Commit | Line | Data |
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736759ef | 1 | // SPDX-License-Identifier: GPL-2.0+ |
98d9f30c BH |
2 | /* |
3 | * PCI <-> OF mapping helpers | |
4 | * | |
5 | * Copyright 2011 IBM Corp. | |
98d9f30c | 6 | */ |
4670d610 | 7 | #define pr_fmt(fmt) "PCI: OF: " fmt |
98d9f30c | 8 | |
b165e2b6 | 9 | #include <linux/irqdomain.h> |
98d9f30c BH |
10 | #include <linux/kernel.h> |
11 | #include <linux/pci.h> | |
12 | #include <linux/of.h> | |
c8d17588 | 13 | #include <linux/of_irq.h> |
4670d610 | 14 | #include <linux/of_address.h> |
98d9f30c BH |
15 | #include <linux/of_pci.h> |
16 | #include "pci.h" | |
17 | ||
40e5d614 | 18 | #ifdef CONFIG_PCI |
98d9f30c BH |
19 | void pci_set_of_node(struct pci_dev *dev) |
20 | { | |
21 | if (!dev->bus->dev.of_node) | |
22 | return; | |
23 | dev->dev.of_node = of_pci_find_child_device(dev->bus->dev.of_node, | |
24 | dev->devfn); | |
59b099a6 JPB |
25 | if (dev->dev.of_node) |
26 | dev->dev.fwnode = &dev->dev.of_node->fwnode; | |
98d9f30c BH |
27 | } |
28 | ||
29 | void pci_release_of_node(struct pci_dev *dev) | |
30 | { | |
31 | of_node_put(dev->dev.of_node); | |
32 | dev->dev.of_node = NULL; | |
59b099a6 | 33 | dev->dev.fwnode = NULL; |
98d9f30c BH |
34 | } |
35 | ||
36 | void pci_set_bus_of_node(struct pci_bus *bus) | |
37 | { | |
9cb30a71 JPB |
38 | struct device_node *node; |
39 | ||
40 | if (bus->self == NULL) { | |
41 | node = pcibios_get_phb_of_node(bus); | |
42 | } else { | |
43 | node = of_node_get(bus->self->dev.of_node); | |
44 | if (node && of_property_read_bool(node, "external-facing")) | |
45 | bus->self->untrusted = true; | |
46 | } | |
59b099a6 | 47 | |
9cb30a71 | 48 | bus->dev.of_node = node; |
59b099a6 JPB |
49 | |
50 | if (bus->dev.of_node) | |
51 | bus->dev.fwnode = &bus->dev.of_node->fwnode; | |
98d9f30c BH |
52 | } |
53 | ||
54 | void pci_release_bus_of_node(struct pci_bus *bus) | |
55 | { | |
56 | of_node_put(bus->dev.of_node); | |
57 | bus->dev.of_node = NULL; | |
59b099a6 | 58 | bus->dev.fwnode = NULL; |
98d9f30c BH |
59 | } |
60 | ||
61 | struct device_node * __weak pcibios_get_phb_of_node(struct pci_bus *bus) | |
62 | { | |
63 | /* This should only be called for PHBs */ | |
64 | if (WARN_ON(bus->self || bus->parent)) | |
65 | return NULL; | |
66 | ||
4670d610 RH |
67 | /* |
68 | * Look for a node pointer in either the intermediary device we | |
69 | * create above the root bus or its own parent. Normally only | |
98d9f30c BH |
70 | * the later is populated. |
71 | */ | |
72 | if (bus->bridge->of_node) | |
73 | return of_node_get(bus->bridge->of_node); | |
69566dd8 | 74 | if (bus->bridge->parent && bus->bridge->parent->of_node) |
98d9f30c BH |
75 | return of_node_get(bus->bridge->parent->of_node); |
76 | return NULL; | |
77 | } | |
b165e2b6 MZ |
78 | |
79 | struct irq_domain *pci_host_bridge_of_msi_domain(struct pci_bus *bus) | |
80 | { | |
81 | #ifdef CONFIG_IRQ_DOMAIN | |
b165e2b6 MZ |
82 | struct irq_domain *d; |
83 | ||
84 | if (!bus->dev.of_node) | |
85 | return NULL; | |
86 | ||
87 | /* Start looking for a phandle to an MSI controller. */ | |
c8d17588 MZ |
88 | d = of_msi_get_domain(&bus->dev, bus->dev.of_node, DOMAIN_BUS_PCI_MSI); |
89 | if (d) | |
90 | return d; | |
471c931c MZ |
91 | |
92 | /* | |
93 | * If we don't have an msi-parent property, look for a domain | |
94 | * directly attached to the host bridge. | |
95 | */ | |
