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authorCoolStar <coolstarorganization@gmail.com>2023-06-28 13:10:50 -0700
committerFelix Held <felix-coreboot@felixheld.de>2023-07-20 13:11:16 +0000
commit545d9992dc9cdfc06708019b4ecdbb75d2d06721 (patch)
tree425dbd00a766bdfb34101388416402cbeab89df2 /src/soc/amd/common/block
parent97439ecc0178a0935d50a4b3a1774027ae7bebbf (diff)
mb/google/link: rework TP/TS ACPI for new Windows I2C driver
This supports a brand new I2C driver that is designed specifically for the Pixel 2013 chromebook (LINK). The GMBus interface on the IGPU is an i2c-compatible interface, but AFAIK only Link has touch devices attached in this way. On Windows, the PCIe device for the IGP is owned by the Intel proprietary driver, hence a separate ACPI device has to be added for the I2C driver arbitrator to attach to. The MMIO method is used instead of _CRS so that Windows does not try to assign ownership of the resource to our device (even though we're using the MMIO registers at the same time as the IGP driver). Even though in theory 2 drivers accessing the same MMIO may cause problems, in testing, there has been no issues with sleep/wake/hibernate, updating/installing/uninstalling the IGP driver, or changing display resolutions with the i2c driver attached. The arbitrator is necessary as well, since even though there are multiple i2c buses, the MMIO registers are shared. Hence a shared lock is required for i2c access across the buses. The original Sleep Button devices are preserved for Linux due to the completely custom and non-standard implementation of the Windows driver in order to work around the non-standard nature of Link's hardware. Change-Id: If7ee05d15bc17d335cf8c1a8e80bea62800de475 Signed-off-by: CoolStar <coolstarorganization@gmail.com> Reviewed-on: https://review.coreboot.org/c/coreboot/+/76159 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Nico Huber <nico.h@gmx.de> Reviewed-by: Eric Lai <eric_lai@quanta.corp-partner.google.com> Reviewed-by: Matt DeVillier <matt.devillier@gmail.com>
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