drivers/soc/brcmstb/wktmr.c - kernel/lockdown - Git at Google

 /*
  * Copyright © 2014-2015 Broadcom Corporation
  *
  * 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.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  * GNU General Public License for more details.
  */

 #define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt

 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/stat.h>
 #include <linux/device.h>
 #include <linux/platform_device.h>
 #include <linux/suspend.h>
 #include <linux/err.h>
 #include <linux/of.h>
 #include <linux/pm.h>
 #include <linux/io.h>
 #include <linux/interrupt.h>
 #include <linux/irqreturn.h>
 #include <linux/pm_wakeup.h>
 #include <linux/reboot.h>
 #include <linux/rtc.h>

 #include <asm/mach/time.h>

 #define DRV_NAME	"brcm-waketimer"

 static struct brcmstb_waketmr {
 	struct rtc_device *rtc;
 	struct device *dev;
 	void __iomem *base;
 	unsigned int irq;
 	int wake_timeout;
 	struct notifier_block reboot_notifier;
 	bool alarm_is_active;
 } wktimer;

 /* No timeout */
 #define BRCMSTB_WKTMR_DEFAULT_TIMEOUT	(-1)

 #define BRCMSTB_WKTMR_EVENT		0x00
 #define BRCMSTB_WKTMR_COUNTER		0x04
 #define BRCMSTB_WKTMR_ALARM		0x08
 #define BRCMSTB_WKTMR_PRESCALER		0x0C
 #define BRCMSTB_WKTMR_PRESCALER_VAL	0x10

 static inline void brcmstb_waketmr_clear_alarm(struct brcmstb_waketmr *timer)
 {
 	writel_relaxed(1, timer->base + BRCMSTB_WKTMR_EVENT);
 	(void)readl_relaxed(timer->base + BRCMSTB_WKTMR_EVENT);
 	timer->alarm_is_active = false;
 }

 static void brcmstb_waketmr_set_alarm(struct brcmstb_waketmr *timer,
 		unsigned int secs, bool sysfs)
 {
 	unsigned int t = 0;

 	brcmstb_waketmr_clear_alarm(timer);

 	if (sysfs)
 		t = readl_relaxed(timer->base + BRCMSTB_WKTMR_COUNTER);
 	writel_relaxed(t + secs + 1, timer->base + BRCMSTB_WKTMR_ALARM);
 	timer->alarm_is_active = true;
 }

 static irqreturn_t brcmstb_waketmr_irq(int irq, void *data)
 {
 	struct brcmstb_waketmr *timer = data;
 	pm_wakeup_event(timer->dev, 0);
 	timer->alarm_is_active = false;
 	return IRQ_HANDLED;
 }

 /* Fixed 27Mhz frequency since WKTMR is in the UPG clock domain. This
  * information should come from Device Tree eventually
  */
 #define WKTMR_FREQ		27000000

 struct wktmr_time {
 	u32			sec;
 	u32			pre;
 };

 static void wktmr_read(struct wktmr_time *t)
 {
 	u32 tmp;

 	do {
 		t->sec = readl_relaxed(wktimer.base + BRCMSTB_WKTMR_COUNTER);
 		tmp = readl_relaxed(wktimer.base + BRCMSTB_WKTMR_PRESCALER_VAL);
 	} while (tmp >= WKTMR_FREQ);

 	t->pre = WKTMR_FREQ - tmp;
 }

 static void brcmstb_waketmr_read_persistent_clock(struct timespec64 *ts)
 {
 	struct wktmr_time now;

 	wktmr_read(&now);

 	ts->tv_sec = now.sec;
 	ts->tv_nsec = now.pre * (NSEC_PER_SEC / WKTMR_FREQ);
 }

 static ssize_t brcmstb_waketmr_timeout_show(struct device *dev,
 		struct device_attribute *attr, char *buf)
 {
 	struct brcmstb_waketmr *timer = dev_get_drvdata(dev);

 	return snprintf(buf, PAGE_SIZE, "%d\n", timer->wake_timeout);
 }

 static ssize_t brcmstb_waketmr_timeout_store(struct device *dev,
 		struct device_attribute *attr, const char *buf, size_t count)
 {
 	struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
 	int timeout;
 	int ret;

