--- a/drivers/mtd/spi-nor/spi-nor.c +++ b/drivers/mtd/spi-nor/spi-nor.c @@ -1020,6 +1020,66 @@ write_err: return ret; } +static int spi_nor_chunked_write(struct mtd_info *mtd, loff_t _to, size_t _len, + size_t *_retlen, const u_char *_buf) +{ + struct spi_nor *nor = mtd_to_spi_nor(mtd); + int chunk_size; + int retlen = 0; + int ret; + + chunk_size = nor->chunk_size; + if (!chunk_size) + chunk_size = _len; + + if (nor->addr_width > 3) + chunk_size -= nor->addr_width - 3; + + while (retlen < _len) { + size_t len = min_t(int, chunk_size, _len - retlen); + const u_char *buf = _buf + retlen; + loff_t to = _to + retlen; + + if (nor->flags & SNOR_F_SST) + ret = sst_write(mtd, to, len, &retlen, buf); + else + ret = spi_nor_write(mtd, to, len, &retlen, buf); + if (ret) + return ret; + } + + *_retlen += retlen; + return 0; +} + +static int spi_nor_chunked_read(struct mtd_info *mtd, loff_t _from, size_t _len, + size_t *_retlen, u_char *_buf) +{ + struct spi_nor *nor = mtd_to_spi_nor(mtd); + int chunk_size; + int ret; + + chunk_size = nor->chunk_size; + if (!chunk_size) + chunk_size = _len; + + *_retlen = 0; + while (*_retlen < _len) { + size_t len = min_t(int, chunk_size, _len - *_retlen); + u_char *buf = _buf + *_retlen; + loff_t from = _from + *_retlen; + int retlen = 0; + + ret = spi_nor_read(mtd, from, len, &retlen, buf); + if (ret) + return ret; + + *_retlen += retlen; + } + + return 0; +} + static int macronix_quad_enable(struct spi_nor *nor) { int ret, val; @@ -1207,10 +1267,12 @@ int spi_nor_scan(struct spi_nor *nor, co } /* sst nor chips use AAI word program */ - if (info->flags & SST_WRITE) + if (info->flags & SST_WRITE) { mtd->_write = sst_write; - else + nor->flags |= SNOR_F_SST; + } else { mtd->_write = spi_nor_write; + } if (info->flags & USE_FSR) nor->flags |= SNOR_F_USE_FSR; @@ -1238,11 +1300,20 @@ int spi_nor_scan(struct spi_nor *nor, co mtd->writebufsize = nor->page_size; if (np) { + u32 val; + /* If we were instantiated by DT, use it */ if (of_property_read_bool(np, "m25p,fast-read")) nor->flash_read = SPI_NOR_FAST; else nor->flash_read = SPI_NOR_NORMAL; + + if (!of_property_read_u32(np, "m25p,chunked-io", &val)) { + dev_info(dev, "using chunked io (size=%d)\n", val); + mtd->_read = spi_nor_chunked_read; + mtd->_write = spi_nor_chunked_write; + nor->chunk_size = val; + } } else { /* If we weren't instantiated by DT, default to fast-read */ nor->flash_read = SPI_NOR_FAST; --- a/include/linux/mtd/spi-nor.h +++ b/include/linux/mtd/spi-nor.h @@ -116,6 +116,7 @@ enum spi_nor_ops { enum spi_nor_option_flags { SNOR_F_USE_FSR = BIT(0), + SNOR_F_SST = BIT(1), }; /** @@ -156,6 +157,7 @@ struct spi_nor { struct device *dev; struct device_node *flash_node; u32 page_size; + u16 chunk_size; u8 addr_width; u8 erase_opcode; u8 read_opcode;