From cc77f36d2ea812027dc2a8a94c788c4c145f82dc Mon Sep 17 00:00:00 2001
From: John Crispin <blogic@openwrt.org>
Date: Mon, 22 Oct 2012 10:25:39 +0200
Subject: [PATCH 33/40] MTD: lantiq: xway: make nand actually work

http://lists.infradead.org/pipermail/linux-mtd/2012-September/044240.html

Signed-off-by: John Crispin <blogic@openwrt.org>
---
 drivers/mtd/nand/xway_nand.c |   54 +++++++++++++++++++++++++++++++++++-------
 1 file changed, 45 insertions(+), 9 deletions(-)

--- a/drivers/mtd/nand/xway_nand.c
+++ b/drivers/mtd/nand/xway_nand.c
@@ -54,19 +54,29 @@
 #define NAND_CON_CSMUX		(1 << 1)
 #define NAND_CON_NANDM		1
 
+static u32 xway_latchcmd;
+
 static void xway_reset_chip(struct nand_chip *chip)
 {
 	unsigned long nandaddr = (unsigned long) chip->IO_ADDR_W;
 	unsigned long flags;
+	unsigned long timeout;
 
 	nandaddr &= ~NAND_WRITE_ADDR;
 	nandaddr |= NAND_WRITE_CMD;
 
 	/* finish with a reset */
+	timeout = jiffies + msecs_to_jiffies(200);
+
 	spin_lock_irqsave(&ebu_lock, flags);
+
 	writeb(NAND_WRITE_CMD_RESET, (void __iomem *) nandaddr);
-	while ((ltq_ebu_r32(EBU_NAND_WAIT) & NAND_WAIT_WR_C) == 0)
-		;
+	do {
+		if ((ltq_ebu_r32(EBU_NAND_WAIT) & NAND_WAIT_WR_C) == 0)
+			break;
+		cond_resched();
+	} while (!time_after_eq(jiffies, timeout));
+
 	spin_unlock_irqrestore(&ebu_lock, flags);
 }
 
@@ -94,17 +104,15 @@ static void xway_cmd_ctrl(struct mtd_inf
 	unsigned long flags;
 
 	if (ctrl & NAND_CTRL_CHANGE) {
-		nandaddr &= ~(NAND_WRITE_CMD | NAND_WRITE_ADDR);
 		if (ctrl & NAND_CLE)
-			nandaddr |= NAND_WRITE_CMD;
-		else
-			nandaddr |= NAND_WRITE_ADDR;
-		this->IO_ADDR_W = (void __iomem *) nandaddr;
+			xway_latchcmd = NAND_WRITE_CMD;
+		else if (ctrl & NAND_ALE)
+			xway_latchcmd = NAND_WRITE_ADDR;
 	}
 
 	if (cmd != NAND_CMD_NONE) {
 		spin_lock_irqsave(&ebu_lock, flags);
-		writeb(cmd, this->IO_ADDR_W);
+		writeb(cmd, (void __iomem *) (nandaddr | xway_latchcmd));
 		while ((ltq_ebu_r32(EBU_NAND_WAIT) & NAND_WAIT_WR_C) == 0)
 			;
 		spin_unlock_irqrestore(&ebu_lock, flags);
@@ -124,12 +132,38 @@ static unsigned char xway_read_byte(stru
 	int ret;
 
 	spin_lock_irqsave(&ebu_lock, flags);
-	ret = ltq_r8((void __iomem *)(nandaddr + NAND_READ_DATA));
+	ret = ltq_r8((void __iomem *)(nandaddr | NAND_READ_DATA));
 	spin_unlock_irqrestore(&ebu_lock, flags);
 
 	return ret;
 }
 
+static void xway_read_buf(struct mtd_info *mtd, u_char *buf, int len)
+{
+	struct nand_chip *this = mtd->priv;
+	unsigned long nandaddr = (unsigned long) this->IO_ADDR_R;
+	unsigned long flags;
+	int i;
+
+	spin_lock_irqsave(&ebu_lock, flags);
+	for (i = 0; i < len; i++)
+		buf[i] = ltq_r8((void __iomem *)(nandaddr | NAND_READ_DATA));
+	spin_unlock_irqrestore(&ebu_lock, flags);
+}
+
+static void xway_write_buf(struct mtd_info *mtd, const u_char *buf, int len)
+{
+	struct nand_chip *this = mtd->priv;
+	unsigned long nandaddr = (unsigned long) this->IO_ADDR_W;
+	unsigned long flags;
+	int i;
+
+	spin_lock_irqsave(&ebu_lock, flags);
+	for (i = 0; i < len; i++)
+		ltq_w8(buf[i], (void __iomem *)nandaddr);
+	spin_unlock_irqrestore(&ebu_lock, flags);
+}
+
 static int xway_nand_probe(struct platform_device *pdev)
 {
 	struct nand_chip *this = platform_get_drvdata(pdev);
@@ -175,6 +209,8 @@ static struct platform_nand_data xway_na
 		.dev_ready	= xway_dev_ready,
 		.select_chip	= xway_select_chip,
 		.read_byte	= xway_read_byte,
+		.read_buf	= xway_read_buf,
+		.write_buf	= xway_write_buf,
 	}
 };