From patchwork Wed Aug 2 01:18:43 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dmitry Baryshkov X-Patchwork-Id: 13337497 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2B4FDC001E0 for ; Wed, 2 Aug 2023 01:18:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230288AbjHBBSy (ORCPT ); Tue, 1 Aug 2023 21:18:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34570 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229827AbjHBBSv (ORCPT ); Tue, 1 Aug 2023 21:18:51 -0400 Received: from mail-lf1-x136.google.com (mail-lf1-x136.google.com [IPv6:2a00:1450:4864:20::136]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CC4DB1FD6 for ; Tue, 1 Aug 2023 18:18:49 -0700 (PDT) Received: by mail-lf1-x136.google.com with SMTP id 2adb3069b0e04-4fe11652b64so10470278e87.0 for ; Tue, 01 Aug 2023 18:18:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1690939128; x=1691543928; 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=prG8zaTCxCmOYhLMj8L/mJstXroO5EIKvx4tl+wA6H4=; b=QTL8kacDrJN2dKkgS9qL0ela9TkebQqioHm00mmaY8X1HJxQQZDhTQVWVNK0PdZ/Tr i3/fYbxeSfqhekTGaRaexWBRL224W50eh9FTPoO71tBa7cDaLbTXfFKFHFigfISFZ3t9 cQkLzAsTK70GZOLhb9UdiE95Ik9jJ0iMxEmue/UaK0sCrGZMHCv/0G+VWcSYzBH3Gh/O VBIAZ1D2uZ6SILR5i0Ao2CDINk9BLhU7gXMK1T6t4tjub4VB/6ykGAGUG8Hi0kMlSz/K jan5lC46ETDmA73PkpMekHOkm7NAR0QkXO56kLzkOBzCSk7IYuUKx1M6tEwbsQLMm9Ei 0L1Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1690939128; x=1691543928; 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=prG8zaTCxCmOYhLMj8L/mJstXroO5EIKvx4tl+wA6H4=; b=eQFJsN9cpv7alWFaru2N9cP3ObedFoA73ZItTTpCy9aIEoZfOT8Y2kCWH5i8rmWA7s sjsH9Dq+Tn+9T7dtuZpjzHHDCaw8gawkMuWOq6lnq0B75k2NHAmKSAaHNWdKncixPT7/ k44pblPJZtohtcfI/ukOaKSVwhfytMcoCG3qdlayTbU5aUFVCIr60Ioedymh8+BU7sAj cX45te22tGQhKrqfSUkpdIi6E6eN/cluHGwzwMGt49Cbz+/Rjthrb87dVf+hmHVHhXzR EOjYQuKK3GC0lFpTw7uXgs9nB/dmFSu6ubwd62SwON304ZW75ZUgeav3SVqUk6V3rGLJ xYug== X-Gm-Message-State: ABy/qLZs+LE32b4ONHJDkEoCX3v6EUAPSpHmHJNpQ0Vf+wnDgt7mhSK7 Pz2GXl4mfNXAX2cdskzB7Gix2w== X-Google-Smtp-Source: APBJJlG7bj9ZR1MQqNhlwB2//hMQIp56VcR1vZUL0RLpRmo9O3tRdpQJ2BDpr/B+acT2X7asSFIeCw== X-Received: by 2002:a19:9111:0:b0:4fb:8a92:4fba with SMTP id t17-20020a199111000000b004fb8a924fbamr3175637lfd.25.1690939127790; Tue, 01 Aug 2023 18:18:47 -0700 (PDT) Received: from umbar.unikie.fi ([192.130.178.91]) by smtp.gmail.com with ESMTPSA id n14-20020a056512388e00b004faeedbb29dsm2775842lft.64.2023.08.01.18.18.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 01 Aug 2023 18:18:47 -0700 (PDT) From: Dmitry Baryshkov To: David Airlie , Daniel Vetter , Andy Gross , Bjorn Andersson , Konrad Dybcio , Vinod Koul , Kishon Vijay Abraham I , Heikki Krogerus , Greg Kroah-Hartman , Neil Armstrong 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 v3 1/3] drm/display: add transparent bridge helper Date: Wed, 2 Aug 2023 04:18:43 +0300 Message-Id: <20230802011845.4176631-2-dmitry.baryshkov@linaro.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230802011845.4176631-1-dmitry.baryshkov@linaro.org> References: <20230802011845.4176631-1-dmitry.baryshkov@linaro.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org 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/display/Kconfig | 9 ++ drivers/gpu/drm/display/Makefile | 2 + drivers/gpu/drm/display/drm_simple_bridge.c | 127 ++++++++++++++++++++ include/drm/display/drm_simple_bridge.h | 19 +++ 4 files changed, 157 insertions(+) create mode 100644 drivers/gpu/drm/display/drm_simple_bridge.c create mode 100644 include/drm/display/drm_simple_bridge.h diff --git a/drivers/gpu/drm/display/Kconfig b/drivers/gpu/drm/display/Kconfig index 09712b88a5b8..a6132984b9e3 100644 --- a/drivers/gpu/drm/display/Kconfig +++ b/drivers/gpu/drm/display/Kconfig @@ -49,3 +49,12 @@ config DRM_DP_CEC Note: not all adapters support this feature, and even for those that do support this they often do not hook up the CEC pin. + +config DRM_SIMPLE_BRIDGE + tristate + depends on DRM + select