de6cc6515a
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 675 mass ave cambridge ma 02139 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 77 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Armijn Hemel <armijn@tjaldur.nl> Reviewed-by: Richard Fontana <rfontana@redhat.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.837555891@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
158 lines
3.3 KiB
C
158 lines
3.3 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* cpufreq driver for the cell processor
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*
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* (C) Copyright IBM Deutschland Entwicklung GmbH 2005-2007
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*
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* Author: Christian Krafft <krafft@de.ibm.com>
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*/
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#include <linux/cpufreq.h>
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#include <linux/module.h>
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#include <linux/of_platform.h>
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#include <asm/machdep.h>
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#include <asm/prom.h>
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#include <asm/cell-regs.h>
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#include "ppc_cbe_cpufreq.h"
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/* the CBE supports an 8 step frequency scaling */
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static struct cpufreq_frequency_table cbe_freqs[] = {
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{0, 1, 0},
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{0, 2, 0},
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{0, 3, 0},
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{0, 4, 0},
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{0, 5, 0},
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{0, 6, 0},
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{0, 8, 0},
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{0, 10, 0},
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{0, 0, CPUFREQ_TABLE_END},
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};
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/*
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* hardware specific functions
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*/
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static int set_pmode(unsigned int cpu, unsigned int slow_mode)
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{
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int rc;
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if (cbe_cpufreq_has_pmi)
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rc = cbe_cpufreq_set_pmode_pmi(cpu, slow_mode);
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else
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rc = cbe_cpufreq_set_pmode(cpu, slow_mode);
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pr_debug("register contains slow mode %d\n", cbe_cpufreq_get_pmode(cpu));
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return rc;
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}
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/*
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* cpufreq functions
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*/
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static int cbe_cpufreq_cpu_init(struct cpufreq_policy *policy)
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{
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struct cpufreq_frequency_table *pos;
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const u32 *max_freqp;
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u32 max_freq;
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int cur_pmode;
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struct device_node *cpu;
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cpu = of_get_cpu_node(policy->cpu, NULL);
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if (!cpu)
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return -ENODEV;
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pr_debug("init cpufreq on CPU %d\n", policy->cpu);
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/*
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* Let's check we can actually get to the CELL regs
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*/
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if (!cbe_get_cpu_pmd_regs(policy->cpu) ||
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!cbe_get_cpu_mic_tm_regs(policy->cpu)) {
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pr_info("invalid CBE regs pointers for cpufreq\n");
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of_node_put(cpu);
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return -EINVAL;
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}
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max_freqp = of_get_property(cpu, "clock-frequency", NULL);
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of_node_put(cpu);
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if (!max_freqp)
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return -EINVAL;
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/* we need the freq in kHz */
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max_freq = *max_freqp / 1000;
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pr_debug("max clock-frequency is at %u kHz\n", max_freq);
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pr_debug("initializing frequency table\n");
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/* initialize frequency table */
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cpufreq_for_each_entry(pos, cbe_freqs) {
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pos->frequency = max_freq / pos->driver_data;
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pr_debug("%d: %d\n", (int)(pos - cbe_freqs), pos->frequency);
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}
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/* if DEBUG is enabled set_pmode() measures the latency
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* of a transition */
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policy->cpuinfo.transition_latency = 25000;
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cur_pmode = cbe_cpufreq_get_pmode(policy->cpu);
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pr_debug("current pmode is at %d\n",cur_pmode);
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policy->cur = cbe_freqs[cur_pmode].frequency;
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#ifdef CONFIG_SMP
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cpumask_copy(policy->cpus, cpu_sibling_mask(policy->cpu));
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#endif
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policy->freq_table = cbe_freqs;
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return 0;
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}
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static int cbe_cpufreq_target(struct cpufreq_policy *policy,
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unsigned int cbe_pmode_new)
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{
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pr_debug("setting frequency for cpu %d to %d kHz, " \
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"1/%d of max frequency\n",
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policy->cpu,
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cbe_freqs[cbe_pmode_new].frequency,
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cbe_freqs[cbe_pmode_new].driver_data);
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return set_pmode(policy->cpu, cbe_pmode_new);
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}
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static struct cpufreq_driver cbe_cpufreq_driver = {
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.verify = cpufreq_generic_frequency_table_verify,
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.target_index = cbe_cpufreq_target,
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.init = cbe_cpufreq_cpu_init,
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.name = "cbe-cpufreq",
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.flags = CPUFREQ_CONST_LOOPS,
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};
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/*
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* module init and destoy
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*/
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static int __init cbe_cpufreq_init(void)
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{
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if (!machine_is(cell))
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return -ENODEV;
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return cpufreq_register_driver(&cbe_cpufreq_driver);
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}
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static void __exit cbe_cpufreq_exit(void)
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{
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cpufreq_unregister_driver(&cbe_cpufreq_driver);
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}
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module_init(cbe_cpufreq_init);
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module_exit(cbe_cpufreq_exit);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Christian Krafft <krafft@de.ibm.com>");
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