[v8 05/14] media: rppx1: awbg: Add support for white balance gain settings

Niklas Söderlund
2026-05-04T01:09:05Z

Extend the RPPX1 driver to allow setting the white balance gain
configuration parameters. It uses the RPPX1 framework for parameters and
its writer abstraction to allow the user to control how, and when,
configuration is applied to the RPPX1.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Co-developed-by: Jai Luthra <jai.luthra+renesas@ideasonboard.com>
Signed-off-by: Jai Luthra <jai.luthra+renesas@ideasonboard.com>
---
.../platform/dreamchip/rppx1/rpp_module.h | 1 +
.../platform/dreamchip/rppx1/rpp_params.c | 5 +++
.../platform/dreamchip/rppx1/rppx1_awbg.c | 32 +++++++++++++++
.../uapi/linux/media/dreamchip/rppx1-config.h | 40 ++++++++++++++++++-
4 files changed, 77 insertions(+), 1 deletion(-)

diff --git a/drivers/media/platform/dreamchip/rppx1/rpp_module.h b/drivers/media/platform/dreamchip/rppx1/rpp_module.h
index 85fb23174e57..76adfe95777d 100644
--- a/drivers/media/platform/dreamchip/rppx1/rpp_module.h
+++ b/drivers/media/platform/dreamchip/rppx1/rpp_module.h
@@ -85,6 +85,7 @@ void rpp_module_clrset(struct rpp_module *mod, u32 offset, u32 mask, u32 value);

union rppx1_params_block {
struct v4l2_isp_params_block_header header;
+ struct rppx1_awbg_params awbg;
struct rppx1_wbmeas_params wbmeas;
};

diff --git a/drivers/media/platform/dreamchip/rppx1/rpp_params.c b/drivers/media/platform/dreamchip/rppx1/rpp_params.c
index 1262350d2190..0ac9bf1f9a65 100644
--- a/drivers/media/platform/dreamchip/rppx1/rpp_params.c
+++ b/drivers/media/platform/dreamchip/rppx1/rpp_params.c
@@ -16,6 +16,8 @@

static const struct v4l2_isp_block_type_info
rppx1_ext_params_blocks_info[] = {
+ RPPX1_PARAMS_BLOCK_INFO(AWBG_PRE1, awbg),
+ RPPX1_PARAMS_BLOCK_INFO(AWBG_PRE2, awbg),
RPPX1_PARAMS_BLOCK_INFO(WBMEAS_POST, wbmeas),
};

@@ -51,6 +53,9 @@ int rppx1_params(struct rppx1 *rpp, struct vb2_buffer *vb, size_t max_size,
block_offset += block->header.size;

switch (block->header.type) {
+ case RPPX1_PARAMS_BLOCK_TYPE_AWBG_PRE1:
+ module = &rpp->pre1.awbg;
+ break;
case RPPX1_PARAMS_BLOCK_TYPE_WBMEAS_POST:
module = &rpp->post.wbmeas;
break;
diff --git a/drivers/media/platform/dreamchip/rppx1/rppx1_awbg.c b/drivers/media/platform/dreamchip/rppx1/rppx1_awbg.c
index e20bc369ca8c..dcccb1a2e28f 100644
--- a/drivers/media/platform/dreamchip/rppx1/rppx1_awbg.c
+++ b/drivers/media/platform/dreamchip/rppx1/rppx1_awbg.c
@@ -25,6 +25,38 @@ static int rppx1_awbg_probe(struct rpp_module *mod)
return 0;
}

