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/of.h>
20#include <linux/platform_device.h>
21#include <linux/pwm.h>
22#include <linux/slab.h>
23#include <linux/workqueue.h>
24
25struct pwm_beeper {
26	struct input_dev *input;
27	struct pwm_device *pwm;
28	struct work_struct work;
29	unsigned long period;
30};
31
32#define HZ_TO_NANOSECONDS(x) (1000000000UL/(x))
33
34static void __pwm_beeper_set(struct pwm_beeper *beeper)
35{
36	unsigned long period = beeper->period;
37
38	if (period) {
39		pwm_config(beeper->pwm, period / 2, period);
40		pwm_enable(beeper->pwm);
41	} else
42		pwm_disable(beeper->pwm);
43}
44
45static void pwm_beeper_work(struct work_struct *work)
46{
47	struct pwm_beeper *beeper =
48		container_of(work, struct pwm_beeper, work);
49
50	__pwm_beeper_set(beeper);
51}
52
53static int pwm_beeper_event(struct input_dev *input,
54			    unsigned int type, unsigned int code, int value)
55{
56	struct pwm_beeper *beeper = input_get_drvdata(input);
57
58	if (type != EV_SND || value < 0)
59		return -EINVAL;
60
61	switch (code) {
62	case SND_BELL:
63		value = value ? 1000 : 0;
64		break;
65	case SND_TONE:
66		break;
67	default:
68		return -EINVAL;
69	}
70
71	if (value == 0)
72		beeper->period = 0;
73	else
74		beeper->period = HZ_TO_NANOSECONDS(value);
75
76	schedule_work(&beeper->work);
77
78	return 0;
79}
80
81static void pwm_beeper_stop(struct pwm_beeper *beeper)
82{
83	cancel_work_sync(&beeper->work);
84
85	if (beeper->period)
86		pwm_disable(beeper->pwm);
87}
88
89static void pwm_beeper_close(struct input_dev *input)
90{
91	struct pwm_beeper *beeper = input_get_drvdata(input);
92
93	pwm_beeper_stop(beeper);
94}
95
96static int pwm_beeper_probe(struct platform_device *pdev)
97{
98	unsigned long pwm_id = (unsigned long)dev_get_platdata(&pdev->dev);
99	struct pwm_beeper *beeper;
100	int error;
101
102	beeper = kzalloc(sizeof(*beeper), GFP_KERNEL);
103	if (!beeper)
104		return -ENOMEM;
105
106	beeper->pwm = pwm_get(&pdev->dev, NULL);
107	if (IS_ERR(beeper->pwm)) {
108		dev_dbg(&pdev->dev, "unable to request PWM, trying legacy API\n");
109		beeper->pwm = pwm_request(pwm_id, "pwm beeper");
110	}
111
112	if (IS_ERR(beeper->pwm)) {
113		error = PTR_ERR(beeper->pwm);
114		dev_err(&pdev->dev, "Failed to request pwm device: %d\n", error);
115		goto err_free;
116	}
117
118	INIT_WORK(&beeper->work, pwm_beeper_work);
119
120	beeper->input = input_allocate_device();
121	if (!beeper->input) {
122		dev_err(&pdev->dev, "Failed to allocate input device\n");
123		error = -ENOMEM;
124		goto err_pwm_free;
125	}
126	beeper->input->dev.parent = &pdev->dev;
127
128	beeper->input->name = "pwm-beeper";
129	beeper->input->phys = "pwm/input0";
130	beeper->input->id.bustype = BUS_HOST;
131	beeper->input->id.vendor = 0x001f;
132	beeper->input->id.product = 0x0001;
133	beeper->input->id.version = 0x0100;
134
135	beeper->input->evbit[0] = BIT(EV_SND);
136	beeper->input->sndbit[0] = BIT(SND_TONE) | BIT(SND_BELL);
137
138	beeper->input->event = pwm_beeper_event;
139	beeper->input->close = pwm_beeper_close;
140
141	input_set_drvdata(beeper->input, beeper);
142
143	error = input_register_device(beeper->input);
144	if (error) {
145		dev_err(&pdev->dev, "Failed to register input device: %d\n", error);
146		goto err_input_free;
147	}
148
149	platform_set_drvdata(pdev, beeper);
150
151	return 0;
152
153err_input_free:
154	input_free_device(beeper->input);
155err_pwm_free:
156	pwm_free(beeper->pwm);
157err_free:
158	kfree(beeper);
159
160	return error;
161}
162
163static int pwm_beeper_remove(struct platform_device *pdev)
164{
165	struct pwm_beeper *beeper = platform_get_drvdata(pdev);
166
167	input_unregister_device(beeper->input);
168
169	pwm_free(beeper->pwm);
170
171	kfree(beeper);
172
173	return 0;
174}
175
176static int __maybe_unused pwm_beeper_suspend(struct device *dev)
177{
178	struct pwm_beeper *beeper = dev_get_drvdata(dev);
179
180	pwm_beeper_stop(beeper);
181
182	return 0;
183}
184
185static int __maybe_unused pwm_beeper_resume(struct device *dev)
186{
187	struct pwm_beeper *beeper = dev_get_drvdata(dev);
188
189	if (beeper->period)
190		__pwm_beeper_set(beeper);
191
192	return 0;
193}
194
195static SIMPLE_DEV_PM_OPS(pwm_beeper_pm_ops,
196			 pwm_beeper_suspend, pwm_beeper_resume);
197
198#ifdef CONFIG_OF
199static const struct of_device_id pwm_beeper_match[] = {
200	{ .compatible = "pwm-beeper", },
201	{ },
202};
203#endif
204
205static struct platform_driver pwm_beeper_driver = {
206	.probe	= pwm_beeper_probe,
207	.remove = pwm_beeper_remove,
208	.driver = {
209		.name	= "pwm-beeper",
210		.pm	= &pwm_beeper_pm_ops,
211		.of_match_table = of_match_ptr(pwm_beeper_match),
212	},
213};
214module_platform_driver(pwm_beeper_driver);
215
216MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
217MODULE_DESCRIPTION("PWM beeper driver");
218MODULE_LICENSE("GPL");
219MODULE_ALIAS("platform:pwm-beeper");
220