6c4a3372f0
As discussed during the original HiSilicon v3xx SPI driver upstreaming, currently there is no method for the ACPI SPI Serial Bus Connection Resource Descriptor to define the data buswidth [0], [1]. So we can look to get the ACPI spec updated for this, and I have submitted a proposal for a new feature here: https://bugzilla.tianocore.org/show_bug.cgi?id=2557 However I am not sure how successful that will be. In the meantime, as an alternate approach, this RFC proposes to allow the SPI controller driver override the device buswidth. In this example, the driver uses DMI quirks to discover the host machine and set the buswidth override accordingly when the machine is known to support dual or quad mode of operation. I also have included a fix for dual and quad modes in the driver. Comments welcome. thanks. [0] https://lore.kernel.org/linux-mtd/20200109212842.GK3702@sirena.org.uk/ [1] https://uefi.org/sites/default/files/resources/ACPI_6_3_final_Jan30.pdf, 19.6.126 John Garry (3): spi: Allow SPI controller override device buswidth spi: HiSilicon v3xx: Properly set CMD_CONFIG for Dual/Quad modes spi: HiSilicon v3xx: Use DMI quirk to set controller buswidth override bits drivers/spi/spi-hisi-sfc-v3xx.c | 99 ++++++++++++++++++++++++++++++++- drivers/spi/spi.c | 4 +- include/linux/spi/spi.h | 3 + 3 files changed, 104 insertions(+), 2 deletions(-) -- 2.17.1 ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/
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