drivers/regulator/event.c

   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
  15 static atomic_t reg_event_seqnum = ATOMIC_INIT(0);
  16
  17 static const struct genl_multicast_group reg_event_mcgrps[] = {
  18         { .name = REG_GENL_MCAST_GROUP_NAME, },
  19 };
  20
  21 static 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
  30 int 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
  74 static int __init reg_event_genetlink_init(void)
  75 {
  76         return genl_register_family(&reg_event_genl_family);
  77 }
  78
  79 static 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
  91 fs_initcall(reg_event_init);