xref: /openbmc/linux/drivers/mtd/maps/physmap-core.c (revision 27ab1c1c)
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 		goto out;
74 
75 	if (info->cmtd) {
76 		err = mtd_device_unregister(info->cmtd);
77 		if (err)
78 			goto out;
79 
80 		if (info->cmtd != info->mtds[0])
81 			mtd_concat_destroy(info->cmtd);
82 	}
83 
84 	for (i = 0; i < info->nmaps; i++) {
85 		if (info->mtds[i])
86 			map_destroy(info->mtds[i]);
87 	}
88 
89 	physmap_data = dev_get_platdata(&dev->dev);
90 	if (physmap_data && physmap_data->exit)
91 		physmap_data->exit(dev);
92 
93 out:
94 	pm_runtime_put(&dev->dev);
95 	pm_runtime_disable(&dev->dev);
96 	return err;
97 }
98 
99 static void physmap_set_vpp(struct map_info *map, int state)
100 {
101 	struct platform_device *pdev;
102 	struct physmap_flash_data *physmap_data;
103 	struct physmap_flash_info *info;
104 	unsigned long flags;
105 
106 	pdev = (struct platform_device *)map->map_priv_1;
107 	physmap_data = dev_get_platdata(&pdev->dev);
108 
109 	if (!physmap_data->set_vpp)
110 		return;
111 
112 	info = platform_get_drvdata(pdev);
113 
114 	spin_lock_irqsave(&info->vpp_lock, flags);
115 	if (state) {
116 		if (++info->vpp_refcnt == 1)    /* first nested 'on' */
117 			physmap_data->set_vpp(pdev, 1);
118 	} else {
119 		if (--info->vpp_refcnt == 0)    /* last nested 'off' */
120 			physmap_data->set_vpp(pdev, 0);
121 	}
122 	spin_unlock_irqrestore(&info->vpp_lock, flags);
123 }
124 
125 #if IS_ENABLED(CONFIG_MTD_PHYSMAP_GPIO_ADDR)
126 static void physmap_set_addr_gpios(struct physmap_flash_info *info,
127 				   unsigned long ofs)
128 {
129 	unsigned int i;
130 
131 	ofs >>= info->win_order;
132 	if (info->gpio_values == ofs)
133 		return;
134 
135 	for (i = 0; i < info->gpios->ndescs; i++) {
136 		if ((BIT(i) & ofs) == (BIT(i) & info->gpio_values))
137 			continue;
138 
139 		gpiod_set_value(info->gpios->desc[i], !!(BIT(i) & ofs));
140 	}
141 
142 	info->gpio_values = ofs;
143 }
144 
145 #define win_mask(order)		(BIT(order) - 1)
146 
147 static map_word physmap_addr_gpios_read(struct map_info *map,
148 					unsigned long ofs)
149 {
150 	struct platform_device *pdev;
151 	struct physmap_flash_info *info;
152 	map_word mw;
153 	u16 word;
154 
155 	pdev = (struct platform_device *)map->map_priv_1;
156 	info = platform_get_drvdata(pdev);
157 	physmap_set_addr_gpios(info, ofs);
158 
159 	word = readw(map->virt + (ofs & win_mask(info->win_order)));
160 	mw.x[0] = word;
161 	return mw;
162 }
163 
164 static void physmap_addr_gpios_copy_from(struct map_info *map, void *buf,
165 					 unsigned long ofs, ssize_t len)
166 {
167 	struct platform_device *pdev;
168 	struct physmap_flash_info *info;
169 
170 	pdev = (struct platform_device *)map->map_priv_1;
171 	info = platform_get_drvdata(pdev);
172 
173 	while (len) {
174 		unsigned int winofs = ofs & win_mask(info->win_order);
175 		unsigned int chunklen = min_t(unsigned int, len,
176 					      BIT(info->win_order) - winofs);
177 
178 		physmap_set_addr_gpios(info, ofs);
179 		memcpy_fromio(buf, map->virt + winofs, chunklen);
180 		len -= chunklen;
181 		buf += chunklen;
182 		ofs += chunklen;
183 	}
184 }
185 
186 static void physmap_addr_gpios_write(struct map_info *map, map_word mw,
187 				     unsigned long ofs)
188 {
189 	struct platform_device *pdev;
190 	struct physmap_flash_info *info;
191 	u16 word;
192 
