m68k: Hook up rtc-generic

m68k has been a long time user of the generic RTC abstraction, so hook up
rtc-generic:
  - Create the "rtc-generic" platform device if mach_hwclk is set,
  - Add checks for mach_hwclk, in anticipation of RTC chip drivers being moved
    to drivers/rtc/.

Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>

arch/m68k/include/asm/rtc.h

@@ -36,13 +36,16 @@ static inline unsigned int get_rtc_time(struct rtc_time *time)
 	 * RTC has RTC_DAY_OF_WEEK, we ignore it, as it is only updated
 	 * by the RTC when initially set to a non-zero value.
 	 */
-	mach_hwclk(0, time);
+	if (mach_hwclk)
+		mach_hwclk(0, time);
 	return RTC_24H;
 }
 
 static inline int set_rtc_time(struct rtc_time *time)
 {
-	return mach_hwclk(1, time);
+	if (mach_hwclk)
+		return mach_hwclk(1, time);
+	return -EINVAL;
 }
 
 static inline unsigned int get_rtc_ss(void)

arch/m68k/kernel/time.c

@@ -18,6 +18,7 @@
 #include <linux/string.h>
 #include <linux/mm.h>
 #include <linux/rtc.h>
+#include <linux/platform_device.h>
 
 #include <asm/machdep.h>
 #include <asm/io.h>
@@ -159,3 +160,20 @@ int do_settimeofday(struct timespec *tv)
 }
 
 EXPORT_SYMBOL(do_settimeofday);
+
+
+static int __init rtc_init(void)
+{
+	struct platform_device *pdev;
+
+	if (!mach_hwclk)
+		return -ENODEV;
+
+	pdev = platform_device_register_simple("rtc-generic", -1, NULL, 0);
+	if (IS_ERR(pdev))
+		return PTR_ERR(pdev);
+
+	return 0;
+}
+
+module_init(rtc_init);

drivers/rtc/Kconfig

@@ -692,7 +692,7 @@ config RTC_DRV_GENERIC
 	tristate "Generic RTC support"
 	# Please consider writing a new RTC driver instead of using the generic
 	# RTC abstraction
-	depends on PARISC
+	depends on PARISC || M68K
 	help
 	  Say Y or M here to enable RTC support on systems using the generic
 	  RTC abstraction. If you do not know what you are doing, you should