c8d17588 | 96 | d = irq_find_matching_host(bus->dev.of_node, DOMAIN_BUS_PCI_MSI); |
b165e2b6 MZ |
97 | if (d) |
98 | return d; | |
99 | ||
c8d17588 | 100 | return irq_find_host(bus->dev.of_node); |
b165e2b6 MZ |
101 | #else |
102 | return NULL; | |
103 | #endif | |
104 | } | |
4670d610 | 105 | |
4670d610 RH |
106 | static inline int __of_pci_pci_compare(struct device_node *node, |
107 | unsigned int data) | |
108 | { | |
109 | int devfn; | |
110 | ||
111 | devfn = of_pci_get_devfn(node); | |
112 | if (devfn < 0) | |
113 | return 0; | |
114 | ||
115 | return devfn == data; | |
116 | } | |
117 | ||
118 | struct device_node *of_pci_find_child_device(struct device_node *parent, | |
119 | unsigned int devfn) | |
120 | { | |
121 | struct device_node *node, *node2; | |
122 | ||
123 | for_each_child_of_node(parent, node) { | |
124 | if (__of_pci_pci_compare(node, devfn)) | |
125 | return node; | |
126 | /* | |
127 | * Some OFs create a parent node "multifunc-device" as | |
128 | * a fake root for all functions of a multi-function | |
129 | * device we go down them as well. | |
130 | */ | |
83a50d3a | 131 | if (of_node_name_eq(node, "multifunc-device")) { |
4670d610 RH |
132 | for_each_child_of_node(node, node2) { |
133 | if (__of_pci_pci_compare(node2, devfn)) { | |
134 | of_node_put(node); | |
135 | return node2; | |
136 | } | |
137 | } | |
138 | } | |
139 | } | |
140 | return NULL; | |
141 | } | |
142 | EXPORT_SYMBOL_GPL(of_pci_find_child_device); | |
143 | ||
144 | /** | |
145 | * of_pci_get_devfn() - Get device and function numbers for a device node | |
146 | * @np: device node | |
147 | * | |
148 | * Parses a standard 5-cell PCI resource and returns an 8-bit value that can | |
149 | * be passed to the PCI_SLOT() and PCI_FUNC() macros to extract the device | |
150 | * and function numbers respectively. On error a negative error code is | |
151 | * returned. | |
152 | */ | |
153 | int of_pci_get_devfn(struct device_node *np) | |
154 | { | |
155 | u32 reg[5]; | |
156 | int error; | |
157 | ||
158 | error = of_property_read_u32_array(np, "reg", reg, ARRAY_SIZE(reg)); | |
159 | if (error) | |
160 | return error; | |
161 | ||
162 | return (reg[0] >> 8) & 0xff; | |
163 | } | |
164 | EXPORT_SYMBOL_GPL(of_pci_get_devfn); | |
165 | ||
166 | /** | |
167 | * of_pci_parse_bus_range() - parse the bus-range property of a PCI device | |
168 | * @node: device node | |
169 | * @res: address to a struct resource to return the bus-range | |
170 | * | |
171 | * Returns 0 on success or a negative error-code on failure. | |
172 | */ | |
173 | int of_pci_parse_bus_range(struct device_node *node, struct resource *res) | |
174 | { | |
175 | u32 bus_range[2]; | |
176 | int error; | |
177 | ||
178 | error = of_property_read_u32_array(node, "bus-range", bus_range, | |
179 | ARRAY_SIZE(bus_range)); | |
180 | if (error) | |
181 | return error; | |
182 | ||
183 | res->name = node->name; | |
184 | res->start = bus_range[0]; | |
185 | res->end = bus_range[1]; | |
186 | res->flags = IORESOURCE_BUS; | |
187 | ||
188 | return 0; | |
189 | } | |
190 | EXPORT_SYMBOL_GPL(of_pci_parse_bus_range); | |
191 | ||
192 | /** | |
193 | * This function will try to obtain the host bridge domain number by | |
194 | * finding a property called "linux,pci-domain" of the given device node. | |
195 | * | |
196 | * @node: device tree node with the domain information | |
197 | * | |
198 | * Returns the associated domain number from DT in the range [0-0xffff], or | |
