rtc: Add support for the rtc found in the MC13892 PMIC

The mfd driver for MC13783 recently got support for MC13892 and was
renamed accordingly from mc13783-core to mc13xxx-core.  Do the same for
rtc-mc13783.

The only relevant change is to use platform id's to tell the platform bus
that this driver is responsible for mc13892-rtc devices, too.

Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

1 files changed, 437 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-mc13xxx.c b/drivers/rtc/rtc-mc13xxx.c
new file mode 100644
index 0000000..5314b15
--- /dev/null
+++ b/drivers/rtc/rtc-mc13xxx.c
@@ -0,0 +1,437 @@
+/*
+ * 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
+
+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_irq_enable(struct device *dev,
+		unsigned int enabled, int irq)
+{
+	struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
+	int ret;
+
+	mc13xxx_lock(priv->mc13xxx);
+
+	ret = mc13xxx_rtc_irq_enable_unlocked(dev, enabled, irq);
+
+	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;
+	unsigned long s1970;
+	int ret;
+
+	mc13xxx_lock(priv->mc13xxx);
+
+	if (!priv->valid) {
+		ret = -ENODATA;
+		goto out;
+	}
+
+	ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCDAY, &days1);
+	if (unlikely(ret))
+		goto out;
+
+	ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCTOD, &seconds);
+	if (unlikely(ret))
+		goto out;
+
+	ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCDAY, &days2);
+out:
+	mc13xxx_unlock(priv->mc13xxx);
+
+	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 mc13xxx_rtc_set_mmss(struct device *dev, unsigned long secs)
+{
+	struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
+	unsigned int seconds, days;
+	unsigned int alarmseconds;
+	int ret;
+
+	seconds = secs % 86400;
+	days = secs / 86400;
+
+	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 < 86400) {
+		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 < 86400) {
+		ret = mc13xxx_reg_write(priv->mc13xxx,
+				MC13XXX_RTCTODA, alarmseconds);
+		if (unlikely(ret))
+			goto out;
+	}
+
+	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;
+	unsigned long 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 >= 86400) {
+		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 = days * 86400 + seconds;
+
+	rtc_time_to_tm(s1970, &alarm->time);
+	dev_dbg(dev, "%s: %lu\n", __func__, s1970);
+
+	return 0;
+}
+
+static int mc13xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+	struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
+	unsigned long s1970;
+	unsigned 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;
+
+	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 = mc13xxx_rtc_irq_enable_unlocked(dev, alarm->enabled,
+			MC13XXX_IRQ_TODA);
+	if (unlikely(ret))
+		goto out;
+
+	seconds = s1970 % 86400;
+	days = s1970 / 86400;
+
+	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;
+
+	dev_dbg(&priv->rtc->dev, "Alarm\n");
+
+	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;
+
+	dev_dbg(&priv->rtc->dev, "1HZ\n");
+
+	rtc_update_irq(priv->rtc, 1, RTC_IRQF | RTC_UF);
+
+	mc13xxx_irq_ack(mc13xxx, irq);
+
+	return IRQ_HANDLED;
+}
+
+static int mc13xxx_rtc_update_irq_enable(struct device *dev,
+		unsigned int enabled)
+{
+	return mc13xxx_rtc_irq_enable(dev, enabled, MC13XXX_IRQ_1HZ);
+}
+
+static int mc13xxx_rtc_alarm_irq_enable(struct device *dev,
