From 53e1cb469e6cf353aa581e6b0a36cca359ecee25 Mon Sep 17 00:00:00 2001
From: Paul Walmsley
Date: Sat, 26 Jan 2013 00:58:14 -0700
Subject: ARM: OMAP2+: clockdomain: add pwrdm_state_switch() call to
 clkdm_sleep()

In clkdm_sleep(), the powerdomain should be eligible to switch power
states right after the call to the low-level clockdomain sleep
function.  We should have been tracking that with the
pwrdm_state_switch() code, but we weren't, for whatever reason.  Fix that.

This resolves the "pwrdm state mismatch(cam_pwrdm) 3 != 0" that appears
during the OMAP4460 Pandaboard-ES PM test, e.g. here:

http://www.pwsan.com/omap/testlogs/test_v3.8-rc5/20130126003323/pm/4460pandaes/4460pandaes_log.txt

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Tero Kristo <t-kristo@ti.com>
---
 arch/arm/mach-omap2/clockdomain.c | 1 +
 1 file changed, 1 insertion(+)

(limited to 'arch/arm/mach-omap2/clockdomain.c')

diff --git a/arch/arm/mach-omap2/clockdomain.c b/arch/arm/mach-omap2/clockdomain.c
index 7faf82d4e85c..f0ec51497ce2 100644
--- a/arch/arm/mach-omap2/clockdomain.c
+++ b/arch/arm/mach-omap2/clockdomain.c
@@ -764,6 +764,7 @@ int clkdm_sleep(struct clockdomain *clkdm)
 	spin_lock_irqsave(&clkdm->lock, flags);
 	clkdm->_flags &= ~_CLKDM_FLAG_HWSUP_ENABLED;
 	ret = arch_clkdm->clkdm_sleep(clkdm);
+	ret |= pwrdm_state_switch(clkdm->pwrdm.ptr);
 	spin_unlock_irqrestore(&clkdm->lock, flags);
 	return ret;
 }
-- 
cgit v1.2.3


From 3a090284056954f382612da42ebe9f3147403ef5 Mon Sep 17 00:00:00 2001
From: Paul Walmsley
Date: Sat, 26 Jan 2013 00:58:16 -0700
Subject: ARM: OMAP2+: powerdomain/clockdomain: add a per-powerdomain spinlock

Add a per-powerdomain spinlock.  Use that instead of the clockdomain
spinlock.  Add pwrdm_lock()/pwrdm_unlock() functions to allow other
code to acquire or release the powerdomain spinlock without reaching
directly into the struct powerdomain.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Jean Pihet <jean.pihet@newoldbits.com>
---
 arch/arm/mach-omap2/clockdomain.c | 172 +++++++++++++++++++++++++-------------
 arch/arm/mach-omap2/clockdomain.h |   6 +-
 arch/arm/mach-omap2/powerdomain.c |  60 +++++++++++--
 arch/arm/mach-omap2/powerdomain.h |  11 ++-
 4 files changed, 176 insertions(+), 73 deletions(-)

(limited to 'arch/arm/mach-omap2/clockdomain.c')

diff --git a/arch/arm/mach-omap2/clockdomain.c b/arch/arm/mach-omap2/clockdomain.c
index f0ec51497ce2..275bdfbb6fc5 100644
--- a/arch/arm/mach-omap2/clockdomain.c
+++ b/arch/arm/mach-omap2/clockdomain.c
@@ -92,8 +92,6 @@ static int _clkdm_register(struct clockdomain *clkdm)
 
 	pwrdm_add_clkdm(pwrdm, clkdm);
 
-	spin_lock_init(&clkdm->lock);
-
 	pr_debug("clockdomain: registered %s\n", clkdm->name);
 
 	return 0;
@@ -734,18 +732,17 @@ int clkdm_clear_all_sleepdeps(struct clockdomain *clkdm)
 }
 
 /**
- * clkdm_sleep - force clockdomain sleep transition
+ * clkdm_sleep_nolock - force clockdomain sleep transition (lockless)
  * @clkdm: struct clockdomain *
  *
  * Instruct the CM to force a sleep transition on the specified
- * clockdomain @clkdm.  Returns -EINVAL if @clkdm is NULL or if
- * clockdomain does not support software-initiated sleep; 0 upon
- * success.
+ * clockdomain @clkdm.  Only for use by the powerdomain code.  Returns
+ * -EINVAL if @clkdm is NULL or if clockdomain does not support
+ * software-initiated sleep; 0 upon success.
  */
-int clkdm_sleep(struct clockdomain *clkdm)
+int clkdm_sleep_nolock(struct clockdomain *clkdm)
 {
 	int ret;
-	unsigned long flags;
 
 	if (!clkdm)
 		return -EINVAL;
@@ -761,27 +758,45 @@ int clkdm_sleep(struct clockdomain *clkdm)
 
 	pr_debug("clockdomain: forcing sleep on %s\n", clkdm->name);
 
-	spin_lock_irqsave(&clkdm->lock, flags);
 	clkdm->_flags &= ~_CLKDM_FLAG_HWSUP_ENABLED;
 	ret = arch_clkdm->clkdm_sleep(clkdm);
-	ret |= pwrdm_state_switch(clkdm->pwrdm.ptr);
-	spin_unlock_irqrestore(&clkdm->lock, flags);
+	ret |= pwrdm_state_switch_nolock(clkdm->pwrdm.ptr);
+
 	return ret;
 }
 
 /**
- * clkdm_wakeup - force clockdomain wakeup transition
+ * clkdm_sleep - force clockdomain sleep transition
  * @clkdm: struct clockdomain *
  *
- * Instruct the CM to force a wakeup transition on the specified
- * clockdomain @clkdm.  Returns -EINVAL if @clkdm is NULL or if the
- * clockdomain does not support software-controlled wakeup; 0 upon
+ * Instruct the CM to force a sleep transition on the specified
+ * clockdomain @clkdm.  Returns -EINVAL if @clkdm is NULL or if
+ * clockdomain does not support software-initiated sleep; 0 upon
  * success.
  */
-int clkdm_wakeup(struct clockdomain *clkdm)
+int clkdm_sleep(struct clockdomain *clkdm)
+{
+	int ret;
+
+	pwrdm_lock(clkdm->pwrdm.ptr);
+	ret = clkdm_sleep_nolock(clkdm);
+	pwrdm_unlock(clkdm->pwrdm.ptr);
+
+	return ret;
+}
+
+/**
+ * clkdm_wakeup_nolock - force clockdomain wakeup transition (lockless)
+ * @clkdm: struct clockdomain *
+ *
+ * Instruct the CM to force a wakeup transition on the specified
+ * clockdomain @clkdm.  Only for use by the powerdomain code.  Returns
+ * -EINVAL if @clkdm is NULL or if the clockdomain does not support
+ * software-controlled wakeup; 0 upon success.
+ */
+int clkdm_wakeup_nolock(struct clockdomain *clkdm)
 {
 	int ret;
-	unsigned long flags;
 
 	if (!clkdm)
 		return -EINVAL;
@@ -797,28 +812,46 @@ int clkdm_wakeup(struct clockdomain *clkdm)
 
 	pr_debug("clockdomain: forcing wakeup on %s\n", clkdm->name);
 
-	spin_lock_irqsave(&clkdm->lock, flags);
 	clkdm->_flags &= ~_CLKDM_FLAG_HWSUP_ENABLED;
 	ret = arch_clkdm->clkdm_wakeup(clkdm);
-	ret |= pwrdm_state_switch(clkdm->pwrdm.ptr);
-	spin_unlock_irqrestore(&clkdm->lock, flags);
+	ret |= pwrdm_state_switch_nolock(clkdm->pwrdm.ptr);
+
 	return ret;
 }
 
