![Geert Uytterhoeven](/assets/img/avatar_default.png)
Several clock API functions handle NULL clocks when the Common Clock Framework is used, while their legacy SH counterparts don't, and would just crash when a NULL clock is passed. Add NULL checks to clk_get_rate(), clk_set_rate(), clk_get_parent(), and clk_round_rate(), to avoid different behavior in drivers shared between legacy and CCF-based platforms. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
624 lines
13 KiB
C
624 lines
13 KiB
C
/*
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* SuperH clock framework
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*
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* Copyright (C) 2005 - 2010 Paul Mundt
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*
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* This clock framework is derived from the OMAP version by:
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*
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* Copyright (C) 2004 - 2008 Nokia Corporation
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* Written by Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>
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*
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* Modified for omap shared clock framework by Tony Lindgren <tony@atomide.com>
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*/
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#define pr_fmt(fmt) "clock: " fmt
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/mutex.h>
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#include <linux/list.h>
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#include <linux/syscore_ops.h>
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#include <linux/seq_file.h>
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#include <linux/err.h>
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#include <linux/io.h>
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#include <linux/cpufreq.h>
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#include <linux/clk.h>
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#include <linux/sh_clk.h>
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static LIST_HEAD(clock_list);
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static DEFINE_SPINLOCK(clock_lock);
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static DEFINE_MUTEX(clock_list_sem);
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/* clock disable operations are not passed on to hardware during boot */
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static int allow_disable;
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void clk_rate_table_build(struct clk *clk,
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struct cpufreq_frequency_table *freq_table,
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int nr_freqs,
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struct clk_div_mult_table *src_table,
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unsigned long *bitmap)
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{
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unsigned long mult, div;
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unsigned long freq;
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int i;
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clk->nr_freqs = nr_freqs;
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for (i = 0; i < nr_freqs; i++) {
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div = 1;
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mult = 1;
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if (src_table->divisors && i < src_table->nr_divisors)
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div = src_table->divisors[i];
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if (src_table->multipliers && i < src_table->nr_multipliers)
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mult = src_table->multipliers[i];
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if (!div || !mult || (bitmap && !test_bit(i, bitmap)))
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freq = CPUFREQ_ENTRY_INVALID;
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else
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freq = clk->parent->rate * mult / div;
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freq_table[i].driver_data = i;
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freq_table[i].frequency = freq;
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}
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/* Termination entry */
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freq_table[i].driver_data = i;
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freq_table[i].frequency = CPUFREQ_TABLE_END;
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}
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struct clk_rate_round_data;
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struct clk_rate_round_data {
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unsigned long rate;
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unsigned int min, max;
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long (*func)(unsigned int, struct clk_rate_round_data *);
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void *arg;
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};
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#define for_each_frequency(pos, r, freq) \
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for (pos = r->min, freq = r->func(pos, r); \
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pos <= r->max; pos++, freq = r->func(pos, r)) \
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if (unlikely(freq == 0)) \
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; \
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else
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static long clk_rate_round_helper(struct clk_rate_round_data *rounder)
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{
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unsigned long rate_error, rate_error_prev = ~0UL;
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unsigned long highest, lowest, freq;
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long rate_best_fit = -ENOENT;
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int i;
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highest = 0;
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lowest = ~0UL;
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for_each_frequency(i, rounder, freq) {
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if (freq > highest)
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highest = freq;
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if (freq < lowest)
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lowest = freq;
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rate_error = abs(freq - rounder->rate);
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if (rate_error < rate_error_prev) {
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rate_best_fit = freq;
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rate_error_prev = rate_error;
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}
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if (rate_error == 0)
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break;
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}
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if (rounder->rate >= highest)
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rate_best_fit = highest;
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if (rounder->rate <= lowest)
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rate_best_fit = lowest;
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return rate_best_fit;
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}
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static long clk_rate_table_iter(unsigned int pos,
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struct clk_rate_round_data *rounder)
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{
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struct cpufreq_frequency_table *freq_table = rounder->arg;
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unsigned long freq = freq_table[pos].frequency;
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if (freq == CPUFREQ_ENTRY_INVALID)
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freq = 0;
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return freq;
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}
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long clk_rate_table_round(struct clk *clk,
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struct cpufreq_frequency_table *freq_table,
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unsigned long rate)
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{
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struct clk_rate_round_data table_round = {
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.min = 0,
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.max = clk->nr_freqs - 1,
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.func = clk_rate_table_iter,
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.arg = freq_table,
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.rate = rate,
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};
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if (clk->nr_freqs < 1)
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return -ENOSYS;
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return clk_rate_round_helper(&table_round);
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}
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static long clk_rate_div_range_iter(unsigned int pos,
