[PATCH 0/7] spi-nor: Add parallel and stacked memories support

[Michal Simek]

On 8/18/23 06:21, Ashok Reddy Soma wrote:
> This series adds support for Xilinx qspi parallel and stacked memeories.
> 
> In parallel mode, the current implementation assumes that a maximum of
> two flashes are connected. The QSPI controller splits the data evenly
> between both the flashes so, both the flashes that are connected in
> parallel mode should be identical.
> During each operation SPI-NOR sets 0th bit for CS0 & 1st bit for CS1 in
> nor->flags.
> 
> In stacked mode the current implementation assumes that a maximum of two
> flashes are connected and both the flashes are of same make but can
> differ in sizes. So, except the sizes all other flash parameters of both
> the flashes are identical
> 
> Spi-nor will pass on the appropriate flash select flag to low level
> driver, and it will select pass all the data to that particular flash.
> 
> Write operation in parallel mode are performed in page size * 2 chunks as
> each write operation results in writing both the flashes. For doubling
> the address space each operation is performed at addr/2 flash offset,
> where addr is the address specified by the user.
> 
> Similarly for read and erase operations it will read from both flashes,
> so size and offset are divided by 2 and send to flash.
> 
> 
> 
> Ashok Reddy Soma (7):
>    dm: core: support reading a single indexed u64 value
>    mtd: spi-nor: Add parallel and stacked memories support
>    mtd: spi-nor: Add parallel memories support for read_sr and read_fsr
>    mtd: spi-nor: Add parallel and stacked memories support in read_bar
>      and write_bar
>    spi: spi-uclass: Read chipselect and restrict capabilities
>    spi: zynqmp_gqspi: Add parallel memories support in GQSPI driver
>    spi: zynq_qspi: Add parallel memories support in QSPI driver
> 
>   drivers/core/of_access.c       |  22 ++
>   drivers/core/ofnode.c          |  30 +++
>   drivers/mtd/spi/spi-nor-core.c | 385 ++++++++++++++++++++++++++++-----
>   drivers/spi/spi-uclass.c       |  21 +-
>   drivers/spi/xilinx_spi.c       |   4 +-
>   drivers/spi/zynq_qspi.c        | 145 +++++++++++--
>   drivers/spi/zynq_spi.c         |   6 +-
>   drivers/spi/zynqmp_gqspi.c     | 146 +++++++++++--
>   include/dm/of_access.h         |  19 ++
>   include/dm/ofnode.h            |  12 +
>   include/linux/mtd/spi-nor.h    |  13 ++
>   include/spi.h                  |  29 ++-
>   12 files changed, 737 insertions(+), 95 deletions(-)
> 

I put this to CI and I see a lot of issue that's why v2 is definitely required 
but would be good if someone can review it from high level point of view.

Thanks,
Michal