target/linux/xburst/patches-2.6.35/107-pwm-beeper.patch

   1 From d7894c598e2c1e5c1d173ca808694de523f1a06a Mon Sep 17 00:00:00 2001
   2 From: Lars-Peter Clausen <lars@metafoo.de>
   3 Date: Wed, 14 Jul 2010 00:25:21 -0700
   4 Subject: [PATCH] Input: Add pwm beeper driver
   5
   6 This patch adds a simple driver which allows to use pwm based beepers (for
   7 example piezo elements) as a pcspkr-like device.
   8
   9 Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
  10 Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
  11 ---
  12  drivers/input/misc/Kconfig      |   11 ++
  13  drivers/input/misc/Makefile     |    1 +
  14  drivers/input/misc/pwm-beeper.c |  199 +++++++++++++++++++++++++++++++++++++++
  15  3 files changed, 211 insertions(+), 0 deletions(-)
  16  create mode 100644 drivers/input/misc/pwm-beeper.c
  17
  18 --- a/drivers/input/misc/Kconfig
  19 +++ b/drivers/input/misc/Kconfig
  20 @@ -327,6 +327,17 @@ config INPUT_PCF8574
  21           To compile this driver as a module, choose M here: the
  22           module will be called pcf8574_keypad.
  23
  24 +config INPUT_PWM_BEEPER
  25 +       tristate "PWM beeper support"
  26 +       depends on HAVE_PWM
  27 +       help
  28 +         Say Y here to get support for PWM based beeper devices.
  29 +
  30 +         If unsure, say N.
  31 +
  32 +         To compile this driver as a module, choose M here: the module will be
  33 +         called pwm-beeper.
  34 +
  35  config INPUT_GPIO_ROTARY_ENCODER
  36         tristate "Rotary encoders connected to GPIO pins"
  37         depends on GPIOLIB && GENERIC_GPIO
  38 --- a/drivers/input/misc/Makefile
  39 +++ b/drivers/input/misc/Makefile
  40 @@ -26,6 +26,7 @@ obj-$(CONFIG_INPUT_PCF50633_PMU)      += pcf5
  41  obj-$(CONFIG_INPUT_PCF8574)            += pcf8574_keypad.o
  42  obj-$(CONFIG_INPUT_PCSPKR)             += pcspkr.o
  43  obj-$(CONFIG_INPUT_POWERMATE)          += powermate.o
  44 +obj-$(CONFIG_INPUT_PWM_BEEPER)         += pwm-beeper.o
  45  obj-$(CONFIG_INPUT_RB532_BUTTON)       += rb532_button.o
  46  obj-$(CONFIG_INPUT_GPIO_ROTARY_ENCODER)        += rotary_encoder.o
  47  obj-$(CONFIG_INPUT_SGI_BTNS)           += sgi_btns.o
  48 --- /dev/null
  49 +++ b/drivers/input/misc/pwm-beeper.c
  50 @@ -0,0 +1,199 @@
  51 +/*
  52 + *  Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
  53 + *  PWM beeper driver
  54 + *
  55 + *  This program is free software; you can redistribute it and/or modify it
  56 + *  under  the terms of the GNU General  Public License as published by the
  57 + *  Free Software Foundation;  either version 2 of the License, or (at your
  58 + *  option) any later version.
  59 + *
  60 + *  You should have received a copy of the GNU General Public License along
  61 + *  with this program; if not, write to the Free Software Foundation, Inc.,
  62 + *  675 Mass Ave, Cambridge, MA 02139, USA.
  63 + *
  64 + */
  65 +
  66 +#include <linux/input.h>
  67 +#include <linux/module.h>
  68 +#include <linux/kernel.h>
  69 +#include <linux/platform_device.h>
  70 +#include <linux/pwm.h>
  71 +#include <linux/slab.h>
  72 +
  73 +struct pwm_beeper {
  74 +       struct input_dev *input;
  75 +       struct pwm_device *pwm;
  76 +       unsigned long period;
  77 +};
  78 +
  79 +#define HZ_TO_NANOSECONDS(x) (1000000000UL/(x))
  80 +
  81 +static int pwm_beeper_event(struct input_dev *input,
  82 +                           unsigned int type, unsigned int code, int value)
  83 +{
  84 +       int ret = 0;
  85 +       struct pwm_beeper *beeper = input_get_drvdata(input);
  86 +       unsigned long period;
  87 +
  88 +       if (type != EV_SND || value < 0)
  89 +               return -EINVAL;
  90 +
  91 +       switch (code) {
  92 +       case SND_BELL:
  93 +               value = value ? 1000 : 0;
  94 +               break;
  95 +       case SND_TONE:
  96 +               break;
  97 +       default:
  98 +               return -EINVAL;
  99 +       }
 100 +
 101 +       if (value == 0) {
 102 +               pwm_config(beeper->pwm, 0, 0);
 103 +               pwm_disable(beeper->pwm);
 104 +       } else {
 105 +               period = HZ_TO_NANOSECONDS(value);
 106 +               ret = pwm_config(beeper->pwm, period / 2, period);
 107 +               if (ret)
 108 +                       return ret;
 109 +               ret = pwm_enable(beeper->pwm);
 110 +               if (ret)
