From nobody Sat Feb 7 05:52:14 2026 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BA0531FECBA; Sun, 19 Oct 2025 10:06:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760868398; cv=none; b=FUn3hTx2IZjNBA6Rf7/1ASWBBYOwDYj8ivJbyBVDcVXyLXt3YEq6SyEWxQyumYgUx3SMPc2g4kVCg6klVAXhzUHhlLCHSS9z+q4ukIX3rB/1+1X9djn8tzYg92Im8BU/VlX1O2i8IhYRa89PS20HHDaVjiHa05zucOL9c0t2QUg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760868398; c=relaxed/simple; bh=XQQgofJudbriAeCJs0tZgb1MfSx1gi2mWWsOK6rlBek=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=kl9k1+XpY198ASWldFDh7RsIGo2rAgjKgDZOgeworCWVw4dDk6rdt4dk6M4mIqKBPuB0d5efU6MGxjRD6CVOIyQ2Qkm1ldIhZoSLhSl6jcGBRzXjPzlhQnqSKHIrd9GAZoYYRxSXHCOFPDgBCN7fo8LbmETfq0m1V5g+/T7xBHs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=I7T12PEc; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="I7T12PEc" Received: by smtp.kernel.org (Postfix) with ESMTPS id 4B816C4CEE7; Sun, 19 Oct 2025 10:06:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1760868397; bh=XQQgofJudbriAeCJs0tZgb1MfSx1gi2mWWsOK6rlBek=; h=From:Date:Subject:To:Cc:Reply-To:From; b=I7T12PEc583v9tT9+U1j/s/Fp7xV18BWGRl8Pt/twrFFS/Rd9ptAbfBVp30yfJ8pn ttTW22XhLR9cTBv1IYEYJKMILT3YZbMdvlI/1SpXvCNA+engLgvG4tWpNEBMUxYDHI DrvleTx8gcTx+gZ7kv5fY0IIzDXOrWn78qI0BD4yrTQWBnd/qFzv6UGHKkCSn2//jL JpJJKoSy+l8+w5/yQiFB4WEaluQJ5dWK6xZSJcVNTnc2ObNGCKN2r+I2zvW75F9qjY +cYRise34g9bPTixqsR2JqD448r/XCOflA5tMh+mCRo3AGC0PXYynXaN/Z7oLtFEZt CWavVkwRWIX8w== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3C216CCD184; Sun, 19 Oct 2025 10:06:37 +0000 (UTC) From: Federico Amedeo Izzo via B4 Relay Date: Sun, 19 Oct 2025 12:06:32 +0200 Subject: [PATCH v3] drm/msm/dpu: Add DSPP GC driver to provide GAMMA_LUT DRM property Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20251019-dpu-add-dspp-gc-driver-v3-1-840491934e56@izzo.pro> X-B4-Tracking: v=1; b=H4sIACe49GgC/3XNQQ6CMBCF4auQrh3TFrHgynsYF9AZYTa2abVRC He3kJiwYfm/ZL6ZRKTAFMWlmESgxJHdM0d5KIQd2mdPwJhbaKkrJZUB9G9oEQGj99BbwMCJAtg KlZV1R8ZIkY99oAd/Vvh2zz1wfLnwXf8ktax/st4jkwIFhLI8N1qddKWvPI7u6IMTi5j0Vml2F Z2VUtradqaxnTIbZZ7nH0h6BOEBAQAA X-Change-ID: 20251017-dpu-add-dspp-gc-driver-c5d1c08be770 To: Rob Clark , Dmitry Baryshkov , Abhinav Kumar , Jessica Zhang , Sean Paul , Marijn Suijten , David Airlie , Simona Vetter Cc: linux-arm-msm@vger.kernel.org, dri-devel@lists.freedesktop.org, freedreno@lists.freedesktop.org, linux-kernel@vger.kernel.org, phone-devel@vger.kernel.org, ~postmarketos/upstreaming@lists.sr.ht, nicola@corna.info, David Heidelberg , =?utf-8?q?Guido_G=C3=BCnther?= , Federico Amedeo Izzo X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=ed25519-sha256; t=1760868393; l=13130; i=federico@izzo.pro; s=20251017; h=from:subject:message-id; bh=sGyLQADlCgm+S2ot+5F46BMiy9lWRv+mg/a7BnD79xM=; b=ex//RqaFYyymVQ+b3MpmlkTkJj+sDAmDZcfor7VDvw84VMgCZvKjyGC6bBAOZVH+DrfoF+YwX +4PNpal81cDDxlPXSLygrPA4ovcAYnXkB0LBpT38Gymh9OzewAhDuvc X-Developer-Key: i=federico@izzo.pro; a=ed25519; pk=XfmNfpH48k8jLbId5NKrp0yoKoFb/uLjr97qIxBImBw= X-Endpoint-Received: by B4 Relay for federico@izzo.pro/20251017 with auth_id=544 X-Original-From: Federico Amedeo Izzo Reply-To: federico@izzo.pro From: