/*
   * Copyright (C) 2013-2015 ARM Limited, All Rights Reserved.
   * Author: Marc Zyngier <marc.zyngier@arm.com>
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   *
   * 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.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
   */
  
  #include <linux/device.h>
  #include <linux/msi.h>
  #include <linux/of.h>
  #include <linux/of_irq.h>
  
  static struct irq_chip its_pmsi_irq_chip = {
  	.name			= "ITS-pMSI",
  };
  
  static int its_pmsi_prepare(struct irq_domain *domain, struct device *dev,
  			    int nvec, msi_alloc_info_t *info)
  {
  	struct msi_domain_info *msi_info;
  	u32 dev_id;

  	int ret, index = 0;

  
  	msi_info = msi_get_domain_info(domain->parent);
  
  	/* Suck the DeviceID out of the msi-parent property */

  	do {
  		struct of_phandle_args args;
  
  		ret = of_parse_phandle_with_args(dev->of_node,
  						 "msi-parent", "#msi-cells",
  						 index, &args);
  		if (args.np == irq_domain_get_of_node(domain)) {
  			if (WARN_ON(args.args_count != 1))
  				return -EINVAL;
  			dev_id = args.args[0];
  			break;
  		}
  	} while (!ret);

  	if (ret)
  		return ret;
  
  	/* ITS specific DeviceID, as the core ITS ignores dev. */
  	info->scratchpad[0].ul = dev_id;
  
  	return msi_info->ops->msi_prepare(domain->parent,
  					  dev, nvec, info);
  }
  
  static struct msi_domain_ops its_pmsi_ops = {
  	.msi_prepare	= its_pmsi_prepare,
  };
  
  static struct msi_domain_info its_pmsi_domain_info = {
  	.flags	= (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS),
  	.ops	= &its_pmsi_ops,
  	.chip	= &its_pmsi_irq_chip,
  };
  
  static struct of_device_id its_device_id[] = {
  	{	.compatible	= "arm,gic-v3-its",	},
  	{},
  };
  
  static int __init its_pmsi_init(void)
  {
  	struct device_node *np;
  	struct irq_domain *parent;
  
  	for (np = of_find_matching_node(NULL, its_device_id); np;
  	     np = of_find_matching_node(np, its_device_id)) {
  		if (!of_property_read_bool(np, "msi-controller"))
  			continue;
  
  		parent = irq_find_matching_host(np, DOMAIN_BUS_NEXUS);
  		if (!parent || !msi_get_domain_info(parent)) {
  			pr_err("%s: unable to locate ITS domain
  ",
  			       np->full_name);
  			continue;
  		}

  		if (!platform_msi_create_irq_domain(of_node_to_fwnode(np),
  						    &its_pmsi_domain_info,

  						    parent)) {
  			pr_err("%s: unable to create platform domain
  ",
  			       np->full_name);
  			continue;
  		}
  
  		pr_info("Platform MSI: %s domain created
  ", np->full_name);
  	}
  
  	return 0;
  }
  early_initcall(its_pmsi_init);