mfd : Check if the other db8500 core is in WFI

This patch allows to check if the other core is in WFI
mode. It is the last check the idle routine has to do before
entering into the retention state.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/mfd/db8500-prcmu.c b/drivers/mfd/db8500-prcmu.c
index 4e27db8..a1b3464 100644
--- a/drivers/mfd/db8500-prcmu.c
+++ b/drivers/mfd/db8500-prcmu.c
@@ -904,6 +904,18 @@
 }
 
 /*
+ * This function checks if the specified cpu is in in WFI. It's usage
+ * makes sense only if the gic is decoupled with the db8500_prcmu_gic_decouple
+ * function. Of course passing smp_processor_id() to this function will
+ * always return false...
+ */
+bool db8500_prcmu_is_cpu_in_wfi(int cpu)
+{
+	return readl(PRCM_ARM_WFI_STANDBY) & cpu ? PRCM_ARM_WFI_STANDBY_WFI1 :
+		     PRCM_ARM_WFI_STANDBY_WFI0;
+}
+
+/*
  * This function copies the gic SPI settings to the prcmu in order to
  * monitor them and abort/finish the retention/off sequence or state.
  */