diff options
Diffstat (limited to 'arch/mips/sibyte/bcm1480/time.c')
-rw-r--r-- | arch/mips/sibyte/bcm1480/time.c | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/arch/mips/sibyte/bcm1480/time.c b/arch/mips/sibyte/bcm1480/time.c new file mode 100644 index 000000000000..e545752695a1 --- /dev/null +++ b/arch/mips/sibyte/bcm1480/time.c | |||
@@ -0,0 +1,138 @@ | |||
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 | |||
52 | extern int bcm1480_steal_irq(int irq); | ||
53 | |||
54 | void 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 | |||
104 | void 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 | */ | ||
132 | unsigned 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 | } | ||