git.zerfleddert.de Git - ms2-fixes/blob - debounce.c

   1 #include <linux/module.h>
   2 #include <linux/device.h>
   3 #include <linux/platform_device.h>
   4 #include <linux/gpio_event.h>
   5
   6 #define PREFIX "debounce: "
   7
   8 static int delay = 5;
   9
  10 module_param(delay, int, S_IRUSR | S_IRGRP | S_IROTH);
  11 MODULE_PARM_DESC(delay, "debouncing delay (ms), default: 5");
  12
  13 static int find_ms2_dev(struct device *dev, void *data)
  14 {
  15         if (!strncmp((char*)data, dev_name(dev), strlen((char*)data))) {
  16                 printk(KERN_INFO PREFIX "Found it\n");
  17                 return 1;
  18         }
  19         return 0;
  20 }
  21
  22 static int __init debounce_init(void)
  23 {
  24         struct device *event_dev = NULL;
  25         struct gpio_event_platform_data *gpio_epd;
  26         struct gpio_event_info *gpio_ei;
  27         struct gpio_event_matrix_info *gpio_evmi;
  28
  29         printk(KERN_INFO PREFIX "Searching for " GPIO_EVENT_DEV_NAME "...\n");
  30
  31
  32         event_dev = device_find_child(&platform_bus, GPIO_EVENT_DEV_NAME, find_ms2_dev);
  33         if (event_dev == NULL)
  34                 return -ENODEV;
  35
  36         gpio_epd = (struct gpio_event_platform_data*)event_dev->platform_data;
  37         printk(KERN_INFO PREFIX "And there is a %s connected...\n", gpio_epd->name);
  38         if (strcmp(gpio_epd->name, "sholes-keypad"))
  39                 return -ENODEV;
  40
  41         gpio_ei = (struct gpio_event_info*)gpio_epd->info[0];
  42         gpio_evmi = container_of(gpio_ei, struct gpio_event_matrix_info, info);
  43
  44         printk(KERN_INFO PREFIX "settle_time: %u\n", gpio_evmi->settle_time.tv.nsec);
  45         printk(KERN_INFO PREFIX "poll_time: %u\n", gpio_evmi->poll_time.tv.nsec);
  46         printk(KERN_INFO PREFIX "debounce_delay: %u\n", gpio_evmi->debounce_delay.tv.nsec);
  47         printk(KERN_INFO PREFIX "flags: 0x%x\n", gpio_evmi->flags);
  48
  49         /* GPIOKPF_DEBOUNCE should already be set by GPIOKPF_REMOVE_PHANTOM_KEYS */
  50         if (!(gpio_evmi->flags & GPIOKPF_DEBOUNCE)) {
  51                 printk(KERN_INFO PREFIX "Activating debounce\n");
  52                 gpio_evmi->flags |= GPIOKPF_DEBOUNCE;
  53                 printk(KERN_INFO PREFIX "flags: 0x%x\n", gpio_evmi->flags);
  54         }
  55
  56         if (gpio_evmi->debounce_delay.tv.nsec != delay * NSEC_PER_MSEC) {
  57                 printk(KERN_INFO PREFIX "Changing debounce_delay\n");
  58                 gpio_evmi->debounce_delay.tv.nsec = delay * NSEC_PER_MSEC;
  59                 printk(KERN_INFO PREFIX "debounce_delay: %u\n", gpio_evmi->debounce_delay.tv.nsec);
  60         }
  61
  62         return 0;
  63 }
  64
  65 static void __exit debounce_exit(void)
  66 {
  67 }
  68
  69 module_init(debounce_init);
  70 module_exit(debounce_exit);
  71
  72 MODULE_LICENSE("GPL");
  73 MODULE_AUTHOR("Michael Gernoth <michael@gernoth.net>");