cregit-Linux how code gets into the kernel

Release 4.10 arch/m68k/coldfire/pit.c

/***************************************************************************/

/*
 *      pit.c -- Freescale ColdFire PIT timer. Currently this type of
 *               hardware timer only exists in the Freescale ColdFire
 *               5270/5271, 5282 and 5208 CPUs. No doubt newer ColdFire
 *               family members will probably use it too.
 *
 *      Copyright (C) 1999-2008, Greg Ungerer (gerg@snapgear.com)
 *      Copyright (C) 2001-2004, SnapGear Inc. (www.snapgear.com)
 */

/***************************************************************************/

#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/param.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/clockchips.h>
#include <asm/machdep.h>
#include <asm/io.h>
#include <asm/coldfire.h>
#include <asm/mcfpit.h>
#include <asm/mcfsim.h>

/***************************************************************************/

/*
 *      By default use timer1 as the system clock timer.
 */

#define	FREQ	((MCF_CLK / 2) / 64)

#define	TA(a)	(MCFPIT_BASE1 + (a))

#define PIT_CYCLES_PER_JIFFY (FREQ / HZ)


static u32 pit_cnt;

/*
 * Initialize the PIT timer.
 *
 * This is also called after resume to bring the PIT into operation again.
 */


static int cf_pit_set_periodic(struct clock_event_device *evt) { __raw_writew(MCFPIT_PCSR_DISABLE, TA(MCFPIT_PCSR)); __raw_writew(PIT_CYCLES_PER_JIFFY, TA(MCFPIT_PMR)); __raw_writew(MCFPIT_PCSR_EN | MCFPIT_PCSR_PIE | MCFPIT_PCSR_OVW | MCFPIT_PCSR_RLD | MCFPIT_PCSR_CLK64, TA(MCFPIT_PCSR)); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
sebastian andrzej siewiorsebastian andrzej siewior4586.54%133.33%
viresh kumarviresh kumar611.54%133.33%
greg ungerergreg ungerer11.92%133.33%
Total52100.00%3100.00%


static int cf_pit_set_oneshot(struct clock_event_device *evt) { __raw_writew(MCFPIT_PCSR_DISABLE, TA(MCFPIT_PCSR)); __raw_writew(MCFPIT_PCSR_EN | MCFPIT_PCSR_PIE | MCFPIT_PCSR_OVW | MCFPIT_PCSR_CLK64, TA(MCFPIT_PCSR)); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
viresh kumarviresh kumar2152.50%150.00%
sebastian andrzej siewiorsebastian andrzej siewior1947.50%150.00%
Total40100.00%2100.00%


static int cf_pit_shutdown(struct clock_event_device *evt) { __raw_writew(MCFPIT_PCSR_DISABLE, TA(MCFPIT_PCSR)); return 0; }

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PersonTokensPropCommitsCommitProp
viresh kumarviresh kumar1562.50%150.00%
sebastian andrzej siewiorsebastian andrzej siewior937.50%150.00%
Total24100.00%2100.00%

/* * Program the next event in oneshot mode * * Delta is given in PIT ticks */
static int cf_pit_next_event(unsigned long delta, struct clock_event_device *evt) { __raw_writew(delta, TA(MCFPIT_PMR)); return 0; }

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sebastian andrzej siewiorsebastian andrzej siewior28100.00%1100.00%
Total28100.00%1100.00%

struct clock_event_device cf_pit_clockevent = { .name = "pit", .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT, .set_state_shutdown = cf_pit_shutdown, .set_state_periodic = cf_pit_set_periodic, .set_state_oneshot = cf_pit_set_oneshot, .set_next_event = cf_pit_next_event, .shift = 32, .irq = MCF_IRQ_PIT1, }; /***************************************************************************/
static irqreturn_t pit_tick(int irq, void *dummy) { struct clock_event_device *evt = &cf_pit_clockevent; u16 pcsr; /* Reset the ColdFire timer */ pcsr = __raw_readw(TA(MCFPIT_PCSR)); __raw_writew(pcsr | MCFPIT_PCSR_PIF, TA(MCFPIT_PCSR)); pit_cnt += PIT_CYCLES_PER_JIFFY; evt->event_handler(evt); return IRQ_HANDLED; }

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PersonTokensPropCommitsCommitProp
greg ungerergreg ungerer4573.77%480.00%
sebastian andrzej siewiorsebastian andrzej siewior1626.23%120.00%
Total61100.00%5100.00%

/***************************************************************************/ static struct irqaction pit_irq = { .name = "timer", .flags = IRQF_TIMER, .handler = pit_tick, }; /***************************************************************************/
static u64 pit_read_clk(struct clocksource *cs) { unsigned long flags; u32 cycles; u16 pcntr; local_irq_save(flags); pcntr = __raw_readw(TA(MCFPIT_PCNTR)); cycles = pit_cnt; local_irq_restore(flags); return cycles + PIT_CYCLES_PER_JIFFY - pcntr; }

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PersonTokensPropCommitsCommitProp
greg ungerergreg ungerer4688.46%125.00%
magnus dammmagnus damm47.69%125.00%
thomas gleixnerthomas gleixner11.92%125.00%
sebastian andrzej siewiorsebastian andrzej siewior11.92%125.00%
Total52100.00%4100.00%

/***************************************************************************/ static struct clocksource pit_clk = { .name = "pit", .rating = 100, .read = pit_read_clk, .mask = CLOCKSOURCE_MASK(32), }; /***************************************************************************/
void hw_timer_init(irq_handler_t handler) { cf_pit_clockevent.cpumask = cpumask_of(smp_processor_id()); cf_pit_clockevent.mult = div_sc(FREQ, NSEC_PER_SEC, 32); cf_pit_clockevent.max_delta_ns = clockevent_delta2ns(0xFFFF, &cf_pit_clockevent); cf_pit_clockevent.min_delta_ns = clockevent_delta2ns(0x3f, &cf_pit_clockevent); clockevents_register_device(&cf_pit_clockevent); setup_irq(MCF_IRQ_PIT1, &pit_irq); clocksource_register_hz(&pit_clk, FREQ); }

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PersonTokensPropCommitsCommitProp
sebastian andrzej siewiorsebastian andrzej siewior5267.53%110.00%
greg ungerergreg ungerer2025.97%660.00%
john stultzjohn stultz33.90%110.00%
steven kingsteven king11.30%110.00%
rusty russellrusty russell11.30%110.00%
Total77100.00%10100.00%

/***************************************************************************/

Overall Contributors

PersonTokensPropCommitsCommitProp
greg ungerergreg ungerer22444.62%853.33%
sebastian andrzej siewiorsebastian andrzej siewior21342.43%16.67%
viresh kumarviresh kumar5410.76%16.67%
magnus dammmagnus damm40.80%16.67%
john stultzjohn stultz30.60%16.67%
steven kingsteven king20.40%16.67%
rusty russellrusty russell10.20%16.67%
thomas gleixnerthomas gleixner10.20%16.67%
Total502100.00%15100.00%
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