OpenCloudOS-Kernel/drivers/sh/clk/core.c

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/*
* SuperH clock framework
*
* Copyright (C) 2005 - 2010 Paul Mundt
*
* This clock framework is derived from the OMAP version by:
*
* Copyright (C) 2004 - 2008 Nokia Corporation
* Written by Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>
*
* Modified for omap shared clock framework by Tony Lindgren <tony@atomide.com>
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#define pr_fmt(fmt) "clock: " fmt
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/list.h>
#include <linux/syscore_ops.h>
#include <linux/seq_file.h>
#include <linux/err.h>
sh: clkfwk: support clock remapping. This implements support for ioremapping of register windows that encapsulate clock control registers used by a struct clk, with transparent sibling inheritance. Root clocks at the top of a given topology often encapsulate the entire register space of all of their sibling clocks, so this mapping can be done once and handed down. A given clock enable/disable case maps out to a single bit in a shared register, so this prevents creating multiple overlapping mappings. The mapping case breaks down in to a couple of different situations: - Sibling clocks without a specific mapping. - Root clocks without a specific mapping. - Any of sibling/root clocks with a specific mapping. Sibling clocks with no specified mapping will grovel up the clock chain and install the root clock mapping unconditionally at registration time. Root clocks without their own mappings have a dummy BSS-initialized mapping inserted that is handed down the chain just like any other mapping. This permits all of the sibling clock ops to read/write using the mapping offsets without any special configuration, enabling them to not care whether access ultimately goes through translatable or untranslatable memory. Any clock with its own mapping will have the window initialized at registration time and be ready for use by its clock ops. Failure to establish the mapping will prevent registration, so no additional sanity checks are needed. Sibling clocks that double as parents for the moment will not propagate their mapping down, but this is easily tunable if the need arises. All clock mappings are kref refcounted, with each instance of mapping inheritance incrementing the refcount. Tested-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2010-10-15 15:46:37 +08:00
#include <linux/io.h>
#include <linux/cpufreq.h>
#include <linux/clk.h>
#include <linux/sh_clk.h>
static LIST_HEAD(clock_list);
static DEFINE_SPINLOCK(clock_lock);
static DEFINE_MUTEX(clock_list_sem);
/* clock disable operations are not passed on to hardware during boot */
static int allow_disable;
void clk_rate_table_build(struct clk *clk,
struct cpufreq_frequency_table *freq_table,
int nr_freqs,
struct clk_div_mult_table *src_table,
unsigned long *bitmap)
{
unsigned long mult, div;
unsigned long freq;
int i;
clk->nr_freqs = nr_freqs;
for (i = 0; i < nr_freqs; i++) {
div = 1;
mult = 1;
if (src_table->divisors && i < src_table->nr_divisors)
div = src_table->divisors[i];
if (src_table->multipliers && i < src_table->nr_multipliers)
mult = src_table->multipliers[i];
if (!div || !mult || (bitmap && !test_bit(i, bitmap)))
freq = CPUFREQ_ENTRY_INVALID;
else
freq = clk->parent->rate * mult / div;
freq_table[i].index = i;
freq_table[i].frequency = freq;
}
/* Termination entry */
freq_table[i].index = i;
freq_table[i].frequency = CPUFREQ_TABLE_END;
}
struct clk_rate_round_data;
struct clk_rate_round_data {
unsigned long rate;
unsigned int min, max;
long (*func)(unsigned int, struct clk_rate_round_data *);
void *arg;
};
#define for_each_frequency(pos, r, freq) \
for (pos = r->min, freq = r->func(pos, r); \
pos <= r->max; pos++, freq = r->func(pos, r)) \
if (unlikely(freq == 0)) \
; \
else
static long clk_rate_round_helper(struct clk_rate_round_data *rounder)
{
unsigned long rate_error, rate_error_prev = ~0UL;
unsigned long highest, lowest, freq;
long rate_best_fit = -ENOENT;
int i;
highest = 0;
lowest = ~0UL;
for_each_frequency(i, rounder, freq) {
if (freq > highest)
