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1// SPDX-License-Identifier: GPL-2.0+2#include <linux/clk.h>3#include <linux/clocksource.h>4#include <linux/clockchips.h>5#include <linux/cpuhotplug.h>6#include <linux/interrupt.h>7#include <linux/io.h>8#include <linux/iopoll.h>9#include <linux/err.h>10#include <linux/of.h>11#include <linux/of_address.h>12#include <linux/of_irq.h>13#include <linux/sched_clock.h>14 15#include <linux/clk/clk-conf.h>16 17#include <clocksource/timer-ti-dm.h>18#include <dt-bindings/bus/ti-sysc.h>19 20/* For type1, set SYSC_OMAP2_CLOCKACTIVITY for fck off on idle, l4 clock on */21#define DMTIMER_TYPE1_ENABLE	((1 << 9) | (SYSC_IDLE_SMART << 3) | \22				 SYSC_OMAP2_ENAWAKEUP | SYSC_OMAP2_AUTOIDLE)23#define DMTIMER_TYPE1_DISABLE	(SYSC_OMAP2_SOFTRESET | SYSC_OMAP2_AUTOIDLE)24#define DMTIMER_TYPE2_ENABLE	(SYSC_IDLE_SMART_WKUP << 2)25#define DMTIMER_RESET_WAIT	10000026 27#define DMTIMER_INST_DONT_CARE	~0U28 29static int counter_32k;30static u32 clocksource;31static u32 clockevent;32 33/*34 * Subset of the timer registers we use. Note that the register offsets35 * depend on the timer revision detected.36 */37struct dmtimer_systimer {38	void __iomem *base;39	u8 sysc;40	u8 irq_stat;41	u8 irq_ena;42	u8 pend;43	u8 load;44	u8 counter;45	u8 ctrl;46	u8 wakeup;47	u8 ifctrl;48	struct clk *fck;49	struct clk *ick;50	unsigned long rate;51};52 53struct dmtimer_clockevent {54	struct clock_event_device dev;55	struct dmtimer_systimer t;56	u32 period;57};58 59struct dmtimer_clocksource {60	struct clocksource dev;61	struct dmtimer_systimer t;62	unsigned int loadval;63};64 65/* Assumes v1 ip if bits [31:16] are zero */66static bool dmtimer_systimer_revision1(struct dmtimer_systimer *t)67{68	u32 tidr = readl_relaxed(t->base);69 70	return !(tidr >> 16);71}72 73static void dmtimer_systimer_enable(struct dmtimer_systimer *t)74{75	u32 val;76 77	if (dmtimer_systimer_revision1(t))78		val = DMTIMER_TYPE1_ENABLE;79	else80		val = DMTIMER_TYPE2_ENABLE;81 82	writel_relaxed(val, t->base + t->sysc);83}84 85static void dmtimer_systimer_disable(struct dmtimer_systimer *t)86{87	if (!dmtimer_systimer_revision1(t))88		return;89 90	writel_relaxed(DMTIMER_TYPE1_DISABLE, t->base + t->sysc);91}92 93static int __init dmtimer_systimer_type1_reset(struct dmtimer_systimer *t)94{95	void __iomem *syss = t->base + OMAP_TIMER_V1_SYS_STAT_OFFSET;96	int ret;97	u32 l;98 99	dmtimer_systimer_enable(t);100	writel_relaxed(BIT(1) | BIT(2), t->base + t->ifctrl);101	ret = readl_poll_timeout_atomic(syss, l, l & BIT(0), 100,102					DMTIMER_RESET_WAIT);103 104	return ret;105}106 107/* Note we must use io_base instead of func_base for type2 OCP regs */108static int __init dmtimer_systimer_type2_reset(struct dmtimer_systimer *t)109{110	void __iomem *sysc = t->base + t->sysc;111	u32 l;112 113	dmtimer_systimer_enable(t);114	l = readl_relaxed(sysc);115	l |= BIT(0);116	writel_relaxed(l, sysc);117 118	return readl_poll_timeout_atomic(sysc, l, !