rtc: class driver for ppc_md RTC functions

This hooks up the platform-specific [gs]et_rtc_time functions so that
kernels using CONFIG_RTC_CLASS have RTC support on most PowerPC platforms.

A new driver, and one which we've been shipping in Fedora for a while
already, since otherwise RTC support breaks.

[akpm@linux-foundation.org: fix Kconfig indenting]
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Acked-by: David Brownell <david-b@pacbell.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 78 insertions, 0 deletions

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 6cc2c0330230..60f8afc7a56e 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -534,4 +534,12 @@ config RTC_DRV_RS5C313
         help
           If you say yes here you get support for the Ricoh RS5C313 RTC chips.
 
+config RTC_DRV_PPC
+       tristate "PowerPC machine dependent RTC support"
+       depends on PPC_MERGE
+       help
+         The PowerPC kernel has machine-specific functions for accessing
+         the RTC. This exposes that functionality through the generic RTC
+         class.
+
 endif # RTC_CLASS
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 872f1218ff9f..ebe871cf16c1 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -54,3 +54,4 @@ obj-$(CONFIG_RTC_DRV_TEST)	+= rtc-test.o
 obj-$(CONFIG_RTC_DRV_V3020)     += rtc-v3020.o
 obj-$(CONFIG_RTC_DRV_VR41XX)    += rtc-vr41xx.o
 obj-$(CONFIG_RTC_DRV_X1205)     += rtc-x1205.o
+obj-$(CONFIG_RTC_DRV_PPC)       += rtc-ppc.o
diff --git a/drivers/rtc/rtc-ppc.c b/drivers/rtc/rtc-ppc.c
new file mode 100644
index 000000000000..c8e97e25ef7e
--- /dev/null
+++ b/drivers/rtc/rtc-ppc.c
@@ -0,0 +1,69 @@
+/*
+ * RTC driver for ppc_md RTC functions
+ *
+ * © 2007 Red Hat, Inc.
+ *
+ * Author: David Woodhouse <dwmw2@infradead.org>
+ *
+ * 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/module.h>
+#include <linux/err.h>
+#include <linux/rtc.h>
+#include <linux/platform_device.h>
+#include <asm/machdep.h>
+
+static int ppc_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+        ppc_md.get_rtc_time(tm);
+        return 0;
+}
+
+static int ppc_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+        return ppc_md.set_rtc_time(tm);
+}
+
+static const struct rtc_class_ops ppc_rtc_ops = {
+        .set_time = ppc_rtc_set_time,
+        .read_time = ppc_rtc_read_time,
+};
+
+static struct rtc_device *rtc;
+static struct platform_device *ppc_rtc_pdev;
+
+static int __init ppc_rtc_init(void)
+{
+        if (!ppc_md.get_rtc_time || !ppc_md.set_rtc_time)
+                return -ENODEV;
+
+        ppc_rtc_pdev = platform_device_register_simple("ppc-rtc", 0, NULL, 0);
+        if (IS_ERR(ppc_rtc_pdev))
+                return PTR_ERR(ppc_rtc_pdev);
+
+        rtc = rtc_device_register("ppc_md", &ppc_rtc_pdev->dev,
+                                  &ppc_rtc_ops, THIS_MODULE);
+        if (IS_ERR(rtc)) {
+                platform_device_unregister(ppc_rtc_pdev);
+                return PTR_ERR(rtc);
+        }
+
+        return 0;
+}
+
+static void __exit ppc_rtc_exit(void)
+{
+        rtc_device_unregister(rtc);
+        platform_device_unregister(ppc_rtc_pdev);
+}
+
+module_init(ppc_rtc_init);
+module_exit(ppc_rtc_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
+MODULE_DESCRIPTION("Generic RTC class driver for PowerPC");