On Friday 17 January 2014 12:36 PM, Jagan Teki wrote:
On Fri, Jan 17, 2014 at 7:32 AM, Huang Shijie<b32955@xxxxxxxxxxxxx> wrote:
On Thu, Jan 16, 2014 at 03:09:13PM +0530, Jagan Teki wrote:
After this patch, the layer is like:
MTD
------------------------
spi-nor
------------------------
m25p80
------------------------
spi bus driver
------------------------
SPI NOR chip
Just for looking on your new framework, is that above link correct.
I guess it should be MTD -- m25p80 -- spi-nor -- spi bus driver -- SPI NOR chip
I do not think so.
The spi-nor layer does not contact with the spi bus driver directly.
Yes - now I understand the flow from seeing the code.
With your new framework
1. not an exact spi-nor
have one controller driver at drivers/spi/* will register to spi core.
have m25p80.c will scan the flash details from
drivers/mtd/spi-nor/spi-nor.c and
m25p80 will register the MTD core and for transfer calls m25p80
will calls spi core.
2. spi-nor style
have one controller driver at drivers/mtd/spi-nor/fsl-quadspi.c
will register MTD core
and scan the flash details from drivers/mtd/spi-nor/spi-nor.c and
for transfer will calls
through direct writel and readl with cmd+data fashion.
Correct me If my understanding was wrong.
3) Can you explain your framework precisely take an example of like
spi_controller_A with spi_flash_A
and qspi_controller_B and qspi_flash_B - how will this new framework
operates.
The framework is just cloned from the m25p80.c, and extract the common code,
and provides more
hooks such as
@prepare/unpreare: used to do some work before or after the
read/write/erase/lock/unlock.
@read_xfer/write_xfer: We can use these two hooks to code all
the following hooks if the driver tries to implement them
by itself.
@read_reg: used to read the registers, such as read status register,
read configure register.
@write_reg: used to write the registers, such as write enable,
erase sector.
@read_id: read out the ID info.
@wait_till_ready: wait till the NOR becomes ready.
@read: read out the data from the NOR.
@write: write data to the NOR.
@erase: erase a sector of the NOR.
My basic question is like I have a qspi spi controller in my SOC and I
designed two boards B1 and B2
okay.
B1 with quad spi controller connected with non-flash as a slave and B2
with quad spi controller connected
with quad flash as a slave.
You can use the framework for B2. But for B1, you should not use the framework,
since this framework is just for the SPI-NOR. If you do not connected with
a NOR, i think it's better to code another driver for your controller.
Means we have two separate controller drivers for same controller one
with spi-nor and
another with spi is it?
Do you think this is a good idea, I understand you have a complete and
well guided new
spi-nor framework.
I dont think its a good idea to support a single controller with two
drivers for two different usecase.
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