On Tue, Oct 15, 2013 at 11:19:53AM +0530, Pekon Gupta wrote: > current implementation in omap3_init_bch() has some redundant code like: > (1) omap3_init_bch() re-probes the DT-binding to detect presence of ELM h/w > engine on SoC. And based on that it selects implemetation of ecc-scheme. > However, this is already done as part of GPMC DT parsing. > (2) As omap3_init_bch() serves as common function for configuring all types of > BCHx ecc-schemes, so there are multiple levels of redudant if..then..else > checks while populating nand_chip->ecc. > > This patch make following changes to OMAP NAND driver: > (1) removes omap3_init_bch(): each ecc-scheme is individually configured in > omap_nand_probe() there by removing redundant if..then..else checks. > (2) adds is_elm_present(): re-probing of ELM device via DT is not required as > it's done in GPMC driver probe. Thus is_elm_present() just initializes ELM > driver with NAND probe data, when ecc-scheme with h/w based error-detection > is used. > (3) separates out configuration of different flavours of "BCH4" and "BCH8" > ecc-schemes as given in below table > (4) conditionally compiles callbacks implementations of ecc.hwctl(), > ecc.calculate(), ecc.correct() to avoid warning of un-used functions. > > +---------------------------------------+---------------+---------------+ > | ECC scheme |ECC calculation|Error detection| > +---------------------------------------+---------------+---------------+ > |OMAP_ECC_HAM1_CODE_HW |H/W (GPMC) |S/W | > +---------------------------------------+---------------+---------------+ > |OMAP_ECC_BCH4_CODE_HW_DETECTION_SW |H/W (GPMC) |S/W (lib/bch.c)| > | (needs CONFIG_MTD_NAND_ECC_BCH) | | | > | | | | > |OMAP_ECC_BCH4_CODE_HW |H/W (GPMC) |H/W (ELM) | > | (needs CONFIG_MTD_NAND_OMAP_BCH && | | | > | ti,elm-id) | | | > +---------------------------------------+---------------+---------------+ > |OMAP_ECC_BCH8_CODE_HW_DETECTION_SW |H/W (GPMC) |S/W (lib/bch.c)| > | (needs CONFIG_MTD_NAND_ECC_BCH) | | | > | | | | > |OMAP_ECC_BCH8_CODE_HW |H/W (GPMC) |H/W (ELM) | > | (needs CONFIG_MTD_NAND_OMAP_BCH && | | | > | ti,elm-id) | | | > +---------------------------------------+---------------+---------------+ > > - 'CONFIG_MTD_NAND_ECC_BCH' is generic KConfig required to build lib/bch.c > which is required for ECC error detection done in software. > (mainly used for legacy platforms which do not have on-chip ELM engine) > > - 'CONFIG_MTD_NAND_OMAP_BCH' is OMAP specific Kconfig to detemine presence > on ELM h/w engine on SoC. > > Signed-off-by: Pekon Gupta <pekon@xxxxxx> This patch looks good to me. Brian -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
