4 files changed, 66 insertions, 0 deletions

diff --git a/src/acpi/acpigen_dptf.c b/src/acpi/acpigen_dptf.c
index c18caf673e..6caf8bfcaf 100644
--- a/src/acpi/acpigen_dptf.c
+++ b/src/acpi/acpigen_dptf.c
@@ -12,6 +12,7 @@
 enum {
 	ART_REVISION			= 0,
 	DEFAULT_PRIORITY		= 100,
+	DEFAULT_TRIP_POINT		= 0xFFFFFFFFull,
 	DEFAULT_WEIGHT			= 100,
 	DPTF_MAX_ART_THRESHOLDS		= 10,
 };
@@ -321,3 +322,39 @@ void dptf_write_charger_perf(const struct dptf_charger_perf *states, int max_cou
 	acpigen_pop_len(); /* Method PPSS */
 	acpigen_pop_len(); /* Scope */
 }
+
+void dptf_write_fan_perf(const struct dptf_fan_perf *states, int max_count)
+{
+	char *pkg_count;
+	int i;
+
+	if (!max_count || !states[0].percent)
+		return;
+
+	dptf_write_scope(DPTF_FAN);
+
+	/* _FPS - Fan Performance States */
+	acpigen_write_name("_FPS");
+	pkg_count = acpigen_write_package(0);
+
+	for (i = 0; i < max_count; ++i) {
+		/*
+		 * Some _FPS tables do include a last entry where Percent is 0, but Power is
+		 * called out, so this table is finished when both are zero.
+		 */
+		if (!states[i].percent && !states[i].power)
+			break;
+
+		(*pkg_count)++;
+		acpigen_write_package(5);
+		acpigen_write_integer(states[i].percent);
+		acpigen_write_integer(DEFAULT_TRIP_POINT);
+		acpigen_write_integer(states[i].speed);
+		acpigen_write_integer(states[i].noise_level);
+		acpigen_write_integer(states[i].power);
+		acpigen_pop_len(); /* inner Package */
+	}
+
+	acpigen_pop_len(); /* Package */
+	acpigen_pop_len(); /* Scope */
+}
diff --git a/src/drivers/intel/dptf/chip.h b/src/drivers/intel/dptf/chip.h
index 528ba8354e..cc4ae47caf 100644
--- a/src/drivers/intel/dptf/chip.h
+++ b/src/drivers/intel/dptf/chip.h
@@ -14,6 +14,7 @@ struct drivers_intel_dptf_config {
 
 	struct {
 		struct dptf_charger_perf charger_perf[DPTF_MAX_CHARGER_PERF_STATES];
+		struct dptf_fan_perf fan_perf[DPTF_MAX_FAN_PERF_STATES];
 	} controls;
 };
 
diff --git a/src/drivers/intel/dptf/dptf.c b/src/drivers/intel/dptf/dptf.c
index a20087fff3..bfc04200e0 100644
--- a/src/drivers/intel/dptf/dptf.c
+++ b/src/drivers/intel/dptf/dptf.c
@@ -74,6 +74,7 @@ static void dptf_fill_ssdt(const struct device *dev)
 
 	/* Controls */
 	dptf_write_charger_perf(config->controls.charger_perf, DPTF_MAX_CHARGER_PERF_STATES);
+	dptf_write_fan_perf(config->controls.fan_perf, DPTF_MAX_FAN_PERF_STATES);
 
 	printk(BIOS_INFO, "\\_SB.DPTF: %s at %s\n", dev->chip_ops->name, dev_path(dev));
 }
diff --git a/src/include/acpi/acpigen_dptf.h b/src/include/acpi/acpigen_dptf.h
index 7588752aac..3452f79578 100644
--- a/src/include/acpi/acpigen_dptf.h
+++ b/src/include/acpi/acpigen_dptf.h
@@ -32,6 +32,10 @@ enum {
 
 	/* Maximum found by automatic inspection (awk) */
 	DPTF_MAX_CHARGER_PERF_STATES	= 10,
+	DPTF_MAX_FAN_PERF_STATES	= 10,
+
+	/* From ACPI spec 6.3 */
+	DPTF_FIELD_UNUSED		= 0xFFFFFFFFull,
 };
 
 /* Active Policy */
@@ -87,6 +91,18 @@ struct dptf_charger_perf {
 	uint16_t raw_perf;
 };
 
+/* Different levels of fan activity, chosen by active policies */
+struct dptf_fan_perf {
+	/* Fan percentage level */
+	uint8_t percent;
+	/* Fan speed, in RPM */
+	uint16_t speed;
+	/* Noise level, in 0.1 dBs */
+	uint16_t noise_level;
+	/* Power in mA */
+	uint16_t power;
+};
+
 /*
  * This function provides tables of temperature and corresponding fan or percent.  When the
  * temperature thresholds are met (_AC0 - _AC9), the fan is driven to corresponding percentage
@@ -115,6 +131,17 @@ void dptf_write_critical_policies(const struct dptf_critical_policy *policies, i
  */
 void dptf_write_charger_perf(const struct dptf_charger_perf *perf, int max_count);
 
+/*
+ * This function writes an ACPI table describing various performance levels possible for active
+ * policies. They indicate, for a given fan percentage level:
+ *  1) What the corresponding speed is (in RPM)
+ *  2) The expected noise level (in tenths of decibels AKA centibels, or DPTF_FIELD_UNUSED)
+ *  3) The power consumption (in mW, or DPTF_FIELD_UNUSED to indicate this field is unused).
+ *  4) The corresponding active cooling trip point (from _ART) (typically left as
+ *     DPTF_FIELD_UNUSED).
+ */
+void dptf_write_fan_perf(const struct dptf_fan_perf *perf, int max_count);
+
 /* Helper method to open the scope for a given participant. */
 void dptf_write_scope(enum dptf_participant participant);