drm/i915: Document LUT "max" register precision

Document the precision of the LUT "max" registers, just
so we don't have to dig through the spec so much.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221123152638.20622-7-ville.syrjala@linux.intel.com
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Reviewed-by: Uma Shankar <uma.shankar@intel.com>

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 619f11d..7ca676a 100644 (file)
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -3619,7 +3619,7 @@
 
 #define  _PIPEAGCMAX           0x70010
 #define  _PIPEBGCMAX           0x71010
-#define PIPEGCMAX(pipe, i)     _MMIO_PIPE2(pipe, _PIPEAGCMAX + (i) * 4)
+#define PIPEGCMAX(pipe, i)     _MMIO_PIPE2(pipe, _PIPEAGCMAX + (i) * 4) /* u1.16 */
 
 #define _PIPE_ARB_CTL_A                        0x70028 /* icl+ */
 #define PIPE_ARB_CTL(pipe)             _MMIO_PIPE2(pipe, _PIPE_ARB_CTL_A)
@@ -5303,7 +5303,7 @@
 
 #define  _PREC_PIPEAGCMAX              0x4d000
 #define  _PREC_PIPEBGCMAX              0x4d010
-#define PREC_PIPEGCMAX(pipe, i)        _MMIO(_PIPE(pipe, _PIPEAGCMAX, _PIPEBGCMAX) + (i) * 4)
+#define PREC_PIPEGCMAX(pipe, i)        _MMIO(_PIPE(pipe, _PIPEAGCMAX, _PIPEBGCMAX) + (i) * 4) /* u1.16 */
 
 #define _GAMMA_MODE_A          0x4a480
 #define _GAMMA_MODE_B          0x4ac80
@@ -7542,9 +7542,9 @@ enum skl_power_gate {
 
 #define PREC_PAL_INDEX(pipe)           _MMIO_PIPE(pipe, _PAL_PREC_INDEX_A, _PAL_PREC_INDEX_B)
 #define PREC_PAL_DATA(pipe)            _MMIO_PIPE(pipe, _PAL_PREC_DATA_A, _PAL_PREC_DATA_B)
-#define PREC_PAL_GC_MAX(pipe, i)       _MMIO(_PIPE(pipe, _PAL_PREC_GC_MAX_A, _PAL_PREC_GC_MAX_B) + (i) * 4)
-#define PREC_PAL_EXT_GC_MAX(pipe, i)   _MMIO(_PIPE(pipe, _PAL_PREC_EXT_GC_MAX_A, _PAL_PREC_EXT_GC_MAX_B) + (i) * 4)
-#define PREC_PAL_EXT2_GC_MAX(pipe, i)  _MMIO(_PIPE(pipe, _PAL_PREC_EXT2_GC_MAX_A, _PAL_PREC_EXT2_GC_MAX_B) + (i) * 4)
+#define PREC_PAL_GC_MAX(pipe, i)       _MMIO(_PIPE(pipe, _PAL_PREC_GC_MAX_A, _PAL_PREC_GC_MAX_B) + (i) * 4) /* u1.16 */
+#define PREC_PAL_EXT_GC_MAX(pipe, i)   _MMIO(_PIPE(pipe, _PAL_PREC_EXT_GC_MAX_A, _PAL_PREC_EXT_GC_MAX_B) + (i) * 4) /* u3.16 */
+#define PREC_PAL_EXT2_GC_MAX(pipe, i)  _MMIO(_PIPE(pipe, _PAL_PREC_EXT2_GC_MAX_A, _PAL_PREC_EXT2_GC_MAX_B) + (i) * 4) /* glk+, u3.16 */
 
 #define _PRE_CSC_GAMC_INDEX_A  0x4A484
 #define _PRE_CSC_GAMC_INDEX_B  0x4AC84