blob: 75d13c0eff1243ebc29bbab45470e34f127e538c [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2010-2011 Canonical Ltd <jeremy.kerr@canonical.com>
* Copyright (C) 2011-2012 Linaro Ltd <mturquette@linaro.org>
*
* Standard functionality for the common clock API. See Documentation/driver-api/clk.rst
*/
#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/clk/clk-conf.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/err.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/device.h>
#include <linux/init.h>
#include <linux/pm_runtime.h>
#include <linux/sched.h>
#include <linux/clkdev.h>
#include "clk.h"
static DEFINE_SPINLOCK(enable_lock);
static DEFINE_MUTEX(prepare_lock);
static struct task_struct *prepare_owner;
static struct task_struct *enable_owner;
static int prepare_refcnt;
static int enable_refcnt;
static HLIST_HEAD(clk_root_list);
static HLIST_HEAD(clk_orphan_list);
static LIST_HEAD(clk_notifier_list);
/*** private data structures ***/
struct clk_core {
const char *name;
const struct clk_ops *ops;
struct clk_hw *hw;
struct module *owner;
struct device *dev;
struct clk_core *parent;
const char **parent_names;
struct clk_core **parents;
u8 num_parents;
u8 new_parent_index;
unsigned long rate;
unsigned long req_rate;
unsigned long new_rate;
struct clk_core *new_parent;
struct clk_core *new_child;
unsigned long flags;
bool orphan;
unsigned int enable_count;
unsigned int prepare_count;
unsigned int protect_count;
unsigned long min_rate;
unsigned long max_rate;
unsigned long accuracy;
int phase;
struct clk_duty duty;
struct hlist_head children;
struct hlist_node child_node;
struct hlist_head clks;
unsigned int notifier_count;
#ifdef CONFIG_DEBUG_FS
struct dentry *dentry;
struct hlist_node debug_node;
#endif
struct kref ref;
};
#define CREATE_TRACE_POINTS
#include <trace/events/clk.h>
struct clk {
struct clk_core *core;
const char *dev_id;
const char *con_id;
unsigned long min_rate;
unsigned long max_rate;
unsigned int exclusive_count;
struct hlist_node clks_node;
};
/*** runtime pm ***/
static int clk_pm_runtime_get(struct clk_core *core)
{
int ret = 0;
if (!core->dev)
return 0;
ret = pm_runtime_get_sync(core->dev);
return ret < 0 ? ret : 0;
}
static void clk_pm_runtime_put(struct clk_core *core)
{
if (!core->dev)
return;
pm_runtime_put_sync(core->dev);
}
/*** locking ***/
static void clk_prepare_lock(void)
{
if (!mutex_trylock(&prepare_lock)) {
if (prepare_owner == current) {
prepare_refcnt++;
return;
}
mutex_lock(&prepare_lock);
}
WARN_ON_ONCE(prepare_owner != NULL);
WARN_ON_ONCE(prepare_refcnt != 0);
prepare_owner = current;
prepare_refcnt = 1;
}
static void clk_prepare_unlock(void)
{
WARN_ON_ONCE(prepare_owner != current);
WARN_ON_ONCE(prepare_refcnt == 0);
if (--prepare_refcnt)
return;
prepare_owner = NULL;
mutex_unlock(&prepare_lock);
}
static unsigned long clk_enable_lock(void)
__acquires(enable_lock)
{
unsigned long flags;
/*
* On UP systems, spin_trylock_irqsave() always returns true, even if
* we already hold the lock. So, in that case, we rely only on
* reference counting.
*/
if (!IS_ENABLED(CONFIG_SMP) ||
!spin_trylock_irqsave(&enable_lock, flags)) {
if (enable_owner == current) {
enable_refcnt++;
__acquire(enable_lock);
if (!IS_ENABLED(CONFIG_SMP))
local_save_flags(flags);
return flags;
}
spin_lock_irqsave(&enable_lock, flags);
}
WARN_ON_ONCE(enable_owner != NULL);
WARN_ON_ONCE(enable_refcnt != 0);
enable_owner = current;
enable_refcnt = 1;
return flags;
}
static void clk_enable_unlock(unsigned long flags)
__releases(enable_lock)
{
WARN_ON_ONCE(enable_owner != current);
WARN_ON_ONCE(enable_refcnt == 0);
if (--enable_refcnt) {
__release(enable_lock);
return;
}
enable_owner = NULL;
spin_unlock_irqrestore(&enable_lock, flags);
}
static bool clk_core_rate_is_protected(struct clk_core *core)
{
return core->protect_count;
}
static bool clk_core_is_prepared(struct clk_core *core)
{
bool ret = false;
/*
* .is_prepared is optional for clocks that can prepare
* fall back to software usage counter if it is missing
*/
if (!core->ops->is_prepared)
return core->prepare_count;
if (!clk_pm_runtime_get(core)) {
ret = core->ops->is_prepared(core->hw);
clk_pm_runtime_put(core);
}
return ret;
}
static bool clk_core_is_enabled(struct clk_core *core)
{
bool ret = false;
/*
* .is_enabled is only mandatory for clocks that gate
* fall back to software usage counter if .is_enabled is missing
*/
if (!core->ops->is_enabled)
return core->enable_count;
/*
* Check if clock controller's device is runtime active before
* calling .is_enabled callback. If not, assume that clock is
* disabled, because we might be called from atomic context, from
* which pm_runtime_get() is not allowed.
* This function is called mainly from clk_disable_unused_subtree,
* which ensures proper runtime pm activation of controller before
* taking enable spinlock, but the below check is needed if one tries
* to call it from other places.
*/
if (core->dev) {
pm_runtime_get_noresume(core->dev);
if (!pm_runtime_active(core->dev)) {
ret = false;
goto done;
}
}
ret = core->ops->is_enabled(core->hw);
done:
if (core->dev)
pm_runtime_put(core->dev);
return ret;
}
/*** helper functions ***/
const char *__clk_get_name(const struct clk *clk)
{
return !clk ? NULL : clk->core->name;
}
EXPORT_SYMBOL_GPL(__clk_get_name);
const char *clk_hw_get_name(const struct clk_hw *hw)
{
return hw->core->name;
}
EXPORT_SYMBOL_GPL(clk_hw_get_name);
struct clk_hw *__clk_get_hw(struct clk *clk)
{
return !clk ? NULL : clk->core->hw;
}
EXPORT_SYMBOL_GPL(__clk_get_hw);
unsigned int clk_hw_get_num_parents(const struct clk_hw *hw)
{
return hw->core->num_parents;
}
EXPORT_SYMBOL_GPL(clk_hw_get_num_parents);
struct clk_hw *clk_hw_get_parent(const struct clk_hw *hw)
{
return hw->core->parent ? hw->core->parent->hw : NULL;
}
EXPORT_SYMBOL_GPL(clk_hw_get_parent);
static struct clk_core *__clk_lookup_subtree(const char *name,
struct clk_core *core)
{
struct clk_core *child;
struct clk_core *ret;
if (!strcmp(core->name, name))
return core;
hlist_for_each_entry(child, &core->children, child_node) {
ret = __clk_lookup_subtree(name, child);
if (ret)
return ret;
}
return NULL;
}
static struct clk_core *clk_core_lookup(const char *name)
{
struct clk_core *root_clk;
struct clk_core *ret;
if (!name)
return NULL;
/* search the 'proper' clk tree first */
hlist_for_each_entry(root_clk, &clk_root_list, child_node) {
ret = __clk_lookup_subtree(name, root_clk);
if (ret)
return ret;
}
/* if not found, then search the orphan tree */
hlist_for_each_entry(root_clk, &clk_orphan_list, child_node) {
ret = __clk_lookup_subtree(name, root_clk);
if (ret)
return ret;
}
return NULL;
}
static struct clk_core *clk_core_get_parent_by_index(struct clk_core *core,
u8 index)
{
if (!core || index >= core->num_parents)
return NULL;
if (!core->parents[index])
core->parents[index] =
clk_core_lookup(core->parent_names[index]);
return core->parents[index];
}
struct clk_hw *
clk_hw_get_parent_by_index(const struct clk_hw *hw, unsigned int index)
{
struct clk_core *parent;
parent = clk_core_get_parent_by_index(hw->core, index);
return !parent ? NULL : parent->hw;
}
EXPORT_SYMBOL_GPL(clk_hw_get_parent_by_index);
unsigned int __clk_get_enable_count(struct clk *clk)
{
return !clk ? 0 : clk->core->enable_count;
}
static unsigned long clk_core_get_rate_nolock(struct clk_core *core)
{
unsigned long ret;
if (!core) {
ret = 0;
goto out;
}
ret = core->rate;
if (!core->num_parents)
goto out;
if (!core->parent)
ret = 0;
out:
return ret;
}
unsigned long clk_hw_get_rate(const struct clk_hw *hw)
{
return clk_core_get_rate_nolock(hw->core);
}
EXPORT_SYMBOL_GPL(clk_hw_get_rate);
static unsigned long __clk_get_accuracy(struct clk_core *core)
{
if (!core)
return 0;
return core->accuracy;
}
unsigned long __clk_get_flags(struct clk *clk)
{
return !clk ? 0 : clk->core->flags;
}
EXPORT_SYMBOL_GPL(__clk_get_flags);
unsigned long clk_hw_get_flags(const struct clk_hw *hw)
{
return hw->core->flags;
}
EXPORT_SYMBOL_GPL(clk_hw_get_flags);
bool clk_hw_is_prepared(const struct clk_hw *hw)
{
return clk_core_is_prepared(hw->core);
}
bool clk_hw_rate_is_protected(const struct clk_hw *hw)
{
return clk_core_rate_is_protected(hw->core);
}
bool clk_hw_is_enabled(const struct clk_hw *hw)
{
return clk_core_is_enabled(hw->core);
}
bool __clk_is_enabled(struct clk *clk)
{
if (!clk)
return false;
return clk_core_is_enabled(clk->core);
}
EXPORT_SYMBOL_GPL(__clk_is_enabled);
static bool mux_is_better_rate(unsigned long rate, unsigned long now,
unsigned long best, unsigned long flags)
