STRUCT RPPX1_LIN_PARAMS(9)

💖 struct rppx1_lin_params(9) 💖

okay so bestie, welcome to the Kernel API Manual ✨ — this is the page for struct rppx1_lin_params, aka the linearization (sensor de-gamma) config, and honestly? it's giving "small struct, big responsibilities" 👑

---

🌸 NAME 🌸

struct rppx1_lin_params — the linearization (sensor de-gamma) configuration 🎀

---

✨ SYNOPSIS ✨

struct rppx1_lin_params {
    struct v4l2_isp_params_block_header header;
    __u32 curve_r[RPPX1_LIN_DEGAMMA_CURVE_NUM];
    __u32 curve_g[RPPX1_LIN_DEGAMMA_CURVE_NUM];
    __u32 curve_b[RPPX1_LIN_DEGAMMA_CURVE_NUM];
    __u8 dx[RPPX1_LIN_SAMPLE_POINTS_NUM];
    __u32 reserved;
 };

no cap, that's the whole vibe right there 🫶

---

🦋 Members 🦋

• header — the block header, and its type is literally either RPPX1_PARAMS_BLOCK_TYPE_LIN_PRE1 or RPPX1_PARAMS_BLOCK_TYPE_LIN_PRE2 💅 that's how you tell it which pipe you're on
• curve_r — the de-gamma linearization curve for the red channel 🍓
• curve_g — the de-gamma linearization curve for the green channel 🌿
• curve_b — the de-gamma linearization curve for the blue channel 🦋
• dx — the input sampling points 📍
• reserved — padding, it's just there chillin' (don't touch it, bestie) 🙈

---

🌈 Description 🌈

so the RPP-X1 linearization module is available on the PRE1 and PRE2 pre-fusion pipes 🔥 and userspace gets to pick which pipe it's operating on by setting the header.type field to RPPX1_PARAMS_BLOCK_TYPE_LIN_PRE1 or RPPX1_PARAMS_BLOCK_TYPE_LIN_PRE2 — main character energy, you choose 👑

The LIN module applies the per-color channel de-gamma linearization curves curve_r, curve_g and curve_b, all defined on the input sampling points dx. teamwork, fr fr 🤝

Now here's the part where the bit-depth match matters, so lock in 🧠✨:

• For the PRE1 pipe, the de-gamma curve values are 24-bits 💖
• For the PRE2 pipe, the de-gamma curve values are 12-bits 🎀
• For the PRE1 pipe, the de-gamma module sampling points dx values are in the range [0, 15] (4 bits) 🌸
• For the PRE2 pipe, the de-gamma module sampling points values are in the range [0, 7] (3 bits) 🦋

⚠️ ok so this is the important one: userspace is expected to provide the curve values and the sampling points with a bit-depth matching the one of the pipe in use. mismatch = not the move, bestie 😭

---

💜 SEE ALSO 💜

Kernel file ./include/uapi/linux/media/dreamchip/rppx1-config.h — plus the whole friend group 👯‍♀️:

• struct rppx1_window(9)
• enum rppx1_meas_chan(9)
• enum rppx1_params_block_type(9)
• enum rppx1_wbmeas_mode(9)
• struct rppx1_wbmeas_params(9)
• struct rppx1_awbg_params(9)
• enum rppx1_exm_mode(9)
• struct rppx1_exm_params(9)
• enum rppx1_hist_mode(9)
• struct rppx1_hist_params(9)
• struct rppx1_bls_fixed(9)
• enum rppx1_bls_mode(9)
• enum rppx1_bls_win_en(9)
• struct rppx1_bls_params(9)
• struct rppx1_ccor_params(9)
• struct rppx1_lsc_params(9)
• enum rppx1_ga_seg_mode(9)
• struct rppx1_ga_params(9)
• RPPX1_PARAMS_MAX_SIZE(9)
• enum rppx1_stats_block_type(9)
• struct rppx1_wbmeas_stats(9)
• struct rppx1_exm_stats(9)
• struct rppx1_hist_stats(9)
• RPPX1_STATS_MAX_SIZE(9)

---

and that's the page!! 💅 this one lives at ./include/uapi/linux/media/dre... and it's stamped October 2026 — so go off, read the headers, slay your de-gamma curves, and remember: match that bit-depth bestie, iykyk 💖✨🎀🫶