xref: /openbmc/linux/drivers/mtd/maps/physmap-core.c (revision 06b72824)
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-gemini.h"
45 #include "physmap-ixp4xx.h"
46 #include "physmap-versatile.h"
47 
48 struct physmap_flash_info {
49 	unsigned int		nmaps;
50 	struct mtd_info		**mtds;
51 	struct mtd_info		*cmtd;
52 	struct map_info		*maps;
53 	spinlock_t		vpp_lock;
54 	int			vpp_refcnt;
55 	const char		*probe_type;
56 	const char * const	*part_types;
57 	unsigned int		nparts;
58 	const struct mtd_partition *parts;
59 	struct gpio_descs	*gpios;
60 	unsigned int		gpio_values;
61 	unsigned int		win_order;
62 };
63 
64 static int physmap_flash_remove(struct platform_device *dev)
65 {
66 	struct physmap_flash_info *info;
67 	struct physmap_flash_data *physmap_data;
68 	int i, err = 0;
69 
70 	info = platform_get_drvdata(dev);
71 	if (!info)
72 		goto out;
73 
74 	if (info->cmtd) {
75 		err = mtd_device_unregister(info->cmtd);
76 		if (err)
77 			goto out;
78 
79 		if (info->cmtd != info->mtds[0])
80 			mtd_concat_destroy(info->cmtd);
81 	}
82 
83 	for (i = 0; i < info->nmaps; i++) {
84 		if (info->mtds[i])
85 			map_destroy(info->mtds[i]);
86 	}
87 
88 	physmap_data = dev_get_platdata(&dev->dev);
89 	if (physmap_data && physmap_data->exit)
90 		physmap_data->exit(dev);
91 
92 out:
93 	pm_runtime_put(&dev->dev);
94 	pm_runtime_disable(&dev->dev);
95 	return err;
96 }
97 
98 static void physmap_set_vpp(struct map_info *map, int state)
99 {
100 	struct platform_device *pdev;
101 	struct physmap_flash_data *physmap_data;
102 	struct physmap_flash_info *info;
103 	unsigned long flags;
104 
105 	pdev = (struct platform_device *)map->map_priv_1;
106 	physmap_data = dev_get_platdata(&pdev->dev);
107 
108 	if (!physmap_data->set_vpp)
109 		return;
110 
111 	info = platform_get_drvdata(pdev);
112 
113 	spin_lock_irqsave(&info->vpp_lock, flags);
114 	if (state) {
115 		if (++info->vpp_refcnt == 1)    /* first nested 'on' */
116 			physmap_data->set_vpp(pdev, 1);
117 	} else {
118 		if (--info->vpp_refcnt == 0)    /* last nested 'off' */
119 			physmap_data->set_vpp(pdev, 0);
120 	}
121 	spin_unlock_irqrestore(&info->vpp_lock, flags);
122 }
123 
124 #if IS_ENABLED(CONFIG_MTD_PHYSMAP_GPIO_ADDR)
125 static void physmap_set_addr_gpios(struct physmap_flash_info *info,
126 				   unsigned long ofs)
127 {
128 	unsigned int i;
129 
130 	ofs >>= info->win_order;
131 	if (info->gpio_values == ofs)
132 		return;
133 
134 	for (i = 0; i < info->gpios->ndescs; i++) {
135 		if ((BIT(i) & ofs) == (BIT(i) & info->gpio_values))
136 			continue;
137 
138 		gpiod_set_value(info->gpios->desc[i], !!(BIT(i) & ofs));
139 	}
140 
141 	info->gpio_values = ofs;
142 }
143 
144 #define win_mask(order)		(BIT(order) - 1)
145 
146 static map_word physmap_addr_gpios_read(struct map_info *map,
147 					unsigned long ofs)
148 {
149 	struct platform_device *pdev;
150 	struct physmap_flash_info *info;
151 	map_word mw;
152 	u16 word;
153 
154 	pdev = (struct platform_device *)map->map_priv_1;
155 	info = platform_get_drvdata(pdev);
156 	physmap_set_addr_gpios(info, ofs);
157 
158 	word = readw(map->virt + (ofs & win_mask(info->win_order)));
159 	mw.x[0] = word;
160 	return mw;
161 }
162 
163 static void physmap_addr_gpios_copy_from(struct map_info *map, void *buf,
164 					 unsigned long ofs, ssize_t len)
