kernel/git/next/linux-next.git/drivers/auxdisplay/hd44780_common.c, branch master

kernel.h: drop hex.h and update all hex.h users

2026-01-21T03:44:19+00:00

Remove from and update all users/callers of hex.h interfaces to directly #include as part of the process of putting kernel.h on a diet. Removing hex.h from kernel.h means that 36K C source files don't have to pay the price of parsing hex.h for the roughly 120 C source files that need it. This change has been build-tested with allmodconfig on most ARCHes. Also, all users/callers of in the entire source tree have been updated if needed (if not already #included). Link: https://lkml.kernel.org/r/20251215005206.2362276-1-rdunlap@infradead.org Signed-off-by: Randy Dunlap Reviewed-by: Andy Shevchenko Cc: Ingo Molnar Cc: Yury Norov (NVIDIA) Signed-off-by: Andrew Morton

auxdisplay: hd44780: Rename hd to hdc in hd44780_common_alloc()

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

The hd44780_common_alloc() uses hd for local variable while the respective header uses hdc, rename to make it consistent and avoid potential confuse with the drivers that use both for different reasons. No functional changes intended. Signed-off-by: Andy Shevchenko

auxdisplay: hd44780: Call charlcd_alloc() from hd44780_common_alloc()

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

HD44780 APIs all operate on struct charlcd objects. Moreover, the current users always call charlcd_alloc() and hd44780_common_alloc(). Make the latter call the former, so eliminate the additional allocation, to make it consistent with the rest of API and avoid duplication. Signed-off-by: Andy Shevchenko Reviewed-by: Geert Uytterhoeven

auxdisplay: hd44780: Introduce hd44780_common_free()

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

Introduce hd44780_common_free() for symmetrical operation to hd44780_common_alloc(). It will allow to modify both in the future without touching the users. Signed-off-by: Andy Shevchenko Reviewed-by: Geert Uytterhoeven

auxdisplay: hd44780: add missing MODULE_DESCRIPTION() macro

2024-06-04T07:29:36+00:00

make allmodconfig && make W=1 C=1 reports: WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/auxdisplay/hd44780_common.o Add the missing invocation of the MODULE_DESCRIPTION() macro. Signed-off-by: Jeff Johnson Reviewed-by: Geert Uytterhoeven Signed-off-by: Andy Shevchenko

auxdisplay: hd44780: move cursor home after clear display command

2023-08-19T19:53:49+00:00

The DISPLAY_CLEAR command on the NewHaven NHD-0220DZW-AG5 display does NOT change the DDRAM address to 00h (home position) like the standard Hitachi HD44780 controller. As a consequence, the starting position of the initial string LCD_INIT_TEXT is not guaranteed to be at 0,0 depending on where the cursor was before the DISPLAY_CLEAR command. Extract of DISPLAY_CLEAR command from datasheets of: Hitachi HD44780: ... It then sets DDRAM address 0 into the address counter... NewHaven NHD-0220DZW-AG5 datasheet: ... This instruction does not change the DDRAM Address Move the cursor home after sending DISPLAY_CLEAR command to support non-standard LCDs. Signed-off-by: Hugo Villeneuve Reviewed-by: Geert Uytterhoeven Tested-by: David Reaver Link: https://lore.kernel.org/r/20230722180925.1408885-1-hugo@hugovil.com 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

auxdisplay: hd44780_common: Reduce clear_display timeout

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

Digging in the hd44780 datasheet revealed that the timeout needed after clearing the whole display is only 1,64ms not 15ms. So we can reduce that timeout. Link: https://lore.kernel.org/lkml/20200922092121.GG16421@1wt.eu/ Link: https://www.crystalfontz.com/controllers/Hitachi/HD44780/433/ Signed-off-by: Lars Poeschel Signed-off-by: Miguel Ojeda

auxdisplay: Move char redefine code to hd44780_common

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

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

auxdisplay: implement various hd44780_common_ functions

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

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