From b1f6cfe48c3cb1dfa77db3d2f42f765febaef9bc Mon Sep 17 00:00:00 2001 From: Paul Mundt Date: Tue, 12 May 2009 04:27:43 +0900 Subject: [PATCH] sh: clkfwk: refactor rate propagation. This resyncs the rate propagation strategy with the scheme used by the OMAP clock framework. Child clocks are tracked on a list under each parent and propagation happens there specifically rather than constantly iterating over the global clock list. Signed-off-by: Paul Mundt --- arch/sh/include/asm/clock.h | 9 +- arch/sh/kernel/cpu/clock.c | 120 ++++++++++++++++--------- arch/sh/kernel/cpu/sh4a/clock-sh7722.c | 8 +- 3 files changed, 85 insertions(+), 52 deletions(-) diff --git a/arch/sh/include/asm/clock.h b/arch/sh/include/asm/clock.h index 241f1c1d9ce..5dc8b73a2bd 100644 --- a/arch/sh/include/asm/clock.h +++ b/arch/sh/include/asm/clock.h @@ -27,6 +27,9 @@ struct clk { struct clk *parent; struct clk_ops *ops; + struct list_head children; + struct list_head sibling; /* node for children */ + int usecount; unsigned long rate; @@ -35,7 +38,6 @@ struct clk { }; #define CLK_ALWAYS_ENABLED (1 << 0) -#define CLK_RATE_PROPAGATES (1 << 1) #define CLK_NEEDS_INIT (1 << 2) /* Should be defined by processor-specific code */ @@ -44,9 +46,10 @@ int __init arch_clk_init(void); /* arch/sh/kernel/cpu/clock.c */ int clk_init(void); -unsigned long followparent_recalc(struct clk *clk); +unsigned long followparent_recalc(struct clk *); +void recalculate_root_clocks(void); +void propagate_rate(struct clk *); void clk_recalc_rate(struct clk *); - int clk_register(struct clk *); void clk_unregister(struct clk *); diff --git a/arch/sh/kernel/cpu/clock.c b/arch/sh/kernel/cpu/clock.c index 17f6c078e85..0a06df8cde2 100644 --- a/arch/sh/kernel/cpu/clock.c +++ b/arch/sh/kernel/cpu/clock.c @@ -1,11 +1,11 @@ /* * arch/sh/kernel/cpu/clock.c - SuperH clock framework * - * Copyright (C) 2005, 2006, 2007 Paul Mundt + * Copyright (C) 2005 - 2009 Paul Mundt * * This clock framework is derived from the OMAP version by: * - * Copyright (C) 2004 - 2005 Nokia Corporation + * Copyright (C) 2004 - 2008 Nokia Corporation * Written by Tuukka Tikkanen * * Modified for omap shared clock framework by Tony Lindgren @@ -43,20 +43,20 @@ static DEFINE_MUTEX(clock_list_sem); */ static struct clk master_clk = { .name = "master_clk", - .flags = CLK_ALWAYS_ENABLED | CLK_RATE_PROPAGATES, + .flags = CLK_ALWAYS_ENABLED, .rate = CONFIG_SH_PCLK_FREQ, }; static struct clk module_clk = { .name = "module_clk", .parent = &master_clk, - .flags = CLK_ALWAYS_ENABLED | CLK_RATE_PROPAGATES, + .flags = CLK_ALWAYS_ENABLED, }; static struct clk bus_clk = { .name = "bus_clk", .parent = &master_clk, - .flags = CLK_ALWAYS_ENABLED | CLK_RATE_PROPAGATES, + .flags = CLK_ALWAYS_ENABLED, }; static struct clk cpu_clk = { @@ -75,27 +75,24 @@ static struct clk *onchip_clocks[] = { &cpu_clk, }; +/* Used for clocks that always have same value as the parent clock */ +unsigned long followparent_recalc(struct clk *clk) +{ + return clk->parent->rate; +} + /* Propagate rate to children */ -static void propagate_rate(struct clk *clk) +void propagate_rate(struct clk *tclk) { struct clk *clkp; - list_for_each_entry(clkp, &clock_list, node) { - if (likely(clkp->parent != clk)) - continue; - if (likely(clkp->ops && clkp->ops->recalc)) + list_for_each_entry(clkp, &tclk->children, sibling) { + if (clkp->ops->recalc) clkp->rate = clkp->ops->recalc(clkp); - if (unlikely(clkp->flags & CLK_RATE_PROPAGATES)) - propagate_rate(clkp); + propagate_rate(clkp); } } -/* Used for clocks that always have same value as the parent clock */ -unsigned long followparent_recalc(struct clk *clk) -{ - return