{
if (flags & CLK_MUX_ROUND_CLOSEST)
return abs(now - rate) < abs(best - rate);
return now <= rate && now > best;
}
int clk_mux_determine_rate_flags(struct clk_hw *hw,
struct clk_rate_request *req,
unsigned long flags)
{
struct clk_core *core = hw->core, *parent, *best_parent = NULL;
int i, num_parents, ret;
unsigned long best = 0;
struct clk_rate_request parent_req = *req;
/* if NO_REPARENT flag set, pass through to current parent */
if (core->flags & CLK_SET_RATE_NO_REPARENT) {
parent = core->parent;
if (core->flags & CLK_SET_RATE_PARENT) {
ret = __clk_determine_rate(parent ? parent->hw : NULL,
&parent_req);
if (ret)
return ret;
best = parent_req.rate;
} else if (parent) {
best = clk_core_get_rate_nolock(parent);
} else {
best = clk_core_get_rate_nolock(core);
}
goto out;
}
/* find the parent that can provide the fastest rate <= rate */
num_parents = core->num_parents;
for (i = 0; i < num_parents; i++) {
parent = clk_core_get_parent_by_index(core, i);
if (!parent)
continue;
if (core->flags & CLK_SET_RATE_PARENT) {
parent_req = *req;
ret = __clk_determine_rate(parent->hw, &parent_req);
if (ret)
continue;
} else {
parent_req.rate = clk_core_get_rate_nolock(parent);
}
if (mux_is_better_rate(req->rate, parent_req.rate,
best, flags)) {
best_parent = parent;
best = parent_req.rate;
}
}
if (!best_parent)
return -EINVAL;
out:
if (best_parent)
req->best_parent_hw = best_parent->hw;
req->best_parent_rate = best;
req->rate = best;
return 0;
}
EXPORT_SYMBOL_GPL(clk_mux_determine_rate_flags);
struct clk *__clk_lookup(const char *name)
{
struct clk_core *core = clk_core_lookup(name);
return !core ? NULL : core->hw->clk;
}
static void clk_core_get_boundaries(struct clk_core *core,
unsigned long *min_rate,
unsigned long *max_rate)
{
struct clk *clk_user;
*min_rate = core->min_rate;
*max_rate = core->max_rate;
hlist_for_each_entry(clk_user, &core->clks, clks_node)
*min_rate = max(*min_rate, clk_user->min_rate);
hlist_for_each_entry(clk_user, &core->clks, clks_node)
*max_rate = min(*max_rate, clk_user->max_rate);
}
void clk_hw_set_rate_range(struct clk_hw *hw, unsigned long min_rate,
unsigned long max_rate)
{
hw->core->min_rate = min_rate;
hw->core->max_rate = max_rate;
}
EXPORT_SYMBOL_GPL(clk_hw_set_rate_range);
/*
* Helper for finding best parent to provide a given frequency. This can be used
* directly as a determine_rate callback (e.g. for a mux), or from a more
* complex clock that may combine a mux with other operations.
*/
int __clk_mux_determine_rate(struct clk_hw *hw,
struct clk_rate_request *req)
{
return clk_mux_determine_rate_flags(hw, req, 0);
}
EXPORT_SYMBOL_GPL(__clk_mux_determine_rate);
int __clk_mux_determine_rate_closest(struct clk_hw *hw,
struct clk_rate_request *req)
{
return clk_mux_determine_rate_flags(hw, req, CLK_MUX_ROUND_CLOSEST);
}
EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest);
/*** clk api ***/
static void clk_core_rate_unprotect(struct clk_core *core)
{
lockdep_assert_held(&prepare_lock);
if (!core)
return;
if (WARN(core->protect_count == 0,
"%s already unprotected\n", core->name))
return;
if (--core->protect_count > 0)
return;
clk_core_rate_unprotect(core->parent);
}
static int clk_core_rate_nuke_protect(struct clk_core *core)
{
int ret;
lockdep_assert_held(&prepare_lock);
if (!core)
return -EINVAL;
if (core->protect_count == 0)
return 0;
ret = core->protect_count;
core->protect_count = 1;
clk_core_rate_unprotect(core);
return ret;
}
/**
* clk_rate_exclusive_put - release exclusivity over clock rate control
* @clk: the clk over which the exclusivity is released
*
* clk_rate_exclusive_put() completes a critical section during which a clock
* consumer cannot tolerate any other consumer making any operation on the
* clock which could result in a rate change or rate glitch. Exclusive clocks
* cannot have their rate changed, either directly or indirectly due to changes
* further up the parent chain of clocks. As a result, clocks up parent chain
* also get under exclusive control of the calling consumer.
*
* If exlusivity is claimed more than once on clock, even by the same consumer,
* the rate effectively gets locked as exclusivity can't be preempted.
*
* Calls to clk_rate_exclusive_put() must be balanced with calls to
* clk_rate_exclusive_get(). Calls to this function may sleep, and do not return
* error status.
*/
void clk_rate_exclusive_put(struct clk *clk)
{
if (!clk)
return;
clk_prepare_lock();
/*
* if there is something wrong with this consumer protect count, stop
* here before messing with the provider
*/
if (WARN_ON(clk->exclusive_count <= 0))
goto out;
clk_core_rate_unprotect(clk->core);
clk->exclusive_count--;
out:
clk_prepare_unlock();
}
EXPORT_SYMBOL_GPL(clk_rate_exclusive_put);
static void clk_core_rate_protect(struct clk_core *core)
{
lockdep_assert_held(&prepare_lock);
if (!core)
return;
if (core->protect_count == 0)
clk_core_rate_protect(core->parent);
core->protect_count++;
}
static void clk_core_rate_restore_protect(struct clk_core *core, int count)
{
lockdep_assert_held(&prepare_lock);
if (!core)
return;
if (count == 0)
return;
clk_core_rate_protect(core);
core->protect_count = count;
}
/**
* clk_rate_exclusive_get - get exclusivity over the clk rate control
* @clk: the clk over which the exclusity of rate control is requested
*
* clk_rate_exlusive_get() begins a critical section during which a clock
* consumer cannot tolerate any other consumer making any operation on the
* clock which could result in a rate change or rate glitch. Exclusive clocks
* cannot have their rate changed, either directly or indirectly due to changes
* further up the parent chain of clocks. As a result, clocks up parent chain
* also get under exclusive control of the calling consumer.
*
* If exlusivity is claimed more than once on clock, even by the same consumer,
* the rate effectively gets locked as exclusivity can't be preempted.
*
* Calls to clk_rate_exclusive_get() should be balanced with calls to
* clk_rate_exclusive_put(). Calls to this function may sleep.
* Returns 0 on success, -EERROR otherwise
*/
int clk_rate_exclusive_get(struct clk *clk)
{
if (!clk)
return 0;
clk_prepare_lock();
clk_core_rate_protect(clk->core);
clk->exclusive_count++;
clk_prepare_unlock();
return 0;
}
EXPORT_SYMBOL_GPL(clk_rate_exclusive_get);
static void clk_core_unprepare(struct clk_core *core)
{
lockdep_assert_held(&prepare_lock);
if (!core)
return;
if (WARN(core->prepare_count == 0,
"%s already unprepared\n", core->name))
return;
if (WARN(core->prepare_count == 1 && core->flags & CLK_IS_CRITICAL,
"Unpreparing critical %s\n", core->name))
return;
if (core->flags & CLK_SET_RATE_GATE)
clk_core_rate_unprotect(core);
if (--core->prepare_count > 0)
return;
WARN(core->enable_count > 0, "Unpreparing enabled %s\n", core->name);
trace_clk_unprepare(core);
if (core->ops->unprepare)
core->ops->unprepare(core->hw);
clk_pm_runtime_put(core);
trace_clk_unprepare_complete(core);
clk_core_unprepare(core->parent);
}
static void clk_core_unprepare_lock(struct clk_core *core)
{
clk_prepare_lock();
clk_core_unprepare(core);
clk_prepare_unlock();
}
/**
* clk_unprepare - undo preparation of a clock source
* @clk: the clk being unprepared
*
* clk_unprepare may sleep, which differentiates it from clk_disable. In a
* simple case, clk_unprepare can be used instead of clk_disable to gate a clk
* if the operation may sleep. One example is a clk which is accessed over
* I2c. In the complex case a clk gate operation may require a fast and a slow
* part. It is this reason that clk_unprepare and clk_disable are not mutually
* exclusive. In fact clk_disable must be called before clk_unprepare.
*/
void clk_unprepare(struct clk *clk)
{
if (IS_ERR_OR_NULL(clk))
return;
clk_core_unprepare_lock(clk->core);
}
EXPORT_SYMBOL_GPL(clk_unprepare);
static int clk_core_prepare(struct clk_core *core)
{
int ret = 0;
lockdep_assert_held(&prepare_lock);
if (!core)
return 0;
if (core->prepare_count == 0) {
ret = clk_pm_runtime_get(core);
if (ret)
return ret;
ret = clk_core_prepare(core->parent);
if (ret)
goto runtime_put;
trace_clk_prepare(core);
if (core->ops->prepare)
ret = core->ops->prepare(core->hw);
trace_clk_prepare_complete(core);
if (ret)
goto unprepare;
}
core->prepare_count++;
/*
* CLK_SET_RATE_GATE is a special case of clock protection
* Instead of a consumer claiming exclusive rate control, it is
* actually the provider which prevents any consumer from making any
* operation which could result in a rate change or rate glitch while
* the clock is prepared.
