xref: /rk3399_rockchip-uboot/cmd/pci.c (revision 3751f4dcdb135d4e1c1965191bb1dd6d39b1092e)
1 /*
2  * (C) Copyright 2001 Sysgo Real-Time Solutions, GmbH <www.elinos.com>
3  * Andreas Heppel <aheppel@sysgo.de>
4  *
5  * (C) Copyright 2002
6  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
7  * Wolfgang Grandegger, DENX Software Engineering, wg@denx.de.
8  *
9  * SPDX-License-Identifier:	GPL-2.0+
10  */
11 
12 /*
13  * PCI routines
14  */
15 
16 #include <common.h>
17 #include <bootretry.h>
18 #include <cli.h>
19 #include <command.h>
20 #include <console.h>
21 #include <dm.h>
22 #include <asm/processor.h>
23 #include <asm/io.h>
24 #include <pci.h>
25 
26 struct pci_reg_info {
27 	const char *name;
28 	enum pci_size_t size;
29 	u8 offset;
30 };
31 
32 static int pci_byte_size(enum pci_size_t size)
33 {
34 	switch (size) {
35 	case PCI_SIZE_8:
36 		return 1;
37 	case PCI_SIZE_16:
38 		return 2;
39 	case PCI_SIZE_32:
40 	default:
41 		return 4;
42 	}
43 }
44 
45 static int pci_field_width(enum pci_size_t size)
46 {
47 	return pci_byte_size(size) * 2;
48 }
49 
50 static void pci_show_regs(struct udevice *dev, struct pci_reg_info *regs)
51 {
52 	for (; regs->name; regs++) {
53 		unsigned long val;
54 
55 		dm_pci_read_config(dev, regs->offset, &val, regs->size);
56 		printf("  %s =%*s%#.*lx\n", regs->name,
57 		       (int)(28 - strlen(regs->name)), "",
58 		       pci_field_width(regs->size), val);
59 	}
60 }
61 
62 static int pci_bar_show(struct udevice *dev)
63 {
64 	u8 header_type;
65 	int bar_cnt, bar_id, mem_type;
66 	bool is_64, is_io;
67 	u32 base_low, base_high;
68 	u32 size_low, size_high;
69 	u64 base, size;
70 	u32 reg_addr;
71 	int prefetchable;
72 
73 	dm_pci_read_config8(dev, PCI_HEADER_TYPE, &header_type);
74 	header_type &= 0x7f;
75 
76 	if (header_type == PCI_HEADER_TYPE_CARDBUS) {
77 		printf("CardBus doesn't support BARs\n");
78 		return -ENOSYS;
79 	} else if (header_type != PCI_HEADER_TYPE_NORMAL &&
80 		   header_type != PCI_HEADER_TYPE_BRIDGE) {
81 		printf("unknown header type\n");
82 		return -ENOSYS;
83 	}
84 
85 	bar_cnt = (header_type == PCI_HEADER_TYPE_NORMAL) ? 6 : 2;
86 
87 	printf("ID   Base                Size                Width  Type\n");
88 	printf("----------------------------------------------------------\n");
89 
90 	bar_id = 0;
91 	reg_addr = PCI_BASE_ADDRESS_0;
92 	while (bar_cnt) {
93 		dm_pci_read_config32(dev, reg_addr, &base_low);
94 		dm_pci_write_config32(dev, reg_addr, 0xffffffff);
