1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * PCI <-> OF mapping helpers
4 *
5 * Copyright 2011 IBM Corp.
6 */
7 #define pr_fmt(fmt) "PCI: OF: " fmt
8
9 #include <linux/cleanup.h>
10 #include <linux/irqdomain.h>
11 #include <linux/kernel.h>
12 #include <linux/pci.h>
13 #include <linux/of.h>
14 #include <linux/of_irq.h>
15 #include <linux/of_address.h>
16 #include <linux/of_pci.h>
17 #include <linux/platform_device.h>
18 #include "pci.h"
19
20 #ifdef CONFIG_PCI
21 /**
22 * pci_set_of_node - Find and set device's DT device_node
23 * @dev: the PCI device structure to fill
24 *
25 * Returns 0 on success with of_node set or when no device is described in the
26 * DT. Returns -ENODEV if the device is present, but disabled in the DT.
27 */
pci_set_of_node(struct pci_dev * dev)28 int pci_set_of_node(struct pci_dev *dev)
29 {
30 if (!dev->bus->dev.of_node)
31 return 0;
32
33 struct device_node *node __free(device_node) =
34 of_pci_find_child_device(dev->bus->dev.of_node, dev->devfn);
35 if (!node)
36 return 0;
37
38 struct device *pdev __free(put_device) =
39 bus_find_device_by_of_node(&platform_bus_type, node);
40 if (pdev)
41 dev->bus->dev.of_node_reused = true;
42
43 device_set_node(&dev->dev, of_fwnode_handle(no_free_ptr(node)));
44 return 0;
45 }
46
pci_release_of_node(struct pci_dev * dev)47 void pci_release_of_node(struct pci_dev *dev)
48 {
49 of_node_put(dev->dev.of_node);
50 device_set_node(&dev->dev, NULL);
51 }
52
pci_set_bus_of_node(struct pci_bus * bus)53 void pci_set_bus_of_node(struct pci_bus *bus)
54 {
55 struct device_node *node;
56
57 if (bus->self == NULL) {
58 node = pcibios_get_phb_of_node(bus);
59 } else {
60 node = of_node_get(bus->self->dev.of_node);
61 if (node && of_property_read_bool(node, "external-facing"))
62 bus->self->external_facing = true;
63 }
64
65 device_set_node(&bus->dev, of_fwnode_handle(node));
66 }
67
pci_release_bus_of_node(struct pci_bus * bus)68 void pci_release_bus_of_node(struct pci_bus *bus)
69 {
70 of_node_put(bus->dev.of_node);
71 device_set_node(&bus->dev, NULL);
72 }
73
pcibios_get_phb_of_node(struct pci_bus * bus)74 struct device_node * __weak pcibios_get_phb_of_node(struct pci_bus *bus)
75 {
76 /* This should only be called for PHBs */
77 if (WARN_ON(bus->self || bus->parent))
78 return NULL;
79
80 /*
81 * Look for a node pointer in either the intermediary device we
82 * create above the root bus or its own parent. Normally only
83 * the later is populated.
84 */
85 if (bus->bridge->of_node)
86 return of_node_get(bus->bridge->of_node);
87 if (bus->bridge->parent && bus->bridge->parent->of_node)
88 return of_node_get(bus->bridge->parent->of_node);
89 return NULL;
90 }
91
pci_host_bridge_of_msi_domain(struct pci_bus * bus)92 struct irq_domain *pci_host_bridge_of_msi_domain(struct pci_bus *bus)
93 {
94 #ifdef CONFIG_IRQ_DOMAIN
95 struct irq_domain *d;
96
97 if (!bus->dev.of_node)
98 return NULL;
99
100 /* Start looking for a phandle to an MSI controller. */
101 d = of_msi_get_domain(&bus->dev, bus->dev.of_node, DOMAIN_BUS_PCI_MSI);
102 if (d)
103 return d;
104
105 /*
106 * If we don't have an msi-parent property, look for a domain
107 * directly attached to the host bridge.
