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doc/internals/devicetree_language: eSPI doesn't support legacy DRQ

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In contracts to the ISA and LPC bus, eSPI doesn't support legacy
ISA-style DMA any more, so don't list eSPI as interface in the 'drq'
chapter.

The Intel document #841685 "Enhanced Serial Peripheral Interface (eSPI)
Interface Base Specification (for Client and Server Platforms)" revision
1.6 says this about the eSPI interface: "However, 8237 DMA and Firmware
Hub (FWH) are not supported over this interface."

Change-Id: I69d4b09688699dfc984a42671abfe3804d30ade9
Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/87204
Reviewed-by: Matt DeVillier <matt.devillier@gmail.com>
Reviewed-by: Maximilian Brune <maximilian.brune@9elements.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Felix Singer <service+coreboot-gerrit@felixsinger.de>
This commit is contained in:
Felix Held 2025-04-07 22:54:15 +02:00 • committed by Maximilian Brune
commit 3c7f78e1e7
1 changed files with 1 additions and 1 deletions
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Documentation/internals/devicetree_language.md
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@ -444,7 +444,7 @@ end
* Usage: `drq 0x<register #> = <drq line>`
Drq is used to configure a legacy DMA Request line register for a device
on a legacy bus - ISA/LPC/eSPI.
on a legacy bus - ISA/LPC.
The drq configuration is only allowed inside a pnp block.