From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-18.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0B2F5C4727E for ; Mon, 28 Sep 2020 17:14:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B89C32100A for ; Mon, 28 Sep 2020 17:14:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="Fz5jouqA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726684AbgI1ROF (ORCPT ); Mon, 28 Sep 2020 13:14:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37354 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726551AbgI1ROE (ORCPT ); Mon, 28 Sep 2020 13:14:04 -0400 Received: from mail-pf1-x444.google.com (mail-pf1-x444.google.com [IPv6:2607:f8b0:4864:20::444]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5DAF8C061755 for ; Mon, 28 Sep 2020 10:14:04 -0700 (PDT) Received: by mail-pf1-x444.google.com with SMTP id n14so1626666pff.6 for ; Mon, 28 Sep 2020 10:14:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=W8Mrz0VTtam4k9EbDnGZRSgqObwcyTLH3/J7dD64Vgs=; b=Fz5jouqAAhdJbJPD1kRPdhSHIJofwccfCmjqfdybt0lhTyG5brv56COJoDKuN3n8oK 98XSmVlCmafWNIxMFa1Jzs5WyNY28H7ykQb85vWFg/DhK6QARXU9l/o7VRC5TtbRsZRH CjTT2rlNLRhExUDoTBb/XLKJvLetHG+tfieyg= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=W8Mrz0VTtam4k9EbDnGZRSgqObwcyTLH3/J7dD64Vgs=; b=gJw+4TZG6dtffF4o0Yby7UP2AwQIpcTxCXAcTjhcMstqnCFAETJH0r8VgGiTK0Abp+ zn/B/NoaQbj/8eG1z3zyYEBoBINEz8XtbDmPWxZzDukv/0Blo6cGqmoqiTIkGLBw8yzu uoWPRe6Qe8XF2tY6oTxIuOYMTkLp7J8oPQLxsuFn2J4/G7Db9lyn2i6Ru5wUdAhFk6lg cbya5pzpt3XXKzFlizkWgUk3KgHCrAF3/mzmk1sImiMF1od8Y6NsaE5rwmL+/duPC8lN 9gSJSNXqZIY306gihcIekjdDJ3hxjP194VYlwbuuYzK6sSGGqSjGeKqYJbOwV8gzEwom fmmA== X-Gm-Message-State: AOAM531pP7vUy9NUliaHbyTWUmDhWpNm+qHUjSWfpHH2s7HGrX1MVxvS 0M6T6eIs+WC4/ilRukdblraSlQ== X-Google-Smtp-Source: ABdhPJx41eG4F6mpyiywKkL4gfeQHFZKyAqXMkXjrVBIrU9rYI1+EvlvBQle/1ZlRLCL8h7dylaZ9w== X-Received: by 2002:a63:2bd1:: with SMTP id r200mr110395pgr.20.1601313243761; Mon, 28 Sep 2020 10:14:03 -0700 (PDT) Received: from localhost ([2620:15c:202:1:f693:9fff:fef4:e70a]) by smtp.gmail.com with ESMTPSA id d128sm2363412pfc.8.2020.09.28.10.14.02 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 28 Sep 2020 10:14:03 -0700 (PDT) From: Matthias Kaehlcke To: Greg Kroah-Hartman , Rob Herring , Frank Rowand Cc: linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, Bastien Nocera , Stephen Boyd , Douglas Anderson , Alan Stern , Ravi Chandra Sadineni , Krzysztof Kozlowski , devicetree@vger.kernel.org, Peter Chen , Matthias Kaehlcke , "Alexander A. Klimov" , "David S. Miller" , Johan Hovold , Masahiro Yamada , Mauro Carvalho Chehab , Rob Herring Subject: [PATCH v4 2/2] USB: misc: Add onboard_usb_hub driver Date: Mon, 28 Sep 2020 10:13:55 -0700 Message-Id: <20200928101326.v4.2.I7c9a1f1d6ced41dd8310e8a03da666a32364e790@changeid> X-Mailer: git-send-email 2.28.0.709.gb0816b6eb0-goog In-Reply-To: <20200928101326.v4.1.I248292623d3d0f6a4f0c5bc58478ca3c0062b49a@changeid> References: <20200928101326.v4.1.I248292623d3d0f6a4f0c5bc58478ca3c0062b49a@changeid> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org The main issue this driver addresses is that a USB hub needs to be powered before it can be discovered. For discrete onboard hubs (an example for such a hub is the Realtek RTS5411) this is often solved by supplying the hub with an 'always-on' regulator, which is kind of a hack. Some onboard hubs may require further initialization steps, like changing the