95 		dm_pci_read_config32(dev, reg_addr, &size_low);
96 		dm_pci_write_config32(dev, reg_addr, base_low);
97 		reg_addr += 4;
98 
99 		base = base_low & ~0xf;
100 		size = size_low & ~0xf;
101 		base_high = 0x0;
102 		size_high = 0xffffffff;
103 		is_64 = 0;
104 		prefetchable = base_low & PCI_BASE_ADDRESS_MEM_PREFETCH;
105 		is_io = base_low & PCI_BASE_ADDRESS_SPACE_IO;
106 		mem_type = base_low & PCI_BASE_ADDRESS_MEM_TYPE_MASK;
107 
108 		if (mem_type == PCI_BASE_ADDRESS_MEM_TYPE_64) {
109 			dm_pci_read_config32(dev, reg_addr, &base_high);
110 			dm_pci_write_config32(dev, reg_addr, 0xffffffff);
111 			dm_pci_read_config32(dev, reg_addr, &size_high);
112 			dm_pci_write_config32(dev, reg_addr, base_high);
113 			bar_cnt--;
114 			reg_addr += 4;
115 			is_64 = 1;
116 		}
117 
118 		base = base | ((u64)base_high << 32);
119 		size = size | ((u64)size_high << 32);
120 
121 		if ((!is_64 && size_low) || (is_64 && size)) {
122 			size = ~size + 1;
123 			printf(" %d   %#018llx  %#018llx  %d     %s   %s\n",
124 			       bar_id, (unsigned long long)base,
125 			       (unsigned long long)size, is_64 ? 64 : 32,
126 			       is_io ? "I/O" : "MEM",
127 			       prefetchable ? "Prefetchable" : "");
128 		}
129 
130 		bar_id++;
131 		bar_cnt--;
132 	}
133 
134 	return 0;
135 }
136 
137 static struct pci_reg_info regs_start[] = {
138 	{ "vendor ID", PCI_SIZE_16, PCI_VENDOR_ID },
139 	{ "device ID", PCI_SIZE_16, PCI_DEVICE_ID },
140 	{ "command register ID", PCI_SIZE_16, PCI_COMMAND },
141 	{ "status register", PCI_SIZE_16, PCI_STATUS },
142 	{ "revision ID", PCI_SIZE_8, PCI_REVISION_ID },
143 	{},
144 };
145 
146 static struct pci_reg_info regs_rest[] = {
147 	{ "sub class code", PCI_SIZE_8, PCI_CLASS_SUB_CODE },
148 	{ "programming interface", PCI_SIZE_8, PCI_CLASS_PROG },
149 	{ "cache line", PCI_SIZE_8, PCI_CACHE_LINE_SIZE },
150 	{ "latency time", PCI_SIZE_8, PCI_LATENCY_TIMER },
151 	{ "header type", PCI_SIZE_8, PCI_HEADER_TYPE },
152 	{ "BIST", PCI_SIZE_8, PCI_BIST },
153 	{ "base address 0", PCI_SIZE_32, PCI_BASE_ADDRESS_0 },
154 	{},
155 };
156 
157 static struct pci_reg_info regs_normal[] = {
158 	{ "base address 1", PCI_SIZE_32, PCI_BASE_ADDRESS_1 },
159 	{ "base address 2", PCI_SIZE_32, PCI_BASE_ADDRESS_2 },
160 	{ "base address 3", PCI_SIZE_32, PCI_BASE_ADDRESS_3 },
161 	{ "base address 4", PCI_SIZE_32, PCI_BASE_ADDRESS_4 },
162 	{ "base address 5", PCI_SIZE_32, PCI_BASE_ADDRESS_5 },
163 	{ "cardBus CIS pointer", PCI_SIZE_32, PCI_CARDBUS_CIS },