highest = freq;
if (freq < lowest)
lowest = freq;
rate_error = abs(freq - rounder->rate);
if (rate_error < rate_error_prev) {
rate_best_fit = freq;
rate_error_prev = rate_error;
}
if (rate_error == 0)
break;
}
if (rounder->rate >= highest)
rate_best_fit = highest;
if (rounder->rate <= lowest)
rate_best_fit = lowest;
return rate_best_fit;
}
static long clk_rate_table_iter(unsigned int pos,
struct clk_rate_round_data *rounder)
{
struct cpufreq_frequency_table *freq_table = rounder->arg;
unsigned long freq = freq_table[pos].frequency;
if (freq == CPUFREQ_ENTRY_INVALID)
freq = 0;
return freq;
}
long clk_rate_table_round(struct clk *clk,
struct cpufreq_frequency_table *freq_table,
unsigned long rate)
{
struct clk_rate_round_data table_round = {
.min = 0,
.max = clk->nr_freqs - 1,
.func = clk_rate_table_iter,
.arg = freq_table,
.rate = rate,
};
if (clk->nr_freqs < 1)
return -ENOSYS;
return clk_rate_round_helper(&table_round);
}
static long clk_rate_div_range_iter(unsigned int pos,
struct clk_rate_round_data *rounder)
{
return clk_get_rate(rounder->arg) / pos;
}
long clk_rate_div_range_round(struct clk *clk, unsigned int div_min,
unsigned int div_max, unsigned long rate)
{
struct clk_rate_round_data div_range_round = {
.min = div_min,
.max = div_max,
.func = clk_rate_div_range_iter,
.arg = clk_get_parent(clk),
.rate = rate,
};
return clk_rate_round_helper(&div_range_round);
}
static long clk_rate_mult_range_iter(unsigned int pos,
struct clk_rate_round_data *rounder)
{
return clk_get_rate(rounder->arg) * pos;
}
long clk_rate_mult_range_round(struct clk *clk, unsigned int mult_min,
unsigned int mult_max, unsigned long rate)
{
struct clk_rate_round_data mult_range_round = {
.min = mult_min,
.max = mult_max,
.func = clk_rate_mult_range_iter,
.arg = clk_get_parent(clk),
.rate = rate,
};
return clk_rate_round_helper(&mult_range_round);
}
int clk_rate_table_find(struct clk *clk,
struct cpufreq_frequency_table *freq_table,
unsigned long rate)
{
int i;
for (i = 0; freq_table[i].frequency != CPUFREQ_TABLE_END; i++) {
unsigned long freq = freq_table[i].frequency;
if (freq == CPUFREQ_ENTRY_INVALID)
continue;
if (freq == rate)
return i;
}
return -ENOENT;
}
/* Used for clocks that always have same value as the parent clock */
unsigned long followparent_recalc(struct clk *clk)
{
return clk->parent ? clk->parent->rate : 0;
}
int clk_reparent(struct clk *child, struct clk *parent)
{
list_del_init(&child->sibling);
if (parent)
list_add(&child->sibling, &parent->children);
child->parent = parent;
return 0;
}
/* Propagate rate to children */
void propagate_rate(struct clk *tclk)
{
struct clk *clkp;
list_for_each_entry(clkp, &tclk->children, sibling) {
if (clkp->ops && clkp->ops->recalc)
clkp->rate = clkp->ops->recalc(clkp);
propagate_rate(clkp);
}
}
static void __clk_disable(struct clk *clk)
{
if (WARN(!clk->usecount, "Trying to disable clock %p with 0 usecount\n",
clk))
return;
if (!(--clk->usecount)) {
if (likely(allow_disable && clk->ops && clk->ops->disable))
clk->ops->disable(clk);
if (likely(clk->parent))
__clk_disable(clk->parent);
}
}
void clk_disable(struct clk *clk)
{
unsigned long flags;
if (!clk)
return;
spin_lock_irqsave(&clock_lock, flags);
__clk_disable(clk);
spin_unlock_irqrestore(&clock_lock, flags);
}
EXPORT_SYMBOL_GPL(clk_disable);
static int __clk_enable(struct clk *clk)
{
int ret = 0;
if (clk->usecount++ == 0) {
if (clk->parent) {
ret = __clk_enable(clk->parent);
if (unlikely(ret))
goto err;
}
if (clk->ops && clk->ops->enable) {
ret = clk->ops->enable(clk);
if (ret) {
if (clk->parent)
__clk_disable(clk->parent);
goto err;
}
}
}
return ret;
err:
clk->usecount--;
return ret;
}
int clk_enable(struct clk *clk)
{
unsigned long flags;
int ret;
if (!clk)
return -EINVAL;
spin_lock_irqsave(&clock_lock, flags);
ret = __clk_enable(clk);
spin_unlock_irqrestore(&clock_lock, flags);
return ret;
}
EXPORT_SYMBOL_GPL(clk_enable);
static LIST_HEAD(root_clks);
/**
* recalculate_root_clocks - recalculate and propagate all root clocks
*
* Recalculates all root clocks (clocks with no parent), which if the
* clock's .recalc is set correctly, should also propagate their rates.
