diff options
| -rw-r--r-- | Documentation/ABI/testing/sysfs-class-led-trigger-usbport | 12 | ||||
| -rw-r--r-- | Documentation/leds/ledtrig-usbport.txt | 41 | ||||
| -rw-r--r-- | drivers/usb/core/Kconfig | 8 | ||||
| -rw-r--r-- | drivers/usb/core/Makefile | 2 | ||||
| -rw-r--r-- | drivers/usb/core/ledtrig-usbport.c | 314 |
5 files changed, 377 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-led-trigger-usbport b/Documentation/ABI/testing/sysfs-class-led-trigger-usbport new file mode 100644 index 000000000000..f440e690daef --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-led-trigger-usbport @@ -0,0 +1,12 @@ +What: /sys/class/leds/<led>/ports/<port> +Date: September 2016 +KernelVersion: 4.9 +Contact: linux-leds@vger.kernel.org + linux-usb@vger.kernel.org +Description: + Every dir entry represents a single USB port that can be + selected for the USB port trigger. Selecting ports makes trigger + observing them for any connected devices and lighting on LED if + there are any. + Echoing "1" value selects USB port. Echoing "0" unselects it. + Current state can be also read. diff --git a/Documentation/leds/ledtrig-usbport.txt b/Documentation/leds/ledtrig-usbport.txt new file mode 100644 index 000000000000..69f54bfb4789 --- /dev/null +++ b/Documentation/leds/ledtrig-usbport.txt @@ -0,0 +1,41 @@ +USB port LED trigger +==================== + +This LED trigger can be used for signalling to the user a presence of USB device +in a given port. It simply turns on LED when device appears and turns it off +when it disappears. + +It requires selecting USB ports that should be observed. All available ones are +listed as separated entries in a "ports" subdirectory. Selecting is handled by +echoing "1" to a chosen port. + +Please note that this trigger allows selecting multiple USB ports for a single +LED. This can be useful in two cases: + +1) Device with single USB LED and few physical ports + +In such a case LED will be turned on as long as there is at least one connected +USB device. + +2) Device with a physical port handled by few controllers + +Some devices may have one controller per PHY standard. E.g. USB 3.0 physical +port may be handled by ohci-platform, ehci-platform and xhci-hcd. If there is +only one LED user will most likely want to assign ports from all 3 hubs. + + +This trigger can be activated from user space on led class devices as shown +below: + + echo usbport > trigger + +This adds sysfs attributes to the LED that are documented in: +Documentation/ABI/testing/sysfs-class-led-trigger-usbport + +Example use-case: + + echo usbport > trigger + echo 1 > ports/usb1-port1 + echo 1 > ports/usb2-port1 + cat ports/usb1-port1 + echo 0 > ports/usb1-port1 diff --git a/drivers/usb/core/Kconfig b/drivers/usb/core/Kconfig index d6e43ce96799..0e5a889742b3 100644 --- a/drivers/usb/core/Kconfig +++ b/drivers/usb/core/Kconfig @@ -82,3 +82,11 @@ config USB_OTG_FSM help Implements OTG Finite State Machine as specified in On-The-Go and Embedded Host Supplement to the USB Revision 2.0 Specification. + +config USB_LEDS_TRIGGER_USBPORT + tristate "USB port LED trigger" + depends on USB && LEDS_TRIGGERS + help + This driver allows LEDs to be controlled by USB events. Enabling this + trigger allows specifying list of USB ports that should turn on LED + when some USB device gets connected. diff --git a/drivers/usb/core/Makefile b/drivers/usb/core/Makefile index da36b784a0ef..b99b871c4b9d 100644 --- a/drivers/usb/core/Makefile +++ b/drivers/usb/core/Makefile @@ -12,3 +12,5 @@ usbcore-$(CONFIG_PCI) += hcd-pci.o usbcore-$(CONFIG_ACPI) += usb-acpi.o obj-$(CONFIG_USB) += usbcore.o + +obj-$(CONFIG_USB_LEDS_TRIGGER_USBPORT) += ledtrig-usbport.o diff --git a/drivers/usb/core/ledtrig-usbport.c b/drivers/usb/core/ledtrig-usbport.c new file mode 100644 index 000000000000..3ed5162677ad --- /dev/null +++ b/drivers/usb/core/ledtrig-usbport.c @@ -0,0 +1,314 @@ +/* + * USB port LED trigger + * + * Copyright (C) 2016 Rafał Miłecki <rafal@milecki.pl> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/device.h> +#include <linux/leds.