This backports upstream accepted fix.
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
--- /dev/null
+From 0f247626cbbfa2010d2b86fdee652605e084e248 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
+Date: Fri, 16 Sep 2016 16:13:48 +0200
+Subject: [PATCH] usb: core: Introduce a USB port LED trigger
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+This commit adds a new trigger responsible for turning on LED when USB
+device gets connected to the selected USB port. This can can useful for
+various home routers that have USB port(s) and a proper LED telling user
+a device is connected.
+
+The trigger gets its documentation file but basically it just requires
+enabling it and selecting USB ports (e.g. echo 1 > ports/usb1-1).
+
+There was a long discussion on design of this driver. Its current state
+is a result of picking them most adjustable solution as others couldn't
+handle all cases.
+
+1) It wasn't possible for the driver to register separated trigger for
+ each USB port. Some physical USB ports are handled by more than one
+ controller and so by more than one USB port. E.g. USB 2.0 physical
+ port may be handled by OHCI's port and EHCI's port.
+ It's also not possible to assign more than 1 trigger to a single LED
+ and implementing such feature would be tricky due to syncing triggers
+ and sysfs conflicts with old triggers.
+
+2) Another idea was to register trigger per USB hub. This wouldn't allow
+ handling devices with multiple USB LEDs and controllers (hubs)
+ controlling more than 1 physical port. It's common for hubs to have
+ few ports and each may have its own LED.
+
+This final trigger is highly flexible. It allows selecting any USB ports
+for any LED. It was also modified (comparing to the initial version) to
+allow choosing ports rather than having user /guess/ proper names. It
+was successfully tested on SmartRG SR400ac which has 3 USB LEDs,
+2 physical ports and 3 controllers.
+
+It was noted USB subsystem already has usb-gadget and usb-host triggers
+but they are pretty trivial ones. They indicate activity only and can't
+have ports specified.
+
+In future it may be good idea to consider adding activity support to
+usbport as well. This should allow switching to this more generic driver
+and maybe marking old ones as obsolete.
+This can be implemented with another sysfs file for setting mode. The
+default mode wouldn't change so there won't be ABI breakage and so such
+feature can be safely implemented later.
+
+There was also an idea of supporting other devices (PCI, SDIO, etc.) but
+as this driver already contains some USB specific code (and will get
+more) these should be probably separated drivers (triggers).
+
+Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ .../ABI/testing/sysfs-class-led-trigger-usbport | 12 +
+ Documentation/leds/ledtrig-usbport.txt | 41 +++
+ drivers/usb/core/Kconfig | 8 +
+ drivers/usb/core/Makefile | 2 +
+ drivers/usb/core/ledtrig-usbport.c | 314 +++++++++++++++++++++
+ 5 files changed, 377 insertions(+)
+ create mode 100644 Documentation/ABI/testing/sysfs-class-led-trigger-usbport
+ create mode 100644 Documentation/leds/ledtrig-usbport.txt
+ create mode 100644 drivers/usb/core/ledtrig-usbport.c
+
+--- /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.
+--- /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
+--- a/drivers/usb/core/Kconfig
++++ b/drivers/usb/core/Kconfig
+@@ -103,3 +103,11 @@ config USB_ULPI_BUS
+
+ To compile this driver as a module, choose M here: the module will
+ be called ulpi.
++
++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.
+--- a/drivers/usb/core/Makefile
++++ b/drivers/usb/core/Makefile
+@@ -11,3 +11,5 @@ 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
+--- /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");
--- /dev/null
+From 89778ba335e302a450932ce5b703c1ee6216e949 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
+Date: Tue, 6 Dec 2016 00:39:33 +0100
+Subject: [PATCH] usb: core: usbport: Use proper LED API to fix potential crash
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Calling brightness_set manually isn't safe as some LED drivers don't
+implement this callback. The best idea is to just use a proper helper
+which will fallback to the brightness_set_blocking callback if needed.
+
+This fixes:
+[ 1461.761528] Unable to handle kernel NULL pointer dereference at virtual address 00000000
+(...)
