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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Copyright (C) 2007 PA Semi, Inc4 *5 * Authors: Egor Martovetsky <egor@pasemi.com>6 * Olof Johansson <olof@lixom.net>7 *8 * Maintained by: Olof Johansson <olof@lixom.net>9 *10 * Based on arch/powerpc/platforms/cell/cbe_cpufreq.c:11 * (C) Copyright IBM Deutschland Entwicklung GmbH 200512 */13 14#include <linux/cpufreq.h>15#include <linux/timer.h>16#include <linux/module.h>17#include <linux/of_address.h>18 19#include <asm/hw_irq.h>20#include <asm/io.h>21#include <asm/time.h>22#include <asm/smp.h>23 24#include <platforms/pasemi/pasemi.h>25 26#define SDCASR_REG 0x010027#define SDCASR_REG_STRIDE 0x100028#define SDCPWR_CFGA0_REG 0x010029#define SDCPWR_PWST0_REG 0x000030#define SDCPWR_GIZTIME_REG 0x044031 32/* SDCPWR_GIZTIME_REG fields */33#define SDCPWR_GIZTIME_GR 0x8000000034#define SDCPWR_GIZTIME_LONGLOCK 0x000000ff35 36/* Offset of ASR registers from SDC base */37#define SDCASR_OFFSET 0x12000038 39static void __iomem *sdcpwr_mapbase;40static void __iomem *sdcasr_mapbase;41 42/* Current astate, is used when waking up from power savings on43 * one core, in case the other core has switched states during44 * the idle time.45 */46static int current_astate;47 48/* We support 5(A0-A4) power states excluding turbo(A5-A6) modes */49static struct cpufreq_frequency_table pas_freqs[] = {50 {0, 0, 0},51 {0, 1, 0},52 {0, 2, 0},53 {0, 3, 0},54 {0, 4, 0},55 {0, 0, CPUFREQ_TABLE_END},56};57 58/*59 * hardware specific functions60 */61 62static int get_astate_freq(int astate)63{64 u32 ret;65 ret = in_le32(sdcpwr_mapbase + SDCPWR_CFGA0_REG + (astate * 0x10));66 67 return ret & 0x3f;68}69 70static int get_cur_astate(int cpu)71{72 u32 ret;73 74 ret = in_le32(sdcpwr_mapbase + SDCPWR_PWST0_REG);75 ret = (ret >> (cpu * 4)) & 0x7;76 77 return ret;78}79 80static int get_gizmo_latency(void)81{82 u32 giztime, ret;83 84 giztime = in_le32(sdcpwr_mapbase + SDCPWR_GIZTIME_REG);85 86 /* just provide the upper bound */87 if (giztime & SDCPWR_GIZTIME_GR)88 ret = (giztime & SDCPWR_GIZTIME_LONGLOCK) * 128000;89 else90 ret = (giztime & SDCPWR_GIZTIME_LONGLOCK) * 1000;91 92 return ret;93}94 95static void set_astate(int cpu, unsigned int astate)96{97 unsigned long flags;98 99 /* Return if called before init has run */100 if (unlikely(!sdcasr_mapbase))101 return;102 103 local_irq_save(flags);104 105 out_le32(sdcasr_mapbase + SDCASR_REG + SDCASR_REG_STRIDE*cpu, astate);106 107 local_irq_restore(flags);108}109 110int check_astate(void)111{112 return get_cur_astate(hard_smp_processor_id());113}114 115void restore_astate(int cpu)116{117 set_astate(cpu, current_astate);118}119 120/*121 * cpufreq functions122 */123 124static int pas_cpufreq_cpu_init(struct cpufreq_policy *policy)125{126 struct cpufreq_frequency_table *pos;127 const u32 *max_freqp;128 u32 max_freq;129 int cur_astate, idx;130 struct resource res;131 struct device_node *cpu, *dn;132 int err = -ENODEV;133 134 cpu = of_get_cpu_node(policy->cpu, NULL);135 if (!cpu)136 goto out;137 138 max_freqp = of_get_property(cpu, "clock-frequency", NULL);139 of_node_put(cpu);140 if (!max_freqp) {141 err = -EINVAL;142 goto out;143 }144 145 /* we need the freq in kHz */146 max_freq = *max_freqp / 1000;147 148 dn = of_find_compatible_node(NULL, NULL, "1682m-sdc");149 