soc/intel/apollolake: Add PM methods to power gate PCIe

This implements GNVS variable to store the address of PERST_0,
_ON/_OFF methods to power gate PCIe during S0ix entry, and
PERST_0 assertion/de-assertion methods.

BUG=chrome-os-partner:55877
TEST=Suspend and resume using 'echo freeze > /sys/power/state'.
System should resume with PCIE and wifi functional.

Change-Id: I9f63ca0b8a6565b6d21deaa6d3dfa34678714c19
Signed-off-by: Vaibhav Shankar <vaibhav.shankar@intel.com>
Reviewed-on: https://review.coreboot.org/16351
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>

src/soc/intel/apollolake/acpi.c

@@ -29,6 +29,7 @@
 #include <soc/nvs.h>
 #include <soc/pci_devs.h>
 #include <string.h>
+#include <soc/gpio.h>
 #include "chip.h"
 
 #define CSTATE_RES(address_space, width, offset, address)		\
@@ -175,6 +176,10 @@ static void acpi_create_gnvs(struct global_nvs_t *gnvs)
 
 	/* Enable DPTF based on mainboard configuration */
 	gnvs->dpte = cfg->dptf_enable;
+
+	/* Assign address of PERST_0 if GPIO is defined in devicetree */
+	if (cfg->prt0_gpio != GPIO_PRT0_UDEF)
+		gnvs->prt0 = (uintptr_t)gpio_dwx_address(cfg->prt0_gpio);
 }
 
 /* Save wake source information for calculating ACPI _SWS values */

src/soc/intel/apollolake/acpi/globalnvs.asl

@@ -38,6 +38,7 @@ Field (GNVS, ByteAcc, NoLock, Preserve)
 	GPEI,	64,     // 0x11 - 0x18 - GPE Wake Source
 	NHLA,	64,     // 0x19 - 0x20 - NHLT Address
 	NHLL,	32,     // 0x21 - 0x24 - NHLT Length
+	PRT0,	32,     // 0x25 - 0x28 - PERST_0 Address
 
 	/* ChromeOS stuff (0x100 -> 0xfff, size 0xeff) */
 	Offset (0x100),

src/soc/intel/apollolake/acpi/gpio.asl

@@ -15,6 +15,7 @@
  * GNU General Public License for more details.
  */
 #include <soc/gpio_defs.h>
+#include "gpiolib.asl"
 
 scope (\_SB) {
 
@@ -141,6 +142,38 @@ scope (\_SB) {
 			Return(0xf)
 		}
 	}
+
+	Scope(\_SB.PCI0) {
+		/* PERST Assertion
+		 * Note: PERST is Active High
+		 */
+		Method (PRAS, 0x1, Serialized)
+		{
+			/*
+			 * Assert PERST
+			 * local1 - to toggle Tx pin of Dw0
+			 * local2 - Address of PERST
+			 */
+			Store (Arg0, Local2)
+			Store (\_SB.GPC0 (Local2), Local1)
+			Or (Local1, PAD_CFG0_TX_STATE, Local1)
+			\_SB.SPC0 (Local2, Local1)
+		}
+
+		/* PERST DE-Assertion */
+		Method (PRDA, 0x1, Serialized)
+		{
+			/*
+			 * De-assert PERST
+			 * local1 - to toggle Tx pin of Dw0
+			 * local2 - Address of PERST
+			 */
+			Store (Arg0, Local2)
+			Store (\_SB.GPC0 (Local2), Local1)
+			And (Local1, Not (PAD_CFG0_TX_STATE), Local1)
+			\_SB.SPC0 (Local2, Local1)
+		}
+	}
 }
 
 Scope(\_GPE)

src/soc/intel/apollolake/acpi/gpiolib.asl

@@ -0,0 +1,67 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2016 Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+Scope (\_SB)
+{
+	/* Get Pad Configuration DW0 register value */
+	Method (GPC0, 0x1, Serialized)
+	{
+		/* Arg0 - GPIO DW0 address */
+		Store (Arg0, Local0)
+		OperationRegion (PDW0, SystemMemory, Local0, 4)
+		Field (PDW0, AnyAcc, NoLock, Preserve) {
+			TEMP, 32
+		}
+		Return (TEMP)
+	}
+
+	/* Set Pad Configuration DW0 register value */
+	Method (SPC0, 0x2, Serialized)
+	{
+		/* Arg0 - GPIO DW0 address */
+		/* Arg1 - Value for DW0 register */
+		Store (Arg0, Local0)
+		OperationRegion (PDW0, SystemMemory, Local0, 4)
+		Field (PDW0, AnyAcc, NoLock, Preserve) {
+			TEMP,32
+		}
+		Store (Arg1, TEMP)
+	}
+
+	/* Get Pad Configuration DW1 register value */
+	Method (GPC1, 0x1, Serialized)
+	{
+		/* Arg0 - GPIO DW0 address */
+		Store (Add (Arg0, 0x4), Local0)
+		OperationRegion (PDW1, SystemMemory, Local0, 4)
+		Field (PDW1, AnyAcc, NoLock, Preserve) {
+			TEMP, 32
+		}
+		Return (TEMP)
+	}
+
+	/* Set Pad Configuration DW1 register value */
+	Method (SPC1, 0x2, Serialized)
+	{
+		/* Arg0 - GPIO DW0 address */
+		/* Arg1 - Value for DW1 register */
+		Store (Add (Arg0, 0x4), Local0)
+		OperationRegion (PDW1, SystemMemory, Local0, 4)
+		Field(PDW1, AnyAcc, NoLock, Preserve) {
+			TEMP,32
+		}
+		Store (Arg1, TEMP)
+	}
+}

