[PATCH] OneNAND: Simple Bad Block handling support

Based on NAND memory bad block table code
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

drivers/mtd/onenand/Makefile

@@ -3,7 +3,9 @@
 #
 
 # Core functionality.
-obj-$(CONFIG_MTD_ONENAND)		+= onenand_base.o
+obj-$(CONFIG_MTD_ONENAND)		+= onenand.o
 
 # Board specific.
 obj-$(CONFIG_MTD_ONENAND_OMAP)		+= omap-onenand.o
+
+onenand-objs = onenand_base.o onenand_bbt.o

drivers/mtd/onenand/onenand_base.c

@@ -311,19 +311,21 @@ static int onenand_wait(struct mtd_info *mtd, int state)
 	ctrl = this->read_word(this->base + ONENAND_REG_CTRL_STATUS);
 
 	if (ctrl & ONENAND_CTRL_ERROR) {
-		DEBUG(MTD_DEBUG_LEVEL0, "onenand_wait: controller error = 0x%04x", ctrl);
-		return -EIO;
+		/* It maybe occur at initial bad block */
+		DEBUG(MTD_DEBUG_LEVEL0, "onenand_wait: controller error = 0x%04x\n", ctrl);
+		/* Clear other interrupt bits for preventing ECC error */
+		interrupt &= ONENAND_INT_MASTER;
 	}
 
 	if (ctrl & ONENAND_CTRL_LOCK) {
-		DEBUG(MTD_DEBUG_LEVEL0, "onenand_wait: it's locked error = 0x%04x", ctrl);
-		return -EIO;
+		DEBUG(MTD_DEBUG_LEVEL0, "onenand_wait: it's locked error = 0x%04x\n", ctrl);
+		return -EACCES;
 	}
 
 	if (interrupt & ONENAND_INT_READ) {
 		ecc = this->read_word(this->base + ONENAND_REG_ECC_STATUS);
 		if (ecc & ONENAND_ECC_2BIT_ALL) {
-			DEBUG(MTD_DEBUG_LEVEL0, "onenand_wait: ECC error = 0x%04x", ecc);
+			DEBUG(MTD_DEBUG_LEVEL0, "onenand_wait: ECC error = 0x%04x\n", ecc);
 			return -EBADMSG;
 		}
 	}
@@ -1059,6 +1061,25 @@ static int onenand_writev(struct mtd_info *mtd, const struct kvec *vecs,
 	return onenand_writev_ecc(mtd, vecs, count, to, retlen, NULL, NULL);
 }
 
+/**
+ * onenand_block_checkbad - [GENERIC] Check if a block is marked bad
+ * @param mtd		MTD device structure
+ * @param ofs		offset from device start
+ * @param getchip	0, if the chip is already selected
+ * @param allowbbt	1, if its allowed to access the bbt area
+ *
+ * Check, if the block is bad. Either by reading the bad block table or
+ * calling of the scan function.
+ */
+static int onenand_block_checkbad(struct mtd_info *mtd, loff_t ofs, int getchip, int allowbbt)
+{
+	struct onenand_chip *this = mtd->priv;
+	struct bbm_info *bbm = this->bbm;
+
+	/* Return info from the table */
+	return bbm->isbad_bbt(mtd, ofs, allowbbt);
+}
+
 /**
  * onenand_erase - [MTD Interface] erase block(s)
  * @param mtd		MTD device structure
@@ -1109,7 +1130,12 @@ static int onenand_erase(struct mtd_info *mtd, struct erase_info *instr)
 
 	while (len) {
 
-		/* TODO Check badblock */
+		/* Check if we have a bad block, we do not erase bad blocks */
+		if (onenand_block_checkbad(mtd, addr, 0, 0)) {
+			printk (KERN_WARNING "onenand_erase: attempt to erase a bad block at addr 0x%08x\n", (unsigned int) addr);
+			instr->state = MTD_ERASE_FAILED;
+			goto erase_exit;
+		}
 
 		this->command(mtd, ONENAND_CMD_ERASE, addr, block_size);
 
@@ -1161,34 +1187,70 @@ static void onenand_sync(struct mtd_info *mtd)
 	onenand_release_device(mtd);
 }
 
