From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752243AbdLGIdu (ORCPT ); Thu, 7 Dec 2017 03:33:50 -0500 Received: from smtp2-2.goneo.de ([85.220.129.34]:45978 "EHLO smtp2-2.goneo.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750970AbdLGIds (ORCPT ); Thu, 7 Dec 2017 03:33:48 -0500 X-Spam-Flag: NO X-Spam-Score: -3.329 From: Lars Poeschel To: Geert Uytterhoeven Cc: David Airlie , Rob Herring , Mark Rutland , Bartlomiej Zolnierkiewicz , Manuel =?ISO-8859-1?Q?Sch=F6lling?= , Greg Kroah-Hartman , Daniel Vetter , Stafford Horne , Christophe Leroy , Randy Dunlap , Kate Stewart , Philippe Ombredanne , Sean Paul , Thomas Gleixner , DRI Development , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Linux Fbdev development list Subject: Re: [PATCH] video: hd44780: Add hd44780 lcd display driver Date: Thu, 07 Dec 2017 09:33:21 +0100 Message-ID: <2226720.5tM4mKizis@lem-wkst-02> User-Agent: KMail/5.2.3 (Linux/4.13.0-rc4+; KDE/5.37.0; x86_64; ; ) In-Reply-To: References: <20171206135255.6990-1-poeschel@lemonage.de> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Dec 6, 2017 at 16:04:10 CET Geert Uytterhoeven wrote: > Hi Lars, > > On Wed, Dec 6, 2017 at 2:52 PM, Lars Poeschel wrote: > > This adds a console driver for hd44780 based character lcd displays and > > clones. The driver currently supports 20x4 character displays with > > character ROMs A00 and A02. > > The hardware wirings to the display have to be supplied to the kernel in > > the devicetree. The binding doc has the necessary information. > > There are also tons of these cheap displays sold with a serial > > interface. Many of them use a simple pcf8574 gpio expanders. An example > > for using that kind of display is also in the binding doc. > > > > Signed-off-by: Lars Poeschel > > Thanks for your patch! > > > --- > > > > .../bindings/video/console/hd44780con.txt | 42 ++ > > drivers/video/console/Kconfig | 13 + > > drivers/video/console/Makefile | 1 + > > drivers/video/console/hd44780con.c | 676 > > +++++++++++++++++++++ > I'm wondering if you could implement this on top of the existing charlcd > framework: > > drivers/auxdisplay/charlcd.c > include/misc/charlcd.h > > which can use the existing hd44780 backend: > > Documentation/devicetree/bindings/auxdisplay/hit,hd44780.txt > drivers/auxdisplay/hd44780.c > > That way it can be used on other character LCDs, like the one supported by > drivers/auxdisplay/panel.c. Oh! Yes, this is a very interesting idea! This would involve multiple steps until this would be useful for me, but I will definitely have a look at this! So, please drop my patch for now. If for some reason in the future I find, that it should go upstream, I will submit it again. BTW thanks for the hint about the hd44780 charlcd backend. I did not know about this. My hd44780 console driver is quite a bit old. I just found time to clean up, rebase, test and submit it now. Regards, Lars From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lars Poeschel Subject: Re: [PATCH] video: hd44780: Add hd44780 lcd display driver Date: Thu, 07 Dec 2017 09:33:21 +0100 Message-ID: <2226720.5tM4mKizis@lem-wkst-02> References: <20171206135255.6990-1-poeschel@lemonage.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Geert Uytterhoeven Cc: David Airlie , Rob Herring , Mark Rutland , Bartlomiej Zolnierkiewicz , Manuel =?ISO-8859-1?Q?Sch=F6lling?= , Greg Kroah-Hartman , Daniel Vetter , Stafford Horne , Christophe Leroy , Randy Dunlap , Kate Stewart , Philippe Ombredanne , Sean Paul , Thomas Gleixner , DRI Development , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Linux List-Id: devicetree@vger.kernel.org On Wed, Dec 6, 2017 at 16:04:10 CET Geert Uytterhoeven wrote: > Hi Lars, > > On Wed, Dec 6, 2017 at 2:52 PM, Lars Poeschel wrote: > > This adds a console driver for hd44780 based character lcd displays and > > clones. The driver currently supports 20x4 character displays with > > character ROMs A00 and A02. > > The hardware wirings to the display have to be supplied