^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * Sample kset and ktype implementation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Copyright (C) 2004-2007 Greg Kroah-Hartman <greg@kroah.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) * Copyright (C) 2007 Novell Inc.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) #include <linux/kobject.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) #include <linux/string.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <linux/sysfs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <linux/init.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) * This module shows how to create a kset in sysfs called
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) * /sys/kernel/kset-example
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) * Then tree kobjects are created and assigned to this kset, "foo", "baz",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) * and "bar". In those kobjects, attributes of the same name are also
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) * created and if an integer is written to these files, it can be later
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) * read out of it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) * This is our "object" that we will create a few of and register them with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) * sysfs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) struct foo_obj {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) struct kobject kobj;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) int foo;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) int baz;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) int bar;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) #define to_foo_obj(x) container_of(x, struct foo_obj, kobj)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) /* a custom attribute that works just for a struct foo_obj. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) struct foo_attribute {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) struct attribute attr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) ssize_t (*show)(struct foo_obj *foo, struct foo_attribute *attr, char *buf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) ssize_t (*store)(struct foo_obj *foo, struct foo_attribute *attr, const char *buf, size_t count);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) #define to_foo_attr(x) container_of(x, struct foo_attribute, attr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) * The default show function that must be passed to sysfs. This will be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) * called by sysfs for whenever a show function is called by the user on a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) * sysfs file associated with the kobjects we have registered. We need to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) * transpose back from a "default" kobject to our custom struct foo_obj and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) * then call the show function for that specific object.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) static ssize_t foo_attr_show(struct kobject *kobj,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) struct attribute *attr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) char *buf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) struct foo_attribute *attribute;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) struct foo_obj *foo;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) attribute = to_foo_attr(attr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) foo = to_foo_obj(kobj);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) if (!attribute->show)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) return -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) return attribute->show(foo, attribute, buf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) * Just like the default show function above, but this one is for when the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) * sysfs "store" is requested (when a value is written to a file.)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) static ssize_t foo_attr_store(struct kobject *kobj,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) struct attribute *attr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) const char *buf, size_t len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) struct foo_attribute *attribute;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) struct foo_obj *foo;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) attribute = to_foo_attr(attr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) foo = to_foo_obj(kobj);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) if (!attribute->store)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) return -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) return attribute->store(foo, attribute, buf, len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) /* Our custom sysfs_ops that we will associate with our ktype later on */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) static const struct sysfs_ops foo_sysfs_ops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) .show = foo_attr_show,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) .store = foo_attr_store,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) * The release function for our object. This is REQUIRED by the kernel to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) * have. We free the memory held in our object here.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) * NEVER try to get away with just a "blank" release function to try to be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) * smarter than the kernel. Turns out, no one ever is...
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) static void foo_release(struct kobject *kobj)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) struct foo_obj *foo;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) foo = to_foo_obj(kobj);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) kfree(foo);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) * The "foo" file where the .foo variable is read from and written to.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) static ssize_t foo_show(struct foo_obj *foo_obj, struct foo_attribute *attr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) char *buf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) return sprintf(buf, "%d\n", foo_obj->foo);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) static ssize_t foo_store(struct foo_obj *foo_obj, struct foo_attribute *attr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) const char *buf, size_t count)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) ret = kstrtoint(buf, 10, &foo_obj->foo);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) if (ret < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) return count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) /* Sysfs attributes cannot be world-writable. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) static struct foo_attribute foo_attribute =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) __ATTR(foo, 0664, foo_show, foo_store);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) * More complex function where we determine which variable is being accessed by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) * looking at the attribute for the "baz" and "bar" files.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) static ssize_t b_show(struct foo_obj *foo_obj, struct foo_attribute *attr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) char *buf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) int var;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) if (strcmp(attr->attr.name, "baz") == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) var = foo_obj->baz;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) var = foo_obj->bar;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) return sprintf(buf, "%d\n", var);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) static ssize_t b_store(struct foo_obj *foo_obj, struct foo_attribute *attr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) const char *buf, size_t count)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) int var, ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) ret = kstrtoint(buf, 10, &var);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) if (ret < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) if (strcmp(attr->attr.name, "baz") == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) foo_obj->baz = var;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) foo_obj->bar = var;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) return count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) static struct foo_attribute baz_attribute =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) __ATTR(baz, 0664, b_show, b_store);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) static struct foo_attribute bar_attribute =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) __ATTR(bar, 0664, b_show, b_store);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) * Create a group of attributes so that we can create and destroy them all
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) * at once.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) static struct attribute *foo_default_attrs[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) &foo_attribute.attr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) &baz_attribute.attr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) &bar_attribute.attr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) NULL, /* need to NULL terminate the list of attributes */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) ATTRIBUTE_GROUPS(foo_default);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) * Our own ktype for our kobjects. Here we specify our sysfs ops, the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) * release function, and the set of default attributes we want created
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) * whenever a kobject of this type is registered with the kernel.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) static struct kobj_type foo_ktype = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) .sysfs_ops = &foo_sysfs_ops,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) .release = foo_release,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) .default_groups = foo_default_groups,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) static struct kset *example_kset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) static struct foo_obj *foo_obj;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) static struct foo_obj *bar_obj;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) static struct foo_obj *baz_obj;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) static struct foo_obj *create_foo_obj(const char *name)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) struct foo_obj *foo;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) int retval;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) /* allocate the memory for the whole object */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) foo = kzalloc(sizeof(*foo), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) if (!foo)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) * As we have a kset for this kobject, we need to set it before calling
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) * the kobject core.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) foo->kobj.kset = example_kset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) * Initialize and add the kobject to the kernel. All the default files
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) * will be created here. As we have already specified a kset for this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) * kobject, we don't have to set a parent for the kobject, the kobject
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) * will be placed beneath that kset automatically.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) retval = kobject_init_and_add(&foo->kobj, &foo_ktype, NULL, "%s", name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) if (retval) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) kobject_put(&foo->kobj);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) * We are always responsible for sending the uevent that the kobject
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) * was added to the system.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) kobject_uevent(&foo->kobj, KOBJ_ADD);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) return foo;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) static void destroy_foo_obj(struct foo_obj *foo)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) kobject_put(&foo->kobj);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) static int __init example_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) * Create a kset with the name of "kset_example",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) * located under /sys/kernel/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) example_kset = kset_create_and_add("kset_example", NULL, kernel_kobj);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) if (!example_kset)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) * Create three objects and register them with our kset
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) foo_obj = create_foo_obj("foo");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) if (!foo_obj)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) goto foo_error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) bar_obj = create_foo_obj("bar");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) if (!bar_obj)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) goto bar_error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) baz_obj = create_foo_obj("baz");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) if (!baz_obj)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) goto baz_error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) baz_error:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) destroy_foo_obj(bar_obj);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) bar_error:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) destroy_foo_obj(foo_obj);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) foo_error:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) kset_unregister(example_kset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) static void __exit example_exit(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) destroy_foo_obj(baz_obj);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) destroy_foo_obj(bar_obj);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) destroy_foo_obj(foo_obj);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) kset_unregister(example_kset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) module_init(example_init);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) module_exit(example_exit);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) MODULE_LICENSE("GPL v2");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) MODULE_AUTHOR("Greg Kroah-Hartman <greg@kroah.com>");
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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