*/
if (core->flags & CLK_SET_RATE_GATE)
clk_core_rate_protect(core);
return 0;
unprepare:
clk_core_unprepare(core->parent);
runtime_put:
clk_pm_runtime_put(core);
return ret;
}
static int clk_core_prepare_lock(struct clk_core *core)
{
int ret;
clk_prepare_lock();
ret = clk_core_prepare(core);
clk_prepare_unlock();
return ret;
}
/**
* clk_prepare - prepare a clock source
* @clk: the clk being prepared
*
* clk_prepare may sleep, which differentiates it from clk_enable. In a simple
* case, clk_prepare can be used instead of clk_enable to ungate a clk if the
* operation may sleep. One example is a clk which is accessed over I2c. In
* the complex case a clk ungate operation may require a fast and a slow part.
* It is this reason that clk_prepare and clk_enable are not mutually
* exclusive. In fact clk_prepare must be called before clk_enable.
* Returns 0 on success, -EERROR otherwise.
*/
int clk_prepare(struct clk *clk)
{
if (!clk)
return 0;
return clk_core_prepare_lock(clk->core);
}
EXPORT_SYMBOL_GPL(clk_prepare);
static void clk_core_disable(struct clk_core *core)
{
lockdep_assert_held(&enable_lock);
if (!core)
return;
if (WARN(core->enable_count == 0, "%s already disabled\n", core->name))
return;
if (WARN(core->enable_count == 1 && core->flags & CLK_IS_CRITICAL,
"Disabling critical %s\n", core->name))
return;
if (--core->enable_count > 0)
return;
trace_clk_disable_rcuidle(core);
if (core->ops->disable)
core->ops->disable(core->hw);
trace_clk_disable_complete_rcuidle(core);
clk_core_disable(core->parent);
}
static void clk_core_disable_lock(struct clk_core *core)
{
unsigned long flags;
flags = clk_enable_lock();
clk_core_disable(core);
clk_enable_unlock(flags);
}
/**
* clk_disable - gate a clock
* @clk: the clk being gated
*
* clk_disable must not sleep, which differentiates it from clk_unprepare. In
* a simple case, clk_disable can be used instead of clk_unprepare to gate a
* clk if the operation is fast and will never sleep. One example is a
* SoC-internal clk which is controlled via simple register writes. In the
* complex case a clk gate operation may require a fast and a slow part. It is
* this reason that clk_unprepare and clk_disable are not mutually exclusive.
* In fact clk_disable must be called before clk_unprepare.
*/
void clk_disable(struct clk *clk)
{
if (IS_ERR_OR_NULL(clk))
return;
clk_core_disable_lock(clk->core);
}
EXPORT_SYMBOL_GPL(clk_disable);
static int clk_core_enable(struct clk_core *core)
{
int ret = 0;
lockdep_assert_held(&enable_lock);
if (!core)
return 0;
if (WARN(core->prepare_count == 0,
"Enabling unprepared %s\n", core->name))
return -ESHUTDOWN;
if (core->enable_count == 0) {
ret = clk_core_enable(core->parent);
if (ret)
return ret;
trace_clk_enable_rcuidle(core);
if (core->ops->enable)
ret = core->ops->enable(core->hw);
trace_clk_enable_complete_rcuidle(core);
if (ret) {
clk_core_disable(core->parent);
return ret;
}
}
core->enable_count++;
return 0;
}
static int clk_core_enable_lock(struct clk_core *core)
{
unsigned long flags;
int ret;
flags = clk_enable_lock();
ret = clk_core_enable(core);
clk_enable_unlock(flags);
return ret;
}
/**
* clk_gate_restore_context - restore context for poweroff
* @hw: the clk_hw pointer of clock whose state is to be restored
*
* The clock gate restore context function enables or disables
* the gate clocks based on the enable_count. This is done in cases
* where the clock context is lost and based on the enable_count
* the clock either needs to be enabled/disabled. This
* helps restore the state of gate clocks.
*/
void clk_gate_restore_context(struct clk_hw *hw)
{
struct clk_core *core = hw->core;
if (core->enable_count)
core->ops->enable(hw);
else
core->ops->disable(hw);
}
EXPORT_SYMBOL_GPL(clk_gate_restore_context);
static int clk_core_save_context(struct clk_core *core)
{
struct clk_core *child;
int ret = 0;
hlist_for_each_entry(child, &core->children, child_node) {
ret = clk_core_save_context(child);
if (ret < 0)
return ret;
}
if (core->ops && core->ops->save_context)
ret = core->ops->save_context(core->hw);
return ret;
}
static void clk_core_restore_context(struct clk_core *core)
{
struct clk_core *child;
if (core->ops && core->ops->restore_context)
core->ops->restore_context(core->hw);
hlist_for_each_entry(child, &core->children, child_node)
clk_core_restore_context(child);
}
/**
* clk_save_context - save clock context for poweroff
*
* Saves the context of the clock register for powerstates in which the
* contents of the registers will be lost. Occurs deep within the suspend
* code. Returns 0 on success.
*/
int clk_save_context(void)
{
struct clk_core *clk;
int ret;
hlist_for_each_entry(clk, &clk_root_list, child_node) {
ret = clk_core_save_context(clk);
if (ret < 0)
return ret;
}
hlist_for_each_entry(clk, &clk_orphan_list, child_node) {
ret = clk_core_save_context(clk);
if (ret < 0)
return ret;
}
return 0;
}
EXPORT_SYMBOL_GPL(clk_save_context);
/**
* clk_restore_context - restore clock context after poweroff
*
* Restore the saved clock context upon resume.
*
*/
void clk_restore_context(void)
{
struct clk_core *core;
hlist_for_each_entry(core, &clk_root_list, child_node)
clk_core_restore_context(core);
hlist_for_each_entry(core, &clk_orphan_list, child_node)
clk_core_restore_context(core);
}
EXPORT_SYMBOL_GPL(clk_restore_context);
/**
* clk_enable - ungate a clock
* @clk: the clk being ungated
*
* clk_enable must not sleep, which differentiates it from clk_prepare. In a
* simple case, clk_enable can be used instead of clk_prepare to ungate a clk
* if the operation will never sleep. One example is a SoC-internal clk which
* is controlled via simple register writes. In the complex case a clk ungate
* operation may require a fast and a slow part. It is this reason that
* clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare
* must be called before clk_enable. Returns 0 on success, -EERROR
* otherwise.
*/
int clk_enable(struct clk *clk)
{
if (!clk)
return 0;
return clk_core_enable_lock(clk->core);
}
EXPORT_SYMBOL_GPL(clk_enable);
static int clk_core_prepare_enable(struct clk_core *core)
{
int ret;
ret = clk_core_prepare_lock(core);
if (ret)
return ret;
ret = clk_core_enable_lock(core);
if (ret)
clk_core_unprepare_lock(core);
return ret;
}
static void clk_core_disable_unprepare(struct clk_core *core)
{
clk_core_disable_lock(core);
clk_core_unprepare_lock(core);
}
static void clk_unprepare_unused_subtree(struct clk_core *core)
{
struct clk_core *child;
lockdep_assert_held(&prepare_lock);
hlist_for_each_entry(child, &core->children, child_node)
clk_unprepare_unused_subtree(child);
if (core->prepare_count)
return;
if (core->flags & CLK_IGNORE_UNUSED)
return;
if (clk_pm_runtime_get(core))
return;
if (clk_core_is_prepared(core)) {
trace_clk_unprepare(core);
if (core->ops->unprepare_unused)
core->ops->unprepare_unused(core->hw);
else if (core->ops->unprepare)
core->ops->unprepare(core->hw);
trace_clk_unprepare_complete(core);
}
clk_pm_runtime_put(core);
}
static void clk_disable_unused_subtree(struct clk_core *core)
{
struct clk_core *child;
unsigned long flags;
lockdep_assert_held(&prepare_lock);
hlist_for_each_entry(child, &core->children, child_node)
clk_disable_unused_subtree(child);
if (core->flags & CLK_OPS_PARENT_ENABLE)
clk_core_prepare_enable(core->parent);
if (clk_pm_runtime_get(core))
goto unprepare_out;
flags = clk_enable_lock();
if (core->enable_count)
goto unlock_out;
if (core->flags & CLK_IGNORE_UNUSED)
goto unlock_out;
/*
* some gate clocks have special needs during the disable-unused
* sequence. call .disable_unused if available, otherwise fall
* back to .disable
*/
if (clk_core_is_enabled(core)) {
trace_clk_disable(core);
if (core->ops->disable_unused)
core->ops->disable_unused(core->hw);
else if (core->ops->disable)
core->ops->disable(core->hw);
trace_clk_disable_complete(core);
}
unlock_out:
clk_enable_unlock(flags);
clk_pm_runtime_put(core);
unprepare_out:
if (core->flags & CLK_OPS_PARENT_ENABLE)
clk_core_disable_unprepare(core->parent);
}
static bool clk_ignore_unused;
static int __init clk_ignore_unused_setup(char *__unused)
{
clk_ignore_unused = true;
return 1;
}
__setup("clk_ignore_unused", clk_ignore_unused_setup);
static int clk_disable_unused(void)
{
struct clk_core *core;
if (clk_ignore_unused) {
pr_warn("clk: Not disabling unused clocks\n");
return 0;
}
clk_prepare_lock();
hlist_for_each_entry(core, &clk_root_list, child_node)
clk_disable_unused_subtree(core);
hlist_for_each_entry(core, &clk_orphan_list, child_node)
clk_disable_unused_subtree(core);
hlist_for_each_entry(core, &clk_root_list, child_node)
clk_unprepare_unused_subtree(core);
hlist_for_each_entry(core, &clk_orphan_list, child_node)
clk_unprepare_unused_subtree(core);
clk_prepare_unlock();
return 0;
}
late_initcall_sync(clk_disable_unused);
static int clk_core_determine_round_nolock(struct clk_core *core,
struct clk_rate_request *req)
{
long rate;
lockdep_assert_held(&prepare_lock);
if (!core)
return 0;
/*
* At this point, core protection will be disabled if
* - if the provider is not protected at all
* - if the calling consumer is the only one which has exclusivity
* over the provider
*/
if (clk_core_rate_is_protected(core)) {
req->rate = core->rate;
} else if (core->ops->determine_rate) {
return core->ops->determine_rate(core->hw, req);
} else if (core->ops->round_rate) {
rate = core->ops->round_rate(core->hw, req->rate,
&req->best_parent_rate);
if (rate < 0)
return rate;
req->rate = rate;
} else {
return -EINVAL;
}
return 0;
}
static void clk_core_init_rate_req(struct clk_core * const core,
struct clk_rate_request *req)
{
struct clk_core *parent;
if (WARN_ON(!core || !req))
return;
parent = core->parent;
if (parent) {
req->best_parent_hw = parent->hw;
req->best_parent_rate = parent->rate;
} else {
req->best_parent_hw = NULL;
req->best_parent_rate = 0;
}
}
static bool clk_core_can_round(struct clk_core * const core)
{
if (core->ops->determine_rate || core->ops->round_rate)
return true;
return false;
}
static int clk_core_round_rate_nolock(struct clk_core *core,
struct clk_rate_request *req)
{
lockdep_assert_held(&prepare_lock);
if (!core) {
req->rate = 0;
return 0;
}
clk_core_init_rate_req(core, req);
if (clk_core_can_round(core))
return clk_core_determine_round_nolock(core, req);
else if (core->flags & CLK_SET_RATE_PARENT)
return clk_core_round_rate_nolock(core->parent, req);
req->rate = core->rate;
return 0;
}
/**
* __clk_determine_rate - get the closest rate actually supported by a clock
* @hw: determine the rate of this clock
* @req: target rate request
*
* Useful for clk_ops such as .set_rate and .determine_rate.
