soc/intel/common/block/acpi: Move pep.asl to acpigen

There is a use-case for generating the AML bytecode at runtime for the
Intel Power Engine device, which comes in a followup patch.

BUG=b:185437326
TEST=verified on google/brya and google/dratini by dumping SSDT and
verifying the PEPD device matches what was previously in the DSDT:
    Scope (\_SB.PCI0)
    {
        Device (PEPD)
        {
            Name (_HID, "INT33A1")
            Name (_CID, EisaId ("PNP0D80")
            Method (_DSM, 4, Serialized)
            {
                ToBuffer (Arg0, Local0)
                If ((Local0 == ToUUID ("c4eb40a0-6cd2-11e2-bcfd-0800200c9a66")))
                {
                    ToInteger (Arg2, Local1)
                    If ((Local1 == Zero))
                    {
                        Return (Buffer (One)
                        {
                             0x63
                        })
                    }
		    If ((Local1 == One))
                    {
                        Return (Package (0x01)
                        {
                            Package (0x03)
                            {
                                \NULL,
                                Zero,
                                Package (0x02)
                                {
                                    Zero,
                                    Package (0x02)
                                    {
                                        0xFF,
                                        Zero
                                    }
                                }
			   }
                       })
                    }
                    If ((Local1 == 0x02)){}
                    If ((Local1 == 0x03)){}
                    If ((Local1 == 0x04)){}
                    If ((Local1 == 0x05))
                    {
                        If (CondRefOf (\_SB.PCI0.LPCB.EC0.S0IX))
                        {
                            \_SB.PCI0.LPCB.EC0.S0IX (One)
                        }

                        If (CondRefOf (\_SB.MS0X))
                        {
                            \_SB.MS0X (One)
                        }

                        If (CondRefOf (\_SB.PCI0.EGPM))
                        {
                            \_SB.PCI0.EGPM ()
                        }
                    }

                    If ((Local1 == 0x06))
                    {
                        If (CondRefOf (\_SB.PCI0.LPCB.EC0.S0IX))
                        {
                            \_SB.PCI0.LPCB.EC0.S0IX (Zero)
                        }

                        If (CondRefOf (\_SB.MS0X))
                        {
                            \_SB.MS0X (Zero)
                        }

                        If (CondRefOf (\_SB.PCI0.RGPM))
                        {
                            \_SB.PCI0.RGPM ()
                        }
                    }

                    Return (Buffer (One)
                    {
                         0x00
                    })
                }

Signed-off-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Change-Id: Ie83722e0ed5792e338fc5c39a57eef43b7464e3b
Reviewed-on: https://review.coreboot.org/c/coreboot/+/56004
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>

4 files changed, 133 insertions, 1 deletions

diff --git a/src/soc/intel/common/block/acpi/Kconfig b/src/soc/intel/common/block/acpi/Kconfig
index 6aa3abcad9..cc4cd71fdc 100644
--- a/src/soc/intel/common/block/acpi/Kconfig
+++ b/src/soc/intel/common/block/acpi/Kconfig
@@ -15,6 +15,13 @@ config SOC_INTEL_COMMON_BLOCK_ACPI_LPIT
 	help
 	  Generate LPIT table with LPI state entries
 
+config SOC_INTEL_COMMON_BLOCK_ACPI_PEP
+	bool
+	depends on HAVE_ACPI_TABLES
+	help
+	  Generate an Intel Power Engine device object in the SSDT. This is
+	  usually used for providing ACPI hooks for S0ix exit/entry.
+
 config SOC_INTEL_COMMON_BLOCK_CRASHLOG
 	bool
 	depends on SOC_INTEL_CRASHLOG
@@ -28,5 +35,4 @@ config SOC_INTEL_COMMON_BLOCK_ACPI_CPPC
 	help
 	  Generate CPPC entries for Intel SpeedShift
 
