1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * ACPI GSI IRQ layer
4 *
5 * Copyright (C) 2015 ARM Ltd.
6 * Author: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
7 */
8 #include <linux/acpi.h>
9 #include <linux/irq.h>
10 #include <linux/irqdomain.h>
11 #include <linux/of.h>
12
13 enum acpi_irq_model_id acpi_irq_model;
14
15 static struct fwnode_handle *acpi_gsi_domain_id;
16
17 /**
18 * acpi_gsi_to_irq() - Retrieve the linux irq number for a given GSI
19 * @gsi: GSI IRQ number to map
20 * @irq: pointer where linux IRQ number is stored
21 *
22 * irq location updated with irq value [>0 on success, 0 on failure]
23 *
24 * Returns: 0 on success
25 * -EINVAL on failure
26 */
27 int acpi_gsi_to_irq(u32 gsi, unsigned int *irq)
28 {
29 struct irq_domain *d = irq_find_matching_fwnode(acpi_gsi_domain_id,
30 DOMAIN_BUS_ANY);
31
32 *irq = irq_find_mapping(d, gsi);
33 /*
34 * *irq == 0 means no mapping, that should
35 * be reported as a failure
36 */
37 return (*irq > 0) ? 0 : -EINVAL;
38 }
39 EXPORT_SYMBOL_GPL(acpi_gsi_to_irq);
40
41 /**
42 * acpi_register_gsi() - Map a GSI to a linux IRQ number
43 * @dev: device for which IRQ has to be mapped
44 * @gsi: GSI IRQ number
45 * @trigger: trigger type of the GSI number to be mapped
46 * @polarity: polarity of the GSI to be mapped
47 *
48 * Returns: a valid linux IRQ number on success
49 * -EINVAL on failure
50 */
51 int acpi_register_gsi(struct device *dev, u32 gsi, int trigger,
52 int polarity)
53 {
54 struct irq_fwspec fwspec;
55
56 if (WARN_ON(!acpi_gsi_domain_id)) {
57 pr_warn("GSI: No registered irqchip, giving up\n");
58 return -EINVAL;
59 }
60
61 fwspec.fwnode = acpi_gsi_domain_id;
62 fwspec.param[0] = gsi;
63 fwspec.param[1] = acpi_dev_get_irq_type(trigger, polarity);
64 fwspec.param_count = 2;
65
66 return irq_create_fwspec_mapping(&fwspec);
67 }
68 EXPORT_SYMBOL_GPL(acpi_register_gsi);
69
70 /**
71 * acpi_unregister_gsi() - Free a GSI<->linux IRQ number mapping
72 * @gsi: GSI IRQ number
73 */
74 void acpi_unregister_gsi(u32 gsi)
75 {
76 struct irq_domain *d = irq_find_matching_fwnode(acpi_gsi_domain_id,
77 DOMAIN_BUS_ANY);
78 int irq = irq_find_mapping(d, gsi);
79
80 irq_dispose_mapping(irq);
81 }
82 EXPORT_SYMBOL_GPL(acpi_unregister_gsi);
83
84 /**
85 * acpi_get_irq_source_fwhandle() - Retrieve fwhandle from IRQ resource source.
86 * @source: acpi_resource_source to use for the lookup.
87 *
88 * Description:
89 * Retrieve the fwhandle of the device referenced by the given IRQ resource
90 * source.
91 *
92 * Return:
93 * The referenced device fwhandle or NULL on failure
94 */
95 static struct fwnode_handle *
96 acpi_get_irq_source_fwhandle(const struct acpi_resource_source *source)
97 {
98 struct fwnode_handle *result;
99 struct acpi_device *device;
100 acpi_handle handle;
101 acpi_status status;
102
103 if (!source->string_length)
104 return acpi_gsi_domain_id;
105
106 status = acpi_get_handle(NULL, source->string_ptr, &handle);
107 if (WARN_ON(ACPI_FAILURE(status)))
108 return NULL;
109
110 device = acpi_bus_get_acpi_device(handle);
111 if (WARN_ON(!device))
112 return NULL;
113
114 result = &device->fwnode;
115 acpi_bus_put_acpi_device(device);
116 return result;
117 }
118
119 /*
120 * Context for the resource walk used to lookup IRQ resources.
