diff options
Diffstat (limited to 'drivers/mtd/nand/gpmi-nand')
-rw-r--r-- | drivers/mtd/nand/gpmi-nand/gpmi-lib.c | 153 | ||||
-rw-r--r-- | drivers/mtd/nand/gpmi-nand/gpmi-nand.c | 201 | ||||
-rw-r--r-- | drivers/mtd/nand/gpmi-nand/gpmi-nand.h | 6 |
3 files changed, 360 insertions, 0 deletions
diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-lib.c b/drivers/mtd/nand/gpmi-nand/gpmi-lib.c index 87e658ce23ef..27f272ed502a 100644 --- a/drivers/mtd/nand/gpmi-nand/gpmi-lib.c +++ b/drivers/mtd/nand/gpmi-nand/gpmi-lib.c @@ -1353,3 +1353,156 @@ int gpmi_read_page(struct gpmi_nand_data *this, set_dma_type(this, DMA_FOR_READ_ECC_PAGE); return start_dma_with_bch_irq(this, desc); } + +/** + * gpmi_copy_bits - copy bits from one memory region to another + * @dst: destination buffer + * @dst_bit_off: bit offset we're starting to write at + * @src: source buffer + * @src_bit_off: bit offset we're starting to read from + * @nbits: number of bits to copy + * + * This functions copies bits from one memory region to another, and is used by + * the GPMI driver to copy ECC sections which are not guaranteed to be byte + * aligned. + * + * src and dst should not overlap. + * + */ +void gpmi_copy_bits(u8 *dst, size_t dst_bit_off, + const u8 *src, size_t src_bit_off, + size_t nbits) +{ + size_t i; + size_t nbytes; + u32 src_buffer = 0; + size_t bits_in_src_buffer = 0; + + if (!nbits) + return; + + /* + * Move src and dst pointers to the closest byte pointer and store bit + * offsets within a byte. + */ + src += src_bit_off / 8; + src_bit_off %= 8; + + dst += dst_bit_off / 8; + dst_bit_off %= 8; + + /* + * Initialize the src_buffer value with bits available in the first + * byte of data so that we end up with a byte aligned src pointer. + */ + if (src_bit_off) { + src_buffer = src[0] >> src_bit_off; + if (nbits >= (8 - src_bit_off)) { + bits_in_src_buffer += 8 - src_bit_off; + } else { + src_buffer &= GENMASK(nbits - 1, 0); + bits_in_src_buffer += nbits; + } + nbits -= bits_in_src_buffer; + src++; + } + + /* Calculate the number of bytes that can be copied from src to dst. */ + nbytes = nbits / 8; + + /* Try to align dst to a byte boundary. */ + if (dst_bit_off) { + if (bits_in_src_buffer < (8 - dst_bit_off) && nbytes) { + src_buffer |= src[0] << bits_in_src_buffer; + bits_in_src_buffer += 8; + src++; + nbytes--; + } + + if (bits_in_src_buffer >= (8 - dst_bit_off)) { + dst[0] &= GENMASK(dst_bit_off - 1, 0); + dst[0] |= src_buffer << dst_bit_off; + src_buffer >>= (8 - dst_bit_off); + bits_in_src_buffer -= (8 - dst_bit_off); + dst_bit_off = 0; + dst++; + if (bits_in_src_buffer > 7) { + bits_in_src_buffer -= 8; + dst[0] = src_buffer; + dst++; + src_buffer >>= 8; + } + } + } + + if (!bits_in_src_buffer && !dst_bit_off) { + /* + * Both src and dst pointers are byte aligned, thus we can + * just use the optimized memcpy function. + */ + if (nbytes) + memcpy(dst, src, nbytes); + } else { + /* + * src buffer is not byte aligned, hence we have to copy each + * src byte to the src_buffer variable before extracting a byte + * to store in dst. + */ + for (i = 0; i < nbytes; i++) { + src_buffer |= src[i] << bits_in_src_buffer; + dst[i] = src_buffer; + src_buffer >>= 8; + } + } + /* Update dst and src pointers */ + dst += nbytes; + src += nbytes; + + /* + * nbits is the number of remaining bits. It should not exceed 8 as + * we've already copied as much bytes as possible. + */ + nbits %= 8; + + /* + * If there's no more bits to copy to the destination and src buffer + * was already byte aligned, then we're done. + */ + if (!nbits && !bits_in_src_buffer) + return; + + /* Copy the remaining bits to src_buffer */ + if (nbits) + src_buffer |= (*src & GENMASK(nbits - 1, 0)) << + bits_in_src_buffer; + bits_in_src_buffer += nbits; + + /* + * In case there were not enough bits to get a byte aligned dst buffer + * prepare the src_buffer variable to match the dst organization (shift + * src_buffer by dst_bit_off and retrieve the least significant bits + * from dst). + */ + if (dst_bit_off) + src_buffer = (src_buffer << dst_bit_off) | + (*dst & GENMASK(dst_bit_off - 1, 0)); + bits_in_src_buffer += dst_bit_off; + + /* + * Keep most significant