 /**
- * clkdm_allow_idle - enable hwsup idle transitions for clkdm
+ * clkdm_wakeup - force clockdomain wakeup transition
  * @clkdm: struct clockdomain *
  *
- * Allow the hardware to automatically switch the clockdomain @clkdm into
- * active or idle states, as needed by downstream clocks.  If the
+ * Instruct the CM to force a wakeup transition on the specified
+ * clockdomain @clkdm.  Returns -EINVAL if @clkdm is NULL or if the
+ * clockdomain does not support software-controlled wakeup; 0 upon
+ * success.
+ */
+int clkdm_wakeup(struct clockdomain *clkdm)
+{
+	int ret;
+
+	pwrdm_lock(clkdm->pwrdm.ptr);
+	ret = clkdm_wakeup_nolock(clkdm);
+	pwrdm_unlock(clkdm->pwrdm.ptr);
+
+	return ret;
+}
+
+/**
+ * clkdm_allow_idle_nolock - enable hwsup idle transitions for clkdm
+ * @clkdm: struct clockdomain *
+ *
+ * Allow the hardware to automatically switch the clockdomain @clkdm
+ * into active or idle states, as needed by downstream clocks.  If the
  * clockdomain has any downstream clocks enabled in the clock
  * framework, wkdep/sleepdep autodependencies are added; this is so
- * device drivers can read and write to the device.  No return value.
+ * device drivers can read and write to the device.  Only for use by
+ * the powerdomain code.  No return value.
  */
-void clkdm_allow_idle(struct clockdomain *clkdm)
+void clkdm_allow_idle_nolock(struct clockdomain *clkdm)
 {
-	unsigned long flags;
-
 	if (!clkdm)
 		return;
 
@@ -834,11 +867,26 @@ void clkdm_allow_idle(struct clockdomain *clkdm)
 	pr_debug("clockdomain: enabling automatic idle transitions for %s\n",
 		 clkdm->name);
 
-	spin_lock_irqsave(&clkdm->lock, flags);
 	clkdm->_flags |= _CLKDM_FLAG_HWSUP_ENABLED;
 	arch_clkdm->clkdm_allow_idle(clkdm);
-	pwrdm_state_switch(clkdm->pwrdm.ptr);
-	spin_unlock_irqrestore(&clkdm->lock, flags);
+	pwrdm_state_switch_nolock(clkdm->pwrdm.ptr);
+}
+
+/**
+ * clkdm_allow_idle - enable hwsup idle transitions for clkdm
+ * @clkdm: struct clockdomain *
+ *
+ * Allow the hardware to automatically switch the clockdomain @clkdm into
+ * active or idle states, as needed by downstream clocks.  If the
+ * clockdomain has any downstream clocks enabled in the clock
+ * framework, wkdep/sleepdep autodependencies are added; this is so
+ * device drivers can read and write to the device.  No return value.
+ */
+void clkdm_allow_idle(struct clockdomain *clkdm)
+{
+	pwrdm_lock(clkdm->pwrdm.ptr);
+	clkdm_allow_idle_nolock(clkdm);
+	pwrdm_unlock(clkdm->pwrdm.ptr);
 }
 
 /**
@@ -848,12 +896,11 @@ void clkdm_allow_idle(struct clockdomain *clkdm)
  * Prevent the hardware from automatically switching the clockdomain
  * @clkdm into inactive or idle states.  If the clockdomain has
  * downstream clocks enabled in the clock framework, wkdep/sleepdep
- * autodependencies are removed.  No return value.
+ * autodependencies are removed.  Only for use by the powerdomain
+ * code.  No return value.
  */
-void clkdm_deny_idle(struct clockdomain *clkdm)
+void clkdm_deny_idle_nolock(struct clockdomain *clkdm)
 {
-	unsigned long flags;
-
 	if (!clkdm)
 		return;
 
@@ -869,11 +916,25 @@ void clkdm_deny_idle(struct clockdomain *clkdm)
 	pr_debug("clockdomain: disabling automatic idle transitions for %s\n",
 		 clkdm->name);
 
-	spin_lock_irqsave(&clkdm->lock, flags);
 	clkdm->_flags &= ~_CLKDM_FLAG_HWSUP_ENABLED;
 	arch_clkdm->clkdm_deny_idle(clkdm);
-	pwrdm_state_switch(clkdm->pwrdm.ptr);
-	spin_unlock_irqrestore(&clkdm->lock, flags);
+	pwrdm_state_switch_nolock(clkdm->pwrdm.ptr);
+}
+
+/**
+ * clkdm_deny_idle - disable hwsup idle transitions for clkdm
+ * @clkdm: struct clockdomain *
+ *
+ * Prevent the hardware from automatically switching the clockdomain
+ * @clkdm into inactive or idle states.  If the clockdomain has
+ * downstream clocks enabled in the clock framework, wkdep/sleepdep
+ * autodependencies are removed.  No return value.
+ */
+void clkdm_deny_idle(struct clockdomain *clkdm)
+{
+	pwrdm_lock(clkdm->pwrdm.ptr);
+	clkdm_deny_idle_nolock(clkdm);
+	pwrdm_unlock(clkdm->pwrdm.ptr);
 }
 
 /**
@@ -890,14 +951,11 @@ void clkdm_deny_idle(struct clockdomain *clkdm)
 bool clkdm_in_hwsup(struct clockdomain *clkdm)
 {
 	bool ret;
-	unsigned long flags;
 
 	if (!clkdm)
 		return false;
 
-	spin_lock_irqsave(&clkdm->lock, flags);
 	ret = (clkdm->_flags & _CLKDM_FLAG_HWSUP_ENABLED) ? true : false;
-	spin_unlock_irqrestore(&clkdm->lock, flags);
 
 	return ret;
 }
@@ -923,12 +981,10 @@ bool clkdm_missing_idle_reporting(struct clockdomain *clkdm)
 
 static int _clkdm_clk_hwmod_enable(struct clockdomain *clkdm)
 {
-	unsigned long flags;
-
 	if (!clkdm || !arch_clkdm || !arch_clkdm->clkdm_clk_enable)
 		return -EINVAL;
 
-	spin_lock_irqsave(&clkdm->lock, flags);
+	pwrdm_lock(clkdm->pwrdm.ptr);
 
 	/*
 	 * For arch's with no autodeps, clkcm_clk_enable
@@ -936,13 +992,13 @@ static int _clkdm_clk_hwmod_enable(struct clockdomain *clkdm)
 	 * enabled, so the clkdm can be force woken up.
 	 */
 	if ((atomic_inc_return(&clkdm->usecount) > 1) && autodeps) {
-		spin_unlock_irqrestore(&clkdm->lock, flags);
+		pwrdm_unlock(clkdm->pwrdm.ptr);
 		return 0;
 	}
 
 	arch_clkdm->clkdm_clk_enable(clkdm);
-	pwrdm_state_switch(clkdm->pwrdm.ptr);
-	spin_unlock_irqrestore(&clkdm->lock, flags);
+	pwrdm_state_switch_nolock(clkdm->pwrdm.ptr);
+	pwrdm_unlock(clkdm->pwrdm.ptr);
 
 	pr_debug("clockdomain: %s: enabled\n", clkdm->name);
 
@@ -991,12 +1047,10 @@ int clkdm_clk_enable(struct clockdomain *clkdm, struct clk *clk)
  */
 int clkdm_clk_disable(struct clockdomain *clkdm, struct clk *clk)
 {
-	unsigned long flags;
-
 	if (!clkdm || !clk || !arch_clkdm || !arch_clkdm->clkdm_clk_disable)
 		return -EINVAL;
 
-	spin_lock_irqsave(&clkdm->lock, flags);
+	pwrdm_lock(clkdm->pwrdm.ptr);
 
 	/* corner case: disabling unused clocks */
 	if ((__clk_get_enable_count(clk) == 0) &&
@@ -1004,23 +1058,23 @@ int clkdm_clk_disable(struct clockdomain *clkdm, struct clk *clk)
 		goto ccd_exit;
 
 	if (atomic_read(&clkdm->usecount) == 0) {
-		spin_unlock_irqrestore(&clkdm->lock, flags);
+		pwrdm_unlock(clkdm->pwrdm.ptr);
 		WARN_ON(1); /* underflow */
 		return -ERANGE;
 	}
 
 	if (atomic_dec_return(&clkdm->usecount) > 0) {
-		spin_unlock_irqrestore(&clkdm->lock, flags);
+		pwrdm_unlock(clkdm->pwrdm.ptr);
 		return 0;
 	}
 
 	arch_clkdm->clkdm_clk_disable(clkdm);
-	pwrdm_state_switch(clkdm->pwrdm.ptr);
+	pwrdm_state_switch_nolock(clkdm->pwrdm.ptr);
 
 	pr_debug("clockdomain: %s: disabled\n", clkdm->name);
 
 ccd_exit:
-	spin_unlock_irqrestore(&clkdm->lock, flags);
+	pwrdm_unlock(clkdm->pwrdm.ptr);
 
 	return 0;
 }
@@ -1073,8 +1127,6 @@ int clkdm_hwmod_enable(struct clockdomain *clkdm, struct omap_hwmod *oh)
  */
 int clkdm_hwmod_disable(struct clockdomain *clkdm, struct omap_hwmod *oh)
 {
-	unsigned long flags;
-
 	/* The clkdm attribute does not exist yet prior OMAP4 */
 	if (cpu_is_omap24xx() || cpu_is_omap34xx())
 		return 0;
@@ -1087,22 +1139,22 @@ int clkdm_hwmod_disable(struct clockdomain *clkdm, struct omap_hwmod *oh)
 	if (!clkdm || !oh || !arch_clkdm || !arch_clkdm->clkdm_clk_disable)
 		return -EINVAL;
 
