[MTD] [NAND] Add support for NAND on the Socrates board

Signed-off-by: Ilya Yanok <yanok@emcraft.com>
Acked-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

drivers/mtd/nand/Kconfig

@@ -440,4 +440,10 @@ config MTD_NAND_TXX9NDFMC
 	help
 	  This enables the NAND flash controller on the TXx9 SoCs.
 
+config MTD_NAND_SOCRATES
+	tristate "Support for NAND on Socrates board"
+	depends on MTD_NAND && SOCRATES
+	help
+	  Enables support for NAND Flash chips wired onto Socrates board.
+
 endif # MTD_NAND

drivers/mtd/nand/Makefile

@@ -37,6 +37,7 @@ obj-$(CONFIG_MTD_NAND_FSL_ELBC)		+= fsl_elbc_nand.o
 obj-$(CONFIG_MTD_NAND_FSL_UPM)		+= fsl_upm.o
 obj-$(CONFIG_MTD_NAND_SH_FLCTL)		+= sh_flctl.o
 obj-$(CONFIG_MTD_NAND_MXC)		+= mxc_nand.o
+obj-$(CONFIG_MTD_NAND_SOCRATES)		+= socrates_nand.o
 obj-$(CONFIG_MTD_NAND_TXX9NDFMC)	+= txx9ndfmc.o
 
