[PATCH v2 1/2] media: arm: mali-c55: Add support for CCM
From: Jacopo Mondi
Date: Tue Jun 16 2026 - 10:42:27 EST
From: Jacopo Mondi <jacopo.mondi+renesas@xxxxxxxxxxxxxxxx>
Add support for the CCM (Color Correction Matrix) for the Mali C55 ISP.
Define a new block in the uAPI using the extensible v4l2-isp format and
implement support for configuring the CCM parameters in the mali-c55
ISP driver.
Signed-off-by: Jacopo Mondi <jacopo.mondi+renesas@xxxxxxxxxxxxxxxx>
---
.../media/platform/arm/mali-c55/mali-c55-params.c | 52 ++++++++++++++++++++++
include/uapi/linux/media/arm/mali-c55-config.h | 41 ++++++++++++++++-
2 files changed, 92 insertions(+), 1 deletion(-)
diff --git a/drivers/media/platform/arm/mali-c55/mali-c55-params.c b/drivers/media/platform/arm/mali-c55/mali-c55-params.c
index de0e9d898db7..96f1b28a6d77 100644
--- a/drivers/media/platform/arm/mali-c55/mali-c55-params.c
+++ b/drivers/media/platform/arm/mali-c55/mali-c55-params.c
@@ -46,6 +46,7 @@
* @awb_config: For header->type == MALI_C55_PARAM_BLOCK_AWB_CONFIG
* @shading_config: For header->type == MALI_C55_PARAM_MESH_SHADING_CONFIG
* @shading_selection: For header->type == MALI_C55_PARAM_MESH_SHADING_SELECTION
+ * @ccm: For header->type == MALI_C55_PARAM_BLOCK_CCM
* @data: Allows easy initialisation of a union variable with a
* pointer into a __u8 array.
*/
@@ -59,6 +60,7 @@ union mali_c55_params_block {
const struct mali_c55_params_awb_config *awb_config;
const struct mali_c55_params_mesh_shading_config *shading_config;
const struct mali_c55_params_mesh_shading_selection *shading_selection;
+ const struct mali_c55_params_ccm *ccm;
const __u8 *data;
};
@@ -414,6 +416,52 @@ static void mali_c55_params_lsc_selection(struct mali_c55 *mali_c55,
params->mesh_strength);
}
+static void mali_c55_params_ccm(struct mali_c55 *mali_c55,
+ union mali_c55_params_block block)
+{
+ const struct mali_c55_params_ccm *params = block.ccm;
+
+ if (block.header->flags & V4L2_ISP_PARAMS_FL_BLOCK_DISABLE) {
+ mali_c55_ctx_write(mali_c55, MALI_C55_REG_CCM_ENABLE, 0);
+ return;
+ }
+
+ mali_c55_ctx_update_bits(mali_c55, MALI_C55_REG_CCM_COEF_R_R,
+ MALI_C55_CCM_COEF_MASK, params->coeffs[0][0]);
+ mali_c55_ctx_update_bits(mali_c55, MALI_C55_REG_CCM_COEF_R_G,
+ MALI_C55_CCM_COEF_MASK, params->coeffs[0][1]);
+ mali_c55_ctx_update_bits(mali_c55, MALI_C55_REG_CCM_COEF_R_B,
+ MALI_C55_CCM_COEF_MASK, params->coeffs[0][2]);
+ mali_c55_ctx_update_bits(mali_c55, MALI_C55_REG_CCM_COEF_G_R,
+ MALI_C55_CCM_COEF_MASK, params->coeffs[1][0]);
+ mali_c55_ctx_update_bits(mali_c55, MALI_C55_REG_CCM_COEF_G_G,
+ MALI_C55_CCM_COEF_MASK, params->coeffs[1][1]);
+ mali_c55_ctx_update_bits(mali_c55, MALI_C55_REG_CCM_COEF_G_B,
+ MALI_C55_CCM_COEF_MASK, params->coeffs[1][2]);
+ mali_c55_ctx_update_bits(mali_c55, MALI_C55_REG_CCM_COEF_B_R,
+ MALI_C55_CCM_COEF_MASK, params->coeffs[2][0]);
+ mali_c55_ctx_update_bits(mali_c55, MALI_C55_REG_CCM_COEF_B_G,
+ MALI_C55_CCM_COEF_MASK, params->coeffs[2][1]);
+ mali_c55_ctx_update_bits(mali_c55, MALI_C55_REG_CCM_COEF_B_B,
+ MALI_C55_CCM_COEF_MASK, params->coeffs[2][2]);
+
+ mali_c55_ctx_update_bits(mali_c55, MALI_C55_REG_CCM_ANTIFOG_GAIN_R,
+ MALI_C55_CCM_ANTIFOG_GAIN_MASK, params->gains[0]);
+ mali_c55_ctx_update_bits(mali_c55, MALI_C55_REG_CCM_ANTIFOG_GAIN_G,
+ MALI_C55_CCM_ANTIFOG_GAIN_MASK, params->gains[1]);
+ mali_c55_ctx_update_bits(mali_c55, MALI_C55_REG_CCM_ANTIFOG_GAIN_B,
+ MALI_C55_CCM_ANTIFOG_GAIN_MASK, params->gains[2]);
+
+ mali_c55_ctx_update_bits(mali_c55, MALI_C55_REG_CCM_ANTIFOG_OFFSET_R,
+ MALI_C55_CCM_ANTIFOG_OFFSET_MASK, params->offs[0]);
+ mali_c55_ctx_update_bits(mali_c55, MALI_C55_REG_CCM_ANTIFOG_OFFSET_G,
+ MALI_C55_CCM_ANTIFOG_OFFSET_MASK, params->offs[1]);
+ mali_c55_ctx_update_bits(mali_c55, MALI_C55_REG_CCM_ANTIFOG_OFFSET_B,
+ MALI_C55_CCM_ANTIFOG_OFFSET_MASK, params->offs[2]);
+
+ mali_c55_ctx_write(mali_c55, MALI_C55_REG_CCM_ENABLE, 1);