state of a GPIO or enabling a clock, which requires even more hacks. This driver creates a platform device representing the hub which performs the necessary initialization. Currently it only supports switching on a single regulator, support for multiple regulators or other actions can be added as needed. Different initialization sequences can be supported based on the compatible string. Besides performing the initialization the driver can be configured to power the hub off during system suspend. This can help to extend battery life on battery powered devices which have no requirements to keep the hub powered during suspend. The driver can also be configured to leave the hub powered when a wakeup capable USB device is connected when suspending, and power it off otherwise. Technically the driver consists of two drivers, the platform driver described above and a very thin USB driver that subclasses the generic driver. The purpose of this driver is to provide the platform driver with the USB devices corresponding to the hub(s) (a hub controller may provide multiple 'logical' hubs, e.g. one to support USB 2.0 and another for USB 3.x). Co-developed-by: Ravi Chandra Sadineni Signed-off-by: Ravi Chandra Sadineni Signed-off-by: Matthias Kaehlcke --- Changes in v4: - updated Kconfig documentation - changed the loop in onboard_hub_remove() to release the hub lock before unbinding the USB device and make self deadlock prevention less clunky - fixed return value in onboard_hub_usbdev_probe() - added entry to MAINTAINERS file Changes in v3: - updated the commit message - updated description in Kconfig - remove include of 'core/usb.h' - use 'is_powered_on' flag instead of 'has_wakeup_capable_descendants' - added 'going_away' flag to struct onboard_hub - don't allow adding new USB devices when the platform device is going away - don't bother with deleting the list item in onboard_hub_remove_usbdev() when the platform device is going away - don't assume in onboard_hub_suspend() that all USB hub devices are connected to the same controller - removed unnecessary devm_kfree() from onboard_hub_remove_usbdev() - fixed error handling in onboard_hub_remove_usbdev() - use kstrtobool() instead of strtobool() in power_off_in_suspend_store() - unbind USB devices in onboard_hub_remove() to avoid dangling references to the platform device - moved put_device() for platform device to _find_onboard_hub() - changed return value of onboard_hub_remove_usbdev() to void - evaluate return value of onboard_hub_add_usbdev() - register 'power_off_in_suspend' as managed device attribute - use USB_DEVICE macro instead manual initialization - add unwinding to onboard_hub_init() - updated MODULE_DESCRIPTION - use module_init() instead of device_initcall() Changes in v2: - check wakeup enabled state of the USB controller instead of using 'wakeup-source' property - use sysfs attribute instead of DT property to determine if the hub should be powered off at all during system suspend - added missing brace in onboard_hub_suspend() - updated commit message - use pm_ptr for pm_ops as suggested by Alan Changes in v1: - renamed the driver to 'onboard_usb_hub' - single file for platform and USB driver - USB hub devices register with the platform device - the DT includes a phandle of the platform device - the platform device now controls when power is turned off - the USB driver became a very thin subclass