1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
|
/*
* arch/arm/plat-orion/time.c
*
* Marvell Orion SoC timer handling.
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*
* Timer 0 is used as free-running clocksource, while timer 1 is
* used as clock_event_device.
*/
#include <linux/kernel.h>
#include <linux/timer.h>
#include <linux/clockchips.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/sched_clock.h>
#include <plat/time.h>
/*
* MBus bridge block registers.
*/
#define BRIDGE_CAUSE_OFF 0x0110
#define BRIDGE_MASK_OFF 0x0114
#define BRIDGE_INT_TIMER0 0x0002
#define BRIDGE_INT_TIMER1 0x0004
/*
* Timer block registers.
*/
#define TIMER_CTRL_OFF 0x0000
#define TIMER0_EN 0x0001
#define TIMER0_RELOAD_EN 0x0002
#define TIMER1_EN 0x0004
#define TIMER1_RELOAD_EN 0x0008
#define TIMER0_RELOAD_OFF 0x0010
#define TIMER0_VAL_OFF 0x0014
#define TIMER1_RELOAD_OFF 0x0018
#define TIMER1_VAL_OFF 0x001c
/*
* SoC-specific data.
*/
static void __iomem *bridge_base;
static u32 bridge_timer1_clr_mask;
static void __iomem *timer_base;
/*
* Number of timer ticks per jiffy.
*/
static u32 ticks_per_jiffy;
/*
* Orion's sched_clock implementation. It has a resolution of
* at least 7.5ns (133MHz TCLK).
*/
static u32 notrace orion_read_sched_clock(void)
{
return ~readl(timer_base + TIMER0_VAL_OFF);
}
/*
* Clockevent handling.
*/
static int
orion_clkevt_next_event(unsigned long delta, struct clock_event_device *dev)
{
unsigned long flags;
u32 u;
if (delta == 0)
return -ETIME;
local_irq_save(flags);
/*
* Clear and enable clockevent timer interrupt.
*/
writel(bridge_timer1_clr_mask, bridge_base + BRIDGE_CAUSE_OFF);
u = readl(bridge_base + BRIDGE_MASK_OFF);
u |= BRIDGE_INT_TIMER1;
writel(u, bridge_base + BRIDGE_MASK_OFF);
/*
* Setup new clockevent timer value.
*/
writel(delta, timer_base + TIMER1_VAL_OFF);
/*
* Enable the timer.
*/
u = readl(timer_base + TIMER_CTRL_OFF);
u = (u & ~TIMER1_RELOAD_EN) | TIMER1_EN;
writel(u, timer_base + TIMER_CTRL_OFF);
local_irq_restore(flags);
return 0;
}
static void
orion_clkevt_mode(enum clock_event_mode mode, struct clock_event_device *dev)
{
unsigned long flags;
u32 u;
local_irq_save(flags);
if (mode == CLOCK_EVT_MODE_PERIODIC) {
/*
* Setup timer to fire at 1/HZ intervals.
*/
writel(ticks_per_jiffy - 1, timer_base + TIMER1_RELOAD_OFF);
writel(ticks_per_jiffy - 1, timer_base + TIMER1_VAL_OFF);
/*
* Enable timer interrupt.
*/
u = readl(bridge_base + BRIDGE_MASK_OFF);
writel(u | BRIDGE_INT_TIMER1, bridge_base + BRIDGE_MASK_OFF);
/*
* Enable timer.
*/
u = readl(timer_base + TIMER_CTRL_OFF);
writel(u | TIMER1_EN | TIMER1_RELOAD_EN,
timer_base + TIMER_CTRL_OFF);
} else {
/*
* Disable timer.
*/
u = readl(timer_base + TIMER_CTRL_OFF);
writel(u & ~TIMER1_EN, timer_base + TIMER_CTRL_OFF);
/*
* Disable timer interrupt.
*/
u = readl(bridge_base + BRIDGE_MASK_OFF);
writel(u & ~BRIDGE_INT_TIMER1, bridge_base + BRIDGE_MASK_OFF);
/*
* ACK pending timer interrupt.
*/
writel(bridge_timer1_clr_mask, bridge_base + BRIDGE_CAUSE_OFF);
}
local_irq_restore(flags);
}
static struct clock_event_device orion_clkevt = {
.name = "orion_tick",
.features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC,
.rating = 300,
.set_next_event = orion_clkevt_next_event,
.set_mode = orion_clkevt_mode,
};
static irqreturn_t orion_timer_interrupt(int irq, void *dev_id)
{
/*
* ACK timer interrupt and call event handler.
*/
writel(bridge_timer1_clr_mask, bridge_base + BRIDGE_CAUSE_OFF);
orion_clkevt.event_handler(&orion_clkevt);
return IRQ_HANDLED;
}
static struct irqaction orion_timer_irq = {
.name = "orion_tick",
.flags = IRQF_TIMER,
.handler = orion_timer_interrupt
};
void __init
orion_time_set_base(void __iomem *_timer_base)
{
timer_base = _timer_base;
}
void __init
orion_time_init(void __iomem *_bridge_base, u32 _bridge_timer1_clr_mask,
unsigned int irq, unsigned int tclk)
{
u32 u;
/*
* Set SoC-specific data.
*/
bridge_base = _bridge_base;
bridge_timer1_clr_mask = _bridge_timer1_clr_mask;
ticks_per_jiffy = (tclk + HZ/2) / HZ;
/*
* Set scale and timer for sched_clock.
*/
setup_sched_clock(orion_read_sched_clock, 32, tclk);
/*
* Setup free-running clocksource timer (interrupts
* disabled).
*/
writel(0xffffffff, timer_base + TIMER0_VAL_OFF);
writel(0xffffffff, timer_base + TIMER0_RELOAD_OFF);
u = readl(bridge_base + BRIDGE_MASK_OFF);
writel(u & ~BRIDGE_INT_TIMER0, bridge_base + BRIDGE_MASK_OFF);
u = readl(timer_base + TIMER_CTRL_OFF);
writel(u | TIMER0_EN | TIMER0_RELOAD_EN, timer_base + TIMER_CTRL_OFF);
clocksource_mmio_init(timer_base + TIMER0_VAL_OFF, "orion_clocksource",
tclk, 300, 32, clocksource_mmio_readl_down);
/*
* Setup clockevent timer (interrupt-driven).
*/
setup_irq(irq, &orion_timer_irq);
orion_clkevt.cpumask = cpumask_of(0);
clockevents_config_and_register(&orion_clkevt, tclk, 1, 0xfffffffe);
}
|