if (!dn)150 dn = of_find_compatible_node(NULL, NULL,151 "pasemi,pwrficient-sdc");152 if (!dn)153 goto out;154 err = of_address_to_resource(dn, 0, &res);155 of_node_put(dn);156 if (err)157 goto out;158 sdcasr_mapbase = ioremap(res.start + SDCASR_OFFSET, 0x2000);159 if (!sdcasr_mapbase) {160 err = -EINVAL;161 goto out;162 }163 164 dn = of_find_compatible_node(NULL, NULL, "1682m-gizmo");165 if (!dn)166 dn = of_find_compatible_node(NULL, NULL,167 "pasemi,pwrficient-gizmo");168 if (!dn) {169 err = -ENODEV;170 goto out_unmap_sdcasr;171 }172 err = of_address_to_resource(dn, 0, &res);173 of_node_put(dn);174 if (err)175 goto out_unmap_sdcasr;176 sdcpwr_mapbase = ioremap(res.start, 0x1000);177 if (!sdcpwr_mapbase) {178 err = -EINVAL;179 goto out_unmap_sdcasr;180 }181 182 pr_debug("init cpufreq on CPU %d\n", policy->cpu);183 pr_debug("max clock-frequency is at %u kHz\n", max_freq);184 pr_debug("initializing frequency table\n");185 186 /* initialize frequency table */187 cpufreq_for_each_entry_idx(pos, pas_freqs, idx) {188 pos->frequency = get_astate_freq(pos->driver_data) * 100000;189 pr_debug("%d: %d\n", idx, pos->frequency);190 }191 192 cur_astate = get_cur_astate(policy->cpu);193 pr_debug("current astate is at %d\n",cur_astate);194 195 policy->cur = pas_freqs[cur_astate].frequency;196 ppc_proc_freq = policy->cur * 1000ul;197 198 cpufreq_generic_init(policy, pas_freqs, get_gizmo_latency());199 return 0;200 201out_unmap_sdcasr:202 iounmap(sdcasr_mapbase);203out:204 return err;205}206 207static void pas_cpufreq_cpu_exit(struct cpufreq_policy *policy)208{209 /*210 * We don't support CPU hotplug. Don't unmap after the system211 * has already made it to a running state.212 */213 if (system_state >= SYSTEM_RUNNING)214 return;215 216 if (sdcasr_mapbase)217 iounmap(sdcasr_mapbase);218 if (sdcpwr_mapbase)219 iounmap(sdcpwr_mapbase);220}221 222static int pas_cpufreq_target(struct cpufreq_policy *policy,223 unsigned int pas_astate_new)224{225 int i;226 227 pr_debug("setting frequency for cpu %d to %d kHz, 1/%d of max frequency\n",228 policy->cpu,229 pas_freqs[pas_astate_new].frequency,230 pas_freqs[pas_astate_new].driver_data);231 232 current_astate = pas_astate_new;233 234 for_each_online_cpu(i)235 set_astate(i, pas_astate_new);236 237 ppc_proc_freq = pas_freqs[pas_astate_new].frequency * 1000ul;238 return 0;239}240 241static struct cpufreq_driver pas_cpufreq_driver = {242 .name = "pas-cpufreq",243 .flags = CPUFREQ_CONST_LOOPS,244 .init = pas_cpufreq_cpu_init,245 .exit = pas_cpufreq_cpu_exit,246 .verify = cpufreq_generic_frequency_table_verify,247 .target_index = pas_cpufreq_target,248 .attr = cpufreq_generic_attr,249};250 251/*252 * module init and destoy253 */254 255static int __init pas_cpufreq_init(void)256{257 if (!of_machine_is_compatible("PA6T-1682M") &&258 !of_machine_is_compatible("pasemi,pwrficient"))259 return -ENODEV;260 261 return cpufreq_register_driver(&pas_cpufreq_driver);262}263 264static void __exit pas_cpufreq_exit(void)265{266 cpufreq_unregister_driver(&pas_cpufreq_driver);267}268 269module_init(pas_cpufreq_init);270module_exit(pas_cpufreq_exit);271 272MODULE_DESCRIPTION("cpufreq driver for PA Semi PWRficient");273MODULE_LICENSE("GPL");274MODULE_AUTHOR("Egor Martovetsky <egor@pasemi.com>, Olof Johansson <olof@lixom.net>");275