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

Miquel Raynal
2023-09-11T07:43:00Z

Hi Alexander,

+ Mark Brown + spi list
+ spi-nor maintainers

alexander.usyskin@intel.com 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@intel.com>
>
>
> 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