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
|
/*
* 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/sched_clock.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#define TIMER_IRQ_EN_REG 0x00
#define TIMER_IRQ_EN(val) BIT(val)
#define TIMER_IRQ_ST_REG 0x04
#define TIMER_CTL_REG(val) (0x10 * val + 0x10)
#define TIMER_CTL_ENABLE BIT(0)
#define TIMER_CTL_RELOAD BIT(1)
#define TIMER_CTL_ONESHOT BIT(7)
#define TIMER_INTVAL_REG(val) (0x10 * (val) + 0x14)
#define TIMER_CNTVAL_REG(val) (0x10 * (val) + 0x18)
#define TIMER_SCAL 16
static void __iomem *timer_base;
static void sun4i_clkevt_mode(enum clock_event_mode mode,
struct clock_event_device *clk)
{
u32 u = readl(timer_base + TIMER_CTL_REG(0));
switch (mode) {
case CLOCK_EVT_MODE_PERIODIC:
u &= ~(TIMER_CTL_ONESHOT);
writel(u | TIMER_CTL_ENABLE, timer_base + TIMER_CTL_REG(0));
break;
case CLOCK_EVT_MODE_ONESHOT:
writel(u | TIMER_CTL_ONESHOT, timer_base + TIMER_CTL_REG(0));
break;
case CLOCK_EVT_MODE_UNUSED:
case CLOCK_EVT_MODE_SHUTDOWN:
default:
writel(u & ~(TIMER_CTL_ENABLE), timer_base + TIMER_CTL_REG(0));
break;
}
}
static int sun4i_clkevt_next_event(unsigned long evt,
struct clock_event_device *unused)
{
u32 u = readl(timer_base + TIMER_CTL_REG(0));
writel(evt, timer_base + TIMER_CNTVAL_REG(0));
writel(u | TIMER_CTL_ENABLE | TIMER_CTL_AUTORELOAD,
timer_base + TIMER_CTL_REG(0));
return 0;
}
static struct clock_event_device sun4i_clockevent = {
.name = "sun4i_tick",
.rating = 300,
.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
.set_mode = sun4i_clkevt_mode,
.set_next_event = sun4i_clkevt_next_event,
};
static irqreturn_t sun4i_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 sun4i_timer_irq = {
.name = "sun4i_timer0",
.flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
.handler = sun4i_timer_interrupt,
.dev_id = &sun4i_clockevent,
};
static u32 sun4i_timer_sched_read(void)
{
return ~readl(timer_base + TIMER_CNTVAL_REG(1));
}
static void __init sun4i_timer_init(struct device_node *node)
{
unsigned long rate = 0;
struct clk *clk;
int ret, irq;
u32 val;
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");
clk = of_clk_get(node, 0);
if (IS_ERR(clk))
panic("Can't get timer clock");
rate = clk_get_rate(clk);
writel(~0, timer_base + TIMER_INTVAL_REG(1));
writel(TIMER_CTL_ENABLE | TIMER_CTL_RELOAD |
TIMER_CTL_CLK_SRC(TIMER_CTL_CLK_SRC_OSC24M),
timer_base + TIMER_CTL_REG(1));
setup_sched_clock(sun4i_timer_sched_read, 32, rate);
clocksource_mmio_init(timer_base + TIMER_CNTVAL_REG(1), node->name,
rate, 300, 32, clocksource_mmio_readl_down);
writel(rate / (TIMER_SCAL * HZ),
timer_base + TIMER_INTVAL_REG(0));
/* set clock source to HOSC, 16 pre-division */
val = readl(timer_base + TIMER_CTL_REG(0));
val &= ~(0x07 << 4);
val &= ~(0x03 << 2);
val |= (4 << 4) | (1 << 2);
writel(val, timer_base + TIMER_CTL_REG(0));
/* set mode to auto reload */
val = readl(timer_base + TIMER_CTL_REG(0));
writel(val | TIMER_CTL_RELOAD, timer_base + TIMER_CTL_REG(0));
ret = setup_irq(irq, &sun4i_timer_irq);
if (ret)
pr_warn("failed to setup irq %d\n", irq);
/* Enable timer0 interrupt */
val = readl(timer_base + TIMER_IRQ_EN_REG);
writel(val | TIMER_IRQ_EN(0), timer_base + TIMER_IRQ_EN_REG);
sun4i_clockevent.cpumask = cpumask_of(0);
clockevents_config_and_register(&sun4i_clockevent, rate / TIMER_SCAL,
0x1, 0xff);
}
CLOCKSOURCE_OF_DECLARE(sun4i, "allwinner,sun4i-timer",
sun4i_timer_init);
|