 #ifdef CONFIG_RTC_CLASS
 	dev_warn(dev, "Using sysfs attributes, consider using 'rtcwake'\n");
 #endif
 	ret = kstrtoint(buf, 0, &timeout);
 	if (ret < 0)
 		return ret;

 	/* Allow -1 as "no timeout" */
 	if (timeout < -1)
 		return -EINVAL;

 	timer->wake_timeout = timeout;

 	return count;
 }

 static const DEVICE_ATTR(timeout, S_IRUGO | S_IWUSR,
 		brcmstb_waketmr_timeout_show,
 		brcmstb_waketmr_timeout_store);

 static int brcmstb_waketmr_prepare_suspend(struct brcmstb_waketmr *timer)
 {
 	struct device *dev = timer->dev;
 	int ret;

 	if (device_may_wakeup(dev) && timer->wake_timeout >= 0) {
 		dev_dbg(dev, "enable wake IRQ\n");
 		ret = enable_irq_wake(timer->irq);
 		if (ret) {
 			dev_err(dev, "failed to enable wake-up interrupt\n");
 			return ret;
 		}

 		/*
 		 * Using the ioctl() interface, the alarm timer will have
 		 * already been enabled in brcmstb_waketmr_setalarm().
 		 * However, using the sysfs interface, we have to enable it
 		 * here, because brcmstb_waketmr_setalarm() isn't called.
 		 */
 		if (!timer->alarm_is_active)
 			brcmstb_waketmr_set_alarm(timer, timer->wake_timeout,
 						  true);
 	} else {
 		dev_dbg(dev, "nothing to do: wake_timeout: %d\n",
 				timer->wake_timeout);
 	}
 	return 0;
 }

 /* If enabled as a wakeup-source, arm the timer when powering off */
 static int brcmstb_waketmr_reboot(struct notifier_block *nb,
 		unsigned long action, void *data)
 {
 	struct brcmstb_waketmr *timer;
 	timer = container_of(nb, struct brcmstb_waketmr, reboot_notifier);

 	/* Set timer for cold boot */
 	if (action == SYS_POWER_OFF)
 		brcmstb_waketmr_prepare_suspend(timer);

 	return NOTIFY_DONE;
 }

 #ifdef CONFIG_RTC_CLASS
 static int brcmstb_waketmr_gettime(struct device *dev,
 				   struct rtc_time *tm)
 {
 	struct wktmr_time now;

 	wktmr_read(&now);

 	rtc_time_to_tm(now.sec, tm);

 	return 0;
 }

 static int brcmstb_waketmr_settime(struct device *dev,
 				   struct rtc_time *tm)
 {
 	struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
 	unsigned long sec;
 	int ret;

 	ret = rtc_valid_tm(tm);
 	if (ret)
 		return ret;

 	rtc_tm_to_time(tm, &sec);

 	dev_dbg(dev, "%s: sec=%ld\n", __FUNCTION__, sec);
 	writel_relaxed(sec, timer->base + BRCMSTB_WKTMR_COUNTER);

 	return 0;
 }

 static int brcmstb_waketmr_getalarm(struct device *dev,
 				    struct rtc_wkalrm *alarm)
 {
 	struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
 	unsigned long sec;
 	u32 reg;

 	sec = readl_relaxed(timer->base + BRCMSTB_WKTMR_ALARM);
 	if (sec == 0) {
 		/* Alarm is disabled */
 		alarm->enabled = 0;
 		alarm->time.tm_mon = -1;
 		alarm->time.tm_mday = -1;
 		alarm->time.tm_year = -1;
 		alarm->time.tm_hour = -1;
 		alarm->time.tm_min = -1;
 		alarm->time.tm_sec = -1;
 		dev_dbg(dev, "%s: alarm is disabled\n", __FUNCTION__);
 	} else {
 		/* Alarm is enabled */
 		alarm->enabled = 1;
 		rtc_time_to_tm(sec, &alarm->time);
 		dev_dbg(dev, "%s: alarm is enabled\n", __FUNCTION__);
 	}