*/
int __clk_determine_rate(struct clk_hw *hw, struct clk_rate_request *req)
{
if (!hw) {
req->rate = 0;
return 0;
}
return clk_core_round_rate_nolock(hw->core, req);
}
EXPORT_SYMBOL_GPL(__clk_determine_rate);
unsigned long clk_hw_round_rate(struct clk_hw *hw, unsigned long rate)
{
int ret;
struct clk_rate_request req;
clk_core_get_boundaries(hw->core, &req.min_rate, &req.max_rate);
req.rate = rate;
ret = clk_core_round_rate_nolock(hw->core, &req);
if (ret)
return 0;
return req.rate;
}
EXPORT_SYMBOL_GPL(clk_hw_round_rate);
/**
* clk_round_rate - round the given rate for a clk
* @clk: the clk for which we are rounding a rate
* @rate: the rate which is to be rounded
*
* Takes in a rate as input and rounds it to a rate that the clk can actually
* use which is then returned. If clk doesn't support round_rate operation
* then the parent rate is returned.
*/
long clk_round_rate(struct clk *clk, unsigned long rate)
{
struct clk_rate_request req;
int ret;
if (!clk)
return 0;
clk_prepare_lock();
if (clk->exclusive_count)
clk_core_rate_unprotect(clk->core);
clk_core_get_boundaries(clk->core, &req.min_rate, &req.max_rate);
req.rate = rate;
ret = clk_core_round_rate_nolock(clk->core, &req);
if (clk->exclusive_count)
clk_core_rate_protect(clk->core);
clk_prepare_unlock();
if (ret)
return ret;
return req.rate;
}
EXPORT_SYMBOL_GPL(clk_round_rate);
/**
* __clk_notify - call clk notifier chain
* @core: clk that is changing rate
* @msg: clk notifier type (see include/linux/clk.h)
* @old_rate: old clk rate
* @new_rate: new clk rate
*
* Triggers a notifier call chain on the clk rate-change notification
* for 'clk'. Passes a pointer to the struct clk and the previous
* and current rates to the notifier callback. Intended to be called by
* internal clock code only. Returns NOTIFY_DONE from the last driver
* called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if
* a driver returns that.
*/
static int __clk_notify(struct clk_core *core, unsigned long msg,
unsigned long old_rate, unsigned long new_rate)
{
struct clk_notifier *cn;
struct clk_notifier_data cnd;
int ret = NOTIFY_DONE;
cnd.old_rate = old_rate;
cnd.new_rate = new_rate;
list_for_each_entry(cn, &clk_notifier_list, node) {
if (cn->clk->core == core) {
cnd.clk = cn->clk;
ret = srcu_notifier_call_chain(&cn->notifier_head, msg,
&cnd);
if (ret & NOTIFY_STOP_MASK)
return ret;
}
}
return ret;
}
/**
* __clk_recalc_accuracies
* @core: first clk in the subtree
*
* Walks the subtree of clks starting with clk and recalculates accuracies as
* it goes. Note that if a clk does not implement the .recalc_accuracy
* callback then it is assumed that the clock will take on the accuracy of its
* parent.
*/
static void __clk_recalc_accuracies(struct clk_core *core)
{
unsigned long parent_accuracy = 0;
struct clk_core *child;
lockdep_assert_held(&prepare_lock);
if (core->parent)
parent_accuracy = core->parent->accuracy;
if (core->ops->recalc_accuracy)
core->accuracy = core->ops->recalc_accuracy(core->hw,
parent_accuracy);
else
core->accuracy = parent_accuracy;
hlist_for_each_entry(child, &core->children, child_node)
__clk_recalc_accuracies(child);
}
static long clk_core_get_accuracy(struct clk_core *core)
{
unsigned long accuracy;
clk_prepare_lock();
if (core && (core->flags & CLK_GET_ACCURACY_NOCACHE))
__clk_recalc_accuracies(core);
accuracy = __clk_get_accuracy(core);
clk_prepare_unlock();
return accuracy;
}
/**
* clk_get_accuracy - return the accuracy of clk
* @clk: the clk whose accuracy is being returned
*
* Simply returns the cached accuracy of the clk, unless
* CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be
* issued.
* If clk is NULL then returns 0.
*/
long clk_get_accuracy(struct clk *clk)
{
if (!clk)
return 0;
return clk_core_get_accuracy(clk->core);
}
EXPORT_SYMBOL_GPL(clk_get_accuracy);
static unsigned long clk_recalc(struct clk_core *core,
unsigned long parent_rate)
{
unsigned long rate = parent_rate;
if (core->ops->recalc_rate && !clk_pm_runtime_get(core)) {
rate = core->ops->recalc_rate(core->hw, parent_rate);
clk_pm_runtime_put(core);
}
return rate;
}
/**
* __clk_recalc_rates
* @core: first clk in the subtree
* @msg: notification type (see include/linux/clk.h)
*
* Walks the subtree of clks starting with clk and recalculates rates as it
* goes. Note that if a clk does not implement the .recalc_rate callback then
* it is assumed that the clock will take on the rate of its parent.
*
* clk_recalc_rates also propagates the POST_RATE_CHANGE notification,
* if necessary.
*/
static void __clk_recalc_rates(struct clk_core *core, unsigned long msg)
{
unsigned long old_rate;
unsigned long parent_rate = 0;
struct clk_core *child;
lockdep_assert_held(&prepare_lock);
old_rate = core->rate;
if (core->parent)
parent_rate = core->parent->rate;
core->rate = clk_recalc(core, parent_rate);
/*
* ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
* & ABORT_RATE_CHANGE notifiers
*/
if (core->notifier_count && msg)
__clk_notify(core, msg, old_rate, core->rate);
hlist_for_each_entry(child, &core->children, child_node)
__clk_recalc_rates(child, msg);
}
static unsigned long clk_core_get_rate(struct clk_core *core)
{
unsigned long rate;
clk_prepare_lock();
if (core && (core->flags & CLK_GET_RATE_NOCACHE))
__clk_recalc_rates(core, 0);
rate = clk_core_get_rate_nolock(core);
clk_prepare_unlock();
return rate;
}
/**
* clk_get_rate - return the rate of clk
* @clk: the clk whose rate is being returned
*
* Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
* is set, which means a recalc_rate will be issued.
* If clk is NULL then returns 0.
*/
unsigned long clk_get_rate(struct clk *clk)
{
if (!clk)
return 0;
return clk_core_get_rate(clk->core);
}
EXPORT_SYMBOL_GPL(clk_get_rate);
static int clk_fetch_parent_index(struct clk_core *core,
struct clk_core *parent)
{
int i;
if (!parent)
return -EINVAL;
for (i = 0; i < core->num_parents; i++)
if (clk_core_get_parent_by_index(core, i) == parent)
return i;
return -EINVAL;
}
/*
* Update the orphan status of @core and all its children.