164 	{ "sub system vendor ID", PCI_SIZE_16, PCI_SUBSYSTEM_VENDOR_ID },
165 	{ "sub system ID", PCI_SIZE_16, PCI_SUBSYSTEM_ID },
166 	{ "expansion ROM base address", PCI_SIZE_32, PCI_ROM_ADDRESS },
167 	{ "interrupt line", PCI_SIZE_8, PCI_INTERRUPT_LINE },
168 	{ "interrupt pin", PCI_SIZE_8, PCI_INTERRUPT_PIN },
169 	{ "min Grant", PCI_SIZE_8, PCI_MIN_GNT },
170 	{ "max Latency", PCI_SIZE_8, PCI_MAX_LAT },
171 	{},
172 };
173 
174 static struct pci_reg_info regs_bridge[] = {
175 	{ "base address 1", PCI_SIZE_32, PCI_BASE_ADDRESS_1 },
176 	{ "primary bus number", PCI_SIZE_8, PCI_PRIMARY_BUS },
177 	{ "secondary bus number", PCI_SIZE_8, PCI_SECONDARY_BUS },
178 	{ "subordinate bus number", PCI_SIZE_8, PCI_SUBORDINATE_BUS },
179 	{ "secondary latency timer", PCI_SIZE_8, PCI_SEC_LATENCY_TIMER },
180 	{ "IO base", PCI_SIZE_8, PCI_IO_BASE },
181 	{ "IO limit", PCI_SIZE_8, PCI_IO_LIMIT },
182 	{ "secondary status", PCI_SIZE_16, PCI_SEC_STATUS },
183 	{ "memory base", PCI_SIZE_16, PCI_MEMORY_BASE },
184 	{ "memory limit", PCI_SIZE_16, PCI_MEMORY_LIMIT },
185 	{ "prefetch memory base", PCI_SIZE_16, PCI_PREF_MEMORY_BASE },
186 	{ "prefetch memory limit", PCI_SIZE_16, PCI_PREF_MEMORY_LIMIT },
187 	{ "prefetch memory base upper", PCI_SIZE_32, PCI_PREF_BASE_UPPER32 },
188 	{ "prefetch memory limit upper", PCI_SIZE_32, PCI_PREF_LIMIT_UPPER32 },
189 	{ "IO base upper 16 bits", PCI_SIZE_16, PCI_IO_BASE_UPPER16 },
190 	{ "IO limit upper 16 bits", PCI_SIZE_16, PCI_IO_LIMIT_UPPER16 },
191 	{ "expansion ROM base address", PCI_SIZE_32, PCI_ROM_ADDRESS1 },
192 	{ "interrupt line", PCI_SIZE_8, PCI_INTERRUPT_LINE },
193 	{ "interrupt pin", PCI_SIZE_8, PCI_INTERRUPT_PIN },
194 	{ "bridge control", PCI_SIZE_16, PCI_BRIDGE_CONTROL },
195 	{},
196 };
197 
198 static struct pci_reg_info regs_cardbus[] = {
199 	{ "capabilities", PCI_SIZE_8, PCI_CB_CAPABILITY_LIST },
200 	{ "secondary status", PCI_SIZE_16, PCI_CB_SEC_STATUS },
201 	{ "primary bus number", PCI_SIZE_8, PCI_CB_PRIMARY_BUS },
202 	{ "CardBus number", PCI_SIZE_8, PCI_CB_CARD_BUS },
203 	{ "subordinate bus number", PCI_SIZE_8, PCI_CB_SUBORDINATE_BUS },
204 	{ "CardBus latency timer", PCI_SIZE_8, PCI_CB_LATENCY_TIMER },
205 	{ "CardBus memory base 0", PCI_SIZE_32, PCI_CB_MEMORY_BASE_0 },
206 	{ "CardBus memory limit 0", PCI_SIZE_32, PCI_CB_MEMORY_LIMIT_0 },
207 	{ "CardBus memory base 1", PCI_SIZE_32, PCI_CB_MEMORY_BASE_1 },
208 	{ "CardBus memory limit 1", PCI_SIZE_32, PCI_CB_MEMORY_LIMIT_1 },