-	spin_lock_irqsave(&clkdm->lock, flags);
+	pwrdm_lock(clkdm->pwrdm.ptr);
 
 	if (atomic_read(&clkdm->usecount) == 0) {
-		spin_unlock_irqrestore(&clkdm->lock, flags);
+		pwrdm_unlock(clkdm->pwrdm.ptr);
 		WARN_ON(1); /* underflow */
 		return -ERANGE;
 	}
 
 	if (atomic_dec_return(&clkdm->usecount) > 0) {
-		spin_unlock_irqrestore(&clkdm->lock, flags);
+		pwrdm_unlock(clkdm->pwrdm.ptr);
 		return 0;
 	}
 
 	arch_clkdm->clkdm_clk_disable(clkdm);
-	pwrdm_state_switch(clkdm->pwrdm.ptr);
-	spin_unlock_irqrestore(&clkdm->lock, flags);
+	pwrdm_state_switch_nolock(clkdm->pwrdm.ptr);
+	pwrdm_unlock(clkdm->pwrdm.ptr);
 
 	pr_debug("clockdomain: %s: disabled\n", clkdm->name);
 
diff --git a/arch/arm/mach-omap2/clockdomain.h b/arch/arm/mach-omap2/clockdomain.h
index bc42446e23ab..e7f1b4ba2d5b 100644
--- a/arch/arm/mach-omap2/clockdomain.h
+++ b/arch/arm/mach-omap2/clockdomain.h
@@ -15,7 +15,6 @@
 #define __ARCH_ARM_MACH_OMAP2_CLOCKDOMAIN_H
 
 #include <linux/init.h>
-#include <linux/spinlock.h>
 
 #include "powerdomain.h"
 #include "clock.h"
@@ -139,7 +138,6 @@ struct clockdomain {
 	struct clkdm_dep *sleepdep_srcs;
 	atomic_t usecount;
 	struct list_head node;
-	spinlock_t lock;
 };
 
 /**
@@ -196,12 +194,16 @@ int clkdm_del_sleepdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2);
 int clkdm_read_sleepdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2);
 int clkdm_clear_all_sleepdeps(struct clockdomain *clkdm);
 
+void clkdm_allow_idle_nolock(struct clockdomain *clkdm);
 void clkdm_allow_idle(struct clockdomain *clkdm);
+void clkdm_deny_idle_nolock(struct clockdomain *clkdm);
 void clkdm_deny_idle(struct clockdomain *clkdm);
 bool clkdm_in_hwsup(struct clockdomain *clkdm);
 bool clkdm_missing_idle_reporting(struct clockdomain *clkdm);
 
+int clkdm_wakeup_nolock(struct clockdomain *clkdm);
 int clkdm_wakeup(struct clockdomain *clkdm);
+int clkdm_sleep_nolock(struct clockdomain *clkdm);
 int clkdm_sleep(struct clockdomain *clkdm);
 
 int clkdm_clk_enable(struct clockdomain *clkdm, struct clk *clk);
diff --git a/arch/arm/mach-omap2/powerdomain.c b/arch/arm/mach-omap2/powerdomain.c
index 65c34645c8ed..8e61d80bf6b3 100644
--- a/arch/arm/mach-omap2/powerdomain.c
+++ b/arch/arm/mach-omap2/powerdomain.c
@@ -19,6 +19,7 @@
 #include <linux/list.h>
 #include <linux/errno.h>
 #include <linux/string.h>
+#include <linux/spinlock.h>
 #include <trace/events/power.h>
 
 #include "cm2xxx_3xxx.h"
@@ -111,6 +112,7 @@ static int _pwrdm_register(struct powerdomain *pwrdm)
 	pwrdm->voltdm.ptr = voltdm;
 	INIT_LIST_HEAD(&pwrdm->voltdm_node);
 	voltdm_add_pwrdm(voltdm, pwrdm);
+	spin_lock_init(&pwrdm->_lock);
 
 	list_add(&pwrdm->node, &pwrdm_list);
 
@@ -241,7 +243,7 @@ static u8 _pwrdm_save_clkdm_state_and_activate(struct powerdomain *pwrdm,
 			sleep_switch = LOWPOWERSTATE_SWITCH;
 		} else {
 			*hwsup = clkdm_in_hwsup(pwrdm->pwrdm_clkdms[0]);
-			clkdm_wakeup(pwrdm->pwrdm_clkdms[0]);
+			clkdm_wakeup_nolock(pwrdm->pwrdm_clkdms[0]);
 			sleep_switch = FORCEWAKEUP_SWITCH;
 		}
 	} else {
@@ -271,15 +273,15 @@ static void _pwrdm_restore_clkdm_state(struct powerdomain *pwrdm,
 	switch (sleep_switch) {
 	case FORCEWAKEUP_SWITCH:
 		if (hwsup)
-			clkdm_allow_idle(pwrdm->pwrdm_clkdms[0]);
+			clkdm_allow_idle_nolock(pwrdm->pwrdm_clkdms[0]);
 		else
-			clkdm_sleep(pwrdm->pwrdm_clkdms[0]);
+			clkdm_sleep_nolock(pwrdm->pwrdm_clkdms[0]);
 		break;
 	case LOWPOWERSTATE_SWITCH:
 		if (pwrdm->flags & PWRDM_HAS_LOWPOWERSTATECHANGE &&
 		    arch_pwrdm->pwrdm_set_lowpwrstchange)
 			arch_pwrdm->pwrdm_set_lowpwrstchange(pwrdm);
-		pwrdm_state_switch(pwrdm);
+		pwrdm_state_switch_nolock(pwrdm);
 		break;
 	}
 }
@@ -359,6 +361,30 @@ int pwrdm_complete_init(void)
 	return 0;
 }
 
+/**
+ * pwrdm_lock - acquire a Linux spinlock on a powerdomain
+ * @pwrdm: struct powerdomain * to lock
+ *
+ * Acquire the powerdomain spinlock on @pwrdm.  No return value.
+ */
+void pwrdm_lock(struct powerdomain *pwrdm)
+	__acquires(&pwrdm->_lock)
+{
+	spin_lock_irqsave(&pwrdm->_lock, pwrdm->_lock_flags);
+}
+
+/**
+ * pwrdm_unlock - release a Linux spinlock on a powerdomain
+ * @pwrdm: struct powerdomain * to unlock
+ *
+ * Release the powerdomain spinlock on @pwrdm.  No return value.
+ */
+void pwrdm_unlock(struct powerdomain *pwrdm)
+	__releases(&pwrdm->_lock)
+{
+	spin_unlock_irqrestore(&pwrdm->_lock, pwrdm->_lock_flags);
+}
+
 /**
  * pwrdm_lookup - look up a powerdomain by name, return a pointer
  * @name: name of powerdomain
@@ -1005,7 +1031,7 @@ bool pwrdm_has_hdwr_sar(struct powerdomain *pwrdm)
 	return (pwrdm && pwrdm->flags & PWRDM_HAS_HDWR_SAR) ? 1 : 0;
 }
 
-int pwrdm_state_switch(struct powerdomain *pwrdm)
+int pwrdm_state_switch_nolock(struct powerdomain *pwrdm)
 {
 	int ret;
 
@@ -1019,6 +1045,17 @@ int pwrdm_state_switch(struct powerdomain *pwrdm)
 	return ret;
 }
 
+int __deprecated pwrdm_state_switch(struct powerdomain *pwrdm)
+{
+	int ret;
+
+	pwrdm_lock(pwrdm);
+	ret = pwrdm_state_switch_nolock(pwrdm);
+	pwrdm_unlock(pwrdm);
+
+	return ret;
+}
+
 int pwrdm_pre_transition(struct powerdomain *pwrdm)
 {
 	if (pwrdm)
@@ -1067,15 +1104,19 @@ int omap_set_pwrdm_state(struct powerdomain *pwrdm, u8 pwrst)
 		pwrst--;
 	}
 
