mn10300: use RTC_DRV_CMOS instead of CONFIG_RTC

nn10300 has a dependency on mc146818_get_time/mc146818_set_time,
which we want to move from the mc146818rtc.h header into the
rtc subsystem, which in turn is not usable on mn10300.

This changes mn10300 to use the modern rtc-cmos driver instead
of the old RTC driver, and that in turn lets us completely
remove the read_persistent_clock/update_persistent_clock callbacks.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

1 files changed, 9 insertions, 95 deletions

diff --git a/arch/mn10300/kernel/rtc.c b/arch/mn10300/kernel/rtc.c
index 77e0be4d92ea..f81f37025072 100644
--- a/arch/mn10300/kernel/rtc.c
+++ b/arch/mn10300/kernel/rtc.c
@@ -12,107 +12,19 @@
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/mc146818rtc.h>
-#include <linux/bcd.h>
-#include <linux/timex.h>
+#include <linux/ioport.h>
+#include <linux/platform_device.h>
+
 #include <asm/rtc-regs.h>
 #include <asm/rtc.h>
 
 DEFINE_SPINLOCK(rtc_lock);
 EXPORT_SYMBOL(rtc_lock);
 
-/*
- * Read the current RTC time
- */
-void read_persistent_clock(struct timespec *ts)
-{
-	struct rtc_time tm;
-
-	mc146818_set_time(&tm);
-
-	ts->tv_nsec = 0;
-	ts->tv_sec = mktime(tm.tm_year, tm.tm_mon, tm.tm_mday,
-			    tm.tm_hour, tm.tm_min, tm.tm_sec);
-
-	/* if rtc is way off in the past, set something reasonable */
-	if (ts->tv_sec < 0)
-		ts->tv_sec = mktime(2009, 1, 1, 12, 0, 0);
-}
-
-/*
- * In order to set the CMOS clock precisely, set_rtc_mmss has to be called 500
- * ms after the second nowtime has started, because when nowtime is written
- * into the registers of the CMOS clock, it will jump to the next second
- * precisely 500 ms later.  Check the Motorola MC146818A or Dallas DS12887 data
- * sheet for details.
- *
- * BUG: This routine does not handle hour overflow properly; it just
- *      sets the minutes. Usually you'll only notice that after reboot!
- */
-static int set_rtc_mmss(unsigned long nowtime)
-{
-	unsigned char save_control, save_freq_select;
-	int retval = 0;
-	int real_seconds, real_minutes, cmos_minutes;
-
-	/* gets recalled with irq locally disabled */
-	spin_lock(&rtc_lock);
-	save_control = CMOS_READ(RTC_CONTROL); /* tell the clock it's being
-						* set */
-	CMOS_WRITE(save_control | RTC_SET, RTC_CONTROL);
-
-	save_freq_select = CMOS_READ(RTC_FREQ_SELECT); /* stop and reset
-							* prescaler */
-	CMOS_WRITE(save_freq_select | RTC_DIV_RESET2, RTC_FREQ_SELECT);
-
-	cmos_minutes = CMOS_READ(RTC_MINUTES);
-	if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
-		cmos_minutes = bcd2bin(cmos_minutes);
-
-	/*
-	 * since we're only adjusting minutes and seconds,
-	 * don't interfere with hour overflow. This avoids
-	 * messing with unknown time zones but requires your
-	 * RTC not to be off by more than 15 minutes
-	 */
-	real_seconds = nowtime % 60;
-	real_minutes = nowtime / 60;
-	if (((abs(real_minutes - cmos_minutes) + 15) / 30) & 1)
-		/* correct for half hour time zone */
-		real_minutes += 30;
-	real_minutes %= 60;
-
-	if (abs(real_minutes - cmos_minutes) < 30) {
-		if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
-			real_seconds = bin2bcd(real_seconds);
-			real_minutes = bin2bcd(real_minutes);
-		}
-		CMOS_WRITE(real_seconds, RTC_SECONDS);
-		CMOS_WRITE(real_minutes, RTC_MINUTES);
-	} else {
-		printk_once(KERN_NOTICE
-		       "set_rtc_mmss: can't update from %d to %d\n",
-		       cmos_minutes, real_minutes);
-		retval = -1;
-	}
-
-	/* The following flags have to be released exactly in this order,
-	 * otherwise the DS12887 (popular MC146818A clone with integrated
-	 * battery and quartz) will not reset the oscillator and will not
-	 * update precisely 500 ms later. You won't find this mentioned in
-	 * the Dallas Semiconductor data sheets, but who believes data
-	 * sheets anyway ...                           -- Markus Kuhn
-	 */
-	CMOS_WRITE(save_control, RTC_CONTROL);
-	CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT);
-	spin_unlock(&rtc_lock);
-
-	return retval;
-}
-
-int update_persistent_clock(struct timespec now)
-{
-	return set_rtc_mmss(now.tv_sec);
-}
+static const __initdata struct resource res[] = {
+	DEFINE_RES_IO(RTC_PORT(0), RTC_IO_EXTENT),
+	DEFINE_RES_IRQ(RTC_IRQ),
+};
 
 /*
  * calibrate the TSC clock against the RTC
@@ -129,4 +41,6 @@ void __init calibrate_clock(void)
 	RTCRA |= RTCRA_DVR;
 	RTCRA &= ~RTCRA_DVR;
 	RTCRB &= ~RTCRB_SET;
+
+	platform_device_register_simple("rtc_cmos", -1, res, ARRAY_SIZE(res));
 }