1 files changed, 117 insertions, 0 deletions
diff --git a/drivers/gpu/drm/gma500/backlight.c b/drivers/gpu/drm/gma500/backlight.c
new file mode 100644
index 0000000000..8711a7a5b8
--- /dev/null
+++ b/drivers/gpu/drm/gma500/backlight.c
@@ -0,0 +1,117 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * GMA500 Backlight Interface
+ *
+ * Copyright (c) 2009-2011, Intel Corporation.
+ *
+ * Authors: Eric Knopp
+ */
+
+#include <linux/backlight.h>
+
+#include <acpi/video.h>
+
+#include "psb_drv.h"
+#include "psb_intel_reg.h"
+#include "psb_intel_drv.h"
+#include "intel_bios.h"
+#include "power.h"
+
+void gma_backlight_enable(struct drm_device *dev)
+{
+	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
+
+	dev_priv->backlight_enabled = true;
+	dev_priv->ops->backlight_set(dev, dev_priv->backlight_level);
+}
+
+void gma_backlight_disable(struct drm_device *dev)
+{
+	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
+
+	dev_priv->backlight_enabled = false;
+	dev_priv->ops->backlight_set(dev, 0);
+}
+
+void gma_backlight_set(struct drm_device *dev, int v)
+{
+	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
+
+	dev_priv->backlight_level = v;
+	if (dev_priv->backlight_enabled)
+		dev_priv->ops->backlight_set(dev, v);
+}
+
+static int gma_backlight_get_brightness(struct backlight_device *bd)
+{
+	struct drm_device *dev = bl_get_data(bd);
+	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
+
+	if (dev_priv->ops->backlight_get)
+		return dev_priv->ops->backlight_get(dev);
+
+	return dev_priv->backlight_level;
+}
+
+static int gma_backlight_update_status(struct backlight_device *bd)
+{
+	struct drm_device *dev = bl_get_data(bd);
+	int level = backlight_get_brightness(bd);
+
+	/* Percentage 1-100% being valid */
+	if (level < 1)
+		level = 1;
+
+	gma_backlight_set(dev, level);
+	return 0;
+}
+
+static const struct backlight_ops gma_backlight_ops __maybe_unused = {
+	.get_brightness = gma_backlight_get_brightness,
+	.update_status  = gma_backlight_update_status,
+};
+
+int gma_backlight_init(struct drm_device *dev)
+{
+	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
+	struct backlight_properties props __maybe_unused = {};
+	int ret;
+
+	dev_priv->backlight_enabled = true;
+	dev_priv->backlight_level = 100;
+
+	ret = dev_priv->ops->backlight_init(dev);
+	if (ret)
+		return ret;
+
+	if (!acpi_video_backlight_use_native()) {
+		drm_info(dev, "Skipping %s backlight registration\n",
+			 dev_priv->ops->backlight_name);
+		return 0;
+	}
+
+#ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
+	props.brightness = dev_priv->backlight_level;
+	props.max_brightness = PSB_MAX_BRIGHTNESS;
+	props.type = BACKLIGHT_RAW;
+
+	dev_priv->backlight_device =
+		backlight_device_register(dev_priv->ops->backlight_name,
+					  dev->dev, dev,
+					  &gma_backlight_ops, &props);
+	if (IS_ERR(dev_priv->backlight_device))
+		return PTR_ERR(dev_priv->backlight_device);
+#endif
+
+	return 0;
+}
+
+void gma_backlight_exit(struct drm_device *dev)
+{
+#ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
+	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
+
+	if (dev_priv->backlight_device)
+		backlight_device_unregister(dev_priv->backlight_device);
+#endif
+}