of the generic USB driver - enabled autosuspend support MAINTAINERS | 7 + drivers/usb/misc/Kconfig | 17 ++ drivers/usb/misc/Makefile | 1 + drivers/usb/misc/onboard_usb_hub.c | 371 +++++++++++++++++++++++++++++ 4 files changed, 396 insertions(+) create mode 100644 drivers/usb/misc/onboard_usb_hub.c diff --git a/MAINTAINERS b/MAINTAINERS index 0d0862b19ce5..fa7502ed6771 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -12859,6 +12859,13 @@ T: git git://linuxtv.org/media_tree.git F: Documentation/devicetree/bindings/media/i2c/ov9650.txt F: drivers/media/i2c/ov9650.c +ONBOARD USB HUB DRIVER +M: Matthias Kaehlcke +L: linux-usb@vger.kernel.org +S: Maintained +F: Documentation/devicetree/bindings/usb/onboard_usb_hub.yaml +F: drivers/usb/misc/onboard_usb_hub.c + ONENAND FLASH DRIVER M: Kyungmin Park L: linux-mtd@lists.infradead.org diff --git a/drivers/usb/misc/Kconfig b/drivers/usb/misc/Kconfig index 6818ea689cd9..09e6ca1a004c 100644 --- a/drivers/usb/misc/Kconfig +++ b/drivers/usb/misc/Kconfig @@ -275,3 +275,20 @@ config USB_CHAOSKEY To compile this driver as a module, choose M here: the module will be called chaoskey. + +config USB_ONBOARD_HUB + tristate "Onboard USB hub support" + depends on OF || COMPILE_TEST + help + Say Y here if you want to support discrete onboard USB hubs that + don't require an additional control bus for initialization, but + need some nontrivial form of initialization, such as enabling a + power regulator. An example for such a hub is the Realtek + RTS5411. + + The driver can be configured to turn off the power of the hub + during system suspend. This may reduce power consumption while + the system is suspended. + + To compile this driver as a module, choose M here: the + module will be called onboard_usb_hub. diff --git a/drivers/usb/misc/Makefile b/drivers/usb/misc/Makefile index da39bddb0604..6f10a1c6f7e9 100644 --- a/drivers/usb/misc/Makefile +++ b/drivers/usb/misc/Makefile @@ -31,3 +31,4 @@ obj-$(CONFIG_USB_CHAOSKEY) += chaoskey.o obj-$(CONFIG_USB_SISUSBVGA) += sisusbvga/ obj-$(CONFIG_USB_LINK_LAYER_TEST) += lvstest.o +obj-$(CONFIG_USB_ONBOARD_HUB) += onboard_usb_hub.o diff --git a/drivers/usb/misc/onboard_usb_hub.c b/drivers/usb/misc/onboard_usb_hub.c new file mode 100644 index 000000000000..eb3ba7512c69 --- /dev/null +++ b/drivers/usb/misc/onboard_usb_hub.c @@ -0,0 +1,371 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Driver for onboard USB hubs + * + * Copyright (c) 2020, Google LLC + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/************************** Platform driver **************************/ + +struct udev_node { + struct usb_device *udev; + struct list_head list; +}; + +struct onboard_hub { + struct regulator *vdd; + struct device *dev; + bool power_off_in_suspend; + bool is_powered_on; + bool going_away; + struct list_head udev_list; + struct mutex lock; +}; + +static int onboard_hub_power_on(struct onboard_hub *hub) +{ + int err; + + err = regulator_enable(hub->vdd); + if (err) { + dev_err(hub->dev, "failed to enable regulator: %d\n", err); + return err; + } + + hub->is_powered_on = true; + + return 0; +} + +static int onboard_hub_power_off(struct onboard_hub *hub) +{ + int err; + + err = regulator_disable(hub->vdd); + if (err) { + dev_err(hub->dev, "failed to enable regulator: %d\n", err); + return err; + } + + hub->is_powered_on = false; + + return 0; +} + +static int __maybe_unused