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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/char/misc.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'drivers/char/misc.c')
-rw-r--r--drivers/char/misc.c331
1 files changed, 331 insertions, 0 deletions
diff --git a/drivers/char/misc.c b/drivers/char/misc.c
new file mode 100644
index 000000000000..0937544762da
--- /dev/null
+++ b/drivers/char/misc.c
@@ -0,0 +1,331 @@
+/*
+ * linux/drivers/char/misc.c
+ *
+ * Generic misc open routine by Johan Myreen
+ *
+ * Based on code from Linus
+ *
+ * Teemu Rantanen's Microsoft Busmouse support and Derrick Cole's
+ * changes incorporated into 0.97pl4
+ * by Peter Cervasio (pete%q106fm.uucp@wupost.wustl.edu) (08SEP92)
+ * See busmouse.c for particulars.
+ *
+ * Made things a lot mode modular - easy to compile in just one or two
+ * of the misc drivers, as they are now completely independent. Linus.
+ *
+ * Support for loadable modules. 8-Sep-95 Philip Blundell <pjb27@cam.ac.uk>
+ *
+ * Fixed a failing symbol register to free the device registration
+ * Alan Cox <alan@lxorguk.ukuu.org.uk> 21-Jan-96
+ *
+ * Dynamic minors and /proc/mice by Alessandro Rubini. 26-Mar-96
+ *
+ * Renamed to misc and miscdevice to be more accurate. Alan Cox 26-Mar-96
+ *
+ * Handling of mouse minor numbers for kerneld:
+ * Idea by Jacques Gelinas <jack@solucorp.qc.ca>,
+ * adapted by Bjorn Ekwall <bj0rn@blox.se>
+ * corrected by Alan Cox <alan@lxorguk.ukuu.org.uk>
+ *
+ * Changes for kmod (from kerneld):
+ * Cyrus Durgin <cider@speakeasy.org>
+ *
+ * Added devfs support. Richard Gooch <rgooch@atnf.csiro.au> 10-Jan-1998
+ */
+
+#include <linux/module.h>
+#include <linux/config.h>
+
+#include <linux/fs.h>
+#include <linux/errno.h>
+#include <linux/miscdevice.h>
+#include <linux/kernel.h>
+#include <linux/major.h>
+#include <linux/slab.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/devfs_fs_kernel.h>
+#include <linux/stat.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/tty.h>
+#include <linux/kmod.h>
+
+/*
+ * Head entry for the doubly linked miscdevice list
+ */
+static LIST_HEAD(misc_list);
+static DECLARE_MUTEX(misc_sem);
+
+/*
+ * Assigned numbers, used for dynamic minors
+ */
+#define DYNAMIC_MINORS 64 /* like dynamic majors */
+static unsigned char misc_minors[DYNAMIC_MINORS / 8];
+
+extern int rtc_DP8570A_init(void);
+extern int rtc_MK48T08_init(void);
+extern int pmu_device_init(void);
+extern int tosh_init(void);
+extern int i8k_init(void);
+
+#ifdef CONFIG_PROC_FS
+static void *misc_seq_start(struct seq_file *seq, loff_t *pos)
+{
+ struct miscdevice *p;
+ loff_t off = 0;
+
+ down(&misc_sem);
+ list_for_each_entry(p, &misc_list, list) {
+ if (*pos == off++)
+ return p;
+ }
+ return NULL;
+}
+
+static void *misc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+ struct list_head *n = ((struct miscdevice *)v)->list.next;
+
+ ++*pos;
+
+ return (n != &misc_list) ? list_entry(n, struct miscdevice, list)
+ : NULL;
+}
+
+static void misc_seq_stop(struct seq_file *seq, void *v)
+{
+ up(&misc_sem);
+}
+
+static int misc_seq_show(struct seq_file *seq, void *v)
+{
+ const struct miscdevice *p = v;
+
+ seq_printf(seq, "%3i %s\n", p->minor, p->name ? p->name : "");
+ return 0;
+}
+
+
+static struct seq_operations misc_seq_ops = {
+ .start = misc_seq_start,
+ .next = misc_seq_next,
+ .stop = misc_seq_stop,
+ .show = misc_seq_show,
+};
+
+static int misc_seq_open(struct inode *inode, struct file *file)
+{
+ return seq_open(file, &misc_seq_ops);
+}
+
+static struct file_operations misc_proc_fops = {
+ .owner = THIS_MODULE,
+ .open = misc_seq_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+#endif
+
+static int misc_open(struct inode * inode, struct file * file)
+{
+ int minor = iminor(inode);
+ struct miscdevice *c;
+ int err = -ENODEV;
+ struct file_operations *old_fops, *new_fops = NULL;
+
+ down(&misc_sem);
+
+ list_for_each_entry(c, &misc_list, list) {
+ if (c->minor == minor) {
+ new_fops = fops_get(c->fops);
+ break;
+ }
+ }
+
+ if (!new_fops) {
+ up(&misc_sem);
+ request_module("char-major-%d-%d", MISC_MAJOR, minor);
+ down(&misc_sem);
+
+ list_for_each_entry(c, &misc_list, list) {
+ if (c->minor == minor) {
+ new_fops = fops_get(c->fops);
+ break;
+ }
+ }
+ if (!new_fops)
+ goto fail;
+ }
+
+ err = 0;
+ old_fops = file->f_op;
+ file->f_op = new_fops;
+ if (file->f_op->open) {
+ err=file->f_op->open(inode,file);
+ if (err) {
+ fops_put(file->f_op);
+ file->f_op = fops_get(old_fops);
+ }
+ }
+ fops_put(old_fops);
+fail:
+ up(&misc_sem);
+ return err;
+}
+
+/*
+ * TODO for 2.7:
+ * - add a struct class_device to struct miscdevice and make all usages of
+ * them dynamic.
