2 * Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
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.
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.
16 #include <linux/input.h>
17 #include <linux/module.h>
18 #include <linux/kernel.h>
20 #include <linux/platform_device.h>
21 #include <linux/pwm.h>
22 #include <linux/slab.h>
23 #include <linux/workqueue.h>
26 struct input_dev
*input
;
27 struct pwm_device
*pwm
;
28 struct work_struct work
;
33 #define HZ_TO_NANOSECONDS(x) (1000000000UL/(x))
35 static void __pwm_beeper_set(struct pwm_beeper
*beeper
)
37 unsigned long period
= beeper
->period
;
40 pwm_config(beeper
->pwm
, period
/ 2, period
);
41 pwm_enable(beeper
->pwm
);
43 pwm_disable(beeper
->pwm
);
46 static void pwm_beeper_work(struct work_struct
*work
)
48 struct pwm_beeper
*beeper
=
49 container_of(work
, struct pwm_beeper
, work
);
51 __pwm_beeper_set(beeper
);
54 static int pwm_beeper_event(struct input_dev
*input
,
55 unsigned int type
, unsigned int code
, int value
)
57 struct pwm_beeper
*beeper
= input_get_drvdata(input
);
59 if (type
!= EV_SND
|| value
< 0)
64 value
= value
? 1000 : 0;
75 beeper
->period
= HZ_TO_NANOSECONDS(value
);
77 if (!beeper
->suspended
)
78 schedule_work(&beeper
->work
);
83 static void pwm_beeper_stop(struct pwm_beeper
*beeper
)
85 cancel_work_sync(&beeper
->work
);
88 pwm_disable(beeper
->pwm
);
91 static void pwm_beeper_close(struct input_dev
*input
)
93 struct pwm_beeper
*beeper
= input_get_drvdata(input
);
95 pwm_beeper_stop(beeper
);
98 static int pwm_beeper_probe(struct platform_device
*pdev
)
100 struct device
*dev
= &pdev
->dev
;
101 struct pwm_beeper
*beeper
;
104 beeper
= devm_kzalloc(dev
, sizeof(*beeper
), GFP_KERNEL
);
108 beeper
->pwm
= devm_pwm_get(dev
, NULL
);
109 if (IS_ERR(beeper
->pwm
)) {
110 error
= PTR_ERR(beeper
->pwm
);
111 if (error
!= -EPROBE_DEFER
)
112 dev_err(dev
, "Failed to request PWM device: %d\n",
118 * FIXME: pwm_apply_args() should be removed when switching to
119 * the atomic PWM API.
121 pwm_apply_args(beeper
->pwm
);
123 INIT_WORK(&beeper
->work
, pwm_beeper_work
);
125 beeper
->input
= devm_input_allocate_device(dev
);
126 if (!beeper
->input
) {
127 dev_err(dev
, "Failed to allocate input device\n");
131 beeper
->input
->name
= "pwm-beeper";
132 beeper
->input
->phys
= "pwm/input0";
133 beeper
->input
->id
.bustype
= BUS_HOST
;
134 beeper
->input
->id
.vendor
= 0x001f;
135 beeper
->input
->id
.product
= 0x0001;
136 beeper
->input
->id
.version
= 0x0100;
138 input_set_capability(beeper
->input
, EV_SND
, SND_TONE
);
139 input_set_capability(beeper
->input
, EV_SND
, SND_BELL
);
141 beeper
->input
->event
= pwm_beeper_event
;
142 beeper
->input
->close
= pwm_beeper_close
;
144 input_set_drvdata(beeper
->input
, beeper
);
146 error
= input_register_device(beeper
->input
);
148 dev_err(dev
, "Failed to register input device: %d\n", error
);
152 platform_set_drvdata(pdev
, beeper
);
157 static int __maybe_unused
pwm_beeper_suspend(struct device
*dev
)
159 struct pwm_beeper
*beeper
= dev_get_drvdata(dev
);
162 * Spinlock is taken here is not to protect write to
163 * beeper->suspended, but to ensure that pwm_beeper_event
164 * does not re-submit work once flag is set.
166 spin_lock_irq(&beeper
->input
->event_lock
);
167 beeper
->suspended
= true;
168 spin_unlock_irq(&beeper
->input
->event_lock
);
170 pwm_beeper_stop(beeper
);
175 static int __maybe_unused
pwm_beeper_resume(struct device
*dev
)
177 struct pwm_beeper
*beeper
= dev_get_drvdata(dev
);
179 spin_lock_irq(&beeper
->input
->event_lock
);
180 beeper
->suspended
= false;
181 spin_unlock_irq(&beeper
->input
->event_lock
);
183 /* Let worker figure out if we should resume beeping */
184 schedule_work(&beeper
->work
);
189 static SIMPLE_DEV_PM_OPS(pwm_beeper_pm_ops
,
190 pwm_beeper_suspend
, pwm_beeper_resume
);
193 static const struct of_device_id pwm_beeper_match
[] = {
194 { .compatible
= "pwm-beeper", },
197 MODULE_DEVICE_TABLE(of
, pwm_beeper_match
);
200 static struct platform_driver pwm_beeper_driver
= {
201 .probe
= pwm_beeper_probe
,
203 .name
= "pwm-beeper",
204 .pm
= &pwm_beeper_pm_ops
,
205 .of_match_table
= of_match_ptr(pwm_beeper_match
),
208 module_platform_driver(pwm_beeper_driver
);
210 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
211 MODULE_DESCRIPTION("PWM beeper driver");
212 MODULE_LICENSE("GPL");
213 MODULE_ALIAS("platform:pwm-beeper");