From patchwork Mon Aug 12 20:18:30 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Thomas_Wei=C3=9Fschuh?= X-Patchwork-Id: 13761004 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 3B8A9C52D7C for ; Mon, 12 Aug 2024 20:19:10 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 62E4610E2B5; Mon, 12 Aug 2024 20:19:09 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (1024-bit key; unprotected) header.d=weissschuh.net header.i=@weissschuh.net header.b="gexMGifY"; dkim-atps=neutral Received: from todd.t-8ch.de (todd.t-8ch.de [159.69.126.157]) by gabe.freedesktop.org (Postfix) with ESMTPS id A238310E2B3; Mon, 12 Aug 2024 20:19:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=weissschuh.net; s=mail; t=1723493938; bh=bHgOhr6or/SwGLEdEV9JOQYT34N0Gx3xsfkrcrMNeq4=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=gexMGifYe4MS3CyRTEPcPRaJ40Uf9RvD2BsFsUE9ogq1LiEYEYDU0TsPuYqKMyOB/ zRVJL31SLUyGAC7h9+W9R8DZHqX8M4BnP3ZOTyzC3SJRvU92z2pRmQvagRfAUrVS7d 7+6tT7ffQdZe8THe8JrnuXRAshC25gI7qTuv5IeQ= From: =?utf-8?q?Thomas_Wei=C3=9Fschuh?= Date: Mon, 12 Aug 2024 22:18:30 +0200 Subject: [PATCH v4 1/3] drm: Add panel backlight quirks MIME-Version: 1.0 Message-Id: <20240812-amdgpu-min-backlight-quirk-v4-1-56a63ff897b7@weissschuh.net> References: <20240812-amdgpu-min-backlight-quirk-v4-0-56a63ff897b7@weissschuh.net> In-Reply-To: <20240812-amdgpu-min-backlight-quirk-v4-0-56a63ff897b7@weissschuh.net> To: Alex Deucher , =?utf-8?q?Christian_K=C3=B6nig?= , David Airlie , Daniel Vetter , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , Harry Wentland , Leo Li , Rodrigo Siqueira , Mario Limonciello , Matt Hartley , Kieran Levin , Hans de Goede , Jani Nikula , Xinhui Pan , Jonathan Corbet Cc: amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Dustin Howett , linux-doc@vger.kernel.org, =?utf-8?q?Thomas_Wei=C3=9Fschuh?= X-Mailer: b4 0.14.1 X-Developer-Signature: v=1; a=ed25519-sha256; t=1723493938; l=4897; i=linux@weissschuh.net; s=20221212; h=from:subject:message-id; bh=bHgOhr6or/SwGLEdEV9JOQYT34N0Gx3xsfkrcrMNeq4=; b=OvUCCXJEvFEfiLy9TekOirXYrgAax/+xC4CXyIZIwC0tlNAxn+ARJLaNrvBrQeSebqSZ3yuxN DJcg2+Bel8qBQzKk9lWjnwj2ZKwxdzScYvQ1yHrGLdMgcNPhV33Oy49 X-Developer-Key: i=linux@weissschuh.net; a=ed25519; pk=KcycQgFPX2wGR5azS7RhpBqedglOZVgRPfdFSPB1LNw= 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: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Panels using a PWM-controlled backlight source without an do not have a standard way to communicate their valid PWM ranges. On x86 the ranges are read from ACPI through driver-specific tables. The built-in ranges are not necessarily correct, or may grow stale if an older device can be retrofitted with newer panels. Add a quirk infrastructure with which the minimum valid backlight value can be maintained as part of the kernel. Signed-off-by: Thomas Weißschuh --- Documentation/gpu/drm-kms-helpers.rst | 3 ++ drivers/gpu/drm/Kconfig | 4 ++ drivers/gpu/drm/Makefile | 1 + drivers/gpu/drm/drm_panel_backlight_quirks.c | 69 ++++++++++++++++++++++++++++ include/drm/drm_utils.h | 3 ++ 5 files changed, 80 insertions(+) diff --git a/Documentation/gpu/drm-kms-helpers.rst b/Documentation/gpu/drm-kms-helpers.rst index 8435e8621cc0..a26989500129 100644 --- a/Documentation/gpu/drm-kms-helpers.rst +++ b/Documentation/gpu/drm-kms-helpers.rst @@ -230,6 +230,9 @@ Panel Helper Reference .. kernel-doc:: drivers/gpu/drm/drm_panel_orientation_quirks.c :export: +.. kernel-doc:: drivers/gpu/drm/drm_panel_backlight_quirks.c + :export: + Panel Self Refresh Helper Reference =================================== diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig index 6b2c6b91f962..9ebb8cdb535e 100644 --- a/drivers/gpu/drm/Kconfig +++ b/drivers/gpu/drm/Kconfig @@ -454,6 +454,10 @@ config DRM_HYPERV config DRM_EXPORT_FOR_TESTS bool +# Separate option as not all DRM drivers use it +config DRM_PANEL_BACKLIGHT_QUIRKS + tristate + config DRM_LIB_RANDOM bool default n diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile index 68cc9258ffc4..adf85999aee2 100644 --- a/drivers/gpu/drm/Makefile +++ b/drivers/gpu/drm/Makefile @@ -92,6 +92,7 @@ drm-$(CONFIG_DRM_PANIC) += drm_panic.o obj-$(CONFIG_DRM) += drm.o obj-$(CONFIG_DRM_PANEL_ORIENTATION_QUIRKS) += drm_panel_orientation_quirks.o +obj-$(CONFIG_DRM_PANEL_BACKLIGHT_QUIRKS) += drm_panel_backlight_quirks.o # # Memory-management helpers diff --git a/drivers/gpu/drm/drm_panel_backlight_quirks.c b/drivers/gpu/drm/drm_panel_backlight_quirks.c new file mode 100644 index 000000000000..a88e77db97c5 --- /dev/null +++ b/drivers/gpu/drm/drm_panel_backlight_quirks.c @@ -0,0 +1,69 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include +#include +#include +#include + +struct drm_panel_min_backlight_quirk { + struct { + enum dmi_field field; + const char * const value; + } dmi_match; + struct drm_edid_ident ident; + u8 min_brightness; +}; + +static const struct drm_panel_min_backlight_quirk drm_panel_min_backlight_quirks[] = { +}; + +static bool drm_panel_min_backlight_quirk_matches(const struct drm_panel_min_backlight_quirk *quirk, + const struct drm_edid *edid) +{ + if (!dmi_match(quirk->dmi_match.field, quirk->dmi_match.value)) + return false; + + if (!drm_edid_match(edid, &quirk->ident)) + return false; + + return true; +} + +/** + * drm_get_panel_min_brightness_quirk - Get minimum supported brightness level for a panel. + * @edid: EDID of the panel to check + * + * This function checks for platform specific (e.g. DMI based) quirks + * providing info on the minimum backlight brightness for systems where this + * cannot be probed correctly from the hard-/firm-ware. + * + * Returns: + * A negative error value or + * an override value in the range [0, 255] representing 0-100% to be scaled to + * the drivers target range. + */ +int drm_get_panel_min_brightness_quirk(const struct drm_edid *edid) +{ + const struct drm_panel_min_backlight_quirk *quirk; + size_t i; + + if (!IS_ENABLED(CONFIG_DMI)) + return -ENODATA; + + if (!edid) + return -EINVAL; + + for (i = 0; i < ARRAY_SIZE(drm_panel_min_backlight_quirks); i++) { + quirk = &drm_panel_min_backlight_quirks[i]; + + if (drm_panel_min_backlight_quirk_matches(quirk, edid)) + return quirk->min_brightness; + } + + return -ENODATA; +} +EXPORT_SYMBOL(drm_get_panel_min_brightness_quirk); + +MODULE_DESCRIPTION("Quirks for panel backlight overrides"); +MODULE_LICENSE("GPL"); diff --git a/include/drm/drm_utils.h b/include/drm/drm_utils.h index 70775748d243..267711028dd4 100644 --- a/include/drm/drm_utils.h +++ b/include/drm/drm_utils.h @@ -11,9 +11,12 @@ #define __DRM_UTILS_H__ #include +#include int drm_get_panel_orientation_quirk(int width, int height); +int drm_get_panel_min_brightness_quirk(const struct drm_edid *edid); + signed long drm_timeout_abs_to_jiffies(int64_t timeout_nsec); #endif