dm: cpu: Add a new get_count method to cpu uclass

Introduce a new method 'get_count' in the UCLASS_CPU ops to get
the number of CPUs in the system.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>

drivers/cpu/cpu-uclass.c

@@ -32,6 +32,16 @@ int cpu_get_info(struct udevice *dev, struct cpu_info *info)
 	return ops->get_info(dev, info);
 }
 
+int cpu_get_count(struct udevice *dev)
+{
+	struct cpu_ops *ops = cpu_get_ops(dev);
+
+	if (!ops->get_count)
+		return -ENOSYS;
+
+	return ops->get_count(dev);
+}
+
 U_BOOT_DRIVER(cpu_bus) = {
 	.name	= "cpu_bus",
 	.id	= UCLASS_SIMPLE_BUS,

include/cpu.h

@@ -58,6 +58,14 @@ struct cpu_ops {
 	 * @return 0 if OK, -ve on error
 	 */
 	int (*get_info)(struct udevice *dev, struct cpu_info *info);
+
+	/**
+	 * get_count() - Get number of CPUs
+	 *
+	 * @dev:	Device to check (UCLASS_CPU)
+	 * @return CPU count if OK, -ve on error
+	 */
+	int (*get_count)(struct udevice *dev);
 };
 
 #define cpu_get_ops(dev)        ((struct cpu_ops *)(dev)->driver->ops)
@@ -81,4 +89,12 @@ int cpu_get_desc(struct udevice *dev, char *buf, int size);
  */
 int cpu_get_info(struct udevice *dev, struct cpu_info *info);
 
+/**
+ * cpu_get_count() - Get number of CPUs
+ *
+ * @dev:	Device to check (UCLASS_CPU)
+ * @return CPU count if OK, -ve on error
+ */
+int cpu_get_count(struct udevice *dev);
+
 #endif