/* * pmi backend for the cbe_cpufreq driver * * (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/kernel.h> #include <linux/types.h> #include <linux/timer.h> #include <linux/of_platform.h> #include <asm/processor.h> #include <asm/prom.h> #include <asm/pmi.h> #include <asm/cell-regs.h> #ifdef DEBUG #include <asm/time.h> #endif #include "cbe_cpufreq.h" static u8 pmi_slow_mode_limit[MAX_CBE]; bool cbe_cpufreq_has_pmi = false; EXPORT_SYMBOL_GPL(cbe_cpufreq_has_pmi); /* * hardware specific functions */ int cbe_cpufreq_set_pmode_pmi(int cpu, unsigned int pmode) { int ret; pmi_message_t pmi_msg; #ifdef DEBUG long time; #endif pmi_msg.type = PMI_TYPE_FREQ_CHANGE; pmi_msg.data1 = cbe_cpu_to_node(cpu); pmi_msg.data2 = pmode; #ifdef DEBUG time = jiffies; #endif pmi_send_message(pmi_msg); #ifdef DEBUG time = jiffies - time; time = jiffies_to_msecs(time); pr_debug("had to wait %lu ms for a transition using " \ "PMI\n", time); #endif ret = pmi_msg.data2; pr_debug("PMI returned slow mode %d\n", ret); return ret; } EXPORT_SYMBOL_GPL(cbe_cpufreq_set_pmode_pmi); static void cbe_cpufreq_handle_pmi(pmi_message_t pmi_msg) { u8 node, slow_mode; BUG_ON(pmi_msg.type != PMI_TYPE_FREQ_CHANGE); node = pmi_msg.data1; slow_mode = pmi_msg.data2; pmi_slow_mode_limit[node] = slow_mode; pr_debug("cbe_handle_pmi: node: %d max_freq: %d\n", node, slow_mode); } static int pmi_notifier(struct notifier_block *nb, unsigned long event, void *data) { struct cpufreq_policy *policy = data; struct cpufreq_frequency_table *cbe_freqs; u8 node; /* Should this really be called for CPUFREQ_ADJUST, CPUFREQ_INCOMPATIBLE * and CPUFREQ_NOTIFY policy events?) */ if (event == CPUFREQ_START) return 0; cbe_freqs = cpufreq_frequency_get_table(policy->cpu); node = cbe_cpu_to_node(policy->cpu); pr_debug("got notified, event=%lu, node=%u\n", event, node); if (pmi_slow_mode_limit[node] != 0) { pr_debug("limiting node %d to slow mode %d\n", node, pmi_slow_mode_limit[node]); cpufreq_verify_within_limits(policy, 0, cbe_freqs[pmi_slow_mode_limit[node]].frequency); } return 0; } static struct notifier_block pmi_notifier_block = { .notifier_call = pmi_notifier, }; static struct pmi_handler cbe_pmi_handler = { .type = PMI_TYPE_FREQ_CHANGE, .handle_pmi_message = cbe_cpufreq_handle_pmi, }; static int __init cbe_cpufreq_pmi_init(void) { cbe_cpufreq_has_pmi = pmi_register_handler(&cbe_pmi_handler) == 0; if (!cbe_cpufreq_has_pmi) return -ENODEV; cpufreq_register_notifier(&pmi_notifier_block, CPUFREQ_POLICY_NOTIFIER); return 0; } static void __exit cbe_cpufreq_pmi_exit(void) { cpufreq_unregister_notifier(&pmi_notifier_block, CPUFREQ_POLICY_NOTIFIER); pmi_unregister_handler(&cbe_pmi_handler); } module_init(cbe_cpufreq_pmi_init); module_exit(cbe_cpufreq_pmi_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Christian Krafft <krafft@de.ibm.com>");