diff options
Diffstat (limited to 'drivers/clocksource')
| -rw-r--r-- | drivers/clocksource/Kconfig | 7 | ||||
| -rw-r--r-- | drivers/clocksource/Makefile | 1 | ||||
| -rw-r--r-- | drivers/clocksource/timer-goldfish.c | 153 |
3 files changed, 161 insertions, 0 deletions
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig index 1589ae7d5abb..06866bfa1826 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" + depends on M68K || COMPILE_TEST + depends on RTC_DRV_GOLDFISH + help + Support for the timer/counter of goldfish-rtc + endmenu diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile index 9c85ee2bb373..b839beb6ea53 100644 --- a/drivers/clocksource/Makefile +++ b/drivers/clocksource/Makefile @@ -88,3 +88,4 @@ obj-$(CONFIG_GX6605S_TIMER) += timer-gx6605s.o obj-$(CONFIG_HYPERV_TIMER) += hyperv_timer.o obj-$(CONFIG_MICROCHIP_PIT64B) += timer-microchip-pit64b.o obj-$(CONFIG_MSC313E_TIMER) += timer-msc313e.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 000000000000..0512d5eabc82 --- /dev/null +++ b/drivers/clocksource/timer-goldfish.c @@ -0,0 +1,153 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/interrupt.h> +#include <linux/ioport.h> +#include <linux/clocksource.h> +#include <linux/clockchips.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/goldfish.h> +#include <clocksource/timer-goldfish.h> + +struct goldfish_timer { + struct clocksource cs; + struct clock_event_device ced; + struct resource res; + void __iomem *base; +}; + +static struct goldfish_timer *ced_to_gf(struct clock_event_device *ced) +{ + return container_of(ced, struct goldfish_timer, ced); +} + +static struct goldfish_timer *cs_to_gf(struct clocksource *cs) +{ + return container_of(cs, struct goldfish_timer, cs); +} + +static u64 goldfish_timer_read(struct clocksource *cs) +{ + struct goldfish_timer *timerdrv = cs_to_gf(cs); + void __iomem *base = timerdrv->base; + u32 time_low, time_high; + u64 ticks; + + /* + * time_low: get low bits of current time and update time_high + * time_high: get high bits of time at last time_low read + */ + time_low = gf_ioread32(base + TIMER_TIME_LOW); + time_high = gf_ioread32(base + TIMER_TIME_HIGH); + + ticks = ((u64)time_high << 32) | time_low; + + return ticks; +} + +static int goldfish_timer_set_oneshot(struct clock_event_device *evt) +{ + struct goldfish_timer *timerdrv = ced_to_gf(evt); + void __iomem *base = timerdrv->base; + + gf_iowrite32(0, base + TIMER_ALARM_HIGH); + gf_iowrite32(0, base + TIMER_ALARM_LOW); + gf_iowrite32(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; + + gf_iowrite32(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; + + now = goldfish_timer_read(&timerdrv->cs); + + now += delta; + + gf_iowrite32(upper_32_bits(now), base + TIMER_ALARM_HIGH); + gf_iowrite32(lower_32_bits(now), base + TIMER_ALARM_LOW); + + return 0; +} + +static irqreturn_t goldfish_timer_irq(int irq, void *dev_id) +{ + struct goldfish_timer *timerdrv = dev_id; + struct clock_event_device *evt = &timerdrv->ced; + void __iomem *base = timerdrv->base; + + gf_iowrite32(1, base + TIMER_CLEAR_INTERRUPT); + + evt->event_handler(evt); + + return IRQ_HANDLED; +} + +int __init goldfish_timer_init(int irq, void __iomem *base) +{ + struct goldfish_timer *timerdrv; + int ret; + + timerdrv = kzalloc(sizeof(*timerdrv), GFP_KERNEL); + if (!timerdrv) + return -ENOMEM; + + timerdrv->base = base; + + 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, + }; + + timerdrv->res = (struct resource){ + .name = "goldfish_timer", + .start = (unsigned long)base, + .end = (unsigned long)base + 0xfff, + }; + + ret = request_resource(&iomem_resource, &timerdrv->res); + if (ret) { + pr_err("Cannot allocate '%s' resource\n", timerdrv->res.name); + return ret; + } + + timerdrv->cs = (struct clocksource){ + .name = "goldfish_timer", + .rating = 400, + .read = goldfish_timer_read, + .mask = CLOCKSOURCE_MASK(64), + .flags = 0, + .max_idle_ns = LONG_MAX, + }; + + clocksource_register_hz(&timerdrv->cs, NSEC_PER_SEC); + + ret = request_irq(irq, goldfish_timer_irq, IRQF_TIMER, + "goldfish_timer", timerdrv); + if (ret) { + pr_err("Couldn't register goldfish-timer interrupt\n"); + return ret; + } + + clockevents_config_and_register(&timerdrv->ced, NSEC_PER_SEC, + 1, 0xffffffff); + + return 0; +} |