1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * PWM vibrator driver
4 *
5 * Copyright (C) 2017 Collabora Ltd.
6 *
7 * Based on previous work from:
8 * Copyright (C) 2012 Dmitry Torokhov <dmitry.torokhov@gmail.com>
9 *
10 * Based on PWM beeper driver:
11 * Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
12 */
13
14 #include <linux/input.h>
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/of_device.h>
18 #include <linux/platform_device.h>
19 #include <linux/property.h>
20 #include <linux/pwm.h>
21 #include <linux/regulator/consumer.h>
22 #include <linux/slab.h>
23
24 struct pwm_vibrator {
25 struct input_dev *input;
26 struct pwm_device *pwm;
27 struct pwm_device *pwm_dir;
28 struct regulator *vcc;
29
30 struct work_struct play_work;
31 u16 level;
32 u32 direction_duty_cycle;
33 bool vcc_on;
34 };
35
pwm_vibrator_start(struct pwm_vibrator * vibrator)36 static int pwm_vibrator_start(struct pwm_vibrator *vibrator)
37 {
38 struct device *pdev = vibrator->input->dev.parent;
39 struct pwm_state state;
40 int err;
41
42 if (!vibrator->vcc_on) {
43 err = regulator_enable(vibrator->vcc);
44 if (err) {
45 dev_err(pdev, "failed to enable regulator: %d", err);
46 return err;
47 }
48 vibrator->vcc_on = true;
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
pwm_vibrator_stop(struct pwm_vibrator * vibrator)77 static void pwm_vibrator_stop(struct pwm_vibrator *vibrator)
78 {
79 if (vibrator->pwm_dir)
80 pwm_disable(vibrator->pwm_dir);
81 pwm_disable(vibrator->pwm);
82
83 if (vibrator->vcc_on) {
84 regulator_disable(vibrator->vcc);
85 vibrator->vcc_on = false;
86 }
87 }
88
pwm_vibrator_play_work(struct work_struct * work)89 static void pwm_vibrator_play_work(struct work_struct *work)
90 {
91 struct pwm_vibrator *vibrator = container_of(work,
92 struct pwm_vibrator, play_work);
93
94 if (vibrator->level)
95 pwm_vibrator_start(vibrator);
96 else
97 pwm_vibrator_stop(vibrator);
98 }
99
pwm_vibrator_play_effect(struct input_dev * dev,void * data,struct ff_effect * effect)100 static int pwm_vibrator_play_effect(struct input_dev *dev, void *data,
101 struct ff_effect *effect)
102 {
103 struct pwm_vibrator *vibrator = input_get_drvdata(dev);
104
105 vibrator->level = effect->u.rumble.strong_magnitude;
106 if (!vibrator->level)
107 vibrator->level = effect->u.rumble.weak_magnitude;
108
109 schedule_work(&vibrator->play_work);
110
111 return 0;
112 }
113
pwm_vibrator_close(struct input_dev * input)114 static void pwm_vibrator_close(struct input_dev *input)
115 {
116 struct pwm_vibrator *vibrator = input_get_drvdata(input);
117
118 cancel_work_sync(&vibrator->play_work);
119 pwm_vibrator_stop(vibrator);
120 }
121
pwm_vibrator_probe(struct platform_device * pdev)122 static int pwm_vibrator_probe(struct platform_device *pdev)
123 {
124 struct pwm_vibrator *vibrator;
125 struct pwm_state state;
126 int err;
127
128 vibrator = devm_kzalloc(&pdev->dev, sizeof(*vibrator), GFP_KERNEL);
129 if (!vibrator)
130 return -ENOMEM;
131
132 vibrator->input = devm_input_allocate_device(&pdev->dev);
133 if (!vibrator->input)
134 return -ENOMEM;
135
136 vibrator->vcc = devm_regulator_get(&pdev->dev, "vcc");
137 err = PTR_ERR_OR_ZERO(vibrator->vcc);
138 if (err) {
139 if (err != -EPROBE_DEFER)
140 dev_err(&pdev->dev, "Failed to request regulator: %d",
141 err);
142 return err;
143 }
144
145 vibrator->pwm = devm_pwm_get(&pdev->dev, "enable");
146 err = PTR_ERR_OR_ZERO(vibrator->pwm);
147 if (err) {