+	pwrdm_lock(pwrdm);
+
 	curr_pwrst = pwrdm_read_pwrst(pwrdm);
 	next_pwrst = pwrdm_read_next_pwrst(pwrdm);
 	if (curr_pwrst == pwrst && next_pwrst == pwrst)
-		return ret;
+		goto osps_out;
 
 	sleep_switch = _pwrdm_save_clkdm_state_and_activate(pwrdm, curr_pwrst,
 							    pwrst, &hwsup);
-	if (sleep_switch == ERROR_SWITCH)
-		return -EINVAL;
+	if (sleep_switch == ERROR_SWITCH) {
+		ret = -EINVAL;
+		goto osps_out;
+	}
 
 	ret = pwrdm_set_next_pwrst(pwrdm, pwrst);
 	if (ret)
@@ -1084,6 +1125,9 @@ int omap_set_pwrdm_state(struct powerdomain *pwrdm, u8 pwrst)
 
 	_pwrdm_restore_clkdm_state(pwrdm, sleep_switch, hwsup);
 
+osps_out:
+	pwrdm_unlock(pwrdm);
+
 	return ret;
 }
 
diff --git a/arch/arm/mach-omap2/powerdomain.h b/arch/arm/mach-omap2/powerdomain.h
index 93e7df824650..909cc5c1c23a 100644
--- a/arch/arm/mach-omap2/powerdomain.h
+++ b/arch/arm/mach-omap2/powerdomain.h
@@ -19,8 +19,7 @@
 
 #include <linux/types.h>
 #include <linux/list.h>
-
-#include <linux/atomic.h>
+#include <linux/spinlock.h>
 
 #include "voltage.h"
 
@@ -103,6 +102,8 @@ struct powerdomain;
  * @state_counter:
  * @timer:
  * @state_timer:
+ * @_lock: spinlock used to serialize powerdomain and some clockdomain ops
+ * @_lock_flags: stored flags when @_lock is taken
  *
  * @prcm_partition possible values are defined in mach-omap2/prcm44xx.h.
  */
@@ -127,7 +128,8 @@ struct powerdomain {
 	unsigned state_counter[PWRDM_MAX_PWRSTS];
 	unsigned ret_logic_off_counter;
 	unsigned ret_mem_off_counter[PWRDM_MAX_MEM_BANKS];
-
+	spinlock_t _lock;
+	unsigned long _lock_flags;
 	const u8 pwrstctrl_offs;
 	const u8 pwrstst_offs;
 	const u32 logicretstate_mask;
@@ -235,6 +237,7 @@ int pwrdm_enable_hdwr_sar(struct powerdomain *pwrdm);
 int pwrdm_disable_hdwr_sar(struct powerdomain *pwrdm);
 bool pwrdm_has_hdwr_sar(struct powerdomain *pwrdm);
 
+int pwrdm_state_switch_nolock(struct powerdomain *pwrdm);
 int pwrdm_state_switch(struct powerdomain *pwrdm);
 int pwrdm_pre_transition(struct powerdomain *pwrdm);
 int pwrdm_post_transition(struct powerdomain *pwrdm);
@@ -262,5 +265,7 @@ extern u32 omap2_pwrdm_get_mem_bank_stst_mask(u8 bank);
 extern struct powerdomain wkup_omap2_pwrdm;
 extern struct powerdomain gfx_omap2_pwrdm;
 
+extern void pwrdm_lock(struct powerdomain *pwrdm);
+extern void pwrdm_unlock(struct powerdomain *pwrdm);
 
 #endif
-- 
cgit v1.2.3


From 65958fb6ca7b7e504caf852e492fe554224de1ba Mon Sep 17 00:00:00 2001
From: Paul Walmsley
Date: Sat, 26 Jan 2013 00:58:17 -0700
Subject: ARM: OMAP2+: clockdomain: work on wkdep/sleepdep functions

Split the clkdm_(add|del)_(wk|sleep)dep() functions into lockless and
locking versions -- this will be needed in a subsequent patch.  Also,
while here, remove the leading underscore, since these are not
currently static functions.  And for functions that have
kerneldoc-style comment blocks, but which are missing the initial
'/**' tag, fix the tag to indicate that they are kerneldoc.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
---
 arch/arm/mach-omap2/clockdomain.c | 394 ++++++++++++++++++++++----------------
 arch/arm/mach-omap2/clockdomain.h |   5 +-
 arch/arm/mach-omap2/cm3xxx.c      |   8 +-
 3 files changed, 240 insertions(+), 167 deletions(-)

(limited to 'arch/arm/mach-omap2/clockdomain.c')

diff --git a/arch/arm/mach-omap2/clockdomain.c b/arch/arm/mach-omap2/clockdomain.c
index 275bdfbb6fc5..ab194753eb7a 100644
--- a/arch/arm/mach-omap2/clockdomain.c
+++ b/arch/arm/mach-omap2/clockdomain.c
@@ -120,7 +120,7 @@ static struct clkdm_dep *_clkdm_deps_lookup(struct clockdomain *clkdm,
 	return cd;
 }
 
-/*
+/**
  * _autodep_lookup - resolve autodep clkdm names to clkdm pointers; store
  * @autodep: struct clkdm_autodep * to resolve
  *
@@ -152,88 +152,202 @@ static void _autodep_lookup(struct clkdm_autodep *autodep)
 	autodep->clkdm.ptr = clkdm;
 }
 
-/*
- * _clkdm_add_autodeps - add auto sleepdeps/wkdeps to clkdm upon clock enable
- * @clkdm: struct clockdomain *
+/**
+ * _resolve_clkdm_deps() - resolve clkdm_names in @clkdm_deps to clkdms
+ * @clkdm: clockdomain that we are resolving dependencies for
+ * @clkdm_deps: ptr to array of struct clkdm_deps to resolve
  *
- * Add the "autodep" sleep & wakeup dependencies to clockdomain 'clkdm'
- * in hardware-supervised mode.  Meant to be called from clock framework
- * when a clock inside clockdomain 'clkdm' is enabled.	No return value.
+ * Iterates through @clkdm_deps, looking up the struct clockdomain named by
+ * clkdm_name and storing the clockdomain pointer in the struct clkdm_dep.
+ * No return value.
+ */
+static void _resolve_clkdm_deps(struct clockdomain *clkdm,
+				struct clkdm_dep *clkdm_deps)
+{
+	struct clkdm_dep *cd;
+
+	for (cd = clkdm_deps; cd && cd->clkdm_name; cd++) {
+		if (cd->clkdm)
+			continue;
+		cd->clkdm = _clkdm_lookup(cd->clkdm_name);
+
+		WARN(!cd->clkdm, "clockdomain: %s: could not find clkdm %s while resolving dependencies - should never happen",
+		     clkdm->name, cd->clkdm_name);
+	}
+}
+
+/**
+ * _clkdm_add_wkdep - add a wakeup dependency from clkdm2 to clkdm1 (lockless)
+ * @clkdm1: wake this struct clockdomain * up (dependent)
+ * @clkdm2: when this struct clockdomain * wakes up (source)
  *
- * XXX autodeps are deprecated and should be removed at the earliest
- * opportunity
+ * When the clockdomain represented by @clkdm2 wakes up, wake up
+ * @clkdm1. Implemented in hardware on the OMAP, this feature is
+ * designed to reduce wakeup latency of the dependent clockdomain @clkdm1.
+ * Returns -EINVAL if presented with invalid clockdomain pointers,
+ * -ENOENT if @clkdm2 cannot wake up clkdm1 in hardware, or 0 upon
+ * success.
  */
-void _clkdm_add_autodeps(struct clockdomain *clkdm)
+static int _clkdm_add_wkdep(struct clockdomain *clkdm1,
+			    struct clockdomain *clkdm2)
 {
-	struct clkdm_autodep *autodep;
+	struct clkdm_dep *cd;
+	int ret = 0;
 
-	if (!autodeps || clkdm->flags & CLKDM_NO_AUTODEPS)
-		return;
+	if (!clkdm1 || !clkdm2)
+		return -EINVAL;
 
-	for (autodep = autodeps; autodep->clkdm.ptr; autodep++) {
-		if (IS_ERR(autodep->clkdm.ptr))
-			continue;
+	cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs);
+	if (IS_ERR(cd))
+		ret = PTR_ERR(cd);
 
-		pr_debug("clockdomain: %s: adding %s sleepdep/wkdep\n",
-			 clkdm->name, autodep->clkdm.ptr->name);
+	if (!arch_clkdm || !arch_clkdm->clkdm_add_wkdep)
+		ret = -EINVAL;
 
