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
|
/*
* Amlogic Meson6 SoCs timer handling.
*
* Copyright (C) 2014 Carlo Caione <carlo@caione.org>
*
* Based on code from Amlogic, Inc
*
* 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 CED_ID 0
#define CSD_ID 4
#define TIMER_ISA_MUX 0
#define TIMER_ISA_VAL(t) (((t) + 1) << 2)
#define TIMER_INPUT_BIT(t) (2 * (t))
#define TIMER_ENABLE_BIT(t) (16 + (t))
#define TIMER_PERIODIC_BIT(t) (12 + (t))
#define TIMER_CED_INPUT_MASK (3UL << TIMER_INPUT_BIT(CED_ID))
#define TIMER_CSD_INPUT_MASK (7UL << TIMER_INPUT_BIT(CSD_ID))
#define TIMER_CED_UNIT_1US 0
#define TIMER_CSD_UNIT_1US 1
static void __iomem *timer_base;
static u64 notrace meson6_timer_sched_read(void)
{
return (u64)readl(timer_base + TIMER_ISA_VAL(CSD_ID));
}
static void meson6_clkevt_time_stop(unsigned char timer)
{
u32 val = readl(timer_base + TIMER_ISA_MUX);
writel(val & ~TIMER_ENABLE_BIT(timer), timer_base + TIMER_ISA_MUX);
}
static void meson6_clkevt_time_setup(unsigned char timer, unsigned long delay)
{
writel(delay, timer_base + TIMER_ISA_VAL(timer));
}
static void meson6_clkevt_time_start(unsigned char timer, bool periodic)
{
u32 val = readl(timer_base + TIMER_ISA_MUX);
if (periodic)
val |= TIMER_PERIODIC_BIT(timer);
else
val &= ~TIMER_PERIODIC_BIT(timer);
writel(val | TIMER_ENABLE_BIT(timer), timer_base + TIMER_ISA_MUX);
}
static int meson6_shutdown(struct clock_event_device *evt)
{
meson6_clkevt_time_stop(CED_ID);
return 0;
}
static int meson6_set_oneshot(struct clock_event_device *evt)
{
meson6_clkevt_time_stop(CED_ID);
meson6_clkevt_time_start(CED_ID, false);
return 0;
}
static int meson6_set_periodic(struct clock_event_device *evt)
{
meson6_clkevt_time_stop(CED_ID);
meson6_clkevt_time_setup(CED_ID, USEC_PER_SEC / HZ - 1);
meson6_clkevt_time_start(CED_ID, true);
return 0;
}
static int meson6_clkevt_next_event(unsigned long evt,
struct clock_event_device *unused)
{
meson6_clkevt_time_stop(CED_ID);
meson6_clkevt_time_setup(CED_ID, evt);
meson6_clkevt_time_start(CED_ID, false);
return 0;
}
static struct clock_event_device meson6_clockevent = {
.name = "meson6_tick",
.rating = 400,
.features = CLOCK_EVT_FEAT_PERIODIC |
CLOCK_EVT_FEAT_ONESHOT,
.set_state_shutdown = meson6_shutdown,
.set_state_periodic = meson6_set_periodic,
.set_state_oneshot = meson6_set_oneshot,
.tick_resume = meson6_shutdown,
.set_next_event = meson6_clkevt_next_event,
};
static irqreturn_t meson6_timer_interrupt(int irq, void *dev_id)
{
struct clock_event_device *evt = (struct clock_event_device *)dev_id;
evt->event_handler(evt);
return IRQ_HANDLED;
}
static struct irqaction meson6_timer_irq = {
.name = "meson6_timer",
.flags = IRQF_TIMER | IRQF_IRQPOLL,
.handler = meson6_timer_interrupt,
.dev_id = &meson6_clockevent,
};
static int __init meson6_timer_init(struct device_node *node)
{
u32 val;
int ret, irq;
timer_base = of_io_request_and_map(node, 0, "meson6-timer");
if (IS_ERR(timer_base)) {
pr_err("Can't map registers\n");
return -ENXIO;
}
irq = irq_of_parse_and_map(node, 0);
if (irq <= 0) {
pr_err("Can't parse IRQ\n");
return -EINVAL;
}
/* Set 1us for timer E */
val = readl(timer_base + TIMER_ISA_MUX);
val &= ~TIMER_CSD_INPUT_MASK;
val |= TIMER_CSD_UNIT_1US << TIMER_INPUT_BIT(CSD_ID);
writel(val, timer_base + TIMER_ISA_MUX);
sched_clock_register(meson6_timer_sched_read, 32, USEC_PER_SEC);
clocksource_mmio_init(timer_base + TIMER_ISA_VAL(CSD_ID), node->name,
1000 * 1000, 300, 32, clocksource_mmio_readl_up);
/* Timer A base 1us */
val &= ~TIMER_CED_INPUT_MASK;
val |= TIMER_CED_UNIT_1US << TIMER_INPUT_BIT(CED_ID);
writel(val, timer_base + TIMER_ISA_MUX);
/* Stop the timer A */
meson6_clkevt_time_stop(CED_ID);
ret = setup_irq(irq, &meson6_timer_irq);
if (ret) {
pr_warn("failed to setup irq %d\n", irq);
return ret;
}
meson6_clockevent.cpumask = cpu_possible_mask;
meson6_clockevent.irq = irq;
clockevents_config_and_register(&meson6_clockevent, USEC_PER_SEC,
1, 0xfffe);
return 0;
}
TIMER_OF_DECLARE(meson6, "amlogic,meson6-timer",
meson6_timer_init);
|
