Re: [PATCH v9 11/13] media: rppx1: lsc: Add support for lens shade correction

From: Jacopo Mondi

Date: Wed Jun 03 2026 - 10:41:27 EST

Hi Niklas

On Sat, May 16, 2026 at 11:13:18PM +0200, Niklas Söderlund wrote:
> Extend the RPPX1 driver to allow setting the lens shade correction
> 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@xxxxxxxxxxxx>
> Co-developed-by: Jai Luthra <jai.luthra+renesas@xxxxxxxxxxxxxxxx>
> Signed-off-by: Jai Luthra <jai.luthra+renesas@xxxxxxxxxxxxxxxx>
> Co-developed-by: Jacopo Mondi <jacopo.mondi+renesas@xxxxxxxxxxxxxxxx>
> Signed-off-by: Jacopo Mondi <jacopo.mondi+renesas@xxxxxxxxxxxxxxxx>
> ---
> .../platform/dreamchip/rppx1/rpp_module.h | 1 +
> .../platform/dreamchip/rppx1/rpp_params.c | 5 +
> .../platform/dreamchip/rppx1/rppx1_lsc.c | 119 ++++++++++++++++++
> .../uapi/linux/media/dreamchip/rppx1-config.h | 54 +++++++-
> 4 files changed, 178 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/media/platform/dreamchip/rppx1/rpp_module.h b/drivers/media/platform/dreamchip/rppx1/rpp_module.h
> index e039746ac542..48b61b5c35b4 100644
> --- a/drivers/media/platform/dreamchip/rppx1/rpp_module.h
> +++ b/drivers/media/platform/dreamchip/rppx1/rpp_module.h
> @@ -48,6 +48,7 @@ void rpp_module_clrset(struct rpp_module *mod, u32 offset, u32 mask, u32 value);
> union rppx1_params_block {
> struct v4l2_isp_block_header header;
> struct rppx1_bls_params bls;
> + struct rppx1_lsc_params lsc;
> struct rppx1_awbg_params awbg;
> struct rppx1_ccor_params ccor;
> struct rppx1_hist_params hist;
> diff --git a/drivers/media/platform/dreamchip/rppx1/rpp_params.c b/drivers/media/platform/dreamchip/rppx1/rpp_params.c
> index a83d393d0504..8d85d0c7bff1 100644
> --- a/drivers/media/platform/dreamchip/rppx1/rpp_params.c
> +++ b/drivers/media/platform/dreamchip/rppx1/rpp_params.c
> @@ -19,6 +19,8 @@ static const struct v4l2_isp_params_block_type_info
> rppx1_ext_params_blocks_info[] = {
> RPPX1_PARAMS_BLOCK_INFO(BLS_PRE1, bls),
> RPPX1_PARAMS_BLOCK_INFO(BLS_PRE2, bls),
> + RPPX1_PARAMS_BLOCK_INFO(LSC_PRE1, lsc),
> + RPPX1_PARAMS_BLOCK_INFO(LSC_PRE2, lsc),
> RPPX1_PARAMS_BLOCK_INFO(AWBG_PRE1, awbg),
> RPPX1_PARAMS_BLOCK_INFO(AWBG_PRE2, awbg),
> RPPX1_PARAMS_BLOCK_INFO(CCOR_POST, ccor),
> @@ -64,6 +66,9 @@ int rppx1_params(struct rppx1 *rpp, struct vb2_buffer *vb, size_t max_size,
> case RPPX1_PARAMS_BLOCK_TYPE_BLS_PRE1:
> module = &rpp->pre1.bls;
> break;
> + case RPPX1_PARAMS_BLOCK_TYPE_LSC_PRE1:
> + module = &rpp->pre1.lsc;
> + break;
> case RPPX1_PARAMS_BLOCK_TYPE_AWBG_PRE1:
> module = &rpp->pre1.awbg;
> break;
> diff --git a/drivers/media/platform/dreamchip/rppx1/rppx1_lsc.c b/drivers/media/platform/dreamchip/rppx1/rppx1_lsc.c
> index be49fc17ea26..8badeca23e24 100644
> --- a/drivers/media/platform/dreamchip/rppx1/rppx1_lsc.c
> +++ b/drivers/media/platform/dreamchip/rppx1/rppx1_lsc.c
> @@ -55,6 +55,10 @@
> #define LSC_TABLE_SEL_REG 0x00a8
> #define LSC_STATUS_REG 0x00ac
>
> +#define LSC_R_TABLE_DATA_VALUE(v1, v2) (((v1) & 0xfff) | (((v2) & 0xfff) << 12))
> +#define LSC_GRAD_VALUE(v1, v2) (((v1) & 0xfff) | (((v2) & 0xfff) << 16))