193 	pdev = (struct platform_device *)map->map_priv_1;
194 	info = platform_get_drvdata(pdev);
195 	physmap_set_addr_gpios(info, ofs);
196 
197 	word = mw.x[0];
198 	writew(word, map->virt + (ofs & win_mask(info->win_order)));
199 }
200 
201 static void physmap_addr_gpios_copy_to(struct map_info *map, unsigned long ofs,
202 				       const void *buf, ssize_t len)
203 {
204 	struct platform_device *pdev;
205 	struct physmap_flash_info *info;
206 
207 	pdev = (struct platform_device *)map->map_priv_1;
208 	info = platform_get_drvdata(pdev);
209 
210 	while (len) {
211 		unsigned int winofs = ofs & win_mask(info->win_order);
212 		unsigned int chunklen = min_t(unsigned int, len,
213 					      BIT(info->win_order) - winofs);
214 
215 		physmap_set_addr_gpios(info, ofs);
216 		memcpy_toio(map->virt + winofs, buf, chunklen);
217 		len -= chunklen;
218 		buf += chunklen;
219 		ofs += chunklen;
220 	}
221 }
222 
223 static int physmap_addr_gpios_map_init(struct map_info *map)
224 {
225 	map->phys = NO_XIP;
226 	map->read = physmap_addr_gpios_read;
227 	map->copy_from = physmap_addr_gpios_copy_from;
228 	map->write = physmap_addr_gpios_write;
229 	map->copy_to = physmap_addr_gpios_copy_to;
230 
231 	return 0;
232 }
233 #else
234 static int physmap_addr_gpios_map_init(struct map_info *map)
235 {
236 	return -ENOTSUPP;
237 }
238 #endif
239 
240 #if IS_ENABLED(CONFIG_MTD_PHYSMAP_OF)
241 static const struct of_device_id of_flash_match[] = {
242 	{
243 		.compatible = "cfi-flash",
244 		.data = "cfi_probe",
245 	},
246 	{
247 		/*
248 		 * FIXME: JEDEC chips can't be safely and reliably
249 		 * probed, although the mtd code gets it right in
250 		 * practice most of the time.  We should use the
251 		 * vendor and device ids specified by the binding to
252 		 * bypass the heuristic probe code, but the mtd layer
253 		 * provides, at present, no interface for doing so
254 		 * :(.
255 		 */
256 		.compatible = "jedec-flash",
257 		.data = "jedec_probe",
258 	},
259 	{
260 		.compatible = "mtd-ram",
261 		.data = "map_ram",
262 	},
263 	{
264 		.compatible = "mtd-rom",
265 		.data = "map_rom",
266 	},
267 	{
268 		.type = "rom",
269 		.compatible = "direct-mapped"
270 	},
271 	{ /* sentinel */ },
272 };
273 MODULE_DEVICE_TABLE(of, of_flash_match);
274 
275 static const char * const of_default_part_probes[] = {
276 	"cmdlinepart", "RedBoot", "ofpart", "ofoldpart", NULL
277 };
278 
279 static const char * const *of_get_part_probes(struct platform_device *dev)
280 {
281 	struct device_node *dp = dev->dev.of_node;
282 	const char **res;
283 	int count;
284 
285 	count = of_property_count_strings(dp, "linux,part-probe");
286 	if (count < 0)
287 		return of_default_part_probes;
288 
289 	res = devm_kcalloc(&dev->dev, count + 1, sizeof(*res), GFP_KERNEL);
290 	if (!res)
291 		return NULL;
292 
293 	count = of_property_read_string_array(dp, "linux,part-probe", res,
294 					      count);
295 	if (count < 0)
296 		return NULL;
297 
298 	return res;
299 }
300 
301 static const char *of_select_probe_type(struct platform_device *dev)
302 {
303 	struct device_node *dp = dev->dev.of_node;
304 	const struct of_device_id *match;
305 	const char *probe_type;
306 
307 	match = of_match_device(of_flash_match, &dev->dev);
308 	probe_type = match->data;
309 	if (probe_type)
310 		return probe_type;
311 
312 	dev_warn(&dev->dev,