 nand-objs := nand_base.o nand_bbt.o

drivers/mtd/nand/socrates_nand.c

+/*
+ * drivers/mtd/nand/socrates_nand.c
+ *
+ *  Copyright © 2008 Ilya Yanok, Emcraft Systems
+ *
+ *
+ * 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/module.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/nand.h>
+#include <linux/mtd/partitions.h>
+#include <linux/of_platform.h>
+#include <linux/io.h>
+
+#define FPGA_NAND_CMD_MASK		(0x7 << 28)
+#define FPGA_NAND_CMD_COMMAND		(0x0 << 28)
+#define FPGA_NAND_CMD_ADDR		(0x1 << 28)
+#define FPGA_NAND_CMD_READ		(0x2 << 28)
+#define FPGA_NAND_CMD_WRITE		(0x3 << 28)
+#define FPGA_NAND_BUSY			(0x1 << 15)
+#define FPGA_NAND_ENABLE		(0x1 << 31)
+#define FPGA_NAND_DATA_SHIFT		16
+
+struct socrates_nand_host {
+	struct nand_chip	nand_chip;
+	struct mtd_info		mtd;
+	void __iomem		*io_base;
+	struct device		*dev;
+};
+
+/**
+ * socrates_nand_write_buf -  write buffer to chip
+ * @mtd:	MTD device structure
+ * @buf:	data buffer
+ * @len:	number of bytes to write
+ */
+static void socrates_nand_write_buf(struct mtd_info *mtd,
+		const uint8_t *buf, int len)
+{
+	int i;
+	struct nand_chip *this = mtd->priv;
+	struct socrates_nand_host *host = this->priv;
+
+	for (i = 0; i < len; i++) {
+		out_be32(host->io_base, FPGA_NAND_ENABLE |
+				FPGA_NAND_CMD_WRITE |
+				(buf[i] << FPGA_NAND_DATA_SHIFT));
+	}
+}
+
+/**
+ * socrates_nand_read_buf -  read chip data into buffer
+ * @mtd:	MTD device structure
+ * @buf:	buffer to store date
+ * @len:	number of bytes to read
+ */
+static void socrates_nand_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
+{
+	int i;
+	struct nand_chip *this = mtd->priv;
+	struct socrates_nand_host *host = this->priv;
+	uint32_t val;
+
+	val = FPGA_NAND_ENABLE | FPGA_NAND_CMD_READ;
+
+	out_be32(host->io_base, val);
+	for (i = 0; i < len; i++) {
+		buf[i] = (in_be32(host->io_base) >>
+				FPGA_NAND_DATA_SHIFT) & 0xff;
+	}
+}
+
+/**
+ * socrates_nand_read_byte -  read one byte from the chip
+ * @mtd:	MTD device structure
+ */
+static uint8_t socrates_nand_read_byte(struct mtd_info *mtd)
+{
+	uint8_t byte;
+	socrates_nand_read_buf(mtd, &byte, sizeof(byte));
+	return byte;
+}
+
+/**
+ * socrates_nand_read_word -  read one word from the chip
+ * @mtd:	MTD device structure
+ */
+static uint16_t socrates_nand_read_word(struct mtd_info *mtd)
+{
+	uint16_t word;
+	socrates_nand_read_buf(mtd, (uint8_t *)&word, sizeof(word));
+	return word;
+}
+
+/**
+ * socrates_nand_verify_buf -  Verify chip data against buffer
+ * @mtd:	MTD device structure
+ * @buf:	buffer containing the data to compare
+ * @len:	number of bytes to compare
+ */
+static int socrates_nand_verify_buf(struct mtd_info *mtd, const u8 *buf,
+		int len)
+{
+	int i;
+
+	for (i = 0; i < len; i++) {
+		if (buf[i] != socrates_nand_read_byte(mtd))
+			return -EFAULT;
+	}
+	return 0;
+}
+
+/*
+ * Hardware specific access to control-lines
+ */
+static void socrates_nand_cmd_ctrl(struct mtd_info *mtd, int cmd,
+		unsigned int ctrl)
+{
+	struct nand_chip *nand_chip = mtd->priv;
+	struct socrates_nand_host *host = nand_chip->priv;
+	uint32_t val;
+
+	if (cmd == NAND_CMD_NONE)
+		return;
+
+	if (ctrl & NAND_CLE)
+		val = FPGA_NAND_CMD_COMMAND;
+	else
+		val = FPGA_NAND_CMD_ADDR;
+
+	if (ctrl & NAND_NCE)
+		val |= FPGA_NAND_ENABLE;
+
+	val |= (cmd & 0xff) << FPGA_NAND_DATA_SHIFT;
+
+	out_be32(host->io_base, val);
+}
+
+/*
+ * Read the Device Ready pin.
+ */
+static int socrates_nand_device_ready(struct mtd_info *mtd)
+{
+	struct nand_chip *nand_chip = mtd->priv;
+	struct socrates_nand_host *host = nand_chip->priv;
+
+	if (in_be32(host->io_base) & FPGA_NAND_BUSY)
+		return 0; /* busy */
+	return 1;
+}
+
+#ifdef CONFIG_MTD_PARTITIONS
+static const char *part_probes[] = { "cmdlinepart", NULL };
+#endif
+
+/*
+ * Probe for the NAND device.
+ */
+static int __devinit socrates_nand_probe(struct of_device *ofdev,
