diff options
Diffstat (limited to 'drivers/sh/clk/core.c')
-rw-r--r-- | drivers/sh/clk/core.c | 624 |
1 files changed, 624 insertions, 0 deletions
diff --git a/drivers/sh/clk/core.c b/drivers/sh/clk/core.c new file mode 100644 index 000000000..9475353f4 --- /dev/null +++ b/drivers/sh/clk/core.c @@ -0,0 +1,624 @@ +/* + * 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> +#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].driver_data = i; + freq_table[i].frequency = freq; + } + + /* Termination entry */ + freq_table[i].driver_data = 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) +{ + struct cpufreq_frequency_table *pos; + int idx; + + cpufreq_for_each_valid_entry_idx(pos, freq_table, idx) + if (pos->frequency == rate) + return idx; + + 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); + } +} + +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; + } + + /* + * 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; + 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; + + kref_put(&mapping->ref, clk_destroy_mapping); + clk->mapping = NULL; +out: + clk->mapped_reg = NULL; +} + +int clk_register(struct clk *clk) +{ + 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; + + 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 + +out_unlock: + mutex_unlock(&clock_list_sem); + + 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); + 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) +{ + if (!clk) + return 0; + + 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; + + if (!clk) + return 0; + + 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) +{ + if (!clk) + return NULL; + + return clk->parent; +} +EXPORT_SYMBOL_GPL(clk_get_parent); + +long clk_round_rate(struct clk *clk, unsigned long rate) +{ + if (!clk) + return 0; + + 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); + +#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); |