From patchwork Mon Apr 11 20:35:31 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marek Vasut X-Patchwork-Id: 12809622 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A32D7C433EF for ; Mon, 11 Apr 2022 20:35:49 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 0852F10E00D; Mon, 11 Apr 2022 20:35:49 +0000 (UTC) Received: from phobos.denx.de (phobos.denx.de [85.214.62.61]) by gabe.freedesktop.org (Postfix) with ESMTPS id 189BA10E00C for ; Mon, 11 Apr 2022 20:35:47 +0000 (UTC) Received: from tr.lan (ip-86-49-12-201.net.upcbroadband.cz [86.49.12.201]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: marex@denx.de) by phobos.denx.de (Postfix) with ESMTPSA id 35D88811D8; Mon, 11 Apr 2022 22:35:45 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=denx.de; s=phobos-20191101; t=1649709345; bh=VJZN6aUkBXUaW76O9wqHNZ/O2S7aKgaReWYJ8/H1GUQ=; h=From:To:Cc:Subject:Date:From; b=RISDhEOPttjogdK5/FKV7Nm/HH+CrtEygg6pSVQ3yVcvNYuu3s6MKFN6GEMKnrgQE MMqEbatsN79c7EUKCP+GXw6c1lf6mgt8S0WnBaXkMT9dYstes5wQAU1ebMbyHNjmLi K6HTEvq0q4B9HjHfpismmeAR1GGBGhwGuC1Ct4zZRgb9ikTNZ0nZ8lTcMb0YCAbIXh CUubhIFvq5Y1RBW4B5i6MhRul4viuyHUBRtqYYpF+jnsRfPSF3dSNQPhiPbG316Q6Q cCHAQlO3KVYG6NOZ4koBkjP7xoNfuh43dszRomAMhzWEmbnosFYV/EqiTmHOHj7Ycq Ro6mgcjdx0vKg== From: Marek Vasut To: dri-devel@lists.freedesktop.org Subject: [PATCH v2] drm: mxsfb: Implement LCDIF scanout CRC32 support Date: Mon, 11 Apr 2022 22:35:31 +0200 Message-Id: <20220411203531.774958-1-marex@denx.de> X-Mailer: git-send-email 2.35.1 MIME-Version: 1.0 X-Virus-Scanned: clamav-milter 0.103.5 at phobos.denx.de X-Virus-Status: Clean X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Marek Vasut , Peng Fan , Alexander Stein , robert.foss@linaro.org, Laurent Pinchart , Robby Cai , Sam Ravnborg Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" The LCDIF controller as present in i.MX28/i.MX6SX/i.MX8M Mini/Nano has CRC_STAT register, which contains CRC32 of the frame as it was clocked out of the DPI interface of the LCDIF. This is most likely meant as a functional safety feature. Unfortunately, there is zero documentation on how the CRC32 is calculated, there is no documentation of the polynomial, the init value, nor on which data is the checksum applied. By applying brute-force on 8 pixel / 2 line frame, which is the minimum size LCDIF would work with, it turns out the polynomial is CRC32_POLY_LE 0xedb88320 , init value is 0xffffffff , the input data are bitrev32() of the entire frame and the resulting CRC has to be also bitrev32()ed. Doing this calculation in kernel for each frame is unrealistic due to the CPU demand, so attach the CRC collected from hardware to a frame instead. The DRM subsystem already has an interface for this purpose and the CRC can be accessed e.g. via debugfs: " $ echo auto > /sys/kernel/debug/dri/1/crtc-0/crc/control $ cat /sys/kernel/debug/dri/1/crtc-0/crc/data 