[PATCH v3] drm/amd/pm: Disable fan control if not supported

[Elena Sakhnovitch]

On Sienna Cichild, not all platforms use PMFW based fan control
(ex: fanless systems). On such ASICs fan control by PMFW will be
disabled in PPTable. Disable hwmon knobs for fan control also as
it is not possible to report or control fan speed on such platforms
through driver.

v3: FeaturesToRun casted as uint64_t

Signed-off-by: Elena Sakhnovitch  <elena.sakhnovitch at amd.com>
---
 .../drm/amd/pm/swsmu/smu11/sienna_cichlid_ppt.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu11/sienna_cichlid_ppt.c b/drivers/gpu/drm/amd/pm/swsmu/smu11/sienna_cichlid_ppt.c
index ab3e9d8b831e..9ec44b4e9f83 100644
--- a/drivers/gpu/drm/amd/pm/swsmu/smu11/sienna_cichlid_ppt.c
+++ b/drivers/gpu/drm/amd/pm/swsmu/smu11/sienna_cichlid_ppt.c
@@ -371,6 +371,22 @@ static void sienna_cichlid_check_bxco_support(struct smu_context *smu)
 	}
 }
 
+static void sienna_cichlid_check_fan_support(struct smu_context *smu)
+{
+	struct smu_table_context *table_context = &smu->smu_table;
+	PPTable_t *pptable = table_context->driver_pptable;
+	uint64_t features = *(uint64_t *) pptable->FeaturesToRun;
+
+	/* Fan control is not possible if PPTable has it disabled */
+	smu->adev->pm.no_fan =
+		!(features & (1ULL << FEATURE_FAN_CONTROL_BIT));
+	if (smu->adev->pm.no_fan)
+		dev_info_once(smu->adev->dev,
+			      "PMFW based fan control disabled");
+
+
+}
+
 static int sienna_cichlid_check_powerplay_table(struct smu_context *smu)
 {
 	struct smu_table_context *table_context = &smu->smu_table;
@@ -381,6 +397,7 @@ static int sienna_cichlid_check_powerplay_table(struct smu_context *smu)
 		smu->dc_controlled_by_gpio = true;
 
 	sienna_cichlid_check_bxco_support(smu);
+	sienna_cichlid_check_fan_support(smu);
 
 	table_context->thermal_controller_type =
 		powerplay_table->thermal_controller_type;
-- 
2.25.1