-		clkdm_add_sleepdep(clkdm, autodep->clkdm.ptr);
-		clkdm_add_wkdep(clkdm, autodep->clkdm.ptr);
+	if (ret) {
+		pr_debug("clockdomain: hardware cannot set/clear wake up of %s when %s wakes up\n",
+			 clkdm1->name, clkdm2->name);
+		return ret;
+	}
+
+	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);
+
+		ret = arch_clkdm->clkdm_add_wkdep(clkdm1, clkdm2);
 	}
+
+	return ret;
 }
 
-/*
- * _clkdm_add_autodeps - remove auto sleepdeps/wkdeps from clkdm
- * @clkdm: struct clockdomain *
+/**
+ * _clkdm_del_wkdep - remove a wakeup dep from clkdm2 to clkdm1 (lockless)
+ * @clkdm1: wake this struct clockdomain * up (dependent)
+ * @clkdm2: when this struct clockdomain * wakes up (source)
  *
- * Remove the "autodep" sleep & wakeup dependencies from clockdomain 'clkdm'
- * in hardware-supervised mode.  Meant to be called from clock framework
- * when a clock inside clockdomain 'clkdm' is disabled.  No return value.
+ * Remove a wakeup dependency causing @clkdm1 to wake up when @clkdm2
+ * wakes up.  Returns -EINVAL if presented with invalid clockdomain
+ * pointers, -ENOENT if @clkdm2 cannot wake up clkdm1 in hardware, or
+ * 0 upon success.
+ */
+static int _clkdm_del_wkdep(struct clockdomain *clkdm1,
+			    struct clockdomain *clkdm2)
+{
+	struct clkdm_dep *cd;
+	int ret = 0;
+
+	if (!clkdm1 || !clkdm2)
+		return -EINVAL;
+
+	cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs);
+	if (IS_ERR(cd))
+		ret = PTR_ERR(cd);
+
+	if (!arch_clkdm || !arch_clkdm->clkdm_del_wkdep)
+		ret = -EINVAL;
+
+	if (ret) {
+		pr_debug("clockdomain: hardware cannot set/clear wake up of %s when %s wakes up\n",
+			 clkdm1->name, clkdm2->name);
+		return ret;
+	}
+
+	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);
+
+		ret = arch_clkdm->clkdm_del_wkdep(clkdm1, clkdm2);
+	}
+
+	return ret;
+}
+
+/**
+ * _clkdm_add_sleepdep - add a sleep dependency from clkdm2 to clkdm1 (lockless)
+ * @clkdm1: prevent this struct clockdomain * from sleeping (dependent)
+ * @clkdm2: when this struct clockdomain * is active (source)
  *
- * XXX autodeps are deprecated and should be removed at the earliest
- * opportunity
+ * Prevent @clkdm1 from automatically going inactive (and then to
+ * retention or off) if @clkdm2 is active.  Returns -EINVAL if
+ * presented with invalid clockdomain pointers or called on a machine
+ * that does not support software-configurable hardware sleep
+ * dependencies, -ENOENT if the specified dependency cannot be set in
+ * hardware, or 0 upon success.
  */
-void _clkdm_del_autodeps(struct clockdomain *clkdm)
+static int _clkdm_add_sleepdep(struct clockdomain *clkdm1,
+			       struct clockdomain *clkdm2)
 {
-	struct clkdm_autodep *autodep;
+	struct clkdm_dep *cd;
+	int ret = 0;
 
-	if (!autodeps || clkdm->flags & CLKDM_NO_AUTODEPS)
-		return;
+	if (!clkdm1 || !clkdm2)
+		return -EINVAL;
 
-	for (autodep = autodeps; autodep->clkdm.ptr; autodep++) {
-		if (IS_ERR(autodep->clkdm.ptr))
-			continue;
+	cd = _clkdm_deps_lookup(clkdm2, clkdm1->sleepdep_srcs);
+	if (IS_ERR(cd))
+		ret = PTR_ERR(cd);
 
-		pr_debug("clockdomain: %s: removing %s sleepdep/wkdep\n",
-			 clkdm->name, autodep->clkdm.ptr->name);
+	if (!arch_clkdm || !arch_clkdm->clkdm_add_sleepdep)
+		ret = -EINVAL;
 
-		clkdm_del_sleepdep(clkdm, autodep->clkdm.ptr);
-		clkdm_del_wkdep(clkdm, autodep->clkdm.ptr);
+	if (ret) {
+		pr_debug("clockdomain: hardware cannot set/clear sleep dependency affecting %s from %s\n",
+			 clkdm1->name, clkdm2->name);
+		return ret;
 	}
+
+	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);
+
+		ret = arch_clkdm->clkdm_add_sleepdep(clkdm1, clkdm2);
+	}
+
+	return ret;
 }
 
 /**
- * _resolve_clkdm_deps() - resolve clkdm_names in @clkdm_deps to clkdms
- * @clkdm: clockdomain that we are resolving dependencies for
- * @clkdm_deps: ptr to array of struct clkdm_deps to resolve
+ * _clkdm_del_sleepdep - remove a sleep dep from clkdm2 to clkdm1 (lockless)
+ * @clkdm1: prevent this struct clockdomain * from sleeping (dependent)
+ * @clkdm2: when this struct clockdomain * is active (source)
  *
- * Iterates through @clkdm_deps, looking up the struct clockdomain named by
- * clkdm_name and storing the clockdomain pointer in the struct clkdm_dep.
- * No return value.
+ * Allow @clkdm1 to automatically go inactive (and then to retention or
+ * off), independent of the activity state of @clkdm2.  Returns -EINVAL
+ * if presented with invalid clockdomain pointers or called on a machine
+ * that does not support software-configurable hardware sleep dependencies,
+ * -ENOENT if the specified dependency cannot be cleared in hardware, or
+ * 0 upon success.
  */
-static void _resolve_clkdm_deps(struct clockdomain *clkdm,
-				struct clkdm_dep *clkdm_deps)
+static int _clkdm_del_sleepdep(struct clockdomain *clkdm1,
+			       struct clockdomain *clkdm2)
 {
 	struct clkdm_dep *cd;
+	int ret = 0;
 
-	for (cd = clkdm_deps; cd && cd->clkdm_name; cd++) {
-		if (cd->clkdm)
-			continue;
-		cd->clkdm = _clkdm_lookup(cd->clkdm_name);
+	if (!clkdm1 || !clkdm2)
+		return -EINVAL;
 
-		WARN(!cd->clkdm, "clockdomain: %s: could not find clkdm %s while resolving dependencies - should never happen",
-		     clkdm->name, cd->clkdm_name);
+	cd = _clkdm_deps_lookup(clkdm2, clkdm1->sleepdep_srcs);
+	if (IS_ERR(cd))
+		ret = PTR_ERR(cd);
+
+	if (!arch_clkdm || !arch_clkdm->clkdm_del_sleepdep)
+		ret = -EINVAL;
+
+	if (ret) {
+		pr_debug("clockdomain: hardware cannot set/clear sleep dependency affecting %s from %s\n",
+			 clkdm1->name, clkdm2->name);
+		return ret;
 	}
+
+	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);
+
+		ret = arch_clkdm->clkdm_del_sleepdep(clkdm1, clkdm2);
+	}
+
+	return ret;
 }
 
 /* Public functions */
@@ -453,33 +567,7 @@ struct powerdomain *clkdm_get_pwrdm(struct clockdomain *clkdm)
  */
 int clkdm_add_wkdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
 {
-	struct clkdm_dep *cd;
-	int ret = 0;
-
-	if (!clkdm1 || !clkdm2)
-		return -EINVAL;
-
-	cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs);
-	if (IS_ERR(cd))
-		ret = PTR_ERR(cd);
-
-	if (!arch_clkdm || !arch_clkdm->clkdm_add_wkdep)
-		ret = -EINVAL;
-
-	if (ret) {
-		pr_debug("clockdomain: hardware cannot set/clear wake up of %s when %s wakes up\n",
-			 clkdm1->name, clkdm2->name);
-		return ret;
-	}
-
-	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);
-
-		ret = arch_clkdm->clkdm_add_wkdep(clkdm1, clkdm2);
-	}
-
-	return ret;
+	return _clkdm_add_wkdep(clkdm1, clkdm2);
 }
 