(l & BIT(0)), 100,119					 DMTIMER_RESET_WAIT);120}121 122static int __init dmtimer_systimer_reset(struct dmtimer_systimer *t)123{124	int ret;125 126	if (dmtimer_systimer_revision1(t))127		ret = dmtimer_systimer_type1_reset(t);128	else129		ret = dmtimer_systimer_type2_reset(t);130	if (ret < 0) {131		pr_err("%s failed with %i\n", __func__, ret);132 133		return ret;134	}135 136	return 0;137}138 139static const struct of_device_id counter_match_table[] = {140	{ .compatible = "ti,omap-counter32k" },141	{ /* Sentinel */ },142};143 144/*145 * Check if the SoC als has a usable working 32 KiHz counter. The 32 KiHz146 * counter is handled by timer-ti-32k, but we need to detect it as it147 * affects the preferred dmtimer system timer configuration. There is148 * typically no use for a dmtimer clocksource if the 32 KiHz counter is149 * present, except on am437x as described below.150 */151static void __init dmtimer_systimer_check_counter32k(void)152{153	struct device_node *np;154 155	if (counter_32k)156		return;157 158	np = of_find_matching_node(NULL, counter_match_table);159	if (!np) {160		counter_32k = -ENODEV;161 162		return;163	}164 165	if (of_device_is_available(np))166		counter_32k = 1;167	else168		counter_32k = -ENODEV;169 170	of_node_put(np);171}172 173static const struct of_device_id dmtimer_match_table[] = {174	{ .compatible = "ti,omap2420-timer", },175	{ .compatible = "ti,omap3430-timer", },176	{ .compatible = "ti,omap4430-timer", },177	{ .compatible = "ti,omap5430-timer", },178	{ .compatible = "ti,am335x-timer", },179	{ .compatible = "ti,am335x-timer-1ms", },180	{ .compatible = "ti,dm814-timer", },181	{ .compatible = "ti,dm816-timer", },182	{ /* Sentinel */ },183};184 185/*186 * Checks that system timers are configured to not reset and idle during187 * the generic timer-ti-dm device driver probe. And that the system timer188 * source clocks are properly configured. Also, let's not hog any DSP and189 * PWM capable timers unnecessarily as system timers.190 */191static bool __init dmtimer_is_preferred(struct device_node *np)192{193	if (!of_device_is_available(np))194		return false;195 196	if (!of_property_read_bool(np->parent,197				   "ti,no-reset-on-init"))198		return false;199 200	if (!of_property_read_bool(np->parent, "ti,no-idle"))201		return false;202 203	/* Secure gptimer12 is always clocked with a fixed source */204	if (!of_property_read_bool(np, "ti,timer-secure")) {205		if (!of_property_read_bool(np, "assigned-clocks"))206			return false;207 208		if (!of_property_read_bool(np, "assigned-clock-parents"))209			return false;210	}211 212	if (of_property_read_bool(np, "ti,timer-dsp"))213		return false;214 215	if (of_property_read_bool(np, "ti,timer-pwm"))216		return false;217 218	return true;219}220 221/*222 * Finds the first available usable always-on timer, and assigns it to either223 * clockevent or clocksource depending if the counter_32k is available on the224 * SoC or not.225 *226 * Some omap3 boards with unreliable oscillator must not use the counter_32k227 * or dmtimer1 with 32 KiHz source. Additionally, the boards with unreliable228 * oscillator should really set counter_32k as disabled, and delete dmtimer1229 * ti,always-on property, but let's not count on it. For these quirky cases,230 * we prefer using the always-on secure dmtimer12 with the internal 32 KiHz231 * clock as the clocksource, and any available dmtimer as clockevent.232 *233 * For am437x, we are using am335x style dmtimer clocksource. It is unclear234 * if this quirk handling is really needed, but let's change it separately235 * based on testing as it might cause side effects.236 */237static void __init dmtimer_systimer_assign_alwon(void)238{239	struct device_node *np;240	u32 pa = 0;241	bool quirk_unreliable_oscillator = false;242 243	/* Quirk unreliable 32 KiHz oscillator with incomplete dts */244	if (of_machine_is_compatible("ti,omap3-beagle-ab4")) {245		