Federico Amedeo Izzo Add support for DSPP GC block in DPU driver for Qualcomm SoCs. Expose the GAMMA_LUT DRM property, which is needed to enable night light and basic screen color calibration. I used LineageOS downstream kernel as a reference and found the LUT format by trial-and-error on OnePlus 6. Tested on oneplus-enchilada (sdm845-mainline 6.16-dev) and xiaomi-tissot (msm8953-mainline 6.12/main). Tested-by: David Heidelberg # Pixel 3 (next-20251018) Tested-by: Guido G=C3=BCnther # on sdm845-shift-axolotl Signed-off-by: Federico Amedeo Izzo Reviewed-by: Dmitry Baryshkov Tested-by: Steev Klimaszewski --- DRM GAMMA_LUT support was missing on sdm845 and other Qualcomm SoCs using DPU for CRTC. This is needed in userspace to enable features like Night Light or basic color calibration. I wrote this driver to enable Night Light on OnePlus 6, and after the driver was working I found out it applies to the 29 different Qualcomm SoCs that use the DPU display engine, including X1E for laptops. I used the LineageOS downstream kernel as reference and found the correct=20 LUT format by trial-and-error on OnePlus 6. This was my first Linux driver and it's been a great learning experience. The patch was reviewed by postmarketOS contributors here:=20 https://gitlab.com/sdm845-mainline/linux/-/merge_requests/137 During review the patch was tested successfully on hamoa (X1E). --- Changes in v3: - Remove memset() after kzalloc() in dpu_crtc.c - Simplify error messages in dpu_crtc.c and dpu_hw_dspp.c - Use 0 for DPU_REG_WRITE() instead of reg =3D 0 in dpu_hw_dspp.c - Link to v2: https://lore.kernel.org/r/20251019-dpu-add-dspp-gc-driver-v2-= 1-30c8cb79cb17@izzo.pro Changes in v2: - Fix gc register .len and .version in dpu_hw_catalog.c - Apply coding style suggestions - Link to v1: https://lore.kernel.org/r/20251018-dpu-add-dspp-gc-driver-v1-= 1-ed0369214252@izzo.pro --- drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c | 86 +++++++++++++++++++++-= ---- drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.c | 4 ++ drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h | 4 ++ drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.c | 3 + drivers/gpu/drm/msm/disp/dpu1/dpu_hw_dspp.c | 54 ++++++++++++++++ drivers/gpu/drm/msm/disp/dpu1/dpu_hw_dspp.h | 26 ++++++++ 6 files changed, 163 insertions(+), 14 deletions(-) diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c b/drivers/gpu/drm/msm= /disp/dpu1/dpu_crtc.c index 4b970a59deaf..94445144971e 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c @@ -812,12 +812,42 @@ static void _dpu_crtc_get_pcc_coeff(struct drm_crtc_s= tate *state, cfg->b.b =3D CONVERT_S3_15(ctm->matrix[8]); } =20 +static void _dpu_crtc_get_gc_lut(struct drm_crtc_state *state, + struct dpu_hw_gc_lut *gc_lut) +{ + struct drm_color_lut *lut; + int i; + u32 val_even, val_odd; + + lut =3D (struct drm_color_lut *)state->gamma_lut->data; + + if (!lut) + return; + + /* Pack 1024 10-bit entries in 512 32-bit registers */ + for (i =3D 0; i < PGC_TBL_LEN; i++) { + val_even =3D drm_color_lut_extract(lut[i * 2].green, 10); + val_odd =3D drm_color_lut_extract(lut[i * 2 + 1].green, 10); + gc_lut->c0[i] =3D