sh: dreamcast: rtc: push down rtc class ops into driver

The SH RTC support has an extra level of indirection to provide
either the old read_persistent_clock/update_persistent_clock
interface or the rtc-generic device for hctosys/systohc.

Both do the same thing for dreamcast, so we can do away with the
abstraction and simply let the RTC core code to take care of it.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

arch/sh/boards/mach-dreamcast/Makefile

@@ -2,5 +2,5 @@
 # Makefile for the Sega Dreamcast specific parts of the kernel
 #
 
-obj-y	 := setup.o irq.o rtc.o
-
+obj-y	 := setup.o irq.o
+obj-$(CONFIG_RTC_DRV_GENERIC) += rtc.o

arch/sh/boards/mach-dreamcast/rtc.c

@@ -11,8 +11,9 @@
  */
 
 #include <linux/time.h>
-#include <asm/rtc.h>
-#include <asm/io.h>
+#include <linux/rtc.h>
+#include <linux/io.h>
+#include <linux/platform_device.h>
 
 /* The AICA RTC has an Epoch of 1/1/1950, so we must subtract 20 years (in
    seconds) to get the standard Unix Epoch when getting the time, and add
@@ -26,13 +27,15 @@
 
 /**
  * aica_rtc_gettimeofday - Get the time from the AICA RTC
- * @ts: pointer to resulting timespec
+ * @dev: the RTC device (ignored)
+ * @tm: pointer to resulting RTC time structure
  *
  * Grabs the current RTC seconds counter and adjusts it to the Unix Epoch.
  */
-static void aica_rtc_gettimeofday(struct timespec *ts)
+static int aica_rtc_gettimeofday(struct device *dev, struct rtc_time *tm)
 {
 	unsigned long val1, val2;
+	time64_t t;
 
 	do {
 		val1 = ((__raw_readl(AICA_RTC_SECS_H) & 0xffff) << 16) |
@@ -42,22 +45,26 @@ static void aica_rtc_gettimeofday(struct timespec *ts)
 			(__raw_readl(AICA_RTC_SECS_L) & 0xffff);
 	} while (val1 != val2);
 
-	ts->tv_sec = val1 - TWENTY_YEARS;
+	/* normalize to 1970..2106 time range */
+	t = (u32)(val1 - TWENTY_YEARS);
 
-	/* Can't get nanoseconds with just a seconds counter. */
-	ts->tv_nsec = 0;
+	rtc_time64_to_tm(t, tm);
+
+	return 0;
 }
 
 /**
  * aica_rtc_settimeofday - Set the AICA RTC to the current time
- * @secs: contains the time_t to set
+ * @dev: the RTC device (ignored)
+ * @tm: pointer to new RTC time structure
  *
  * Adjusts the given @tv to the AICA Epoch and sets the RTC seconds counter.
  */
-static int aica_rtc_settimeofday(const time_t secs)
+static int aica_rtc_settimeofday(struct device *dev, struct rtc_time *tm)
 {
 	unsigned long val1, val2;
-	unsigned long adj = secs + TWENTY_YEARS;
+	time64_t secs = rtc_tm_to_time64(tm);
+	u32 adj = secs + TWENTY_YEARS;
 
 	do {
 		__raw_writel((adj & 0xffff0000) >> 16, AICA_RTC_SECS_H);
@@ -73,9 +80,19 @@ static int aica_rtc_settimeofday(const time_t secs)
 	return 0;
 }
 
-void aica_time_init(void)
-{
-	rtc_sh_get_time = aica_rtc_gettimeofday;
-	rtc_sh_set_time = aica_rtc_settimeofday;
-}
+static const struct rtc_class_ops rtc_generic_ops = {
+	.read_time = aica_rtc_gettimeofday,
+	.set_time = aica_rtc_settimeofday,
+};
 
+static int __init aica_time_init(void)
+{
+	struct platform_device *pdev;
+
+	pdev = platform_device_register_data(NULL, "rtc-generic", -1,
+					     &rtc_generic_ops,
+					     sizeof(rtc_generic_ops));
+
+	return PTR_ERR_OR_ZERO(pdev);
+}
+arch_initcall(aica_time_init);

arch/sh/boards/mach-dreamcast/setup.c

@@ -30,7 +30,6 @@
 
 static void __init dreamcast_setup(char **cmdline_p)
 {
-	board_time_init = aica_time_init;
 }
 
 static struct sh_machine_vector mv_dreamcast __initmv = {

arch/sh/configs/dreamcast_defconfig

@@ -70,3 +70,5 @@ CONFIG_PROC_KCORE=y
 CONFIG_TMPFS=y
 CONFIG_HUGETLBFS=y
 # CONFIG_CRYPTO_ANSI_CPRNG is not set
+CONFIG_RTC_CLASS=y
+CONFIG_RTC_DRV_GENERIC=y

arch/sh/include/mach-dreamcast/mach/sysasic.h

@@ -42,7 +42,6 @@
 /* arch/sh/boards/mach-dreamcast/irq.c */
 extern int systemasic_irq_demux(int);
 extern void systemasic_irq_init(void);
-extern void aica_time_init(void);
 
 #endif /* __ASM_SH_DREAMCAST_SYSASIC_H */