summaryrefslogtreecommitdiffstats
path: root/drivers/rtc/rtc-mc13783.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/rtc/rtc-mc13783.c')
-rw-r--r--drivers/rtc/rtc-mc13783.c262
1 files changed, 262 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-mc13783.c b/drivers/rtc/rtc-mc13783.c
new file mode 100644
index 0000000..850f983
--- /dev/null
+++ b/drivers/rtc/rtc-mc13783.c
@@ -0,0 +1,262 @@
+/*
+ * 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/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_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;
+ int ret;
+
+ seconds = secs % 86400;
+ days = secs / 86400;
+
+ mc13783_lock(priv->mc13783);
+
+ /*
+ * first 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;
+
+ ret = mc13783_ackirq(priv->mc13783, MC13783_IRQ_RTCRST);
+ if (unlikely(ret))
+ goto out;
+
+ ret = mc13783_unmask(priv->mc13783, MC13783_IRQ_RTCRST);
+out:
+ priv->valid = !ret;
+
+ mc13783_unlock(priv->mc13783);
+
+ return ret;
+}
+
+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_ackirq(mc13783, irq);
+
+ return IRQ_HANDLED;
+}
+
+static int mc13783_rtc_update_irq_enable(struct device *dev,
+ unsigned int enabled)
+{
+ struct mc13783_rtc *priv = dev_get_drvdata(dev);
+ int ret = -ENODATA;
+
+ mc13783_lock(priv->mc13783);
+ if (!priv->valid)
+ goto out;
+
+ ret = (enabled ? mc13783_unmask : mc13783_mask)(priv->mc13783,
+ MC13783_IRQ_1HZ);
+out:
+ mc13783_unlock(priv->mc13783);
+
+ return ret;
+}
+
+static const struct rtc_class_ops mc13783_rtc_ops = {
+ .read_time = mc13783_rtc_read_time,
+ .set_mmss = mc13783_rtc_set_mmss,
+ .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_mask(mc13783, irq);
+
+ return IRQ_HANDLED;
+}
+
+static int __devinit mc13783_rtc_probe(struct platform_device *pdev)
+{
+ int ret;
+ struct mc13783_rtc *priv;
+
+ priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->mc13783 = dev_get_drvdata(pdev->dev.parent);
+ platform_set_drvdata(pdev, priv);
+
+ priv->valid = 1;
+
+ mc13783_lock(priv->mc13783);
+
+ ret = mc13783_irq_request(priv->mc13783, MC13783_IRQ_RTCRST,
+ mc13783_rtc_reset_handler, DRIVER_NAME, priv);
+ if (ret)
+ goto err_reset_irq_request;
+
+ ret = mc13783_irq_request_nounmask(priv->mc13783, MC13783_IRQ_1HZ,
+ mc13783_rtc_update_handler, DRIVER_NAME, priv);
+ if (ret)
+ goto err_update_irq_request;
+
+ mc13783_unlock(priv->mc13783);
+
+ 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_lock(priv->mc13783);
+
+ mc13783_irq_free(priv->mc13783, MC13783_IRQ_1HZ, priv);
+err_update_irq_request:
+
+ mc13783_irq_free(priv->mc13783, MC13783_IRQ_RTCRST, priv);
+err_reset_irq_request:
+
+ mc13783_unlock(priv->mc13783);
+
+ platform_set_drvdata(pdev, NULL);
+ kfree(priv);
+ }
+
+ return ret;
+}
+
+static int __devexit mc13783_rtc_remove(struct platform_device *pdev)
+{
+ struct mc13783_rtc *priv = platform_get_drvdata(pdev);
+
+ rtc_device_unregister(priv->rtc);
+
+ mc13783_lock(priv->mc13783);
+
+ 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);
OpenPOWER on IntegriCloud