[PATCH 5.13 033/151] drm/i915/display: Fix the 12 BPC bits for PIPE_MISC reg

Greg Kroah-Hartman
2021-08-16T13:23:35Z

From: Ankit Nautiyal <ankit.k.nautiyal@intel.com>

commit abd9d66a055722393d33685214c08386694871d7 upstream.

Till DISPLAY12 the PIPE_MISC bits 5-7 are used to set the
Dithering BPC, with valid values of 6, 8, 10 BPC.
For ADLP+ these bits are used to set the PORT OUTPUT BPC, with valid
values of: 6, 8, 10, 12 BPC, and need to be programmed whether
dithering is enabled or not.

This patch:
-corrects the bits 5-7 for PIPE MISC register for 12 BPC.
-renames the bits and mask to have generic names for these bits for
dithering bpc and port output bpc.

v3: Added a note for MIPI DSI which uses the PIPE_MISC for readout
for pipe_bpp. (Uma Shankar)

v2: Added 'display' to the subject and fixes tag. (Uma Shankar)

Fixes: 756f85cffef2 ("drm/i915/bdw: Broadwell has PIPEMISC")
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com> (v1)
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: intel-gfx@lists.freedesktop.org
Cc: <stable@vger.kernel.org> # v3.13+

Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Signed-off-by: Uma Shankar <uma.shankar@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210811051857.109723-1-ankit.k.nautiyal@intel.com
(cherry picked from commit 70418a68713c13da3f36c388087d0220b456a430)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/gpu/drm/i915/display/intel_display.c | 34 +++++++++++++++++++--------
drivers/gpu/drm/i915/i915_reg.h | 16 ++++++++----
2 files changed, 35 insertions(+), 15 deletions(-)

--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -5424,16 +5424,18 @@ static void bdw_set_pipemisc(const struc

switch (crtc_state->pipe_bpp) {
case 18:
- val |= PIPEMISC_DITHER_6_BPC;
+ val |= PIPEMISC_6_BPC;
break;
case 24:
- val |= PIPEMISC_DITHER_8_BPC;
+ val |= PIPEMISC_8_BPC;
break;
case 30:
- val |= PIPEMISC_DITHER_10_BPC;
+ val |= PIPEMISC_10_BPC;
break;
case 36:
- val |= PIPEMISC_DITHER_12_BPC;
+ /* Port output 12BPC defined for ADLP+ */
+ if (DISPLAY_VER(dev_priv) > 12)
+ val |= PIPEMISC_12_BPC_ADLP;
break;
default:
MISSING_CASE(crtc_state->pipe_bpp);
@@ -5469,15 +5471,27 @@ int bdw_get_pipemisc_bpp(struct intel_cr

tmp = intel_de_read(dev_priv, PIPEMISC(crtc->pipe));

- switch (tmp & PIPEMISC_DITHER_BPC_MASK) {
- case PIPEMISC_DITHER_6_BPC:
+ switch (tmp & PIPEMISC_BPC_MASK) {
+ case PIPEMISC_6_BPC:
return 18;
- case PIPEMISC_DITHER_8_BPC:
+ case PIPEMISC_8_BPC:
return 24;
- case PIPEMISC_DITHER_10_BPC:
+ case PIPEMISC_10_BPC:
return 30;
- case PIPEMISC_DITHER_12_BPC:
- return 36;
+ /*
+ * PORT OUTPUT 12 BPC defined for ADLP+.
+ *
+ * TODO:
+ * For previous platforms with DSI interface, bits 5:7
+ * are used for storing pipe_bpp irrespective of dithering.
+ * Since the value of 12 BPC is not defined for these bits
+ * on older platforms, need to find a workaround for 12 BPC
+ * MIPI DSI HW readout.
+ */
+ case PIPEMISC_12_BPC_ADLP:
+ if (DISPLAY_VER(dev_priv) > 12)
+ return 36;
+ fallthrough;
default:
MISSING_CASE(tmp);
return 0;
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -6134,11 +6134,17 @@ enum {
#define PIPEMISC_HDR_MODE_PRECISION (1 << 23) /* icl+ */
#define PIPEMISC_OUTPUT_COLORSPACE_YUV (1 << 11)
#define PIPEMISC_PIXEL_ROUNDING_TRUNC REG_BIT(8) /* tgl+ */
-#define PIPEMISC_DITHER_BPC_MASK (7 << 5)
-#define PIPEMISC_DITHER_8_BPC (0 << 5)
-#define PIPEMISC_DITHER_10_BPC (1 << 5)
-#define PIPEMISC_DITHER_6_BPC (2 << 5)
-#define PIPEMISC_DITHER_12_BPC (3 << 5)
+/*
+ * For Display < 13, Bits 5-7 of PIPE MISC represent DITHER BPC with
+ * valid values of: 6, 8, 10 BPC.
+ * ADLP+, the bits 5-7 represent PORT OUTPUT BPC with valid values of:
+ * 6, 8, 10, 12 BPC.
+ */
+#define PIPEMISC_BPC_MASK (7 << 5)
+#define PIPEMISC_8_BPC (0 << 5)
+#define PIPEMISC_10_BPC (1 << 5)
+#define PIPEMISC_6_BPC (2 << 5)
+#define PIPEMISC_12_BPC_ADLP (4 << 5) /* adlp+ */
#define PIPEMISC_DITHER_ENABLE (1 << 4)
#define PIPEMISC_DITHER_TYPE_MASK (3 << 2)
#define PIPEMISC_DITHER_TYPE_SP (0 << 2)