drm/radeon/kms: add support for internal thermal sensors (v3)

rv6xx/rv7xx/evergreen families supported; older asics did
not have an internal thermal sensor.

Note, not all oems use the internal thermal sensor, so it's
only exposed in cases where it is used.

Note also, that most laptops use an oem specific ACPI solution for
GPU thermal information rather than using the internal thermal
sensor directly.

v2: export millidegrees celsius, use hwmon device properly.
v3: fix Kconfig

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 82 insertions, 0 deletions

diff --git a/drivers/gpu/drm/radeon/radeon_pm.c b/drivers/gpu/drm/radeon/radeon_pm.c
index 115d26b..ed66062 100644
--- a/drivers/gpu/drm/radeon/radeon_pm.c
+++ b/drivers/gpu/drm/radeon/radeon_pm.c
@@ -27,6 +27,8 @@
 #include <linux/acpi.h>
 #endif
 #include <linux/power_supply.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
 
 #define RADEON_IDLE_LOOP_MS 100
 #define RADEON_RECLOCK_DELAY_MS 200
@@ -423,6 +425,82 @@ fail:
 static DEVICE_ATTR(power_profile, S_IRUGO | S_IWUSR, radeon_get_pm_profile, radeon_set_pm_profile);
 static DEVICE_ATTR(power_method, S_IRUGO | S_IWUSR, radeon_get_pm_method, radeon_set_pm_method);
 
+static ssize_t radeon_hwmon_show_temp(struct device *dev,
+				      struct device_attribute *attr,
+				      char *buf)
+{
+	struct drm_device *ddev = pci_get_drvdata(to_pci_dev(dev));
+	struct radeon_device *rdev = ddev->dev_private;
+	u32 temp;
+
+	switch (rdev->pm.int_thermal_type) {
+	case THERMAL_TYPE_RV6XX:
+		temp = rv6xx_get_temp(rdev);
+		break;
+	case THERMAL_TYPE_RV770:
+		temp = rv770_get_temp(rdev);
+		break;
+	case THERMAL_TYPE_EVERGREEN:
+		temp = evergreen_get_temp(rdev);
+		break;
+	default:
+		temp = 0;
+		break;
+	}
+
+	return snprintf(buf, PAGE_SIZE, "%d\n", temp);
+}
+
+static ssize_t radeon_hwmon_show_name(struct device *dev,
+				      struct device_attribute *attr,
+				      char *buf)
+{
+	return sprintf(buf, "radeon\n");
+}
+
+static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, radeon_hwmon_show_temp, NULL, 0);
+static SENSOR_DEVICE_ATTR(name, S_IRUGO, radeon_hwmon_show_name, NULL, 0);
+
+static struct attribute *hwmon_attributes[] = {
+	&sensor_dev_attr_temp1_input.dev_attr.attr,
+	&sensor_dev_attr_name.dev_attr.attr,
+	NULL
+};
+
+static const struct attribute_group hwmon_attrgroup = {
+	.attrs = hwmon_attributes,
+};
+
+static void radeon_hwmon_init(struct radeon_device *rdev)
+{
+	int err;
+
+	rdev->pm.int_hwmon_dev = NULL;
+
+	switch (rdev->pm.int_thermal_type) {
+	case THERMAL_TYPE_RV6XX:
+	case THERMAL_TYPE_RV770:
+	case THERMAL_TYPE_EVERGREEN:
+		rdev->pm.int_hwmon_dev = hwmon_device_register(rdev->dev);
+		dev_set_drvdata(rdev->pm.int_hwmon_dev, rdev->ddev);
+		err = sysfs_create_group(&rdev->pm.int_hwmon_dev->kobj,
+					 &hwmon_attrgroup);
+		if (err)
+			DRM_ERROR("Unable to create hwmon sysfs file: %d\n", err);
+		break;
+	default:
+		break;
+	}
+}
+
+static void radeon_hwmon_fini(struct radeon_device *rdev)
+{
+	if (rdev->pm.int_hwmon_dev) {
+		sysfs_remove_group(&rdev->pm.int_hwmon_dev->kobj, &hwmon_attrgroup);
+		hwmon_device_unregister(rdev->pm.int_hwmon_dev);
+	}
+}
+
 void radeon_pm_suspend(struct radeon_device *rdev)
 {
 	bool flush_wq = false;
@@ -470,6 +548,7 @@ int radeon_pm_init(struct radeon_device *rdev)
 	rdev->pm.dynpm_can_downclock = true;
 	rdev->pm.current_sclk = rdev->clock.default_sclk;
 	rdev->pm.current_mclk = rdev->clock.default_mclk;
+	rdev->pm.int_thermal_type = THERMAL_TYPE_NONE;
 
 	if (rdev->bios) {
 		if (rdev->is_atom_bios)
@@ -480,6 +559,8 @@ int radeon_pm_init(struct radeon_device *rdev)
 		radeon_pm_init_profile(rdev);
 	}
 
+	/* set up the internal thermal sensor if applicable */
+	radeon_hwmon_init(rdev);
 	if (rdev->pm.num_power_states > 1) {
 		/* where's the best place to put these? */
 		ret = device_create_file(rdev->dev, &dev_attr_power_profile);
@@ -535,6 +616,7 @@ void radeon_pm_fini(struct radeon_device *rdev)
 #endif
 	}
 
+	radeon_hwmon_fini(rdev);
 	if (rdev->pm.i2c_bus)
 		radeon_i2c_destroy(rdev->pm.i2c_bus);
 }