quirk_unreliable_oscillator = true;246		counter_32k = -ENODEV;247	}248 249	/* Quirk am437x using am335x style dmtimer clocksource */250	if (of_machine_is_compatible("ti,am43"))251		counter_32k = -ENODEV;252 253	for_each_matching_node(np, dmtimer_match_table) {254		struct resource res;255		if (!dmtimer_is_preferred(np))256			continue;257 258		if (!of_property_read_bool(np, "ti,timer-alwon"))259			continue;260 261		if (of_address_to_resource(np, 0, &res))262			continue;263 264		pa = res.start;265 266		/* Quirky omap3 boards must use dmtimer12 */267		if (quirk_unreliable_oscillator && pa == 0x48318000)268			continue;269 270		of_node_put(np);271		break;272	}273 274	/* Usually no need for dmtimer clocksource if we have counter32 */275	if (counter_32k >= 0) {276		clockevent = pa;277		clocksource = 0;278	} else {279		clocksource = pa;280		clockevent = DMTIMER_INST_DONT_CARE;281	}282}283 284/* Finds the first usable dmtimer, used for the don't care case */285static u32 __init dmtimer_systimer_find_first_available(void)286{287	struct device_node *np;288	u32 pa = 0;289 290	for_each_matching_node(np, dmtimer_match_table) {291		struct resource res;292		if (!dmtimer_is_preferred(np))293			continue;294 295		if (of_address_to_resource(np, 0, &res))296			continue;297 298		if (res.start == clocksource || res.start == clockevent)299			continue;300 301		pa = res.start;302		of_node_put(np);303		break;304	}305 306	return pa;307}308 309/* Selects the best clocksource and clockevent to use */310static void __init dmtimer_systimer_select_best(void)311{312	dmtimer_systimer_check_counter32k();313	dmtimer_systimer_assign_alwon();314 315	if (clockevent == DMTIMER_INST_DONT_CARE)316		clockevent = dmtimer_systimer_find_first_available();317 318	pr_debug("%s: counter_32k: %i clocksource: %08x clockevent: %08x\n",319		 __func__, counter_32k, clocksource, clockevent);320}321 322/* Interface clocks are only available on some SoCs variants */323static int __init dmtimer_systimer_init_clock(struct dmtimer_systimer *t,324					      struct device_node *np,325					      const char *name,326					      unsigned long *rate)327{328	struct clk *clock;329	unsigned long r;330	bool is_ick = false;331	int error;332 333	is_ick = !strncmp(name, "ick", 3);334 335	clock = of_clk_get_by_name(np, name);336	if ((PTR_ERR(clock) == -EINVAL) && is_ick)337		return 0;338	else if (IS_ERR(clock))339		return PTR_ERR(clock);340 341	error = clk_prepare_enable(clock);342	if (error)343		return error;344 345	r = clk_get_rate(clock);346	if (!r) {347		clk_disable_unprepare(clock);348		return -ENODEV;349	}350 351	if (is_ick)352		t->ick = clock;353	else354		t->fck = clock;355 356	*rate = r;357 358	return 0;359}360 361static int __init dmtimer_systimer_setup(struct device_node *np,362					 struct dmtimer_systimer *t)363{364	unsigned long rate;365	u8 regbase;366	int error;367 368	if (!of_device_is_compatible(np->parent, "ti,sysc"))369		return -EINVAL;370 371	t->base = of_iomap(np, 0);372	if (!t->base)373		return -ENXIO;374 375	/*376	 * Enable optional assigned-clock-parents configured at the timer377	 * node level. For regular device drivers, this is done automatically378	 * by bus related code such as platform_drv_probe().379	 */380	error = of_clk_set_defaults(np, false);381	if (error < 0)382		pr_err("%s: clock source init failed: %i\n", __func__, error);383 384	/* For ti-sysc, we have timer clocks at the parent module level */385	error = dmtimer_systimer_init_clock(t, np->parent, "fck", &rate);386	if (error)387		goto err_unmap;388 389	t->rate = rate;390 391	error = dmtimer_systimer_init_clock(t, np->parent, "ick", &rate);392	if (error)393		goto err_unmap;394 395	if (dmtimer_systimer_revision1(t)) {396		t->irq_stat = OMAP_TIMER_V1_STAT_OFFSET;397		t->irq_ena = OMAP_TIMER_V1_INT_EN_OFFSET;398		t->pend = _OMAP_TIMER_WRITE_PEND_OFFSET;399		regbase = 0;400	} else {401		t->irq_stat = OMAP_TIMER_V2_IRQSTATUS;402		t->irq_ena = OMAP_TIMER_V2_IRQENABLE_SET;403		regbase = OMAP_TIMER_V2_FUNC_OFFSET;404		t->pend = regbase + _OMAP_TIMER_WRITE_PEND_OFFSET;405	}406 407	t->sysc = OMAP_TIMER_OCP_CFG_OFFSET;408	t->load = regbase + _OMAP_TIMER_LOAD_OFFSET;409	t->counter = regbase + _OMAP_TIMER_COUNTER_OFFSET;410	t->ctrl = regbase + _OMAP_TIMER_CTRL_OFFSET;411	t->wakeup = regbase + _OMAP_TIMER_WAKEUP_EN_OFFSET;412	t->ifctrl = regbase + _OMAP_TIMER_IF_CTRL_OFFSET;413 414	dmtimer_systimer_reset(t);415	dmtimer_systimer_enable(t);416	pr_debug("dmtimer rev %08x sysc %08x\n", readl_relaxed(t->base),417		 readl_relaxed(t->base + t->sysc));418 419	return 0;420 421err_unmap:422	iounmap(t->base);423 424	return error;425}426 427/* Clockevent */428static struct dmtimer_clockevent *429to_dmtimer_clockevent(struct clock_event_device *clockevent)430{431	return container_of(clockevent, struct dmtimer_clockevent, dev);432}433 434static irqreturn_t dmtimer_clockevent_interrupt(int irq, void *data)435{436	struct dmtimer_clockevent *clkevt = data;437	struct dmtimer_systimer *t = &clkevt->t;438 439	writel_relaxed(OMAP_TIMER_INT_OVERFLOW, t->base + t->irq_stat);440	clkevt->dev.event_handler(&clkevt->dev);441 442	return IRQ_HANDLED;443}444 445static int dmtimer_set_next_event(unsigned long cycles,446				  struct clock_event_device *evt)447{448	struct dmtimer_clockevent *clkevt = to_dmtimer_clockevent(evt);449	struct dmtimer_systimer *t = &clkevt->t;450	void __iomem *pend = t->base + t->pend;451 452	while (readl_relaxed(pend) & WP_TCRR)453		cpu_relax();454	writel_relaxed(0xffffffff - cycles, t->base + t->counter);455 456	while (readl_relaxed(pend) & WP_TCLR)457		cpu_relax();458	writel_relaxed(OMAP_TIMER_CTRL_ST, t->base + t->ctrl);459 460	return 0;461}462 463static int dmtimer_clockevent_shutdown(struct clock_event_device *evt)464{465	struct dmtimer_clockevent *clkevt = to_dmtimer_clockevent(evt);466	struct dmtimer_systimer *t = &clkevt->t;467	void __iomem *ctrl = t->base + t->ctrl;468	u32 l;469 470	l = readl_relaxed(ctrl);471	if (l & OMAP_TIMER_CTRL_ST) {472		l &= ~BIT(0);473		writel_relaxed(l, ctrl);474		/* Flush posted write */475		l = readl_relaxed(ctrl);476		/*  Wait for functional clock period x 3.5 */477		udelay(3500000 / t->rate + 1);478	}479	writel_relaxed(OMAP_TIMER_INT_OVERFLOW, t->base + t->irq_stat);480 481	return 0;482}483 484static int dmtimer_set_periodic(struct clock_event_device *evt)485{486	struct dmtimer_clockevent *clkevt = to_dmtimer_clockevent(evt);487	struct dmtimer_systimer *t = &clkevt->t;488	void __iomem *pend = t->base + t->pend;489 490	dmtimer_clockevent_shutdown(evt);491 492	/* Looks like we need to first set the load value separately */493	while (readl_relaxed(pend) & WP_TLDR)494		cpu_relax();495	writel_relaxed(clkevt->period, t->base + t->load);496 497	while (readl_relaxed(pend) & WP_TCRR)498		cpu_relax();499	writel_relaxed(clkevt->period, t->base + t->counter);500 501	while (readl_relaxed(pend) & WP_TCLR)502		cpu_relax();503	