diff options
| -rw-r--r-- | Documentation/devicetree/bindings/mtd/atmel-nand.txt | 6 | ||||
| -rw-r--r-- | drivers/mtd/nand/atmel_nand.c | 81 | ||||
| -rw-r--r-- | drivers/mtd/nand/atmel_nand_ecc.h | 4 |
3 files changed, 85 insertions, 6 deletions
diff --git a/Documentation/devicetree/bindings/mtd/atmel-nand.txt b/Documentation/devicetree/bindings/mtd/atmel-nand.txt index 6edc3b616e98..1fe6dde98499 100644 --- a/Documentation/devicetree/bindings/mtd/atmel-nand.txt +++ b/Documentation/devicetree/bindings/mtd/atmel-nand.txt @@ -5,7 +5,9 @@ Required properties: - 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 - PMECC, PMECC Error Location controller and ROM which has lookup tables. + PMECC and PMECC Error Location controller. + The PMECC lookup table address and size in ROM is optional. If not + specified, driver will build it in runtime. - atmel,nand-addr-offset : offset for the address latch. - atmel,nand-cmd-offset : offset for the command latch. - #address-cells, #size-cells : Must be present if the device has sub-nodes @@ -27,7 +29,7 @@ Optional properties: are: 512, 1024. - atmel,pmecc-lookup-table-offset : includes two offsets of lookup table in ROM for different sector size. First one is for sector size 512, the next is for - sector size 1024. + sector size 1024. If not specified, driver will build the table in runtime. - nand-bus-width : 8 or 16 bus width if not present 8 - nand-on-flash-bbt: boolean to enable on flash bbt option if not present false - Nand Flash Controller(NFC) is a slave driver under Atmel nand flash diff --git a/drivers/mtd/nand/atmel_nand.c b/drivers/mtd/nand/atmel_nand.c index 19d1e9d17bf9..5c1423a2ffb5 100644 --- a/drivers/mtd/nand/atmel_nand.c +++ b/drivers/mtd/nand/atmel_nand.c @@ -127,6 +127,7 @@ struct atmel_nand_host { bool has_pmecc; u8 pmecc_corr_cap; u16 pmecc_sector_size; + bool has_no_lookup_table; u32 pmecc_lookup_table_offset; u32 pmecc_lookup_table_offset_512; u32 pmecc_lookup_table_offset_1024; @@ -1112,12 +1113,66 @@ static int pmecc_choose_ecc(struct atmel_nand_host *host, return 0; } +static inline int deg(unsigned int poly) +{ + /* polynomial degree is the most-significant bit index */ + return fls(poly) - 1; +} + +static int build_gf_tables(int mm, unsigned int poly, + int16_t *index_of, int16_t *alpha_to) +{ + unsigned int i, x = 1; + const unsigned int k = 1 << deg(poly); + unsigned int nn = (1 << mm) - 1; + + /* primitive polynomial must be of degree m */ + if (k != (1u << mm)) + return -EINVAL; + + for (i = 0; i < nn; i++) { + alpha_to[i] = x; + index_of[x] = i; + if (i && (x == 1)) + /* polynomial is not primitive (a^i=1 with 0<i<2^m-1) */ + return -EINVAL; + x <<= 1; + if (x & k) + x ^= poly; + } + alpha_to[nn] = 1; + index_of[0] = 0; + + return 0; +} + +static uint16_t *create_lookup_table(struct device *dev, int sector_size) +{ + int degree = (sector_size == 512) ? + PMECC_GF_DIMENSION_13 : + PMECC_GF_DIMENSION_14; + unsigned int poly = (sector_size == 512) ? + PMECC_GF_13_PRIMITIVE_POLY : + PMECC_GF_14_PRIMITIVE_POLY; + int table_size = (sector_size == 512) ? + PMECC_LOOKUP_TABLE_SIZE_512 : + PMECC_LOOKUP_TABLE_SIZE_1024; + + int16_t *addr = devm_kzalloc(dev, 2 * table_size * sizeof(uint16_t), + GFP_KERNEL); + if (addr && build_gf_tables(degree, poly, addr, addr + table_size)) + return NULL; + + return addr; +} + static int atmel_pmecc_nand_init_params(struct platform_device *pdev, struct atmel_nand_host *host) { struct mtd_info *mtd = &host->mtd; struct nand_chip *nand_chip = &host->nand_chip; struct resource *regs, *regs_pmerr, *regs_rom; + uint16_t *galois_table; int cap, sector_size, err_no; err_no = pmecc_choose_ecc(host, &cap, §or_size); @@ -1163,8 +1218,24 @@ static int atmel_pmecc_nand_init_params(struct platform_device *pdev, regs_rom = platform_get_resource(pdev, IORESOURCE_MEM, 3); host->pmecc_rom_base = devm_ioremap_resource(&pdev->dev, regs_rom); if (IS_ERR(host->pmecc_rom_base)) { - err_no = PTR_ERR(host->pmecc_rom_base); - goto err; + if (!host->has_no_lookup_table) + /* Don't display the information again */ + dev_err(host->dev, "Can not get I/O resource for ROM, will build a lookup table in runtime!\n"); + + host->has_no_lookup_table = true; + } + + if (host->has_no_lookup_table) { + /* Build the look-up table in runtime */ + galois_table = create_lookup_table(host->dev, sector_size); + if (!galois_table) { + dev_err(host->dev, "Failed to build a lookup table in runtime!\n"); + err_no = -EINVAL; + goto err; + } + + host->pmecc_rom_base = (void __iomem *)galois_table; + host->pmecc_lookup_table_offset = 0; } nand_chip->ecc.size = sector_size; @@ -1501,8 +1572,10 @@ static int atmel_of_init_port(struct atmel_nand_host *host, if (of_property_read_u32_array(np, "atmel,pmecc-lookup-table-offset", offset, 2) != 0) { - dev_err(host->dev, "Cannot get PMECC lookup table offset\n"); - return -EINVAL; + dev_err(host->dev, "Cannot get PMECC lookup table offset, will build a lookup table in runtime.\n"); + host->has_no_lookup_table = true; + /* Will build a lookup table and initialize the offset later */ + return 0; } if (!offset[0] && !offset[1]) { dev_err(host->dev, "Invalid PMECC lookup table offset\n"); diff --git a/drivers/mtd/nand/atmel_nand_ecc.h b/drivers/mtd/nand/atmel_nand_ecc.h index 8a1e9a686759..d4035e335ad8 100644 --- a/drivers/mtd/nand/atmel_nand_ecc.h +++ b/drivers/mtd/nand/atmel_nand_ecc.h @@ -142,6 +142,10 @@ #define PMECC_GF_DIMENSION_13 13 #define PMECC_GF_DIMENSION_14 14 +/* Primitive Polynomial used by PMECC */ +#define PMECC_GF_13_PRIMITIVE_POLY 0x201b +#define PMECC_GF_14_PRIMITIVE_POLY 0x4443 + #define PMECC_LOOKUP_TABLE_SIZE_512 0x2000 #define PMECC_LOOKUP_TABLE_SIZE_1024 0x4000 |