199 | * a negative value if the required property is not found. | |
200 | */ | |
201 | int of_get_pci_domain_nr(struct device_node *node) | |
202 | { | |
203 | u32 domain; | |
204 | int error; | |
205 | ||
206 | error = of_property_read_u32(node, "linux,pci-domain", &domain); | |
207 | if (error) | |
208 | return error; | |
209 | ||
210 | return (u16)domain; | |
211 | } | |
212 | EXPORT_SYMBOL_GPL(of_get_pci_domain_nr); | |
213 | ||
4670d610 RH |
214 | /** |
215 | * of_pci_check_probe_only - Setup probe only mode if linux,pci-probe-only | |
216 | * is present and valid | |
217 | */ | |
218 | void of_pci_check_probe_only(void) | |
219 | { | |
220 | u32 val; | |
221 | int ret; | |
222 | ||
223 | ret = of_property_read_u32(of_chosen, "linux,pci-probe-only", &val); | |
224 | if (ret) { | |
225 | if (ret == -ENODATA || ret == -EOVERFLOW) | |
226 | pr_warn("linux,pci-probe-only without valid value, ignoring\n"); | |
227 | return; | |
228 | } | |
229 | ||
230 | if (val) | |
231 | pci_add_flags(PCI_PROBE_ONLY); | |
232 | else | |
233 | pci_clear_flags(PCI_PROBE_ONLY); | |
234 | ||
235 | pr_info("PROBE_ONLY %sabled\n", val ? "en" : "dis"); | |
236 | } | |
237 | EXPORT_SYMBOL_GPL(of_pci_check_probe_only); | |
238 | ||
239 | #if defined(CONFIG_OF_ADDRESS) | |
240 | /** | |
5bd51b35 JK |
241 | * devm_of_pci_get_host_bridge_resources() - Resource-managed parsing of PCI |
242 | * host bridge resources from DT | |
055f87a2 | 243 | * @dev: host bridge device |
4670d610 RH |
244 | * @busno: bus number associated with the bridge root bus |
245 | * @bus_max: maximum number of buses for this bridge | |
246 | * @resources: list where the range of resources will be added after DT parsing | |
247 | * @io_base: pointer to a variable that will contain on return the physical | |
248 | * address for the start of the I/O range. Can be NULL if the caller doesn't | |
249 | * expect I/O ranges to be present in the device tree. | |
250 | * | |
4670d610 RH |
251 | * This function will parse the "ranges" property of a PCI host bridge device |
252 | * node and setup the resource mapping based on its content. It is expected | |
253 | * that the property conforms with the Power ePAPR document. | |
254 | * | |
255 | * It returns zero if the range parsing has been successful or a standard error | |
256 | * value if it failed. | |
257 | */ | |
5bd51b35 | 258 | int devm_of_pci_get_host_bridge_resources(struct device *dev, |
4670d610 RH |
259 | unsigned char busno, unsigned char bus_max, |
260 | struct list_head *resources, resource_size_t *io_base) | |
261 | { | |
055f87a2 | 262 | struct device_node *dev_node = dev->of_node; |
93c9a7f8 | 263 | struct resource *res, tmp_res; |
4670d610 RH |
264 | struct resource *bus_range; |
265 | struct of_pci_range range; | |
266 | struct of_pci_range_parser parser; | |
267 | char range_type[4]; | |
268 | int err; | |
269 | ||
270 | if (io_base) | |
271 | *io_base = (resource_size_t)OF_BAD_ADDR; | |
272 | ||
5bd51b35 | 273 | bus_range = devm_kzalloc(dev, sizeof(*bus_range), GFP_KERNEL); |
4670d610 RH |
274 | if (!bus_range) |
275 | return -ENOMEM; | |
276 | ||
d9c5d5ac | 277 | dev_info(dev, "host bridge %pOF ranges:\n", dev_node); |
4670d610 | 278 | |
126b7de6 | 279 | err = of_pci_parse_bus_range(dev_node, bus_range); |
4670d610 RH |
280 | if (err) { |
281 | bus_range->start = busno; | |
282 | bus_range->end = bus_max; | |
283 | bus_range->flags = IORESOURCE_BUS; | |
