[sergeyvl12]

lipc-wait-event -m com.lab126.powerd goingToScreenSaver,outOfScreenSaver

doesn't work for me because I turn off the screen saver during my program execution:

# prevent screensaver activation
lipc-set-prop com.lab126.powerd preventScreenSaver 1
...
# restore screensaver
lipc-set-prop com.lab126.powerd preventScreenSaver 0

exploring kernel sources I've found yoshi_button.c.

So, I can get power button release event using netlink socket:

code sample

Spoiler:

#include <sys/socket.h>
#include <linux/netlink.h>

#define MAX_PAYLOAD 1024  /* maximum payload size*/

struct sockaddr_nl src_addr, dest_addr;
struct nlmsghdr *nlh = NULL;
struct msghdr msg;
struct iovec iov;
int sock_fd;

int main()
{
   /* Changed LJ article example to use NETLINK_KOBJECT_UEVENT */
   sock_fd=socket(PF_NETLINK, SOCK_RAW, NETLINK_KOBJECT_UEVENT);

   memset(&src_addr, 0, sizeof(src_addr));
   src_addr.nl_family = AF_NETLINK;
   src_addr.nl_pid = getpid(); // self pid
   src_addr.nl_groups = 1;     // interested in group 1<<0

   bind(sock_fd, (struct sockaddr*)&src_addr, sizeof(src_addr));

   memset(&dest_addr, 0, sizeof(dest_addr));

   nlh = (struct nlmsghdr *)malloc(NLMSG_SPACE(MAX_PAYLOAD));
   memset(nlh, 0, NLMSG_SPACE(MAX_PAYLOAD));

   iov.iov_base = (void *)nlh;
   iov.iov_len = NLMSG_SPACE(MAX_PAYLOAD);
   msg.msg_name = (void *)&dest_addr;
   msg.msg_namelen = sizeof(dest_addr);
   msg.msg_iov = &iov;
   msg.msg_iovlen = 1;

   printf("Waiting for message from kernel\n");

   /* Read message from kernel */
   recvmsg(sock_fd, &msg, 0);

   printf("Received message payload: %s\n",  NLMSG_DATA(nlh));

   close(sock_fd);

   return 0;
}

Message for power button is: "virtual/misc/yoshibutton"

Probably it will be useful for sombody else. It works at least for KT and KPW-1. KPW-2 seems to use another approach (through event-N).

Now I need to get the sleepcover event also. But the main problem that I have no sleep cover on my KT.

Please, I need to know, does sleep cover use the same approach?