rtc: cmos: move mc146818rtc code out of asm-generic/rtc.h

Drivers should not really include stuff from asm-generic directly,
and the PC-style cmos rtc driver does this in order to reuse the
mc146818 implementation of get_rtc_time/set_rtc_time rather than
the architecture specific one for the architecture it gets built for.

To make it more obvious what is going on, this moves and renames the
two functions into include/linux/mc146818rtc.h, which holds the
other mc146818 specific code. Ideally it would be in a .c file,
but that would require extra infrastructure as the functions are
called by multiple drivers with conflicting dependencies.

With this change, the asm-generic/rtc.h header also becomes much
more generic, so it can be reused more easily across any architecture
that still relies on the genrtc driver.

The only caller of the internal __get_rtc_time/__set_rtc_time
functions is in arch/alpha/kernel/rtc.c, and we just change those
over to the new naming.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c
index fbe9c72..cf8eb98 100644
--- a/drivers/rtc/rtc-cmos.c
+++ b/drivers/rtc/rtc-cmos.c
@@ -43,7 +43,7 @@
 #include <linux/of_platform.h>
 
 /* this is for "generic access to PC-style RTC" using CMOS_READ/CMOS_WRITE */
-#include <asm-generic/rtc.h>
+#include <linux/mc146818rtc.h>
 
 struct cmos_rtc {
 	struct rtc_device	*rtc;
@@ -190,10 +190,10 @@
 static int cmos_read_time(struct device *dev, struct rtc_time *t)
 {
 	/* REVISIT:  if the clock has a "century" register, use
-	 * that instead of the heuristic in get_rtc_time().
+	 * that instead of the heuristic in mc146818_get_time().
 	 * That'll make Y3K compatility (year > 2070) easy!
 	 */
-	get_rtc_time(t);
+	mc146818_get_time(t);
 	return 0;
 }
 
@@ -205,7 +205,7 @@
 	 * takes effect exactly 500ms after we write the register.
 	 * (Also queueing and other delays before we get this far.)
 	 */
-	return set_rtc_time(t);
+	return mc146818_set_time(t);
 }
 
 static int cmos_read_alarm(struct device *dev, struct rtc_wkalrm *t)
@@ -1142,14 +1142,14 @@
 	if (val)
 		CMOS_WRITE(be32_to_cpup(val), RTC_FREQ_SELECT);
 
-	get_rtc_time(&time);
+	cmos_read_time(&pdev->dev, &time);
 	ret = rtc_valid_tm(&time);
 	if (ret) {
 		struct rtc_time def_time = {
 			.tm_year = 1,
 			.tm_mday = 1,
 		};
-		set_rtc_time(&def_time);
+		cmos_set_time(&pdev->dev, &def_time);
 	}
 }
 #else