From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D7CEDEB64DA for ; Thu, 20 Jul 2023 16:56:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230049AbjGTQ4P (ORCPT ); Thu, 20 Jul 2023 12:56:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45352 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229689AbjGTQ4M (ORCPT ); Thu, 20 Jul 2023 12:56:12 -0400 X-Greylist: delayed 362 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Thu, 20 Jul 2023 09:56:09 PDT Received: from smtp4.goneo.de (smtp4.goneo.de [IPv6:2001:1640:5::8:59]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8CDAC119 for ; Thu, 20 Jul 2023 09:56:09 -0700 (PDT) Received: from hub1.goneo.de (hub1.goneo.de [85.220.129.52]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by smtp4.goneo.de (Postfix) with ESMTPS id 47BAB10A1E83; Thu, 20 Jul 2023 18:50:02 +0200 (CEST) Received: from hub1.goneo.de (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by hub1.goneo.de (Postfix) with ESMTPS id B2A55105C5F8; Thu, 20 Jul 2023 18:50:00 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=lemonage.de; s=DKIM001; t=1689871800; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=iWOmNXCe1n/AaDrwwRNqn13hsApWVf7kAvHyrB0V0vg=; b=O267U7dftQNtEcPGlVfA3cEXnQXDCz0DY/e9grKyujNdPLAs8Z4QDweI+9V5IZ8+lk7WoZ eec1lKtdMHTvyM8s75vwxonXRkNcGguOPJHYhBVFt8nbRvs5dpndoONgev9zw0nw/7L1co syVsee07nYS3Fqo52Bez14iQRec9MOqiqGMTpzWcmXbU4vI0byi81ZjiuhF/VDNXMZO8rb loydPvPZBt9RrjQOql5rw6k1hGB8A7rcarc5Dn8yt2L1tlyiB9F9YRuAzJBYwWCfSao/fY INEuOBisRWgfQKzwN9IvZqbRN9YrJDDje3C9plzYNIa4TRHYHaHfWcwCp5+rAA== Received: from webmail.goneo.de (webmail.goneo.de [IPv6:2001:1640:5::2:12]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by hub1.goneo.de (Postfix) with ESMTPSA id 6407D105C5C4; Thu, 20 Jul 2023 18:49:59 +0200 (CEST) MIME-Version: 1.0 Date: Thu, 20 Jul 2023 18:49:59 +0200 From: poeschel@lemonage.de To: Hugo Villeneuve Cc: Miguel Ojeda , Miguel Ojeda , Hugo Villeneuve , linux-kernel@vger.kernel.org, geert@linux-m68k.org, Christian Meusel Subject: Re: [PATCH] auxdisplay: hd44780: move cursor home after clear display command In-Reply-To: <20230706154937.1380bdcf9d84e1cff78911fa@hugovil.com> References: <20230706185100.84322-1-hugo@hugovil.com> <20230706154937.1380bdcf9d84e1cff78911fa@hugovil.com> User-Agent: goneo Webmail Message-ID: <7eb2d50baf269310e51854f700936e94@lemonage.de> X-Sender: poeschel@lemonage.de Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Rspamd-UID: 22c9a0 X-Rspamd-UID: cd634c Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am 2023-07-06 21:49, schrieb Hugo Villeneuve: > On Thu, 6 Jul 2023 21:33:05 +0200 > Miguel Ojeda wrote: > >> On Thu, Jul 6, 2023 at 8:51 PM Hugo Villeneuve >> wrote: >> > >> > The "clear display" 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 clear display >> > command. >> > >> > Extract of CLEAR_DISPLAY 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 clear display command to support >> > non-standard LCDs. >> > >> > Signed-off-by: Hugo Villeneuve >> >> Thanks! Sounds good to me, as long the extra command does not >> introduce some issue with the actual HD44780 -- can we double-check >> the HD44780 still works as expected? >> >> Cc'ing Lars and Geert since they may be able to give it a quick test. > > Hi Miguel, > I do not have a standard Hitachi controller to test it on, so lets wait > for feedback from Lars and Geert or others. Sorry guys, I do not have access to the relevant hardware anymore. I am CC'ing Christian, who has the relevant hardware and maybe he can help testing the patch. Christian is on vacation up until mid august, so we have to wait a bit more for someone able to test this. BTW: The displays I did the work back then on were for sure not genuine Hitachi ones either. I do not see, that the little patch should do any harm. Regards, Lars