Граф коммитов

12 Коммитов

Автор SHA1 Сообщение Дата
Jia-Ju Bai 171613926a auxdisplay: charlcd: delete mdelay in long_sleep
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>
2018-08-01 18:55:36 +02:00
Miguel Ojeda 351f683b98 auxdisplay: Replace licenses with SPDX identifiers
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Acked-by: Willy Tarreau <w@1wt.eu>
Acked-by: Linus Walleij <triad@dflund.se>
Acked-by: Robin van der Gracht <robin@protonic.nl>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
2018-04-12 19:02:45 +02:00
Miguel Ojeda b34050fadb auxdisplay: charlcd: Fix and clean up handling of x/y commands
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>
2018-04-12 19:02:44 +02:00
Robert Abel 2e8c04f757 auxdisplay: charlcd: fix hex literal ranges for graphics command
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>
2018-04-12 19:02:44 +02:00
Robert Abel 99b9b4909c auxdisplay: charlcd: fix two-line command ^[[LN not marked as processed
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>
2018-04-12 19:02:43 +02:00
Robert Abel 9629ccca3b auxdisplay: charlcd: replace octal literal with form-feed escape sequence
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>
2018-04-12 19:02:43 +02:00
Robert Abel 8c483758af auxdisplay: charlcd: use null character instead of zero literal to terminate strings
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>
2018-04-12 19:02:43 +02:00
Sean Young 54bc937f0c auxdisplay: charlcd: no need to call charlcd_gotoxy() if nothing changes
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>
2018-04-12 19:02:42 +02:00
Willy Tarreau 93dc1774d2 auxdisplay: charlcd: properly restore atomic counter on error path
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>
2017-09-18 16:06:00 +02:00
Geert Uytterhoeven 1d3b2af213 auxdisplay: charlcd: Add support for displays with more than two lines
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>
2017-03-17 15:10:49 +09:00
Geert Uytterhoeven ac201479cc auxdisplay: charlcd: Add support for 4-bit interfaces
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>
2017-03-17 15:10:49 +09:00
Geert Uytterhoeven 39f8ea4672 auxdisplay: charlcd: Extract character LCD core from misc/panel
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>
2017-03-17 15:10:49 +09:00