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 */
sibyte_set_mode(enum clock_event_mode mode,struct clock_event_device * evt)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
47 cfg = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG));
48 init = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_INIT));
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);
54 __raw_writeq(M_SCD_TIMER_ENABLE | M_SCD_TIMER_MODE_CONTINUOUS,
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
sibyte_next_event(unsigned long delta,struct clock_event_device * cd)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
75 cfg = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG));
76 init = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_INIT));
77
78 __raw_writeq(0, cfg);
79 __raw_writeq(delta - 1, init);
80 __raw_writeq(M_SCD_TIMER_ENABLE, cfg);
81
82 return 0;
83 }
84
sibyte_counter_handler(int irq,void * dev_id)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)
93 tmode = M_SCD_TIMER_ENABLE | M_SCD_TIMER_MODE_CONTINUOUS;
94 else
95 tmode = 0;
96
97 /* ACK interrupt */
98 cfg = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG));
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
sb1250_clockevent_init(void)110 void sb1250_clockevent_init(void)
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;
133 clockevents_register_device(cd);
134
135 sb1250_mask_irq(cpu, irq);
136
137 /*
138 * Map the timer interrupt to IP[4] of this cpu
139 */
140 __raw_writeq(IMR_IP4_VAL,
141 IOADDR(A_IMR_REGISTER(cpu, R_IMR_INTERRUPT_MAP_BASE) +
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 }
154