drm/amd/display: Add dpp_get_gamut_remap functions

We want to be able to read the DPP's gamut remap matrix.

v2:
- code-style and doc comments clean-up (Melissa)

Signed-off-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Melissa Wen <mwen@igalia.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

2 files changed, 38 insertions, 0 deletions

diff --git a/drivers/gpu/drm/amd/display/dc/basics/conversion.c b/drivers/gpu/drm/amd/display/dc/basics/conversion.c
index 1090d235086a..bd1f60ecaba4 100644
--- a/drivers/gpu/drm/amd/display/dc/basics/conversion.c
+++ b/drivers/gpu/drm/amd/display/dc/basics/conversion.c
@@ -101,6 +101,40 @@ void convert_float_matrix(
 	}
 }
 
+static struct fixed31_32 int_frac_to_fixed_point(uint16_t arg,
+						 uint8_t integer_bits,
+						 uint8_t fractional_bits)
+{
+	struct fixed31_32 result;
+	uint16_t sign_mask = 1 << (fractional_bits + integer_bits);
+	uint16_t value_mask = sign_mask - 1;
+
+	result.value = (long long)(arg & value_mask) <<
+		       (FIXED31_32_BITS_PER_FRACTIONAL_PART - fractional_bits);
+
+	if (arg & sign_mask)
+		result = dc_fixpt_neg(result);
+
+	return result;
+}
+
+/**
+ * convert_hw_matrix - converts HW values into fixed31_32 matrix.
+ * @matrix: fixed point 31.32 matrix
+ * @reg: array of register values
+ * @buffer_size: size of the array of register values
+ *
+ * Converts HW register spec defined format S2D13 into a fixed-point 31.32
+ * matrix.
+ */
+void convert_hw_matrix(struct fixed31_32 *matrix,
+		       uint16_t *reg,
+		       uint32_t buffer_size)
+{
+	for (int i = 0; i < buffer_size; ++i)
+		matrix[i] = int_frac_to_fixed_point(reg[i], 2, 13);
+}
+
 static uint32_t find_gcd(uint32_t a, uint32_t b)
 {
 	uint32_t remainder;
diff --git a/drivers/gpu/drm/amd/display/dc/basics/conversion.h b/drivers/gpu/drm/amd/display/dc/basics/conversion.h
index 81da4e6f7a1a..a433cef78496 100644
--- a/drivers/gpu/drm/amd/display/dc/basics/conversion.h
+++ b/drivers/gpu/drm/amd/display/dc/basics/conversion.h
@@ -41,6 +41,10 @@ void convert_float_matrix(
 void reduce_fraction(uint32_t num, uint32_t den,
 		uint32_t *out_num, uint32_t *out_den);
 
+void convert_hw_matrix(struct fixed31_32 *matrix,
+		       uint16_t *reg,
+		       uint32_t buffer_size);
+
 static inline unsigned int log_2(unsigned int num)
 {
 	return ilog2(num);