> +#define LSC_SIZE_VALUE(v1, v2) (((v1) & 0x1ff) | (((v2) & 0x1ff) << 16))
> +
> static int rppx1_lsc_probe(struct rpp_module *mod)
> {
> /* Version check. */
> @@ -64,6 +68,121 @@ static int rppx1_lsc_probe(struct rpp_module *mod)
> return 0;
> }
>
> +static int
> +rppx1_lsc_fill_params(struct rpp_module *mod,
> + const union rppx1_params_block *block,
> + rppx1_reg_write write, void *priv)
> +{
> + const struct rppx1_lsc_params *cfg = &block->lsc;
> + const __u16 *v;
> +
> + /* Always disable module as it needs be disabled before configuring. */
> + write(priv, mod->base + LSC_CTRL_REG, 0);
> + if (cfg->header.flags & V4L2_ISP_PARAMS_FL_BLOCK_DISABLE)
> + return 0;
> +
> + /*
> + * Program the color correction sectors.
> + *
> + * There are two tables to one can program and switch between. As the
> + * RPPX1 supports preparing a buffer of commands to be applied later
> + * only use table 0. This works as long as the ISP is not used in
> + * inline-mode.
> + *
> + * For inline-mode support using DMA for configuration is not possible
> + * so this is not an issue, but needs to be address if inline-mode
> + * support is added to the driver.
> + */
> +
> + /* Start writing at beginning of table 0. */
> + write(priv, mod->base + LSC_R_TABLE_ADDR_REG, 0);
> + write(priv, mod->base + LSC_GR_TABLE_ADDR_REG, 0);
> + write(priv, mod->base + LSC_B_TABLE_ADDR_REG, 0);
> + write(priv, mod->base + LSC_GB_TABLE_ADDR_REG, 0);
> +
> + /* Program data tables. */
> + for (unsigned int i = 0; i < RPPX1_LSC_SAMPLES_MAX; i++) {
> + const __u16 *r = cfg->r_data[i];
> + const __u16 *gr = cfg->gr_data[i];
> + const __u16 *b = cfg->b_data[i];
> + const __u16 *gb = cfg->gb_data[i];
> + unsigned int j;
> +
> + for (j = 0; j < RPPX1_LSC_SAMPLES_MAX - 1; j += 2) {
> + write(priv, mod->base + LSC_R_TABLE_DATA_REG,
> + LSC_R_TABLE_DATA_VALUE(r[j], r[j + 1]));
> + write(priv, mod->base + LSC_GR_TABLE_DATA_REG,
> + LSC_R_TABLE_DATA_VALUE(gr[j], gr[j + 1]));
> + write(priv, mod->base + LSC_B_TABLE_DATA_REG,
> + LSC_R_TABLE_DATA_VALUE(b[j], b[j + 1]));
> + write(priv, mod->base + LSC_GB_TABLE_DATA_REG,
> + LSC_R_TABLE_DATA_VALUE(gb[j], gb[j + 1]));
> + }
> +
> + write(priv, mod->base + LSC_R_TABLE_DATA_REG,
> + LSC_R_TABLE_DATA_VALUE(r[j], 0));
> + write(priv, mod->base + LSC_GR_TABLE_DATA_REG,
> + LSC_R_TABLE_DATA_VALUE(gr[j], 0));
> + write(priv, mod->base + LSC_B_TABLE_DATA_REG,
> + LSC_R_TABLE_DATA_VALUE(b[j], 0));
> + write(priv, mod->base + LSC_GB_TABLE_DATA_REG,
> + LSC_R_TABLE_DATA_VALUE(gb[j], 0));
> + }
> +
> + /* Activate table 0. */
> + write(priv, mod->base + LSC_TABLE_SEL_REG, 0);
> +
> + /*
> + * Program X- and Y- sizes, and gradients.
> + */
> +
> + v = cfg->x_grad;
> + write(priv, mod->base + LSC_XGRAD_01_REG, LSC_GRAD_VALUE(v[0], v[1]));
> + write(priv, mod->base + LSC_XGRAD_23_REG, LSC_GRAD_VALUE(v[2], v[3]));
> + write(priv, mod->base + LSC_XGRAD_45_REG, LSC_GRAD_VALUE(v[4], v[5]));
> + write(priv, mod->base + LSC_XGRAD_67_REG, LSC_GRAD_VALUE(v[6], v[7]));
> + write(priv, mod->base + LSC_XGRAD_89_REG, LSC_GRAD_VALUE(v[8], v[9]));
