xref: /openbmc/linux/drivers/mtd/maps/physmap-core.c (revision 2f164822)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Normal mappings of chips in physical memory
4  *
5  * Copyright (C) 2003 MontaVista Software Inc.
6  * Author: Jun Sun, jsun@mvista.com or jsun@junsun.net
7  *
8  * 031022 - [jsun] add run-time configure and partition setup
9  *
10  * Device tree support:
11  *    Copyright (C) 2006 MontaVista Software Inc.
12  *    Author: Vitaly Wool <vwool@ru.mvista.com>
13  *
14  *    Revised to handle newer style flash binding by:
15  *    Copyright (C) 2007 David Gibson, IBM Corporation.
16  *
17  * GPIO address extension:
18  *    Handle the case where a flash device is mostly addressed using physical
19  *    line and supplemented by GPIOs.  This way you can hook up say a 8MiB flash
20  *    to a 2MiB memory range and use the GPIOs to select a particular range.
21  *
22  *    Copyright © 2000 Nicolas Pitre <nico@cam.org>
23  *    Copyright © 2005-2009 Analog Devices Inc.
24  */
25 
26 #include <linux/module.h>
27 #include <linux/types.h>
28 #include <linux/kernel.h>
29 #include <linux/init.h>
30 #include <linux/slab.h>
31 #include <linux/device.h>
32 #include <linux/platform_device.h>
33 #include <linux/mtd/mtd.h>
34 #include <linux/mtd/map.h>
35 #include <linux/mtd/partitions.h>
36 #include <linux/mtd/physmap.h>
37 #include <linux/mtd/concat.h>
38 #include <linux/mtd/cfi_endian.h>
39 #include <linux/io.h>
40 #include <linux/of_device.h>
41 #include <linux/pm_runtime.h>
42 #include <linux/gpio/consumer.h>
43 
44 #include "physmap-bt1-rom.h"
45 #include "physmap-gemini.h"
46 #include "physmap-ixp4xx.h"
47 #include "physmap-versatile.h"
48 
49 struct physmap_flash_info {
50 	unsigned int		nmaps;
51 	struct mtd_info		**mtds;
52 	struct mtd_info		*cmtd;
53 	struct map_info		*maps;
54 	spinlock_t		vpp_lock;
55 	int			vpp_refcnt;
56 	const char		*probe_type;
57 	const char * const	*part_types;
58 	unsigned int		nparts;
59 	const struct mtd_partition *parts;
60 	struct gpio_descs	*gpios;
61 	unsigned int		gpio_values;
62 	unsigned int		win_order;
63 };
64 
65 static int physmap_flash_remove(struct platform_device *dev)
66 {
67 	struct physmap_flash_info *info;
68 	struct physmap_flash_data *physmap_data;
69 	int i;
70 
71 	info = platform_get_drvdata(dev);
72 
73 	if (info->cmtd) {
74 		WARN_ON(mtd_device_unregister(info->cmtd));
75 
76 		if (info->cmtd != info->mtds[0])
77 			mtd_concat_destroy(info->cmtd);
78 	}
79 
80 	for (i = 0; i < info->nmaps; i++) {
81 		if (info->mtds[i])
82 			map_destroy(info->mtds[i]);
83 	}
84 
85 	physmap_data = dev_get_platdata(&dev->dev);
86 	if (physmap_data && physmap_data->exit)
87 		physmap_data->exit(dev);
88 
89 	pm_runtime_put(&dev->dev);
90 	pm_runtime_disable(&dev->dev);
91 	return 0;
92 }
93 
94 static void physmap_set_vpp(struct map_info *map, int state)
95 {
96 	struct platform_device *pdev;
97 	struct physmap_flash_data *physmap_data;
98 	struct physmap_flash_info *info;
99 	unsigned long flags;
100 
101 	pdev = (struct platform_device *)map->map_priv_1;
102 	physmap_data = dev_get_platdata(&pdev->dev);
103 
104 	if (!physmap_data->set_vpp)
105 		return;
106 
107 	info = platform_get_drvdata(pdev);
108 
109 	spin_lock_irqsave(&info->vpp_lock, flags);
110 	if (state) {
111 		if (++info->vpp_refcnt == 1)    /* first nested 'on' */
112 			physmap_data->set_vpp(pdev, 1);
113 	} else {
114 		if (--info->vpp_refcnt == 0)    /* last nested 'off' */
115 			physmap_data->set_vpp(pdev, 0);
116 	}
117 	spin_unlock_irqrestore(&info->vpp_lock, flags);
118 }
119 
120 #if IS_ENABLED(CONFIG_MTD_PHYSMAP_GPIO_ADDR)
121 static void physmap_set_addr_gpios(struct physmap_flash_info *info,
