MTD driver for Intel IXP4xx platform (from MTD CVS tree)

Patch from Deepak Saxena <dsaxena@plexity.net>

drivers/mtd/maps/Kconfig

@@ -404,6 +404,15 @@ config MTD_IQ80310
 	  IQ80310 evaluation board. If you have one of these boards and would 
 	  like to use the flash chips on it, say 'Y'.
 
+config MTD_IXP4XX
+	tristate "CFI Flash device mapped on Intel IXP4xx based systems"
+	depends on ARM && MTD_CFI && MTD_COMPLEX_MAPPINGS && ARCH_IXP4XX
+	help
+	  This eables MTD access to flash devices on platforms based 
+	  on Intel's IXP4xx family of network processors such as the
+	  IXDP425 and Coyote. If you have an IXP4xx based board and
+	  would like to use the flash chips on it, say 'Y'.
+
 config MTD_EPXA10DB
 	tristate "CFI Flash device mapped on Epxa10db"
 	depends on ARM && MTD_CFI && MTD_PARTITIONS && ARCH_CAMELOT

drivers/mtd/maps/Makefile

@@ -55,3 +55,4 @@ obj-$(CONFIG_MTD_EBONY)		+= ebony.o
 obj-$(CONFIG_MTD_BEECH)		+= beech-mtd.o
 obj-$(CONFIG_MTD_ARCTIC)	+= arctic-mtd.o
 obj-$(CONFIG_MTD_H720X)		+= h720x-flash.o
+obj-$(CONFIG_MTD_IXP4XX)	+= ixp4xx.o

