--- /dev/null
+/*
+ * Real Time Clock driver for Freescale MC13XXX 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/mc13xxx.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 "mc13xxx-rtc"
+
+#define MC13XXX_RTCTOD 20
+#define MC13XXX_RTCTODA 21
+#define MC13XXX_RTCDAY 22
+#define MC13XXX_RTCDAYA 23
+
+#define SEC_PER_DAY (24 * 60 * 60)
+
+struct mc13xxx_rtc {
+ struct rtc_device *rtc;
+ struct mc13xxx *mc13xxx;
+ int valid;
+};
+
+static int mc13xxx_rtc_irq_enable_unlocked(struct device *dev,
+ unsigned int enabled, int irq)
+{
+ struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
+ int (*func)(struct mc13xxx *mc13xxx, int irq);
+
+ if (!priv->valid)
+ return -ENODATA;
+
+ func = enabled ? mc13xxx_irq_unmask : mc13xxx_irq_mask;
+ return func(priv->mc13xxx, irq);
+}
+
+static int mc13xxx_rtc_alarm_irq_enable(struct device *dev,
+ unsigned int enabled)
+{
+ struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
+ int ret;
+
+ mc13xxx_lock(priv->mc13xxx);
+
+ ret = mc13xxx_rtc_irq_enable_unlocked(dev, enabled, MC13XXX_IRQ_TODA);
+
+ mc13xxx_unlock(priv->mc13xxx);
+
+ return ret;
+}
+
+static int mc13xxx_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+ struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
+ unsigned int seconds, days1, days2;
+
+ if (!priv->valid)
+ return -ENODATA;
+
+ do {
+ int ret;
+
+ ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCDAY, &days1);
+ if (ret)
+ return ret;
+
+ ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCTOD, &seconds);
+ if (ret)
+ return ret;
+
+ ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCDAY, &days2);
+ if (ret)
+ return ret;
+ } while (days1 != days2);
+
+ rtc_time64_to_tm((time64_t)days1 * SEC_PER_DAY + seconds, tm);
+
+ return rtc_valid_tm(tm);
+}
+
+static int mc13xxx_rtc_set_mmss(struct device *dev, time64_t secs)
+{
+ struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
+ unsigned int seconds, days;
+ unsigned int alarmseconds;
+ int ret;
+
+ days = div_s64_rem(secs, SEC_PER_DAY, &seconds);
+
+ mc13xxx_lock(priv->mc13xxx);
+
+ /*
+ * temporarily invalidate alarm to prevent triggering it when the day is
+ * already updated while the time isn't yet.
+ */
+ ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCTODA, &alarmseconds);
+ if (unlikely(ret))
+ goto out;
+
+ if (alarmseconds < SEC_PER_DAY) {
+ ret = mc13xxx_reg_write(priv->mc13xxx,
+ MC13XXX_RTCTODA, 0x1ffff);
+ if (unlikely(ret))
+ goto out;
+ }
+
+ /*
+ * write seconds=0 to prevent a day switch between writing days
+ * and seconds below
+ */
+ ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCTOD, 0);
+ if (unlikely(ret))
+ goto out;
+
+ ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCDAY, days);
+ if (unlikely(ret))
+ goto out;
+
+ ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCTOD, seconds);
+ if (unlikely(ret))
+ goto out;
+
+ /* restore alarm */
+ if (alarmseconds < SEC_PER_DAY) {
+ ret = mc13xxx_reg_write(priv->mc13xxx,
+ MC13XXX_RTCTODA, alarmseconds);
+ if (unlikely(ret))
+ goto out;
+ }
+
+ if (!priv->valid) {
+ ret = mc13xxx_irq_ack(priv->mc13xxx, MC13XXX_IRQ_RTCRST);
+ if (unlikely(ret))
+ goto out;
+
+ ret = mc13xxx_irq_unmask(priv->mc13xxx, MC13XXX_IRQ_RTCRST);
+ }
+
+out:
+ priv->valid = !ret;
+
+ mc13xxx_unlock(priv->mc13xxx);
+
+ return ret;
+}
+
+static int mc13xxx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+ struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
+ unsigned seconds, days;
+ time64_t s1970;
+ int enabled, pending;
+ int ret;
+
+ mc13xxx_lock(priv->mc13xxx);
+
+ ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCTODA, &seconds);
+ if (unlikely(ret))
+ goto out;
+ if (seconds >= SEC_PER_DAY) {
+ ret = -ENODATA;
+ goto out;
+ }
+
+ ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCDAY, &days);
+ if (unlikely(ret))
+ goto out;
+
+ ret = mc13xxx_irq_status(priv->mc13xxx, MC13XXX_IRQ_TODA,
+ &enabled, &pending);
+
+out:
+ mc13xxx_unlock(priv->mc13xxx);
+
+ if (ret)
+ return ret;
+
+ alarm->enabled = enabled;
+ alarm->pending = pending;
+
+ s1970 = (time64_t)days * SEC_PER_DAY + seconds;
+
+ rtc_time64_to_tm(s1970, &alarm->time);
+ dev_dbg(dev, "%s: %lld\n", __func__, (long long)s1970);
+
+ return 0;
+}
+
