drm/nv50/backlight: express brightness level in percent

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

1 files changed, 7 insertions, 3 deletions

diff --git a/drivers/gpu/drm/nouveau/nouveau_backlight.c b/drivers/gpu/drm/nouveau/nouveau_backlight.c
index 4f3d1ff3e472..757a6f87edf2 100644
--- a/drivers/gpu/drm/nouveau/nouveau_backlight.c
+++ b/drivers/gpu/drm/nouveau/nouveau_backlight.c
@@ -100,8 +100,11 @@ nv50_get_intensity(struct backlight_device *bd)
         struct nouveau_encoder *nv_encoder = bl_get_data(bd);
         struct drm_device *dev = nv_encoder->base.base.dev;
         int or = nv_encoder->or;
+        u32 div = 1025;
+        u32 val;
 
-        return nv_rd32(dev, NV50_PDISPLAY_SOR_BACKLIGHT + (or * 0x800));
+        val = nv_rd32(dev, NV50_PDISPLAY_SOR_BACKLIGHT + (or * 0x800));
+        return ((val * 100) + (div / 2)) / div;
 }
 
 static int
@@ -109,8 +112,9 @@ nv50_set_intensity(struct backlight_device *bd)
 {
         struct nouveau_encoder *nv_encoder = bl_get_data(bd);
         struct drm_device *dev = nv_encoder->base.base.dev;
-        int val = bd->props.brightness;
         int or = nv_encoder->or;
+        u32 div = 1025;
+        u32 val = (bd->props.brightness * div) / 100;
 
         nv_wr32(dev, NV50_PDISPLAY_SOR_BACKLIGHT + (or * 0x800),
                 val | NV50_PDISPLAY_SOR_BACKLIGHT_ENABLE);
@@ -147,7 +151,7 @@ nv50_backlight_init(struct drm_connector *connector)
 
         memset(&props, 0, sizeof(struct backlight_properties));
         props.type = BACKLIGHT_RAW;
-        props.max_brightness = 1025;
+        props.max_brightness = 100;
         bd = backlight_device_register("nv_backlight", &connector->kdev,
                                        nv_encoder, &nv50_bl_ops, &props);
         if (IS_ERR(bd))