xref: /openbmc/linux/drivers/mtd/maps/physmap-core.c (revision 63705da3)
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, err = 0;
70 
71 	info = platform_get_drvdata(dev);
72 	if (!info) {
73 		err = -EINVAL;
74 		goto out;
75 	}
76 
77 	if (info->cmtd) {
78 		err = mtd_device_unregister(info->cmtd);
79 		if (err)
80 			goto out;
81 
82 		if (info->cmtd != info->mtds[0])
83 			mtd_concat_destroy(info->cmtd);
84 	}
85 
86 	for (i = 0; i < info->nmaps; i++) {
87 		if (info->mtds[i])
88 			map_destroy(info->mtds[i]);
89 	}
90 
91 	physmap_data = dev_get_platdata(&dev->dev);
92 	if (physmap_data && physmap_data->exit)
93 		physmap_data->exit(dev);
94 
95 out:
96 	pm_runtime_put(&dev->dev);
97 	pm_runtime_disable(&dev->dev);
98 	return err;
99 }
100 
101 static void physmap_set_vpp(struct map_info *map, int state)
102 {
103 	struct platform_device *pdev;
104 	struct physmap_flash_data *physmap_data;
105 	struct physmap_flash_info *info;
106 	unsigned long flags;
107 
108 	pdev = (struct platform_device *)map->map_priv_1;
109 	physmap_data = dev_get_platdata(&pdev->dev);
110 
111 	if (!physmap_data->set_vpp)
112 		return;
113 
114 	info = platform_get_drvdata(pdev);
115 
116 	spin_lock_irqsave(&info->vpp_lock, flags);
117 	if (state) {
118 		if (++info->vpp_refcnt == 1)    /* first nested 'on' */
119 			physmap_data->set_vpp(pdev, 1);
120 	} else {
121 		if (--info->vpp_refcnt == 0)    /* last nested 'off' */
122 			physmap_data->set_vpp(pdev, 0);
123 	}
124 	spin_unlock_irqrestore(&info->vpp_lock, flags);
125 }
126 
127 #if IS_ENABLED(CONFIG_MTD_PHYSMAP_GPIO_ADDR)
128 static void physmap_set_addr_gpios(struct physmap_flash_info *info,
129 				   unsigned long ofs)
130 {
131 	unsigned int i;
132 
133 	ofs >>= info->win_order;
134 	if (info->gpio_values == ofs)
135 		return;
136 
137 	for (i = 0; i < info->gpios->ndescs; i++) {
138 		if ((BIT(i) & ofs) == (BIT(i) & info->gpio_values))
139 			continue;
140 
141 		gpiod_set_value(info->gpios->desc[i], !!(BIT(i) & ofs));
142 	}
143 
144 	info->gpio_values = ofs;
145 }
146 
147 #define win_mask(order)		(BIT(order) - 1)
148 
149 static map_word physmap_addr_gpios_read(struct map_info *map,
150 					unsigned long ofs)
151 {
152 	struct platform_device *pdev;
153 	struct physmap_flash_info *info;
154 	map_word mw;
155 	u16 word;
156 
157 	pdev = (struct platform_device *)map->map_priv_1;
158 	info = platform_get_drvdata(pdev);
159 	physmap_set_addr_gpios(info, ofs);
160 
161 	word = readw(map->virt + (ofs & win_mask(info->win_order)));
162 	mw.x[0] = word;
163 	return mw;
164 }
165 
166 static void physmap_addr_gpios_copy_from(struct map_info *map, void *buf,
167 					 unsigned long ofs, ssize_t len)
168 {
169 	struct platform_device *pdev;
170 	struct physmap_flash_info *info;
171 
172 	pdev = (struct platform_device *)map->map_priv_1;
173 	info = platform_get_drvdata(pdev);
174 
175 	while (len) {
176 		unsigned int winofs = ofs & win_mask(info->win_order);
177 		unsigned int chunklen = min_t(unsigned int, len,
178 					      BIT(info->win_order) - winofs);
179 
180 		physmap_set_addr_gpios(info, ofs);
181 		memcpy_fromio(buf, map->virt + winofs, chunklen);
182 		len -= chunklen;
183 		buf += chunklen;
184 		ofs += chunklen;
185 	}
186 }
187 
188 static void physmap_addr_gpios_write(struct map_info *map, map_word mw,
189 				     unsigned long ofs)
190 {