+static int mc13xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+ struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
+ time64_t s1970;
+ u32 seconds, days;
+ int ret;
+
+ mc13xxx_lock(priv->mc13xxx);
+
+ /* disable alarm to prevent false triggering */
+ ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCTODA, 0x1ffff);
+ if (unlikely(ret))
+ goto out;
+
+ ret = mc13xxx_irq_ack(priv->mc13xxx, MC13XXX_IRQ_TODA);
+ if (unlikely(ret))
+ goto out;
+
+ s1970 = rtc_tm_to_time64(&alarm->time);
+
+ dev_dbg(dev, "%s: o%2.s %lld\n", __func__, alarm->enabled ? "n" : "ff",
+ (long long)s1970);
+
+ ret = mc13xxx_rtc_irq_enable_unlocked(dev, alarm->enabled,
+ MC13XXX_IRQ_TODA);
+ if (unlikely(ret))
+ goto out;
+
+ days = div_s64_rem(s1970, SEC_PER_DAY, &seconds);
+
+ ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCDAYA, days);
+ if (unlikely(ret))
+ goto out;
+
+ ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCTODA, seconds);
+
+out:
+ mc13xxx_unlock(priv->mc13xxx);
+
+ return ret;
+}
+
+static irqreturn_t mc13xxx_rtc_alarm_handler(int irq, void *dev)
+{
+ struct mc13xxx_rtc *priv = dev;
+ struct mc13xxx *mc13xxx = priv->mc13xxx;
+
+ rtc_update_irq(priv->rtc, 1, RTC_IRQF | RTC_AF);
+
+ mc13xxx_irq_ack(mc13xxx, irq);
+
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t mc13xxx_rtc_update_handler(int irq, void *dev)
+{
+ struct mc13xxx_rtc *priv = dev;
+ struct mc13xxx *mc13xxx = priv->mc13xxx;
+
+ rtc_update_irq(priv->rtc, 1, RTC_IRQF | RTC_UF);
+
+ mc13xxx_irq_ack(mc13xxx, irq);
+
+ return IRQ_HANDLED;
+}
+
+static const struct rtc_class_ops mc13xxx_rtc_ops = {
+ .read_time = mc13xxx_rtc_read_time,
+ .set_mmss64 = mc13xxx_rtc_set_mmss,
+ .read_alarm = mc13xxx_rtc_read_alarm,
+ .set_alarm = mc13xxx_rtc_set_alarm,
+ .alarm_irq_enable = mc13xxx_rtc_alarm_irq_enable,
+};
+
+static irqreturn_t mc13xxx_rtc_reset_handler(int irq, void *dev)
+{
+ struct mc13xxx_rtc *priv = dev;
+ struct mc13xxx *mc13xxx = priv->mc13xxx;
+
+ priv->valid = 0;
+
+ mc13xxx_irq_mask(mc13xxx, irq);
+
+ return IRQ_HANDLED;
+}
+
+static int __init mc13xxx_rtc_probe(struct platform_device *pdev)
+{
+ int ret;
+ struct mc13xxx_rtc *priv;
+ struct mc13xxx *mc13xxx;
+
+ priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ mc13xxx = dev_get_drvdata(pdev->dev.parent);
+ priv->mc13xxx = mc13xxx;
+ priv->valid = 1;
+
+ platform_set_drvdata(pdev, priv);
+
+ mc13xxx_lock(mc13xxx);
+
+ mc13xxx_irq_ack(mc13xxx, MC13XXX_IRQ_RTCRST);
+
+ ret = mc13xxx_irq_request(mc13xxx, MC13XXX_IRQ_RTCRST,
+ mc13xxx_rtc_reset_handler, DRIVER_NAME, priv);
+ if (ret)
+ goto err_irq_request;
+
+ ret = mc13xxx_irq_request(mc13xxx, MC13XXX_IRQ_1HZ,
+ mc13xxx_rtc_update_handler, DRIVER_NAME, priv);
+ if (ret)
+ goto err_irq_request;
+
+ ret = mc13xxx_irq_request_nounmask(mc13xxx, MC13XXX_IRQ_TODA,
+ mc13xxx_rtc_alarm_handler, DRIVER_NAME, priv);
+ if (ret)
+ goto err_irq_request;
+
+ mc13xxx_unlock(mc13xxx);
+
+ priv->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
+ &mc13xxx_rtc_ops, THIS_MODULE);
+
+ return 0;
+
+err_irq_request:
+ mc13xxx_irq_free(mc13xxx, MC13XXX_IRQ_TODA, priv);
+ mc13xxx_irq_free(mc13xxx, MC13XXX_IRQ_1HZ, priv);
+ mc13xxx_irq_free(mc13xxx, MC13XXX_IRQ_RTCRST, priv);
+
+ mc13xxx_unlock(mc13xxx);
+
+ return ret;
+}
+
+static int mc13xxx_rtc_remove(struct platform_device *pdev)
+{
+ struct mc13xxx_rtc *priv = platform_get_drvdata(pdev);
+
+ mc13xxx_lock(priv->mc13xxx);
+
+ mc13xxx_irq_free(priv->mc13xxx, MC13XXX_IRQ_TODA, priv);
+ mc13xxx_irq_free(priv->mc13xxx, MC13XXX_IRQ_1HZ, priv);
+ mc13xxx_irq_free(priv->mc13xxx, MC13XXX_IRQ_RTCRST, priv);
+
+ mc13xxx_unlock(priv->mc13xxx);
+
+ return 0;
+}
+
+static const struct platform_device_id mc13xxx_rtc_idtable[] = {
+ {
+ .name = "mc13783-rtc",
+ }, {
+ .name = "mc13892-rtc",
+ }, {
+ .name = "mc34708-rtc",
+ },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(platform, mc13xxx_rtc_idtable);
+
+static struct platform_driver mc13xxx_rtc_driver = {
+ .id_table = mc13xxx_rtc_idtable,
+ .remove = mc13xxx_rtc_remove,
+ .driver = {
+ .name = DRIVER_NAME,
+ },
+};
+
+module_platform_driver_probe(mc13xxx_rtc_driver, &mc13xxx_rtc_probe);
+
+MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
+MODULE_DESCRIPTION("RTC driver for Freescale MC13XXX PMIC");
+MODULE_LICENSE("GPL v2");
Code Review / kvmfornfv.git / blobdiff