7  * Copyright (C) 2007 Ralf Baechle <ralf@linux-mips.org>
10 #include <linux/interrupt.h>
17 #include <asm/cevt-r4k.h>
28 	res = ((int)(read_c0_count() - cnt) >= 0) ? -ETIME : 0;  in mips_next_event()
33  * calculate_min_delta() - Calculate a good minimum delta for mips_next_event().
67 			cnt = read_c0_count() - cnt;  in calculate_min_delta()
73 						  j, ARRAY_SIZE(buf1) - 1);  in calculate_min_delta()
74 					for (; l > k; --l)  in calculate_min_delta()
75 						buf1[l] = buf1[l - 1];  in calculate_min_delta()
85 			if (buf1[ARRAY_SIZE(buf1) - 1] < buf2[k]) {  in calculate_min_delta()
87 					  i, ARRAY_SIZE(buf2) - 1);  in calculate_min_delta()
88 				for (; l > k; --l)  in calculate_min_delta()
89 					buf2[l] = buf2[l - 1];  in calculate_min_delta()
94 			buf2[k] = buf1[ARRAY_SIZE(buf1) - 1];  in calculate_min_delta()
98 	min_delta = buf2[ARRAY_SIZE(buf2) - 1] * 2;  in calculate_min_delta()
105 		 __func__, buf2[ARRAY_SIZE(buf2) - 1], min_delta);  in calculate_min_delta()
113  * Possibly handle a performance counter interrupt.
114  * Return true if the timer interrupt should not be checked
119 	 * The performance counter overflow interrupt may be shared with the  in handle_perf_irq()
120 	 * timer interrupt (cp0_perfcount_irq < 0). If it is and a  in handle_perf_irq()
121 	 * performance counter has overflowed (perf_irq() == IRQ_HANDLED)  in handle_perf_irq()
122 	 * and we can't reliably determine if a counter interrupt has also  in handle_perf_irq()
123 	 * happened (!r2) then don't check for a timer interrupt.  in handle_perf_irq()
139 	 * performance counter interrupt was pending, so we have to run  in c0_compare_interrupt()
140 	 * the performance counter interrupt handler anyway.  in c0_compare_interrupt()
146 	 * The same applies to performance counter interrupts.	But with the  in c0_compare_interrupt()
148 	 * interrupt.  Being the paranoiacs we are we check anyway.  in c0_compare_interrupt()
151 		/* Clear Count/Compare Interrupt */  in c0_compare_interrupt()
154 		cd->event_handler(cd);  in c0_compare_interrupt()
165 	 * IRQF_SHARED: The timer interrupt may be shared with other interrupts
166 	 * such as perf counter and FDC interrupts.
178  * FIXME: This doesn't hold for the relocated E9000 compare interrupt.
187  * Compare interrupt can be routed and latched outside the core,
188  * so wait up to worst case number of cycle counter ticks for timer interrupt
203 		write_c0_compare(cnt - 1);  in c0_compare_int_usable()
217 		if ((int)(read_c0_count() - cnt) < 0)  in c0_compare_int_usable()
222 	while ((int)(read_c0_count() - cnt) <= 0)  in c0_compare_int_usable()
231 	write_c0_compare(cnt - 1);  in c0_compare_int_usable()
263 		mips_ref_freq = freq->old;  in r4k_cpufreq_callback()
267 				     freq->new);  in r4k_cpufreq_callback()
269 		for_each_cpu(cpu, freq->policy->cpus) {  in r4k_cpufreq_callback()
301 		return -ENXIO;  in r4k_clockevent_init()
304 		return -ENXIO;  in r4k_clockevent_init()
308 	cd->name		= "MIPS";  in r4k_clockevent_init()
309 	cd->features		= CLOCK_EVT_FEAT_ONESHOT |  in r4k_clockevent_init()
315 	cd->rating		= 300;  in r4k_clockevent_init()
316 	cd->cpumask		= cpumask_of(cpu);  in r4k_clockevent_init()
317 	cd->set_next_event	= mips_next_event;  in r4k_clockevent_init()
318 	cd->event_handler	= mips_event_handler;  in r4k_clockevent_init()
330 	 * interrupt number of its liking.  in r4k_clockevent_init()