+
 /**
  * onenand_block_isbad - [MTD Interface] Check whether the block at the given offset is bad
  * @param mtd		MTD device structure
  * @param ofs		offset relative to mtd start
+ *
+ * Check whether the block is bad
  */
 static int onenand_block_isbad(struct mtd_info *mtd, loff_t ofs)
 {
-	/*
-	 * TODO 
-	 * 1. Bad block table (BBT)
-	 *   -> using NAND BBT to support JFFS2
-	 * 2. Bad block management (BBM)
-	 *   -> bad block replace scheme
-	 *
-	 * Currently we do nothing
-	 */
-	return 0;
+	/* Check for invalid offset */
+	if (ofs > mtd->size)
+		return -EINVAL;
+
+	return onenand_block_checkbad(mtd, ofs, 1, 0);
+}
+
+/**
+ * onenand_default_block_markbad - [DEFAULT] mark a block bad
+ * @param mtd		MTD device structure
+ * @param ofs		offset from device start
+ *
+ * This is the default implementation, which can be overridden by
+ * a hardware specific driver.
+ */
+static int onenand_default_block_markbad(struct mtd_info *mtd, loff_t ofs)
+{
+	struct onenand_chip *this = mtd->priv;
+	struct bbm_info *bbm = this->bbm;
+	u_char buf[2] = {0, 0};
+	size_t retlen;
+	int block;
+
+	/* Get block number */
+	block = ((int) ofs) >> bbm->bbt_erase_shift;
+        if (bbm->bbt)
+                bbm->bbt[block >> 2] |= 0x01 << ((block & 0x03) << 1);
+
+        /* We write two bytes, so we dont have to mess with 16 bit access */
+        ofs += mtd->oobsize + (bbm->badblockpos & ~0x01);
+        return mtd->write_oob(mtd, ofs , 2, &retlen, buf);
 }
 
 /**
  * onenand_block_markbad - [MTD Interface] Mark the block at the given offset as bad
  * @param mtd		MTD device structure
  * @param ofs		offset relative to mtd start
+ *
+ * Mark the block as bad
  */
 static int onenand_block_markbad(struct mtd_info *mtd, loff_t ofs)
 {
-	/* see above */
-	return 0;
+	struct onenand_chip *this = mtd->priv;
+	int ret;
+
+	ret = onenand_block_isbad(mtd, ofs);
+	if (ret) {
+		/* If it was bad already, return success and do nothing */
+		if (ret > 0)
+			return 0;
+		return ret;
+	}
+
+	return this->block_markbad(mtd, ofs);
 }
 
 /**
@@ -1411,6 +1473,11 @@ int onenand_scan(struct mtd_info *mtd, int maxchips)
 	if (!this->write_bufferram)
 		this->write_bufferram = onenand_write_bufferram;
 
+	if (!this->block_markbad)
+		this->block_markbad = onenand_default_block_markbad;
+	if (!this->scan_bbt)
+		this->scan_bbt = onenand_default_bbt;
+
 	if (onenand_probe(mtd))
 		return -ENXIO;
 
@@ -1472,7 +1539,7 @@ int onenand_scan(struct mtd_info *mtd, int maxchips)
 	/* Unlock whole block */
 	mtd->unlock(mtd, 0x0, this->chipsize);
 
-	return 0;
+	return this->scan_bbt(mtd);
 }
 
 /**

include/linux/mtd/onenand.h

@@ -14,6 +14,7 @@
 
 #include <linux/spinlock.h>
 #include <linux/mtd/onenand_regs.h>
+#include <linux/mtd/bbm.h>
 
 #define MAX_BUFFERRAM		2
 
@@ -67,10 +68,14 @@ struct onenand_bufferram {
  * @param wait		[REPLACEABLE] hardware specific function for wait on ready
  * @param read_bufferram	[REPLACEABLE] hardware specific function for BufferRAM Area
  * @param write_bufferram	[REPLACEABLE] hardware specific function for BufferRAM Area
+ * @param read_word	[REPLACEABLE] hardware specific function for read register of OneNAND
+ * @param write_word	[REPLACEABLE] hardware specific function for write register of OneNAND
+ * @param scan_bbt	[REPLACEALBE] hardware specific function for scaning Bad block Table
  * @param chip_lock	[INTERN] spinlock used to protect access to this structure and the chip
  * @param wq		[INTERN] wait queue to sleep on if a OneNAND operation is in progress
  * @param state		[INTERN] the current state of the OneNAND device
  * @param autooob	[REPLACEABLE] the default (auto)placement scheme
+ * @param bbm		[REPLACEABLE] pointer to Bad Block Management 
  * @param priv		[OPTIONAL] pointer to private chip date
  */
 struct onenand_chip {
@@ -96,6 +101,8 @@ struct onenand_chip {
 	unsigned short (*read_word)(void __iomem *addr);
 	void (*write_word)(unsigned short value, void __iomem *addr);
 	void (*mmcontrol)(struct mtd_info *mtd, int sync_read);
+	int (*block_markbad)(struct mtd_info *mtd, loff_t ofs);
+	int (*scan_bbt)(struct mtd_info *mtd);
 
 	spinlock_t		chip_lock;
 	wait_queue_head_t	wq;
@@ -103,6 +110,8 @@ struct onenand_chip {
 
 	struct nand_oobinfo	*autooob;
 
+	void 			*bbm;
+
 	void			*priv;
 };