mtd: cfi_cmdset_0001.c: add support for Sharp LH28F640BF NOR

This family of chips was long ago supported by the pre-cfi driver.
CFI code tested on several Zaurus SL-5500 (Collie) 2x16 on 32 bit bus.

Function is_LH28F640BF() mimics is_m29ew() from cmdset_0002.c

Buffer write fixes as seen in 2007 patch c/o
Anti Sullin <anti.sullin <at> artecdesign.ee>
http://comments.gmane.org/gmane.linux.ports.arm.kernel/36733

[Brian: this patch is semi-urgent, because the following patch switches
  to using CFI detection for a chip which (until now) is unsupported by
  the CFI driver

  92183103  ARM: 8084/1: sa1100: collie: revert back to cfi_probe
]
Signed-off-by: Andrea Adami <andrea.adami@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

drivers/mtd/chips/cfi_cmdset_0001.c

@@ -52,6 +52,11 @@
 /* Atmel chips */
 #define AT49BV640D	0x02de
 #define AT49BV640DT	0x02db
+/* Sharp chips */
+#define LH28F640BFHE_PTTL90	0x00b0
+#define LH28F640BFHE_PBTL90	0x00b1
+#define LH28F640BFHE_PTTL70A	0x00b2
+#define LH28F640BFHE_PBTL70A	0x00b3
 
 static int cfi_intelext_read (struct mtd_info *, loff_t, size_t, size_t *, u_char *);
 static int cfi_intelext_write_words(struct mtd_info *, loff_t, size_t, size_t *, const u_char *);
@@ -258,6 +263,36 @@ static void fixup_st_m28w320cb(struct mtd_info *mtd)
 		(cfi->cfiq->EraseRegionInfo[1] & 0xffff0000) | 0x3e;
 };
 
+static int is_LH28F640BF(struct cfi_private *cfi)
+{
+	/* Sharp LH28F640BF Family */
+	if (cfi->mfr == CFI_MFR_SHARP && (
+	    cfi->id == LH28F640BFHE_PTTL90 || cfi->id == LH28F640BFHE_PBTL90 ||
+	    cfi->id == LH28F640BFHE_PTTL70A || cfi->id == LH28F640BFHE_PBTL70A))
+		return 1;
+	return 0;
+}
+
+static void fixup_LH28F640BF(struct mtd_info *mtd)
+{
+	struct map_info *map = mtd->priv;
+	struct cfi_private *cfi = map->fldrv_priv;
+	struct cfi_pri_intelext *extp = cfi->cmdset_priv;
+
+	/* Reset the Partition Configuration Register on LH28F640BF
+	 * to a single partition (PCR = 0x000): PCR is embedded into A0-A15. */
+	if (is_LH28F640BF(cfi)) {
+		printk(KERN_INFO "Reset Partition Config. Register: 1 Partition of 4 planes\n");
+		map_write(map, CMD(0x60), 0);
+		map_write(map, CMD(0x04), 0);
+
+		/* We have set one single partition thus
+		 * Simultaneous Operations are not allowed */
+		printk(KERN_INFO "cfi_cmdset_0001: Simultaneous Operations disabled\n");
+		extp->FeatureSupport &= ~512;
+	}
+}
+
 static void fixup_use_point(struct mtd_info *mtd)
 {
 	struct map_info *map = mtd->priv;
@@ -309,6 +344,8 @@ static struct cfi_fixup cfi_fixup_table[] = {
 	{ CFI_MFR_ST, 0x00ba, /* M28W320CT */ fixup_st_m28w320ct },
 	{ CFI_MFR_ST, 0x00bb, /* M28W320CB */ fixup_st_m28w320cb },
 	{ CFI_MFR_INTEL, CFI_ID_ANY, fixup_unlock_powerup_lock },
+	{ CFI_MFR_SHARP, CFI_ID_ANY, fixup_unlock_powerup_lock },
+	{ CFI_MFR_SHARP, CFI_ID_ANY, fixup_LH28F640BF },
 	{ 0, 0, NULL }
 };
 
@@ -1649,6 +1686,12 @@ static int __xipram do_write_buffer(struct map_info *map, struct flchip *chip,
 	initial_adr = adr;
 	cmd_adr = adr & ~(wbufsize-1);
 
+	/* Sharp LH28F640BF chips need the first address for the
+	 * Page Buffer Program command. See Table 5 of
+	 * LH28F320BF, LH28F640BF, LH28F128BF Series (Appendix FUM00701) */
+	if (is_LH28F640BF(cfi))
+		cmd_adr = adr;
+
 	/* Let's determine this according to the interleave only once */
 	write_cmd = (cfi->cfiq->P_ID != P_ID_INTEL_PERFORMANCE) ? CMD(0xe8) : CMD(0xe9);