xtensa: simplify addition of new core variants

Instead of adding new Kconfig options and Makefile rules for each new
core variant provide XTENSA_VARIANT_CUSTOM variant and record variant
name in the XTENSA_VARIANT_NAME variable. Adding new core variant now
means providing directory structure under arch/xtensa/variant and
specifying correct name in kernel configuration.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

2 files changed, 37 insertions, 6 deletions

diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index 3a617af60d46..7feca8dfdff2 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -62,7 +62,9 @@ config TRACE_IRQFLAGS_SUPPORT
         def_bool y
 
 config MMU
-        def_bool n
+        bool
+        default n if !XTENSA_VARIANT_CUSTOM
+        default XTENSA_VARIANT_MMU if XTENSA_VARIANT_CUSTOM
 
 config VARIANT_IRQ_SWITCH
         def_bool n
@@ -102,8 +104,40 @@ config XTENSA_VARIANT_S6000
         select VARIANT_IRQ_SWITCH
         select ARCH_REQUIRE_GPIOLIB
         select XTENSA_CALIBRATE_CCOUNT
+
+config XTENSA_VARIANT_CUSTOM
+        bool "Custom Xtensa processor configuration"
+        select MAY_HAVE_SMP
+        select HAVE_XTENSA_GPIO32
+        help
+          Select this variant to use a custom Xtensa processor configuration.
+          You will be prompted for a processor variant CORENAME.
 endchoice
 
+config XTENSA_VARIANT_CUSTOM_NAME
+        string "Xtensa Processor Custom Core Variant Name"
+        depends on XTENSA_VARIANT_CUSTOM
+        help
+          Provide the name of a custom Xtensa processor variant.
+          This CORENAME selects arch/xtensa/variant/CORENAME.
+          Dont forget you have to select MMU if you have one.
+
+config XTENSA_VARIANT_NAME
+        string
+        default "dc232b"                        if XTENSA_VARIANT_DC232B
+        default "dc233c"                        if XTENSA_VARIANT_DC233C
+        default "fsf"                           if XTENSA_VARIANT_FSF
+        default "s6000"                         if XTENSA_VARIANT_S6000
+        default XTENSA_VARIANT_CUSTOM_NAME      if XTENSA_VARIANT_CUSTOM
+
+config XTENSA_VARIANT_MMU
+        bool "Core variant has a Full MMU (TLB, Pages, Protection, etc)"
+        depends on XTENSA_VARIANT_CUSTOM
+        default y
+        help
+          Build a Conventional Kernel with full MMU support,
+          ie: it supports a TLB with auto-loading, page protection.
+
 config XTENSA_UNALIGNED_USER
         bool "Unaligned memory access in use space"
         help
diff --git a/arch/xtensa/Makefile b/arch/xtensa/Makefile
index 81250ece3062..472533064b46 100644
--- a/arch/xtensa/Makefile
+++ b/arch/xtensa/Makefile
@@ -4,6 +4,7 @@
 # for more details.
 #
 # Copyright (C) 2001 - 2005  Tensilica Inc.
+# Copyright (C) 2014 Cadence Design Systems Inc.
 #
 # This file is included by the global makefile so that you can add your own
 # architecture-specific flags and dependencies. Remember to do have actions
@@ -13,11 +14,7 @@
 # Core configuration.
 # (Use VAR=<xtensa_config> to use another default compiler.)
 
-variant-$(CONFIG_XTENSA_VARIANT_FSF)            := fsf
-variant-$(CONFIG_XTENSA_VARIANT_DC232B)         := dc232b
-variant-$(CONFIG_XTENSA_VARIANT_DC233C)         := dc233c
-variant-$(CONFIG_XTENSA_VARIANT_S6000)          := s6000
-variant-$(CONFIG_XTENSA_VARIANT_LINUX_CUSTOM)   := custom
+variant-y := $(patsubst "%",%,$(CONFIG_XTENSA_VARIANT_NAME))
 
 VARIANT = $(variant-y)
 export VARIANT