register: Add block initialise helper

Add a helper that will scan a static RegisterAccessInfo Array
and populate a container MemoryRegion with registers as defined.

Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Signed-off-by: Alistair Francis <alistair.francis@xilinx.com>
Message-id: 347b810b2799e413c98d5bbeca97bcb1557946c3.1467053537.git.alistair.francis@xilinx.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

hw/core/register.c

@@ -229,6 +229,51 @@ uint64_t register_read_memory(void *opaque, hwaddr addr,
     return extract64(read_val, 0, size * 8);
 }
 
+RegisterInfoArray *register_init_block32(DeviceState *owner,
+                                         const RegisterAccessInfo *rae,
+                                         int num, RegisterInfo *ri,
+                                         uint32_t *data,
+                                         const MemoryRegionOps *ops,
+                                         bool debug_enabled,
+                                         uint64_t memory_size)
+{
+    const char *device_prefix = object_get_typename(OBJECT(owner));
+    RegisterInfoArray *r_array = g_new0(RegisterInfoArray, 1);
+    int i;
+
+    r_array->r = g_new0(RegisterInfo *, num);
+    r_array->num_elements = num;
+    r_array->debug = debug_enabled;
+    r_array->prefix = device_prefix;
+
+    for (i = 0; i < num; i++) {
+        int index = rae[i].addr / 4;
+        RegisterInfo *r = &ri[index];
+
+        *r = (RegisterInfo) {
+            .data = &data[index],
+            .data_size = sizeof(uint32_t),
+            .access = &rae[i],
+            .opaque = owner,
+        };
+        register_init(r);
+
+        r_array->r[i] = r;
+    }
+
+    memory_region_init_io(&r_array->mem, OBJECT(owner), ops, r_array,
+                          device_prefix, memory_size);
+
+    return r_array;
+}
+
+void register_finalize_block(RegisterInfoArray *r_array)
+{
+    object_unparent(OBJECT(&r_array->mem));
+    g_free(r_array->r);
+    g_free(r_array);
+}
+
 static const TypeInfo register_info = {
     .name  = TYPE_REGISTER,
     .parent = TYPE_DEVICE,

include/hw/register.h

@@ -100,6 +100,8 @@ struct RegisterInfo {
  */
 
 struct RegisterInfoArray {
+    MemoryRegion mem;
+
     int num_elements;
     RegisterInfo **r;
 
@@ -166,6 +168,44 @@ void register_write_memory(void *opaque, hwaddr addr, uint64_t value,
 
 uint64_t register_read_memory(void *opaque, hwaddr addr, unsigned size);
 
+/**
+ * Init a block of registers into a container MemoryRegion. A
+ * number of constant register definitions are parsed to create a corresponding
+ * array of RegisterInfo's.
+ *
+ * @owner: device owning the registers
+ * @rae: Register definitions to init
+ * @num: number of registers to init (length of @rae)
+ * @ri: Register array to init, must already be allocated
+ * @data: Array to use for register data, must already be allocated
+ * @ops: Memory region ops to access registers.
+ * @debug enabled: turn on/off verbose debug information
+ * returns: A structure containing all of the registers and an initialized
+ *          memory region (r_array->mem) the caller should add to a container.
+ */
+
+RegisterInfoArray *register_init_block32(DeviceState *owner,
+                                         const RegisterAccessInfo *rae,
+                                         int num, RegisterInfo *ri,
+                                         uint32_t *data,
+                                         const MemoryRegionOps *ops,
+                                         bool debug_enabled,
+                                         uint64_t memory_size);
+
+/**
+ * This function should be called to cleanup the registers that were initialized
+ * when calling register_init_block32(). This function should only be called
+ * from the device's instance_finalize function.
+ *
+ * Any memory operations that the device performed that require cleanup (such
+ * as creating subregions) need to be called before calling this function.
+ *
+ * @r_array: A structure containing all of the registers, as returned by
+ *           register_init_block32()
+ */
+
+void register_finalize_block(RegisterInfoArray *r_array);
+
 /* Define constants for a 32 bit register */
 
 /* This macro will define A_FOO, for the byte address of a register