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soc/amd/common/block/i2c: Add support for shared TPM_I2C controller 

There are platforms equipped with AMD SoC where I2C3 controller
connected to TPM device is shared between X86 and PSP. In order to
handle this, PSP acts as an I2C-arbitrator, where x86 (kernel) sends
acquire and release requests to be accepted by PSP. An example of
implementation within Linux kernel is available [1].

There is a need to introduce new ACPI_ID ("AMDI0019") so that dedicated
driver on OS side can bind to it and handle this special setup. Since
PSP takes care of I2C controller power management, we need to remove
PowerResource object from DSDT.

BUG=b:204508404
BRANCH=guybrush

[1]: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=78d5e9e299e31bc2deaaa94a45bf8ea024f27e8c

Signed-off-by: Jan Dabros <jsd@semihalf.com>
Change-Id: Iccfc09d8c580d7ab2acb69d26b9c293cf625fb34
Reviewed-on: https://review.coreboot.org/c/coreboot/+/61863
Reviewed-by: Raul Rangel <rrangel@chromium.org>
Reviewed-by: Karthik Ramasubramanian <kramasub@google.com>
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
This commit is contained in:
Jan Dabros 2022-02-04 10:40:37 +01:00 committed by Felix Held
parent c17330c1dd
commit 282d715133
2 changed files with 17 additions and 0 deletions
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7
src/soc/amd/cezanne/acpi/mmio.asl
View File

@ -232,7 +232,11 @@ Device (I2C2) {
Device (I2C3)
{
#if CONFIG(SOC_AMD_COMMON_BLOCK_I2C3_TPM_SHARED_WITH_PSP)
Name (_HID, "AMDI0019")
#else
Name (_HID, "AMDI0010")
#endif
Name (_UID, 0x3)
Method (_CRS, 0) {
Local0 = ResourceTemplate() {
@ -263,7 +267,10 @@ Device (I2C3)
Return (0x0F)
}
/* If this device is shared with PSP, then PSP takes care of power management */
#if !CONFIG(SOC_AMD_COMMON_BLOCK_I2C3_TPM_SHARED_WITH_PSP)
AOAC_DEVICE(FCH_AOAC_DEV_I2C3, 0)
#endif
}
Device (MISC)

10
src/soc/amd/common/block/i2c/Kconfig
View File

@ -14,3 +14,13 @@ config SOC_AMD_COMMON_BLOCK_I23C_PAD_CTRL
help
Select this option to add FCH I2C/I3C pad configuration functions to
the build.
config SOC_AMD_COMMON_BLOCK_I2C3_TPM_SHARED_WITH_PSP
bool
depends on !SOC_AMD_PICASSO && !SOC_AMD_STONEYRIDGE
default n
help
Enable PSP I2C arbitration if there is I2C3 controller with TPM device
connected, which is shared between x86 and PSP. This is necessary to
ensure proper communication with I2C peripherals connected to such
bus.