108 */
109 d = irq_find_matching_host(bus->dev.of_node, DOMAIN_BUS_PCI_MSI);
110 if (d)
111 return d;
112
113 return irq_find_host(bus->dev.of_node);
114 #else
115 return NULL;
116 #endif
117 }
118
pci_host_of_has_msi_map(struct device * dev)119 bool pci_host_of_has_msi_map(struct device *dev)
120 {
121 if (dev && dev->of_node)
122 return of_get_property(dev->of_node, "msi-map", NULL);
123 return false;
124 }
125
__of_pci_pci_compare(struct device_node * node,unsigned int data)126 static inline int __of_pci_pci_compare(struct device_node *node,
127 unsigned int data)
128 {
129 int devfn;
130
131 devfn = of_pci_get_devfn(node);
132 if (devfn < 0)
133 return 0;
134
135 return devfn == data;
136 }
137
of_pci_find_child_device(struct device_node * parent,unsigned int devfn)138 struct device_node *of_pci_find_child_device(struct device_node *parent,
139 unsigned int devfn)
140 {
141 struct device_node *node, *node2;
142
143 for_each_child_of_node(parent, node) {
144 if (__of_pci_pci_compare(node, devfn))
145 return node;
146 /*
147 * Some OFs create a parent node "multifunc-device" as
148 * a fake root for all functions of a multi-function
149 * device we go down them as well.
150 */
151 if (of_node_name_eq(node, "multifunc-device")) {
152 for_each_child_of_node(node, node2) {
153 if (__of_pci_pci_compare(node2, devfn)) {
154 of_node_put(node);
155 return node2;
156 }
157 }
158 }
159 }
160 return NULL;
161 }
162 EXPORT_SYMBOL_GPL(of_pci_find_child_device);
163
164 /**
165 * of_pci_get_devfn() - Get device and function numbers for a device node
166 * @np: device node
167 *
168 * Parses a standard 5-cell PCI resource and returns an 8-bit value that can
169 * be passed to the PCI_SLOT() and PCI_FUNC() macros to extract the device
170 * and function numbers respectively. On error a negative error code is
171 * returned.
172 */
of_pci_get_devfn(struct device_node * np)173 int of_pci_get_devfn(struct device_node *np)
174 {
175 u32 reg[5];
176 int error;
177
178 error = of_property_read_u32_array(np, "reg", reg, ARRAY_SIZE(reg));
179 if (error)
180 return error;
181
182 return (reg[0] >> 8) & 0xff;
183 }
184 EXPORT_SYMBOL_GPL(of_pci_get_devfn);
185
186 /**
187 * of_pci_parse_bus_range() - parse the bus-range property of a PCI device
188 * @node: device node
189 * @res: address to a struct resource to return the bus-range
190 *
191 * Returns 0 on success or a negative error-code on failure.
192 */
of_pci_parse_bus_range(struct device_node * node,struct resource * res)193 int of_pci_parse_bus_range(struct device_node *node, struct resource *res)
194 {
195 u32 bus_range[2];
196 int error;
197
198 error = of_property_read_u32_array(node, "bus-range", bus_range,
199 ARRAY_SIZE(bus_range));
200 if (error)
201 return error;
202
203 res->name = node->name;
204 res->start = bus_range[0];
205 res->end = bus_range[1];
206 res->flags = IORESOURCE_BUS;
207
208 return 0;
209 }
210 EXPORT_SYMBOL_GPL(of_pci_parse_bus_range);
211
212 /**
213 * of_get_pci_domain_nr - Find the host bridge domain number
214 * of the given device node.
215 * @node: Device tree node with the domain information.
216 *
217 * This function will try to obtain the host bridge domain number by finding
218 * a property called "linux,pci-domain" of the given device node.
219 *
220 * Return:
221 * * > 0 - On success, an associated domain number.
222 * * -EINVAL - The property "linux,pci-domain" does not exist.
