xref: /openbmc/linux/drivers/input/misc/pwm-beeper.c (revision 861e10be)
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 
23 struct 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 
31 static 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 
68 static int 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_get(&pdev->dev, NULL);
79 	if (IS_ERR(beeper->pwm)) {
80 		dev_dbg(&pdev->dev, "unable to request PWM, trying legacy API\n");
81 		beeper->pwm = pwm_request(pwm_id, "pwm beeper");
82 	}
83 
84 	if (IS_ERR(beeper->pwm)) {
85 		error = PTR_ERR(beeper->pwm);
86 		dev_err(&pdev->dev, "Failed to request pwm device: %d\n", error);
87 		goto err_free;
88 	}
89 
90 	beeper->input = input_allocate_device();
91 	if (!beeper->input) {
92 		dev_err(&pdev->dev, "Failed to allocate input device\n");
93 		error = -ENOMEM;
94 		goto err_pwm_free;
95 	}
96 	beeper->input->dev.parent = &pdev->dev;
97 
98 	beeper->input->name = "pwm-beeper";
99 	beeper->input->phys = "pwm/input0";
100 	beeper->input->id.bustype = BUS_HOST;
101 	beeper->input->id.vendor = 0x001f;
102 	beeper->input->id.product = 0x0001;
103 	beeper->input->id.version = 0x0100;
104 
105 	beeper->input->evbit[0] = BIT(EV_SND);
106 	beeper->input->sndbit[0] = BIT(SND_TONE) | BIT(SND_BELL);
107 
108 	beeper->input->event = pwm_beeper_event;
109 
110 	input_set_drvdata(beeper->input, beeper);
111 
112 	error = input_register_device(beeper->input);
113 	if (error) {
114 		dev_err(&pdev->dev, "Failed to register input device: %d\n", error);
115 		goto err_input_free;
116 	}
117 
118 	platform_set_drvdata(pdev, beeper);
119 
120 	return 0;
121 
122 err_input_free:
123 	input_free_device(beeper->input);
124 err_pwm_free:
125 	pwm_free(beeper->pwm);
126 err_free:
127 	kfree(beeper);
128 
129 	return error;
130 }
131 
132 static int pwm_beeper_remove(struct platform_device *pdev)
133 {
134 	struct pwm_beeper *beeper = platform_get_drvdata(pdev);
135 
136 	platform_set_drvdata(pdev, NULL);
137 	input_unregister_device(beeper->input);
138 
139 	pwm_disable(beeper->pwm);
140 	pwm_free(beeper->pwm);
141 
142 	kfree(beeper);
143 
144 	return 0;
145 }
146 
147 #ifdef CONFIG_PM
148 static int pwm_beeper_suspend(struct device *dev)
149 {
150 	struct pwm_beeper *beeper = dev_get_drvdata(dev);
151 
152 	if (beeper->period)
153 		pwm_disable(beeper->pwm);
154 
155 	return 0;
156 }
157 
158 static int pwm_beeper_resume(struct device *dev)
159 {
160 	struct pwm_beeper *beeper = dev_get_drvdata(dev);
161 
162 	if (beeper->period) {
163 		pwm_config(beeper->pwm, beeper->period / 2, beeper->period);
164 		pwm_enable(beeper->pwm);
165 	}
166 
167 	return 0;
168 }
169 
170 static SIMPLE_DEV_PM_OPS(pwm_beeper_pm_ops,
171 			 pwm_beeper_suspend, pwm_beeper_resume);
172 
173 #define PWM_BEEPER_PM_OPS (&pwm_beeper_pm_ops)
174 #else
175 #define PWM_BEEPER_PM_OPS NULL
176 #endif
177 
178 #ifdef CONFIG_OF
179 static const struct of_device_id pwm_beeper_match[] = {
180 	{ .compatible = "pwm-beeper", },
181 	{ },
182 };
183 #endif
184 
185 static struct platform_driver pwm_beeper_driver = {
186 	.probe	= pwm_beeper_probe,
187 	.remove = pwm_beeper_remove,
188 	.driver = {
189 		.name	= "pwm-beeper",
190 		.owner	= THIS_MODULE,
191 		.pm	= PWM_BEEPER_PM_OPS,
192 		.of_match_table = of_match_ptr(pwm_beeper_match),
193 	},
194 };
195 module_platform_driver(pwm_beeper_driver);
196 
197 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
198 MODULE_DESCRIPTION("PWM beeper driver");
199 MODULE_LICENSE("GPL");
200 MODULE_ALIAS("platform:pwm-beeper");
201