Instantiate a single LED based on the "led" subnode in DT.
This allows the user to control display brightness and blinking (backed
by hardware support) through the LED class API and triggers, and exposes
the display color.  The LED will be named
"auxdisplay:<color>:<function>".

When running in dot-matrix mode and if no "led" subnode is found, the
driver falls back to the traditional backlight mode, to preserve
backwards compatibility.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Marek Behún <kabel@kernel.org>
Reviewed-by: Robin van der Gracht <robin@protonic.nl>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Extend the Holtek HT16K33 LED controller Device Tree bindings with an
LED subnode, conforming to the standard LED bindings.

This allows the user to exert more control, like specifying LED color,
function, and/or trigger, to extend LED functionality beyond a simple
display backlight.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

The Holtek HT16K33 LED controller is not only used for driving
dot-matrix displays, but also for driving segment displays.

Add support for 4-digit 7-segment and quad 14-segment alphanumeric
displays, like the Adafruit 7-segment and 14-segment display backpack
and FeatherWing expansion boards.  Use the character line display core
support to display a message, which will be scrolled if it doesn't fit.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Robin van der Gracht <robin@protonic.nl>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Extract all frame buffer (including backlight) probing into
ht16k33_fbdev_probe().

Call ht16k33_fbdev_probe() after ht16k33_keypad_probe(), as the latter
does not need any manual cleanup in the probe error path.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Robin van der Gracht <robin@protonic.nl>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Extract brightness handling into a helper function, so it can be called
from multiple places.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Robin van der Gracht <robin@protonic.nl>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Move delayed_work from ht16k33_fbdev to ht16k33_priv, as it is not
specific to dot-matrix displays, but common to all display types.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Robin van der Gracht <robin@protonic.nl>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

This driver has many users of "client->dev".  Add shorthands to simplify
the code.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Robin van der Gracht <robin@protonic.nl>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

ht16k33_probe() does not use the passed i2c_device_id, so the driver can
be converted trivially to the new-style of i2c probing.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Robin van der Gracht <robin@protonic.nl>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

There is no need to check the return code of input_register_device(),
just propagate it to the caller.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Robin van der Gracht <robin@protonic.nl>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Use the existing HT16K33_FB_SIZE definition instead of open-coding the
same calculation using an hardcoded value.
While at it, restore reverse Christmas tree variable declaration order.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Robin van der Gracht <robin@protonic.nl>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

As the ht16k33 frame buffer sub-driver does not register an
fb_ops.fb_blank() handler, blanking does not work:

    $ echo 1 > /sys/class/graphics/fb0/blank
    sh: write error: Invalid argument

Fix this by providing a handler that always returns zero, to make sure
blank events will be sent to the actual device handling the backlight.
Reported-by: Robin van der Gracht <robin@protonic.nl>
Suggested-by: Robin van der Gracht <robin@protonic.nl>
Fixes: 8992da44 ("auxdisplay: ht16k33: Driver for LED controller")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Currently /sys/class/graphics/fb0/bl_curve is not accessible (-ENODEV),
as the driver does not connect the backlight to the frame buffer device.
Fix this moving backlight initialization up, and filling in
fb_info.bl_dev.

Fixes: 8992da44 ("auxdisplay: ht16k33: Driver for LED controller")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Robin van der Gracht <robin@protonic.nl>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

If the message to display is longer than the number of characters that
the display can show, the message will be scrolled.  Currently the
scroll rate is fixed, moving every 500 ms.

Add support for changing the scroll rate through a "scroll_step_ms"
device attribute in sysfs.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Use the existing kmemdup_nul() helper instead of open-coding the same
operation.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Extract the character line display core support from the simple ASCII
LCD driver for the MIPS Boston, Malta & SEAD3 development boards into
its own subdriver, so it can be reused for other displays.

As this moves the "message" device attribute in sysfs in a "linedisp.N"
subdirectory, a symlink is added to preserve backwards compatibility.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Convert the "message" device attribute from sprintf() to sysfs_emit(),
as the latter is aware of the PAGE_SIZE buffer.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

img_ascii_lcd_probe() has many users of "pdev->dev".  Add a shorthand to
simplify the code.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

While writing an empty string to a device attribute is a no-op, and thus
does not need explicit safeguards, the user can still write a single
newline to an attribute file:

    echo > .../message

If that happens, img_ascii_lcd_display() trims the newline, yielding an
empty string, and causing an infinite loop in img_ascii_lcd_scroll().

