linux-stable.git/drivers/auxdisplay, branch linux-5.4.y

auxdisplay: ht16k33: Fix frame buffer device blanking

2021-11-17T08:48:45+00:00

[ Upstream commit 840fe258332544aa7321921e1723d37b772af7a9 ]

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 
Suggested-by: Robin van der Gracht 
Fixes: 8992da44c6805d53 ("auxdisplay: ht16k33: Driver for LED controller")
Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Miguel Ojeda 
Signed-off-by: Sasha Levin

auxdisplay: ht16k33: Connect backlight to fbdev

2021-11-17T08:48:45+00:00

[ Upstream commit 80f9eb70fd9276938f0a131f76d438021bfd8b34 ]

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: 8992da44c6805d53 ("auxdisplay: ht16k33: Driver for LED controller")
Signed-off-by: Geert Uytterhoeven 
Reviewed-by: Robin van der Gracht 
Signed-off-by: Miguel Ojeda 
Signed-off-by: Sasha Levin

auxdisplay: img-ascii-lcd: Fix lock-up when displaying empty string

2021-11-17T08:48:45+00:00

[ Upstream commit afcb5a811ff3ab3969f09666535eb6018a160358 ]

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: 0cad855fbd083ee5 ("auxdisplay: img-ascii-lcd: driver for simple ASCII LCD displays")
Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Miguel Ojeda 
Signed-off-by: Sasha Levin

auxdisplay: ht16k33: Fix refresh rate handling

2021-03-04T09:26:30+00:00

[ Upstream commit e89b0a426721a8ca5971bc8d70aa5ea35c020f90 ]

Drop the call to msecs_to_jiffies(), as "HZ / fbdev->refresh_rate" is
already the number of jiffies to wait.

Fixes: 8992da44c6805d53 ("auxdisplay: ht16k33: Driver for LED controller")
Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Miguel Ojeda 
Signed-off-by: Sasha Levin

Merge tag 'docs-5.4' of git://git.lwn.net/linux

2019-09-17T23:22:26+00:00

Pull documentation updates from Jonathan Corbet:
 "It's a somewhat calmer cycle for docs this time, as the churn of the
  mass RST conversion is happily mostly behind us.

   - A new document on reproducible builds.

   - We finally got around to zapping the documentation for hardware
     support that was removed in 2004; one doesn't want to rush these
     things.

   - The usual assortment of fixes, typo corrections, etc"

* tag 'docs-5.4' of git://git.lwn.net/linux: (67 commits)
  Documentation: kbuild: Add document about reproducible builds
  docs: printk-formats: Stop encouraging use of unnecessary %h[xudi] and %hh[xudi]
  Documentation: Add "earlycon=sbi" to the admin guide
  doc:lock: remove reference to clever use of read-write lock
  devices.txt: improve entry for comedi (char major 98)
  docs: mtd: Update spi nor reference driver
  doc: arm64: fix grammar dtb placed in no attributes region
  Documentation: sysrq: don't recommend 'S' 'U' before 'B'
  mailmap: Update email address for Quentin Perret
  docs: ftrace: clarify when tracing is disabled by the trace file
  docs: process: fix broken link
  Documentation/arm/samsung-s3c24xx: Remove stray U+FEFF character to fix title
  Documentation/arm/sa1100/assabet: Fix 'make assabet_defconfig' command
  Documentation/arm/sa1100: Remove some obsolete documentation
  docs/zh_CN: update Chinese howto.rst for latexdocs making
  Documentation: virt: Fix broken reference to virt tree's index
  docs: Fix typo on pull requests guide
  kernel-doc: Allow anonymous enum
  Documentation: sphinx: Don't parse socket() as identifier reference
  Documentation: sphinx: Add missing comma to list of strings
  ...

auxdisplay: ht16k33: Make ht16k33_fb_fix and ht16k33_fb_var constant

2019-08-20T09:48:54+00:00

The static structures ht16k33_fb_fix and ht16k33_fb_var, of types
fb_fix_screeninfo and fb_var_screeninfo respectively, are not used
except to be copied into other variables. Hence make both of them
constant to prevent unintended modification.
Issue found with
Coccinelle.

Acked-by: Robin van der Gracht 
Signed-off-by: Nishka Dasgupta 
Signed-off-by: Miguel Ojeda

auxdisplay: charlcd: add include guard to charlcd.h

2019-08-08T17:59:50+00:00

Add a header include guard just in case.

Signed-off-by: Masahiro Yamada 
Signed-off-by: Miguel Ojeda

auxdisplay: charlcd: move charlcd.h to drivers/auxdisplay

2019-08-08T17:59:17+00:00

This header is included in drivers/auxdisplay/. Make it a local header.

Reviewed-by: Geert Uytterhoeven 
Signed-off-by: Masahiro Yamada 
Signed-off-by: Miguel Ojeda

auxdisplay: charlcd: add help text for backlight initial state

2019-08-05T21:03:16+00:00

While the individual CHARLCD_BL_xxx options have help texts, the
menu itself does not.  Fix this.

Suggested-by: Linus Torvalds 
Signed-off-by: Mans Rullgard 
[Added a bit more text to address Linus' suggestion]
Signed-off-by: Miguel Ojeda

auxdisplay: panel: need to delete scan_timer when misc_register fails in panel_attach

2019-08-05T20:33:31+00:00

In panel_attach, if misc_register fails, we need to delete scan_timer,
which was setup in keypad_init->init_scan_timer.

Reported-by: Hulk Robot 
Signed-off-by: zhengbin 
Signed-off-by: Miguel Ojeda