122 				   unsigned long ofs)
123 {
124 	unsigned int i;
125 
126 	ofs >>= info->win_order;
127 	if (info->gpio_values == ofs)
128 		return;
129 
130 	for (i = 0; i < info->gpios->ndescs; i++) {
131 		if ((BIT(i) & ofs) == (BIT(i) & info->gpio_values))
132 			continue;
133 
134 		gpiod_set_value(info->gpios->desc[i], !!(BIT(i) & ofs));
135 	}
136 
137 	info->gpio_values = ofs;
138 }
139 
140 #define win_mask(order)		(BIT(order) - 1)
141 
142 static map_word physmap_addr_gpios_read(struct map_info *map,
143 					unsigned long ofs)
144 {
145 	struct platform_device *pdev;
146 	struct physmap_flash_info *info;
147 	map_word mw;
148 	u16 word;
149 
150 	pdev = (struct platform_device *)map->map_priv_1;
151 	info = platform_get_drvdata(pdev);
152 	physmap_set_addr_gpios(info, ofs);
153 
154 	word = readw(map->virt + (ofs & win_mask(info->win_order)));
155 	mw.x[0] = word;
156 	return mw;
157 }
158 
159 static void physmap_addr_gpios_copy_from(struct map_info *map, void *buf,
160 					 unsigned long ofs, ssize_t len)
161 {
162 	struct platform_device *pdev;
163 	struct physmap_flash_info *info;
164 
165 	pdev = (struct platform_device *)map->map_priv_1;
166 	info = platform_get_drvdata(pdev);
167 
168 	while (len) {
169 		unsigned int winofs = ofs & win_mask(info->win_order);
170 		unsigned int chunklen = min_t(unsigned int, len,
171 					      BIT(info->win_order) - winofs);
172 
173 		physmap_set_addr_gpios(info, ofs);
174 		memcpy_fromio(buf, map->virt + winofs, chunklen);
175 		len -= chunklen;
176 		buf += chunklen;
177 		ofs += chunklen;
178 	}
179 }
180 
181 static void physmap_addr_gpios_write(struct map_info *map, map_word mw,
182 				     unsigned long ofs)
183 {
184 	struct platform_device *pdev;
185 	struct physmap_flash_info *info;
186 	u16 word;
187 
188 	pdev = (struct platform_device *)map->map_priv_1;
189 	info = platform_get_drvdata(pdev);
190 	physmap_set_addr_gpios(info, ofs);
191 
192 	word = mw.x[0];
193 	writew(word, map->virt + (ofs & win_mask(info->win_order)));
194 }
195 
196 static void physmap_addr_gpios_copy_to(struct map_info *map, unsigned long ofs,
197 				       const void *buf, ssize_t len)
198 {
199 	struct platform_device *pdev;
200 	struct physmap_flash_info *info;
201 
202 	pdev = (struct platform_device *)map->map_priv_1;
203 	info = platform_get_drvdata(pdev);
204 
205 	while (len) {
206 		unsigned int winofs = ofs & win_mask(info->win_order);
207 		unsigned int chunklen = min_t(unsigned int, len,
208 					      BIT(info->win_order) - winofs);
209 
210 		physmap_set_addr_gpios(info, ofs);
211 		memcpy_toio(map->virt + winofs, buf, chunklen);
212 		len -= chunklen;
213 		buf += chunklen;
214 		ofs += chunklen;
215 	}
216 }
217 
218 static int physmap_addr_gpios_map_init(struct map_info *map)
219 {
220 	map->phys = NO_XIP;
221 	map->read = physmap_addr_gpios_read;
222 	map->copy_from = physmap_addr_gpios_copy_from;
223 	map->write = physmap_addr_gpios_write;
224 	map->copy_to = physmap_addr_gpios_copy_to;
225 
226 	return 0;
227 }
228 #else
229 static int physmap_addr_gpios_map_init(struct map_info *map)
230 {
231 	return -ENOTSUPP;
232 }
233 #endif
234 
235 #if IS_ENABLED(CONFIG_MTD_PHYSMAP_OF)
236 static const struct of_device_id of_flash_match[] = {
237 	{
238 		.compatible = "cfi-flash",
239 		.data = "cfi_probe",
240 	},
241 	{
242 		/*
243 		 * FIXME: JEDEC chips can't be safely and reliably
244 		 * probed, although the mtd code gets it right in
245 		 * practice most of the time.  We should use the
246 		 * vendor and device ids specified by the binding to
247 		 * bypass the heuristic probe code, but the mtd layer
248 		 * provides, at present, no interface for doing so
249 		 * :(.