+		unsigned int enabled)
+{
+	return mc13xxx_rtc_irq_enable(dev, enabled, MC13XXX_IRQ_TODA);
+}
+
+static const struct rtc_class_ops mc13xxx_rtc_ops = {
+	.read_time = mc13xxx_rtc_read_time,
+	.set_mmss = mc13xxx_rtc_set_mmss,
+	.read_alarm = mc13xxx_rtc_read_alarm,
+	.set_alarm = mc13xxx_rtc_set_alarm,
+	.alarm_irq_enable = mc13xxx_rtc_alarm_irq_enable,
+	.update_irq_enable = mc13xxx_rtc_update_irq_enable,
+};
+
+static irqreturn_t mc13xxx_rtc_reset_handler(int irq, void *dev)
+{
+	struct mc13xxx_rtc *priv = dev;
+	struct mc13xxx *mc13xxx = priv->mc13xxx;
+
+	dev_dbg(&priv->rtc->dev, "RTCRST\n");
+	priv->valid = 0;
+
+	mc13xxx_irq_mask(mc13xxx, irq);
+
+	return IRQ_HANDLED;
+}
+
+static int __devinit mc13xxx_rtc_probe(struct platform_device *pdev)
+{
+	int ret;
+	struct mc13xxx_rtc *priv;
+	struct mc13xxx *mc13xxx;
+	int rtcrst_pending;
+
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	mc13xxx = dev_get_drvdata(pdev->dev.parent);
+	priv->mc13xxx = mc13xxx;
+
+	platform_set_drvdata(pdev, priv);
+
+	mc13xxx_lock(mc13xxx);
+
+	ret = mc13xxx_irq_request(mc13xxx, MC13XXX_IRQ_RTCRST,
+			mc13xxx_rtc_reset_handler, DRIVER_NAME, priv);
+	if (ret)
+		goto err_reset_irq_request;
+
+	ret = mc13xxx_irq_status(mc13xxx, MC13XXX_IRQ_RTCRST,
+			NULL, &rtcrst_pending);
+	if (ret)
+		goto err_reset_irq_status;
+
+	priv->valid = !rtcrst_pending;
+
+	ret = mc13xxx_irq_request_nounmask(mc13xxx, MC13XXX_IRQ_1HZ,
+			mc13xxx_rtc_update_handler, DRIVER_NAME, priv);
+	if (ret)
+		goto err_update_irq_request;
+
+	ret = mc13xxx_irq_request_nounmask(mc13xxx, MC13XXX_IRQ_TODA,
+			mc13xxx_rtc_alarm_handler, DRIVER_NAME, priv);
+	if (ret)
+		goto err_alarm_irq_request;
+
+	priv->rtc = rtc_device_register(pdev->name,
+			&pdev->dev, &mc13xxx_rtc_ops, THIS_MODULE);
+	if (IS_ERR(priv->rtc)) {
+		ret = PTR_ERR(priv->rtc);
+
+		mc13xxx_irq_free(mc13xxx, MC13XXX_IRQ_TODA, priv);
+err_alarm_irq_request:
+
+		mc13xxx_irq_free(mc13xxx, MC13XXX_IRQ_1HZ, priv);
+err_update_irq_request:
+
+err_reset_irq_status:
+
+		mc13xxx_irq_free(mc13xxx, MC13XXX_IRQ_RTCRST, priv);
+err_reset_irq_request:
+
+		platform_set_drvdata(pdev, NULL);
+		kfree(priv);
+	}
+
+	mc13xxx_unlock(mc13xxx);
+
+	return ret;
+}
+
+static int __devexit mc13xxx_rtc_remove(struct platform_device *pdev)
+{
+	struct mc13xxx_rtc *priv = platform_get_drvdata(pdev);
+
+	mc13xxx_lock(priv->mc13xxx);
+
+	rtc_device_unregister(priv->rtc);
+
+	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);
+
+	platform_set_drvdata(pdev, NULL);
+
+	kfree(priv);
+
+	return 0;
+}
+
+const struct platform_device_id mc13xxx_rtc_idtable[] = {
+	{
+		.name = "mc13783-rtc",
+	}, {
+		.name = "mc13892-rtc",
+	},
+};
+
+static struct platform_driver mc13xxx_rtc_driver = {
+	.id_table = mc13xxx_rtc_idtable,
+	.remove = __devexit_p(mc13xxx_rtc_remove),
+	.driver = {
+		.name = DRIVER_NAME,
+		.owner = THIS_MODULE,
+	},
+};
+
+static int __init mc13xxx_rtc_init(void)
+{
+	return platform_driver_probe(&mc13xxx_rtc_driver, &mc13xxx_rtc_probe);
+}
+module_init(mc13xxx_rtc_init);
+
+static void __exit mc13xxx_rtc_exit(void)
+{
+	platform_driver_unregister(&mc13xxx_rtc_driver);
+}
+module_exit(mc13xxx_rtc_exit);
+
+MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
+MODULE_DESCRIPTION("RTC driver for Freescale MC13XXX PMIC");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" DRIVER_NAME);