1 files changed, 196 insertions, 20 deletions

diff --git a/arch/arm/mach-omap2/clockdomain.c b/arch/arm/mach-omap2/clockdomain.c
index 2af9996f010b..6eaa9314cd64 100644
--- a/arch/arm/mach-omap2/clockdomain.c
+++ b/arch/arm/mach-omap2/clockdomain.c
@@ -113,7 +113,6 @@ static struct clkdm_dep *_clkdm_deps_lookup(struct clockdomain *clkdm,
 		return ERR_PTR(-EINVAL);
 
 	for (cd = deps; cd->clkdm_name; cd++) {
-
 		if (!omap_chip_is(cd->omap_chip))
 			continue;
 
@@ -122,7 +121,6 @@ static struct clkdm_dep *_clkdm_deps_lookup(struct clockdomain *clkdm,
 
 		if (cd->clkdm == clkdm)
 			break;
-
 	}
 
 	if (!cd->clkdm_name)
@@ -254,6 +252,96 @@ 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 */
 
@@ -272,6 +360,7 @@ void clkdm_init(struct clockdomain **clkdms,
 		struct clkdm_autodep *init_autodeps)
 {
 	struct clockdomain **c = NULL;
+	struct clockdomain *clkdm;
 	struct clkdm_autodep *autodep = NULL;
 
 	if (clkdms)
@@ -282,6 +371,15 @@ void clkdm_init(struct clockdomain **clkdms,
 	if (autodeps)
 		for (autodep = autodeps; autodep->clkdm.ptr; autodep++)
 			_autodep_lookup(autodep);
+
+	/*
+	 * Ensure that the *dep_usecount registers reflect the current
+	 * state of the PRCM.
+	 */
+	list_for_each_entry(clkdm, &clkdm_list, node) {
+		_init_wkdep_usecount(clkdm);
+		_init_sleepdep_usecount(clkdm);
+	}
 }
 
 /**
@@ -387,11 +485,13 @@ int clkdm_add_wkdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
 		return PTR_ERR(cd);
 	}
 
-	pr_debug("clockdomain: hardware will wake up %s when %s wakes up\n",
-		 clkdm1->name, clkdm2->name);
+	if (atomic_inc_return(&cd->wkdep_usecount) == 1) {
+		pr_debug("clockdomain: hardware will wake up %s when %s wakes "
+			 "up\n", clkdm1->name, clkdm2->name);
 
-	prm_set_mod_reg_bits((1 << clkdm2->dep_bit),
-			     clkdm1->pwrdm.ptr->prcm_offs, PM_WKDEP);
+		prm_set_mod_reg_bits((1 << clkdm2->dep_bit),
+				     clkdm1->pwrdm.ptr->prcm_offs, PM_WKDEP);
+	}
 
 	return 0;
 }
@@ -420,11 +520,13 @@ int clkdm_del_wkdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
 		return PTR_ERR(cd);
 	}
 
-	pr_debug("clockdomain: hardware will no longer wake up %s after %s "
-		 "wakes up\n", clkdm1->name, clkdm2->name);
+	if (atomic_dec_return(&cd->wkdep_usecount) == 0) {
+		pr_debug("clockdomain: hardware will no longer wake up %s "
+			 "after %s wakes up\n", clkdm1->name, clkdm2->name);
 
-	prm_clear_mod_reg_bits((1 << clkdm2->dep_bit),
-			       clkdm1->pwrdm.ptr->prcm_offs, PM_WKDEP);
+		prm_clear_mod_reg_bits((1 << clkdm2->dep_bit),
+				       clkdm1->pwrdm.ptr->prcm_offs, PM_WKDEP);
+	}
 
 	return 0;
 }
@@ -457,11 +559,44 @@ int clkdm_read_wkdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
 		return PTR_ERR(cd);
 	}
 
+	/* XXX It's faster to return the atomic wkdep_usecount */
 	return prm_read_mod_bits_shift(clkdm1->pwrdm.ptr->prcm_offs, PM_WKDEP,
 				       (1 << clkdm2->dep_bit));
 }
 