165 {
166 	struct platform_device *pdev;
167 	struct physmap_flash_info *info;
168 
169 	pdev = (struct platform_device *)map->map_priv_1;
170 	info = platform_get_drvdata(pdev);
171 
172 	while (len) {
173 		unsigned int winofs = ofs & win_mask(info->win_order);
174 		unsigned int chunklen = min_t(unsigned int, len,
175 					      BIT(info->win_order) - winofs);
176 
177 		physmap_set_addr_gpios(info, ofs);
178 		memcpy_fromio(buf, map->virt + winofs, chunklen);
179 		len -= chunklen;
180 		buf += chunklen;
181 		ofs += chunklen;
182 	}
183 }
184 
185 static void physmap_addr_gpios_write(struct map_info *map, map_word mw,
186 				     unsigned long ofs)
187 {
188 	struct platform_device *pdev;
189 	struct physmap_flash_info *info;
190 	u16 word;
191 
192 	pdev = (struct platform_device *)map->map_priv_1;
193 	info = platform_get_drvdata(pdev);
194 	physmap_set_addr_gpios(info, ofs);
195 
196 	word = mw.x[0];
197 	writew(word, map->virt + (ofs & win_mask(info->win_order)));
198 }
199 
200 static void physmap_addr_gpios_copy_to(struct map_info *map, unsigned long ofs,
201 				       const void *buf, ssize_t len)
202 {
203 	struct platform_device *pdev;
204 	struct physmap_flash_info *info;
205 
206 	pdev = (struct platform_device *)map->map_priv_1;
207 	info = platform_get_drvdata(pdev);
208 
209 	while (len) {
210 		unsigned int winofs = ofs & win_mask(info->win_order);
211 		unsigned int chunklen = min_t(unsigned int, len,
212 					      BIT(info->win_order) - winofs);
213 
214 		physmap_set_addr_gpios(info, ofs);
215 		memcpy_toio(map->virt + winofs, buf, chunklen);
216 		len -= chunklen;
217 		buf += chunklen;
218 		ofs += chunklen;
219 	}
220 }
221 
222 static int physmap_addr_gpios_map_init(struct map_info *map)
223 {
224 	map->phys = NO_XIP;
225 	map->read = physmap_addr_gpios_read;
226 	map->copy_from = physmap_addr_gpios_copy_from;
227 	map->write = physmap_addr_gpios_write;
228 	map->copy_to = physmap_addr_gpios_copy_to;
229 
230 	return 0;
231 }
232 #else
233 static int physmap_addr_gpios_map_init(struct map_info *map)
234 {
235 	return -ENOTSUPP;
236 }
237 #endif
238 
239 #if IS_ENABLED(CONFIG_MTD_PHYSMAP_OF)
240 static const struct of_device_id of_flash_match[] = {
241 	{
242 		.compatible = "cfi-flash",
243 		.data = "cfi_probe",
244 	},
245 	{
246 		/*
247 		 * FIXME: JEDEC chips can't be safely and reliably
248 		 * probed, although the mtd code gets it right in
249 		 * practice most of the time.  We should use the
250 		 * vendor and device ids specified by the binding to
251 		 * bypass the heuristic probe code, but the mtd layer
252 		 * provides, at present, no interface for doing so
253 		 * :(.
254 		 */
255 		.compatible = "jedec-flash",
256 		.data = "jedec_probe",
257 	},
258 	{
259 		.compatible = "mtd-ram",
260 		.data = "map_ram",
261 	},
262 	{
263 		.compatible = "mtd-rom",
264 		.data = "map_rom",
265 	},
266 	{
267 		.type = "rom",
268 		.compatible = "direct-mapped"
269 	},
270 	{ /* sentinel */ },
271 };
272 MODULE_DEVICE_TABLE(of, of_flash_match);
273 
274 static const char * const of_default_part_probes[] = {
275 	"cmdlinepart", "RedBoot", "ofpart", "ofoldpart", NULL
276 };
277 
278 static const char * const *of_get_part_probes(struct platform_device *dev)
279 {
280 	struct device_node *dp = dev->dev.of_node;