*/
static void clk_core_update_orphan_status(struct clk_core *core, bool is_orphan)
{
struct clk_core *child;
core->orphan = is_orphan;
hlist_for_each_entry(child, &core->children, child_node)
clk_core_update_orphan_status(child, is_orphan);
}
static void clk_reparent(struct clk_core *core, struct clk_core *new_parent)
{
bool was_orphan = core->orphan;
hlist_del(&core->child_node);
if (new_parent) {
bool becomes_orphan = new_parent->orphan;
/* avoid duplicate POST_RATE_CHANGE notifications */
if (new_parent->new_child == core)
new_parent->new_child = NULL;
hlist_add_head(&core->child_node, &new_parent->children);
if (was_orphan != becomes_orphan)
clk_core_update_orphan_status(core, becomes_orphan);
} else {
hlist_add_head(&core->child_node, &clk_orphan_list);
if (!was_orphan)
clk_core_update_orphan_status(core, true);
}
core->parent = new_parent;
}
static struct clk_core *__clk_set_parent_before(struct clk_core *core,
struct clk_core *parent)
{
unsigned long flags;
struct clk_core *old_parent = core->parent;
/*
* 1. enable parents for CLK_OPS_PARENT_ENABLE clock
*
* 2. Migrate prepare state between parents and prevent race with
* clk_enable().
*
* If the clock is not prepared, then a race with
* clk_enable/disable() is impossible since we already have the
* prepare lock (future calls to clk_enable() need to be preceded by
* a clk_prepare()).
*
* If the clock is prepared, migrate the prepared state to the new
* parent and also protect against a race with clk_enable() by
* forcing the clock and the new parent on. This ensures that all
* future calls to clk_enable() are practically NOPs with respect to
* hardware and software states.
*
* See also: Comment for clk_set_parent() below.
*/
/* enable old_parent & parent if CLK_OPS_PARENT_ENABLE is set */
if (core->flags & CLK_OPS_PARENT_ENABLE) {
clk_core_prepare_enable(old_parent);
clk_core_prepare_enable(parent);
}
/* migrate prepare count if > 0 */
if (core->prepare_count) {
clk_core_prepare_enable(parent);
clk_core_enable_lock(core);
}
/* update the clk tree topology */
flags = clk_enable_lock();
clk_reparent(core, parent);
clk_enable_unlock(flags);
return old_parent;
}
static void __clk_set_parent_after(struct clk_core *core,
struct clk_core *parent,
struct clk_core *old_parent)
{
/*
* Finish the migration of prepare state and undo the changes done
* for preventing a race with clk_enable().
*/
if (core->prepare_count) {
clk_core_disable_lock(core);
clk_core_disable_unprepare(old_parent);
}
/* re-balance ref counting if CLK_OPS_PARENT_ENABLE is set */
if (core->flags & CLK_OPS_PARENT_ENABLE) {
clk_core_disable_unprepare(parent);
clk_core_disable_unprepare(old_parent);
}
}
static int __clk_set_parent(struct clk_core *core, struct clk_core *parent,
u8 p_index)
{
unsigned long flags;
int ret = 0;
struct clk_core *old_parent;
old_parent = __clk_set_parent_before(core, parent);
trace_clk_set_parent(core, parent);
/* change clock input source */
if (parent && core->ops->set_parent)
ret = core->ops->set_parent(core->hw, p_index);
trace_clk_set_parent_complete(core, parent);
if (ret) {
flags = clk_enable_lock();
clk_reparent(core, old_parent);
clk_enable_unlock(flags);
__clk_set_parent_after(core, old_parent, parent);
return ret;
}
__clk_set_parent_after(core, parent, old_parent);
return 0;
}
/**
* __clk_speculate_rates
* @core: first clk in the subtree
* @parent_rate: the "future" rate of clk's parent
*
* Walks the subtree of clks starting with clk, speculating rates as it
* goes and firing off PRE_RATE_CHANGE notifications as necessary.
*
* Unlike clk_recalc_rates, clk_speculate_rates exists only for sending
* pre-rate change notifications and returns early if no clks in the
* subtree have subscribed to the notifications. Note that if a clk does not
* implement the .recalc_rate callback then it is assumed that the clock will
* take on the rate of its parent.
*/
static int __clk_speculate_rates(struct clk_core *core,
unsigned long parent_rate)
{
struct clk_core *child;
unsigned long new_rate;
int ret = NOTIFY_DONE;
lockdep_assert_held(&prepare_lock);
new_rate = clk_recalc(core, parent_rate);
/* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
if (core->notifier_count)
ret = __clk_notify(core, PRE_RATE_CHANGE, core->rate, new_rate);
if (ret & NOTIFY_STOP_MASK) {
pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n",
__func__, core->name, ret);
goto out;
}
hlist_for_each_entry(child, &core->children, child_node) {
ret = __clk_speculate_rates(child, new_rate);
if (ret & NOTIFY_STOP_MASK)
break;
}
out:
return ret;
}
static void clk_calc_subtree(struct clk_core *core, unsigned long new_rate,
struct clk_core *new_parent, u8 p_index)
{
struct clk_core *child;
core->new_rate = new_rate;
core->new_parent = new_parent;
core->new_parent_index = p_index;
/* include clk in new parent's PRE_RATE_CHANGE notifications */
core->new_child = NULL;
if (new_parent && new_parent != core->parent)
new_parent->new_child = core;
hlist_for_each_entry(child, &core->children, child_node) {
child->new_rate = clk_recalc(child, new_rate);
clk_calc_subtree(child, child->new_rate, NULL, 0);
}
}
/*
* calculate the new rates returning the topmost clock that has to be
* changed.
*/
static struct clk_core *clk_calc_new_rates(struct clk_core *core,
unsigned long rate)
{
struct clk_core *top = core;
struct clk_core *old_parent, *parent;
unsigned long best_parent_rate = 0;
unsigned long new_rate;
unsigned long min_rate;
unsigned long max_rate;
int p_index = 0;
long ret;
/* sanity */
if (IS_ERR_OR_NULL(core))
return NULL;
/* save parent rate, if it exists */
parent = old_parent = core->parent;
if (parent)
best_parent_rate = parent->rate;
clk_core_get_boundaries(core, &min_rate, &max_rate);
/* find the closest rate and parent clk/rate */
if (clk_core_can_round(core)) {
struct clk_rate_request req;
req.rate = rate;
req.min_rate = min_rate;
req.max_rate = max_rate;
clk_core_init_rate_req(core, &req);
ret = clk_core_determine_round_nolock(core, &req);
if (ret < 0)
return NULL;
best_parent_rate = req.best_parent_rate;
new_rate = req.rate;
parent = req.best_parent_hw ? req.best_parent_hw->core : NULL;
if (new_rate < min_rate || new_rate > max_rate)
return NULL;
} else if (!parent || !(core->flags & CLK_SET_RATE_PARENT)) {
/* pass-through clock without adjustable parent */
core->new_rate = core->rate;
return NULL;
} else {
/* pass-through clock with adjustable parent */
top = clk_calc_new_rates(parent, rate);
new_rate = parent->new_rate;
goto out;
}
/* some clocks must be gated to change parent */
if (parent != old_parent &&
(core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) {
pr_debug("%s: %s not gated but wants to reparent\n",
__func__, core->name);
return NULL;
}
/* try finding the new parent index */
if (parent && core->num_parents > 1) {
p_index = clk_fetch_parent_index(core, parent);
if (p_index < 0) {
pr_debug("%s: clk %s can not be parent of clk %s\n",
__func__, parent->name, core->name);
return NULL;
}
}
if ((core->flags & CLK_SET_RATE_PARENT) && parent &&
best_parent_rate != parent->rate)
top = clk_calc_new_rates(parent, best_parent_rate);
out:
clk_calc_subtree(core, new_rate, parent, p_index);
return top;
}
/*
* Notify about rate changes in a subtree. Always walk down the whole tree
* so that in case of an error we can walk down the whole tree again and
* abort the change.
*/
static struct clk_core *clk_propagate_rate_change(struct clk_core *core,
unsigned long event)
{
struct clk_core *child, *tmp_clk, *fail_clk = NULL;
int ret = NOTIFY_DONE;
if (core->rate == core->new_rate)
return NULL;
if (core->notifier_count) {
ret = __clk_notify(core, event, core->rate, core->new_rate);
if (ret & NOTIFY_STOP_MASK)
fail_clk = core;
}
hlist_for_each_entry(child, &core->children, child_node) {
/* Skip children who will be reparented to another clock */
if (child->new_parent && child->new_parent != core)
continue;
tmp_clk = clk_propagate_rate_change(child, event);
if (tmp_clk)
fail_clk = tmp_clk;
}
/* handle the new child who might not be in core->children yet */
if (core->new_child) {
tmp_clk = clk_propagate_rate_change(core->new_child, event);
if (tmp_clk)
fail_clk = tmp_clk;
}
return fail_clk;
}
/*
* walk down a subtree and set the new rates notifying the rate
* change on the way
*/
static void clk_change_rate(struct clk_core *core)
{
struct clk_core *child;
struct hlist_node *tmp;
unsigned long old_rate;
unsigned long best_parent_rate = 0;
bool skip_set_rate = false;
struct clk_core *old_parent;
struct clk_core *parent = NULL;
old_rate = core->rate;
if (core->new_parent) {
parent = core->new_parent;
best_parent_rate = core->new_parent->rate;
} else if (core->parent) {
parent = core->parent;
best_parent_rate = core->parent->rate;
}
if (clk_pm_runtime_get(core))
return;
if (core->flags & CLK_SET_RATE_UNGATE) {
unsigned long flags;
clk_core_prepare(core);
flags = clk_enable_lock();
clk_core_enable(core);
clk_enable_unlock(flags);
}
if (core->new_parent && core->new_parent != core->parent) {
old_parent = __clk_set_parent_before(core, core->new_parent);
trace_clk_set_parent(core, core->new_parent);
if (core->ops->set_rate_and_parent) {
skip_set_rate = true;
core->ops->set_rate_and_parent(core->hw, core->new_rate,
best_parent_rate,
core->new_parent_index);
} else if (core->ops->set_parent) {
core->ops->set_parent(core->hw, core->new_parent_index);
}
trace_clk_set_parent_complete(core, core->new_parent);
__clk_set_parent_after(core, core->new_parent, old_parent);
}
if (core->flags & CLK_OPS_PARENT_ENABLE)
clk_core_prepare_enable(parent);
trace_clk_set_rate(core, core->new_rate);
if (!skip_set_rate && core->ops->set_rate)
core->ops->set_rate(core->hw, core->new_rate, best_parent_rate);
trace_clk_set_rate_complete(core, core->new_rate);
core->rate = clk_recalc(core, best_parent_rate);
if (core->flags & CLK_SET_RATE_UNGATE) {
unsigned long flags;
flags = clk_enable_lock();
clk_core_disable(core);
clk_enable_unlock(flags);
clk_core_unprepare(core);
}
if (core->flags & CLK_OPS_PARENT_ENABLE)
clk_core_disable_unprepare(parent);
if (core->notifier_count && old_rate != core->rate)
__clk_notify(core, POST_RATE_CHANGE, old_rate, core->rate);
if (core->flags & CLK_RECALC_NEW_RATES)
(void)clk_calc_new_rates(core, core->new_rate);
/*
* Use safe iteration, as change_rate can actually swap parents
* for certain clock types.
