| /* |
| * cpufreq driver for the cell processor |
| * |
| * (C) Copyright IBM Deutschland Entwicklung GmbH 2005-2007 |
| * |
| * Author: Christian Krafft <krafft@de.ibm.com> |
| * |
| * 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. |
| */ |
| |
| #include <linux/cpufreq.h> |
| #include <linux/module.h> |
| #include <linux/of_platform.h> |
| |
| #include <asm/machdep.h> |
| #include <asm/prom.h> |
| #include <asm/cell-regs.h> |
| |
| #include "ppc_cbe_cpufreq.h" |
| |
| static DEFINE_MUTEX(cbe_switch_mutex); |
| |
| |
| /* the CBE supports an 8 step frequency scaling */ |
| static struct cpufreq_frequency_table cbe_freqs[] = { |
| {1, 0}, |
| {2, 0}, |
| {3, 0}, |
| {4, 0}, |
| {5, 0}, |
| {6, 0}, |
| {8, 0}, |
| {10, 0}, |
| {0, CPUFREQ_TABLE_END}, |
| }; |
| |
| /* |
| * hardware specific functions |
| */ |
| |
| static int set_pmode(unsigned int cpu, unsigned int slow_mode) |
| { |
| int rc; |
| |
| if (cbe_cpufreq_has_pmi) |
| rc = cbe_cpufreq_set_pmode_pmi(cpu, slow_mode); |
| else |
| rc = cbe_cpufreq_set_pmode(cpu, slow_mode); |
| |
| pr_debug("register contains slow mode %d\n", cbe_cpufreq_get_pmode(cpu)); |
| |
| return rc; |
| } |
| |
| /* |
| * cpufreq functions |
| */ |
| |
| static int cbe_cpufreq_cpu_init(struct cpufreq_policy *policy) |
| { |
| const u32 *max_freqp; |
| u32 max_freq; |
| int i, cur_pmode; |
| struct device_node *cpu; |
| |
| cpu = of_get_cpu_node(policy->cpu, NULL); |
| |
| if (!cpu) |
| return -ENODEV; |
| |
| pr_debug("init cpufreq on CPU %d\n", policy->cpu); |
| |
| /* |
| * Let's check we can actually get to the CELL regs |
| */ |
| if (!cbe_get_cpu_pmd_regs(policy->cpu) || |
| !cbe_get_cpu_mic_tm_regs(policy->cpu)) { |
| pr_info("invalid CBE regs pointers for cpufreq\n"); |
| return -EINVAL; |
| } |
| |
| max_freqp = of_get_property(cpu, "clock-frequency", NULL); |
| |
| of_node_put(cpu); |
| |
| if (!max_freqp) |
| return -EINVAL; |
| |
| /* we need the freq in kHz */ |
| max_freq = *max_freqp / 1000; |
| |
| pr_debug("max clock-frequency is at %u kHz\n", max_freq); |
| pr_debug("initializing frequency table\n"); |
| |
| /* initialize frequency table */ |
| for (i=0; cbe_freqs[i].frequency!=CPUFREQ_TABLE_END; i++) { |
| cbe_freqs[i].frequency = max_freq / cbe_freqs[i].index; |
| pr_debug("%d: %d\n", i, cbe_freqs[i].frequency); |
| } |
| |
| /* if DEBUG is enabled set_pmode() measures the latency |
| * of a transition */ |
| policy->cpuinfo.transition_latency = 25000; |
| |
| cur_pmode = cbe_cpufreq_get_pmode(policy->cpu); |
| pr_debug("current pmode is at %d\n",cur_pmode); |
| |
| policy->cur = cbe_freqs[cur_pmode].frequency; |
| |
| #ifdef CONFIG_SMP |
| cpumask_copy(policy->cpus, cpu_sibling_mask(policy->cpu)); |
| #endif |
| |
| cpufreq_frequency_table_get_attr(cbe_freqs, policy->cpu); |
| |
| /* this ensures that policy->cpuinfo_min |
| * and policy->cpuinfo_max are set correctly */ |
| return cpufreq_frequency_table_cpuinfo(policy, cbe_freqs); |
| } |
| |
| static int cbe_cpufreq_cpu_exit(struct cpufreq_policy *policy) |
| { |
| cpufreq_frequency_table_put_attr(policy->cpu); |
| return 0; |
| } |
| |
| static int cbe_cpufreq_verify(struct cpufreq_policy *policy) |
| { |
| return cpufreq_frequency_table_verify(policy, cbe_freqs); |
| } |
| |
| static int cbe_cpufreq_target(struct cpufreq_policy *policy, |
| unsigned int target_freq, |
| unsigned int relation) |
| { |
| int rc; |
| struct cpufreq_freqs freqs; |
| unsigned int cbe_pmode_new; |
| |
| cpufreq_frequency_table_target(policy, |
| cbe_freqs, |
| target_freq, |
| relation, |
| &cbe_pmode_new); |
| |
| freqs.old = policy->cur; |
| freqs.new = cbe_freqs[cbe_pmode_new].frequency; |
| freqs.cpu = policy->cpu; |
| |
| mutex_lock(&cbe_switch_mutex); |
| cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); |
| |
| pr_debug("setting frequency for cpu %d to %d kHz, " \ |
| "1/%d of max frequency\n", |
| policy->cpu, |
| cbe_freqs[cbe_pmode_new].frequency, |
| cbe_freqs[cbe_pmode_new].index); |
| |
| rc = set_pmode(policy->cpu, cbe_pmode_new); |
| |
| cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); |
| mutex_unlock(&cbe_switch_mutex); |
| |
| return rc; |
| } |
| |
| static struct cpufreq_driver cbe_cpufreq_driver = { |
| .verify = cbe_cpufreq_verify, |
| .target = cbe_cpufreq_target, |
| .init = cbe_cpufreq_cpu_init, |
| .exit = cbe_cpufreq_cpu_exit, |
| .name = "cbe-cpufreq", |
| .owner = THIS_MODULE, |
| .flags = CPUFREQ_CONST_LOOPS, |
| }; |
| |
| /* |
| * module init and destoy |
| */ |
| |
| static int __init cbe_cpufreq_init(void) |
| { |
| if (!machine_is(cell)) |
| return -ENODEV; |
| |
| return cpufreq_register_driver(&cbe_cpufreq_driver); |
| } |
| |
| static void __exit cbe_cpufreq_exit(void) |
| { |
| cpufreq_unregister_driver(&cbe_cpufreq_driver); |
| } |
| |
| module_init(cbe_cpufreq_init); |
| module_exit(cbe_cpufreq_exit); |
| |
| MODULE_LICENSE("GPL"); |
| MODULE_AUTHOR("Christian Krafft <krafft@de.ibm.com>"); |