+[ 1462.117049] Backtrace:
+[ 1462.119521] [<bf228164>] (usbport_trig_port_store [ledtrig_usbport]) from [<c023f758>] (dev_attr_store+0x20/0x2c)
+[ 1462.129826] r7:dcabc7c0 r6:dee0ff80 r5:00000002 r4:bf228164
+[ 1462.135511] [<c023f738>] (dev_attr_store) from [<c0169310>] (sysfs_kf_write+0x48/0x4c)
+[ 1462.143459] r5:00000002 r4:c023f738
+[ 1462.147049] [<c01692c8>] (sysfs_kf_write) from [<c0168ab8>] (kernfs_fop_write+0xf8/0x1f8)
+[ 1462.155258] r5:00000002 r4:df4a1000
+[ 1462.158850] [<c01689c0>] (kernfs_fop_write) from [<c0100c78>] (__vfs_write+0x34/0x120)
+[ 1462.166800] r10:00000000 r9:dee0e000 r8:c000fc24 r7:00000002 r6:dee0ff80 r5:c01689c0
+[ 1462.174660] r4:df727a80
+[ 1462.177204] [<c0100c44>] (__vfs_write) from [<c0101ae4>] (vfs_write+0xac/0x170)
+[ 1462.184543] r9:dee0e000 r8:c000fc24 r7:dee0ff80 r6:b6f092d0 r5:df727a80 r4:00000002
+[ 1462.192319] [<c0101a38>] (vfs_write) from [<c01028dc>] (SyS_write+0x4c/0xa8)
+[ 1462.199396] r9:dee0e000 r8:c000fc24 r7:00000002 r6:b6f092d0 r5:df727a80 r4:df727a80
+[ 1462.207174] [<c0102890>] (SyS_write) from [<c000fa60>] (ret_fast_syscall+0x0/0x3c)
+[ 1462.214774] r7:00000004 r6:ffffffff r5:00000000 r4:00000000
+[ 1462.220456] Code: bad PC value
+[ 1462.223560] ---[ end trace 676638a3a12c7a56 ]---
+
+Reported-by: Ralph Sennhauser <ralph.sennhauser@gmail.com>
+Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
+Fixes: 0f247626cbb ("usb: core: Introduce a USB port LED trigger")
+Cc: stable@vger.kernel.org # 4.9+
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/usb/core/ledtrig-usbport.c | 7 +++----
+ 1 file changed, 3 insertions(+), 4 deletions(-)
+
+--- a/drivers/usb/core/ledtrig-usbport.c
++++ b/drivers/usb/core/ledtrig-usbport.c
+@@ -74,8 +74,7 @@ static void usbport_trig_update_count(st
+
+ 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);
++ led_set_brightness(led_cdev, usbport_data->count ? LED_FULL : LED_OFF);
+ }
+
+ /***************************************
+@@ -228,12 +227,12 @@ static int usbport_trig_notify(struct no
+ 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);
++ led_set_brightness(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);
++ led_set_brightness(led_cdev, LED_OFF);
+ return NOTIFY_OK;
+ }
+
+++ /dev/null
-From 0f247626cbbfa2010d2b86fdee652605e084e248 Mon Sep 17 00:00:00 2001
-From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
-Date: Fri, 16 Sep 2016 16:13:48 +0200
-Subject: [PATCH] usb: core: Introduce a USB port LED trigger
-MIME-Version: 1.0
-Content-Type: text/plain; charset=UTF-8
-Content-Transfer-Encoding: 8bit
-
-This commit adds a new trigger responsible for turning on LED when USB
-device gets connected to the selected USB port. This can can useful for
-various home routers that have USB port(s) and a proper LED telling user
-a device is connected.
-
-The trigger gets its documentation file but basically it just requires
-enabling it and selecting USB ports (e.g. echo 1 > ports/usb1-1).
-
-There was a long discussion on design of this driver. Its current state
-is a result of picking them most adjustable solution as others couldn't
-handle all cases.
-
-1) It wasn't possible for the driver to register separated trigger for
- each USB port. Some physical USB ports are handled by more than one
- controller and so by more than one USB port. E.g. USB 2.0 physical
- port may be handled by OHCI's port and EHCI's port.
- It's also not possible to assign more than 1 trigger to a single LED
- and implementing such feature would be tricky due to syncing triggers
- and sysfs conflicts with old triggers.
-
-2) Another idea was to register trigger per USB hub. This wouldn't allow
- handling devices with multiple USB LEDs and controllers (hubs)
- controlling more than 1 physical port. It's common for hubs to have
- few ports and each may have its own LED.
-
-This final trigger is highly flexible. It allows selecting any USB ports
-for any LED. It was also modified (comparing to the initial version) to
-allow choosing ports rather than having user /guess/ proper names. It
-was successfully tested on SmartRG SR400ac which has 3 USB LEDs,
-2 physical ports and 3 controllers.
-
-It was noted USB subsystem already has usb-gadget and usb-host triggers
-but they are pretty trivial ones. They indicate activity only and can't
-have ports specified.
-
-In future it may be good idea to consider adding activity support to
-usbport as well. This should allow switching to this more generic driver
-and maybe marking old ones as obsolete.
-This can be implemented with another sysfs file for setting mode. The
-default mode wouldn't change so there won't be ABI breakage and so such
-feature can be safely implemented later.
-
-There was also an idea of supporting other devices (PCI, SDIO, etc.) but
-as this driver already contains some USB specific code (and will get
-more) these should be probably separated drivers (triggers).
-
-Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
-Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
----
- .../ABI/testing/sysfs-class-led-trigger-usbport | 12 +
- Documentation/leds/ledtrig-usbport.txt | 41 +++
- drivers/usb/core/Kconfig | 8 +
- drivers/usb/core/Makefile | 2 +
- drivers/usb/core/ledtrig-usbport.c | 314 +++++++++++++++++++++
- 5 files changed, 377 insertions(+)
- create mode 100644 Documentation/ABI/testing/sysfs-class-led-trigger-usbport
- create mode 100644 Documentation/leds/ledtrig-usbport.txt
- create mode 100644 drivers/usb/core/ledtrig-usbport.c
-
---- /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.
---- /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
---- a/drivers/usb/core/Kconfig
-+++ b/drivers/usb/core/Kconfig
-@@ -103,3 +103,11 @@ config USB_ULPI_BUS
-
- To compile this driver as a module, choose M here: the module will
- be called ulpi.
-+
-+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.
---- a/drivers/usb/core/Makefile
-+++ b/drivers/usb/core/Makefile
-@@ -11,3 +11,5 @@ 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
---- /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");
projects / openwrt / staging / blogic.git / commitdiff