313 		 "Device tree uses obsolete \"direct-mapped\" flash binding\n");
314 
315 	of_property_read_string(dp, "probe-type", &probe_type);
316 	if (!probe_type)
317 		return NULL;
318 
319 	if (!strcmp(probe_type, "CFI")) {
320 		probe_type = "cfi_probe";
321 	} else if (!strcmp(probe_type, "JEDEC")) {
322 		probe_type = "jedec_probe";
323 	} else if (!strcmp(probe_type, "ROM")) {
324 		probe_type = "map_rom";
325 	} else {
326 		dev_warn(&dev->dev,
327 			 "obsolete_probe: don't know probe type '%s', mapping as rom\n",
328 			 probe_type);
329 		probe_type = "map_rom";
330 	}
331 
332 	return probe_type;
333 }
334 
335 static int physmap_flash_of_init(struct platform_device *dev)
336 {
337 	struct physmap_flash_info *info = platform_get_drvdata(dev);
338 	struct device_node *dp = dev->dev.of_node;
339 	const char *mtd_name = NULL;
340 	int err, swap = 0;
341 	bool map_indirect;
342 	unsigned int i;
343 	u32 bankwidth;
344 
345 	if (!dp)
346 		return -EINVAL;
347 
348 	info->probe_type = of_select_probe_type(dev);
349 
350 	info->part_types = of_get_part_probes(dev);
351 	if (!info->part_types)
352 		return -ENOMEM;
353 
354 	of_property_read_string(dp, "linux,mtd-name", &mtd_name);
355 
356 	map_indirect = of_property_read_bool(dp, "no-unaligned-direct-access");
357 
358 	err = of_property_read_u32(dp, "bank-width", &bankwidth);
359 	if (err) {
360 		dev_err(&dev->dev, "Can't get bank width from device tree\n");
361 		return err;
362 	}
363 
364 	if (of_property_read_bool(dp, "big-endian"))
365 		swap = CFI_BIG_ENDIAN;
366 	else if (of_property_read_bool(dp, "little-endian"))
367 		swap = CFI_LITTLE_ENDIAN;
368 
369 	for (i = 0; i < info->nmaps; i++) {
370 		info->maps[i].name = mtd_name;
371 		info->maps[i].swap = swap;
372 		info->maps[i].bankwidth = bankwidth;
373 		info->maps[i].device_node = dp;
374 
375 		err = of_flash_probe_bt1_rom(dev, dp, &info->maps[i]);
376 		if (err)
377 			return err;
378 
379 		err = of_flash_probe_gemini(dev, dp, &info->maps[i]);
380 		if (err)
381 			return err;
382 
383 		err = of_flash_probe_ixp4xx(dev, dp, &info->maps[i]);
384 		if (err)
385 			return err;
386 
387 		err = of_flash_probe_versatile(dev, dp, &info->maps[i]);
388 		if (err)
389 			return err;
390 
391 		/*
392 		 * On some platforms (e.g. MPC5200) a direct 1:1 mapping
393 		 * may cause problems with JFFS2 usage, as the local bus (LPB)
394 		 * doesn't support unaligned accesses as implemented in the
395 		 * JFFS2 code via memcpy(). By setting NO_XIP, the
396 		 * flash will not be exposed directly to the MTD users
397 		 * (e.g. JFFS2) any more.
398 		 */
399 		if (map_indirect)
400 			info->maps[i].phys = NO_XIP;
401 	}
402 
403 	return 0;
404 }
405 #else /* IS_ENABLED(CONFIG_MTD_PHYSMAP_OF) */
406 #define of_flash_match NULL
407 
408 static int physmap_flash_of_init(struct platform_device *dev)
409 {
410 	return -ENOTSUPP;
411 }
412 #endif /* IS_ENABLED(CONFIG_MTD_PHYSMAP_OF) */
413 
414 static const char * const rom_probe_types[] = {
415 	"cfi_probe", "jedec_probe", "qinfo_probe", "map_rom",
416 };
417 
418 static const char * const part_probe_types[] = {
419 	"cmdlinepart", "RedBoot", "afs", NULL
420 };
421 
422 static int physmap_flash_pdata_init(struct platform_device *dev)
423 {
424 	struct physmap_flash_info *info = platform_get_drvdata(dev);
425 	struct physmap_flash_data *physmap_data;
