soc/apollolake: Set up GPIO_TIER1_SCI_EN properly

Currently we are setting the gpio_tier1_sci in smihandler before
going to S3. But this won't work for S0iX as it happens from Linux
kernel and SMI handler is not involved in that flow. We need to
set this bit i.e. bit 15 in ACPI gpe0a register at 0x430h. The Linux
kernel before going to sleep checks what values are passed through
ASL as wake events (through _PRW), keeps those enabled only and
clears other bits in gpe0 enable registers. So we need to inform
the kernel to keep gpio_tier_sci also set as these are needed for
any wake event. This patch adds ASL code for sleep button device with
HID id PNP0C0E. We are adding _PRW method for sleep button device
with this patch.

BUG=chrome-os-partner:56483
TEST=System resumes from S3 on lidopen, powerbutton and USB wake.
     Also from S0iX system is resuming for WIFI wake.

Change-Id: Ie8517cad9cd37c25788c22250894d4f9db344ff9
Signed-off-by: Shaunak Saha <shaunak.saha@intel.com>
Reviewed-on: https://review.coreboot.org/16564
Tested-by: build bot (Jenkins)
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>

1 files changed, 13 insertions, 0 deletions

diff --git a/src/soc/intel/apollolake/acpi/gpio.asl b/src/soc/intel/apollolake/acpi/gpio.asl
index 5660dfa830..4f3bc3ee2c 100644
--- a/src/soc/intel/apollolake/acpi/gpio.asl
+++ b/src/soc/intel/apollolake/acpi/gpio.asl
@@ -174,6 +174,19 @@ scope (\_SB) {
 			\_SB.SPC0 (Local2, Local1)
 		}
 	}
+
+	/*
+	 * Sleep button device ASL code. We are using this device to
+	 * add the _PRW method for a dummy wake event to kernel so that
+	 * before going to sleep kernel does not clear bit 15 in ACPI
+	 * gpe0a enable register which is actually the GPIO_TIER1_SCI_EN bit.
+	 */
+	Device (SLP)
+	{
+		Name (_HID, EisaId ("PNP0C0E"))
+
+		Name (_PRW, Package() { GPE0A_GPIO_TIER1_SCI_STS, 0x3 })
+	}
 }
 
 Scope(\_GPE)