add partition mtd support

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

3 files changed, 146 insertions, 0 deletions

diff --git a/drivers/mtd/Makefile b/drivers/mtd/Makefile
index 87ee6f45d3..299cca13ad 100644
--- a/drivers/mtd/Makefile
+++ b/drivers/mtd/Makefile
@@ -1 +1,2 @@
 obj-$(CONFIG_NAND)	+= nand/
+obj-$(CONFIG_PARTITION_NEED_MTD)	+= partition.o
diff --git a/drivers/mtd/nand/nand.c b/drivers/mtd/nand/nand.c
index 4927231c17..6a150fe0cb 100644
--- a/drivers/mtd/nand/nand.c
+++ b/drivers/mtd/nand/nand.c
@@ -123,6 +123,7 @@ static int nand_ioctl(struct cdev *cdev, int request, void *buf)
 		user->size	= info->size;
 		user->erasesize	= info->erasesize;
 		user->oobsize	= info->oobsize;
+		user->mtd	= info;
 		/* The below fields are obsolete */
 		user->ecctype	= -1;
 		user->eccsize	= 0;
@@ -220,6 +221,7 @@ int add_mtd_device(struct mtd_info *mtd)
 	mtd->cdev.name = asprintf("nand%d", mtd->class_dev.id);
 	mtd->cdev.priv = mtd;
 	mtd->cdev.dev = &mtd->class_dev;
+	mtd->cdev.mtd = mtd;
 
 	sprintf(str, "%u", mtd->size);
 	dev_add_param_fixed(&mtd->class_dev, "size", str);
diff --git a/drivers/mtd/partition.c b/drivers/mtd/partition.c
new file mode 100644
index 0000000000..df2eb40bf8
--- /dev/null
+++ b/drivers/mtd/partition.c
@@ -0,0 +1,143 @@
+#include <common.h>
+#include <errno.h>
+#include <malloc.h>
+#include <linux/err.h>
+#include <linux/mtd/mtd.h>
+
+struct mtd_part {
+	struct mtd_info mtd;
+	struct mtd_info *master;
+	uint64_t offset;
+	struct list_head list;
+};
+
+#define PART(x)  ((struct mtd_part *)(x))
+
+static int mtd_part_read(struct mtd_info *mtd, loff_t from, size_t len,
+                size_t *retlen, u_char *buf)
+{
+	struct mtd_part *part = PART(mtd);
+	struct mtd_ecc_stats stats;
+	int res;
+
+	stats = part->master->ecc_stats;
+
+	if (from >= mtd->size)
+		len = 0;
+	else if (from + len > mtd->size)
+		len = mtd->size - from;
+	res = part->master->read(part->master, from + part->offset,
+				len, retlen, buf);
+	return res;
+}
+
+static int mtd_part_write(struct mtd_info *mtd, loff_t to, size_t len,
+                size_t *retlen, const u_char *buf)
+{
+	struct mtd_part *part = PART(mtd);
+
+	if (!(mtd->flags & MTD_WRITEABLE))
+		return -EROFS;
+	if (to >= mtd->size)
+		len = 0;
+	else if (to + len > mtd->size)
+		len = mtd->size - to;
+	return part->master->write(part->master, to + part->offset,
+					len, retlen, buf);
+}
+
+static int mtd_part_erase(struct mtd_info *mtd, struct erase_info *instr)
+{
+	struct mtd_part *part = PART(mtd);
+	int ret;
+
+	if (!(mtd->flags & MTD_WRITEABLE))
+		return -EROFS;
+	if (instr->addr >= mtd->size)
+		return -EINVAL;
+	instr->addr += part->offset;
+	ret = part->master->erase(part->master, instr);
+	if (ret) {
+		if (instr->fail_addr != 0xffffffff)
+			instr->fail_addr -= part->offset;
+		instr->addr -= part->offset;
+	}
+	return ret;
+}
+
+static int mtd_part_block_isbad(struct mtd_info *mtd, loff_t ofs)
+{
+	struct mtd_part *part = PART(mtd);
+	if (ofs >= mtd->size)
+		return -EINVAL;
+	ofs += part->offset;
+	return part->master->block_isbad(part->master, ofs);
+}
+
+static int mtd_part_block_markbad(struct mtd_info *mtd, loff_t ofs)
+{
+	struct mtd_part *part = PART(mtd);
+	int res;
+
+	if (!(mtd->flags & MTD_WRITEABLE))
+		return -EROFS;
+	if (ofs >= mtd->size)
+		return -EINVAL;
+	ofs += part->offset;
+	res = part->master->block_markbad(part->master, ofs);
+	if (!res)
+		mtd->ecc_stats.badblocks++;
+	return res;
+}
+
+struct mtd_info *mtd_add_partition(struct mtd_info *mtd, off_t offset, size_t size,
+		unsigned long flags, const char *name)
+{
+	struct mtd_part *slave;
+	struct mtd_info *slave_mtd;
+	int start = 0, end = 0, i;
+
+	slave = xzalloc(sizeof(*slave));
+	slave_mtd = &slave->mtd;
+
+	memcpy(slave_mtd, mtd, sizeof(*slave));
+
+	/*
+	 * find the number of eraseregions the partition includes.
+	 * Do not bother to create the mtd_erase_region_infos as
+	 * ubi is only interested in its number. UBI does not
+	 * yet support multiple erase regions.
+	 */
+	for (i = mtd->numeraseregions - 1; i >= 0; i--) {
+		struct mtd_erase_region_info *region = &mtd->eraseregions[i];
+		if (offset >= region->offset &&
+		    offset < region->offset + region->erasesize * region->numblocks)
+			start = i;
+		if (offset + size >= region->offset &&
+		    offset + size <= region->offset + region->erasesize * region->numblocks)
+			end = i;
+	}
+
+	slave_mtd->numeraseregions = end - start;
+
+	slave_mtd->read = mtd_part_read;
+	slave_mtd->write = mtd_part_write;
+	slave_mtd->erase = mtd_part_erase;
+	slave_mtd->block_isbad = mtd->block_isbad ? mtd_part_block_isbad : NULL;
+	slave_mtd->block_markbad = mtd->block_markbad ? mtd_part_block_markbad : NULL;
+	slave_mtd->size = size;
+	slave_mtd->name = strdup(name);
+
+	slave->offset = offset;
+	slave->master = mtd;
+
+	return slave_mtd;
+}
+
+void mtd_del_partition(struct mtd_info *mtd)
+{
+	struct mtd_part *part = PART(mtd);
+
+	free(mtd->name);
+	free(part);
+}