> + write(priv, mod->base + LSC_XGRAD_1011_REG, LSC_GRAD_VALUE(v[10], v[11]));
> + write(priv, mod->base + LSC_XGRAD_1213_REG, LSC_GRAD_VALUE(v[12], v[13]));
> + write(priv, mod->base + LSC_XGRAD_1415_REG, LSC_GRAD_VALUE(v[14], v[15]));
> +
> + v = cfg->y_grad;
> + write(priv, mod->base + LSC_YGRAD_01_REG, LSC_GRAD_VALUE(v[0], v[1]));
> + write(priv, mod->base + LSC_YGRAD_23_REG, LSC_GRAD_VALUE(v[2], v[3]));
> + write(priv, mod->base + LSC_YGRAD_45_REG, LSC_GRAD_VALUE(v[4], v[5]));
> + write(priv, mod->base + LSC_YGRAD_67_REG, LSC_GRAD_VALUE(v[6], v[7]));
> + write(priv, mod->base + LSC_YGRAD_89_REG, LSC_GRAD_VALUE(v[8], v[9]));
> + write(priv, mod->base + LSC_YGRAD_1011_REG, LSC_GRAD_VALUE(v[10], v[11]));
> + write(priv, mod->base + LSC_YGRAD_1213_REG, LSC_GRAD_VALUE(v[12], v[13]));
> + write(priv, mod->base + LSC_YGRAD_1415_REG, LSC_GRAD_VALUE(v[14], v[15]));
> +
> + v = cfg->x_sect_size;
> + write(priv, mod->base + LSC_XSIZE_01_REG, LSC_GRAD_VALUE(v[0], v[1]));
> + write(priv, mod->base + LSC_XSIZE_23_REG, LSC_GRAD_VALUE(v[2], v[3]));
> + write(priv, mod->base + LSC_XSIZE_45_REG, LSC_GRAD_VALUE(v[4], v[5]));
> + write(priv, mod->base + LSC_XSIZE_67_REG, LSC_GRAD_VALUE(v[6], v[7]));
> + write(priv, mod->base + LSC_XSIZE_89_REG, LSC_GRAD_VALUE(v[8], v[9]));
> + write(priv, mod->base + LSC_XSIZE_1011_REG, LSC_GRAD_VALUE(v[10], v[11]));
> + write(priv, mod->base + LSC_XSIZE_1213_REG, LSC_GRAD_VALUE(v[12], v[13]));
> + write(priv, mod->base + LSC_XSIZE_1415_REG, LSC_GRAD_VALUE(v[14], v[15]));
> +
> + v = cfg->y_sect_size;
> + write(priv, mod->base + LSC_YSIZE_01_REG, LSC_GRAD_VALUE(v[0], v[1]));
> + write(priv, mod->base + LSC_YSIZE_23_REG, LSC_GRAD_VALUE(v[2], v[3]));
> + write(priv, mod->base + LSC_YSIZE_45_REG, LSC_GRAD_VALUE(v[4], v[5]));
> + write(priv, mod->base + LSC_YSIZE_67_REG, LSC_GRAD_VALUE(v[6], v[7]));
> + write(priv, mod->base + LSC_YSIZE_89_REG, LSC_GRAD_VALUE(v[8], v[9]));
> + write(priv, mod->base + LSC_YSIZE_1011_REG, LSC_GRAD_VALUE(v[10], v[11]));
> + write(priv, mod->base + LSC_YSIZE_1213_REG, LSC_GRAD_VALUE(v[12], v[13]));
> + write(priv, mod->base + LSC_YSIZE_1415_REG, LSC_GRAD_VALUE(v[14], v[15]));
> +
> + /* Enable module. */
> + write(priv, mod->base + LSC_CTRL_REG, LSC_CTRL_LSC_EN);
> +
> + return 0;
> +}
> +
> const struct rpp_module_ops rppx1_lsc_ops = {
> .probe = rppx1_lsc_probe,
> + .fill_params = rppx1_lsc_fill_params,
> };
> diff --git a/include/uapi/linux/media/dreamchip/rppx1-config.h b/include/uapi/linux/media/dreamchip/rppx1-config.h
> index 97c333c72d56..7ebcc00ace04 100644
> --- a/include/uapi/linux/media/dreamchip/rppx1-config.h
> +++ b/include/uapi/linux/media/dreamchip/rppx1-config.h
> @@ -89,6 +89,8 @@ enum rppx1_meas_chan {
> * @RPPX1_PARAMS_BLOCK_TYPE_BLS_PRE1: PRE1 pipe Black Level Subtraction
> * @RPPX1_PARAMS_BLOCK_TYPE_BLS_PRE2: PRE2 pipe Black Level Subtraction
> * @RPPX1_PARAMS_BLOCK_TYPE_CCOR_POST: POST pipe Color Correction
> + * @RPPX1_PARAMS_BLOCK_TYPE_LSC_PRE1: PRE1 pipe Lens Shading Correction
> + * @RPPX1_PARAMS_BLOCK_TYPE_LSC_PRE2: PRE2 Lens Shading Correction

