1 /* 2 * Copyright (C) 2017 Bartosz Golaszewski <brgl@bgdev.pl> 3 * 4 * This program is free software; you can redistribute it and/or modify it 5 * under the terms of the GNU General Public License as published by the 6 * Free Software Foundation; either version 2 of the License, or (at your 7 * option) any later version. 8 */ 9 10 #include <linux/irq_sim.h> 11 #include <linux/irq.h> 12 13 struct irq_sim_devres { 14 struct irq_sim *sim; 15 }; 16 17 static void irq_sim_irqmask(struct irq_data *data) 18 { 19 struct irq_sim_irq_ctx *irq_ctx = irq_data_get_irq_chip_data(data); 20 21 irq_ctx->enabled = false; 22 } 23 24 static void irq_sim_irqunmask(struct irq_data *data) 25 { 26 struct irq_sim_irq_ctx *irq_ctx = irq_data_get_irq_chip_data(data); 27 28 irq_ctx->enabled = true; 29 } 30 31 static struct irq_chip irq_sim_irqchip = { 32 .name = "irq_sim", 33 .irq_mask = irq_sim_irqmask, 34 .irq_unmask = irq_sim_irqunmask, 35 }; 36 37 static void irq_sim_handle_irq(struct irq_work *work) 38 { 39 struct irq_sim_work_ctx *work_ctx; 40 41 work_ctx = container_of(work, struct irq_sim_work_ctx, work); 42 handle_simple_irq(irq_to_desc(work_ctx->irq)); 43 } 44 45 /** 46 * irq_sim_init - Initialize the interrupt simulator: allocate a range of 47 * dummy interrupts. 48 * 49 * @sim: The interrupt simulator object to initialize. 50 * @num_irqs: Number of interrupts to allocate 51 * 52 * Returns 0 on success and a negative error number on failure. 53 */ 54 int irq_sim_init(struct irq_sim *sim, unsigned int num_irqs) 55 { 56 int i; 57 58 sim->irqs = kmalloc_array(num_irqs, sizeof(*sim->irqs), GFP_KERNEL); 59 if (!sim->irqs) 60 return -ENOMEM; 61 62 sim->irq_base = irq_alloc_descs(-1, 0, num_irqs, 0); 63 if (sim->irq_base < 0) { 64 kfree(sim->irqs); 65 return sim->irq_base; 66 } 67 68 for (i = 0; i < num_irqs; i++) { 69 sim->irqs[i].irqnum = sim->irq_base + i; 70 sim->irqs[i].enabled = false; 71 irq_set_chip(sim->irq_base + i, &irq_sim_irqchip); 72 irq_set_chip_data(sim->irq_base + i, &sim->irqs[i]); 73 irq_set_handler(sim->irq_base + i, &handle_simple_irq); 74 irq_modify_status(sim->irq_base + i, 75 IRQ_NOREQUEST | IRQ_NOAUTOEN, IRQ_NOPROBE); 76 } 77 78 init_irq_work(&sim->work_ctx.work, irq_sim_handle_irq); 79 sim->irq_count = num_irqs; 80 81 return 0; 82 } 83 EXPORT_SYMBOL_GPL(irq_sim_init); 84 85 /** 86 * irq_sim_fini - Deinitialize the interrupt simulator: free the interrupt 87 * descriptors and allocated memory. 88 * 89 * @sim: The interrupt simulator to tear down. 90 */ 91 void irq_sim_fini(struct irq_sim *sim) 92 { 93 irq_work_sync(&sim->work_ctx.work); 94 irq_free_descs(sim->irq_base, sim->irq_count); 95 kfree(sim->irqs); 96 } 97 EXPORT_SYMBOL_GPL(irq_sim_fini); 98 99 static void devm_irq_sim_release(struct device *dev, void *res) 100 { 101 struct irq_sim_devres *this = res; 102 103 irq_sim_fini(this->sim); 104 } 105 106 /** 107 * irq_sim_init - Initialize the interrupt simulator for a managed device. 108 * 109 * @dev: Device to initialize the simulator object for. 110 * @sim: The interrupt simulator object to initialize. 111 * @num_irqs: Number of interrupts to allocate 112 * 113 * Returns 0 on success and a negative error number on failure. 114 */ 115 int devm_irq_sim_init(struct device *dev, struct irq_sim *sim, 116 unsigned int num_irqs) 117 { 118 struct irq_sim_devres *dr; 119 int rv; 120 121 dr = devres_alloc(devm_irq_sim_release, sizeof(*dr), GFP_KERNEL); 122 if (!dr) 123 return -ENOMEM; 124 125 rv = irq_sim_init(sim, num_irqs); 126 if (rv) { 127 devres_free(dr); 128 return rv; 129 } 130 131 dr->sim = sim; 132 devres_add(dev, dr); 133 134 return 0; 135 } 136 EXPORT_SYMBOL_GPL(devm_irq_sim_init); 137 138 /** 139 * irq_sim_fire - Enqueue an interrupt. 140 * 141 * @sim: The interrupt simulator object. 142 * @offset: Offset of the simulated interrupt which should be fired. 143 */ 144 void irq_sim_fire(struct irq_sim *sim, unsigned int offset) 145 { 146 if (sim->irqs[offset].enabled) { 147 sim->work_ctx.irq = irq_sim_irqnum(sim, offset); 148 irq_work_queue(&sim->work_ctx.work); 149 } 150 } 151 EXPORT_SYMBOL_GPL(irq_sim_fire); 152 153 /** 154 * irq_sim_irqnum - Get the allocated number of a dummy interrupt. 155 * 156 * @sim: The interrupt simulator object. 157 * @offset: Offset of the simulated interrupt for which to retrieve 158 * the number. 159 */ 160 int irq_sim_irqnum(struct irq_sim *sim, unsigned int offset) 161 { 162 return sim->irqs[offset].irqnum; 163 } 164 EXPORT_SYMBOL_GPL(irq_sim_irqnum); 165