[MTD] NAND: add subpage write support

Many SLC NANDs support up to 4 writes at one NAND page. Add support
of this feature.

Signed-off-by: Artem Bityutskiy <dedekind@infradead.org>

2 files changed, 11 insertions, 0 deletions

diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h
index e34bbc98d4fe..18acb6d0033b 100644
--- a/include/linux/mtd/mtd.h
+++ b/include/linux/mtd/mtd.h
@@ -200,6 +200,8 @@ struct mtd_info {
 
         /* ECC status information */
         struct mtd_ecc_stats ecc_stats;
+        /* Subpage shift (NAND) */
+        int subpage_sft;
 
         void *priv;
 
diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
index 6fc3e07497e0..1aeedf27a1ff 100644
--- a/include/linux/mtd/nand.h
+++ b/include/linux/mtd/nand.h
@@ -166,6 +166,9 @@ typedef enum {
  * for all large page devices, as they do not support
  * autoincrement.*/
 #define NAND_NO_READRDY         0x00000100
+/* Chip does not allow subpage writes */
+#define NAND_NO_SUBPAGE_WRITE   0x00000200
+
 
 /* Options valid for Samsung large page devices */
 #define NAND_SAMSUNG_LP_OPTIONS \
@@ -193,6 +196,9 @@ typedef enum {
 /* Nand scan has allocated controller struct */
 #define NAND_CONTROLLER_ALLOC   0x80000000
 
+/* Cell info constants */
+#define NAND_CI_CHIPNR_MSK      0x03
+#define NAND_CI_CELLTYPE_MSK    0x0C
 
 /*
  * nand_state_t - chip states
@@ -341,6 +347,7 @@ struct nand_buffers {
  * @chipsize:           [INTERN] the size of one chip for multichip arrays
  * @pagemask:           [INTERN] page number mask = number of (pages / chip) - 1
  * @pagebuf:            [INTERN] holds the pagenumber which is currently in data_buf
+ * @subpagesize:        [INTERN] holds the subpagesize
  * @ecclayout:          [REPLACEABLE] the default ecc placement scheme
  * @bbt:                [INTERN] bad block table pointer
  * @bbt_td:             [REPLACEABLE] bad block table descriptor for flash lookup
@@ -388,6 +395,8 @@ struct nand_chip {
         unsigned long   chipsize;
         int             pagemask;
         int             pagebuf;
+        int             subpagesize;
+        uint8_t         cellinfo;
         int             badblockpos;
 
         nand_state_t    state;