[ Upstream commit 43007b89fb ]
When multiple Apple devices are connected concurrently, the
apple-mfi-fastcharge driver fails to probe the subsequent devices with
the following error:
sysfs: cannot create duplicate filename '/class/power_supply/apple_mfi_fastcharge'
apple-mfi-fastcharge 5-2.4.3.3: probe of 5-2.4.3.3 failed with error -17
This happens because the driver uses a fixed power supply name
("apple_mfi_fastcharge") for all devices, causing a sysfs name
conflict when a second device is connected.
Fix this by generating unique names using the USB bus and device
number (e.g., "apple_mfi_fastcharge_5-12"). This ensures each
connected device gets a unique power supply entry in sysfs.
The change requires storing a copy of the power_supply_desc structure
in the per-device mfi_device struct, since the name pointer needs to
remain valid for the lifetime of the power supply registration.
Fixes: 249fa8217b ("USB: Add driver to control USB fast charge for iOS devices")
Signed-off-by: Charalampos Mitrodimas <charmitro@posteo.net>
Link: https://lore.kernel.org/r/20250602-apple-mfi-fastcharge-duplicate-sysfs-v1-1-5d84de34fac6@posteo.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d73dc7b182 ]
[Syzbot reported two possible deadlocks]
The first possible deadlock is:
WARNING: possible recursive locking detected
6.12.0-rc1-syzkaller-00027-g4a9fe2a8ac53 #0 Not tainted
--------------------------------------------
syz-executor363/2651 is trying to acquire lock:
ffffffff89b120e8 (chaoskey_list_lock){+.+.}-{3:3}, at: chaoskey_release+0x15d/0x2c0 drivers/usb/misc/chaoskey.c:322
but task is already holding lock:
ffffffff89b120e8 (chaoskey_list_lock){+.+.}-{3:3}, at: chaoskey_release+0x7f/0x2c0 drivers/usb/misc/chaoskey.c:299
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(chaoskey_list_lock);
lock(chaoskey_list_lock);
*** DEADLOCK ***
The second possible deadlock is:
WARNING: possible circular locking dependency detected
6.12.0-rc1-syzkaller-00027-g4a9fe2a8ac53 #0 Not tainted
------------------------------------------------------
kworker/0:2/804 is trying to acquire lock:
ffffffff899dadb0 (minor_rwsem){++++}-{3:3}, at: usb_deregister_dev+0x7c/0x1e0 drivers/usb/core/file.c:186
but task is already holding lock:
ffffffff89b120e8 (chaoskey_list_lock){+.+.}-{3:3}, at: chaoskey_disconnect+0xa8/0x2a0 drivers/usb/misc/chaoskey.c:235
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (chaoskey_list_lock){+.+.}-{3:3}:
__mutex_lock_common kernel/locking/mutex.c:608 [inline]
__mutex_lock+0x175/0x9c0 kernel/locking/mutex.c:752
chaoskey_open+0xdd/0x220 drivers/usb/misc/chaoskey.c:274
usb_open+0x186/0x220 drivers/usb/core/file.c:47
chrdev_open+0x237/0x6a0 fs/char_dev.c:414
do_dentry_open+0x6cb/0x1390 fs/open.c:958
vfs_open+0x82/0x3f0 fs/open.c:1088
do_open fs/namei.c:3774 [inline]
path_openat+0x1e6a/0x2d60 fs/namei.c:3933
do_filp_open+0x1dc/0x430 fs/namei.c:3960
do_sys_openat2+0x17a/0x1e0 fs/open.c:1415
do_sys_open fs/open.c:1430 [inline]
__do_sys_openat fs/open.c:1446 [inline]
__se_sys_openat fs/open.c:1441 [inline]
__x64_sys_openat+0x175/0x210 fs/open.c:1441
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #0 (minor_rwsem){++++}-{3:3}:
check_prev_add kernel/locking/lockdep.c:3161 [inline]
check_prevs_add kernel/locking/lockdep.c:3280 [inline]
validate_chain kernel/locking/lockdep.c:3904 [inline]
__lock_acquire+0x250b/0x3ce0 kernel/locking/lockdep.c:5202
lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5825
down_write+0x93/0x200 kernel/locking/rwsem.c:1577
usb_deregister_dev+0x7c/0x1e0 drivers/usb/core/file.c:186
chaoskey_disconnect+0xb7/0x2a0 drivers/usb/misc/chaoskey.c:236
usb_unbind_interface+0x1e8/0x970 drivers/usb/core/driver.c:461
device_remove drivers/base/dd.c:569 [inline]
device_remove+0x122/0x170 drivers/base/dd.c:561
__device_release_driver drivers/base/dd.c:1273 [inline]
device_release_driver_internal+0x44a/0x610 drivers/base/dd.c:1296
bus_remove_device+0x22f/0x420 drivers/base/bus.c:576
device_del+0x396/0x9f0 drivers/base/core.c:3864
usb_disable_device+0x36c/0x7f0 drivers/usb/core/message.c:1418
usb_disconnect+0x2e1/0x920 drivers/usb/core/hub.c:2304
hub_port_connect drivers/usb/core/hub.c:5361 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5661 [inline]
port_event drivers/usb/core/hub.c:5821 [inline]
hub_event+0x1bed/0x4f40 drivers/usb/core/hub.c:5903
process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229
process_scheduled_works kernel/workqueue.c:3310 [inline]
worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391
kthread+0x2c1/0x3a0 kernel/kthread.c:389
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(chaoskey_list_lock);
lock(minor_rwsem);
lock(chaoskey_list_lock);
lock(minor_rwsem);
*** DEADLOCK ***
[Analysis]
The first is AA lock, it because wrong logic, it need a unlock.
