[PATCH] add sysfs mem device support [2/4]

From: Greg KH
Date: Mon Dec 22 2003 - 19:35:27 EST


This adds /sys/class/mem which enables all mem char devices to show up
properly in udev.

Has been posted to linux-kernel every so often since last July, and
acked by a number of other kernel developers.


diff -Nru a/drivers/char/mem.c b/drivers/char/mem.c
--- a/drivers/char/mem.c Mon Dec 22 16:02:08 2003
+++ b/drivers/char/mem.c Mon Dec 22 16:02:08 2003
@@ -24,6 +24,7 @@
#include <linux/smp_lock.h>
#include <linux/devfs_fs_kernel.h>
#include <linux/ptrace.h>
+#include <linux/device.h>

#include <asm/uaccess.h>
#include <asm/io.h>
@@ -657,7 +658,7 @@
.open = memory_open, /* just a selector for the real open */
};

-static const struct {
+static const struct mem_dev {
unsigned int minor;
char *name;
umode_t mode;
@@ -676,6 +677,23 @@
{11,"kmsg", S_IRUGO | S_IWUSR, &kmsg_fops},
};

+static void release_mem_dev(struct class_device *class_dev)
+{
+ kfree(class_dev);
+}
+
+static struct class mem_class = {
+ .name = "mem",
+ .release = &release_mem_dev,
+};
+
+static ssize_t show_dev(struct class_device *class_dev, char *buf)
+{
+ struct mem_dev *mem_dev = class_get_devdata(class_dev);
+ return print_dev_t(buf, MKDEV(MEM_MAJOR, mem_dev->minor));
+}
+static CLASS_DEVICE_ATTR(dev, S_IRUGO, show_dev, NULL);
+
static int __init chr_dev_init(void)
{
int i;
@@ -683,7 +701,20 @@
if (register_chrdev(MEM_MAJOR,"mem",&memory_fops))
printk("unable to get major %d for memory devs\n", MEM_MAJOR);

+ class_register(&mem_class);
for (i = 0; i < ARRAY_SIZE(devlist); i++) {
+ struct class_device *class_dev;
+
+ class_dev = kmalloc(sizeof(*class_dev), GFP_KERNEL);
+ if (class_dev) {
+ memset(class_dev, 0x00, sizeof(*class_dev));
+ class_dev->class = &mem_class;
+ strncpy(class_dev->class_id, devlist[i].name, BUS_ID_SIZE);
+ class_set_devdata(class_dev, (void *)&devlist[i]);
+ if (!class_device_register(class_dev));
+ class_device_create_file(class_dev, &class_device_attr_dev);
+ }
+
devfs_mk_cdev(MKDEV(MEM_MAJOR, devlist[i].minor),
S_IFCHR | devlist[i].mode, devlist[i].name);
}
-
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