_err(pdev, "failed to enable regulator: %d", err);
50 return err;
51 }
52 vibrator->vcc_on = true;
53 }
54
55 pwm_get_state(vibrator->pwm, &state);
56 pwm_set_relative_duty_cycle(&state, vibrator->level, 0xffff);
57 state.enabled = true;
58
59 err = pwm_apply_state(vibrator->pwm, &state);
60 if (err) {
61 dev_err(pdev, "failed to apply pwm state: %d", err);
62 return err;
63 }
64
65 if (vibrator->pwm_dir) {
66 pwm_get_state(vibrator->pwm_dir, &state);
67 state.duty_cycle = vibrator->direction_duty_cycle;
68 state.enabled = true;
69
70 err = pwm_apply_state(vibrator->pwm_dir, &state);
71 if (err) {
72 dev_err(pdev, "failed to apply dir-pwm state: %d", err);
73 pwm_disable(vibrator->pwm);
74 return err;
75 }
76 }
77
78 return 0;
79}
80
81static void pwm_vibrator_stop(struct pwm_vibrator *vibrator)
82{
83 if (vibrator->pwm_dir)
84 pwm_disable(vibrator->pwm_dir);
85 pwm_disable(vibrator->pwm);
86
87 if (vibrator->vcc_on) {
88 regulator_disable(vibrator->vcc);
89 vibrator->vcc_on = false;
90 }
91}
92
93static void pwm_vibrator_play_work(struct work_struct *work)
94{
95 struct pwm_vibrator *vibrator = container_of(work,
96 struct pwm_vibrator, play_work);
97
98 if (vibrator->level)
99 pwm_vibrator_start(vibrator);
100 else
101 pwm_vibrator_stop(vibrator);
102}
103
104static int pwm_vibrator_play_effect(struct input_dev *dev, void *data,
105 struct ff_effect *effect)
106{
107 struct pwm_vibrator *vibrator = input_get_drvdata(dev);
108
109 vibrator->level = effect->u.rumble.strong_magnitude;
110 if (!vibrator->level)
111 vibrator->level = effect->u.rumble.weak_magnitude;
112
113 schedule_work(&vibrator->play_work);
114
115 return 0;
116}
117
118static void pwm_vibrator_close(struct input_dev *input)
119{
120 struct pwm_vibrator *vibrator = input_get_drvdata(input);
121
122 cancel_work_sync(&vibrator->play_work);
123 pwm_vibrator_stop(vibrator);
124}
125
126static int pwm_vibrator_probe(struct platform_device *pdev)
127{
128 struct pwm_vibrator *vibrator;
129 struct pwm_state state;
130 int err;
131
132 vibrator = devm_kzalloc(&pdev->dev, sizeof(*vibrator), GFP_KERNEL);
133 if (!vibrator)
134 return -ENOMEM;
135
136 vibrator->input = devm_input_allocate_device(&pdev->dev);
137 if (!vibrator->input)
138 return -ENOMEM;
139
140 vibrator->vcc = devm_regulator_get(&pdev->dev, "vcc");
141 err = PTR_ERR_OR_ZERO(vibrator->vcc);
142 if (err) {
143 if (err != -EPROBE_DEFER)
144 dev_err(&pdev->dev, "Failed to request regulator: %d",
145 err);
146 return err;
147 }
148
149 vibrator->pwm = devm_pwm_get(&pdev->dev, "enable");
150 err = PTR_ERR_OR_ZERO(vibrator->pwm);
151 if (err) {
152 if (err != -EPROBE_DEFER)
153 dev_err(&pdev->dev, "Failed to request main pwm: %d",
154 err);
155 return err;
156 }
157
158 INIT_WORK(&vibrator->play_work, pwm_vibrator_play_work);
159
160 /* Sync up PWM state and ensure it is off. */
161 pwm_init_state(vibrator->pwm, &state);
162 state.enabled = false;
163 err = pwm_apply_state(vibrator->pwm, &state);
164 if (err) {
