drm/i915: Clean up glk_pipe_scaler_clock_gating_wa()

glk_pipe_scaler_clock_gating_wa() is messy. Clean it up via
intel_de_rmw(), and also just pass in the whole crtc so the
caller doesn't have to dance around so much.
Reviewed-by: Vandita Kulkarni <vandita.kulkarni@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240402135148.23011-4-ville.syrjala@linux.intel.com

drivers/gpu/drm/i915/display/intel_display.c

@@ -1551,18 +1551,13 @@ static void ilk_crtc_enable(struct intel_atomic_state *state,
 	intel_set_pch_fifo_underrun_reporting(dev_priv, pipe, true);
 }
 
-static void glk_pipe_scaler_clock_gating_wa(struct drm_i915_private *dev_priv,
-					    enum pipe pipe, bool apply)
+static void glk_pipe_scaler_clock_gating_wa(struct intel_crtc *crtc, bool enable)
 {
-	u32 val = intel_de_read(dev_priv, CLKGATE_DIS_PSL(pipe));
+	struct drm_i915_private *i915 = to_i915(crtc->base.dev);
 	u32 mask = DPF_GATING_DIS | DPF_RAM_GATING_DIS | DPFR_GATING_DIS;
 
-	if (apply)
-		val |= mask;
-	else
-		val &= ~mask;
-
-	intel_de_write(dev_priv, CLKGATE_DIS_PSL(pipe), val);
+	intel_de_rmw(i915, CLKGATE_DIS_PSL(crtc->pipe),
+		     mask, enable ? mask : 0);
 }
 
 static void hsw_set_linetime_wm(const struct intel_crtc_state *crtc_state)
@@ -1638,8 +1633,8 @@ static void hsw_crtc_enable(struct intel_atomic_state *state,
 	const struct intel_crtc_state *new_crtc_state =
 		intel_atomic_get_new_crtc_state(state, crtc);
 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
-	enum pipe pipe = crtc->pipe, hsw_workaround_pipe;
 	enum transcoder cpu_transcoder = new_crtc_state->cpu_transcoder;
+	enum pipe hsw_workaround_pipe;
 	bool psl_clkgate_wa;
 
 	if (drm_WARN_ON(&dev_priv->drm, crtc->active))
@@ -1677,7 +1672,7 @@ static void hsw_crtc_enable(struct intel_atomic_state *state,
 	psl_clkgate_wa = DISPLAY_VER(dev_priv) == 10 &&
 		new_crtc_state->pch_pfit.enabled;
 	if (psl_clkgate_wa)
-		glk_pipe_scaler_clock_gating_wa(dev_priv, pipe, true);
+		glk_pipe_scaler_clock_gating_wa(crtc, true);
 
 	if (DISPLAY_VER(dev_priv) >= 9)
 		skl_pfit_enable(new_crtc_state);
@@ -1709,7 +1704,7 @@ static void hsw_crtc_enable(struct intel_atomic_state *state,
 
 	if (psl_clkgate_wa) {
 		intel_crtc_wait_for_next_vblank(crtc);
-		glk_pipe_scaler_clock_gating_wa(dev_priv, pipe, false);
+		glk_pipe_scaler_clock_gating_wa(crtc, false);
 	}
 
 	/* If we change the relative order between pipe/planes enabling, we need