250 		 */
251 		.compatible = "jedec-flash",
252 		.data = "jedec_probe",
253 	},
254 	{
255 		.compatible = "mtd-ram",
256 		.data = "map_ram",
257 	},
258 	{
259 		.compatible = "mtd-rom",
260 		.data = "map_rom",
261 	},
262 	{
263 		.type = "rom",
264 		.compatible = "direct-mapped"
265 	},
266 	{ /* sentinel */ },
267 };
268 MODULE_DEVICE_TABLE(of, of_flash_match);
269 
270 static const char * const of_default_part_probes[] = {
271 	"cmdlinepart", "RedBoot", "ofpart", "ofoldpart", NULL
272 };
273 
274 static const char * const *of_get_part_probes(struct platform_device *dev)
275 {
276 	struct device_node *dp = dev->dev.of_node;
277 	const char **res;
278 	int count;
279 
280 	count = of_property_count_strings(dp, "linux,part-probe");
281 	if (count < 0)
282 		return of_default_part_probes;
283 
284 	res = devm_kcalloc(&dev->dev, count + 1, sizeof(*res), GFP_KERNEL);
285 	if (!res)
286 		return NULL;
287 
288 	count = of_property_read_string_array(dp, "linux,part-probe", res,
289 					      count);
290 	if (count < 0)
291 		return NULL;
292 
293 	return res;
294 }
295 
296 static const char *of_select_probe_type(struct platform_device *dev)
297 {
298 	struct device_node *dp = dev->dev.of_node;
299 	const struct of_device_id *match;
300 	const char *probe_type;
301 
302 	match = of_match_device(of_flash_match, &dev->dev);
303 	if (!match)
304 		return NULL;
305 
306 	probe_type = match->data;
307 	if (probe_type)
308 		return probe_type;
309 
310 	dev_warn(&dev->dev,
311 		 "Device tree uses obsolete \"direct-mapped\" flash binding\n");
312 
313 	of_property_read_string(dp, "probe-type", &probe_type);
314 	if (!probe_type)
315 		return NULL;
316 
317 	if (!strcmp(probe_type, "CFI")) {
318 		probe_type = "cfi_probe";
319 	} else if (!strcmp(probe_type, "JEDEC")) {
320 		probe_type = "jedec_probe";
321 	} else if (!strcmp(probe_type, "ROM")) {
322 		probe_type = "map_rom";
323 	} else {
324 		dev_warn(&dev->dev,
325 			 "obsolete_probe: don't know probe type '%s', mapping as rom\n",
326 			 probe_type);
327 		probe_type = "map_rom";
328 	}
329 
330 	return probe_type;
331 }
332 
333 static int physmap_flash_of_init(struct platform_device *dev)
334 {
335 	struct physmap_flash_info *info = platform_get_drvdata(dev);
336 	struct device_node *dp = dev->dev.of_node;
337 	const char *mtd_name = NULL;
338 	int err, swap = 0;
339 	bool map_indirect;
340 	unsigned int i;
341 	u32 bankwidth;
342 
343 	if (!dp)
344 		return -EINVAL;
345 
346 	info->probe_type = of_select_probe_type(dev);
347 
348 	info->part_types = of_get_part_probes(dev);
349 	if (!info->part_types)
350 		return -ENOMEM;
351 
352 	of_property_read_string(dp, "linux,mtd-name", &mtd_name);
353 
354 	map_indirect = of_property_read_bool(dp, "no-unaligned-direct-access");
355 
356 	err = of_property_read_u32(dp, "bank-width", &bankwidth);
357 	if (err) {
358 		dev_err(&dev->dev, "Can't get bank width from device tree\n");
359 		return err;
360 	}
361 
362 	if (of_property_read_bool(dp, "big-endian"))