* Called at init.
*/
void recalculate_root_clocks(void)
{
struct clk *clkp;
list_for_each_entry(clkp, &root_clks, sibling) {
if (clkp->ops && clkp->ops->recalc)
clkp->rate = clkp->ops->recalc(clkp);
propagate_rate(clkp);
}
}
sh: clkfwk: support clock remapping. This implements support for ioremapping of register windows that encapsulate clock control registers used by a struct clk, with transparent sibling inheritance. Root clocks at the top of a given topology often encapsulate the entire register space of all of their sibling clocks, so this mapping can be done once and handed down. A given clock enable/disable case maps out to a single bit in a shared register, so this prevents creating multiple overlapping mappings. The mapping case breaks down in to a couple of different situations: - Sibling clocks without a specific mapping. - Root clocks without a specific mapping. - Any of sibling/root clocks with a specific mapping. Sibling clocks with no specified mapping will grovel up the clock chain and install the root clock mapping unconditionally at registration time. Root clocks without their own mappings have a dummy BSS-initialized mapping inserted that is handed down the chain just like any other mapping. This permits all of the sibling clock ops to read/write using the mapping offsets without any special configuration, enabling them to not care whether access ultimately goes through translatable or untranslatable memory. Any clock with its own mapping will have the window initialized at registration time and be ready for use by its clock ops. Failure to establish the mapping will prevent registration, so no additional sanity checks are needed. Sibling clocks that double as parents for the moment will not propagate their mapping down, but this is easily tunable if the need arises. All clock mappings are kref refcounted, with each instance of mapping inheritance incrementing the refcount. Tested-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2010-10-15 15:46:37 +08:00
static struct clk_mapping dummy_mapping;
static struct clk *lookup_root_clock(struct clk *clk)
{
while (clk->parent)
clk = clk->parent;
return clk;
}
static int clk_establish_mapping(struct clk *clk)
{
struct clk_mapping *mapping = clk->mapping;
/*
* Propagate mappings.
*/
if (!mapping) {
struct clk *clkp;
/*
* dummy mapping for root clocks with no specified ranges
*/
if (!clk->parent) {
clk->mapping = &dummy_mapping;
goto out;
sh: clkfwk: support clock remapping. This implements support for ioremapping of register windows that encapsulate clock control registers used by a struct clk, with transparent sibling inheritance. Root clocks at the top of a given topology often encapsulate the entire register space of all of their sibling clocks, so this mapping can be done once and handed down. A given clock enable/disable case maps out to a single bit in a shared register, so this prevents creating multiple overlapping mappings. The mapping case breaks down in to a couple of different situations: - Sibling clocks without a specific mapping. - Root clocks without a specific mapping. - Any of sibling/root clocks with a specific mapping. Sibling clocks with no specified mapping will grovel up the clock chain and install the root clock mapping unconditionally at registration time. Root clocks without their own mappings have a dummy BSS-initialized mapping inserted that is handed down the chain just like any other mapping. This permits all of the sibling clock ops to read/write using the mapping offsets without any special configuration, enabling them to not care whether access ultimately goes through translatable or untranslatable memory. Any clock with its own mapping will have the window initialized at registration time and be ready for use by its clock ops. Failure to establish the mapping will prevent registration, so no additional sanity checks are needed. Sibling clocks that double as parents for the moment will not propagate their mapping down, but this is easily tunable if the need arises. All clock mappings are kref refcounted, with each instance of mapping inheritance incrementing the refcount. Tested-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2010-10-15 15:46:37 +08:00
}
/*
* If we're on a child clock and it provides no mapping of its
* own, inherit the mapping from its root clock.
