cregit-Linux how code gets into the kernel

Release 4.7 drivers/clocksource/pxa_timer.c

/*
 * arch/arm/mach-pxa/time.c
 *
 * PXA clocksource, clockevents, and OST interrupt handlers.
 * Copyright (c) 2007 by Bill Gatliff <bgat@billgatliff.com>.
 *
 * Derived from Nicolas Pitre's PXA timer handler Copyright (c) 2001
 * by MontaVista Software, Inc.  (Nico, your code rocks!)
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/clk.h>
#include <linux/clockchips.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/sched_clock.h>

#include <asm/div64.h>


#define OSMR0		0x00	
/* OS Timer 0 Match Register */

#define OSMR1		0x04	
/* OS Timer 1 Match Register */

#define OSMR2		0x08	
/* OS Timer 2 Match Register */

#define OSMR3		0x0C	
/* OS Timer 3 Match Register */


#define OSCR		0x10	
/* OS Timer Counter Register */

#define OSSR		0x14	
/* OS Timer Status Register */

#define OWER		0x18	
/* OS Timer Watchdog Enable Register */

#define OIER		0x1C	
/* OS Timer Interrupt Enable Register */


#define OSSR_M3		(1 << 3)	
/* Match status channel 3 */

#define OSSR_M2		(1 << 2)	
/* Match status channel 2 */

#define OSSR_M1		(1 << 1)	
/* Match status channel 1 */

#define OSSR_M0		(1 << 0)	
/* Match status channel 0 */


#define OIER_E0		(1 << 0)	
/* Interrupt enable channel 0 */

/*
 * This is PXA's sched_clock implementation. This has a resolution
 * of at least 308 ns and a maximum value of 208 days.
 *
 * The return value is guaranteed to be monotonic in that range as
 * long as there is always less than 582 seconds between successive
 * calls to sched_clock() which should always be the case in practice.
 */


#define timer_readl(reg) readl_relaxed(timer_base + (reg))

#define timer_writel(val, reg) writel_relaxed((val), timer_base + (reg))


static void __iomem *timer_base;


static u64 notrace pxa_read_sched_clock(void) { return timer_readl(OSCR); }

Contributors

PersonTokensPropCommitsCommitProp
nicolas pitrenicolas pitre640.00%114.29%
russell kingrussell king426.67%342.86%
marc zyngiermarc zyngier320.00%114.29%
robert jarzmikrobert jarzmik16.67%114.29%
stephen boydstephen boyd16.67%114.29%
Total15100.00%7100.00%

#define MIN_OSCR_DELTA 16
static irqreturn_t pxa_ost0_interrupt(int irq, void *dev_id) { struct clock_event_device *c = dev_id; /* Disarm the compare/match, signal the event. */ timer_writel(timer_readl(OIER) & ~OIER_E0, OIER); timer_writel(OSSR_M0, OSSR); c->event_handler(c); return IRQ_HANDLED; }

Contributors

PersonTokensPropCommitsCommitProp
bill gatliffbill gatliff2243.14%114.29%
russell kingrussell king1427.45%342.86%
nicolas pitrenicolas pitre1223.53%228.57%
robert jarzmikrobert jarzmik35.88%114.29%
Total51100.00%7100.00%


static int pxa_osmr0_set_next_event(unsigned long delta, struct clock_event_device *dev) { unsigned long next, oscr; timer_writel(timer_readl(OIER) | OIER_E0, OIER); next = timer_readl(OSCR) + delta; timer_writel(next, OSMR0); oscr = timer_readl(OSCR); return (signed)(next - oscr) <= MIN_OSCR_DELTA ? -ETIME : 0; }

Contributors

PersonTokensPropCommitsCommitProp
russell kingrussell king4257.53%350.00%
bill gatliffbill gatliff2534.25%116.67%
robert jarzmikrobert jarzmik56.85%116.67%
nicolas pitrenicolas pitre11.37%116.67%
Total73100.00%6100.00%


static int pxa_osmr0_shutdown(struct clock_event_device *evt) { /* initializing, released, or preparing for suspend */ timer_writel(timer_readl(OIER) & ~OIER_E0, OIER); timer_writel(OSSR_M0, OSSR); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
russell kingrussell king1337.14%240.00%
bill gatliffbill gatliff1337.14%120.00%
viresh kumarviresh kumar617.14%120.00%
robert jarzmikrobert jarzmik38.57%120.00%
Total35100.00%5100.00%

#ifdef CONFIG_PM static unsigned long osmr[4], oier, oscr;
static void pxa_timer_suspend(struct clock_event_device *cedev) { osmr[0] = timer_readl(OSMR0); osmr[1] = timer_readl(OSMR1); osmr[2] = timer_readl(OSMR2); osmr[3] = timer_readl(OSMR3); oier = timer_readl(OIER); oscr = timer_readl(OSCR); }