The second is AB lock, it needs to rearrange the order of lock usage.
Fixes: 422dc0a4d1 ("USB: chaoskey: fail open after removal")
Reported-by: syzbot+685e14d04fe35692d3bc@syzkaller.appspotmail.com
Reported-by: syzbot+1f8ca5ee82576ec01f12@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=685e14d04fe35692d3bc
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
Tested-by: syzbot+685e14d04fe35692d3bc@syzkaller.appspotmail.com
Reported-by: syzbot+5f1ce62e956b7b19610e@syzkaller.appspotmail.com
Tested-by: syzbot+5f1ce62e956b7b19610e@syzkaller.appspotmail.com
Tested-by: syzbot+1f8ca5ee82576ec01f12@syzkaller.appspotmail.com
Link: https://lore.kernel.org/r/tencent_84EB865C89862EC22EE94CB3A7C706C59206@qq.com
Cc: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 44feafbaa6 ]
iowarrior_read() uses the iowarrior dev structure, but does not use any
lock on the structure. This can cause various bugs including data-races,
so it is more appropriate to use a mutex lock to safely protect the
iowarrior dev structure. When using a mutex lock, you should split the
branch to prevent blocking when the O_NONBLOCK flag is set.
In addition, it is unnecessary to check for NULL on the iowarrior dev
structure obtained by reading file->private_data. Therefore, it is
better to remove the check.
Fixes: 946b960d13 ("USB: add driver for iowarrior devices.")
Signed-off-by: Jeongjun Park <aha310510@gmail.com>
Link: https://lore.kernel.org/r/20240919103403.3986-1-aha310510@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 86b20af11e ]
There is a general misunderstanding amongst engineers that {v}snprintf()
returns the length of the data *actually* encoded into the destination
array. However, as per the C99 standard {v}snprintf() really returns
the length of the data that *would have been* written if there were
enough space for it. This misunderstanding has led to buffer-overruns
in the past. It's generally considered safer to use the {v}scnprintf()
variants in their place (or even sprintf() in simple cases). So let's
do that.
Whilst we're at it, let's define some magic numbers to increase
readability and ease of maintenance.
Link: https://lwn.net/Articles/69419/
Link: https://github.com/KSPP/linux/issues/105
Cc: Tomoki Sekiyama <tomoki.sekiyama@gmail.com>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20231213164246.1021885-9-lee@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: 93907620b3 ("USB: misc: yurex: fix race between read and write")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d97b4b35ad ]
Genesys Logic GL3523 is a 4-port USB 3.1 hub that has a reset pin to
toggle and a 5.0V core supply exported though an integrated LDO is
available for powering it.
Add the support for this hub, for controlling the reset pin and the core
power supply.
Signed-off-by: Anand Moon <linux.amoon@gmail.com>
[m.felsch@pengutronix.de: include review feedback & port to 6.4]
Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
Link: https://lore.kernel.org/r/20230623142228.4069084-2-m.felsch@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: e59e38158c ("usb: misc: onboard_hub: add support for Microchip USB2412 USB 2.0 hub")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 9bae996ffa ]
Genesys Logic GL850G is a 4-port USB 2.0 STT hub that has a reset pin to
toggle and a 3.3V core supply exported (although an integrated LDO is
available for powering it with 5V).
Add the support for this hub, for controlling the reset pin and the core
power supply.