+static int
+rppx1_awbg_fill_params(struct rpp_module *mod,
+ const union rppx1_params_block *block,
+ rppx1_reg_write write, void *priv)
+{
+ const struct rppx1_awbg_params *cfg = &block->awbg;
+
+ /* If the modules is disabled, simply bypass it. */
+ if (cfg->header.flags & V4L2_ISP_PARAMS_FL_BLOCK_DISABLE) {
+ write(priv, mod->base + AWB_ENABLE_REG, 0);
+ return 0;
+ }
+
+ /*
+ * RPP gains are 18-bit with 12 bit fractional part and 0x1000 = 1.0,
+ * giving a possible range of 0.0 to 64.0. NOTE: RPP documentation is
+ * contradictory this is the register definition, the function
+ * description states 0x400 = 1.0 AND 18-bit with 12 fractional bits,
+ * which is not possible...
+ */
+
+ write(priv, mod->base + AWB_GAIN_GR_REG, cfg->gain_green_r);
+ write(priv, mod->base + AWB_GAIN_GB_REG, cfg->gain_green_b);
+ write(priv, mod->base + AWB_GAIN_R_REG, cfg->gain_red);
+ write(priv, mod->base + AWB_GAIN_B_REG, cfg->gain_blue);
+
+ write(priv, mod->base + AWB_ENABLE_REG, AWB_ENABLE_AWB_GAIN_EN);
+
+ return 0;
+}
+
const struct rpp_module_ops rppx1_awbg_ops = {
.probe = rppx1_awbg_probe,
+ .fill_params = rppx1_awbg_fill_params,
};
diff --git a/include/uapi/linux/media/dreamchip/rppx1-config.h b/include/uapi/linux/media/dreamchip/rppx1-config.h
index 1d76a85164c8..e96308b4e308 100644
--- a/include/uapi/linux/media/dreamchip/rppx1-config.h
+++ b/include/uapi/linux/media/dreamchip/rppx1-config.h
@@ -46,9 +46,15 @@ struct rppx1_window {
* NOTE: Only append to the enumeration as the numbers are uAPI.
*
* @RPPX1_PARAMS_BLOCK_TYPE_WBMEAS_POST: AWB Measurement Configuration
+ * @RPPX1_PARAMS_BLOCK_TYPE_AWBG_PRE1: PRE1 pipe White Balance Gains
+ * @RPPX1_PARAMS_BLOCK_TYPE_AWBG_PRE2: PRE2 White Balance Gains
+ * @RPPX1_PARAMS_BLOCK_TYPE_AWBG_POST: MAIN_POST White Balance Gains
*/
enum rppx1_params_block_type {
RPPX1_PARAMS_BLOCK_TYPE_WBMEAS_POST,
+ RPPX1_PARAMS_BLOCK_TYPE_AWBG_PRE1,
+ RPPX1_PARAMS_BLOCK_TYPE_AWBG_PRE2,
+ RPPX1_PARAMS_BLOCK_TYPE_AWBG_POST,
};

/**
@@ -107,6 +113,35 @@ struct rppx1_wbmeas_params {
__u32 ccor_offs[3];
};

+/**
+ * struct rppx1_awbg_params - WB gain configuration
+ *
+ * The RPP-X1 White Balance Gain module is available in the PRE1 and PRE2
+ * pre-fusion pipes and in the MAIN_POST post-fusion pipe. Userspace selects
+ * which pipe to operate by setting the @header.type field to
+ * RPPX1_PARAMS_BLOCK_TYPE_AWBG_PRE1, RPPX1_PARAMS_BLOCK_TYPE_AWBG_PRE2
+ * or RPPX1_PARAMS_BLOCK_TYPE_AWBG_POST.
+ *
+ * The White Balance module allows to specify per-color channel gains, expressed
+ * as unsigned fixed-point values as 18 bits unsigned integers in Q6.12 format
+ * with a maximum of 63.999.
+ *
+ * @header: block header (type = RPPX1_PARAMS_BLOCK_TYPE_AWBG_PRE1 or
+ * type = RPPX1_PARAMS_BLOCK_TYPE_AWBG_PRE2 or
+ * type = RPPX1_PARAMS_BLOCK_TYPE_AWBG_POST)
+ * @gain_red: gain for red component, 18-bit (unsigned Q6.12)
+ * @gain_green_r: gain for green component in red lines, 18-bit (unsigned Q6.12)
+ * @gain_blue: gain for blue component, 18-bit (unsigned Q6.12)
+ * @gain_green_b: gain for green component in blue lines, 18-bit (unsigned Q6.12)
+ */
+struct rppx1_awbg_params {
+ struct v4l2_isp_params_block_header header;
+ __u32 gain_red;
+ __u32 gain_green_r;
+ __u32 gain_blue;
+ __u32 gain_green_b;
+};
+
/**
* RPPX1_PARAMS_MAX_SIZE - Maximum size of all RPP-X1 parameter blocks
*
@@ -114,7 +149,10 @@ struct rppx1_wbmeas_params {
* multiple pipes.
*/
#define RPPX1_PARAMS_MAX_SIZE \
- (sizeof(struct rppx1_wbmeas_params))
+ (sizeof(struct rppx1_wbmeas_params) + \
+ sizeof(struct rppx1_awbg_params) + \
+ sizeof(struct rppx1_awbg_params) + \
+ sizeof(struct rppx1_awbg_params))

/* ---------------------------------------------------------------------------
* Statistics Structures
--
2.54.0