From 0cad855fbd083ee5fd0584a47c2aaa7dca936fd4 Mon Sep 17 00:00:00 2001 From: Paul Burton Date: Fri, 26 Aug 2016 15:17:49 +0100 Subject: auxdisplay: img-ascii-lcd: driver for simple ASCII LCD displays 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 (UTS_RELEASE). - 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. Signed-off-by: Paul Burton Cc: Mauro Carvalho Chehab Cc: Miguel Ojeda Sandonis Cc: Guenter Roeck Cc: David S. Miller Cc: Greg Kroah-Hartman Cc: Geert Uytterhoeven Cc: Andrew Morton Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/14062/ Signed-off-by: Ralf Baechle --- MAINTAINERS | 1 + 1 file changed, 1 insertion(+) (limited to 'MAINTAINERS') diff --git a/MAINTAINERS b/MAINTAINERS index 7b24f9f30f47..1f1790031dbc 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -5968,6 +5968,7 @@ IMGTEC ASCII LCD DRIVER M: Paul Burton S: Maintained F: Documentation/devicetree/bindings/auxdisplay/img-ascii-lcd.txt +F: drivers/auxdisplay/img-ascii-lcd.c INA209 HARDWARE MONITOR DRIVER M: Guenter Roeck -- cgit v1.2.1