// SPDX-License-Identifier:  GPL-2.0+
/*
 * mtd.c
 *
 * Generic command to handle basic operations on any memory device.
 *
 * Copyright: Bootlin, 2018
 * Author: Miquèl Raynal <miquel.raynal@bootlin.com>
 */

#include <command.h>
#include <common.h>
#include <console.h>
#include <malloc.h>
#include <mapmem.h>
#include <mtd.h>

static uint mtd_len_to_pages(struct mtd_info *mtd, u64 len)
{
	do_div(len, mtd->writesize);

	return len;
}

static bool mtd_is_aligned_with_min_io_size(struct mtd_info *mtd, u64 size)
{
	return !do_div(size, mtd->writesize);
}

static bool mtd_is_aligned_with_block_size(struct mtd_info *mtd, u64 size)
{
	return !do_div(size, mtd->erasesize);
}

static void mtd_dump_buf(const u8 *buf, uint len, uint offset)
{
	int i, j;

	for (i = 0; i < len; ) {
		printf("0x%08x:\t", offset + i);
		for (j = 0; j < 8; j++)
			printf("%02x ", buf[i + j]);
		printf(" ");
		i += 8;
		for (j = 0; j < 8; j++)
			printf("%02x ", buf[i + j]);
		printf("\n");
		i += 8;
	}
}

static void mtd_dump_device_buf(struct mtd_info *mtd, u64 start_off,
				const u8 *buf, u64 len, bool woob)
{
	bool has_pages = mtd->type == MTD_NANDFLASH ||
		mtd->type == MTD_MLCNANDFLASH;
	int npages = mtd_len_to_pages(mtd, len);
	uint page;

	if (has_pages) {
		for (page = 0; page < npages; page++) {
			u64 data_off = page * mtd->writesize;

			printf("\nDump %d data bytes from 0x%08llx:\n",
			       mtd->writesize, start_off + data_off);
			mtd_dump_buf(&buf[data_off],
				     mtd->writesize, start_off + data_off);

			if (woob) {
				u64 oob_off = page * mtd->oobsize;

				printf("Dump %d OOB bytes from page at 0x%08llx:\n",
				       mtd->oobsize, start_off + data_off);
				mtd_dump_buf(&buf[len + oob_off],
					     mtd->oobsize, 0);
			}
		}
	} else {
		printf("\nDump %lld data bytes from 0x%llx:\n",
		       len, start_off);
		mtd_dump_buf(buf, len, start_off);
	}
}

static void mtd_show_parts(struct mtd_info *mtd, int level)
{
	struct mtd_info *part;
	int i;

	list_for_each_entry(part, &mtd->partitions, node) {
		for (i = 0; i < level; i++)
			printf("\t");
		printf("  - 0x%012llx-0x%012llx : \"%s\"\n",
		       part->offset, part->offset + part->size, part->name);

		mtd_show_parts(part, level + 1);
	}
}

static void mtd_show_device(struct mtd_info *mtd)
{
	/* Device */
	printf("* %s\n", mtd->name);
#if defined(CONFIG_DM)
	if (mtd->dev) {
		printf("  - device: %s\n", mtd->dev->name);
		printf("  - parent: %s\n", mtd->dev->parent->name);
		printf("  - driver: %s\n", mtd->dev->driver->name);
	}
#endif