0x0000408c 0xa4e5cdd8 0x0000408d 0x72f537b4 " The per-frame CRC can be used by userspace e.g. during automated testing, to verify that whatever buffer was sent to be scanned out was actually scanned out of the LCDIF correctly. Signed-off-by: Marek Vasut Cc: Alexander Stein Cc: Laurent Pinchart Cc: Lucas Stach Cc: Peng Fan Cc: Robby Cai Cc: Sam Ravnborg Cc: Stefan Agner Acked-by: Lucas Stach Acked-by: Stefan Agner --- V2: Check crtc for non-NULL before dereferencing it in mxsfb_crtc_set_crc_source --- drivers/gpu/drm/mxsfb/mxsfb_drv.c | 15 +++++++- drivers/gpu/drm/mxsfb/mxsfb_drv.h | 3 ++ drivers/gpu/drm/mxsfb/mxsfb_kms.c | 61 ++++++++++++++++++++++++++++-- drivers/gpu/drm/mxsfb/mxsfb_regs.h | 1 + 4 files changed, 75 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/mxsfb/mxsfb_drv.c b/drivers/gpu/drm/mxsfb/mxsfb_drv.c index 94cafff7f68d5..ccf4107476ecc 100644 --- a/drivers/gpu/drm/mxsfb/mxsfb_drv.c +++ b/drivers/gpu/drm/mxsfb/mxsfb_drv.c @@ -9,6 +9,7 @@ */ #include +#include #include #include #include @@ -52,6 +53,7 @@ static const struct mxsfb_devdata mxsfb_devdata[] = { .hs_wdth_shift = 24, .has_overlay = false, .has_ctrl2 = false, + .has_crc32 = false, }, [MXSFB_V4] = { .transfer_count = LCDC_V4_TRANSFER_COUNT, @@ -61,6 +63,7 @@ static const struct mxsfb_devdata mxsfb_devdata[] = { .hs_wdth_shift = 18, .has_overlay = false, .has_ctrl2 = true, + .has_crc32 = true, }, [MXSFB_V6] = { .transfer_count = LCDC_V4_TRANSFER_COUNT, @@ -70,6 +73,7 @@ static const struct mxsfb_devdata mxsfb_devdata[] = { .hs_wdth_shift = 18, .has_overlay = true, .has_ctrl2 = true, + .has_crc32 = true, }, }; @@ -145,12 +149,19 @@ static irqreturn_t mxsfb_irq_handler(int irq, void *data) { struct drm_device *drm = data; struct mxsfb_drm_private *mxsfb = drm->dev_private; - u32 reg; + u32 reg, crc; + u64 vbc; reg = readl(mxsfb->base + LCDC_CTRL1); - if (reg & CTRL1_CUR_FRAME_DONE_IRQ) + if (reg & CTRL1_CUR_FRAME_DONE_IRQ) { drm_crtc_handle_vblank(&mxsfb->crtc); + if (mxsfb->crc_active) { + crc = readl(mxsfb->base + LCDC_V4_CRC_STAT); + vbc = drm_crtc_accurate_vblank_count(&mxsfb->crtc); + drm_crtc_add_crc_entry(&mxsfb->crtc, true, vbc, &crc); + } + } writel(CTRL1_CUR_FRAME_DONE_IRQ, mxsfb->base + LCDC_CTRL1 + REG_CLR); diff --git a/drivers/gpu/drm/mxsfb/mxsfb_drv.h b/drivers/gpu/drm/mxsfb/mxsfb_drv.h index ddb5b0417a82c..d160d921b25fc 100644 --- a/drivers/gpu/drm/mxsfb/mxsfb_drv.h +++ b/drivers/gpu/drm/mxsfb/mxsfb_drv.h @@ -23,6 +23,7 @@ struct mxsfb_devdata { unsigned int hs_wdth_shift; bool has_overlay; bool has_ctrl2; + bool has_crc32; }; struct mxsfb_drm_private { @@ -44,6 +45,8 @@ struct mxsfb_drm_private { struct drm_encoder encoder; struct drm_connector *connector; struct drm_bridge *bridge; + + bool crc_active; }; static inline struct mxsfb_drm_private * diff --git a/drivers/gpu/drm/mxsfb/mxsfb_kms.c b/drivers/gpu/drm/mxsfb/mxsfb_kms.c