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ARM: OMAP2+: powerdomain/clockdomain: add a per-powerdomain spinlock
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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>
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Paul Walmsley committed Jan 29, 2013
1 parent c4978fb commit 3a09028
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Showing 4 changed files with 176 additions and 73 deletions.
172 changes: 112 additions & 60 deletions arch/arm/mach-omap2/clockdomain.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand Down Expand Up @@ -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;
Expand All @@ -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;
Expand All @@ -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;

Expand All @@ -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);
}

/**
Expand All @@ -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;

Expand All @@ -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);
}

/**
Expand All @@ -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;
}
Expand All @@ -923,26 +981,24 @@ 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
* 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) {
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);

Expand Down Expand Up @@ -991,36 +1047,34 @@ 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) &&
(atomic_read(&clkdm->usecount) == 0))
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;
}
Expand Down Expand Up @@ -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;
Expand All @@ -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);

Expand Down
6 changes: 4 additions & 2 deletions arch/arm/mach-omap2/clockdomain.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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"
Expand Down Expand Up @@ -139,7 +138,6 @@ struct clockdomain {
struct clkdm_dep *sleepdep_srcs;
atomic_t usecount;
struct list_head node;
spinlock_t lock;
};

/**
Expand Down Expand Up @@ -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);
Expand Down
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