[v4,2/2] USB: misc: Add onboard_usb_hub driver

Message ID	20200928101326.v4.2.I7c9a1f1d6ced41dd8310e8a03da666a32364e790@changeid (mailing list archive)
State	New, archived
Headers	show Return-Path: <SRS0=Yi4h=DF=vger.kernel.org=linux-usb-owner@kernel.org> From: Matthias Kaehlcke <mka@chromium.org> To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Rob Herring <robh+dt@kernel.org>, Frank Rowand <frowand.list@gmail.com> Cc: linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, Bastien Nocera <hadess@hadess.net>, Stephen Boyd <swboyd@chromium.org>, Douglas Anderson <dianders@chromium.org>, Alan Stern <stern@rowland.harvard.edu>, Ravi Chandra Sadineni <ravisadineni@chromium.org>, Krzysztof Kozlowski <krzk@kernel.org>, devicetree@vger.kernel.org, Peter Chen <peter.chen@nxp.com>, Matthias Kaehlcke <mka@chromium.org>, "Alexander A. Klimov" <grandmaster@al2klimov.de>, "David S. Miller" <davem@davemloft.net>, Johan Hovold <johan@kernel.org>, Masahiro Yamada <yamada.masahiro@socionext.com>, Mauro Carvalho Chehab <mchehab+huawei@kernel.org>, Rob Herring <robh@kernel.org> 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> In-Reply-To: <20200928101326.v4.1.I248292623d3d0f6a4f0c5bc58478ca3c0062b49a@changeid> References: <20200928101326.v4.1.I248292623d3d0f6a4f0c5bc58478ca3c0062b49a@changeid> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	[v4,1/2] dt-bindings: usb: Add binding for discrete onboard USB hubs \| expand [v4,1/2] dt-bindings: usb: Add binding for discrete onboard USB hubs [v4,2/2] USB: misc: Add onboard_usb_hub driver

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 <mka@chromium.org> +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 <kyungmin.park@samsung.com> 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 <linux/device.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/of.h> +#include <linux/of_platform.h> +#include <linux/platform_device.h> +#include <linux/regulator/consumer.h> +#include <linux/suspend.h> +#include <linux/usb.h> +#include <linux/usb/hcd.h> + +/************************** 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 <mka@chromium.org>"); +MODULE_DESCRIPTION("Driver for discrete onboard USB hubs"); +MODULE_LICENSE("GPL v2");

[v4,2/2] USB: misc: Add onboard_usb_hub driver

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