drivers/irqchip/irq-gic-v3-its-platform-msi.c

   1 /*
   2  * Copyright (C) 2013-2015 ARM Limited, All Rights Reserved.
   3  * Author: Marc Zyngier <marc.zyngier@arm.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include <linux/device.h>
  19 #include <linux/msi.h>
  20 #include <linux/of.h>
  21 #include <linux/of_irq.h>
  22
  23 static struct irq_chip its_pmsi_irq_chip = {
  24         .name                   = "ITS-pMSI",
  25 };
  26
  27 static int of_pmsi_get_dev_id(struct irq_domain *domain, struct device *dev,
  28                                   u32 *dev_id)
  29 {
  30         int ret, index = 0;
  31
  32         /* Suck the DeviceID out of the msi-parent property */
  33         do {
  34                 struct of_phandle_args args;
  35
  36                 ret = of_parse_phandle_with_args(dev->of_node,
  37                                                  "msi-parent", "#msi-cells",
  38                                                  index, &args);
  39                 if (args.np == irq_domain_get_of_node(domain)) {
  40                         if (WARN_ON(args.args_count != 1))
  41                                 return -EINVAL;
  42                         *dev_id = args.args[0];
  43                         break;
  44                 }
  45         } while (!ret);
  46
  47         return ret;
  48 }
  49
  50 static int its_pmsi_prepare(struct irq_domain *domain, struct device *dev,
  51                             int nvec, msi_alloc_info_t *info)
  52 {
  53         struct msi_domain_info *msi_info;
  54         u32 dev_id;
  55         int ret;
  56
  57         msi_info = msi_get_domain_info(domain->parent);
  58
  59         ret = of_pmsi_get_dev_id(domain, dev, &dev_id);
  60         if (ret)
  61                 return ret;
  62
  63         /* ITS specific DeviceID, as the core ITS ignores dev. */
  64         info->scratchpad[0].ul = dev_id;
  65
  66         return msi_info->ops->msi_prepare(domain->parent,
  67                                           dev, nvec, info);
  68 }
  69
  70 static struct msi_domain_ops its_pmsi_ops = {
  71         .msi_prepare    = its_pmsi_prepare,
  72 };
  73
  74 static struct msi_domain_info its_pmsi_domain_info = {
  75         .flags  = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS),
  76         .ops    = &its_pmsi_ops,
  77         .chip   = &its_pmsi_irq_chip,
  78 };
  79
  80 static struct of_device_id its_device_id[] = {
  81         {       .compatible     = "arm,gic-v3-its",     },
  82         {},
  83 };
  84
  85 static int __init its_pmsi_init_one(struct fwnode_handle *fwnode,
  86                                 const char *name)
  87 {
  88         struct irq_domain *parent;
  89
  90         parent = irq_find_matching_fwnode(fwnode, DOMAIN_BUS_NEXUS);
  91         if (!parent || !msi_get_domain_info(parent)) {
  92                 pr_err("%s: unable to locate ITS domain\n", name);
  93                 return -ENXIO;
  94         }
  95
  96         if (!platform_msi_create_irq_domain(fwnode, &its_pmsi_domain_info,
  97                                             parent)) {
  98                 pr_err("%s: unable to create platform domain\n", name);
  99                 return -ENXIO;
 100         }
 101
 102         pr_info("Platform MSI: %s domain created\n", name);
 103         return 0;
 104 }
 105
 106 static void __init its_pmsi_of_init(void)
 107 {
 108         struct device_node *np;
 109
 110         for (np = of_find_matching_node(NULL, its_device_id); np;
 111              np = of_find_matching_node(np, its_device_id)) {
 112                 if (!of_property_read_bool(np, "msi-controller"))
 113                         continue;
 114
 115                 its_pmsi_init_one(of_node_to_fwnode(np), np->full_name);
 116         }
 117 }
 118
 119 static int __init its_pmsi_init(void)
 120 {
 121         its_pmsi_of_init();
 122         return 0;
 123 }
 124 early_initcall(its_pmsi_init);