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path: root/drivers/mtd/maps/ixp4xx.c
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Diffstat (limited to 'drivers/mtd/maps/ixp4xx.c')
-rw-r--r--drivers/mtd/maps/ixp4xx.c261
1 files changed, 261 insertions, 0 deletions
diff --git a/drivers/mtd/maps/ixp4xx.c b/drivers/mtd/maps/ixp4xx.c
new file mode 100644
index 000000000..b44307410
--- /dev/null
+++ b/drivers/mtd/maps/ixp4xx.c
@@ -0,0 +1,261 @@
+/*
+ * 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/err.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/ioport.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/map.h>
+#include <linux/mtd/partitions.h>
+
+#include <asm/io.h>
+#include <asm/mach/flash.h>
+
+#include <linux/reboot.h>
+
+/*
+ * Read/write a 16 bit word from flash address 'addr'.
+ *
+ * When the cpu is in little-endian mode it swizzles the address lines
+ * ('address coherency') so we need to undo the swizzling to ensure commands
+ * and the like end up on the correct flash address.
+ *
+ * To further complicate matters, due to the way the expansion bus controller
+ * handles 32 bit reads, the byte stream ABCD is stored on the flash as:
+ * D15 D0
+ * +---+---+
+ * | A | B | 0
+ * +---+---+
+ * | C | D | 2
+ * +---+---+
+ * This means that on LE systems each 16 bit word must be swapped. Note that
+ * this requires CONFIG_MTD_CFI_BE_BYTE_SWAP to be enabled to 'unswap' the CFI
+ * data and other flash commands which are always in D7-D0.
+ */
+#ifndef __ARMEB__
+#ifndef CONFIG_MTD_CFI_BE_BYTE_SWAP
+# error CONFIG_MTD_CFI_BE_BYTE_SWAP required
+#endif
+
+static inline u16 flash_read16(void __iomem *addr)
+{
+ return be16_to_cpu(__raw_readw((void __iomem *)((unsigned long)addr ^ 0x2)));
+}
+
+static inline void flash_write16(u16 d, void __iomem *addr)
+{
+ __raw_writew(cpu_to_be16(d), (void __iomem *)((unsigned long)addr ^ 0x2));
+}
+
+#define BYTE0(h) ((h) & 0xFF)
+#define BYTE1(h) (((h) >> 8) & 0xFF)
+
+#else
+
+static inline u16 flash_read16(const void __iomem *addr)
+{
+ return __raw_readw(addr);
+}
+
+static inline void flash_write16(u16 d, void __iomem *addr)
+{
+ __raw_writew(d, addr);
+}
+
+#define BYTE0(h) (((h) >> 8) & 0xFF)
+#define BYTE1(h) ((h) & 0xFF)
+#endif
+
+static map_word ixp4xx_read16(struct map_info *map, unsigned long ofs)
+{
+ map_word val;
+ val.x[0] = flash_read16(map->virt + ofs);
+ return val;
+}
+
+/*
+ * 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)
+{
+ u8 *dest = (u8 *) to;
+ void __iomem *src = map->virt + from;
+
+ if (len <= 0)
+ return;
+
+ if (from & 1) {
+ *dest++ = BYTE1(flash_read16(src-1));
+ src++;
+ --len;
+ }
+
+ while (len >= 2) {
+ u16 data = flash_read16(src);
+ *dest++ = BYTE0(data);
+ *dest++ = BYTE1(data);
+ src += 2;
+ len -= 2;
+ }
+
+ if (len > 0)
+ *dest++ = BYTE0(flash_read16(src));
+}
+
+/*
+ * Unaligned writes are ignored, causing the 8-bit
+ * probe to fail and proceed to the 16-bit probe (which succeeds).
+ */
+static void ixp4xx_probe_write16(struct map_info *map, map_word d, unsigned long adr)
+{
+ if (!(adr & 1))
+ flash_write16(d.x[0], map->virt + adr);
+}
+
+/*
+ * Fast write16 function without the probing check above
+ */
+static void ixp4xx_write16(struct map_info *map, map_word d, unsigned long adr)
+{
+ flash_write16(d.x[0], map->virt + adr);
+}
+
+struct ixp4xx_flash_info {
+ struct mtd_info *mtd;
+ struct map_info map;
+ struct resource *res;
+};
+
+static const char * const probes[] = { "RedBoot", "cmdlinepart", NULL };
+
+static int ixp4xx_flash_remove(struct platform_device *dev)
+{
+ struct flash_platform_data *plat = dev_get_platdata(&dev->dev);
+ struct ixp4xx_flash_info *info = platform_get_drvdata(dev);
+
+ if(!info)
+ return 0;
+
+ if (info->mtd) {
+ mtd_device_unregister(info->mtd);
+ map_destroy(info->mtd);
+ }
+
+ if (plat->exit)
+ plat->exit();
+
+ return 0;
+}
+
+static int ixp4xx_flash_probe(struct platform_device *dev)
+{
+ struct flash_platform_data *plat = dev_get_platdata(&dev->dev);
+ struct ixp4xx_flash_info *info;
+ struct mtd_part_parser_data ppdata = {
+ .origin = dev->resource->start,
+ };
+ int err = -1;
+
+ if (!plat)
+ return -ENODEV;
+
+ if (plat->init) {
+ err = plat->init();
+ if (err)
+ return err;
+ }
+
+ info = devm_kzalloc(&dev->dev, sizeof(struct ixp4xx_flash_info),
+ GFP_KERNEL);
+ if(!info) {
+ err = -ENOMEM;
+ goto Error;
+ }
+
+ platform_set_drvdata(dev, info);
+
+ /*
+ * 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 = resource_size(dev->resource);
+
+ /*
+ * 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.bankwidth = 2;
+ info->map.name = dev_name(&dev->dev);
+ info->map.read = ixp4xx_read16;
+ info->map.write = ixp4xx_probe_write16;
+ info->map.copy_from = ixp4xx_copy_from;
+
+ info->map.virt = devm_ioremap_resource(&dev->dev, dev->resource);
+ if (IS_ERR(info->map.virt)) {
+ err = PTR_ERR(info->map.virt);
+ 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;
+
+ /* Use the fast version */
+ info->map.write = ixp4xx_write16;
+
+ err = mtd_device_parse_register(info->mtd, probes, &ppdata,
+ plat->parts, plat->nr_parts);
+ if (err) {
+ printk(KERN_ERR "Could not parse partitions\n");
+ goto Error;
+ }
+
+ return 0;
+
+Error:
+ ixp4xx_flash_remove(dev);
+ return err;
+}
+
+static struct platform_driver ixp4xx_flash_driver = {
+ .probe = ixp4xx_flash_probe,
+ .remove = ixp4xx_flash_remove,
+ .driver = {
+ .name = "IXP4XX-Flash",
+ },
+};
+
+module_platform_driver(ixp4xx_flash_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("MTD map driver for Intel IXP4xx systems");
+MODULE_AUTHOR("Deepak Saxena");
+MODULE_ALIAS("platform:IXP4XX-Flash");