drm/i915: keep max backlight internal to intel_panel.c
In preparation of adding locking to backlight, make max backlight value
(the modulation frequency the PWM duty cycle value must not exceed)
internal to intel_panel.c.
Have intel_panel_set_backlight() accept a caller defined range for level,
and scale input to max backlight value internally.
Clean up intel_panel_get_max_backlight() and usage internally.
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c
index eb5e6e9..63a7c36 100644
--- a/drivers/gpu/drm/i915/intel_panel.c
+++ b/drivers/gpu/drm/i915/intel_panel.c
@@ -130,6 +130,9 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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;