+}
+
static const mali_c55_params_handler mali_c55_params_handlers[] = {
[MALI_C55_PARAM_BLOCK_SENSOR_OFFS] = &mali_c55_params_sensor_offs,
[MALI_C55_PARAM_BLOCK_AEXP_HIST] = &mali_c55_params_aexp_hist,
@@ -426,6 +474,7 @@ static const mali_c55_params_handler mali_c55_params_handlers[] = {
[MALI_C55_PARAM_BLOCK_AWB_GAINS_AEXP] = &mali_c55_params_awb_gains,
[MALI_C55_PARAM_MESH_SHADING_CONFIG] = &mali_c55_params_lsc_config,
[MALI_C55_PARAM_MESH_SHADING_SELECTION] = &mali_c55_params_lsc_selection,
+ [MALI_C55_PARAM_BLOCK_CCM] = &mali_c55_params_ccm,
};
static const struct v4l2_isp_params_block_type_info
@@ -463,6 +512,9 @@ mali_c55_params_block_types_info[] = {
[MALI_C55_PARAM_MESH_SHADING_SELECTION] = {
.size = sizeof(struct mali_c55_params_mesh_shading_selection),
},
+ [MALI_C55_PARAM_BLOCK_CCM] = {
+ .size = sizeof(struct mali_c55_params_ccm),
+ },
};
static_assert(ARRAY_SIZE(mali_c55_params_handlers) ==
diff --git a/include/uapi/linux/media/arm/mali-c55-config.h b/include/uapi/linux/media/arm/mali-c55-config.h
index 3d335f950eeb..0b2085eed81b 100644
--- a/include/uapi/linux/media/arm/mali-c55-config.h
+++ b/include/uapi/linux/media/arm/mali-c55-config.h
@@ -219,6 +219,7 @@ struct mali_c55_stats_buffer {
* @MALI_C55_PARAM_BLOCK_AWB_GAINS_AEXP: Auto-white balance gains for AEXP-0 tap
* @MALI_C55_PARAM_MESH_SHADING_CONFIG : Mesh shading tables configuration
* @MALI_C55_PARAM_MESH_SHADING_SELECTION: Mesh shading table selection
+ * @MALI_C55_PARAM_BLOCK_CCM: Colour correction matrix
*/
enum mali_c55_param_block_type {
MALI_C55_PARAM_BLOCK_SENSOR_OFFS,
@@ -232,6 +233,7 @@ enum mali_c55_param_block_type {
MALI_C55_PARAM_BLOCK_AWB_GAINS_AEXP,
MALI_C55_PARAM_MESH_SHADING_CONFIG,
MALI_C55_PARAM_MESH_SHADING_SELECTION,
+ MALI_C55_PARAM_BLOCK_CCM,
};
/**
@@ -757,6 +759,42 @@ struct mali_c55_params_mesh_shading_selection {
__u16 mesh_strength;
};
+/**
+ * struct mali_c55_params_ccm - Coefficients, offsets and gains for the colour
+ * correction matrix
+ *
+ * The colour correction module converts images data from a sensor-specific
+ * colour space to known one.
+ *
+ * Colour correction is applied after demosaicing and each pixel is represented
+ * as a column vector of the three RGB colour channels on which the following
+ * operations take place:
+ * 1) An offset is subtracted from each colour channel
+ * 2) Each colour channel is multiplied by a gain
+ * 3) The pixel column vector is multiplied by the colour correction matrix
+ *
+ * This struct allows users to configure the coefficients for CCM and the
+ * per-channel offsets and gains. The nine matrix coefficients are expressed as
+ * signed Q4.8 Sign/Magnitude fixed-point numbers, the three gain multipliers
+ * are expressed as unsigned Q4.8 fixed-point numbers and the three offsets are
+ * expressed as a 12-bit unsigned integers.
+ *
+ * header.type should be set to MALI_C55_PARAM_BLOCK_CCM from
+ * :c:type:`mali_c55_param_block_type`.
+ *
+ * @header: The Mali-C55 parameters block header
+ * @coeffs: 3x3 color conversion matrix coefficients in sign/magnitude
+ * Q4.8 format
+ * @gains: Gains for red, green and blue channels in unsigned Q4.8 format
+ * @offs: Offsets for red, green and blue channels
+ */
+struct mali_c55_params_ccm {
+ struct v4l2_isp_params_block_header header;
+ __u16 coeffs[3][3];
+ __u16 gains[3];
+ __u16 offs[3];
+};
+
/**
* define MALI_C55_PARAMS_MAX_SIZE - Maximum size of all Mali C55 Parameters
*
@@ -780,6 +818,7 @@ struct mali_c55_params_mesh_shading_selection {
sizeof(struct mali_c55_params_awb_config) + \
sizeof(struct mali_c55_params_awb_gains) + \
sizeof(struct mali_c55_params_mesh_shading_config) + \
- sizeof(struct mali_c55_params_mesh_shading_selection))
+ sizeof(struct mali_c55_params_mesh_shading_selection) + \
+ sizeof(struct mali_c55_params_ccm))
#endif /* __UAPI_MALI_C55_CONFIG_H */
--
2.54.0