mfd: Versatile Express system registers driver

This is a platform driver for Versatile Express' "system
register" block. It's a random collection of registers providing
the following functionality:

- low level platform functions like board ID access; in order to
  use those, the driver must be initialized early, either statically
  or based on the DT

- config bus bridge via "system control" interface; as the response
  from the controller does not generate interrupt (yet), the status
  register is periodically polled using a timer

- pseudo GPIO lines providing MMC card status and Flash WP#
  signal control

- LED interface for a set of 8 LEDs on the motherboard, with
  "heartbeat", "mmc0" and "cpu0" to "cpu5" as default triggers

Signed-off-by: Pawel Moll <pawel.moll@arm.com>
diff --git a/include/linux/vexpress.h b/include/linux/vexpress.h
index c2d877a..09c81d7 100644
--- a/include/linux/vexpress.h
+++ b/include/linux/vexpress.h
@@ -24,6 +24,17 @@
 #define VEXPRESS_CONFIG_STATUS_DONE	0
 #define VEXPRESS_CONFIG_STATUS_WAIT	1
 
+#define VEXPRESS_GPIO_MMC_CARDIN	0
+#define VEXPRESS_GPIO_MMC_WPROT		1
+#define VEXPRESS_GPIO_FLASH_WPn		2
+
+#define VEXPRESS_RES_FUNC(_site, _func)	\
+{					\
+	.start = (_site),		\
+	.end = (_func),			\
+	.flags = IORESOURCE_BUS,	\
+}
+
 /* Config bridge API */
 
 /**
@@ -82,4 +93,18 @@
 int vexpress_config_write(struct vexpress_config_func *func, int offset,
 		u32 data);
 
+/* Platform control */
+
+u32 vexpress_get_procid(int site);
+u32 vexpress_get_hbi(int site);
+void *vexpress_get_24mhz_clock_base(void);
+void vexpress_flags_set(u32 data);
+
+#define vexpress_get_site_by_node(node) __vexpress_get_site(NULL, node)
+#define vexpress_get_site_by_dev(dev) __vexpress_get_site(dev, NULL)
+unsigned __vexpress_get_site(struct device *dev, struct device_node *node);
+
+void vexpress_sysreg_early_init(void __iomem *base);
+void vexpress_sysreg_of_early_init(void);
+
 #endif