soc/intel/skylake: Add detailed information about PME wake sources

Add more fine-grained details about what device caused the PME wake
event. This requires checking the PME status bit (bit 15) in PCI PM
control and status register for the PCI device.

BUG=b:37088992
TEST=Verifed that XHCI wake source was identified correctly:
135 | 2017-05-25 15:28:17 | ACPI Enter | S3
136 | 2017-05-25 15:28:26 | ACPI Wake | S3
137 | 2017-05-25 15:28:26 | Wake Source | PME - XHCI | 0

Change-Id: I6fc6284cd04db311f1f86b8a86d0bb708392e5d5
Signed-off-by: Furquan Shaikh <furquan@chromium.org>
Reviewed-on: https://review.coreboot.org/19925
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

1 files changed, 62 insertions, 1 deletions

diff --git a/src/soc/intel/skylake/elog.c b/src/soc/intel/skylake/elog.c
index 6db15f5e6123..d127fcc2464f 100644
--- a/src/soc/intel/skylake/elog.c
+++ b/src/soc/intel/skylake/elog.c
@@ -17,8 +17,10 @@
 #include <bootstate.h>
 #include <cbmem.h>
 #include <console/console.h>
+#include <device/pci_ops.h>
 #include <stdint.h>
 #include <elog.h>
+#include <soc/pci_devs.h>
 #include <soc/pm.h>
 #include <soc/smbus.h>
 
@@ -34,6 +36,65 @@ static void pch_log_gpio_gpe(u32 gpe0_sts, u32 gpe0_en, int start)
 	}
 }
 
+struct pme_status_info {
+	int devfn;
+	uint8_t reg_offset;
+	uint32_t elog_event;
+};
+
+#define PME_STS_BIT		(1 << 15)
+
+static void pch_log_pme_internal_wake_source(void)
+{
+	size_t i;
+	device_t dev;
+	uint16_t val;
+	bool dev_found = false;
+
+	static const struct pme_status_info pme_status_info[] = {
+		{ PCH_DEVFN_HDA, 0x54, ELOG_WAKE_SOURCE_PME_HDA },
+		{ PCH_DEVFN_GBE, 0xcc, ELOG_WAKE_SOURCE_PME_GBE },
+		{ PCH_DEVFN_EMMC, 0x84, ELOG_WAKE_SOURCE_PME_EMMC },
+		{ PCH_DEVFN_SDCARD, 0x84, ELOG_WAKE_SOURCE_PME_SDCARD },
+		{ PCH_DEVFN_PCIE1, 0xa4, ELOG_WAKE_SOURCE_PME_PCIE1 },
+		{ PCH_DEVFN_PCIE2, 0xa4, ELOG_WAKE_SOURCE_PME_PCIE2 },
+		{ PCH_DEVFN_PCIE3, 0xa4, ELOG_WAKE_SOURCE_PME_PCIE3 },
+		{ PCH_DEVFN_PCIE4, 0xa4, ELOG_WAKE_SOURCE_PME_PCIE4 },
+		{ PCH_DEVFN_PCIE5, 0xa4, ELOG_WAKE_SOURCE_PME_PCIE5 },
+		{ PCH_DEVFN_PCIE6, 0xa4, ELOG_WAKE_SOURCE_PME_PCIE6 },
+		{ PCH_DEVFN_PCIE7, 0xa4, ELOG_WAKE_SOURCE_PME_PCIE7 },
+		{ PCH_DEVFN_PCIE8, 0xa4, ELOG_WAKE_SOURCE_PME_PCIE8 },
+		{ PCH_DEVFN_PCIE9, 0xa4, ELOG_WAKE_SOURCE_PME_PCIE9 },
+		{ PCH_DEVFN_PCIE10, 0xa4, ELOG_WAKE_SOURCE_PME_PCIE10 },
+		{ PCH_DEVFN_PCIE11, 0xa4, ELOG_WAKE_SOURCE_PME_PCIE11 },
+		{ PCH_DEVFN_PCIE12, 0xa4, ELOG_WAKE_SOURCE_PME_PCIE12 },
+		{ PCH_DEVFN_SATA, 0x74, ELOG_WAKE_SOURCE_PME_SATA },
+		{ PCH_DEVFN_CSE, 0x54, ELOG_WAKE_SOURCE_PME_CSE },
+		{ PCH_DEVFN_CSE_2, 0x54, ELOG_WAKE_SOURCE_PME_CSE2 },
+		{ PCH_DEVFN_CSE_3, 0x54, ELOG_WAKE_SOURCE_PME_CSE3 },
+		{ PCH_DEVFN_XHCI, 0x74, ELOG_WAKE_SOURCE_PME_XHCI },
+		{ PCH_DEVFN_USBOTG, 0x84, ELOG_WAKE_SOURCE_PME_XDCI },
+	};
+
+	for (i = 0; i < ARRAY_SIZE(pme_status_info); i++) {
+		dev = dev_find_slot(0, pme_status_info[i].devfn);
+
+		if (!dev)
+			continue;
+
+		val = pci_read_config16(dev, pme_status_info[i].reg_offset);
+
+		if ((val == 0xFFFF) || !(val & PME_STS_BIT))
+			continue;
+
+		elog_add_event_wake(pme_status_info[i].elog_event, 0);
+		dev_found = true;
+	}
+
+	if (!dev_found)
+		elog_add_event_wake(ELOG_WAKE_SOURCE_PME_INTERNAL, 0);
+}
+
 static void pch_log_wake_source(struct chipset_power_state *ps)
 {
 	/* Power Button */
@@ -54,7 +115,7 @@ static void pch_log_wake_source(struct chipset_power_state *ps)
 
 	/* Internal PME (TODO: determine wake device) */
 	if (ps->gpe0_sts[GPE_STD] & PME_B0_STS)
-		elog_add_event_wake(ELOG_WAKE_SOURCE_PME_INTERNAL, 0);
+		pch_log_pme_internal_wake_source();
 
 	/* SMBUS Wake */
 	if (ps->gpe0_sts[GPE_STD] & SMB_WAK_STS)