thermal: intel_pch_thermal: Add an ACPI passive trip

On the platforms which has an ACPI companion device associated with
PCH thermal device, read passive trip temperature via ACPI _PSV
control method.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

1 files changed, 51 insertions, 0 deletions

diff --git a/drivers/thermal/intel_pch_thermal.c b/drivers/thermal/intel_pch_thermal.c
index 9b4815e81b0d..5cf644a2c012 100644
--- a/drivers/thermal/intel_pch_thermal.c
+++ b/drivers/thermal/intel_pch_thermal.c
@@ -20,6 +20,7 @@
 #include <linux/types.h>
 #include <linux/init.h>
 #include <linux/pci.h>
+#include <linux/acpi.h>
 #include <linux/thermal.h>
 #include <linux/pm.h>
 
@@ -66,9 +67,53 @@ struct pch_thermal_device {
         unsigned long crt_temp;
         int hot_trip_id;
         unsigned long hot_temp;
+        int psv_trip_id;
+        unsigned long psv_temp;
         bool bios_enabled;
 };
 
+#ifdef CONFIG_ACPI
+
+/*
+ * On some platforms, there is a companion ACPI device, which adds
+ * passive trip temperature using _PSV method. There is no specific
+ * passive temperature setting in MMIO interface of this PCI device.
+ */
+static void pch_wpt_add_acpi_psv_trip(struct pch_thermal_device *ptd,
+                                      int *nr_trips)
+{
+        struct acpi_device *adev;
+
+        ptd->psv_trip_id = -1;
+
+        adev = ACPI_COMPANION(&ptd->pdev->dev);
+        if (adev) {
+                unsigned long long r;
+                acpi_status status;
+
+                status = acpi_evaluate_integer(adev->handle, "_PSV", NULL,
+                                               &r);
+                if (ACPI_SUCCESS(status)) {
+                        unsigned long trip_temp;
+
+                        trip_temp = DECI_KELVIN_TO_MILLICELSIUS(r);
+                        if (trip_temp) {
+                                ptd->psv_temp = trip_temp;
+                                ptd->psv_trip_id = *nr_trips;
+                                ++(*nr_trips);
+                        }
+                }
+        }
+}
+#else
+static void pch_wpt_add_acpi_psv_trip(struct pch_thermal_device *ptd,
+                                      int *nr_trips)
+{
+        ptd->psv_trip_id = -1;
+
+}
+#endif
+
 static int pch_wpt_init(struct pch_thermal_device *ptd, int *nr_trips)
 {
         u8 tsel;
@@ -119,6 +164,8 @@ read_trips:
                 ++(*nr_trips);
         }
 
+        pch_wpt_add_acpi_psv_trip(ptd, nr_trips);
+
         return 0;
 }
 
@@ -194,6 +241,8 @@ static int pch_get_trip_type(struct thermal_zone_device *tzd, int trip,
                 *type = THERMAL_TRIP_CRITICAL;
         else if (ptd->hot_trip_id == trip)
                 *type = THERMAL_TRIP_HOT;
+        else if (ptd->psv_trip_id == trip)
+                *type = THERMAL_TRIP_PASSIVE;
         else
                 return -EINVAL;
 
@@ -208,6 +257,8 @@ static int pch_get_trip_temp(struct thermal_zone_device *tzd, int trip, int *tem
                 *temp = ptd->crt_temp;
         else if (ptd->hot_trip_id == trip)
                 *temp = ptd->hot_temp;
+        else if (ptd->psv_trip_id == trip)
+                *temp = ptd->psv_temp;
         else
                 return -EINVAL;