[added to the 3.18 stable tree] xtensa: xtfpga: fix hardware lockup caused by LCD driver

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From: Max Filippov <jcmvbkbc@xxxxxxxxx>

This patch has been added to the 3.18 stable tree. If you have any
objections, please let us know.

===============

[ Upstream commit 4949009eb8d40a441dcddcd96e101e77d31cf1b2 ]

LCD driver is always built for the XTFPGA platform, but its base address
is not configurable, and is wrong for ML605/KC705. Its initialization
locks up KC705 board hardware.

Make the whole driver optional, and its base address and bus width
configurable. Implement 4-bit bus access method.

Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Max Filippov <jcmvbkbc@xxxxxxxxx>
Signed-off-by: Sasha Levin <sasha.levin@xxxxxxxxxx>
---
 arch/xtensa/Kconfig | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index 73d328f..e28ef29 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -436,6 +436,36 @@ config XTFPGA_LCD_8BIT_ACCESS
 	  only be used with 8-bit interface. Please consult prototyping user
 	  guide for your board for the correct interface width.
 
+config XTFPGA_LCD
+	bool "Enable XTFPGA LCD driver"
+	depends on XTENSA_PLATFORM_XTFPGA
+	default n
+	help
+	  There's a 2x16 LCD on most of XTFPGA boards, kernel may output
+	  progress messages there during bootup/shutdown. It may be useful
+	  during board bringup.
+
+	  If unsure, say N.
+
+config XTFPGA_LCD_BASE_ADDR
+	hex "XTFPGA LCD base address"
+	depends on XTFPGA_LCD
+	default "0x0d0c0000"
+	help
+	  Base address of the LCD controller inside KIO region.
+	  Different boards from XTFPGA family have LCD controller at different
+	  addresses. Please consult prototyping user guide for your board for
+	  the correct address. Wrong address here may lead to hardware lockup.
+
+config XTFPGA_LCD_8BIT_ACCESS
+	bool "Use 8-bit access to XTFPGA LCD"
+	depends on XTFPGA_LCD
+	default n
+	help
+	  LCD may be connected with 4- or 8-bit interface, 8-bit access may
+	  only be used with 8-bit interface. Please consult prototyping user
+	  guide for your board for the correct interface width.
+
 endmenu
 
 menu "Executable file formats"
-- 
2.1.0

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