rtc: add Freescale MC13783 RTC driver

This driver provides support for the RTC part integrated into the
Freescale MC13783 PMIC and bases on patch created earlier by Sascha
Hauer.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Valentin Longchamp <valentin.longchamp@epfl.ch>
Cc: Paul Gortmaker <p_gortmaker@yahoo.com>
Signed-off-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 71fbd6e..564f3d1 100644 (file)
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -846,4 +846,10 @@ config RTC_DRV_PCAP
          If you say Y here you will get support for the RTC found on
          the PCAP2 ASIC used on some Motorola phones.
 
+config RTC_DRV_MC13783
+       depends on MFD_MC13783
+       tristate "Freescale MC13783 RTC"
+       help
+         This enables support for the Freescale MC13783 PMIC RTC
+
 endif # RTC_CLASS

diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 7da6efb..6fa20f4 100644 (file)
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -52,6 +52,7 @@ obj-$(CONFIG_RTC_DRV_M48T86)  += rtc-m48t86.o
 obj-$(CONFIG_RTC_MXC)          += rtc-mxc.o
 obj-$(CONFIG_RTC_DRV_MAX6900)  += rtc-max6900.o
 obj-$(CONFIG_RTC_DRV_MAX6902)  += rtc-max6902.o
+obj-$(CONFIG_RTC_DRV_MC13783)  += rtc-mc13783.o
 obj-$(CONFIG_RTC_DRV_MSM6242)  += rtc-msm6242.o
 obj-$(CONFIG_RTC_DRV_MV)       += rtc-mv.o
 obj-$(CONFIG_RTC_DRV_OMAP)     += rtc-omap.o

diff --git a/drivers/rtc/rtc-mc13783.c b/drivers/rtc/rtc-mc13783.c
new file mode 100644 (file)
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);