val_even | (val_odd << 16); + val_even =3D drm_color_lut_extract(lut[i * 2].blue, 10); + val_odd =3D drm_color_lut_extract(lut[i * 2 + 1].blue, 10); + gc_lut->c1[i] =3D val_even | (val_odd << 16); + val_even =3D drm_color_lut_extract(lut[i * 2].red, 10); + val_odd =3D drm_color_lut_extract(lut[i * 2 + 1].red, 10); + gc_lut->c2[i] =3D val_even | (val_odd << 16); + } + + /* Disable 8-bit rounding mode */ + gc_lut->flags =3D 0; +} + static void _dpu_crtc_setup_cp_blocks(struct drm_crtc *crtc) { struct drm_crtc_state *state =3D crtc->state; struct dpu_crtc_state *cstate =3D to_dpu_crtc_state(crtc->state); struct dpu_crtc_mixer *mixer =3D cstate->mixers; struct dpu_hw_pcc_cfg cfg; + struct dpu_hw_gc_lut *gc_lut; struct dpu_hw_ctl *ctl; struct dpu_hw_dspp *dspp; int i; @@ -830,19 +860,38 @@ static void _dpu_crtc_setup_cp_blocks(struct drm_crtc= *crtc) ctl =3D mixer[i].lm_ctl; dspp =3D mixer[i].hw_dspp; =20 - if (!dspp || !dspp->ops.setup_pcc) + if (!dspp) continue; =20 - if (!state->ctm) { - dspp->ops.setup_pcc(dspp, NULL); - } else { - _dpu_crtc_get_pcc_coeff(state, &cfg); - dspp->ops.setup_pcc(dspp, &cfg); + if (dspp->ops.setup_pcc) { + if (!state->ctm) { + dspp->ops.setup_pcc(dspp, NULL); + } else { + _dpu_crtc_get_pcc_coeff(state, &cfg); + dspp->ops.setup_pcc(dspp, &cfg); + } + + /* stage config flush mask */ + ctl->ops.update_pending_flush_dspp(ctl, + mixer[i].hw_dspp->idx, DPU_DSPP_PCC); } =20 - /* stage config flush mask */ - ctl->ops.update_pending_flush_dspp(ctl, - mixer[i].hw_dspp->idx, DPU_DSPP_PCC); + if (dspp->ops.setup_gc) { + if (!state->gamma_lut) { + dspp->ops.setup_gc(dspp, NULL); + } else { + gc_lut =3D kzalloc(sizeof(*gc_lut), GFP_KERNEL); + if (!gc_lut) + continue; + _dpu_crtc_get_gc_lut(state, gc_lut); + dspp->ops.setup_gc(dspp, gc_lut); + kfree(gc_lut); + } + + /* stage config flush mask */ + ctl->ops.update_pending_flush_dspp(ctl, + mixer[i].hw_dspp->idx, DPU_DSPP_GC); + } } } =20 @@ -1340,7 +1389,7 @@ static struct msm_display_topology dpu_crtc_get_topol= ogy( * * If DSC is enabled, use 2 LMs for 2:2:1 topology * - * Add dspps to the reservation requirements if ctm is requested + * Add dspps to the reservation requirements if ctm or gamma_lut are requ= ested * * Only hardcode num_lm to 2 for cases where num_intf =3D=3D 2 and CWB is= not * enabled. This is because in cases where CWB is enabled, num_intf will @@ -1359,7 +1408,7 @@ static struct msm_display_topology dpu_crtc_get_topol= ogy( else topology.num_lm =3D 1; =20 - if (crtc_state->ctm) + if (crtc_state->ctm || crtc_state->gamma_lut) topology.num_dspp =3D topology.num_lm; =20 return topology; @@ -1471,7 +1520,8 @@ static int dpu_crtc_atomic_check(struct drm_crtc *crt= c, bool needs_dirtyfb =3D dpu_crtc_needs_dirtyfb(crtc_state); =20 /* don't reallocate resources if only ACTIVE has beeen changed */ - if (crtc_state->mode_changed || crtc_state->connectors_changed) { + if (crtc_state->mode_changed || crtc_state->connectors_changed || + crtc_state->color_mgmt_changed) { rc =3D dpu_crtc_assign_resources(crtc, crtc_state); if (rc < 0) return rc; @@ -1831,8 +1881,16 @@ struct drm_crtc *dpu_crtc_init(struct