[PATCHv2 07/10] drivers: mtd: m25p80: Adapt driver to support memory mapped read.
Sourav Poddar
sourav.poddar at ti.com
Thu Dec 12 03:15:24 EST 2013
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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