![Viresh Kumar](/assets/img/avatar_default.png)
Most of the drivers do following in their ->target_index() routines: struct cpufreq_freqs freqs; freqs.old = old freq... freqs.new = new freq... cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE); /* Change rate here */ cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE); This is replicated over all cpufreq drivers today and there doesn't exists a good enough reason why this shouldn't be moved to cpufreq core instead. There are few special cases though, like exynos5440, which doesn't do everything on the call to ->target_index() routine and call some kind of bottom halves for doing this work, work/tasklet/etc.. They may continue doing notification from their own code as flag: CPUFREQ_ASYNC_NOTIFICATION is already set for them. All drivers are also modified in this patch to avoid breaking 'git bisect', as double notification would happen otherwise. Acked-by: Hans-Christian Egtvedt <egtvedt@samfundet.no> Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> Acked-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Russell King <linux@arm.linux.org.uk> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Andrew Lunn <andrew@lunn.ch> Tested-by: Nicolas Pitre <nicolas.pitre@linaro.org> Reviewed-by: Lan Tianyu <tianyu.lan@intel.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
340 lines
8.1 KiB
C
340 lines
8.1 KiB
C
/*
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* Copyright 2013 Freescale Semiconductor, Inc.
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*
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* CPU Frequency Scaling driver for Freescale PowerPC corenet SoCs.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/clk.h>
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#include <linux/cpufreq.h>
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#include <linux/errno.h>
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#include <sysdev/fsl_soc.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/mutex.h>
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#include <linux/of.h>
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#include <linux/slab.h>
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#include <linux/smp.h>
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/**
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* struct cpu_data - per CPU data struct
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* @clk: the clk of CPU
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* @parent: the parent node of cpu clock
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* @table: frequency table
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*/
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struct cpu_data {
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struct clk *clk;
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struct device_node *parent;
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struct cpufreq_frequency_table *table;
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};
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/**
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* struct soc_data - SoC specific data
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* @freq_mask: mask the disallowed frequencies
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* @flag: unique flags
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*/
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struct soc_data {
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u32 freq_mask[4];
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u32 flag;
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};
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#define FREQ_MASK 1
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/* see hardware specification for the allowed frqeuencies */
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static const struct soc_data sdata[] = {
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{ /* used by p2041 and p3041 */
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.freq_mask = {0x8, 0x8, 0x2, 0x2},
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.flag = FREQ_MASK,
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},
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{ /* used by p5020 */
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.freq_mask = {0x8, 0x2},
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.flag = FREQ_MASK,
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},
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{ /* used by p4080, p5040 */
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.freq_mask = {0},
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.flag = 0,
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},
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};
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/*
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* the minimum allowed core frequency, in Hz
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* for chassis v1.0, >= platform frequency
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* for chassis v2.0, >= platform frequency / 2
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*/
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static u32 min_cpufreq;
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static const u32 *fmask;
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static DEFINE_PER_CPU(struct cpu_data *, cpu_data);
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/* cpumask in a cluster */
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static DEFINE_PER_CPU(cpumask_var_t, cpu_mask);
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#ifndef CONFIG_SMP
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static inline const struct cpumask *cpu_core_mask(int cpu)
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{
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return cpumask_of(0);
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}
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#endif
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static unsigned int corenet_cpufreq_get_speed(unsigned int cpu)
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{
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struct cpu_data *data = per_cpu(cpu_data, cpu);
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return clk_get_rate(data->clk) / 1000;
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}
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/* reduce the duplicated frequencies in frequency table */
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static void freq_table_redup(struct cpufreq_frequency_table *freq_table,
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int count)
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{
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int i, j;
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for (i = 1; i < count; i++) {
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for (j = 0; j < i; j++) {
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if (freq_table[j].frequency == CPUFREQ_ENTRY_INVALID ||
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freq_table[j].frequency !=
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freq_table[i].frequency)
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continue;
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freq_table[i].frequency = CPUFREQ_ENTRY_INVALID;
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break;
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}
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}
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}