363 		swap = CFI_BIG_ENDIAN;
364 	else if (of_property_read_bool(dp, "little-endian"))
365 		swap = CFI_LITTLE_ENDIAN;
366 
367 	for (i = 0; i < info->nmaps; i++) {
368 		info->maps[i].name = mtd_name;
369 		info->maps[i].swap = swap;
370 		info->maps[i].bankwidth = bankwidth;
371 		info->maps[i].device_node = dp;
372 
373 		err = of_flash_probe_bt1_rom(dev, dp, &info->maps[i]);
374 		if (err)
375 			return err;
376 
377 		err = of_flash_probe_gemini(dev, dp, &info->maps[i]);
378 		if (err)
379 			return err;
380 
381 		err = of_flash_probe_ixp4xx(dev, dp, &info->maps[i]);
382 		if (err)
383 			return err;
384 
385 		err = of_flash_probe_versatile(dev, dp, &info->maps[i]);
386 		if (err)
387 			return err;
388 
389 		/*
390 		 * On some platforms (e.g. MPC5200) a direct 1:1 mapping
391 		 * may cause problems with JFFS2 usage, as the local bus (LPB)
392 		 * doesn't support unaligned accesses as implemented in the
393 		 * JFFS2 code via memcpy(). By setting NO_XIP, the
394 		 * flash will not be exposed directly to the MTD users
395 		 * (e.g. JFFS2) any more.
396 		 */
397 		if (map_indirect)
398 			info->maps[i].phys = NO_XIP;
399 	}
400 
401 	return 0;
402 }
403 #else /* IS_ENABLED(CONFIG_MTD_PHYSMAP_OF) */
404 #define of_flash_match NULL
405 
406 static int physmap_flash_of_init(struct platform_device *dev)
407 {
408 	return -ENOTSUPP;
409 }
410 #endif /* IS_ENABLED(CONFIG_MTD_PHYSMAP_OF) */
411 
412 static const char * const rom_probe_types[] = {
413 	"cfi_probe", "jedec_probe", "qinfo_probe", "map_rom",
414 };
415 
416 static const char * const part_probe_types[] = {
417 	"cmdlinepart", "RedBoot", "afs", NULL
418 };
419 
420 static int physmap_flash_pdata_init(struct platform_device *dev)
421 {
422 	struct physmap_flash_info *info = platform_get_drvdata(dev);
423 	struct physmap_flash_data *physmap_data;
424 	unsigned int i;
425 	int err;
426 
427 	physmap_data = dev_get_platdata(&dev->dev);
428 	if (!physmap_data)
429 		return -EINVAL;
430 
431 	info->probe_type = physmap_data->probe_type;
432 	info->part_types = physmap_data->part_probe_types ? : part_probe_types;
433 	info->parts = physmap_data->parts;
434 	info->nparts = physmap_data->nr_parts;
435 
436 	if (physmap_data->init) {
437 		err = physmap_data->init(dev);
438 		if (err)
439 			return err;
440 	}
441 
442 	for (i = 0; i < info->nmaps; i++) {
443 		info->maps[i].bankwidth = physmap_data->width;
444 		info->maps[i].pfow_base = physmap_data->pfow_base;
445 		info->maps[i].set_vpp = physmap_set_vpp;
446 	}
447 
448 	return 0;
449 }
450 
451 static int physmap_flash_probe(struct platform_device *dev)
452 {
453 	struct physmap_flash_info *info;
454 	int err = 0;
455 	int i;
456 
457 	if (!dev->dev.of_node && !dev_get_platdata(&dev->dev))
458 		return -EINVAL;
459 
460 	info = devm_kzalloc(&dev->dev, sizeof(*info), GFP_KERNEL);
461 	if (!info)
462 		return -ENOMEM;
463 
464 	while (platform_get_resource(dev, IORESOURCE_MEM, info->nmaps))
465 		info->nmaps++;
466 
467 	if (!info->nmaps)
468 		return -ENODEV;
