Check if the pointer lcd->ops->init_display exists before dereferencing it.
If a driver called charlcd_init() without defining the ops, this would
return segmentation fault, as happened to me when implementing a charlcd
driver. Checking the pointer before dereferencing protects from
segmentation fault.
Signed-off-by: Luiz Sampaio <sampaio.ime@gmail.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Removing 'int' from 'unsigned long int' declaration, which is unnecessary.
Signed-off-by: Luiz Sampaio <sampaio.ime@gmail.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Resolves the checkpatch error.
Signed-off-by: Huiquan Deng <denghuiquan@cdjrlc.com>
[reworded and avoid moving the line]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
ht16k33.c doesn't use any macro or function declared in
linux/slab.h. Thus, these files can be removed from ht16k33.c
safely without affecting the compilation.
Signed-off-by: Mianhan Liu <liumh1@shanghaitech.edu.cn>
Acked-by: Robin van der Gracht <robin@protonic.nl>
[reworded]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
ks0108.c doesn't use any macro or function declared in
linux/fs.h, linux/io.h and linux/uaccess.h. Thus,
these files can be removed from ks0108.c safely without
affecting the compilation.
Signed-off-by: Mianhan Liu <liumh1@shanghaitech.edu.cn>
[reworded]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
cfag12864bfb.c doesn't use any macro or function declared in
linux/delay.h, linux/string.h and linux/uaccess.h. Thus,
these files can be removed from cfag12864bfb.c safely without
affecting the compilation.
Signed-off-by: Mianhan Liu <liumh1@shanghaitech.edu.cn>
[reworded]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
The device property API allows drivers to gather device resources from
different sources, such as ACPI, and lift the dependency on Device Tree.
Convert the driver to unleash the power of the device property API.
Suggested-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Robin van der Gracht <robin@protonic.nl>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
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>
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: 8992da44c6 ("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: 8992da44c6 ("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: 0cad855fbd ("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>
Switch to use module_parport_driver() to reduce boilerplate code.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
For structure initializers the fields are 0 (or NULL) by default, so
there is no need to fill them explicitly. Besides that, much easier
to read when initializers use C99 style. Hence, convert to C99 style
as well.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
The section "19) Editor modelines and other cruft" in
Documentation/process/coding-style.rst clearly says, "Do not include any
of these in source files."
I recently receive a patch to explicitly add a new one.
Let's do treewide cleanups, otherwise some people follow the existing code
and attempt to upstream their favoriate editor setups.
It is even nicer if scripts/checkpatch.pl can check it.
If we like to impose coding style in an editor-independent manner, I think
editorconfig (patch [1]) is a saner solution.
[1] https://lore.kernel.org/lkml/20200703073143.423557-1-danny@kdrag0n.dev/
Link: https://lkml.kernel.org/r/20210324054457.1477489-1-masahiroy@kernel.org
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org> [auxdisplay]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
charlcd_write() is invoked as a VFS->write() callback and as such it is
always invoked from preemptible context and may sleep.
charlcd_puts() is invoked from register/unregister callback which is
preemptible. The reboot notifier callback is also invoked from
preemptible context.
Therefore there is no need to use in_interrupt() to figure out if it
is safe to sleep because it always is. in_interrupt() and related
context checks are being removed from non-core code.
Using schedule() to schedule (and be friendly to others) is
discouraged and cond_resched() should be used instead.
Remove in_interrupt() and use cond_resched() to schedule every 32
iterations if needed.
Link: https://lkml.kernel.org/r/20200914204209.256266093@linutronix.de
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
[mo: fixed a couple typos in comment and commit message]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
A second CHARLCD config symbol was added instead of moving the existing
one. Fix this by removing the old one.
Fixes: 718e05ed92 ("auxdisplay: Introduce hd44780_common.[ch]")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Drop the call to msecs_to_jiffies(), as "HZ / fbdev->refresh_rate" is
already the number of jiffies to wait.
Fixes: 8992da44c6 ("auxdisplay: ht16k33: Driver for LED controller")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Keyscan should be optional to support simple LED matrix displays (output
only).