223 * * -ENODATA - The linux,pci-domain" property does not have value.
224 * * -EOVERFLOW - Invalid "linux,pci-domain" property value.
225 *
226 * Returns the associated domain number from DT in the range [0-0xffff], or
227 * a negative value if the required property is not found.
228 */
of_get_pci_domain_nr(struct device_node * node)229 int of_get_pci_domain_nr(struct device_node *node)
230 {
231 u32 domain;
232 int error;
233
234 error = of_property_read_u32(node, "linux,pci-domain", &domain);
235 if (error)
236 return error;
237
238 return (u16)domain;
239 }
240 EXPORT_SYMBOL_GPL(of_get_pci_domain_nr);
241
242 /**
243 * of_pci_preserve_config - Return true if the boot configuration needs to
244 * be preserved
245 * @node: Device tree node.
246 *
247 * Look for "linux,pci-probe-only" property for a given PCI controller's
248 * node and return true if found. Also look in the chosen node if the
249 * property is not found in the given controller's node. Having this
250 * property ensures that the kernel doesn't reconfigure the BARs and bridge
251 * windows that are already done by the platform firmware.
252 *
253 * Return: true if the property exists; false otherwise.
254 */
of_pci_preserve_config(struct device_node * node)255 bool of_pci_preserve_config(struct device_node *node)
256 {
257 u32 val = 0;
258 int ret;
259
260 if (!node) {
261 pr_warn("device node is NULL, trying with of_chosen\n");
262 node = of_chosen;
263 }
264
265 retry:
266 ret = of_property_read_u32(node, "linux,pci-probe-only", &val);
267 if (ret) {
268 if (ret == -ENODATA || ret == -EOVERFLOW) {
269 pr_warn("Incorrect value for linux,pci-probe-only in %pOF, ignoring\n",
270 node);
271 return false;
272 }
273 if (ret == -EINVAL) {
274 if (node == of_chosen)
275 return false;
276
277 node = of_chosen;
278 goto retry;
279 }
280 }
281
282 if (val)
283 return true;
284 else
285 return false;
286 }
287
288 /**
289 * of_pci_check_probe_only - Setup probe only mode if linux,pci-probe-only
290 * is present and valid
291 */
of_pci_check_probe_only(void)292 void of_pci_check_probe_only(void)
293 {
294 if (of_pci_preserve_config(of_chosen))
295 pci_add_flags(PCI_PROBE_ONLY);
296 else
297 pci_clear_flags(PCI_PROBE_ONLY);
298 }
299 EXPORT_SYMBOL_GPL(of_pci_check_probe_only);
300
301 /**
302 * devm_of_pci_get_host_bridge_resources() - Resource-managed parsing of PCI
303 * host bridge resources from DT
304 * @dev: host bridge device
305 * @busno: bus number associated with the bridge root bus
306 * @bus_max: maximum number of buses for this bridge
307 * @resources: list where the range of resources will be added after DT parsing
308 * @ib_resources: list where the range of inbound resources (with addresses
309 * from 'dma-ranges') will be added after DT parsing
310 * @io_base: pointer to a variable that will contain on return the physical
311 * address for the start of the I/O range. Can be NULL if the caller doesn't
312 * expect I/O ranges to be present in the device tree.
313 *
314 * This function will parse the "ranges" property of a PCI host bridge device
315 * node and setup the resource mapping based on its content. It is expected
316 * that the property conforms with the Power ePAPR document.
317 *
318 * It returns zero if the range parsing has been successful or a standard error
319 * value if it failed.
