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-rw-r--r--arch/arm/mach-realview/localtimer.c186
1 files changed, 5 insertions, 181 deletions
diff --git a/arch/arm/mach-realview/localtimer.c b/arch/arm/mach-realview/localtimer.c
index d0d39adf6407..60b4e111f459 100644
--- a/arch/arm/mach-realview/localtimer.c
+++ b/arch/arm/mach-realview/localtimer.c
@@ -9,194 +9,18 @@
9 * published by the Free Software Foundation. 9 * published by the Free Software Foundation.
10 */ 10 */
11#include <linux/init.h> 11#include <linux/init.h>
12#include <linux/kernel.h>
13#include <linux/delay.h>
14#include <linux/device.h>
15#include <linux/smp.h> 12#include <linux/smp.h>
16#include <linux/jiffies.h>
17#include <linux/percpu.h>
18#include <linux/clockchips.h> 13#include <linux/clockchips.h>
19#include <linux/irq.h>
20#include <linux/io.h>
21 14
22#include <asm/hardware/arm_twd.h>
23#include <asm/hardware/gic.h>
24#include <mach/hardware.h>
25#include <asm/irq.h> 15#include <asm/irq.h>
26 16#include <asm/smp_twd.h>
27static DEFINE_PER_CPU(struct clock_event_device, local_clockevent); 17#include <asm/localtimer.h>
28
29/*
30 * Used on SMP for either the local timer or IPI_TIMER
31 */
32void local_timer_interrupt(void)
33{
34 struct clock_event_device *clk = &__get_cpu_var(local_clockevent);
35
36 clk->event_handler(clk);
37}
38
39#ifdef CONFIG_LOCAL_TIMERS
40
41/* set up by the platform code */
42void __iomem *twd_base;
43
44static unsigned long mpcore_timer_rate;
45
46static void local_timer_set_mode(enum clock_event_mode mode,
47 struct clock_event_device *clk)
48{
49 unsigned long ctrl;
50
51 switch(mode) {
52 case CLOCK_EVT_MODE_PERIODIC:
53 /* timer load already set up */
54 ctrl = TWD_TIMER_CONTROL_ENABLE | TWD_TIMER_CONTROL_IT_ENABLE
55 | TWD_TIMER_CONTROL_PERIODIC;
56 break;
57 case CLOCK_EVT_MODE_ONESHOT:
58 /* period set, and timer enabled in 'next_event' hook */
59 ctrl = TWD_TIMER_CONTROL_IT_ENABLE | TWD_TIMER_CONTROL_ONESHOT;
60 break;
61 case CLOCK_EVT_MODE_UNUSED:
62 case CLOCK_EVT_MODE_SHUTDOWN:
63 default:
64 ctrl = 0;
65 }
66
67 __raw_writel(ctrl, twd_base + TWD_TIMER_CONTROL);
68}
69
70static int local_timer_set_next_event(unsigned long evt,
71 struct clock_event_device *unused)
72{
73 unsigned long ctrl = __raw_readl(twd_base + TWD_TIMER_CONTROL);
74
75 __raw_writel(evt, twd_base + TWD_TIMER_COUNTER);
76 __raw_writel(ctrl | TWD_TIMER_CONTROL_ENABLE, twd_base + TWD_TIMER_CONTROL);
77
78 return 0;
79}
80
81/*
82 * local_timer_ack: checks for a local timer interrupt.
83 *
84 * If a local timer interrupt has occurred, acknowledge and return 1.
85 * Otherwise, return 0.