 	reg = readl_relaxed(timer->base + BRCMSTB_WKTMR_EVENT);
 	alarm->pending = !!(reg & 1);
 	dev_dbg(dev, "%s: alarm pending=%d\n", __FUNCTION__, alarm->pending);

 	return 0;
 }

 static int brcmstb_waketmr_setalarm(struct device *dev,
 				     struct rtc_wkalrm *alarm)
 {
 	struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
 	unsigned long sec;

 	if (alarm->enabled)
 		rtc_tm_to_time(&alarm->time, &sec);
 	else
 		sec = 0;

 	timer->wake_timeout = sec;
 	dev_dbg(dev, "%s: timeout=%ld\n", __FUNCTION__, sec);
 	brcmstb_waketmr_set_alarm(timer, sec, false);

 	return 0;
 }

 /*
  * Does not do much but keep the RTC class happy. We always support
  * alarms.
  */
 static int brcmstb_waketmr_alarm_enable(struct device *dev,
 					unsigned int enabled)
 {
 	dev_dbg(dev, "%s: enabled=%d\n", __FUNCTION__, enabled);
 	return 0;
 }

 static const struct rtc_class_ops brcmstb_waketmr_ops = {
 	.read_time	= brcmstb_waketmr_gettime,
 	.set_time	= brcmstb_waketmr_settime,
 	.read_alarm	= brcmstb_waketmr_getalarm,
 	.set_alarm	= brcmstb_waketmr_setalarm,
 	.alarm_irq_enable = brcmstb_waketmr_alarm_enable,
 };
 #endif /* CONFIG_RTC_CLASS */

 static int __init brcmstb_waketmr_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct brcmstb_waketmr *timer = &wktimer;
 	struct resource *res;
 	int ret;

 	platform_set_drvdata(pdev, timer);

 	if (timer->dev)
 		return -EBUSY;

 	timer->dev = dev;

 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	timer->base = devm_ioremap_resource(dev, res);
 	if (IS_ERR(timer->base))
 		return PTR_ERR(timer->base);

 	/*
 	 * Set wakeup capability before requesting wakeup interrupt, so we can
 	 * process boot-time "wakeups" (e.g., from S5 soft-off)
 	 */
 	device_set_wakeup_capable(dev, true);
 	device_wakeup_enable(dev);

 	timer->irq = platform_get_irq(pdev, 0);
 	if ((int)timer->irq < 0)
 		return -ENODEV;

 	ret = devm_request_irq(dev, timer->irq, brcmstb_waketmr_irq, 0,
 			       DRV_NAME, timer);
 	if (ret < 0)
 		return ret;

 	timer->reboot_notifier.notifier_call = brcmstb_waketmr_reboot;
 	register_reboot_notifier(&timer->reboot_notifier);

 	timer->wake_timeout = BRCMSTB_WKTMR_DEFAULT_TIMEOUT;
 #ifdef CONFIG_RTC_CLASS
 	timer->rtc = rtc_device_register("brcmstb-waketmr", dev,
 					 &brcmstb_waketmr_ops, THIS_MODULE);
 	if (IS_ERR(timer->rtc)) {
 		dev_err(dev, "unable to register device\n");
 		return PTR_ERR(timer->rtc);
 	}
 #endif

 	ret = device_create_file(dev, &dev_attr_timeout);
 	if (ret) {
 		unregister_reboot_notifier(&timer->reboot_notifier);
 		return ret;
 	}

 	register_persistent_clock(NULL, brcmstb_waketmr_read_persistent_clock);

 	dev_info(dev, "registered, with irq %d\n", timer->irq);
 	return ret;
 }

 static int brcmstb_waketmr_remove(struct platform_device *pdev)
 {
 	struct brcmstb_waketmr *timer = dev_get_drvdata(&pdev->dev);

