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path: root/drivers/rtc/rtc-mc13xxx.c
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Diffstat (limited to 'drivers/rtc/rtc-mc13xxx.c')
-rw-r--r--drivers/rtc/rtc-mc13xxx.c437
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 000000000000..5314b153bfba
--- /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);