drm/i915: i830M has watermarks like i855

So shuffle the checks around a bit. Also give all the structs and
functions proper prefixes: i830_ for the dual-pipe mobile platforms
and i845_ for the two single-pipe desktop platforms.

Note that the max fifo value isn't actually correct for the i830M, but
since we don't frob the fifo split we don't actually need it. This is
different for some gen3 devices where we need the full fifo for self
refresh mode.

Cc: Thomas Richter <richter@rus.uni-stuttgart.de>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_pm.c

@@ -824,7 +824,7 @@ static int i9xx_get_fifo_size(struct drm_device *dev, int plane)
 	return size;
 }
 
-static int i85x_get_fifo_size(struct drm_device *dev, int plane)
+static int i830_get_fifo_size(struct drm_device *dev, int plane)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	uint32_t dsparb = I915_READ(DSPARB);
@@ -857,21 +857,6 @@ static int i845_get_fifo_size(struct drm_device *dev, int plane)
 	return size;
 }
 
-static int i830_get_fifo_size(struct drm_device *dev, int plane)
-{
-	struct drm_i915_private *dev_priv = dev->dev_private;
-	uint32_t dsparb = I915_READ(DSPARB);
-	int size;
-
-	size = dsparb & 0x7f;
-	size >>= 1; /* Convert to cachelines */
-
-	DRM_DEBUG_KMS("FIFO size - (0x%08x) %s: %d\n", dsparb,
-		      plane ? "B" : "A", size);
-
-	return size;
-}
-
 /* Pineview has different values for various configs */
 static const struct intel_watermark_params pineview_display_wm = {
 	PINEVIEW_DISPLAY_FIFO,
@@ -950,14 +935,14 @@ static const struct intel_watermark_params i915_wm_info = {
 	2,
 	I915_FIFO_LINE_SIZE
 };
-static const struct intel_watermark_params i855_wm_info = {
+static const struct intel_watermark_params i830_wm_info = {
 	I855GM_FIFO_SIZE,
 	I915_MAX_WM,
 	1,
 	2,
 	I830_FIFO_LINE_SIZE
 };
-static const struct intel_watermark_params i830_wm_info = {
+static const struct intel_watermark_params i845_wm_info = {
 	I830_FIFO_SIZE,
 	I915_MAX_WM,
 	1,
@@ -1515,7 +1500,7 @@ static void i9xx_update_wm(struct drm_crtc *unused_crtc)
 	else if (!IS_GEN2(dev))
 		wm_info = &i915_wm_info;
 	else
-		wm_info = &i855_wm_info;
+		wm_info = &i830_wm_info;
 
 	fifo_size = dev_priv->display.get_fifo_size(dev, 0);
 	crtc = intel_get_crtc_for_plane(dev, 0);
@@ -1622,7 +1607,7 @@ static void i9xx_update_wm(struct drm_crtc *unused_crtc)
 	}
 }
 
-static void i830_update_wm(struct drm_crtc *unused_crtc)
+static void i845_update_wm(struct drm_crtc *unused_crtc)
 {
 	struct drm_device *dev = unused_crtc->dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
@@ -1637,7 +1622,7 @@ static void i830_update_wm(struct drm_crtc *unused_crtc)
 
 	adjusted_mode = &to_intel_crtc(crtc)->config.adjusted_mode;
 	planea_wm = intel_calculate_wm(adjusted_mode->crtc_clock,
-				       &i830_wm_info,
+				       &i845_wm_info,
 				       dev_priv->display.get_fifo_size(dev, 0),
 				       4, latency_ns);
 	fwater_lo = I915_READ(FW_BLC) & ~0xfff;
@@ -5628,21 +5613,21 @@ void intel_init_pm(struct drm_device *dev)
 		dev_priv->display.update_wm = i9xx_update_wm;
 		dev_priv->display.get_fifo_size = i9xx_get_fifo_size;
 		dev_priv->display.init_clock_gating = gen3_init_clock_gating;
-	} else if (IS_I865G(dev)) {
-		dev_priv->display.update_wm = i830_update_wm;
-		dev_priv->display.init_clock_gating = i85x_init_clock_gating;
-		dev_priv->display.get_fifo_size = i830_get_fifo_size;
-	} else if (IS_I85X(dev)) {
-		dev_priv->display.update_wm = i9xx_update_wm;
-		dev_priv->display.get_fifo_size = i85x_get_fifo_size;
-		dev_priv->display.init_clock_gating = i85x_init_clock_gating;
-	} else {
-		dev_priv->display.update_wm = i830_update_wm;
-		dev_priv->display.init_clock_gating = i830_init_clock_gating;
-		if (IS_845G(dev))
+	} else if (IS_GEN2(dev)) {
+		if (INTEL_INFO(dev)->num_pipes == 1) {
+			dev_priv->display.update_wm = i845_update_wm;
 			dev_priv->display.get_fifo_size = i845_get_fifo_size;
-		else
+		} else {
+			dev_priv->display.update_wm = i9xx_update_wm;
 			dev_priv->display.get_fifo_size = i830_get_fifo_size;
+		}
+
+		if (IS_I85X(dev) || IS_I865G(dev))
+			dev_priv->display.init_clock_gating = i85x_init_clock_gating;
+		else
+			dev_priv->display.init_clock_gating = i830_init_clock_gating;
+	} else {
+		DRM_ERROR("unexpected fall-through in intel_init_pm\n");
 	}
 }