1c92e7ef1SLaurent Vivier // SPDX-License-Identifier: GPL-2.0
2c92e7ef1SLaurent Vivier
3c92e7ef1SLaurent Vivier #include <linux/interrupt.h>
4c92e7ef1SLaurent Vivier #include <linux/ioport.h>
5c92e7ef1SLaurent Vivier #include <linux/clocksource.h>
6c92e7ef1SLaurent Vivier #include <linux/clockchips.h>
7c92e7ef1SLaurent Vivier #include <linux/module.h>
8c92e7ef1SLaurent Vivier #include <linux/slab.h>
9c92e7ef1SLaurent Vivier #include <linux/goldfish.h>
10c92e7ef1SLaurent Vivier #include <clocksource/timer-goldfish.h>
11c92e7ef1SLaurent Vivier
12c92e7ef1SLaurent Vivier struct goldfish_timer {
13c92e7ef1SLaurent Vivier struct clocksource cs;
14c92e7ef1SLaurent Vivier struct clock_event_device ced;
15c92e7ef1SLaurent Vivier struct resource res;
16c92e7ef1SLaurent Vivier void __iomem *base;
17c92e7ef1SLaurent Vivier };
18c92e7ef1SLaurent Vivier
ced_to_gf(struct clock_event_device * ced)19c92e7ef1SLaurent Vivier static struct goldfish_timer *ced_to_gf(struct clock_event_device *ced)
20c92e7ef1SLaurent Vivier {
21c92e7ef1SLaurent Vivier return container_of(ced, struct goldfish_timer, ced);
22c92e7ef1SLaurent Vivier }
23c92e7ef1SLaurent Vivier
cs_to_gf(struct clocksource * cs)24c92e7ef1SLaurent Vivier static struct goldfish_timer *cs_to_gf(struct clocksource *cs)
25c92e7ef1SLaurent Vivier {
26c92e7ef1SLaurent Vivier return container_of(cs, struct goldfish_timer, cs);
27c92e7ef1SLaurent Vivier }
28c92e7ef1SLaurent Vivier
goldfish_timer_read(struct clocksource * cs)29c92e7ef1SLaurent Vivier static u64 goldfish_timer_read(struct clocksource *cs)
30c92e7ef1SLaurent Vivier {
31c92e7ef1SLaurent Vivier struct goldfish_timer *timerdrv = cs_to_gf(cs);
32c92e7ef1SLaurent Vivier void __iomem *base = timerdrv->base;
33c92e7ef1SLaurent Vivier u32 time_low, time_high;
34c92e7ef1SLaurent Vivier u64 ticks;
35c92e7ef1SLaurent Vivier
36c92e7ef1SLaurent Vivier /*
37c92e7ef1SLaurent Vivier * time_low: get low bits of current time and update time_high
38c92e7ef1SLaurent Vivier * time_high: get high bits of time at last time_low read
39c92e7ef1SLaurent Vivier */
40c92e7ef1SLaurent Vivier time_low = gf_ioread32(base + TIMER_TIME_LOW);
41c92e7ef1SLaurent Vivier time_high = gf_ioread32(base + TIMER_TIME_HIGH);
42c92e7ef1SLaurent Vivier
43c92e7ef1SLaurent Vivier ticks = ((u64)time_high << 32) | time_low;
44c92e7ef1SLaurent Vivier
45c92e7ef1SLaurent Vivier return ticks;
46c92e7ef1SLaurent Vivier }
47c92e7ef1SLaurent Vivier
goldfish_timer_set_oneshot(struct clock_event_device * evt)48c92e7ef1SLaurent Vivier static int goldfish_timer_set_oneshot(struct clock_event_device *evt)
49c92e7ef1SLaurent Vivier {
