Simone
4697ce3e3b
Add a driver for the integrated memory controller (iMC) SMBus engine on Intel Skylake-X / Cascade Lake-X processors (socket LGA 2066, platform X299, PCU function 8086:2085). The engine provides two SMBus channels — one per pair of DIMM slots — over which SPD EEPROMs, DDR4 thermal sensors and third-party LED controllers are accessible. Exposing it as a pair of standard Linux I2C adapters lets existing tools (i2c-tools, lm-sensors) use it without bespoke sysfs hacks. Key design decisions: - ECAM MMIO access instead of CF8/CFC port I/O (SMM traps port writes) - Dynamic MCFG table parsing for mmcfg_base (no hardcoding) - Support for SMBus BYTE_DATA and WORD_DATA transfers - devm-managed resources with automatic cleanup - Global mutex to serialize transactions across both channels sharing the same ECAM mapping Signed-off-by: Simone Chifari <simone.chifari@gmail.com>
19 lines
857 B
Plaintext
19 lines
857 B
Plaintext
config I2C_IMC_SKYLAKE
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tristate "Intel Skylake-X iMC SMBus adapter"
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depends on PCI && ACPI && X86
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help
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Say Y here if you want kernel support for the integrated memory
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controller (iMC) SMBus engine found in Intel Skylake-X / Cascade
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Lake-X processors (socket LGA 2066, platform X299, PCU function
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8086:2085).
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The engine is exposed through the PCI configuration space of the
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PCU function and is driven via ECAM MMIO (not CF8/CFC port I/O,
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which is trapped by System Management Mode on this platform).
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Two I2C adapters are registered, one per hardware SMBus channel,
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allowing access to DDR4 DIMM SPD EEPROMs (0x50-0x57) and thermal
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sensors from userspace via standard i2c-tools and lm-sensors.
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If unsure, say N. This driver is only useful on Intel X299 desktop
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/ HEDT systems with the Skylake-X or Cascade Lake-X CPU.
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