+ */
+static struct class_simple *misc_class;
+
+static struct file_operations misc_fops = {
+ .owner = THIS_MODULE,
+ .open = misc_open,
+};
+
+
+/**
+ * misc_register - register a miscellaneous device
+ * @misc: device structure
+ *
+ * Register a miscellaneous device with the kernel. If the minor
+ * number is set to %MISC_DYNAMIC_MINOR a minor number is assigned
+ * and placed in the minor field of the structure. For other cases
+ * the minor number requested is used.
+ *
+ * The structure passed is linked into the kernel and may not be
+ * destroyed until it has been unregistered.
+ *
+ * A zero is returned on success and a negative errno code for
+ * failure.
+ */
+
+int misc_register(struct miscdevice * misc)
+{
+ struct miscdevice *c;
+ dev_t dev;
+ int err;
+
+ down(&misc_sem);
+ list_for_each_entry(c, &misc_list, list) {
+ if (c->minor == misc->minor) {
+ up(&misc_sem);
+ return -EBUSY;
+ }
+ }
+
+ if (misc->minor == MISC_DYNAMIC_MINOR) {
+ int i = DYNAMIC_MINORS;
+ while (--i >= 0)
+ if ( (misc_minors[i>>3] & (1 << (i&7))) == 0)
+ break;
+ if (i<0) {
+ up(&misc_sem);
+ return -EBUSY;
+ }
+ misc->minor = i;
+ }
+
+ if (misc->minor < DYNAMIC_MINORS)
+ misc_minors[misc->minor >> 3] |= 1 << (misc->minor & 7);
+ if (misc->devfs_name[0] == '\0') {
+ snprintf(misc->devfs_name, sizeof(misc->devfs_name),
+ "misc/%s", misc->name);
+ }
+ dev = MKDEV(MISC_MAJOR, misc->minor);
+
+ misc->class = class_simple_device_add(misc_class, dev,
+ misc->dev, misc->name);
+ if (IS_ERR(misc->class)) {
+ err = PTR_ERR(misc->class);
+ goto out;
+ }
+
+ err = devfs_mk_cdev(dev, S_IFCHR|S_IRUSR|S_IWUSR|S_IRGRP,
+ misc->devfs_name);
+ if (err) {
+ class_simple_device_remove(dev);
+ goto out;
+ }
+
+ /*
+ * Add it to the front, so that later devices can "override"
+ * earlier defaults
+ */
+ list_add(&misc->list, &misc_list);
+ out:
+ up(&misc_sem);
+ return err;
+}
+
+/**
+ * misc_deregister - unregister a miscellaneous device
+ * @misc: device to unregister
+ *
+ * Unregister a miscellaneous device that was previously
+ * successfully registered with misc_register(). Success
+ * is indicated by a zero return, a negative errno code
+ * indicates an error.
+ */
+
+int misc_deregister(struct miscdevice * misc)
+{
+ int i = misc->minor;
+
+ if (list_empty(&misc->list))
+ return -EINVAL;
+
+ down(&misc_sem);
+ list_del(&misc->list);
+ class_simple_device_remove(MKDEV(MISC_MAJOR, misc->minor));
+ devfs_remove(misc->devfs_name);
+ if (i < DYNAMIC_MINORS && i>0) {
+ misc_minors[i>>3] &= ~(1 << (misc->minor & 7));
+ }
+ up(&misc_sem);
+ return 0;
+}
+
+EXPORT_SYMBOL(misc_register);
+EXPORT_SYMBOL(misc_deregister);
+
+static int __init misc_init(void)
+{
+#ifdef CONFIG_PROC_FS
+ struct proc_dir_entry *ent;
+
+ ent = create_proc_entry("misc", 0, NULL);
+ if (ent)
+ ent->proc_fops = &misc_proc_fops;
+#endif
+ misc_class = class_simple_create(THIS_MODULE, "misc");
+ if (IS_ERR(misc_class))
+ return PTR_ERR(misc_class);
+#ifdef CONFIG_MVME16x
+ rtc_MK48T08_init();
+#endif
+#ifdef CONFIG_BVME6000
+ rtc_DP8570A_init();
+#endif
+#ifdef CONFIG_PMAC_PBOOK
+ pmu_device_init();
+#endif
+#ifdef CONFIG_TOSHIBA
+ tosh_init();
+#endif
+#ifdef CONFIG_I8K
+ i8k_init();
+#endif
+ if (register_chrdev(MISC_MAJOR,"misc",&misc_fops)) {
+ printk("unable to get major %d for misc devices\n",
+ MISC_MAJOR);
+ class_simple_destroy(misc_class);
+ return -EIO;
+ }
+ return 0;
+}
+subsys_initcall(misc_init);