drivers/input/misc/pwm-beeper.c

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