#include <linux/bitrev.h>
/*
+ * In "reliable mode" consecutive 2k pages are used in parallel (in some
+ * fashion) to store the same data. The data can be read back from the
+ * even-numbered pages in the normal manner; odd-numbered pages will appear to
+ * contain junk. Systems that boot from the docg4 typically write the secondary
+ * program loader (SPL) code in this mode. The SPL is loaded by the initial
+ * program loader (IPL, stored in the docg4's 2k NOR-like region that is mapped
+ * to the reset vector address). This module parameter enables you to use this
+ * driver to write the SPL. When in this mode, no more than 2k of data can be
+ * written at a time, because the addresses do not increment in the normal
+ * manner, and the starting offset must be within an even-numbered 2k region;
+ * i.e., invalid starting offsets are 0x800, 0xa00, 0xc00, 0xe00, 0x1800,
+ * 0x1a00, ... Reliable mode is a special case and should not be used unless
+ * you know what you're doing.
+ */
+static bool reliable_mode;
+module_param(reliable_mode, bool, 0);
+MODULE_PARM_DESC(reliable_mode, "pages are programmed in reliable mode");
+
+/*
* You'll want to ignore badblocks if you're reading a partition that contains
* data written by the TrueFFS library (i.e., by PalmOS, Windows, etc), since
* it does not use mtd nand's method for marking bad blocks (using oob area).
#define DOCG4_SEQ_PAGEWRITE 0x16
#define DOCG4_SEQ_PAGEPROG 0x1e
#define DOCG4_SEQ_BLOCKERASE 0x24
+#define DOCG4_SEQ_SETMODE 0x45
/* DOC_FLASHCOMMAND register commands */
#define DOCG4_CMD_PAGE_READ 0x00
#define DOC_CMD_PROG_BLOCK_ADDR 0x60
#define DOCG4_CMD_PAGEWRITE 0x80
#define DOC_CMD_PROG_CYCLE2 0x10
+#define DOCG4_CMD_FAST_MODE 0xa3 /* functionality guessed */
+#define DOC_CMD_RELIABLE_MODE 0x22
#define DOC_CMD_RESET 0xff
/* DOC_POWERMODE register bits */
dev_dbg(doc->dev,
"docg4: %s: g4 addr: %x\n", __func__, docg4_addr);
sequence_reset(mtd);
+
+ if (unlikely(reliable_mode)) {
+ writew(DOCG4_SEQ_SETMODE, docptr + DOC_FLASHSEQUENCE);
+ writew(DOCG4_CMD_FAST_MODE, docptr + DOC_FLASHCOMMAND);
+ writew(DOC_CMD_RELIABLE_MODE, docptr + DOC_FLASHCOMMAND);
+ write_nop(docptr);
+ }
+
writew(DOCG4_SEQ_PAGEWRITE, docptr + DOC_FLASHSEQUENCE);
writew(DOCG4_CMD_PAGEWRITE, docptr + DOC_FLASHCOMMAND);
write_nop(docptr);
break;
case NAND_CMD_SEQIN:
+ if (unlikely(reliable_mode)) {
+ uint16_t g4_page = g4_addr >> 16;
+
+ /* writes to odd-numbered 2k pages are invalid */
+ if (g4_page & 0x01)
+ dev_warn(doc->dev,
+ "invalid reliable mode address\n");
+ }
+
write_page_prologue(mtd, g4_addr);
/* hack for deferred write of oob bytes */