Re: [PATCH v2 17/19] auxdisplay: img-ascii-lcd: driver for simple ASCII LCD displays

From: Ralf Baechle
Date: Tue Sep 27 2016 - 14:53:00 EST

On Fri, Aug 26, 2016 at 03:17:49PM +0100, Paul Burton wrote:

> Add a driver for simple ASCII LCD displays found on the MIPS Boston,
> Malta & SEAD3 development boards. The Boston display is an independent
> memory mapped device with a simple memory mapped 8 byte register space
> containing the 8 ASCII characters to display. The Malta display is
> exposed as part of the Malta board registers, and provides 8 registers
> each of which corresponds to one of the ASCII characters to display. The
> SEAD3 display is slightly more complex, exposing an interface to an
> S6A0069 LCD controller via registers provided by the boards CPLD.
> However although the displays differ in their register interface, we
> require similar functionality on each board so abstracting away the
> differences within a single driver allows us to share a significant
> amount of code & ensure consistent behaviour.
> The driver displays the Linux kernel version as the default message, but
> allows the message to be changed via a character device. Messages longer
> then the number of characters that the display can show will scroll.
> This provides different behaviour to the existing LCD display code for
> the MIPS Malta or MIPS SEAD3 platforms in the following ways:
> - The default string to display is not "LINUX ON MALTA" or "LINUX ON
> SEAD3" but "Linux" followed by the version number of the kernel
> - Since that string tends to be significantly longer it scrolls twice
> as fast, moving every 500ms rather than every 1s.
> - The LCD won't be updated until the driver is probed, so it doesn't
> provide the early "LINUX" string.

Right now parts 15..18 of this series are stalled due to the lack of an
ack for this patch.