[MTD] NAND s3c2410: Simplify command handling

Updated with tglx's suggestion to simply the command invocation by
simply changing the address of the IO write area

Signed-off-by: Ben Dooks <ben@simtec.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/drivers/mtd/nand/s3c2410.c b/drivers/mtd/nand/s3c2410.c
index cb04b3c..64b1d95 100644 (file)
--- a/drivers/mtd/nand/s3c2410.c
+++ b/drivers/mtd/nand/s3c2410.c
@@ -11,9 +11,10 @@
  *     23-Sep-2004  BJD  Mulitple device support
  *     28-Sep-2004  BJD  Fixed ECC placement for Hardware mode
  *     12-Oct-2004  BJD  Fixed errors in use of platform data
- *     18-Feb-2004  BJD  Fix sparse errors
+ *     18-Feb-2005  BJD  Fix sparse errors
+ *     14-Mar-2005  BJD  Applied tglx's code reduction patch
  *
- * $Id: s3c2410.c,v 1.8 2005/02/18 14:46:12 bjd Exp $
+ * $Id: s3c2410.c,v 1.12 2005/03/17 11:31:26 bjd Exp $
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -236,6 +237,7 @@ static void s3c2410_nand_select_chip(struct mtd_info *mtd, int chip)
 static void s3c2410_nand_hwcontrol(struct mtd_info *mtd, int cmd)
 {
        struct s3c2410_nand_info *info = s3c2410_nand_mtd_toinfo(mtd);
+       struct nand_chip *chip = mtd->priv;
        unsigned long cur;
 
        switch (cmd) {
@@ -251,117 +253,22 @@ static void s3c2410_nand_hwcontrol(struct mtd_info *mtd, int cmd)
                writel(cur, info->regs + S3C2410_NFCONF);
                break;
 
-               /* we don't need to implement these */
        case NAND_CTL_SETCLE:
-       case NAND_CTL_CLRCLE:
-       case NAND_CTL_SETALE:
-       case NAND_CTL_CLRALE:
-               pr_debug(PFX "s3c2410_nand_hwcontrol(%d) unusedn", cmd);
+               chip->IO_ADDR_W    = info->regs + S3C2410_NFCMD;
                break;
-       }
-}
-
-/* s3c2410_nand_command
- *
- * This function implements sending commands and the relevant address
- * information to the chip, via the hardware controller. Since the
- * S3C2410 generates the correct ALE/CLE signaling automatically, we
- * do not need to use hwcontrol.
-*/
-
-static void s3c2410_nand_command (struct mtd_info *mtd, unsigned command,
-                                 int column, int page_addr)
-{
-       register struct s3c2410_nand_info *info = s3c2410_nand_mtd_toinfo(mtd);
-       register struct nand_chip *this = mtd->priv;
-
-       /*
-        * Write out the command to the device.
-        */
-       if (command == NAND_CMD_SEQIN) {
-               int readcmd;
-
-               if (column >= mtd->oobblock) {
-                       /* OOB area */
-                       column -= mtd->oobblock;
-                       readcmd = NAND_CMD_READOOB;
-               } else if (column < 256) {
-                       /* First 256 bytes --> READ0 */
-                       readcmd = NAND_CMD_READ0;
-               } else {
-                       column -= 256;
-                       readcmd = NAND_CMD_READ1;
-               }
-               
-               writeb(readcmd, info->regs + S3C2410_NFCMD);
-       }
-       writeb(command, info->regs + S3C2410_NFCMD);
-
-       /* Set ALE and clear CLE to start address cycle */
 
-       if (column != -1 || page_addr != -1) {
+       case NAND_CTL_SETALE:
+               chip->IO_ADDR_W    = info->regs + S3C2410_NFADDR;
+               break;
 
-               /* Serially input address */
-               if (column != -1) {
-                       /* Adjust columns for 16 bit buswidth */
-                       if (this->options & NAND_BUSWIDTH_16)
-                               column >>= 1;
-                       writeb(column, info->regs + S3C2410_NFADDR);
-               }
-               if (page_addr != -1) {
-                       writeb((unsigned char) (page_addr), info->regs + S3C2410_NFADDR);
-                       writeb((unsigned char) (page_addr >> 8), info->regs + S3C2410_NFADDR);
-                       /* One more address cycle for higher density devices */
-                       if (this->chipsize & 0x0c000000) 
-                               writeb((unsigned char) ((page_addr >> 16) & 0x0f),
-                                      info->regs + S3C2410_NFADDR);
-               }
-               /* Latch in address */
-       }
-       
-       /* 
-        * program and erase have their own busy handlers 
-        * status and sequential in needs no delay
-       */
-       switch (command) {
-                       
-       case NAND_CMD_PAGEPROG:
-       case NAND_CMD_ERASE1:
-       case NAND_CMD_ERASE2:
-       case NAND_CMD_SEQIN:
-       case NAND_CMD_STATUS:
-               return;
-
-       case NAND_CMD_RESET:
-               if (this->dev_ready)    
-                       break;
-
-               udelay(this->chip_delay);
-               writeb(NAND_CMD_STATUS, info->regs + S3C2410_NFCMD);
-
-               while ( !(this->read_byte(mtd) & 0x40));
-               return;
-
-       /* This applies to read commands */     
+               /* NAND_CTL_CLRCLE: */
+               /* NAND_CTL_CLRALE: */
        default:
-               /* 
-                * If we don't have access to the busy pin, we apply the given
-                * command delay
-               */
-               if (!this->dev_ready) {
-                       udelay (this->chip_delay);
-                       return;
-               }       
+               chip->IO_ADDR_W    = info->regs + S3C2410_NFDATA;
+               break;
        }
-       
-       /* Apply this short delay always to ensure that we do wait tWB in
-        * any case on any machine. */
-       ndelay (100);
-       /* wait until command is processed */
-       while (!this->dev_ready(mtd));
 }
 
-
 /* s3c2410_nand_devready()
  *
  * returns 0 if the nand is busy, 1 if it is ready
@@ -529,7 +436,6 @@ static void s3c2410_nand_init_chip(struct s3c2410_nand_info *info,
        chip->IO_ADDR_W    = info->regs + S3C2410_NFDATA;
        chip->hwcontrol    = s3c2410_nand_hwcontrol;
        chip->dev_ready    = s3c2410_nand_devready;
-       chip->cmdfunc      = s3c2410_nand_command;
        chip->write_buf    = s3c2410_nand_write_buf;
        chip->read_buf     = s3c2410_nand_read_buf;
        chip->select_chip  = s3c2410_nand_select_chip;