bits from dst if we end up with an unaligned + * number of bits. + */ + nbytes = bits_in_src_buffer / 8; + if (bits_in_src_buffer % 8) { + src_buffer |= (dst[nbytes] & + GENMASK(7, bits_in_src_buffer % 8)) << + (nbytes * 8); + nbytes++; + } + + /* Copy the remaining bytes to dst */ + for (i = 0; i < nbytes; i++) { + dst[i] = src_buffer; + src_buffer >>= 8; + } +} diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c index 959cb9b70310..4f3851a24bb2 100644 --- a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c +++ b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c @@ -791,6 +791,7 @@ static void gpmi_free_dma_buffer(struct gpmi_nand_data *this) this->page_buffer_phys); kfree(this->cmd_buffer); kfree(this->data_buffer_dma); + kfree(this->raw_buffer); this->cmd_buffer = NULL; this->data_buffer_dma = NULL; @@ -837,6 +838,9 @@ static int gpmi_alloc_dma_buffer(struct gpmi_nand_data *this) if (!this->page_buffer_virt) goto error_alloc; + this->raw_buffer = kzalloc(mtd->writesize + mtd->oobsize, GFP_KERNEL); + if (!this->raw_buffer) + goto error_alloc; /* Slice up the page buffer. */ this->payload_virt = this->page_buffer_virt; @@ -1347,6 +1351,199 @@ gpmi_ecc_write_oob(struct mtd_info *mtd, struct nand_chip *chip, int page) return status & NAND_STATUS_FAIL ? -EIO : 0; } +/* + * This function reads a NAND page without involving the ECC engine (no HW + * ECC correction). + * The tricky part in the GPMI/BCH controller is that it stores ECC bits + * inline (interleaved with payload DATA), and do not align data chunk on + * byte boundaries. + * We thus need to take care moving the payload data and ECC bits stored in the + * page into the provided buffers, which is why we're using gpmi_copy_bits. + * + * See set_geometry_by_ecc_info inline comments to have a full description + * of the layout used by the GPMI controller. + */ +static int gpmi_ecc_read_page_raw(struct mtd_info *mtd, + struct nand_chip *chip, uint8_t *buf, + int oob_required, int page) +{ + struct gpmi_nand_data *this = chip->priv; + struct bch_geometry *nfc_geo = &this->bch_geometry; + int eccsize = nfc_geo->ecc_chunk_size; + int eccbits = nfc_geo->ecc_strength * nfc_geo->gf_len; + u8 *tmp_buf = this->raw_buffer; + size_t src_bit_off; + size_t oob_bit_off; + size_t oob_byte_off; + uint8_t *oob = chip->oob_poi; + int step; + + chip->read_buf(mtd, tmp_buf, + mtd->writesize + mtd->oobsize); + + /* + * If required, swap the bad block marker and the data stored in the + * metadata section, so that we don't wrongly consider a block as bad. + * + * See the layout description for a detailed explanation on why this + * is needed. + */ + if (this->swap_block_mark) { + u8 swap = tmp_buf[0]; + + tmp_buf[0] = tmp_buf[mtd->writesize]; + tmp_buf[mtd->writesize] = swap; + } + + /* + * Copy the metadata section into the oob buffer (this section is + * guaranteed to be aligned on a byte boundary). + */ + if (oob_required) + memcpy(oob, tmp_buf, nfc_geo->metadata_size); + + oob_bit_off = nfc_geo->metadata_size * 8; + src_bit_off = oob_bit_off; + + /* Extract interleaved payload data and ECC bits */ + for (step = 0; step < nfc_geo->ecc_chunk_count; step++) { + if (buf) + gpmi_copy_bits(buf, step * eccsize * 8, + tmp_buf, src_bit_off, + eccsize * 8); + src_bit_off += eccsize * 8; + + /* Align last ECC block to align a byte boundary */ + if (step == nfc_geo->ecc_chunk_count - 1 && + (oob_bit_off + eccbits) % 8) + eccbits += 8 - ((oob_bit_off + eccbits) % 8); + + if (oob_required) + gpmi_copy_bits(oob, oob_bit_off, + tmp_buf, src_bit_off, + eccbits); + + src_bit_off += eccbits; + oob_bit_off += eccbits; + } + + if (oob_required) { + oob_byte_off = oob_bit_off / 8; + + if (oob_byte_off < mtd->oobsize) + memcpy(oob + oob_byte_off, + tmp_buf + mtd->writesize + oob_byte_off, + mtd->oobsize - oob_byte_off); + } + + return 0; +} + +/* + * This function writes a NAND page without involving the ECC engine (no HW + * ECC generation). + * The tricky part in the GPMI/BCH controller is that it stores ECC bits + * inline (interleaved with payload DATA), and do not align data chunk on + * byte boundaries. + * We thus need to take care moving the OOB area at the right place