 /**
@@ -494,33 +582,7 @@ int clkdm_add_wkdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
  */
 int clkdm_del_wkdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
 {
-	struct clkdm_dep *cd;
-	int ret = 0;
-
-	if (!clkdm1 || !clkdm2)
-		return -EINVAL;
-
-	cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs);
-	if (IS_ERR(cd))
-		ret = PTR_ERR(cd);
-
-	if (!arch_clkdm || !arch_clkdm->clkdm_del_wkdep)
-		ret = -EINVAL;
-
-	if (ret) {
-		pr_debug("clockdomain: hardware cannot set/clear wake up of %s when %s wakes up\n",
-			 clkdm1->name, clkdm2->name);
-		return ret;
-	}
-
-	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);
-
-		ret = arch_clkdm->clkdm_del_wkdep(clkdm1, clkdm2);
-	}
-
-	return ret;
+	return _clkdm_del_wkdep(clkdm1, clkdm2);
 }
 
 /**
@@ -597,33 +659,7 @@ int clkdm_clear_all_wkdeps(struct clockdomain *clkdm)
  */
 int clkdm_add_sleepdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
 {
-	struct clkdm_dep *cd;
-	int ret = 0;
-
-	if (!clkdm1 || !clkdm2)
-		return -EINVAL;
-
-	cd = _clkdm_deps_lookup(clkdm2, clkdm1->sleepdep_srcs);
-	if (IS_ERR(cd))
-		ret = PTR_ERR(cd);
-
-	if (!arch_clkdm || !arch_clkdm->clkdm_add_sleepdep)
-		ret = -EINVAL;
-
-	if (ret) {
-		pr_debug("clockdomain: hardware cannot set/clear sleep dependency affecting %s from %s\n",
-			 clkdm1->name, clkdm2->name);
-		return ret;
-	}
-
-	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);
-
-		ret = arch_clkdm->clkdm_add_sleepdep(clkdm1, clkdm2);
-	}
-
-	return ret;
+	return _clkdm_add_sleepdep(clkdm1, clkdm2);
 }
 
 /**
@@ -640,33 +676,7 @@ int clkdm_add_sleepdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
  */
 int clkdm_del_sleepdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
 {
-	struct clkdm_dep *cd;
-	int ret = 0;
-
-	if (!clkdm1 || !clkdm2)
-		return -EINVAL;
-
-	cd = _clkdm_deps_lookup(clkdm2, clkdm1->sleepdep_srcs);
-	if (IS_ERR(cd))
-		ret = PTR_ERR(cd);
-
-	if (!arch_clkdm || !arch_clkdm->clkdm_del_sleepdep)
-		ret = -EINVAL;
-
-	if (ret) {
-		pr_debug("clockdomain: hardware cannot set/clear sleep dependency affecting %s from %s\n",
-			 clkdm1->name, clkdm2->name);
-		return ret;
-	}
-
-	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);
-
-		ret = arch_clkdm->clkdm_del_sleepdep(clkdm1, clkdm2);
-	}
-
-	return ret;
+	return _clkdm_del_sleepdep(clkdm1, clkdm2);
 }
 
 /**
@@ -977,6 +987,68 @@ bool clkdm_missing_idle_reporting(struct clockdomain *clkdm)
 	return (clkdm->flags & CLKDM_MISSING_IDLE_REPORTING) ? true : false;
 }
 
+/* Public autodep handling functions (deprecated) */
+
+/**
+ * clkdm_add_autodeps - add auto sleepdeps/wkdeps to clkdm upon clock enable
+ * @clkdm: struct clockdomain *
+ *
+ * Add the "autodep" sleep & wakeup dependencies to clockdomain 'clkdm'
+ * in hardware-supervised mode.  Meant to be called from clock framework
+ * when a clock inside clockdomain 'clkdm' is enabled.	No return value.
+ *
+ * XXX autodeps are deprecated and should be removed at the earliest
+ * opportunity
+ */
+void clkdm_add_autodeps(struct clockdomain *clkdm)
+{
+	struct clkdm_autodep *autodep;
+
+	if (!autodeps || clkdm->flags & CLKDM_NO_AUTODEPS)
+		return;
+
+	for (autodep = autodeps; autodep->clkdm.ptr; autodep++) {
+		if (IS_ERR(autodep->clkdm.ptr))
+			continue;
+
+		pr_debug("clockdomain: %s: adding %s sleepdep/wkdep\n",
+			 clkdm->name, autodep->clkdm.ptr->name);
+
+		_clkdm_add_sleepdep(clkdm, autodep->clkdm.ptr);
+		_clkdm_add_wkdep(clkdm, autodep->clkdm.ptr);
+	}
+}
+
+/**
+ * clkdm_del_autodeps - remove auto sleepdeps/wkdeps from clkdm
+ * @clkdm: struct clockdomain *
+ *
+ * Remove the "autodep" sleep & wakeup dependencies from clockdomain 'clkdm'
+ * in hardware-supervised mode.  Meant to be called from clock framework
+ * when a clock inside clockdomain 'clkdm' is disabled.  No return value.
+ *
+ * XXX autodeps are deprecated and should be removed at the earliest
+ * opportunity
+ */
+void clkdm_del_autodeps(struct clockdomain *clkdm)
+{
+	struct clkdm_autodep *autodep;
+
+	if (!autodeps || clkdm->flags & CLKDM_NO_AUTODEPS)
+		return;
+
+	for (autodep = autodeps; autodep->clkdm.ptr; autodep++) {
+		if (IS_ERR(autodep->clkdm.ptr))
+			continue;
+
+		pr_debug("clockdomain: %s: removing %s sleepdep/wkdep\n",
+			 clkdm->name, autodep->clkdm.ptr->name);
+
+		_clkdm_del_sleepdep(clkdm, autodep->clkdm.ptr);
+		_clkdm_del_wkdep(clkdm, autodep->clkdm.ptr);
+	}
+}
+
 /* Clockdomain-to-clock/hwmod framework interface code */
 
 static int _clkdm_clk_hwmod_enable(struct clockdomain *clkdm)
diff --git a/arch/arm/mach-omap2/clockdomain.h b/arch/arm/mach-omap2/clockdomain.h
index e7f1b4ba2d5b..50c3cd8bd706 100644
--- a/arch/arm/mach-omap2/clockdomain.h
+++ b/arch/arm/mach-omap2/clockdomain.h
@@ -216,8 +216,9 @@ extern void __init omap243x_clockdomains_init(void);
 extern void __init omap3xxx_clockdomains_init(void);
 extern void __init am33xx_clockdomains_init(void);
 extern void __init omap44xx_clockdomains_init(void);
-extern void _clkdm_add_autodeps(struct clockdomain *clkdm);
-extern void _clkdm_del_autodeps(struct clockdomain *clkdm);
+
+extern void clkdm_add_autodeps(struct clockdomain *clkdm);
+extern void clkdm_del_autodeps(struct clockdomain *clkdm);
 
 extern struct clkdm_ops omap2_clkdm_operations;
 extern struct clkdm_ops omap3_clkdm_operations;
diff --git a/arch/arm/mach-omap2/cm3xxx.c b/arch/arm/mach-omap2/cm3xxx.c
index c2086f2e86b6..b94af4cb9dd9 100644
--- a/arch/arm/mach-omap2/cm3xxx.c
+++ b/arch/arm/mach-omap2/cm3xxx.c
@@ -210,7 +210,7 @@ static int omap3xxx_clkdm_wakeup(struct clockdomain *clkdm)
 static void omap3xxx_clkdm_allow_idle(struct clockdomain *clkdm)
 {
 	if (atomic_read(&clkdm->usecount) > 0)
-		_clkdm_add_autodeps(clkdm);
+		clkdm_add_autodeps(clkdm);
 
 	omap3xxx_cm_clkdm_enable_hwsup(clkdm->pwrdm.ptr->prcm_offs,
 				       clkdm->clktrctrl_mask);
@@ -222,7 +222,7 @@ static void omap3xxx_clkdm_deny_idle(struct clockdomain *clkdm)
 					clkdm->clktrctrl_mask);
 
 	if (atomic_read(&clkdm->usecount) > 0)
-		_clkdm_del_autodeps(clkdm);
+		clkdm_del_autodeps(clkdm);
 }
 
 static int omap3xxx_clkdm_clk_enable(struct clockdomain *clkdm)
@@ -250,7 +250,7 @@ static int omap3xxx_clkdm_clk_enable(struct clockdomain *clkdm)
 		/* Disable HW transitions when we are changing deps */
 		omap3xxx_cm_clkdm_disable_hwsup(clkdm->pwrdm.ptr->prcm_offs,
 						clkdm->clktrctrl_mask);
-		_clkdm_add_autodeps(clkdm);
+		clkdm_add_autodeps(clkdm);
 		omap3xxx_cm_clkdm_enable_hwsup(clkdm->pwrdm.ptr->prcm_offs,
 					       clkdm->clktrctrl_mask);
 	} else {
@@ -287,7 +287,7 @@ static int omap3xxx_clkdm_clk_disable(struct clockdomain *clkdm)
 		/* Disable HW transitions when we are changing deps */
 		omap3xxx_cm_clkdm_disable_hwsup(clkdm->pwrdm.ptr->prcm_offs,
 						clkdm->clktrctrl_mask);
-		_clkdm_del_autodeps(clkdm);
+		clkdm_del_autodeps(clkdm);
 		omap3xxx_cm_clkdm_enable_hwsup(clkdm->pwrdm.ptr->prcm_offs,
 					       clkdm->clktrctrl_mask);
 	} else {
-- 
cgit v1.2.3


