[MTD NAND] Update CS553x NAND driver: Hardware ECC support, optimisations.

- Implement HW ECC support,
- Provide read_buf() and write_buf() routines using memcpy
- Use on-flash bad block table
- Fix module refcounting
- Avoid read/modify/write in hwcontrol()
- Minor cosmetic fixes

Partly based on code and ideas from Tom Sylla <tom.sylla@amd.com>

Signed-off-by: David Woodhouse <dwmw2@infradead.org>

1 files changed, 75 insertions, 27 deletions

diff --git a/drivers/mtd/nand/cs553x_nand.c b/drivers/mtd/nand/cs553x_nand.c
index 91207a45ad55..4f0b338f2f30 100644
--- a/drivers/mtd/nand/cs553x_nand.c
+++ b/drivers/mtd/nand/cs553x_nand.c
@@ -4,6 +4,7 @@
  * (C) 2005, 2006 Red Hat Inc.
  *
  * Author: David Woodhouse <dwmw2@infradead.org>
+ *         Tom Sylla <tom.sylla@amd.com>
  *
  * 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
@@ -22,6 +23,7 @@
 #include <linux/pci.h>
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/nand.h>
+#include <linux/mtd/nand_ecc.h>
 #include <linux/mtd/partitions.h>
 
 #include <asm/msr.h>
@@ -87,11 +89,34 @@
 #define CS_NAND_ECC_CLRECC      (1<<1)
 #define CS_NAND_ECC_ENECC       (1<<0)
 
+static void cs553x_read_buf(struct mtd_info *mtd, u_char *buf, int len)
+{
+        struct nand_chip *this = mtd->priv;
+
+        while (unlikely(len > 0x800)) {
+                memcpy_fromio(buf, this->IO_ADDR_R, 0x800);
+                buf += 0x800;
+                len -= 0x800;
+        }
+        memcpy_fromio(buf, this->IO_ADDR_R, len);
+}
+
+static void cs553x_write_buf(struct mtd_info *mtd, const u_char *buf, int len)
+{
+        struct nand_chip *this = mtd->priv;
+
+        while (unlikely(len > 0x800)) {
+                memcpy_toio(this->IO_ADDR_R, buf, 0x800);
+                buf += 0x800;
+                len -= 0x800;
+        }
+        memcpy_toio(this->IO_ADDR_R, buf, len);
+}
+
 static unsigned char cs553x_read_byte(struct mtd_info *mtd)
 {
         struct nand_chip *this = mtd->priv;
-        unsigned char foo = readb(this->IO_ADDR_R);
-        return foo;
+        return readb(this->IO_ADDR_R);
 }
 
 static void cs553x_write_byte(struct mtd_info *mtd, u_char byte)
@@ -110,35 +135,29 @@ static void cs553x_hwcontrol(struct mtd_info *mtd, int cmd)
 {
         struct nand_chip *this = mtd->priv;
         void __iomem *mmio_base = this->IO_ADDR_R;
-
-        uint8_t old = readb(mmio_base + MM_NAND_CTL);
+        unsigned char ctl;
 
         switch(cmd) {
         case NAND_CTL_SETCLE:
-                old |= CS_NAND_CTL_CLE;
+                ctl = CS_NAND_CTL_CLE;
                 break;
 
         case NAND_CTL_CLRCLE:
-                old &= ~CS_NAND_CTL_CLE;
-                break;
-
-        case NAND_CTL_SETALE:
-                old |= CS_NAND_CTL_ALE;
-                break;
-
         case NAND_CTL_CLRALE:
-                old &= ~CS_NAND_CTL_ALE;
+        case NAND_CTL_SETNCE:
+                ctl = 0;
                 break;
 
-        case NAND_CTL_SETNCE:
-                old &= ~CS_NAND_CTL_CE;
+        case NAND_CTL_SETALE:
+                ctl = CS_NAND_CTL_ALE;
                 break;
 
+        default:
         case NAND_CTL_CLRNCE:
-                old |= CS_NAND_CTL_CE;
+                ctl = CS_NAND_CTL_CE;
                 break;
         }
-        writeb(old, mmio_base + MM_NAND_CTL);
+        writeb(ctl, mmio_base + MM_NAND_CTL);
 }
 
