mtd: nand_ids: introduce helper macros

Introduce helper macros for defining NAND chips. These macros do not really add
much value in the current code-base. However, we are going to add full ID
support which adds some more complexity to the table, and helper macros become
useful for readability.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

drivers/mtd/nand/sm_common.c

@@ -67,39 +67,37 @@ static int sm_block_markbad(struct mtd_info *mtd, loff_t ofs)
 	return error;
 }
 
-
 static struct nand_flash_dev nand_smartmedia_flash_ids[] = {
-	{"SmartMedia 2MiB 3,3V ROM",    0x5d, 512, 2, 0x2000, NAND_ROM},
-	{"SmartMedia 4MiB 3,3V",        0xe3, 512, 4, 0x2000, 0},
-	{"SmartMedia 4MiB 3,3/5V",      0xe5, 512, 4, 0x2000, 0},
-	{"SmartMedia 4MiB 5V",          0x6b, 512, 4, 0x2000, 0},
-	{"SmartMedia 4MiB 3,3V ROM",    0xd5, 512, 4, 0x2000, NAND_ROM},
-	{"SmartMedia 8MiB 3,3V",        0xe6, 512, 8, 0x2000, 0},
-	{"SmartMedia 8MiB 3,3V ROM",    0xd6, 512, 8, 0x2000, NAND_ROM},
-	{"SmartMedia 16MiB 3,3V",       0x73, 512, 16, 0x4000, 0},
-	{"SmartMedia 16MiB 3,3V ROM",   0x57, 512, 16, 0x4000, NAND_ROM},
-	{"SmartMedia 32MiB 3,3V",       0x75, 512, 32, 0x4000, 0},
-	{"SmartMedia 32MiB 3,3V ROM",   0x58, 512, 32, 0x4000, NAND_ROM},
-	{"SmartMedia 64MiB 3,3V",       0x76, 512, 64, 0x4000, 0},
-	{"SmartMedia 64MiB 3,3V ROM",   0xd9, 512, 64, 0x4000, NAND_ROM},
-	{"SmartMedia 128MiB 3,3V",      0x79, 512, 128, 0x4000, 0},
-	{"SmartMedia 128MiB 3,3V ROM",  0xda, 512, 128, 0x4000, NAND_ROM},
-	{"SmartMedia 256MiB 3,3V",      0x71, 512, 256, 0x4000 },
-	{"SmartMedia 256MiB 3,3V ROM",  0x5b, 512, 256, 0x4000, NAND_ROM},
-	{NULL,}
+	LEGACY_ID_NAND("SmartMedia 2MiB 3,3V ROM",   0x5d, 512, 2,   0x2000, NAND_ROM),
+	LEGACY_ID_NAND("SmartMedia 4MiB 3,3V",       0xe3, 512, 4,   0x2000, 0),
+	LEGACY_ID_NAND("SmartMedia 4MiB 3,3/5V",     0xe5, 512, 4,   0x2000, 0),
+	LEGACY_ID_NAND("SmartMedia 4MiB 5V",         0x6b, 512, 4,   0x2000, 0),
+	LEGACY_ID_NAND("SmartMedia 4MiB 3,3V ROM",   0xd5, 512, 4,   0x2000, NAND_ROM),
+	LEGACY_ID_NAND("SmartMedia 8MiB 3,3V",       0xe6, 512, 8,   0x2000, 0),
+	LEGACY_ID_NAND("SmartMedia 8MiB 3,3V ROM",   0xd6, 512, 8,   0x2000, NAND_ROM),
+	LEGACY_ID_NAND("SmartMedia 16MiB 3,3V",      0x73, 512, 16,  0x4000, 0),
+	LEGACY_ID_NAND("SmartMedia 16MiB 3,3V ROM",  0x57, 512, 16,  0x4000, NAND_ROM),
+	LEGACY_ID_NAND("SmartMedia 32MiB 3,3V",      0x75, 512, 32,  0x4000, 0),
+	LEGACY_ID_NAND("SmartMedia 32MiB 3,3V ROM",  0x58, 512, 32,  0x4000, NAND_ROM),
+	LEGACY_ID_NAND("SmartMedia 64MiB 3,3V",      0x76, 512, 64,  0x4000, 0),
+	LEGACY_ID_NAND("SmartMedia 64MiB 3,3V ROM",  0xd9, 512, 64,  0x4000, NAND_ROM),
+	LEGACY_ID_NAND("SmartMedia 128MiB 3,3V",     0x79, 512, 128, 0x4000, 0),
+	LEGACY_ID_NAND("SmartMedia 128MiB 3,3V ROM", 0xda, 512, 128, 0x4000, NAND_ROM),
+	LEGACY_ID_NAND("SmartMedia 256MiB 3, 3V",    0x71, 512, 256, 0x4000, 0),
+	LEGACY_ID_NAND("SmartMedia 256MiB 3,3V ROM", 0x5b, 512, 256, 0x4000, NAND_ROM),
+	{NULL}
 };
 