320 */
devm_of_pci_get_host_bridge_resources(struct device * dev,unsigned char busno,unsigned char bus_max,struct list_head * resources,struct list_head * ib_resources,resource_size_t * io_base)321 static int devm_of_pci_get_host_bridge_resources(struct device *dev,
322 unsigned char busno, unsigned char bus_max,
323 struct list_head *resources,
324 struct list_head *ib_resources,
325 resource_size_t *io_base)
326 {
327 struct device_node *dev_node = dev->of_node;
328 struct resource *res, tmp_res;
329 struct resource *bus_range;
330 struct of_pci_range range;
331 struct of_pci_range_parser parser;
332 const char *range_type;
333 int err;
334
335 if (io_base)
336 *io_base = (resource_size_t)OF_BAD_ADDR;
337
338 bus_range = devm_kzalloc(dev, sizeof(*bus_range), GFP_KERNEL);
339 if (!bus_range)
340 return -ENOMEM;
341
342 dev_info(dev, "host bridge %pOF ranges:\n", dev_node);
343
344 err = of_pci_parse_bus_range(dev_node, bus_range);
345 if (err) {
346 bus_range->start = busno;
347 bus_range->end = bus_max;
348 bus_range->flags = IORESOURCE_BUS;
349 dev_info(dev, " No bus range found for %pOF, using %pR\n",
350 dev_node, bus_range);
351 } else {
352 if (bus_range->end > bus_range->start + bus_max)
353 bus_range->end = bus_range->start + bus_max;
354 }
355 pci_add_resource(resources, bus_range);
356
357 /* Check for ranges property */
358 err = of_pci_range_parser_init(&parser, dev_node);
359 if (err)
360 return 0;
361
362 dev_dbg(dev, "Parsing ranges property...\n");
363 for_each_of_pci_range(&parser, &range) {
364 /* Read next ranges element */
365 if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_IO)
366 range_type = "IO";
367 else if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_MEM)
368 range_type = "MEM";
369 else
370 range_type = "err";
371 dev_info(dev, " %6s %#012llx..%#012llx -> %#012llx\n",
372 range_type, range.cpu_addr,
373 range.cpu_addr + range.size - 1, range.pci_addr);
374
375 /*
376 * If we failed translation or got a zero-sized region
377 * then skip this range
378 */
379 if (range.cpu_addr == OF_BAD_ADDR || range.size == 0)
380 continue;
381
382 err = of_pci_range_to_resource(&range, dev_node, &tmp_res);
383 if (err)
384 continue;
385
386 res = devm_kmemdup(dev, &tmp_res, sizeof(tmp_res), GFP_KERNEL);
387 if (!res) {
388 err = -ENOMEM;
389 goto failed;
390 }
391
392 if (resource_type(res) == IORESOURCE_IO) {
393 if (!io_base) {
394 dev_err(dev, "I/O range found for %pOF. Please provide an io_base pointer to save CPU base address\n",
395 dev_node);
396 err = -EINVAL;
397 goto failed;
398 }
399 if (*io_base != (resource_size_t)OF_BAD_ADDR)
400 dev_warn(dev, "More than one I/O resource converted for %pOF. CPU base address for old range lost!\n",
401 dev_node);
402 *io_base = range.cpu_addr;
403 } else if (resource_type(res) == IORESOURCE_MEM) {
404 res->flags &= ~IORESOURCE_MEM_64;
405 }
406
407 pci_add_resource_offset(resources, res, res->start - range.pci_addr);
408 }
409
410 /* Check for dma-ranges property */
411 if (!ib_resources)
412 return 0;
413 err = of_pci_dma_range_parser_init(&parser, dev_node);
414 if (err)
415 return 0;
416
417 dev_dbg(dev, "Parsing dma-ranges property...\n");
418 for_each_of_pci_range(&parser, &range) {
419 /*
420 * If we failed translation or got a zero-sized region
421 * then skip this range
422 */
423 if (((range.flags & IORESOURCE_TYPE_BITS) != IORESOURCE_MEM) ||
424 range.cpu_addr == OF_BAD_ADDR || range.size == 0)
425 continue;
426
427 dev_info(dev, " %6s %#012llx..%#012llx -> %#012llx\n",
428 "IB MEM", range.cpu_addr,
429 range.cpu_addr + range.size - 1, range.pci_addr);
430
431
432 err = of_pci_range_to_resource(&range, dev_node, &tmp_res);
433 if (err)
434 continue;
435
436 res = devm_kmemdup(dev, &tmp_res, sizeof(tmp_res), GFP_KERNEL);
437 if (!res) {
438 err = -ENOMEM;
439 goto failed;
440 }
441
442 pci_add_resource_offset(ib_resources, res,
443 res->start - range.pci_addr);
444 }
445
446 return 0;
447
448 failed:
449 pci_free_resource_list(resources);
450 return err;
451 }
452
453 #if IS_ENABLED(CONFIG_OF_IRQ)
454 /**
455 * of_irq_parse_pci - Resolve the interrupt for a PCI device
456 * @pdev: the device whose interrupt is to be resolved
457 * @out_irq: structure of_phandle_args filled by this function
458 *
459 * This function resolves the PCI interrupt for a given PCI device. If a
460 * device node exists for a given pci_dev, it will use normal OF tree
461 * walking. If not, it will implement standard swizzling and walk up the
462 * PCI tree until a device node is found, at which point it will finish
463 * resolving using the OF tree walking.
