u-boot/drivers/mtd/mtd_uboot.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * (C) Copyright 2014
 * Heiko Schocher, DENX Software Engineering, hs@denx.de.
 */
#include <common.h>
#include <dm/device.h>
#include <dm/uclass-internal.h>
#include <jffs2/jffs2.h> /* LEGACY */
#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>
#include <mtd.h>

#define MTD_NAME_MAX_LEN 20


/**
 * mtd_search_alternate_name - Search an alternate name for @mtdname thanks to
 *                             the mtdids legacy environment variable.
 *
 * The mtdids string is a list of comma-separated 'dev_id=mtd_id' tupples.
 * Check if one of the mtd_id matches mtdname, in this case save dev_id in
 * altname.
 *
 * @mtdname: Current MTD device name
 * @altname: Alternate name to return
 * @max_len: Length of the alternate name buffer
 *
 * @return 0 on success, an error otherwise.
 */
int mtd_search_alternate_name(const char *mtdname, char *altname,
			      unsigned int max_len)
{
	const char *mtdids, *equal, *comma, *dev_id, *mtd_id;
	int dev_id_len, mtd_id_len;

	mtdids = env_get("mtdids");
	if (!mtdids)
		return -EINVAL;

	do {
		/* Find the '=' sign */
		dev_id = mtdids;
		equal = strchr(dev_id, '=');
		if (!equal)
			break;
		dev_id_len = equal - mtdids;
		mtd_id = equal + 1;

		/* Find the end of the tupple */
		comma = strchr(mtdids, ',');
		if (comma)
			mtd_id_len = comma - mtd_id;
		else
			mtd_id_len = &mtdids[strlen(mtdids)] - mtd_id + 1;

		if (!dev_id_len || !mtd_id_len)
			return -EINVAL;

		if (dev_id_len + 1 > max_len)
			continue;

		/* Compare the name we search with the current mtd_id */
		if (!strncmp(mtdname, mtd_id, mtd_id_len)) {
			strncpy(altname, dev_id, dev_id_len);
			altname[dev_id_len] = 0;

			return 0;
		}

		/* Go to the next tupple */
		mtdids = comma + 1;
	} while (comma);

	return -EINVAL;
}

#if IS_ENABLED(CONFIG_MTD)
static void mtd_probe_uclass_mtd_devs(void)
{
	struct udevice *dev;
	int idx = 0;

	/* Probe devices with DM compliant drivers */
	while (!uclass_find_device(UCLASS_MTD, idx, &dev) && dev) {
		mtd_probe(dev);
		idx++;
	}
}
#else
static void mtd_probe_uclass_mtd_devs(void) { }
#endif

#if defined(CONFIG_MTD_PARTITIONS)
int mtd_probe_devices(void)
{
	static char *old_mtdparts;
	static char *old_mtdids;
	const char *mtdparts = env_get("mtdparts");
	const char *mtdids = env_get("mtdids");
	bool remaining_partitions = true;
	struct mtd_info *mtd;

	mtd_probe_uclass_mtd_devs();

	/* Check if mtdparts/mtdids changed since last call, otherwise: exit */
	if ((!mtdparts && !old_mtdparts && !mtdids && !old_mtdids) ||
	    (mtdparts && old_mtdparts && mtdids && old_mtdids &&
	     !strcmp(mtdparts, old_mtdparts) &&
	     !strcmp(mtdids, old_mtdids)))
		return 0;

	/* Update the local copy of mtdparts */
	free(old_mtdparts);
	free(old_mtdids);
	old_mtdparts = strdup(mtdparts);
	old_mtdids = strdup(mtdids);

	/* If at least one partition is still in use, do not delete anything */
	mtd_for_each_device(mtd) {
		if (mtd->usecount) {
			printf("Partition \"%s\" already in use, aborting\n",
			       mtd->name);
			return -EACCES;
		}
	}

	/*
	 * Everything looks clear, remove all partitions. It is not safe to
	 * remove entries from the mtd_for_each_device loop as it uses idr
	 * indexes and the partitions removal is done in bulk (all partitions of
	 * one device at the same time), so break and iterate from start each
	 * time a new partition is found and deleted.
	 */
	while (remaining_partitions) {
		remaining_partitions = false;
		mtd_for_each_device(mtd) {
			if (!mtd_is_partition(mtd) && mtd_has_partitions(mtd)) {
				del_mtd_partitions(mtd);
				remaining_partitions = true;
				break;
			}
		}
	}

	/* If either mtdparts or mtdids is empty, then exit */
	if (!mtdparts || !mtdids)
		return 0;

	/* Start the parsing by ignoring the extra 'mtdparts=' prefix, if any */
	if (strstr(mtdparts, "mtdparts="))
		mtdparts += 9;

