Initial import

1 files changed, 515 insertions, 0 deletions

diff --git a/drivers/mtd/nand/au1550nd.c b/drivers/mtd/nand/au1550nd.c
new file mode 100644
index 000000000..c0c3be180
--- /dev/null
+++ b/drivers/mtd/nand/au1550nd.c
@@ -0,0 +1,515 @@
+/*
+ *  drivers/mtd/nand/au1550nd.c
+ *
+ *  Copyright (C) 2004 Embedded Edge, LLC
+ *
+ * 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
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/slab.h>
+#include <linux/gpio.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/nand.h>
+#include <linux/mtd/partitions.h>
+#include <linux/platform_device.h>
+#include <asm/io.h>
+#include <asm/mach-au1x00/au1000.h>
+#include <asm/mach-au1x00/au1550nd.h>
+
+
+struct au1550nd_ctx {
+	struct mtd_info info;
+	struct nand_chip chip;
+
+	int cs;
+	void __iomem *base;
+	void (*write_byte)(struct mtd_info *, u_char);
+};
+
+/**
+ * au_read_byte -  read one byte from the chip
+ * @mtd:	MTD device structure
+ *
+ * read function for 8bit buswidth
+ */
+static u_char au_read_byte(struct mtd_info *mtd)
+{
+	struct nand_chip *this = mtd->priv;
+	u_char ret = readb(this->IO_ADDR_R);
+	wmb(); /* drain writebuffer */
+	return ret;
+}
+
+/**
+ * au_write_byte -  write one byte to the chip
+ * @mtd:	MTD device structure
+ * @byte:	pointer to data byte to write
+ *
+ * write function for 8it buswidth
+ */
+static void au_write_byte(struct mtd_info *mtd, u_char byte)
+{
+	struct nand_chip *this = mtd->priv;
+	writeb(byte, this->IO_ADDR_W);
+	wmb(); /* drain writebuffer */
+}
+
+/**
+ * au_read_byte16 -  read one byte endianness aware from the chip
+ * @mtd:	MTD device structure
+ *
+ * read function for 16bit buswidth with endianness conversion
+ */
+static u_char au_read_byte16(struct mtd_info *mtd)
+{
+	struct nand_chip *this = mtd->priv;
+	u_char ret = (u_char) cpu_to_le16(readw(this->IO_ADDR_R));
+	wmb(); /* drain writebuffer */
+	return ret;
+}
+
+/**
+ * au_write_byte16 -  write one byte endianness aware to the chip
+ * @mtd:	MTD device structure
+ * @byte:	pointer to data byte to write
+ *
+ * write function for 16bit buswidth with endianness conversion
+ */
+static void au_write_byte16(struct mtd_info *mtd, u_char byte)
+{
+	struct nand_chip *this = mtd->priv;
+	writew(le16_to_cpu((u16) byte), this->IO_ADDR_W);
+	wmb(); /* drain writebuffer */
+}
+
+/**
+ * au_read_word -  read one word from the chip
+ * @mtd:	MTD device structure
+ *
+ * read function for 16bit buswidth without endianness conversion
+ */
+static u16 au_read_word(struct mtd_info *mtd)
+{
+	struct nand_chip *this = mtd->priv;
+	u16 ret = readw(this->IO_ADDR_R);
+	wmb(); /* drain writebuffer */
+	return ret;
+}
+
+/**
+ * au_write_buf -  write buffer to chip
+ * @mtd:	MTD device structure
+ * @buf:	data buffer
+ * @len:	number of bytes to write
+ *
+ * write function for 8bit buswidth
+ */
+static void au_write_buf(struct mtd_info *mtd, const u_char *buf, int len)
+{
+	int i;
+	struct nand_chip *this = mtd->priv;
+
+	for (i = 0; i < len; i++) {
+		writeb(buf[i], this->IO_ADDR_W);
+		wmb(); /* drain writebuffer */
+	}
+}
+
+/**
+ * au_read_buf -  read chip data into buffer
+ * @mtd:	MTD device structure
+ * @buf:	buffer to store date
+ * @len:	number of bytes to read
