tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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>
17#include <linux/module.h>
18#include <linux/kernel.h>
19#include <linux/platform_device.h>
20#include <linux/pwm.h>
21#include <linux/slab.h>
22
23struct pwm_beeper {
24 struct input_dev *input;
25 struct pwm_device *pwm;
26 unsigned long period;
27};
28
29#define HZ_TO_NANOSECONDS(x) (1000000000UL/(x))
30
31static int pwm_beeper_event(struct input_dev *input,
32 unsigned int type, unsigned int code, int value)
33{
34 int ret = 0;
35 struct pwm_beeper *beeper = input_get_drvdata(input);
36 unsigned long period;
37
38 if (type != EV_SND || value < 0)
39 return -EINVAL;
40
41 switch (code) {
42 case SND_BELL:
43 value = value ? 1000 : 0;
44 break;
45 case SND_TONE:
46 break;
47 default:
48 return -EINVAL;
49 }
50
51 if (value == 0) {
52 pwm_config(beeper->pwm, 0, 0);
53 pwm_disable(beeper->pwm);
54 } else {
55 period = HZ_TO_NANOSECONDS(value);
56 ret = pwm_config(beeper->pwm, period / 2, period);
57 if (ret)
58 return ret;
59 ret = pwm_enable(beeper->pwm);
60 if (ret)
61 return ret;
62 beeper->period = period;
63 }
64
65 return 0;
66}
67
68static int __devinit pwm_beeper_probe(struct platform_device *pdev)
69{
70 unsigned long pwm_id = (unsigned long)pdev->dev.platform_data;
71 struct pwm_beeper *beeper;
72 int error;
73
74 beeper = kzalloc(sizeof(*beeper), GFP_KERNEL);
75 if (!beeper)
76 return -ENOMEM;
77
78 beeper->pwm = pwm_request(pwm_id, "pwm beeper");
79
80 if (IS_ERR(beeper->pwm)) {
81 error = PTR_ERR(beeper->pwm);
82 dev_err(&pdev->dev, "Failed to request pwm device: %d\n", error);
83 goto err_free;
84 }
85
86 beeper->input = input_allocate_device();
87 if (!beeper->input) {
88 dev_err(&pdev->dev, "Failed to allocate input device\n");
89 error = -ENOMEM;
90 goto err_pwm_free;
91 }
92 beeper->input->dev.parent = &pdev->dev;
93
94 beeper->input->name = "pwm-beeper";
95 beeper->input->phys = "pwm/input0";
96 beeper->input->id.bustype = BUS_HOST;
97 beeper->input->id.vendor = 0x001f;
98 beeper->input->id.product = 0x0001;
99 beeper->input->id.version = 0x0100;
100
101 beeper->input->evbit[0] = BIT(EV_SND);
102 beeper->input->sndbit[0] = BIT(SND_TONE) | BIT(SND_BELL);
103
104 beeper->input->event = pwm_beeper_event;
105
106 input_set_drvdata(beeper->input, beeper);
107
108 error = input_register_device(beeper->input);
109 if (error) {
110 dev_err(&pdev->dev, "Failed to register input device: %d\n", error);
111 goto err_input_free;
112 }
113
114 platform_set_drvdata(pdev, beeper);
115
116 return 0;
117
118err_input_free:
119 input_free_device(beeper->input);
120err_pwm_free:
121 pwm_free(beeper->pwm);
122err_free:
123 kfree(beeper);
124
125 return error;
126}
127
128static int __devexit pwm_beeper_remove(struct platform_device *pdev)
129{
130 struct pwm_beeper *beeper = platform_get_drvdata(pdev);
131
132 platform_set_drvdata(pdev, NULL);
133 input_unregister_device(beeper->input);
134
135 pwm_disable(beeper->pwm);
136 pwm_free(beeper->pwm);
137
138 kfree(beeper);
139
140 return 0;
141}
142
143#ifdef CONFIG_PM
144static int pwm_beeper_suspend(struct device *dev)
145{
146 struct pwm_beeper *beeper = dev_get_drvdata(dev);
147
148 if (beeper->period)
149 pwm_disable(beeper->pwm);
150
151 return 0;
152}
153
154static int pwm_beeper_resume(struct device *dev)
155{
156 struct pwm_beeper *beeper = dev_get_drvdata(dev);
157
158 if (beeper->period) {
159 pwm_config(beeper->pwm, beeper->period / 2, beeper->period);
160 pwm_enable(beeper->pwm);
161 }
162
163 return 0;
164}
165
166static SIMPLE_DEV_PM_OPS(pwm_beeper_pm_ops,
167 pwm_beeper_suspend, pwm_beeper_resume);
168
169#define PWM_BEEPER_PM_OPS (&pwm_beeper_pm_ops)
170#else
171#define PWM_BEEPER_PM_OPS NULL
172#endif
173
174static struct platform_driver pwm_beeper_driver = {
175 .probe = pwm_beeper_probe,
176 .remove = __devexit_p(pwm_beeper_remove),
177 .driver = {
178 .name = "pwm-beeper",
179 .owner = THIS_MODULE,
180 .pm = PWM_BEEPER_PM_OPS,
181 },
182};
183
184static int __init pwm_beeper_init(void)
185{
186 return platform_driver_register(&pwm_beeper_driver);
187}
188module_init(pwm_beeper_init);
189
190static void __exit pwm_beeper_exit(void)
191{
192 platform_driver_unregister(&pwm_beeper_driver);
193}
194module_exit(pwm_beeper_exit);
195
196MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
197MODULE_DESCRIPTION("PWM beeper driver");
198MODULE_LICENSE("GPL");
199MODULE_ALIAS("platform:pwm-beeper");