From 92493870196f52c743330db7b545b54b2abfda82 Mon Sep 17 00:00:00 2001
From: Paul Walmsley
Date: Sat, 26 Jan 2013 00:58:17 -0700
Subject: ARM: OMAP2+: clockdomain: convert existing atomic usecounts into
 spinlock-protected shorts/ints

The atomic usecounts seem to be confusing, and are no longer needed
since the operations that they are attached to really should take
place under lock.  Replace the atomic counters with simple integers,
protected by the enclosing powerdomain spinlock.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Kevin Hilman <khilman@deeprootsystems.com>
---
 arch/arm/mach-omap2/clockdomain.c  | 96 +++++++++++++++++++++++++++++++-------
 arch/arm/mach-omap2/clockdomain.h  |  6 +--
 arch/arm/mach-omap2/cm3xxx.c       |  6 +--
 arch/arm/mach-omap2/cminst44xx.c   |  2 +-
 arch/arm/mach-omap2/pm-debug.c     |  6 +--
 arch/arm/mach-omap2/pm.c           |  3 +-
 arch/arm/mach-omap2/prm2xxx_3xxx.c |  3 +-
 7 files changed, 92 insertions(+), 30 deletions(-)

(limited to 'arch/arm/mach-omap2/clockdomain.c')

diff --git a/arch/arm/mach-omap2/clockdomain.c b/arch/arm/mach-omap2/clockdomain.c
index ab194753eb7a..2da3b5ec010c 100644
--- a/arch/arm/mach-omap2/clockdomain.c
+++ b/arch/arm/mach-omap2/clockdomain.c
@@ -210,7 +210,8 @@ static int _clkdm_add_wkdep(struct clockdomain *clkdm1,
 		return ret;
 	}
 
-	if (atomic_inc_return(&cd->wkdep_usecount) == 1) {
+	cd->wkdep_usecount++;
+	if (cd->wkdep_usecount == 1) {
 		pr_debug("clockdomain: hardware will wake up %s when %s wakes up\n",
 			 clkdm1->name, clkdm2->name);
 
@@ -252,7 +253,8 @@ static int _clkdm_del_wkdep(struct clockdomain *clkdm1,
 		return ret;
 	}
 
-	if (atomic_dec_return(&cd->wkdep_usecount) == 0) {
+	cd->wkdep_usecount--;
+	if (cd->wkdep_usecount == 0) {
 		pr_debug("clockdomain: hardware will no longer wake up %s after %s wakes up\n",
 			 clkdm1->name, clkdm2->name);
 
@@ -296,7 +298,8 @@ static int _clkdm_add_sleepdep(struct clockdomain *clkdm1,
 		return ret;
 	}
 
-	if (atomic_inc_return(&cd->sleepdep_usecount) == 1) {
+	cd->sleepdep_usecount++;
+	if (cd->sleepdep_usecount == 1) {
 		pr_debug("clockdomain: will prevent %s from sleeping if %s is active\n",
 			 clkdm1->name, clkdm2->name);
 
@@ -340,7 +343,8 @@ static int _clkdm_del_sleepdep(struct clockdomain *clkdm1,
 		return ret;
 	}
 
-	if (atomic_dec_return(&cd->sleepdep_usecount) == 0) {
+	cd->sleepdep_usecount--;
+	if (cd->sleepdep_usecount == 0) {
 		pr_debug("clockdomain: will no longer prevent %s from sleeping if %s is active\n",
 			 clkdm1->name, clkdm2->name);
 
@@ -567,7 +571,21 @@ struct powerdomain *clkdm_get_pwrdm(struct clockdomain *clkdm)
  */
 int clkdm_add_wkdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
 {
-	return _clkdm_add_wkdep(clkdm1, clkdm2);
+	struct clkdm_dep *cd;
+	int ret;
+
+	if (!clkdm1 || !clkdm2)
+		return -EINVAL;
+
+	cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs);
+	if (IS_ERR(cd))
+		return PTR_ERR(cd);
+
+	pwrdm_lock(cd->clkdm->pwrdm.ptr);
+	ret = _clkdm_add_wkdep(clkdm1, clkdm2);
+	pwrdm_unlock(cd->clkdm->pwrdm.ptr);
+
+	return ret;
 }
 
 /**
@@ -582,7 +600,21 @@ int clkdm_add_wkdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
  */
 int clkdm_del_wkdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
 {
-	return _clkdm_del_wkdep(clkdm1, clkdm2);
+	struct clkdm_dep *cd;
+	int ret;
+
+	if (!clkdm1 || !clkdm2)
+		return -EINVAL;
+
+	cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs);
+	if (IS_ERR(cd))
+		return PTR_ERR(cd);
+
+	pwrdm_lock(cd->clkdm->pwrdm.ptr);
+	ret = _clkdm_del_wkdep(clkdm1, clkdm2);
+	pwrdm_unlock(cd->clkdm->pwrdm.ptr);
+
+	return ret;
 }
 
 /**
@@ -620,7 +652,7 @@ int clkdm_read_wkdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
 		return ret;
 	}
 
-	/* XXX It's faster to return the atomic wkdep_usecount */
+	/* XXX It's faster to return the wkdep_usecount */
 	return arch_clkdm->clkdm_read_wkdep(clkdm1, clkdm2);
 }
 
@@ -659,7 +691,21 @@ int clkdm_clear_all_wkdeps(struct clockdomain *clkdm)
  */
 int clkdm_add_sleepdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
 {
-	return _clkdm_add_sleepdep(clkdm1, clkdm2);
+	struct clkdm_dep *cd;
+	int ret;
+
+	if (!clkdm1 || !clkdm2)
+		return -EINVAL;
+
+	cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs);
+	if (IS_ERR(cd))
+		return PTR_ERR(cd);
+
+	pwrdm_lock(cd->clkdm->pwrdm.ptr);
+	ret = _clkdm_add_sleepdep(clkdm1, clkdm2);
+	pwrdm_unlock(cd->clkdm->pwrdm.ptr);
+
+	return ret;
 }
 
 /**
@@ -676,7 +722,21 @@ int clkdm_add_sleepdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
  */
 int clkdm_del_sleepdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
 {
-	return _clkdm_del_sleepdep(clkdm1, clkdm2);
+	struct clkdm_dep *cd;
+	int ret;
+
+	if (!clkdm1 || !clkdm2)
+		return -EINVAL;
+
+	cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs);
+	if (IS_ERR(cd))
+		return PTR_ERR(cd);
+
+	pwrdm_lock(cd->clkdm->pwrdm.ptr);
+	ret = _clkdm_del_sleepdep(clkdm1, clkdm2);
+	pwrdm_unlock(cd->clkdm->pwrdm.ptr);
+
+	return ret;
 }
 
 /**
@@ -716,7 +776,7 @@ int clkdm_read_sleepdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
 		return ret;
 	}
 
-	/* XXX It's faster to return the atomic sleepdep_usecount */
+	/* XXX It's faster to return the sleepdep_usecount */
 	return arch_clkdm->clkdm_read_sleepdep(clkdm1, clkdm2);
 }
 
@@ -1063,7 +1123,8 @@ static int _clkdm_clk_hwmod_enable(struct clockdomain *clkdm)
 	 * should be called for every clock instance or hwmod that is
 	 * enabled, so the clkdm can be force woken up.
 	 */
-	if ((atomic_inc_return(&clkdm->usecount) > 1) && autodeps) {
+	clkdm->usecount++;
+	if (clkdm->usecount > 1 && autodeps) {
 		pwrdm_unlock(clkdm->pwrdm.ptr);
 		return 0;
 	}
@@ -1125,17 +1186,17 @@ int clkdm_clk_disable(struct clockdomain *clkdm, struct clk *clk)
 	pwrdm_lock(clkdm->pwrdm.ptr);
 
