char: rtc: remove unused rtc_control() API

Since commit 34ce71a9 ("ALSA: timer: remove legacy rtctimer"), the
rtc_register/rtc_control/rtc_unregister API is unused. As it is highly
unlikely to be needed again, remove it.
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

drivers/char/rtc.c

@@ -809,89 +809,6 @@ static __poll_t rtc_poll(struct file *file, poll_table *wait)
 }
 #endif
 
-int rtc_register(rtc_task_t *task)
-{
-#ifndef RTC_IRQ
-	return -EIO;
-#else
-	if (task == NULL || task->func == NULL)
-		return -EINVAL;
-	spin_lock_irq(&rtc_lock);
-	if (rtc_status & RTC_IS_OPEN) {
-		spin_unlock_irq(&rtc_lock);
-		return -EBUSY;
-	}
-	spin_lock(&rtc_task_lock);
-	if (rtc_callback) {
-		spin_unlock(&rtc_task_lock);
-		spin_unlock_irq(&rtc_lock);
-		return -EBUSY;
-	}
-	rtc_status |= RTC_IS_OPEN;
-	rtc_callback = task;
-	spin_unlock(&rtc_task_lock);
-	spin_unlock_irq(&rtc_lock);
-	return 0;
-#endif
-}
-EXPORT_SYMBOL(rtc_register);
-
-int rtc_unregister(rtc_task_t *task)
-{
-#ifndef RTC_IRQ
-	return -EIO;
-#else
-	unsigned char tmp;
-
-	spin_lock_irq(&rtc_lock);
-	spin_lock(&rtc_task_lock);
-	if (rtc_callback != task) {
-		spin_unlock(&rtc_task_lock);
-		spin_unlock_irq(&rtc_lock);
-		return -ENXIO;
-	}
-	rtc_callback = NULL;
-
-	/* disable controls */
-	if (!hpet_mask_rtc_irq_bit(RTC_PIE | RTC_AIE | RTC_UIE)) {
-		tmp = CMOS_READ(RTC_CONTROL);
-		tmp &= ~RTC_PIE;
-		tmp &= ~RTC_AIE;
-		tmp &= ~RTC_UIE;
-		CMOS_WRITE(tmp, RTC_CONTROL);
-		CMOS_READ(RTC_INTR_FLAGS);
-	}
-	if (rtc_status & RTC_TIMER_ON) {
-		rtc_status &= ~RTC_TIMER_ON;
-		del_timer(&rtc_irq_timer);
-	}
-	rtc_status &= ~RTC_IS_OPEN;
-	spin_unlock(&rtc_task_lock);
-	spin_unlock_irq(&rtc_lock);
-	return 0;
-#endif
-}
-EXPORT_SYMBOL(rtc_unregister);
-
-int rtc_control(rtc_task_t *task, unsigned int cmd, unsigned long arg)
-{
-#ifndef RTC_IRQ
-	return -EIO;
-#else
-	unsigned long flags;
-	if (cmd != RTC_PIE_ON && cmd != RTC_PIE_OFF && cmd != RTC_IRQP_SET)
-		return -EINVAL;
-	spin_lock_irqsave(&rtc_task_lock, flags);
-	if (rtc_callback != task) {
-		spin_unlock_irqrestore(&rtc_task_lock, flags);
-		return -ENXIO;
-	}
-	spin_unlock_irqrestore(&rtc_task_lock, flags);
-	return rtc_do_ioctl(cmd, arg, 1);
-#endif
-}
-EXPORT_SYMBOL(rtc_control);
-
 /*
  *	The various file operations we support.
  */

include/linux/rtc.h

@@ -211,10 +211,6 @@ void rtc_aie_update_irq(void *private);
 void rtc_uie_update_irq(void *private);
 enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer);
 
-int rtc_register(rtc_task_t *task);
-int rtc_unregister(rtc_task_t *task);
-int rtc_control(rtc_task_t *t, unsigned int cmd, unsigned long arg);
-
 void rtc_timer_init(struct rtc_timer *timer, void (*f)(void *p), void *data);
 int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer *timer,
 		    ktime_t expires, ktime_t period);