From: Jordan Friendshuh <jfriendshuh@xxxxxxxxxxx>
Support the generic nand-ecc-mode and nand-ecc-strength device-tree
properties with the Freescale UPM NAND driver.
This patch preserves the default software ECC mode while adding the
ability to use BCH ECC for larger NAND devices.
Signed-off-by: Jordan Friendshuh <jfriendshuh@xxxxxxxxxxx>
Signed-off-by: Aaron Sierra <asierra@xxxxxxxxxxx>
---
.../devicetree/bindings/mtd/fsl-upm-nand.txt | 2 ++
drivers/mtd/nand/Kconfig | 1 +
drivers/mtd/nand/fsl_upm.c | 33 ++++++++++++++++++----
3 files changed, 31 insertions(+), 5 deletions(-)
diff --git a/Documentation/devicetree/bindings/mtd/fsl-upm-nand.txt b/Documentation/devicetree/bindings/mtd/fsl-upm-nand.txt
index fce4894..a9906f6 100644
--- a/Documentation/devicetree/bindings/mtd/fsl-upm-nand.txt
+++ b/Documentation/devicetree/bindings/mtd/fsl-upm-nand.txt
@@ -18,6 +18,8 @@ Optional properties:
- chip-delay : chip dependent delay for transferring data from array to
read registers (tR). Required if property "gpios" is not used
(R/B# pins not connected).
+- nand-ecc-mode : as defined by nand.txt ("soft" and "soft_bch", only).
+- nand-ecc-strength : as defined by nand.txt.
Each flash chip described may optionally contain additional sub-nodes
describing partitions of the address space. See partition.txt for more
diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
index f1cf503..85c0243 100644
--- a/drivers/mtd/nand/Kconfig
+++ b/drivers/mtd/nand/Kconfig
@@ -439,6 +439,7 @@ config MTD_NAND_FSL_UPM
tristate "Support for NAND on Freescale UPM"
depends on PPC_83xx || PPC_85xx
select FSL_LBC
+ select MTD_NAND_ECC_BCH
help
Enables support for NAND Flash chips wired onto Freescale PowerPC
processor localbus with User-Programmable Machine support.
diff --git a/drivers/mtd/nand/fsl_upm.c b/drivers/mtd/nand/fsl_upm.c
index 4d203e8..1fea897 100644
--- a/drivers/mtd/nand/fsl_upm.c
+++ b/drivers/mtd/nand/fsl_upm.c
@@ -160,6 +160,12 @@ static int fun_chip_init(struct fsl_upm_nand *fun,
int ret;
struct device_node *flash_np;
struct mtd_part_parser_data ppdata;
+ const char *mode;
+ u32 strength;
+
+ flash_np = of_get_next_child(upm_np, NULL);
+ if (!flash_np)
+ return -ENODEV;
fun->chip.IO_ADDR_R = fun->io_base;
fun->chip.IO_ADDR_W = fun->io_base;
@@ -168,7 +174,28 @@ static int fun_chip_init(struct fsl_upm_nand *fun,
fun->chip.read_byte = fun_read_byte;
fun->chip.read_buf = fun_read_buf;
fun->chip.write_buf = fun_write_buf;
- fun->chip.ecc.mode = NAND_ECC_SOFT;
+
+ if (of_property_read_string(flash_np, "nand-ecc-mode", &mode) ||
+ !strcmp(mode, "soft")) {
+ fun->chip.ecc.mode = NAND_ECC_SOFT;
+ } else if (!strcmp(mode, "soft_bch")) {
+ fun->chip.ecc.mode = NAND_ECC_SOFT_BCH;
+ } else {
+ dev_err(fun->dev, "ECC mode '%s' unsupported", mode);
+ goto err;
+ }
+
+ if (of_property_read_u32(flash_np, "nand-ecc-strength", &strength)) {
+ if (fun->chip.ecc.mode == NAND_ECC_SOFT_BCH) {
+ dev_err(fun->dev, "BCH ECC strength unspecified\n");
+ goto err;
+ }
+ } else if (fun->chip.ecc.mode == NAND_ECC_SOFT) {
+ dev_warn(fun->dev, "Ignoring %d-bit software ECC\n", strength);
+ } else if (fun->chip.ecc.mode == NAND_ECC_SOFT_BCH) {
+ fun->chip.ecc.strength = strength;
+ }
+
if (fun->mchip_count > 1)
fun->chip.select_chip = fun_select_chip;
@@ -178,10 +205,6 @@ static int fun_chip_init(struct fsl_upm_nand *fun,
fun->mtd.priv = &fun->chip;
fun->mtd.owner = THIS_MODULE;
- flash_np = of_get_next_child(upm_np, NULL);
- if (!flash_np)
- return -ENODEV;
-
fun->mtd.name = kasprintf(GFP_KERNEL, "0x%llx.%s", (u64)io_res->start,
flash_np->name);
if (!fun->mtd.name) {
--
1.9.1
--
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