Problems compiling a function of pps_kernel.h

david1984ba · 03-28-2017, 11:11 PM

Hello, I need to get a timestamp using a function declared in pps_kernel.h. My code is

Code:

#include <linux/pps_kernel.h>
#include <linux/timekeeping.h>

static inline void pps_get_my_ts(struct pps_event_time *ts)
{
        struct system_time_snapshot snap;

        ktime_get_snapshot(&snap);
        ts->ts_real = ktime_to_timespec64(snap.real);
		#ifdef CONFIG_NTP_PPS
			ts->ts_raw = ktime_to_timespec64(snap.raw);
		#endif 
}

struct pps_event_time {
	#ifdef CONFIG_NTP_PPS
		struct timespec64 ts_raw;
	#endif  CONFIG_NTP_PPS 
		struct timespec64 ts_real;
};

void main()
{
	struct pps_event_time my_ts;
	const struct pps_gpio_device_data *info;	
	pps_get_my_ts(&my_ts);
	printf("%ld -- %ld\n",my_ts.ts_real,my_ts.ts_raw);
	
}

I'm new programer in C and I think my code is correct, so when I tried to compile with gcc thrown many errors

I attach a txt file with the errors.

Can someone explain to me that it is wrong?

NevemTeve · 03-29-2017, 02:11 AM

Is your program supposed to be a normal userland program? If so, you are not to use any kernel-components.

rtmistler · 03-29-2017, 06:56 AM

If it is supposed to be a kernel space module, then you need to include additional terms within the source and build it differently.

If you need a system time stamp, there are other ways to get one. Some give you seconds and nanoseconds since the epoch, some give you local time, some give you seconds and nanoseconds since the start of the system. It will be helpful for you to explain your needs for the time stamp you wish.

Further, in any future case when you experience a compile problem, it will be helpful to use the -v flag to increase the output for the gcc call, and also show the gcc call as well as the output to the terminal for your compilation attempt. This will give all the flags to readers for their benefit as they evaluate the errors, and also it will show the specific errors for people to review and offer comments about.

Also, not sure but I think you should not have anything except a comment after the #endif term, you can have a comment, but you should not have the CONFIG_NTP_PPS there. That may have changed with C99, I don't know in the past that would've been an error and my practice is to always have nothing, or a comment to link it back to the start of the #if or #ifdef term for my code notes.