 111 +                       return ret;
 112 +               beeper->period = period;
 113 +       }
 114 +
 115 +       return 0;
 116 +}
 117 +
 118 +static int __devinit pwm_beeper_probe(struct platform_device *pdev)
 119 +{
 120 +       unsigned long pwm_id = (unsigned long)pdev->dev.platform_data;
 121 +       struct pwm_beeper *beeper;
 122 +       int error;
 123 +
 124 +       beeper = kzalloc(sizeof(*beeper), GFP_KERNEL);
 125 +       if (!beeper)
 126 +               return -ENOMEM;
 127 +
 128 +       beeper->pwm = pwm_request(pwm_id, "pwm beeper");
 129 +
 130 +       if (IS_ERR(beeper->pwm)) {
 131 +               error = PTR_ERR(beeper->pwm);
 132 +               dev_err(&pdev->dev, "Failed to request pwm device: %d\n", error);
 133 +               goto err_free;
 134 +       }
 135 +
 136 +       beeper->input = input_allocate_device();
 137 +       if (!beeper->input) {
 138 +               dev_err(&pdev->dev, "Failed to allocate input device\n");
 139 +               error = -ENOMEM;
 140 +               goto err_pwm_free;
 141 +       }
 142 +       beeper->input->dev.parent = &pdev->dev;
 143 +
 144 +       beeper->input->name = "pwm-beeper";
 145 +       beeper->input->phys = "pwm/input0";
 146 +       beeper->input->id.bustype = BUS_HOST;
 147 +       beeper->input->id.vendor = 0x001f;
 148 +       beeper->input->id.product = 0x0001;
 149 +       beeper->input->id.version = 0x0100;
 150 +
 151 +       beeper->input->evbit[0] = BIT(EV_SND);
 152 +       beeper->input->sndbit[0] = BIT(SND_TONE) | BIT(SND_BELL);
 153 +
 154 +       beeper->input->event = pwm_beeper_event;
 155 +
 156 +       input_set_drvdata(beeper->input, beeper);
 157 +
 158 +       error = input_register_device(beeper->input);
 159 +       if (error) {
 160 +               dev_err(&pdev->dev, "Failed to register input device: %d\n", error);
 161 +               goto err_input_free;
 162 +       }
 163 +
 164 +       platform_set_drvdata(pdev, beeper);
 165 +
 166 +       return 0;
 167 +
 168 +err_input_free:
 169 +       input_free_device(beeper->input);
 170 +err_pwm_free:
 171 +       pwm_free(beeper->pwm);
 172 +err_free:
 173 +       kfree(beeper);
 174 +
 175 +       return error;
 176 +}
 177 +
 178 +static int __devexit pwm_beeper_remove(struct platform_device *pdev)
 179 +{
 180 +       struct pwm_beeper *beeper = platform_get_drvdata(pdev);
 181 +
 182 +       platform_set_drvdata(pdev, NULL);
 183 +       input_unregister_device(beeper->input);
 184 +
 185 +       pwm_disable(beeper->pwm);
 186 +       pwm_free(beeper->pwm);
 187 +
 188 +       kfree(beeper);
 189 +
 190 +       return 0;
 191 +}
 192 +
 193 +#ifdef CONFIG_PM
 194 +static int pwm_beeper_suspend(struct device *dev)
 195 +{
 196 +       struct pwm_beeper *beeper = dev_get_drvdata(dev);
 197 +
 198 +       if (beeper->period)
 199 +               pwm_disable(beeper->pwm);
 200 +
 201 +       return 0;
 202 +}
 203 +
 204 +static int pwm_beeper_resume(struct device *dev)
 205 +{
 206 +       struct pwm_beeper *beeper = dev_get_drvdata(dev);
 207 +
 208 +       if (beeper->period) {
 209 +               pwm_config(beeper->pwm, beeper->period / 2, beeper->period);
 210 +               pwm_enable(beeper->pwm);
 211 +       }
 212 +
 213 +       return 0;
 214 +}
 215 +
 216 +static SIMPLE_DEV_PM_OPS(pwm_beeper_pm_ops,
 217 +                        pwm_beeper_suspend, pwm_beeper_resume);
 218 +
 219 +#define PWM_BEEPER_PM_OPS (&pwm_beeper_pm_ops)
 220 +#else
 221 +#define PWM_BEEPER_PM_OPS NULL
 222 +#endif
 223 +
 224 +static struct platform_driver pwm_beeper_driver = {
 225 +       .probe  = pwm_beeper_probe,
 226 +       .remove = __devexit_p(pwm_beeper_remove),
 227 +       .driver = {
 228 +               .name   = "pwm-beeper",
 229 +               .owner  = THIS_MODULE,
 230 +               .pm     = PWM_BEEPER_PM_OPS,
 231 +       },
 232 +};
 233 +
 234 +static int __init pwm_beeper_init(void)
 235 +{
 236 +       return platform_driver_register(&pwm_beeper_driver);
 237 +}
 238 +module_init(pwm_beeper_init);
 239 +
 240 +static void __exit pwm_beeper_exit(void)
 241 +{
 242 +       platform_driver_unregister(&pwm_beeper_driver);
 243 +}
 244 +module_exit(pwm_beeper_exit);
 245 +
 246 +MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
 247 +MODULE_DESCRIPTION("PWM beeper driver");
 248 +MODULE_LICENSE("GPL");
 249 +MODULE_ALIAS("platform:pwm-beeper");