OMAP4: hwmod & CM: Implement the omap4_cm_wait_module_ready function

The return of the omap4_cm_wait_module_ready function is checked
in order to avoid accessing the sysconfig register if the module is
not in the correct state.
In that case the _setup will exit without trying to reset
using sysconfig.
For the moment a warning is printed. A proper management of fclk
and module reset will have to be done in order to init correctly
the problematic IPs listed below.

  <4>omap_hwmod: ivahd: cannot be enabled (3)
  <4>omap_hwmod: iss: cannot be enabled (3)
  <4>omap_hwmod: tesla: cannot be enabled (3)
  <4>omap_hwmod: sdma: cannot be enabled (3)
  <4>omap_hwmod: sl2: cannot be enabled (3)
  <4>omap_hwmod: sad2d: cannot be enabled (3)
  <4>omap_hwmod: ducati: cannot be enabled (3)

Signed-off-by: Benoit Cousson <b-cousson@ti.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>

1 files changed, 29 insertions, 7 deletions

diff --git a/arch/arm/mach-omap2/cm4xxx.c b/arch/arm/mach-omap2/cm4xxx.c
index af32a457a46b..b101091e95d6 100644
--- a/arch/arm/mach-omap2/cm4xxx.c
+++ b/arch/arm/mach-omap2/cm4xxx.c
@@ -21,19 +21,41 @@
 
 #include <asm/atomic.h>
 
+#include <plat/common.h>
+
 #include "cm.h"
 #include "cm-regbits-44xx.h"
 
 /**
- * omap4_cm_wait_idlest_ready - wait for a module to leave idle or standby
- * @prcm_mod: PRCM module offset (XXX example)
- * @prcm_dev_offs: PRCM device offset (e.g. MCASP XXX example)
+ * omap4_cm_wait_module_ready - wait for a module to be in 'func' state
+ * @clkctrl_reg: CLKCTRL module address
+ *
+ * Wait for the module IDLEST to be functional. If the idle state is in any
+ * the non functional state (trans, idle or disabled), module and thus the
+ * sysconfig cannot be accessed and will probably lead to an "imprecise
+ * external abort"
+ *
+ * Module idle state:
+ *   0x0 func:     Module is fully functional, including OCP
+ *   0x1 trans:    Module is performing transition: wakeup, or sleep, or sleep
+ *                 abortion
+ *   0x2 idle:     Module is in Idle mode (only OCP part). It is functional if
+ *                 using separate functional clock
+ *   0x3 disabled: Module is disabled and cannot be accessed
  *
- * XXX document
+ * TODO: Need to handle module accessible in idle state
  */
-int omap4_cm_wait_idlest_ready(u32 prcm_mod, u8 prcm_dev_offs)
+int omap4_cm_wait_module_ready(void __iomem *clkctrl_reg)
 {
-	/* FIXME: Add clock manager related code */
-	return 0;
+	int i = 0;
+
+	if (!clkctrl_reg)
+		return 0;
+
+	omap_test_timeout(((__raw_readl(clkctrl_reg) &
+			    OMAP4430_IDLEST_MASK) == 0),
+			  MAX_MODULE_READY_TIME, i);
+
+	return (i < MAX_MODULE_READY_TIME) ? 0 : -EBUSY;
 }