OMAP clockdomain: initialize clockdomain registers when the clockdomain layer starts

When the clockdomain layer initializes, place all clockdomains into
software-supervised mode, and clear all wakeup and sleep dependencies
immediately, rather than waiting for the PM code to do this later.
This fixes a major bug where critical sleep dependencies added by the
hwmod code are cleared during late PM init.

As a side benefit, the _init_{wk,sleep}dep_usecount() functions are no
longer needed, so remove them.

Kevin Hilman <khilman@deeprootsystems.com> did all the really hard work on
this, identifying the problem and finding the bug.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

diff --git a/arch/arm/mach-omap2/clockdomain.c b/arch/arm/mach-omap2/clockdomain.c
index 5d80cb8..6fb61b1 100644 (file)
--- a/arch/arm/mach-omap2/clockdomain.c
+++ b/arch/arm/mach-omap2/clockdomain.c
@@ -258,97 +258,6 @@ static void _omap2_clkdm_set_hwsup(struct clockdomain *clkdm, int enable)
 
 }
 
-/**
- * _init_wkdep_usecount - initialize wkdep usecounts to match hardware
- * @clkdm: clockdomain to initialize wkdep usecounts
- *
- * Initialize the wakeup dependency usecount variables for clockdomain @clkdm.
- * If a wakeup dependency is present in the hardware, the usecount will be
- * set to 1; otherwise, it will be set to 0.  Software should clear all
- * software wakeup dependencies prior to calling this function if it wishes
- * to ensure that all usecounts start at 0.  No return value.
- */
-static void _init_wkdep_usecount(struct clockdomain *clkdm)
-{
-       u32 v;
-       struct clkdm_dep *cd;
-
-       if (!clkdm->wkdep_srcs)
-               return;
-
-       for (cd = clkdm->wkdep_srcs; cd->clkdm_name; cd++) {
-               if (!omap_chip_is(cd->omap_chip))
-                       continue;
-
-               if (!cd->clkdm && cd->clkdm_name)
-                       cd->clkdm = _clkdm_lookup(cd->clkdm_name);
-
-               if (!cd->clkdm) {
-                       WARN(!cd->clkdm, "clockdomain: %s: wkdep clkdm %s not "
-                            "found\n", clkdm->name, cd->clkdm_name);
-                       continue;
-               }
-
-               v = prm_read_mod_bits_shift(clkdm->pwrdm.ptr->prcm_offs,
-                                           PM_WKDEP,
-                                           (1 << cd->clkdm->dep_bit));
-
-               if (v)
-                       pr_debug("clockdomain: %s: wakeup dependency already "
-                                "set to wake up when %s wakes\n",
-                                clkdm->name, cd->clkdm->name);
-
-               atomic_set(&cd->wkdep_usecount, (v) ? 1 : 0);
-       }
-}
-
-/**
- * _init_sleepdep_usecount - initialize sleepdep usecounts to match hardware
- * @clkdm: clockdomain to initialize sleepdep usecounts
- *
- * Initialize the sleep dependency usecount variables for clockdomain @clkdm.
- * If a sleep dependency is present in the hardware, the usecount will be
- * set to 1; otherwise, it will be set to 0.  Software should clear all
- * software sleep dependencies prior to calling this function if it wishes
- * to ensure that all usecounts start at 0.  No return value.
- */
-static void _init_sleepdep_usecount(struct clockdomain *clkdm)
-{
-       u32 v;
-       struct clkdm_dep *cd;
-
-       if (!cpu_is_omap34xx())
-               return;
-
-       if (!clkdm->sleepdep_srcs)
-               return;
-
-       for (cd = clkdm->sleepdep_srcs; cd->clkdm_name; cd++) {
-               if (!omap_chip_is(cd->omap_chip))
-                       continue;
-
-               if (!cd->clkdm && cd->clkdm_name)
-                       cd->clkdm = _clkdm_lookup(cd->clkdm_name);
-
-               if (!cd->clkdm) {
-                       WARN(!cd->clkdm, "clockdomain: %s: sleepdep clkdm %s "
-                            "not found\n", clkdm->name, cd->clkdm_name);
-                       continue;
-               }
-
-               v = prm_read_mod_bits_shift(clkdm->pwrdm.ptr->prcm_offs,
-                                           OMAP3430_CM_SLEEPDEP,
-                                           (1 << cd->clkdm->dep_bit));
-
-               if (v)
-                       pr_debug("clockdomain: %s: sleep dependency already "
-                                "set to prevent from idling until %s "
-                                "idles\n", clkdm->name, cd->clkdm->name);
-
-               atomic_set(&cd->sleepdep_usecount, (v) ? 1 : 0);
-       }
-};
-
 /* Public functions */
 
 /**
@@ -379,12 +288,17 @@ void clkdm_init(struct clockdomain **clkdms,
                        _autodep_lookup(autodep);
 
        /*
-        * Ensure that the *dep_usecount registers reflect the current
-        * state of the PRCM.
+        * Put all clockdomains into software-supervised mode; PM code
+        * should later enable hardware-supervised mode as appropriate
         */
        list_for_each_entry(clkdm, &clkdm_list, node) {
-               _init_wkdep_usecount(clkdm);
-               _init_sleepdep_usecount(clkdm);
+               if (clkdm->flags & CLKDM_CAN_FORCE_WAKEUP)
+                       omap2_clkdm_wakeup(clkdm);
+               else if (clkdm->flags & CLKDM_CAN_DISABLE_AUTO)
+                       omap2_clkdm_deny_idle(clkdm);
+
+               clkdm_clear_all_wkdeps(clkdm);
+               clkdm_clear_all_sleepdeps(clkdm);
        }
 }
 
@@ -592,6 +506,9 @@ int clkdm_clear_all_wkdeps(struct clockdomain *clkdm)
                if (!omap_chip_is(cd->omap_chip))
                        continue;
 
+               if (!cd->clkdm && cd->clkdm_name)
+                       cd->clkdm = _clkdm_lookup(cd->clkdm_name);
+
                /* PRM accesses are slow, so minimize them */
                mask |= 1 << cd->clkdm->dep_bit;
                atomic_set(&cd->wkdep_usecount, 0);
@@ -752,6 +669,9 @@ int clkdm_clear_all_sleepdeps(struct clockdomain *clkdm)
                if (!omap_chip_is(cd->omap_chip))
                        continue;
 
+               if (!cd->clkdm && cd->clkdm_name)
+                       cd->clkdm = _clkdm_lookup(cd->clkdm_name);
+
                /* PRM accesses are slow, so minimize them */
                mask |= 1 << cd->clkdm->dep_bit;
                atomic_set(&cd->sleepdep_usecount, 0);

diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c
index f5f1dbd..d2b940c 100644 (file)
--- a/arch/arm/mach-omap2/pm34xx.c
+++ b/arch/arm/mach-omap2/pm34xx.c
@@ -949,9 +949,6 @@ static int __init pwrdms_setup(struct powerdomain *pwrdm, void *unused)
  */
 static int __init clkdms_setup(struct clockdomain *clkdm, void *unused)
 {
-       clkdm_clear_all_wkdeps(clkdm);
-       clkdm_clear_all_sleepdeps(clkdm);
-
        if (clkdm->flags & CLKDM_CAN_ENABLE_AUTO)
                omap2_clkdm_allow_idle(clkdm);
        else if (clkdm->flags & CLKDM_CAN_FORCE_SLEEP &&