Re: [PATCH 00/10] drm/i915/spi: spi access for discrete graphics

[Miquel Raynal <miquel.raynal@xxxxxxxxxxx>]

Hi Alexander,

+ Mark Brown + spi list
+ spi-nor maintainers

alexander.usyskin@xxxxxxxxx wrote on Sun, 10 Sep 2023 15:39:39 +0300:

> Add driver for access to the discrete graphics card
> internal SPI device.
> Expose device on auxiliary bus and provide driver to register
> this device with MTD framework.

Maybe you can explain why you think auxiliary bus is relevant here? The
cover letter might maybe be a bit more verbose to give us more context?

I've looked at the series, it looks like you try to expose a spi
memory connected to a spi controller on your hardware. We usually
expect the spi controller driver to register in the spi core and
provide spi-mem operations for that.

I don't know if this memory is supposed to be used as general purpose,
but if it's not I would advise to use some kind of firmware mechanism
instead. Also, what is the purpose of exposing this content in this
case?

Well, I'm partially convinced here, I would like to hear from the other
maintainers, maybe your choices are legitimate and I'm off topic.

Thanks,
Miquèl

> This series is intended to be upstreamed through drm tree.
>
> Signed-off-by: Alexander Usyskin <alexander.usyskin@xxxxxxxxx>
> 
> 
> Alexander Usyskin (3):
>   drm/i915/spi: align 64bit read and write
>   drm/i915/spi: wake card on operations
>   drm/i915/spi: add support for access mode
> 
> Jani Nikula (1):
>   drm/i915/spi: add spi device for discrete graphics
> 
> Tomas Winkler (6):
>   drm/i915/spi: add intel_spi_region map
>   drm/i915/spi: add driver for on-die spi device
>   drm/i915/spi: implement region enumeration
>   drm/i915/spi: implement spi access functions
>   drm/i915/spi: spi register with mtd
>   drm/i915/spi: mtd: implement access handlers
> 
>  drivers/gpu/drm/i915/Kconfig             |   1 +
>  drivers/gpu/drm/i915/Makefile            |   6 +
>  drivers/gpu/drm/i915/i915_driver.c       |   7 +
>  drivers/gpu/drm/i915/i915_drv.h          |   4 +
>  drivers/gpu/drm/i915/i915_reg.h          |   1 +
>  drivers/gpu/drm/i915/spi/intel_spi.c     | 101 +++
>  drivers/gpu/drm/i915/spi/intel_spi.h     |  33 +
>  drivers/gpu/drm/i915/spi/intel_spi_drv.c | 865 +++++++++++++++++++++++
>  8 files changed, 1018 insertions(+)
>  create mode 100644 drivers/gpu/drm/i915/spi/intel_spi.c
>  create mode 100644 drivers/gpu/drm/i915/spi/intel_spi.h
>  create mode 100644 drivers/gpu/drm/i915/spi/intel_spi_drv.c

Thanks,
Miquèl