191 	struct platform_device *pdev;
192 	struct physmap_flash_info *info;
193 	u16 word;
194 
195 	pdev = (struct platform_device *)map->map_priv_1;
196 	info = platform_get_drvdata(pdev);
197 	physmap_set_addr_gpios(info, ofs);
198 
199 	word = mw.x[0];
200 	writew(word, map->virt + (ofs & win_mask(info->win_order)));
201 }
202 
203 static void physmap_addr_gpios_copy_to(struct map_info *map, unsigned long ofs,
204 				       const void *buf, ssize_t len)
205 {
206 	struct platform_device *pdev;
207 	struct physmap_flash_info *info;
208 
209 	pdev = (struct platform_device *)map->map_priv_1;
210 	info = platform_get_drvdata(pdev);
211 
212 	while (len) {
213 		unsigned int winofs = ofs & win_mask(info->win_order);
214 		unsigned int chunklen = min_t(unsigned int, len,
215 					      BIT(info->win_order) - winofs);
216 
217 		physmap_set_addr_gpios(info, ofs);
218 		memcpy_toio(map->virt + winofs, buf, chunklen);
219 		len -= chunklen;
220 		buf += chunklen;
221 		ofs += chunklen;
222 	}
223 }
224 
225 static int physmap_addr_gpios_map_init(struct map_info *map)
226 {
227 	map->phys = NO_XIP;
228 	map->read = physmap_addr_gpios_read;
229 	map->copy_from = physmap_addr_gpios_copy_from;
230 	map->write = physmap_addr_gpios_write;
231 	map->copy_to = physmap_addr_gpios_copy_to;
232 
233 	return 0;
234 }
235 #else
236 static int physmap_addr_gpios_map_init(struct map_info *map)
237 {
238 	return -ENOTSUPP;
239 }
240 #endif
241 
242 #if IS_ENABLED(CONFIG_MTD_PHYSMAP_OF)
243 static const struct of_device_id of_flash_match[] = {
244 	{
245 		.compatible = "cfi-flash",
246 		.data = "cfi_probe",
247 	},
248 	{
249 		/*
250 		 * FIXME: JEDEC chips can't be safely and reliably
251 		 * probed, although the mtd code gets it right in
252 		 * practice most of the time.  We should use the
253 		 * vendor and device ids specified by the binding to
254 		 * bypass the heuristic probe code, but the mtd layer
255 		 * provides, at present, no interface for doing so
256 		 * :(.
257 		 */
258 		.compatible = "jedec-flash",
259 		.data = "jedec_probe",
260 	},
261 	{
262 		.compatible = "mtd-ram",
263 		.data = "map_ram",
264 	},
265 	{
266 		.compatible = "mtd-rom",
267 		.data = "map_rom",
268 	},
269 	{
270 		.type = "rom",
271 		.compatible = "direct-mapped"
272 	},
273 	{ /* sentinel */ },
274 };
275 MODULE_DEVICE_TABLE(of, of_flash_match);
276 
277 static const char * const of_default_part_probes[] = {
278 	"cmdlinepart", "RedBoot", "ofpart", "ofoldpart", NULL
279 };
280 
281 static const char * const *of_get_part_probes(struct platform_device *dev)
282 {
283 	struct device_node *dp = dev->dev.of_node;
284 	const char **res;
285 	int count;
286 
287 	count = of_property_count_strings(dp, "linux,part-probe");
288 	if (count < 0)
289 		return of_default_part_probes;
290 
291 	res = devm_kcalloc(&dev->dev, count + 1, sizeof(*res), GFP_KERNEL);
292 	if (!res)
293 		return NULL;
294 
295 	count = of_property_read_string_array(dp, "linux,part-probe", res,
296 					      count);
297 	if (count < 0)
298 		return NULL;
299 
300 	return res;
301 }
302 
303 static const char *of_select_probe_type(struct platform_device *dev)
304 {
305 	struct device_node *dp = dev->dev.of_node;
306 	const struct of_device_id *match;
307 	const char *probe_type;
308 
309 	match = of_match_device(of_flash_match, &dev->dev);
310 	probe_type = match->data;
311 	if (probe_type)
