[PATCHv2 07/10] drivers: mtd: m25p80: Adapt driver to support memory mapped read.
Huang Shijie
shijie8 at gmail.com
Thu Dec 12 02:55:37 EST 2013
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
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