[U-Boot] [PATCH ARM] Update the s3c2410 nand driver from linux-2.6.31.5

[kevin.morfitt at fearnside-systems.co.uk <kevin.morfitt@fearnside-systems.co.uk>]

This patch updates the s3c2410 nand driver from that of linux 2.6.31.5, 
modified to make it work in the u-boot mtd nand architecture and to allow
setting the flash timing parameters from a board config file instead of
being hard coded. Note that this modified driver supports s3c2410 and 
s3c2440.

Signed-off-by: Kevin Morfitt <kevin.morfitt@fearnside-systems.co.uk>
---

checkpatch.pl shows no errors or warnings, and MAKEALL ARM9 shows no new
errors or warnings.

Tested on an Embest SBC2440-II Board with local s3c2440 patches as I don't
have an s3c2410 board.

 drivers/mtd/nand/s3c2410_nand.c        |  134 +++++++++++++++++--------------
 include/asm-arm/arch-s3c24x0/s3c2410.h |   25 ++++++
 2 files changed, 98 insertions(+), 61 deletions(-)

diff --git a/drivers/mtd/nand/s3c2410_nand.c b/drivers/mtd/nand/s3c2410_nand.c
index 9f02dd8..7d3f79d 100644
--- a/drivers/mtd/nand/s3c2410_nand.c
+++ b/drivers/mtd/nand/s3c2410_nand.c
@@ -2,6 +2,10 @@
  * (C) Copyright 2006 OpenMoko, Inc.
  * Author: Harald Welte <laforge@openmoko.org>
  *
+ * Modified to add S3C2440 support by
+ * (C) Copyright 2009
+ * Kevin Morfitt, Fearnside Systems Ltd, <kevin.morfitt@fearnside-systems.co.uk>
+ *
  * 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 the Free Software Foundation; either version 2 of
@@ -21,48 +25,53 @@
 #include <common.h>
 
 #include <nand.h>
+#include <linux/mtd/nand_ecc.h>
 #include <asm/arch/s3c2410.h>
 #include <asm/io.h>
 
-#define S3C2410_NFCONF_EN          (1<<15)
-#define S3C2410_NFCONF_512BYTE     (1<<14)
-#define S3C2410_NFCONF_4STEP       (1<<13)
-#define S3C2410_NFCONF_INITECC     (1<<12)
-#define S3C2410_NFCONF_nFCE        (1<<11)
-#define S3C2410_NFCONF_TACLS(x)    ((x)<<8)
-#define S3C2410_NFCONF_TWRPH0(x)   ((x)<<4)
-#define S3C2410_NFCONF_TWRPH1(x)   ((x)<<0)
+#if defined(CONFIG_S3C2410_NAND_HWECC) && defined(CONFIG_SYS_NAND_LARGEPAGE)
+/* new oob placement block for use with hardware ecc generation
+ */
+static struct nand_ecclayout nand_hw_eccoob = {
+	.eccbytes = 3,
+	.eccpos = {0, 1, 2},
+	.oobfree = { {8, 8} }
+};
+#endif
 
-#define S3C2410_ADDR_NALE 4
-#define S3C2410_ADDR_NCLE 8
+static void s3c2410_nand_select_chip(struct mtd_info *mtd, int chip)
+{
+	struct s3c2410_nand *nand = s3c2410_get_base_nand();
+	unsigned long reg = readl(&nand->S3C24X0_NAND_CTRL_REG);
+
+	if (chip == -1) {
+		debugX(1, "Negating nFCE\n");
+		reg |= S3C24X0_NAND_nFCE_BIT;
+	} else {
+		debugX(1, "Asserting nFCE\n");
+		reg &= ~S3C24X0_NAND_nFCE_BIT;
+	}
+	writel(reg, &nand->S3C24X0_NAND_CTRL_REG);
+}
 
 static void s3c2410_hwcontrol(struct mtd_info *mtd, int cmd, unsigned int ctrl)
 {
-	struct nand_chip *chip = mtd->priv;
 	struct s3c2410_nand *nand = s3c2410_get_base_nand();
 
 	debugX(1, "hwcontrol(): 0x%02x 0x%02x\n", cmd, ctrl);
 