+ *
+ * read function for 8bit buswidth
+ */
+static void au_read_buf(struct mtd_info *mtd, u_char *buf, int len)
+{
+	int i;
+	struct nand_chip *this = mtd->priv;
+
+	for (i = 0; i < len; i++) {
+		buf[i] = readb(this->IO_ADDR_R);
+		wmb(); /* drain writebuffer */
+	}
+}
+
+/**
+ * au_write_buf16 -  write buffer to chip
+ * @mtd:	MTD device structure
+ * @buf:	data buffer
+ * @len:	number of bytes to write
+ *
+ * write function for 16bit buswidth
+ */
+static void au_write_buf16(struct mtd_info *mtd, const u_char *buf, int len)
+{
+	int i;
+	struct nand_chip *this = mtd->priv;
+	u16 *p = (u16 *) buf;
+	len >>= 1;
+
+	for (i = 0; i < len; i++) {
+		writew(p[i], this->IO_ADDR_W);
+		wmb(); /* drain writebuffer */
+	}
+
+}
+
+/**
+ * au_read_buf16 -  read chip data into buffer
+ * @mtd:	MTD device structure
+ * @buf:	buffer to store date
+ * @len:	number of bytes to read
+ *
+ * read function for 16bit buswidth
+ */
+static void au_read_buf16(struct mtd_info *mtd, u_char *buf, int len)
+{
+	int i;
+	struct nand_chip *this = mtd->priv;
+	u16 *p = (u16 *) buf;
+	len >>= 1;
+
+	for (i = 0; i < len; i++) {
+		p[i] = readw(this->IO_ADDR_R);
+		wmb(); /* drain writebuffer */
+	}
+}
+
+/* Select the chip by setting nCE to low */
+#define NAND_CTL_SETNCE		1
+/* Deselect the chip by setting nCE to high */
+#define NAND_CTL_CLRNCE		2
+/* Select the command latch by setting CLE to high */
+#define NAND_CTL_SETCLE		3
+/* Deselect the command latch by setting CLE to low */
+#define NAND_CTL_CLRCLE		4
+/* Select the address latch by setting ALE to high */
+#define NAND_CTL_SETALE		5
+/* Deselect the address latch by setting ALE to low */
+#define NAND_CTL_CLRALE		6
+
+static void au1550_hwcontrol(struct mtd_info *mtd, int cmd)
+{
+	struct au1550nd_ctx *ctx = container_of(mtd, struct au1550nd_ctx, info);
+	struct nand_chip *this = mtd->priv;
+
+	switch (cmd) {
+
+	case NAND_CTL_SETCLE:
+		this->IO_ADDR_W = ctx->base + MEM_STNAND_CMD;
+		break;
+
+	case NAND_CTL_CLRCLE:
+		this->IO_ADDR_W = ctx->base + MEM_STNAND_DATA;
+		break;
+
+	case NAND_CTL_SETALE:
+		this->IO_ADDR_W = ctx->base + MEM_STNAND_ADDR;
+		break;
+
+	case NAND_CTL_CLRALE:
+		this->IO_ADDR_W = ctx->base + MEM_STNAND_DATA;
+		/* FIXME: Nobody knows why this is necessary,
+		 * but it works only that way */
+		udelay(1);
+		break;
+
+	case NAND_CTL_SETNCE:
+		/* assert (force assert) chip enable */
+		alchemy_wrsmem((1 << (4 + ctx->cs)), AU1000_MEM_STNDCTL);
+		break;
+
+	case NAND_CTL_CLRNCE:
+		/* deassert chip enable */
+		alchemy_wrsmem(0, AU1000_MEM_STNDCTL);
+		break;
+	}
+
+	this->IO_ADDR_R = this->IO_ADDR_W;
+
+	wmb(); /* Drain the writebuffer */
+}
+
+int au1550_device_ready(struct mtd_info *mtd)
+{
+	return (alchemy_rdsmem(AU1000_MEM_STSTAT) & 0x1) ? 1 : 0;
+}
+
+/**
+ * au1550_select_chip - control -CE line
+ *	Forbid driving -CE manually permitting the NAND controller to do this.
+ *	Keeping -CE asserted during the whole sector reads interferes with the
+ *	NOR flash and PCMCIA drivers as it causes contention on the static bus.
+ *	We only have to hold -CE low for the NAND read commands since the flash
+ *	chip needs it to be asserted during chip not ready time but the NAND
+ *	controller keeps it released.