-
 endif
diff --git a/src/soc/intel/common/block/acpi/Makefile.inc b/src/soc/intel/common/block/acpi/Makefile.inc
index c78dbc0d84..c8eaad5c25 100644
--- a/src/soc/intel/common/block/acpi/Makefile.inc
+++ b/src/soc/intel/common/block/acpi/Makefile.inc
@@ -3,3 +3,4 @@ ramstage-$(CONFIG_SOC_INTEL_COMMON_BLOCK_ACPI_GPIO) += gpio.c
 ramstage-$(CONFIG_SOC_INTEL_COMMON_BLOCK_ACPI_LPIT) += lpit.c
 ramstage-$(CONFIG_ACPI_BERT) += acpi_bert.c
 ramstage-$(CONFIG_SOC_INTEL_COMMON_ACPI_WAKE_SOURCE) += acpi_wake_source.c
+ramstage-$(CONFIG_SOC_INTEL_COMMON_BLOCK_ACPI_PEP) += pep.c
diff --git a/src/soc/intel/common/block/acpi/pep.c b/src/soc/intel/common/block/acpi/pep.c
new file mode 100644
index 0000000000..9b15bf3b32
--- /dev/null
+++ b/src/soc/intel/common/block/acpi/pep.c
@@ -0,0 +1,122 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#include <acpi/acpigen.h>
+#include <console/console.h>
+#include <intelblocks/acpi.h>
+#include <types.h>
+
+#define LPI_S0_HELPER_UUID		"c4eb40a0-6cd2-11e2-bcfd-0800200c9a66"
+#define SYSTEM_POWER_MANAGEMENT_HID	"INT33A1"
+#define SYSTEM_POWER_MANAGEMENT_CID	"PNP0D80"
+#define EC_S0IX_HOOK			"\\_SB.PCI0.LPCB.EC0.S0IX"
+#define MAINBOARD_HOOK			"\\_SB.MS0X"
+#define ENABLE_PM_BITS_HOOK		"\\_SB.PCI0.EGPM"
+#define RESTORE_PM_BITS_HOOK		"\\_SB.PCI0.RGPM"
+#define LPI_STATES_ALL			0xff
+#define MIN_DEVICE_STATE		ACPI_DEVICE_SLEEP_D0
+#define PEPD_SCOPE			"\\_SB.PCI0"
+
+/*
+ * For now there is only one disabled non-existent device, because Windows
+ * expects at least one device and crashes without it with a bluescreen
+ * (`INTERNAL_POWER_ERROR`). Returning an empty package does not work.
+ */
+static void lpi_get_constraints(void *unused)
+{
+	/*
+	 * Return (Package() {
+	 *     Package() { "\NULL", 0,
+	 *         Package() { 0,
+	 *             Package() { 0xff, 0 }}}})
+	 */
+	acpigen_emit_byte(RETURN_OP);
+	acpigen_write_package(1);
+	{
+		acpigen_write_package(3);
+		{
+			acpigen_emit_namestring("\\NULL");
+			acpigen_write_integer(0); /* device disabled */
+			acpigen_write_package(2);
+			{
+				acpigen_write_integer(0); /* revision */
+				acpigen_write_package(2);
+				{
+					acpigen_write_integer(LPI_STATES_ALL);
+					acpigen_write_integer(MIN_DEVICE_STATE);
+				}
+				acpigen_write_package_end();
+			}
+			acpigen_write_package_end();
+		}
+		acpigen_write_package_end();
+	}
+	acpigen_write_package_end();
+}
+
+static void lpi_s0ix_entry(void *unused)
+{
+	/* Inform the EC */
+	acpigen_write_if_cond_ref_of(EC_S0IX_HOOK);
+	acpigen_emit_namestring(EC_S0IX_HOOK);
+	acpigen_write_integer(1);
+	acpigen_write_if_end();
+
+	/* Provide a board level S0ix hook */
+	acpigen_write_if_cond_ref_of(MAINBOARD_HOOK);
+	acpigen_emit_namestring(MAINBOARD_HOOK);
+	acpigen_write_integer(1);
+	acpigen_write_if_end();
+
+	/* Save the current PM bits then enable GPIO PM with
+	   MISCCFG_GPIO_PM_CONFIG_BITS */
+	acpigen_write_if_cond_ref_of(ENABLE_PM_BITS_HOOK);
+	acpigen_emit_namestring(ENABLE_PM_BITS_HOOK);
+	acpigen_write_if_end();
+}
+
+static void lpi_s0ix_exit(void *unused)
+{
+	/* Inform the EC */
+	acpigen_write_if_cond_ref_of(EC_S0IX_HOOK);
+	acpigen_emit_namestring(EC_S0IX_HOOK);
+	acpigen_write_integer(0);
+	acpigen_write_if_end();
+
+	/* Provide a board level S0ix hook */
+	acpigen_write_if_cond_ref_of(MAINBOARD_HOOK);
+	acpigen_emit_namestring(MAINBOARD_HOOK);
+	acpigen_write_integer(0);
+	acpigen_write_if_end();
+
+	/* Restore GPIO all Community PM */
+	acpigen_write_if_cond_ref_of(RESTORE_PM_BITS_HOOK);
+	acpigen_emit_namestring(RESTORE_PM_BITS_HOOK);
+	acpigen_write_if_end();
+}
+
+static void (*lpi_s0_helpers[])(void *) = {
+	NULL,			/* enumerate functions (autogenerated) */
+	lpi_get_constraints,	/* get device constraints */
+	NULL,			/* get crash dump device */
+	NULL,			/* display off notify */
+	NULL,			/* display on notify */
+	lpi_s0ix_entry,		/* s0ix entry */
+	lpi_s0ix_exit,		/* s0ix exit */
+};
+
+void generate_acpi_power_engine(void)
+{
+	acpigen_write_scope(PEPD_SCOPE);
+	acpigen_write_device("PEPD");
+
+	acpigen_write_name_string("_HID", SYSTEM_POWER_MANAGEMENT_HID);
+	acpigen_write_name("_CID");
+	acpigen_emit_eisaid(SYSTEM_POWER_MANAGEMENT_CID);
+
+	acpigen_write_dsm(LPI_S0_HELPER_UUID, lpi_s0_helpers, ARRAY_SIZE(lpi_s0_helpers), NULL);
+
+	acpigen_write_device_end();
+	acpigen_write_scope_end();
+
+	printk(BIOS_INFO, PEPD_SCOPE ".PEPD: Intel Power Engine Plug-in\n");
+}
diff --git a/src/soc/intel/common/block/include/intelblocks/acpi.h b/src/soc/intel/common/block/include/intelblocks/acpi.h
index 90d5e5e522..5eb1a9bf48 100644
--- a/src/soc/intel/common/block/include/intelblocks/acpi.h
+++ b/src/soc/intel/common/block/include/intelblocks/acpi.h
@@ -90,4 +90,7 @@ struct madt_ioapic_info {
  */
 const struct madt_ioapic_info *soc_get_ioapic_info(size_t *entries);
 
+/* Generate an Intel Power Engine ACPI device */
+void generate_acpi_power_engine(void);
+
 #endif				/* _SOC_INTEL_COMMON_BLOCK_ACPI_H_ */