From mboxrd@z Thu Jan 1 00:00:00 1970 From: Fabio Giovagnini Date: Wed, 26 May 2010 07:54:48 +0000 Subject: Re: LCDC of 7203 Message-Id: <201005260954.48760.fabio.giovagnini@aurion-tech.com> List-Id: References: <201005241912.44976.fabio.giovagnini@aurion-tech.com> In-Reply-To: <201005241912.44976.fabio.giovagnini@aurion-tech.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable To: linux-sh@vger.kernel.org There are some low cost LCD having a parallel interface with the synch sign= als=20 and 16 / 18 bit of data. The sh2a LCDC can manage such LCD panels Am I right or not? In data mercoled=EC 26 maggio 2010 09:34:36, Magnus Damm ha scritto: : > On Wed, May 26, 2010 at 3:14 AM, Paul Mundt wrote: > > On Wed, May 26, 2010 at 02:20:05AM -0400, Magnus Damm wrote: > >> On Mon, May 24, 2010 at 1:12 PM, Fabio Giovagnini > >> > >> wrote: > >> > Hi all, > >> > I have a little problem with LCDC of sh2a 7203. > >> > I seem not to see the driver into the last kernel. > >> > Where could I find a good reference? > >> > >> I don't think there is any upstream 7203 LCDC driver. It's a shame, I > >> really wish people would submit their code upstream. > > > > I don't remember the details specifically, I thought the issue was panel > > control via MSIOF and so on, which isn't too different from G3EVM? >=20 > Some LCD panels come with a dedicated control channel over SPI/I2C, > and some have their control channel muxed with pixel data like SYS or > MIPI. >=20 > I think rsk7203 dealt with the LCD panel setup over SPI, and most > likely that SPI channel was hooked up to an SIOF or SIO. The MSIOF > only exists on newer SH-Mobiles, so we would need a new SPI driver for > SIOF or whatever is there to begin with. Perhaps the easiest is just > to use an GPIO bitbang driver, but that requires pinmux support which > probably is in place on some sh2a processor at least. >=20 > > The existing "drivers" are much like the early G3EVM LCD support, so > > while references are readily available, there's little that is directly > > usable without some serious work on the infrastructure side. Perhaps we > > can reuse parts of the SH-Mobile LCD support? > > > >From my POV, the biggest showstopper is that the SPI code is lacking >=20 > support for using the bus without the driver model. I2C allows this, > good or bad. It's sort of a hack, but there is nothing better > available either. With I2C we can have some board specific support > code for the LCD panel like the hack on Migo-R. This is not possible > with SPI AFAIK. >=20 > Perhaps the proper way is to add the LCD panel to the driver model and > then write a normal SPI driver for the LCD, but that brings up init > order issues. >=20 > The G3EVM code is setting up the LCD panel using the MSIOF in SPI > mode. The original code just accessed the MSIOF directly, but we > should be able to use the SPI driver instead. The MSIOF hardware block > on SH-Mobile ARM is unfortunately not working well with the MSIOF > driver, so it's a bit of a mess. SPI bitbang could be useful in this > case too though if the SPI-without-driver-model could be sorted out. >=20 > I think the MIPI work by Guennadi is one step in the right direction. >=20 > / magnus > -- > To unsubscribe from this list: send the line "unsubscribe linux-sh" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >=20 --=20 Fabio Giovagnini Aurion s.r.l. P.I e C.F. 00885711200 Tel. +39.051.594.78.24 Cell. +39.335.83.50.919