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
|
/*
* Allwinner A1X SoCs timer handling.
*
* Copyright (C) 2012 Maxime Ripard
*
* Maxime Ripard <maxime.ripard@free-electrons.com>
*
* Based on code from
* Allwinner Technology Co., Ltd. <www.allwinnertech.com>
* Benn Huang <benn@allwinnertech.com>
*
* 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.
*/
#include <linux/clk.h>
#include <linux/clockchips.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/irqreturn.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/sunxi_timer.h>
#include <linux/clk/sunxi.h>
#define TIMER_CTL_REG 0x00
#define TIMER_CTL_ENABLE (1 << 0)
#define TIMER_IRQ_ST_REG 0x04
#define TIMER0_CTL_REG 0x10
#define TIMER0_CTL_ENABLE (1 << 0)
#define TIMER0_CTL_AUTORELOAD (1 << 1)
#define TIMER0_CTL_ONESHOT (1 << 7)
#define TIMER0_INTVAL_REG 0x14
#define TIMER0_CNTVAL_REG 0x18
#define TIMER_SCAL 16
static void __iomem *timer_base;
static void sunxi_clkevt_mode(enum clock_event_mode mode,
struct clock_event_device *clk)
{
u32 u = readl(timer_base + TIMER0_CTL_REG);
switch (mode) {
case CLOCK_EVT_MODE_PERIODIC:
u &= ~(TIMER0_CTL_ONESHOT);
writel(u | TIMER0_CTL_ENABLE, timer_base + TIMER0_CTL_REG);
break;
case CLOCK_EVT_MODE_ONESHOT:
writel(u | TIMER0_CTL_ONESHOT, timer_base + TIMER0_CTL_REG);
break;
case CLOCK_EVT_MODE_UNUSED:
case CLOCK_EVT_MODE_SHUTDOWN:
default:
writel(u & ~(TIMER0_CTL_ENABLE), timer_base + TIMER0_CTL_REG);
break;
}
}
static int sunxi_clkevt_next_event(unsigned long evt,
struct clock_event_device *unused)
{
u32 u = readl(timer_base + TIMER0_CTL_REG);
writel(evt, timer_base + TIMER0_CNTVAL_REG);
writel(u | TIMER0_CTL_ENABLE | TIMER0_CTL_AUTORELOAD,
timer_base + TIMER0_CTL_REG);
return 0;
}
static struct clock_event_device sunxi_clockevent = {
.name = "sunxi_tick",
.shift = 32,
.rating = 300,
.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
.set_mode = sunxi_clkevt_mode,
.set_next_event = sunxi_clkevt_next_event,
};
static irqreturn_t sunxi_timer_interrupt(int irq, void *dev_id)
{
struct clock_event_device *evt = (struct clock_event_device *)dev_id;
writel(0x1, timer_base + TIMER_IRQ_ST_REG);
evt->event_handler(evt);
return IRQ_HANDLED;
}
static struct irqaction sunxi_timer_irq = {
.name = "sunxi_timer0",
.flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
.handler = sunxi_timer_interrupt,
.dev_id = &sunxi_clockevent,
};
static struct of_device_id sunxi_timer_dt_ids[] = {
{ .compatible = "allwinner,sunxi-timer" },
{ }
};
void __init sunxi_timer_init(void)
{
struct device_node *node;
unsigned long rate = 0;
struct clk *clk;
int ret, irq;
u32 val;
node = of_find_matching_node(NULL, sunxi_timer_dt_ids);
if (!node)
panic("No sunxi timer node");
timer_base = of_iomap(node, 0);
if (!timer_base)
panic("Can't map registers");
irq = irq_of_parse_and_map(node, 0);
if (irq <= 0)
panic("Can't parse IRQ");
sunxi_init_clocks();
clk = of_clk_get(node, 0);
if (IS_ERR(clk))
panic("Can't get timer clock");
rate = clk_get_rate(clk);
writel(rate / (TIMER_SCAL * HZ),
timer_base + TIMER0_INTVAL_REG);
/* set clock source to HOSC, 16 pre-division */
val = readl(timer_base + TIMER0_CTL_REG);
val &= ~(0x07 << 4);
val &= ~(0x03 << 2);
val |= (4 << 4) | (1 << 2);
writel(val, timer_base + TIMER0_CTL_REG);
/* set mode to auto reload */
val = readl(timer_base + TIMER0_CTL_REG);
writel(val | TIMER0_CTL_AUTORELOAD, timer_base + TIMER0_CTL_REG);
ret = setup_irq(irq, &sunxi_timer_irq);
if (ret)
pr_warn("failed to setup irq %d\n", irq);
/* Enable timer0 interrupt */
val = readl(timer_base + TIMER_CTL_REG);
writel(val | TIMER_CTL_ENABLE, timer_base + TIMER_CTL_REG);
sunxi_clockevent.mult = div_sc(rate / TIMER_SCAL,
NSEC_PER_SEC,
sunxi_clockevent.shift);
sunxi_clockevent.max_delta_ns = clockevent_delta2ns(0xff,
&sunxi_clockevent);
sunxi_clockevent.min_delta_ns = clockevent_delta2ns(0x1,
&sunxi_clockevent);
sunxi_clockevent.cpumask = cpumask_of(0);
clockevents_register_device(&sunxi_clockevent);
}
|