 	device_remove_file(&pdev->dev, &dev_attr_timeout);
 	unregister_reboot_notifier(&timer->reboot_notifier);
 #ifdef CONFIG_RTC_CLASS
 	rtc_device_unregister(timer->rtc);
 #endif

 	return 0;
 }

 #ifdef CONFIG_PM_SLEEP
 static int brcmstb_waketmr_suspend(struct device *dev)
 {
 	struct brcmstb_waketmr *timer = dev_get_drvdata(dev);

 	return brcmstb_waketmr_prepare_suspend(timer);
 }

 static int brcmstb_waketmr_resume(struct device *dev)
 {
 	struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
 	int ret;

 	if (!device_may_wakeup(dev) || timer->wake_timeout < 0)
 		return 0;

 	ret = disable_irq_wake(timer->irq);

 	brcmstb_waketmr_clear_alarm(timer);

 	return ret;
 }
 #endif /* CONFIG_PM_SLEEP */

 static SIMPLE_DEV_PM_OPS(brcmstb_waketmr_pm_ops, brcmstb_waketmr_suspend,
 		brcmstb_waketmr_resume);

 static const struct of_device_id brcmstb_waketmr_of_match[] = {
 	{ .compatible = "brcm,brcmstb-waketimer" },
 	{},
 };

 static struct platform_driver brcmstb_waketmr_driver = {
 	.remove			= brcmstb_waketmr_remove,
 	.driver = {
 		.name		= DRV_NAME,
 		.pm		= &brcmstb_waketmr_pm_ops,
 		.of_match_table	= of_match_ptr(brcmstb_waketmr_of_match),
 	}
 };

 static int __init brcmstb_waketmr_init(void)
 {
 	return platform_driver_probe(&brcmstb_waketmr_driver,
 				     brcmstb_waketmr_probe);
 }

 static void __exit brcmstb_waketmr_exit(void)
 {
 	platform_driver_unregister(&brcmstb_waketmr_driver);
 }

 module_init(brcmstb_waketmr_init);
 module_exit(brcmstb_waketmr_exit);

 MODULE_LICENSE("GPL v2");
 MODULE_AUTHOR("Brian Norris");
 MODULE_DESCRIPTION("Wake-up timer driver for STB chips");
	/*
	* Copyright © 2014-2015 Broadcom Corporation
	*
	* 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.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*/

	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/init.h>
	#include <linux/stat.h>
	#include <linux/device.h>
	#include <linux/platform_device.h>
	#include <linux/suspend.h>
	#include <linux/err.h>
	#include <linux/of.h>
	#include <linux/pm.h>
	#include <linux/io.h>
	#include <linux/interrupt.h>
	#include <linux/irqreturn.h>
	#include <linux/pm_wakeup.h>
	#include <linux/reboot.h>
	#include <linux/rtc.h>

	#include <asm/mach/time.h>

	#define DRV_NAME "brcm-waketimer"

	static struct brcmstb_waketmr {
	struct rtc_device *rtc;
	struct device *dev;
	void __iomem *base;
	unsigned int irq;
	int wake_timeout;
	struct notifier_block reboot_notifier;
	bool alarm_is_active;
	} wktimer;

	/* No timeout */
	#define BRCMSTB_WKTMR_DEFAULT_TIMEOUT (-1)

	#define BRCMSTB_WKTMR_EVENT 0x00
	#define BRCMSTB_WKTMR_COUNTER 0x04
	#define BRCMSTB_WKTMR_ALARM 0x08
	#define BRCMSTB_WKTMR_PRESCALER 0x0C
	#define BRCMSTB_WKTMR_PRESCALER_VAL 0x10

	static inline void brcmstb_waketmr_clear_alarm(struct brcmstb_waketmr *timer)
	{
	writel_relaxed(1, timer->base + BRCMSTB_WKTMR_EVENT);
	(void)readl_relaxed(timer->base + BRCMSTB_WKTMR_EVENT);
	timer->alarm_is_active = false;
	}