-	if (ctrl & NAND_CTRL_CHANGE) {
-		ulong IO_ADDR_W = (ulong)nand;
-
-		if (!(ctrl & NAND_CLE))
-			IO_ADDR_W |= S3C2410_ADDR_NCLE;
-		if (!(ctrl & NAND_ALE))
-			IO_ADDR_W |= S3C2410_ADDR_NALE;
-
-		chip->IO_ADDR_W = (void *)IO_ADDR_W;
+	if (cmd == NAND_CMD_NONE)
+		return;
 
-		if (ctrl & NAND_NCE)
-			writel(readl(&nand->NFCONF) & ~S3C2410_NFCONF_nFCE,
-			       &nand->NFCONF);
-		else
-			writel(readl(&nand->NFCONF) | S3C2410_NFCONF_nFCE,
-			       &nand->NFCONF);
+	if (ctrl & NAND_CLE) {
+		debugX(1, "NFCMD = 0x%08X\n", cmd);
+		writel(cmd, &nand->NFCMD);
 	}
 
-	if (cmd != NAND_CMD_NONE)
-		writeb(cmd, chip->IO_ADDR_W);
+	if (ctrl & NAND_ALE) {
+		debugX(1, "NFADDR = 0x%08X\n", cmd);
+		writel(cmd, &nand->NFADDR);
+	}
 }
 
 static int s3c2410_dev_ready(struct mtd_info *mtd)
@@ -76,39 +85,32 @@ static int s3c2410_dev_ready(struct mtd_info *mtd)
 void s3c2410_nand_enable_hwecc(struct mtd_info *mtd, int mode)
 {
 	struct s3c2410_nand *nand = s3c2410_get_base_nand();
+	unsigned long reg = readl(&nand->S3C24X0_NAND_CTRL_REG);
+
 	debugX(1, "s3c2410_nand_enable_hwecc(%p, %d)\n", mtd, mode);
-	writel(readl(&nand->NFCONF) | S3C2410_NFCONF_INITECC, &nand->NFCONF);
+	reg |= S3C24X0_NAND_INITECC_BIT;
+	writel(reg, &nand->S3C24X0_NAND_CTRL_REG);
 }
 
 static int s3c2410_nand_calculate_ecc(struct mtd_info *mtd, const u_char *dat,
 				      u_char *ecc_code)
 {
-	ecc_code[0] = NFECC0;
-	ecc_code[1] = NFECC1;
-	ecc_code[2] = NFECC2;
+	struct s3c2410_nand *nand = s3c2410_get_base_nand();
+	unsigned long ecc = readl(&nand->S3C24X0_NAND_ECC_REG);
+
+	ecc_code[0] = ecc;
+	ecc_code[1] = ecc >> 8;
+	ecc_code[2] = ecc >> 16;
 	debugX(1, "s3c2410_nand_calculate_hwecc(%p,): 0x%02x 0x%02x 0x%02x\n",
-	       mtd , ecc_code[0], ecc_code[1], ecc_code[2]);
+	       mtd, ecc_code[0], ecc_code[1], ecc_code[2]);
 
 	return 0;
 }
-
-static int s3c2410_nand_correct_data(struct mtd_info *mtd, u_char *dat,
-				     u_char *read_ecc, u_char *calc_ecc)
-{
-	if (read_ecc[0] == calc_ecc[0] &&
-	    read_ecc[1] == calc_ecc[1] &&
-	    read_ecc[2] == calc_ecc[2])
-		return 0;
-
-	printf("s3c2410_nand_correct_data: not implemented\n");
-	return -1;
-}
 #endif
 
 int board_nand_init(struct nand_chip *nand)
 {
-	u_int32_t cfg;
-	u_int8_t tacls, twrph0, twrph1;
+	unsigned long reg;
 	struct s3c24x0_clock_power *clk_power = s3c24x0_get_base_clock_power();
 	struct s3c2410_nand *nand_reg = s3c2410_get_base_nand();
 
@@ -117,15 +119,12 @@ int board_nand_init(struct nand_chip *nand)
 	writel(readl(&clk_power->CLKCON) | (1 << 4), &clk_power->CLKCON);
 
