tile: add an RTC driver for the Tilera hypervisor

This is a simple RTC driver that lets Tilera hardware boot up and
set the clock correctly.

Acked-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>

3 files changed, 170 insertions, 0 deletions

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index e1878877399c..d2c615fcaa10 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -995,4 +995,11 @@ config RTC_DRV_TEGRA
           This drive can also be built as a module. If so, the module
           will be called rtc-tegra.
 
+config RTC_DRV_TILE
+        tristate "Tilera hypervisor RTC support"
+        depends on TILE
+        help
+          Enable support for the Linux driver side of the Tilera
+          hypervisor's real-time clock interface.
+
 endif # RTC_CLASS
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index ca91c3c42e98..9574748d1c73 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -93,6 +93,7 @@ obj-$(CONFIG_RTC_DRV_STMP)	+= rtc-stmp3xxx.o
 obj-$(CONFIG_RTC_DRV_SUN4V)     += rtc-sun4v.o
 obj-$(CONFIG_RTC_DRV_TEGRA)     += rtc-tegra.o
 obj-$(CONFIG_RTC_DRV_TEST)      += rtc-test.o
+obj-$(CONFIG_RTC_DRV_TILE)      += rtc-tile.o
 obj-$(CONFIG_RTC_DRV_TWL4030)   += rtc-twl.o
 obj-$(CONFIG_RTC_DRV_TX4939)    += rtc-tx4939.o
 obj-$(CONFIG_RTC_DRV_V3020)     += rtc-v3020.o
diff --git a/drivers/rtc/rtc-tile.c b/drivers/rtc/rtc-tile.c
new file mode 100644
index 000000000000..eb65dafee66e
--- /dev/null
+++ b/drivers/rtc/rtc-tile.c
@@ -0,0 +1,162 @@
+/*
+ * Copyright 2011 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ *
+ * Tilera-specific RTC driver.
+ */
+
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/rtc.h>
+#include <linux/platform_device.h>
+
+/* Platform device pointer. */
+static struct platform_device *tile_rtc_platform_device;
+
+/*
+ * RTC read routine.  Gets time info from RTC chip via hypervisor syscall.
+ */
+static int read_rtc_time(struct device *dev, struct rtc_time *tm)
+{
+        HV_RTCTime hvtm = hv_get_rtc();
+
+        tm->tm_sec = hvtm.tm_sec;
+        tm->tm_min = hvtm.tm_min;
+        tm->tm_hour = hvtm.tm_hour;
+        tm->tm_mday = hvtm.tm_mday;
+        tm->tm_mon = hvtm.tm_mon;
+        tm->tm_year = hvtm.tm_year;
+        tm->tm_wday = 0;
+        tm->tm_yday = 0;
+        tm->tm_isdst = 0;
+
+        if (rtc_valid_tm(tm) < 0)
+                dev_warn(dev, "Read invalid date/time from RTC\n");
+
+        return 0;
+}
+
+/*
+ * RTC write routine.  Sends time info to hypervisor via syscall, to be
+ * written to RTC chip.
+ */
+static int set_rtc_time(struct device *dev, struct rtc_time *tm)
+{
+        HV_RTCTime hvtm;
+
+        hvtm.tm_sec = tm->tm_sec;
+        hvtm.tm_min = tm->tm_min;
+        hvtm.tm_hour = tm->tm_hour;
+        hvtm.tm_mday = tm->tm_mday;
+        hvtm.tm_mon = tm->tm_mon;
+        hvtm.tm_year = tm->tm_year;
+
+        hv_set_rtc(hvtm);
+
+        return 0;
+}
+
+/*
+ * RTC read/write ops.
+ */
+static const struct rtc_class_ops tile_rtc_ops = {
+        .read_time      = read_rtc_time,
+        .set_time       = set_rtc_time,
+};
+
+/*
+ * Device probe routine.
+ */
+static int __devinit tile_rtc_probe(struct platform_device *dev)
+{
+        struct rtc_device *rtc;
+
+        rtc = rtc_device_register("tile",
+                                  &dev->dev, &tile_rtc_ops, THIS_MODULE);
+
+        if (IS_ERR(rtc))
+                return PTR_ERR(rtc);
+
+        platform_set_drvdata(dev, rtc);
+
+        return 0;
+}
+
+/*
+ * Device cleanup routine.
+ */
+static int __devexit tile_rtc_remove(struct platform_device *dev)
+{
+        struct rtc_device *rtc = platform_get_drvdata(dev);
+
+        if (rtc)
+                rtc_device_unregister(rtc);
+
+        platform_set_drvdata(dev, NULL);
+
+        return 0;
+}
+
+static struct platform_driver tile_rtc_platform_driver = {
+        .driver         = {
+                .name   = "rtc-tile",
+                .owner  = THIS_MODULE,
+        },
+        .probe          = tile_rtc_probe,
+        .remove         = __devexit_p(tile_rtc_remove),
+};
+
+/*
+ * Driver init routine.
+ */
+static int __init tile_rtc_driver_init(void)
+{
+        int err;
+
+        err = platform_driver_register(&tile_rtc_platform_driver);
+        if (err)
+                return err;
+
+        tile_rtc_platform_device = platform_device_alloc("rtc-tile", 0);
+        if (tile_rtc_platform_device == NULL) {
+                err = -ENOMEM;
+                goto exit_driver_unregister;
+        }
+
+        err = platform_device_add(tile_rtc_platform_device);
+        if (err)
+                goto exit_device_put;
+
+        return 0;
+
+exit_device_put:
+        platform_device_put(tile_rtc_platform_device);
+
+exit_driver_unregister:
+        platform_driver_unregister(&tile_rtc_platform_driver);
+        return err;
+}
+
+/*
+ * Driver cleanup routine.
+ */
+static void __exit tile_rtc_driver_exit(void)
+{
+        platform_driver_unregister(&tile_rtc_platform_driver);
+}
+
+module_init(tile_rtc_driver_init);
+module_exit(tile_rtc_driver_exit);
+
+MODULE_DESCRIPTION("Tilera-specific Real Time Clock Driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:rtc-tile");