This function is used to convert drm_color_ctm S31.32 sign-magnitude
value to komeda required Q2.12 2's complement
Signed-off-by: james qian wang (Arm Technology China) <james.qian.w...@arm.com>
---
.../arm/display/komeda/komeda_color_mgmt.c | 27 +++++++++++++++++++
.../arm/display/komeda/komeda_color_mgmt.h | 1 +
2 files changed, 28 insertions(+)
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_color_mgmt.c
b/drivers/gpu/drm/arm/display/komeda/komeda_color_mgmt.c
index c180ce70c26c..c92c82eebddb 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_color_mgmt.c
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_color_mgmt.c
@@ -117,3 +117,30 @@ void drm_lut_to_fgamma_coeffs(struct drm_property_blob
*lut_blob, u32 *coeffs)
{
drm_lut_to_coeffs(lut_blob, coeffs, sector_tbl, ARRAY_SIZE(sector_tbl));
}
+
+/* Convert from S31.32 sign-magnitude to HW Q2.12 2's complement */
+static s32 drm_ctm_s31_32_to_q2_12(u64 input)
+{
+ u64 mag = (input & ~BIT_ULL(63)) >> 20;
+ bool negative = !!(input & BIT_ULL(63));
+ u32 val;
+
+ /* the range of signed 2s complement is [-2^n, 2^n - 1] */
+ val = clamp_val(mag, 0, negative ? BIT(14) : BIT(14) - 1);
+
+ return negative ? 0 - val : val;
+}
+
+void drm_ctm_to_coeffs(struct drm_property_blob *ctm_blob, u32 *coeffs)
+{
+ struct drm_color_ctm *ctm;
+ u32 i;
+
+ if (!ctm_blob)
+ return;
+
+ ctm = ctm_blob->data;
+
+ for (i = 0; i < KOMEDA_N_CTM_COEFFS; i++)
+ coeffs[i] = drm_ctm_s31_32_to_q2_12(ctm->matrix[i]);
+}
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_color_mgmt.h
b/drivers/gpu/drm/arm/display/komeda/komeda_color_mgmt.h
index 08ab69281648..2f4668466112 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_color_mgmt.h
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_color_mgmt.h
@@ -18,6 +18,7 @@
#define KOMEDA_N_CTM_COEFFS 9
void drm_lut_to_fgamma_coeffs(struct drm_property_blob *lut_blob, u32 *coeffs);
+void drm_ctm_to_coeffs(struct drm_property_blob *ctm_blob, u32 *coeffs);
const s32 *komeda_select_yuv2rgb_coeffs(u32 color_encoding, u32 color_range);
--
2.20.1
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