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authorLinus Torvalds <torvalds@linux-foundation.org>2023-08-29 18:32:28 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2023-08-29 18:32:28 +0300
commit5ea0cf77583ec768c8e2403ecb2a930fa948b444 (patch)
tree301d2df73a26eac7c1d59e4e27abc62447d63234
parenta031fe8d1d32898582e36ccbffa9847d16f67aa2 (diff)
parent35b464e32c8bccef435e415db955787ead4ab44c (diff)
downloadlinux-5ea0cf77583ec768c8e2403ecb2a930fa948b444.tar.xz
Merge tag 'auxdisplay-6.6' of https://github.com/ojeda/linux
Pull auxdisplay update from Miguel Ojeda: - hd44780: move cursor home after clear display command The change allows to support displays like the NewHaven NHD-0220DZW-AG5 which has a non-standard controller. * tag 'auxdisplay-6.6' of https://github.com/ojeda/linux: auxdisplay: hd44780: move cursor home after clear display command
-rw-r--r--drivers/auxdisplay/hd44780_common.c10
1 files changed, 9 insertions, 1 deletions
diff --git a/drivers/auxdisplay/hd44780_common.c b/drivers/auxdisplay/hd44780_common.c
index 3934c2eebf33..7cbf375b0fa5 100644
--- a/drivers/auxdisplay/hd44780_common.c
+++ b/drivers/auxdisplay/hd44780_common.c
@@ -82,7 +82,15 @@ int hd44780_common_clear_display(struct charlcd *lcd)
hdc->write_cmd(hdc, LCD_CMD_DISPLAY_CLEAR);
/* datasheet says to wait 1,64 milliseconds */
long_sleep(2);
- return 0;
+
+ /*
+ * The Hitachi HD44780 controller (and compatible ones) reset the DDRAM
+ * address when executing the DISPLAY_CLEAR command, thus the
+ * following call is not required. However, other controllers do not
+ * (e.g. NewHaven NHD-0220DZW-AG5), thus move the cursor to home
+ * unconditionally to support both.
+ */
+ return hd44780_common_home(lcd);
}
EXPORT_SYMBOL_GPL(hd44780_common_clear_display);