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