drm/i915: Introduce CRTC output format

This patch adds an enum "intel_output_format" to represent
the output format of a particular CRTC. This enum will be
used to produce a RGB/YCBCR4:4:4/YCBCR4:2:0 output format
during the atomic modeset calculations.

V5:
- Created this separate patch to introduce and init output_format.
- Initialize parameters of output_format_str respectively (Jani N).
- Call it intel_output_format than crtc_output_format(Ville).
- Set output format in pipe_config for every encoder (Ville).
- Get rid of extra DRM_DEBUG_KMS during get_pipe_config (Ville)

V6: Rebase
V7: Fixed alignment warnings (checkpatch)
V8: Another check[atch warning for alignment
V9: Rebase
V10: Rebase on top of DSI restructure
V11: Addressed review comment from Ville
	- Set CRTC format for pre-HSW get_pipe_config() function too.
     Added Ville's R-B

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Shashank Sharma <shashank.sharma@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1539325394-20788-1-git-send-email-shashank.sharma@intel.com
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 980f4ea..7e7742a 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -7800,6 +7800,7 @@ static bool i9xx_get_pipe_config(struct intel_crtc *crtc,
 	if (!intel_display_power_get_if_enabled(dev_priv, power_domain))
 		return false;
 
+	pipe_config->output_format = INTEL_OUTPUT_FORMAT_RGB;
 	pipe_config->cpu_transcoder = (enum transcoder) crtc->pipe;
 	pipe_config->shared_dpll = NULL;
 
@@ -8849,6 +8850,7 @@ static bool ironlake_get_pipe_config(struct intel_crtc *crtc,
 	if (!intel_display_power_get_if_enabled(dev_priv, power_domain))
 		return false;
 
+	pipe_config->output_format = INTEL_OUTPUT_FORMAT_RGB;
 	pipe_config->cpu_transcoder = (enum transcoder) crtc->pipe;
 	pipe_config->shared_dpll = NULL;
 
@@ -9504,6 +9506,7 @@ static bool haswell_get_pipe_config(struct intel_crtc *crtc,
 		}
 	}
 
+	pipe_config->output_format = INTEL_OUTPUT_FORMAT_RGB;
 	power_domain = POWER_DOMAIN_PIPE_PANEL_FITTER(crtc->pipe);
 	if (intel_display_power_get_if_enabled(dev_priv, power_domain)) {
 		power_domain_mask |= BIT_ULL(power_domain);
@@ -10919,6 +10922,18 @@ static void snprintf_output_types(char *buf, size_t len,
 	WARN_ON_ONCE(output_types != 0);
 }
 
+static const char * const output_format_str[] = {
+	[INTEL_OUTPUT_FORMAT_INVALID] = "Invalid",
+	[INTEL_OUTPUT_FORMAT_RGB] = "RGB",
+};
+
+static const char *output_formats(enum intel_output_format format)
+{
+	if (format != INTEL_OUTPUT_FORMAT_RGB)
+		format = INTEL_OUTPUT_FORMAT_INVALID;
+	return output_format_str[format];
+}
+
 static void intel_dump_pipe_config(struct intel_crtc *crtc,
 				   struct intel_crtc_state *pipe_config,
 				   const char *context)
@@ -10938,6 +10953,9 @@ static void intel_dump_pipe_config(struct intel_crtc *crtc,
 	DRM_DEBUG_KMS("output_types: %s (0x%x)\n",
 		      buf, pipe_config->output_types);
 
+	DRM_DEBUG_KMS("output format: %s\n",
+		      output_formats(pipe_config->output_format));
+
 	DRM_DEBUG_KMS("cpu_transcoder: %s, pipe bpp: %i, dithering: %i\n",
 		      transcoder_name(pipe_config->cpu_transcoder),
 		      pipe_config->pipe_bpp, pipe_config->dither);
@@ -11527,6 +11545,7 @@ intel_pipe_config_compare(struct drm_i915_private *dev_priv,
 	PIPE_CONF_CHECK_I(base.adjusted_mode.crtc_vsync_end);
 
 	PIPE_CONF_CHECK_I(pixel_multiplier);
+	PIPE_CONF_CHECK_I(output_format);
 	PIPE_CONF_CHECK_BOOL(has_hdmi_sink);
 	if ((INTEL_GEN(dev_priv) < 8 && !IS_HASWELL(dev_priv)) ||
 	    IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))