Signed-off-by: Icenowy Zheng <uwu@icenowy.me>
Acked-by: Matthias Kaehlcke <mka@chromium.org>
Link: https://lore.kernel.org/r/20221206055228.306074-4-uwu@icenowy.me
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: e59e38158c ("usb: misc: onboard_hub: add support for Microchip USB2412 USB 2.0 hub")
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit cde37881e2 upstream.
Currently each onboard_hub platform device owns an 'attach' work,
which is scheduled when the device probes. With this deadlocks
have been reported on a Raspberry Pi 3 B+ [1], which has nested
onboard hubs.
The flow of the deadlock is something like this (with the onboard_hub
driver built as a module) [2]:
- USB root hub is instantiated
- core hub driver calls onboard_hub_create_pdevs(), which creates the
'raw' platform device for the 1st level hub
- 1st level hub is probed by the core hub driver
- core hub driver calls onboard_hub_create_pdevs(), which creates
the 'raw' platform device for the 2nd level hub
- onboard_hub platform driver is registered
- platform device for 1st level hub is probed
- schedules 'attach' work
- platform device for 2nd level hub is probed
- schedules 'attach' work
- onboard_hub USB driver is registered
- device (and parent) lock of hub is held while the device is
re-probed with the onboard_hub driver
- 'attach' work (running in another thread) calls driver_attach(), which
blocks on one of the hub device locks
- onboard_hub_destroy_pdevs() is called by the core hub driver when one
of the hubs is detached
- destroying the pdevs invokes onboard_hub_remove(), which waits for the
'attach' work to complete
- waits forever, since the 'attach' work can't acquire the device lock
Use a single work struct for the driver instead of having a work struct
per onboard hub platform driver instance. With that it isn't necessary
to cancel the work in onboard_hub_remove(), which fixes the deadlock.
The work is only cancelled when the driver is unloaded.
[1] https://lore.kernel.org/r/d04bcc45-3471-4417-b30b-5cf9880d785d@i2se.com/
[2] https://lore.kernel.org/all/Y6OrGbqaMy2iVDWB@google.com/
Cc: stable@vger.kernel.org
Fixes: 8bc063641c ("usb: misc: Add onboard_usb_hub driver")
Link: https://lore.kernel.org/r/d04bcc45-3471-4417-b30b-5cf9880d785d@i2se.com/
Link: https://lore.kernel.org/all/Y6OrGbqaMy2iVDWB@google.com/
Reported-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Link: https://lore.kernel.org/r/20230110172954.v2.2.I16b51f32db0c32f8a8532900bfe1c70c8572881a@changeid
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e5854355d7 upstream.
The onboard_hub 'driver' consists of two drivers, a platform
driver and a USB driver. Currently when the onboard hub driver
is initialized it first registers the platform driver, then the
USB driver. This results in a race condition when the 'attach'
work is executed, which is scheduled when the platform device
is probed. The purpose of fhe 'attach' work is to bind elegible
USB hub devices to the onboard_hub USB driver. This fails if
the work runs before the USB driver has been registered.
Register the USB driver first, then the platform driver. This
increases the chances that the onboard_hub USB devices are probed
before their corresponding platform device, which the USB driver
tries to locate in _probe(). The driver already handles this
situation and defers probing if the onboard hub platform device
doesn't exist yet.
Cc: stable@vger.kernel.org
Fixes: 8bc063641c ("usb: misc: Add onboard_usb_hub driver")
Link: https://lore.kernel.org/lkml/Y6W00vQm3jfLflUJ@hovoldconsulting.com/T/#m0d64295f017942fd988f7c53425db302d61952b4
Reported-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Link: https://lore.kernel.org/r/20230110172954.v2.1.I75494ebee7027a50235ce4b1e930fa73a578fbe2@changeid
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull USB / Thunderbolt updates from Greg KH:
"Here is the big set of USB and Thunderbolt driver changes for 6.1-rc1.
Nothing major in here, lots of little things with new devices
supported and updates for a few drivers. Highlights include:
- thunderbolt/USB4 devices supported a bit better than before, and
some new ids to enable new hardware devices
- USB gadget uvc updates for newer video formats and better v4l
integration (the v4l portions were acked by those maintainers)
- typec updates for tiny issues and more typec drivers for new chips.
- xhci tiny updates for minor issues
- big usb-serial ftdi_sio driver update to handle new devices better
- lots of tiny dwc3 fixes and updates for the IP block that is
showing up everywhere these days
- dts updates for new devices being supported
- other tiny janitorial and cleanups fixes for lots of different USB
drivers. Full details are in the shortlog.