Reported-by: Michael Kaplan <M.KAPLAN@evva.com>
Signed-off-by: Robin van der Gracht <robin@protonic.nl>
[geert: Rebased]
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>
The three struct charlcd_ops contain the same data, so we only need one
of this structures. The other two are removed.
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
charlcd drivers need to provide some print function to charlcd. For
hd44780 based panel driver this function was missing. We provide the
generic hd44780_common_print function which should be suitable.
Fixes: b26deabb1d ("auxdisplay: hd44780_common_print")
Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
drivers/auxdisplay/lcd2s.c:373:3-8: No need to set .owner here. The core will do it.
Remove .owner field if calls are used which set it automatically
Generated by: scripts/coccinelle/api/platform_no_drv_owner.cocci
Fixes: 8c9108d014 ("auxdisplay: add a driver for lcd2s character display")
CC: Lars Poeschel <poeschel@lemonage.de>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: kernel test robot <lkp@intel.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
The kfree() needs to be moved down a line to prevent a use after free.
Fixes: 8c9108d014 ("auxdisplay: add a driver for lcd2s character display")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
When building the hd44780_common driver without a driver that actually
uses it like panel or hd44780 you get a build error, because
hd44780_common uses charlcd, but did not select it. Its users did
select it.
This is fixed now. hd4478_common now selects charlcd in Kconfig and
panel and hd44780 do not. They only select hd44780_common.
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
This driver allows to use a lcd2s 20x4 character display from Modtronix
engineering as an auxdisplay charlcd device.
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Skip printing characters at the end of a display line. This fits to the
behaviour we already had, that the cursor is nailed to the last position
of a line.
This might slightly change behaviour.
On hd44780 displays with one or two lines the previous implementation
did still write characters to the buffer of the display even if they are
currently not visible. The shift_display command could be used to set
the "viewing window" to a new position in the buffer and then you could
see the characters previously written.
This described behaviour does not work for hd44780 displays with more
than two display lines. There simply is not enough buffer.
So the behaviour was a bit inconsistent across different displays.
The new behaviour is to stop writing characters at the end of a visible
line, even if there would be room in the buffer. This allows us to have
an easy implementation, that should behave equal on all supported
displays. This is not hd44780 hardware dependent anymore.
Reviewed-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Change the calling interface for gotoxy from supplying the x and y
coordinates in the charlcd struct to explicitly supplying x and y in
the function arguments. This is more intuitive and allows for moving
the cursor to positions independent from the position saved in the
charlcd struct.
Reviewed-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
These are the last bits left in charlcd.c that are device specific and
they are removed now.
In detail this is:
* bwidth, which is the width of the display buffer per line. This is
replaced by width of the display.
* hwidth, which is the size of the display buffer as a whole. This is
replaced by looping all chars of a line by all lines.
* the hd44780_common header include can go away.
Reviewed-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
We remove the hd44780_clear_fast (display) clear implementation. With
the new timeout the normal clear_display is reasonably fast. So there is
no need for a clear_fast anymore.
Link: https://lore.kernel.org/lkml/20200922092121.GG16421@1wt.eu/
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
This moves the call to charlcd_backlight from the end of the switch
into the actual case statement that originates the change of the
backlight. This is more consistent to what is now found in this switch.
Reviewed-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Take the code to redefine characters out of charlcd and move it to
hd44780_common, as this is hd44780 specific.
There is now a function hd44780_common_redefine_char that drivers use
and charlcd calls it through its ops function pointer.
Reviewed-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
This cleans up now unnecessary hd44780 specific code from charlcd. We
obsoleted this with the last patch. So another chunk of hd44780 specific
code can be dropped from charlcd.
Reviewed-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
This implements various hd44780_common_ functions for hd44780 compatible
display drivers to use. charlcd then calls these functions through its
ops function pointer.
The functions namely are:
- hd44780_common_shift_cursor
- hd44780_common_display_shift
- hd44780_common_display
- hd44780_common_cursor
- hd44780_common_blink
- hd44780_common_fontsize
- hd44780_common_lines
Reviewed-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
The init_display function is moved over to hd44780_common. charlcd uses
it via its ops function pointer and drivers initialize the ops with the
common hd44780_common_init_display function.
Reviewed-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Luiz Sampaio