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/gpio/consumer.h>
15 #include <linux/input.h>
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/of.h>
19 #include <linux/platform_device.h>
20 #include <linux/property.h>
21 #include <linux/pwm.h>
22 #include <linux/regulator/consumer.h>
23 #include <linux/slab.h>
24
25 struct pwm_vibrator {
26 struct input_dev *input;
27 struct gpio_desc *enable_gpio;
28 struct pwm_device *pwm;
29 struct pwm_device *pwm_dir;
30 struct regulator *vcc;
31
32 struct work_struct play_work;
33 u16 level;
34 u32 direction_duty_cycle;
35 bool vcc_on;
36 };
37
pwm_vibrator_start(struct pwm_vibrator * vibrator)38 static int pwm_vibrator_start(struct pwm_vibrator *vibrator)
39 {
40 struct device *pdev = vibrator->input->dev.parent;
41 struct pwm_state state;
42 int err;
43
44 if (!vibrator->vcc_on) {
45 err = regulator_enable(vibrator->vcc);
46 if (err) {
47 dev_err(pdev, "failed to enable regulator: %d\n", err);
48 return err;
49 }
50 vibrator->vcc_on = true;
51 }
52
53 gpiod_set_value_cansleep(vibrator->enable_gpio, 1);
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_might_sleep(vibrator->pwm, &state);
60 if (err) {
61 dev_err(pdev, "failed to apply pwm state: %d\n", 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_might_sleep(vibrator->pwm_dir, &state);
71 if (err) {
72 dev_err(pdev, "failed to apply dir-pwm state: %d\n", err);
73 pwm_disable(vibrator->pwm);
74 return err;
75 }
76 }
77
78 return 0;
79 }
80
pwm_vibrator_stop(struct pwm_vibrator * vibrator)81 static 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 gpiod_set_value_cansleep(vibrator->enable_gpio, 0);
88
89 if (vibrator->vcc_on) {
90 regulator_disable(vibrator->vcc);
91 vibrator->vcc_on = false;
92 }
93 }
94
pwm_vibrator_play_work(struct work_struct * work)95 static void pwm_vibrator_play_work(struct work_struct *work)
96 {
97 struct pwm_vibrator *vibrator = container_of(work,
98 struct pwm_vibrator, play_work);
99
100 if (vibrator->level)
101 pwm_vibrator_start(vibrator);
102 else
103 pwm_vibrator_stop(vibrator);
104 }
105
pwm_vibrator_play_effect(struct input_dev * dev,void * data,struct ff_effect * effect)106 static int pwm_vibrator_play_effect(struct input_dev *dev, void *data,
107 struct ff_effect *effect)
108 {
109 struct pwm_vibrator *vibrator = input_get_drvdata(dev);
110
111 vibrator->level = effect->u.rumble.strong_magnitude;
112 if (!vibrator->level)
113 vibrator->level = effect->u.rumble.weak_magnitude;
114
115 schedule_work(&vibrator->play_work);
116
117 return 0;
118 }
119
pwm_vibrator_close(struct input_dev * input)120 static void pwm_vibrator_close(struct input_dev *input)
121 {
122 struct pwm_vibrator *vibrator = input_get_drvdata(input);
123
124 cancel_work_sync(&vibrator->play_work);
125 pwm_vibrator_stop(vibrator);
126 }
127
pwm_vibrator_probe(struct platform_device * pdev)128 static int pwm_vibrator_probe(struct platform_device *pdev)
129 {
130 struct pwm_vibrator *vibrator;
131 struct pwm_state state;
132 int err;
133
134 vibrator = devm_kzalloc(&pdev->dev, sizeof(*vibrator), GFP_KERNEL);
135 if (!vibrator)
136 return -ENOMEM;
137
138 vibrator->input = devm_input_allocate_device(&pdev->dev);
139 if (!vibrator->input)
140 return -ENOMEM;
141
142 vibrator->vcc = devm_regulator_get(&pdev->dev, "vcc");
143 if (IS_ERR(vibrator->vcc))
144 return dev_err_probe(&pdev->dev, PTR_ERR(vibrator->vcc),
145 "Failed to request regulator\n");
146
147 vibrator->enable_gpio = devm_gpiod_get_optional(&pdev->dev, "enable",
148 GPIOD_OUT_LOW);
149 if (IS_ERR(vibrator->enable_gpio))
150 return dev_err_probe(&pdev->dev, PTR_ERR(vibrator->enable_gpio),
151 "Failed to request enable gpio\n");
152
153 vibrator->pwm = devm_pwm_get(&pdev->dev, "enable");
154 if (IS_ERR(vibrator->pwm))
155 return dev_err_probe(&pdev->dev, PTR_ERR(vibrator->pwm),
156 "Failed to request main pwm\n");
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_might_sleep(vibrator->pwm, &state);
164 if (err) {
165 dev_err(&pdev->dev, "failed to apply initial PWM state: %d\n",
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_might_sleep(vibrator->pwm_dir, &state);
178 if (err) {
179 dev_err(&pdev->dev, "failed to apply initial PWM state: %d\n",
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\n", err);
197 fallthrough;
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\n", 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\n", err);
221 return err;
222 }
223
224 platform_set_drvdata(pdev, vibrator);
225
226 return 0;
227 }
228
pwm_vibrator_suspend(struct device * dev)229 static int 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
pwm_vibrator_resume(struct device * dev)240 static int 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
250 static DEFINE_SIMPLE_DEV_PM_OPS(pwm_vibrator_pm_ops,
251 pwm_vibrator_suspend, pwm_vibrator_resume);
252
253 #ifdef CONFIG_OF
254 static const struct of_device_id pwm_vibra_dt_match_table[] = {
255 { .compatible = "pwm-vibrator" },
256 {},
257 };
258 MODULE_DEVICE_TABLE(of, pwm_vibra_dt_match_table);
259 #endif
260
261 static struct platform_driver pwm_vibrator_driver = {
262 .probe = pwm_vibrator_probe,
263 .driver = {
264 .name = "pwm-vibrator",
265 .pm = pm_sleep_ptr(&pwm_vibrator_pm_ops),
266 .of_match_table = of_match_ptr(pwm_vibra_dt_match_table),
267 },
268 };
269 module_platform_driver(pwm_vibrator_driver);
270
271 MODULE_AUTHOR("Sebastian Reichel <sre@kernel.org>");
272 MODULE_DESCRIPTION("PWM vibrator driver");
273 MODULE_LICENSE("GPL");
274 MODULE_ALIAS("platform:pwm-vibrator");
275