Can anybody help me to sort this out plz, since I cannot find any example I can \"copy\" it for my implementation and i urgently need it to get my testscope running. I forgot to mention that i already read the highrest.txt, but it doesnt help me since there is no detailed information on what exactly mult and shift is. \"nanoseconds to cycles multiplier\" and divisor dont make click for me either and the mask member seems to have to do something with the timeroverrun, but is it the mask for the counter register, when it throw the interrupts and starts from BOTTOM again. What if i don use a power of two number as a compare match as interrupt source (for example 0x47), can i do that or is it restricted? Im somehow in the dark here... Any help would be highly appreciated. Kind regards Johannes Bauer ----- Original von: Johannes Bauer > Hi RT Mailing List! Im trying to implement a clocksource driver for my board, which is a mach-lpc22xx board. I downloaded linux2-6.33 and patched it with the latest RT patch in order to get a RT kernel. Then I realized that i had to enable the hrtimer support in order to gain the benefit of preempt-rt. However, to use hrt it seems i need to use the GENERIC_CLOCKEVENT timer instead of the old one using timer_tick(). I do not find a detailed documentation on this clockevent subsystem, and i dont grasp the aspect of clocksource and clockevent, what is the difference? I also dont know what exactly the shift and mult struct entities are in specific. I have a PIT running at 72MHz, and providing a 32bit prescaler counter and a 32 bit counter register, I want to use as the tick counter. So if i set the prescaler counter to 71 (0x47) my timer counter runs with 1Mhz (increments every us). I can configure any number in 32bit compare register in order to throw an interrupt and reseting the counter and prescaler counter. My cpu (lpc2478) runs with 288MHz. So in thsi example, what would be the ideal configuration for my timer to achieve highest resultion for hrt and what would be the corresponding settings for shift and mult? I hope you can help me to run the system with the PIT as jiffy tick and for hrt usage. Thank you very much in advance Jhannes Bauer -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
