1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (c) 2024, NVIDIA CORPORATION & AFFILIATES 4 */ 5 6 #include <linux/auxiliary_bus.h> 7 #include <linux/slab.h> 8 9 #define AUXILIARY_MAX_IRQ_NAME 11 10 11 struct auxiliary_irq_info { 12 struct device_attribute sysfs_attr; 13 char name[AUXILIARY_MAX_IRQ_NAME]; 14 }; 15 16 static struct attribute *auxiliary_irq_attrs[] = { 17 NULL 18 }; 19 20 static const struct attribute_group auxiliary_irqs_group = { 21 .name = "irqs", 22 .attrs = auxiliary_irq_attrs, 23 }; 24 25 static int auxiliary_irq_dir_prepare(struct auxiliary_device *auxdev) 26 { 27 int ret = 0; 28 29 guard(mutex)(&auxdev->sysfs.lock); 30 if (auxdev->sysfs.irq_dir_exists) 31 return 0; 32 33 ret = devm_device_add_group(&auxdev->dev, &auxiliary_irqs_group); 34 if (ret) 35 return ret; 36 37 auxdev->sysfs.irq_dir_exists = true; 38 xa_init(&auxdev->sysfs.irqs); 39 return 0; 40 } 41 42 /** 43 * auxiliary_device_sysfs_irq_add - add a sysfs entry for the given IRQ 44 * @auxdev: auxiliary bus device to add the sysfs entry. 45 * @irq: The associated interrupt number. 46 * 47 * This function should be called after auxiliary device have successfully 48 * received the irq. 49 * The driver is responsible to add a unique irq for the auxiliary device. The 50 * driver can invoke this function from multiple thread context safely for 51 * unique irqs of the auxiliary devices. The driver must not invoke this API 52 * multiple times if the irq is already added previously. 53 * 54 * Return: zero on success or an error code on failure. 55 */ 56 int auxiliary_device_sysfs_irq_add(struct auxiliary_device *auxdev, int irq) 57 { 58 struct auxiliary_irq_info *info __free(kfree) = NULL; 59 struct device *dev = &auxdev->dev; 60 int ret; 61 62 ret = auxiliary_irq_dir_prepare(auxdev); 63 if (ret) 64 return ret; 65 66 info = kzalloc(sizeof(*info), GFP_KERNEL); 67 if (!info) 68 return -ENOMEM; 69 70 sysfs_attr_init(&info->sysfs_attr.attr); 71 snprintf(info->name, AUXILIARY_MAX_IRQ_NAME, "%d", irq); 72 73 ret = xa_insert(&auxdev->sysfs.irqs, irq, info, GFP_KERNEL); 74 if (ret) 75 return ret; 76 77 info->sysfs_attr.attr.name = info->name; 78 ret = sysfs_add_file_to_group(&dev->kobj, &info->sysfs_attr.attr, 79 auxiliary_irqs_group.name); 80 if (ret) 81 goto sysfs_add_err; 82 83 xa_store(&auxdev->sysfs.irqs, irq, no_free_ptr(info), GFP_KERNEL); 84 return 0; 85 86 sysfs_add_err: 87 xa_erase(&auxdev->sysfs.irqs, irq); 88 return ret; 89 } 90 EXPORT_SYMBOL_GPL(auxiliary_device_sysfs_irq_add); 91 92 /** 93 * auxiliary_device_sysfs_irq_remove - remove a sysfs entry for the given IRQ 94 * @auxdev: auxiliary bus device to add the sysfs entry. 95 * @irq: the IRQ to remove. 96 * 97 * This function should be called to remove an IRQ sysfs entry. 98 * The driver must invoke this API when IRQ is released by the device. 99 */ 100 void auxiliary_device_sysfs_irq_remove(struct auxiliary_device *auxdev, int irq) 101 { 102 struct auxiliary_irq_info *info __free(kfree) = xa_load(&auxdev->sysfs.irqs, irq); 103 struct device *dev = &auxdev->dev; 104 105 if (!info) { 106 dev_err(&auxdev->dev, "IRQ %d doesn't exist\n", irq); 107 return; 108 } 109 sysfs_remove_file_from_group(&dev->kobj, &info->sysfs_attr.attr, 110 auxiliary_irqs_group.name); 111 xa_erase(&auxdev->sysfs.irqs, irq); 112 } 113 EXPORT_SYMBOL_GPL(auxiliary_device_sysfs_irq_remove); 114