	/* For each MTD device in mtdparts */
	while (mtdparts[0] != '\0') {
		char mtd_name[MTD_NAME_MAX_LEN], *colon;
		struct mtd_partition *parts;
		int mtd_name_len, nparts;
		int ret;

		colon = strchr(mtdparts, ':');
		if (!colon) {
			printf("Wrong mtdparts: %s\n", mtdparts);
			return -EINVAL;
		}

		mtd_name_len = colon - mtdparts;
		strncpy(mtd_name, mtdparts, mtd_name_len);
		mtd_name[mtd_name_len] = '\0';
		/* Move the pointer forward (including the ':') */
		mtdparts += mtd_name_len + 1;
		mtd = get_mtd_device_nm(mtd_name);
		if (IS_ERR_OR_NULL(mtd)) {
			char linux_name[MTD_NAME_MAX_LEN];

			/*
			 * The MTD device named "mtd_name" does not exist. Try
			 * to find a correspondance with an MTD device having
			 * the same type and number as defined in the mtdids.
			 */
			debug("No device named %s\n", mtd_name);
			ret = mtd_search_alternate_name(mtd_name, linux_name,
							MTD_NAME_MAX_LEN);
			if (!ret)
				mtd = get_mtd_device_nm(linux_name);

			/*
			 * If no device could be found, move the mtdparts
			 * pointer forward until the next set of partitions.
			 */
			if (ret || IS_ERR_OR_NULL(mtd)) {
				printf("Could not find a valid device for %s\n",
				       mtd_name);
				mtdparts = strchr(mtdparts, ';');
				if (mtdparts)
					mtdparts++;

				continue;
			}
		}

		/*
		 * Parse the MTD device partitions. It will update the mtdparts
		 * pointer, create an array of parts (that must be freed), and
		 * return the number of partition structures in the array.
		 */
		ret = mtd_parse_partitions(mtd, &mtdparts, &parts, &nparts);
		if (ret) {
			printf("Could not parse device %s\n", mtd->name);
			put_mtd_device(mtd);
			return -EINVAL;
		}

		if (!nparts)
			continue;

		/* Create the new MTD partitions */
		add_mtd_partitions(mtd, parts, nparts);

		/* Free the structures allocated during the parsing */
		mtd_free_parsed_partitions(parts, nparts);

		put_mtd_device(mtd);
	}

	return 0;
}
#else
int mtd_probe_devices(void)
{
	mtd_probe_uclass_mtd_devs();

	return 0;
}
#endif /* defined(CONFIG_MTD_PARTITIONS) */

/* Legacy */

static int get_part(const char *partname, int *idx, loff_t *off, loff_t *size,
		loff_t *maxsize, int devtype)
{
#ifdef CONFIG_CMD_MTDPARTS
	struct mtd_device *dev;
	struct part_info *part;
	u8 pnum;
	int ret;

	ret = mtdparts_init();
	if (ret)
		return ret;

	ret = find_dev_and_part(partname, &dev, &pnum, &part);
	if (ret)
		return ret;

	if (dev->id->type != devtype) {
		printf("not same typ %d != %d\n", dev->id->type, devtype);
		return -1;
	}

	*off = part->offset;
	*size = part->size;
	*maxsize = part->size;
	*idx = dev->id->num;

	return 0;
#else
	puts("mtdparts support missing.\n");
	return -1;
#endif
}

int mtd_arg_off(const char *arg, int *idx, loff_t *off, loff_t *size,
		loff_t *maxsize, int devtype, uint64_t chipsize)
{
	if (!str2off(arg, off))
		return get_part(arg, idx, off, size, maxsize, devtype);

	if (*off >= chipsize) {
		puts("Offset exceeds device limit\n");
		return -1;
	}

	*maxsize = chipsize - *off;
	*size = *maxsize;
	return 0;
}

int mtd_arg_off_size(int argc, char *const argv[], int *idx, loff_t *off,
		     loff_t *size, loff_t *maxsize, int devtype,
		     uint64_t chipsize)
{
	int ret;

	if (argc == 0) {
		*off = 0;
		*size = chipsize;
		*maxsize = *size;
		goto print;
	}

	ret = mtd_arg_off(argv[0], idx, off, size, maxsize, devtype,
			  chipsize);
	if (ret)
		return ret;

	if (argc == 1)
		goto print;

	if (!str2off(argv[1], size)) {
		printf("'%s' is not a number\n", argv[1]);
		return -1;
	}

	if (*size > *maxsize) {
		puts("Size exceeds partition or device limit\n");
		return -1;
	}

print:
	printf("device %d ", *idx);
	if (*size == chipsize)
		puts("whole chip\n");
	else
		printf("offset 0x%llx, size 0x%llx\n",
		       (unsigned long long)*off, (unsigned long long)*size);
	return 0;
}