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624 lines
13 KiB
624 lines
13 KiB
/* |
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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 <[email protected]> |
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* |
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* Modified for omap shared clock framework by Tony Lindgren <[email protected]> |
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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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|
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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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int idx; |
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cpufreq_for_each_valid_entry_idx(pos, freq_table, idx) |
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if (pos->frequency == rate) |
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return idx; |
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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(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)) { |
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unsigned long rate = clkp->rate; |
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if (likely(clkp->ops->set_parent)) |
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clkp->ops->set_parent(clkp, |
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clkp->parent); |
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if (likely(clkp->ops->set_rate)) |
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clkp->ops->set_rate(clkp, rate); |
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else if (likely(clkp->ops->recalc)) |
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clkp->rate = clkp->ops->recalc(clkp); |
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} |
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} |
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} |
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static struct syscore_ops clks_syscore_ops = { |
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.resume = clks_core_resume, |
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}; |
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static int __init clk_syscore_init(void) |
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{ |
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register_syscore_ops(&clks_syscore_ops); |
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return 0; |
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} |
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subsys_initcall(clk_syscore_init); |
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#endif |
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static int __init clk_late_init(void) |
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{ |
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unsigned long flags; |
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struct clk *clk; |
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/* disable all clocks with zero use count */ |
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mutex_lock(&clock_list_sem); |
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spin_lock_irqsave(&clock_lock, flags); |
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list_for_each_entry(clk, &clock_list, node) |
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if (!clk->usecount && clk->ops && clk->ops->disable) |
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clk->ops->disable(clk); |
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/* from now on allow clock disable operations */ |
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allow_disable = 1; |
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spin_unlock_irqrestore(&clock_lock, flags); |
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mutex_unlock(&clock_list_sem); |
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return 0; |
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} |
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late_initcall(clk_late_init);
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