in the + * final page, which is why we're using gpmi_copy_bits. + * + * See set_geometry_by_ecc_info inline comments to have a full description + * of the layout used by the GPMI controller. + */ +static int gpmi_ecc_write_page_raw(struct mtd_info *mtd, + struct nand_chip *chip, + const uint8_t *buf, + int oob_required) +{ + struct gpmi_nand_data *this = chip->priv; + struct bch_geometry *nfc_geo = &this->bch_geometry; + int eccsize = nfc_geo->ecc_chunk_size; + int eccbits = nfc_geo->ecc_strength * nfc_geo->gf_len; + u8 *tmp_buf = this->raw_buffer; + uint8_t *oob = chip->oob_poi; + size_t dst_bit_off; + size_t oob_bit_off; + size_t oob_byte_off; + int step; + + /* + * Initialize all bits to 1 in case we don't have a buffer for the + * payload or oob data in order to leave unspecified bits of data + * to their initial state. + */ + if (!buf || !oob_required) + memset(tmp_buf, 0xff, mtd->writesize + mtd->oobsize); + + /* + * First copy the metadata section (stored in oob buffer) at the + * beginning of the page, as imposed by the GPMI layout. + */ + memcpy(tmp_buf, oob, nfc_geo->metadata_size); + oob_bit_off = nfc_geo->metadata_size * 8; + dst_bit_off = oob_bit_off; + + /* Interleave payload data and ECC bits */ + for (step = 0; step < nfc_geo->ecc_chunk_count; step++) { + if (buf) + gpmi_copy_bits(tmp_buf, dst_bit_off, + buf, step * eccsize * 8, eccsize * 8); + dst_bit_off += eccsize * 8; + + /* Align last ECC block to align a byte boundary */ + if (step == nfc_geo->ecc_chunk_count - 1 && + (oob_bit_off + eccbits) % 8) + eccbits += 8 - ((oob_bit_off + eccbits) % 8); + + if (oob_required) + gpmi_copy_bits(tmp_buf, dst_bit_off, + oob, oob_bit_off, eccbits); + + dst_bit_off += eccbits; + oob_bit_off += eccbits; + } + + oob_byte_off = oob_bit_off / 8; + + if (oob_required && oob_byte_off < mtd->oobsize) + memcpy(tmp_buf + mtd->writesize + oob_byte_off, + oob + oob_byte_off, mtd->oobsize - oob_byte_off); + + /* + * If required, swap the bad block marker and the first byte of the + * metadata section, so that we don't modify the bad block marker. + * + * See the layout description for a detailed explanation on why this + * is needed. + */ + if (this->swap_block_mark) { + u8 swap = tmp_buf[0]; + + tmp_buf[0] = tmp_buf[mtd->writesize]; + tmp_buf[mtd->writesize] = swap; + } + + chip->write_buf(mtd, tmp_buf, mtd->writesize + mtd->oobsize); + + return 0; +} + +static int gpmi_ecc_read_oob_raw(struct mtd_info *mtd, struct nand_chip *chip, + int page) +{ + chip->cmdfunc(mtd, NAND_CMD_READ0, 0, page); + + return gpmi_ecc_read_page_raw(mtd, chip, NULL, 1, page); +} + +static int gpmi_ecc_write_oob_raw(struct mtd_info *mtd, struct nand_chip *chip, + int page) +{ + chip->cmdfunc(mtd, NAND_CMD_SEQIN, 0, page); + + return gpmi_ecc_write_page_raw(mtd, chip, NULL, 1); +} + static int gpmi_block_markbad(struct mtd_info *mtd, loff_t ofs) { struct nand_chip *chip = mtd->priv; @@ -1664,6 +1861,10 @@ static int gpmi_init_last(struct gpmi_nand_data *this) ecc->write_page = gpmi_ecc_write_page; ecc->read_oob = gpmi_ecc_read_oob; ecc->write_oob = gpmi_ecc_write_oob; + ecc->read_page_raw = gpmi_ecc_read_page_raw; + ecc->write_page_raw = gpmi_ecc_write_page_raw; + ecc->read_oob_raw = gpmi_ecc_read_oob_raw; + ecc->write_oob_raw = gpmi_ecc_write_oob_raw; ecc->mode = NAND_ECC_HW; ecc->size = bch_geo->ecc_chunk_size; ecc->strength = bch_geo->ecc_strength; diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-nand.h b/drivers/mtd/nand/gpmi-nand/gpmi-nand.h index 32c6ba49f986..544062f65020 100644 --- a/drivers/mtd/nand/gpmi-nand/gpmi-nand.h +++ b/drivers/mtd/nand/gpmi-nand/gpmi-nand.h @@ -189,6 +189,8 @@ struct gpmi_nand_data { void *auxiliary_virt; dma_addr_t auxiliary_phys; + void *raw_buffer; + /* DMA channels */ #define DMA_CHANS 8 struct dma_chan *dma_chans[DMA_CHANS]; @@ -290,6 +292,10 @@ extern int gpmi_send_page(struct gpmi_nand_data *, extern int gpmi_read_page(struct gpmi_nand_data *, dma_addr_t payload, dma_addr_t auxiliary); +void gpmi_copy_bits(u8 *dst, size_t dst_bit_off, + const u8 *src, size_t src_bit_off, + size_t nbits); + /* BCH : Status Block Completion Codes */ #define STATUS_GOOD 0x00 #define STATUS_ERASED 0xff |