thermal: intel_pch_thermal: Add suspend/resume callback

Added suspend/resume callback to disable/enable PCH thermal sensor
respectively. If the sensor is enabled by the BIOS, then the sensor status
will not be changed during suspend/resume.

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

1 files changed, 59 insertions, 1 deletions

diff --git a/drivers/thermal/intel_pch_thermal.c b/drivers/thermal/intel_pch_thermal.c
index 6a6ec1c95a7a..9b4815e81b0d 100644
--- a/drivers/thermal/intel_pch_thermal.c
+++ b/drivers/thermal/intel_pch_thermal.c
@@ -21,6 +21,7 @@
 #include <linux/init.h>
 #include <linux/pci.h>
 #include <linux/thermal.h>
+#include <linux/pm.h>
 
 /* Intel PCH thermal Device IDs */
 #define PCH_THERMAL_DID_WPT     0x9CA4 /* Wildcat Point */
@@ -65,6 +66,7 @@ struct pch_thermal_device {
         unsigned long crt_temp;
         int hot_trip_id;
         unsigned long hot_temp;
+        bool bios_enabled;
 };
 
 static int pch_wpt_init(struct pch_thermal_device *ptd, int *nr_trips)
@@ -75,8 +77,10 @@ static int pch_wpt_init(struct pch_thermal_device *ptd, int *nr_trips)
         *nr_trips = 0;
 
         /* Check if BIOS has already enabled thermal sensor */
-        if (WPT_TSS_TSDSS & readb(ptd->hw_base + WPT_TSS))
+        if (WPT_TSS_TSDSS & readb(ptd->hw_base + WPT_TSS)) {
+                ptd->bios_enabled = true;
                 goto read_trips;
+        }
 
         tsel = readb(ptd->hw_base + WPT_TSEL);
         /*
@@ -130,9 +134,39 @@ static int pch_wpt_get_temp(struct pch_thermal_device *ptd, int *temp)
         return 0;
 }
 
+static int pch_wpt_suspend(struct pch_thermal_device *ptd)
+{
+        u8 tsel;
+
+        if (ptd->bios_enabled)
+                return 0;
+
+        tsel = readb(ptd->hw_base + WPT_TSEL);
+
+        writeb(tsel & 0xFE, ptd->hw_base + WPT_TSEL);
+
+        return 0;
+}
+
+static int pch_wpt_resume(struct pch_thermal_device *ptd)
+{
+        u8 tsel;
+
+        if (ptd->bios_enabled)
+                return 0;
+
+        tsel = readb(ptd->hw_base + WPT_TSEL);
+
+        writeb(tsel | WPT_TSEL_ETS, ptd->hw_base + WPT_TSEL);
+
+        return 0;
+}
+
 struct pch_dev_ops {
         int (*hw_init)(struct pch_thermal_device *ptd, int *nr_trips);
         int (*get_temp)(struct pch_thermal_device *ptd, int *temp);
+        int (*suspend)(struct pch_thermal_device *ptd);
+        int (*resume)(struct pch_thermal_device *ptd);
 };
 
 
@@ -140,6 +174,8 @@ struct pch_dev_ops {
 static const struct pch_dev_ops pch_dev_ops_wpt = {
         .hw_init = pch_wpt_init,
         .get_temp = pch_wpt_get_temp,
+        .suspend = pch_wpt_suspend,
+        .resume = pch_wpt_resume,
 };
 
 static int pch_thermal_get_temp(struct thermal_zone_device *tzd, int *temp)
@@ -269,6 +305,22 @@ static void intel_pch_thermal_remove(struct pci_dev *pdev)
         pci_disable_device(pdev);
 }
 
+static int intel_pch_thermal_suspend(struct device *device)
+{
+        struct pci_dev *pdev = to_pci_dev(device);
+        struct pch_thermal_device *ptd = pci_get_drvdata(pdev);
+
+        return ptd->ops->suspend(ptd);
+}
+
+static int intel_pch_thermal_resume(struct device *device)
+{
+        struct pci_dev *pdev = to_pci_dev(device);
+        struct pch_thermal_device *ptd = pci_get_drvdata(pdev);
+
+        return ptd->ops->resume(ptd);
+}
+
 static struct pci_device_id intel_pch_thermal_id[] = {
         { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCH_THERMAL_DID_WPT) },
         { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCH_THERMAL_DID_SKL) },
@@ -276,11 +328,17 @@ static struct pci_device_id intel_pch_thermal_id[] = {
 };
 MODULE_DEVICE_TABLE(pci, intel_pch_thermal_id);
 
+static const struct dev_pm_ops intel_pch_pm_ops = {
+        .suspend = intel_pch_thermal_suspend,
+        .resume = intel_pch_thermal_resume,
+};
+
 static struct pci_driver intel_pch_thermal_driver = {
         .name           = "intel_pch_thermal",
         .id_table       = intel_pch_thermal_id,
         .probe          = intel_pch_thermal_probe,
         .remove         = intel_pch_thermal_remove,
+        .driver.pm      = &intel_pch_pm_ops,
 };
 
 module_pci_driver(intel_pch_thermal_driver);