From patchwork Sun Dec 3 11:43:28 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dmitry Baryshkov X-Patchwork-Id: 750371 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="QEFu1r8S" Received: from mail-lj1-x235.google.com (mail-lj1-x235.google.com [IPv6:2a00:1450:4864:20::235]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F413CE3 for ; Sun, 3 Dec 2023 03:43:36 -0800 (PST) Received: by mail-lj1-x235.google.com with SMTP id 38308e7fff4ca-2c9f559b82cso7559201fa.0 for ; Sun, 03 Dec 2023 03:43:36 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1701603815; x=1702208615; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=FLMeGR8g0M1G6Cc/8n9JC9W0cxmAoHOfp3zgP4y1Lrk=; b=QEFu1r8SPNbeEXeuYGxWL7BulvxVJKSjFh0y0OOiu8WZbYCIyunEnlO70RJNdCg3cO 2b71AhgumWMy0efhlaNIjhhfm7a3nYifnANvgKZzzIeOmsAeujmuelGZgUW59GACb+t8 jpdQcUGue4hyfgrIyceXvPmQSsKY4Vw0YQ9fhlXykIETu+8fpoeuFqCMnkSeroa9wQYK 9QNLdJdZMTuXSlIOAH3O/IQic0TSYBytiCI/6SaKphANgN7mZfVNIQ8iyTsOuuwFTrrY k0Q0QSsG+5FqjKcH160Qy3JeIcBNEFym2HpOuc6Uf4Vrn0uszvVlqzA/q5zDRpHjCDDK V/Gg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1701603815; x=1702208615; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=FLMeGR8g0M1G6Cc/8n9JC9W0cxmAoHOfp3zgP4y1Lrk=; b=ZHR13pP53qtoFfYo5znJW+ytC79NCjxDgiWBdnLqnsE0BmPiZEeipMH+988cFWifH2 jOmirqe01+uQmcw269+t3JU2Jkrlywptk86yNwgzK1DLoepe5x/9bLVShIJGYg6RQY1z hs7LXwIuEFccpZNq+is5b6LyR8vwRGDUwt9UI03N//Q8nUNiyFBgNaz9+VEnua/AvgLq WBJgohK5P1yCLiErmJa2nKpaiao9mCnnR9M3UgE09VPW52anCEgimYkDxVyCHjySVlrA URUSK4yoUDJsiY3DoIvRDexrCWhUCVhTRN9VXmhd26bnjc+lnTcgFSSFEcTwJAXCKZLQ UFZg== X-Gm-Message-State: AOJu0YwBOMn2Onp37g6wk78Ices/UeV5bbqbKAlifWMrbifqLL5KCnVy 4G80/IwUaF+J7p1/6iQREjAo61Mu5uSTa1VmeJ8= X-Google-Smtp-Source: AGHT+IG/YwWznfB07jLqx6YXqnCXGzRNSUNjT1p5TDbnkaR8/pSEt/QRIRyE/eNsrkyYVr4SFow4fQ== X-Received: by 2002:a2e:7c05:0:b0:2c9:ebd6:ed11 with SMTP id x5-20020a2e7c05000000b002c9ebd6ed11mr1006232ljc.45.1701603815199; Sun, 03 Dec 2023 03:43:35 -0800 (PST) Received: from umbar.unikie.fi ([192.130.178.91]) by smtp.gmail.com with ESMTPSA id o17-20020a2e90d1000000b002c993c5d4c6sm894666ljg.105.2023.12.03.03.43.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 03 Dec 2023 03:43:34 -0800 (PST) From: Dmitry Baryshkov To: Greg Kroah-Hartman , David Airlie , Daniel Vetter , Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , "Bryan O'Donoghue" , Guenter Roeck , Heikki Krogerus , Janne Grunau , Simon Ser , Andy Gross , Bjorn Andersson , Konrad Dybcio Cc: dri-devel@lists.freedesktop.org, linux-arm-msm@vger.kernel.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, freedreno@lists.freedesktop.org Subject: [PATCH RESEND 1/6] drm/bridge: add transparent bridge helper Date: Sun, 3 Dec 2023 14:43:28 +0300 Message-Id: <20231203114333.1305826-2-dmitry.baryshkov@linaro.