// SPDX-License-Identifier: GPL-2.0

  /*
   * Freescale Management Complex (MC) bus driver MSI support
   *

   * Copyright (C) 2015-2016 Freescale Semiconductor, Inc.

   * Author: German Rivera <German.Rivera@freescale.com>
   *

   */

  #include <linux/of_device.h>
  #include <linux/of_address.h>

  #include <linux/irq.h>
  #include <linux/msi.h>
  #include <linux/of.h>
  #include <linux/of_irq.h>

  #include <linux/fsl/mc.h>

  
  static struct irq_chip its_msi_irq_chip = {

  	.name = "ITS-fMSI",

  	.irq_mask = irq_chip_mask_parent,
  	.irq_unmask = irq_chip_unmask_parent,
  	.irq_eoi = irq_chip_eoi_parent,
  	.irq_set_affinity = msi_domain_set_affinity
  };
  
  static int its_fsl_mc_msi_prepare(struct irq_domain *msi_domain,
  				  struct device *dev,
  				  int nvec, msi_alloc_info_t *info)
  {
  	struct fsl_mc_device *mc_bus_dev;
  	struct msi_domain_info *msi_info;

  	if (!dev_is_fsl_mc(dev))

  		return -EINVAL;
  
  	mc_bus_dev = to_fsl_mc_device(dev);

  	if (!(mc_bus_dev->flags & FSL_MC_IS_DPRC))

  		return -EINVAL;
  
  	/*
  	 * Set the device Id to be passed to the GIC-ITS:
  	 *
  	 * NOTE: This device id corresponds to the IOMMU stream ID
  	 * associated with the DPRC object (ICID).
  	 */
  	info->scratchpad[0].ul = mc_bus_dev->icid;
  	msi_info = msi_get_domain_info(msi_domain->parent);

  
  	/* Allocate at least 32 MSIs, and always as a power of 2 */
  	nvec = max_t(int, 32, roundup_pow_of_two(nvec));

  	return msi_info->ops->msi_prepare(msi_domain->parent, dev, nvec, info);
  }

  static struct msi_domain_ops its_fsl_mc_msi_ops __ro_after_init = {

  	.msi_prepare = its_fsl_mc_msi_prepare,
  };
  
  static struct msi_domain_info its_fsl_mc_msi_domain_info = {
  	.flags	= (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS),
  	.ops	= &its_fsl_mc_msi_ops,
  	.chip	= &its_msi_irq_chip,
  };
  
  static const struct of_device_id its_device_id[] = {
  	{	.compatible	= "arm,gic-v3-its",	},
  	{},
  };

  static int __init its_fsl_mc_msi_init(void)

  {
  	struct device_node *np;
  	struct irq_domain *parent;
  	struct irq_domain *mc_msi_domain;
  
  	for (np = of_find_matching_node(NULL, its_device_id); np;
  	     np = of_find_matching_node(np, its_device_id)) {

  		if (!of_device_is_available(np))
  			continue;

  		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("%pOF: unable to locate ITS domain
  ", np);

  			continue;
  		}
  
  		mc_msi_domain = fsl_mc_msi_create_irq_domain(
  						 of_node_to_fwnode(np),
  						 &its_fsl_mc_msi_domain_info,
  						 parent);
  		if (!mc_msi_domain) {

  			pr_err("%pOF: unable to create fsl-mc domain
  ", np);

  			continue;
  		}

  		pr_info("fsl-mc MSI: %pOF domain created
  ", np);

  	}
  
  	return 0;
  }

  
  early_initcall(its_fsl_mc_msi_init);