soc/amd/cezanne/root_complex: generate DPTC ACPI method

This adds support for convertible devices to support different maximum
power and thermal configurations. The dynamic power and thermal
configuration (DPTC) via ACPI ALIB calls allows to change the parameters
during runtime. This code contains the assumption that
\_SB.PCI0.LPCB.EC0.TBMD exists when ACPI code calls the DPTC method. At
the moment only chromeec declares EC0.TBMD, but it's also the only code
that calls the DPTC method. The definition of DPTC_INPUTS isn't moved to
the common code directory, since it's currently unsure if we might need
to configure more than those 4 parameters for Cezanne.

Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Change-Id: Ibdfc056cb325a32d87505dd93e01c9af81dfd6c5
Reviewed-on: https://review.coreboot.org/c/coreboot/+/54074
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Raul Rangel <rrangel@chromium.org>

2 files changed, 76 insertions, 0 deletions

diff --git a/src/soc/amd/cezanne/Kconfig b/src/soc/amd/cezanne/Kconfig
index 327ec124d2..2cedf8c2d0 100644
--- a/src/soc/amd/cezanne/Kconfig
+++ b/src/soc/amd/cezanne/Kconfig
@@ -38,6 +38,7 @@ config SOC_SPECIFIC_OPTIONS
 	select SOC_AMD_COMMON_BLOCK_ACP
 	select SOC_AMD_COMMON_BLOCK_ACPI
 	select SOC_AMD_COMMON_BLOCK_ACPIMMIO
+	select SOC_AMD_COMMON_BLOCK_ACPI_ALIB
 	select SOC_AMD_COMMON_BLOCK_ACPI_GPIO
 	select SOC_AMD_COMMON_BLOCK_AOAC
 	select SOC_AMD_COMMON_BLOCK_APOB
diff --git a/src/soc/amd/cezanne/root_complex.c b/src/soc/amd/cezanne/root_complex.c
index 5d021baa5b..3ed137ce19 100644
--- a/src/soc/amd/cezanne/root_complex.c
+++ b/src/soc/amd/cezanne/root_complex.c
@@ -1,6 +1,8 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 
+#include <acpi/acpigen.h>
 #include <amdblocks/acpi.h>
+#include <amdblocks/alib.h>
 #include <amdblocks/ioapic.h>
 #include <amdblocks/memmap.h>
 #include <arch/ioapic.h>
@@ -13,6 +15,37 @@
 #include <fsp/util.h>
 #include <soc/iomap.h>
 #include <stdint.h>
+#include "chip.h"
+
+#define DPTC_TOTAL_UPDATE_PARAMS	4
+
+struct dptc_input {
+	uint16_t size;
+	struct alib_dptc_param params[DPTC_TOTAL_UPDATE_PARAMS];
+} __packed;
+
+#define DPTC_INPUTS(_thermctllmit, _sustained, _fast, _slow)			\
+	{									\
+		.size = sizeof(struct dptc_input),				\
+		.params = {							\
+			{							\
+				.id = ALIB_DPTC_THERMAL_CONTROL_LIMIT_ID,	\
+				.value = _thermctllmit,				\
+			},							\
+			{							\
+				.id = ALIB_DPTC_SUSTAINED_POWER_LIMIT_ID,	\
+				.value = _sustained,				\
+			},							\
+			{							\
+				.id = ALIB_DPTC_FAST_PPT_LIMIT_ID,		\
+				.value = _fast,					\
+			},							\
+			{							\
+				.id = ALIB_DPTC_SLOW_PPT_LIMIT_ID,		\
+				.value = _slow,					\
+			},							\
+		},								\
+	}
 
 /*
  *
@@ -146,9 +179,51 @@ static void root_complex_init(struct device *dev)
 	setup_ioapic((u8 *)GNB_IO_APIC_ADDR, GNB_IOAPIC_ID);
 }
 
+static void acipgen_dptci(void)
+{
+	const struct soc_amd_cezanne_config *config = config_of_soc();
+
+	if (!config->dptc_enable)
+		return;
+
+	struct dptc_input default_input = DPTC_INPUTS(config->thermctl_limit_degreeC,
+					config->sustained_power_limit_mW,
+					config->fast_ppt_limit_mW,
+					config->slow_ppt_limit_mW);
+	struct dptc_input tablet_mode_input = DPTC_INPUTS(
+					config->thermctl_limit_tablet_mode_degreeC,
+					config->sustained_power_limit_tablet_mode_mW,
+					config->fast_ppt_limit_tablet_mode_mW,
+					config->slow_ppt_limit_tablet_mode_mW);
+	/* Scope (\_SB) */
+	acpigen_write_scope("\\_SB");
+
+	/* Method(DPTC, 0, Serialized) */
+	acpigen_write_method_serialized("DPTC", 0);
+
+	/* TODO: The code assumes that if DPTC gets called the following object exists */
+	/* If (LEqual ("\_SB.PCI0.LPCB.EC0.TBMD", 1)) */
+	acpigen_write_if_lequal_namestr_int("\\_SB.PCI0.LPCB.EC0.TBMD", 1);
+
+	acpigen_dptc_call_alib("TABB", (uint8_t *)(void *)&tablet_mode_input,
+			sizeof(tablet_mode_input));
+
+	/* Else */
+	acpigen_write_else();
+
+	acpigen_dptc_call_alib("DEFB", (uint8_t *)(void *)&default_input,
+			sizeof(default_input));
+
+	acpigen_pop_len(); /* Else */
+
+	acpigen_pop_len(); /* Method DPTC */
+	acpigen_pop_len(); /* Scope \_SB */
+}
+
 static void root_complex_fill_ssdt(const struct device *device)
 {
 	acpi_fill_root_complex_tom(device);
+	acipgen_dptci();
 }
 
 static const char *gnb_acpi_name(const struct device *dev)