All of these have been in linux-next for a while with no reported
issues"
* tag 'usb-6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (169 commits)
usb: gadget: uvc: don't put item still in use
usb: gadget: uvc: Fix argument to sizeof() in uvc_register_video()
usb: host: ehci-exynos: switch to using gpiod API
Revert "usb: dwc3: Don't switch OTG -> peripheral if extcon is present"
Revert "USB: fixup for merge issue with "usb: dwc3: Don't switch OTG -> peripheral if extcon is present""
dt-bindings: usb: Convert FOTG210 to dt schema
usb: mtu3: fix failed runtime suspend in host only mode
USB: omap_udc: Fix spelling mistake: "tranceiver_ctrl" -> "transceiver_ctrl"
usb: typec: ucsi_ccg: Disable UCSI ALT support on Tegra
usb: typec: Replace custom implementation of device_match_fwnode()
usb: typec: ucsi: Don't warn on probe deferral
usb: add quirks for Lenovo OneLink+ Dock
MAINTAINERS: switch dwc3 to Thinh
usb: idmouse: fix an uninit-value in idmouse_open
USB: PHY: JZ4770: Switch to use dev_err_probe() helper
usb: phy: generic: Switch to use dev_err_probe() helper
usb: ulpi: use DEFINE_SHOW_ATTRIBUTE to simplify ulpi_regs
usb: cdns3: remove dead code
usb: cdc-wdm: Use skb_put_data() instead of skb_put/memcpy pair
usb: musb: sunxi: Switch to use dev_err_probe() helper
...
In idmouse_create_image, if any ftip_command fails, it will
go to the reset label. However, this leads to the data in
bulk_in_buffer[HEADER..IMGSIZE] uninitialized. And the check
for valid image incurs an uninitialized dereference.
Fix this by moving the check before reset label since this
check only be valid if the data after bulk_in_buffer[HEADER]
has concrete data.
Note that this is found by KMSAN, so only kernel compilation
is tested.
Reported-by: syzbot+79832d33eb89fb3cd092@syzkaller.appspotmail.com
Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
Link: https://lore.kernel.org/r/20220922134847.1101921-1-dzm91@hust.edu.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Smatch reports the following warning:
drivers/usb/misc/usb3503.c:267 usb3503_probe() warn: 'hub->clk'
from clk_prepare_enable() not released on lines: 240,246,252
Fix this by adding a flag to indicate if hub->clk is prepared or not
and invoke clk_disable_unprepare in the error handling.
Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
Link: https://lore.kernel.org/r/20220908055903.3550723-1-dzm91@hust.edu.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Smatch reports the following error: uninitialized symbol 'rlen'
drivers/usb/misc/uss720.c:514 parport_uss720_epp_write_data() error
drivers/usb/misc/uss720.c:575 parport_uss720_ecp_write_data() error
drivers/usb/misc/uss720.c:593 parport_uss720_ecp_read_data() error
drivers/usb/misc/uss720.c:626 parport_uss720_write_compat() error
The root cause is, the failure of usb_bulk_msg leads to the
uninitialized variable rlen in printk function.
Fix this by initializing rlen with zero.
Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
Link: https://lore.kernel.org/r/20220903100004.2874741-1-dzm91@hust.edu.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We need the USB fixes in here and this resolves the merge issue in:
drivers/usb/dwc3/gadget.c
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull tty / serial driver updates from Greg KH:
"Here is the big set of tty and serial driver changes for 6.0-rc1.
It was delayed from last week as I wanted to make sure the last commit
here got some good testing in linux-next and elsewhere as it seemed to
show up only late in testing for some reason.
Nothing major here, just lots of cleanups from Jiri and Ilpo to make
the tty core cleaner (Jiri) and the rs485 code simpler to use (Ilpo).
Also included in here is the obligatory n_gsm updates from Daniel
Starke and lots of tiny driver updates and minor fixes and tweaks for
other smaller serial drivers.