	static void brcmstb_waketmr_set_alarm(struct brcmstb_waketmr *timer,
	unsigned int secs, bool sysfs)
	{
	unsigned int t = 0;

	brcmstb_waketmr_clear_alarm(timer);

	if (sysfs)
	t = readl_relaxed(timer->base + BRCMSTB_WKTMR_COUNTER);
	writel_relaxed(t + secs + 1, timer->base + BRCMSTB_WKTMR_ALARM);
	timer->alarm_is_active = true;
	}

	static irqreturn_t brcmstb_waketmr_irq(int irq, void *data)
	{
	struct brcmstb_waketmr *timer = data;
	pm_wakeup_event(timer->dev, 0);
	timer->alarm_is_active = false;
	return IRQ_HANDLED;
	}

	/* Fixed 27Mhz frequency since WKTMR is in the UPG clock domain. This
	* information should come from Device Tree eventually
	*/
	#define WKTMR_FREQ 27000000

	struct wktmr_time {
	u32 sec;
	u32 pre;
	};

	static void wktmr_read(struct wktmr_time *t)
	{
	u32 tmp;

	do {
	t->sec = readl_relaxed(wktimer.base + BRCMSTB_WKTMR_COUNTER);
	tmp = readl_relaxed(wktimer.base + BRCMSTB_WKTMR_PRESCALER_VAL);
	} while (tmp >= WKTMR_FREQ);

	t->pre = WKTMR_FREQ - tmp;
	}

	static void brcmstb_waketmr_read_persistent_clock(struct timespec64 *ts)
	{
	struct wktmr_time now;

	wktmr_read(&now);

	ts->tv_sec = now.sec;
	ts->tv_nsec = now.pre * (NSEC_PER_SEC / WKTMR_FREQ);
	}

	static ssize_t brcmstb_waketmr_timeout_show(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct brcmstb_waketmr *timer = dev_get_drvdata(dev);

	return snprintf(buf, PAGE_SIZE, "%d\n", timer->wake_timeout);
	}

	static ssize_t brcmstb_waketmr_timeout_store(struct device *dev,
	struct device_attribute attr, const char buf, size_t count)
	{
	struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
	int timeout;
	int ret;

	#ifdef CONFIG_RTC_CLASS
	dev_warn(dev, "Using sysfs attributes, consider using 'rtcwake'\n");
	#endif
	ret = kstrtoint(buf, 0, &timeout);
	if (ret < 0)
	return ret;

	/* Allow -1 as "no timeout" */
	if (timeout < -1)
	return -EINVAL;

	timer->wake_timeout = timeout;

	return count;
	}

	static const DEVICE_ATTR(timeout, S_IRUGO \| S_IWUSR,
	brcmstb_waketmr_timeout_show,
	brcmstb_waketmr_timeout_store);

	static int brcmstb_waketmr_prepare_suspend(struct brcmstb_waketmr *timer)
	{
	struct device *dev = timer->dev;
	int ret;

	if (device_may_wakeup(dev) && timer->wake_timeout >= 0) {
	dev_dbg(dev, "enable wake IRQ\n");
	ret = enable_irq_wake(timer->irq);
	if (ret) {
	dev_err(dev, "failed to enable wake-up interrupt\n");
	return ret;
	}

	/*
	* Using the ioctl() interface, the alarm timer will have
	* already been enabled in brcmstb_waketmr_setalarm().
	* However, using the sysfs interface, we have to enable it
	* here, because brcmstb_waketmr_setalarm() isn't called.
	*/
	if (!timer->alarm_is_active)
	brcmstb_waketmr_set_alarm(timer, timer->wake_timeout,
	true);
	} else {
	dev_dbg(dev, "nothing to do: wake_timeout: %d\n",
	timer->wake_timeout);
	}
	return 0;
	}

