ec_sys.c

/*
 * ec_sys.c
 *
 * Copyright (C) 2010 SUSE Products GmbH/Novell
 * Author:
 *      Thomas Renninger <trenn@suse.de>
 *
 * This work is licensed under the terms of the GNU GPL, version 2.
 */

#include <linux/kernel.h>
#include <linux/acpi.h>
#include <linux/debugfs.h>
#include "internal.h"

MODULE_AUTHOR("Thomas Renninger <trenn@suse.de>");
MODULE_DESCRIPTION("ACPI EC sysfs access driver");
MODULE_LICENSE("GPL");

static bool write_support;
module_param(write_support, bool, 0644);
MODULE_PARM_DESC(write_support, "Dangerous, reboot and removal of battery may "
		 "be needed.");

#define EC_SPACE_SIZE 256

static struct dentry *acpi_ec_debugfs_dir;

static int acpi_ec_open_io(struct inode *i, struct file *f)
{
	f->private_data = i->i_private;
	return 0;
}

static ssize_t acpi_ec_read_io(struct file *f, char __user *buf,
			       size_t count, loff_t *off)
{
	/* Use this if support reading/writing multiple ECs exists in ec.c:
	 * struct acpi_ec *ec = ((struct seq_file *)f->private_data)->private;
	 */
	unsigned int size = EC_SPACE_SIZE;
	u8 *data = (u8 *) buf;
	loff_t init_off = *off;
	int err = 0;

	if (*off >= size)
		return 0;
	if (*off + count >= size) {
		size -= *off;
		count = size;
	} else
		size = count;

	while (size) {
		err = ec_read(*off, &data[*off - init_off]);
		if (err)
			return err;
		*off += 1;
		size--;
	}
	return count;
}

static ssize_t acpi_ec_write_io(struct file *f, const char __user *buf,
				size_t count, loff_t *off)
{
	/* Use this if support reading/writing multiple ECs exists in ec.c:
	 * struct acpi_ec *ec = ((struct seq_file *)f->private_data)->private;
	 */