1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * Copyright (C) 2017-2018 Bartosz Golaszewski <brgl@bgdev.pl> 4 * Copyright (C) 2020 Bartosz Golaszewski <bgolaszewski@baylibre.com> 5 */ 6 7 #include <linux/irq.h> 8 #include <linux/irq_sim.h> 9 #include <linux/irq_work.h> 10 #include <linux/interrupt.h> 11 #include <linux/slab.h> 12 13 struct irq_sim_work_ctx { 14 struct irq_work work; 15 int irq_base; 16 unsigned int irq_count; 17 unsigned long *pending; 18 struct irq_domain *domain; 19 }; 20 21 struct irq_sim_irq_ctx { 22 int irqnum; 23 bool enabled; 24 struct irq_sim_work_ctx *work_ctx; 25 }; 26 27 struct irq_sim_devres { 28 struct irq_domain *domain; 29 }; 30 31 static void irq_sim_irqmask(struct irq_data *data) 32 { 33 struct irq_sim_irq_ctx *irq_ctx = irq_data_get_irq_chip_data(data); 34 35 irq_ctx->enabled = false; 36 } 37 38 static void irq_sim_irqunmask(struct irq_data *data) 39 { 40 struct irq_sim_irq_ctx *irq_ctx = irq_data_get_irq_chip_data(data); 41 42 irq_ctx->enabled = true; 43 } 44 45 static int irq_sim_set_type(struct irq_data *data, unsigned int type) 46 { 47 /* We only support rising and falling edge trigger types. */ 48 if (type & ~IRQ_TYPE_EDGE_BOTH) 49 return -EINVAL; 50 51 irqd_set_trigger_type(data, type); 52 53 return 0; 54 } 55 56 static int irq_sim_get_irqchip_state(struct irq_data *data, 57 enum irqchip_irq_state which, bool *state) 58 { 59 struct irq_sim_irq_ctx *irq_ctx = irq_data_get_irq_chip_data(data); 60 irq_hw_number_t hwirq = irqd_to_hwirq(data); 61 62 switch (which) { 63 case IRQCHIP_STATE_PENDING: 64 if (irq_ctx->enabled) 65 *state = test_bit(hwirq, irq_ctx->work_ctx->pending); 66 break; 67 default: 68 return -EINVAL; 69 } 70 71 return 0; 72 } 73 74 static int irq_sim_set_irqchip_state(struct irq_data *data, 75 enum irqchip_irq_state which, bool state) 76 { 77 struct irq_sim_irq_ctx *irq_ctx = irq_data_get_irq_chip_data(data); 78 irq_hw_number_t hwirq = irqd_to_hwirq(data); 79 80 switch (which) { 81 case IRQCHIP_STATE_PENDING: 82 if (irq_ctx->enabled) { 83 assign_bit(hwirq, irq_ctx->work_ctx->pending, state); 84 if (state) 85 irq_work_queue(&irq_ctx->work_ctx->work); 86 } 87 break; 88 default: 89 return -EINVAL; 90 } 91 92 return 0; 93 } 94 95 static struct irq_chip irq_sim_irqchip = { 96 .name = "irq_sim", 97 .irq_mask = irq_sim_irqmask, 98 .irq_unmask = irq_sim_irqunmask, 99 .irq_set_type = irq_sim_set_type, 100 .irq_get_irqchip_state = irq_sim_get_irqchip_state, 101 .irq_set_irqchip_state = irq_sim_set_irqchip_state, 102 }; 103 104 static void irq_sim_handle_irq(struct irq_work *work) 105 { 106 struct irq_sim_work_ctx *work_ctx; 107 unsigned int offset = 0; 108 int irqnum; 109 110 work_ctx = container_of(work, struct irq_sim_work_ctx, work); 111 112 while (!bitmap_empty(work_ctx->pending, work_ctx->irq_count)) { 113 offset = find_next_bit(work_ctx->pending, 114 work_ctx->irq_count, offset); 115 clear_bit(offset, work_ctx->pending); 116 irqnum = irq_find_mapping(work_ctx->domain, offset); 117 handle_simple_irq(irq_to_desc(irqnum)); 118 } 119 } 120 121 static int irq_sim_domain_map(struct irq_domain *domain, 122 unsigned int virq, irq_hw_number_t hw) 123 { 124 struct irq_sim_work_ctx *work_ctx = domain->host_data; 125 struct irq_sim_irq_ctx *irq_ctx; 126 127 irq_ctx = kzalloc(sizeof(*irq_ctx), GFP_KERNEL); 128 if (!irq_ctx) 129 return -ENOMEM; 130 131 irq_set_chip(virq, &irq_sim_irqchip); 132 irq_set_chip_data(virq, irq_ctx); 133 irq_set_handler(virq, handle_simple_irq); 134 irq_modify_status(virq, IRQ_NOREQUEST | IRQ_NOAUTOEN, IRQ_NOPROBE); 135 irq_ctx->work_ctx = work_ctx; 136 137 return 0; 138 } 139 140 static void irq_sim_domain_unmap(struct irq_domain *domain, unsigned int virq) 141 { 142 struct irq_sim_irq_ctx *irq_ctx; 143 struct irq_data *irqd; 144 145 irqd = irq_domain_get_irq_data(domain, virq); 146 irq_ctx = irq_data_get_irq_chip_data(irqd); 147 148 irq_set_handler(virq, NULL); 149 irq_domain_reset_irq_data(irqd); 150 kfree(irq_ctx); 151 } 152 153 static const struct irq_domain_ops irq_sim_domain_ops = { 154 .map = irq_sim_domain_map, 155 .unmap = irq_sim_domain_unmap, 156 }; 157 158 /** 159 * irq_domain_create_sim - Create a new interrupt simulator irq_domain and 160 * allocate a range of dummy interrupts. 161 * 162 * @fnode: struct fwnode_handle to be associated with this domain. 163 * @num_irqs: Number of interrupts to allocate. 164 * 165 * On success: return a new irq_domain object. 166 * On failure: a negative errno wrapped with ERR_PTR(). 167 */ 168 struct irq_domain *irq_domain_create_sim(struct fwnode_handle *fwnode, 169 unsigned int num_irqs) 170 { 171 struct irq_sim_work_ctx *work_ctx; 172 173 work_ctx = kmalloc(sizeof(*work_ctx), GFP_KERNEL); 174 if (!work_ctx) 175 goto err_out; 176 177 work_ctx->pending = bitmap_zalloc(num_irqs, GFP_KERNEL); 178 if (!work_ctx->pending) 179 goto err_free_work_ctx; 180 181 work_ctx->domain = irq_domain_create_linear(fwnode, num_irqs, 182 &irq_sim_domain_ops, 183 work_ctx); 184 if (!work_ctx->domain) 185 goto err_free_bitmap; 186 187 work_ctx->irq_count = num_irqs; 188 init_irq_work(&work_ctx->work, irq_sim_handle_irq); 189 190 return work_ctx->domain; 191 192 err_free_bitmap: 193 bitmap_free(work_ctx->pending); 194 err_free_work_ctx: 195 kfree(work_ctx); 196 err_out: 197 return ERR_PTR(-ENOMEM); 198 } 199 EXPORT_SYMBOL_GPL(irq_domain_create_sim); 200 201 /** 202 * irq_domain_remove_sim - Deinitialize the interrupt simulator domain: free 203 * the interrupt descriptors and allocated memory. 204 * 205 * @domain: The interrupt simulator domain to tear down. 206 */ 207 void irq_domain_remove_sim(struct irq_domain *domain) 208 { 209 struct irq_sim_work_ctx *work_ctx = domain->host_data; 210 211 irq_work_sync(&work_ctx->work); 212 bitmap_free(work_ctx->pending); 213 kfree(work_ctx); 214 215 irq_domain_remove(domain); 216 } 217 EXPORT_SYMBOL_GPL(irq_domain_remove_sim); 218 219 static void devm_irq_domain_release_sim(struct device *dev, void *res) 220 { 221 struct irq_sim_devres *this = res; 222 223 irq_domain_remove_sim(this->domain); 224 } 225 226 /** 227 * devm_irq_domain_create_sim - Create a new interrupt simulator for 228 * a managed device. 229 * 230 * @dev: Device to initialize the simulator object for. 231 * @fnode: struct fwnode_handle to be associated with this domain. 232 * @num_irqs: Number of interrupts to allocate 233 * 234 * On success: return a new irq_domain object. 235 * On failure: a negative errno wrapped with ERR_PTR(). 236 */ 237 struct irq_domain *devm_irq_domain_create_sim(struct device *dev, 238 struct fwnode_handle *fwnode, 239 unsigned int num_irqs) 240 { 241 struct irq_sim_devres *dr; 242 243 dr = devres_alloc(devm_irq_domain_release_sim, 244 sizeof(*dr), GFP_KERNEL); 245 if (!dr) 246 return ERR_PTR(-ENOMEM); 247 248 dr->domain = irq_domain_create_sim(fwnode, num_irqs); 249 if (IS_ERR(dr->domain)) { 250 devres_free(dr); 251 return dr->domain; 252 } 253 254 devres_add(dev, dr); 255 return dr->domain; 256 } 257 EXPORT_SYMBOL_GPL(devm_irq_domain_create_sim); 258