 /**
+ * clkdm_clear_all_wkdeps - remove all wakeup dependencies from target clkdm
+ * @clkdm: struct clockdomain * to remove all wakeup dependencies from
+ *
+ * Remove all inter-clockdomain wakeup dependencies that could cause
+ * @clkdm to wake.  Intended to be used during boot to initialize the
+ * PRCM to a known state, after all clockdomains are put into swsup idle
+ * and woken up.  Returns -EINVAL if @clkdm pointer is invalid, or
+ * 0 upon success.
+ */
+int clkdm_clear_all_wkdeps(struct clockdomain *clkdm)
+{
+	struct clkdm_dep *cd;
+	u32 mask = 0;
+
+	if (!clkdm)
+		return -EINVAL;
+
+	for (cd = clkdm->wkdep_srcs; cd && cd->clkdm_name; cd++) {
+		if (!omap_chip_is(cd->omap_chip))
+			continue;
+
+		/* PRM accesses are slow, so minimize them */
+		mask |= 1 << cd->clkdm->dep_bit;
+		atomic_set(&cd->wkdep_usecount, 0);
+	}
+
+	prm_clear_mod_reg_bits(mask, clkdm->pwrdm.ptr->prcm_offs, PM_WKDEP);
+
+	return 0;
+}
+
+/**
  * clkdm_add_sleepdep - add a sleep dependency from clkdm2 to clkdm1
  * @clkdm1: prevent this struct clockdomain * from sleeping (dependent)
  * @clkdm2: when this struct clockdomain * is active (source)
@@ -491,12 +626,14 @@ int clkdm_add_sleepdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
 		return PTR_ERR(cd);
 	}
 
-	pr_debug("clockdomain: will prevent %s from sleeping if %s is active\n",
-		 clkdm1->name, clkdm2->name);
+	if (atomic_inc_return(&cd->sleepdep_usecount) == 1) {
+		pr_debug("clockdomain: will prevent %s from sleeping if %s "
+			 "is active\n", clkdm1->name, clkdm2->name);
 
-	cm_set_mod_reg_bits((1 << clkdm2->dep_bit),
-			    clkdm1->pwrdm.ptr->prcm_offs,
-			    OMAP3430_CM_SLEEPDEP);
+		cm_set_mod_reg_bits((1 << clkdm2->dep_bit),
+				    clkdm1->pwrdm.ptr->prcm_offs,
+				    OMAP3430_CM_SLEEPDEP);
+	}
 
 	return 0;
 }
@@ -531,12 +668,15 @@ int clkdm_del_sleepdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
 		return PTR_ERR(cd);
 	}
 
-	pr_debug("clockdomain: will no longer prevent %s from sleeping if "
-		 "%s is active\n", clkdm1->name, clkdm2->name);
+	if (atomic_dec_return(&cd->sleepdep_usecount) == 0) {
+		pr_debug("clockdomain: will no longer prevent %s from "
+			 "sleeping if %s is active\n", clkdm1->name,
+			 clkdm2->name);
 
-	cm_clear_mod_reg_bits((1 << clkdm2->dep_bit),
-			      clkdm1->pwrdm.ptr->prcm_offs,
-			      OMAP3430_CM_SLEEPDEP);
+		cm_clear_mod_reg_bits((1 << clkdm2->dep_bit),
+				      clkdm1->pwrdm.ptr->prcm_offs,
+				      OMAP3430_CM_SLEEPDEP);
+	}
 
 	return 0;
 }
@@ -575,11 +715,47 @@ int clkdm_read_sleepdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
 		return PTR_ERR(cd);
 	}
 
+	/* XXX It's faster to return the atomic sleepdep_usecount */
 	return prm_read_mod_bits_shift(clkdm1->pwrdm.ptr->prcm_offs,
 				       OMAP3430_CM_SLEEPDEP,
 				       (1 << clkdm2->dep_bit));
 }
 
+/**
+ * clkdm_clear_all_sleepdeps - remove all sleep dependencies from target clkdm
+ * @clkdm: struct clockdomain * to remove all sleep dependencies from
+ *
+ * Remove all inter-clockdomain sleep dependencies that could prevent
+ * @clkdm from idling.  Intended to be used during boot to initialize the
+ * PRCM to a known state, after all clockdomains are put into swsup idle
+ * and woken up.  Returns -EINVAL if @clkdm pointer is invalid, or
+ * 0 upon success.
+ */
+int clkdm_clear_all_sleepdeps(struct clockdomain *clkdm)
+{
+	struct clkdm_dep *cd;
+	u32 mask = 0;
+
+	if (!cpu_is_omap34xx())
+		return -EINVAL;
+
+	if (!clkdm)
+		return -EINVAL;
+
+	for (cd = clkdm->sleepdep_srcs; cd && cd->clkdm_name; cd++) {
+		if (!omap_chip_is(cd->omap_chip))
+			continue;
+
+		/* PRM accesses are slow, so minimize them */
+		mask |= 1 << cd->clkdm->dep_bit;
+		atomic_set(&cd->sleepdep_usecount, 0);
+	}
+
+	prm_clear_mod_reg_bits(mask, clkdm->pwrdm.ptr->prcm_offs,
+			       OMAP3430_CM_SLEEPDEP);
+
+	return 0;
+}
 
 /**
  * omap2_clkdm_clktrctrl_read - read the clkdm's current state transition mode