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/cleanup.h>
8 #include <linux/interrupt.h>
9 #include <linux/irq.h>
10 #include <linux/irq_sim.h>
11 #include <linux/irq_work.h>
12 #include <linux/slab.h>
13
14 struct irq_sim_work_ctx {
15 struct irq_work work;
16 int irq_base;
17 unsigned int irq_count;
18 unsigned long *pending;
19 struct irq_domain *domain;
20 struct irq_sim_ops ops;
21 void *user_data;
22 };
23
24 struct irq_sim_irq_ctx {
25 bool enabled;
26 struct irq_sim_work_ctx *work_ctx;
27 };
28
29 static void irq_sim_irqmask(struct irq_data *data)
30 {
31 struct irq_sim_irq_ctx *irq_ctx = irq_data_get_irq_chip_data(data);
32
33 irq_ctx->enabled = false;
34 }
35
36 static void irq_sim_irqunmask(struct irq_data *data)
37 {
38 struct irq_sim_irq_ctx *irq_ctx = irq_data_get_irq_chip_data(data);
39
40 irq_ctx->enabled = true;
41 }
42
43 static int irq_sim_set_type(struct irq_data *data, unsigned int type)
44 {
45 /* We only support rising and falling edge trigger types. */
46 if (type & ~IRQ_TYPE_EDGE_BOTH)
47 return -EINVAL;
48
49 irqd_set_trigger_type(data, type);
50
51 return 0;
52 }
53
54 static int irq_sim_get_irqchip_state(struct irq_data *data,
55 enum irqchip_irq_state which, bool *state)
56 {
57 struct irq_sim_irq_ctx *irq_ctx = irq_data_get_irq_chip_data(data);
58 irq_hw_number_t hwirq = irqd_to_hwirq(data);
59
60 switch (which) {
61 case IRQCHIP_STATE_PENDING:
62 if (irq_ctx->enabled)
63 *state = test_bit(hwirq, irq_ctx->work_ctx->pending);
64 break;
65 default:
66 return -EINVAL;
67 }
68
69 return 0;
70 }
71
72 static int irq_sim_set_irqchip_state(struct irq_data *data,
73 enum irqchip_irq_state which, bool state)
74 {
75 struct irq_sim_irq_ctx *irq_ctx = irq_data_get_irq_chip_data(data);
76 irq_hw_number_t hwirq = irqd_to_hwirq(data);
77
78 switch (which) {
79 case IRQCHIP_STATE_PENDING:
80 if (irq_ctx->enabled) {
81 assign_bit(hwirq, irq_ctx->work_ctx->pending, state);
82 if (state)
83 irq_work_queue(&irq_ctx->work_ctx->work);
84 }
85 break;
86 default:
87 return -EINVAL;
88 }
89
90 return 0;
91 }
92
93 static int irq_sim_request_resources(struct irq_data *data)
94 {
95 struct irq_sim_irq_ctx *irq_ctx = irq_data_get_irq_chip_data(data);
96 struct irq_sim_work_ctx *work_ctx = irq_ctx->work_ctx;
97 irq_hw_number_t hwirq = irqd_to_hwirq(data);
98
99 if (work_ctx->ops.irq_sim_irq_requested)
100 return work_ctx->ops.irq_sim_irq_requested(work_ctx->domain,
101 hwirq,
102 work_ctx->user_data);
103
104 return 0;
105 }
106
107 static void irq_sim_release_resources(struct irq_data *data)
108 {
109 struct irq_sim_irq_ctx *irq_ctx = irq_data_get_irq_chip_data(data);
110 struct irq_sim_work_ctx *work_ctx = irq_ctx->work_ctx;
111 irq_hw_number_t hwirq = irqd_to_hwirq(data);
112
113 if (work_ctx->ops.irq_sim_irq_released)
114 work_ctx->ops.irq_sim_irq_released(work_ctx->domain, hwirq,
115 work_ctx->user_data);
116 }
117
118 static struct irq_chip irq_sim_irqchip = {
119 .name = "irq_sim",
120 .irq_mask = irq_sim_irqmask,
121 .irq_unmask = irq_sim_irqunmask,
122 .irq_set_type = irq_sim_set_type,
123 .irq_get_irqchip_state = irq_sim_get_irqchip_state,
124 .irq_set_irqchip_state = irq_sim_set_irqchip_state,
125 .irq_request_resources = irq_sim_request_resources,
126 .irq_release_resources = irq_sim_release_resources,
127 };
128
129 static void irq_sim_handle_irq(struct irq_work *work)
130 {
131 struct irq_sim_work_ctx *work_ctx;
132 unsigned int offset = 0;
133 int irqnum;
134
135 work_ctx = container_of(work, struct irq_sim_work_ctx, work);
136
137 while (!bitmap_empty(work_ctx->pending, work_ctx->irq_count)) {
138 offset = find_next_bit(work_ctx->pending,
139 work_ctx->irq_count, offset);
140 clear_bit(offset, work_ctx->pending);
141 irqnum = irq_find_mapping(work_ctx->domain, offset);
142 handle_simple_irq(irq_to_desc(irqnum));
143 }
144 }
145
146 static int irq_sim_domain_map(struct irq_domain *domain,
147 unsigned int virq, irq_hw_number_t hw)
148 {
149 struct irq_sim_work_ctx *work_ctx = domain->host_data;
150 struct irq_sim_irq_ctx *irq_ctx;
151
152 irq_ctx = kzalloc(sizeof(*irq_ctx), GFP_KERNEL);
153 if (!irq_ctx)
154 return -ENOMEM;
155
156 irq_set_chip(virq, &irq_sim_irqchip);
157 irq_set_chip_data(virq, irq_ctx);
158 irq_set_handler(virq, handle_simple_irq);
159 irq_modify_status(virq, IRQ_NOREQUEST | IRQ_NOAUTOEN, IRQ_NOPROBE);
160 irq_ctx->work_ctx = work_ctx;
161
162 return 0;
163 }
164
165 static void irq_sim_domain_unmap(struct irq_domain *domain, unsigned int virq)
166 {
167 struct irq_sim_irq_ctx *irq_ctx;
168 struct irq_data *irqd;
169
170 irqd = irq_domain_get_irq_data(domain, virq);
171 irq_ctx = irq_data_get_irq_chip_data(irqd);
172
173 irq_set_handler(virq, NULL);
174 irq_domain_reset_irq_data(irqd);
175 kfree(irq_ctx);
176 }
177
178 static const struct irq_domain_ops irq_sim_domain_ops = {
179 .map = irq_sim_domain_map,
180 .unmap = irq_sim_domain_unmap,
181 };
182
183 /**
184 * irq_domain_create_sim - Create a new interrupt simulator irq_domain and
185 * allocate a range of dummy interrupts.