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/usb.h> + +struct usbport_trig_data { + struct led_classdev *led_cdev; + struct list_head ports; + struct notifier_block nb; + int count; /* Amount of connected matching devices */ +}; + +struct usbport_trig_port { + struct usbport_trig_data *data; + struct usb_device *hub; + int portnum; + char *port_name; + bool observed; + struct device_attribute attr; + struct list_head list; +}; + +/*************************************** + * Helpers + ***************************************/ + +/** + * usbport_trig_usb_dev_observed - Check if dev is connected to observed port + */ +static bool usbport_trig_usb_dev_observed(struct usbport_trig_data *usbport_data, + struct usb_device *usb_dev) +{ + struct usbport_trig_port *port; + + if (!usb_dev->parent) + return false; + + list_for_each_entry(port, &usbport_data->ports, list) { + if (usb_dev->parent == port->hub && + usb_dev->portnum == port->portnum) + return port->observed; + } + + return false; +} + +static int usbport_trig_usb_dev_check(struct usb_device *usb_dev, void *data) +{ + struct usbport_trig_data *usbport_data = data; + + if (usbport_trig_usb_dev_observed(usbport_data, usb_dev)) + usbport_data->count++; + + return 0; +} + +/** + * usbport_trig_update_count - Recalculate amount of connected matching devices + */ +static void usbport_trig_update_count(struct usbport_trig_data *usbport_data) +{ + struct led_classdev *led_cdev = usbport_data->led_cdev; + + usbport_data->count = 0; + usb_for_each_dev(usbport_data, usbport_trig_usb_dev_check); + led_cdev->brightness_set(led_cdev, + usbport_data->count ? LED_FULL : LED_OFF); +} + +/*************************************** + * Device attr + ***************************************/ + +static ssize_t usbport_trig_port_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct usbport_trig_port *port = container_of(attr, + struct usbport_trig_port, + attr); + + return sprintf(buf, "%d\n", port->observed) + 1; +} + +static ssize_t usbport_trig_port_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t size) +{ + struct usbport_trig_port *port = container_of(attr, + struct usbport_trig_port, + attr); + + if (!strcmp(buf, "0") || !strcmp(buf, "0\n")) + port->observed = 0; + else if (!strcmp(buf, "1") || !strcmp(buf, "1\n")) + port->observed = 1; + else + return -EINVAL; + + usbport_trig_update_count(port->data); + + return size; +} + +static struct attribute *ports_attrs[] = { + NULL, +}; +static const struct attribute_group ports_group = { + .name = "ports", + .attrs = ports_attrs, +}; + +/*************************************** + * Adding & removing ports + ***************************************/ + +static int usbport_trig_add_port(struct usbport_trig_data *usbport_data, + struct usb_device *usb_dev, + const char *hub_name, int portnum) +{ + struct led_classdev *led_cdev = usbport_data->led_cdev; + struct usbport_trig_port *port; + size_t len; + int err; + + port = kzalloc(sizeof(*port), GFP_KERNEL); + if (!port) { + err = -ENOMEM; + goto err_out; + } + + port->data = usbport_data; + port->hub = usb_dev; + port->portnum = portnum; + + len = strlen(hub_name) + 8; + port->port_name = kzalloc(len, GFP_KERNEL); + if (!port->port_name) { + err = -ENOMEM; + goto err_free_port; + } + snprintf(port->port_name, len, "%s-port%d", hub_name, portnum); + + port->attr.attr.name = port->port_name; + port->attr.attr.mode = S_IRUSR | S_IWUSR; + port->attr.show = usbport_trig_port_show; + port->attr.store = usbport_trig_port_store; + + err = sysfs_add_file_to_group(&led_cdev->dev->kobj, &port->attr.attr, + ports_group.name); + if (err) + goto