In default way, we use the ecc-strength/ecc-step-size calculated by ourselves
and use all the OOB area.
This patch adds a new property : "fsl,use-minimum-ecc"
If we enable it, we will use the datasheet's minimum required ECC provided by
the MTD layer (the ecc_strength_ds/ecc_strength_ds fields in the nand_chip{}).
So we may have free space in the OOB area by using the minimum ECC, and we may
support JFFS2 with some SLC NANDs, such as Micron's SLC NAND.
Signed-off-by: Huang Shijie <b32955@xxxxxxxxxxxxx>
---
.../devicetree/bindings/mtd/gpmi-nand.txt | 6 ++++++
drivers/mtd/nand/gpmi-nand/gpmi-nand.c | 4 ++++
2 files changed, 10 insertions(+), 0 deletions(-)
diff --git a/Documentation/devicetree/bindings/mtd/gpmi-nand.txt b/Documentation/devicetree/bindings/mtd/gpmi-nand.txt
index 551b2a1..7a5afa8 100644
--- a/Documentation/devicetree/bindings/mtd/gpmi-nand.txt
+++ b/Documentation/devicetree/bindings/mtd/gpmi-nand.txt
@@ -17,6 +17,12 @@ Required properties:
Optional properties:
- nand-on-flash-bbt: boolean to enable on flash bbt option if not
present false
+ - fsl,use-minimum-ecc: By enabling this boolean property, the gpmi will try
+ to use the datasheet's minimum required ECC provided by
+ the MTD layer (the ecc_strength_ds/ecc_strength_ds fields
+ in the nand_chip{}). So we may have free space in the OOB
+ area by using the minimum ECC, and we may support JFFS2
+ with some SLC NANDs, such as Micron's SLC NAND.
The device tree may optionally contain sub-nodes describing partitions of the
address space. See partition.txt for more detail.
diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
index 43a62e8..d0ae7f4 100644
--- a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
+++ b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
@@ -352,6 +352,10 @@ static int legacy_set_geometry(struct gpmi_nand_data *this)
int common_nfc_set_geometry(struct gpmi_nand_data *this)
{
+ if (of_property_read_bool(this->dev->of_node, "fsl,use-minimum-ecc"))
+ return set_geometry_by_ecc_info(this) ? 0 :
+ legacy_set_geometry(this);
+
return legacy_set_geometry(this) ?
(!set_geometry_by_ecc_info(this)) : 0;
}
--
1.7.2.rc3
--
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