On Thursday 12 December 2013 01:25 PM, Huang Shijie wrote:
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?

We need a way to provoke this, currently it is placed in m25p80. If m25p80
is removed, for where should I handle these in 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.
My controller can be used as spi flash controller as well as a spi
controller.
thanks
Huang Shijie



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