dptf: Add support for Fan and TSR options

DPTF has several options on how to control the fan (fine-grained speed
control, minimum speed change in percentage points, and whether or not
the DPTF device should notify the Fan if it detects low speed).
Individual TSRs can also set GTSH, which is the amount of hysteresis
inherent in the measurement, either from circuitry (if analog), or in
firmware (if digital).

BUG=b:143539650
TEST=compiles

Change-Id: I42d789d877da28c163e394d7de5fb1ff339264eb
Signed-off-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41891
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>

src/acpi/acpigen_dptf.c

@@ -404,3 +404,31 @@ void dptf_write_power_limits(const struct dptf_power_limits *limits)
 	acpigen_pop_len(); /* Method */
 	acpigen_pop_len(); /* Scope */
 }
+
+void dptf_write_STR(const char *str)
+{
+	if (!str)
+		return;
+
+	acpigen_write_name_string("_STR", str);
+}
+
+void dptf_write_fan_options(bool fine_grained, int step_size, bool low_speed_notify)
+{
+	acpigen_write_name("_FIF");
+	acpigen_write_package(4);
+
+	acpigen_write_integer(0); /* Revision */
+	acpigen_write_integer(fine_grained);
+	acpigen_write_integer(step_size);
+	acpigen_write_integer(low_speed_notify);
+	acpigen_pop_len(); /* Package */
+}
+
+void dptf_write_tsr_hysteresis(uint8_t hysteresis)
+{
+	if (!hysteresis)
+		return;
+
+	acpigen_write_name_integer("GTSH", hysteresis);
+}

src/drivers/intel/dptf/chip.h

@@ -17,6 +17,33 @@ struct drivers_intel_dptf_config {
 		struct dptf_fan_perf fan_perf[DPTF_MAX_FAN_PERF_STATES];
 		struct dptf_power_limits power_limits;
 	} controls;
+
+	/* Note that all values in this struct are optional */
+	struct {
+		struct {
+			/* True means _FSL is percentages, False means _FSL is Control values */
+			bool fine_grained_control;
+			/*
+			 * Recommended minimum step size in percentage points to adjust fan
+			 * speed when utilizing fine-grained control (1-9)
+			 */
+			uint8_t step_size;
+			/*
+			 * True means the platform will issue a Notify (0x80) to the fan device
+			 * if a a low fan speed is detected
+			 */
+			bool low_speed_notify;
+		} fan;
+		struct {
+			/*
+			 * The amount of hysteresis implemented in circuitry or in the platform
+			 * EC's firmware implementation (using the GTSH object)
+			 */
+			uint8_t hysteresis;
+			/* Name applied to TSR (using the _STR object) */
+			const char *desc;
+		} tsr[DPTF_MAX_TSR];
+	} options;
 };
 
 #endif /* _DRIVERS_INTEL_DPTF_CHIP_H_ */

src/drivers/intel/dptf/dptf.c

@@ -62,6 +62,12 @@ static const char *dptf_acpi_name(const struct device *dev)
 static void dptf_fill_ssdt(const struct device *dev)
 {
 	struct drivers_intel_dptf_config *config = config_of(dev);
+	enum dptf_participant p;
+	bool tsr_en[DPTF_MAX_TSR] = {false};
+	int i;
+
+	for (p = DPTF_TEMP_SENSOR_0, i = 0; p <= DPTF_TEMP_SENSOR_3; ++p, ++i)
+		tsr_en[i] = is_participant_used(config, p);
 
 	dptf_write_active_policies(config->policies.active,
 				   DPTF_MAX_ACTIVE_POLICIES);
@@ -77,6 +83,19 @@ static void dptf_fill_ssdt(const struct device *dev)
 	dptf_write_fan_perf(config->controls.fan_perf, DPTF_MAX_FAN_PERF_STATES);
 	dptf_write_power_limits(&config->controls.power_limits);
 
+	/* Fan options */
+	dptf_write_fan_options(config->options.fan.fine_grained_control,
+			       config->options.fan.step_size,
+			       config->options.fan.low_speed_notify);
+
+	/* TSR options */
+	for (p = DPTF_TEMP_SENSOR_0, i = 0; p <= DPTF_TEMP_SENSOR_3; ++p, ++i) {
+		if (tsr_en[i]) {
+			dptf_write_tsr_hysteresis(config->options.tsr[i].hysteresis);
+			dptf_write_STR(config->options.tsr[i].desc);
+		}
+	}
+
 	printk(BIOS_INFO, "\\_SB.DPTF: %s at %s\n", dev->chip_ops->name, dev_path(dev));
 }
 

src/include/acpi/acpigen_dptf.h

@@ -36,6 +36,9 @@ enum {
 
 	/* From ACPI spec 6.3 */
 	DPTF_FIELD_UNUSED		= 0xFFFFFFFFull,
+
+	/* Max supported by DPTF */
+	DPTF_MAX_TSR			= 4,
 };
 
 /* Active Policy */
@@ -169,6 +172,18 @@ void dptf_write_fan_perf(const struct dptf_fan_perf *perf, int max_count);
  */
 void dptf_write_power_limits(const struct dptf_power_limits *limits);
 
+/* Set the _STR Name */
+void dptf_write_STR(const char *str);
+
+/* Set options in the _FIF table */
+void dptf_write_fan_options(bool fine_grained, int step_size, bool low_speed_notify);
+
+/*
+ * Sets the amount of inherent hysteresis in temperature sensor readings (either from hardware
+ * circuitry or possibly from the EC's firmware implementation.
+ */
+void dptf_write_tsr_hysteresis(uint8_t hysteresis);
+
 /* Helper method to open the scope for a given participant. */
 void dptf_write_scope(enum dptf_participant participant);