	/* If enabled as a wakeup-source, arm the timer when powering off */
	static int brcmstb_waketmr_reboot(struct notifier_block *nb,
	unsigned long action, void *data)
	{
	struct brcmstb_waketmr *timer;
	timer = container_of(nb, struct brcmstb_waketmr, reboot_notifier);

	/* Set timer for cold boot */
	if (action == SYS_POWER_OFF)
	brcmstb_waketmr_prepare_suspend(timer);

	return NOTIFY_DONE;
	}

	#ifdef CONFIG_RTC_CLASS
	static int brcmstb_waketmr_gettime(struct device *dev,
	struct rtc_time *tm)
	{
	struct wktmr_time now;

	wktmr_read(&now);

	rtc_time_to_tm(now.sec, tm);

	return 0;
	}

	static int brcmstb_waketmr_settime(struct device *dev,
	struct rtc_time *tm)
	{
	struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
	unsigned long sec;
	int ret;

	ret = rtc_valid_tm(tm);
	if (ret)
	return ret;

	rtc_tm_to_time(tm, &sec);

	dev_dbg(dev, "%s: sec=%ld\n", __FUNCTION__, sec);
	writel_relaxed(sec, timer->base + BRCMSTB_WKTMR_COUNTER);

	return 0;
	}

	static int brcmstb_waketmr_getalarm(struct device *dev,
	struct rtc_wkalrm *alarm)
	{
	struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
	unsigned long sec;
	u32 reg;

	sec = readl_relaxed(timer->base + BRCMSTB_WKTMR_ALARM);
	if (sec == 0) {
	/* Alarm is disabled */
	alarm->enabled = 0;
	alarm->time.tm_mon = -1;
	alarm->time.tm_mday = -1;
	alarm->time.tm_year = -1;
	alarm->time.tm_hour = -1;
	alarm->time.tm_min = -1;
	alarm->time.tm_sec = -1;
	dev_dbg(dev, "%s: alarm is disabled\n", __FUNCTION__);
	} else {
	/* Alarm is enabled */
	alarm->enabled = 1;
	rtc_time_to_tm(sec, &alarm->time);
	dev_dbg(dev, "%s: alarm is enabled\n", __FUNCTION__);
	}

	reg = readl_relaxed(timer->base + BRCMSTB_WKTMR_EVENT);
	alarm->pending = !!(reg & 1);
	dev_dbg(dev, "%s: alarm pending=%d\n", __FUNCTION__, alarm->pending);

	return 0;
	}

	static int brcmstb_waketmr_setalarm(struct device *dev,
	struct rtc_wkalrm *alarm)
	{
	struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
	unsigned long sec;

	if (alarm->enabled)
	rtc_tm_to_time(&alarm->time, &sec);
	else
	sec = 0;

	timer->wake_timeout = sec;
	dev_dbg(dev, "%s: timeout=%ld\n", __FUNCTION__, sec);
	brcmstb_waketmr_set_alarm(timer, sec, false);

	return 0;
	}

	/*
	* Does not do much but keep the RTC class happy. We always support
	* alarms.
	*/
	static int brcmstb_waketmr_alarm_enable(struct device *dev,
	unsigned int enabled)
	{
	dev_dbg(dev, "%s: enabled=%d\n", __FUNCTION__, enabled);
	return 0;
	}

	static const struct rtc_class_ops brcmstb_waketmr_ops = {
	.read_time = brcmstb_waketmr_gettime,
	.set_time = brcmstb_waketmr_settime,
	.read_alarm = brcmstb_waketmr_getalarm,
	.set_alarm = brcmstb_waketmr_setalarm,
	.alarm_irq_enable = brcmstb_waketmr_alarm_enable,
	};
	#endif /* CONFIG_RTC_CLASS */

	static int __init brcmstb_waketmr_probe(struct platform_device *pdev)
	{
	struct device *dev = &pdev->dev;
	struct brcmstb_waketmr *timer = &wktimer;
	struct resource *res;
	int ret;

	platform_set_drvdata(pdev, timer);

	if (timer->dev)
	return -EBUSY;

	timer->dev = dev;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	timer->base = devm_ioremap_resource(dev, res);
	if (IS_ERR(timer->base))
	return PTR_ERR(timer->base);

