drm/i915: Simplify intel_get_crtc_ycbcr_config()

Make intel_get_crtc_ycbcr_config() simpler and rename it
to bdw_get_pipemisc_output_format() to better reflect what
it does.

Also toss in some comments to document that the 4:2:0 PIPECONF
bits are glk+ only. They are mbz on earlier platforms so reading
them unconditionally is safe however.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190718145053.25808-9-ville.syrjala@linux.intel.com
Reviewed-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>

diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index 44460bf70d6bf6fd21a20304ceb5fb8989385ba7..95a63acc43a302e4565f78bd66fbafe4aa482d19 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -8727,47 +8727,24 @@ static void chv_crtc_clock_get(struct intel_crtc *crtc,
        pipe_config->port_clock = chv_calc_dpll_params(refclk, &clock);
 }
 
-static void intel_get_crtc_ycbcr_config(struct intel_crtc *crtc,
-                                       struct intel_crtc_state *pipe_config)
+static enum intel_output_format
+bdw_get_pipemisc_output_format(struct intel_crtc *crtc)
 {
        struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
-       enum intel_output_format output = INTEL_OUTPUT_FORMAT_RGB;
-
-       pipe_config->lspcon_downsampling = false;
-
-       if (IS_BROADWELL(dev_priv) || INTEL_GEN(dev_priv) >= 9) {
-               u32 tmp = I915_READ(PIPEMISC(crtc->pipe));
-
-               if (tmp & PIPEMISC_OUTPUT_COLORSPACE_YUV) {
-                       bool ycbcr420_enabled = tmp & PIPEMISC_YUV420_ENABLE;
-                       bool blend = tmp & PIPEMISC_YUV420_MODE_FULL_BLEND;
-
-                       if (ycbcr420_enabled) {
-                               /* We support 4:2:0 in full blend mode only */
-                               if (!blend)
-                                       output = INTEL_OUTPUT_FORMAT_INVALID;
-                               else if (!(IS_GEMINILAKE(dev_priv) ||
-                                          INTEL_GEN(dev_priv) >= 10))
-                                       output = INTEL_OUTPUT_FORMAT_INVALID;
-                               else
-                                       output = INTEL_OUTPUT_FORMAT_YCBCR420;
-                       } else {
-                               /*
-                                * Currently there is no interface defined to
-                                * check user preference between RGB/YCBCR444
-                                * or YCBCR420. So the only possible case for
-                                * YCBCR444 usage is driving YCBCR420 output
-                                * with LSPCON, when pipe is configured for
-                                * YCBCR444 output and LSPCON takes care of
-                                * downsampling it.
-                                */
-                               pipe_config->lspcon_downsampling = true;
-                               output = INTEL_OUTPUT_FORMAT_YCBCR444;
-                       }
-               }
-       }
+       u32 tmp;
+
+       tmp = I915_READ(PIPEMISC(crtc->pipe));
 
-       pipe_config->output_format = output;
+       if (tmp & PIPEMISC_YUV420_ENABLE) {
+               /* We support 4:2:0 in full blend mode only */
+               WARN_ON((tmp & PIPEMISC_YUV420_MODE_FULL_BLEND) == 0);
+
+               return INTEL_OUTPUT_FORMAT_YCBCR420;
+       } else if (tmp & PIPEMISC_OUTPUT_COLORSPACE_YUV) {
+               return INTEL_OUTPUT_FORMAT_YCBCR444;
+       } else {
+               return INTEL_OUTPUT_FORMAT_RGB;
+       }
 }
 
 static void i9xx_get_pipe_color_config(struct intel_crtc_state *crtc_state)
@@ -10462,7 +10439,23 @@ static bool haswell_get_pipe_config(struct intel_crtc *crtc,
        }
 
        intel_get_pipe_src_size(crtc, pipe_config);
-       intel_get_crtc_ycbcr_config(crtc, pipe_config);
+
+       if (INTEL_GEN(dev_priv) >= 9 || IS_BROADWELL(dev_priv)) {
+               pipe_config->output_format =
+                       bdw_get_pipemisc_output_format(crtc);
+
+               /*
+                * Currently there is no interface defined to
+                * check user preference between RGB/YCBCR444
+                * or YCBCR420. So the only possible case for
+                * YCBCR444 usage is driving YCBCR420 output
+                * with LSPCON, when pipe is configured for
+                * YCBCR444 output and LSPCON takes care of
+                * downsampling it.
+                */
+               pipe_config->lspcon_downsampling =
+                       pipe_config->output_format == INTEL_OUTPUT_FORMAT_YCBCR444;
+       }
 
        pipe_config->gamma_mode = I915_READ(GAMMA_MODE(crtc->pipe));
 

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 2a1a1e84d1bc35e9097413d0d8acbfd8bdc026a9..3cc1baa0b9152f9ef9d09209c46c18e4ea21ba0e 100644 (file)
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -5775,8 +5775,8 @@ enum {
 
 #define _PIPE_MISC_A                   0x70030
 #define _PIPE_MISC_B                   0x71030
-#define   PIPEMISC_YUV420_ENABLE       (1 << 27)
-#define   PIPEMISC_YUV420_MODE_FULL_BLEND (1 << 26)
+#define   PIPEMISC_YUV420_ENABLE       (1 << 27) /* glk+ */
+#define   PIPEMISC_YUV420_MODE_FULL_BLEND (1 << 26) /* glk+ */
 #define   PIPEMISC_HDR_MODE_PRECISION  (1 << 23) /* icl+ */
 #define   PIPEMISC_OUTPUT_COLORSPACE_YUV  (1 << 11)
 #define   PIPEMISC_DITHER_BPC_MASK     (7 << 5)