drm_device *de= v, struct drm_plane *plane, =20 drm_crtc_helper_add(crtc, &dpu_crtc_helper_funcs); =20 - if (dpu_kms->catalog->dspp_count) - drm_crtc_enable_color_mgmt(crtc, 0, true, 0); + if (dpu_kms->catalog->dspp_count) { + const struct dpu_dspp_cfg *dspp =3D &dpu_kms->catalog->dspp[0]; + + if (dspp->sblk->gc.base) { + drm_mode_crtc_set_gamma_size(crtc, DPU_GAMMA_LUT_SIZE); + drm_crtc_enable_color_mgmt(crtc, 0, true, DPU_GAMMA_LUT_SIZE); + } else { + drm_crtc_enable_color_mgmt(crtc, 0, true, 0); + } + } =20 /* save user friendly CRTC name for later */ snprintf(dpu_crtc->name, DPU_CRTC_NAME_SIZE, "crtc%u", crtc->base.id); diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.c b/drivers/gpu/d= rm/msm/disp/dpu1/dpu_hw_catalog.c index 6641455c4ec6..8bcfab70f023 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.c +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.c @@ -382,11 +382,15 @@ static const struct dpu_lm_sub_blks qcm2290_lm_sblk = =3D { static const struct dpu_dspp_sub_blks msm8998_dspp_sblk =3D { .pcc =3D {.name =3D "pcc", .base =3D 0x1700, .len =3D 0x90, .version =3D 0x10007}, + .gc =3D {.name =3D "gc", .base =3D 0x17c0, + .len =3D 0x40, .version =3D 0x10007}, }; =20 static const struct dpu_dspp_sub_blks sdm845_dspp_sblk =3D { .pcc =3D {.name =3D "pcc", .base =3D 0x1700, .len =3D 0x90, .version =3D 0x40000}, + .gc =3D {.name =3D "gc", .base =3D 0x17c0, + .len =3D 0x40, .version =3D 0x10008}, }; =20 static const struct dpu_dspp_sub_blks sm8750_dspp_sblk =3D { diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h b/drivers/gpu/d= rm/msm/disp/dpu1/dpu_hw_catalog.h index f0768f54e9b3..3ea67c1cf5c0 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h @@ -77,9 +77,11 @@ enum { /** * DSPP sub-blocks * @DPU_DSPP_PCC Panel color correction block + * @DPU_DSPP_GC Gamma correction block */ enum { DPU_DSPP_PCC =3D 0x1, + DPU_DSPP_GC, DPU_DSPP_MAX }; =20 @@ -314,9 +316,11 @@ struct dpu_lm_sub_blks { /** * struct dpu_dspp_sub_blks: Information of DSPP block * @pcc: pixel color correction block + * @gc: gamma correction block */ struct dpu_dspp_sub_blks { struct dpu_pp_blk pcc; + struct dpu_pp_blk gc; }; =20 struct dpu_pingpong_sub_blks { diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.c b/drivers/gpu/drm/m= sm/disp/dpu1/dpu_hw_ctl.c index ac834db2e4c1..36a497f1d6c1 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.c +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.c @@ -399,6 +399,9 @@ static void dpu_hw_ctl_update_pending_flush_dspp_sub_bl= ocks( case DPU_DSPP_PCC: ctx->pending_dspp_flush_mask[dspp - DSPP_0] |=3D BIT(4); break; + case DPU_DSPP_GC: + ctx->pending_dspp_flush_mask[dspp - DSPP_0] |=3D BIT(5); + break; default: return; } diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_dspp.c b/drivers/gpu/drm/= msm/disp/dpu1/dpu_hw_dspp.c index 54b20faa0b69..188ee0af2c90 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_dspp.c +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_dspp.c @@ -24,6 +24,18 @@ #define PCC_BLUE_G_OFF 0x24 #define PCC_BLUE_B_OFF 0x30 =20 +/* DSPP_GC */ +#define GC_EN BIT(0) +#define GC_DIS 0 +#define GC_8B_ROUND_EN BIT(1) +#define