464 */
of_irq_parse_pci(const struct pci_dev * pdev,struct of_phandle_args * out_irq)465 static int of_irq_parse_pci(const struct pci_dev *pdev, struct of_phandle_args *out_irq)
466 {
467 struct device_node *dn, *ppnode = NULL;
468 struct pci_dev *ppdev;
469 __be32 laddr[3];
470 u8 pin;
471 int rc;
472
473 /*
474 * Check if we have a device node, if yes, fallback to standard
475 * device tree parsing
476 */
477 dn = pci_device_to_OF_node(pdev);
478 if (dn) {
479 rc = of_irq_parse_one(dn, 0, out_irq);
480 if (!rc)
481 return rc;
482 }
483
484 /*
485 * Ok, we don't, time to have fun. Let's start by building up an
486 * interrupt spec. we assume #interrupt-cells is 1, which is standard
487 * for PCI. If you do different, then don't use that routine.
488 */
489 rc = pci_read_config_byte(pdev, PCI_INTERRUPT_PIN, &pin);
490 if (rc != 0)
491 goto err;
492 /* No pin, exit with no error message. */
493 if (pin == 0)
494 return -ENODEV;
495
496 /* Local interrupt-map in the device node? Use it! */
497 if (of_property_present(dn, "interrupt-map")) {
498 pin = pci_swizzle_interrupt_pin(pdev, pin);
499 ppnode = dn;
500 }
501
502 /* Now we walk up the PCI tree */
503 while (!ppnode) {
504 /* Get the pci_dev of our parent */
505 ppdev = pdev->bus->self;
506
507 /* Ouch, it's a host bridge... */
508 if (ppdev == NULL) {
509 ppnode = pci_bus_to_OF_node(pdev->bus);
510
511 /* No node for host bridge ? give up */
512 if (ppnode == NULL) {
513 rc = -EINVAL;
514 goto err;
515 }
516 } else {
517 /* We found a P2P bridge, check if it has a node */
518 ppnode = pci_device_to_OF_node(ppdev);
519 }
520
521 /*
522 * Ok, we have found a parent with a device node, hand over to
523 * the OF parsing code.
524 *
525 * We build a unit address from the linux device to be used for
526 * resolution. Note that we use the linux bus number which may
527 * not match your firmware bus numbering.
528 *
529 * Fortunately, in most cases, interrupt-map-mask doesn't
530 * include the bus number as part of the matching.
531 *
532 * You should still be careful about that though if you intend
533 * to rely on this function (you ship a firmware that doesn't
534 * create device nodes for all PCI devices).