Fix this by adding a check for empty strings.  Clear the display in case
one is encountered.

Fixes: 0cad855f ("auxdisplay: img-ascii-lcd: driver for simple ASCII LCD displays")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

The Holtek HT16K33 LED controller is not only used for driving
dot-matrix displays, but also for driving segment displays.

Document compatible values for the Adafruit 7-segment[1] and
14-segment[2] FeatherWing expansion boards with red displays.  According
to the schematics, all other Adafruit 7-segment and 14-segment display
backpack and FeatherWing expansion boards (including bare boards and
boards fitted with displays) are compatible with these two boards.

[1] https://www.adafruit.com/product/3108
[2] https://www.adafruit.com/product/3130Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Add a header file providing translation primitives and tables for the
conversion of (ASCII) characters to a 14-segments notation, as used by
14-segment alphanumeric displays.

This follows the spirit of include/uapi/linux/map_to_7segment.h.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Pull libata fixes from Damien Le Moal:
 "Two fixes for this cycle:

   - Fix a null pointer dereference in ahci-platform driver (from Hai)

   - Fix uninitialized variables in pata_legacy driver (from Dan)"

* tag 'libata-5.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/libata:
  ata: ahci_platform: fix null-ptr-deref in ahci_platform_enable_regulators()
  pata_legacy: fix a couple uninitialized variable bugs

Pull block fixes from Jens Axboe:
 "Bigger than usual for this point in time, the majority is fixing some
  issues around BDI lifetimes with the move from the request_queue to
  the disk in this release. In detail:

   - Series on draining fs IO for del_gendisk() (Christoph)

   - NVMe pull request via Christoph:
        - fix the abort command id (Keith Busch)
        - nvme: fix per-namespace chardev deletion (Adam Manzanares)

   - brd locking scope fix (Tetsuo)

   - BFQ fix (Paolo)"

* tag 'block-5.15-2021-10-17' of git://git.kernel.dk/linux-block:
  block, bfq: reset last_bfqq_created on group change
  block: warn when putting the final reference on a registered disk
  brd: reduce the brd_devices_mutex scope
  kyber: avoid q->disk dereferences in trace points
  block: keep q_usage_counter in atomic mode after del_gendisk
  block: drain file system I/O on del_gendisk
  block: split bio_queue_enter from blk_queue_enter
  block: factor out a blk_try_enter_queue helper
  block: call submit_bio_checks under q_usage_counter
  nvme: fix per-namespace chardev deletion
  block/rnbd-clt-sysfs: fix a couple uninitialized variable bugs
  nvme-pci: Fix abort command id

Pull io_uring fix from Jens Axboe:
 "Just a single fix for a wrong condition for grabbing a lock, a
  regression in this merge window"

* tag 'io_uring-5.15-2021-10-17' of git://git.kernel.dk/linux-block:
  io_uring: fix wrong condition to grab uring lock

Pull virtio fixes from Michael Tsirkin:
 "Fixes up some issues in rc5"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  vhost-vdpa: Fix the wrong input in config_cb
  VDUSE: fix documentation underline warning
  Revert "virtio-blk: Add validation for block size in config space"
  vhost_vdpa: unset vq irq before freeing irq
  virtio: write back F_VERSION_1 before validate

Pull powerpc fixes from Michael Ellerman:

 - Fix a bug where guests on P9 with interrupts passed through could get
   stuck in synchronize_irq().

 - Fix a bug in KVM on P8 where secondary threads entering a guest would
   write outside their allocated stack.

 - Fix a bug in KVM on P8 where secondary threads could confuse the host
   offline code and cause the guest or host to crash.

Thanks to Cédric Le Goater.

* tag 'powerpc-5.15-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  KVM: PPC: Book3S HV: Make idle_kvm_start_guest() return 0 if it went to guest
  KVM: PPC: Book3S HV: Fix stack handling in idle_kvm_start_guest()
  powerpc/xive: Discard disabled interrupts in get_irqchip_state()

Pull objtool fixes from Borislav Petkov:

 - Update section headers before the respective relocations to not
   trigger a safety check in elftoolchain's implementation of libelf

 - Do not add garbage data to the .rela.orc_unwind_ip section

* tag 'objtool_urgent_for_v5.15_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool: Update section header before relocations
  objtool: Check for gelf_update_rel[a] failures

Pull EDAC fix from Borislav Petkov:

 - Log the "correct" uncorrectable error count in the armada_xp driver

* tag 'edac_urgent_for_v5.15_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras:
  EDAC/armada-xp: Fix output of uncorrectable error counter

Pull perf fix from Borislav Petkov:

 - Add Sapphire Rapids to the list of CPUs supporting the SMI count MSR

* tag 'perf_urgent_for_v5.15_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/msr: Add Sapphire Rapids CPU support

Pull EFI fixes from Borislav Petkov:
 "Forwarded from Ard Biesheuvel through the tip tree. Ard will send
  stuff directly in the near future.

