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