skylake: take into account deep s3 in power failure check

If a resume from S3 is occuring one needs to take into account
deep S3 in order to check the proper power failure bits.
When deep S3 is enabled the suspend well will be turned off.
Therefore don't look for that bit when determining a power
failure.

BUG=chrome-os-partner:42847
BRANCH=None
TEST=Suspend and resumed with deep s3 enabled and disabled.

Change-Id: I2b3372a40b3d8295ee881a283b31ca7704e6764a
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: a3ba22be37d8700f4e8a4a0f5c05fb9290cfc9b2
Original-Change-Id: I890f71a7cbea65f1db942fe2229a220cf0e721b0
Original-Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/286271
Original-Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-on: http://review.coreboot.org/11007
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>

2 files changed, 27 insertions, 2 deletions

diff --git a/src/soc/intel/skylake/include/soc/pm.h b/src/soc/intel/skylake/include/soc/pm.h
index 4d9abcb20d..2e722bf206 100644
--- a/src/soc/intel/skylake/include/soc/pm.h
+++ b/src/soc/intel/skylake/include/soc/pm.h
@@ -21,6 +21,9 @@
 #ifndef _SOC_PM_H_
 #define _SOC_PM_H_
 
+#include <arch/io.h>
+#include <soc/pmc.h>
+
 /* ACPI_BASE_ADDRESS / PMBASE */
 
 #define PM1_STS			0x00
@@ -169,4 +172,12 @@ uint8_t *pmc_mmio_regs(void);
 /* Get base address of TCO I/O registers. */
 uint16_t pmc_tco_regs(void);
 
+static inline int deep_s3_enabled(void)
+{
+	uint32_t deep_s3_pol;
+
+	deep_s3_pol = read32(pmc_mmio_regs() + S3_PWRGATE_POL);
+	return !!(deep_s3_pol & (S3DC_GATE_SUS | S3AC_GATE_SUS));
+}
+
 #endif
diff --git a/src/soc/intel/skylake/romstage/power_state.c b/src/soc/intel/skylake/romstage/power_state.c
index 4ffa381b11..5c94e89fd7 100644
--- a/src/soc/intel/skylake/romstage/power_state.c
+++ b/src/soc/intel/skylake/romstage/power_state.c
@@ -74,8 +74,22 @@ static int prev_sleep_state(struct chipset_power_state *ps)
 		outl(ps->pm1_cnt & ~(SLP_TYP), ACPI_BASE_ADDRESS + PM1_CNT);
 	}
 
-	if (ps->gen_pmcon_b & (PWR_FLR | SUS_PWR_FLR))
-		prev_sleep_state = SLEEP_STATE_S5;
+	/*
+	 * If waking from S3 determine if deep S3 is enabled. If not,
+	 * need to check both deep sleep well and normal suspend well.
+	 * Otherwise just check deep sleep well.
+	 */
+	if (prev_sleep_state == SLEEP_STATE_S3) {
+		/* PWR_FLR represents deep sleep power well loss. */
+		uint32_t mask = PWR_FLR;
+
+		/* If deep s3 isn't enabled check the suspend well too. */
+		if (!deep_s3_enabled())
+			mask |= SUS_PWR_FLR;
+
+		if (ps->gen_pmcon_b & mask)
+			prev_sleep_state = SLEEP_STATE_S5;
+	}
 
 	return prev_sleep_state;
 }