469 
470 	info->maps = devm_kzalloc(&dev->dev,
471 				  sizeof(*info->maps) * info->nmaps,
472 				  GFP_KERNEL);
473 	if (!info->maps)
474 		return -ENOMEM;
475 
476 	info->mtds = devm_kzalloc(&dev->dev,
477 				  sizeof(*info->mtds) * info->nmaps,
478 				  GFP_KERNEL);
479 	if (!info->mtds)
480 		return -ENOMEM;
481 
482 	platform_set_drvdata(dev, info);
483 
484 	info->gpios = devm_gpiod_get_array_optional(&dev->dev, "addr",
485 						    GPIOD_OUT_LOW);
486 	if (IS_ERR(info->gpios))
487 		return PTR_ERR(info->gpios);
488 
489 	if (info->gpios && info->nmaps > 1) {
490 		dev_err(&dev->dev, "addr-gpios only supported for nmaps == 1\n");
491 		return -EINVAL;
492 	}
493 
494 	pm_runtime_enable(&dev->dev);
495 	pm_runtime_get_sync(&dev->dev);
496 
497 	if (dev->dev.of_node)
498 		err = physmap_flash_of_init(dev);
499 	else
500 		err = physmap_flash_pdata_init(dev);
501 
502 	if (err) {
503 		pm_runtime_put(&dev->dev);
504 		pm_runtime_disable(&dev->dev);
505 		return err;
506 	}
507 
508 	for (i = 0; i < info->nmaps; i++) {
509 		struct resource *res;
510 
511 		res = platform_get_resource(dev, IORESOURCE_MEM, i);
512 		info->maps[i].virt = devm_ioremap_resource(&dev->dev, res);
513 		if (IS_ERR(info->maps[i].virt)) {
514 			err = PTR_ERR(info->maps[i].virt);
515 			goto err_out;
516 		}
517 
518 		dev_notice(&dev->dev, "physmap platform flash device: %pR\n",
519 			   res);
520 
521 		if (!info->maps[i].name)
522 			info->maps[i].name = dev_name(&dev->dev);
523 
524 		if (!info->maps[i].phys)
525 			info->maps[i].phys = res->start;
526 
527 		info->win_order = get_bitmask_order(resource_size(res)) - 1;
528 		info->maps[i].size = BIT(info->win_order +
529 					 (info->gpios ?
530 					  info->gpios->ndescs : 0));
531 
532 		info->maps[i].map_priv_1 = (unsigned long)dev;
533 
534 		if (info->gpios) {
535 			err = physmap_addr_gpios_map_init(&info->maps[i]);
536 			if (err)
537 				goto err_out;
538 		}
539 
540 #ifdef CONFIG_MTD_COMPLEX_MAPPINGS
541 		/*
542 		 * Only use the simple_map implementation if map hooks are not
543 		 * implemented. Since map->read() is mandatory checking for its
544 		 * presence is enough.
545 		 */
546 		if (!info->maps[i].read)
547 			simple_map_init(&info->maps[i]);
548 #else
549 		simple_map_init(&info->maps[i]);
550 #endif
551 
552 		if (info->probe_type) {
553 			info->mtds[i] = do_map_probe(info->probe_type,
554 						     &info->maps[i]);
555 		} else {
556 			int j;
557 
558 			for (j = 0; j < ARRAY_SIZE(rom_probe_types); j++) {
559 				info->mtds[i] = do_map_probe(rom_probe_types[j],
560 							     &info->maps[i]);
561 				if (info->mtds[i])
562 					break;
563 			}
564 		}
565 
566 		if (!info->mtds[i]) {
567 			dev_err(&dev->dev, "map_probe failed\n");
568 			err = -ENXIO;
569 			goto err_out;
570 		}
571 		info->mtds[i]->dev.parent = &dev->dev;
572 	}
573 
574 	if (info->nmaps == 1) {
575 		info->cmtd = info->mtds[0];
576 	} else {
577 		/*
578 		 * We detected multiple devices. Concatenate them together.