209 	{ "CardBus IO base 0", PCI_SIZE_16, PCI_CB_IO_BASE_0 },
210 	{ "CardBus IO base high 0", PCI_SIZE_16, PCI_CB_IO_BASE_0_HI },
211 	{ "CardBus IO limit 0", PCI_SIZE_16, PCI_CB_IO_LIMIT_0 },
212 	{ "CardBus IO limit high 0", PCI_SIZE_16, PCI_CB_IO_LIMIT_0_HI },
213 	{ "CardBus IO base 1", PCI_SIZE_16, PCI_CB_IO_BASE_1 },
214 	{ "CardBus IO base high 1", PCI_SIZE_16, PCI_CB_IO_BASE_1_HI },
215 	{ "CardBus IO limit 1", PCI_SIZE_16, PCI_CB_IO_LIMIT_1 },
216 	{ "CardBus IO limit high 1", PCI_SIZE_16, PCI_CB_IO_LIMIT_1_HI },
217 	{ "interrupt line", PCI_SIZE_8, PCI_INTERRUPT_LINE },
218 	{ "interrupt pin", PCI_SIZE_8, PCI_INTERRUPT_PIN },
219 	{ "bridge control", PCI_SIZE_16, PCI_CB_BRIDGE_CONTROL },
220 	{ "subvendor ID", PCI_SIZE_16, PCI_CB_SUBSYSTEM_VENDOR_ID },
221 	{ "subdevice ID", PCI_SIZE_16, PCI_CB_SUBSYSTEM_ID },
222 	{ "PC Card 16bit base address", PCI_SIZE_32, PCI_CB_LEGACY_MODE_BASE },
223 	{},
224 };
225 
226 /**
227  * pci_header_show() - Show the header of the specified PCI device.
228  *
229  * @dev: Bus+Device+Function number
230  */
231 static void pci_header_show(struct udevice *dev)
232 {
233 	unsigned long class, header_type;
234 
235 	dm_pci_read_config(dev, PCI_CLASS_CODE, &class, PCI_SIZE_8);
236 	dm_pci_read_config(dev, PCI_HEADER_TYPE, &header_type, PCI_SIZE_8);
237 	pci_show_regs(dev, regs_start);
238 	printf("  class code =                  0x%.2x (%s)\n", (int)class,
239 	       pci_class_str(class));
240 	pci_show_regs(dev, regs_rest);
241 
242 	switch (header_type & 0x03) {
243 	case PCI_HEADER_TYPE_NORMAL:	/* "normal" PCI device */
244 		pci_show_regs(dev, regs_normal);
245 		break;
246 	case PCI_HEADER_TYPE_BRIDGE:	/* PCI-to-PCI bridge */
247 		pci_show_regs(dev, regs_bridge);
248 		break;
249 	case PCI_HEADER_TYPE_CARDBUS:	/* PCI-to-CardBus bridge */
250 		pci_show_regs(dev, regs_cardbus);
251 		break;
252 
253 	default:
254 		printf("unknown header\n");
255 		break;
256     }
257 }
258 
259 static void pciinfo_header(int busnum, bool short_listing)
260 {
261 	printf("Scanning PCI devices on bus %d\n", busnum);
262 
263 	if (short_listing) {
264 		printf("BusDevFun  VendorId   DeviceId   Device Class       Sub-Class\n");
265 		printf("_____________________________________________________________\n");
266 	}
267 }
268 
269 /**
270  * pci_header_show_brief() - Show the short-form PCI device header
271  *
272  * Reads and prints the header of the specified PCI device in short form.