missing 'pipe' after PRE2. Sorry, my mistake probably

Reviewed-by: Jacopo Mondi <jacopo.mondi@xxxxxxxxxxxxxxxx>

Thanks
j

> */
> enum rppx1_params_block_type {
> RPPX1_PARAMS_BLOCK_TYPE_WBMEAS_POST,
> @@ -103,6 +105,8 @@ enum rppx1_params_block_type {
> RPPX1_PARAMS_BLOCK_TYPE_BLS_PRE1,
> RPPX1_PARAMS_BLOCK_TYPE_BLS_PRE2,
> RPPX1_PARAMS_BLOCK_TYPE_CCOR_POST,
> + RPPX1_PARAMS_BLOCK_TYPE_LSC_PRE1,
> + RPPX1_PARAMS_BLOCK_TYPE_LSC_PRE2,
> };
>
> /**
> @@ -447,6 +451,52 @@ struct rppx1_ccor_params {
> __u32 offset[3];
> };
>
> +/* Lens Shade Correction */
> +#define RPPX1_LSC_SAMPLES_MAX 17
> +#define RPPX1_LSC_NUM_SECTORS 16
> +
> +/**
> + * struct rppx1_lsc_params - Lens Shading Correction configuration
> + *
> + * The RPP-X1 Lens shading correction module is available on the PRE1 and PRE2
> + * pre-fusion pipes. Userspace selects which pipe to operate by setting the
> + * @header.type field to RPPX1_PARAMS_BLOCK_TYPE_LSC_PRE1 or
> + * RPPX1_PARAMS_BLOCK_TYPE_LSC_PRE2.
> + *
> + * The module applies per-color channel correction factors @r_data, @gr_data,
> + * @gb_data and @b_data as a 16x16 grid mapped on the image. The size of each
> + * grid segment is expressed by the @x_sect_size and @y_sect_size arrays. Each
> + * segment shall be at least 8 pixels in size and the sum of all horizontal
> + * segments @x_sect_size shall match the input frame size width.
> + *
> + * The correction factors values are expressed as unsigned Q2.10 integers
> + * ranging from 1 to 3.999.
> + *
> + * Pre-calculated interpolation factors shall be provided in the @x_grad
> + * and @y_grad fields, expressed as 12 bits integer values.
> + *
> + * @header: block header (type = RPPX1_PARAMS_BLOCK_TYPE_LSC)
> + * @r_data: correction factors for the red channel in Q2.10 format
> + * @gr_data: correction factors for the green (red) channel in Q2.10 format
> + * @gb_data: correction factors for the green (blue) channel in Q2.10 format
> + * @b_data: correction factors for the blue channel in Q2.10 format
> + * @x_grad: Interpolation gradients for each horizontal sector (12 bits)
> + * @y_grad: Interpolation gradients for each vertical sector (12 bits)
> + * @x_sect_size: Horizontal sectors sizes
> + * @y_sect_size: Vertical sectors sizes
> + */
> +struct rppx1_lsc_params {
> + struct v4l2_isp_params_block_header header;
> + __u16 r_data[RPPX1_LSC_SAMPLES_MAX][RPPX1_LSC_SAMPLES_MAX];
> + __u16 gr_data[RPPX1_LSC_SAMPLES_MAX][RPPX1_LSC_SAMPLES_MAX];
> + __u16 gb_data[RPPX1_LSC_SAMPLES_MAX][RPPX1_LSC_SAMPLES_MAX];
> + __u16 b_data[RPPX1_LSC_SAMPLES_MAX][RPPX1_LSC_SAMPLES_MAX];
> + __u16 x_grad[RPPX1_LSC_NUM_SECTORS];
> + __u16 y_grad[RPPX1_LSC_NUM_SECTORS];
> + __u16 x_sect_size[RPPX1_LSC_NUM_SECTORS];
> + __u16 y_sect_size[RPPX1_LSC_NUM_SECTORS];
> +};
> +
> /**
> * RPPX1_PARAMS_MAX_SIZE - Maximum size of all RPP-X1 parameter blocks
> *
> @@ -465,7 +515,9 @@ struct rppx1_ccor_params {
> sizeof(struct rppx1_hist_params) + \
> sizeof(struct rppx1_bls_params) + \
> sizeof(struct rppx1_bls_params) + \
> - sizeof(struct rppx1_ccor_params))
> + sizeof(struct rppx1_ccor_params) + \
> + sizeof(struct rppx1_lsc_params) + \
> + sizeof(struct rppx1_lsc_params))
>
> /* ---------------------------------------------------------------------------
> * Statistics Structures
> --
> 2.54.0
>