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/arch/mips/sgi-ip27/ip27-timer.c

https://bitbucket.org/thekraven/iscream_thunderc-2.6.35
C | 249 lines | 181 code | 40 blank | 28 comment | 8 complexity | 28b40958375fd10687fbfaca66080edb MD5 | raw file
Possible License(s): GPL-2.0, LGPL-2.0, AGPL-1.0
  1/*
  2 * Copytight (C) 1999, 2000, 05, 06 Ralf Baechle (ralf@linux-mips.org)
  3 * Copytight (C) 1999, 2000 Silicon Graphics, Inc.
  4 */
  5#include <linux/bcd.h>
  6#include <linux/clockchips.h>
  7#include <linux/init.h>
  8#include <linux/kernel.h>
  9#include <linux/sched.h>
 10#include <linux/interrupt.h>
 11#include <linux/kernel_stat.h>
 12#include <linux/param.h>
 13#include <linux/smp.h>
 14#include <linux/time.h>
 15#include <linux/timex.h>
 16#include <linux/mm.h>
 17#include <linux/platform_device.h>
 18
 19#include <asm/time.h>
 20#include <asm/pgtable.h>
 21#include <asm/sgialib.h>
 22#include <asm/sn/ioc3.h>
 23#include <asm/sn/klconfig.h>
 24#include <asm/sn/arch.h>
 25#include <asm/sn/addrs.h>
 26#include <asm/sn/sn_private.h>
 27#include <asm/sn/sn0/ip27.h>
 28#include <asm/sn/sn0/hub.h>
 29
 30#define TICK_SIZE (tick_nsec / 1000)
 31
 32/* Includes for ioc3_init().  */
 33#include <asm/sn/types.h>
 34#include <asm/sn/sn0/addrs.h>
 35#include <asm/sn/sn0/hubni.h>
 36#include <asm/sn/sn0/hubio.h>
 37#include <asm/pci/bridge.h>
 38
 39static void enable_rt_irq(unsigned int irq)
 40{
 41}
 42
 43static void disable_rt_irq(unsigned int irq)
 44{
 45}
 46
 47static struct irq_chip rt_irq_type = {
 48	.name		= "SN HUB RT timer",
 49	.ack		= disable_rt_irq,
 50	.mask		= disable_rt_irq,
 51	.mask_ack	= disable_rt_irq,
 52	.unmask		= enable_rt_irq,
 53	.eoi		= enable_rt_irq,
 54};
 55
 56static int rt_next_event(unsigned long delta, struct clock_event_device *evt)
 57{
 58	unsigned int cpu = smp_processor_id();
 59	int slice = cputoslice(cpu);
 60	unsigned long cnt;
 61
 62	cnt = LOCAL_HUB_L(PI_RT_COUNT);
 63	cnt += delta;
 64	LOCAL_HUB_S(PI_RT_COMPARE_A + PI_COUNT_OFFSET * slice, cnt);
 65
 66	return LOCAL_HUB_L(PI_RT_COUNT) >= cnt ? -ETIME : 0;
 67}
 68
 69static void rt_set_mode(enum clock_event_mode mode,
 70		struct clock_event_device *evt)
 71{
 72	switch (mode) {
 73	case CLOCK_EVT_MODE_ONESHOT:
 74		/* The only mode supported */
 75		break;
 76
 77	case CLOCK_EVT_MODE_PERIODIC:
 78	case CLOCK_EVT_MODE_UNUSED:
 79	case CLOCK_EVT_MODE_SHUTDOWN:
 80	case CLOCK_EVT_MODE_RESUME:
 81		/* Nothing to do  */
 82		break;
 83	}
 84}
 85
 86int rt_timer_irq;
 87
 88static DEFINE_PER_CPU(struct clock_event_device, hub_rt_clockevent);
 89static DEFINE_PER_CPU(char [11], hub_rt_name);
 90
 91static irqreturn_t hub_rt_counter_handler(int irq, void *dev_id)
 92{
 93	unsigned int cpu = smp_processor_id();
 94	struct clock_event_device *cd = &per_cpu(hub_rt_clockevent, cpu);
 95	int slice = cputoslice(cpu);
 96
 97	/*
 98	 * Ack
 99	 */
100	LOCAL_HUB_S(PI_RT_PEND_A + PI_COUNT_OFFSET * slice, 0);
101	cd->event_handler(cd);
102
103	return IRQ_HANDLED;
104}
105
106struct irqaction hub_rt_irqaction = {
107	.handler	= hub_rt_counter_handler,
108	.flags		= IRQF_DISABLED | IRQF_PERCPU | IRQF_TIMER,
109	.name		= "hub-rt",
110};
111
112/*
113 * This is a hack; we really need to figure these values out dynamically
114 *
115 * Since 800 ns works very well with various HUB frequencies, such as
116 * 360, 380, 390 and 400 MHZ, we use 800 ns rtc cycle time.
117 *
118 * Ralf: which clock rate is used to feed the counter?
