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Hugo Villeneuve a491c7be35 auxdisplay: hd44780: move cursor home after clear display command

commit 35b464e32c8bccef435e415db955787ead4ab44c upstream.

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 <hvilleneuve@dimonoff.com>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: David Reaver <me@davidreaver.com>
Link: https://lore.kernel.org/r/20230722180925.1408885-1-hugo@hugovil.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2023-12-08 08:51:16 +01:00

arm-charlcd.c

auxdisplay: Replace HTTP links with HTTPS ones

2020-08-08 16:10:03 +02:00

cfag12864b.c

auxdisplay: Replace symbolic permissions with octal permissions

2021-07-16 07:42:35 +02:00

cfag12864bfb.c

auxdisplay: cfag12864bfb: code indent should use tabs where possible

2021-10-22 00:13:16 +02:00

charlcd.c

auxdisplay: charlcd: checking for pointer reference before dereferencing