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>

arch/tile/configs/tile_defconfig

@@ -796,6 +796,7 @@ CONFIG_RTC_INTF_DEV=y
 #
 # on-CPU RTC drivers
 #
+CONFIG_RTC_DRV_TILE=y
 # CONFIG_DMADEVICES is not set
 # CONFIG_AUXDISPLAY is not set
 # CONFIG_UIO is not set

arch/tile/configs/tilegx_defconfig

@@ -1135,8 +1135,6 @@ CONFIG_HVC_DRIVER=y
 # CONFIG_IPMI_HANDLER is not set
 CONFIG_HW_RANDOM=y
 CONFIG_HW_RANDOM_TIMERIOMEM=m
-# CONFIG_RTC is not set
-# CONFIG_GEN_RTC is not set
 # CONFIG_R3964 is not set
 # CONFIG_APPLICOM is not set
 
@@ -1277,7 +1275,66 @@ CONFIG_MFD_SUPPORT=y
 # CONFIG_ACCESSIBILITY is not set
 # CONFIG_INFINIBAND is not set
 # CONFIG_EDAC is not set
-# CONFIG_RTC_CLASS is not set
+CONFIG_RTC_LIB=y
+CONFIG_RTC_CLASS=y
+CONFIG_RTC_HCTOSYS=y
+CONFIG_RTC_HCTOSYS_DEVICE="rtc0"
+# CONFIG_RTC_DEBUG is not set
+
+#
+# RTC interfaces
+#
+CONFIG_RTC_INTF_SYSFS=y
+CONFIG_RTC_INTF_PROC=y
+CONFIG_RTC_INTF_DEV=y
+# CONFIG_RTC_INTF_DEV_UIE_EMUL is not set
+# CONFIG_RTC_DRV_TEST is not set
+
+#
+# I2C RTC drivers
+#
+# CONFIG_RTC_DRV_DS1307 is not set
+# CONFIG_RTC_DRV_DS1374 is not set
+# CONFIG_RTC_DRV_DS1672 is not set
+# CONFIG_RTC_DRV_DS3232 is not set
+# CONFIG_RTC_DRV_MAX6900 is not set
+# CONFIG_RTC_DRV_RS5C372 is not set
+# CONFIG_RTC_DRV_ISL1208 is not set
+# CONFIG_RTC_DRV_ISL12022 is not set
+# CONFIG_RTC_DRV_X1205 is not set
+# CONFIG_RTC_DRV_PCF8563 is not set
+# CONFIG_RTC_DRV_PCF8583 is not set
+# CONFIG_RTC_DRV_M41T80 is not set
+# CONFIG_RTC_DRV_BQ32K is not set
+# CONFIG_RTC_DRV_S35390A is not set
+# CONFIG_RTC_DRV_FM3130 is not set
+# CONFIG_RTC_DRV_RX8581 is not set
+# CONFIG_RTC_DRV_RX8025 is not set
+
+#
+# SPI RTC drivers
+#
+
+#
+# Platform RTC drivers
+#
+# CONFIG_RTC_DRV_DS1286 is not set
+# CONFIG_RTC_DRV_DS1511 is not set
+# CONFIG_RTC_DRV_DS1553 is not set
+# CONFIG_RTC_DRV_DS1742 is not set
+# CONFIG_RTC_DRV_STK17TA8 is not set
+# CONFIG_RTC_DRV_M48T86 is not set
+# CONFIG_RTC_DRV_M48T35 is not set
+# CONFIG_RTC_DRV_M48T59 is not set
+# CONFIG_RTC_DRV_MSM6242 is not set
+# CONFIG_RTC_DRV_BQ4802 is not set
+# CONFIG_RTC_DRV_RP5C01 is not set
+# CONFIG_RTC_DRV_V3020 is not set
+
+#
+# on-CPU RTC drivers
+#
+CONFIG_RTC_DRV_TILE=y
 # CONFIG_DMADEVICES is not set
 # CONFIG_AUXDISPLAY is not set
 # CONFIG_UIO is not set

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

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

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");