writel_relaxed(OMAP_TIMER_CTRL_AR | OMAP_TIMER_CTRL_ST,504		       t->base + t->ctrl);505 506	return 0;507}508 509static void omap_clockevent_idle(struct clock_event_device *evt)510{511	struct dmtimer_clockevent *clkevt = to_dmtimer_clockevent(evt);512	struct dmtimer_systimer *t = &clkevt->t;513 514	dmtimer_systimer_disable(t);515	clk_disable(t->fck);516}517 518static void omap_clockevent_unidle(struct clock_event_device *evt)519{520	struct dmtimer_clockevent *clkevt = to_dmtimer_clockevent(evt);521	struct dmtimer_systimer *t = &clkevt->t;522	int error;523 524	error = clk_enable(t->fck);525	if (error)526		pr_err("could not enable timer fck on resume: %i\n", error);527 528	dmtimer_systimer_enable(t);529	writel_relaxed(OMAP_TIMER_INT_OVERFLOW, t->base + t->irq_ena);530	writel_relaxed(OMAP_TIMER_INT_OVERFLOW, t->base + t->wakeup);531}532 533static int __init dmtimer_clkevt_init_common(struct dmtimer_clockevent *clkevt,534					     struct device_node *np,535					     unsigned int features,536					     const struct cpumask *cpumask,537					     const char *name,538					     int rating)539{540	struct clock_event_device *dev;541	struct dmtimer_systimer *t;542	int error;543 544	t = &clkevt->t;545	dev = &clkevt->dev;546 547	/*548	 * We mostly use cpuidle_coupled with ARM local timers for runtime,549	 * so there's probably no use for CLOCK_EVT_FEAT_DYNIRQ here.550	 */551	dev->features = features;552	dev->rating = rating;553	dev->set_next_event = dmtimer_set_next_event;554	dev->set_state_shutdown = dmtimer_clockevent_shutdown;555	dev->set_state_periodic = dmtimer_set_periodic;556	dev->set_state_oneshot = dmtimer_clockevent_shutdown;557	dev->set_state_oneshot_stopped = dmtimer_clockevent_shutdown;558	dev->tick_resume = dmtimer_clockevent_shutdown;559	dev->cpumask = cpumask;560 561	dev->irq = irq_of_parse_and_map(np, 0);562	if (!dev->irq)563		return -ENXIO;564 565	error = dmtimer_systimer_setup(np, &clkevt->t);566	if (error)567		return error;568 569	clkevt->period = 0xffffffff - DIV_ROUND_CLOSEST(t->rate, HZ);570 571	/*572	 * For clock-event timers we never read the timer counter and573	 * so we are not impacted by errata i103 and i767. Therefore,574	 * we can safely ignore this errata for clock-event timers.575	 */576	writel_relaxed(OMAP_TIMER_CTRL_POSTED, t->base + t->ifctrl);577 578	error = request_irq(dev->irq, dmtimer_clockevent_interrupt,579			    IRQF_TIMER, name, clkevt);580	if (error)581		goto err_out_unmap;582 583	writel_relaxed(OMAP_TIMER_INT_OVERFLOW, t->base + t->irq_ena);584	writel_relaxed(OMAP_TIMER_INT_OVERFLOW, t->base + t->wakeup);585 586	pr_info("TI gptimer %s: %s%lu Hz at %pOF\n",587		name, of_property_read_bool(np, "ti,timer-alwon") ?588		"always-on " : "", t->rate, np->parent);589 590	return 0;591 592err_out_unmap:593	iounmap(t->base);594 595	return error;596}597 598static int __init dmtimer_clockevent_init(struct device_node *np)599{600	struct dmtimer_clockevent *clkevt;601	int error;602 603	clkevt = kzalloc(sizeof(*clkevt), GFP_KERNEL);604	if (!clkevt)605		return -ENOMEM;606 607	error = dmtimer_clkevt_init_common(clkevt, np,608					   CLOCK_EVT_FEAT_PERIODIC |609					   CLOCK_EVT_FEAT_ONESHOT,610					   cpu_possible_mask, "clockevent",611					   300);612	if (error)613		goto err_out_free;614 615	clockevents_config_and_register(&clkevt->dev, clkevt->t.rate,616					3, /* Timer internal resync latency */617					0xffffffff);618 619	if (of_machine_is_compatible("ti,am33xx") ||620	    