diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig index f65e31bab9ae26..6ca9bb78407d3e 100644 --- a/drivers/clocksource/Kconfig +++ b/drivers/clocksource/Kconfig @@ -711,4 +711,11 @@ config MICROCHIP_PIT64B modes and high resolution. It is used as a clocksource and a clockevent. +config GOLDFISH_TIMER + bool "Clocksource using goldfish-rtc" + select RTC_CLASS + select RTC_DRV_GOLDFISH + help + Support for the timer/counter of goldfish-rtc + endmenu diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile index c17ee32a71515b..e624a1a2702740 100644 --- a/drivers/clocksource/Makefile +++ b/drivers/clocksource/Makefile @@ -88,3 +88,4 @@ obj-$(CONFIG_CSKY_MP_TIMER) += timer-mp-csky.o obj-$(CONFIG_GX6605S_TIMER) += timer-gx6605s.o obj-$(CONFIG_HYPERV_TIMER) += hyperv_timer.o obj-$(CONFIG_MICROCHIP_PIT64B) += timer-microchip-pit64b.o +obj-$(CONFIG_GOLDFISH_TIMER) += timer-goldfish.o diff --git a/drivers/clocksource/timer-goldfish.c b/drivers/clocksource/timer-goldfish.c new file mode 100644 index 00000000000000..b1553c3c945624 --- /dev/null +++ b/drivers/clocksource/timer-goldfish.c @@ -0,0 +1,130 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include +#include +#include +#include +#include + +#define TIMER_TIME_LOW 0x00 /* get low bits of current time */ + /* and update TIMER_TIME_HIGH */ +#define TIMER_TIME_HIGH 0x04 /* get high bits of time at last */ + /* TIMER_TIME_LOW read */ +#define TIMER_ALARM_LOW 0x08 /* set low bits of alarm and */ + /* activate it */ +#define TIMER_ALARM_HIGH 0x0c /* set high bits of next alarm */ +#define TIMER_IRQ_ENABLED 0x10 +#define TIMER_CLEAR_ALARM 0x14 +#define TIMER_ALARM_STATUS 0x18 +#define TIMER_CLEAR_INTERRUPT 0x1c + +struct goldfish_timer { + struct clock_event_device ced; + struct resource res; + void __iomem *base; + int irq; +}; + +static struct goldfish_timer *ced_to_gf(struct clock_event_device *ced) +{ + return container_of(ced, struct goldfish_timer, ced); +} + +static int goldfish_timer_set_oneshot(struct clock_event_device *evt) +{ + struct goldfish_timer *timerdrv = ced_to_gf(evt); + void __iomem *base = timerdrv->base; + + __raw_writel(0, base + TIMER_ALARM_HIGH); + __raw_writel(0, base + TIMER_ALARM_LOW); + __raw_writel(1, base + TIMER_IRQ_ENABLED); + + return 0; +} + +static int goldfish_timer_shutdown(struct clock_event_device *evt) +{ + struct goldfish_timer *timerdrv = ced_to_gf(evt); + void __iomem *base = timerdrv->base; + + __raw_writel(0, base + TIMER_IRQ_ENABLED); + + return 0; +} + +static int goldfish_timer_next_event(unsigned long delta, + struct clock_event_device *evt) +{ + struct goldfish_timer *timerdrv = ced_to_gf(evt); + void __iomem *base = timerdrv->base; + u64 now; + + __raw_writel(1, base + TIMER_CLEAR_INTERRUPT); + + /* + * time_low: get low bits of current time and update time_high + * time_high: get high bits of time at last time_low read + */ + now = __raw_readl(base + TIMER_TIME_LOW); + now += (u64)__raw_readl(base + TIMER_TIME_HIGH) << 32; + + now += delta; + + __raw_writel(upper_32_bits(now), base + TIMER_ALARM_HIGH); + __raw_writel(lower_32_bits(now), base + TIMER_ALARM_LOW); + + return 0; +} + +static irqreturn_t golfish_timer_tick(int irq, void *dev_id) +{ + struct clock_event_device *evt = dev_id; + + evt->event_handler(evt); + + return IRQ_HANDLED; +} + +void __init goldfish_timer_init(int irq, void __iomem *base) +{ + struct goldfish_timer *timerdrv; + int ret; + + timerdrv = kzalloc(sizeof(*timerdrv), GFP_KERNEL); + if (!timerdrv) + return; + + timerdrv->base = base; + timerdrv->irq = irq; + + timerdrv->ced = (struct clock_event_device){ + .name = "goldfish_timer", + .features = CLOCK_EVT_FEAT_ONESHOT, + .set_state_shutdown = goldfish_timer_shutdown, + .set_state_oneshot = goldfish_timer_set_oneshot, + .set_next_event = goldfish_timer_next_event, + .shift = 32, + }; + timerdrv->res = (struct resource){ + .name = "goldfish_timer", + .start = (unsigned long)base, + .end = (unsigned long)base + 0xfff, + }; + + if (request_resource(&iomem_resource, &timerdrv->res)) { + pr_err("Cannot allocate goldfish-timer resource\n"); + return; + } + + ret = request_irq(timerdrv->irq, golfish_timer_tick, IRQF_TIMER, + "goldfish_timer", &timerdrv->ced); + if (ret) { + pr_err("Couldn't register goldfish-timer interrupt\n"); + return; + } + + clockevents_config_and_register(&timerdrv->ced, NSEC_PER_SEC, + 1, 0xffffffff); +} +EXPORT_SYMBOL_GPL(goldfish_timer_init); diff --git a/include/clocksource/timer-goldfish.h b/include/clocksource/timer-goldfish.h new file mode 100644 index 00000000000000..12bcd08f90af4f --- /dev/null +++ b/include/clocksource/timer-goldfish.h @@ -0,0 +1,12 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * goldfish-timer clocksource + */ + +#ifndef _CLOCKSOURCE_GOLDFISH_TIMER_H +#define _CLOCKSOURCE_GOLDFISH_TIMER_H + +extern void goldfish_timer_init(int irq, void __iomem *base); + +#endif /* _CLOCKSOURCE_GOLDFISH_TIMER_H */ +