From: Greg KH <greg@kroah.com>
Adds a "simple" class device interface to the kernel for char devices
that don't want to roll their own struct class_device handling logic.
25-akpm/drivers/base/Makefile | 2
25-akpm/drivers/base/class_simple.c | 123 ++++++++++++++++++++++++++++++++++++
25-akpm/include/linux/device.h | 5 +
3 files changed, 129 insertions(+), 1 deletion(-)
diff -puN /dev/null drivers/base/class_simple.c
--- /dev/null Thu Apr 11 07:25:15 2002
+++ 25-akpm/drivers/base/class_simple.c Tue Dec 23 13:43:21 2003
@@ -0,0 +1,123 @@
+/*
+ * class_simple.c - basic char device support
+ *
+ * Copyright (c) 2003 Greg Kroah-Hartman <greg@kroah.com>
+ * Copyright (c) 2003 IBM Corp.
+ *
+ * This file is released under the GPLv2
+ *
+ */
+
+#undef DEBUG
+
+#include <linux/device.h>
+#include <linux/kdev_t.h>
+#include <linux/err.h>
+
+struct simple_dev {
+ struct list_head node;
+ dev_t dev;
+ struct class_device class_dev;
+};
+#define to_simple_dev(d) container_of(d, struct simple_dev, class_dev)
+
+static LIST_HEAD(simple_dev_list);
+static spinlock_t simple_dev_list_lock = SPIN_LOCK_UNLOCKED;
+
+static void release_simple_dev(struct class_device *class_dev)
+{
+ struct simple_dev *s_dev = to_simple_dev(class_dev);
+ kfree(s_dev);
+}
+
+static ssize_t show_dev(struct class_device *class_dev, char *buf)
+{
+ struct simple_dev *s_dev = to_simple_dev(class_dev);
+ return print_dev_t(buf, s_dev->dev);
+}
+static CLASS_DEVICE_ATTR(dev, S_IRUGO, show_dev, NULL);
+
+/**
+ * simple_add_class_device - adds a class device to sysfs for a character driver
+ * @class: pointer to the struct class that this device should be registered to.
+ * @dev: the dev_t for the device to be added.
+ * @device: a pointer to a struct device that is assiociated with this class device.
+ * @fmt: string for the class device's name
+ *
+ * This function can be used by simple char device classes that do not
+ * implement their own class device registration. A struct class_device will
+ * be created in sysfs, registered to the specified class. A "dev" file will
+ * be created, showing the dev_t for the device. The pointer to the struct
+ * class_device will be returned from the call. Any further sysfs files that
+ * might be required can be created using this pointer.
+ * Note: the struct class passed to this function must have previously been
+ * registered with a call to register_class().
+ */
+struct class_device *simple_add_class_device(struct class *class, dev_t dev, struct device *device, const char *fmt, ...)
+{
+ va_list args;
+ struct simple_dev *s_dev;
+ int retval;
+
+ s_dev = kmalloc(sizeof(*s_dev), GFP_KERNEL);
+ if (!s_dev) {
+ retval = -ENOMEM;
+ goto error;
+ }
+ memset(s_dev, 0x00, sizeof(*s_dev));
+
+ class->release = &release_simple_dev;
+ s_dev->dev = dev;
+ s_dev->class_dev.dev = device;
+ s_dev->class_dev.class = class;
+
+ va_start(args,fmt);
+ vsnprintf(s_dev->class_dev.class_id, BUS_ID_SIZE, fmt, args);
+ va_end(args);
+ retval = class_device_register(&s_dev->class_dev);
+ if (retval)
+ goto error;
+ class_device_create_file(&s_dev->class_dev, &class_device_attr_dev);
+ spin_lock(&simple_dev_list_lock);
+ list_add(&s_dev->node, &simple_dev_list);
+ spin_unlock(&simple_dev_list_lock);
+
+ return &s_dev->class_dev;
+
+error:
+ kfree(s_dev);
+ return ERR_PTR(retval);
+}
+EXPORT_SYMBOL(simple_add_class_device);
+
+/**
+ * simple_remove_class_device - removes a class device that was created with simple_add_class_device()
+ * @dev: the dev_t of the device that was previously registered.
+ *
+ * This call unregisters and cleans up a class device that was created with a
+ * call to simple_add_class_device()
+ */
+void simple_remove_class_device(dev_t dev)
+{
+ struct simple_dev *s_dev = NULL;
+ struct list_head *tmp;
+ int found = 0;
+
+ spin_lock(&simple_dev_list_lock);
+ list_for_each(tmp, &simple_dev_list) {
+ s_dev = list_entry(tmp, struct simple_dev, node);
+ if (s_dev->dev == dev) {
+ found = 1;
+ break;
+ }
+ }
+ if (found) {
+ list_del(&s_dev->node);
+ spin_unlock(&simple_dev_list_lock);
+ class_device_unregister(&s_dev->class_dev);
+ } else {
+ spin_unlock(&simple_dev_list_lock);
+ }
+}
+EXPORT_SYMBOL(simple_remove_class_device);
+
diff -puN drivers/base/Makefile~sysfs-add-simple-class-device-support drivers/base/Makefile
--- 25/drivers/base/Makefile~sysfs-add-simple-class-device-support Tue Dec 23 13:43:21 2003
+++ 25-akpm/drivers/base/Makefile Tue Dec 23 13:43:21 2003
@@ -1,7 +1,7 @@
# Makefile for the Linux device tree
obj-y := core.o sys.o interface.o bus.o \
- driver.o class.o platform.o \
+ driver.o class.o class_simple.o platform.o \
cpu.o firmware.o init.o map.o
obj-y += power/
obj-$(CONFIG_FW_LOADER) += firmware_class.o
diff -puN include/linux/device.h~sysfs-add-simple-class-device-support include/linux/device.h
--- 25/include/linux/device.h~sysfs-add-simple-class-device-support Tue Dec 23 13:43:21 2003
+++ 25-akpm/include/linux/device.h Tue Dec 23 13:43:21 2003
@@ -246,6 +246,11 @@ struct class_interface {
extern int class_interface_register(struct class_interface *);
extern void class_interface_unregister(struct class_interface *);
+/* interface for simple class devices */
+extern struct class_device *simple_add_class_device(struct class *class, dev_t dev, struct device *device, const char *fmt, ...)
+ __attribute__((format(printf,4,5)));
+extern void simple_remove_class_device(dev_t dev);
+
struct device {
struct list_head node; /* node in sibling list */
_