clk->parent->rate; -} - static void __clk_init(struct clk *clk) { /* @@ -180,10 +177,46 @@ void clk_disable(struct clk *clk) } EXPORT_SYMBOL_GPL(clk_disable); +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->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); + + if (clk->parent) + list_add(&clk->sibling, &clk->parent->children); + else + list_add(&clk->sibling, &root_clks); + list_add(&clk->node, &clock_list); clk->usecount = 0; clk->flags |= CLK_NEEDS_INIT; @@ -205,6 +238,7 @@ 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); } @@ -231,50 +265,53 @@ int clk_set_rate_ex(struct clk *clk, unsigned long rate, int algo_id) spin_lock_irqsave(&clock_lock, flags); ret = clk->ops->set_rate(clk, rate, algo_id); + if (ret == 0) { + if (clk->ops->recalc) + clk->rate = clk->ops->recalc(clk); + propagate_rate(clk); + } 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; + unsigned long flags; - spin_lock_irqsave(&clock_lock, flags); - clk->rate = clk->ops->recalc(clk); - spin_unlock_irqrestore(&clock_lock, flags); - } + if (!clk->ops->recalc) + return; - if (unlikely(clk->flags & CLK_RATE_PROPAGATES)) - propagate_rate(clk); + spin_lock_irqsave(&clock_lock, flags); + clk->rate = clk->ops->recalc(clk); + propagate_rate(clk); + spin_unlock_irqrestore(&clock_lock, flags); } EXPORT_SYMBOL_GPL(clk_recalc_rate); int clk_set_parent(struct clk *clk, struct clk *parent) { + unsigned long flags; int ret = -EINVAL; - struct clk *old; if (!parent || !clk) return ret; - old = clk->parent; - if (likely(clk->ops && clk->ops->set_parent)) { - unsigned long flags; - spin_lock_irqsave(&clock_lock, flags); - ret = clk->ops->set_parent(clk, parent); - spin_unlock_irqrestore(&clock_lock, flags); - clk->parent = (ret ? old : parent); - } + spin_lock_irqsave(&clock_lock, flags); + if (clk->usecount == 0) { + if (clk->ops->set_parent) + ret = clk->ops->set_parent(clk, parent); + if (ret == 0) { + if (clk->ops->recalc) + clk->rate = clk->ops->recalc(clk); + propagate_rate(clk); + } + } else + ret = -EBUSY; + spin_unlock_irqrestore(&clock_lock, flags); - if (unlikely(clk->flags & CLK_RATE_PROPAGATES)) - propagate_rate(clk); return ret; } EXPORT_SYMBOL_GPL(clk_set_parent); @@ -457,8 +494,7 @@ int __init clk_init(void) ret |= arch_clk_init(); /* Kick the child clocks.. */ - propagate_rate(&master_clk); - propagate_rate(&bus_clk); + recalculate_root_clocks(); return ret; } diff --git a/arch/sh/kernel/cpu/sh4a/clock-sh7722.c b/arch/sh/kernel/cpu/sh4a/clock-sh7722.c index 4bdae84aa6b..8e53829ca07 100644 --- a/arch/sh/kernel/cpu/sh4a/clock-sh7722.c +++ b/arch/sh/kernel/cpu/sh4a/clock-sh7722.c @@ -161,9 +161,7 @@ static unsigned long master_clk_recalc(struct clk *clk) static void master_clk_init(struct clk *clk) { clk->parent = NULL; - clk->flags |= CLK_RATE_PROPAGATES; - clk->rate = CONFIG_SH_PCLK_FREQ; - master_clk_recalc(clk); + clk->rate = master_clk_recalc(clk); } static unsigned long module_clk_recalc(struct clk *clk) @@ -541,19 +539,16 @@ static struct clk_ops sh7722_video_clk_ops = { static struct clk sh7722_umem_clock = { .name = "umem_clk", .ops = &sh7722_frqcr_clk_ops, - .flags = CLK_RATE_PROPAGATES, }; static struct clk sh7722_sh_clock = { .name = "sh_clk", .ops = &sh7722_frqcr_clk_ops, - .flags = CLK_RATE_PROPAGATES, }; static struct clk sh7722_peripheral_clock = { .name = "peripheral_clk", .ops = &sh7722_frqcr_clk_ops, - .flags = CLK_RATE_PROPAGATES, }; static struct clk sh7722_sdram_clock = { @@ -564,7 +559,6 @@ static struct clk sh7722_sdram_clock = { static struct clk sh7722_r_clock = { .name = "r_clk", .rate = 32768, - .flags = CLK_RATE_PROPAGATES, }; #if !defined(CONFIG_CPU_SUBTYPE_SH7343) &&\ -- 2.43.2