drivers/clocksource/timer-digicolor.c

Source file repositories/reference/linux-study-clean/drivers/clocksource/timer-digicolor.c

File Facts

System
Linux kernel
Corpus path
drivers/clocksource/timer-digicolor.c
Extension
.c
Size
5044 bytes
Lines
205
Domain
Driver Families
Bucket
drivers/clocksource
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

struct digicolor_timer {
	struct clock_event_device ce;
	void __iomem *base;
	u32 ticks_per_jiffy;
	int timer_id; /* one of TIMER_* */
};

static struct digicolor_timer *dc_timer(struct clock_event_device *ce)
{
	return container_of(ce, struct digicolor_timer, ce);
}

static inline void dc_timer_disable(struct clock_event_device *ce)
{
	struct digicolor_timer *dt = dc_timer(ce);
	writeb(CONTROL_DISABLE, dt->base + CONTROL(dt->timer_id));
}

static inline void dc_timer_enable(struct clock_event_device *ce, u32 mode)
{
	struct digicolor_timer *dt = dc_timer(ce);
	writeb(CONTROL_ENABLE | mode, dt->base + CONTROL(dt->timer_id));
}

static inline void dc_timer_set_count(struct clock_event_device *ce,
				      unsigned long count)
{
	struct digicolor_timer *dt = dc_timer(ce);
	writel(count, dt->base + COUNT(dt->timer_id));
}

static int digicolor_clkevt_shutdown(struct clock_event_device *ce)
{
	dc_timer_disable(ce);
	return 0;
}

static int digicolor_clkevt_set_oneshot(struct clock_event_device *ce)
{
	dc_timer_disable(ce);
	dc_timer_enable(ce, CONTROL_MODE_ONESHOT);
	return 0;
}

static int digicolor_clkevt_set_periodic(struct clock_event_device *ce)
{
	struct digicolor_timer *dt = dc_timer(ce);

	dc_timer_disable(ce);
	dc_timer_set_count(ce, dt->ticks_per_jiffy);
	dc_timer_enable(ce, CONTROL_MODE_PERIODIC);
	return 0;
}

static int digicolor_clkevt_next_event(unsigned long evt,
				       struct clock_event_device *ce)
{
	dc_timer_disable(ce);
	dc_timer_set_count(ce, evt);
	dc_timer_enable(ce, CONTROL_MODE_ONESHOT);

	return 0;
}

static struct digicolor_timer dc_timer_dev = {
	.ce = {
		.name = "digicolor_tick",
		.rating = 340,
		.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
		.set_state_shutdown = digicolor_clkevt_shutdown,
		.set_state_periodic = digicolor_clkevt_set_periodic,
		.set_state_oneshot = digicolor_clkevt_set_oneshot,
		.tick_resume = digicolor_clkevt_shutdown,
		.set_next_event = digicolor_clkevt_next_event,
	},
	.timer_id = TIMER_C,
};

static irqreturn_t digicolor_timer_interrupt(int irq, void *dev_id)
{
	struct clock_event_device *evt = dev_id;

	evt->event_handler(evt);

	return IRQ_HANDLED;
}

static u64 notrace digicolor_timer_sched_read(void)
{
	return ~readl(dc_timer_dev.base + COUNT(TIMER_B));

Annotation

Implementation Notes