579 		 */
580 		info->cmtd = mtd_concat_create(info->mtds, info->nmaps,
581 					       dev_name(&dev->dev));
582 		if (!info->cmtd)
583 			err = -ENXIO;
584 	}
585 	if (err)
586 		goto err_out;
587 
588 	spin_lock_init(&info->vpp_lock);
589 
590 	mtd_set_of_node(info->cmtd, dev->dev.of_node);
591 	err = mtd_device_parse_register(info->cmtd, info->part_types, NULL,
592 					info->parts, info->nparts);
593 	if (err)
594 		goto err_out;
595 
596 	return 0;
597 
598 err_out:
599 	physmap_flash_remove(dev);
600 	return err;
601 }
602 
603 #ifdef CONFIG_PM
604 static void physmap_flash_shutdown(struct platform_device *dev)
605 {
606 	struct physmap_flash_info *info = platform_get_drvdata(dev);
607 	int i;
608 
609 	for (i = 0; i < info->nmaps && info->mtds[i]; i++)
610 		if (mtd_suspend(info->mtds[i]) == 0)
611 			mtd_resume(info->mtds[i]);
612 }
613 #else
614 #define physmap_flash_shutdown NULL
615 #endif
616 
617 static struct platform_driver physmap_flash_driver = {
618 	.probe		= physmap_flash_probe,
619 	.remove		= physmap_flash_remove,
620 	.shutdown	= physmap_flash_shutdown,
621 	.driver		= {
622 		.name	= "physmap-flash",
623 		.of_match_table = of_flash_match,
624 	},
625 };
626 
627 #ifdef CONFIG_MTD_PHYSMAP_COMPAT
628 static struct physmap_flash_data physmap_flash_data = {
629 	.width		= CONFIG_MTD_PHYSMAP_BANKWIDTH,
630 };
631 
632 static struct resource physmap_flash_resource = {
633 	.start		= CONFIG_MTD_PHYSMAP_START,
634 	.end		= CONFIG_MTD_PHYSMAP_START + CONFIG_MTD_PHYSMAP_LEN - 1,
635 	.flags		= IORESOURCE_MEM,
636 };
637 
638 static struct platform_device physmap_flash = {
639 	.name		= "physmap-flash",
640 	.id		= 0,
641 	.dev		= {
642 		.platform_data	= &physmap_flash_data,
643 	},
644 	.num_resources	= 1,
645 	.resource	= &physmap_flash_resource,
646 };
647 #endif
648 
649 static int __init physmap_init(void)
650 {
651 	int err;
652 
653 	err = platform_driver_register(&physmap_flash_driver);
654 #ifdef CONFIG_MTD_PHYSMAP_COMPAT
655 	if (err == 0) {
656 		err = platform_device_register(&physmap_flash);
657 		if (err)
658 			platform_driver_unregister(&physmap_flash_driver);
659 	}
660 #endif
661 
662 	return err;
663 }
664 
665 static void __exit physmap_exit(void)
666 {
667 #ifdef CONFIG_MTD_PHYSMAP_COMPAT
668 	platform_device_unregister(&physmap_flash);
669 #endif
670 	platform_driver_unregister(&physmap_flash_driver);
671 }
672 
673 module_init(physmap_init);
674 module_exit(physmap_exit);
675 
676 MODULE_LICENSE("GPL");
677 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
678 MODULE_AUTHOR("Vitaly Wool <vwool@ru.mvista.com>");
679 MODULE_AUTHOR("Mike Frysinger <vapier@gentoo.org>");
680 MODULE_DESCRIPTION("Generic configurable MTD map driver");
681 
682 /* legacy platform drivers can't hotplug or coldplg */
683 #ifndef CONFIG_MTD_PHYSMAP_COMPAT
684 /* work with hotplug and coldplug */
685 MODULE_ALIAS("platform:physmap-flash");
686 #endif
687