ARM: vexpress: refine dependencies for new code

The versatile express changes for 3.16 introduced a number of
build regressions for randconfig kernels by not tracking dependencies
between the components right.

This patch tries to rectify that:

* the mach-vexpress code cannot link without the syscfg driver,
  which in turn needs MFD_VEXPRESS_SYSREG
* various drivers call devm_regmap_init_vexpress_config(), which
  has to be exported so it can be used by loadable modules
* the configuration bus uses OF DT helper functions that are not
  available to platforms disable CONFIG_OF
* The sysreg driver exports GPIOs through gpiolib, which can
  be disabled on some platforms.
* The clocksource code cannot be built on platforms that don't
  use modern timekeeping but rely on gettimeoffset.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

2 files changed, 2 insertions, 1 deletions

diff --git a/drivers/bus/Kconfig b/drivers/bus/Kconfig
index f24e79dd51bf..286342778884 100644
--- a/drivers/bus/Kconfig
+++ b/drivers/bus/Kconfig
@@ -46,6 +46,7 @@ config VEXPRESS_CONFIG
         bool "Versatile Express configuration bus"
         default y if ARCH_VEXPRESS
         depends on ARM || ARM64
+        depends on OF
         select REGMAP
         help
           Platform configuration infrastructure for the ARM Ltd.
diff --git a/drivers/bus/vexpress-config.c b/drivers/bus/vexpress-config.c
index 27a07dfcd626..a64763b6b5fd 100644
--- a/drivers/bus/vexpress-config.c
+++ b/drivers/bus/vexpress-config.c
@@ -118,7 +118,7 @@ struct regmap *devm_regmap_init_vexpress_config(struct device *dev)
 
         return regmap;
 }
-
+EXPORT_SYMBOL_GPL(devm_regmap_init_vexpress_config);
 
 struct device *vexpress_config_bridge_register(struct device *parent,
                 struct vexpress_config_bridge_ops *ops, void *context)