1 files changed, 37 insertions, 0 deletions

diff --git a/drivers/gpu/drm/tegra/dc.c b/drivers/gpu/drm/tegra/dc.c
index b905a4e2bdf9..5d6c00abd203 100644
--- a/drivers/gpu/drm/tegra/dc.c
+++ b/drivers/gpu/drm/tegra/dc.c
@@ -1213,12 +1213,49 @@ int tegra_dc_state_setup_clock(struct tegra_dc *dc,
 	return 0;
 }
 
+static void tegra_dc_commit_state(struct tegra_dc *dc,
+				  struct tegra_dc_state *state)
+{
+	u32 value;
+	int err;
+
+	err = clk_set_parent(dc->clk, state->clk);
+	if (err < 0)
+		dev_err(dc->dev, "failed to set parent clock: %d\n", err);
+
+	/*
+	 * Outputs may not want to change the parent clock rate. This is only
+	 * relevant to Tegra20 where only a single display PLL is available.
+	 * Since that PLL would typically be used for HDMI, an internal LVDS
+	 * panel would need to be driven by some other clock such as PLL_P
+	 * which is shared with other peripherals. Changing the clock rate
+	 * should therefore be avoided.
+	 */
+	if (state->pclk > 0) {
+		err = clk_set_rate(state->clk, state->pclk);
+		if (err < 0)
+			dev_err(dc->dev,
+				"failed to set clock rate to %lu Hz\n",
+				state->pclk);
+	}
+
+	DRM_DEBUG_KMS("rate: %lu, div: %u\n", clk_get_rate(dc->clk),
+		      state->div);
+	DRM_DEBUG_KMS("pclk: %lu\n", state->pclk);
+
+	value = SHIFT_CLK_DIVIDER(state->div) | PIXEL_CLK_DIVIDER_PCD1;
+	tegra_dc_writel(dc, value, DC_DISP_DISP_CLOCK_CONTROL);
+}
+
 static void tegra_crtc_mode_set_nofb(struct drm_crtc *crtc)
 {
 	struct drm_display_mode *mode = &crtc->state->adjusted_mode;
+	struct tegra_dc_state *state = to_dc_state(crtc->state);
 	struct tegra_dc *dc = to_tegra_dc(crtc);
 	u32 value;
 
+	tegra_dc_commit_state(dc, state);
+
 	/* program display mode */
 	tegra_dc_set_timings(dc, mode);