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e22739d0 LPC |
1 | /* |
2 | * Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de> | |
3 | * PWM beeper driver | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify it | |
6 | * under the terms of the GNU General Public License as published by the | |
7 | * Free Software Foundation; either version 2 of the License, or (at your | |
8 | * option) any later version. | |
9 | * | |
10 | * You should have received a copy of the GNU General Public License along | |
11 | * with this program; if not, write to the Free Software Foundation, Inc., | |
12 | * 675 Mass Ave, Cambridge, MA 02139, USA. | |
13 | * | |
14 | */ | |
15 | ||
16 | #include <linux/input.h> | |
9e549244 | 17 | #include <linux/regulator/consumer.h> |
e22739d0 LPC |
18 | #include <linux/module.h> |
19 | #include <linux/kernel.h> | |
9dbe4c32 | 20 | #include <linux/of.h> |
e22739d0 | 21 | #include <linux/platform_device.h> |
fad358a0 | 22 | #include <linux/property.h> |
e22739d0 LPC |
23 | #include <linux/pwm.h> |
24 | #include <linux/slab.h> | |
f49cf3b8 | 25 | #include <linux/workqueue.h> |
e22739d0 LPC |
26 | |
27 | struct pwm_beeper { | |
28 | struct input_dev *input; | |
29 | struct pwm_device *pwm; | |
9e549244 | 30 | struct regulator *amplifier; |
f49cf3b8 | 31 | struct work_struct work; |
e22739d0 | 32 | unsigned long period; |
fad358a0 | 33 | unsigned int bell_frequency; |
e9728f0d | 34 | bool suspended; |
9e549244 | 35 | bool amplifier_on; |
e22739d0 LPC |
36 | }; |
37 | ||
38 | #define HZ_TO_NANOSECONDS(x) (1000000000UL/(x)) | |
39 | ||
9e549244 | 40 | static int pwm_beeper_on(struct pwm_beeper *beeper, unsigned long period) |
f49cf3b8 | 41 | { |
2de8b411 | 42 | struct pwm_state state; |
9e549244 DL |
43 | int error; |
44 | ||
2de8b411 DT |
45 | pwm_get_state(beeper->pwm, &state); |
46 | ||
47 | state.enabled = true; | |
48 | state.period = period; | |
49 | pwm_set_relative_duty_cycle(&state, 50, 100); | |
9e549244 | 50 | |
2de8b411 | 51 | error = pwm_apply_state(beeper->pwm, &state); |
9e549244 DL |
52 | if (error) |
53 | return error; | |
54 | ||
55 | if (!beeper->amplifier_on) { | |
56 | error = regulator_enable(beeper->amplifier); | |
57 | if (error) { | |
58 | pwm_disable(beeper->pwm); | |
59 | return error; | |
60 | } | |
f49cf3b8 | 61 | |
9e549244 DL |
62 | beeper->amplifier_on = true; |
63 | } | |
64 | ||
65 | return 0; | |
66 | } | |
67 | ||
68 | static void pwm_beeper_off(struct pwm_beeper *beeper) | |
69 | { | |
70 | if (beeper->amplifier_on) { | |
71 | regulator_disable(beeper->amplifier); | |
72 | beeper->amplifier_on = false; | |
73 | } | |
74 | ||
75 | pwm_disable(beeper->pwm); | |
f49cf3b8 MS |
76 | } |
77 | ||
78 | static void pwm_beeper_work(struct work_struct *work) | |
79 | { | |
9e549244 DL |
80 | struct pwm_beeper *beeper = container_of(work, struct pwm_beeper, work); |
81 | unsigned long period = READ_ONCE(beeper->period); | |
f49cf3b8 | 82 | |
9e549244 DL |
83 | if (period) |
84 | pwm_beeper_on(beeper, period); | |
85 | else | |
86 | pwm_beeper_off(beeper); | |
f49cf3b8 MS |
87 | } |
88 | ||
e22739d0 LPC |
89 | static int pwm_beeper_event(struct input_dev *input, |
90 | unsigned int type, unsigned int code, int value) | |
