From patchwork Wed Oct 25 22:28:02 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dmitry Baryshkov X-Patchwork-Id: 13436888 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (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 C64F7381A7 for ; Wed, 25 Oct 2023 22:30:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="kq674Udc" Received: from mail-lj1-x230.google.com (mail-lj1-x230.google.com [IPv6:2a00:1450:4864:20::230]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9478493 for ; Wed, 25 Oct 2023 15:30:32 -0700 (PDT) Received: by mail-lj1-x230.google.com with SMTP id 38308e7fff4ca-2c3e23a818bso2742571fa.0 for ; Wed, 25 Oct 2023 15:30:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1698273031; x=1698877831; 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=sArdhuc4iKCJ+mSoLILv4KY0dReGLNYPv+iFk9YYQww=; b=kq674UdcPyRZkAARzptcw0IPqPqgVgMx+2EDt19UI48fhzHmEUJ0HE4Mol54LuPZPr 9Z/6lCNeKwDFt5aBbtDeJlQTyjQzf0VXr/W8Xu5lP8rSoztvDFBw4hLyOHgr/FpooNtq qhl0hd3rjNYjDFzRcYv7o2dpJ7nIiEKXKQIIXlH89bVu46h1dkXAAdEpDS0czeG1cr4U TMXTRIKOkaMznF2GPC+UX3o/ZHaJjWVHpeCDe65yHidgYjoSQLPCkmThL56vo6C8Xfaz 7PWcGbERNkXRwuVNUveN0yVAT+mG37LlcrxOrKk9dBTTqEhYpYjwXSQejhDswW78OAnB pRCA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1698273031; x=1698877831; 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=sArdhuc4iKCJ+mSoLILv4KY0dReGLNYPv+iFk9YYQww=; b=dMs6P4X1PNc9y4NcvnCigKMsRmPb9LrBSzzLWbH/DMQmhiajEAMqmcBe9RXmqti4H3 j1OffYkXgD7tgFq1UT868qS+2V0bWTav53Qql+tCXK+AvYoYO1QzDtnyDU6d7k87ZY1g Vv+zvMqGdBMF57k73bnRNM8RlNP61Iz5e/eUdJqD1Gqvi5fiDjFd4vOr7I2j+H5kBJoO cHa8I+auEhY79gQNO9E132Hjkh8MLHG0kn/ZWWzLHNinfnCZxTO5BbnAaGKUqBmfVUVy NFdQJVVH9n7WTlr8dvhMUTGH/jOze9RVX5y3TC6UY16b/Myc7f+0gEvyQVW9OsaExO/m 3Tzg== X-Gm-Message-State: AOJu0YznaXPySQNc5OqhecIY8kvdzbTrEwOirIOXdes2fYz6jiCiKywI roWHez31/fY5L14/bz4Tdlnh1w== X-Google-Smtp-Source: AGHT+IGMbDj/tGOVEpuADIA/1vGnsuQ09EnDPWk98s/5NXuGvDdo/wUjtn17dhtMRVS8NNEmB9Kf+g== X-Received: by 2002:a2e:a309:0:b0:2c4:e5d4:d246 with SMTP id l9-20020a2ea309000000b002c4e5d4d246mr333427lje.7.1698273030939; Wed, 25 Oct 2023 15:30:30 -0700 (PDT) Received: from eriador.lan ([37.153.55.125]) by smtp.gmail.com with ESMTPSA id a36-20020a05651c212400b002bcbae4c21fsm2612543ljq.50.2023.10.25.15.30.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 25 Oct 2023 15:30:29 -0700 (PDT) From: Dmitry Baryshkov To: David Airlie , Daniel Vetter , Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Andy Gross , Bjorn Andersson , Konrad Dybcio , Vinod Koul , Kishon Vijay Abraham I , Heikki Krogerus , Greg Kroah-Hartman Cc: dri-devel@lists.freedesktop.org, linux-arm-msm@vger.kernel.org, linux-phy@lists.infradead.org, linux-usb@vger.kernel.org, freedreno@lists.freedesktop.org Subject: [PATCH v5 1/6] drm/bridge: add transparent bridge helper Date: Thu, 26 Oct 2023 01:28:02 +0300 Message-ID: <20231025223027.943563-2-dmitry.baryshkov@linaro.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231025223027.943563-1-dmitry.baryshkov@linaro.org> References: <20231025223027.943563-1-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. 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