*/
clkp = lookup_root_clock(clk);
mapping = clkp->mapping;
BUG_ON(!mapping);
}
/*
* Establish initial mapping.
*/
if (!mapping->base && mapping->phys) {
kref_init(&mapping->ref);
mapping->base = ioremap_nocache(mapping->phys, mapping->len);
if (unlikely(!mapping->base))
return -ENXIO;
} else if (mapping->base) {
/*
* Bump the refcount for an existing mapping
*/
kref_get(&mapping->ref);
}
clk->mapping = mapping;
out:
clk->mapped_reg = clk->mapping->base;
clk->mapped_reg += (phys_addr_t)clk->enable_reg - clk->mapping->phys;
sh: clkfwk: support clock remapping. This implements support for ioremapping of register windows that encapsulate clock control registers used by a struct clk, with transparent sibling inheritance. Root clocks at the top of a given topology often encapsulate the entire register space of all of their sibling clocks, so this mapping can be done once and handed down. A given clock enable/disable case maps out to a single bit in a shared register, so this prevents creating multiple overlapping mappings. The mapping case breaks down in to a couple of different situations: - Sibling clocks without a specific mapping. - Root clocks without a specific mapping. - Any of sibling/root clocks with a specific mapping. Sibling clocks with no specified mapping will grovel up the clock chain and install the root clock mapping unconditionally at registration time. Root clocks without their own mappings have a dummy BSS-initialized mapping inserted that is handed down the chain just like any other mapping. This permits all of the sibling clock ops to read/write using the mapping offsets without any special configuration, enabling them to not care whether access ultimately goes through translatable or untranslatable memory. Any clock with its own mapping will have the window initialized at registration time and be ready for use by its clock ops. Failure to establish the mapping will prevent registration, so no additional sanity checks are needed. Sibling clocks that double as parents for the moment will not propagate their mapping down, but this is easily tunable if the need arises. All clock mappings are kref refcounted, with each instance of mapping inheritance incrementing the refcount. Tested-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2010-10-15 15:46:37 +08:00
return 0;
}
static void clk_destroy_mapping(struct kref *kref)
{
struct clk_mapping *mapping;
mapping = container_of(kref, struct clk_mapping, ref);
iounmap(mapping->base);
}
static void clk_teardown_mapping(struct clk *clk)
{
struct clk_mapping *mapping = clk->mapping;
/* Nothing to do */
if (mapping == &dummy_mapping)
goto out;
sh: clkfwk: support clock remapping. This implements support for ioremapping of register windows that encapsulate clock control registers used by a struct clk, with transparent sibling inheritance. Root clocks at the top of a given topology often encapsulate the entire register space of all of their sibling clocks, so this mapping can be done once and handed down. A given clock enable/disable case maps out to a single bit in a shared register, so this prevents creating multiple overlapping mappings. The mapping case breaks down in to a couple of different situations: - Sibling clocks without a specific mapping. - Root clocks without a specific mapping. - Any of sibling/root clocks with a specific mapping. Sibling clocks with no specified mapping will grovel up the clock chain and install the root clock mapping unconditionally at registration time. Root clocks without their own mappings have a dummy BSS-initialized mapping inserted that is handed down the chain just like any other mapping. This permits all of the sibling clock ops to read/write using the mapping offsets without any special configuration, enabling them to not care whether access ultimately goes through translatable or untranslatable memory. Any clock with its own mapping will have the window initialized at registration time and be ready for use by its clock ops. Failure to establish the mapping will prevent registration, so no additional sanity checks are needed. Sibling clocks that double as parents for the moment will not propagate their mapping down, but this is easily tunable if the need arises. All clock mappings are kref refcounted, with each instance of mapping inheritance incrementing the refcount. Tested-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2010-10-15 15:46:37 +08:00