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/* sort the frequencies in frequency table in descenting order */
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static void freq_table_sort(struct cpufreq_frequency_table *freq_table,
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int count)
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{
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int i, j, ind;
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unsigned int freq, max_freq;
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struct cpufreq_frequency_table table;
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for (i = 0; i < count - 1; i++) {
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max_freq = freq_table[i].frequency;
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ind = i;
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for (j = i + 1; j < count; j++) {
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freq = freq_table[j].frequency;
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if (freq == CPUFREQ_ENTRY_INVALID ||
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freq <= max_freq)
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continue;
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ind = j;
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max_freq = freq;
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}
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if (ind != i) {
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/* exchange the frequencies */
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table.driver_data = freq_table[i].driver_data;
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table.frequency = freq_table[i].frequency;
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freq_table[i].driver_data = freq_table[ind].driver_data;
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freq_table[i].frequency = freq_table[ind].frequency;
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freq_table[ind].driver_data = table.driver_data;
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freq_table[ind].frequency = table.frequency;
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}
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}
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}
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static int corenet_cpufreq_cpu_init(struct cpufreq_policy *policy)
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{
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struct device_node *np;
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int i, count, ret;
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u32 freq, mask;
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struct clk *clk;
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struct cpufreq_frequency_table *table;
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struct cpu_data *data;
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unsigned int cpu = policy->cpu;
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np = of_get_cpu_node(cpu, NULL);
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if (!np)
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return -ENODEV;
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data = kzalloc(sizeof(*data), GFP_KERNEL);
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if (!data) {
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pr_err("%s: no memory\n", __func__);
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goto err_np;
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}
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data->clk = of_clk_get(np, 0);
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if (IS_ERR(data->clk)) {
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pr_err("%s: no clock information\n", __func__);
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goto err_nomem2;
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}
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data->parent = of_parse_phandle(np, "clocks", 0);
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if (!data->parent) {
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pr_err("%s: could not get clock information\n", __func__);
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goto err_nomem2;
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}
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count = of_property_count_strings(data->parent, "clock-names");
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table = kcalloc(count + 1, sizeof(*table), GFP_KERNEL);
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if (!table) {
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pr_err("%s: no memory\n", __func__);
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goto err_node;
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}
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if (fmask)
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mask = fmask[get_hard_smp_processor_id(cpu)];
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else
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mask = 0x0;
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for (i = 0; i < count; i++) {
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clk = of_clk_get(data->parent, i);
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freq = clk_get_rate(clk);
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/*
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* the clock is valid if its frequency is not masked
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* and large than minimum allowed frequency.
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*/
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if (freq < min_cpufreq || (mask & (1 << i)))
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table[i].frequency = CPUFREQ_ENTRY_INVALID;
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else
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table[i].frequency = freq / 1000;
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table[i].driver_data = i;
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}
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freq_table_redup(table, count);
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freq_table_sort(table, count);
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table[i].frequency = CPUFREQ_TABLE_END;
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/* set the min and max frequency properly */
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ret = cpufreq_table_validate_and_show(policy, table);
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if (ret) {
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pr_err("invalid frequency table: %d\n", ret);
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goto err_nomem1;
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}
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data->table = table;
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per_cpu(cpu_data, cpu) = data;
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/* update ->cpus if we have cluster, no harm if not */
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cpumask_copy(policy->cpus, per_cpu(cpu_mask, cpu));
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for_each_cpu(i, per_cpu(cpu_mask, cpu))
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per_cpu(cpu_data, i) = data;
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policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
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of_node_put(np);
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return 0;
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err_nomem1:
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kfree(table);
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err_node:
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of_node_put(data->parent);
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err_nomem2:
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per_cpu(cpu_data, cpu) = NULL;
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kfree(data);
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err_np:
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of_node_put(np);
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return -ENODEV;
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}
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static int __exit corenet_cpufreq_cpu_exit(struct cpufreq_policy *policy)
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{
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struct cpu_data *data = per_cpu(cpu_data, policy->cpu);
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unsigned int cpu;
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cpufreq_frequency_table_put_attr(policy->cpu);
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of_node_put(data->parent);
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kfree(data->table);
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kfree(data);
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for_each_cpu(cpu, per_cpu(cpu_mask, policy->cpu))
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per_cpu(cpu_data, cpu) = NULL;
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return 0;
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}
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static int corenet_cpufreq_target(struct cpufreq_policy *policy,
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unsigned int index)
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{
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struct clk *parent;
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struct cpu_data *data = per_cpu(cpu_data, policy->cpu);
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parent = of_clk_get(data->parent, data->table[index].driver_data);
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return clk_set_parent(data->clk, parent);
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}
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static struct cpufreq_driver ppc_corenet_cpufreq_driver = {
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.name = "ppc_cpufreq",
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.flags = CPUFREQ_CONST_LOOPS,
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.init = corenet_cpufreq_cpu_init,
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.exit = __exit_p(corenet_cpufreq_cpu_exit),
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.verify = cpufreq_generic_frequency_table_verify,
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.target_index = corenet_cpufreq_target,
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.get = corenet_cpufreq_get_speed,
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.attr = cpufreq_generic_attr,
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};
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static const struct of_device_id node_matches[] __initdata = {
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{ .compatible = "fsl,p2041-clockgen", .data = &sdata[0], },
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{ .compatible = "fsl,p3041-clockgen", .data = &sdata[0], },
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{ .compatible = "fsl,p5020-clockgen", .data = &sdata[1], },
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{ .compatible = "fsl,p4080-clockgen", .data = &sdata[2], },
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{ .compatible = "fsl,p5040-clockgen", .data = &sdata[2], },
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{ .compatible = "fsl,qoriq-clockgen-2.0", },
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{}
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};
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static int __init ppc_corenet_cpufreq_init(void)
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{
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int ret;
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struct device_node *np;
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const struct of_device_id *match;
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const struct soc_data *data;
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unsigned int cpu;
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np = of_find_matching_node(NULL, node_matches);
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if (!np)
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return -ENODEV;
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for_each_possible_cpu(cpu) {
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if (!alloc_cpumask_var(&per_cpu(cpu_mask, cpu), GFP_KERNEL))
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goto err_mask;
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cpumask_copy(per_cpu(cpu_mask, cpu), cpu_core_mask(cpu));
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}
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match = of_match_node(node_matches, np);
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data = match->data;
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if (data) {
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if (data->flag)
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fmask = data->freq_mask;
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min_cpufreq = fsl_get_sys_freq();
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} else {
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min_cpufreq = fsl_get_sys_freq() / 2;
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}
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of_node_put(np);
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ret = cpufreq_register_driver(&ppc_corenet_cpufreq_driver);
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if (!ret)
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pr_info("Freescale PowerPC corenet CPU frequency scaling driver\n");
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return ret;
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err_mask:
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for_each_possible_cpu(cpu)
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free_cpumask_var(per_cpu(cpu_mask, cpu));
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return -ENOMEM;
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}
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module_init(ppc_corenet_cpufreq_init);
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static void __exit ppc_corenet_cpufreq_exit(void)
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{
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unsigned int cpu;
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for_each_possible_cpu(cpu)
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free_cpumask_var(per_cpu(cpu_mask, cpu));
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cpufreq_unregister_driver(&ppc_corenet_cpufreq_driver);
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}
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module_exit(ppc_corenet_cpufreq_exit);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Tang Yuantian <Yuantian.Tang@freescale.com>");
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MODULE_DESCRIPTION("cpufreq driver for Freescale e500mc series SoCs");
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