  Low priority fixes but fixes nonetheless:

   - update stub diagnostic print that is no longer accurate

   - avoid statically allocated buffer for CPER error record decoding

   - avoid sleeping on the efi_runtime semaphore when calling the
     ResetSystem EFI runtime service"

* tag 'efi-urgent-for-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi: Change down_interruptible() in virt_efi_reset_system() to down_trylock()
  efi/cper: use stack buffer for error record decoding
  efi/libstub: Simplify "Exiting bootservices" message

Pull x86 fixes from Borislav Petkov:

 - Do not enable AMD memory encryption in Kconfig by default due to
   shortcomings of some platforms, leading to boot failures.

 - Mask out invalid bits in the MXCSR for 32-bit kernels again because
   Thomas and I don't know how to mask out bits properly. Third time's
   the charm.

* tag 'x86_urgent_for_v5.15_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/fpu: Mask out the invalid MXCSR bits properly
  x86/Kconfig: Do not enable AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT automatically

Merge tag 'driver-core-5.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core fixes from Greg KH:
 "Here are some small driver core fixes for 5.15-rc6, all of which have
  been in linux-next for a while with no reported issues.

  They include:

   - kernfs negative dentry bugfix

   - simple pm bus fixes to resolve reported issues"

* tag 'driver-core-5.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  drivers: bus: Delete CONFIG_SIMPLE_PM_BUS
  drivers: bus: simple-pm-bus: Add support for probing simple bus only devices
  driver core: Reject pointless SYNC_STATE_ONLY device links
  kernfs: don't create a negative dentry if inactive node exists

Pull char/misc driver fixes from Greg KH:
 "Here are some small char/misc driver fixes for 5.15-rc6 for reported
  issues that include:

   - habanalabs driver fixes

   - mei driver fixes and new ids

   - fpga new device ids

   - MAINTAINER file updates for fpga subsystem

   - spi module id table additions and fixes

   - fastrpc locking fixes

   - nvmem driver fix

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'char-misc-5.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  eeprom: 93xx46: fix MODULE_DEVICE_TABLE
  nvmem: Fix shift-out-of-bound (UBSAN) with byte size cells
  mei: hbm: drop hbm responses on early shutdown
  mei: me: add Ice Lake-N device id.
  eeprom: 93xx46: Add SPI device ID table
  eeprom: at25: Add SPI ID table
  misc: HI6421V600_IRQ should depend on HAS_IOMEM
  misc: fastrpc: Add missing lock before accessing find_vma()
  cb710: avoid NULL pointer subtraction
  misc: gehc: Add SPI ID table
  MAINTAINERS: Drop outdated FPGA Manager website
  MAINTAINERS: Add Hao and Yilun as maintainers
  habanalabs: fix resetting args in wait for CS IOCTL
  fpga: ice40-spi: Add SPI device ID table

Pull staging and IIO driver fixes from Greg KH:
 "Here are a number of small IIO and staging driver fixes for 5.15-rc6.

  They include:

   - vc04_services bugfix for reported problem

   - r8188eu array underflow fix

   - iio driver fixes for a lot of tiny reported issues.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'staging-5.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  staging: r8188eu: prevent array underflow in rtw_hal_update_ra_mask()
  staging: vc04_services: shut up out-of-range warning
  iio: light: opt3001: Fixed timeout error when 0 lux
  iio: adis16480: fix devices that do not support sleep mode
  iio: mtk-auxadc: fix case IIO_CHAN_INFO_PROCESSED
  iio: adis16475: fix deadlock on frequency set
  iio: ssp_sensors: add more range checking in ssp_parse_dataframe()
  iio: ssp_sensors: fix error code in ssp_print_mcu_debug()
  iio: adc: ad7793: Fix IRQ flag
  iio: adc: ad7780: Fix IRQ flag
  iio: adc: ad7192: Add IRQ flag
  iio: adc: aspeed: set driver data when adc probe.
  iio: adc: rzg2l_adc: add missing clk_disable_unprepare() in rzg2l_adc_pm_runtime_resume()
  iio: adc: max1027: Fix the number of max1X31 channels
  iio: adc: max1027: Fix wrong shift with 12-bit devices
  iio: adc128s052: Fix the error handling path of 'adc128_probe()'
  iio: adc: rzg2l_adc: Fix -EBUSY timeout error return
  iio: accel: fxls8962af: return IRQ_HANDLED when fifo is flushed
  iio: dac: ti-dac5571: fix an error code in probe()