err_free_port_name; + + list_add_tail(&port->list, &usbport_data->ports); + + return 0; + +err_free_port_name: + kfree(port->port_name); +err_free_port: + kfree(port); +err_out: + return err; +} + +static int usbport_trig_add_usb_dev_ports(struct usb_device *usb_dev, + void *data) +{ + struct usbport_trig_data *usbport_data = data; + int i; + + for (i = 1; i <= usb_dev->maxchild; i++) + usbport_trig_add_port(usbport_data, usb_dev, + dev_name(&usb_dev->dev), i); + + return 0; +} + +static void usbport_trig_remove_port(struct usbport_trig_data *usbport_data, + struct usbport_trig_port *port) +{ + struct led_classdev *led_cdev = usbport_data->led_cdev; + + list_del(&port->list); + sysfs_remove_file_from_group(&led_cdev->dev->kobj, &port->attr.attr, + ports_group.name); + kfree(port->port_name); + kfree(port); +} + +static void usbport_trig_remove_usb_dev_ports(struct usbport_trig_data *usbport_data, + struct usb_device *usb_dev) +{ + struct usbport_trig_port *port, *tmp; + + list_for_each_entry_safe(port, tmp, &usbport_data->ports, list) { + if (port->hub == usb_dev) + usbport_trig_remove_port(usbport_data, port); + } +} + +/*************************************** + * Init, exit, etc. + ***************************************/ + +static int usbport_trig_notify(struct notifier_block *nb, unsigned long action, + void *data) +{ + struct usbport_trig_data *usbport_data = + container_of(nb, struct usbport_trig_data, nb); + struct led_classdev *led_cdev = usbport_data->led_cdev; + struct usb_device *usb_dev = data; + bool observed; + + observed = usbport_trig_usb_dev_observed(usbport_data, usb_dev); + + switch (action) { + case USB_DEVICE_ADD: + usbport_trig_add_usb_dev_ports(usb_dev, usbport_data); + if (observed && usbport_data->count++ == 0) + led_cdev->brightness_set(led_cdev, LED_FULL); + return NOTIFY_OK; + case USB_DEVICE_REMOVE: + usbport_trig_remove_usb_dev_ports(usbport_data, usb_dev); + if (observed && --usbport_data->count == 0) + led_cdev->brightness_set(led_cdev, LED_OFF); + return NOTIFY_OK; + } + + return NOTIFY_DONE; +} + +static void usbport_trig_activate(struct led_classdev *led_cdev) +{ + struct usbport_trig_data *usbport_data; + int err; + + usbport_data = kzalloc(sizeof(*usbport_data), GFP_KERNEL); + if (!usbport_data) + return; + usbport_data->led_cdev = led_cdev; + + /* List of ports */ + INIT_LIST_HEAD(&usbport_data->ports); + err = sysfs_create_group(&led_cdev->dev->kobj, &ports_group); + if (err) + goto err_free; + usb_for_each_dev(usbport_data, usbport_trig_add_usb_dev_ports); + + /* Notifications */ + usbport_data->nb.notifier_call = usbport_trig_notify, + led_cdev->trigger_data = usbport_data; + usb_register_notify(&usbport_data->nb); + + led_cdev->activated = true; + return; + +err_free: + kfree(usbport_data); +} + +static void usbport_trig_deactivate(struct led_classdev *led_cdev) +{ + struct usbport_trig_data *usbport_data = led_cdev->trigger_data; + struct usbport_trig_port *port, *tmp; + + if (!led_cdev->activated) + return; + + list_for_each_entry_safe(port, tmp, &usbport_data->ports, list) { + usbport_trig_remove_port(usbport_data, port); + } + + usb_unregister_notify(&usbport_data->nb); + + sysfs_remove_group(&led_cdev->dev->kobj, &ports_group); + + kfree(usbport_data); + + led_cdev->activated = false; +} + +static struct led_trigger usbport_led_trigger = { + .name = "usbport", + .activate = usbport_trig_activate, + .deactivate = usbport_trig_deactivate, +}; + +static int __init usbport_trig_init(void) +{ + return led_trigger_register(&usbport_led_trigger); +} + +static void __exit usbport_trig_exit(void) +{ + led_trigger_unregister(&usbport_led_trigger); +} + +module_init(usbport_trig_init); +module_exit(usbport_trig_exit); + +MODULE_AUTHOR("Rafał Miłecki <rafal@milecki.pl>"); +MODULE_DESCRIPTION("USB port trigger"); +MODULE_LICENSE("GPL v2"); |