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