text: /*
   * Helpers for open firmware matrix keyboard bindings
   *
   * Copyright (C) 2012 Google, Inc
   *
   * Author:
   *	Olof Johansson <olof@lixom.net>
   *
   * This software is licensed under the terms of the GNU General Public
   * License version 2, as published by the Free Software Foundation, and
   * may be copied, distributed, and modified under those terms.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   */
  
  #include <linux/kernel.h>
  #include <linux/types.h>
  #include <linux/input.h>
  #include <linux/of.h>
  #include <linux/input/matrix_keypad.h>
  #include <linux/export.h>
  #include <linux/gfp.h>
  #include <linux/slab.h>
  
  struct matrix_keymap_data *
  matrix_keyboard_of_fill_keymap(struct device_node *np,
  			       const char *propname)
  {
  	struct matrix_keymap_data *kd;
  	u32 *keymap;
  	int proplen, i;
  	const __be32 *prop;
  
  	if (!np)
  		return NULL;
  
  	if (!propname)
  		propname = "linux,keymap";
  
  	prop = of_get_property(np, propname, &proplen);
  	if (!prop)
  		return NULL;
  
  	if (proplen % sizeof(u32)) {
  		pr_warn("Malformed keymap property %s in %s\n",
  			propname, np->full_name);
  		return NULL;
  	}
  
  	kd = kzalloc(sizeof(*kd), GFP_KERNEL);
  	if (!kd)
  		return NULL;
  
  	kd->keymap = keymap = kzalloc(proplen, GFP_KERNEL);
  	if (!kd->keymap) {
  		kfree(kd);
  		return NULL;
  	}
  
  	kd->keymap_size = proplen / sizeof(u32);
  
  	for (i = 0; i < kd->keymap_size; i++) {
  		u32 tmp = be32_to_cpup(prop + i);
  		int key_code, row, col;
  
  		row = (tmp >> 24) & 0xff;
  		col = (tmp >> 16) & 0xff;
  		key_code = tmp & 0xffff;
  		keymap[i] = KEY(row, col, key_code);
  	}
  
  	return kd;
  }
  EXPORT_SYMBOL_GPL(matrix_keyboard_of_fill_keymap);
  
  void matrix_keyboard_of_free_keymap(const struct matrix_keymap_data *kd)
  {
  	if (kd) {
  		kfree(kd->keymap);
  		kfree(kd);
  	}
  }
  EXPORT_SYMBOL_GPL(matrix_keyboard_of_free_keymap);
  