diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/sh/Makefile | 1 | ||||
| -rw-r--r-- | drivers/sh/clk.c | 548 |
2 files changed, 549 insertions, 0 deletions
diff --git a/drivers/sh/Makefile b/drivers/sh/Makefile index 4956bf1f2134..033a949c496a 100644 --- a/drivers/sh/Makefile +++ b/drivers/sh/Makefile @@ -4,4 +4,5 @@ obj-$(CONFIG_SUPERHYWAY) += superhyway/ obj-$(CONFIG_MAPLE) += maple/ obj-$(CONFIG_GENERIC_GPIO) += pfc.o +obj-$(CONFIG_SUPERH) += clk.o obj-y += intc.o diff --git a/drivers/sh/clk.c b/drivers/sh/clk.c new file mode 100644 index 000000000000..c90a3e1e1085 --- /dev/null +++ b/drivers/sh/clk.c @@ -0,0 +1,548 @@ +/* + * drivers/sh/clk.c - SuperH clock framework + * + * Copyright (C) 2005 - 2009 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. + */ +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/list.h> +#include <linux/kobject.h> +#include <linux/sysdev.h> +#include <linux/seq_file.h> +#include <linux/err.h> +#include <linux/platform_device.h> +#include <linux/debugfs.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); + +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; + + 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; +} + +long clk_rate_table_round(struct clk *clk, + struct cpufreq_frequency_table *freq_table, + unsigned long rate) +{ + unsigned long rate_error, rate_error_prev = ~0UL; + unsigned long rate_best_fit = rate; + unsigned long highest, lowest; + int i; + + highest = lowest = 0; + + 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 > highest) + highest = freq; + if (freq < lowest) + lowest = freq; + + rate_error = abs(freq - rate); + if (rate_error < rate_error_prev) { + rate_best_fit = freq; + rate_error_prev = rate_error; + } + + if (rate_error == 0) + break; + } + + if (rate >= highest) + rate_best_fit = highest; + if (rate <= lowest) + rate_best_fit = lowest; + + return rate_best_fit; +} + +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; + + /* now do the debugfs renaming to reattach the child + to the proper 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 (clk->usecount == 0) { + printk(KERN_ERR "Trying disable clock %s with 0 usecount\n", + clk->name); + WARN_ON(1); + return; + } + + if (!(--clk->usecount)) { + if (likely(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); + } +} + +int clk_register(struct clk *clk) +{ + if (clk == NULL || IS_ERR(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; + + if (clk->parent) + list_add(&clk->sibling, &clk->parent->children); + else + list_add(&clk->sibling, &root_clks); + + list_add(&clk->node, &clock_list); + if (clk->ops && clk->ops->init) + clk->ops->init(clk); + mutex_unlock(&clock_list_sem); + + return 0; +} +EXPORT_SYMBOL_GPL(clk_register); + +void clk_unregister(struct clk *clk) +{ + mutex_lock(&clock_list_sem); + list_del(&clk->sibling); + list_del(&clk->node); + 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) +{ + return clk_set_rate_ex(clk, rate, 0); +} +EXPORT_SYMBOL_GPL(clk_set_rate); + +int clk_set_rate_ex(struct clk *clk, unsigned long rate, int algo_id) +{ + 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, algo_id); + 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_ex); + +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) { + pr_debug("clock: set parent of %s to %s (new rate %ld)\n", + clk->name, clk->parent->name, clk->rate); + if (clk->ops->recalc) + clk->rate = clk->ops->recalc(clk); + 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); + +#ifdef CONFIG_PM +static int clks_sysdev_suspend(struct sys_device *dev, pm_message_t state) +{ + static pm_message_t prev_state; + struct clk *clkp; + + switch (state.event) { + case PM_EVENT_ON: + /* Resumeing from hibernation */ + if (prev_state.event != PM_EVENT_FREEZE) + break; + + list_for_each_entry(clkp, &clock_list, node) { + if (likely(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, NO_CHANGE); + else if (likely(clkp->ops->recalc)) + clkp->rate = clkp->ops->recalc(clkp); + } + } + break; + case PM_EVENT_FREEZE: + break; + case PM_EVENT_SUSPEND: + break; + } + + prev_state = state; + return 0; +} + +static int clks_sysdev_resume(struct sys_device *dev) +{ + return clks_sysdev_suspend(dev, PMSG_ON); +} + +static struct sysdev_class clks_sysdev_class = { + .name = "clks", +}; + +static struct sysdev_driver clks_sysdev_driver = { + .suspend = clks_sysdev_suspend, + .resume = clks_sysdev_resume, +}; + +static struct sys_device clks_sysdev_dev = { + .cls = &clks_sysdev_class, +}; + +static int __init clk_sysdev_init(void) +{ + sysdev_class_register(&clks_sysdev_class); + sysdev_driver_register(&clks_sysdev_class, &clks_sysdev_driver); + sysdev_register(&clks_sysdev_dev); + + return 0; +} +subsys_initcall(clk_sysdev_init); +#endif + +/* + * debugfs support to trace clock tree hierarchy and attributes + */ +static struct dentry *clk_debugfs_root; + +static int clk_debugfs_register_one(struct clk *c) +{ + int err; + struct dentry *d, *child, *child_tmp; + struct clk *pa = c->parent; + char s[255]; + char *p = s; + + p += sprintf(p, "%s", c->name); + if (c->id >= 0) + sprintf(p, ":%d", c->id); + d = debugfs_create_dir(s, pa ? pa->dentry : clk_debugfs_root); + if (!d) + return -ENOMEM; + c->dentry = d; + + d = debugfs_create_u8("usecount", S_IRUGO, c->dentry, (u8 *)&c->usecount); + if (!d) { + err = -ENOMEM; + goto err_out; + } + d = debugfs_create_u32("rate", S_IRUGO, c->dentry, (u32 *)&c->rate); + if (!d) { + err = -ENOMEM; + goto err_out; + } + d = debugfs_create_x32("flags", S_IRUGO, c->dentry, (u32 *)&c->flags); + if (!d) { + err = -ENOMEM; + goto err_out; + } + return 0; + +err_out: + d = c->dentry; + list_for_each_entry_safe(child, child_tmp, &d->d_subdirs, d_u.d_child) + debugfs_remove(child); + debugfs_remove(c->dentry); + return err; +} + +static int clk_debugfs_register(struct clk *c) +{ + int err; + struct clk *pa = c->parent; + + if (pa && !pa->dentry) { + err = clk_debugfs_register(pa); + if (err) + return err; + } + + if (!c->dentry && c->name) { + err = clk_debugfs_register_one(c); + if (err) + return err; + } + return 0; +} + +static int __init clk_debugfs_init(void) +{ + struct clk *c; + struct dentry *d; + int err; + + d = debugfs_create_dir("clock", NULL); + if (!d) + return -ENOMEM; + clk_debugfs_root = d; + + list_for_each_entry(c, &clock_list, node) { + err = clk_debugfs_register(c); + if (err) + goto err_out; + } + return 0; +err_out: + debugfs_remove_recursive(clk_debugfs_root); + return err; +} +late_initcall(clk_debugfs_init); |