Pull serial driver fix from Greg KH:
 "Here is a single 8250 Kconfig fix for 5.15-rc6 that resolves a
  regression that showed up in 5.15-rc1. It has been in linux-next for a
  while with no reported issues"

* tag 'tty-5.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  serial: 8250: allow disabling of Freescale 16550 compile test

Pull USB fixes from Greg KH:
 "Here are some small USB fixes that resolve a number of tiny issues.
  They include:

   - new USB serial driver ids

   - xhci driver fixes for a bunch of issues

   - musb error path fixes.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'usb-5.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  usb: musb: dsps: Fix the probe error path
  xhci: Enable trust tx length quirk for Fresco FL11 USB controller
  xhci: Fix command ring pointer corruption while aborting a command
  USB: xhci: dbc: fix tty registration race
  xhci: add quirk for host controllers that don't update endpoint DCS
  xhci: guard accesses to ep_state in xhci_endpoint_reset()
  USB: serial: qcserial: add EM9191 QDL support
  USB: serial: option: add Quectel EC200S-CN module support
  USB: serial: option: add prod. id for Quectel EG91
  USB: serial: option: add Telit LE910Cx composition 0x1204

Pull input fixes from Dmitry Torokhov:

 - a new product ID for the xpad joystick driver

 - fixes to resistive-adc-touch and snvs_pwrkey drivers

 - a change to touchscreen helpers to make clang happier

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: touchscreen - avoid bitwise vs logical OR warning
  Input: xpad - add support for another USB ID of Nacon GC-100
  Input: resistive-adc-touch - fix division by zero error on z1 == 0
  Input: snvs_pwrkey - add clk handling

Since commit 430a67f9 ("block, bfq: merge bursts of newly-created
queues"), BFQ maintains a per-group pointer to the last bfq_queue
created. If such a queue, say bfqq, happens to move to a different
group, then bfqq is no more a valid last bfq_queue created for its
previous group. That pointer must then be cleared. Not resetting such
a pointer may also cause UAF, if bfqq happens to also be freed after
being moved to a different group. This commit performs this missing
reset. As such it fixes commit 430a67f9 ("block, bfq: merge bursts
of newly-created queues").

Such a missing reset is most likely the cause of the crash reported in [1].
With some analysis, we found that this crash was due to the
above UAF. And such UAF did go away with this commit applied [1].

Anyway, before this commit, that crash happened to be triggered in
conjunction with commit 2d52c58b ("block, bfq: honor already-setup
queue merges"). The latter was then reverted by commit ebc69e89
("Revert "block, bfq: honor already-setup queue merges""). Yet commit
2d52c58b ("block, bfq: honor already-setup queue merges") contains
no error related with the above UAF, and can then be restored.

[1] https://bugzilla.kernel.org/show_bug.cgi?id=214503

Fixes: 430a67f9 ("block, bfq: merge bursts of newly-created queues")
Tested-by: Grzegorz Kowal <custos.mentis@gmail.com>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Link: https://lore.kernel.org/r/20211015144336.45894-2-paolo.valente@linaro.orgSigned-off-by: Jens Axboe <axboe@kernel.dk>

Warn when the last reference on a live disk is put without calling
del_gendisk first.  There are some BDI related bug reports that look
like a case of this, so make sure we have the proper instrumentation
to catch it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20211014130231.1468538-1-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

As with commit 8b52d8be ("loop: reorder loop_exit"),
unregister_blkdev() needs to be called first in order to avoid calling
brd_alloc() from brd_probe() after brd_del_one() from brd_exit(). Then,
we can avoid holding global mutex during add_disk()/del_gendisk() as with
commit 1c500ad7 ("loop: reduce the loop_ctl_mutex scope").
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/e205f13d-18ff-a49c-0988-7de6ea5ff823@i-love.sakura.ne.jpSigned-off-by: Jens Axboe <axboe@kernel.dk>