 static struct nand_flash_dev nand_xd_flash_ids[] = {
-
-	{"xD 16MiB 3,3V",    0x73, 512, 16, 0x4000, 0},
-	{"xD 32MiB 3,3V",    0x75, 512, 32, 0x4000, 0},
-	{"xD 64MiB 3,3V",    0x76, 512, 64, 0x4000, 0},
-	{"xD 128MiB 3,3V",   0x79, 512, 128, 0x4000, 0},
-	{"xD 256MiB 3,3V",   0x71, 512, 256, 0x4000, NAND_BROKEN_XD},
-	{"xD 512MiB 3,3V",   0xdc, 512, 512, 0x4000, NAND_BROKEN_XD},
-	{"xD 1GiB 3,3V",     0xd3, 512, 1024, 0x4000, NAND_BROKEN_XD},
-	{"xD 2GiB 3,3V",     0xd5, 512, 2048, 0x4000, NAND_BROKEN_XD},
-	{NULL,}
+	LEGACY_ID_NAND("xD 16MiB 3,3V",  0x73, 512, 16,   0x4000, 0),
+	LEGACY_ID_NAND("xD 32MiB 3,3V",  0x75, 512, 32,   0x4000, 0),
+	LEGACY_ID_NAND("xD 64MiB 3,3V",  0x76, 512, 64,   0x4000, 0),
+	LEGACY_ID_NAND("xD 128MiB 3,3V", 0x79, 512, 128,  0x4000, 0),
+	LEGACY_ID_NAND("xD 256MiB 3,3V", 0x71, 512, 256,  0x4000, NAND_BROKEN_XD),
+	LEGACY_ID_NAND("xD 512MiB 3,3V", 0xdc, 512, 512,  0x4000, NAND_BROKEN_XD),
+	LEGACY_ID_NAND("xD 1GiB 3,3V",   0xd3, 512, 1024, 0x4000, NAND_BROKEN_XD),
+	LEGACY_ID_NAND("xD 2GiB 3,3V",   0xd5, 512, 2048, 0x4000, NAND_BROKEN_XD),
+	{NULL}
 };
 
 int sm_register_device(struct mtd_info *mtd, int smartmedia)

include/linux/mtd/nand.h

@@ -546,6 +546,30 @@ struct nand_chip {
 #define NAND_MFR_MACRONIX	0xc2
 #define NAND_MFR_EON		0x92
 
+/*
+ * A helper for defining older NAND chips where the second ID byte fully
+ * defined the chip, including the geometry (chip size, eraseblock size, page
+ * size).
+ */
+#define LEGACY_ID_NAND(nm, devid, pagesz, chipsz, erasesz, opts) \
+	{ .name = (nm), .dev_id = (devid), .pagesize = (pagesz), \
+	  .chipsize = (chipsz), .erasesize = (erasesz),          \
+	  .options = (opts) }
+
+/*
+ * A helper for defining newer chips which report their page size and
+ * eraseblock size via the extended ID bytes.
+ *
+ * The real difference between LEGACY_ID_NAND and EXTENDED_ID_NAND is that with
+ * EXTENDED_ID_NAND, manufacturers overloaded the same device ID so that the
+ * device ID now only represented a particular total chip size (and voltage,
+ * buswidth), and the page size, eraseblock size, and OOB size could vary while
+ * using the same device ID.
+ */
+#define EXTENDED_ID_NAND(nm, devid, chipsz, opts)                \
+	{ .name = (nm), .dev_id = (devid), .chipsize = (chipsz), \
+	  .options = (opts) }
+
 /**
  * struct nand_flash_dev - NAND Flash Device ID Structure
  * @name: a human-readable name of the NAND chip