2 files changed, 56 insertions, 0 deletions

diff --git a/arch/arm/mach-omap2/prm44xx.c b/arch/arm/mach-omap2/prm44xx.c
index f106d21ff581..28ffbc55f8d6 100644
--- a/arch/arm/mach-omap2/prm44xx.c
+++ b/arch/arm/mach-omap2/prm44xx.c
@@ -233,6 +233,60 @@ void omap44xx_prm_restore_irqen(u32 *saved_mask)
                                  OMAP4_PRM_IRQENABLE_MPU_2_OFFSET);
 }
 
+/**
+ * omap44xx_prm_reconfigure_io_chain - clear latches and reconfigure I/O chain
+ *
+ * Clear any previously-latched I/O wakeup events and ensure that the
+ * I/O wakeup gates are aligned with the current mux settings.  Works
+ * by asserting WUCLKIN, waiting for WUCLKOUT to be asserted, and then
+ * deasserting WUCLKIN and waiting for WUCLKOUT to be deasserted.
+ * No return value. XXX Are the final two steps necessary?
+ */
+void omap44xx_prm_reconfigure_io_chain(void)
+{
+        int i = 0;
+        u32 v;
+
+        v = omap4_prm_read_inst_reg(OMAP4430_PRM_DEVICE_INST,
+                                    OMAP4_PRM_IO_PMCTRL_OFFSET);
+
+        /* Enable GLOBAL_WUEN */
+        if (!(v & OMAP4430_GLOBAL_WUEN_MASK))
+                omap4_prm_rmw_inst_reg_bits(OMAP4430_GLOBAL_WUEN_MASK,
+                                            OMAP4430_GLOBAL_WUEN_MASK,
+                                            OMAP4430_PRM_DEVICE_INST,
+                                            OMAP4_PRM_IO_PMCTRL_OFFSET);
+
+        /* Trigger WUCLKIN enable */
+        omap4_prm_rmw_inst_reg_bits(OMAP4430_WUCLK_CTRL_MASK,
+                                    OMAP4430_WUCLK_CTRL_MASK,
+                                    OMAP4430_PRM_DEVICE_INST,
+                                    OMAP4_PRM_IO_PMCTRL_OFFSET);
+        omap_test_timeout(
+                (((omap4_prm_read_inst_reg(OMAP4430_PRM_DEVICE_INST,
+                                           OMAP4_PRM_IO_PMCTRL_OFFSET) &
+                   OMAP4430_WUCLK_STATUS_MASK) >>
+                  OMAP4430_WUCLK_STATUS_SHIFT) == 1),
+                MAX_IOPAD_LATCH_TIME, i);
+        if (i == MAX_IOPAD_LATCH_TIME)
+                pr_warn("PRM: I/O chain clock line assertion timed out\n");
+
+        /* Trigger WUCLKIN disable */
+        omap4_prm_rmw_inst_reg_bits(OMAP4430_WUCLK_CTRL_MASK, 0x0,
+                                    OMAP4430_PRM_DEVICE_INST,
+                                    OMAP4_PRM_IO_PMCTRL_OFFSET);
+        omap_test_timeout(
+                (((omap4_prm_read_inst_reg(OMAP4430_PRM_DEVICE_INST,
+                                           OMAP4_PRM_IO_PMCTRL_OFFSET) &
+                   OMAP4430_WUCLK_STATUS_MASK) >>
+                  OMAP4430_WUCLK_STATUS_SHIFT) == 0),
+                MAX_IOPAD_LATCH_TIME, i);
+        if (i == MAX_IOPAD_LATCH_TIME)
+                pr_warn("PRM: I/O chain clock line deassertion timed out\n");
+
+        return;
+}
+
 static int __init omap4xxx_prcm_init(void)
 {
         if (cpu_is_omap44xx())
diff --git a/arch/arm/mach-omap2/prm44xx.h b/arch/arm/mach-omap2/prm44xx.h
index 7978092946db..ee72ae6bd8c9 100644
--- a/arch/arm/mach-omap2/prm44xx.h
+++ b/arch/arm/mach-omap2/prm44xx.h
@@ -763,6 +763,8 @@ extern u32 omap4_prm_vcvp_read(u8 offset);
 extern void omap4_prm_vcvp_write(u32 val, u8 offset);
 extern u32 omap4_prm_vcvp_rmw(u32 mask, u32 bits, u8 offset);
 
+extern void omap44xx_prm_reconfigure_io_chain(void);
+
 /* PRM interrupt-related functions */
 extern void omap44xx_prm_read_pending_irqs(unsigned long *events);
 extern void omap44xx_prm_ocp_barrier(void);