kref_put(&mapping->ref, clk_destroy_mapping);
clk->mapping = NULL;
out:
clk->mapped_reg = NULL;
sh: clkfwk: support clock remapping. This implements support for ioremapping of register windows that encapsulate clock control registers used by a struct clk, with transparent sibling inheritance. Root clocks at the top of a given topology often encapsulate the entire register space of all of their sibling clocks, so this mapping can be done once and handed down. A given clock enable/disable case maps out to a single bit in a shared register, so this prevents creating multiple overlapping mappings. The mapping case breaks down in to a couple of different situations: - Sibling clocks without a specific mapping. - Root clocks without a specific mapping. - Any of sibling/root clocks with a specific mapping. Sibling clocks with no specified mapping will grovel up the clock chain and install the root clock mapping unconditionally at registration time. Root clocks without their own mappings have a dummy BSS-initialized mapping inserted that is handed down the chain just like any other mapping. This permits all of the sibling clock ops to read/write using the mapping offsets without any special configuration, enabling them to not care whether access ultimately goes through translatable or untranslatable memory. Any clock with its own mapping will have the window initialized at registration time and be ready for use by its clock ops. Failure to establish the mapping will prevent registration, so no additional sanity checks are needed. Sibling clocks that double as parents for the moment will not propagate their mapping down, but this is easily tunable if the need arises. All clock mappings are kref refcounted, with each instance of mapping inheritance incrementing the refcount. Tested-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2010-10-15 15:46:37 +08:00
}
int clk_register(struct clk *clk)
{
sh: clkfwk: support clock remapping. This implements support for ioremapping of register windows that encapsulate clock control registers used by a struct clk, with transparent sibling inheritance. Root clocks at the top of a given topology often encapsulate the entire register space of all of their sibling clocks, so this mapping can be done once and handed down. A given clock enable/disable case maps out to a single bit in a shared register, so this prevents creating multiple overlapping mappings. The mapping case breaks down in to a couple of different situations: - Sibling clocks without a specific mapping. - Root clocks without a specific mapping. - Any of sibling/root clocks with a specific mapping. Sibling clocks with no specified mapping will grovel up the clock chain and install the root clock mapping unconditionally at registration time. Root clocks without their own mappings have a dummy BSS-initialized mapping inserted that is handed down the chain just like any other mapping. This permits all of the sibling clock ops to read/write using the mapping offsets without any special configuration, enabling them to not care whether access ultimately goes through translatable or untranslatable memory. Any clock with its own mapping will have the window initialized at registration time and be ready for use by its clock ops. Failure to establish the mapping will prevent registration, so no additional sanity checks are needed. Sibling clocks that double as parents for the moment will not propagate their mapping down, but this is easily tunable if the need arises. All clock mappings are kref refcounted, with each instance of mapping inheritance incrementing the refcount. Tested-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2010-10-15 15:46:37 +08:00
int ret;
if (IS_ERR_OR_NULL(clk))
return -EINVAL;
/*
* trap out already registered clocks
*/
if (clk->node.next || clk->node.prev)
return 0;
mutex_lock(&clock_list_sem);
INIT_LIST_HEAD(&clk->children);
clk->usecount = 0;