281 	const char **res;
282 	int count;
283 
284 	count = of_property_count_strings(dp, "linux,part-probe");
285 	if (count < 0)
286 		return of_default_part_probes;
287 
288 	res = devm_kcalloc(&dev->dev, count + 1, sizeof(*res), GFP_KERNEL);
289 	if (!res)
290 		return NULL;
291 
292 	count = of_property_read_string_array(dp, "linux,part-probe", res,
293 					      count);
294 	if (count < 0)
295 		return NULL;
296 
297 	return res;
298 }
299 
300 static const char *of_select_probe_type(struct platform_device *dev)
301 {
302 	struct device_node *dp = dev->dev.of_node;
303 	const struct of_device_id *match;
304 	const char *probe_type;
305 
306 	match = of_match_device(of_flash_match, &dev->dev);
307 	probe_type = match->data;
308 	if (probe_type)
309 		return probe_type;
310 
311 	dev_warn(&dev->dev,
312 		 "Device tree uses obsolete \"direct-mapped\" flash binding\n");
313 
314 	of_property_read_string(dp, "probe-type", &probe_type);
315 	if (!probe_type)
316 		return NULL;
317 
318 	if (!strcmp(probe_type, "CFI")) {
319 		probe_type = "cfi_probe";
320 	} else if (!strcmp(probe_type, "JEDEC")) {
321 		probe_type = "jedec_probe";
322 	} else if (!strcmp(probe_type, "ROM")) {
323 		probe_type = "map_rom";
324 	} else {
325 		dev_warn(&dev->dev,
326 			 "obsolete_probe: don't know probe type '%s', mapping as rom\n",
327 			 probe_type);
328 		probe_type = "map_rom";
329 	}
330 
331 	return probe_type;
332 }
333 
334 static int physmap_flash_of_init(struct platform_device *dev)
335 {
336 	struct physmap_flash_info *info = platform_get_drvdata(dev);
337 	struct device_node *dp = dev->dev.of_node;
338 	const char *mtd_name = NULL;
339 	int err, swap = 0;
340 	bool map_indirect;
341 	unsigned int i;
342 	u32 bankwidth;
343 
344 	if (!dp)
345 		return -EINVAL;
346 
347 	info->probe_type = of_select_probe_type(dev);
348 
349 	info->part_types = of_get_part_probes(dev);
350 	if (!info->part_types)
351 		return -ENOMEM;
352 
353 	of_property_read_string(dp, "linux,mtd-name", &mtd_name);
354 
355 	map_indirect = of_property_read_bool(dp, "no-unaligned-direct-access");
356 
357 	err = of_property_read_u32(dp, "bank-width", &bankwidth);
358 	if (err) {
359 		dev_err(&dev->dev, "Can't get bank width from device tree\n");
360 		return err;
361 	}
362 
363 	if (of_property_read_bool(dp, "big-endian"))
364 		swap = CFI_BIG_ENDIAN;
365 	else if (of_property_read_bool(dp, "little-endian"))
366 		swap = CFI_LITTLE_ENDIAN;
367 
368 	for (i = 0; i < info->nmaps; i++) {
369 		info->maps[i].name = mtd_name;
370 		info->maps[i].swap = swap;
371 		info->maps[i].bankwidth = bankwidth;
372 		info->maps[i].device_node = dp;
373 
374 		err = of_flash_probe_gemini(dev, dp, &info->maps[i]);
375 		if (err)
376 			return err;
377 
378 		err = of_flash_probe_ixp4xx(dev, dp, &info->maps[i]);
379 		if (err)
380 			return err;
381 
382 		err = of_flash_probe_versatile(dev, dp, &info->maps[i]);
383 		if (err)
384 			return err;
385 
386 		/*
387 		 * On some platforms (e.g. MPC5200) a direct 1:1 mapping
388 		 * may cause problems with JFFS2 usage, as the local bus (LPB)
389 		 * doesn't support unaligned accesses as implemented in the
390 		 * JFFS2 code via memcpy(). By setting NO_XIP, the
391 		 * flash will not be exposed directly to the MTD users
392 		 * (e.g. JFFS2) any more.