+ *
+ * @mtd:	MTD device structure
+ * @chip:	chipnumber to select, -1 for deselect
+ */
+static void au1550_select_chip(struct mtd_info *mtd, int chip)
+{
+}
+
+/**
+ * au1550_command - Send command to NAND device
+ * @mtd:	MTD device structure
+ * @command:	the command to be sent
+ * @column:	the column address for this command, -1 if none
+ * @page_addr:	the page address for this command, -1 if none
+ */
+static void au1550_command(struct mtd_info *mtd, unsigned command, int column, int page_addr)
+{
+	struct au1550nd_ctx *ctx = container_of(mtd, struct au1550nd_ctx, info);
+	struct nand_chip *this = mtd->priv;
+	int ce_override = 0, i;
+	unsigned long flags = 0;
+
+	/* Begin command latch cycle */
+	au1550_hwcontrol(mtd, NAND_CTL_SETCLE);
+	/*
+	 * Write out the command to the device.
+	 */
+	if (command == NAND_CMD_SEQIN) {
+		int readcmd;
+
+		if (column >= mtd->writesize) {
+			/* OOB area */
+			column -= mtd->writesize;
+			readcmd = NAND_CMD_READOOB;
+		} else if (column < 256) {
+			/* First 256 bytes --> READ0 */
+			readcmd = NAND_CMD_READ0;
+		} else {
+			column -= 256;
+			readcmd = NAND_CMD_READ1;
+		}
+		ctx->write_byte(mtd, readcmd);
+	}
+	ctx->write_byte(mtd, command);
+
+	/* Set ALE and clear CLE to start address cycle */
+	au1550_hwcontrol(mtd, NAND_CTL_CLRCLE);
+
+	if (column != -1 || page_addr != -1) {
+		au1550_hwcontrol(mtd, NAND_CTL_SETALE);
+
+		/* Serially input address */
+		if (column != -1) {
+			/* Adjust columns for 16 bit buswidth */
+			if (this->options & NAND_BUSWIDTH_16 &&
+					!nand_opcode_8bits(command))
+				column >>= 1;
+			ctx->write_byte(mtd, column);
+		}
+		if (page_addr != -1) {
+			ctx->write_byte(mtd, (u8)(page_addr & 0xff));
+
+			if (command == NAND_CMD_READ0 ||
+			    command == NAND_CMD_READ1 ||
+			    command == NAND_CMD_READOOB) {
+				/*
+				 * NAND controller will release -CE after
+				 * the last address byte is written, so we'll
+				 * have to forcibly assert it. No interrupts
+				 * are allowed while we do this as we don't
+				 * want the NOR flash or PCMCIA drivers to
+				 * steal our precious bytes of data...
+				 */
+				ce_override = 1;
+				local_irq_save(flags);
+				au1550_hwcontrol(mtd, NAND_CTL_SETNCE);
+			}
+
+			ctx->write_byte(mtd, (u8)(page_addr >> 8));
+
+			/* One more address cycle for devices > 32MiB */
+			if (this->chipsize > (32 << 20))
+				ctx->write_byte(mtd,
+						((page_addr >> 16) & 0x0f));
+		}
+		/* Latch in address */
+		au1550_hwcontrol(mtd, NAND_CTL_CLRALE);
+	}
+
+	/*
+	 * Program and erase have their own busy handlers.
