allow tuning of more flags in /sys/devices/debounce

[ms2-fixes] / debounce.c

#include <linux/module.h>
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/gpio_event.h>

#define PREFIX "debounce: "

static int debounce_delay = 15;

static unsigned old_flags = 0;
ktime_t old_debounce_delay;
ktime_t old_settle_time;
ktime_t old_poll_time;
static struct gpio_event_matrix_info *gpio_evmi = NULL;

module_param(debounce_delay, int, S_IRUSR | S_IRGRP | S_IROTH);
MODULE_PARM_DESC(debounce_delay, "debouncing delay (ms), default: 15");

static int find_ms2_dev(struct device *dev, void *data)
{
	if (!strncmp((char*)data, dev_name(dev), strlen((char*)data))) {
		printk(KERN_INFO PREFIX "Found it\n");
		return 1;
	}
	return 0;
}

static ssize_t show_debounce_delay(struct device *dev, struct device_attribute *attr, char *buf)
{
	if (!gpio_evmi) 
		return -ENODEV;

	return snprintf(buf, PAGE_SIZE, "%ld\n", (gpio_evmi->debounce_delay.tv.nsec / NSEC_PER_MSEC));
}

static void set_debounce_delay(long delay)
{
	if (gpio_evmi->debounce_delay.tv.nsec != delay * NSEC_PER_MSEC) {
		printk(KERN_INFO PREFIX "Changing debounce_delay\n");
		gpio_evmi->debounce_delay.tv.nsec = delay * NSEC_PER_MSEC;
		debounce_delay = delay;
		printk(KERN_INFO PREFIX "debounce_delay: %u\n", gpio_evmi->debounce_delay.tv.nsec);
	}

	if (gpio_evmi->debounce_delay.tv.nsec != 0) {
		if (!(gpio_evmi->flags & GPIOKPF_DEBOUNCE)) {
			printk(KERN_INFO PREFIX "Activating debounce\n");
			gpio_evmi->flags |= GPIOKPF_DEBOUNCE;
		}
	} else {
		if (gpio_evmi->flags & GPIOKPF_DEBOUNCE) {
			printk(KERN_INFO PREFIX "Deactivating debounce\n");
			gpio_evmi->flags &= ~GPIOKPF_DEBOUNCE;
		}
	}
}

static ssize_t store_debounce_delay(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
	long int delay;

	if (!gpio_evmi) 
		return -ENODEV;

	sscanf(buf, "%ld", &delay);
	set_debounce_delay(delay);

	return strnlen(buf, PAGE_SIZE);
}

static ssize_t show_settle_time(struct device *dev, struct device_attribute *attr, char *buf)
{
	if (!gpio_evmi) 
		return -ENODEV;

	return snprintf(buf, PAGE_SIZE, "%ld\n", (gpio_evmi->settle_time.tv.nsec / NSEC_PER_USEC));
}

static ssize_t store_settle_time(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
	long int delay;

	if (!gpio_evmi) 
		return -ENODEV;

	sscanf(buf, "%ld", &delay);
	gpio_evmi->settle_time.tv.nsec = delay * NSEC_PER_USEC;

	return strnlen(buf, PAGE_SIZE);
}

static ssize_t show_poll_time(struct device *dev, struct device_attribute *attr, char *buf)
{
	if (!gpio_evmi) 
		return -ENODEV;

	return snprintf(buf, PAGE_SIZE, "%ld\n", (gpio_evmi->poll_time.tv.nsec / NSEC_PER_MSEC));
}

static ssize_t store_poll_time(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
	long int delay;

	if (!gpio_evmi) 
		return -ENODEV;

	sscanf(buf, "%ld", &delay);
	gpio_evmi->poll_time.tv.nsec = delay * NSEC_PER_MSEC;

	return strnlen(buf, PAGE_SIZE);
}

static ssize_t show_flags(struct device *dev, struct device_attribute *attr, char *buf)
{
	if (!gpio_evmi) 
		return -ENODEV;

	return snprintf(buf, PAGE_SIZE, "0x%x\n", gpio_evmi->flags);
}

static ssize_t store_flags(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
	unsigned flags;

	if (!gpio_evmi) 
		return -ENODEV;

	sscanf(buf, "0x%x", &flags);
	gpio_evmi->flags = flags;