186 *
187 * @fwnode: struct fwnode_handle to be associated with this domain.
188 * @num_irqs: Number of interrupts to allocate.
189 *
190 * On success: return a new irq_domain object.
191 * On failure: a negative errno wrapped with ERR_PTR().
192 */
193 struct irq_domain *irq_domain_create_sim(struct fwnode_handle *fwnode,
194 unsigned int num_irqs)
195 {
196 return irq_domain_create_sim_full(fwnode, num_irqs, NULL, NULL);
197 }
198 EXPORT_SYMBOL_GPL(irq_domain_create_sim);
199
200 struct irq_domain *irq_domain_create_sim_full(struct fwnode_handle *fwnode,
201 unsigned int num_irqs,
202 const struct irq_sim_ops *ops,
203 void *data)
204 {
205 struct irq_sim_work_ctx *work_ctx __free(kfree) =
206 kmalloc(sizeof(*work_ctx), GFP_KERNEL);
207
208 if (!work_ctx)
209 return ERR_PTR(-ENOMEM);
210
211 unsigned long *pending __free(bitmap) = bitmap_zalloc(num_irqs, GFP_KERNEL);
212 if (!pending)
213 return ERR_PTR(-ENOMEM);
214
215 work_ctx->domain = irq_domain_create_linear(fwnode, num_irqs,
216 &irq_sim_domain_ops,
217 work_ctx);
218 if (!work_ctx->domain)
219 return ERR_PTR(-ENOMEM);
220
221 work_ctx->irq_count = num_irqs;
222 work_ctx->work = IRQ_WORK_INIT_HARD(irq_sim_handle_irq);
223 work_ctx->pending = no_free_ptr(pending);
224 work_ctx->user_data = data;
225
226 if (ops)
227 memcpy(&work_ctx->ops, ops, sizeof(*ops));
228
229 return no_free_ptr(work_ctx)->domain;
230 }
231 EXPORT_SYMBOL_GPL(irq_domain_create_sim_full);
232
233 /**
234 * irq_domain_remove_sim - Deinitialize the interrupt simulator domain: free
235 * the interrupt descriptors and allocated memory.
236 *
237 * @domain: The interrupt simulator domain to tear down.
238 */
239 void irq_domain_remove_sim(struct irq_domain *domain)
240 {
241 struct irq_sim_work_ctx *work_ctx = domain->host_data;
242
243 irq_work_sync(&work_ctx->work);
244 bitmap_free(work_ctx->pending);
245 kfree(work_ctx);
246
247 irq_domain_remove(domain);
248 }
249 EXPORT_SYMBOL_GPL(irq_domain_remove_sim);
250
251 static void devm_irq_domain_remove_sim(void *data)
252 {
253 struct irq_domain *domain = data;
254
255 irq_domain_remove_sim(domain);
256 }
257
258 /**
259 * devm_irq_domain_create_sim - Create a new interrupt simulator for
260 * a managed device.
261 *
262 * @dev: Device to initialize the simulator object for.
263 * @fwnode: struct fwnode_handle to be associated with this domain.
264 * @num_irqs: Number of interrupts to allocate
265 *
266 * On success: return a new irq_domain object.
267 * On failure: a negative errno wrapped with ERR_PTR().
268 */
269 struct irq_domain *devm_irq_domain_create_sim(struct device *dev,
270 struct fwnode_handle *fwnode,
271 unsigned int num_irqs)
272 {
273 return devm_irq_domain_create_sim_full(dev, fwnode, num_irqs,
274 NULL, NULL);
275 }
276 EXPORT_SYMBOL_GPL(devm_irq_domain_create_sim);
277
278 struct irq_domain *
279 devm_irq_domain_create_sim_full(struct device *dev,
280 struct fwnode_handle *fwnode,
281 unsigned int num_irqs,
282 const struct irq_sim_ops *ops,
283 void *data)
284 {
285 struct irq_domain *domain;
286 int ret;
287
288 domain = irq_domain_create_sim_full(fwnode, num_irqs, ops, data);
289 if (IS_ERR(domain))
290 return domain;
291
292 ret = devm_add_action_or_reset(dev, devm_irq_domain_remove_sim, domain);
293 if (ret)
294 return ERR_PTR(ret);
295
296 return domain;
297 }
298 EXPORT_SYMBOL_GPL(devm_irq_domain_create_sim_full);
299
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