sh: clkfwk: support clock remapping. This implements support for ioremapping of register windows that encapsulate clock control registers used by a struct clk, with transparent sibling inheritance. Root clocks at the top of a given topology often encapsulate the entire register space of all of their sibling clocks, so this mapping can be done once and handed down. A given clock enable/disable case maps out to a single bit in a shared register, so this prevents creating multiple overlapping mappings. The mapping case breaks down in to a couple of different situations: - Sibling clocks without a specific mapping. - Root clocks without a specific mapping. - Any of sibling/root clocks with a specific mapping. Sibling clocks with no specified mapping will grovel up the clock chain and install the root clock mapping unconditionally at registration time. Root clocks without their own mappings have a dummy BSS-initialized mapping inserted that is handed down the chain just like any other mapping. This permits all of the sibling clock ops to read/write using the mapping offsets without any special configuration, enabling them to not care whether access ultimately goes through translatable or untranslatable memory. Any clock with its own mapping will have the window initialized at registration time and be ready for use by its clock ops. Failure to establish the mapping will prevent registration, so no additional sanity checks are needed. Sibling clocks that double as parents for the moment will not propagate their mapping down, but this is easily tunable if the need arises. All clock mappings are kref refcounted, with each instance of mapping inheritance incrementing the refcount. Tested-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2010-10-15 15:46:37 +08:00
ret = clk_establish_mapping(clk);
if (unlikely(ret))
goto out_unlock;
if (clk->parent)
list_add(&clk->sibling, &clk->parent->children);
else
list_add(&clk->sibling, &root_clks);
list_add(&clk->node, &clock_list);
#ifdef CONFIG_SH_CLK_CPG_LEGACY
if (clk->ops && clk->ops->init)
clk->ops->init(clk);
#endif
sh: clkfwk: support clock remapping. This implements support for ioremapping of register windows that encapsulate clock control registers used by a struct clk, with transparent sibling inheritance. Root clocks at the top of a given topology often encapsulate the entire register space of all of their sibling clocks, so this mapping can be done once and handed down. A given clock enable/disable case maps out to a single bit in a shared register, so this prevents creating multiple overlapping mappings. The mapping case breaks down in to a couple of different situations: - Sibling clocks without a specific mapping. - Root clocks without a specific mapping. - Any of sibling/root clocks with a specific mapping. Sibling clocks with no specified mapping will grovel up the clock chain and install the root clock mapping unconditionally at registration time. Root clocks without their own mappings have a dummy BSS-initialized mapping inserted that is handed down the chain just like any other mapping. This permits all of the sibling clock ops to read/write using the mapping offsets without any special configuration, enabling them to not care whether access ultimately goes through translatable or untranslatable memory. Any clock with its own mapping will have the window initialized at registration time and be ready for use by its clock ops. Failure to establish the mapping will prevent registration, so no additional sanity checks are needed. Sibling clocks that double as parents for the moment will not propagate their mapping down, but this is easily tunable if the need arises. All clock mappings are kref refcounted, with each instance of mapping inheritance incrementing the refcount. Tested-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2010-10-15 15:46:37 +08:00
out_unlock:
mutex_unlock(&clock_list_sem);
