soc/amd/picasso: add dptc support

add dptc support for different power parameter on tablet/clamshell mode

The BIOS may choose to adjust power and/or thermal parameters at its own
discretion. The DPTC interface(DPTCi) ALIB Function adds flexibility by
allowing  the BIOS to request power state changes independently of specific
 events.

BUG=b:157943445
BRANCH=none
TEST=Build.Generated ASL code from SSDT by acipgen_dptci().check the setting changed.

Signed-off-by: Chris Wang <chris.wang@amd.corp-partner.google.com>
Change-Id: Icae94103f254f8fdb84e6ee0f5404fb09fa97b2d
Reviewed-on: https://review.coreboot.org/c/coreboot/+/43408
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>

2 files changed, 97 insertions, 0 deletions

diff --git a/src/soc/amd/picasso/chip.h b/src/soc/amd/picasso/chip.h
index e3da2553b9..11675097cf 100644
--- a/src/soc/amd/picasso/chip.h
+++ b/src/soc/amd/picasso/chip.h
@@ -90,6 +90,14 @@ struct soc_amd_picasso_config {
 	uint32_t stapm_time_constant;
 	uint32_t sustained_power_limit;
 
+	/* Enable dptc for tablet mode (0 = disable, 1 = enable) */
+	uint8_t dptc_enable;
+
+	/* STAPM Configuration for tablet mode (need enable dptc_enable first) */
+	uint32_t fast_ppt_limit_tablet_mode;
+	uint32_t slow_ppt_limit_tablet_mode;
+	uint32_t sustained_power_limit_tablet_mode;
+
 	/* PROCHOT_L de-assertion Ramp Time */
 	uint32_t prochot_l_deassertion_ramp_time;
 
diff --git a/src/soc/amd/picasso/root_complex.c b/src/soc/amd/picasso/root_complex.c
index 21af481732..6c721e17c8 100644
--- a/src/soc/amd/picasso/root_complex.c
+++ b/src/soc/amd/picasso/root_complex.c
@@ -13,7 +13,44 @@
 #include <stdint.h>
 #include <soc/memmap.h>
 #include <soc/iomap.h>
+#include "chip.h"
 
+enum {
+	ALIB_DPTCI_FUNCTION_ID = 0xc,
+	SUSTAINED_POWER_LIMIT_PARAM_ID = 0x5,
+	FAST_PPT_LIMIT_PARAM_ID = 0x6,
+	SLOW_PPT_LIMIT_PARAM_ID = 0x7,
+	DPTC_TOTAL_UPDATE_PARAMS = 3,
+};
+
+struct dptc_param {
+	uint8_t id;
+	uint32_t value;
+} __packed;
+
+struct dptc_input {
+	uint16_t size;
+	struct dptc_param params[DPTC_TOTAL_UPDATE_PARAMS];
+} __packed;
+
+#define DPTC_INPUTS(_sustained, _fast, _slow)					\
+		{								\
+			.size = sizeof(struct dptc_input),			\
+			.params = {						\
+				{						\
+					.id = SUSTAINED_POWER_LIMIT_PARAM_ID,	\
+					.value = _sustained,			\
+				},						\
+				{						\
+					.id = FAST_PPT_LIMIT_PARAM_ID,		\
+					.value = _fast,				\
+				},						\
+				{						\
+					.id = SLOW_PPT_LIMIT_PARAM_ID,		\
+					.value = _slow,				\
+				},						\
+			},							\
+		}
 /*
  *
  *                     +--------------------------------+
@@ -139,6 +176,57 @@ static void read_resources(struct device *dev)
 	gnb_apic->flags = IORESOURCE_MEM | IORESOURCE_ASSIGNED | IORESOURCE_FIXED;
 }
 
+static void dptc_call_alib(const char *buf_name, uint8_t *buffer, size_t size)
+{
+	/* Name (buf_name, Buffer(size) {...} */
+	acpigen_write_name(buf_name);
+	acpigen_write_byte_buffer(buffer, size);
+
+	/* \_SB.ALIB(0xc, buf_name) */
+	acpigen_emit_namestring("\\_SB.ALIB");
+	acpigen_write_integer(ALIB_DPTCI_FUNCTION_ID);
+	acpigen_emit_namestring(buf_name);
+}
+
+static void acipgen_dptci(void)
+{
+	const config_t *config = config_of_soc();
+
+	if (!config->dptc_enable)
+		return;
+
+	struct dptc_input default_input = DPTC_INPUTS(config->sustained_power_limit,
+							config->fast_ppt_limit,
+							config->slow_ppt_limit);
+	struct dptc_input tablet_mode_input = DPTC_INPUTS(
+					config->sustained_power_limit_tablet_mode,
+					config->fast_ppt_limit_tablet_mode,
+					config->slow_ppt_limit_tablet_mode);
+	/* Scope (\_SB) */
+	acpigen_write_scope("\\_SB");
+
+	/* Method(DPTC, 0, Serialized) */
+	acpigen_write_method_serialized("DPTC", 0);
+
+	/* If (LEqual ("\_SB.PCI0.LPCB.EC0.TBMD", 1)) */
+	acpigen_write_if_lequal_namestr_int("\\_SB.PCI0.LPCB.EC0.TBMD", 1);
+
+	dptc_call_alib("TABB", (uint8_t *)(void *)&tablet_mode_input,
+			sizeof(tablet_mode_input));
+
+	acpigen_pop_len(); /* If */
+
+	/* Else */
+	acpigen_write_else();
+
+	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 */
+}
+
 /* Used by \_SB.PCI0._CRS */
 static void root_complex_fill_ssdt(const struct device *device)
 {
@@ -164,6 +252,7 @@ static void root_complex_fill_ssdt(const struct device *device)
 	 */
 	acpigen_write_name_dword("TOM2", (msr.hi << 12) | msr.lo >> 20);
 	acpigen_pop_len();
+	acipgen_dptci();
 }
 
 static struct device_operations root_complex_operations = {