273  *
274  * @dev: PCI device to show
275  */
276 static void pci_header_show_brief(struct udevice *dev)
277 {
278 	ulong vendor, device;
279 	ulong class, subclass;
280 
281 	dm_pci_read_config(dev, PCI_VENDOR_ID, &vendor, PCI_SIZE_16);
282 	dm_pci_read_config(dev, PCI_DEVICE_ID, &device, PCI_SIZE_16);
283 	dm_pci_read_config(dev, PCI_CLASS_CODE, &class, PCI_SIZE_8);
284 	dm_pci_read_config(dev, PCI_CLASS_SUB_CODE, &subclass, PCI_SIZE_8);
285 
286 	printf("0x%.4lx     0x%.4lx     %-23s 0x%.2lx\n",
287 	       vendor, device,
288 	       pci_class_str(class), subclass);
289 }
290 
291 static void pciinfo(struct udevice *bus, bool short_listing)
292 {
293 	struct udevice *dev;
294 
295 	pciinfo_header(bus->seq, short_listing);
296 
297 	for (device_find_first_child(bus, &dev);
298 	     dev;
299 	     device_find_next_child(&dev)) {
300 		struct pci_child_platdata *pplat;
301 
302 		pplat = dev_get_parent_platdata(dev);
303 		if (short_listing) {
304 			printf("%02x.%02x.%02x   ", bus->seq,
305 			       PCI_DEV(pplat->devfn), PCI_FUNC(pplat->devfn));
306 			pci_header_show_brief(dev);
307 		} else {
308 			printf("\nFound PCI device %02x.%02x.%02x:\n", bus->seq,
309 			       PCI_DEV(pplat->devfn), PCI_FUNC(pplat->devfn));
310 			pci_header_show(dev);
311 		}
312 	}
313 }
314 
315 /**
316  * get_pci_dev() - Convert the "bus.device.function" identifier into a number
317  *
318  * @name: Device string in the form "bus.device.function" where each is in hex
319  * @return encoded pci_dev_t or -1 if the string was invalid
320  */
321 static pci_dev_t get_pci_dev(char *name)
322 {
323 	char cnum[12];
324 	int len, i, iold, n;
325 	int bdfs[3] = {0,0,0};
326 
327 	len = strlen(name);
328 	if (len > 8)
329 		return -1;
330 	for (i = 0, iold = 0, n = 0; i < len; i++) {
331 		if (name[i] == '.') {
332 			memcpy(cnum, &name[iold], i - iold);
333 			cnum[i - iold] = '\0';
334 			bdfs[n++] = simple_strtoul(cnum, NULL, 16);
335 			iold = i + 1;
336 		}
337 	}
338 	strcpy(cnum, &name[iold]);
339 	if (n == 0)
340 		n = 1;
341 	bdfs[n] = simple_strtoul(cnum, NULL, 16);
342 
343 	return PCI_BDF(bdfs[0], bdfs[1], bdfs[2]);
344 }
345 
346 static int pci_cfg_display(struct udevice *dev, ulong addr,
347 			   enum pci_size_t size, ulong length)
348 {
349 #define DISP_LINE_LEN	16
350 	ulong i, nbytes, linebytes;
351 	int byte_size;
352 	int rc = 0;
353 
354 	byte_size = pci_byte_size(size);
355 	if (length == 0)
356 		length = 0x40 / byte_size; /* Standard PCI config space */
357 
358 	/* Print the lines.
359 	 * once, and all accesses are with the specified bus width.
360 	 */
361 	nbytes = length * byte_size;
362 	do {
363 		printf("%08lx:", addr);
364 		linebytes = (nbytes > DISP_LINE_LEN) ? DISP_LINE_LEN : nbytes;
365 		for (i = 0; i < linebytes; i += byte_size) {
366 			unsigned long val;
367 
368 			dm_pci_read_config(dev, addr, &val, size);
369 			printf(" %0*lx", pci_field_width(size), val);
370 			addr += byte_size;
371 		}
372 		printf("\n");
373 		nbytes -= linebytes;
374 		if (ctrlc()) {
375 			rc = 1;
376 			break;
377 		}
378 	} while (nbytes > 0);
379 
380 	return (rc);
381 }
382 
383 static int pci_cfg_modify(struct udevice *dev, ulong addr, ulong size,
384 			  ulong value, int incrflag)
385 {
386 	ulong	i;
387 	int	nbytes;
388 	ulong val;
389 
390 	/* Print the address, followed by value.  Then accept input for
391 	 * the next value.  A non-converted value exits.
