dm: Implement a CPU uclass
It is useful to be able to keep track of the available CPUs in a multi-CPU
system. This uclass is mostly intended for use with SMP systems.
The uclass provides methods for getting basic information about each CPU.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/include/cpu.h b/include/cpu.h
new file mode 100644
index 0000000..34c60bc
--- /dev/null
+++ b/include/cpu.h
@@ -0,0 +1,84 @@
+/*
+ * Copyright (c) 2015 Google, Inc
+ * Written by Simon Glass <sjg@chromium.org>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#ifndef __CPU_H
+#define __CPU_H
+
+/**
+ * struct cpu_platdata - platform data for a CPU
+ *
+ * This can be accessed with dev_get_parent_platdata() for any UCLASS_CPU
+ * device.
+ *
+ * @cpu_id: Platform-specific way of identifying the CPU.
+ */
+struct cpu_platdata {
+ int cpu_id;
+};
+
+/* CPU features - mostly just a placeholder for now */
+enum {
+ CPU_FEAT_L1_CACHE = 0, /* Supports level 1 cache */
+ CPU_FEAT_MMU = 1, /* Supports virtual memory */
+
+ CPU_FEAT_COUNT,
+};
+
+/**
+ * struct cpu_info - Information about a CPU
+ *
+ * @cpu_freq: Current CPU frequency in Hz
+ * @features: Flags for supported CPU features
+ */
+struct cpu_info {
+ ulong cpu_freq;
+ ulong features;
+};
+
+struct cpu_ops {
+ /**
+ * get_desc() - Get a description string for a CPU
+ *
+ * @dev: Device to check (UCLASS_CPU)
+ * @buf: Buffer to place string
+ * @size: Size of string space
+ * @return 0 if OK, -ENOSPC if buffer is too small, other -ve on error
+ */
+ int (*get_desc)(struct udevice *dev, char *buf, int size);
+
+ /**
+ * get_info() - Get information about a CPU
+ *
+ * @dev: Device to check (UCLASS_CPU)
+ * @info: Returns CPU info
+ * @return 0 if OK, -ve on error
+ */
+ int (*get_info)(struct udevice *dev, struct cpu_info *info);
+};
+
+#define cpu_get_ops(dev) ((struct cpu_ops *)(dev)->driver->ops)
+
+/**
+ * cpu_get_desc() - Get a description string for a CPU
+ *
+ * @dev: Device to check (UCLASS_CPU)
+ * @buf: Buffer to place string
+ * @size: Size of string space
+ * @return 0 if OK, -ENOSPC if buffer is too small, other -ve on error
+ */
+int cpu_get_desc(struct udevice *dev, char *buf, int size);
+
+/**
+ * cpu_get_info() - Get information about a CPU
+ *
+ * @dev: Device to check (UCLASS_CPU)
+ * @info: Returns CPU info
+ * @return 0 if OK, -ve on error
+ */
+int cpu_get_info(struct udevice *dev, struct cpu_info *info);
+
+#endif
diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
index fddfd35..395e25a 100644
--- a/include/dm/uclass-id.h
+++ b/include/dm/uclass-id.h
@@ -45,6 +45,7 @@
UCLASS_USB_HUB, /* USB hub */
UCLASS_USB_DEV_GENERIC, /* USB generic device */
UCLASS_MASS_STORAGE, /* Mass storage device */
+ UCLASS_CPU, /* CPU, typically part of an SoC */
UCLASS_COUNT,
UCLASS_INVALID = -1,