xref: /openbmc/linux/drivers/input/misc/pwm-vibra.c (revision a10c3d5f)
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