 	/* corner case: disabling unused clocks */
-	if ((__clk_get_enable_count(clk) == 0) &&
-	    (atomic_read(&clkdm->usecount) == 0))
+	if ((__clk_get_enable_count(clk) == 0) && clkdm->usecount == 0)
 		goto ccd_exit;
 
-	if (atomic_read(&clkdm->usecount) == 0) {
+	if (clkdm->usecount == 0) {
 		pwrdm_unlock(clkdm->pwrdm.ptr);
 		WARN_ON(1); /* underflow */
 		return -ERANGE;
 	}
 
-	if (atomic_dec_return(&clkdm->usecount) > 0) {
+	clkdm->usecount--;
+	if (clkdm->usecount > 0) {
 		pwrdm_unlock(clkdm->pwrdm.ptr);
 		return 0;
 	}
@@ -1213,13 +1274,14 @@ int clkdm_hwmod_disable(struct clockdomain *clkdm, struct omap_hwmod *oh)
 
 	pwrdm_lock(clkdm->pwrdm.ptr);
 
-	if (atomic_read(&clkdm->usecount) == 0) {
+	if (clkdm->usecount == 0) {
 		pwrdm_unlock(clkdm->pwrdm.ptr);
 		WARN_ON(1); /* underflow */
 		return -ERANGE;
 	}
 
-	if (atomic_dec_return(&clkdm->usecount) > 0) {
+	clkdm->usecount--;
+	if (clkdm->usecount > 0) {
 		pwrdm_unlock(clkdm->pwrdm.ptr);
 		return 0;
 	}
diff --git a/arch/arm/mach-omap2/clockdomain.h b/arch/arm/mach-omap2/clockdomain.h
index 50c3cd8bd706..2da37656a693 100644
--- a/arch/arm/mach-omap2/clockdomain.h
+++ b/arch/arm/mach-omap2/clockdomain.h
@@ -91,8 +91,8 @@ struct clkdm_autodep {
 struct clkdm_dep {
 	const char *clkdm_name;
 	struct clockdomain *clkdm;
-	atomic_t wkdep_usecount;
-	atomic_t sleepdep_usecount;
+	s16 wkdep_usecount;
+	s16 sleepdep_usecount;
 };
 
 /* Possible flags for struct clockdomain._flags */
@@ -136,7 +136,7 @@ struct clockdomain {
 	const u16 clkdm_offs;
 	struct clkdm_dep *wkdep_srcs;
 	struct clkdm_dep *sleepdep_srcs;
-	atomic_t usecount;
+	int usecount;
 	struct list_head node;
 };
 
diff --git a/arch/arm/mach-omap2/cm3xxx.c b/arch/arm/mach-omap2/cm3xxx.c
index b94af4cb9dd9..9061c307d915 100644
--- a/arch/arm/mach-omap2/cm3xxx.c
+++ b/arch/arm/mach-omap2/cm3xxx.c
@@ -186,7 +186,7 @@ static int omap3xxx_clkdm_clear_all_sleepdeps(struct clockdomain *clkdm)
 			continue; /* only happens if data is erroneous */
 
 		mask |= 1 << cd->clkdm->dep_bit;
-		atomic_set(&cd->sleepdep_usecount, 0);
+		cd->sleepdep_usecount = 0;
 	}
 	omap2_cm_clear_mod_reg_bits(mask, clkdm->pwrdm.ptr->prcm_offs,
 				    OMAP3430_CM_SLEEPDEP);
@@ -209,7 +209,7 @@ static int omap3xxx_clkdm_wakeup(struct clockdomain *clkdm)
 
 static void omap3xxx_clkdm_allow_idle(struct clockdomain *clkdm)
 {
-	if (atomic_read(&clkdm->usecount) > 0)
+	if (clkdm->usecount > 0)
 		clkdm_add_autodeps(clkdm);
 
 	omap3xxx_cm_clkdm_enable_hwsup(clkdm->pwrdm.ptr->prcm_offs,
@@ -221,7 +221,7 @@ static void omap3xxx_clkdm_deny_idle(struct clockdomain *clkdm)
 	omap3xxx_cm_clkdm_disable_hwsup(clkdm->pwrdm.ptr->prcm_offs,
 					clkdm->clktrctrl_mask);
 
-	if (atomic_read(&clkdm->usecount) > 0)
+	if (clkdm->usecount > 0)
 		clkdm_del_autodeps(clkdm);
 }
 
diff --git a/arch/arm/mach-omap2/cminst44xx.c b/arch/arm/mach-omap2/cminst44xx.c
index 7f9a464f01e9..f0290f5566fe 100644
--- a/arch/arm/mach-omap2/cminst44xx.c
+++ b/arch/arm/mach-omap2/cminst44xx.c
@@ -393,7 +393,7 @@ static int omap4_clkdm_clear_all_wkup_sleep_deps(struct clockdomain *clkdm)
 			continue; /* only happens if data is erroneous */
 
 		mask |= 1 << cd->clkdm->dep_bit;
-		atomic_set(&cd->wkdep_usecount, 0);
+		cd->wkdep_usecount = 0;
 	}
 
 	omap4_cminst_clear_inst_reg_bits(mask, clkdm->prcm_partition,
diff --git a/arch/arm/mach-omap2/pm-debug.c b/arch/arm/mach-omap2/pm-debug.c
index e2c291f52f92..6db89ae92389 100644
--- a/arch/arm/mach-omap2/pm-debug.c
+++ b/arch/arm/mach-omap2/pm-debug.c
@@ -83,10 +83,8 @@ static int clkdm_dbg_show_counter(struct clockdomain *clkdm, void *user)
 		strncmp(clkdm->name, "dpll", 4) == 0)
 		return 0;
 
-	seq_printf(s, "%s->%s (%d)", clkdm->name,
-			clkdm->pwrdm.ptr->name,
-			atomic_read(&clkdm->usecount));
-	seq_printf(s, "\n");
+	seq_printf(s, "%s->%s (%d)\n", clkdm->name, clkdm->pwrdm.ptr->name,
+		   clkdm->usecount);
 
 	return 0;
 }
diff --git a/arch/arm/mach-omap2/pm.c b/arch/arm/mach-omap2/pm.c
index 48d6d5d2c926..88586d15004a 100644
--- a/arch/arm/mach-omap2/pm.c
+++ b/arch/arm/mach-omap2/pm.c
@@ -110,11 +110,12 @@ static void __init omap2_init_processor_devices(void)
 
 int __init omap_pm_clkdms_setup(struct clockdomain *clkdm, void *unused)
 {
+	/* XXX The usecount test is racy */
 	if ((clkdm->flags & CLKDM_CAN_ENABLE_AUTO) &&
 	    !(clkdm->flags & CLKDM_MISSING_IDLE_REPORTING))
 		clkdm_allow_idle(clkdm);
 	else if (clkdm->flags & CLKDM_CAN_FORCE_SLEEP &&
-		 atomic_read(&clkdm->usecount) == 0)
+		 clkdm->usecount == 0)
 		clkdm_sleep(clkdm);
 	return 0;
 }
diff --git a/arch/arm/mach-omap2/prm2xxx_3xxx.c b/arch/arm/mach-omap2/prm2xxx_3xxx.c
index a3e121f94a86..947f6adfed0c 100644
--- a/arch/arm/mach-omap2/prm2xxx_3xxx.c
+++ b/arch/arm/mach-omap2/prm2xxx_3xxx.c
@@ -210,6 +210,7 @@ int omap2_clkdm_read_wkdep(struct clockdomain *clkdm1,
 					     PM_WKDEP, (1 << clkdm2->dep_bit));
 }
 
+/* XXX Caller must hold the clkdm's powerdomain lock */
 int omap2_clkdm_clear_all_wkdeps(struct clockdomain *clkdm)
 {
 	struct clkdm_dep *cd;
@@ -221,7 +222,7 @@ int omap2_clkdm_clear_all_wkdeps(struct clockdomain *clkdm)
 
 		/* PRM accesses are slow, so minimize them */
 		mask |= 1 << cd->clkdm->dep_bit;
-		atomic_set(&cd->wkdep_usecount, 0);
+		cd->wkdep_usecount = 0;
 	}
 
 	omap2_prm_clear_mod_reg_bits(mask, clkdm->pwrdm.ptr->prcm_offs,
-- 
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