	/* MTD device information */
	printf("  - type: ");
	switch (mtd->type) {
	case MTD_RAM:
		printf("RAM\n");
		break;
	case MTD_ROM:
		printf("ROM\n");
		break;
	case MTD_NORFLASH:
		printf("NOR flash\n");
		break;
	case MTD_NANDFLASH:
		printf("NAND flash\n");
		break;
	case MTD_DATAFLASH:
		printf("Data flash\n");
		break;
	case MTD_UBIVOLUME:
		printf("UBI volume\n");
		break;
	case MTD_MLCNANDFLASH:
		printf("MLC NAND flash\n");
		break;
	case MTD_ABSENT:
	default:
		printf("Unknown\n");
		break;
	}

	printf("  - block size: 0x%x bytes\n", mtd->erasesize);
	printf("  - min I/O: 0x%x bytes\n", mtd->writesize);

	if (mtd->oobsize) {
		printf("  - OOB size: %u bytes\n", mtd->oobsize);
		printf("  - OOB available: %u bytes\n", mtd->oobavail);
	}

	if (mtd->ecc_strength) {
		printf("  - ECC strength: %u bits\n", mtd->ecc_strength);
		printf("  - ECC step size: %u bytes\n", mtd->ecc_step_size);
		printf("  - bitflip threshold: %u bits\n",
		       mtd->bitflip_threshold);
	}

	printf("  - 0x%012llx-0x%012llx : \"%s\"\n",
	       mtd->offset, mtd->offset + mtd->size, mtd->name);

	/* MTD partitions, if any */
	mtd_show_parts(mtd, 1);
}

/* Logic taken from fs/ubifs/recovery.c:is_empty() */
static bool mtd_oob_write_is_empty(struct mtd_oob_ops *op)
{
	int i;

	for (i = 0; i < op->len; i++)
		if (op->datbuf[i] != 0xff)
			return false;

	for (i = 0; i < op->ooblen; i++)
		if (op->oobbuf[i] != 0xff)
			return false;

	return true;
}

static int do_mtd_list(void)
{
	struct mtd_info *mtd;
	int dev_nb = 0;

	/* Ensure all devices (and their partitions) are probed */
	mtd_probe_devices();

	printf("List of MTD devices:\n");
	mtd_for_each_device(mtd) {
		if (!mtd_is_partition(mtd))
			mtd_show_device(mtd);

		dev_nb++;
	}

	if (!dev_nb) {
		printf("No MTD device found\n");
		return CMD_RET_FAILURE;
	}

	return CMD_RET_SUCCESS;
}

static int mtd_special_write_oob(struct mtd_info *mtd, u64 off,
				 struct mtd_oob_ops *io_op,
				 bool write_empty_pages, bool woob)
{
	int ret = 0;

	/*
	 * By default, do not write an empty page.
	 * Skip it by simulating a successful write.
	 */
	if (!write_empty_pages && mtd_oob_write_is_empty(io_op)) {
		io_op->retlen = mtd->writesize;
		io_op->oobretlen = woob ? mtd->oobsize : 0;
	} else {
		ret = mtd_write_oob(mtd, off, io_op);
	}

	return ret;
}

static int do_mtd(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
	struct mtd_info *mtd;
	const char *cmd;
	char *mtd_name;

	/* All MTD commands need at least two arguments */
	if (argc < 2)
		return CMD_RET_USAGE;

	/* Parse the command name and its optional suffixes */
	cmd = argv[1];

	/* List the MTD devices if that is what the user wants */
	if (strcmp(cmd, "list") == 0)
		return do_mtd_list();

	/*
	 * The remaining commands require also at least a device ID.
	 * Check the selected device is valid. Ensure it is probed.
	 */
	if (argc < 3)
		return CMD_RET_USAGE;

	mtd_name = argv[2];
	mtd_probe_devices();
	mtd = get_mtd_device_nm(mtd_name);
	if (IS_ERR_OR_NULL(mtd)) {
		printf("MTD device %s not found, ret %ld\n",
		       mtd_name, PTR_ERR(mtd));
		return CMD_RET_FAILURE;
	}
	put_mtd_device(mtd);

	argc -= 3;
	argv += 3;

