The charlcd driver currently flashes the backlight once on init.
This may not be desirable. Thus, add options for turning the
backlight off or on as well.
Signed-off-by: Mans Rullgard <mans@mansr.com>
Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
If CONFIG_PANEL_CHANGE_MESSAGE is set, CONFIG_PANEL_BOOT_MESSAGE will
also be defined, so the double ifdef is pointless. Simplify the code
further by using an intermediate macro rather duplicating most of the
line.
Signed-off-by: Mans Rullgard <mans@mansr.com>
Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
The charlcd_free() is a counterpart to charlcd_alloc()
and should be called symmetrically on tear down.
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
In order to be more particular in names, rename to_priv() macro
to charlcd_to_priv().
No functional change intended.
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
The x/y command parsing has been broken since commit 129957069e
("staging: panel: Fixed checkpatch warning about simple_strtoul()").
Commit b34050fadb ("auxdisplay: charlcd: Fix and clean up handling of
x/y commands") fixed some problems by rewriting the parsing code,
but also broke things further by removing the check for a complete
command before attempting to parse it. As a result, parsing is
terminated at the first x or y character.
This reinstates the check for a final semicolon. Whereas the original
code use strchr(), this is wasteful seeing as the semicolon is always
at the end of the buffer. Thus check this character directly instead.
Signed-off-by: Mans Rullgard <mans@mansr.com>
Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
The function long_sleep() calls mdelay() when in an interrupt handler.
But only charlcd_clear_display() and charlcd_init_display calls
long_sleep(), and my tool finds that the two functions
are never called in an interrupt handler.
Thus mdelay() and in_interrupt() are not necessary.
This is found by a static analysis tool named DCNS written by myself.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Acked-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
The current version is not parsing multiple x/y commands as the code
originally intended. On top of that, kstrtoul() expects
NULL-terminated strings. Finally, the code does two passes over
the string.
Some explanations about the supported syntax are added as well.
Cc: Willy Tarreau <w@1wt.eu>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Robert Abel <rabel@robertabel.eu>
Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
The graphics command expects 16 hexadecimal literals, but would allow
characters in range [0-9a-zA-Z] instead of [0-9a-fA-F].
Signed-off-by: Robert Abel <rabel@robertabel.eu>
Acked-by: Willy Tarreau <w@1wt.eu>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Signed-off-by: Robert Abel <rabel@robertabel.eu>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
There is no need to resort to octal escape sequence for the form feed
character when an established escape sequence exists.
Signed-off-by: Robert Abel <rabel@robertabel.eu>
Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Using '\0' instead of plain 0 makes the intent clearer that this is
indeed a string and not a series of integers.
Signed-off-by: Robert Abel <rabel@robertabel.eu>
Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
If the line extends beyond the width to the screen, nothing changes. The
existing code will call charlcd_gotoxy every time for this case.
Signed-off-by: Sean Young <sean@mess.org>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Commit f4757af ("staging: panel: Fix single-open policy race condition")
introduced in 3.19-rc1 attempted to fix a race condition on the open, but
failed to properly do it and used to exit without restoring the semaphore.
This results in -EBUSY being returned after the first open error until
the module is reloaded or the system restarted (ie: consecutive to a
dual open resulting in -EBUSY or to a permission error).
[ Note for stable maintainers: the code moved from drivers/misc/panel.c
to drivers/auxdisplay/{charlcd,panel}.c during 4.12. The patch easily
applies there (modulo the renamed atomic counter) but I can provide a
tested backport if desired. ]
Fixes: f4757af85 # 3.19-rc1
Cc: stable@vger.kernel.org
Cc: Mariusz Gorski <marius.gorski@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Miguel Ojeda Sandonis <miguel.ojeda.sandonis@gmail.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On displays with more than two lines, the additional lines are stored in
the buffers used for the first two lines, but beyond the visible parts.
Adjust the DDRAM address calculation to cater for this.
When clearing the display, avoid writing more spaces than the actual
size of the physical buffer.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In 4-bit mode, 8-bit commands and data are written using two raw writes
to the data interface: high nibble first, low nibble last. This must be
handled by the low-level driver.
However, as we don't know in which mode (4-bit or 8-bit) nor 4-bit phase
the LCD was left, initialization must always be handled using raw
writes, and needs to configure the LCD for 8-bit mode first.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Extract the character LCD core from the Parallel port LCD/Keypad Panel
driver in the misc subsystem, and convert it into a subdriver in the
auxdisplay subsystem. This allows the character LCD core to be used by
other drivers later.
Compilation is controlled by its own Kconfig symbol CHARLCD, which is to
be selected by its users, but can be enabled manually for
compile-testing.
All functions changed their prefix from "lcd_" to "charlcd_", and gained
a "struct charlcd *" parameter to operate on a specific instance.
While the driver API thus is ready to support multiple instances, the
current limitation of a single display (/dev/lcd has a single misc minor
assigned) is retained.
No functional changes intended.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Mans Rullgard