91 | { | |
e22739d0 | 92 | struct pwm_beeper *beeper = input_get_drvdata(input); |
e22739d0 LPC |
93 | |
94 | if (type != EV_SND || value < 0) | |
95 | return -EINVAL; | |
96 | ||
97 | switch (code) { | |
98 | case SND_BELL: | |
fad358a0 | 99 | value = value ? beeper->bell_frequency : 0; |
e22739d0 LPC |
100 | break; |
101 | case SND_TONE: | |
102 | break; | |
103 | default: | |
104 | return -EINVAL; | |
105 | } | |
106 | ||
f49cf3b8 MS |
107 | if (value == 0) |
108 | beeper->period = 0; | |
109 | else | |
110 | beeper->period = HZ_TO_NANOSECONDS(value); | |
111 | ||
e9728f0d DT |
112 | if (!beeper->suspended) |
113 | schedule_work(&beeper->work); | |
e22739d0 LPC |
114 | |
115 | return 0; | |
116 | } | |
117 | ||
f49cf3b8 MS |
118 | static void pwm_beeper_stop(struct pwm_beeper *beeper) |
119 | { | |
120 | cancel_work_sync(&beeper->work); | |
9e549244 | 121 | pwm_beeper_off(beeper); |
f49cf3b8 MS |
122 | } |
123 | ||
124 | static void pwm_beeper_close(struct input_dev *input) | |
125 | { | |
126 | struct pwm_beeper *beeper = input_get_drvdata(input); | |
127 | ||
128 | pwm_beeper_stop(beeper); | |
129 | } | |
130 | ||
5298cc4c | 131 | static int pwm_beeper_probe(struct platform_device *pdev) |
e22739d0 | 132 | { |
bcf4b046 | 133 | struct device *dev = &pdev->dev; |
e22739d0 | 134 | struct pwm_beeper *beeper; |
2de8b411 | 135 | struct pwm_state state; |
fad358a0 | 136 | u32 bell_frequency; |
e22739d0 LPC |
137 | int error; |
138 | ||
bcf4b046 | 139 | beeper = devm_kzalloc(dev, sizeof(*beeper), GFP_KERNEL); |
e22739d0 LPC |
140 | if (!beeper) |
141 | return -ENOMEM; | |
142 | ||
bcf4b046 | 143 | beeper->pwm = devm_pwm_get(dev, NULL); |
e22739d0 LPC |
144 | if (IS_ERR(beeper->pwm)) { |
145 | error = PTR_ERR(beeper->pwm); | |
62481881 DL |
146 | if (error != -EPROBE_DEFER) |
147 | dev_err(dev, "Failed to request PWM device: %d\n", | |
148 | error); | |
bcf4b046 | 149 | return error; |
e22739d0 LPC |
150 | } |
151 | ||
2de8b411 DT |
152 | /* Sync up PWM state and ensure it is off. */ |
153 | pwm_init_state(beeper->pwm, &state); | |
154 | state.enabled = false; | |
155 | error = pwm_apply_state(beeper->pwm, &state); | |
156 | if (error) { | |
157 | dev_err(dev, "failed to apply initial PWM state: %d\n", | |
158 | error); | |
159 | return error; | |
160 | } | |
cfae56f1 | 161 | |
9e549244 DL |
162 | beeper->amplifier = devm_regulator_get(dev, "amp"); |
163 | if (IS_ERR(beeper->amplifier)) { | |
164 | error = PTR_ERR(beeper->amplifier); | |
165 | if (error != -EPROBE_DEFER) | |
166 | dev_err(dev, "Failed to get 'amp' regulator: %d\n", | |
167 | error); | |
168 | return error; | |
169 | } | |
170 | ||
f49cf3b8 MS |
171 | INIT_WORK(&beeper->work, pwm_beeper_work); |
172 | ||
fad358a0 GB |
173 | error = device_property_read_u32(dev, "beeper-hz", &bell_frequency); |
174 | if (error) { | |
175 | bell_frequency = 1000; | |
176 | dev_dbg(dev, | |
177 | "failed to parse 'beeper-hz' property, using default: %uHz\n", | |
178 | bell_frequency); | |
179 | } | |
180 | ||
181 | beeper->bell_frequency = bell_frequency; | |
182 | ||
bcf4b046 | 183 | beeper->input = devm_input_allocate_device(dev); |
e22739d0 | 184 | if (!beeper->input) { |
bcf4b046 DT |
185 | dev_err(dev, "Failed to allocate input device\n"); |
