From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 16 Apr 2005 15:20:36 -0700 Subject: Linux-2.6.12-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! --- drivers/char/misc.c | 331 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 331 insertions(+) create mode 100644 drivers/char/misc.c (limited to 'drivers/char/misc.c') diff --git a/drivers/char/misc.c b/drivers/char/misc.c new file mode 100644 index 00000000000..0937544762d --- /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 + * + * Fixed a failing symbol register to free the device registration + * Alan Cox 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 , + * adapted by Bjorn Ekwall + * corrected by Alan Cox + * + * Changes for kmod (from kerneld): + * Cyrus Durgin + * + * Added devfs support. Richard Gooch 10-Jan-1998 + */ + +#include +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* + * 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); -- cgit v1.2.3