diff options
| author | Patrick Georgi <pgeorgi@google.com> | 2017-08-18 21:06:24 +0200 |
|---|---|---|
| committer | Patrick Georgi <pgeorgi@google.com> | 2017-08-22 17:59:20 +0000 |
| commit | 4bd68b8e4f7195d48d742deb2da848b31733e57e (patch) | |
| tree | 8e317897811f7415de867e2a09bf5785d9788372 /src | |
| parent | fbf1018805d108ea59ea000fec459e5a44110d7a (diff) | |
ec/google: Detect keyboard backlight at runtime
This enables adding the backlight driver to boards that may or may not
come with a keyboard backlight function.
It's the responsibility of the EC to report if that feature exists, but
that's not a big extra burden given that it already keeps track of
everything else related to the backlight.
BUG=b:64705535
BRANCH=none
CQ-DEPEND=CL:620595
TEST=configured KBLE manually and noticed the presence/absence of
/sys/devices/platform/GOOG0002:00/ on a Chrome OS Linux kernel,
corresponding to the value reported by the EC.
Change-Id: Idc36bfaa6e69581ba19b52d37af6956f63cfdb8f
Signed-off-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-on: https://review.coreboot.org/21099
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Diffstat (limited to 'src')
| -rw-r--r-- | src/ec/google/chromeec/acpi/ec.asl | 2 | ||||
| -rw-r--r-- | src/ec/google/chromeec/acpi/keyboard_backlight.asl | 14 |
2 files changed, 16 insertions, 0 deletions
diff --git a/src/ec/google/chromeec/acpi/ec.asl b/src/ec/google/chromeec/acpi/ec.asl index a5324920e6..422abe1881 100644 --- a/src/ec/google/chromeec/acpi/ec.asl +++ b/src/ec/google/chromeec/acpi/ec.asl @@ -54,6 +54,8 @@ Device (EC0) PATC, 8, // Programmable Auxiliary Trip Commit CHGL, 8, // Charger Current Limit TBMD, 1, // Tablet mode + Offset (0x0a), + KBLE, 1, // Keyboard Backlight exists } #if IS_ENABLED(CONFIG_EC_GOOGLE_CHROMEEC_ACPI_MEMMAP) diff --git a/src/ec/google/chromeec/acpi/keyboard_backlight.asl b/src/ec/google/chromeec/acpi/keyboard_backlight.asl index 75a8df3cca..d76bed87ea 100644 --- a/src/ec/google/chromeec/acpi/keyboard_backlight.asl +++ b/src/ec/google/chromeec/acpi/keyboard_backlight.asl @@ -23,6 +23,20 @@ Scope (\_SB) Name (_HID, "GOOG0002") Name (_UID, 1) + /* Ask EC if we even have a backlight + * Return 0xf (present, enabled, show in UI, functioning) or 0 + * + * With older EC codebases that don't support the Device + * Features bitfield, this reports the keyboard backlight as + * enabled since reads to undefined addresses in EC address + * space return 0xff and so KBLE will be 1. + */ + Method (_STA, 0, NotSerialized) + { + Multiply (0xf, \_SB.PCI0.LPCB.EC0.KBLE, Local0) + Return (Local0) + } + /* Read current backlight value */ Method (KBQC, 0, NotSerialized) { |