GC_LUT_SWAP_OFF 0x1c +#define GC_C0_OFF 0x4 +#define GC_C1_OFF 0xc +#define GC_C2_OFF 0x14 +#define GC_C0_INDEX_OFF 0x8 +#define GC_C1_INDEX_OFF 0x10 +#define GC_C2_INDEX_OFF 0x18 + static void dpu_setup_dspp_pcc(struct dpu_hw_dspp *ctx, struct dpu_hw_pcc_cfg *cfg) { @@ -63,6 +75,46 @@ static void dpu_setup_dspp_pcc(struct dpu_hw_dspp *ctx, DPU_REG_WRITE(&ctx->hw, base, PCC_EN); } =20 +static void dpu_setup_dspp_gc(struct dpu_hw_dspp *ctx, + struct dpu_hw_gc_lut *gc_lut) +{ + int i =3D 0; + u32 base, reg; + + if (!ctx) { + DRM_ERROR("invalid ctx\n"); + return; + } + + base =3D ctx->cap->sblk->gc.base; + + if (!base) { + DRM_ERROR("invalid ctx %pK gc base\n", ctx); + return; + } + + if (!gc_lut) { + DRM_DEBUG_DRIVER("disable gc feature\n"); + DPU_REG_WRITE(&ctx->hw, base, GC_DIS); + return; + } + + DPU_REG_WRITE(&ctx->hw, base + GC_C0_INDEX_OFF, 0); + DPU_REG_WRITE(&ctx->hw, base + GC_C1_INDEX_OFF, 0); + DPU_REG_WRITE(&ctx->hw, base + GC_C2_INDEX_OFF, 0); + + for (i =3D 0; i < PGC_TBL_LEN; i++) { + DPU_REG_WRITE(&ctx->hw, base + GC_C0_OFF, gc_lut->c0[i]); + DPU_REG_WRITE(&ctx->hw, base + GC_C1_OFF, gc_lut->c1[i]); + DPU_REG_WRITE(&ctx->hw, base + GC_C2_OFF, gc_lut->c2[i]); + } + + DPU_REG_WRITE(&ctx->hw, base + GC_LUT_SWAP_OFF, BIT(0)); + + reg =3D GC_EN | ((gc_lut->flags & PGC_8B_ROUND) ? GC_8B_ROUND_EN : 0); + DPU_REG_WRITE(&ctx->hw, base, reg); +} + /** * dpu_hw_dspp_init() - Initializes the DSPP hw driver object. * should be called once before accessing every DSPP. @@ -92,6 +144,8 @@ struct dpu_hw_dspp *dpu_hw_dspp_init(struct drm_device *= dev, c->cap =3D cfg; if (c->cap->sblk->pcc.base) c->ops.setup_pcc =3D dpu_setup_dspp_pcc; + if (c->cap->sblk->gc.base) + c->ops.setup_gc =3D dpu_setup_dspp_gc; =20 return c; } diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_dspp.h b/drivers/gpu/drm/= msm/disp/dpu1/dpu_hw_dspp.h index 45c26cd49fa3..58eca1ed8509 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_dspp.h +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_dspp.h @@ -33,6 +33,25 @@ struct dpu_hw_pcc_cfg { struct dpu_hw_pcc_coeff b; }; =20 +#define DPU_GAMMA_LUT_SIZE 1024 +#define PGC_TBL_LEN 512 +#define PGC_8B_ROUND BIT(0) + +/** + * struct dpu_hw_gc_lut - gc lut feature structure + * @flags: flags for the feature values can be: + * - PGC_8B_ROUND + * @c0: color0 component lut + * @c1: color1 component lut + * @c2: color2 component lut + */ +struct dpu_hw_gc_lut { + __u64 flags; + __u32 c0[PGC_TBL_LEN]; + __u32 c1[PGC_TBL_LEN]; + __u32 c2[PGC_TBL_LEN]; +}; + /** * struct dpu_hw_dspp_ops - interface to the dspp hardware driver functions * Caller must call the init function to get the dspp context for each dspp @@ -46,6 +65,13 @@ struct dpu_hw_dspp_ops { */ void (*setup_pcc)(struct dpu_hw_dspp *ctx, struct dpu_hw_pcc_cfg *cfg); =20 + /** + * setup_gc - setup dspp gc + * @ctx: Pointer to dspp context + * @gc_lut: Pointer to lut content + */ + void (*setup_gc)(struct dpu_hw_dspp *ctx, struct dpu_hw_gc_lut *gc_lut); + }; =20 /** --- base-commit: 2433b84761658ef123ae683508bc461b07c5b0f0 change-id: 20251017-dpu-add-dspp-gc-driver-c5d1c08be770 Best regards, --=20 Federico Amedeo Izzo