/* * Real Time Clock driver for Freescale MC13783 PMIC * * (C) 2009 Sascha Hauer, Pengutronix * (C) 2009 Uwe Kleine-Koenig, Pengutronix * * 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/mfd/mc13783.h> #include <linux/platform_device.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/slab.h> #include <linux/rtc.h> #define DRIVER_NAME "mc13783-rtc" #define MC13783_RTCTOD 20 #define MC13783_RTCTODA 21 #define MC13783_RTCDAY 22 #define MC13783_RTCDAYA 23 struct mc13783_rtc { struct rtc_device *rtc; struct mc13783 *mc13783; int valid; }; static int mc13783_rtc_irq_enable_unlocked(struct device *dev, unsigned int enabled, int irq) { struct mc13783_rtc *priv = dev_get_drvdata(dev); int (*func)(struct mc13783 *mc13783, int irq); if (!priv->valid) return -ENODATA; func = enabled ? mc13783_irq_unmask : mc13783_irq_mask; return func(priv->mc13783, irq); } static int mc13783_rtc_irq_enable(struct device *dev, unsigned int enabled, int irq) { struct mc13783_rtc *priv = dev_get_drvdata(dev); int ret; mc13783_lock(priv->mc13783); ret = mc13783_rtc_irq_enable_unlocked(dev, enabled, irq); mc13783_unlock(priv->mc13783); return ret; } static int mc13783_rtc_read_time(struct device *dev, struct rtc_time *tm) { struct mc13783_rtc *priv = dev_get_drvdata(dev); unsigned int seconds, days1, days2; unsigned long s1970; int ret; mc13783_lock(priv->mc13783); if (!priv->valid) { ret = -ENODATA; goto out; } ret = mc13783_reg_read(priv->mc13783, MC13783_RTCDAY, &days1); if (unlikely(ret)) goto out; ret = mc13783_reg_read(priv->mc13783, MC13783_RTCTOD, &seconds); if (unlikely(ret)) goto out; ret = mc13783_reg_read(priv->mc13783, MC13783_RTCDAY, &days2); out: mc13783_unlock(priv->mc13783); if (ret) return ret; if (days2 == days1 + 1) { if (seconds >= 86400 / 2) days2 = days1; else days1 = days2; } if (days1 != days2) return -EIO; s1970 = days1 * 86400 + seconds; rtc_time_to_tm(s1970, tm); return rtc_valid_tm(tm); } static int mc13783_rtc_set_mmss(struct device *dev, unsigned long secs) { struct mc13783_rtc *priv = dev_get_drvdata(dev); unsigned int seconds, days; unsigned int alarmseconds; int ret; seconds = secs % 86400; days = secs / 86400; mc13783_lock(priv->mc13783); /* * temporarily invalidate alarm to prevent triggering it when the day is * already updated while the time isn't yet. */ ret = mc13783_reg_read(priv->mc13783, MC13783_RTCTODA, &alarmseconds); if (unlikely(ret)) goto out; if (alarmseconds < 86400) { ret = mc13783_reg_write(priv->mc13783, MC13783_RTCTODA, 0x1ffff); if (unlikely(ret)) goto out; } /* * write seconds=0 to prevent a day switch between writing days * and seconds below */ ret = mc13783_reg_write(priv->mc13783, MC13783_RTCTOD, 0); if (unlikely(ret)) goto out; ret = mc13783_reg_write(priv->mc13783, MC13783_RTCDAY, days); if (unlikely(ret)) goto out; ret = mc13783_reg_write(priv->mc13783, MC13783_RTCTOD, seconds); if (unlikely(ret)) goto out; /* restore alarm */ if (alarmseconds < 86400) { ret = mc13783_reg_write(priv->mc13783, MC13783_RTCTODA, alarmseconds); if (unlikely(ret)) goto out; } ret = mc13783_irq_ack(priv->mc13783, MC13783_IRQ_RTCRST); if (unlikely(ret)) goto out; ret = mc13783_irq_unmask(priv->mc13783, MC13783_IRQ_RTCRST); out: priv->valid = !ret; mc13783_unlock(priv->mc13783); return ret; } static int mc13783_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) { struct mc13783_rtc *priv = dev_get_drvdata(dev); unsigned seconds, days; unsigned long s1970; int enabled, pending; int ret; mc13783_lock(priv->mc13783); ret = mc13783_reg_read(priv->mc13783, MC13783_RTCTODA, &seconds); if (unlikely(ret)) goto out; if (seconds >= 86400) { ret = -ENODATA; goto out; } ret = mc13783_reg_read(priv->mc13783, MC13783_RTCDAY, &days); if (unlikely(ret)) goto out; ret = mc13783_irq_status(priv->mc13783, MC13783_IRQ_TODA, &enabled, &pending); out: mc13783_unlock(priv->mc13783); if (ret) return ret; alarm->enabled = enabled; alarm->pending = pending; s1970 = days * 86400 + seconds; rtc_time_to_tm(s1970, &alarm->time); dev_dbg(dev, "%s: %lu\n", __func__, s1970); return 0; } static int mc13783_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) { struct mc13783_rtc *priv = dev_get_drvdata(dev); unsigned long s1970; unsigned seconds, days; int ret; mc13783_lock(priv->mc13783); /* disable alarm to prevent false triggering */ ret = mc13783_reg_write(priv->mc13783, MC13783_RTCTODA, 0x1ffff); if (unlikely(ret)) goto out; ret = mc13783_irq_ack(priv->mc13783, MC13783_IRQ_TODA); if (unlikely(ret)) goto out; ret = rtc_tm_to_time(&alarm->time, &s1970); if (unlikely(ret)) goto out; dev_dbg(dev, "%s: o%2.s %lu\n", __func__, alarm->enabled ? "n" : "ff", s1970); ret = mc13783_rtc_irq_enable_unlocked(dev, alarm->enabled, MC13783_IRQ_TODA); if (unlikely(ret)) goto out; seconds = s1970 % 86400; days = s1970 / 86400; ret = mc13783_reg_write(priv->mc13783, MC13783_RTCDAYA, days); if (unlikely(ret)) goto out; ret = mc13783_reg_write(priv->mc13783, MC13783_RTCTODA, seconds); out: mc13783_unlock(priv->mc13783); return ret; } static irqreturn_t mc13783_rtc_alarm_handler(int irq, void *dev) { struct mc13783_rtc *priv = dev; struct mc13783 *mc13783 = priv->mc13783; dev_dbg(&priv->rtc->dev, "Alarm\n"); rtc_update_irq(priv->rtc, 1, RTC_IRQF | RTC_AF); mc13783_irq_ack(mc13783, irq); return IRQ_HANDLED; } static irqreturn_t mc13783_rtc_update_handler(int irq, void *dev) { struct mc13783_rtc *priv = dev; struct mc13783 *mc13783 = priv->mc13783; dev_dbg(&priv->rtc->dev, "1HZ\n"); rtc_update_irq(priv->rtc, 1, RTC_IRQF | RTC_UF); mc13783_irq_ack(mc13783, irq); return IRQ_HANDLED; } static int mc13783_rtc_update_irq_enable(struct device *dev, unsigned int enabled) { return mc13783_rtc_irq_enable(dev, enabled, MC13783_IRQ_1HZ); } static int mc13783_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) { return mc13783_rtc_irq_enable(dev, enabled, MC13783_IRQ_TODA); } static const struct rtc_class_ops mc13783_rtc_ops = { .read_time = mc13783_rtc_read_time, .set_mmss = mc13783_rtc_set_mmss, .read_alarm = mc13783_rtc_read_alarm, .set_alarm = mc13783_rtc_set_alarm, .alarm_irq_enable = mc13783_rtc_alarm_irq_enable, .update_irq_enable = mc13783_rtc_update_irq_enable, }; static irqreturn_t mc13783_rtc_reset_handler(int irq, void *dev) { struct mc13783_rtc *priv = dev; struct mc13783 *mc13783 = priv->mc13783; dev_dbg(&priv->rtc->dev, "RTCRST\n"); priv->valid = 0; mc13783_irq_mask(mc13783, irq); return IRQ_HANDLED; } static int __devinit mc13783_rtc_probe(struct platform_device *pdev) { int ret; struct mc13783_rtc *priv; struct mc13783 *mc13783; int rtcrst_pending; priv = kzalloc(sizeof(*priv), GFP_KERNEL); if (!priv) return -ENOMEM; mc13783 = dev_get_drvdata(pdev->dev.parent); priv->mc13783 = mc13783; platform_set_drvdata(pdev, priv); mc13783_lock(mc13783); ret = mc13783_irq_request(mc13783, MC13783_IRQ_RTCRST, mc13783_rtc_reset_handler, DRIVER_NAME, priv); if (ret) goto err_reset_irq_request; ret = mc13783_irq_status(mc13783, MC13783_IRQ_RTCRST, NULL, &rtcrst_pending); if (ret) goto err_reset_irq_status; priv->valid = !rtcrst_pending; ret = mc13783_irq_request_nounmask(mc13783, MC13783_IRQ_1HZ, mc13783_rtc_update_handler, DRIVER_NAME, priv); if (ret) goto err_update_irq_request; ret = mc13783_irq_request_nounmask(mc13783, MC13783_IRQ_TODA, mc13783_rtc_alarm_handler, DRIVER_NAME, priv); if (ret) goto err_alarm_irq_request; priv->rtc = rtc_device_register(pdev->name, &pdev->dev, &mc13783_rtc_ops, THIS_MODULE); if (IS_ERR(priv->rtc)) { ret = PTR_ERR(priv->rtc); mc13783_irq_free(mc13783, MC13783_IRQ_TODA, priv); err_alarm_irq_request: mc13783_irq_free(mc13783, MC13783_IRQ_1HZ, priv); err_update_irq_request: err_reset_irq_status: mc13783_irq_free(mc13783, MC13783_IRQ_RTCRST, priv); err_reset_irq_request: platform_set_drvdata(pdev, NULL); kfree(priv); } mc13783_unlock(mc13783); return ret; } static int __devexit mc13783_rtc_remove(struct platform_device *pdev) { struct mc13783_rtc *priv = platform_get_drvdata(pdev); mc13783_lock(priv->mc13783); rtc_device_unregister(priv->rtc); mc13783_irq_free(priv->mc13783, MC13783_IRQ_TODA, priv); mc13783_irq_free(priv->mc13783, MC13783_IRQ_1HZ, priv); mc13783_irq_free(priv->mc13783, MC13783_IRQ_RTCRST, priv); mc13783_unlock(priv->mc13783); platform_set_drvdata(pdev, NULL); kfree(priv); return 0; } static struct platform_driver mc13783_rtc_driver = { .remove = __devexit_p(mc13783_rtc_remove), .driver = { .name = DRIVER_NAME, .owner = THIS_MODULE, }, }; static int __init mc13783_rtc_init(void) { return platform_driver_probe(&mc13783_rtc_driver, &mc13783_rtc_probe); } module_init(mc13783_rtc_init); static void __exit mc13783_rtc_exit(void) { platform_driver_unregister(&mc13783_rtc_driver); } module_exit(mc13783_rtc_exit); MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>"); MODULE_DESCRIPTION("RTC driver for Freescale MC13783 PMIC"); MODULE_LICENSE("GPL v2"); MODULE_ALIAS("platform:" DRIVER_NAME);