[MTD] NAND Modularize read function

Split the core of the read function out and implement
seperate handling functions for software and hardware
ECC.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

drivers/mtd/nand/diskonchip.c

@@ -968,12 +968,14 @@ static int doc200x_calculate_ecc(struct mtd_info *mtd, const u_char *dat, unsign
 	return 0;
 }
 
-static int doc200x_correct_data(struct mtd_info *mtd, u_char *dat, u_char *read_ecc, u_char *calc_ecc)
+static int doc200x_correct_data(struct mtd_info *mtd, u_char *dat,
+				u_char *read_ecc, u_char *isnull)
 {
 	int i, ret = 0;
 	struct nand_chip *this = mtd->priv;
 	struct doc_priv *doc = this->priv;
 	void __iomem *docptr = doc->virtadr;
+	uint8_t calc_ecc[6];
 	volatile u_char dummy;
 	int emptymatch = 1;
 

drivers/mtd/nand/rtc_from4.c

@@ -444,7 +444,8 @@ static int rtc_from4_correct_data(struct mtd_info *mtd, const u_char *buf, u_cha
  * note: see pages 34..37 of data sheet for details.
  *
  */
-static int rtc_from4_errstat(struct mtd_info *mtd, struct nand_chip *this, int state, int status, int page)
+static int rtc_from4_errstat(struct mtd_info *mtd, struct nand_chip *this,
+			     int state, int status, int page)
 {
 	int er_stat = 0;
 	int rtn, retlen;
@@ -455,39 +456,50 @@ static int rtc_from4_errstat(struct mtd_info *mtd, struct nand_chip *this, int s
 	this->cmdfunc(mtd, NAND_CMD_STATUS_CLEAR, -1, -1);
 
 	if (state == FL_ERASING) {
+
 		for (i = 0; i < 4; i++) {
-			if (status & 1 << (i + 1)) {
-				this->cmdfunc(mtd, (NAND_CMD_STATUS_ERROR + i + 1), -1, -1);
-				rtn = this->read_byte(mtd);
-				this->cmdfunc(mtd, NAND_CMD_STATUS_RESET, -1, -1);
-				if (!(rtn & ERR_STAT_ECC_AVAILABLE)) {
-					er_stat |= 1 << (i + 1);	/* err_ecc_not_avail */
-				}
-			}
+			if (!(status & 1 << (i + 1)))
+				continue;
+			this->cmdfunc(mtd, (NAND_CMD_STATUS_ERROR + i + 1),
+				      -1, -1);
+			rtn = this->read_byte(mtd);
+			this->cmdfunc(mtd, NAND_CMD_STATUS_RESET, -1, -1);
+
+			/* err_ecc_not_avail */
+			if (!(rtn & ERR_STAT_ECC_AVAILABLE))
+				er_stat |= 1 << (i + 1);
 		}
+
 	} else if (state == FL_WRITING) {
+
+		unsigned long corrected = mtd->ecc_stats.corrected;
+
 		/* single bank write logic */
 		this->cmdfunc(mtd, NAND_CMD_STATUS_ERROR, -1, -1);
 		rtn = this->read_byte(mtd);
 		this->cmdfunc(mtd, NAND_CMD_STATUS_RESET, -1, -1);
+
 		if (!(rtn & ERR_STAT_ECC_AVAILABLE)) {
-			er_stat |= 1 << 1;	/* err_ecc_not_avail */
-		} else {
-			len = mtd->writesize;
-			buf = kmalloc(len, GFP_KERNEL);
-			if (!buf) {
-				printk(KERN_ERR "rtc_from4_errstat: Out of memory!\n");
-				er_stat = 1;	/* if we can't check, assume failed */
-			} else {
-				/* recovery read */
-				/* page read */
-				rtn = nand_do_read_ecc(mtd, page, len, &retlen, buf, NULL, this->autooob, 1);
-				if (rtn) {	/* if read failed or > 1-bit error corrected */
-					er_stat |= 1 << 1;	/* ECC read failed */
-				}
-				kfree(buf);
-			}
+			/* err_ecc_not_avail */
+			er_stat |= 1 << 1;
+			goto out;
 		}
+
+		len = mtd->writesize;
+		buf = kmalloc(len, GFP_KERNEL);
+		if (!buf) {
+			printk(KERN_ERR "rtc_from4_errstat: Out of memory!\n");
+			er_stat = 1;
+			goto out;
+		}
+
+		/* recovery read */
+		rtn = nand_do_read(mtd, page, len, &retlen, buf);
+
+		/* if read failed or > 1-bit error corrected */
+		if (rtn || (mtd->ecc_stats.corrected - corrected) > 1) {
+			er_stat |= 1 << 1;
+		kfree(buf);
 	}
 
 	rtn = status;

include/linux/mtd/nand.h

@@ -479,14 +479,14 @@ struct nand_bbt_descr {
 /* The maximum number of blocks to scan for a bbt */
 #define NAND_BBT_SCAN_MAXBLOCKS	4
 
-extern int nand_scan_bbt (struct mtd_info *mtd, struct nand_bbt_descr *bd);
-extern int nand_update_bbt (struct mtd_info *mtd, loff_t offs);
-extern int nand_default_bbt (struct mtd_info *mtd);
-extern int nand_isbad_bbt (struct mtd_info *mtd, loff_t offs, int allowbbt);
-extern int nand_erase_nand (struct mtd_info *mtd, struct erase_info *instr, int allowbbt);
-extern int nand_do_read_ecc (struct mtd_info *mtd, loff_t from, size_t len,
-			     size_t * retlen, uint8_t * buf, uint8_t * oob_buf,
-			     struct nand_oobinfo *oobsel, int flags);
+extern int nand_scan_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd);
+extern int nand_update_bbt(struct mtd_info *mtd, loff_t offs);
+extern int nand_default_bbt(struct mtd_info *mtd);
+extern int nand_isbad_bbt(struct mtd_info *mtd, loff_t offs, int allowbbt);
+extern int nand_erase_nand(struct mtd_info *mtd, struct erase_info *instr,
+			   int allowbbt);
+extern int nand_do_read(struct mtd_info *mtd, loff_t from, size_t len,
+			size_t * retlen, uint8_t * buf);
 
 /*
 * Constants for oob configuration