426 	unsigned int i;
427 	int err;
428 
429 	physmap_data = dev_get_platdata(&dev->dev);
430 	if (!physmap_data)
431 		return -EINVAL;
432 
433 	info->probe_type = physmap_data->probe_type;
434 	info->part_types = physmap_data->part_probe_types ? : part_probe_types;
435 	info->parts = physmap_data->parts;
436 	info->nparts = physmap_data->nr_parts;
437 
438 	if (physmap_data->init) {
439 		err = physmap_data->init(dev);
440 		if (err)
441 			return err;
442 	}
443 
444 	for (i = 0; i < info->nmaps; i++) {
445 		info->maps[i].bankwidth = physmap_data->width;
446 		info->maps[i].pfow_base = physmap_data->pfow_base;
447 		info->maps[i].set_vpp = physmap_set_vpp;
448 	}
449 
450 	return 0;
451 }
452 
453 static int physmap_flash_probe(struct platform_device *dev)
454 {
455 	struct physmap_flash_info *info;
456 	int err = 0;
457 	int i;
458 
459 	if (!dev->dev.of_node && !dev_get_platdata(&dev->dev))
460 		return -EINVAL;
461 
462 	info = devm_kzalloc(&dev->dev, sizeof(*info), GFP_KERNEL);
463 	if (!info)
464 		return -ENOMEM;
465 
466 	while (platform_get_resource(dev, IORESOURCE_MEM, info->nmaps))
467 		info->nmaps++;
468 
469 	if (!info->nmaps)
470 		return -ENODEV;
471 
472 	info->maps = devm_kzalloc(&dev->dev,
473 				  sizeof(*info->maps) * info->nmaps,
474 				  GFP_KERNEL);
475 	if (!info->maps)
476 		return -ENOMEM;
477 
478 	info->mtds = devm_kzalloc(&dev->dev,
479 				  sizeof(*info->mtds) * info->nmaps,
480 				  GFP_KERNEL);
481 	if (!info->mtds)
482 		return -ENOMEM;
483 
484 	platform_set_drvdata(dev, info);
485 
486 	info->gpios = devm_gpiod_get_array_optional(&dev->dev, "addr",
487 						    GPIOD_OUT_LOW);
488 	if (IS_ERR(info->gpios))
489 		return PTR_ERR(info->gpios);
490 
491 	if (info->gpios && info->nmaps > 1) {
492 		dev_err(&dev->dev, "addr-gpios only supported for nmaps == 1\n");
493 		return -EINVAL;
494 	}
495 
496 	pm_runtime_enable(&dev->dev);
497 	pm_runtime_get_sync(&dev->dev);
498 
499 	if (dev->dev.of_node)
500 		err = physmap_flash_of_init(dev);
501 	else
502 		err = physmap_flash_pdata_init(dev);
503 
504 	if (err) {
505 		pm_runtime_put(&dev->dev);
506 		pm_runtime_disable(&dev->dev);
507 		return err;
508 	}
509 
510 	for (i = 0; i < info->nmaps; i++) {
511 		struct resource *res;
512 
513 		res = platform_get_resource(dev, IORESOURCE_MEM, i);
514 		info->maps[i].virt = devm_ioremap_resource(&dev->dev, res);
515 		if (IS_ERR(info->maps[i].virt)) {
516 			err = PTR_ERR(info->maps[i].virt);
517 			goto err_out;
518 		}
519 
520 		dev_notice(&dev->dev, "physmap platform flash device: %pR\n",
521 			   res);
522 
523 		if (!info->maps[i].name)
524 			info->maps[i].name = dev_name(&dev->dev);
525 
526 		if (!info->maps[i].phys)
527 			info->maps[i].phys = res->start;
528 
529 		info->win_order = get_bitmask_order(resource_size(res)) - 1;
530 		info->maps[i].size = BIT(info->win_order +
531 					 (info->gpios ?
532 					  info->gpios->ndescs : 0));
533 
534 		info->maps[i].map_priv_1 = (unsigned long)dev;
535 
536 		if (info->gpios) {
537 			err = physmap_addr_gpios_map_init(&info->maps[i]);
538 			if (err)
539 				goto err_out;
540 		}
541 
542 #ifdef CONFIG_MTD_COMPLEX_MAPPINGS
543 		/*
544 		 * Only use the simple_map implementation if map hooks are not
545 		 * implemented. Since map->read() is mandatory checking for its
546 		 * presence is enough.
