kernel/linux.git/drivers/auxdisplay/charlcd.c, branch v7.1

auxdisplay: charlcd: Partially revert "Move hwidth and bwidth to struct hd44780_common"

2025-03-10T16:02:31+00:00

Commit 2545c1c948a6 ("auxdisplay: Move hwidth and bwidth to struct hd44780_common") makes charlcd_alloc() argument-less effectively dropping the single allocation for the struct charlcd_priv object along with the driver specific one. Restore that behaviour here. Signed-off-by: Andy Shevchenko Reviewed-by: Geert Uytterhoeven

[tree-wide] finally take no_llseek out

2024-09-27T15:18:43+00:00

no_llseek had been defined to NULL two years ago, in commit 868941b14441 ("fs: remove no_llseek") To quote that commit, At -rc1 we'll need do a mechanical removal of no_llseek - git grep -l -w no_llseek | grep -v porting.rst | while read i; do sed -i '/\/d' $i done would do it. Unfortunately, that hadn't been done. Linus, could you do that now, so that we could finally put that thing to rest? All instances are of the form .llseek = no_llseek, so it's obviously safe. Signed-off-by: Al Viro Signed-off-by: Linus Torvalds

auxdisplay: charlcd: Don't rebuild when CONFIG_PANEL_BOOT_MESSAGE=y

2024-04-11T10:34:29+00:00

When CONFIG_PANEL_BOOT_MESSAGE=y the module still includes the generated header and gets rebuilt even if it doesn't use anything from that header. Include generated header conditionally to avoid unnecessary rebuilds. Reviewed-by: Geert Uytterhoeven Signed-off-by: Andy Shevchenko

auxdisplay: charlcd: Add missing MODULE_DESCRIPTION()

2024-04-11T10:32:05+00:00

The modpost script is not happy WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/auxdisplay/charlcd.o because there is a missing module description. Add it to the module. Reviewed-by: Geert Uytterhoeven Signed-off-by: Andy Shevchenko

auxdisplay: charlcd: checking for pointer reference before dereferencing

2021-11-24T10:46:52+00:00

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 Signed-off-by: Miguel Ojeda

auxdisplay: charlcd: fixing coding style issue

2021-11-24T10:46:42+00:00

Removing 'int' from 'unsigned long int' declaration, which is unnecessary. Signed-off-by: Luiz Sampaio Signed-off-by: Miguel Ojeda

auxdisplay: charlcd: Drop unneeded initializers and switch to C99 style

2021-07-16T05:42:35+00:00

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 Acked-by: Willy Tarreau Signed-off-by: Miguel Ojeda

auxdisplay: Remove in_interrupt() usage.

2021-03-16T15:32:40+00:00

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 [mo: fixed a couple typos in comment and commit message] Signed-off-by: Miguel Ojeda

auxdisplay: charlcd: Do not print chars at end of line

2020-11-04T10:04:05+00:00

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 Signed-off-by: Lars Poeschel Signed-off-by: Miguel Ojeda

auxdisplay: Change gotoxy calling interface

2020-11-04T10:04:04+00:00

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 Signed-off-by: Lars Poeschel Signed-off-by: Miguel Ojeda