AUXILIARY_BUS + select DRM_PANEL_BRIDGE + help + Simple transparent bridge that is used by several drivers to build + bridges chain. diff --git a/drivers/gpu/drm/display/Makefile b/drivers/gpu/drm/display/Makefile index 17ac4a1006a8..6e2b0d7f24b3 100644 --- a/drivers/gpu/drm/display/Makefile +++ b/drivers/gpu/drm/display/Makefile @@ -16,3 +16,5 @@ drm_display_helper-$(CONFIG_DRM_DP_AUX_CHARDEV) += drm_dp_aux_dev.o drm_display_helper-$(CONFIG_DRM_DP_CEC) += drm_dp_cec.o obj-$(CONFIG_DRM_DISPLAY_HELPER) += drm_display_helper.o + +obj-$(CONFIG_DRM_SIMPLE_BRIDGE) += drm_simple_bridge.o diff --git a/drivers/gpu/drm/display/drm_simple_bridge.c b/drivers/gpu/drm/display/drm_simple_bridge.c new file mode 100644 index 000000000000..9e80efe67b93 --- /dev/null +++ b/drivers/gpu/drm/display/drm_simple_bridge.c @@ -0,0 +1,127 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2023 Linaro Ltd. + * + * Author: Dmitry Baryshkov + */ +#include +#include + +#include +#include + +static DEFINE_IDA(simple_bridge_ida); + +static void drm_simple_bridge_release(struct device *dev) +{ + struct auxiliary_device *adev = to_auxiliary_dev(dev); + + kfree(adev); +} + +static void drm_simple_bridge_unregister_adev(void *_adev) +{ + struct auxiliary_device *adev = _adev; + + auxiliary_device_delete(adev); + auxiliary_device_uninit(adev); +} + +int drm_simple_bridge_register(struct device *parent) +{ + struct auxiliary_device *adev; + int ret; + + adev = kzalloc(sizeof(*adev), GFP_KERNEL); + if (!adev) + return -ENOMEM; + + ret = ida_alloc(&simple_bridge_ida, GFP_KERNEL); + if (ret < 0) + return ret; + + adev->id = ret; + adev->name = "simple_bridge"; + adev->dev.parent = parent; + adev->dev.of_node = parent->of_node; + adev->dev.release = drm_simple_bridge_release; + + ret = auxiliary_device_init(adev); + if (ret) { + 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_simple_bridge_unregister_adev, adev); +} +EXPORT_SYMBOL_GPL(drm_simple_bridge_register); + +struct drm_simple_bridge_data { + struct drm_bridge bridge; + struct drm_bridge *next_bridge; + struct device *dev; +}; + +static int drm_simple_bridge_attach(struct drm_bridge *bridge, + enum drm_bridge_attach_flags flags) +{ + struct drm_simple_bridge_data *data; + + if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)) + return -EINVAL; + + data = container_of(bridge, struct drm_simple_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_simple_bridge_funcs = { + .attach = drm_simple_bridge_attach, +}; + +static int drm_simple_bridge_probe(struct auxiliary_device *auxdev, + const struct auxiliary_device_id *id) +{ + struct drm_simple_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_simple_bridge_funcs; +#ifdef CONFIG_OF + data->bridge.of_node = data->dev->of_node; +#endif + + return devm_drm_bridge_add(data->dev, &data->bridge); +} + +static const struct auxiliary_device_id drm_simple_bridge_table[] = { + { .name = KBUILD_MODNAME ".simple_bridge" }, + {}, +}; +MODULE_DEVICE_TABLE(auxiliary, drm_simple_bridge_table); + +struct auxiliary_driver drm_simple_bridge_drv = { + .name = "simple_bridge", + .id_table = drm_simple_bridge_table, + .probe = drm_simple_bridge_probe, +}; +module_auxiliary_driver(drm_simple_bridge_drv); + +MODULE_AUTHOR("Dmitry Baryshkov "); +MODULE_DESCRIPTION("DRM simple bridge helper"); +MODULE_LICENSE("GPL"); diff --git a/include/drm/display/drm_simple_bridge.h b/include/drm/display/drm_simple_bridge.h new file mode 100644 index 000000000000..3da8e1fb1137 --- /dev/null +++ b/include/drm/display/drm_simple_bridge.h @@ -0,0 +1,19 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2023 Linaro Ltd. + * + * Author: Dmitry Baryshkov + */ +#ifndef DRM_SIMPLE_BRIDGE_H +#define DRM_SIMPLE_BRIDGE_H + +#if IS_ENABLED(CONFIG_DRM_SIMPLE_BRIDGE) +int drm_simple_bridge_register(struct device *parent); +#else +static inline int drm_simple_bridge_register(struct device *parent) +{ + return 0; +} +#endif + +#endif