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20231203114333.1305826-1-dmitry.baryshkov@linaro.org> References: <20231203114333.1305826-1-dmitry.baryshkov@linaro.org> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Define a helper for creating simple transparent bridges which serve the only purpose of linking devices into the bridge chain up to the last bridge representing the connector. This is especially useful for DP/USB-C bridge chains, which can span across several devices, but do not require any additional functionality from the intermediate bridges. Reviewed-by: Neil Armstrong Signed-off-by: Dmitry Baryshkov --- drivers/gpu/drm/bridge/Kconfig | 9 ++ drivers/gpu/drm/bridge/Makefile | 1 + drivers/gpu/drm/bridge/aux-bridge.c | 140 ++++++++++++++++++++++++++++ include/drm/bridge/aux-bridge.h | 19 ++++ 4 files changed, 169 insertions(+) create mode 100644 drivers/gpu/drm/bridge/aux-bridge.c create mode 100644 include/drm/bridge/aux-bridge.h diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig index ba82a1142adf..f12eab62799f 100644 --- a/drivers/gpu/drm/bridge/Kconfig +++ b/drivers/gpu/drm/bridge/Kconfig @@ -12,6 +12,15 @@ config DRM_PANEL_BRIDGE help DRM bridge wrapper of DRM panels +config DRM_AUX_BRIDGE + tristate + depends on DRM_BRIDGE && OF + select AUXILIARY_BUS + select DRM_PANEL_BRIDGE + help + Simple transparent bridge that is used by several non-DRM drivers to + build bridges chain. + menu "Display Interface Bridges" depends on DRM && DRM_BRIDGE diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile index 2b892b7ed59e..918e3bfff079 100644 --- a/drivers/gpu/drm/bridge/Makefile +++ b/drivers/gpu/drm/bridge/Makefile @@ -1,4 +1,5 @@ # SPDX-License-Identifier: GPL-2.0 +obj-$(CONFIG_DRM_AUX_BRIDGE) += aux-bridge.o obj-$(CONFIG_DRM_CHIPONE_ICN6211) += chipone-icn6211.o obj-$(CONFIG_DRM_CHRONTEL_CH7033) += chrontel-ch7033.o obj-$(CONFIG_DRM_CROS_EC_ANX7688) += cros-ec-anx7688.o diff --git a/drivers/gpu/drm/bridge/aux-bridge.c b/drivers/gpu/drm/bridge/aux-bridge.c new file mode 100644 index 000000000000..6245976b8fef --- /dev/null +++ b/drivers/gpu/drm/bridge/aux-bridge.c @@ -0,0 +1,140 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2023 Linaro Ltd. + * + * Author: Dmitry Baryshkov + */ +#include +#include + +#include +#include + +static DEFINE_IDA(drm_aux_bridge_ida); + +static void drm_aux_bridge_release(struct device *dev) +{ + struct auxiliary_device *adev = to_auxiliary_dev(dev); + + ida_free(&drm_aux_bridge_ida, adev->id); + + kfree(adev); +} + +static void drm_aux_bridge_unregister_adev(void *_adev) +{ + struct auxiliary_device *adev = _adev; + + auxiliary_device_delete(adev); + auxiliary_device_uninit(adev); +} + +/** + * drm_aux_bridge_register - Create a simple bridge device to link the chain + * @parent: device instance providing this bridge + * + * Creates a simple DRM bridge that doesn't implement any drm_bridge + * operations. Such bridges merely fill a place in the bridge chain linking + * surrounding DRM bridges. + * + * Return: zero on success, negative error code on failure + */ +int drm_aux_bridge_register(struct device *parent) +{ + struct auxiliary_device *adev; + int ret; + + adev = kzalloc(sizeof(*adev), GFP_KERNEL); + if (!adev) + return -ENOMEM; + + ret = ida_alloc(&drm_aux_bridge_ida, GFP_KERNEL); + if (ret < 0) { + kfree(adev); + return ret; + } + + adev->id = ret; + adev->name = "aux_bridge"; + adev->dev.parent = parent; + adev->dev.of_node = parent->of_node; + adev->dev.release = drm_aux_bridge_release; + + ret = auxiliary_device_init(adev); + if (ret) { + ida_free(&drm_aux_bridge_ida, adev->id); + kfree(adev); + return ret; + } + + ret = auxiliary_device_add(adev); + if (ret) { + auxiliary_device_uninit(adev); + return ret; + } + + return devm_add_action_or_reset(parent, drm_aux_bridge_unregister_adev, adev); +} +EXPORT_SYMBOL_GPL(drm_aux_bridge_register); + +struct drm_aux_bridge_data { + struct drm_bridge bridge; + struct drm_bridge *next_bridge; + struct device *dev; +}; + +static int drm_aux_bridge_attach(struct drm_bridge *bridge, + enum drm_bridge_attach_flags flags) +{ + struct drm_aux_bridge_data *data; + + if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)) + return -EINVAL; + + data = container_of(bridge, struct drm_aux_bridge_data, bridge); + + return drm_bridge_attach(bridge->encoder, data->next_bridge, bridge, + DRM_BRIDGE_ATTACH_NO_CONNECTOR); +} + +static const struct drm_bridge_funcs drm_aux_bridge_funcs = { + .attach = drm_aux_bridge_attach, +}; + +static int drm_aux_bridge_probe(struct auxiliary_device *auxdev, + const struct auxiliary_device_id *id) +{ + struct drm_aux_bridge_data *data; + + data = devm_kzalloc(&auxdev->dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + data->dev = &auxdev->dev; + data->next_bridge = devm_drm_of_get_bridge(&auxdev->dev, auxdev->dev.of_node, 0, 0); + if (IS_ERR(data->next_bridge)) + return dev_err_probe(&auxdev->dev, PTR_ERR(data->next_bridge), + "failed to acquire drm_bridge\n"); + + data->bridge.funcs = &drm_aux_bridge_funcs; + data->bridge.of_node = data->dev->of_node; + + return devm_drm_bridge_add(data->dev, &data->bridge); +} + +static const struct auxiliary_device_id drm_aux_bridge_table[] = { + { .name = KBUILD_MODNAME ".aux_bridge" }, + {}, +}; +MODULE_DEVICE_TABLE(auxiliary, drm_aux_bridge_table); + +static struct auxiliary_driver drm_aux_bridge_drv = { + .name = "aux_bridge", + .id_table = drm_aux_bridge_table, + .probe = drm_aux_bridge_probe, +}; +module_auxiliary_driver(drm_aux_bridge_drv); + +MODULE_AUTHOR("Dmitry Baryshkov "); +MODULE_DESCRIPTION("DRM transparent bridge"); +MODULE_LICENSE("GPL"); diff --git a/include/drm/bridge/aux-bridge.h b/include/drm/bridge/aux-bridge.h new file mode 100644 index 000000000000..441ab3f0e920 --- /dev/null +++ b/include/drm/bridge/aux-bridge.h @@ -0,0 +1,19 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2023 Linaro Ltd. + * + * Author: Dmitry Baryshkov + */ +#ifndef DRM_AUX_BRIDGE_H +#define DRM_AUX_BRIDGE_H + +#if IS_ENABLED(CONFIG_DRM_AUX_BRIDGE) +int drm_aux_bridge_register(struct device *parent); +#else +static inline int drm_aux_bridge_register(struct device *parent) +{ + return 0; +} +#endif + +#endif