On Fri, Dec 06, 2013 at 07:54:48PM +0530, Sourav Poddar wrote: > Adapt driver to do a memory mapped read. > @@ -109,6 +109,7 @@ struct m25p { > u8 program_opcode; > u8 *command; > enum read_type flash_read; > + void __iomem *mem_addr; I think we can remove this field. You can use a local variable in the m25p80_read. > }; > > static inline struct m25p *mtd_to_m25p(struct mtd_info *mtd) > @@ -515,6 +516,7 @@ static int m25p80_read(struct mtd_info *mtd, loff_t from, size_t len, > size_t *retlen, u_char *buf) > { > struct m25p *flash = mtd_to_m25p(mtd); > + struct spi_master *master = flash->spi->master; > struct spi_transfer t[2]; > struct spi_message m; > uint8_t opcode; > @@ -523,6 +525,20 @@ static int m25p80_read(struct mtd_info *mtd, loff_t from, size_t len, > pr_debug("%s: %s from 0x%08x, len %zd\n", dev_name(&flash->spi->dev), > __func__, (u32)from, len); > > + if (master->mmap) { > + mutex_lock(&flash->lock); > + /* Wait till previous write/erase is done. */ > + if (wait_till_ready(flash)) { > + mutex_unlock(&flash->lock); > + return 1; > + } > + flash->mem_addr = master->get_buf(master); > + memcpy(buf, flash->mem_addr + from, len); > + master->put_buf(master); > + *retlen = len; > + goto out; > + } > + > spi_message_init(&m); > memset(t, 0, (sizeof t)); > > @@ -558,6 +574,7 @@ static int m25p80_read(struct mtd_info *mtd, loff_t from, size_t len, > > *retlen = m.actual_length - m25p_cmdsz(flash) - dummy; > > +out: > mutex_unlock(&flash->lock); > > return 0; > @@ -1286,6 +1303,9 @@ static int m25p_probe(struct spi_device *spi) > flash->addr_width = 3; > } > > + if (spi->master->configure_from_slave) > + m25p80_fill_flash_information(flash); > + You have add a configure_from_slave hook in the SPI, why you also need a same hook in the SPI-NOR framework? And i think the enable_mmap/disable_mmap is not needed too. All the three hooks are used to set the SPI bus controller. And the SPI-NOR framework only handles the issues between the SPI bus controller and the SPI-NOR, or the SPI-NOR controller and the SPI-NOR. thanks Huang Shijie -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html