mtd: nand: pxa3xx: Add support for 2048 bytes page size devices
This commit adds support for devices with 2048B page sizes and
4-bit ECC strength requirements. This is achieved by enabling the BCH
ECC engine, which provides a higher strength: 16-bit over 2048 bytes.
Additionally, add a proper ECC layout to model the controller's view
of the device (where 'U' means unused and 'B' is the bad block marker):
----------------------------------------------------
| 2048B data | B | B | 30B spare | 30B ECC | U | U |
----------------------------------------------------
Signed-off-by: Rodolfo Giometti <giometti@linux.it>
[Brian: updated with Ezequiel's patch description]
Acked-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
diff --git a/drivers/mtd/nand/pxa3xx_nand.c b/drivers/mtd/nand/pxa3xx_nand.c
index 31aae53..2a7a0b2 100644
--- a/drivers/mtd/nand/pxa3xx_nand.c
+++ b/drivers/mtd/nand/pxa3xx_nand.c
@@ -286,6 +286,16 @@
.pattern = bbt_mirror_pattern
};
+static struct nand_ecclayout ecc_layout_2KB_bch4bit = {
+ .eccbytes = 32,
+ .eccpos = {
+ 32, 33, 34, 35, 36, 37, 38, 39,
+ 40, 41, 42, 43, 44, 45, 46, 47,
+ 48, 49, 50, 51, 52, 53, 54, 55,
+ 56, 57, 58, 59, 60, 61, 62, 63},
+ .oobfree = { {2, 30} }
+};
+
static struct nand_ecclayout ecc_layout_4KB_bch4bit = {
.eccbytes = 64,
.eccpos = {
@@ -1360,6 +1370,17 @@
* Required ECC: 4-bit correction per 512 bytes
* Select: 16-bit correction per 2048 bytes
*/
+ } else if (strength == 4 && ecc_stepsize == 512 && page_size == 2048) {
+ info->ecc_bch = 1;
+ info->chunk_size = 2048;
+ info->spare_size = 32;
+ info->ecc_size = 32;
+ ecc->mode = NAND_ECC_HW;
+ ecc->size = info->chunk_size;
+ ecc->layout = &ecc_layout_2KB_bch4bit;
+ ecc->strength = 16;
+ return 1;
+
} else if (strength == 4 && ecc_stepsize == 512 && page_size == 4096) {
info->ecc_bch = 1;
info->chunk_size = 2048;