sh: clkfwk: support clock remapping. This implements support for ioremapping of register windows that encapsulate clock control registers used by a struct clk, with transparent sibling inheritance. Root clocks at the top of a given topology often encapsulate the entire register space of all of their sibling clocks, so this mapping can be done once and handed down. A given clock enable/disable case maps out to a single bit in a shared register, so this prevents creating multiple overlapping mappings. The mapping case breaks down in to a couple of different situations: - Sibling clocks without a specific mapping. - Root clocks without a specific mapping. - Any of sibling/root clocks with a specific mapping. Sibling clocks with no specified mapping will grovel up the clock chain and install the root clock mapping unconditionally at registration time. Root clocks without their own mappings have a dummy BSS-initialized mapping inserted that is handed down the chain just like any other mapping. This permits all of the sibling clock ops to read/write using the mapping offsets without any special configuration, enabling them to not care whether access ultimately goes through translatable or untranslatable memory. Any clock with its own mapping will have the window initialized at registration time and be ready for use by its clock ops. Failure to establish the mapping will prevent registration, so no additional sanity checks are needed. Sibling clocks that double as parents for the moment will not propagate their mapping down, but this is easily tunable if the need arises. All clock mappings are kref refcounted, with each instance of mapping inheritance incrementing the refcount. Tested-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2010-10-15 15:46:37 +08:00
return ret;
}
EXPORT_SYMBOL_GPL(clk_register);
void clk_unregister(struct clk *clk)
{
mutex_lock(&clock_list_sem);
list_del(&clk->sibling);
list_del(&clk->node);
sh: clkfwk: support clock remapping. This implements support for ioremapping of register windows that encapsulate clock control registers used by a struct clk, with transparent sibling inheritance. Root clocks at the top of a given topology often encapsulate the entire register space of all of their sibling clocks, so this mapping can be done once and handed down. A given clock enable/disable case maps out to a single bit in a shared register, so this prevents creating multiple overlapping mappings. The mapping case breaks down in to a couple of different situations: - Sibling clocks without a specific mapping. - Root clocks without a specific mapping. - Any of sibling/root clocks with a specific mapping. Sibling clocks with no specified mapping will grovel up the clock chain and install the root clock mapping unconditionally at registration time. Root clocks without their own mappings have a dummy BSS-initialized mapping inserted that is handed down the chain just like any other mapping. This permits all of the sibling clock ops to read/write using the mapping offsets without any special configuration, enabling them to not care whether access ultimately goes through translatable or untranslatable memory. Any clock with its own mapping will have the window initialized at registration time and be ready for use by its clock ops. Failure to establish the mapping will prevent registration, so no additional sanity checks are needed. Sibling clocks that double as parents for the moment will not propagate their mapping down, but this is easily tunable if the need arises. All clock mappings are kref refcounted, with each instance of mapping inheritance incrementing the refcount. Tested-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2010-10-15 15:46:37 +08:00
clk_teardown_mapping(clk);
mutex_unlock(&clock_list_sem);
}
EXPORT_SYMBOL_GPL(clk_unregister);
void clk_enable_init_clocks(void)
{
struct clk *clkp;
list_for_each_entry(clkp, &clock_list, node)
if (clkp->flags & CLK_ENABLE_ON_INIT)
clk_enable(clkp);
}
unsigned long clk_get_rate(struct clk *clk)
{
return clk->rate;
}
EXPORT_SYMBOL_GPL(clk_get_rate);
int clk_set_rate(struct clk *clk, unsigned long rate)
{
int ret = -EOPNOTSUPP;
unsigned long flags;
spin_lock_irqsave(&clock_lock, flags);
if (likely(clk->ops && clk->ops->set_rate)) {
ret = clk->ops->set_rate(clk, rate);
if (ret != 0)
goto out_unlock;
} else {
clk->rate = rate;
ret = 0;
}
if (clk->ops && clk->ops->recalc)
clk->rate = clk->ops->recalc(clk);
propagate_rate(clk);