d9c5d5ac JK |
284 | dev_info(dev, " No bus range found for %pOF, using %pR\n", |
285 | dev_node, bus_range); | |
4670d610 RH |
286 | } else { |
287 | if (bus_range->end > bus_range->start + bus_max) | |
288 | bus_range->end = bus_range->start + bus_max; | |
289 | } | |
290 | pci_add_resource(resources, bus_range); | |
291 | ||
292 | /* Check for ranges property */ | |
126b7de6 | 293 | err = of_pci_range_parser_init(&parser, dev_node); |
4670d610 | 294 | if (err) |
5bd51b35 | 295 | goto failed; |
4670d610 | 296 | |
d9c5d5ac | 297 | dev_dbg(dev, "Parsing ranges property...\n"); |
4670d610 RH |
298 | for_each_of_pci_range(&parser, &range) { |
299 | /* Read next ranges element */ | |
300 | if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_IO) | |
301 | snprintf(range_type, 4, " IO"); | |
302 | else if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_MEM) | |
303 | snprintf(range_type, 4, "MEM"); | |
304 | else | |
305 | snprintf(range_type, 4, "err"); | |
d9c5d5ac JK |
306 | dev_info(dev, " %s %#010llx..%#010llx -> %#010llx\n", |
307 | range_type, range.cpu_addr, | |
308 | range.cpu_addr + range.size - 1, range.pci_addr); | |
4670d610 RH |
309 | |
310 | /* | |
311 | * If we failed translation or got a zero-sized region | |
312 | * then skip this range | |
313 | */ | |
314 | if (range.cpu_addr == OF_BAD_ADDR || range.size == 0) | |
315 | continue; | |
316 | ||
93c9a7f8 JK |
317 | err = of_pci_range_to_resource(&range, dev_node, &tmp_res); |
318 | if (err) | |
319 | continue; | |
320 | ||
321 | res = devm_kmemdup(dev, &tmp_res, sizeof(tmp_res), GFP_KERNEL); | |
4670d610 RH |
322 | if (!res) { |
323 | err = -ENOMEM; | |
5bd51b35 | 324 | goto failed; |
4670d610 RH |
325 | } |
326 | ||
4670d610 RH |
327 | if (resource_type(res) == IORESOURCE_IO) { |
328 | if (!io_base) { | |
d9c5d5ac | 329 | dev_err(dev, "I/O range found for %pOF. Please provide an io_base pointer to save CPU base address\n", |
126b7de6 | 330 | dev_node); |
4670d610 | 331 | err = -EINVAL; |
5bd51b35 | 332 | goto failed; |
4670d610 RH |
333 | } |
334 | if (*io_base != (resource_size_t)OF_BAD_ADDR) | |
d9c5d5ac JK |
335 | dev_warn(dev, "More than one I/O resource converted for %pOF. CPU base address for old range lost!\n", |
336 | dev_node); | |
4670d610 RH |
337 | *io_base = range.cpu_addr; |
338 | } | |
339 | ||
340 | pci_add_resource_offset(resources, res, res->start - range.pci_addr); | |
341 | } | |
342 | ||
343 | return 0; | |
344 | ||
5bd51b35 | 345 | failed: |
4670d610 RH |
346 | pci_free_resource_list(resources); |
347 | return err; | |
348 | } | |
5bd51b35 | 349 | EXPORT_SYMBOL_GPL(devm_of_pci_get_host_bridge_resources); |
4670d610 RH |
350 | #endif /* CONFIG_OF_ADDRESS */ |
351 | ||
4670d610 RH |
352 | #if IS_ENABLED(CONFIG_OF_IRQ) |
353 | /** | |
354 | * of_irq_parse_pci - Resolve the interrupt for a PCI device | |
355 | * @pdev: the device whose interrupt is to be resolved | |
b071c1fd | 356 | * @out_irq: structure of_phandle_args filled by this function |
4670d610 RH |
357 | * |
358 | * This function resolves the PCI interrupt for a given PCI device. If a | |
359 | * device-node exists for a given pci_dev, it will use normal OF tree | |
360 | * walking. If not, it will implement standard swizzling and walk up the | |
361 | * PCI tree until an device-node is found, at which point it will finish | |
362 | * resolving using the OF tree walking. | |
363 | */ | |