119 */
120#define NSEC_PER_CYCLE		800
121#define CYCLES_PER_SEC		(NSEC_PER_SEC / NSEC_PER_CYCLE)
122
123void __cpuinit hub_rt_clock_event_init(void)
124{
125	unsigned int cpu = smp_processor_id();
126	struct clock_event_device *cd = &per_cpu(hub_rt_clockevent, cpu);
127	unsigned char *name = per_cpu(hub_rt_name, cpu);
128	int irq = rt_timer_irq;
129
130	sprintf(name, "hub-rt %d", cpu);
131	cd->name		= name;
132	cd->features		= CLOCK_EVT_FEAT_ONESHOT;
133	clockevent_set_clock(cd, CYCLES_PER_SEC);
134	cd->max_delta_ns        = clockevent_delta2ns(0xfffffffffffff, cd);
135	cd->min_delta_ns        = clockevent_delta2ns(0x300, cd);
136	cd->rating		= 200;
137	cd->irq			= irq;
138	cd->cpumask		= cpumask_of(cpu);
139	cd->set_next_event	= rt_next_event;
140	cd->set_mode		= rt_set_mode;
141	clockevents_register_device(cd);
142}
143
144static void __init hub_rt_clock_event_global_init(void)
145{
146	int irq;
147
148	do {
149		smp_wmb();
150		irq = rt_timer_irq;
151		if (irq)
152			break;
153
154		irq = allocate_irqno();
155		if (irq < 0)
156			panic("Allocation of irq number for timer failed");
157	} while (xchg(&rt_timer_irq, irq));
158
159	set_irq_chip_and_handler(irq, &rt_irq_type, handle_percpu_irq);
160	setup_irq(irq, &hub_rt_irqaction);
161}
162
163static cycle_t hub_rt_read(struct clocksource *cs)
164{
165	return REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT);
166}
167
168struct clocksource hub_rt_clocksource = {
169	.name	= "HUB-RT",
170	.rating	= 200,
171	.read	= hub_rt_read,
172	.mask	= CLOCKSOURCE_MASK(52),
173	.flags	= CLOCK_SOURCE_IS_CONTINUOUS,
174};
175
176static void __init hub_rt_clocksource_init(void)
177{
178	struct clocksource *cs = &hub_rt_clocksource;
179
180	clocksource_set_clock(cs, CYCLES_PER_SEC);
181	clocksource_register(cs);
182}
183
184void __init plat_time_init(void)
185{
186	hub_rt_clocksource_init();
187	hub_rt_clock_event_global_init();
188	hub_rt_clock_event_init();
189}
190
191void __cpuinit cpu_time_init(void)
192{
193	lboard_t *board;
194	klcpu_t *cpu;
195	int cpuid;
196
197	/* Don't use ARCS.  ARCS is fragile.  Klconfig is simple and sane.  */
198	board = find_lboard(KL_CONFIG_INFO(get_nasid()), KLTYPE_IP27);
199	if (!board)
200		panic("Can't find board info for myself.");
201
202	cpuid = LOCAL_HUB_L(PI_CPU_NUM) ? IP27_CPU0_INDEX : IP27_CPU1_INDEX;
203	cpu = (klcpu_t *) KLCF_COMP(board, cpuid);
204	if (!cpu)
205		panic("No information about myself?");
206
207	printk("CPU %d clock is %dMHz.\n", smp_processor_id(), cpu->cpu_speed);
208
209	set_c0_status(SRB_TIMOCLK);
210}
211
212void __cpuinit hub_rtc_init(cnodeid_t cnode)
213{
214
215	/*
216	 * We only need to initialize the current node.
217	 * If this is not the current node then it is a cpuless
218	 * node and timeouts will not happen there.
219	 */
220	if (get_compact_nodeid() == cnode) {
221		LOCAL_HUB_S(PI_RT_EN_A, 1);
222		LOCAL_HUB_S(PI_RT_EN_B, 1);
223		LOCAL_HUB_S(PI_PROF_EN_A, 0);
224		LOCAL_HUB_S(PI_PROF_EN_B, 0);
225		LOCAL_HUB_S(PI_RT_COUNT, 0);
226		LOCAL_HUB_S(PI_RT_PEND_A, 0);
227		LOCAL_HUB_S(PI_RT_PEND_B, 0);
228	}
229}
230
231static int __init sgi_ip27_rtc_devinit(void)
232{
233	struct resource res;
234
235	memset(&res, 0, sizeof(res));
236	res.start = XPHYSADDR(KL_CONFIG_CH_CONS_INFO(master_nasid)->memory_base +
237			      IOC3_BYTEBUS_DEV0);
238	res.end = res.start + 32767;
239	res.flags = IORESOURCE_MEM;
240
241	return IS_ERR(platform_device_register_simple("rtc-m48t35", -1,
242						      &res, 1));
243}
244
245/*
246 * kludge make this a device_initcall after ioc3 resource conflicts
247 * are resolved
248 */
249late_initcall(sgi_ip27_rtc_devinit);