50c92e7ef1SLaurent Vivier struct goldfish_timer *timerdrv = ced_to_gf(evt);
51c92e7ef1SLaurent Vivier void __iomem *base = timerdrv->base;
52c92e7ef1SLaurent Vivier
53c92e7ef1SLaurent Vivier gf_iowrite32(0, base + TIMER_ALARM_HIGH);
54c92e7ef1SLaurent Vivier gf_iowrite32(0, base + TIMER_ALARM_LOW);
55c92e7ef1SLaurent Vivier gf_iowrite32(1, base + TIMER_IRQ_ENABLED);
56c92e7ef1SLaurent Vivier
57c92e7ef1SLaurent Vivier return 0;
58c92e7ef1SLaurent Vivier }
59c92e7ef1SLaurent Vivier
goldfish_timer_shutdown(struct clock_event_device * evt)60c92e7ef1SLaurent Vivier static int goldfish_timer_shutdown(struct clock_event_device *evt)
61c92e7ef1SLaurent Vivier {
62c92e7ef1SLaurent Vivier struct goldfish_timer *timerdrv = ced_to_gf(evt);
63c92e7ef1SLaurent Vivier void __iomem *base = timerdrv->base;
64c92e7ef1SLaurent Vivier
65c92e7ef1SLaurent Vivier gf_iowrite32(0, base + TIMER_IRQ_ENABLED);
66c92e7ef1SLaurent Vivier
67c92e7ef1SLaurent Vivier return 0;
68c92e7ef1SLaurent Vivier }
69c92e7ef1SLaurent Vivier
goldfish_timer_next_event(unsigned long delta,struct clock_event_device * evt)70c92e7ef1SLaurent Vivier static int goldfish_timer_next_event(unsigned long delta,
71c92e7ef1SLaurent Vivier struct clock_event_device *evt)
72c92e7ef1SLaurent Vivier {
73c92e7ef1SLaurent Vivier struct goldfish_timer *timerdrv = ced_to_gf(evt);
74c92e7ef1SLaurent Vivier void __iomem *base = timerdrv->base;
75c92e7ef1SLaurent Vivier u64 now;
76c92e7ef1SLaurent Vivier
77c92e7ef1SLaurent Vivier now = goldfish_timer_read(&timerdrv->cs);
78c92e7ef1SLaurent Vivier
79c92e7ef1SLaurent Vivier now += delta;
80c92e7ef1SLaurent Vivier
81c92e7ef1SLaurent Vivier gf_iowrite32(upper_32_bits(now), base + TIMER_ALARM_HIGH);
82c92e7ef1SLaurent Vivier gf_iowrite32(lower_32_bits(now), base + TIMER_ALARM_LOW);
83c92e7ef1SLaurent Vivier
84c92e7ef1SLaurent Vivier return 0;
85c92e7ef1SLaurent Vivier }
86c92e7ef1SLaurent Vivier
goldfish_timer_irq(int irq,void * dev_id)87c92e7ef1SLaurent Vivier static irqreturn_t goldfish_timer_irq(int irq, void *dev_id)
88c92e7ef1SLaurent Vivier {
89c92e7ef1SLaurent Vivier struct goldfish_timer *timerdrv = dev_id;
90c92e7ef1SLaurent Vivier struct clock_event_device *evt = &timerdrv->ced;
91c92e7ef1SLaurent Vivier void __iomem *base = timerdrv->base;
92c92e7ef1SLaurent Vivier
93c92e7ef1SLaurent Vivier gf_iowrite32(1, base + TIMER_CLEAR_INTERRUPT);
94c92e7ef1SLaurent Vivier
95c92e7ef1SLaurent Vivier evt->event_handler(evt);
96c92e7ef1SLaurent Vivier
97c92e7ef1SLaurent Vivier return IRQ_HANDLED;
98c92e7ef1SLaurent Vivier }
99c92e7ef1SLaurent Vivier
goldfish_timer_init(int irq,void __iomem * base)100c92e7ef1SLaurent Vivier int __init goldfish_timer_init(int irq, void __iomem *base)
