ARM: OMAP3: PM: Move IO Daisychain function to omap3 prm file

Since IO Daisychain modifies only PRM registers, it makes sense to move
it to PRM File. Also changed the timeout value for IO chain enable to
100us and added a wait for status disable at the end.

Thanks to Nishanth Menon <nm@ti.com> for contributing a fix to the
timeout code waiting for WUCLKOUT to go high.

Signed-off-by: Vishwanath BS <vishwanath.bs@ti.com>
Signed-off-by: Tero Kristo <t-kristo@ti.com>
Cc: Nishanth Menon <nm@ti.com>
Reviewed-by: Rajendra Nayak <rnayak@ti.com>
[paul@pwsan.com: renamed omap3_trigger_io_chain() to better describe the
 end result and to match other PRM functions; removed
 omap3_disable_io_chain(); moved MAX_IOPAD_LATCH_TIME to prcm-common as it
 will also be used by the OMAP4 code; removed unnecessary barrier;
 added kerneldoc; added credit for fix from Nishanth]
Signed-off-by: Paul Walmsley <paul@pwsan.com>

1 files changed, 31 insertions, 0 deletions

diff --git a/arch/arm/mach-omap2/prm2xxx_3xxx.c b/arch/arm/mach-omap2/prm2xxx_3xxx.c
index 9ce765407ad5..7d62bd654dbe 100644
--- a/arch/arm/mach-omap2/prm2xxx_3xxx.c
+++ b/arch/arm/mach-omap2/prm2xxx_3xxx.c
@@ -301,6 +301,37 @@ void omap3xxx_prm_restore_irqen(u32 *saved_mask)
                                 OMAP3_PRM_IRQENABLE_MPU_OFFSET);
 }
 
+/**
+ * omap3xxx_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 clearing the ST_IO_CHAIN WKST bit.  No
+ * return value.
+ */
+void omap3xxx_prm_reconfigure_io_chain(void)
+{
+        int i = 0;
+
+        omap2_prm_set_mod_reg_bits(OMAP3430_EN_IO_CHAIN_MASK, WKUP_MOD,
+                                   PM_WKEN);
+
+        omap_test_timeout(omap2_prm_read_mod_reg(WKUP_MOD, PM_WKST) &
+                          OMAP3430_ST_IO_CHAIN_MASK,
+                          MAX_IOPAD_LATCH_TIME, i);
+        if (i == MAX_IOPAD_LATCH_TIME)
+                pr_warn("PRM: I/O chain clock line assertion timed out\n");
+
+        omap2_prm_clear_mod_reg_bits(OMAP3430_EN_IO_CHAIN_MASK, WKUP_MOD,
+                                     PM_WKEN);
+
+        omap2_prm_set_mod_reg_bits(OMAP3430_ST_IO_CHAIN_MASK, WKUP_MOD,
+                                   PM_WKST);
+
+        omap2_prm_read_mod_reg(WKUP_MOD, PM_WKST);
+}
+
 static int __init omap3xxx_prcm_init(void)
 {
         if (cpu_is_omap34xx())