diff options
| -rw-r--r-- | drivers/mtd/spi-nor/core.c | 69 |
1 files changed, 68 insertions, 1 deletions
diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c index 1b594f720b6c..20ea80450f22 100644 --- a/drivers/mtd/spi-nor/core.c +++ b/drivers/mtd/spi-nor/core.c @@ -2129,6 +2129,68 @@ read_err: } /* + * On Octal DTR capable flashes, writes cannot start or end at an odd address + * in Octal DTR mode. Extra 0xff bytes need to be appended or prepended to + * make sure the start address and end address are even. 0xff is used because + * on NOR flashes a program operation can only flip bits from 1 to 0, not the + * other way round. 0 to 1 flip needs to happen via erases. + */ +static int spi_nor_octal_dtr_write(struct spi_nor *nor, loff_t to, size_t len, + const u8 *buf) +{ + u8 *tmp_buf; + size_t bytes_written; + loff_t start, end; + int ret; + + if (IS_ALIGNED(to, 2) && IS_ALIGNED(len, 2)) + return spi_nor_write_data(nor, to, len, buf); + + tmp_buf = kmalloc(nor->params->page_size, GFP_KERNEL); + if (!tmp_buf) + return -ENOMEM; + + memset(tmp_buf, 0xff, nor->params->page_size); + + start = round_down(to, 2); + end = round_up(to + len, 2); + + memcpy(tmp_buf + (to - start), buf, len); + + ret = spi_nor_write_data(nor, start, end - start, tmp_buf); + if (ret == 0) { + ret = -EIO; + goto out; + } + if (ret < 0) + goto out; + + /* + * More bytes are written than actually requested, but that number can't + * be reported to the calling function or it will confuse its + * calculations. Calculate how many of the _requested_ bytes were + * written. + */ + bytes_written = ret; + + if (to != start) + ret -= to - start; + + /* + * Only account for extra bytes at the end if they were actually + * written. For example, if for some reason the controller could only + * complete a partial write then the adjustment for the extra bytes at + * the end is not needed. + */ + if (start + bytes_written == end) + ret -= end - (to + len); + +out: + kfree(tmp_buf); + return ret; +} + +/* * Write an address range to the nor chip. Data must be written in * FLASH_PAGESIZE chunks. The address range may be any size provided * it is within the physical boundaries. @@ -2164,7 +2226,12 @@ static int spi_nor_write(struct mtd_info *mtd, loff_t to, size_t len, goto write_err; } - ret = spi_nor_write_data(nor, addr, page_remain, buf + i); + if (nor->write_proto == SNOR_PROTO_8_8_8_DTR) + ret = spi_nor_octal_dtr_write(nor, addr, page_remain, + buf + i); + else + ret = spi_nor_write_data(nor, addr, page_remain, + buf + i); spi_nor_unlock_device(nor); if (ret < 0) goto write_err; |