 	/* initialize hardware */
-	twrph0 = 3;
-	twrph1 = 0;
-	tacls = 0;
-
-	cfg = S3C2410_NFCONF_EN;
-	cfg |= S3C2410_NFCONF_TACLS(tacls - 1);
-	cfg |= S3C2410_NFCONF_TWRPH0(twrph0 - 1);
-	cfg |= S3C2410_NFCONF_TWRPH1(twrph1 - 1);
-	writel(cfg, &nand_reg->NFCONF);
+	reg = S3C24X0_NAND_TACLS_BITS(CONFIG_SYS_NAND_TACLS);
+	reg |= S3C24X0_NAND_TWRPH0_BITS(CONFIG_SYS_NAND_TWRPH0);
+	reg |= S3C24X0_NAND_TWRPH1_BITS(CONFIG_SYS_NAND_TWRPH1);
+	writel(reg, &nand_reg->S3C24X0_NAND_TIMING_REG);
+	reg = S3C24X0_NAND_EN_BIT | S3C24X0_NAND_nFCE_BIT;
+	writel(reg, &nand_reg->S3C24X0_NAND_CTRL_REG);
 
 	/* initialize nand_chip data structure */
 	nand->IO_ADDR_R = nand->IO_ADDR_W = (void *)&nand_reg->NFDATA;
@@ -133,16 +132,29 @@ int board_nand_init(struct nand_chip *nand)
 	/* read_buf and write_buf are default */
 	/* read_byte and write_byte are default */
 
+	nand->select_chip = s3c2410_nand_select_chip;
+	nand->chip_delay = 50;
+
 	/* hwcontrol always must be implemented */
 	nand->cmd_ctrl = s3c2410_hwcontrol;
-
 	nand->dev_ready = s3c2410_dev_ready;
 
 #ifdef CONFIG_S3C2410_NAND_HWECC
-	nand->ecc.hwctl = s3c2410_nand_enable_hwecc;
-	nand->ecc.calculate = s3c2410_nand_calculate_ecc;
-	nand->ecc.correct = s3c2410_nand_correct_data;
-	nand->ecc.mode = NAND_ECC_HW3_512;
+	nand->ecc.correct    = nand_correct_data;
+	nand->ecc.hwctl      = s3c2410_nand_enable_hwecc;
+	nand->ecc.calculate  = s3c2410_nand_calculate_ecc;
+	nand->ecc.mode = NAND_ECC_HW;
+	/* change the behaviour depending on whether we are using
+	 * the large or small page nand device */
+#ifdef CONFIG_SYS_NAND_LARGEPAGE
+	nand->ecc.size    = 512;
+	nand->ecc.bytes   = 3;
+	nand->ecc.layout  = &nand_hw_eccoob;
+#else
+	nand->ecc.size    = 256;
+	nand->ecc.bytes   = 3;
+#endif
+	debugX(2, "ecc: size: %d bytes: %d\n", nand->ecc.size, nand->ecc.bytes);
 #else
 	nand->ecc.mode = NAND_ECC_SOFT;
 #endif
diff --git a/include/asm-arm/arch-s3c24x0/s3c2410.h b/include/asm-arm/arch-s3c24x0/s3c2410.h
index 0543fe1..591dd39 100644
--- a/include/asm-arm/arch-s3c24x0/s3c2410.h
+++ b/include/asm-arm/arch-s3c24x0/s3c2410.h
@@ -160,4 +160,29 @@ static inline struct s3c2410_sdi *s3c2410_get_base_sdi(void)
 	return (struct s3c2410_sdi *)S3C2410_SDI_BASE;
 }
 
+/* Define the registers and bits to use to operate the NAND flash controller. */
+
+/* The NAND control register, */
+#define S3C24X0_NAND_CTRL_REG		NFCONF
+/* NAND Enable/disable bit. */
+#define S3C24X0_NAND_EN_BIT		(1 << 15)
+/* NAND CE enable/disable bit, */
+#define S3C24X0_NAND_nFCE_BIT		(1 << 11)
+/* NAND init ECC bit. */
+#define S3C24X0_NAND_INITECC_BIT	(1 << 12)
+
+/* The NAND timimg register. */
+#define S3C24X0_NAND_TIMING_REG		NFCONF
+/* NAND TACLS field. */
+#define S3C24X0_NAND_TACLS_BITS(x)	((x) << 8)
+/* NAND TWRPH0 field. */
+#define S3C24X0_NAND_TWRPH0_BITS(x)	((x) << 4)
+/* NAND TWRPH1 field. */
+#define S3C24X0_NAND_TWRPH1_BITS(x)	((x) << 0)
+
+/* The NAND ECC register. */
+#define S3C24X0_NAND_ECC_REG		NFECC
+/* NAND INIT ECC bit. */
+#define S3C24X0_NAND_INITECC_BIT	(1 << 12)
+
 #endif /*__S3C2410_H__*/
-- 
1.6.0.6