547 		 */
548 		if (!info->maps[i].read)
549 			simple_map_init(&info->maps[i]);
550 #else
551 		simple_map_init(&info->maps[i]);
552 #endif
553 
554 		if (info->probe_type) {
555 			info->mtds[i] = do_map_probe(info->probe_type,
556 						     &info->maps[i]);
557 		} else {
558 			int j;
559 
560 			for (j = 0; j < ARRAY_SIZE(rom_probe_types); j++) {
561 				info->mtds[i] = do_map_probe(rom_probe_types[j],
562 							     &info->maps[i]);
563 				if (info->mtds[i])
564 					break;
565 			}
566 		}
567 
568 		if (!info->mtds[i]) {
569 			dev_err(&dev->dev, "map_probe failed\n");
570 			err = -ENXIO;
571 			goto err_out;
572 		}
573 		info->mtds[i]->dev.parent = &dev->dev;
574 	}
575 
576 	if (info->nmaps == 1) {
577 		info->cmtd = info->mtds[0];
578 	} else {
579 		/*
580 		 * We detected multiple devices. Concatenate them together.
581 		 */
582 		info->cmtd = mtd_concat_create(info->mtds, info->nmaps,
583 					       dev_name(&dev->dev));
584 		if (!info->cmtd)
585 			err = -ENXIO;
586 	}
587 	if (err)
588 		goto err_out;
589 
590 	spin_lock_init(&info->vpp_lock);
591 
592 	mtd_set_of_node(info->cmtd, dev->dev.of_node);
593 	err = mtd_device_parse_register(info->cmtd, info->part_types, NULL,
594 					info->parts, info->nparts);
595 	if (err)
596 		goto err_out;
597 
598 	return 0;
599 
600 err_out:
601 	physmap_flash_remove(dev);
602 	return err;
603 }
604 
605 #ifdef CONFIG_PM
606 static void physmap_flash_shutdown(struct platform_device *dev)
607 {
608 	struct physmap_flash_info *info = platform_get_drvdata(dev);
609 	int i;
610 
611 	for (i = 0; i < info->nmaps && info->mtds[i]; i++)
612 		if (mtd_suspend(info->mtds[i]) == 0)
613 			mtd_resume(info->mtds[i]);
614 }
615 #else
616 #define physmap_flash_shutdown NULL
617 #endif
618 
619 static struct platform_driver physmap_flash_driver = {
620 	.probe		= physmap_flash_probe,
621 	.remove		= physmap_flash_remove,
622 	.shutdown	= physmap_flash_shutdown,
623 	.driver		= {
624 		.name	= "physmap-flash",
625 		.of_match_table = of_flash_match,
626 	},
627 };
628 
629 #ifdef CONFIG_MTD_PHYSMAP_COMPAT
630 static struct physmap_flash_data physmap_flash_data = {
631 	.width		= CONFIG_MTD_PHYSMAP_BANKWIDTH,
632 };
633 
634 static struct resource physmap_flash_resource = {
635 	.start		= CONFIG_MTD_PHYSMAP_START,
636 	.end		= CONFIG_MTD_PHYSMAP_START + CONFIG_MTD_PHYSMAP_LEN - 1,
637 	.flags		= IORESOURCE_MEM,
638 };
639 
640 static struct platform_device physmap_flash = {
641 	.name		= "physmap-flash",
642 	.id		= 0,
643 	.dev		= {
644 		.platform_data	= &physmap_flash_data,
645 	},
646 	.num_resources	= 1,
647 	.resource	= &physmap_flash_resource,
648 };
649 #endif
650 
651 static int __init physmap_init(void)
652 {
653 	int err;
654 
655 	err = platform_driver_register(&physmap_flash_driver);
656 #ifdef CONFIG_MTD_PHYSMAP_COMPAT
657 	if (err == 0) {
658 		err = platform_device_register(&physmap_flash);
659 		if (err)
660 			platform_driver_unregister(&physmap_flash_driver);
661 	}
662 #endif
663 
664 	return err;
665 }
666 
667 static void __exit physmap_exit(void)
668 {
669 #ifdef CONFIG_MTD_PHYSMAP_COMPAT
670 	platform_device_unregister(&physmap_flash);
671 #endif
672 	platform_driver_unregister(&physmap_flash_driver);
673 }
674 
675 module_init(physmap_init);
676 module_exit(physmap_exit);
677 
678 MODULE_LICENSE("GPL");
679 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
680 MODULE_AUTHOR("Vitaly Wool <vwool@ru.mvista.com>");
681 MODULE_AUTHOR("Mike Frysinger <vapier@gentoo.org>");
682 MODULE_DESCRIPTION("Generic configurable MTD map driver");
683 
684 /* legacy platform drivers can't hotplug or coldplg */
685 #ifndef CONFIG_MTD_PHYSMAP_COMPAT
686 /* work with hotplug and coldplug */
687 MODULE_ALIAS("platform:physmap-flash");
688 #endif
689