1 /*
2 * dim2_sysfs.c - MediaLB sysfs information
3 *
4 * Copyright (C) 2015, Microchip Technology Germany II GmbH & Co. KG
5 *
6 * This program is distributed in the hope that it will be useful,
7 * but WITHOUT ANY WARRANTY; without even the implied warranty of
8 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
9 * GNU General Public License for more details.
10 *
11 * This file is licensed under GPLv2.
12 */
13
14 /* Author: Andrey Shvetsov <andrey.shvetsov@k2l.de> */
15
16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17
18 #include <linux/kernel.h>
19 #include "dim2_sysfs.h"
20
21 struct bus_attr {
22 struct attribute attr;
23 ssize_t (*show)(struct medialb_bus *bus, char *buf);
24 ssize_t (*store)(struct medialb_bus *bus, const char *buf,
25 size_t count);
26 };
27
state_show(struct medialb_bus * bus,char * buf)28 static ssize_t state_show(struct medialb_bus *bus, char *buf)
29 {
30 bool state = dim2_sysfs_get_state_cb();
31
32 return sprintf(buf, "%s\n", state ? "locked" : "");
33 }
34
35 static struct bus_attr state_attr = __ATTR_RO(state);
36
37 static struct attribute *bus_default_attrs[] = {
38 &state_attr.attr,
39 NULL,
40 };
41
42 static const struct attribute_group bus_attr_group = {
43 .attrs = bus_default_attrs,
44 };
45
bus_kobj_release(struct kobject * kobj)46 static void bus_kobj_release(struct kobject *kobj)
47 {
48 }
49
bus_kobj_attr_show(struct kobject * kobj,struct attribute * attr,char * buf)50 static ssize_t bus_kobj_attr_show(struct kobject *kobj, struct attribute *attr,
51 char *buf)
52 {
53 struct medialb_bus *bus =
54 container_of(kobj, struct medialb_bus, kobj_group);
55 struct bus_attr *xattr = container_of(attr, struct bus_attr, attr);
56
57 if (!xattr->show)
58 return -EIO;
59
60 return xattr->show(bus, buf);
61 }
62
bus_kobj_attr_store(struct kobject * kobj,struct attribute * attr,const char * buf,size_t count)63 static ssize_t bus_kobj_attr_store(struct kobject *kobj, struct attribute *attr,
64 const char *buf, size_t count)
65 {
66 struct medialb_bus *bus =
67 container_of(kobj, struct medialb_bus, kobj_group);
68 struct bus_attr *xattr = container_of(attr, struct bus_attr, attr);
69
70 if (!xattr->store)
71 return -EIO;
72
73 return xattr->store(bus, buf, count);
74 }
75
76 static struct sysfs_ops const bus_kobj_sysfs_ops = {
77 .show = bus_kobj_attr_show,
78 .store = bus_kobj_attr_store,
79 };
80
81 static struct kobj_type bus_ktype = {
82 .release = bus_kobj_release,
83 .sysfs_ops = &bus_kobj_sysfs_ops,
84 };
85
dim2_sysfs_probe(struct medialb_bus * bus,struct kobject * parent_kobj)86 int dim2_sysfs_probe(struct medialb_bus *bus, struct kobject *parent_kobj)
87 {
88 int err;
89
90 kobject_init(&bus->kobj_group, &bus_ktype);
91 err = kobject_add(&bus->kobj_group, parent_kobj, "bus");
92 if (err) {
93 pr_err("kobject_add() failed: %d\n", err);
94 goto err_kobject_add;
95 }
96
97 err = sysfs_create_group(&bus->kobj_group, &bus_attr_group);
98 if (err) {
99 pr_err("sysfs_create_group() failed: %d\n", err);
100 goto err_create_group;
101 }
102
103 return 0;
104
105 err_create_group:
106 kobject_put(&bus->kobj_group);
107
108 err_kobject_add:
109 return err;
110 }
111
dim2_sysfs_destroy(struct medialb_bus * bus)112 void dim2_sysfs_destroy(struct medialb_bus *bus)
113 {
114 kobject_put(&bus->kobj_group);
115 }
116