7e297843 | 364 | static int of_irq_parse_pci(const struct pci_dev *pdev, struct of_phandle_args *out_irq) |
4670d610 RH |
365 | { |
366 | struct device_node *dn, *ppnode; | |
367 | struct pci_dev *ppdev; | |
368 | __be32 laddr[3]; | |
369 | u8 pin; | |
370 | int rc; | |
371 | ||
372 | /* | |
373 | * Check if we have a device node, if yes, fallback to standard | |
374 | * device tree parsing | |
375 | */ | |
376 | dn = pci_device_to_OF_node(pdev); | |
377 | if (dn) { | |
378 | rc = of_irq_parse_one(dn, 0, out_irq); | |
379 | if (!rc) | |
380 | return rc; | |
381 | } | |
382 | ||
383 | /* | |
384 | * Ok, we don't, time to have fun. Let's start by building up an | |
385 | * interrupt spec. we assume #interrupt-cells is 1, which is standard | |
386 | * for PCI. If you do different, then don't use that routine. | |
387 | */ | |
388 | rc = pci_read_config_byte(pdev, PCI_INTERRUPT_PIN, &pin); | |
389 | if (rc != 0) | |
390 | goto err; | |
391 | /* No pin, exit with no error message. */ | |
392 | if (pin == 0) | |
393 | return -ENODEV; | |
394 | ||
395 | /* Now we walk up the PCI tree */ | |
396 | for (;;) { | |
397 | /* Get the pci_dev of our parent */ | |
398 | ppdev = pdev->bus->self; | |
399 | ||
400 | /* Ouch, it's a host bridge... */ | |
401 | if (ppdev == NULL) { | |
402 | ppnode = pci_bus_to_OF_node(pdev->bus); | |
403 | ||
404 | /* No node for host bridge ? give up */ | |
405 | if (ppnode == NULL) { | |
406 | rc = -EINVAL; | |
407 | goto err; | |
408 | } | |
409 | } else { | |
410 | /* We found a P2P bridge, check if it has a node */ | |
411 | ppnode = pci_device_to_OF_node(ppdev); | |
412 | } | |
413 | ||
414 | /* | |
415 | * Ok, we have found a parent with a device-node, hand over to | |
416 | * the OF parsing code. | |
417 | * We build a unit address from the linux device to be used for | |
418 | * resolution. Note that we use the linux bus number which may | |
419 | * not match your firmware bus numbering. | |
420 | * Fortunately, in most cases, interrupt-map-mask doesn't | |
421 | * include the bus number as part of the matching. | |
422 | * You should still be careful about that though if you intend | |
423 | * to rely on this function (you ship a firmware that doesn't | |
424 | * create device nodes for all PCI devices). | |
425 | */ | |
426 | if (ppnode) | |
427 | break; | |
428 | ||
429 | /* | |
430 | * We can only get here if we hit a P2P bridge with no node; | |
431 | * let's do standard swizzling and try again | |
432 | */ | |
433 | pin = pci_swizzle_interrupt_pin(pdev, pin); | |
434 | pdev = ppdev; | |
435 | } | |
436 | ||
437 | out_irq->np = ppnode; | |
438 | out_irq->args_count = 1; | |
439 | out_irq->args[0] = pin; | |
440 | laddr[0] = cpu_to_be32((pdev->bus->number << 16) | (pdev->devfn << 8)); | |
441 | laddr[1] = laddr[2] = cpu_to_be32(0); | |
442 | rc = of_irq_parse_raw(laddr, out_irq); | |
443 | if (rc) | |
444 | goto err; | |
445 | return 0; | |
446 | err: | |
447 | if (rc == -ENOENT) { | |
448 | dev_warn(&pdev->dev, | |
449 | "%s: no interrupt-map found, INTx interrupts not available\n", | |
450 | __func__); | |
451 | pr_warn_once("%s: possibly some PCI slots don't have level triggered interrupts capability\n", | |
452 | __func__); | |
453 | } else { | |
454 | dev_err(&pdev->dev, "%s: failed with rc=%d\n", __func__, rc); | |
455 | } | |
456 | return rc; | |
457 | } | |
4670d610 RH |
458 | |
459 | /** | |