393 		 */
394 		if (map_indirect)
395 			info->maps[i].phys = NO_XIP;
396 	}
397 
398 	return 0;
399 }
400 #else /* IS_ENABLED(CONFIG_MTD_PHYSMAP_OF) */
401 #define of_flash_match NULL
402 
403 static int physmap_flash_of_init(struct platform_device *dev)
404 {
405 	return -ENOTSUPP;
406 }
407 #endif /* IS_ENABLED(CONFIG_MTD_PHYSMAP_OF) */
408 
409 static const char * const rom_probe_types[] = {
410 	"cfi_probe", "jedec_probe", "qinfo_probe", "map_rom",
411 };
412 
413 static const char * const part_probe_types[] = {
414 	"cmdlinepart", "RedBoot", "afs", NULL
415 };
416 
417 static int physmap_flash_pdata_init(struct platform_device *dev)
418 {
419 	struct physmap_flash_info *info = platform_get_drvdata(dev);
420 	struct physmap_flash_data *physmap_data;
421 	unsigned int i;
422 	int err;
423 
424 	physmap_data = dev_get_platdata(&dev->dev);
425 	if (!physmap_data)
426 		return -EINVAL;
427 
428 	info->probe_type = physmap_data->probe_type;
429 	info->part_types = physmap_data->part_probe_types ? : part_probe_types;
430 	info->parts = physmap_data->parts;
431 	info->nparts = physmap_data->nr_parts;
432 
433 	if (physmap_data->init) {
434 		err = physmap_data->init(dev);
435 		if (err)
436 			return err;
437 	}
438 
439 	for (i = 0; i < info->nmaps; i++) {
440 		info->maps[i].bankwidth = physmap_data->width;
441 		info->maps[i].pfow_base = physmap_data->pfow_base;
442 		info->maps[i].set_vpp = physmap_set_vpp;
443 	}
444 
445 	return 0;
446 }
447 
448 static int physmap_flash_probe(struct platform_device *dev)
449 {
450 	struct physmap_flash_info *info;
451 	int err = 0;
452 	int i;
453 
454 	if (!dev->dev.of_node && !dev_get_platdata(&dev->dev))
455 		return -EINVAL;
456 
457 	info = devm_kzalloc(&dev->dev, sizeof(*info), GFP_KERNEL);
458 	if (!info)
459 		return -ENOMEM;
460 
461 	while (platform_get_resource(dev, IORESOURCE_MEM, info->nmaps))
462 		info->nmaps++;
463 
464 	if (!info->nmaps)
465 		return -ENODEV;
466 
467 	info->maps = devm_kzalloc(&dev->dev,
468 				  sizeof(*info->maps) * info->nmaps,
469 				  GFP_KERNEL);
470 	if (!info->maps)
471 		return -ENOMEM;
472 
473 	info->mtds = devm_kzalloc(&dev->dev,
474 				  sizeof(*info->mtds) * info->nmaps,
475 				  GFP_KERNEL);
476 	if (!info->mtds)
477 		return -ENOMEM;
478 
479 	platform_set_drvdata(dev, info);
480 
481 	info->gpios = devm_gpiod_get_array_optional(&dev->dev, "addr",
482 						    GPIOD_OUT_LOW);
483 	if (IS_ERR(info->gpios))
484 		return PTR_ERR(info->gpios);
485 
486 	if (info->gpios && info->nmaps > 1) {
487 		dev_err(&dev->dev, "addr-gpios only supported for nmaps == 1\n");
488 		return -EINVAL;
489 	}
490 
491 	pm_runtime_enable(&dev->dev);
492 	pm_runtime_get_sync(&dev->dev);
493 
494 	if (dev->dev.of_node)
495 		err = physmap_flash_of_init(dev);
496 	else
497 		err = physmap_flash_pdata_init(dev);
498 
499 	if (err) {
500 		pm_runtime_put(&dev->dev);
501 		pm_runtime_disable(&dev->dev);
502 		return err;
503 	}
504 
505 	for (i = 0; i < info->nmaps; i++) {
506 		struct resource *res;
507 
508 		res = platform_get_resource(dev, IORESOURCE_MEM, i);
509 		info->maps[i].virt = devm_ioremap_resource(&dev->dev, res);
510 		if (IS_ERR(info->maps[i].virt)) {
511 			err = PTR_ERR(info->maps[i].virt);
512 			goto err_out;
513 		}
514 
515 		dev_notice(&dev->dev, "physmap platform flash device: %pR\n",
516 			   res);
517 
518 		info->maps[i].name = dev_name(&dev->dev);
519 
520 		if (!info->maps[i].phys)
521 			info->maps[i].phys = res->start;
522 
523 		info->win_order = get_bitmask_order(resource_size(res)) - 1;
524 		info->maps[i].size = BIT(info->win_order +
525 					 (info->gpios ?
526 					  info->gpios->ndescs : 0));
527 
528 		info->maps[i].map_priv_1 = (unsigned long)dev;
529 
530 		if (info->gpios) {
531 			err = physmap_addr_gpios_map_init(&info->maps[i]);
532 			if (err)
533 				goto err_out;
534 		}
535 
536 #ifdef CONFIG_MTD_COMPLEX_MAPPINGS
537 		/*
538 		 * Only use the simple_map implementation if map hooks are not
539 		 * implemented. Since map->read() is mandatory checking for its
540 		 * presence is enough.
