xref: /linux/drivers/dca/dca-sysfs.c (revision 7589670f37736bcc119ebfbd69aafea6d585d1d4)
1*7589670fSShannon Nelson #include <linux/kernel.h>
2*7589670fSShannon Nelson #include <linux/spinlock.h>
3*7589670fSShannon Nelson #include <linux/device.h>
4*7589670fSShannon Nelson #include <linux/idr.h>
5*7589670fSShannon Nelson #include <linux/kdev_t.h>
6*7589670fSShannon Nelson #include <linux/err.h>
7*7589670fSShannon Nelson #include <linux/dca.h>
8*7589670fSShannon Nelson 
9*7589670fSShannon Nelson static struct class *dca_class;
10*7589670fSShannon Nelson static struct idr dca_idr;
11*7589670fSShannon Nelson static spinlock_t dca_idr_lock;
12*7589670fSShannon Nelson 
13*7589670fSShannon Nelson int dca_sysfs_add_req(struct dca_provider *dca, struct device *dev, int slot)
14*7589670fSShannon Nelson {
15*7589670fSShannon Nelson 	struct class_device *cd;
16*7589670fSShannon Nelson 
17*7589670fSShannon Nelson 	cd = class_device_create(dca_class, dca->cd, MKDEV(0, slot + 1),
18*7589670fSShannon Nelson 				 dev, "requester%d", slot);
19*7589670fSShannon Nelson 	if (IS_ERR(cd))
20*7589670fSShannon Nelson 		return PTR_ERR(cd);
21*7589670fSShannon Nelson 	return 0;
22*7589670fSShannon Nelson }
23*7589670fSShannon Nelson 
24*7589670fSShannon Nelson void dca_sysfs_remove_req(struct dca_provider *dca, int slot)
25*7589670fSShannon Nelson {
26*7589670fSShannon Nelson 	class_device_destroy(dca_class, MKDEV(0, slot + 1));
27*7589670fSShannon Nelson }
28*7589670fSShannon Nelson 
29*7589670fSShannon Nelson int dca_sysfs_add_provider(struct dca_provider *dca, struct device *dev)
30*7589670fSShannon Nelson {
31*7589670fSShannon Nelson 	struct class_device *cd;
32*7589670fSShannon Nelson 	int err = 0;
33*7589670fSShannon Nelson 
34*7589670fSShannon Nelson idr_try_again:
35*7589670fSShannon Nelson 	if (!idr_pre_get(&dca_idr, GFP_KERNEL))
36*7589670fSShannon Nelson 		return -ENOMEM;
37*7589670fSShannon Nelson 	spin_lock(&dca_idr_lock);
38*7589670fSShannon Nelson 	err = idr_get_new(&dca_idr, dca, &dca->id);
39*7589670fSShannon Nelson 	spin_unlock(&dca_idr_lock);
40*7589670fSShannon Nelson 	switch (err) {
41*7589670fSShannon Nelson 	case 0:
42*7589670fSShannon Nelson 		break;
43*7589670fSShannon Nelson 	case -EAGAIN:
44*7589670fSShannon Nelson 		goto idr_try_again;
45*7589670fSShannon Nelson 	default:
46*7589670fSShannon Nelson 		return err;
47*7589670fSShannon Nelson 	}
48*7589670fSShannon Nelson 
49*7589670fSShannon Nelson 	cd = class_device_create(dca_class, NULL, MKDEV(0, 0),
50*7589670fSShannon Nelson 				 dev, "dca%d", dca->id);
51*7589670fSShannon Nelson 	if (IS_ERR(cd)) {
52*7589670fSShannon Nelson 		spin_lock(&dca_idr_lock);
53*7589670fSShannon Nelson 		idr_remove(&dca_idr, dca->id);
54*7589670fSShannon Nelson 		spin_unlock(&dca_idr_lock);
55*7589670fSShannon Nelson 		return PTR_ERR(cd);
56*7589670fSShannon Nelson 	}
57*7589670fSShannon Nelson 	dca->cd = cd;
58*7589670fSShannon Nelson 	return 0;
59*7589670fSShannon Nelson }
60*7589670fSShannon Nelson 
61*7589670fSShannon Nelson void dca_sysfs_remove_provider(struct dca_provider *dca)
62*7589670fSShannon Nelson {
63*7589670fSShannon Nelson 	class_device_unregister(dca->cd);
64*7589670fSShannon Nelson 	dca->cd = NULL;
65*7589670fSShannon Nelson 	spin_lock(&dca_idr_lock);
66*7589670fSShannon Nelson 	idr_remove(&dca_idr, dca->id);
67*7589670fSShannon Nelson 	spin_unlock(&dca_idr_lock);
68*7589670fSShannon Nelson }
69*7589670fSShannon Nelson 
70*7589670fSShannon Nelson int __init dca_sysfs_init(void)
71*7589670fSShannon Nelson {
72*7589670fSShannon Nelson 	idr_init(&dca_idr);
73*7589670fSShannon Nelson 	spin_lock_init(&dca_idr_lock);
74*7589670fSShannon Nelson 
75*7589670fSShannon Nelson 	dca_class = class_create(THIS_MODULE, "dca");
76*7589670fSShannon Nelson 	if (IS_ERR(dca_class)) {
77*7589670fSShannon Nelson 		idr_destroy(&dca_idr);
78*7589670fSShannon Nelson 		return PTR_ERR(dca_class);
79*7589670fSShannon Nelson 	}
80*7589670fSShannon Nelson 	return 0;
81*7589670fSShannon Nelson }
82*7589670fSShannon Nelson 
83*7589670fSShannon Nelson void __exit dca_sysfs_exit(void)
84*7589670fSShannon Nelson {
85*7589670fSShannon Nelson 	class_destroy(dca_class);
86*7589670fSShannon Nelson 	idr_destroy(&dca_idr);
87*7589670fSShannon Nelson }
88*7589670fSShannon Nelson 
89