drivers/mtd/maps/ixp4xx.c

+/*
+ * $Id: ixp4xx.c,v 1.1 2004/05/13 22:21:26 dsaxena Exp $
+ *
+ * drivers/mtd/maps/ixp4xx.c
+ *
+ * MTD Map file for IXP4XX based systems. Please do not make per-board
+ * changes in here. If your board needs special setup, do it in your
+ * platform level code in arch/arm/mach-ixp4xx/board-setup.c
+ *
+ * Original Author: Intel Corporation
+ * Maintainer: Deepak Saxena <dsaxena@mvista.com>
+ *
+ * Copyright (C) 2002 Intel Corporation
+ * Copyright (C) 2003-2004 MontaVista Software, Inc.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/map.h>
+#include <linux/mtd/partitions.h>
+#include <linux/ioport.h>
+#include <linux/device.h>
+#include <asm/io.h>
+#include <asm/mach-types.h>
+#include <asm/mach/flash.h>
+
+#include <linux/reboot.h>
+
+#ifndef __ARMEB__
+#define	BYTE0(h)	((h) & 0xFF)
+#define	BYTE1(h)	(((h) >> 8) & 0xFF)
+#else
+#define	BYTE0(h)	(((h) >> 8) & 0xFF)
+#define	BYTE1(h)	((h) & 0xFF)
+#endif
+
+static __u16
+ixp4xx_read16(struct map_info *map, unsigned long ofs)
+{
+	return *(__u16 *) (map->map_priv_1 + ofs);
+}
+
+/*
+ * The IXP4xx expansion bus only allows 16-bit wide acceses
+ * when attached to a 16-bit wide device (such as the 28F128J3A),
+ * so we can't just memcpy_fromio().
+ */
+static void
+ixp4xx_copy_from(struct map_info *map, void *to,
+		 unsigned long from, ssize_t len)
+{
+	int i;
+	u8 *dest = (u8 *) to;
+	u16 *src = (u16 *) (map->map_priv_1 + from);
+	u16 data;
+
+	for (i = 0; i < (len / 2); i++) {
+		data = src[i];
+		dest[i * 2] = BYTE0(data);
+		dest[i * 2 + 1] = BYTE1(data);
+	}
+
+	if (len & 1)
+		dest[len - 1] = BYTE0(src[i]);
+}
+
+static void
+ixp4xx_write16(struct map_info *map, __u16 d, unsigned long adr)
+{
+	*(__u16 *) (map->map_priv_1 + adr) = d;
+}
+
+struct ixp4xx_flash_info {
+	struct mtd_info *mtd;
+	struct map_info map;
+	struct mtd_partition *partitions;
+	struct resource *res;
+};
+
+static const char *probes[] = { "RedBoot", "cmdlinepart", NULL };
+
+static int
+ixp4xx_flash_remove(struct device *_dev)
+{
+	struct platform_device *dev = to_platform_device(_dev);
+	struct flash_platform_data *plat = dev->dev.platform_data;
+	struct ixp4xx_flash_info *info = dev_get_drvdata(&dev->dev);
+
+	dev_set_drvdata(&dev->dev, NULL);
+
+	if(!info)
+		return 0;
+
+	/*
+	 * This is required for a soft reboot to work.
+	 */
+	ixp4xx_write16(&info->map, 0xff, 0x55 * 0x2);
+
+	if (info->mtd) {
+		del_mtd_partitions(info->mtd);
+		map_destroy(info->mtd);
+	}
+	if (info->map.map_priv_1)
+		iounmap((void *) info->map.map_priv_1);
+
+	if (info->partitions)
+		kfree(info->partitions);
+
+	if (info->res) {
+		release_resource(info->res);
+		kfree(info->res);
+	}
+
+	if (plat->exit)
+		plat->exit();
+
+	/* Disable flash write */
+	*IXP4XX_EXP_CS0 &= ~IXP4XX_FLASH_WRITABLE;
+
+	return 0;
+}
+
+static int ixp4xx_flash_probe(struct device *_dev)
+{
+	struct platform_device *dev = to_platform_device(_dev);
+	struct flash_platform_data *plat = dev->dev.platform_data;
+	struct ixp4xx_flash_info *info;
+	int err = -1;
+
+	if (!plat)
+		return -ENODEV;
+
+	if (plat->init) {
+		err = plat->init();
+		if (err)
+			return err;
+	}
+
+	info = kmalloc(sizeof(struct ixp4xx_flash_info), GFP_KERNEL);
+	if(!info) {
+		err = -ENOMEM;
+		goto Error;
+	}	
+	memzero(info, sizeof(struct ixp4xx_flash_info));
+
+	dev_set_drvdata(&dev->dev, info);
+
+	/* 
+	 * Enable flash write 
+	 * TODO: Move this out to board specific code
+	 */
+	*IXP4XX_EXP_CS0 |= IXP4XX_FLASH_WRITABLE;
+
+	/*
+	 * Tell the MTD layer we're not 1:1 mapped so that it does
+	 * not attempt to do a direct access on us.
+	 */
+	info->map.phys = NO_XIP;
+	info->map.size = dev->resource->end - dev->resource->start + 1;
+
+	/*
+	 * We only support 16-bit accesses for now. If and when
+	 * any board use 8-bit access, we'll fixup the driver to
+	 * handle that.
+	 */
+	info->map.buswidth = 2;
+	info->map.name = dev->dev.bus_id;
+	info->map.read16 = ixp4xx_read16,
+	info->map.write16 = ixp4xx_write16,
+	info->map.copy_from = ixp4xx_copy_from,
+
+	info->res = request_mem_region(dev->resource->start, 
+			dev->resource->end - dev->resource->start + 1, 
+			"IXP4XXFlash");
+	if (!info->res) {
+		printk(KERN_ERR "IXP4XXFlash: Could not reserve memory region\n");
+		err = -ENOMEM;
+		goto Error;
+	}
+
+	info->map.map_priv_1 =
+	    (unsigned long) ioremap(dev->resource->start, 
+				    dev->resource->end - dev->resource->start + 1);
+	if (!info->map.map_priv_1) {
+		printk(KERN_ERR "IXP4XXFlash: Failed to ioremap region\n");
+		err = -EIO;
+		goto Error;
+	}
+
+	info->mtd = do_map_probe(plat->map_name, &info->map);
+	if (!info->mtd) {
+		printk(KERN_ERR "IXP4XXFlash: map_probe failed\n");
+		err = -ENXIO;
+		goto Error;
+	}
+	info->mtd->owner = THIS_MODULE;
+
+	err = parse_mtd_partitions(info->mtd, probes, &info->partitions, 0);
+	if (err > 0) {
+		err = add_mtd_partitions(info->mtd, info->partitions, err);
+		if(err)
+			printk(KERN_ERR "Could not parse partitions\n");
+	}
+
+	if (err)
+		goto Error;
+
+	return 0;
+
+Error:
+	ixp4xx_flash_remove(_dev);
+	return err;
+}
+
+static struct device_driver ixp4xx_flash_driver = {
+	.name		= "IXP4XX-Flash",
+	.bus		= &platform_bus_type,
+	.probe		= ixp4xx_flash_probe,
+	.remove		= ixp4xx_flash_remove,
+};
+
+static int __init ixp4xx_flash_init(void)
+{
+	return driver_register(&ixp4xx_flash_driver);
+}
+
+static void __exit ixp4xx_flash_exit(void)
+{
+	driver_unregister(&ixp4xx_flash_driver);
+}
+
+
+module_init(ixp4xx_flash_init);
+module_exit(ixp4xx_flash_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("MTD map driver for Intel IXP4xx systems")
+MODULE_AUTHOR("Deepak Saxena");
+