On Wed, 13 Jan 2016 17:34:15 +0100 Romain Izard <romain.izard.pro@xxxxxxxxx> wrote: > Starting with the SAMA5D2, there is a new revision of the Atmel PMECC > controller that can correct 32 bits in each sector. This controller is > not 100% compatible with the previous revision that corrected a maximum > of 24 bits by sector, as some register addresses overlap. > > Using information from the device tree, we can configure the driver to > work with both versions. > > Signed-off-by: Romain Izard <romain.izard.pro@xxxxxxxxx> > --- > .../devicetree/bindings/mtd/atmel-nand.txt | 7 +++++-- > drivers/mtd/nand/atmel_nand.c | 23 +++++++++++++++++++++- > drivers/mtd/nand/atmel_nand_ecc.h | 8 ++++++-- > 3 files changed, 33 insertions(+), 5 deletions(-) > > diff --git a/Documentation/devicetree/bindings/mtd/atmel-nand.txt b/Documentation/devicetree/bindings/mtd/atmel-nand.txt > index 89b0db9801b0..90887b430f03 100644 > --- a/Documentation/devicetree/bindings/mtd/atmel-nand.txt > +++ b/Documentation/devicetree/bindings/mtd/atmel-nand.txt > @@ -1,7 +1,10 @@ > Atmel NAND flash > > Required properties: > -- compatible : should be "atmel,at91rm9200-nand" or "atmel,sama5d4-nand". > +- compatible: The possible values are: > + "atmel,at91rm9200-nand" > + "atmel,sama5d2-nand" > + "atmel,sama5d4-nand" > - reg : should specify localbus address and size used for the chip, > and hardware ECC controller if available. > If the hardware ECC is PMECC, it should contain address and size for > @@ -22,7 +25,7 @@ Optional properties: > Supported values are: "none", "soft", "hw", "hw_syndrome", "hw_oob_first", > "soft_bch". > - atmel,has-pmecc : boolean to enable Programmable Multibit ECC hardware. > - Only supported by at91sam9x5 or later sam9 product. > + Supported by AT91SAM9x5 or later SAM9 chips, and SAMA5 chips. > - atmel,pmecc-cap : error correct capability for Programmable Multibit ECC > Controller. Supported values are: 2, 4, 8, 12, 24. > - atmel,pmecc-sector-size : sector size for ECC computation. Supported values > diff --git a/drivers/mtd/nand/atmel_nand.c b/drivers/mtd/nand/atmel_nand.c > index e5d7e7e63f49..6fe50e2d291f 100644 > --- a/drivers/mtd/nand/atmel_nand.c > +++ b/drivers/mtd/nand/atmel_nand.c > @@ -65,6 +65,7 @@ module_param(on_flash_bbt, int, 0); > > struct atmel_nand_caps { > bool pmecc_correct_erase_page; > + uint8_t pmecc_max_correction; > }; > > struct atmel_nand_nfc_priv { > @@ -146,6 +147,7 @@ struct atmel_nand_host { > int pmecc_cw_len; /* Length of codeword */ > > void __iomem *pmerrloc_base; > + void __iomem *pmerrloc_el_base; > void __iomem *pmecc_rom_base; > > /* lookup table for alpha_to and index_of */ > @@ -817,7 +819,7 @@ static void pmecc_correct_data(struct mtd_info *mtd, uint8_t *buf, uint8_t *ecc, > sector_size = host->pmecc_sector_size; > > while (err_nbr) { > - tmp = pmerrloc_readl_el_relaxed(host->pmerrloc_base, i) - 1; > + tmp = pmerrloc_readl_el_relaxed(host->pmerrloc_el_base, i) - 1; > byte_pos = tmp / 8; > bit_pos = tmp % 8; > > @@ -1208,6 +1210,8 @@ static int atmel_pmecc_nand_init_params(struct platform_device *pdev, > err_no = PTR_ERR(host->pmerrloc_base); > goto err; > } How about putting the comment you added below here: /* * The ATMEL_PMERRLOC_ELx register location depends on the number of * bits corrected by the PMECC controller. Pre-calculate the * pmerrloc_el_base according to the PMECC capabilities. */ > + host->pmerrloc_el_base = host->pmerrloc_base + ATMEL_PMERRLOC_SIGMAx + > + (host->caps->pmecc_max_correction + 1) * 4; > > if (!host->has_no_lookup_table) { > regs_rom = platform_get_resource(pdev, IORESOURCE_MEM, 3); > @@ -2307,17 +2311,34 @@ static int atmel_nand_remove(struct platform_device *pdev) > return 0; > } > > +/* > + * AT91RM9200 does not have PMECC or PMECC Errloc peripherals for > + * BCH ECC. Combined with the "atmel,has-pmecc", it is used to describe > + * devices from the SAM9 family that have those. > + */ > static struct atmel_nand_caps at91rm9200_caps = { > .pmecc_correct_erase_page = false, > + .pmecc_max_correction = 24, > }; > > static struct atmel_nand_caps sama5d4_caps = { > .pmecc_correct_erase_page = true, > + .pmecc_max_correction = 24, > +}; > + > +/* > + * The PMECC Errloc controller starting in SAMA5D2 is not compatible, > + * as the increased correction strength requires more registers. > + */ > +static struct atmel_nand_caps sama5d2_caps = { > + .pmecc_correct_erase_page = true, > + .pmecc_max_correction = 32, > }; > > static const struct of_device_id atmel_nand_dt_ids[] = { > { .compatible = "atmel,at91rm9200-nand", .data = &at91rm9200_caps }, > { .compatible = "atmel,sama5d4-nand", .data = &sama5d4_caps }, > + { .compatible = "atmel,sama5d2-nand", .data = &sama5d2_caps }, > { /* sentinel */ } > }; > > diff --git a/drivers/mtd/nand/atmel_nand_ecc.h b/drivers/mtd/nand/atmel_nand_ecc.h > index 668e7358f19b..ec964c43c932 100644 > --- a/drivers/mtd/nand/atmel_nand_ecc.h > +++ b/drivers/mtd/nand/atmel_nand_ecc.h > @@ -108,7 +108,11 @@ > #define PMERRLOC_ERR_NUM_MASK (0x1f << 8) > #define PMERRLOC_CALC_DONE (1 << 0) > #define ATMEL_PMERRLOC_SIGMAx 0x028 /* Error location SIGMA x */ > -#define ATMEL_PMERRLOC_ELx 0x08c /* Error location x */ > + > +/* > + * The ATMEL_PMERRLOC_ELx register location depends from the number of > + * bits corrected by the PMECC controller. Do not use it. > + */ > > /* Register access macros for PMECC */ > #define pmecc_readl_relaxed(addr, reg) \ > @@ -136,7 +140,7 @@ > readl_relaxed((addr) + ATMEL_PMERRLOC_SIGMAx + ((n) * 4)) > > #define pmerrloc_readl_el_relaxed(addr, n) \ > - readl_relaxed((addr) + ATMEL_PMERRLOC_ELx + ((n) * 4)) > + readl_relaxed((addr) + ((n) * 4)) Another option would have been to pass the maximum ECC strength here, and modify the ATMEL_PMERRLOC_ELx macro to take a max_strength argument and return the adjusted ELx offset. Anyway, both solutions work for me. > > /* Galois field dimension */ > #define PMECC_GF_DIMENSION_13 13 -- Boris Brezillon, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com -- 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