535 */
536 if (ppnode)
537 break;
538
539 /*
540 * We can only get here if we hit a P2P bridge with no node;
541 * let's do standard swizzling and try again
542 */
543 pin = pci_swizzle_interrupt_pin(pdev, pin);
544 pdev = ppdev;
545 }
546
547 out_irq->np = ppnode;
548 out_irq->args_count = 1;
549 out_irq->args[0] = pin;
550 laddr[0] = cpu_to_be32((pdev->bus->number << 16) | (pdev->devfn << 8));
551 laddr[1] = laddr[2] = cpu_to_be32(0);
552 rc = of_irq_parse_raw(laddr, out_irq);
553 if (rc)
554 goto err;
555 return 0;
556 err:
557 if (rc == -ENOENT) {
558 dev_warn(&pdev->dev,
559 "%s: no interrupt-map found, INTx interrupts not available\n",
560 __func__);
561 pr_warn_once("%s: possibly some PCI slots don't have level triggered interrupts capability\n",
562 __func__);
563 } else {
564 dev_err(&pdev->dev, "%s: failed with rc=%d\n", __func__, rc);
565 }
566 return rc;
567 }
568
569 /**
570 * of_irq_parse_and_map_pci() - Decode a PCI IRQ from the device tree and map to a VIRQ
571 * @dev: The PCI device needing an IRQ
572 * @slot: PCI slot number; passed when used as map_irq callback. Unused
573 * @pin: PCI IRQ pin number; passed when used as map_irq callback. Unused
574 *
575 * @slot and @pin are unused, but included in the function so that this
576 * function can be used directly as the map_irq callback to
577 * pci_assign_irq() and struct pci_host_bridge.map_irq pointer
578 */
of_irq_parse_and_map_pci(const struct pci_dev * dev,u8 slot,u8 pin)579 int of_irq_parse_and_map_pci(const struct pci_dev *dev, u8 slot, u8 pin)
580 {
581 struct of_phandle_args oirq;
582 int ret;
583
584 ret = of_irq_parse_pci(dev, &oirq);
585 if (ret)
586 return 0; /* Proper return code 0 == NO_IRQ */
587
588 return irq_create_of_mapping(&oirq);
589 }
590 EXPORT_SYMBOL_GPL(of_irq_parse_and_map_pci);
591 #endif /* CONFIG_OF_IRQ */
592
pci_parse_request_of_pci_ranges(struct device * dev,struct pci_host_bridge * bridge)593 static int pci_parse_request_of_pci_ranges(struct device *dev,
594 struct pci_host_bridge *bridge)
595 {
596 int err, res_valid = 0;
597 resource_size_t iobase;
598 struct resource_entry *win, *tmp;
599
600 INIT_LIST_HEAD(&bridge->windows);
601 INIT_LIST_HEAD(&bridge->dma_ranges);
602
603 err = devm_of_pci_get_host_bridge_resources(dev, 0, 0xff, &bridge->windows,
604 &bridge->dma_ranges, &iobase);
605 if (err)
606 return err;
607
608 err = devm_request_pci_bus_resources(dev, &bridge->windows);
609 if (err)
610 return err;
611
612 resource_list_for_each_entry_safe(win, tmp, &bridge->windows) {
613 struct resource *res = win->res;
614
615 switch (resource_type(res)) {
616 case IORESOURCE_IO:
617 err = devm_pci_remap_iospace(dev, res, iobase);
618 if (err) {
619 dev_warn(dev, "error %d: failed to map resource %pR\n",
620 err, res);
621 resource_list_destroy_entry(win);
622 }
623 break;
624 case IORESOURCE_MEM:
625 res_valid |= !(res->flags & IORESOURCE_PREFETCH);
626
627 if (!(res->flags & IORESOURCE_PREFETCH))
628 if (upper_32_bits(resource_size(res)))
629 dev_warn(dev, "Memory resource size exceeds max for 32 bits\n");
630
631 break;
632 }
633 }
634
635 if (!res_valid)
636 dev_warn(dev, "non-prefetchable memory resource required\n");
637
638 return 0;
639 }
640