541 		 */
542 		if (!info->maps[i].read)
543 			simple_map_init(&info->maps[i]);
544 #else
545 		simple_map_init(&info->maps[i]);
546 #endif
547 
548 		if (info->probe_type) {
549 			info->mtds[i] = do_map_probe(info->probe_type,
550 						     &info->maps[i]);
551 		} else {
552 			int j;
553 
554 			for (j = 0; j < ARRAY_SIZE(rom_probe_types); j++) {
555 				info->mtds[i] = do_map_probe(rom_probe_types[j],
556 							     &info->maps[i]);
557 				if (info->mtds[i])
558 					break;
559 			}
560 		}
561 
562 		if (!info->mtds[i]) {
563 			dev_err(&dev->dev, "map_probe failed\n");
564 			err = -ENXIO;
565 			goto err_out;
566 		}
567 		info->mtds[i]->dev.parent = &dev->dev;
568 	}
569 
570 	if (info->nmaps == 1) {
571 		info->cmtd = info->mtds[0];
572 	} else {
573 		/*
574 		 * We detected multiple devices. Concatenate them together.
575 		 */
576 		info->cmtd = mtd_concat_create(info->mtds, info->nmaps,
577 					       dev_name(&dev->dev));
578 		if (!info->cmtd)
579 			err = -ENXIO;
580 	}
581 	if (err)
582 		goto err_out;
583 
584 	spin_lock_init(&info->vpp_lock);
585 
586 	mtd_set_of_node(info->cmtd, dev->dev.of_node);
587 	err = mtd_device_parse_register(info->cmtd, info->part_types, NULL,
588 					info->parts, info->nparts);
589 	if (err)
590 		goto err_out;
591 
592 	return 0;
593 
594 err_out:
595 	physmap_flash_remove(dev);
596 	return err;
597 }
598 
599 #ifdef CONFIG_PM
600 static void physmap_flash_shutdown(struct platform_device *dev)
601 {
602 	struct physmap_flash_info *info = platform_get_drvdata(dev);
603 	int i;
604 
605 	for (i = 0; i < info->nmaps && info->mtds[i]; i++)
606 		if (mtd_suspend(info->mtds[i]) == 0)
607 			mtd_resume(info->mtds[i]);
608 }
609 #else
610 #define physmap_flash_shutdown NULL
611 #endif
612 
613 static struct platform_driver physmap_flash_driver = {
614 	.probe		= physmap_flash_probe,
615 	.remove		= physmap_flash_remove,
616 	.shutdown	= physmap_flash_shutdown,
617 	.driver		= {
618 		.name	= "physmap-flash",
619 		.of_match_table = of_flash_match,
620 	},
621 };
622 
623 #ifdef CONFIG_MTD_PHYSMAP_COMPAT
624 static struct physmap_flash_data physmap_flash_data = {
625 	.width		= CONFIG_MTD_PHYSMAP_BANKWIDTH,
626 };
627 
628 static struct resource physmap_flash_resource = {
629 	.start		= CONFIG_MTD_PHYSMAP_START,
630 	.end		= CONFIG_MTD_PHYSMAP_START + CONFIG_MTD_PHYSMAP_LEN - 1,
631 	.flags		= IORESOURCE_MEM,
632 };
633 
634 static struct platform_device physmap_flash = {
635 	.name		= "physmap-flash",
636 	.id		= 0,
637 	.dev		= {
638 		.platform_data	= &physmap_flash_data,
639 	},
640 	.num_resources	= 1,
641 	.resource	= &physmap_flash_resource,
642 };
643 #endif
644 
645 static int __init physmap_init(void)
646 {
647 	int err;
648 
649 	err = platform_driver_register(&physmap_flash_driver);
650 #ifdef CONFIG_MTD_PHYSMAP_COMPAT
651 	if (err == 0) {
652 		err = platform_device_register(&physmap_flash);
653 		if (err)
654 			platform_driver_unregister(&physmap_flash_driver);
655 	}
656 #endif
657 
658 	return err;
659 }
660 
661 static void __exit physmap_exit(void)
662 {
663 #ifdef CONFIG_MTD_PHYSMAP_COMPAT
664 	platform_device_unregister(&physmap_flash);
665 #endif
666 	platform_driver_unregister(&physmap_flash_driver);
667 }
668 
669 module_init(physmap_init);
670 module_exit(physmap_exit);
671 
672 MODULE_LICENSE("GPL");
673 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
674 MODULE_AUTHOR("Vitaly Wool <vwool@ru.mvista.com>");
675 MODULE_AUTHOR("Mike Frysinger <vapier@gentoo.org>");
676 MODULE_DESCRIPTION("Generic configurable MTD map driver");
677 
678 /* legacy platform drivers can't hotplug or coldplg */
679 #ifndef CONFIG_MTD_PHYSMAP_COMPAT
680 /* work with hotplug and coldplug */
681 MODULE_ALIAS("platform:physmap-flash");
682 #endif
683