148 if (err != -EPROBE_DEFER)
149 dev_err(&pdev->dev, "Failed to request main pwm: %d",
150 err);
151 return err;
152 }
153
154 INIT_WORK(&vibrator->play_work, pwm_vibrator_play_work);
155
156 /* Sync up PWM state and ensure it is off. */
157 pwm_init_state(vibrator->pwm, &state);
158 state.enabled = false;
159 err = pwm_apply_state(vibrator->pwm, &state);
160 if (err) {
161 dev_err(&pdev->dev, "failed to apply initial PWM state: %d",
162 err);
163 return err;
164 }
165
166 vibrator->pwm_dir = devm_pwm_get(&pdev->dev, "direction");
167 err = PTR_ERR_OR_ZERO(vibrator->pwm_dir);
168 switch (err) {
169 case 0:
170 /* Sync up PWM state and ensure it is off. */
171 pwm_init_state(vibrator->pwm_dir, &state);
172 state.enabled = false;
173 err = pwm_apply_state(vibrator->pwm_dir, &state);
174 if (err) {
175 dev_err(&pdev->dev, "failed to apply initial PWM state: %d",
176 err);
177 return err;
178 }
179
180 vibrator->direction_duty_cycle =
181 pwm_get_period(vibrator->pwm_dir) / 2;
182 device_property_read_u32(&pdev->dev, "direction-duty-cycle-ns",
183 &vibrator->direction_duty_cycle);
184 break;
185
186 case -ENODATA:
187 /* Direction PWM is optional */
188 vibrator->pwm_dir = NULL;
189 break;
190
191 default:
192 dev_err(&pdev->dev, "Failed to request direction pwm: %d", err);
193 fallthrough;
194
195 case -EPROBE_DEFER:
196 return err;
197 }
198
199 vibrator->input->name = "pwm-vibrator";
200 vibrator->input->id.bustype = BUS_HOST;
201 vibrator->input->dev.parent = &pdev->dev;
202 vibrator->input->close = pwm_vibrator_close;
203
204 input_set_drvdata(vibrator->input, vibrator);
205 input_set_capability(vibrator->input, EV_FF, FF_RUMBLE);
206
207 err = input_ff_create_memless(vibrator->input, NULL,
208 pwm_vibrator_play_effect);
209 if (err) {
210 dev_err(&pdev->dev, "Couldn't create FF dev: %d", err);
211 return err;
212 }
213
214 err = input_register_device(vibrator->input);
215 if (err) {
216 dev_err(&pdev->dev, "Couldn't register input dev: %d", err);
217 return err;
218 }
219
220 platform_set_drvdata(pdev, vibrator);
221
222 return 0;
223 }
224
pwm_vibrator_suspend(struct device * dev)225 static int __maybe_unused pwm_vibrator_suspend(struct device *dev)
226 {
227 struct pwm_vibrator *vibrator = dev_get_drvdata(dev);
228
229 cancel_work_sync(&vibrator->play_work);
230 if (vibrator->level)
231 pwm_vibrator_stop(vibrator);
232
233 return 0;
234 }
235
pwm_vibrator_resume(struct device * dev)236 static int __maybe_unused pwm_vibrator_resume(struct device *dev)
237 {
238 struct pwm_vibrator *vibrator = dev_get_drvdata(dev);
239
240 if (vibrator->level)
241 pwm_vibrator_start(vibrator);
242
243 return 0;
244 }
245
246 static SIMPLE_DEV_PM_OPS(pwm_vibrator_pm_ops,
247 pwm_vibrator_suspend, pwm_vibrator_resume);
248
249 #ifdef CONFIG_OF
250 static const struct of_device_id pwm_vibra_dt_match_table[] = {
251 { .compatible = "pwm-vibrator" },
252 {},
253 };
254 MODULE_DEVICE_TABLE(of, pwm_vibra_dt_match_table);
255 #endif
256
257 static struct platform_driver pwm_vibrator_driver = {
258 .probe = pwm_vibrator_probe,
259 .driver = {
260 .name = "pwm-vibrator",
261 .pm = &pwm_vibrator_pm_ops,
262 .of_match_table = of_match_ptr(pwm_vibra_dt_match_table),
263 },
264 };
265 module_platform_driver(pwm_vibrator_driver);
266
267 MODULE_AUTHOR("Sebastian Reichel <sre@kernel.org>");
268 MODULE_DESCRIPTION("PWM vibrator driver");
269 MODULE_LICENSE("GPL");
270 MODULE_ALIAS("platform:pwm-vibrator");
271