of_machine_is_compatible("ti,am43")) {621		clkevt->dev.suspend = omap_clockevent_idle;622		clkevt->dev.resume = omap_clockevent_unidle;623	}624 625	return 0;626 627err_out_free:628	kfree(clkevt);629 630	return error;631}632 633/* Dmtimer as percpu timer. See dra7 ARM architected timer wrap erratum i940 */634static DEFINE_PER_CPU(struct dmtimer_clockevent, dmtimer_percpu_timer);635 636static int __init dmtimer_percpu_timer_init(struct device_node *np, int cpu)637{638	struct dmtimer_clockevent *clkevt;639	int error;640 641	if (!cpu_possible(cpu))642		return -EINVAL;643 644	if (!of_property_read_bool(np->parent, "ti,no-reset-on-init") ||645	    !of_property_read_bool(np->parent, "ti,no-idle"))646		pr_warn("Incomplete dtb for percpu dmtimer %pOF\n", np->parent);647 648	clkevt = per_cpu_ptr(&dmtimer_percpu_timer, cpu);649 650	error = dmtimer_clkevt_init_common(clkevt, np, CLOCK_EVT_FEAT_ONESHOT,651					   cpumask_of(cpu), "percpu-dmtimer",652					   500);653	if (error)654		return error;655 656	return 0;657}658 659/* See TRM for timer internal resynch latency */660static int omap_dmtimer_starting_cpu(unsigned int cpu)661{662	struct dmtimer_clockevent *clkevt = per_cpu_ptr(&dmtimer_percpu_timer, cpu);663	struct clock_event_device *dev = &clkevt->dev;664	struct dmtimer_systimer *t = &clkevt->t;665 666	clockevents_config_and_register(dev, t->rate, 3, ULONG_MAX);667	irq_force_affinity(dev->irq, cpumask_of(cpu));668 669	return 0;670}671 672static int __init dmtimer_percpu_timer_startup(void)673{674	struct dmtimer_clockevent *clkevt = per_cpu_ptr(&dmtimer_percpu_timer, 0);675	struct dmtimer_systimer *t = &clkevt->t;676 677	if (t->sysc) {678		cpuhp_setup_state(CPUHP_AP_TI_GP_TIMER_STARTING,679				  "clockevents/omap/gptimer:starting",680				  omap_dmtimer_starting_cpu, NULL);681	}682 683	return 0;684}685subsys_initcall(dmtimer_percpu_timer_startup);686 687static int __init dmtimer_percpu_quirk_init(struct device_node *np, u32 pa)688{689	struct device_node *arm_timer;690 691	arm_timer = of_find_compatible_node(NULL, NULL, "arm,armv7-timer");692	if (of_device_is_available(arm_timer)) {693		pr_warn_once("ARM architected timer wrap issue i940 detected\n");694		return 0;695	}696 697	if (pa == 0x4882c000)           /* dra7 dmtimer15 */698		return dmtimer_percpu_timer_init(np, 0);699	else if (pa == 0x4882e000)      /* dra7 dmtimer16 */700		return dmtimer_percpu_timer_init(np, 1);701 702	return 0;703}704 705/* Clocksource */706static struct dmtimer_clocksource *707to_dmtimer_clocksource(struct clocksource *cs)708{709	return container_of(cs, struct dmtimer_clocksource, dev);710}711 712static u64 dmtimer_clocksource_read_cycles(struct clocksource *cs)713{714	struct dmtimer_clocksource *clksrc = to_dmtimer_clocksource(cs);715	struct dmtimer_systimer *t = &clksrc->t;716 717	return (u64)readl_relaxed(t->base + t->counter);718}719 720static void __iomem *dmtimer_sched_clock_counter;721 722static u64 notrace dmtimer_read_sched_clock(void)723{724	return readl_relaxed(dmtimer_sched_clock_counter);725}726 727static void dmtimer_clocksource_suspend(struct clocksource *cs)728{729	struct dmtimer_clocksource *clksrc = to_dmtimer_clocksource(cs);730	struct dmtimer_systimer *t = &clksrc->t;731 732	clksrc->loadval = readl_relaxed(t->base + t->counter);733	dmtimer_systimer_disable(t);734	clk_disable(t->fck);735}736 737static void dmtimer_clocksource_resume(struct clocksource *cs)738{739	