usb: core: Use module_led_trigger macro to simplify the code

Use the module_led_trigger macro to simplify the code, which is the
same as declaring with module_init() and module_exit().

Signed-off-by: Li Zetao <lizetao1@huawei.com>
Link: https://lore.kernel.org/r/20230815074648.1015175-1-lizetao1@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: core: ledtrig-usbport: Demote obvious misuse of kerneldoc to standard comment blocks

No attempt has been made to document any of the functions here.

Fixes the following W=1 kernel build warning(s):

drivers/usb/core/ledtrig-usbport.c:42: warning: Function parameter or member 'usbport_data' not described in 'usbport_trig_usb_dev_observed'
drivers/usb/core/ledtrig-usbport.c:42: warning: Function parameter or member 'usb_dev' not described in 'usbport_trig_usb_dev_observed'
drivers/usb/core/ledtrig-usbport.c:71: warning: Function parameter or member 'usbport_data' not described in 'usbport_trig_update_count'
drivers/usb/core/ledtrig-usbport.c:131: warning: Function parameter or member 'usbport_data' not described in 'usbport_trig_port_observed'
drivers/usb/core/ledtrig-usbport.c:131: warning: Function parameter or member 'usb_dev' not described in 'usbport_trig_port_observed'
drivers/usb/core/ledtrig-usbport.c:131: warning: Function parameter or member 'port1' not described in 'usbport_trig_port_observed'

Cc: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20200703174148.2749969-4-lee.jones@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB: leds: fix regression in usbport led trigger

The patch "usb: simplify usbport trigger" together with "leds: triggers:
add device attribute support" caused an regression for the usbport
trigger. it will no longer enumerate any active usb hub ports under the
"ports" directory in the sysfs class directory, if the usb host drivers
are fully initialized before the usbport trigger was loaded.

The reason is that the usbport driver tries to register the sysfs
entries during the activate() callback. And this will fail with -2 /
ENOENT because the patch "leds: triggers: add device attribute support"
made it so that the sysfs "ports" group was only being added after the
activate() callback succeeded.

This version of the patch reverts parts of the "usb: simplify usbport
trigger" patch and restores usbport trigger's functionality.

Fixes: 6f7b0bad8839 ("usb: simplify usbport trigger")
Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
Cc: stable <stable@vger.kernel.org>
Acked-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: simplify usbport trigger

The led trigger core learned a few things that allow to simplify the
trigger drivers. Make use of automated trigger attributes and error
checking of the activate callback. Also use the wrappers to set and get
trigger_data.

Acked-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>

leds: triggers: let struct led_trigger::activate() return an error code

Given that activating a trigger can fail, let the callback return an
indication. This prevents to have a trigger active according to the
"trigger" sysfs attribute but not functional.

All users are changed accordingly to return 0 for now. There is no intended
change in behaviour.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>

USB: of: clean up device-node helper

Clean up the USB device-node helper that is used to look up a device
node given a parent hub device and a port number. Also pass in a struct
usb_device as first argument to provide some type checking.

Give the helper the more descriptive name usb_of_get_device_node(),
which matches the new usb_of_get_interface_node() helper that is used to
look up a second type of of child node from a USB device.

Note that the terms "device node" and "interface node" are defined and
used by the OF Recommended Practice for USB.

Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB: ledtrig-usbport: fix of-node leak

This code looks up a USB device node from a given parent USB device but
never dropped its reference to the returned node.

As only the address of the node is used for a later matching, the
reference can be dropped immediately.

Note that this trigger implementation confuses the description of the
USB device connected to a port with the port itself (which does not have
a device-tree representation).

Fixes: 4f04c210d031 ("usb: core: read USB ports from DT in the usbport LED trigger driver")
Cc: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB: core: Remove redundant license text

Now that the SPDX tag is in all USB files, that identifies the license
in a specific and legally-defined manner. So the extra GPL text wording
can be removed as it is no longer needed at all.

This is done on a quest to remove the 700+ different ways that files in
the kernel describe the GPL license text. And there's unneeded stuff
like the address (sometimes incorrect) for the FSF which is never
needed.

No copyright headers or other non-license-description text was removed.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB: add SPDX identifiers to all remaining files in drivers/usb/

It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the drivers/usb/ and include/linux/usb* files with the correct
SPDX license identifier based on the license text in the file itself.
The SPDX identifier is a legally binding shorthand, which can be used
instead of the full boiler plate text.

This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Acked-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: core: usbport: fix "BUG: key not in .data" when lockdep is enabled

This patch fixes a splat that happens if CONFIG_DEBUG_LOCK_ALLOC
is enabled and the ledtrig_usbport is loaded. (on a device that
has some usb ports).

[ 60.695479] BUG: key c53f8420 not in .data!
[ 60.695521] ------------[ cut here ]------------
[ 60.698542] WARNING: CPU: 1 PID: 854 at kernel/locking/lockdep.c:3134 __kernfs_create_file+0x5c/0xc0
[ 60.703355] DEBUG_LOCKS_WARN_ON(1)
[ 60.712534] Modules linked in:
[ 60.944078] CPU: 1 PID: 854 Comm: S96led Not tainted 4.9.44 #0
[ 60.944329] Hardware name: Generic DT based system
[ 60.950106] [<c021585c>] (unwind_backtrace) from [<c0212150>] (show_stack+0x10/0x14)
[ 60.954878] [<c0212150>] (show_stack) from [<c03a2bc4>] (dump_stack+0x7c/0x9c)
[ 60.962772] [<c03a2bc4>] (dump_stack) from [<c021db34>] (__warn+0xbc/0xec)
[ 60.969799] [<c021db34>] (__warn) from [<c021db98>] (warn_slowpath_fmt+0x34/0x44)
[ 60.976656] [<c021db98>] (warn_slowpath_fmt)
[ 60.984210] [<c0320688>] (__kernfs_create_file)
[ 60.992712] [<c0320ef0>] (sysfs_add_file_mode_ns)
[ 61.002090] [<c0321044>] (sysfs_add_file) from
[ 61.010619] [<c0321094>] (sysfs_add_file_to_group)
[ 61.019263] [<bf24a47c>] (usbport_trig_add_usb_dev_ports [ledtrig_usbport])
[ 61.031002] [<c0430414>] (bus_for_each_dev)
[ 61.042106] [<c0497dc4>] (usb_for_each_dev)
[ 61.050375] [<bf24a2ac>] (usbport_trig_activate [ledtrig_usbport])
[ 61.060685] [<c04e1708>] (led_trigger_set) from [<c04e1834>]
[...]

Signed-off-by: Christian Lamparter <chunkeey@googlemail.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: Convert to using %pOF instead of full_name

Now that we have a custom printf format specifier, convert users of
full_name to use %pOF instead. This is preparation to remove storing
of the full path string for each node.

Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: core: read USB ports from DT in the usbport LED trigger driver

This uses DT info to read relation description of LEDs and USB ports. If
DT has properly described LEDs, trigger will know when to turn them on.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: core: usbport: Use proper LED API to fix potential crash

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>

usb: core: Introduce a USB port LED trigger

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>