460 | * of_irq_parse_and_map_pci() - Decode a PCI IRQ from the device tree and map to a VIRQ | |
461 | * @dev: The PCI device needing an IRQ | |
462 | * @slot: PCI slot number; passed when used as map_irq callback. Unused | |
463 | * @pin: PCI IRQ pin number; passed when used as map_irq callback. Unused | |
464 | * | |
465 | * @slot and @pin are unused, but included in the function so that this | |
466 | * function can be used directly as the map_irq callback to | |
467 | * pci_assign_irq() and struct pci_host_bridge.map_irq pointer | |
468 | */ | |
469 | int of_irq_parse_and_map_pci(const struct pci_dev *dev, u8 slot, u8 pin) | |
470 | { | |
471 | struct of_phandle_args oirq; | |
472 | int ret; | |
473 | ||
474 | ret = of_irq_parse_pci(dev, &oirq); | |
475 | if (ret) | |
476 | return 0; /* Proper return code 0 == NO_IRQ */ | |
477 | ||
478 | return irq_create_of_mapping(&oirq); | |
479 | } | |
480 | EXPORT_SYMBOL_GPL(of_irq_parse_and_map_pci); | |
481 | #endif /* CONFIG_OF_IRQ */ | |
c7f75aec | 482 | |
3a8f77e4 CP |
483 | int pci_parse_request_of_pci_ranges(struct device *dev, |
484 | struct list_head *resources, | |
485 | struct resource **bus_range) | |
486 | { | |
487 | int err, res_valid = 0; | |
3a8f77e4 CP |
488 | resource_size_t iobase; |
489 | struct resource_entry *win, *tmp; | |
490 | ||
491 | INIT_LIST_HEAD(resources); | |
5bd51b35 | 492 | err = devm_of_pci_get_host_bridge_resources(dev, 0, 0xff, resources, |
055f87a2 | 493 | &iobase); |
3a8f77e4 CP |
494 | if (err) |
495 | return err; | |
496 | ||
497 | err = devm_request_pci_bus_resources(dev, resources); | |
498 | if (err) | |
499 | goto out_release_res; | |
500 | ||
501 | resource_list_for_each_entry_safe(win, tmp, resources) { | |
502 | struct resource *res = win->res; | |
503 | ||
504 | switch (resource_type(res)) { | |
505 | case IORESOURCE_IO: | |
a5fb9fb0 | 506 | err = devm_pci_remap_iospace(dev, res, iobase); |
3a8f77e4 CP |
507 | if (err) { |
508 | dev_warn(dev, "error %d: failed to map resource %pR\n", | |
509 | err, res); | |
510 | resource_list_destroy_entry(win); | |
511 | } | |
512 | break; | |
513 | case IORESOURCE_MEM: | |
514 | res_valid |= !(res->flags & IORESOURCE_PREFETCH); | |
515 | break; | |
516 | case IORESOURCE_BUS: | |
517 | if (bus_range) | |
518 | *bus_range = res; | |
519 | break; | |
520 | } | |
521 | } | |
522 | ||
523 | if (res_valid) | |
524 | return 0; | |
525 | ||
526 | dev_err(dev, "non-prefetchable memory resource required\n"); | |
527 | err = -EINVAL; | |
528 | ||
529 | out_release_res: | |
530 | pci_free_resource_list(resources); | |
531 | return err; | |
532 | } | |
c7f75aec | 533 | |
40e5d614 KVA |
534 | #endif /* CONFIG_PCI */ |
535 | ||
536 | /** | |
537 | * This function will try to find the limitation of link speed by finding | |
538 | * a property called "max-link-speed" of the given device node. | |
539 | * | |
540 | * @node: device tree node with the max link speed information | |
541 | * | |
542 | * Returns the associated max link speed from DT, or a negative value if the | |
543 | * required property is not found or is invalid. | |
544 | */ | |
545 | int of_pci_get_max_link_speed(struct device_node *node) | |
546 | { | |
547 | u32 max_link_speed; | |
548 | ||
549 | if (of_property_read_u32(node, "max-link-speed", &max_link_speed) || | |
550 | max_link_speed > 4) | |
551 | return -EINVAL; | |
552 | ||
553 | return max_link_speed; | |
554 | } | |
555 | EXPORT_SYMBOL_GPL(of_pci_get_max_link_speed); |