121 * Contains a return code, the lookup index, and references to the flags
122 * and fwspec where the result is returned.
123 */
124 struct acpi_irq_parse_one_ctx {
125 int rc;
126 unsigned int index;
127 unsigned long *res_flags;
128 struct irq_fwspec *fwspec;
129 };
130
131 /**
132 * acpi_irq_parse_one_match - Handle a matching IRQ resource.
133 * @fwnode: matching fwnode
134 * @hwirq: hardware IRQ number
135 * @triggering: triggering attributes of hwirq
136 * @polarity: polarity attributes of hwirq
137 * @polarity: polarity attributes of hwirq
138 * @shareable: shareable attributes of hwirq
139 * @ctx: acpi_irq_parse_one_ctx updated by this function
140 *
141 * Description:
142 * Handle a matching IRQ resource by populating the given ctx with
143 * the information passed.
144 */
145 static inline void acpi_irq_parse_one_match(struct fwnode_handle *fwnode,
146 u32 hwirq, u8 triggering,
147 u8 polarity, u8 shareable,
148 struct acpi_irq_parse_one_ctx *ctx)
149 {
150 if (!fwnode)
151 return;
152 ctx->rc = 0;
153 *ctx->res_flags = acpi_dev_irq_flags(triggering, polarity, shareable);
154 ctx->fwspec->fwnode = fwnode;
155 ctx->fwspec->param[0] = hwirq;
156 ctx->fwspec->param[1] = acpi_dev_get_irq_type(triggering, polarity);
157 ctx->fwspec->param_count = 2;
158 }
159
160 /**
161 * acpi_irq_parse_one_cb - Handle the given resource.
162 * @ares: resource to handle
163 * @context: context for the walk
164 *
165 * Description:
166 * This is called by acpi_walk_resources passing each resource returned by
167 * the _CRS method. We only inspect IRQ resources. Since IRQ resources
168 * might contain multiple interrupts we check if the index is within this
169 * one's interrupt array, otherwise we subtract the current resource IRQ
170 * count from the lookup index to prepare for the next resource.
171 * Once a match is found we call acpi_irq_parse_one_match to populate
172 * the result and end the walk by returning AE_CTRL_TERMINATE.
173 *
174 * Return:
175 * AE_OK if the walk should continue, AE_CTRL_TERMINATE if a matching
176 * IRQ resource was found.
177 */
178 static acpi_status acpi_irq_parse_one_cb(struct acpi_resource *ares,
179 void *context)
180 {
181 struct acpi_irq_parse_one_ctx *ctx = context;
182 struct acpi_resource_irq *irq;
183 struct acpi_resource_extended_irq *eirq;
184 struct fwnode_handle *fwnode;
185
186 switch (ares->type) {
187 case ACPI_RESOURCE_TYPE_IRQ:
188 irq = &ares->data.irq;
189 if (ctx->index >= irq->interrupt_count) {
190 ctx->index -= irq->interrupt_count;
191 return AE_OK;
192 }
193 fwnode = acpi_gsi_domain_id;
194 acpi_irq_parse_one_match(fwnode, irq->interrupts[ctx->index],
195 irq->triggering, irq->polarity,
196 irq->shareable, ctx);
197 return AE_CTRL_TERMINATE;
198 case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
199 eirq = &ares->data.extended_irq;
200 if (eirq->producer_consumer == ACPI_PRODUCER)
201 return AE_OK;
202 if (ctx->index >= eirq->interrupt_count) {
203 ctx->index -= eirq->interrupt_count;
204 return AE_OK;
205 }
206 fwnode = acpi_get_irq_source_fwhandle(&eirq->resource_source);
207 acpi_irq_parse_one_match(fwnode, eirq->interrupts[ctx->index],
208 eirq->triggering, eirq->polarity,
209 eirq->shareable, ctx);
210 return AE_CTRL_TERMINATE;
211 }
212
213 return AE_OK;
214 }
215
216 /**
217 * acpi_irq_parse_one - Resolve an interrupt for a device
218 * @handle: the device whose interrupt is to be resolved
219 * @index: index of the interrupt to resolve
220 * @fwspec: structure irq_fwspec filled by this function
221 * @flags: resource flags filled by this function
222 *
223 * Description:
224 * Resolves an interrupt for a device by walking its CRS resources to find
225 * the appropriate ACPI IRQ resource and populating the given struct irq_fwspec
226 * and flags.