out_unlock:
spin_unlock_irqrestore(&clock_lock, flags);
return ret;
}
EXPORT_SYMBOL_GPL(clk_set_rate);
int clk_set_parent(struct clk *clk, struct clk *parent)
{
unsigned long flags;
int ret = -EINVAL;
if (!parent || !clk)
return ret;
if (clk->parent == parent)
return 0;
spin_lock_irqsave(&clock_lock, flags);
if (clk->usecount == 0) {
if (clk->ops->set_parent)
ret = clk->ops->set_parent(clk, parent);
else
ret = clk_reparent(clk, parent);
if (ret == 0) {
if (clk->ops->recalc)
clk->rate = clk->ops->recalc(clk);
pr_debug("set parent of %p to %p (new rate %ld)\n",
clk, clk->parent, clk->rate);
propagate_rate(clk);
}
} else
ret = -EBUSY;
spin_unlock_irqrestore(&clock_lock, flags);
return ret;
}
EXPORT_SYMBOL_GPL(clk_set_parent);
struct clk *clk_get_parent(struct clk *clk)
{
return clk->parent;
}
EXPORT_SYMBOL_GPL(clk_get_parent);
long clk_round_rate(struct clk *clk, unsigned long rate)
{
if (likely(clk->ops && clk->ops->round_rate)) {
unsigned long flags, rounded;
spin_lock_irqsave(&clock_lock, flags);
rounded = clk->ops->round_rate(clk, rate);
spin_unlock_irqrestore(&clock_lock, flags);
return rounded;
}
return clk_get_rate(clk);
}
EXPORT_SYMBOL_GPL(clk_round_rate);
long clk_round_parent(struct clk *clk, unsigned long target,
unsigned long *best_freq, unsigned long *parent_freq,
unsigned int div_min, unsigned int div_max)
{
struct cpufreq_frequency_table *freq, *best = NULL;
unsigned long error = ULONG_MAX, freq_high, freq_low, div;
struct clk *parent = clk_get_parent(clk);
if (!parent) {
*parent_freq = 0;
*best_freq = clk_round_rate(clk, target);
return abs(target - *best_freq);
}
for (freq = parent->freq_table; freq->frequency != CPUFREQ_TABLE_END;
freq++) {
if (freq->frequency == CPUFREQ_ENTRY_INVALID)
continue;
if (unlikely(freq->frequency / target <= div_min - 1)) {
unsigned long freq_max;
freq_max = (freq->frequency + div_min / 2) / div_min;
if (error > target - freq_max) {
error = target - freq_max;
best = freq;
if (best_freq)
*best_freq = freq_max;
}
pr_debug("too low freq %u, error %lu\n", freq->frequency,
target - freq_max);
if (!error)
break;
continue;
}
if (unlikely(freq->frequency / target >= div_max)) {
unsigned long freq_min;
freq_min = (freq->frequency + div_max / 2) / div_max;
if (error > freq_min - target) {
error = freq_min - target;
best = freq;
if (best_freq)
*best_freq = freq_min;
}
pr_debug("too high freq %u, error %lu\n", freq->frequency,
freq_min - target);
if (!error)
break;
continue;
}
div = freq->frequency / target;
freq_high = freq->frequency / div;
freq_low = freq->frequency / (div + 1);
if (freq_high - target < error) {
error = freq_high - target;
best = freq;
if (best_freq)
*best_freq = freq_high;
}
if (target - freq_low < error) {
error = target - freq_low;
best = freq;
if (best_freq)
*best_freq = freq_low;
}
pr_debug("%u / %lu = %lu, / %lu = %lu, best %lu, parent %u\n",
freq->frequency, div, freq_high, div + 1, freq_low,
*best_freq, best->frequency);
if (!error)
break;
}
if (parent_freq)
*parent_freq = best->frequency;
return error;
}
EXPORT_SYMBOL_GPL(clk_round_parent);
#ifdef CONFIG_PM
static void clks_core_resume(void)
{
struct clk *clkp;
list_for_each_entry(clkp, &clock_list, node) {
if (likely(clkp->usecount && clkp->ops)) {
unsigned long rate = clkp->rate;
if (likely(clkp->ops->set_parent))
clkp->ops->set_parent(clkp,
clkp->parent);
if (likely(clkp->ops->set_rate))
clkp->ops->set_rate(clkp, rate);
else if (likely(clkp->ops->recalc))
clkp->rate = clkp->ops->recalc(clkp);
}
}
}
static struct syscore_ops clks_syscore_ops = {
.resume = clks_core_resume,
};
static int __init clk_syscore_init(void)
{
register_syscore_ops(&clks_syscore_ops);
return 0;
}
subsys_initcall(clk_syscore_init);
#endif
static int __init clk_late_init(void)
{
unsigned long flags;
struct clk *clk;
/* disable all clocks with zero use count */
mutex_lock(&clock_list_sem);
spin_lock_irqsave(&clock_lock, flags);
list_for_each_entry(clk, &clock_list, node)
if (!clk->usecount && clk->ops && clk->ops->disable)
clk->ops->disable(clk);
/* from now on allow clock disable operations */
allow_disable = 1;
spin_unlock_irqrestore(&clock_lock, flags);
mutex_unlock(&clock_list_sem);
return 0;
}
late_initcall(clk_late_init);