diff options
Diffstat (limited to 'drivers/mtd')
| -rw-r--r-- | drivers/mtd/nand/gpmi-nand/gpmi-nand.c | 132 |
1 files changed, 131 insertions, 1 deletions
diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c index 76d2f41..2ab6b3f 100644 --- a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c +++ b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c @@ -111,7 +111,132 @@ static inline bool gpmi_check_ecc(struct gpmi_nand_data *this) return true; } -int common_nfc_set_geometry(struct gpmi_nand_data *this) +/* + * If we can get the ECC information from the nand chip, we do not + * need to calculate them ourselves. + * + * We may have available oob space in this case. + */ +static bool set_geometry_by_ecc_info(struct gpmi_nand_data *this) +{ + struct bch_geometry *geo = &this->bch_geometry; + struct mtd_info *mtd = &this->mtd; + struct nand_chip *chip = mtd->priv; + struct nand_oobfree *of = gpmi_hw_ecclayout.oobfree; + unsigned int block_mark_bit_offset; + + if (!(chip->ecc_strength_ds > 0 && chip->ecc_step_ds > 0)) + return false; + + switch (chip->ecc_step_ds) { + case SZ_512: + geo->gf_len = 13; + break; + case SZ_1K: + geo->gf_len = 14; + break; + default: + dev_err(this->dev, + "unsupported nand chip. ecc bits : %d, ecc size : %d\n", + chip->ecc_strength_ds, chip->ecc_step_ds); + return false; + } + geo->ecc_chunk_size = chip->ecc_step_ds; + geo->ecc_strength = round_up(chip->ecc_strength_ds, 2); + if (!gpmi_check_ecc(this)) + return false; + + /* Keep the C >= O */ + if (geo->ecc_chunk_size < mtd->oobsize) { + dev_err(this->dev, + "unsupported nand chip. ecc size: %d, oob size : %d\n", + chip->ecc_step_ds, mtd->oobsize); + return false; + } + + /* The default value, see comment in the legacy_set_geometry(). */ + geo->metadata_size = 10; + + geo->ecc_chunk_count = mtd->writesize / geo->ecc_chunk_size; + + /* + * Now, the NAND chip with 2K page(data chunk is 512byte) shows below: + * + * | P | + * |<----------------------------------------------------->| + * | | + * | (Block Mark) | + * | P' | | | | + * |<-------------------------------------------->| D | | O' | + * | |<---->| |<--->| + * V V V V V + * +---+----------+-+----------+-+----------+-+----------+-+-----+ + * | M | data |E| data |E| data |E| data |E| | + * +---+----------+-+----------+-+----------+-+----------+-+-----+ + * ^ ^ + * | O | + * |<------------>| + * | | + * + * P : the page size for BCH module. + * E : The ECC strength. + * G : the length of Galois Field. + * N : The chunk count of per page. + * M : the metasize of per page. + * C : the ecc chunk size, aka the "data" above. + * P': the nand chip's page size. + * O : the nand chip's oob size. + * O': the free oob. + * + * The formula for P is : + * + * E * G * N + * P = ------------ + P' + M + * 8 + * + * The position of block mark moves forward in the ECC-based view + * of page, and the delta is: + * + * E * G * (N - 1) + * D = (---------------- + M) + * 8 + * + * Please see the comment in legacy_set_geometry(). + * With the condition C >= O , we still can get same result. + * So the bit position of the physical block mark within the ECC-based + * view of the page is : + * (P' - D) * 8 + */ + geo->page_size = mtd->writesize + geo->metadata_size + + (geo->gf_len * geo->ecc_strength * geo->ecc_chunk_count) / 8; + + /* The available oob size we have. */ + if (geo->page_size < mtd->writesize + mtd->oobsize) { + of->offset = geo->page_size - mtd->writesize; + of->length = mtd->oobsize - of->offset; + mtd->oobavail = gpmi_hw_ecclayout.oobavail = of->length; + } + + geo->payload_size = mtd->writesize; + + geo->auxiliary_status_offset = ALIGN(geo->metadata_size, 4); + geo->auxiliary_size = ALIGN(geo->metadata_size, 4) + + ALIGN(geo->ecc_chunk_count, 4); + + if (!this->swap_block_mark) + return true; + + /* For bit swap. */ + block_mark_bit_offset = mtd->writesize * 8 - + (geo->ecc_strength * geo->gf_len * (geo->ecc_chunk_count - 1) + + geo->metadata_size * 8); + + geo->block_mark_byte_offset = block_mark_bit_offset / 8; + geo->block_mark_bit_offset = block_mark_bit_offset % 8; + return true; +} + +static int legacy_set_geometry(struct gpmi_nand_data *this) { struct bch_geometry *geo = &this->bch_geometry; struct mtd_info *mtd = &this->mtd; @@ -223,6 +348,11 @@ int common_nfc_set_geometry(struct gpmi_nand_data *this) return 0; } +int common_nfc_set_geometry(struct gpmi_nand_data *this) +{ + return set_geometry_by_ecc_info(this) ? 0 : legacy_set_geometry(this); +} + struct dma_chan *get_dma_chan(struct gpmi_nand_data *this) { int chipnr = this->current_chip; |
