/*
   * Flash partitions described by the OF (or flattened) device tree
   *

   * Copyright © 2006 MontaVista Software Inc.

   * Author: Vitaly Wool <vwool@ru.mvista.com>
   *
   * Revised to handle newer style flash binding by:

   *   Copyright © 2007 David Gibson, IBM Corporation.

   *
   * This program is free software; you can redistribute  it and/or modify it
   * under  the terms of  the GNU General  Public License as published by the
   * Free Software Foundation;  either version 2 of the  License, or (at your
   * option) any later version.
   */
  
  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/of.h>
  #include <linux/mtd/mtd.h>

  #include <linux/slab.h>

  #include <linux/mtd/partitions.h>

  static bool node_has_compatible(struct device_node *pp)
  {
  	return of_get_property(pp, "compatible", NULL);
  }

  static int parse_ofpart_partitions(struct mtd_info *master,
  				   struct mtd_partition **pparts,
  				   struct mtd_part_parser_data *data)
  {

  	struct device_node *node;

  	const char *partname;
  	struct device_node *pp;
  	int nr_parts, i;

  
  	if (!data)
  		return 0;
  
  	node = data->of_node;
  	if (!node)
  		return 0;

  	/* First count the subnodes */

  	nr_parts = 0;

  	for_each_child_of_node(node,  pp) {

  		if (node_has_compatible(pp))
  			continue;

  		nr_parts++;

  	}

  
  	if (nr_parts == 0)
  		return 0;
  
  	*pparts = kzalloc(nr_parts * sizeof(**pparts), GFP_KERNEL);
  	if (!*pparts)
  		return -ENOMEM;

  	i = 0;

  	for_each_child_of_node(node,  pp) {

  		const __be32 *reg;

  		int len;

  		int a_cells, s_cells;

  		if (node_has_compatible(pp))
  			continue;

  		reg = of_get_property(pp, "reg", &len);
  		if (!reg) {

  			nr_parts--;
  			continue;
  		}

  		a_cells = of_n_addr_cells(pp);
  		s_cells = of_n_size_cells(pp);
  		(*pparts)[i].offset = of_read_number(reg, a_cells);
  		(*pparts)[i].size = of_read_number(reg + a_cells, s_cells);

  
  		partname = of_get_property(pp, "label", &len);
  		if (!partname)
  			partname = of_get_property(pp, "name", &len);

  		(*pparts)[i].name = partname;

  
  		if (of_get_property(pp, "read-only", &len))

  			(*pparts)[i].mask_flags |= MTD_WRITEABLE;
  
  		if (of_get_property(pp, "lock", &len))
  			(*pparts)[i].mask_flags |= MTD_POWERUP_LOCK;

  
  		i++;
  	}

  	if (!i) {
  		of_node_put(pp);

  		pr_err("No valid partition found on %s
  ", node->full_name);

  		kfree(*pparts);
  		*pparts = NULL;
  		return -EINVAL;
  	}

  	return nr_parts;
  }

  static struct mtd_part_parser ofpart_parser = {
  	.owner = THIS_MODULE,
  	.parse_fn = parse_ofpart_partitions,
  	.name = "ofpart",
  };

  static int parse_ofoldpart_partitions(struct mtd_info *master,
  				      struct mtd_partition **pparts,
  				      struct mtd_part_parser_data *data)
  {
  	struct device_node *dp;
  	int i, plen, nr_parts;
  	const struct {
  		__be32 offset, len;
  	} *part;
  	const char *names;
  
  	if (!data)
  		return 0;
  
  	dp = data->of_node;
  	if (!dp)
  		return 0;
  
  	part = of_get_property(dp, "partitions", &plen);
  	if (!part)
  		return 0; /* No partitions found */
  
  	pr_warning("Device tree uses obsolete partition map binding: %s
  ",
  			dp->full_name);
  
  	nr_parts = plen / sizeof(part[0]);
  
  	*pparts = kzalloc(nr_parts * sizeof(*(*pparts)), GFP_KERNEL);

  	if (!*pparts)

  		return -ENOMEM;
  
  	names = of_get_property(dp, "partition-names", &plen);
  
  	for (i = 0; i < nr_parts; i++) {
  		(*pparts)[i].offset = be32_to_cpu(part->offset);
  		(*pparts)[i].size   = be32_to_cpu(part->len) & ~1;
  		/* bit 0 set signifies read only partition */
  		if (be32_to_cpu(part->len) & 1)
  			(*pparts)[i].mask_flags = MTD_WRITEABLE;
  
  		if (names && (plen > 0)) {
  			int len = strlen(names) + 1;

  			(*pparts)[i].name = names;

  			plen -= len;
  			names += len;
  		} else {
  			(*pparts)[i].name = "unnamed";
  		}
  
  		part++;
  	}
  
  	return nr_parts;
  }
  
  static struct mtd_part_parser ofoldpart_parser = {
  	.owner = THIS_MODULE,
  	.parse_fn = parse_ofoldpart_partitions,
  	.name = "ofoldpart",
  };

  static int __init ofpart_parser_init(void)
  {

  	register_mtd_parser(&ofpart_parser);
  	register_mtd_parser(&ofoldpart_parser);
  	return 0;

  }

  static void __exit ofpart_parser_exit(void)
  {
  	deregister_mtd_parser(&ofpart_parser);
  	deregister_mtd_parser(&ofoldpart_parser);
  }

  module_init(ofpart_parser_init);

  module_exit(ofpart_parser_exit);

  MODULE_LICENSE("GPL");

  MODULE_DESCRIPTION("Parser for MTD partitioning information in device tree");
  MODULE_AUTHOR("Vitaly Wool, David Gibson");

  /*
   * When MTD core cannot find the requested parser, it tries to load the module
   * with the same name. Since we provide the ofoldpart parser, we should have
   * the corresponding alias.
   */
  MODULE_ALIAS("ofoldpart");