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>

4 files changed, 23 insertions, 0 deletions

diff --git a/drivers/mfd/db8500-prcmu.c b/drivers/mfd/db8500-prcmu.c
index 4e27db841fab..a1b3464cdba3 100644
--- a/drivers/mfd/db8500-prcmu.c
+++ b/drivers/mfd/db8500-prcmu.c
@@ -904,6 +904,18 @@ bool db8500_prcmu_pending_irq(void)
 }
 
 /*
+ * 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.
  */
diff --git a/drivers/mfd/dbx500-prcmu-regs.h b/drivers/mfd/dbx500-prcmu-regs.h
index b9ab4ce62654..3a0bf91d7780 100644
--- a/drivers/mfd/dbx500-prcmu-regs.h
+++ b/drivers/mfd/dbx500-prcmu-regs.h
@@ -79,6 +79,8 @@
 
 /* ARM WFI Standby signal register */
 #define PRCM_ARM_WFI_STANDBY    (_PRCMU_BASE + 0x130)
+#define PRCM_ARM_WFI_STANDBY_WFI0               0x08
+#define PRCM_ARM_WFI_STANDBY_WFI1               0x10
 #define PRCM_IOCR               (_PRCMU_BASE + 0x310)
 #define PRCM_IOCR_IOFORCE                       0x1
 
diff --git a/include/linux/mfd/db8500-prcmu.h b/include/linux/mfd/db8500-prcmu.h
index 926bdb3adc0f..048a534fde38 100644
--- a/include/linux/mfd/db8500-prcmu.h
+++ b/include/linux/mfd/db8500-prcmu.h
@@ -585,6 +585,7 @@ int db8500_prcmu_gic_recouple(void);
 int db8500_prcmu_copy_gic_settings(void);
 bool db8500_prcmu_gic_pending_irq(void);
 bool db8500_prcmu_pending_irq(void);
+bool db8500_prcmu_is_cpu_in_wfi(int cpu);
 void db8500_prcmu_enable_wakeups(u32 wakeups);
 int db8500_prcmu_set_epod(u16 epod_id, u8 epod_state);
 int db8500_prcmu_request_clock(u8 clock, bool enable);
diff --git a/include/linux/mfd/dbx500-prcmu.h b/include/linux/mfd/dbx500-prcmu.h
index 5c72c07e20e4..eaa99a021785 100644
--- a/include/linux/mfd/dbx500-prcmu.h
+++ b/include/linux/mfd/dbx500-prcmu.h
@@ -305,6 +305,14 @@ static inline bool prcmu_gic_pending_irq(void)
                 return db8500_prcmu_gic_pending_irq();
 }
 
+static inline bool prcmu_is_cpu_in_wfi(int cpu)
+{
+        if (cpu_is_u5500())
+                return -EINVAL;
+        else
+                return db8500_prcmu_is_cpu_in_wfi(cpu);
+}
+
 static inline int prcmu_copy_gic_settings(void)
 {
         if (cpu_is_u5500())