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-rw-r--r--arch/mips/sibyte/bcm1480/time.c138
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diff --git a/arch/mips/sibyte/bcm1480/time.c b/arch/mips/sibyte/bcm1480/time.c
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1/*
2 * Copyright (C) 2000,2001,2004 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
19/*
20 * These are routines to set up and handle interrupts from the
21 * bcm1480 general purpose timer 0. We're using the timer as a
22 * system clock, so we set it up to run at 100 Hz. On every
23 * interrupt, we update our idea of what the time of day is,
24 * then call do_timer() in the architecture-independent kernel
25 * code to do general bookkeeping (e.g. update jiffies, run
26 * bottom halves, etc.)
27 */
28#include <linux/config.h>
29#include <linux/interrupt.h>
30#include <linux/sched.h>
31#include <linux/spinlock.h>
32#include <linux/kernel_stat.h>
33
34#include <asm/irq.h>
35#include <asm/ptrace.h>
36#include <asm/addrspace.h>
37#include <asm/time.h>
38#include <asm/io.h>
39
40#include <asm/sibyte/bcm1480_regs.h>
41#include <asm/sibyte/sb1250_regs.h>
42#include <asm/sibyte/bcm1480_int.h>
43#include <asm/sibyte/bcm1480_scd.h>
44
45#include <asm/sibyte/sb1250.h>
46
47
48#define IMR_IP2_VAL K_BCM1480_INT_MAP_I0
49#define IMR_IP3_VAL K_BCM1480_INT_MAP_I1
50#define IMR_IP4_VAL K_BCM1480_INT_MAP_I2
51
52extern int bcm1480_steal_irq(int irq);
53
54void bcm1480_time_init(void)
55{
56 int cpu = smp_processor_id();
57 int irq = K_BCM1480_INT_TIMER_0+cpu;
58
59 /* Only have 4 general purpose timers */
60 if (cpu > 3) {
61 BUG();
62 }
63
64 if (!cpu) {
65 /* Use our own gettimeoffset() routine */
66 do_gettimeoffset = bcm1480_gettimeoffset;
67 }
68
69 bcm1480_mask_irq(cpu, irq);
70
71 /* Map the timer interrupt to ip[4] of this cpu */
72 __raw_writeq(IMR_IP4_VAL, IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_INTERRUPT_MAP_BASE_H)
73 + (irq<<3)));
74
75 /* the general purpose timer ticks at 1 Mhz independent of the rest of the system */
76 /* Disable the timer and set up the count */
77 __raw_writeq(0, IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG)));
78 __raw_writeq(
79#ifndef CONFIG_SIMULATION
80 1000000/HZ
81#else
82 50000/HZ
83#endif
84 , IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_INIT)));
85
86 /* Set the timer running */
87 __raw_writeq(M_SCD_TIMER_ENABLE|M_SCD_TIMER_MODE_CONTINUOUS,
88 IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG)));
89
90 bcm1480_unmask_irq(cpu, irq);
91 bcm1480_steal_irq(irq);
92 /*
93 * This interrupt is "special" in that it doesn't use the request_irq
94 * way to hook the irq line. The timer interrupt is initialized early
95 * enough to make this a major pain, and it's also firing enough to
96 * warrant a bit of special case code. bcm1480_timer_interrupt is
97 * called directly from irq_handler.S when IP[4] is set during an
98 * interrupt
99 */
100}
101
102#include <asm/sibyte/sb1250.h>
103
104void bcm1480_timer_interrupt(struct pt_regs *regs)
105{
106 int cpu = smp_processor_id();
107 int irq = K_BCM1480_INT_TIMER_0+cpu;
108
109 /* Reset the timer */
110 __raw_writeq(M_SCD_TIMER_ENABLE|M_SCD_TIMER_MODE_CONTINUOUS,
111 IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG)));
112
113 /*
114 * CPU 0 handles the global timer interrupt job
115 */
116 if (cpu == 0) {
117 ll_timer_interrupt(irq, regs);
118 }
119
120 /*
121 * every CPU should do profiling and process accouting
122 */
123 ll_local_timer_interrupt(irq, regs);
124}
125
126/*
127 * We use our own do_gettimeoffset() instead of the generic one,
128 * because the generic one does not work for SMP case.
129 * In addition, since we use general timer 0 for system time,
130 * we can get accurate intra-jiffy offset without calibration.
131 */
132unsigned long bcm1480_gettimeoffset(void)
133{
134 unsigned long count =
135 __raw_readq(IOADDR(A_SCD_TIMER_REGISTER(0, R_SCD_TIMER_CNT)));
136
137 return 1000000/HZ - count;
138}