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struct clk_rate_round_data *rounder)
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{
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return clk_get_rate(rounder->arg) / pos;
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}
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long clk_rate_div_range_round(struct clk *clk, unsigned int div_min,
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unsigned int div_max, unsigned long rate)
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{
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struct clk_rate_round_data div_range_round = {
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.min = div_min,
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.max = div_max,
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.func = clk_rate_div_range_iter,
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.arg = clk_get_parent(clk),
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.rate = rate,
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};
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return clk_rate_round_helper(&div_range_round);
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}
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static long clk_rate_mult_range_iter(unsigned int pos,
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struct clk_rate_round_data *rounder)
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{
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return clk_get_rate(rounder->arg) * pos;
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}
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long clk_rate_mult_range_round(struct clk *clk, unsigned int mult_min,
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unsigned int mult_max, unsigned long rate)
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{
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struct clk_rate_round_data mult_range_round = {
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.min = mult_min,
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.max = mult_max,
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.func = clk_rate_mult_range_iter,
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.arg = clk_get_parent(clk),
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.rate = rate,
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};
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return clk_rate_round_helper(&mult_range_round);
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}
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int clk_rate_table_find(struct clk *clk,
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struct cpufreq_frequency_table *freq_table,
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unsigned long rate)
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{
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struct cpufreq_frequency_table *pos;
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cpufreq_for_each_valid_entry(pos, freq_table)
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if (pos->frequency == rate)
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return pos - freq_table;
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return -ENOENT;
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}
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/* Used for clocks that always have same value as the parent clock */
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unsigned long followparent_recalc(struct clk *clk)
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{
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return clk->parent ? clk->parent->rate : 0;
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}
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int clk_reparent(struct clk *child, struct clk *parent)
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{
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list_del_init(&child->sibling);
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if (parent)
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list_add(&child->sibling, &parent->children);
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child->parent = parent;
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return 0;
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}
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/* Propagate rate to children */
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void propagate_rate(struct clk *tclk)
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{
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struct clk *clkp;
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list_for_each_entry(clkp, &tclk->children, sibling) {
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if (clkp->ops && clkp->ops->recalc)
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clkp->rate = clkp->ops->recalc(clkp);
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propagate_rate(clkp);
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}
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}
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static void __clk_disable(struct clk *clk)
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{
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if (WARN(!clk->usecount, "Trying to disable clock %p with 0 usecount\n",
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clk))
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return;
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if (!(--clk->usecount)) {
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if (likely(allow_disable && clk->ops && clk->ops->disable))
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clk->ops->disable(clk);
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if (likely(clk->parent))
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__clk_disable(clk->parent);
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}
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}
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void clk_disable(struct clk *clk)
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{
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unsigned long flags;
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if (!clk)
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return;
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spin_lock_irqsave(&clock_lock, flags);
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__clk_disable(clk);
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spin_unlock_irqrestore(&clock_lock, flags);
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}
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EXPORT_SYMBOL_GPL(clk_disable);
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static int __clk_enable(struct clk *clk)
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{
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int ret = 0;
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if (clk->usecount++ == 0) {
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if (clk->parent) {
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ret = __clk_enable(clk->parent);
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if (unlikely(ret))
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goto err;
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}
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if (clk->ops && clk->ops->enable) {
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ret = clk->ops->enable(clk);
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if (ret) {
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if (clk->parent)
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__clk_disable(clk->parent);
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goto err;
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}
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}
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}
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return ret;
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err:
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clk->usecount--;
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return ret;
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}
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int clk_enable(struct clk *clk)
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{
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unsigned long flags;
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int ret;
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if (!clk)
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return -EINVAL;
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spin_lock_irqsave(&clock_lock, flags);
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ret = __clk_enable(clk);
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spin_unlock_irqrestore(&clock_lock, flags);
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return ret;
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}
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EXPORT_SYMBOL_GPL(clk_enable);
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static LIST_HEAD(root_clks);
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/**
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* recalculate_root_clocks - recalculate and propagate all root clocks
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*
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* Recalculates all root clocks (clocks with no parent), which if the
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* clock's .recalc is set correctly, should also propagate their rates.