*/
hlist_for_each_entry_safe(child, tmp, &core->children, child_node) {
/* Skip children who will be reparented to another clock */
if (child->new_parent && child->new_parent != core)
continue;
clk_change_rate(child);
}
/* handle the new child who might not be in core->children yet */
if (core->new_child)
clk_change_rate(core->new_child);
clk_pm_runtime_put(core);
}
static unsigned long clk_core_req_round_rate_nolock(struct clk_core *core,
unsigned long req_rate)
{
int ret, cnt;
struct clk_rate_request req;
lockdep_assert_held(&prepare_lock);
if (!core)
return 0;
/* simulate what the rate would be if it could be freely set */
cnt = clk_core_rate_nuke_protect(core);
if (cnt < 0)
return cnt;
clk_core_get_boundaries(core, &req.min_rate, &req.max_rate);
req.rate = req_rate;
ret = clk_core_round_rate_nolock(core, &req);
/* restore the protection */
clk_core_rate_restore_protect(core, cnt);
return ret ? 0 : req.rate;
}
static int clk_core_set_rate_nolock(struct clk_core *core,
unsigned long req_rate)
{
struct clk_core *top, *fail_clk;
unsigned long rate;
int ret = 0;
if (!core)
return 0;
rate = clk_core_req_round_rate_nolock(core, req_rate);
/* bail early if nothing to do */
if (rate == clk_core_get_rate_nolock(core))
return 0;
/* fail on a direct rate set of a protected provider */
if (clk_core_rate_is_protected(core))
return -EBUSY;
/* calculate new rates and get the topmost changed clock */
top = clk_calc_new_rates(core, req_rate);
if (!top)
return -EINVAL;
ret = clk_pm_runtime_get(core);
if (ret)
return ret;
/* notify that we are about to change rates */
fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE);
if (fail_clk) {
pr_debug("%s: failed to set %s rate\n", __func__,
fail_clk->name);
clk_propagate_rate_change(top, ABORT_RATE_CHANGE);
ret = -EBUSY;
goto err;
}
/* change the rates */
clk_change_rate(top);
core->req_rate = req_rate;
err:
clk_pm_runtime_put(core);
return ret;
}
/**
* clk_set_rate - specify a new rate for clk
* @clk: the clk whose rate is being changed
* @rate: the new rate for clk
*
* In the simplest case clk_set_rate will only adjust the rate of clk.
*
* Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
* propagate up to clk's parent; whether or not this happens depends on the
* outcome of clk's .round_rate implementation. If *parent_rate is unchanged
* after calling .round_rate then upstream parent propagation is ignored. If
* *parent_rate comes back with a new rate for clk's parent then we propagate
* up to clk's parent and set its rate. Upward propagation will continue
* until either a clk does not support the CLK_SET_RATE_PARENT flag or
* .round_rate stops requesting changes to clk's parent_rate.
*
* Rate changes are accomplished via tree traversal that also recalculates the
* rates for the clocks and fires off POST_RATE_CHANGE notifiers.
*
* Returns 0 on success, -EERROR otherwise.
*/
int clk_set_rate(struct clk *clk, unsigned long rate)
{
int ret;
if (!clk)
return 0;
/* prevent racing with updates to the clock topology */
clk_prepare_lock();
if (clk->exclusive_count)
clk_core_rate_unprotect(clk->core);
ret = clk_core_set_rate_nolock(clk->core, rate);
if (clk->exclusive_count)
clk_core_rate_protect(clk->core);
clk_prepare_unlock();
return ret;
}
EXPORT_SYMBOL_GPL(clk_set_rate);
/**
* clk_set_rate_exclusive - specify a new rate get exclusive control
* @clk: the clk whose rate is being changed
* @rate: the new rate for clk
*
* This is a combination of clk_set_rate() and clk_rate_exclusive_get()
* within a critical section
*
* This can be used initially to ensure that at least 1 consumer is
* statisfied when several consumers are competing for exclusivity over the
* same clock provider.
*
* The exclusivity is not applied if setting the rate failed.
*
* Calls to clk_rate_exclusive_get() should be balanced with calls to
* clk_rate_exclusive_put().
*
* Returns 0 on success, -EERROR otherwise.
*/
int clk_set_rate_exclusive(struct clk *clk, unsigned long rate)
{
int ret;
if (!clk)
return 0;
/* prevent racing with updates to the clock topology */
clk_prepare_lock();
/*
* The temporary protection removal is not here, on purpose
* This function is meant to be used instead of clk_rate_protect,
* so before the consumer code path protect the clock provider
*/
ret = clk_core_set_rate_nolock(clk->core, rate);
if (!ret) {
clk_core_rate_protect(clk->core);
clk->exclusive_count++;
}
clk_prepare_unlock();
return ret;
}
EXPORT_SYMBOL_GPL(clk_set_rate_exclusive);
/**
* clk_set_rate_range - set a rate range for a clock source
* @clk: clock source
* @min: desired minimum clock rate in Hz, inclusive
* @max: desired maximum clock rate in Hz, inclusive
*
* Returns success (0) or negative errno.
*/
int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max)
{
int ret = 0;
unsigned long old_min, old_max, rate;
if (!clk)
return 0;
if (min > max) {
pr_err("%s: clk %s dev %s con %s: invalid range [%lu, %lu]\n",
__func__, clk->core->name, clk->dev_id, clk->con_id,
min, max);
return -EINVAL;
}
clk_prepare_lock();
if (clk->exclusive_count)
clk_core_rate_unprotect(clk->core);
/* Save the current values in case we need to rollback the change */
old_min = clk->min_rate;
old_max = clk->max_rate;
clk->min_rate = min;
clk->max_rate = max;
rate = clk_core_get_rate_nolock(clk->core);
if (rate < min || rate > max) {
/*
* FIXME:
* We are in bit of trouble here, current rate is outside the
* the requested range. We are going try to request appropriate
* range boundary but there is a catch. It may fail for the
* usual reason (clock broken, clock protected, etc) but also
* because:
* - round_rate() was not favorable and fell on the wrong
* side of the boundary
* - the determine_rate() callback does not really check for
* this corner case when determining the rate
*/
if (rate < min)
rate = min;
else
rate = max;
ret = clk_core_set_rate_nolock(clk->core, rate);
if (ret) {
/* rollback the changes */
clk->min_rate = old_min;
clk->max_rate = old_max;
}
}
if (clk->exclusive_count)
clk_core_rate_protect(clk->core);
clk_prepare_unlock();
return ret;
}
EXPORT_SYMBOL_GPL(clk_set_rate_range);
/**
* clk_set_min_rate - set a minimum clock rate for a clock source
* @clk: clock source
* @rate: desired minimum clock rate in Hz, inclusive
*
* Returns success (0) or negative errno.
*/
int clk_set_min_rate(struct clk *clk, unsigned long rate)
{
if (!clk)
return 0;
return clk_set_rate_range(clk, rate, clk->max_rate);
}
EXPORT_SYMBOL_GPL(clk_set_min_rate);
/**
* clk_set_max_rate - set a maximum clock rate for a clock source
* @clk: clock source
* @rate: desired maximum clock rate in Hz, inclusive
*
* Returns success (0) or negative errno.
*/
int clk_set_max_rate(struct clk *clk, unsigned long rate)
{
if (!clk)
return 0;
return clk_set_rate_range(clk, clk->min_rate, rate);
}
EXPORT_SYMBOL_GPL(clk_set_max_rate);
/**
* clk_get_parent - return the parent of a clk
* @clk: the clk whose parent gets returned
*
* Simply returns clk->parent. Returns NULL if clk is NULL.
*/
struct clk *clk_get_parent(struct clk *clk)
{
struct clk *parent;
if (!clk)
return NULL;
clk_prepare_lock();
/* TODO: Create a per-user clk and change callers to call clk_put */
parent = !clk->core->parent ? NULL : clk->core->parent->hw->clk;
clk_prepare_unlock();
return parent;
}
EXPORT_SYMBOL_GPL(clk_get_parent);
static struct clk_core *__clk_init_parent(struct clk_core *core)
{
u8 index = 0;
if (core->num_parents > 1 && core->ops->get_parent)
index = core->ops->get_parent(core->hw);
return clk_core_get_parent_by_index(core, index);
}
static void clk_core_reparent(struct clk_core *core,
struct clk_core *new_parent)
{
clk_reparent(core, new_parent);
__clk_recalc_accuracies(core);
__clk_recalc_rates(core, POST_RATE_CHANGE);
}
void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent)
{
if (!hw)
return;
clk_core_reparent(hw->core, !new_parent ? NULL : new_parent->core);
}
/**
* clk_has_parent - check if a clock is a possible parent for another
* @clk: clock source
* @parent: parent clock source
*
* This function can be used in drivers that need to check that a clock can be
* the parent of another without actually changing the parent.
