1 files changed, 358 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-mc13xxx.c b/drivers/rtc/rtc-mc13xxx.c
new file mode 100644
index 000000000..0fa33708f
--- /dev/null
+++ b/drivers/rtc/rtc-mc13xxx.c
@@ -0,0 +1,358 @@
+/*
+ * 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/mod_devicetable.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 0;
+}
+
+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: %s %lld\n", __func__, alarm->enabled ? "on" : "off",
+			(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 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_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_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_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");