1 files changed, 89 insertions, 5 deletions

diff --git a/drivers/mtd/nand/rtc_from4.c b/drivers/mtd/nand/rtc_from4.c
index a4d8d2e62e9e..031051cbde76 100644
--- a/drivers/mtd/nand/rtc_from4.c
+++ b/drivers/mtd/nand/rtc_from4.c
@@ -6,7 +6,7 @@
  *  Derived from drivers/mtd/nand/spia.c
  *       Copyright (C) 2000 Steven J. Hill (sjhill@realitydiluted.com)
  *
- * $Id: rtc_from4.c,v 1.8 2005/01/17 19:44:36 dmarlin Exp $
+ * $Id: rtc_from4.c,v 1.9 2005/01/24 20:40:11 dmarlin Exp $
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
@@ -83,9 +83,14 @@ static struct mtd_info *rtc_from4_mtd = NULL;
 #define RTC_FROM4_RS_ECC_CHK            (RTC_FROM4_NAND_ADDR_FPGA | 0x00000070)
 #define RTC_FROM4_RS_ECC_CHK_ERROR      (1 << 7)
 
+#define ERR_STAT_ECC_AVAILABLE          0x20
+
 /* Undefine for software ECC */
 #define RTC_FROM4_HWECC 1
 
+/* Define as 1 for no virtual erase blocks (in JFFS2) */
+#define RTC_FROM4_NO_VIRTBLOCKS 0
+
 /*
  * Module stuff
  */
@@ -267,7 +272,6 @@ static void rtc_from4_nand_select_chip(struct mtd_info *mtd, int chip)
 }
 
 
-
 /*
  * rtc_from4_nand_device_ready - hardware specific ready/busy check
  * @mtd:        MTD device structure
@@ -363,6 +367,7 @@ static void rtc_from4_enable_hwecc(struct mtd_info *mtd, int mode)
 
 }
 
+
 /*
  * rtc_from4_calculate_ecc - hardware specific code to read ECC code
  * @mtd:        MTD device structure
@@ -390,6 +395,7 @@ static void rtc_from4_calculate_ecc(struct mtd_info *mtd, const u_char *dat, u_c
         ecc_code[7] |= 0x0f;    /* set the last four bits (not used) */
 }
 
+
 /*
  * rtc_from4_correct_data - hardware specific code to correct data using ECC code
  * @mtd:        MTD device structure
@@ -399,10 +405,8 @@ static void rtc_from4_calculate_ecc(struct mtd_info *mtd, const u_char *dat, u_c
  *
  * The FPGA tells us fast, if there's an error or not. If no, we go back happy
  * else we read the ecc results from the fpga and call the rs library to decode
- * and hopefully correct the error
+ * and hopefully correct the error.
  *
- * For now I use the code, which we read from the FLASH to use the RS lib,
- * as the syndrom conversion has a unresolved issue.
  */
 static int rtc_from4_correct_data(struct mtd_info *mtd, const u_char *buf, u_char *ecc1, u_char *ecc2)
 {
@@ -457,8 +461,79 @@ static int rtc_from4_correct_data(struct mtd_info *mtd, const u_char *buf, u_cha
         }
         return res;
 }
+
+
+/**
+ * rtc_from4_errstat - perform additional error status checks
+ * @mtd:        MTD device structure
+ * @this:       NAND chip structure
+ * @state:      state or the operation
+ * @status:     status code returned from read status
+ * @page:       startpage inside the chip, must be called with (page & this->pagemask)
+ * 
+ * Perform additional error status checks on erase and write failures 
+ * to determine if errors are correctable.  For this device, correctable 
+ * 1-bit errors on erase and write are considered acceptable.
+ *
+ * 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)
+{
+        int     er_stat=0;
+        int     rtn, retlen;
+        size_t  len;
+        uint8_t *buf;
+        int     i;
+
+        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 */
+                                }
+                        }
+                }
+        } else if (state == FL_WRITING) {
+                /* 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->oobblock;
+                        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);
+                        }
+                }
+        }
+
+        rtn = status;
+        if (er_stat == 0) {                             /* if ECC is available   */
+                rtn = (status & ~NAND_STATUS_FAIL);     /*   clear the error bit */
+        }
+
+        return rtn;
+}
 #endif
 
+
 /*
  * Main initialization routine
  */
@@ -518,6 +593,8 @@ int __init rtc_from4_init (void)
 
         this->eccmode = NAND_ECC_HW8_512;
         this->options |= NAND_HWECC_SYNDROME;
+        /* return the status of extra status and ECC checks */
+        this->errstat = rtc_from4_errstat;
         /* set the nand_oobinfo to support FPGA H/W error detection */
         this->autooob = &rtc_from4_nand_oobinfo;
         this->enable_hwecc = rtc_from4_enable_hwecc;
@@ -544,6 +621,13 @@ int __init rtc_from4_init (void)
                 deplete(rtc_from4_mtd, i);
         }
 
+#if RTC_FROM4_NO_VIRTBLOCKS
+        /* use a smaller erase block to minimize wasted space when a block is bad */
+        /* note: this uses eight times as much RAM as using the default and makes */
+        /*       mounts take four times as long. */
+        rtc_from4_mtd->flags |= MTD_NO_VIRTBLOCKS;
+#endif
+
         /* Register the partitions */
         add_mtd_partitions(rtc_from4_mtd, partition_info, NUM_PARTITIONS);