From: Jordan Friendshuh <[email protected]> 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 <[email protected]> Signed-off-by: Aaron Sierra <[email protected]> --- v2: * Now using ECC mode and strength helpers from of_mtd.h * ECC mode and strength checking is more robust .../devicetree/bindings/mtd/fsl-upm-nand.txt | 2 + drivers/mtd/nand/Kconfig | 1 + drivers/mtd/nand/fsl_upm.c | 51 +++++++++++++++++++--- 3 files changed, 49 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..8f38447 100644 --- a/drivers/mtd/nand/fsl_upm.c +++ b/drivers/mtd/nand/fsl_upm.c @@ -18,6 +18,7 @@ #include <linux/mtd/nand_ecc.h> #include <linux/mtd/partitions.h> #include <linux/mtd/mtd.h> +#include <linux/of_mtd.h> #include <linux/of_address.h> #include <linux/of_platform.h> #include <linux/of_gpio.h> @@ -160,6 +161,11 @@ static int fun_chip_init(struct fsl_upm_nand *fun, int ret; struct device_node *flash_np; struct mtd_part_parser_data ppdata; + int mode, 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 +174,46 @@ 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 nand-ecc-strength < 0, require ECC_SOFT, error otherwise. + * If nand-ecc-strength == 0, error. + * If nand-ecc-strength == 1, require ECC_SOFT, error otherwise. + * If nand-ecc-strength > 1, force ECC_SOFT_BCH (warn on mode mismatch). + */ + mode = of_get_nand_ecc_mode(flash_np); + strength = of_get_nand_ecc_strength(flash_np); + if (!of_property_read_bool(flash_np, "nand-ecc-mode")) { + dev_info(fun->dev, "ECC mode defaulting to 'soft'"); + mode = NAND_ECC_SOFT; + } else if (mode != NAND_ECC_SOFT && mode != NAND_ECC_SOFT_BCH) { + dev_err(fun->dev, "ECC mode in device tree is unsupported"); + ret = -EINVAL; + goto err; + } + + /* We know mode is either NAND_ECC_SOFT or NAND_ECC_SOFT_BCH */ + if (strength < 0 && mode == NAND_ECC_SOFT_BCH) { + dev_err(fun->dev, + "ECC BCH mode requires nand-ecc-strength property"); + ret = -EINVAL; + goto err; + } else if (strength == 0) { + dev_err(fun->dev, "ECC strength of 0 bits is unsupported"); + ret = -EINVAL; + goto err; + } else if (strength == 1 && mode == NAND_ECC_SOFT_BCH) { + dev_err(fun->dev, "ECC BCH mode requires > 1-bit strength"); + ret = -EINVAL; + goto err; + } else if (strength > 1 && mode == NAND_ECC_SOFT) { + dev_warn(fun->dev, + "Forcing ECC BCH due to %d-bit strength\n", strength); + mode = NAND_ECC_SOFT_BCH; + } + fun->chip.ecc.mode = mode; + fun->chip.ecc.strength = strength; + if (fun->mchip_count > 1) fun->chip.select_chip = fun_select_chip; @@ -178,10 +223,6 @@ 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 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
