LXR linux/drivers/dca/dca-sysfs.c

   1#include <linux/kernel.h>
   2#include <linux/spinlock.h>
   3#include <linux/device.h>
   4#include <linux/idr.h>
   5#include <linux/kdev_t.h>
   6#include <linux/err.h>
   7#include <linux/dca.h>
   8
   9static struct class *dca_class;
  10static struct idr dca_idr;
  11static spinlock_t dca_idr_lock;
  12
  13int dca_sysfs_add_req(struct dca_provider *dca, struct device *dev, int slot)
  14{
  15        struct device *cd;
  16
  17        cd = device_create(dca_class, dca->cd, MKDEV(0, slot + 1),
  18                           "requester%d", slot);
  19        if (IS_ERR(cd))
  20                return PTR_ERR(cd);
  21        return 0;
  22}
  23
  24void dca_sysfs_remove_req(struct dca_provider *dca, int slot)
  25{
  26        device_destroy(dca_class, MKDEV(0, slot + 1));
  27}
  28
  29int dca_sysfs_add_provider(struct dca_provider *dca, struct device *dev)
  30{
  31        struct device *cd;
  32        int err = 0;
  33
  34idr_try_again:
  35        if (!idr_pre_get(&dca_idr, GFP_KERNEL))
  36                return -ENOMEM;
  37        spin_lock(&dca_idr_lock);
  38        err = idr_get_new(&dca_idr, dca, &dca->id);
  39        spin_unlock(&dca_idr_lock);
  40        switch (err) {
  41        case 0:
  42                break;
  43        case -EAGAIN:
  44                goto idr_try_again;
  45        default:
  46                return err;
  47        }
  48
  49        cd = device_create(dca_class, dev, MKDEV(0, 0), "dca%d", dca->id);
  50        if (IS_ERR(cd)) {
  51                spin_lock(&dca_idr_lock);
  52                idr_remove(&dca_idr, dca->id);
  53                spin_unlock(&dca_idr_lock);
  54                return PTR_ERR(cd);
  55        }
  56        dca->cd = cd;
  57        return 0;
  58}
  59
  60void dca_sysfs_remove_provider(struct dca_provider *dca)
  61{
  62        device_unregister(dca->cd);
  63        dca->cd = NULL;
  64        spin_lock(&dca_idr_lock);
  65        idr_remove(&dca_idr, dca->id);
  66        spin_unlock(&dca_idr_lock);
  67}
  68
  69int __init dca_sysfs_init(void)
  70{
  71        idr_init(&dca_idr);
  72        spin_lock_init(&dca_idr_lock);
  73
  74        dca_class = class_create(THIS_MODULE, "dca");
  75        if (IS_ERR(dca_class)) {
  76                idr_destroy(&dca_idr);
  77                return PTR_ERR(dca_class);
  78        }
  79        return 0;
  80}
  81
  82void __exit dca_sysfs_exit(void)
  83{
  84        class_destroy(dca_class);
  85        idr_destroy(&dca_idr);
  86}
  87
  88