devm_of_pci_bridge_init(struct device * dev,struct pci_host_bridge * bridge)641 int devm_of_pci_bridge_init(struct device *dev, struct pci_host_bridge *bridge)
642 {
643 if (!dev->of_node)
644 return 0;
645
646 bridge->swizzle_irq = pci_common_swizzle;
647 bridge->map_irq = of_irq_parse_and_map_pci;
648
649 return pci_parse_request_of_pci_ranges(dev, bridge);
650 }
651
652 #ifdef CONFIG_PCI_DYNAMIC_OF_NODES
653
of_pci_remove_node(struct pci_dev * pdev)654 void of_pci_remove_node(struct pci_dev *pdev)
655 {
656 struct device_node *np;
657
658 np = pci_device_to_OF_node(pdev);
659 if (!np || !of_node_check_flag(np, OF_DYNAMIC))
660 return;
661 pdev->dev.of_node = NULL;
662
663 of_changeset_revert(np->data);
664 of_changeset_destroy(np->data);
665 of_node_put(np);
666 }
667
of_pci_make_dev_node(struct pci_dev * pdev)668 void of_pci_make_dev_node(struct pci_dev *pdev)
669 {
670 struct device_node *ppnode, *np = NULL;
671 const char *pci_type;
672 struct of_changeset *cset;
673 const char *name;
674 int ret;
675
676 /*
677 * If there is already a device tree node linked to this device,
678 * return immediately.
679 */
680 if (pci_device_to_OF_node(pdev))
681 return;
682
683 /* Check if there is device tree node for parent device */
684 if (!pdev->bus->self)
685 ppnode = pdev->bus->dev.of_node;
686 else
687 ppnode = pdev->bus->self->dev.of_node;
688 if (!ppnode)
689 return;
690
691 if (pci_is_bridge(pdev))
692 pci_type = "pci";
693 else
694 pci_type = "dev";
695
696 name = kasprintf(GFP_KERNEL, "%s@%x,%x", pci_type,
697 PCI_SLOT(pdev->devfn), PCI_FUNC(pdev->devfn));
698 if (!name)
699 return;
700
701 cset = kmalloc(sizeof(*cset), GFP_KERNEL);
702 if (!cset)
703 goto out_free_name;
704 of_changeset_init(cset);
705
706 np = of_changeset_create_node(cset, ppnode, name);
707 if (!np)
708 goto out_destroy_cset;
709
710 ret = of_pci_add_properties(pdev, cset, np);
711 if (ret)
712 goto out_free_node;
713
714 ret = of_changeset_apply(cset);
715 if (ret)
716 goto out_free_node;
717
718 np->data = cset;
719 pdev->dev.of_node = np;
720 kfree(name);
721
722 return;
723
724 out_free_node:
725 of_node_put(np);
726 out_destroy_cset:
727 of_changeset_destroy(cset);
728 kfree(cset);
729 out_free_name:
730 kfree(name);
731 }
732 #endif
733
734 /**
735 * of_pci_supply_present() - Check if the power supply is present for the PCI
736 * device
737 * @np: Device tree node
738 *
739 * Check if the power supply for the PCI device is present in the device tree
740 * node or not.
741 *
742 * Return: true if at least one power supply exists; false otherwise.
743 */
of_pci_supply_present(struct device_node * np)744 bool of_pci_supply_present(struct device_node *np)
745 {
746 struct property *prop;
747 char *supply;
748
749 if (!np)
750 return false;
751
752 for_each_property_of_node(np, prop) {
753 supply = strrchr(prop->name, '-');
754 if (supply && !strcmp(supply, "-supply"))
755 return true;
756 }
757
758 return false;
759 }
760
761 #endif /* CONFIG_PCI */
762
763 /**
764 * of_pci_get_max_link_speed - Find the maximum link speed of the given device node.
765 * @node: Device tree node with the maximum link speed information.
766 *
767 * This function will try to find the limitation of link speed by finding
768 * a property called "max-link-speed" of the given device node.
