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--- linux-2.6.14-rc3/drivers/mtd/maps/ixp4xx.c 2005-10-05 20:35:42.916786530 -0700
+++ linux-2.6.14-rc3/drivers/mtd/maps/ixp4xx.c 2005-10-05 22:42:25.811206514 -0700
@@ -30,18 +30,29 @@
#include <linux/reboot.h>
+/* On a little-endian IXP4XX system (tested on NSLU2) contrary to the
+ * Intel documentation LDRH/STRH appears to XOR the address with 10b.
+ * This causes the cfi commands (sent to the command address, 0xAA for
+ * 16 bit flash) to fail. This is fixed here by XOR'ing the address
+ * before use with 10b. The cost of this is that the flash layout ends
+ * up consistently big-endian, however this is not a problem as the
+ * access code consistently only accesses half words - so the endianness
+ * is not determinable.
+ */
#ifndef __ARMEB__
#define BYTE0(h) ((h) & 0xFF)
#define BYTE1(h) (((h) >> 8) & 0xFF)
+#define FLASHW(a) (*(__u16*)((u32)(a) ^ 2))
#else
#define BYTE0(h) (((h) >> 8) & 0xFF)
#define BYTE1(h) ((h) & 0xFF)
+#define FLASHW(a) (*(__u16*)(a))
#endif
static map_word ixp4xx_read16(struct map_info *map, unsigned long ofs)
{
map_word val;
- val.x[0] = *(__u16 *) (map->map_priv_1 + ofs);
+ val.x[0] = FLASHW(map->map_priv_1 + ofs);
return val;
}
@@ -53,19 +64,23 @@
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;
+ if (len <= 0)
+ return;
- for (i = 0; i < (len / 2); i++) {
- data = src[i];
- dest[i * 2] = BYTE0(data);
- dest[i * 2 + 1] = BYTE1(data);
+ u8 *dest = (u8 *) to;
+ u8 *src = (u8 *) (map->map_priv_1 + from);
+ if (from & 1)
+ *dest++ = BYTE1(FLASHW(src-1)), ++src, --len;
+
+ while (len >= 2) {
+ u16 data = FLASHW(src); src += 2;
+ *dest++ = BYTE0(data);
+ *dest++ = BYTE1(data);
+ len -= 2;
}
- if (len & 1)
- dest[len - 1] = BYTE0(src[i]);
+ if (len > 0)
+ *dest++ = BYTE0(FLASHW(src));
}
/*
@@ -75,7 +90,7 @@
static void ixp4xx_probe_write16(struct map_info *map, map_word d, unsigned long adr)
{
if (!(adr & 1))
- *(__u16 *) (map->map_priv_1 + adr) = d.x[0];
+ FLASHW(map->map_priv_1 + adr) = d.x[0];
}
/*
@@ -83,7 +98,7 @@
*/
static void ixp4xx_write16(struct map_info *map, map_word d, unsigned long adr)
{
- *(__u16 *) (map->map_priv_1 + adr) = d.x[0];
+ FLASHW(map->map_priv_1 + adr) = d.x[0];
}
struct ixp4xx_flash_info {
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