	return strnlen(buf, PAGE_SIZE);
}

static DEVICE_ATTR(debounce_delay, (S_IRUGO | S_IWUGO), &show_debounce_delay, store_debounce_delay);
static DEVICE_ATTR(settle_time, (S_IRUGO | S_IWUGO), &show_settle_time, store_settle_time);
static DEVICE_ATTR(poll_time, (S_IRUGO | S_IWUGO), &show_poll_time, store_poll_time);
static DEVICE_ATTR(flags, (S_IRUGO | S_IWUGO), &show_flags, store_flags);

static void debounce_release(struct device *dev)
{
}

static struct device debounce_device = {
	.init_name = "debounce",
	.release = debounce_release,
};

static int __init debounce_init(void)
{
	struct device *event_dev = NULL;
	struct gpio_event_platform_data *gpio_epd;
	struct gpio_event_info *gpio_ei;
	int err = 0;

	printk(KERN_INFO PREFIX "Searching for " GPIO_EVENT_DEV_NAME "...\n");
	
	event_dev = device_find_child(&platform_bus, GPIO_EVENT_DEV_NAME, find_ms2_dev);
	if (event_dev == NULL)
		return -ENODEV;

	gpio_epd = (struct gpio_event_platform_data*)event_dev->platform_data;
	printk(KERN_INFO PREFIX "And there is a %s connected...\n", gpio_epd->name);
	if (strcmp(gpio_epd->name, "sholes-keypad"))
		return -ENODEV;

	gpio_ei = (struct gpio_event_info*)gpio_epd->info[0];
	gpio_evmi = container_of(gpio_ei, struct gpio_event_matrix_info, info);

	err = device_register(&debounce_device);
	if (err) {
		return err;
	}

	err = device_create_file(&debounce_device, &dev_attr_debounce_delay);
	err = device_create_file(&debounce_device, &dev_attr_settle_time);
	err = device_create_file(&debounce_device, &dev_attr_poll_time);
	err = device_create_file(&debounce_device, &dev_attr_flags);

	printk(KERN_INFO PREFIX "settle_time: %u\n", gpio_evmi->settle_time.tv.nsec);
	printk(KERN_INFO PREFIX "poll_time: %u\n", gpio_evmi->poll_time.tv.nsec);
	printk(KERN_INFO PREFIX "debounce_delay: %u\n", gpio_evmi->debounce_delay.tv.nsec);
	printk(KERN_INFO PREFIX "flags: 0x%x\n", gpio_evmi->flags);

	old_debounce_delay = gpio_evmi->debounce_delay;
	old_settle_time = gpio_evmi->settle_time;
	old_poll_time = gpio_evmi->poll_time;
	old_flags = gpio_evmi->flags;

	set_debounce_delay(debounce_delay);
#if 0
	gpio_evmi->flags &= ~GPIOKPF_REMOVE_SOME_PHANTOM_KEYS;
#endif
	printk(KERN_INFO PREFIX "flags: 0x%x\n", gpio_evmi->flags);

	return 0;
}

static void __exit debounce_exit(void)
{
	if (gpio_evmi) {
		if (gpio_evmi->debounce_delay.tv.nsec != old_debounce_delay.tv.nsec) {
			printk(KERN_INFO PREFIX "Restoring debounce_delay\n");
			gpio_evmi->debounce_delay = old_debounce_delay;
			printk(KERN_INFO PREFIX "debounce_delay: %u\n", gpio_evmi->debounce_delay.tv.nsec);
		}
		if (gpio_evmi->flags != old_flags) {
			printk(KERN_INFO PREFIX "Restoring flags\n");
			gpio_evmi->flags = old_flags;
			printk(KERN_INFO PREFIX "flags: 0x%x\n", gpio_evmi->flags);
		}
		gpio_evmi->settle_time = old_settle_time;
		gpio_evmi->poll_time = old_poll_time;
	}
	device_remove_file(&debounce_device, &dev_attr_debounce_delay);
	device_remove_file(&debounce_device, &dev_attr_settle_time);
	device_remove_file(&debounce_device, &dev_attr_poll_time);
	device_remove_file(&debounce_device, &dev_attr_flags);
	device_unregister(&debounce_device);
}

module_init(debounce_init);
module_exit(debounce_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Michael Gernoth <michael@gernoth.net>");