+	 * Status and sequential in need 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:
+		break;
+
+	case NAND_CMD_READ0:
+	case NAND_CMD_READ1:
+	case NAND_CMD_READOOB:
+		/* Check if we're really driving -CE low (just in case) */
+		if (unlikely(!ce_override))
+			break;
+
+		/* Apply a short delay always to ensure that we do wait tWB. */
+		ndelay(100);
+		/* Wait for a chip to become ready... */
+		for (i = this->chip_delay; !this->dev_ready(mtd) && i > 0; --i)
+			udelay(1);
+
+		/* Release -CE and re-enable interrupts. */
+		au1550_hwcontrol(mtd, NAND_CTL_CLRNCE);
+		local_irq_restore(flags);
+		return;
+	}
+	/* Apply this short delay always to ensure that we do wait tWB. */
+	ndelay(100);
+
+	while(!this->dev_ready(mtd));
+}
+
+static int find_nand_cs(unsigned long nand_base)
+{
+	void __iomem *base =
+			(void __iomem *)KSEG1ADDR(AU1000_STATIC_MEM_PHYS_ADDR);
+	unsigned long addr, staddr, start, mask, end;
+	int i;
+
+	for (i = 0; i < 4; i++) {
+		addr = 0x1000 + (i * 0x10);			/* CSx */
+		staddr = __raw_readl(base + addr + 0x08);	/* STADDRx */
+		/* figure out the decoded range of this CS */
+		start = (staddr << 4) & 0xfffc0000;
+		mask = (staddr << 18) & 0xfffc0000;
+		end = (start | (start - 1)) & ~(start ^ mask);
+		if ((nand_base >= start) && (nand_base < end))
+			return i;
+	}
+
+	return -ENODEV;
+}
+
+static int au1550nd_probe(struct platform_device *pdev)
+{
+	struct au1550nd_platdata *pd;
+	struct au1550nd_ctx *ctx;
+	struct nand_chip *this;
+	struct resource *r;
+	int ret, cs;
+
+	pd = dev_get_platdata(&pdev->dev);
+	if (!pd) {
+		dev_err(&pdev->dev, "missing platform data\n");
+		return -ENODEV;
+	}
+
+	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!r) {
+		dev_err(&pdev->dev, "no NAND memory resource\n");
+		ret = -ENODEV;
+		goto out1;
+	}
+	if (request_mem_region(r->start, resource_size(r), "au1550-nand")) {
+		dev_err(&pdev->dev, "cannot claim NAND memory area\n");
+		ret = -ENOMEM;
+		goto out1;
+	}
+
+	ctx->base = ioremap_nocache(r->start, 0x1000);
+	if (!ctx->base) {
+		dev_err(&pdev->dev, "cannot remap NAND memory area\n");
+		ret = -ENODEV;
+		goto out2;
+	}
+
+	this = &ctx->chip;
+	ctx->info.priv = this;
+	ctx->info.owner = THIS_MODULE;
+
+	/* figure out which CS# r->start belongs to */
+	cs = find_nand_cs(r->start);
+	if (cs < 0) {
+		dev_err(&pdev->dev, "cannot detect NAND chipselect\n");
+		ret = -ENODEV;
+		goto out3;
+	}
+	ctx->cs = cs;
+
+	this->dev_ready = au1550_device_ready;
+	this->select_chip = au1550_select_chip;
+	this->cmdfunc = au1550_command;
+
+	/* 30 us command delay time */
+	this->chip_delay = 30;
+	this->ecc.mode = NAND_ECC_SOFT;
+
+	if (pd->devwidth)
+		this->options |= NAND_BUSWIDTH_16;
+
+	this->read_byte = (pd->devwidth) ? au_read_byte16 : au_read_byte;
+	ctx->write_byte = (pd->devwidth) ? au_write_byte16 : au_write_byte;
+	this->read_word = au_read_word;
+	this->write_buf = (pd->devwidth) ? au_write_buf16 : au_write_buf;
+	this->read_buf = (pd->devwidth) ? au_read_buf16 : au_read_buf;
+
+	ret = nand_scan(&ctx->info, 1);
+	if (ret) {
+		dev_err(&pdev->dev, "NAND scan failed with %d\n", ret);
+		goto out3;
+	}
+
+	mtd_device_register(&ctx->info, pd->parts, pd->num_parts);
+
+	platform_set_drvdata(pdev, ctx);
+
+	return 0;
+
+out3:
+	iounmap(ctx->base);
+out2:
+	release_mem_region(r->start, resource_size(r));
+out1:
+	kfree(ctx);
+	return ret;
+}
+
+static int au1550nd_remove(struct platform_device *pdev)
+{
+	struct au1550nd_ctx *ctx = platform_get_drvdata(pdev);
+	struct resource *r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+	nand_release(&ctx->info);
+	iounmap(ctx->base);
+	release_mem_region(r->start, 0x1000);
+	kfree(ctx);
+	return 0;
+}
+
+static struct platform_driver au1550nd_driver = {
+	.driver = {
+		.name	= "au1550-nand",
+	},
+	.probe		= au1550nd_probe,
+	.remove		= au1550nd_remove,
+};
+
+module_platform_driver(au1550nd_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Embedded Edge, LLC");
+MODULE_DESCRIPTION("Board-specific glue layer for NAND flash on Pb1550 board");