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* Called at init.
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*/
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void recalculate_root_clocks(void)
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{
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struct clk *clkp;
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list_for_each_entry(clkp, &root_clks, sibling) {
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if (clkp->ops && clkp->ops->recalc)
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clkp->rate = clkp->ops->recalc(clkp);
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propagate_rate(clkp);
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}
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}
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static struct clk_mapping dummy_mapping;
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static struct clk *lookup_root_clock(struct clk *clk)
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{
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while (clk->parent)
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clk = clk->parent;
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return clk;
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}
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static int clk_establish_mapping(struct clk *clk)
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{
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struct clk_mapping *mapping = clk->mapping;
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/*
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* Propagate mappings.
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*/
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if (!mapping) {
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struct clk *clkp;
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/*
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* dummy mapping for root clocks with no specified ranges
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*/
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if (!clk->parent) {
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clk->mapping = &dummy_mapping;
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goto out;
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}
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/*
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* If we're on a child clock and it provides no mapping of its
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* own, inherit the mapping from its root clock.
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*/
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clkp = lookup_root_clock(clk);
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mapping = clkp->mapping;
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BUG_ON(!mapping);
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}
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/*
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* Establish initial mapping.
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*/
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if (!mapping->base && mapping->phys) {
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kref_init(&mapping->ref);
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mapping->base = ioremap_nocache(mapping->phys, mapping->len);
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if (unlikely(!mapping->base))
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return -ENXIO;
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} else if (mapping->base) {
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/*
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* Bump the refcount for an existing mapping
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*/
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kref_get(&mapping->ref);
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}
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clk->mapping = mapping;
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out:
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clk->mapped_reg = clk->mapping->base;
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clk->mapped_reg += (phys_addr_t)clk->enable_reg - clk->mapping->phys;
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return 0;
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}
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static void clk_destroy_mapping(struct kref *kref)
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{
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struct clk_mapping *mapping;
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mapping = container_of(kref, struct clk_mapping, ref);
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iounmap(mapping->base);
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}
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static void clk_teardown_mapping(struct clk *clk)
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{
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struct clk_mapping *mapping = clk->mapping;
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/* Nothing to do */
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if (mapping == &dummy_mapping)
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goto out;
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kref_put(&mapping->ref, clk_destroy_mapping);
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clk->mapping = NULL;
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out:
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clk->mapped_reg = NULL;
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}
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int clk_register(struct clk *clk)
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{
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int ret;
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if (IS_ERR_OR_NULL(clk))
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return -EINVAL;
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/*
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* trap out already registered clocks
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*/
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if (clk->node.next || clk->node.prev)
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return 0;
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mutex_lock(&clock_list_sem);
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INIT_LIST_HEAD(&clk->children);
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clk->usecount = 0;
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ret = clk_establish_mapping(clk);
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if (unlikely(ret))
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goto out_unlock;
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if (clk->parent)
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list_add(&clk->sibling, &clk->parent->children);
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else
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list_add(&clk->sibling, &root_clks);
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list_add(&clk->node, &clock_list);
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#ifdef CONFIG_SH_CLK_CPG_LEGACY
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if (clk->ops && clk->ops->init)
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clk->ops->init(clk);
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#endif
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out_unlock:
