lkml.org 
[lkml]   [2020]   [Nov]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v6 19/25] auxdisplay: hd44780_common: Reduce clear_display timeout
Date
From: Lars Poeschel <poeschel@lemonage.de>

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 <poeschel@lemonage.de>
---
Changes in v3:
- This patch is new in v3
---
drivers/auxdisplay/hd44780_common.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/auxdisplay/hd44780_common.c b/drivers/auxdisplay/hd44780_common.c
index c528fb8e8808..bd93a4d3367e 100644
--- a/drivers/auxdisplay/hd44780_common.c
+++ b/drivers/auxdisplay/hd44780_common.c
@@ -83,8 +83,8 @@ int hd44780_common_clear_display(struct charlcd *lcd)
struct hd44780_common *hdc = lcd->drvdata;

hdc->write_cmd(hdc, LCD_CMD_DISPLAY_CLEAR);
- /* we must wait a few milliseconds (15) */
- long_sleep(15);
+ /* datasheet says to wait 1,64 milliseconds */
+ long_sleep(2);
return 0;
}
EXPORT_SYMBOL_GPL(hd44780_common_clear_display);
--
2.28.0
\
 
 \ /
  Last update: 2020-11-03 10:59    [W:0.143 / U:0.040 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site