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authorPaul Burton <paul.burton@imgtec.com>2016-08-26 15:17:49 +0100
committerRalf Baechle <ralf@linux-mips.org>2016-10-06 17:03:41 +0200
commit0cad855fbd083ee5fd0584a47c2aaa7dca936fd4 (patch)
tree6d13b4b74ef0c38be6b715e00983366a97fc16e1 /drivers/auxdisplay/Kconfig
parent8ef3ff2723f8cbaec4fee3c7fa807bf8d6ccd2e5 (diff)
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 <paul.burton@imgtec.com> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: Miguel Ojeda Sandonis <miguel.ojeda.sandonis@gmail.com> Cc: Guenter Roeck <linux@roeck-us.net> Cc: David S. Miller <davem@davemloft.net> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Andrew Morton <akpm@linux-foundation.org> 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 <ralf@linux-mips.org>
Diffstat (limited to 'drivers/auxdisplay/Kconfig')
-rw-r--r--drivers/auxdisplay/Kconfig9
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/auxdisplay/Kconfig b/drivers/auxdisplay/Kconfig
index c07e725ea93d..10e1b9eee10e 100644
--- a/drivers/auxdisplay/Kconfig
+++ b/drivers/auxdisplay/Kconfig
@@ -119,4 +119,13 @@ config CFAG12864B_RATE
If you compile this as a module, you can still override this
value using the module parameters.
+config IMG_ASCII_LCD
+ tristate "Imagination Technologies ASCII LCD Display"
+ default y if MIPS_MALTA || MIPS_SEAD3
+ select SYSCON
+ help
+ Enable this to support the simple ASCII LCD displays found on
+ development boards such as the MIPS Boston, MIPS Malta & MIPS SEAD3
+ from Imagination Technologies.
+
endif # AUXDISPLAY