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cevt-sb1250.c
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1 /*
2  * Copyright (C) 2000, 2001 Broadcom Corporation
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License
6  * as published by the Free Software Foundation; either version 2
7  * of the License, or (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
17  */
18 #include <linux/clockchips.h>
19 #include <linux/interrupt.h>
20 #include <linux/irq.h>
21 #include <linux/percpu.h>
22 #include <linux/smp.h>
23 
24 #include <asm/addrspace.h>
25 #include <asm/io.h>
26 #include <asm/time.h>
27 
28 #include <asm/sibyte/sb1250.h>
29 #include <asm/sibyte/sb1250_regs.h>
30 #include <asm/sibyte/sb1250_int.h>
31 #include <asm/sibyte/sb1250_scd.h>
32 
33 #define IMR_IP2_VAL K_INT_MAP_I0
34 #define IMR_IP3_VAL K_INT_MAP_I1
35 #define IMR_IP4_VAL K_INT_MAP_I2
36 
37 /*
38  * The general purpose timer ticks at 1MHz independent if
39  * the rest of the system
40  */
41 static void sibyte_set_mode(enum clock_event_mode mode,
42  struct clock_event_device *evt)
43 {
44  unsigned int cpu = smp_processor_id();
45  void __iomem *cfg, *init;
46 
49 
50  switch (mode) {
51  case CLOCK_EVT_MODE_PERIODIC:
52  __raw_writeq(0, cfg);
53  __raw_writeq((V_SCD_TIMER_FREQ / HZ) - 1, init);
55  cfg);
56  break;
57 
58  case CLOCK_EVT_MODE_ONESHOT:
59  /* Stop the timer until we actually program a shot */
60  case CLOCK_EVT_MODE_SHUTDOWN:
61  __raw_writeq(0, cfg);
62  break;
63 
64  case CLOCK_EVT_MODE_UNUSED: /* shuddup gcc */
65  case CLOCK_EVT_MODE_RESUME:
66  ;
67  }
68 }
69 
70 static int sibyte_next_event(unsigned long delta, struct clock_event_device *cd)
71 {
72  unsigned int cpu = smp_processor_id();
73  void __iomem *cfg, *init;
74 
77 
78  __raw_writeq(0, cfg);
79  __raw_writeq(delta - 1, init);
81 
82  return 0;
83 }
84 
85 static irqreturn_t sibyte_counter_handler(int irq, void *dev_id)
86 {
87  unsigned int cpu = smp_processor_id();
88  struct clock_event_device *cd = dev_id;
89  void __iomem *cfg;
90  unsigned long tmode;
91 
92  if (cd->mode == CLOCK_EVT_MODE_PERIODIC)
94  else
95  tmode = 0;
96 
97  /* ACK interrupt */
99  ____raw_writeq(tmode, cfg);
100 
101  cd->event_handler(cd);
102 
103  return IRQ_HANDLED;
104 }
105 
106 static DEFINE_PER_CPU(struct clock_event_device, sibyte_hpt_clockevent);
107 static DEFINE_PER_CPU(struct irqaction, sibyte_hpt_irqaction);
108 static DEFINE_PER_CPU(char [18], sibyte_hpt_name);
109 
111 {
112  unsigned int cpu = smp_processor_id();
113  unsigned int irq = K_INT_TIMER_0 + cpu;
114  struct irqaction *action = &per_cpu(sibyte_hpt_irqaction, cpu);
115  struct clock_event_device *cd = &per_cpu(sibyte_hpt_clockevent, cpu);
116  unsigned char *name = per_cpu(sibyte_hpt_name, cpu);
117 
118  /* Only have 4 general purpose timers, and we use last one as hpt */
119  BUG_ON(cpu > 2);
120 
121  sprintf(name, "sb1250-counter-%d", cpu);
122  cd->name = name;
123  cd->features = CLOCK_EVT_FEAT_PERIODIC |
124  CLOCK_EVT_FEAT_ONESHOT;
125  clockevent_set_clock(cd, V_SCD_TIMER_FREQ);
126  cd->max_delta_ns = clockevent_delta2ns(0x7fffff, cd);
127  cd->min_delta_ns = clockevent_delta2ns(2, cd);
128  cd->rating = 200;
129  cd->irq = irq;
130  cd->cpumask = cpumask_of(cpu);
131  cd->set_next_event = sibyte_next_event;
132  cd->set_mode = sibyte_set_mode;
134 
135  sb1250_mask_irq(cpu, irq);
136 
137  /*
138  * Map the timer interrupt to IP[4] of this cpu
139  */
142  (irq << 3)));
143 
144  sb1250_unmask_irq(cpu, irq);
145 
146  action->handler = sibyte_counter_handler;
147  action->flags = IRQF_PERCPU | IRQF_TIMER;
148  action->name = name;
149  action->dev_id = cd;
150 
151  irq_set_affinity(irq, cpumask_of(cpu));
152  setup_irq(irq, action);
153 }