| /* |
| * arch/sh/kernel/cpu/clock.c - SuperH clock framework |
| * |
| * Copyright (C) 2005, 2006, 2007 Paul Mundt |
| * |
| * This clock framework is derived from the OMAP version by: |
| * |
| * Copyright (C) 2004 - 2005 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/kref.h> |
| #include <linux/seq_file.h> |
| #include <linux/err.h> |
| #include <linux/platform_device.h> |
| #include <linux/proc_fs.h> |
| #include <asm/clock.h> |
| #include <asm/timer.h> |
| |
| static LIST_HEAD(clock_list); |
| static DEFINE_SPINLOCK(clock_lock); |
| static DEFINE_MUTEX(clock_list_sem); |
| |
| /* |
| * Each subtype is expected to define the init routines for these clocks, |
| * as each subtype (or processor family) will have these clocks at the |
| * very least. These are all provided through the CPG, which even some of |
| * the more quirky parts (such as ST40, SH4-202, etc.) still have. |
| * |
| * The processor-specific code is expected to register any additional |
| * clock sources that are of interest. |
| */ |
| static struct clk master_clk = { |
| .name = "master_clk", |
| .flags = CLK_ALWAYS_ENABLED | CLK_RATE_PROPAGATES, |
| .rate = CONFIG_SH_PCLK_FREQ, |
| }; |
| |
| static struct clk module_clk = { |
| .name = "module_clk", |
| .parent = &master_clk, |
| .flags = CLK_ALWAYS_ENABLED | CLK_RATE_PROPAGATES, |
| }; |
| |
| static struct clk bus_clk = { |
| .name = "bus_clk", |
| .parent = &master_clk, |
| .flags = CLK_ALWAYS_ENABLED | CLK_RATE_PROPAGATES, |
| }; |
| |
| static struct clk cpu_clk = { |
| .name = "cpu_clk", |
| .parent = &master_clk, |
| .flags = CLK_ALWAYS_ENABLED, |
| }; |
| |
| /* |
| * The ordering of these clocks matters, do not change it. |
| */ |
| static struct clk *onchip_clocks[] = { |
| &master_clk, |
| &module_clk, |
| &bus_clk, |
| &cpu_clk, |
| }; |
| |
| static void propagate_rate(struct clk *clk) |
| { |
| struct clk *clkp; |
| |
| list_for_each_entry(clkp, &clock_list, node) { |
| if (likely(clkp->parent != clk)) |
| continue; |
| if (likely(clkp->ops && clkp->ops->recalc)) |
| clkp->ops->recalc(clkp); |
| if (unlikely(clkp->flags & CLK_RATE_PROPAGATES)) |
| propagate_rate(clkp); |
| } |
| } |
| |
| static int __clk_enable(struct clk *clk) |
| { |
| /* |
| * See if this is the first time we're enabling the clock, some |
| * clocks that are always enabled still require "special" |
| * initialization. This is especially true if the clock mode |
| * changes and the clock needs to hunt for the proper set of |
| * divisors to use before it can effectively recalc. |
| */ |
| if (unlikely(atomic_read(&clk->kref.refcount) == 1)) |
| if (clk->ops && clk->ops->init) |
| clk->ops->init(clk); |
| |
| kref_get(&clk->kref); |
| |
| if (clk->flags & CLK_ALWAYS_ENABLED) |
| return 0; |
| |
| if (likely(clk->ops && clk->ops->enable)) |
| clk->ops->enable(clk); |
| |
| return 0; |
| } |
| |
| int clk_enable(struct clk *clk) |
| { |
| unsigned long flags; |
| int ret; |
| |
| if (!clk) |
| return -EINVAL; |
| |
| clk_enable(clk->parent); |
| |
| spin_lock_irqsave(&clock_lock, flags); |
| ret = __clk_enable(clk); |
| spin_unlock_irqrestore(&clock_lock, flags); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(clk_enable); |
| |
| static void clk_kref_release(struct kref *kref) |
| { |
| /* Nothing to do */ |
| } |
| |
| static void __clk_disable(struct clk *clk) |
| { |
| int count = kref_put(&clk->kref, clk_kref_release); |
| |
| if (clk->flags & CLK_ALWAYS_ENABLED) |
| return; |
| |
| if (!count) { /* count reaches zero, disable the clock */ |
| if (likely(clk->ops && clk->ops->disable)) |
| clk->ops->disable(clk); |
| } |
| } |
| |
| 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); |
| |
| clk_disable(clk->parent); |
| } |
| EXPORT_SYMBOL_GPL(clk_disable); |
| |
| int clk_register(struct clk *clk) |
| { |
| mutex_lock(&clock_list_sem); |
| |
| list_add(&clk->node, &clock_list); |
| kref_init(&clk->kref); |