186 | return -ENOMEM; | |
e22739d0 | 187 | } |
e22739d0 LPC |
188 | |
189 | beeper->input->name = "pwm-beeper"; | |
190 | beeper->input->phys = "pwm/input0"; | |
191 | beeper->input->id.bustype = BUS_HOST; | |
192 | beeper->input->id.vendor = 0x001f; | |
193 | beeper->input->id.product = 0x0001; | |
194 | beeper->input->id.version = 0x0100; | |
195 | ||
48a55d7d DT |
196 | input_set_capability(beeper->input, EV_SND, SND_TONE); |
197 | input_set_capability(beeper->input, EV_SND, SND_BELL); | |
e22739d0 LPC |
198 | |
199 | beeper->input->event = pwm_beeper_event; | |
f49cf3b8 | 200 | beeper->input->close = pwm_beeper_close; |
e22739d0 LPC |
201 | |
202 | input_set_drvdata(beeper->input, beeper); | |
203 | ||
204 | error = input_register_device(beeper->input); | |
205 | if (error) { | |
bcf4b046 DT |
206 | dev_err(dev, "Failed to register input device: %d\n", error); |
207 | return error; | |
e22739d0 LPC |
208 | } |
209 | ||
210 | platform_set_drvdata(pdev, beeper); | |
211 | ||
e22739d0 LPC |
212 | return 0; |
213 | } | |
214 | ||
97a652a8 | 215 | static int __maybe_unused pwm_beeper_suspend(struct device *dev) |
e22739d0 LPC |
216 | { |
217 | struct pwm_beeper *beeper = dev_get_drvdata(dev); | |
218 | ||
e9728f0d DT |
219 | /* |
220 | * Spinlock is taken here is not to protect write to | |
221 | * beeper->suspended, but to ensure that pwm_beeper_event | |
222 | * does not re-submit work once flag is set. | |
223 | */ | |
224 | spin_lock_irq(&beeper->input->event_lock); | |
225 | beeper->suspended = true; | |
226 | spin_unlock_irq(&beeper->input->event_lock); | |
227 | ||
f49cf3b8 | 228 | pwm_beeper_stop(beeper); |
e22739d0 LPC |
229 | |
230 | return 0; | |
231 | } | |
232 | ||
97a652a8 | 233 | static int __maybe_unused pwm_beeper_resume(struct device *dev) |
e22739d0 LPC |
234 | { |
235 | struct pwm_beeper *beeper = dev_get_drvdata(dev); | |
236 | ||
e9728f0d DT |
237 | spin_lock_irq(&beeper->input->event_lock); |
238 | beeper->suspended = false; | |
239 | spin_unlock_irq(&beeper->input->event_lock); | |
240 | ||
241 | /* Let worker figure out if we should resume beeping */ | |
242 | schedule_work(&beeper->work); | |
e22739d0 LPC |
243 | |
244 | return 0; | |
245 | } | |
246 | ||
247 | static SIMPLE_DEV_PM_OPS(pwm_beeper_pm_ops, | |
248 | pwm_beeper_suspend, pwm_beeper_resume); | |
249 | ||
d56a289b SH |
250 | #ifdef CONFIG_OF |
251 | static const struct of_device_id pwm_beeper_match[] = { | |
252 | { .compatible = "pwm-beeper", }, | |
253 | { }, | |
254 | }; | |
544edf56 | 255 | MODULE_DEVICE_TABLE(of, pwm_beeper_match); |
d56a289b SH |
256 | #endif |
257 | ||
e22739d0 LPC |
258 | static struct platform_driver pwm_beeper_driver = { |
259 | .probe = pwm_beeper_probe, | |
e22739d0 LPC |
260 | .driver = { |
261 | .name = "pwm-beeper", | |
ceb5b6c8 | 262 | .pm = &pwm_beeper_pm_ops, |
d56a289b | 263 | .of_match_table = of_match_ptr(pwm_beeper_match), |
e22739d0 LPC |
264 | }, |
265 | }; | |
840a746b | 266 | module_platform_driver(pwm_beeper_driver); |
e22739d0 LPC |
267 | |
268 | MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); | |
269 | MODULE_DESCRIPTION("PWM beeper driver"); | |
270 | MODULE_LICENSE("GPL"); | |
271 | MODULE_ALIAS("platform:pwm-beeper"); |