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mutex_unlock(&clock_list_sem);
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return ret;
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}
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EXPORT_SYMBOL_GPL(clk_register);
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void clk_unregister(struct clk *clk)
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{
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mutex_lock(&clock_list_sem);
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list_del(&clk->sibling);
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list_del(&clk->node);
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clk_teardown_mapping(clk);
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mutex_unlock(&clock_list_sem);
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}
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EXPORT_SYMBOL_GPL(clk_unregister);
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void clk_enable_init_clocks(void)
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{
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struct clk *clkp;
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list_for_each_entry(clkp, &clock_list, node)
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if (clkp->flags & CLK_ENABLE_ON_INIT)
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clk_enable(clkp);
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}
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unsigned long clk_get_rate(struct clk *clk)
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{
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if (!clk)
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return 0;
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return clk->rate;
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}
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EXPORT_SYMBOL_GPL(clk_get_rate);
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int clk_set_rate(struct clk *clk, unsigned long rate)
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{
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int ret = -EOPNOTSUPP;
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unsigned long flags;
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if (!clk)
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return 0;
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spin_lock_irqsave(&clock_lock, flags);
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if (likely(clk->ops && clk->ops->set_rate)) {
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ret = clk->ops->set_rate(clk, rate);
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if (ret != 0)
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goto out_unlock;
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} else {
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clk->rate = rate;
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ret = 0;
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}
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if (clk->ops && clk->ops->recalc)
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clk->rate = clk->ops->recalc(clk);
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propagate_rate(clk);
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out_unlock:
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spin_unlock_irqrestore(&clock_lock, flags);
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return ret;
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}
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EXPORT_SYMBOL_GPL(clk_set_rate);
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int clk_set_parent(struct clk *clk, struct clk *parent)
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{
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unsigned long flags;
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int ret = -EINVAL;
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if (!parent || !clk)
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return ret;
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if (clk->parent == parent)
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return 0;
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spin_lock_irqsave(&clock_lock, flags);
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if (clk->usecount == 0) {
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if (clk->ops->set_parent)
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ret = clk->ops->set_parent(clk, parent);
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else
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ret = clk_reparent(clk, parent);
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if (ret == 0) {
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if (clk->ops->recalc)
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clk->rate = clk->ops->recalc(clk);
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pr_debug("set parent of %p to %p (new rate %ld)\n",
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clk, clk->parent, clk->rate);
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propagate_rate(clk);
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}
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} else
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ret = -EBUSY;
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spin_unlock_irqrestore(&clock_lock, flags);
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return ret;
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}
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EXPORT_SYMBOL_GPL(clk_set_parent);
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struct clk *clk_get_parent(struct clk *clk)
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{
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if (!clk)
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return NULL;
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return clk->parent;
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}
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EXPORT_SYMBOL_GPL(clk_get_parent);
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long clk_round_rate(struct clk *clk, unsigned long rate)
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{
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if (!clk)
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return 0;
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if (likely(clk->ops && clk->ops->round_rate)) {
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unsigned long flags, rounded;
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spin_lock_irqsave(&clock_lock, flags);
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rounded = clk->ops->round_rate(clk, rate);
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spin_unlock_irqrestore(&clock_lock, flags);
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return rounded;
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}
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return clk_get_rate(clk);
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}
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EXPORT_SYMBOL_GPL(clk_round_rate);
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#ifdef CONFIG_PM
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static void clks_core_resume(void)
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{
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struct clk *clkp;
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list_for_each_entry(clkp, &clock_list, node) {
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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);
|