227 *
228 * Return:
229 * The result stored in ctx.rc by the callback, or the default -EINVAL value
230 * if an error occurs.
231 */
232 static int acpi_irq_parse_one(acpi_handle handle, unsigned int index,
233 struct irq_fwspec *fwspec, unsigned long *flags)
234 {
235 struct acpi_irq_parse_one_ctx ctx = { -EINVAL, index, flags, fwspec };
236
237 acpi_walk_resources(handle, METHOD_NAME__CRS, acpi_irq_parse_one_cb, &ctx);
238 return ctx.rc;
239 }
240
241 /**
242 * acpi_irq_get - Lookup an ACPI IRQ resource and use it to initialize resource.
243 * @handle: ACPI device handle
244 * @index: ACPI IRQ resource index to lookup
245 * @res: Linux IRQ resource to initialize
246 *
247 * Description:
248 * Look for the ACPI IRQ resource with the given index and use it to initialize
249 * the given Linux IRQ resource.
250 *
251 * Return:
252 * 0 on success
253 * -EINVAL if an error occurs
254 * -EPROBE_DEFER if the IRQ lookup/conversion failed
255 */
256 int acpi_irq_get(acpi_handle handle, unsigned int index, struct resource *res)
257 {
258 struct irq_fwspec fwspec;
259 struct irq_domain *domain;
260 unsigned long flags;
261 int rc;
262
263 rc = acpi_irq_parse_one(handle, index, &fwspec, &flags);
264 if (rc)
265 return rc;
266
267 domain = irq_find_matching_fwnode(fwspec.fwnode, DOMAIN_BUS_ANY);
268 if (!domain)
269 return -EPROBE_DEFER;
270
271 rc = irq_create_fwspec_mapping(&fwspec);
272 if (rc <= 0)
273 return -EINVAL;
274
275 res->start = rc;
276 res->end = rc;
277 res->flags = flags;
278
279 return 0;
280 }
281 EXPORT_SYMBOL_GPL(acpi_irq_get);
282
283 /**
284 * acpi_set_irq_model - Setup the GSI irqdomain information
285 * @model: the value assigned to acpi_irq_model
286 * @fwnode: the irq_domain identifier for mapping and looking up
287 * GSI interrupts
288 */
289 void __init acpi_set_irq_model(enum acpi_irq_model_id model,
290 struct fwnode_handle *fwnode)
291 {
292 acpi_irq_model = model;
293 acpi_gsi_domain_id = fwnode;
294 }
295
296 /**
297 * acpi_irq_create_hierarchy - Create a hierarchical IRQ domain with the default
298 * GSI domain as its parent.
299 * @flags: Irq domain flags associated with the domain
300 * @size: Size of the domain.
301 * @fwnode: Optional fwnode of the interrupt controller
302 * @ops: Pointer to the interrupt domain callbacks
303 * @host_data: Controller private data pointer
304 */
305 struct irq_domain *acpi_irq_create_hierarchy(unsigned int flags,
306 unsigned int size,
307 struct fwnode_handle *fwnode,
308 const struct irq_domain_ops *ops,
309 void *host_data)
310 {
311 struct irq_domain *d = irq_find_matching_fwnode(acpi_gsi_domain_id,
312 DOMAIN_BUS_ANY);
313
314 if (!d)
315 return NULL;
316
317 return irq_domain_create_hierarchy(d, flags, size, fwnode, ops,
318 host_data);
319 }
320 EXPORT_SYMBOL_GPL(acpi_irq_create_hierarchy);