| |
| mutex_unlock(&clock_list_sem); |
| |
| if (clk->flags & CLK_ALWAYS_ENABLED) { |
| pr_debug( "Clock '%s' is ALWAYS_ENABLED\n", clk->name); |
| if (clk->ops && clk->ops->init) |
| clk->ops->init(clk); |
| if (clk->ops && clk->ops->enable) |
| clk->ops->enable(clk); |
| pr_debug( "Enabled."); |
| } |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(clk_register); |
| |
| void clk_unregister(struct clk *clk) |
| { |
| mutex_lock(&clock_list_sem); |
| list_del(&clk->node); |
| mutex_unlock(&clock_list_sem); |
| } |
| EXPORT_SYMBOL_GPL(clk_unregister); |
| |
| 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; |
| |
| if (likely(clk->ops && clk->ops->set_rate)) { |
| unsigned long flags; |
| |
| spin_lock_irqsave(&clock_lock, flags); |
| ret = clk->ops->set_rate(clk, rate, algo_id); |
| spin_unlock_irqrestore(&clock_lock, flags); |
| } |
| |
| if (unlikely(clk->flags & CLK_RATE_PROPAGATES)) |
| propagate_rate(clk); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(clk_set_rate_ex); |
| |
| void clk_recalc_rate(struct clk *clk) |
| { |
| if (likely(clk->ops && clk->ops->recalc)) { |
| unsigned long flags; |
| |
| spin_lock_irqsave(&clock_lock, flags); |
| clk->ops->recalc(clk); |
| spin_unlock_irqrestore(&clock_lock, flags); |
| } |
| |
| if (unlikely(clk->flags & CLK_RATE_PROPAGATES)) |
| propagate_rate(clk); |
| } |
| EXPORT_SYMBOL_GPL(clk_recalc_rate); |
| |
| 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); |
| |
| /* |
| * Returns a clock. Note that we first try to use device id on the bus |
| * and clock name. If this fails, we try to use clock name only. |
| */ |
| struct clk *clk_get(struct device *dev, const char *id) |
| { |
| struct clk *p, *clk = ERR_PTR(-ENOENT); |
| int idno; |
| |
| if (dev == NULL || dev->bus != &platform_bus_type) |
| idno = -1; |
| else |
| idno = to_platform_device(dev)->id; |
| |
| mutex_lock(&clock_list_sem); |
| list_for_each_entry(p, &clock_list, node) { |
| if (p->id == idno && |
| strcmp(id, p->name) == 0 && try_module_get(p->owner)) { |
| clk = p; |
| goto found; |
| } |
| } |
| |
| list_for_each_entry(p, &clock_list, node) { |
| if (strcmp(id, p->name) == 0 && try_module_get(p->owner)) { |
| clk = p; |
| break; |
| } |
| } |
| |
| found: |
| mutex_unlock(&clock_list_sem); |
| |
| return clk; |
| } |
| EXPORT_SYMBOL_GPL(clk_get); |
| |
| void clk_put(struct clk *clk) |
| { |
| if (clk && !IS_ERR(clk)) |
| module_put(clk->owner); |
| } |
| EXPORT_SYMBOL_GPL(clk_put); |
| |
| void __init __attribute__ ((weak)) |
| arch_init_clk_ops(struct clk_ops **ops, int type) |
| { |
| } |
| |
| int __init __attribute__ ((weak)) |
| arch_clk_init(void) |
| { |
| return 0; |
| } |
| |
| static int show_clocks(char *buf, char **start, off_t off, |
| int len, int *eof, void *data) |
| { |
| struct clk *clk; |
| char *p = buf; |
| |
| list_for_each_entry_reverse(clk, &clock_list, node) { |
| unsigned long rate = clk_get_rate(clk); |
| |
| p += sprintf(p, "%-12s\t: %ld.%02ldMHz\t%s\n", clk->name, |
| rate / 1000000, (rate % 1000000) / 10000, |
| ((clk->flags & CLK_ALWAYS_ENABLED) || |
| (atomic_read(&clk->kref.refcount) != 1)) ? |
| "enabled" : "disabled"); |
| } |
| |
| return p - buf; |
| } |
| |
| int __init clk_init(void) |
| { |
| int i, ret = 0; |
| |
| BUG_ON(!master_clk.rate); |
| |
| for (i = 0; i < ARRAY_SIZE(onchip_clocks); i++) { |
| struct clk *clk = onchip_clocks[i]; |
| |
| arch_init_clk_ops(&clk->ops, i); |
| ret |= clk_register(clk); |
| } |
| |
| ret |= arch_clk_init(); |
| |
| /* Kick the child clocks.. */ |
| propagate_rate(&master_clk); |
| propagate_rate(&bus_clk); |
| |
| return ret; |
| } |
| |
| static int __init clk_proc_init(void) |
| { |
| struct proc_dir_entry *p; |
| p = create_proc_read_entry("clocks", S_IRUSR, NULL, |
| show_clocks, NULL); |
| if (unlikely(!p)) |
| return -EINVAL; |
| |
| return 0; |
| } |
| subsys_initcall(clk_proc_init); |