*
* Returns true if @parent is a possible parent for @clk, false otherwise.
*/
bool clk_has_parent(struct clk *clk, struct clk *parent)
{
struct clk_core *core, *parent_core;
/* NULL clocks should be nops, so return success if either is NULL. */
if (!clk || !parent)
return true;
core = clk->core;
parent_core = parent->core;
/* Optimize for the case where the parent is already the parent. */
if (core->parent == parent_core)
return true;
return match_string(core->parent_names, core->num_parents,
parent_core->name) >= 0;
}
EXPORT_SYMBOL_GPL(clk_has_parent);
static int clk_core_set_parent_nolock(struct clk_core *core,
struct clk_core *parent)
{
int ret = 0;
int p_index = 0;
unsigned long p_rate = 0;
lockdep_assert_held(&prepare_lock);
if (!core)
return 0;
if (core->parent == parent)
return 0;
/* verify ops for for multi-parent clks */
if (core->num_parents > 1 && !core->ops->set_parent)
return -EPERM;
/* check that we are allowed to re-parent if the clock is in use */
if ((core->flags & CLK_SET_PARENT_GATE) && core->prepare_count)
return -EBUSY;
if (clk_core_rate_is_protected(core))
return -EBUSY;
/* try finding the new parent index */
if (parent) {
p_index = clk_fetch_parent_index(core, parent);
if (p_index < 0) {
pr_debug("%s: clk %s can not be parent of clk %s\n",
__func__, parent->name, core->name);
return p_index;
}
p_rate = parent->rate;
}
ret = clk_pm_runtime_get(core);
if (ret)
return ret;
/* propagate PRE_RATE_CHANGE notifications */
ret = __clk_speculate_rates(core, p_rate);
/* abort if a driver objects */
if (ret & NOTIFY_STOP_MASK)
goto runtime_put;
/* do the re-parent */
ret = __clk_set_parent(core, parent, p_index);
/* propagate rate an accuracy recalculation accordingly */
if (ret) {
__clk_recalc_rates(core, ABORT_RATE_CHANGE);
} else {
__clk_recalc_rates(core, POST_RATE_CHANGE);
__clk_recalc_accuracies(core);
}
runtime_put:
clk_pm_runtime_put(core);
return ret;
}
/**
* clk_set_parent - switch the parent of a mux clk
* @clk: the mux clk whose input we are switching
* @parent: the new input to clk
*
* Re-parent clk to use parent as its new input source. If clk is in
* prepared state, the clk will get enabled for the duration of this call. If
* that's not acceptable for a specific clk (Eg: the consumer can't handle
* that, the reparenting is glitchy in hardware, etc), use the
* CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared.
*
* After successfully changing clk's parent clk_set_parent will update the
* clk topology, sysfs topology and propagate rate recalculation via
* __clk_recalc_rates.
*
* Returns 0 on success, -EERROR otherwise.
*/
int clk_set_parent(struct clk *clk, struct clk *parent)
{
int ret;
if (!clk)
return 0;
clk_prepare_lock();
if (clk->exclusive_count)
clk_core_rate_unprotect(clk->core);
ret = clk_core_set_parent_nolock(clk->core,
parent ? parent->core : NULL);
if (clk->exclusive_count)
clk_core_rate_protect(clk->core);
clk_prepare_unlock();
return ret;
}
EXPORT_SYMBOL_GPL(clk_set_parent);
static int clk_core_set_phase_nolock(struct clk_core *core, int degrees)
{
int ret = -EINVAL;
lockdep_assert_held(&prepare_lock);
if (!core)
return 0;
if (clk_core_rate_is_protected(core))
return -EBUSY;
trace_clk_set_phase(core, degrees);
if (core->ops->set_phase) {
ret = core->ops->set_phase(core->hw, degrees);
if (!ret)
core->phase = degrees;
}
trace_clk_set_phase_complete(core, degrees);
return ret;
}
/**
* clk_set_phase - adjust the phase shift of a clock signal
* @clk: clock signal source
* @degrees: number of degrees the signal is shifted
*
* Shifts the phase of a clock signal by the specified
* degrees. Returns 0 on success, -EERROR otherwise.
*
* This function makes no distinction about the input or reference
* signal that we adjust the clock signal phase against. For example
* phase locked-loop clock signal generators we may shift phase with
* respect to feedback clock signal input, but for other cases the
* clock phase may be shifted with respect to some other, unspecified
* signal.
*
* Additionally the concept of phase shift does not propagate through
* the clock tree hierarchy, which sets it apart from clock rates and
* clock accuracy. A parent clock phase attribute does not have an
* impact on the phase attribute of a child clock.
*/
int clk_set_phase(struct clk *clk, int degrees)
{
int ret;
if (!clk)
return 0;
/* sanity check degrees */
degrees %= 360;
if (degrees < 0)
degrees += 360;
clk_prepare_lock();
if (clk->exclusive_count)
clk_core_rate_unprotect(clk->core);
ret = clk_core_set_phase_nolock(clk->core, degrees);
if (clk->exclusive_count)
clk_core_rate_protect(clk->core);
clk_prepare_unlock();
return ret;
}
EXPORT_SYMBOL_GPL(clk_set_phase);
static int clk_core_get_phase(struct clk_core *core)
{
int ret;
clk_prepare_lock();
/* Always try to update cached phase if possible */
if (core->ops->get_phase)
core->phase = core->ops->get_phase(core->hw);
ret = core->phase;
clk_prepare_unlock();
return ret;
}
/**
* clk_get_phase - return the phase shift of a clock signal
* @clk: clock signal source
*
* Returns the phase shift of a clock node in degrees, otherwise returns
* -EERROR.
*/
int clk_get_phase(struct clk *clk)
{
if (!clk)
return 0;
return clk_core_get_phase(clk->core);
}
EXPORT_SYMBOL_GPL(clk_get_phase);
static void clk_core_reset_duty_cycle_nolock(struct clk_core *core)
{
/* Assume a default value of 50% */
core->duty.num = 1;
core->duty.den = 2;
}
static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core);
static int clk_core_update_duty_cycle_nolock(struct clk_core *core)
{
struct clk_duty *duty = &core->duty;
int ret = 0;
if (!core->ops->get_duty_cycle)
return clk_core_update_duty_cycle_parent_nolock(core);
ret = core->ops->get_duty_cycle(core->hw, duty);
if (ret)
goto reset;
/* Don't trust the clock provider too much */
if (duty->den == 0 || duty->num > duty->den) {
ret = -EINVAL;
goto reset;
}
return 0;
reset:
clk_core_reset_duty_cycle_nolock(core);
return ret;
}
static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core)
{
int ret = 0;
if (core->parent &&
core->flags & CLK_DUTY_CYCLE_PARENT) {
ret = clk_core_update_duty_cycle_nolock(core->parent);
memcpy(&core->duty, &core->parent->duty, sizeof(core->duty));
} else {
clk_core_reset_duty_cycle_nolock(core);
}
return ret;
}
static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core,
struct clk_duty *duty);
static int clk_core_set_duty_cycle_nolock(struct clk_core *core,
struct clk_duty *duty)
{
int ret;
lockdep_assert_held(&prepare_lock);
if (clk_core_rate_is_protected(core))
return -EBUSY;
trace_clk_set_duty_cycle(core, duty);
if (!core->ops->set_duty_cycle)
return clk_core_set_duty_cycle_parent_nolock(core, duty);
ret = core->ops->set_duty_cycle(core->hw, duty);
if (!ret)
memcpy(&core->duty, duty, sizeof(*duty));
trace_clk_set_duty_cycle_complete(core, duty);
return ret;
}
static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core,
struct clk_duty *duty)
{
int ret = 0;
if (core->parent &&
core->flags & (CLK_DUTY_CYCLE_PARENT | CLK_SET_RATE_PARENT)) {
ret = clk_core_set_duty_cycle_nolock(core->parent, duty);
memcpy(&core->duty, &core->parent->duty, sizeof(core->duty));
}
return ret;
}
/**
* clk_set_duty_cycle - adjust the duty cycle ratio of a clock signal
* @clk: clock signal source
* @num: numerator of the duty cycle ratio to be applied
* @den: denominator of the duty cycle ratio to be applied
*
* Apply the duty cycle ratio if the ratio is valid and the clock can
* perform this operation
*
* Returns (0) on success, a negative errno otherwise.
*/
int clk_set_duty_cycle(struct clk *clk, unsigned int num, unsigned int den)
{
int ret;
struct clk_duty duty;
if (!clk)
return 0;
/* sanity check the ratio */
if (den == 0 || num > den)
return -EINVAL;
duty.num = num;
duty.den = den;
clk_prepare_lock();
if (clk->exclusive_count)
clk_core_rate_unprotect(clk->core);
ret = clk_core_set_duty_cycle_nolock(clk->core, &duty);
if (clk->exclusive_count)
clk_core_rate_protect(clk->core);
clk_prepare_unlock();
return ret;
}
EXPORT_SYMBOL_GPL(clk_set_duty_cycle);
static int clk_core_get_scaled_duty_cycle(struct clk_core *core,
unsigned int scale)
{
struct clk_duty *duty = &core->duty;
int ret;
clk_prepare_lock();
ret = clk_core_update_duty_cycle_nolock(core);
if (!ret)
ret = mult_frac(scale, duty->num, duty->den);
clk_prepare_unlock();
return ret;
}
/**
* clk_get_scaled_duty_cycle - return the duty cycle ratio of a clock signal
* @clk: clock signal source
* @scale: scaling factor to be applied to represent the ratio as an integer
*
* Returns the duty cycle ratio of a clock node multiplied by the provided
* scaling factor, or negative errno on error.