index c7f14ef1edc25..323087944ac56 100644 --- a/drivers/gpu/drm/mxsfb/mxsfb_kms.c +++ b/drivers/gpu/drm/mxsfb/mxsfb_kms.c @@ -454,6 +454,41 @@ static void mxsfb_crtc_disable_vblank(struct drm_crtc *crtc) writel(CTRL1_CUR_FRAME_DONE_IRQ, mxsfb->base + LCDC_CTRL1 + REG_CLR); } +static int mxsfb_crtc_set_crc_source(struct drm_crtc *crtc, const char *source) +{ + struct mxsfb_drm_private *mxsfb; + + if (!crtc) + return -ENODEV; + + mxsfb = to_mxsfb_drm_private(crtc->dev); + + if (source && strcmp(source, "auto") == 0) + mxsfb->crc_active = true; + else if (!source) + mxsfb->crc_active = false; + else + return -EINVAL; + + return 0; +} + +static int mxsfb_crtc_verify_crc_source(struct drm_crtc *crtc, + const char *source, size_t *values_cnt) +{ + if (!crtc) + return -ENODEV; + + if (source && strcmp(source, "auto") != 0) { + DRM_DEBUG_DRIVER("Unknown CRC source %s for %s\n", + source, crtc->name); + return -EINVAL; + } + + *values_cnt = 1; + return 0; +} + static const struct drm_crtc_helper_funcs mxsfb_crtc_helper_funcs = { .atomic_check = mxsfb_crtc_atomic_check, .atomic_flush = mxsfb_crtc_atomic_flush, @@ -472,6 +507,19 @@ static const struct drm_crtc_funcs mxsfb_crtc_funcs = { .disable_vblank = mxsfb_crtc_disable_vblank, }; +static const struct drm_crtc_funcs mxsfb_crtc_with_crc_funcs = { + .reset = drm_atomic_helper_crtc_reset, + .destroy = drm_crtc_cleanup, + .set_config = drm_atomic_helper_set_config, + .page_flip = drm_atomic_helper_page_flip, + .atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state, + .atomic_destroy_state = drm_atomic_helper_crtc_destroy_state, + .enable_vblank = mxsfb_crtc_enable_vblank, + .disable_vblank = mxsfb_crtc_disable_vblank, + .set_crc_source = mxsfb_crtc_set_crc_source, + .verify_crc_source = mxsfb_crtc_verify_crc_source, +}; + /* ----------------------------------------------------------------------------- * Encoder */ @@ -655,9 +703,16 @@ int mxsfb_kms_init(struct mxsfb_drm_private *mxsfb) } drm_crtc_helper_add(crtc, &mxsfb_crtc_helper_funcs); - ret = drm_crtc_init_with_planes(mxsfb->drm, crtc, - &mxsfb->planes.primary, NULL, - &mxsfb_crtc_funcs, NULL); + if (mxsfb->devdata->has_crc32) { + ret = drm_crtc_init_with_planes(mxsfb->drm, crtc, + &mxsfb->planes.primary, NULL, + &mxsfb_crtc_with_crc_funcs, + NULL); + } else { + ret = drm_crtc_init_with_planes(mxsfb->drm, crtc, + &mxsfb->planes.primary, NULL, + &mxsfb_crtc_funcs, NULL); + } if (ret) return ret; diff --git a/drivers/gpu/drm/mxsfb/mxsfb_regs.h b/drivers/gpu/drm/mxsfb/mxsfb_regs.h index 694fea13e893e..cf813a1da1d78 100644 --- a/drivers/gpu/drm/mxsfb/mxsfb_regs.h +++ b/drivers/gpu/drm/mxsfb/mxsfb_regs.h @@ -26,6 +26,7 @@ #define LCDC_VDCTRL2 0x90 #define LCDC_VDCTRL3 0xa0 #define LCDC_VDCTRL4 0xb0 +#define LCDC_V4_CRC_STAT 0x1a0 #define LCDC_V4_DEBUG0 0x1d0 #define LCDC_V3_DEBUG0 0x1f0 #define LCDC_AS_CTRL 0x210