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, 20 insertions, 13 deletions

diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c
index e436dcb19795..4a134c4d2271 100644
--- a/arch/arm/mach-omap2/omap_hwmod.c
+++ b/arch/arm/mach-omap2/omap_hwmod.c
@@ -819,11 +819,8 @@ static int _wait_target_ready(struct omap_hwmod *oh)
                 ret = omap2_cm_wait_module_ready(oh->prcm.omap2.module_offs,
                                                  oh->prcm.omap2.idlest_reg_id,
                                                  oh->prcm.omap2.idlest_idle_bit);
-#if 0
         } else if (cpu_is_omap44xx()) {
-                ret = omap4_cm_wait_module_ready(oh->prcm.omap4.module_offs,
-                                                 oh->prcm.omap4.device_offs);
-#endif
+                ret = omap4_cm_wait_module_ready(oh->prcm.omap4.clkctrl_reg);
         } else {
                 BUG();
         };
@@ -912,16 +909,21 @@ static int _enable(struct omap_hwmod *oh)
         _add_initiator_dep(oh, mpu_oh);
         _enable_clocks(oh);
 
-        if (oh->class->sysc) {
-                if (!(oh->_int_flags & _HWMOD_SYSCONFIG_LOADED))
-                        _update_sysc_cache(oh);
-                _sysc_enable(oh);
-        }
-
         r = _wait_target_ready(oh);
-        if (!r)
+        if (!r) {
                 oh->_state = _HWMOD_STATE_ENABLED;
 
+                /* Access the sysconfig only if the target is ready */
+                if (oh->class->sysc) {
+                        if (!(oh->_int_flags & _HWMOD_SYSCONFIG_LOADED))
+                                _update_sysc_cache(oh);
+                        _sysc_enable(oh);
+                }
+        } else {
+                pr_debug("omap_hwmod: %s: _wait_target_ready: %d\n",
+                         oh->name, r);
+        }
+
         return r;
 }
 
@@ -999,7 +1001,7 @@ static int _shutdown(struct omap_hwmod *oh)
 static int _setup(struct omap_hwmod *oh)
 {
         struct omap_hwmod_ocp_if *os;
-        int i;
+        int i, r;
 
         if (!oh)
                 return -EINVAL;
@@ -1023,7 +1025,12 @@ static int _setup(struct omap_hwmod *oh)
 
         oh->_state = _HWMOD_STATE_INITIALIZED;
 
-        _enable(oh);
+        r = _enable(oh);
+        if (r) {
+                pr_warning("omap_hwmod: %s: cannot be enabled (%d)\n",
+                           oh->name, oh->_state);
+                return 0;
+        }
 
         if (!(oh->flags & HWMOD_INIT_NO_RESET)) {
                 /*