driver: add cpuidle device driver

Currently, it's only used to load generic cpuidle module. But in the
future, we will add some features such as stats reporting etc.

Signed-off-by: Yongcong Du <ycdu.vmcore@gmail.com>
Signed-off-by: Fredrik Holmqvist <fredrik.holmqvist@gmail.com>

src/add-ons/kernel/drivers/cpuidle/Jamfile

@@ -0,0 +1,5 @@
+SubDir HAIKU_TOP src add-ons kernel drivers cpuidle ;
+
+KernelAddon <driver>cpuidle :
+	cpuidle.cpp
+	;

src/add-ons/kernel/drivers/cpuidle/cpuidle.cpp

@@ -0,0 +1,117 @@
+/*
+ * Copyright 2012, Haiku, Inc. All Rights Reserved.
+ * Distributed under the terms of the MIT License.
+ *
+ * Authors:
+ *		Yongcong Du <ycdu.vmcore@gmail.com>
+ */
+
+#include <Drivers.h>
+#include <KernelExport.h>
+
+#include <cpuidle.h>
+
+#define DEVICE_NAME "cpuidle"
+
+int32 api_version = B_CUR_DRIVER_API_VERSION;
+
+CpuidleModuleInfo *sCpuidleModule;
+
+static status_t
+cpuidle_open(const char *name, uint32 flags, void **cookie)
+{
+	*cookie = NULL;
+	return B_OK;
+}
+
+
+static status_t
+cpuidle_close(void *cookie)
+{
+	return B_OK;
+}
+
+
+static status_t
+cpuidle_free(void *cookie)
+{
+	return B_OK;
+}
+
+
+static status_t
+cpuidle_ioctl(void *cookie, uint32 op, void *buffer, size_t length)
+{
+	return B_OK;
+}
+
+
+static status_t
+cpuidle_read(void *cookie, off_t pos, void *buffer, size_t *length)
+{
+	*length = 0;
+	return B_OK;
+}
+
+
+static status_t
+cpuidle_write(void *cookie, off_t pos, const void *buffer, size_t *_length)
+{
+	return B_OK;
+}
+
+
+status_t
+init_hardware(void)
+{
+	return B_OK;
+}
+
+
+const char **
+publish_devices(void)
+{
+	static const char *devices[] = {
+		DEVICE_NAME,
+		NULL
+	};
+
+	return devices;
+}
+
+
+device_hooks *
+find_device(const char *name)
+{
+	static device_hooks hooks = {
+		&cpuidle_open,
+		&cpuidle_close,
+		&cpuidle_free,
+		&cpuidle_ioctl,
+		&cpuidle_read,
+		&cpuidle_write,
+	};
+
+
+	return &hooks;
+}
+
+
+status_t
+init_driver(void)
+{
+	status_t err;
+
+	err = get_module(B_CPUIDLE_MODULE_NAME, (module_info **)&sCpuidleModule);
+	if (err != B_OK) {
+		dprintf("can't load "B_CPUIDLE_MODULE_NAME"\n");
+	}
+	return B_OK;
+}
+
+
+void
+uninit_driver(void)
+{
+	put_module(B_CPUIDLE_MODULE_NAME);
+}