| /* |
| * 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 <linux/module.h> |
| #include <linux/of_address.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; |
| |
| /* 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}, |
| }; |
| |
| /* |
| * 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) |
| { |
| unsigned long 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].driver_data) * 100000; |
| pr_debug("%d: %d\n", i, pas_freqs[i].frequency); |
| } |
| |
| cur_astate = get_cur_astate(policy->cpu); |
| pr_debug("current astate is at %d\n",cur_astate); |
| |
| policy->cur = pas_freqs[cur_astate].frequency; |
| ppc_proc_freq = policy->cur * 1000ul; |
| |
| return cpufreq_generic_init(policy, pas_freqs, get_gizmo_latency()); |
| |
| 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) |
| { |
| /* |
| * We don't support CPU hotplug. Don't unmap after the system |
| * has already made it to a running state. |
| */ |
| if (system_state != SYSTEM_BOOTING) |
| return 0; |
| |
| if (sdcasr_mapbase) |
| iounmap(sdcasr_mapbase); |
| if (sdcpwr_mapbase) |
| iounmap(sdcpwr_mapbase); |
| |
| return 0; |
| } |
| |
| static int pas_cpufreq_target(struct cpufreq_policy *policy, |
| unsigned int pas_astate_new) |
| { |
| int i; |
| |
| 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].driver_data); |
| |
| current_astate = pas_astate_new; |
| |
| for_each_online_cpu(i) |
| set_astate(i, pas_astate_new); |
| |
| ppc_proc_freq = pas_freqs[pas_astate_new].frequency * 1000ul; |
| return 0; |
| } |
| |
| static struct cpufreq_driver pas_cpufreq_driver = { |
| .name = "pas-cpufreq", |
| .flags = CPUFREQ_CONST_LOOPS, |
| .init = pas_cpufreq_cpu_init, |
| .exit = pas_cpufreq_cpu_exit, |
| .verify = cpufreq_generic_frequency_table_verify, |
| .target_index = pas_cpufreq_target, |
| .attr = cpufreq_generic_attr, |
| }; |
| |
| /* |
| * module init and destoy |
| */ |
| |
| static int __init pas_cpufreq_init(void) |
| { |
| if (!of_machine_is_compatible("PA6T-1682M") && |
| !of_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>"); |