drm/i915: keep max backlight internal to intel_panel.c

[deliverable/linux.git] / drivers / gpu / drm / i915 / intel_panel.c

diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c
index eb5e6e95f3c7ee72e14e9eed3c5cd8167bc7a449..63a7c36a76035bf30f774b07b9179a25f07afb71 100644 (file)
--- a/drivers/gpu/drm/i915/intel_panel.c
+++ b/drivers/gpu/drm/i915/intel_panel.c
@@ -130,6 +130,9 @@ static int is_backlight_combination_mode(struct drm_device *dev)
        return 0;
 }
 
+/* XXX: query mode clock or hardware clock and program max PWM appropriately
+ * when it's 0.
+ */
 static u32 i915_read_blc_pwm_ctl(struct drm_device *dev)
 {
        struct drm_i915_private *dev_priv = dev->dev_private;
@@ -164,7 +167,7 @@ static u32 i915_read_blc_pwm_ctl(struct drm_device *dev)
        return val;
 }
 
-static u32 _intel_panel_get_max_backlight(struct drm_device *dev)
+static u32 intel_panel_get_max_backlight(struct drm_device *dev)
 {
        u32 max;
 
@@ -182,23 +185,8 @@ static u32 _intel_panel_get_max_backlight(struct drm_device *dev)
                        max *= 0xff;
        }
 
-       return max;
-}
-
-u32 intel_panel_get_max_backlight(struct drm_device *dev)
-{
-       u32 max;
-
-       max = _intel_panel_get_max_backlight(dev);
-       if (max == 0) {
-               /* XXX add code here to query mode clock or hardware clock
-                * and program max PWM appropriately.
-                */
-               pr_warn_once("fixme: max PWM is zero\n");
-               return 1;
-       }
-
        DRM_DEBUG_DRIVER("max backlight PWM = %d\n", max);
+
        return max;
 }
 
@@ -217,8 +205,11 @@ static u32 intel_panel_compute_brightness(struct drm_device *dev, u32 val)
                return val;
 
        if (i915_panel_invert_brightness > 0 ||
-           dev_priv->quirks & QUIRK_INVERT_BRIGHTNESS)
-               return intel_panel_get_max_backlight(dev) - val;
+           dev_priv->quirks & QUIRK_INVERT_BRIGHTNESS) {
+               u32 max = intel_panel_get_max_backlight(dev);
+               if (max)
+                       return max - val;
+       }
 
        return val;
 }
@@ -270,6 +261,10 @@ static void intel_panel_actually_set_backlight(struct drm_device *dev, u32 level
                u32 max = intel_panel_get_max_backlight(dev);
                u8 lbpc;
 
+               /* we're screwed, but keep behaviour backwards compatible */
+               if (!max)
+                       max = 1;
+
                lbpc = level * 0xfe / max + 1;
                level /= lbpc;
                pci_write_config_byte(dev->pdev, PCI_LBPC, lbpc);
@@ -282,9 +277,20 @@ static void intel_panel_actually_set_backlight(struct drm_device *dev, u32 level
        I915_WRITE(BLC_PWM_CTL, tmp | level);
 }
 
-void intel_panel_set_backlight(struct drm_device *dev, u32 level)
+/* set backlight brightness to level in range [0..max] */
+void intel_panel_set_backlight(struct drm_device *dev, u32 level, u32 max)
 {
        struct drm_i915_private *dev_priv = dev->dev_private;
+       u32 freq;
+
+       freq = intel_panel_get_max_backlight(dev);
+       if (!freq) {
+               /* we are screwed, bail out */
+               return;
+       }
+
+       /* scale to hardware */
+       level = level * freq / max;
 
        dev_priv->backlight.level = level;
        if (dev_priv->backlight.device)
@@ -405,7 +411,8 @@ intel_panel_detect(struct drm_device *dev)
 static int intel_panel_update_status(struct backlight_device *bd)
 {
        struct drm_device *dev = bl_get_data(bd);
-       intel_panel_set_backlight(dev, bd->props.brightness);
+       intel_panel_set_backlight(dev, bd->props.brightness,
+                                 bd->props.max_brightness);
        return 0;
 }
 
@@ -434,7 +441,7 @@ int intel_panel_setup_backlight(struct drm_connector *connector)
        memset(&props, 0, sizeof(props));
        props.type = BACKLIGHT_RAW;
        props.brightness = dev_priv->backlight.level;
-       props.max_brightness = _intel_panel_get_max_backlight(dev);
+       props.max_brightness = intel_panel_get_max_backlight(dev);
        if (props.max_brightness == 0) {
                DRM_DEBUG_DRIVER("Failed to get maximum backlight value\n");
                return -ENODEV;