*/
int clk_get_scaled_duty_cycle(struct clk *clk, unsigned int scale)
{
if (!clk)
return 0;
return clk_core_get_scaled_duty_cycle(clk->core, scale);
}
EXPORT_SYMBOL_GPL(clk_get_scaled_duty_cycle);
/**
* clk_is_match - check if two clk's point to the same hardware clock
* @p: clk compared against q
* @q: clk compared against p
*
* Returns true if the two struct clk pointers both point to the same hardware
* clock node. Put differently, returns true if struct clk *p and struct clk *q
* share the same struct clk_core object.
*
* Returns false otherwise. Note that two NULL clks are treated as matching.
*/
bool clk_is_match(const struct clk *p, const struct clk *q)
{
/* trivial case: identical struct clk's or both NULL */
if (p == q)
return true;
/* true if clk->core pointers match. Avoid dereferencing garbage */
if (!IS_ERR_OR_NULL(p) && !IS_ERR_OR_NULL(q))
if (p->core == q->core)
return true;
return false;
}
EXPORT_SYMBOL_GPL(clk_is_match);
/*** debugfs support ***/
#ifdef CONFIG_DEBUG_FS
#include <linux/debugfs.h>
static struct dentry *rootdir;
static int inited = 0;
static DEFINE_MUTEX(clk_debug_lock);
static HLIST_HEAD(clk_debug_list);
static struct hlist_head *all_lists[] = {
&clk_root_list,
&clk_orphan_list,
NULL,
};
static struct hlist_head *orphan_list[] = {
&clk_orphan_list,
NULL,
};
static void clk_summary_show_one(struct seq_file *s, struct clk_core *c,
int level)
{
if (!c)
return;
seq_printf(s, "%*s%-*s %7d %8d %8d %11lu %10lu %5d %6d\n",
level * 3 + 1, "",
30 - level * 3, c->name,
c->enable_count, c->prepare_count, c->protect_count,
clk_core_get_rate(c), clk_core_get_accuracy(c),
clk_core_get_phase(c),
clk_core_get_scaled_duty_cycle(c, 100000));
}
static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c,
int level)
{
struct clk_core *child;
if (!c)
return;
clk_summary_show_one(s, c, level);
hlist_for_each_entry(child, &c->children, child_node)
clk_summary_show_subtree(s, child, level + 1);
}
static int clk_summary_show(struct seq_file *s, void *data)
{
struct clk_core *c;
struct hlist_head **lists = (struct hlist_head **)s->private;
seq_puts(s, " enable prepare protect duty\n");
seq_puts(s, " clock count count count rate accuracy phase cycle\n");
seq_puts(s, "---------------------------------------------------------------------------------------------\n");
clk_prepare_lock();
for (; *lists; lists++)
hlist_for_each_entry(c, *lists, child_node)
clk_summary_show_subtree(s, c, 0);
clk_prepare_unlock();
return 0;
}
DEFINE_SHOW_ATTRIBUTE(clk_summary);
static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level)
{
if (!c)
return;
/* This should be JSON format, i.e. elements separated with a comma */
seq_printf(s, "\"%s\": { ", c->name);
seq_printf(s, "\"enable_count\": %d,", c->enable_count);
seq_printf(s, "\"prepare_count\": %d,", c->prepare_count);
seq_printf(s, "\"protect_count\": %d,", c->protect_count);
seq_printf(s, "\"rate\": %lu,", clk_core_get_rate(c));
seq_printf(s, "\"accuracy\": %lu,", clk_core_get_accuracy(c));
seq_printf(s, "\"phase\": %d", clk_core_get_phase(c));
seq_printf(s, "\"duty_cycle\": %u",
clk_core_get_scaled_duty_cycle(c, 100000));
}
static void clk_dump_subtree(struct seq_file *s, struct clk_core *c, int level)
{
struct clk_core *child;
if (!c)
return;
clk_dump_one(s, c, level);
hlist_for_each_entry(child, &c->children, child_node) {
seq_putc(s, ',');
clk_dump_subtree(s, child, level + 1);
}
seq_putc(s, '}');
}
static int clk_dump_show(struct seq_file *s, void *data)
{
struct clk_core *c;
bool first_node = true;
struct hlist_head **lists = (struct hlist_head **)s->private;
seq_putc(s, '{');
clk_prepare_lock();
for (; *lists; lists++) {
hlist_for_each_entry(c, *lists, child_node) {
if (!first_node)
seq_putc(s, ',');
first_node = false;
clk_dump_subtree(s, c, 0);
}
}
clk_prepare_unlock();
seq_puts(s, "}\n");
return 0;
}
DEFINE_SHOW_ATTRIBUTE(clk_dump);
static const struct {
unsigned long flag;
const char *name;
} clk_flags[] = {
#define ENTRY(f) { f, #f }
ENTRY(CLK_SET_RATE_GATE),
ENTRY(CLK_SET_PARENT_GATE),
ENTRY(CLK_SET_RATE_PARENT),
ENTRY(CLK_IGNORE_UNUSED),
ENTRY(CLK_IS_BASIC),
ENTRY(CLK_GET_RATE_NOCACHE),
ENTRY(CLK_SET_RATE_NO_REPARENT),
ENTRY(CLK_GET_ACCURACY_NOCACHE),
ENTRY(CLK_RECALC_NEW_RATES),
ENTRY(CLK_SET_RATE_UNGATE),
ENTRY(CLK_IS_CRITICAL),
ENTRY(CLK_OPS_PARENT_ENABLE),
ENTRY(CLK_DUTY_CYCLE_PARENT),
#undef ENTRY
};
static int clk_flags_show(struct seq_file *s, void *data)
{
struct clk_core *core = s->private;
unsigned long flags = core->flags;
unsigned int i;
for (i = 0; flags && i < ARRAY_SIZE(clk_flags); i++) {
if (flags & clk_flags[i].flag) {
seq_printf(s, "%s\n", clk_flags[i].name);
flags &= ~clk_flags[i].flag;
}
}
if (flags) {
/* Unknown flags */
seq_printf(s, "0x%lx\n", flags);
}
return 0;
}
DEFINE_SHOW_ATTRIBUTE(clk_flags);
static int possible_parents_show(struct seq_file *s, void *data)
{
struct clk_core *core = s->private;
int i;
for (i = 0; i < core->num_parents - 1; i++)
seq_printf(s, "%s ", core->parent_names[i]);
seq_printf(s, "%s\n", core->parent_names[i]);
return 0;
}
DEFINE_SHOW_ATTRIBUTE(possible_parents);
static int clk_duty_cycle_show(struct seq_file *s, void *data)
{
struct clk_core *core = s->private;
struct clk_duty *duty = &core->duty;
seq_printf(s, "%u/%u\n", duty->num, duty->den);
return 0;
}
DEFINE_SHOW_ATTRIBUTE(clk_duty_cycle);
static void clk_debug_create_one(struct clk_core *core, struct dentry *pdentry)
{
struct dentry *root;
if (!core || !pdentry)
return;
root = debugfs_create_dir(core->name, pdentry);
core->dentry = root;
debugfs_create_ulong("clk_rate", 0444, root, &core->rate);
debugfs_create_ulong("clk_accuracy", 0444, root, &core->accuracy);
debugfs_create_u32("clk_phase", 0444, root, &core->phase);
debugfs_create_file("clk_flags", 0444, root, core, &clk_flags_fops);
debugfs_create_u32("clk_prepare_count", 0444, root, &core->prepare_count);
debugfs_create_u32("clk_enable_count", 0444, root, &core->enable_count);
debugfs_create_u32("clk_protect_count", 0444, root, &core->protect_count);
debugfs_create_u32("clk_notifier_count", 0444, root, &core->notifier_count);
debugfs_create_file("clk_duty_cycle", 0444, root, core,
&clk_duty_cycle_fops);
if (core->num_parents > 1)
debugfs_create_file("clk_possible_parents", 0444, root, core,
&possible_parents_fops);
if (core->ops->debug_init)
core->ops->debug_init(core->hw, core->dentry);
}
/**
* clk_debug_register - add a clk node to the debugfs clk directory
* @core: the clk being added to the debugfs clk directory
*
* Dynamically adds a clk to the debugfs clk directory if debugfs has been
* initialized. Otherwise it bails out early since the debugfs clk directory
* will be created lazily by clk_debug_init as part of a late_initcall.
*/
static void clk_debug_register(struct clk_core *core)
{
mutex_lock(&clk_debug_lock);
hlist_add_head(&core->debug_node, &clk_debug_list);
if (inited)
clk_debug_create_one(core, rootdir);
mutex_unlock(&clk_debug_lock);
}
/**
* clk_debug_unregister - remove a clk node from the debugfs clk directory
* @core: the clk being removed from the debugfs clk directory
*
* Dynamically removes a clk and all its child nodes from the
* debugfs clk directory if clk->dentry points to debugfs created by
* clk_debug_register in __clk_core_init.
*/
static void clk_debug_unregister(struct clk_core *core)
{
mutex_lock(&clk_debug_lock);
hlist_del_init(&core->debug_node);
debugfs_remove_recursive(core->dentry);
core->dentry = NULL;
mutex_unlock(&clk_debug_lock);
}
/**
* clk_debug_init - lazily populate the debugfs clk directory
*
* clks are often initialized very early during boot before memory can be
* dynamically allocated and well before debugfs is setup. This function
* populates the debugfs clk directory once at boot-time when we know that
* debugfs is setup. It should only be called once at boot-time, all other clks
* added dynamically will be done so with clk_debug_register.
*/
static int __init clk_debug_init(void)
{
struct clk_core *core;