312 		return probe_type;
313 
314 	dev_warn(&dev->dev,
315 		 "Device tree uses obsolete \"direct-mapped\" flash binding\n");
316 
317 	of_property_read_string(dp, "probe-type", &probe_type);
318 	if (!probe_type)
319 		return NULL;
320 
321 	if (!strcmp(probe_type, "CFI")) {
322 		probe_type = "cfi_probe";
323 	} else if (!strcmp(probe_type, "JEDEC")) {
324 		probe_type = "jedec_probe";
325 	} else if (!strcmp(probe_type, "ROM")) {
326 		probe_type = "map_rom";
327 	} else {
328 		dev_warn(&dev->dev,
329 			 "obsolete_probe: don't know probe type '%s', mapping as rom\n",
330 			 probe_type);
331 		probe_type = "map_rom";
332 	}
333 
334 	return probe_type;
335 }
336 
337 static int physmap_flash_of_init(struct platform_device *dev)
338 {
339 	struct physmap_flash_info *info = platform_get_drvdata(dev);
340 	struct device_node *dp = dev->dev.of_node;
341 	const char *mtd_name = NULL;
342 	int err, swap = 0;
343 	bool map_indirect;
344 	unsigned int i;
345 	u32 bankwidth;
346 
347 	if (!dp)
348 		return -EINVAL;
349 
350 	info->probe_type = of_select_probe_type(dev);
351 
352 	info->part_types = of_get_part_probes(dev);
353 	if (!info->part_types)
354 		return -ENOMEM;
355 
356 	of_property_read_string(dp, "linux,mtd-name", &mtd_name);
357 
358 	map_indirect = of_property_read_bool(dp, "no-unaligned-direct-access");
359 
360 	err = of_property_read_u32(dp, "bank-width", &bankwidth);
361 	if (err) {
362 		dev_err(&dev->dev, "Can't get bank width from device tree\n");
363 		return err;
364 	}
365 
366 	if (of_property_read_bool(dp, "big-endian"))
367 		swap = CFI_BIG_ENDIAN;
368 	else if (of_property_read_bool(dp, "little-endian"))
369 		swap = CFI_LITTLE_ENDIAN;
370 
371 	for (i = 0; i < info->nmaps; i++) {
372 		info->maps[i].name = mtd_name;
373 		info->maps[i].swap = swap;
374 		info->maps[i].bankwidth = bankwidth;
375 		info->maps[i].device_node = dp;
376 
377 		err = of_flash_probe_bt1_rom(dev, dp, &info->maps[i]);
378 		if (err)
379 			return err;
380 
381 		err = of_flash_probe_gemini(dev, dp, &info->maps[i]);
382 		if (err)
383 			return err;
384 
385 		err = of_flash_probe_ixp4xx(dev, dp, &info->maps[i]);
386 		if (err)
387 			return err;
388 
389 		err = of_flash_probe_versatile(dev, dp, &info->maps[i]);
390 		if (err)
391 			return err;
392 
393 		/*
394 		 * On some platforms (e.g. MPC5200) a direct 1:1 mapping
395 		 * may cause problems with JFFS2 usage, as the local bus (LPB)
396 		 * doesn't support unaligned accesses as implemented in the
397 		 * JFFS2 code via memcpy(). By setting NO_XIP, the
398 		 * flash will not be exposed directly to the MTD users
399 		 * (e.g. JFFS2) any more.
400 		 */
401 		if (map_indirect)
402 			info->maps[i].phys = NO_XIP;
403 	}
404 
405 	return 0;
406 }
407 #else /* IS_ENABLED(CONFIG_MTD_PHYSMAP_OF) */
408 #define of_flash_match NULL
409 
410 static int physmap_flash_of_init(struct platform_device *dev)
411 {
412 	return -ENOTSUPP;
413 }
414 #endif /* IS_ENABLED(CONFIG_MTD_PHYSMAP_OF) */
415 
416 static const char * const rom_probe_types[] = {
417 	"cfi_probe", "jedec_probe", "qinfo_probe", "map_rom",
418 };
419 
420 static const char * const part_probe_types[] = {
421 	"cmdlinepart", "RedBoot", "afs", NULL
422 };
423 
424 static int physmap_flash_pdata_init(struct platform_device *dev)
425 {
426 	struct physmap_flash_info *info = platform_get_drvdata(dev);