to the kernel in > > the devicetree. The binding doc has the necessary information. > > There are also tons of these cheap displays sold with a serial > > interface. Many of them use a simple pcf8574 gpio expanders. An example > > for using that kind of display is also in the binding doc. > > > > Signed-off-by: Lars Poeschel > > Thanks for your patch! > > > --- > > > > .../bindings/video/console/hd44780con.txt | 42 ++ > > drivers/video/console/Kconfig | 13 + > > drivers/video/console/Makefile | 1 + > > drivers/video/console/hd44780con.c | 676 > > +++++++++++++++++++++ > I'm wondering if you could implement this on top of the existing charlcd > framework: > > drivers/auxdisplay/charlcd.c > include/misc/charlcd.h > > which can use the existing hd44780 backend: > > Documentation/devicetree/bindings/auxdisplay/hit,hd44780.txt > drivers/auxdisplay/hd44780.c > > That way it can be used on other character LCDs, like the one supported by > drivers/auxdisplay/panel.c. Oh! Yes, this is a very interesting idea! This would involve multiple steps until this would be useful for me, but I will definitely have a look at this! So, please drop my patch for now. If for some reason in the future I find, that it should go upstream, I will submit it again. BTW thanks for the hint about the hd44780 charlcd backend. I did not know about this. My hd44780 console driver is quite a bit old. I just found time to clean up, rebase, test and submit it now. Regards, Lars From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lars Poeschel Date: Thu, 07 Dec 2017 08:33:21 +0000 Subject: Re: [PATCH] video: hd44780: Add hd44780 lcd display driver Message-Id: <2226720.5tM4mKizis@lem-wkst-02> List-Id: References: <20171206135255.6990-1-poeschel@lemonage.de> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Geert Uytterhoeven Cc: David Airlie , Rob Herring , Mark Rutland , Bartlomiej Zolnierkiewicz , Manuel =?ISO-8859-1?Q?Sch=F6lling?= , Greg Kroah-Hartman , Daniel Vetter , Stafford Horne , Christophe Leroy , Randy Dunlap , Kate Stewart , Philippe Ombredanne , Sean Paul , Thomas Gleixner , DRI Development , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Linux On Wed, Dec 6, 2017 at 16:04:10 CET Geert Uytterhoeven wrote: > Hi Lars, > > On Wed, Dec 6, 2017 at 2:52 PM, Lars Poeschel wrote: > > This adds a console driver for hd44780 based character lcd displays and > > clones. The driver currently supports 20x4 character displays with > > character ROMs A00 and A02. > > The hardware wirings to the display have to be supplied to the kernel in > > the devicetree. The binding doc has the necessary information. > > There are also tons of these cheap displays sold with a serial > > interface. Many of them use a simple pcf8574 gpio expanders. An example > > for using that kind of display is also in the binding doc. > > > > Signed-off-by: Lars Poeschel > > Thanks for your patch! > > > --- > > > > .../bindings/video/console/hd44780con.txt | 42 ++ > > drivers/video/console/Kconfig | 13 + > > drivers/video/console/Makefile | 1 + > > drivers/video/console/hd44780con.c | 676 > > +++++++++++++++++++++ > I'm wondering if you could implement this on top of the existing charlcd > framework: > > drivers/auxdisplay/charlcd.c > include/misc/charlcd.h > > which can use the existing hd44780 backend: > > Documentation/devicetree/bindings/auxdisplay/hit,hd44780.txt > drivers/auxdisplay/hd44780.c > > That way it can be used on other character LCDs, like the one supported by > drivers/auxdisplay/panel.c. Oh! Yes, this is a very interesting idea! This would involve multiple steps until this would be useful for me, but I will definitely have a look at this! So, please drop my patch for now. If for some reason in the future I find, that it should go upstream, I will submit it again. BTW thanks for the hint about the hd44780 charlcd backend. I did not know about this. My hd44780 console driver is quite a bit old. I just found time to clean up, rebase, test and submit it now. Regards, Lars