diff options
| author | Kane Chen <kane.chen@intel.com> | 2020-04-13 20:48:54 +0800 |
|---|---|---|
| committer | Tim Wawrzynczak <twawrzynczak@chromium.org> | 2020-04-28 15:43:36 +0000 |
| commit | d2b2be39296d910178173273017800a1b054a1ba (patch) | |
| tree | 093bc25858c3ae8eb5bfb9ab06e361c0eae5d097 /src/soc/intel/cannonlake | |
| parent | 007faee9486bcc24e1bc7011717ae88d7eb5e62b (diff) | |
soc/intel/cannonlake: Report driver strength by _DSM in eMMC ACPI device
According to doc 621880, it suggests setting 40 ohm in byte 185 in extCSD.
This commit provides _DSM method for driver to query driving strength.
TEST=mmc extcsd read |grep HS_TIMING and found bit[7:4] is set to 4
BUG=b:154159888
Signed-off-by: Kane Chen <kane.chen@intel.com>
Change-Id: I1b4df8b0d1d2cad3a7f521ad47ee5a4b3320c767
Reviewed-on: https://review.coreboot.org/c/coreboot/+/40467
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Diffstat (limited to 'src/soc/intel/cannonlake')
| -rw-r--r-- | src/soc/intel/cannonlake/acpi/scs.asl | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/src/soc/intel/cannonlake/acpi/scs.asl b/src/soc/intel/cannonlake/acpi/scs.asl index 775c99781a..8dd3003053 100644 --- a/src/soc/intel/cannonlake/acpi/scs.asl +++ b/src/soc/intel/cannonlake/acpi/scs.asl @@ -20,9 +20,12 @@ Scope (\_SB.PCI0) { Name(_ADR, 0x001A0000) Name (_DDN, "eMMC Controller") Name (TEMP, 0) + Name (DSUU, ToUUID("f6c13ea5-65cd-461f-ab7a-29f7e8d5bd61")) OperationRegion(SCSR, PCI_Config, 0x00, 0x100) Field(SCSR, WordAcc, NoLock, Preserve) { + Offset (0x0), /* PCI VID DID */ + VDID, 32, Offset (0x84), /* PMECTRLSTATUS */ PMCR, 16, Offset (0xA2), /* PG_CONFIG */ @@ -64,6 +67,59 @@ Scope (\_SB.PCI0) { Return (0) } } + /* _DSM x86 Device Specific Method + * Arg0: UUID Unique function identifier + * Arg1: Integer Revision Level + * Arg2: Integer Function Index (0 = Return Supported Functions) + * Arg3: Package Parameters + */ + Method (_DSM, 4) + { + If (LEqual (Arg0, ^DSUU)) { + /* Check the revision */ + If (LGreaterEqual (Arg1, Zero)) { + /* + * Function Index 0 the return value is a buffer + * containing one bit for each function index, starting + * with zero. + * Bit 0 - Indicates whether there is support for any + * functions other than function 0 + * Bit 1 - Indicates support to clear power control + * register + * Bit 2 - Indicates support to set power control + * register + * Bit 3 - Indicates support to set 1.8V signalling + * Bit 4 - Indicates support to set 3.3V signalling + * Bit 5 - Indicates support for HS200 mode + * Bit 6 - Indicates support for HS400 mode + * Bit 9 - Indicates eMMC I/O Driver Strength + */ + If (LEqual (Arg2, Zero)) { + If (Lequal (VDID, 0x02c48086) ) { + /* + * Set bit 9 for CML eMMC to indicate + * eMMC I/O driver strength is supported + */ + Return(Buffer() {0x0, 0x02}) + } + + } + /* + * Function Index 9, the return value is preferred eMMC + * driver strength + * 0 - 50 ohm + * 1 - 33 ohm + * 2 - 66 ohm + * 3 - 100 ohm + * 4 - 40 ohm + */ + If (LEqual (Arg2, 9)) { + Return(Buffer() {0x4}) + } + } + } + Return(Buffer() { 0x0 }) + } } /* SD CARD */ |