src/soc/intel/apollolake/acpi/pcie.asl

@@ -0,0 +1,126 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2016 Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+Device (RP01)
+{
+	Name (_ADR, 0x00140000)
+	Name (_DDN, "PCIe-B 0")
+	Name (PDST, 0) /* present Detect status */
+
+	/* lowest D-state supported by
+	 * PCIe root port during S0 state
+	 */
+	Name (_S0W, 4)
+
+	/* Dynamic Opregion needed to access registers
+	 * when the controller is in D3 cold
+	 */
+	OperationRegion (PX01, PCI_Config, 0x00, 0xFF)
+	Field (PX01, AnyAcc, NoLock, Preserve)
+	{
+		Offset(0x5A),
+		, 6,
+		PDS, 1,		/* 6, Presence detect Change */
+		Offset(0xE2),	/* RPPGEN - Root Port Power Gating Enable */
+		, 2,
+		L23E, 1,	/* 2, L23_Rdy Entry Request (L23ER) */
+		L23R, 1,	/* 3, L23_Rdy to Detect Transition (L23R2DT) */
+		Offset(0xF4),	/* BLKPLLEN */
+		, 10,
+		BPLL, 1,
+	}
+
+	OperationRegion (PX02, PCI_Config, 0x338, 0x4)
+	Field (PX02, AnyAcc, NoLock, Preserve)
+	{
+		, 26,
+		BDQA, 1		/* BLKDQDA */
+	}
+
+	PowerResource (PXP, 0, 0)
+	{
+		/* Define the PowerResource for PCIe slot */
+		Method (_STA, 0, Serialized)
+		{
+			Store (PDS, PDST)
+			If (LEqual (PDS, 1)) {
+				Return (0xf)
+			} Else {
+				Return (0)
+			}
+		}
+
+		Method (_ON, 0, Serialized)
+		{
+			If (LAnd (LEqual (PDST, 1), LNotEqual (\PRT0, 0))) {
+				/* Enter this condition if device
+				 * is connected
+				 */
+
+				/* De-assert PERST */
+				\_SB.PCI0.PRDA (\PRT0)
+
+				Store (0, BDQA) /* Set BLKDQDA to 0 */
+				Store (0, BPLL) /* Set BLKPLLEN to 0 */
+
+				/* Set L23_Rdy to Detect Transition
+				 * (L23R2DT)
+				 */
+				Store (1, L23R)
+				Sleep (16)
+				Store (0, Local0)
+
+				/* Delay for transition Detect
+				 * and link to train
+				 */
+				While (L23R) {
+					If (Lgreater (Local0, 4)) {
+						Break
+					}
+					Sleep (16)
+					Increment (Local0)
+				}
+			} /* End PDS condition check */
+		}
+
+		Method (_OFF, 0, Serialized)
+		{
+			/* Set L23_Rdy Entry Request (L23ER) */
+			If (LAnd (LEqual (PDST, 1), LNotEqual (\PRT0, 0))) {
+				/* enter this condition if device
+				 * is connected
+				 */
+				Store (1, L23E)
+				Sleep (16)
+				Store (0, Local0)
+				While (L23E) {
+					If (Lgreater (Local0, 4)) {
+						Break
+					}
+					Sleep (16)
+					Increment (Local0)
+				}
+				Store (1, BDQA) /* Set BLKDQDA to 1 */
+				Store (1, BPLL) /* Set BLKPLLEN to 1 */
+
+				/* Assert PERST */
+				\_SB.PCI0.PRAS (\PRT0)
+			} /* End PDS condition check */
+		} /* End of Method_OFF */
+	} /* End PXP */
+
+	Name(_PR0, Package() { PXP })
+	Name(_PR3, Package() { PXP })
+}

src/soc/intel/apollolake/acpi/southbridge.asl

@@ -17,6 +17,9 @@
 
 #include <soc/gpe.h>
 
+/* PCIE device */
+#include "pcie.asl"
+
 /* LPSS device */
 #include "lpss.asl"
 

src/soc/intel/apollolake/chip.h

@@ -116,6 +116,9 @@ struct soc_intel_apollolake_config {
 
 	/* SLP S3 minimum assertion width. */
 	int slp_s3_assertion_width_usecs;
+
+	/* GPIO pin for PERST_0 */
+	uint16_t prt0_gpio;
 };
 
 #endif	/* _SOC_APOLLOLAKE_CHIP_H_ */

src/soc/intel/apollolake/include/soc/gpio_defs.h

@@ -414,6 +414,9 @@
 #define LPC_CLKRUNB			243
 #define LPC_FRAMEB			244
 
+/* PERST_0 not defined */
+#define GPIO_PRT0_UDEF			0xFF
+
 #define TOTAL_PADS			245
 #define N_OFFSET			GPIO_0
 #define NW_OFFSET			GPIO_187

src/soc/intel/apollolake/include/soc/nvs.h

@@ -38,7 +38,8 @@ typedef struct global_nvs_t {
 	uint64_t	gpei; /* 0x11 - 0x18 - GPE Wake Source */
 	uint64_t	nhla; /* 0x19 - 0x20 - NHLT Address */
 	uint32_t	nhll; /* 0x21 - 0x24 - NHLT Length */
-	uint8_t		unused[219];
+	uint32_t	prt0; /* 0x25 - 0x28 - PERST_0 Address */
+	uint8_t		unused[215];
 
 	/* ChromeOS specific (0x100 - 0xfff) */
 	chromeos_acpi_t chromeos;