Contributors

PersonTokensPropCommitsCommitProp
russell kingrussell king5584.62%466.67%
robert jarzmikrobert jarzmik69.23%116.67%
stephen warrenstephen warren46.15%116.67%
Total65100.00%6100.00%


static void pxa_timer_resume(struct clock_event_device *cedev) { /* * Ensure that we have at least MIN_OSCR_DELTA between match * register 0 and the OSCR, to guarantee that we will receive * the one-shot timer interrupt. We adjust OSMR0 in preference * to OSCR to guarantee that OSCR is monotonically incrementing. */ if (osmr[0] - oscr < MIN_OSCR_DELTA) osmr[0] += MIN_OSCR_DELTA; timer_writel(osmr[0], OSMR0); timer_writel(osmr[1], OSMR1); timer_writel(osmr[2], OSMR2); timer_writel(osmr[3], OSMR3); timer_writel(oier, OIER); timer_writel(oscr, OSCR); }

Contributors

PersonTokensPropCommitsCommitProp
russell kingrussell king7488.10%466.67%
robert jarzmikrobert jarzmik67.14%116.67%
stephen warrenstephen warren44.76%116.67%
Total84100.00%6100.00%

#else #define pxa_timer_suspend NULL #define pxa_timer_resume NULL #endif static struct clock_event_device ckevt_pxa_osmr0 = { .name = "osmr0", .features = CLOCK_EVT_FEAT_ONESHOT, .rating = 200, .set_next_event = pxa_osmr0_set_next_event, .set_state_shutdown = pxa_osmr0_shutdown, .set_state_oneshot = pxa_osmr0_shutdown, .suspend = pxa_timer_suspend, .resume = pxa_timer_resume, }; static struct irqaction pxa_ost0_irq = { .name = "ost0", .flags = IRQF_TIMER | IRQF_IRQPOLL, .handler = pxa_ost0_interrupt, .dev_id = &ckevt_pxa_osmr0, };
static void __init pxa_timer_common_init(int irq, unsigned long clock_tick_rate) { timer_writel(0, OIER); timer_writel(OSSR_M0 | OSSR_M1 | OSSR_M2 | OSSR_M3, OSSR); sched_clock_register(pxa_read_sched_clock, 32, clock_tick_rate); ckevt_pxa_osmr0.cpumask = cpumask_of(0); setup_irq(irq, &pxa_ost0_irq); clocksource_mmio_init(timer_base + OSCR, "oscr0", clock_tick_rate, 200, 32, clocksource_mmio_readl_up); clockevents_config_and_register(&ckevt_pxa_osmr0, clock_tick_rate, MIN_OSCR_DELTA * 2, 0x7fffffff); }

Contributors

PersonTokensPropCommitsCommitProp
stephen warrenstephen warren6874.73%120.00%
robert jarzmikrobert jarzmik1314.29%240.00%
olof johanssonolof johansson99.89%120.00%
stephen boydstephen boyd11.10%120.00%
Total91100.00%5100.00%


static void __init pxa_timer_dt_init(struct device_node *np) { struct clk *clk; int irq; /* timer registers are shared with watchdog timer */ timer_base = of_iomap(np, 0); if (!timer_base) panic("%s: unable to map resource\n", np->name); clk = of_clk_get(np, 0); if (IS_ERR(clk)) { pr_crit("%s: unable to get clk\n", np->name); return; } clk_prepare_enable(clk); /* we are only interested in OS-timer0 irq */ irq = irq_of_parse_and_map(np, 0); if (irq <= 0) { pr_crit("%s: unable to parse OS-timer0 irq\n", np->name); return; } pxa_timer_common_init(irq, clk_get_rate(clk)); }

Contributors

PersonTokensPropCommitsCommitProp
robert jarzmikrobert jarzmik115100.00%1100.00%
Total115100.00%1100.00%

CLOCKSOURCE_OF_DECLARE(pxa_timer, "marvell,pxa-timer", pxa_timer_dt_init); /* * Legacy timer init for non device-tree boards. */
void __init pxa_timer_nodt_init(int irq, void __iomem *base, unsigned long clock_tick_rate) { struct clk *clk; timer_base = base; clk = clk_get(NULL, "OSTIMER0"); if (clk && !IS_ERR(clk)) clk_prepare_enable(clk); else pr_crit("%s: unable to get clk\n", __func__); pxa_timer_common_init(irq, clock_tick_rate); }

Contributors

PersonTokensPropCommitsCommitProp
robert jarzmikrobert jarzmik66100.00%1100.00%
Total66100.00%1100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
robert jarzmikrobert jarzmik32138.72%28.70%
russell kingrussell king24729.79%939.13%
stephen warrenstephen warren12915.56%14.35%
bill gatliffbill gatliff627.48%14.35%
nicolas pitrenicolas pitre263.14%417.39%
deepak saxenadeepak saxena151.81%14.35%
viresh kumarviresh kumar131.57%14.35%
olof johanssonolof johansson91.09%14.35%
marc zyngiermarc zyngier30.36%14.35%
rob herringrob herring20.24%14.35%
stephen boydstephen boyd20.24%14.35%
Total829100.00%23100.00%
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