GTA03 and E-Ink Interface

Jaya Kumar jayakumar.lkml at gmail.com
Sun Feb 15 06:15:15 CET 2009


On Sun, Feb 15, 2009 at 1:07 PM, Andy Green <andy at openmoko.com> wrote:
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> Somebody in the thread at some point said:
>
> |> You need those 22 gpio *in addition* to the LCM data lines from glamo
> to lcm?
> |
> | Ah, I think I see what you mean. I could convert the LCD data lines,
> | VD0..23 into gpio and then I would have enough pins. Ah, yes, this
> | will work. I had forgotten that S3C2410's VD lines are multifunction.
>
> The LCD bus is coming out of the Glamo, not the CPU on GTA02.

Oh, that would be a problem for me.

>
> There's other confusion in what you wrote, s3c2410 is GTA01 CPU, s3c2442
> is GTA02 and s3c6410 will be GTA03.  GTA02 alone has the Glamo running
> the LCM.

Yes, sorry, I haven't been looking carefully.

>
> There is a command / bypass capability inGLamo LCD controller to send
> commands to smart LCD, maybe it can match the needs of the E-ink
> controller since it's a common async memory bus kind of deal then.
>

I should explain the interface a bit more. Basically, the
communication between the host and the display is not a standard LCD
type interface like the 24-bit AMLCD RGB666/hsync/vsync type, or even
smart LCD (like MIPI-DSI) type, instead it is just GPIO wiggling. For
example,

http://www.arm.linux.org.uk/developer/patches/viewpatch.php?id=5353/1
+static void broadsheet_burst_write(struct broadsheetfb_par *par, int size,
+	par->board->set_ctl(par, BS_CS, 0);
+	par->board->set_ctl(par, BS_DC, 1);
+	for (i = 0; i < size; i++) {
+		par->board->set_ctl(par, BS_WR, 0);
+		tmp = (data[i] & 0x0F) << 4;
+		tmp |= (data[i] & 0x0F00) << 4;
+		par->board->set_hdb(par, tmp);
+		par->board->set_ctl(par, BS_WR, 1);
+	}
+	par->board->set_ctl(par, BS_CS, 1);

so what I am looking for is 22 pins that I can treat in that way, ie:
use as regular GPIO, and are in some way exposed on a connector or a
surface trace that can then be wired to an interface board that will
carry the display controller itself.

Thanks,
jaya



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