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153 lines
3.6 KiB
153 lines
3.6 KiB
// SPDX-License-Identifier: GPL-2.0 |
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#include <linux/interrupt.h> |
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#include <linux/ioport.h> |
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#include <linux/clocksource.h> |
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#include <linux/clockchips.h> |
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#include <linux/module.h> |
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#include <linux/slab.h> |
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#include <linux/goldfish.h> |
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#include <clocksource/timer-goldfish.h> |
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struct goldfish_timer { |
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struct clocksource cs; |
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struct clock_event_device ced; |
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struct resource res; |
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void __iomem *base; |
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}; |
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static struct goldfish_timer *ced_to_gf(struct clock_event_device *ced) |
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{ |
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return container_of(ced, struct goldfish_timer, ced); |
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} |
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static struct goldfish_timer *cs_to_gf(struct clocksource *cs) |
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{ |
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return container_of(cs, struct goldfish_timer, cs); |
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} |
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static u64 goldfish_timer_read(struct clocksource *cs) |
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{ |
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struct goldfish_timer *timerdrv = cs_to_gf(cs); |
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void __iomem *base = timerdrv->base; |
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u32 time_low, time_high; |
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u64 ticks; |
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/* |
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* time_low: get low bits of current time and update time_high |
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* time_high: get high bits of time at last time_low read |
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*/ |
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time_low = gf_ioread32(base + TIMER_TIME_LOW); |
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time_high = gf_ioread32(base + TIMER_TIME_HIGH); |
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ticks = ((u64)time_high << 32) | time_low; |
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return ticks; |
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} |
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static int goldfish_timer_set_oneshot(struct clock_event_device *evt) |
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{ |
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struct goldfish_timer *timerdrv = ced_to_gf(evt); |
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void __iomem *base = timerdrv->base; |
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gf_iowrite32(0, base + TIMER_ALARM_HIGH); |
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gf_iowrite32(0, base + TIMER_ALARM_LOW); |
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gf_iowrite32(1, base + TIMER_IRQ_ENABLED); |
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return 0; |
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} |
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static int goldfish_timer_shutdown(struct clock_event_device *evt) |
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{ |
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struct goldfish_timer *timerdrv = ced_to_gf(evt); |
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void __iomem *base = timerdrv->base; |
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gf_iowrite32(0, base + TIMER_IRQ_ENABLED); |
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return 0; |
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} |
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static int goldfish_timer_next_event(unsigned long delta, |
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struct clock_event_device *evt) |
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{ |
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struct goldfish_timer *timerdrv = ced_to_gf(evt); |
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void __iomem *base = timerdrv->base; |
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u64 now; |
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now = goldfish_timer_read(&timerdrv->cs); |
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now += delta; |
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gf_iowrite32(upper_32_bits(now), base + TIMER_ALARM_HIGH); |
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gf_iowrite32(lower_32_bits(now), base + TIMER_ALARM_LOW); |
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return 0; |
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} |
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static irqreturn_t goldfish_timer_irq(int irq, void *dev_id) |
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{ |
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struct goldfish_timer *timerdrv = dev_id; |
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struct clock_event_device *evt = &timerdrv->ced; |
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void __iomem *base = timerdrv->base; |
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gf_iowrite32(1, base + TIMER_CLEAR_INTERRUPT); |
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evt->event_handler(evt); |
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return IRQ_HANDLED; |
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} |
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int __init goldfish_timer_init(int irq, void __iomem *base) |
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{ |
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struct goldfish_timer *timerdrv; |
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int ret; |
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timerdrv = kzalloc(sizeof(*timerdrv), GFP_KERNEL); |
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if (!timerdrv) |
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return -ENOMEM; |
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timerdrv->base = base; |
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timerdrv->ced = (struct clock_event_device){ |
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.name = "goldfish_timer", |
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.features = CLOCK_EVT_FEAT_ONESHOT, |
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.set_state_shutdown = goldfish_timer_shutdown, |
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.set_state_oneshot = goldfish_timer_set_oneshot, |
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.set_next_event = goldfish_timer_next_event, |
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}; |
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timerdrv->res = (struct resource){ |
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.name = "goldfish_timer", |
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.start = (unsigned long)base, |
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.end = (unsigned long)base + 0xfff, |
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}; |
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ret = request_resource(&iomem_resource, &timerdrv->res); |
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if (ret) { |
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pr_err("Cannot allocate '%s' resource\n", timerdrv->res.name); |
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return ret; |
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} |
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timerdrv->cs = (struct clocksource){ |
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.name = "goldfish_timer", |
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.rating = 400, |
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.read = goldfish_timer_read, |
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.mask = CLOCKSOURCE_MASK(64), |
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.flags = 0, |
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.max_idle_ns = LONG_MAX, |
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}; |
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clocksource_register_hz(&timerdrv->cs, NSEC_PER_SEC); |
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ret = request_irq(irq, goldfish_timer_irq, IRQF_TIMER, |
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"goldfish_timer", timerdrv); |
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if (ret) { |
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pr_err("Couldn't register goldfish-timer interrupt\n"); |
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return ret; |
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} |
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clockevents_config_and_register(&timerdrv->ced, NSEC_PER_SEC, |
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1, 0xffffffff); |
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return 0; |
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}
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