	/* Do the parsing */
	if (!strncmp(cmd, "read", 4) || !strncmp(cmd, "dump", 4) ||
	    !strncmp(cmd, "write", 5)) {
		bool has_pages = mtd->type == MTD_NANDFLASH ||
				 mtd->type == MTD_MLCNANDFLASH;
		bool dump, read, raw, woob, write_empty_pages;
		struct mtd_oob_ops io_op = {};
		uint user_addr = 0, npages;
		u64 start_off, off, len, remaining, default_len;
		u32 oob_len;
		u8 *buf;
		int ret;

		dump = !strncmp(cmd, "dump", 4);
		read = dump || !strncmp(cmd, "read", 4);
		raw = strstr(cmd, ".raw");
		woob = strstr(cmd, ".oob");
		write_empty_pages = !has_pages || strstr(cmd, ".dontskipff");

		if (!dump) {
			if (!argc)
				return CMD_RET_USAGE;

			user_addr = simple_strtoul(argv[0], NULL, 16);
			argc--;
			argv++;
		}

		start_off = argc > 0 ? simple_strtoul(argv[0], NULL, 16) : 0;
		if (!mtd_is_aligned_with_min_io_size(mtd, start_off)) {
			printf("Offset not aligned with a page (0x%x)\n",
			       mtd->writesize);
			return CMD_RET_FAILURE;
		}

		default_len = dump ? mtd->writesize : mtd->size;
		len = argc > 1 ? simple_strtoul(argv[1], NULL, 16) :
				 default_len;
		if (!mtd_is_aligned_with_min_io_size(mtd, len)) {
			len = round_up(len, mtd->writesize);
			printf("Size not on a page boundary (0x%x), rounding to 0x%llx\n",
			       mtd->writesize, len);
		}

		remaining = len;
		npages = mtd_len_to_pages(mtd, len);
		oob_len = woob ? npages * mtd->oobsize : 0;

		if (dump)
			buf = kmalloc(len + oob_len, GFP_KERNEL);
		else
			buf = map_sysmem(user_addr, 0);

		if (!buf) {
			printf("Could not map/allocate the user buffer\n");
			return CMD_RET_FAILURE;
		}

		if (has_pages)
			printf("%s %lld byte(s) (%d page(s)) at offset 0x%08llx%s%s%s\n",
			       read ? "Reading" : "Writing", len, npages, start_off,
			       raw ? " [raw]" : "", woob ? " [oob]" : "",
			       !read && write_empty_pages ? " [dontskipff]" : "");
		else
			printf("%s %lld byte(s) at offset 0x%08llx\n",
			       read ? "Reading" : "Writing", len, start_off);

		io_op.mode = raw ? MTD_OPS_RAW : MTD_OPS_AUTO_OOB;
		io_op.len = has_pages ? mtd->writesize : len;
		io_op.ooblen = woob ? mtd->oobsize : 0;
		io_op.datbuf = buf;
		io_op.oobbuf = woob ? &buf[len] : NULL;

		/* Search for the first good block after the given offset */
		off = start_off;
		while (mtd_block_isbad(mtd, off))
			off += mtd->erasesize;

		/* Loop over the pages to do the actual read/write */
		while (remaining) {
			/* Skip the block if it is bad */
			if (mtd_is_aligned_with_block_size(mtd, off) &&
			    mtd_block_isbad(mtd, off)) {
				off += mtd->erasesize;
				continue;
			}

			if (read)
				ret = mtd_read_oob(mtd, off, &io_op);
			else
				ret = mtd_special_write_oob(mtd, off, &io_op,
							    write_empty_pages,
							    woob);

			if (ret) {
				printf("Failure while %s at offset 0x%llx\n",
				       read ? "reading" : "writing", off);
				return CMD_RET_FAILURE;
			}

			off += io_op.retlen;
			remaining -= io_op.retlen;
			io_op.datbuf += io_op.retlen;
			io_op.oobbuf += io_op.oobretlen;
		}

		if (!ret && dump)
			mtd_dump_device_buf(mtd, start_off, buf, len, woob);

		if (dump)
			kfree(buf);
		else
			unmap_sysmem(buf);

		if (ret) {
			printf("%s on %s failed with error %d\n",
			       read ? "Read" : "Write", mtd->name, ret);
			return CMD_RET_FAILURE;
		}