101c92e7ef1SLaurent Vivier {
102c92e7ef1SLaurent Vivier struct goldfish_timer *timerdrv;
103c92e7ef1SLaurent Vivier int ret;
104c92e7ef1SLaurent Vivier
105c92e7ef1SLaurent Vivier timerdrv = kzalloc(sizeof(*timerdrv), GFP_KERNEL);
106c92e7ef1SLaurent Vivier if (!timerdrv)
107c92e7ef1SLaurent Vivier return -ENOMEM;
108c92e7ef1SLaurent Vivier
109c92e7ef1SLaurent Vivier timerdrv->base = base;
110c92e7ef1SLaurent Vivier
111c92e7ef1SLaurent Vivier timerdrv->ced = (struct clock_event_device){
112c92e7ef1SLaurent Vivier .name = "goldfish_timer",
113c92e7ef1SLaurent Vivier .features = CLOCK_EVT_FEAT_ONESHOT,
114c92e7ef1SLaurent Vivier .set_state_shutdown = goldfish_timer_shutdown,
115c92e7ef1SLaurent Vivier .set_state_oneshot = goldfish_timer_set_oneshot,
116c92e7ef1SLaurent Vivier .set_next_event = goldfish_timer_next_event,
117c92e7ef1SLaurent Vivier };
118c92e7ef1SLaurent Vivier
119c92e7ef1SLaurent Vivier timerdrv->res = (struct resource){
120c92e7ef1SLaurent Vivier .name = "goldfish_timer",
121c92e7ef1SLaurent Vivier .start = (unsigned long)base,
122c92e7ef1SLaurent Vivier .end = (unsigned long)base + 0xfff,
123c92e7ef1SLaurent Vivier };
124c92e7ef1SLaurent Vivier
125c92e7ef1SLaurent Vivier ret = request_resource(&iomem_resource, &timerdrv->res);
126c92e7ef1SLaurent Vivier if (ret) {
127c92e7ef1SLaurent Vivier pr_err("Cannot allocate '%s' resource\n", timerdrv->res.name);
128c92e7ef1SLaurent Vivier return ret;
129c92e7ef1SLaurent Vivier }
130c92e7ef1SLaurent Vivier
131c92e7ef1SLaurent Vivier timerdrv->cs = (struct clocksource){
132c92e7ef1SLaurent Vivier .name = "goldfish_timer",
133c92e7ef1SLaurent Vivier .rating = 400,
134c92e7ef1SLaurent Vivier .read = goldfish_timer_read,
135c92e7ef1SLaurent Vivier .mask = CLOCKSOURCE_MASK(64),
136c92e7ef1SLaurent Vivier .flags = 0,
137c92e7ef1SLaurent Vivier .max_idle_ns = LONG_MAX,
138c92e7ef1SLaurent Vivier };
139c92e7ef1SLaurent Vivier
140c92e7ef1SLaurent Vivier clocksource_register_hz(&timerdrv->cs, NSEC_PER_SEC);
141c92e7ef1SLaurent Vivier
142c92e7ef1SLaurent Vivier ret = request_irq(irq, goldfish_timer_irq, IRQF_TIMER,
143c92e7ef1SLaurent Vivier "goldfish_timer", timerdrv);
144c92e7ef1SLaurent Vivier if (ret) {
145c92e7ef1SLaurent Vivier pr_err("Couldn't register goldfish-timer interrupt\n");
146c92e7ef1SLaurent Vivier return ret;
147c92e7ef1SLaurent Vivier }
148c92e7ef1SLaurent Vivier
149c92e7ef1SLaurent Vivier clockevents_config_and_register(&timerdrv->ced, NSEC_PER_SEC,
150c92e7ef1SLaurent Vivier 1, 0xffffffff);
151c92e7ef1SLaurent Vivier
152c92e7ef1SLaurent Vivier return 0;
153c92e7ef1SLaurent Vivier }
154