	/*
	* Set wakeup capability before requesting wakeup interrupt, so we can
	* process boot-time "wakeups" (e.g., from S5 soft-off)
	*/
	device_set_wakeup_capable(dev, true);
	device_wakeup_enable(dev);

	timer->irq = platform_get_irq(pdev, 0);
	if ((int)timer->irq < 0)
	return -ENODEV;

	ret = devm_request_irq(dev, timer->irq, brcmstb_waketmr_irq, 0,
	DRV_NAME, timer);
	if (ret < 0)
	return ret;

	timer->reboot_notifier.notifier_call = brcmstb_waketmr_reboot;
	register_reboot_notifier(&timer->reboot_notifier);

	timer->wake_timeout = BRCMSTB_WKTMR_DEFAULT_TIMEOUT;
	#ifdef CONFIG_RTC_CLASS
	timer->rtc = rtc_device_register("brcmstb-waketmr", dev,
	&brcmstb_waketmr_ops, THIS_MODULE);
	if (IS_ERR(timer->rtc)) {
	dev_err(dev, "unable to register device\n");
	return PTR_ERR(timer->rtc);
	}
	#endif

	ret = device_create_file(dev, &dev_attr_timeout);
	if (ret) {
	unregister_reboot_notifier(&timer->reboot_notifier);
	return ret;
	}

	register_persistent_clock(NULL, brcmstb_waketmr_read_persistent_clock);

	dev_info(dev, "registered, with irq %d\n", timer->irq);
	return ret;
	}

	static int brcmstb_waketmr_remove(struct platform_device *pdev)
	{
	struct brcmstb_waketmr *timer = dev_get_drvdata(&pdev->dev);

	device_remove_file(&pdev->dev, &dev_attr_timeout);
	unregister_reboot_notifier(&timer->reboot_notifier);
	#ifdef CONFIG_RTC_CLASS
	rtc_device_unregister(timer->rtc);
	#endif

	return 0;
	}

	#ifdef CONFIG_PM_SLEEP
	static int brcmstb_waketmr_suspend(struct device *dev)
	{
	struct brcmstb_waketmr *timer = dev_get_drvdata(dev);

	return brcmstb_waketmr_prepare_suspend(timer);
	}

	static int brcmstb_waketmr_resume(struct device *dev)
	{
	struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
	int ret;

	if (!device_may_wakeup(dev) \|\| timer->wake_timeout < 0)
	return 0;

	ret = disable_irq_wake(timer->irq);

	brcmstb_waketmr_clear_alarm(timer);

	return ret;
	}
	#endif /* CONFIG_PM_SLEEP */

	static SIMPLE_DEV_PM_OPS(brcmstb_waketmr_pm_ops, brcmstb_waketmr_suspend,
	brcmstb_waketmr_resume);

	static const struct of_device_id brcmstb_waketmr_of_match[] = {
	{ .compatible = "brcm,brcmstb-waketimer" },
	{},
	};

	static struct platform_driver brcmstb_waketmr_driver = {
	.remove = brcmstb_waketmr_remove,
	.driver = {
	.name = DRV_NAME,
	.pm = &brcmstb_waketmr_pm_ops,
	.of_match_table = of_match_ptr(brcmstb_waketmr_of_match),
	}
	};

	static int __init brcmstb_waketmr_init(void)
	{
	return platform_driver_probe(&brcmstb_waketmr_driver,
	brcmstb_waketmr_probe);
	}

	static void __exit brcmstb_waketmr_exit(void)
	{
	platform_driver_unregister(&brcmstb_waketmr_driver);
	}

	module_init(brcmstb_waketmr_init);
	module_exit(brcmstb_waketmr_exit);

	MODULE_LICENSE("GPL v2");
	MODULE_AUTHOR("Brian Norris");
	MODULE_DESCRIPTION("Wake-up timer driver for STB chips");