Hi,
Does anyone have any example code demonstrating how to configure a timer/counter interrupt for the AT91 processor running Linux? I'm new to running embedded Linux, and I can't seem to find any information out on the net. All that I am really trying to do is generate a periodic interrupt using one of the built in timer/counter channels.
Any information would be greatly appreciated.
Thanks, Steve
mailto: snipped-for-privacy@powereng.com
Try this
-- _ | | / /__ .----------------------------------------------------------._____/ (___) | Rick Bronson rick at efn dot org Tel 541-485-7264 | (___) | Amazonia Computing
You want to create a device driver kernel module.
So first you need to know how to create a device driver: "Linux device drivers 3rd Edition" by Rubini and Friends.
Then you proceed according to the information the chips data sheet provides.
-Michael
Thanks, Michael. I am able to build a device driver without a problem. I guess my real question is how to actually configure the timer counter in Linux for the AT9200RM processor. I have found an application note on the Atmel site that describes the process without using an OS. My problem is that I'm not sure what to do in Linux. Here's what I am trying, but I think its totally wrong:
volatile AT91PS_TCB p_tcb = (AT91PS_TCB)AT91C_VA_BASE_TCB0; volatile AT91PS_TC p_tc (AT91PS_TC)&p_tcb->TCB_TC0; ...
status = request_irq(AT91C_ID_TC0, timer_isr, SA_INTERRUPT, "timer_isr", NULL); if ( !status ) { p_tc->TC_CCR = AT91_TC_CLKDIS; p_tc->TC_IDR = AT91C_TC_CPCS; dummy = p_tc->TC_SR; p_tc->TC_CMR = AT91C_TC_TIMER_DIV2_CLOCK | AT91C_TC_CPCTRG; p_tc->TC_CCR = AT91C_CLKEN; p_tc->TC_IER = AT91C_TC_CPCS; p_tc->TC_RC = 0x00ff; p_tc->TC_CCR = AT91C_TC_SWTRG; } ....
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