86 */
87int local_timer_ack(void)
88{
89 if (__raw_readl(twd_base + TWD_TIMER_INTSTAT)) {
90 __raw_writel(1, twd_base + TWD_TIMER_INTSTAT);
91 return 1;
92 }
93
94 return 0;
95}
96
97static void __cpuinit twd_calibrate_rate(void)
98{
99 unsigned long load, count;
100 u64 waitjiffies;
101
102 /*
103 * If this is the first time round, we need to work out how fast
104 * the timer ticks
105 */
106 if (mpcore_timer_rate == 0) {
107 printk("Calibrating local timer... ");
108
109 /* Wait for a tick to start */
110 waitjiffies = get_jiffies_64() + 1;
111
112 while (get_jiffies_64() < waitjiffies)
113 udelay(10);
114
115 /* OK, now the tick has started, let's get the timer going */
116 waitjiffies += 5;
117
118 /* enable, no interrupt or reload */
119 __raw_writel(0x1, twd_base + TWD_TIMER_CONTROL);
120
121 /* maximum value */
122 __raw_writel(0xFFFFFFFFU, twd_base + TWD_TIMER_COUNTER);
123
124 while (get_jiffies_64() < waitjiffies)
125 udelay(10);
126
127 count = __raw_readl(twd_base + TWD_TIMER_COUNTER);
128
129 mpcore_timer_rate = (0xFFFFFFFFU - count) * (HZ / 5);
130
131 printk("%lu.%02luMHz.\n", mpcore_timer_rate / 1000000,
132 (mpcore_timer_rate / 100000) % 100);
133 }
134
135 load = mpcore_timer_rate / HZ;
136
137 __raw_writel(load, twd_base + TWD_TIMER_LOAD);
138}
139 18
140/* 19/*
141 * Setup the local clock events for a CPU. 20 * Setup the local clock events for a CPU.
142 */ 21 */
143void __cpuinit local_timer_setup(void) 22void __cpuinit local_timer_setup(struct clock_event_device *evt)
144{
145 unsigned int cpu = smp_processor_id();
146 struct clock_event_device *clk = &per_cpu(local_clockevent, cpu);
147 unsigned long flags;
148
149 twd_calibrate_rate();
150
151 clk->name = "local_timer";
152 clk->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT;
153 clk->rating = 350;
154 clk->set_mode = local_timer_set_mode;
155 clk->set_next_event = local_timer_set_next_event;
156 clk->irq = IRQ_LOCALTIMER;
157 clk->cpumask = cpumask_of(cpu);
158 clk->shift = 20;
159 clk->mult = div_sc(mpcore_timer_rate, NSEC_PER_SEC, clk->shift);
160 clk->max_delta_ns = clockevent_delta2ns(0xffffffff, clk);
161 clk->min_delta_ns = clockevent_delta2ns(0xf, clk);
162
163 /* Make sure our local interrupt controller has this enabled */
164 local_irq_save(flags);
165 get_irq_chip(IRQ_LOCALTIMER)->unmask(IRQ_LOCALTIMER);
166 local_irq_restore(flags);
167
168 clockevents_register_device(clk);
169}
170
171/*
172 * take a local timer down
173 */
174void __cpuexit local_timer_stop(void)
175{ 23{
176 __raw_writel(0, twd_base + TWD_TIMER_CONTROL); 24 evt->irq = IRQ_LOCALTIMER;
25 twd_timer_setup(evt);
177} 26}
178
179#else /* CONFIG_LOCAL_TIMERS */
180
181static void dummy_timer_set_mode(enum clock_event_mode mode,
182 struct clock_event_device *clk)
183{
184}
185
186void __cpuinit local_timer_setup(void)
187{
188 unsigned int cpu = smp_processor_id();
189 struct clock_event_device *clk = &per_cpu(local_clockevent, cpu);
190
191 clk->name = "dummy_timer";
192 clk->features = CLOCK_EVT_FEAT_DUMMY;
193 clk->rating = 200;
194 clk->mult = 1;
195 clk->set_mode = dummy_timer_set_mode;
196 clk->broadcast = smp_timer_broadcast;
197 clk->cpumask = cpumask_of(cpu);
198
199 clockevents_register_device(clk);
200}
201
202#endif /* !CONFIG_LOCAL_TIMERS */
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