From patchwork Thu Feb 23 13:24:50 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bastien Nocera X-Patchwork-Id: 13150340 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 9EBB0C677F1 for ; Thu, 23 Feb 2023 13:25:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233218AbjBWNZD (ORCPT ); Thu, 23 Feb 2023 08:25:03 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56036 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232900AbjBWNZD (ORCPT ); Thu, 23 Feb 2023 08:25:03 -0500 Received: from relay1-d.mail.gandi.net (relay1-d.mail.gandi.net [217.70.183.193]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 358D856794; Thu, 23 Feb 2023 05:25:01 -0800 (PST) Received: (Authenticated sender: hadess@hadess.net) by mail.gandi.net (Postfix) with ESMTPSA id B8A2F240014; Thu, 23 Feb 2023 13:24:57 +0000 (UTC) From: Bastien Nocera To: linux-usb@vger.kernel.org, linux-input@vger.kernel.org Cc: Greg Kroah-Hartman , Alan Stern , Benjamin Tissoires , =?utf-8?q?Filipe_La?= =?utf-8?q?=C3=ADns?= , Nestor Lopez Casado Subject: [PATCH 3/5] USB: core: Add wireless_status sysfs attribute Date: Thu, 23 Feb 2023 14:24:50 +0100 Message-Id: <20230223132452.37958-3-hadess@hadess.net> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230223132452.37958-1-hadess@hadess.net> References: <20230223132452.37958-1-hadess@hadess.net> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Add a wireless_status sysfs attribute to USB devices to keep track of whether a USB device that uses a receiver/emitter combo has its emitter connected or disconnected. By default, the USB device will declare not to use a receiver/emitter. Signed-off-by: Bastien Nocera --- Documentation/ABI/testing/sysfs-bus-usb | 12 ++++++ drivers/usb/core/sysfs.c | 50 +++++++++++++++++++++++++ drivers/usb/core/usb.h | 1 + include/linux/usb.h | 10 +++++ 4 files changed, 73 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-bus-usb b/Documentation/ABI/testing/sysfs-bus-usb index 545c2dd97ed0..0bd22ece05cd 100644 --- a/Documentation/ABI/testing/sysfs-bus-usb +++ b/Documentation/ABI/testing/sysfs-bus-usb @@ -166,6 +166,18 @@ Description: The file will be present for all speeds of USB devices, and will always read "no" for USB 1.1 and USB 2.0 devices. +What: /sys/bus/usb/devices//wireless_status +Date: January 2023 +Contact: Bastien Nocera +Description: + Some USB devices use a small USB receiver coupled with a larger + wireless device, usually communicating using proprietary + wireless protocols. This attribute will read either "connected" + or "disconnected" depending on whether the emitter is turned on, + in range and connected, on the interface which is used to detect + this state. If the device does not use a receiver/emitter combo, + then this attribute will not exist. + What: /sys/bus/usb/devices/...//port Date: August 2012 Contact: Lan Tianyu diff --git a/drivers/usb/core/sysfs.c b/drivers/usb/core/sysfs.c index 8217032dfb85..da3c0f0dd633 100644 --- a/drivers/usb/core/sysfs.c +++ b/drivers/usb/core/sysfs.c @@ -1232,9 +1232,59 @@ static const struct attribute_group intf_assoc_attr_grp = { .is_visible = intf_assoc_attrs_are_visible, }; +static ssize_t wireless_status_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct usb_interface *intf; + + intf = to_usb_interface(dev); + if (intf->wireless_status == USB_WIRELESS_STATUS_DISCONNECTED) + return sysfs_emit(buf, "%s\n", "disconnected"); + return sysfs_emit(buf, "%s\n", "connected"); +} +static DEVICE_ATTR_RO(wireless_status); + +static struct attribute *intf_wireless_status_attrs[] = { + &dev_attr_wireless_status.attr, + NULL +}; + +static umode_t intf_wireless_status_attr_is_visible(struct kobject *kobj, + struct attribute *a, int n) +{ + struct device *dev = kobj_to_dev(kobj); + struct usb_interface *intf = to_usb_interface(dev); + + if (a != &dev_attr_wireless_status.attr || + intf->wireless_status != USB_WIRELESS_STATUS_NA) + return a->mode; + return 0; +} + +static const struct attribute_group intf_wireless_status_attr_grp = { + .attrs = intf_wireless_status_attrs, + .is_visible = intf_wireless_status_attr_is_visible, +}; + +int usb_update_wireless_status_attr(struct usb_interface *intf) +{ + struct device *dev = &intf->dev; + int ret; + + ret = sysfs_update_group(&dev->kobj, &intf_wireless_status_attr_grp); + if (ret < 0) + return ret; + + sysfs_notify(&dev->kobj, NULL, "wireless_status"); + kobject_uevent(&dev->kobj, KOBJ_CHANGE); + + return 0; +} + const struct attribute_group *usb_interface_groups[] = { &intf_attr_grp, &intf_assoc_attr_grp, + &intf_wireless_status_attr_grp, NULL }; diff --git a/drivers/usb/core/usb.h b/drivers/usb/core/usb.h index 0eac7d4285d1..3f14e15f07f6 100644 --- a/drivers/usb/core/usb.h +++ b/drivers/usb/core/usb.h @@ -15,6 +15,7 @@ extern int usb_create_sysfs_dev_files(struct usb_device *dev); extern void usb_remove_sysfs_dev_files(struct usb_device *dev); extern void usb_create_sysfs_intf_files(struct usb_interface *intf); extern void usb_remove_sysfs_intf_files(struct usb_interface *intf); +extern int usb_update_wireless_status_attr(struct usb_interface *intf); extern int usb_create_ep_devs(struct device *parent, struct usb_host_endpoint *endpoint, struct usb_device *udev); diff --git a/include/linux/usb.h b/include/linux/usb.h index 86d1c8e79566..517ae4b4e333 100644 --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -170,6 +170,12 @@ usb_find_last_int_out_endpoint(struct usb_host_interface *alt, return usb_find_common_endpoints_reverse(alt, NULL, NULL, NULL, int_out); } +enum usb_wireless_status { + USB_WIRELESS_STATUS_NA = 0, + USB_WIRELESS_STATUS_DISCONNECTED, + USB_WIRELESS_STATUS_CONNECTED, +}; + /** * struct usb_interface - what usb device drivers talk to * @altsetting: array of interface structures, one for each alternate @@ -203,6 +209,8 @@ usb_find_last_int_out_endpoint(struct usb_host_interface *alt, * @reset_ws: Used for scheduling resets from atomic context. * @resetting_device: USB core reset the device, so use alt setting 0 as * current; needs bandwidth alloc after reset. + * @wireless_status: if the USB device uses a receiver/emitter combo, whether + * the emitter is connected. * * USB device drivers attach to interfaces on a physical device. Each * interface encapsulates a single high level function, such as feeding @@ -253,6 +261,7 @@ struct usb_interface { unsigned needs_binding:1; /* needs delayed unbind/rebind */ unsigned resetting_device:1; /* true: bandwidth alloc after reset */ unsigned authorized:1; /* used for interface authorization */ + enum usb_wireless_status wireless_status; struct device dev; /* interface specific device info */ struct device *usb_dev; @@ -887,6 +896,7 @@ static inline int usb_interface_claimed(struct usb_interface *iface) extern void usb_driver_release_interface(struct usb_driver *driver, struct usb_interface *iface); + const struct usb_device_id *usb_match_id(struct usb_interface *interface, const struct usb_device_id *id); extern int usb_match_one_id(struct usb_interface *interface,