	} else if (!strcmp(cmd, "erase")) {
		bool scrub = strstr(cmd, ".dontskipbad");
		struct erase_info erase_op = {};
		u64 off, len;
		int ret;

		off = argc > 0 ? simple_strtoul(argv[0], NULL, 16) : 0;
		len = argc > 1 ? simple_strtoul(argv[1], NULL, 16) : mtd->size;

		if (!mtd_is_aligned_with_block_size(mtd, off)) {
			printf("Offset not aligned with a block (0x%x)\n",
			       mtd->erasesize);
			return CMD_RET_FAILURE;
		}

		if (!mtd_is_aligned_with_block_size(mtd, len)) {
			printf("Size not a multiple of a block (0x%x)\n",
			       mtd->erasesize);
			return CMD_RET_FAILURE;
		}

		printf("Erasing 0x%08llx ... 0x%08llx (%d eraseblock(s))\n",
		       off, off + len - 1, mtd_div_by_eb(len, mtd));

		erase_op.mtd = mtd;
		erase_op.addr = off;
		erase_op.len = len;
		erase_op.scrub = scrub;

		while (erase_op.len) {
			ret = mtd_erase(mtd, &erase_op);

			/* Abort if its not a bad block error */
			if (ret != -EIO)
				break;

			printf("Skipping bad block at 0x%08llx\n",
			       erase_op.fail_addr);

			/* Skip bad block and continue behind it */
			erase_op.len -= erase_op.fail_addr - erase_op.addr;
			erase_op.len -= mtd->erasesize;
			erase_op.addr = erase_op.fail_addr + mtd->erasesize;
		}

		if (ret && ret != -EIO)
			return CMD_RET_FAILURE;
	} else if (!strcmp(cmd, "bad")) {
		loff_t off;

		if (!mtd_can_have_bb(mtd)) {
			printf("Only NAND-based devices can have bad blocks\n");
			return CMD_RET_SUCCESS;
		}

		printf("MTD device %s bad blocks list:\n", mtd->name);
		for (off = 0; off < mtd->size; off += mtd->erasesize)
			if (mtd_block_isbad(mtd, off))
				printf("\t0x%08llx\n", off);
	} else {
		return CMD_RET_USAGE;
	}

	return CMD_RET_SUCCESS;
}

static char mtd_help_text[] =
#ifdef CONFIG_SYS_LONGHELP
	"- generic operations on memory technology devices\n\n"
	"mtd list\n"
	"mtd read[.raw][.oob]                  <name> <addr> [<off> [<size>]]\n"
	"mtd dump[.raw][.oob]                  <name>        [<off> [<size>]]\n"
	"mtd write[.raw][.oob][.dontskipff]    <name> <addr> [<off> [<size>]]\n"
	"mtd erase[.dontskipbad]               <name>        [<off> [<size>]]\n"
	"\n"
	"Specific functions:\n"
	"mtd bad                               <name>\n"
	"\n"
	"With:\n"
	"\t<name>: NAND partition/chip name\n"
	"\t<addr>: user address from/to which data will be retrieved/stored\n"
	"\t<off>: offset in <name> in bytes (default: start of the part)\n"
	"\t\t* must be block-aligned for erase\n"
	"\t\t* must be page-aligned otherwise\n"
	"\t<size>: length of the operation in bytes (default: the entire device)\n"
	"\t\t* must be a multiple of a block for erase\n"
	"\t\t* must be a multiple of a page otherwise (special case: default is a page with dump)\n"
	"\n"
	"The .dontskipff option forces writing empty pages, don't use it if unsure.\n"
#endif
	"";

U_BOOT_CMD(mtd, 10, 1, do_mtd, "MTD utils", mtd_help_text);