165 dev_err(&pdev->dev, "failed to apply initial PWM state: %d",
166 err);
167 return err;
168 }
169
170 vibrator->pwm_dir = devm_pwm_get(&pdev->dev, "direction");
171 err = PTR_ERR_OR_ZERO(vibrator->pwm_dir);
172 switch (err) {
173 case 0:
174 /* Sync up PWM state and ensure it is off. */
175 pwm_init_state(vibrator->pwm_dir, &state);
176 state.enabled = false;
177 err = pwm_apply_state(vibrator->pwm_dir, &state);
178 if (err) {
179 dev_err(&pdev->dev, "failed to apply initial PWM state: %d",
180 err);
181 return err;
182 }
183
184 vibrator->direction_duty_cycle =
185 pwm_get_period(vibrator->pwm_dir) / 2;
186 device_property_read_u32(&pdev->dev, "direction-duty-cycle-ns",
187 &vibrator->direction_duty_cycle);
188 break;
189
190 case -ENODATA:
191 /* Direction PWM is optional */
192 vibrator->pwm_dir = NULL;
193 break;
194
195 default:
196 dev_err(&pdev->dev, "Failed to request direction pwm: %d", err);
197 /* Fall through */
198
199 case -EPROBE_DEFER:
200 return err;
201 }
202
203 vibrator->input->name = "pwm-vibrator";
204 vibrator->input->id.bustype = BUS_HOST;
205 vibrator->input->dev.parent = &pdev->dev;
206 vibrator->input->close = pwm_vibrator_close;
207
208 input_set_drvdata(vibrator->input, vibrator);
209 input_set_capability(vibrator->input, EV_FF, FF_RUMBLE);
210
211 err = input_ff_create_memless(vibrator->input, NULL,
212 pwm_vibrator_play_effect);
213 if (err) {
214 dev_err(&pdev->dev, "Couldn't create FF dev: %d", err);
215 return err;
216 }
217
218 err = input_register_device(vibrator->input);
219 if (err) {
220 dev_err(&pdev->dev, "Couldn't register input dev: %d", err);
221 return err;
222 }
223
224 platform_set_drvdata(pdev, vibrator);
225
226 return 0;
227}
228
229static int __maybe_unused pwm_vibrator_suspend(struct device *dev)
230{
231 struct pwm_vibrator *vibrator = dev_get_drvdata(dev);
232
233 cancel_work_sync(&vibrator->play_work);
234 if (vibrator->level)
235 pwm_vibrator_stop(vibrator);
236
237 return 0;
238}
239
240static int __maybe_unused pwm_vibrator_resume(struct device *dev)
241{
242 struct pwm_vibrator *vibrator = dev_get_drvdata(dev);
243
244 if (vibrator->level)
245 pwm_vibrator_start(vibrator);
246
247 return 0;
248}
249
250static SIMPLE_DEV_PM_OPS(pwm_vibrator_pm_ops,
251 pwm_vibrator_suspend, pwm_vibrator_resume);
252
253#ifdef CONFIG_OF
254static const struct of_device_id pwm_vibra_dt_match_table[] = {
255 { .compatible = "pwm-vibrator" },
256 {},
257};
258MODULE_DEVICE_TABLE(of, pwm_vibra_dt_match_table);
259#endif
260
261static struct platform_driver pwm_vibrator_driver = {
262 .probe = pwm_vibrator_probe,
263 .driver = {
264 .name = "pwm-vibrator",
265 .pm = &pwm_vibrator_pm_ops,
266 .of_match_table = of_match_ptr(pwm_vibra_dt_match_table),
267 },
268};
269module_platform_driver(pwm_vibrator_driver);
270
271MODULE_AUTHOR("Sebastian Reichel <sre@kernel.org>");
272MODULE_DESCRIPTION("PWM vibrator driver");
273MODULE_LICENSE("GPL");
274MODULE_ALIAS("platform:pwm-vibrator");
275