1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Regulator event over netlink
4 *
5 * Author: Naresh Solanki <Naresh.Solanki@9elements.com>
6 */
7
8#include <regulator/regulator.h>
9#include <net/netlink.h>
10#include <net/genetlink.h>
11#include <linux/atomic.h>
12
13#include "regnl.h"
14
15static atomic_t reg_event_seqnum = ATOMIC_INIT(0);
16
17static const struct genl_multicast_group reg_event_mcgrps[] = {
18	{ .name = REG_GENL_MCAST_GROUP_NAME, },
19};
20
21static struct genl_family reg_event_genl_family __ro_after_init = {
22	.module = THIS_MODULE,
23	.name = REG_GENL_FAMILY_NAME,
24	.version = REG_GENL_VERSION,
25	.maxattr = REG_GENL_ATTR_MAX,
26	.mcgrps = reg_event_mcgrps,
27	.n_mcgrps = ARRAY_SIZE(reg_event_mcgrps),
28};
29
30int reg_generate_netlink_event(const char *reg_name, u64 event)
31{
32	struct sk_buff *skb;
33	struct nlattr *attr;
34	struct reg_genl_event *edata;
35	void *msg_header;
36	int size;
37
38	/* allocate memory */
39	size = nla_total_size(sizeof(struct reg_genl_event)) +
40	    nla_total_size(0);
41
42	skb = genlmsg_new(size, GFP_ATOMIC);
43	if (!skb)
44		return -ENOMEM;
45
46	/* add the genetlink message header */
47	msg_header = genlmsg_put(skb, 0, atomic_inc_return(&reg_event_seqnum),
48				 &reg_event_genl_family, 0, REG_GENL_CMD_EVENT);
49	if (!msg_header) {
50		nlmsg_free(skb);
51		return -ENOMEM;
52	}
53
54	/* fill the data */
55	attr = nla_reserve(skb, REG_GENL_ATTR_EVENT, sizeof(struct reg_genl_event));
56	if (!attr) {
57		nlmsg_free(skb);
58		return -EINVAL;
59	}
60
61	edata = nla_data(attr);
62	memset(edata, 0, sizeof(struct reg_genl_event));
63
64	strscpy(edata->reg_name, reg_name, sizeof(edata->reg_name));
65	edata->event = event;
66
67	/* send multicast genetlink message */
68	genlmsg_end(skb, msg_header);
69	size = genlmsg_multicast(&reg_event_genl_family, skb, 0, 0, GFP_ATOMIC);
70
71	return size;
72}
73
74static int __init reg_event_genetlink_init(void)
75{
76	return genl_register_family(&reg_event_genl_family);
77}
78
79static int __init reg_event_init(void)
80{
81	int error;
82
83	/* create genetlink for acpi event */
84	error = reg_event_genetlink_init();
85	if (error)
86		pr_warn("Failed to create genetlink family for reg event\n");
87
88	return 0;
89}
90
91fs_initcall(reg_event_init);
92