drm/i915: Compute DSI PLL parameters during .compute_config()

Compute the DSI PLL parameters during .compute_config() rather than
.pre_pll_enable() so that we can fail gracefully if we can't find
suitable parameters.

In order to do that we need to store the DSI PLL parameters in
pipe_config.

v2: Handle BXT too

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1460488478-18311-3-git-send-email-ville.syrjala@linux.intel.com
Tested-by: Jani Nikula <jani.nikula@intel.com>

drivers/gpu/drm/i915/intel_display.c

@@ -12763,6 +12763,9 @@ intel_pipe_config_compare(struct drm_device *dev,
 	PIPE_CONF_CHECK_X(dpll_hw_state.cfgcr1);
 	PIPE_CONF_CHECK_X(dpll_hw_state.cfgcr2);
 
+	PIPE_CONF_CHECK_X(dsi_pll.ctrl);
+	PIPE_CONF_CHECK_X(dsi_pll.div);
+
 	if (IS_G4X(dev) || INTEL_INFO(dev)->gen >= 5)
 		PIPE_CONF_CHECK_I(pipe_bpp);
 

drivers/gpu/drm/i915/intel_drv.h

@@ -497,6 +497,11 @@ struct intel_crtc_state {
 	/* Actual register state of the dpll, for shared dpll cross-checking. */
 	struct intel_dpll_hw_state dpll_hw_state;
 
+	/* DSI PLL registers */
+	struct {
+		u32 ctrl, div;
+	} dsi_pll;
+
 	int pipe_bpp;
 	struct intel_link_m_n dp_m_n;
 

drivers/gpu/drm/i915/intel_dsi.c

@@ -292,6 +292,7 @@ static bool intel_dsi_compute_config(struct intel_encoder *encoder,
 	struct intel_connector *intel_connector = intel_dsi->attached_connector;
 	struct drm_display_mode *fixed_mode = intel_connector->panel.fixed_mode;
 	struct drm_display_mode *adjusted_mode = &pipe_config->base.adjusted_mode;
+	int ret;
 
 	DRM_DEBUG_KMS("\n");
 
@@ -311,10 +312,10 @@ static bool intel_dsi_compute_config(struct intel_encoder *encoder,
 			pipe_config->cpu_transcoder = TRANSCODER_DSI_A;
 	}
 
-	/*
-	 * FIXME move the DSI PLL calc from vlv_enable_dsi_pll()
-	 * to .compute_config().
-	 */
+	ret = intel_compute_dsi_pll(encoder, pipe_config);
+	if (ret)
+		return false;
+
 	pipe_config->clock_set = true;
 
 	return true;
@@ -504,6 +505,7 @@ static void intel_dsi_pre_enable(struct intel_encoder *encoder)
 	struct drm_device *dev = encoder->base.dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_dsi *intel_dsi = enc_to_intel_dsi(&encoder->base);
+	struct intel_crtc *crtc = to_intel_crtc(encoder->base.crtc);
 	enum port port;
 	u32 tmp;
 
@@ -514,7 +516,7 @@ static void intel_dsi_pre_enable(struct intel_encoder *encoder)
 	 * lock. It needs to be fully powered down to fix it.
 	 */
 	intel_disable_dsi_pll(encoder);
-	intel_enable_dsi_pll(encoder);
+	intel_enable_dsi_pll(encoder, crtc->config);
 
 	intel_dsi_prepare(encoder);
 
@@ -824,7 +826,8 @@ static void intel_dsi_get_config(struct intel_encoder *encoder,
 	if (IS_BROXTON(dev))
 		bxt_dsi_get_pipe_config(encoder, pipe_config);
 
-	pclk = intel_dsi_get_pclk(encoder, pipe_config->pipe_bpp);
+	pclk = intel_dsi_get_pclk(encoder, pipe_config->pipe_bpp,
+				  pipe_config);
 	if (!pclk)
 		return;
 

drivers/gpu/drm/i915/intel_dsi.h

@@ -127,11 +127,15 @@ static inline struct intel_dsi *enc_to_intel_dsi(struct drm_encoder *encoder)
 }
 
 bool intel_dsi_pll_is_enabled(struct drm_i915_private *dev_priv);
-extern void intel_enable_dsi_pll(struct intel_encoder *encoder);
-extern void intel_disable_dsi_pll(struct intel_encoder *encoder);
-extern u32 intel_dsi_get_pclk(struct intel_encoder *encoder, int pipe_bpp);
-extern void intel_dsi_reset_clocks(struct intel_encoder *encoder,
-							enum port port);
+int intel_compute_dsi_pll(struct intel_encoder *encoder,
+			  struct intel_crtc_state *config);
+void intel_enable_dsi_pll(struct intel_encoder *encoder,
+			  const struct intel_crtc_state *config);
+void intel_disable_dsi_pll(struct intel_encoder *encoder);
+u32 intel_dsi_get_pclk(struct intel_encoder *encoder, int pipe_bpp,
+		       struct intel_crtc_state *config);
+void intel_dsi_reset_clocks(struct intel_encoder *encoder,
+			    enum port port);
 
 struct drm_panel *vbt_panel_init(struct intel_dsi *intel_dsi, u16 panel_id);
 enum mipi_dsi_pixel_format pixel_format_from_register_bits(u32 fmt);