struct dmtimer_clocksource *clksrc = to_dmtimer_clocksource(cs);740	struct dmtimer_systimer *t = &clksrc->t;741	int error;742 743	error = clk_enable(t->fck);744	if (error)745		pr_err("could not enable timer fck on resume: %i\n", error);746 747	dmtimer_systimer_enable(t);748	writel_relaxed(clksrc->loadval, t->base + t->counter);749	writel_relaxed(OMAP_TIMER_CTRL_ST | OMAP_TIMER_CTRL_AR,750		       t->base + t->ctrl);751}752 753static int __init dmtimer_clocksource_init(struct device_node *np)754{755	struct dmtimer_clocksource *clksrc;756	struct dmtimer_systimer *t;757	struct clocksource *dev;758	int error;759 760	clksrc = kzalloc(sizeof(*clksrc), GFP_KERNEL);761	if (!clksrc)762		return -ENOMEM;763 764	dev = &clksrc->dev;765	t = &clksrc->t;766 767	error = dmtimer_systimer_setup(np, t);768	if (error)769		goto err_out_free;770 771	dev->name = "dmtimer";772	dev->rating = 300;773	dev->read = dmtimer_clocksource_read_cycles;774	dev->mask = CLOCKSOURCE_MASK(32);775	dev->flags = CLOCK_SOURCE_IS_CONTINUOUS;776 777	/* Unlike for clockevent, legacy code sets suspend only for am4 */778	if (of_machine_is_compatible("ti,am43")) {779		dev->suspend = dmtimer_clocksource_suspend;780		dev->resume = dmtimer_clocksource_resume;781	}782 783	writel_relaxed(0, t->base + t->counter);784	writel_relaxed(OMAP_TIMER_CTRL_ST | OMAP_TIMER_CTRL_AR,785		       t->base + t->ctrl);786 787	pr_info("TI gptimer clocksource: %s%pOF\n",788		of_property_read_bool(np, "ti,timer-alwon") ?789		"always-on " : "", np->parent);790 791	if (!dmtimer_sched_clock_counter) {792		dmtimer_sched_clock_counter = t->base + t->counter;793		sched_clock_register(dmtimer_read_sched_clock, 32, t->rate);794	}795 796	if (clocksource_register_hz(dev, t->rate))797		pr_err("Could not register clocksource %pOF\n", np);798 799	return 0;800 801err_out_free:802	kfree(clksrc);803 804	return -ENODEV;805}806 807/*808 * To detect between a clocksource and clockevent, we assume the device tree809 * has no interrupts configured for a clocksource timer.810 */811static int __init dmtimer_systimer_init(struct device_node *np)812{813	struct resource res;814	u32 pa;815 816	/* One time init for the preferred timer configuration */817	if (!clocksource && !clockevent)818		dmtimer_systimer_select_best();819 820	if (!clocksource && !clockevent) {821		pr_err("%s: unable to detect system timers, update dtb?\n",822		       __func__);823 824		return -EINVAL;825	}826 827 828	of_address_to_resource(np, 0, &res);829	pa = (u32)res.start;830	if (!pa)831		return -EINVAL;832 833	if (counter_32k <= 0 && clocksource == pa)834		return dmtimer_clocksource_init(np);835 836	if (clockevent == pa)837		return dmtimer_clockevent_init(np);838 839	if (of_machine_is_compatible("ti,dra7"))840		return dmtimer_percpu_quirk_init(np, pa);841 842	return 0;843}844 845TIMER_OF_DECLARE(systimer_omap2, "ti,omap2420-timer", dmtimer_systimer_init);846TIMER_OF_DECLARE(systimer_omap3, "ti,omap3430-timer", dmtimer_systimer_init);847TIMER_OF_DECLARE(systimer_omap4, "ti,omap4430-timer", dmtimer_systimer_init);848TIMER_OF_DECLARE(systimer_omap5, "ti,omap5430-timer", dmtimer_systimer_init);849TIMER_OF_DECLARE(systimer_am33x, "ti,am335x-timer", dmtimer_systimer_init);850TIMER_OF_DECLARE(systimer_am3ms, "ti,am335x-timer-1ms", dmtimer_systimer_init);851TIMER_OF_DECLARE(systimer_dm814, "ti,dm814-timer", dmtimer_systimer_init);852TIMER_OF_DECLARE(systimer_dm816, "ti,dm816-timer", dmtimer_systimer_init);853