--- a/drivers/mtd/devices/m25p80.c +++ b/drivers/mtd/devices/m25p80.c @@ -100,6 +100,7 @@ struct m25p { u16 addr_width; u8 erase_opcode; u8 *command; + size_t max_read_len; }; static inline struct m25p *mtd_to_m25p(struct mtd_info *mtd) @@ -352,6 +353,7 @@ static int m25p80_read(struct mtd_info * struct m25p *flash = mtd_to_m25p(mtd); struct spi_transfer t[2]; struct spi_message m; + loff_t ofs; pr_debug("%s: %s from 0x%08x, len %zd\n", dev_name(&flash->spi->dev), __func__, (u32)from, len); @@ -374,8 +376,6 @@ static int m25p80_read(struct mtd_info * t[0].len = m25p_cmdsz(flash) + FAST_READ_DUMMY_BYTE; spi_message_add_tail(&t[0], &m); - t[1].rx_buf = buf; - t[1].len = len; spi_message_add_tail(&t[1], &m); /* Byte count starts at zero. */ @@ -383,13 +383,6 @@ static int m25p80_read(struct mtd_info * mutex_lock(&flash->lock); - /* Wait till previous write/erase is done. */ - if (wait_till_ready(flash)) { - /* REVISIT status return?? */ - mutex_unlock(&flash->lock); - return 1; - } - /* FIXME switch to OPCODE_FAST_READ. It's required for higher * clocks; and at this writing, every chip this driver handles * supports that opcode. @@ -397,11 +390,44 @@ static int m25p80_read(struct mtd_info * /* Set up the write data buffer. */ flash->command[0] = OPCODE_READ; - m25p_addr2cmd(flash, from, flash->command); - spi_sync(flash->spi, &m); + ofs = 0; + while (len) { + size_t readlen; + size_t done; + int ret; + + ret = wait_till_ready(flash); + if (ret) { + mutex_unlock(&flash->lock); + return 1; + } + + if (flash->max_read_len > 0 && + flash->max_read_len < len) + readlen = flash->max_read_len; + else + readlen = len; + + t[1].rx_buf = buf + ofs; + t[1].len = readlen; + + m25p_addr2cmd(flash, from + ofs, flash->command); + + spi_sync(flash->spi, &m); - *retlen = m.actual_length - m25p_cmdsz(flash) - FAST_READ_DUMMY_BYTE; + done = m.actual_length - m25p_cmdsz(flash) - + FAST_READ_DUMMY_BYTE; + if (done != readlen) { + mutex_unlock(&flash->lock); + return 1; + } + + ofs += done; + len -= done; + } + + *retlen = ofs; mutex_unlock(&flash->lock); @@ -925,6 +951,12 @@ static int __devinit m25p_probe(struct s flash->mtd.erase = m25p80_erase; flash->mtd.read = m25p80_read; + if (data && data->max_read_len) { + flash->max_read_len = data->max_read_len; + dev_warn(&spi->dev, "max_read_len set to %d bytes\n", + flash->max_read_len); + } + /* sst flash chips use AAI word program */ if (JEDEC_MFR(info->jedec_id) == CFI_MFR_SST) flash->mtd.write = sst_write; --- a/include/linux/spi/flash.h +++ b/include/linux/spi/flash.h @@ -25,6 +25,7 @@ struct flash_platform_data { char *type; + size_t max_read_len; /* we'll likely add more ... use JEDEC IDs, etc */ };