769 *
770 * Return:
771 * * > 0 - On success, a maximum link speed.
772 * * -EINVAL - Invalid "max-link-speed" property value, or failure to access
773 * the property of the device tree node.
774 *
775 * Returns the associated max link speed from DT, or a negative value if the
776 * required property is not found or is invalid.
777 */
of_pci_get_max_link_speed(struct device_node * node)778 int of_pci_get_max_link_speed(struct device_node *node)
779 {
780 u32 max_link_speed;
781
782 if (of_property_read_u32(node, "max-link-speed", &max_link_speed) ||
783 max_link_speed == 0 || max_link_speed > 4)
784 return -EINVAL;
785
786 return max_link_speed;
787 }
788 EXPORT_SYMBOL_GPL(of_pci_get_max_link_speed);
789
790 /**
791 * of_pci_get_slot_power_limit - Parses the "slot-power-limit-milliwatt"
792 * property.
793 *
794 * @node: device tree node with the slot power limit information
795 * @slot_power_limit_value: pointer where the value should be stored in PCIe
796 * Slot Capabilities Register format
797 * @slot_power_limit_scale: pointer where the scale should be stored in PCIe
798 * Slot Capabilities Register format
799 *
800 * Returns the slot power limit in milliwatts and if @slot_power_limit_value
801 * and @slot_power_limit_scale pointers are non-NULL, fills in the value and
802 * scale in format used by PCIe Slot Capabilities Register.
803 *
804 * If the property is not found or is invalid, returns 0.
805 */
of_pci_get_slot_power_limit(struct device_node * node,u8 * slot_power_limit_value,u8 * slot_power_limit_scale)806 u32 of_pci_get_slot_power_limit(struct device_node *node,
807 u8 *slot_power_limit_value,
808 u8 *slot_power_limit_scale)
809 {
810 u32 slot_power_limit_mw;
811 u8 value, scale;
812
813 if (of_property_read_u32(node, "slot-power-limit-milliwatt",
814 &slot_power_limit_mw))
815 slot_power_limit_mw = 0;
816
817 /* Calculate Slot Power Limit Value and Slot Power Limit Scale */
818 if (slot_power_limit_mw == 0) {
819 value = 0x00;
820 scale = 0;
821 } else if (slot_power_limit_mw <= 255) {
822 value = slot_power_limit_mw;
823 scale = 3;
824 } else if (slot_power_limit_mw <= 255*10) {
825 value = slot_power_limit_mw / 10;
826 scale = 2;
827 slot_power_limit_mw = slot_power_limit_mw / 10 * 10;
828 } else if (slot_power_limit_mw <= 255*100) {
829 value = slot_power_limit_mw / 100;
830 scale = 1;
831 slot_power_limit_mw = slot_power_limit_mw / 100 * 100;
832 } else if (slot_power_limit_mw <= 239*1000) {
833 value = slot_power_limit_mw / 1000;
834 scale = 0;
835 slot_power_limit_mw = slot_power_limit_mw / 1000 * 1000;
836 } else if (slot_power_limit_mw < 250*1000) {
837 value = 0xEF;
838 scale = 0;
839 slot_power_limit_mw = 239*1000;
840 } else if (slot_power_limit_mw <= 600*1000) {
841 value = 0xF0 + (slot_power_limit_mw / 1000 - 250) / 25;
842 scale = 0;
843 slot_power_limit_mw = slot_power_limit_mw / (1000*25) * (1000*25);
844 } else {
845 value = 0xFE;
846 scale = 0;
847 slot_power_limit_mw = 600*1000;
848 }
849
850 if (slot_power_limit_value)
851 *slot_power_limit_value = value;
852
853 if (slot_power_limit_scale)
854 *slot_power_limit_scale = scale;
855
856 return slot_power_limit_mw;
857 }
858 EXPORT_SYMBOL_GPL(of_pci_get_slot_power_limit);
859