392 	 */
393 	do {
394 		printf("%08lx:", addr);
395 		dm_pci_read_config(dev, addr, &val, size);
396 		printf(" %0*lx", pci_field_width(size), val);
397 
398 		nbytes = cli_readline(" ? ");
399 		if (nbytes == 0 || (nbytes == 1 && console_buffer[0] == '-')) {
400 			/* <CR> pressed as only input, don't modify current
401 			 * location and move to next. "-" pressed will go back.
402 			 */
403 			if (incrflag)
404 				addr += nbytes ? -size : size;
405 			nbytes = 1;
406 			/* good enough to not time out */
407 			bootretry_reset_cmd_timeout();
408 		}
409 #ifdef CONFIG_BOOT_RETRY_TIME
410 		else if (nbytes == -2) {
411 			break;	/* timed out, exit the command	*/
412 		}
413 #endif
414 		else {
415 			char *endp;
416 			i = simple_strtoul(console_buffer, &endp, 16);
417 			nbytes = endp - console_buffer;
418 			if (nbytes) {
419 				/* good enough to not time out
420 				 */
421 				bootretry_reset_cmd_timeout();
422 				dm_pci_write_config(dev, addr, i, size);
423 				if (incrflag)
424 					addr += size;
425 			}
426 		}
427 	} while (nbytes);
428 
429 	return 0;
430 }
431 
432 static const struct pci_flag_info {
433 	uint flag;
434 	const char *name;
435 } pci_flag_info[] = {
436 	{ PCI_REGION_IO, "io" },
437 	{ PCI_REGION_PREFETCH, "prefetch" },
438 	{ PCI_REGION_SYS_MEMORY, "sysmem" },
439 	{ PCI_REGION_RO, "readonly" },
440 	{ PCI_REGION_IO, "io" },
441 };
442 
443 static void pci_show_regions(struct udevice *bus)
444 {
445 	struct pci_controller *hose = dev_get_uclass_priv(bus);
446 	const struct pci_region *reg;
447 	int i, j;
448 
449 	if (!hose) {
450 		printf("Bus '%s' is not a PCI controller\n", bus->name);
451 		return;
452 	}
453 
454 	printf("#   %-18s %-18s %-18s  %s\n", "Bus start", "Phys start", "Size",
455 	       "Flags");
456 	for (i = 0, reg = hose->regions; i < hose->region_count; i++, reg++) {
457 		printf("%d   %#018llx %#018llx %#018llx  ", i,
458 		       (unsigned long long)reg->bus_start,
459 		       (unsigned long long)reg->phys_start,
460 		       (unsigned long long)reg->size);
461 		if (!(reg->flags & PCI_REGION_TYPE))
462 			printf("mem ");
463 		for (j = 0; j < ARRAY_SIZE(pci_flag_info); j++) {
464 			if (reg->flags & pci_flag_info[j].flag)
465 				printf("%s ", pci_flag_info[j].name);
466 		}
467 		printf("\n");
468 	}
469 }
470 
471 /* PCI Configuration Space access commands
472  *
473  * Syntax:
474  *	pci display[.b, .w, .l] bus.device.function} [addr] [len]
475  *	pci next[.b, .w, .l] bus.device.function [addr]
476  *      pci modify[.b, .w, .l] bus.device.function [addr]
477  *      pci write[.b, .w, .l] bus.device.function addr value
478  */
479 static int do_pci(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
480 {
481 	ulong addr = 0, value = 0, cmd_size = 0;
482 	enum pci_size_t size = PCI_SIZE_32;
483 	struct udevice *dev, *bus;
484 	int busnum = 0;
485 	pci_dev_t bdf = 0;
486 	char cmd = 's';
487 	int ret = 0;
488 
489 	if (argc > 1)
490 		cmd = argv[1][0];
491 
492 	switch (cmd) {
493 	case 'd':		/* display */
494 	case 'n':		/* next */