All of these have been in linux-next for a while with no reported
problems"
* tag 'tty-6.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (186 commits)
tty: serial: qcom-geni-serial: Fix %lu -> %u in print statements
tty: amiserial: Fix comment typo
tty: serial: document uart_get_console()
tty: serial: serial_core, reformat kernel-doc for functions
Documentation: serial: link uart_ops properly
Documentation: serial: move GPIO kernel-doc to the functions
Documentation: serial: dedup kernel-doc for uart functions
Documentation: serial: move uart_ops documentation to the struct
dt-bindings: serial: snps-dw-apb-uart: Document Rockchip RV1126
serial: mvebu-uart: uart2 error bits clearing
tty: serial: fsl_lpuart: correct the count of break characters
serial: stm32: make info structs static to avoid sparse warnings
serial: fsl_lpuart: zero out parity bit in CS7 mode
tty: serial: qcom-geni-serial: Fix get_clk_div_rate() which otherwise could return a sub-optimal clock rate.
serial: 8250_bcm2835aux: Add missing clk_disable_unprepare()
tty: vt: initialize unicode screen buffer
serial: remove VR41XX serial driver
serial: 8250: lpc18xx: Remove redundant sanity check for RS485 flags
serial: 8250_dwlib: remove redundant sanity check for RS485 flags
dt_bindings: rs485: Correct delay values
...
Fix the following coccicheck warning:
drivers/usb/misc/ldusb.c:719: WARNING opportunity for max().
drivers/usb/misc/ldusb.c:721: WARNING opportunity for max().
max_t() macro is defined in include/linux/minmax.h. It avoids
multiple evaluations of the arguments when non-constant and performs
strict type-checking.
Signed-off-by: Jiangshan Yi <yijiangshan@kylinos.cn>
Link: https://lore.kernel.org/r/20220713070205.3047256-1-13667453960@163.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The main issue this driver addresses is that a USB hub needs to be
powered before it can be discovered. For discrete onboard hubs (an
example for such a hub is the Realtek RTS5411) this is often solved
by supplying the hub with an 'always-on' regulator, which is kind
of a hack. Some onboard hubs may require further initialization
steps, like changing the state of a GPIO or enabling a clock, which
requires even more hacks. This driver creates a platform device
representing the hub which performs the necessary initialization.
Currently it only supports switching on a single regulator, support
for multiple regulators or other actions can be added as needed.
Different initialization sequences can be supported based on the
compatible string.
Besides performing the initialization the driver can be configured
to power the hub off during system suspend. This can help to extend
battery life on battery powered devices which have no requirements
to keep the hub powered during suspend. The driver can also be
configured to leave the hub powered when a wakeup capable USB device
is connected when suspending, and power it off otherwise.
Technically the driver consists of two drivers, the platform driver
described above and a very thin USB driver that subclasses the
generic driver. The purpose of this driver is to provide the platform
driver with the USB devices corresponding to the hub(s) (a hub
controller may provide multiple 'logical' hubs, e.g. one to support
USB 2.0 and another for USB 3.x).
Co-developed-by: Ravi Chandra Sadineni <ravisadineni@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Ravi Chandra Sadineni <ravisadineni@chromium.org>
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Link: https://lore.kernel.org/r/20220630123445.v24.3.I7c9a1f1d6ced41dd8310e8a03da666a32364e790@changeid
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We need the USB fixes in here, and this resolves a merge issue in
drivers/usb/dwc3/drd.c
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The main issue this driver addresses is that a USB hub needs to be
powered before it can be discovered. For discrete onboard hubs (an
example for such a hub is the Realtek RTS5411) this is often solved
by supplying the hub with an 'always-on' regulator, which is kind
of a hack. Some onboard hubs may require further initialization
steps, like changing the state of a GPIO or enabling a clock, which
requires even more hacks. This driver creates a platform device
representing the hub which performs the necessary initialization.
Currently it only supports switching on a single regulator, support
for multiple regulators or other actions can be added as needed.
Different initialization sequences can be supported based on the
compatible string.
Besides performing the initialization the driver can be configured
to power the hub off during system suspend. This can help to extend
battery life on battery powered devices which have no requirements
to keep the hub powered during suspend. The driver can also be
configured to leave the hub powered when a wakeup capable USB device
is connected when suspending, and power it off otherwise.
Technically the driver consists of two drivers, the platform driver
described above and a very thin USB driver that subclasses the
generic driver. The purpose of this driver is to provide the platform
driver with the USB devices corresponding to the hub(s) (a hub
controller may provide multiple 'logical' hubs, e.g. one to support
USB 2.0 and another for USB 3.x).
Note: the current series only supports hubs connected directly to
a root hub, support for other configurations could be added if
needed.
Co-developed-by: Ravi Chandra Sadineni <ravisadineni@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Ravi Chandra Sadineni <ravisadineni@chromium.org>
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Link: https://lore.kernel.org/r/20220217104219.v21.2.I7c9a1f1d6ced41dd8310e8a03da666a32364e790@changeid
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>