Messages in this thread Patch in this message | | | From | poeschel@lemonage ... | Subject | [PATCH v4 26/32] auxdisplay: hd44780_common: Reduce clear_display timeout | Date | Mon, 5 Oct 2020 15:01:22 +0200 |
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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 82afae78f46e..fbce8835a650 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
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