/* * Copyright (C) 2007 PA Semi, Inc * * Authors: Egor Martovetsky <egor@pasemi.com> * Olof Johansson <olof@lixom.net> * * Maintained by: Olof Johansson <olof@lixom.net> * * Based on arch/powerpc/platforms/cell/cbe_cpufreq.c: * (C) Copyright IBM Deutschland Entwicklung GmbH 2005 * * 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/timer.h> #include <asm/hw_irq.h> #include <asm/io.h> #include <asm/prom.h> #include <asm/time.h> #include <asm/smp.h> #define SDCASR_REG 0x0100 #define SDCASR_REG_STRIDE 0x1000 #define SDCPWR_CFGA0_REG 0x0100 #define SDCPWR_PWST0_REG 0x0000 #define SDCPWR_GIZTIME_REG 0x0440 /* SDCPWR_GIZTIME_REG fields */ #define SDCPWR_GIZTIME_GR 0x80000000 #define SDCPWR_GIZTIME_LONGLOCK 0x000000ff /* Offset of ASR registers from SDC base */ #define SDCASR_OFFSET 0x120000 static void __iomem *sdcpwr_mapbase; static void __iomem *sdcasr_mapbase; static DEFINE_MUTEX(pas_switch_mutex); /* Current astate, is used when waking up from power savings on * one core, in case the other core has switched states during * the idle time. */ static int current_astate; /* We support 5(A0-A4) power states excluding turbo(A5-A6) modes */ static struct cpufreq_frequency_table pas_freqs[] = { {0, 0}, {1, 0}, {2, 0}, {3, 0}, {4, 0}, {0, CPUFREQ_TABLE_END}, }; static struct freq_attr *pas_cpu_freqs_attr[] = { &cpufreq_freq_attr_scaling_available_freqs, NULL, }; /* * hardware specific functions */ static int get_astate_freq(int astate) { u32 ret; ret = in_le32(sdcpwr_mapbase + SDCPWR_CFGA0_REG + (astate * 0x10)); return ret & 0x3f; } static int get_cur_astate(int cpu) { u32 ret; ret = in_le32(sdcpwr_mapbase + SDCPWR_PWST0_REG); ret = (ret >> (cpu * 4)) & 0x7; return ret; } static int get_gizmo_latency(void) { u32 giztime, ret; giztime = in_le32(sdcpwr_mapbase + SDCPWR_GIZTIME_REG); /* just provide the upper bound */ if (giztime & SDCPWR_GIZTIME_GR) ret = (giztime & SDCPWR_GIZTIME_LONGLOCK) * 128000; else ret = (giztime & SDCPWR_GIZTIME_LONGLOCK) * 1000; return ret; } static void set_astate(int cpu, unsigned int astate) { u64 flags; /* Return if called before init has run */ if (unlikely(!sdcasr_mapbase)) return; local_irq_save(flags); out_le32(sdcasr_mapbase + SDCASR_REG + SDCASR_REG_STRIDE*cpu, astate); local_irq_restore(flags); } int check_astate(void) { return get_cur_astate(hard_smp_processor_id()); } void restore_astate(int cpu) { set_astate(cpu, current_astate); } /* * cpufreq functions */ static int pas_cpufreq_cpu_init(struct cpufreq_policy *policy) { const u32 *max_freqp; u32 max_freq; int i, cur_astate; struct resource res; struct device_node *cpu, *dn; int err = -ENODEV; cpu = of_get_cpu_node(policy->cpu, NULL); if (!cpu) goto out; dn = of_find_compatible_node(NULL, NULL, "1682m-sdc"); if (!dn) dn = of_find_compatible_node(NULL, NULL, "pasemi,pwrficient-sdc"); if (!dn) goto out; err = of_address_to_resource(dn, 0, &res); of_node_put(dn); if (err) goto out; sdcasr_mapbase = ioremap(res.start + SDCASR_OFFSET, 0x2000); if (!sdcasr_mapbase) { err = -EINVAL; goto out; } dn = of_find_compatible_node(NULL, NULL, "1682m-gizmo"); if (!dn) dn = of_find_compatible_node(NULL, NULL, "pasemi,pwrficient-gizmo"); if (!dn) { err = -ENODEV; goto out_unmap_sdcasr; } err = of_address_to_resource(dn, 0, &res); of_node_put(dn); if (err) goto out_unmap_sdcasr; sdcpwr_mapbase = ioremap(res.start, 0x1000); if (!sdcpwr_mapbase) { err = -EINVAL; goto out_unmap_sdcasr; } pr_debug("init cpufreq on CPU %d\n", policy->cpu); max_freqp = of_get_property(cpu, "clock-frequency", NULL); if (!max_freqp) { err = -EINVAL; goto out_unmap_sdcpwr; } /* 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; pas_freqs[i].frequency!=CPUFREQ_TABLE_END; i++) { pas_freqs[i].frequency = get_astate_freq(pas_freqs[i].index) * 100000; pr_debug("%d: %d\n", i, pas_freqs[i].frequency); } policy->cpuinfo.transition_latency = get_gizmo_latency(); cur_astate = get_cur_astate(policy->cpu); pr_debug("current astate is at %d\n",cur_astate); policy->cur = pas_freqs[cur_astate].frequency; policy->cpus = cpu_online_map; ppc_proc_freq = policy->cur * 1000ul; cpufreq_frequency_table_get_attr(pas_freqs, policy->cpu); /* this ensures that policy->cpuinfo_min and policy->cpuinfo_max * are set correctly */ return cpufreq_frequency_table_cpuinfo(policy, pas_freqs); out_unmap_sdcpwr: iounmap(sdcpwr_mapbase); out_unmap_sdcasr: iounmap(sdcasr_mapbase); out: return err; } static int pas_cpufreq_cpu_exit(struct cpufreq_policy *policy) { if (sdcasr_mapbase) iounmap(sdcasr_mapbase); if (sdcpwr_mapbase) iounmap(sdcpwr_mapbase); cpufreq_frequency_table_put_attr(policy->cpu); return 0; } static int pas_cpufreq_verify(struct cpufreq_policy *policy) { return cpufreq_frequency_table_verify(policy, pas_freqs); } static int pas_cpufreq_target(struct cpufreq_policy *policy, unsigned int target_freq, unsigned int relation) { struct cpufreq_freqs freqs; int pas_astate_new; int i; cpufreq_frequency_table_target(policy, pas_freqs, target_freq, relation, &pas_astate_new); freqs.old = policy->cur; freqs.new = pas_freqs[pas_astate_new].frequency; freqs.cpu = policy->cpu; mutex_lock(&pas_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, pas_freqs[pas_astate_new].frequency, pas_freqs[pas_astate_new].index); current_astate = pas_astate_new; for_each_online_cpu(i) set_astate(i, pas_astate_new); cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); mutex_unlock(&pas_switch_mutex); ppc_proc_freq = freqs.new * 1000ul; return 0; } static struct cpufreq_driver pas_cpufreq_driver = { .name = "pas-cpufreq", .owner = THIS_MODULE, .flags = CPUFREQ_CONST_LOOPS, .init = pas_cpufreq_cpu_init, .exit = pas_cpufreq_cpu_exit, .verify = pas_cpufreq_verify, .target = pas_cpufreq_target, .attr = pas_cpu_freqs_attr, }; /* * module init and destoy */ static int __init pas_cpufreq_init(void) { if (!machine_is_compatible("PA6T-1682M") && !machine_is_compatible("pasemi,pwrficient")) return -ENODEV; return cpufreq_register_driver(&pas_cpufreq_driver); } static void __exit pas_cpufreq_exit(void) { cpufreq_unregister_driver(&pas_cpufreq_driver); } module_init(pas_cpufreq_init); module_exit(pas_cpufreq_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Egor Martovetsky <egor@pasemi.com>, Olof Johansson <olof@lixom.net>");