427 	struct physmap_flash_data *physmap_data;
428 	unsigned int i;
429 	int err;
430 
431 	physmap_data = dev_get_platdata(&dev->dev);
432 	if (!physmap_data)
433 		return -EINVAL;
434 
435 	info->probe_type = physmap_data->probe_type;
436 	info->part_types = physmap_data->part_probe_types ? : part_probe_types;
437 	info->parts = physmap_data->parts;
438 	info->nparts = physmap_data->nr_parts;
439 
440 	if (physmap_data->init) {
441 		err = physmap_data->init(dev);
442 		if (err)
443 			return err;
444 	}
445 
446 	for (i = 0; i < info->nmaps; i++) {
447 		info->maps[i].bankwidth = physmap_data->width;
448 		info->maps[i].pfow_base = physmap_data->pfow_base;
449 		info->maps[i].set_vpp = physmap_set_vpp;
450 	}
451 
452 	return 0;
453 }
454 
455 static int physmap_flash_probe(struct platform_device *dev)
456 {
457 	struct physmap_flash_info *info;
458 	int err = 0;
459 	int i;
460 
461 	if (!dev->dev.of_node && !dev_get_platdata(&dev->dev))
462 		return -EINVAL;
463 
464 	info = devm_kzalloc(&dev->dev, sizeof(*info), GFP_KERNEL);
465 	if (!info)
466 		return -ENOMEM;
467 
468 	while (platform_get_resource(dev, IORESOURCE_MEM, info->nmaps))
469 		info->nmaps++;
470 
471 	if (!info->nmaps)
472 		return -ENODEV;
473 
474 	info->maps = devm_kzalloc(&dev->dev,
475 				  sizeof(*info->maps) * info->nmaps,
476 				  GFP_KERNEL);
477 	if (!info->maps)
478 		return -ENOMEM;
479 
480 	info->mtds = devm_kzalloc(&dev->dev,
481 				  sizeof(*info->mtds) * info->nmaps,
482 				  GFP_KERNEL);
483 	if (!info->mtds)
484 		return -ENOMEM;
485 
486 	platform_set_drvdata(dev, info);
487 
488 	info->gpios = devm_gpiod_get_array_optional(&dev->dev, "addr",
489 						    GPIOD_OUT_LOW);
490 	if (IS_ERR(info->gpios))
491 		return PTR_ERR(info->gpios);
492 
493 	if (info->gpios && info->nmaps > 1) {
494 		dev_err(&dev->dev, "addr-gpios only supported for nmaps == 1\n");
495 		return -EINVAL;
496 	}
497 
498 	pm_runtime_enable(&dev->dev);
499 	pm_runtime_get_sync(&dev->dev);
500 
501 	if (dev->dev.of_node)
502 		err = physmap_flash_of_init(dev);
503 	else
504 		err = physmap_flash_pdata_init(dev);
505 
506 	if (err) {
507 		pm_runtime_put(&dev->dev);
508 		pm_runtime_disable(&dev->dev);
509 		return err;
510 	}
511 
512 	for (i = 0; i < info->nmaps; i++) {
513 		struct resource *res;
514 
515 		res = platform_get_resource(dev, IORESOURCE_MEM, i);
516 		info->maps[i].virt = devm_ioremap_resource(&dev->dev, res);
517 		if (IS_ERR(info->maps[i].virt)) {
518 			err = PTR_ERR(info->maps[i].virt);
519 			goto err_out;
520 		}
521 
522 		dev_notice(&dev->dev, "physmap platform flash device: %pR\n",
523 			   res);
524 
525 		if (!info->maps[i].name)
526 			info->maps[i].name = dev_name(&dev->dev);
527 
528 		if (!info->maps[i].phys)
529 			info->maps[i].phys = res->start;
530 
531 		info->win_order = get_bitmask_order(resource_size(res)) - 1;
532 		info->maps[i].size = BIT(info->win_order +
533 					 (info->gpios ?
534 					  info->gpios->ndescs : 0));
535 
536 		info->maps[i].map_priv_1 = (unsigned long)dev;
537 
538 		if (info->gpios) {
539 			err = physmap_addr_gpios_map_init(&info->maps[i]);
540 			if (err)
541 				goto err_out;
542 		}
543 
544 #ifdef CONFIG_MTD_COMPLEX_MAPPINGS
545 		/*
546 		 * Only use the simple_map implementation if map hooks are not
547 		 * implemented. Since map->read() is mandatory checking for its
548 		 * presence is enough.