+					 const struct of_device_id *ofid)
+{
+	struct socrates_nand_host *host;
+	struct mtd_info *mtd;
+	struct nand_chip *nand_chip;
+	int res;
+
+#ifdef CONFIG_MTD_PARTITIONS
+	struct mtd_partition *partitions = NULL;
+	int num_partitions = 0;
+#endif
+
+	/* Allocate memory for the device structure (and zero it) */
+	host = kzalloc(sizeof(struct socrates_nand_host), GFP_KERNEL);
+	if (!host) {
+		printk(KERN_ERR
+		       "socrates_nand: failed to allocate device structure.\n");
+		return -ENOMEM;
+	}
+
+	host->io_base = of_iomap(ofdev->node, 0);
+	if (host->io_base == NULL) {
+		printk(KERN_ERR "socrates_nand: ioremap failed\n");
+		kfree(host);
+		return -EIO;
+	}
+
+	mtd = &host->mtd;
+	nand_chip = &host->nand_chip;
+	host->dev = &ofdev->dev;
+
+	nand_chip->priv = host;		/* link the private data structures */
+	mtd->priv = nand_chip;
+	mtd->name = "socrates_nand";
+	mtd->owner = THIS_MODULE;
+	mtd->dev.parent = &ofdev->dev;
+
+	/*should never be accessed directly */
+	nand_chip->IO_ADDR_R = (void *)0xdeadbeef;
+	nand_chip->IO_ADDR_W = (void *)0xdeadbeef;
+
+	nand_chip->cmd_ctrl = socrates_nand_cmd_ctrl;
+	nand_chip->read_byte = socrates_nand_read_byte;
+	nand_chip->read_word = socrates_nand_read_word;
+	nand_chip->write_buf = socrates_nand_write_buf;
+	nand_chip->read_buf = socrates_nand_read_buf;
+	nand_chip->verify_buf = socrates_nand_verify_buf;
+	nand_chip->dev_ready = socrates_nand_device_ready;
+
+	nand_chip->ecc.mode = NAND_ECC_SOFT;	/* enable ECC */
+
+	/* TODO: I have no idea what real delay is. */
+	nand_chip->chip_delay = 20;		/* 20us command delay time */
+
+	dev_set_drvdata(&ofdev->dev, host);
+
+	/* first scan to find the device and get the page size */
+	if (nand_scan_ident(mtd, 1)) {
+		res = -ENXIO;
+		goto out;
+	}
+
+	/* second phase scan */
+	if (nand_scan_tail(mtd)) {
+		res = -ENXIO;
+		goto out;
+	}
+
+#ifdef CONFIG_MTD_PARTITIONS
+#ifdef CONFIG_MTD_CMDLINE_PARTS
+	num_partitions = parse_mtd_partitions(mtd, part_probes,
+					      &partitions, 0);
+	if (num_partitions < 0) {
+		res = num_partitions;
+		goto release;
+	}
+#endif
+
+#ifdef CONFIG_MTD_OF_PARTS
+	if (num_partitions == 0) {
+		num_partitions = of_mtd_parse_partitions(&ofdev->dev,
+							 ofdev->node,
+							 &partitions);
+		if (num_partitions < 0) {
+			res = num_partitions;
+			goto release;
+		}
+	}
+#endif
+	if (partitions && (num_partitions > 0))
+		res = add_mtd_partitions(mtd, partitions, num_partitions);
+	else
+#endif
+		res = add_mtd_device(mtd);
+
+	if (!res)
+		return res;
+
+#ifdef CONFIG_MTD_PARTITIONS
+release:
+#endif
+	nand_release(mtd);
+
+out:
+	dev_set_drvdata(&ofdev->dev, NULL);
+	iounmap(host->io_base);
+	kfree(host);
+	return res;
+}
+
+/*
+ * Remove a NAND device.
+ */
+static int __devexit socrates_nand_remove(struct of_device *ofdev)
+{
+	struct socrates_nand_host *host = dev_get_drvdata(&ofdev->dev);
+	struct mtd_info *mtd = &host->mtd;
+
+	nand_release(mtd);
+
+	dev_set_drvdata(&ofdev->dev, NULL);
+	iounmap(host->io_base);
+	kfree(host);
+
+	return 0;
+}
+
+static struct of_device_id socrates_nand_match[] =
+{
+	{
+		.compatible   = "abb,socrates-nand",
+	},
+	{},
+};
+
+MODULE_DEVICE_TABLE(of, socrates_nand_match);
+
+static struct of_platform_driver socrates_nand_driver = {
+	.name		= "socrates_nand",
+	.match_table	= socrates_nand_match,
+	.probe		= socrates_nand_probe,
+	.remove		= __devexit_p(socrates_nand_remove),
+};
+
+static int __init socrates_nand_init(void)
+{
+	return of_register_platform_driver(&socrates_nand_driver);
+}
+
+static void __exit socrates_nand_exit(void)
+{
+	of_unregister_platform_driver(&socrates_nand_driver);
+}
+
+module_init(socrates_nand_init);
+module_exit(socrates_nand_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Ilya Yanok");
+MODULE_DESCRIPTION("NAND driver for Socrates board");