onboard_hub_suspend(struct device *dev) +{ + struct onboard_hub *hub = dev_get_drvdata(dev); + struct udev_node *node; + bool power_off; + int rc = 0; + + if (!hub->power_off_in_suspend) + return 0; + + power_off = true; + + mutex_lock(&hub->lock); + + list_for_each_entry(node, &hub->udev_list, list) { + if (!device_may_wakeup(node->udev->bus->controller)) + continue; + + if (usb_wakeup_enabled_descendants(node->udev)) { + power_off = false; + break; + } + } + + mutex_unlock(&hub->lock); + + if (power_off) + rc = onboard_hub_power_off(hub); + + return rc; +} + +static int __maybe_unused onboard_hub_resume(struct device *dev) +{ + struct onboard_hub *hub = dev_get_drvdata(dev); + int rc = 0; + + if (!hub->is_powered_on) + rc = onboard_hub_power_on(hub); + + return rc; +} + +static int onboard_hub_add_usbdev(struct onboard_hub *hub, struct usb_device *udev) +{ + struct udev_node *node; + int ret = 0; + + mutex_lock(&hub->lock); + + if (hub->going_away) { + ret = -EINVAL; + goto unlock; + } + + node = devm_kzalloc(hub->dev, sizeof(*node), GFP_KERNEL); + if (!node) { + ret = -ENOMEM; + goto unlock; + } + + node->udev = udev; + + list_add(&node->list, &hub->udev_list); + +unlock: + mutex_unlock(&hub->lock); + + return ret; +} + +static void onboard_hub_remove_usbdev(struct onboard_hub *hub, struct usb_device *udev) +{ + struct udev_node *node; + + mutex_lock(&hub->lock); + + list_for_each_entry(node, &hub->udev_list, list) { + if (node->udev == udev) { + list_del(&node->list); + break; + } + } + + mutex_unlock(&hub->lock); +} + +static ssize_t power_off_in_suspend_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct onboard_hub *hub = dev_get_drvdata(dev); + + return sprintf(buf, "%d\n", hub->power_off_in_suspend); +} + +static ssize_t power_off_in_suspend_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct onboard_hub *hub = dev_get_drvdata(dev); + bool val; + int ret; + + ret = kstrtobool(buf, &val); + if (ret < 0) + return ret; + + hub->power_off_in_suspend = val; + + return count; +} +static DEVICE_ATTR_RW(power_off_in_suspend); + +static struct attribute *onboard_hub_sysfs_entries[] = { + &dev_attr_power_off_in_suspend.attr, + NULL, +}; + +static const struct attribute_group onboard_hub_sysfs_group = { + .attrs = onboard_hub_sysfs_entries, +}; + +static int onboard_hub_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct onboard_hub *hub; + int err; + + hub = devm_kzalloc(dev, sizeof(*hub), GFP_KERNEL); + if (!hub) + return -ENOMEM; + + hub->vdd = devm_regulator_get(dev, "vdd"); + if (IS_ERR(hub->vdd)) + return PTR_ERR(hub->vdd); + + hub->dev = dev; + mutex_init(&hub->lock); + INIT_LIST_HEAD(&hub->udev_list); + + dev_set_drvdata(dev, hub); + + err = devm_device_add_group(dev, &onboard_hub_sysfs_group); + if (err) { + dev_err(dev, "failed to create sysfs entries: %d\n", err); + return err; + } + + return onboard_hub_power_on(hub); +} + +static int onboard_hub_remove(struct platform_device *pdev) +{ + struct onboard_hub *hub = dev_get_drvdata(&pdev->dev); + struct udev_node *node; + struct usb_device *udev; + + hub->going_away = true; + + mutex_lock(&hub->lock); + + /* unbind the USB devices to avoid dangling references to this device */ + while (!list_empty(&hub->udev_list)) { + node = list_first_entry(&hub->udev_list, struct udev_node, list); + udev = node->udev; + + /* + * Unbinding the driver will call onboard_hub_remove_usbdev(), + * which