 
@@ -151,6 +170,29 @@ static int cs553x_device_ready(struct mtd_info *mtd)
         return (foo & CS_NAND_STS_FLASH_RDY) && !(foo & CS_NAND_CTLR_BUSY); 
 }
 
+
+static void cs_enable_hwecc(struct mtd_info *mtd, int mode)
+{
+        struct nand_chip *this = mtd->priv;
+        void __iomem *mmio_base = this->IO_ADDR_R;
+
+        writeb(0x07, mmio_base + MM_NAND_ECC_CTL);
+}
+
+static int cs_calculate_ecc(struct mtd_info *mtd, const u_char *dat, u_char *ecc_code)
+{
+        uint32_t ecc;
+        struct nand_chip *this = mtd->priv;
+        void __iomem *mmio_base = this->IO_ADDR_R;
+
+        ecc = readl(mmio_base + MM_NAND_STS);
+
+        ecc_code[1] = ecc >> 8;
+        ecc_code[0] = ecc >> 16;
+        ecc_code[2] = ecc >> 24;
+        return 0;
+}
+
 static struct mtd_info *cs553x_mtd[4];
 
 static int __init cs553x_init_one(int cs, int mmio, unsigned long adr)
@@ -167,7 +209,7 @@ static int __init cs553x_init_one(int cs, int mmio, unsigned long adr)
         }
 
         /* Allocate memory for MTD device structure and private data */
-        new_mtd = kmalloc (sizeof(struct mtd_info) + sizeof (struct nand_chip), GFP_KERNEL);
+        new_mtd = kmalloc(sizeof(struct mtd_info) + sizeof (struct nand_chip), GFP_KERNEL);
         if (!new_mtd) {
                 printk(KERN_WARNING "Unable to allocate CS553X NAND MTD device structure.\n");
                 err = -ENOMEM;
@@ -178,8 +220,8 @@ static int __init cs553x_init_one(int cs, int mmio, unsigned long adr)
         this = (struct nand_chip *) (&new_mtd[1]);
 
         /* Initialize structures */
-        memset((char *) new_mtd, 0, sizeof(struct mtd_info));
-        memset((char *) this, 0, sizeof(struct nand_chip));
+        memset(new_mtd, 0, sizeof(struct mtd_info));
+        memset(this, 0, sizeof(struct nand_chip));
 
         /* Link the private data with the MTD structure */
         new_mtd->priv = this;
@@ -196,27 +238,33 @@ static int __init cs553x_init_one(int cs, int mmio, unsigned long adr)
         this->dev_ready = cs553x_device_ready;
         this->read_byte = cs553x_read_byte;
         this->write_byte = cs553x_write_byte;
+        this->read_buf = cs553x_read_buf;
+        this->write_buf = cs553x_write_buf;
 
-        /* 20 us command delay time */
-        this->chip_delay = 20;
-        this->eccmode = NAND_ECC_SOFT;
+        this->chip_delay = 0;
 
+        this->eccmode = NAND_ECC_HW3_256;
+        this->enable_hwecc  = cs_enable_hwecc;
+        this->calculate_ecc = cs_calculate_ecc;
+        this->correct_data  = nand_correct_data;
+        
         /* Enable the following for a flash based bad block table */
-        //      this->options = NAND_USE_FLASH_BBT;
+        this->options = NAND_USE_FLASH_BBT | NAND_NO_AUTOINCR;
 
         /* Scan to find existance of the device */
-        if (nand_scan (new_mtd, 1)) {
+        if (nand_scan(new_mtd, 1)) {
                 err = -ENXIO;
                 goto out_ior;
         }
 
+        new_mtd->owner = THIS_MODULE;
         cs553x_mtd[cs] = new_mtd;
         goto out;
 
 out_ior:
         iounmap((void *)this->IO_ADDR_R);
 out_mtd:
-        kfree (new_mtd);
+        kfree(new_mtd);
 out:
         return err;
 }
@@ -283,7 +331,7 @@ static void __exit cs553x_cleanup (void)
                 iounmap(mmio_base);
 
                 /* Free the MTD device structure */
-                kfree (mtd);
+                kfree(mtd);
         }
 }
 module_exit(cs553x_cleanup);