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 its_pmsi_prepare(struct irq_domain *domain, struct device *dev, 28 int nvec, msi_alloc_info_t *info) 29 { 30 struct msi_domain_info *msi_info; 31 u32 dev_id; 32 int ret; 33 34 msi_info = msi_get_domain_info(domain->parent); 35 36 /* Suck the DeviceID out of the msi-parent property */ 37 ret = of_property_read_u32_index(dev->of_node, "msi-parent", 38 1, &dev_id); 39 if (ret) 40 return ret; 41 42 /* ITS specific DeviceID, as the core ITS ignores dev. */ 43 info->scratchpad[0].ul = dev_id; 44 45 return msi_info->ops->msi_prepare(domain->parent, 46 dev, nvec, info); 47 } 48 49 static struct msi_domain_ops its_pmsi_ops = { 50 .msi_prepare = its_pmsi_prepare, 51 }; 52 53 static struct msi_domain_info its_pmsi_domain_info = { 54 .flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS), 55 .ops = &its_pmsi_ops, 56 .chip = &its_pmsi_irq_chip, 57 }; 58 59 static struct of_device_id its_device_id[] = { 60 { .compatible = "arm,gic-v3-its", }, 61 {}, 62 }; 63 64 static int __init its_pmsi_init(void) 65 { 66 struct device_node *np; 67 struct irq_domain *parent; 68 69 for (np = of_find_matching_node(NULL, its_device_id); np; 70 np = of_find_matching_node(np, its_device_id)) { 71 if (!of_property_read_bool(np, "msi-controller")) 72 continue; 73 74 parent = irq_find_matching_host(np, DOMAIN_BUS_NEXUS); 75 if (!parent || !msi_get_domain_info(parent)) { 76 pr_err("%s: unable to locate ITS domain\n", 77 np->full_name); 78 continue; 79 } 80 81 if (!platform_msi_create_irq_domain(np, &its_pmsi_domain_info, 82 parent)) { 83 pr_err("%s: unable to create platform domain\n", 84 np->full_name); 85 continue; 86 } 87 88 pr_info("Platform MSI: %s domain created\n", np->full_name); 89 } 90 91 return 0; 92 } 93 early_initcall(its_pmsi_init); 94