549 		 */
550 		if (!info->maps[i].read)
551 			simple_map_init(&info->maps[i]);
552 #else
553 		simple_map_init(&info->maps[i]);
554 #endif
555 
556 		if (info->probe_type) {
557 			info->mtds[i] = do_map_probe(info->probe_type,
558 						     &info->maps[i]);
559 		} else {
560 			int j;
561 
562 			for (j = 0; j < ARRAY_SIZE(rom_probe_types); j++) {
563 				info->mtds[i] = do_map_probe(rom_probe_types[j],
564 							     &info->maps[i]);
565 				if (info->mtds[i])
566 					break;
567 			}
568 		}
569 
570 		if (!info->mtds[i]) {
571 			dev_err(&dev->dev, "map_probe failed\n");
572 			err = -ENXIO;
573 			goto err_out;
574 		}
575 		info->mtds[i]->dev.parent = &dev->dev;
576 	}
577 
578 	if (info->nmaps == 1) {
579 		info->cmtd = info->mtds[0];
580 	} else {
581 		/*
582 		 * We detected multiple devices. Concatenate them together.
583 		 */
584 		info->cmtd = mtd_concat_create(info->mtds, info->nmaps,
585 					       dev_name(&dev->dev));
586 		if (!info->cmtd)
587 			err = -ENXIO;
588 	}
589 	if (err)
590 		goto err_out;
591 
592 	spin_lock_init(&info->vpp_lock);
593 
594 	mtd_set_of_node(info->cmtd, dev->dev.of_node);
595 	err = mtd_device_parse_register(info->cmtd, info->part_types, NULL,
596 					info->parts, info->nparts);
597 	if (err)
598 		goto err_out;
599 
600 	return 0;
601 
602 err_out:
603 	physmap_flash_remove(dev);
604 	return err;
605 }
606 
607 #ifdef CONFIG_PM
608 static void physmap_flash_shutdown(struct platform_device *dev)
609 {
610 	struct physmap_flash_info *info = platform_get_drvdata(dev);
611 	int i;
612 
613 	for (i = 0; i < info->nmaps && info->mtds[i]; i++)
614 		if (mtd_suspend(info->mtds[i]) == 0)
615 			mtd_resume(info->mtds[i]);
616 }
617 #else
618 #define physmap_flash_shutdown NULL
619 #endif
620 
621 static struct platform_driver physmap_flash_driver = {
622 	.probe		= physmap_flash_probe,
623 	.remove		= physmap_flash_remove,
624 	.shutdown	= physmap_flash_shutdown,
625 	.driver		= {
626 		.name	= "physmap-flash",
627 		.of_match_table = of_flash_match,
628 	},
629 };
630 
631 #ifdef CONFIG_MTD_PHYSMAP_COMPAT
632 static struct physmap_flash_data physmap_flash_data = {
633 	.width		= CONFIG_MTD_PHYSMAP_BANKWIDTH,
634 };
635 
636 static struct resource physmap_flash_resource = {
637 	.start		= CONFIG_MTD_PHYSMAP_START,
638 	.end		= CONFIG_MTD_PHYSMAP_START + CONFIG_MTD_PHYSMAP_LEN - 1,
639 	.flags		= IORESOURCE_MEM,
640 };
641 
642 static struct platform_device physmap_flash = {
643 	.name		= "physmap-flash",
644 	.id		= 0,
645 	.dev		= {
646 		.platform_data	= &physmap_flash_data,
647 	},
648 	.num_resources	= 1,
649 	.resource	= &physmap_flash_resource,
650 };
651 #endif
652 
653 static int __init physmap_init(void)
654 {
655 	int err;
656 
657 	err = platform_driver_register(&physmap_flash_driver);
658 #ifdef CONFIG_MTD_PHYSMAP_COMPAT
659 	if (err == 0) {
660 		err = platform_device_register(&physmap_flash);
661 		if (err)
662 			platform_driver_unregister(&physmap_flash_driver);
663 	}
664 #endif
665 
666 	return err;
667 }
668 
669 static void __exit physmap_exit(void)
670 {
671 #ifdef CONFIG_MTD_PHYSMAP_COMPAT
672 	platform_device_unregister(&physmap_flash);
673 #endif
674 	platform_driver_unregister(&physmap_flash_driver);
675 }
676 
677 module_init(physmap_init);
678 module_exit(physmap_exit);
679 
680 MODULE_LICENSE("GPL");
681 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
682 MODULE_AUTHOR("Vitaly Wool <vwool@ru.mvista.com>");
683 MODULE_AUTHOR("Mike Frysinger <vapier@gentoo.org>");
684 MODULE_DESCRIPTION("Generic configurable MTD map driver");
685 
686 /* legacy platform drivers can't hotplug or coldplg */
687 #ifndef CONFIG_MTD_PHYSMAP_COMPAT
688 /* work with hotplug and coldplug */
689 MODULE_ALIAS("platform:physmap-flash");
690 #endif
691