acquires hub->lock. We must release the lock first. + */ + get_device(&udev->dev); + mutex_unlock(&hub->lock); + device_release_driver(&udev->dev); + put_device(&udev->dev); + mutex_lock(&hub->lock); + } + + mutex_unlock(&hub->lock); + + return onboard_hub_power_off(hub); +} + +static const struct of_device_id onboard_hub_match[] = { + { .compatible = "onboard-usb-hub" }, + { .compatible = "realtek,rts5411" }, + {} +}; +MODULE_DEVICE_TABLE(of, onboard_hub_match); + +static SIMPLE_DEV_PM_OPS(onboard_hub_pm_ops, onboard_hub_suspend, onboard_hub_resume); + +static struct platform_driver onboard_hub_driver = { + .probe = onboard_hub_probe, + .remove = onboard_hub_remove, + + .driver = { + .name = "onboard-usb-hub", + .of_match_table = onboard_hub_match, + .pm = pm_ptr(&onboard_hub_pm_ops), + }, +}; + +/************************** USB driver **************************/ + +#define VENDOR_ID_REALTEK 0x0bda + +static struct onboard_hub *_find_onboard_hub(struct device *dev) +{ + const phandle *ph; + struct device_node *np; + struct platform_device *pdev; + + ph = of_get_property(dev->of_node, "hub", NULL); + if (!ph) { + dev_err(dev, "failed to read 'hub' property\n"); + return ERR_PTR(-EINVAL); + } + + np = of_find_node_by_phandle(be32_to_cpu(*ph)); + if (!np) { + dev_err(dev, "failed find device node for onboard hub\n"); + return ERR_PTR(-EINVAL); + } + + pdev = of_find_device_by_node(np); + of_node_put(np); + if (!pdev) + return ERR_PTR(-EPROBE_DEFER); + + put_device(&pdev->dev); + + return dev_get_drvdata(&pdev->dev); +} + +static int onboard_hub_usbdev_probe(struct usb_device *udev) +{ + struct device *dev = &udev->dev; + struct onboard_hub *hub; + + /* ignore supported hubs without device tree node */ + if (!dev->of_node) + return -ENODEV; + + hub = _find_onboard_hub(dev); + if (IS_ERR(hub)) + return PTR_ERR(hub); + + dev_set_drvdata(dev, hub); + + return onboard_hub_add_usbdev(hub, udev); +} + +static void onboard_hub_usbdev_disconnect(struct usb_device *udev) +{ + struct onboard_hub *hub = dev_get_drvdata(&udev->dev); + + onboard_hub_remove_usbdev(hub, udev); +} + +static const struct usb_device_id onboard_hub_id_table[] = { + { USB_DEVICE(VENDOR_ID_REALTEK, 0x0411) }, /* RTS5411 USB 3.0 */ + { USB_DEVICE(VENDOR_ID_REALTEK, 0x5411) }, /* RTS5411 USB 2.0 */ + {}, +}; + +MODULE_DEVICE_TABLE(usb, onboard_hub_id_table); + +static struct usb_device_driver onboard_hub_usbdev_driver = { + + .name = "onboard-usb-hub", + .probe = onboard_hub_usbdev_probe, + .disconnect = onboard_hub_usbdev_disconnect, + .generic_subclass = 1, + .supports_autosuspend = 1, + .id_table = onboard_hub_id_table, +}; + +/************************** Driver (de)registration **************************/ + +static int __init onboard_hub_init(void) +{ + int ret; + + ret = platform_driver_register(&onboard_hub_driver); + if (ret) + return ret; + + ret = usb_register_device_driver(&onboard_hub_usbdev_driver, THIS_MODULE); + if (ret) + platform_driver_unregister(&onboard_hub_driver); + + return ret; +} +module_init(onboard_hub_init); + +static void __exit onboard_hub_exit(void) +{ + usb_deregister_device_driver(&onboard_hub_usbdev_driver); + platform_driver_unregister(&onboard_hub_driver); +} +module_exit(onboard_hub_exit); + +MODULE_AUTHOR("Matthias Kaehlcke "); +MODULE_DESCRIPTION("Driver for discrete onboard USB hubs"); +MODULE_LICENSE("GPL v2"); -- 2.28.0.709.gb0816b6eb0-goog