mfd/mc13783: new function reading irq mask and status register

The driver for the mc13783 rtc needs to know if the TODA irq is pending.

Instead of tracking in the rtc driver if the irq is enabled provide that
information, too.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Paul Gortmaker <p_gortmaker@yahoo.com>
Cc: Valentin Longchamp <valentin.longchamp@epfl.ch>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Luotao Fu <l.fu@pengutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/mfd/mc13783-core.c

@@ -269,6 +269,41 @@ int mc13783_irq_unmask(struct mc13783 *mc13783, int irq)
 }
 EXPORT_SYMBOL(mc13783_irq_unmask);
 
+int mc13783_irq_status(struct mc13783 *mc13783, int irq,
+		int *enabled, int *pending)
+{
+	int ret;
+	unsigned int offmask = irq < 24 ? MC13783_IRQMASK0 : MC13783_IRQMASK1;
+	unsigned int offstat = irq < 24 ? MC13783_IRQSTAT0 : MC13783_IRQSTAT1;
+	u32 irqbit = 1 << (irq < 24 ? irq : irq - 24);
+
+	if (irq < 0 || irq >= MC13783_NUM_IRQ)
+		return -EINVAL;
+
+	if (enabled) {
+		u32 mask;
+
+		ret = mc13783_reg_read(mc13783, offmask, &mask);
+		if (ret)
+			return ret;
+
+		*enabled = mask & irqbit;
+	}
+
+	if (pending) {
+		u32 stat;
+
+		ret = mc13783_reg_read(mc13783, offstat, &stat);
+		if (ret)
+			return ret;
+
+		*pending = stat & irqbit;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(mc13783_irq_status);
+
 int mc13783_irq_ack(struct mc13783 *mc13783, int irq)
 {
 	unsigned int offstat = irq < 24 ? MC13783_IRQSTAT0 : MC13783_IRQSTAT1;

include/linux/mfd/mc13783.h

@@ -29,6 +29,8 @@ int mc13783_irq_free(struct mc13783 *mc13783, int irq, void *dev);
 
 int mc13783_irq_mask(struct mc13783 *mc13783, int irq);
 int mc13783_irq_unmask(struct mc13783 *mc13783, int irq);
+int mc13783_irq_status(struct mc13783 *mc13783, int irq,
+		int *enabled, int *pending);
 int mc13783_irq_ack(struct mc13783 *mc13783, int irq);
 
 static inline int mc13783_mask(struct mc13783 *mc13783, int irq) __deprecated;