495 	case 'm':		/* modify */
496 	case 'w':		/* write */
497 		/* Check for a size specification. */
498 		cmd_size = cmd_get_data_size(argv[1], 4);
499 		size = (cmd_size == 4) ? PCI_SIZE_32 : cmd_size - 1;
500 		if (argc > 3)
501 			addr = simple_strtoul(argv[3], NULL, 16);
502 		if (argc > 4)
503 			value = simple_strtoul(argv[4], NULL, 16);
504 	case 'h':		/* header */
505 	case 'b':		/* bars */
506 		if (argc < 3)
507 			goto usage;
508 		if ((bdf = get_pci_dev(argv[2])) == -1)
509 			return 1;
510 		break;
511 	case 'e':
512 		pci_init();
513 		return 0;
514 	case 'r': /* no break */
515 	default:		/* scan bus */
516 		value = 1; /* short listing */
517 		if (argc > 1) {
518 			if (cmd != 'r' && argv[argc-1][0] == 'l') {
519 				value = 0;
520 				argc--;
521 			}
522 			if (argc > 1)
523 				busnum = simple_strtoul(argv[1], NULL, 16);
524 		}
525 		ret = uclass_get_device_by_seq(UCLASS_PCI, busnum, &bus);
526 		if (ret) {
527 			printf("No such bus\n");
528 			return CMD_RET_FAILURE;
529 		}
530 		if (cmd == 'r')
531 			pci_show_regions(bus);
532 		else
533 			pciinfo(bus, value);
534 		return 0;
535 	}
536 
537 	ret = dm_pci_bus_find_bdf(bdf, &dev);
538 	if (ret) {
539 		printf("No such device\n");
540 		return CMD_RET_FAILURE;
541 	}
542 
543 	switch (argv[1][0]) {
544 	case 'h':		/* header */
545 		pci_header_show(dev);
546 		break;
547 	case 'd':		/* display */
548 		return pci_cfg_display(dev, addr, size, value);
549 	case 'n':		/* next */
550 		if (argc < 4)
551 			goto usage;
552 		ret = pci_cfg_modify(dev, addr, size, value, 0);
553 		break;
554 	case 'm':		/* modify */
555 		if (argc < 4)
556 			goto usage;
557 		ret = pci_cfg_modify(dev, addr, size, value, 1);
558 		break;
559 	case 'w':		/* write */
560 		if (argc < 5)
561 			goto usage;
562 		ret = dm_pci_write_config(dev, addr, value, size);
563 		break;
564 	case 'b':		/* bars */
565 		return pci_bar_show(dev);
566 	default:
567 		ret = CMD_RET_USAGE;
568 		break;
569 	}
570 
571 	return ret;
572  usage:
573 	return CMD_RET_USAGE;
574 }
575 
576 /***************************************************/
577 
578 #ifdef CONFIG_SYS_LONGHELP
579 static char pci_help_text[] =
580 	"[bus] [long]\n"
581 	"    - short or long list of PCI devices on bus 'bus'\n"
582 	"pci enum\n"
583 	"    - Enumerate PCI buses\n"
584 	"pci header b.d.f\n"
585 	"    - show header of PCI device 'bus.device.function'\n"
586 	"pci bar b.d.f\n"
587 	"    - show BARs base and size for device b.d.f'\n"
588 	"pci regions\n"
589 	"    - show PCI regions\n"
590 	"pci display[.b, .w, .l] b.d.f [address] [# of objects]\n"
591 	"    - display PCI configuration space (CFG)\n"
592 	"pci next[.b, .w, .l] b.d.f address\n"
593 	"    - modify, read and keep CFG address\n"
594 	"pci modify[.b, .w, .l] b.d.f address\n"
595 	"    -  modify, auto increment CFG address\n"
596 	"pci write[.b, .w, .l] b.d.f address value\n"
597 	"    - write to CFG address";
598 #endif
599 
600 U_BOOT_CMD(
601 	pci,	5,	1,	do_pci,
602 	"list and access PCI Configuration Space", pci_help_text
603 );
604