[PATCH] drm/amd/display: add panel_power_savings sysfs entry to eDP connectors

[Hamza Mahfooz]

We want programs besides the compositor to be able to enable or disable
panel power saving features. However, since they are currently only
configurable through DRM properties, that isn't possible. So, to remedy
that issue introduce a new "panel_power_savings" sysfs attribute.

Cc: Mario Limonciello <mario.limonciello at amd.com>
Signed-off-by: Hamza Mahfooz <hamza.mahfooz at amd.com>
---
 .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 59 +++++++++++++++++++
 1 file changed, 59 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index cd98b3565178..b3fcd833015d 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -6534,6 +6534,58 @@ amdgpu_dm_connector_atomic_duplicate_state(struct drm_connector *connector)
 	return &new_state->base;
 }
 
+static ssize_t panel_power_savings_show(struct device *device,
+					struct device_attribute *attr,
+					char *buf)
+{
+	struct drm_connector *connector = dev_get_drvdata(device);
+	struct drm_device *dev = connector->dev;
+	ssize_t val;
+
+	drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
+	val = to_dm_connector_state(connector->state)->abm_level;
+	drm_modeset_unlock(&dev->mode_config.connection_mutex);
+
+	return sysfs_emit(buf, "%lu\n", val);
+}
+
+static ssize_t panel_power_savings_store(struct device *device,
+					 struct device_attribute *attr,
+					 const char *buf, size_t count)
+{
+	struct drm_connector *connector = dev_get_drvdata(device);
+	struct drm_device *dev = connector->dev;
+	long val;
+	int ret;
+
+	ret = kstrtol(buf, 0, &val);
+
+	if (ret)
+		return ret;
+
+	if (val < 0 || val > 4)
+		return -EINVAL;
+
+	drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
+	to_dm_connector_state(connector->state)->abm_level = val ?:
+		ABM_LEVEL_IMMEDIATE_DISABLE;
+	drm_modeset_unlock(&dev->mode_config.connection_mutex);
+
+	return count;
+}
+
+static DEVICE_ATTR_RW(panel_power_savings);
+
+static struct attribute *amdgpu_attrs[] = {
+	&dev_attr_panel_power_savings.attr,
+	NULL
+};
+
+static const struct attribute_group amdgpu_group = {
+	.name = "amdgpu",
+	.attrs = amdgpu_attrs
+};
+
 static int
 amdgpu_dm_connector_late_register(struct drm_connector *connector)
 {
@@ -6541,6 +6593,13 @@ amdgpu_dm_connector_late_register(struct drm_connector *connector)
 		to_amdgpu_dm_connector(connector);
 	int r;
 
+	if (connector->connector_type == DRM_MODE_CONNECTOR_eDP) {
+		r = sysfs_create_group(&connector->kdev->kobj,
+				       &amdgpu_group);
+		if (r)
+			return r;
+	}
+
 	amdgpu_dm_register_backlight_device(amdgpu_dm_connector);
 
 	if ((connector->connector_type == DRM_MODE_CONNECTOR_DisplayPort) ||
-- 
2.43.0