1 /* 2 * Copyright (C) 2007 PA Semi, Inc 3 * 4 * Authors: Egor Martovetsky <egor@pasemi.com> 5 * Olof Johansson <olof@lixom.net> 6 * 7 * Maintained by: Olof Johansson <olof@lixom.net> 8 * 9 * Based on arch/powerpc/platforms/cell/cbe_cpufreq.c: 10 * (C) Copyright IBM Deutschland Entwicklung GmbH 2005 11 * 12 * This program is free software; you can redistribute it and/or modify 13 * it under the terms of the GNU General Public License as published by 14 * the Free Software Foundation; either version 2, or (at your option) 15 * any later version. 16 * 17 * This program is distributed in the hope that it will be useful, 18 * but WITHOUT ANY WARRANTY; without even the implied warranty of 19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 20 * GNU General Public License for more details. 21 * 22 * You should have received a copy of the GNU General Public License 23 * along with this program; if not, write to the Free Software 24 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 25 * 26 */ 27 28 #include <linux/cpufreq.h> 29 #include <linux/timer.h> 30 #include <linux/module.h> 31 32 #include <asm/hw_irq.h> 33 #include <asm/io.h> 34 #include <asm/prom.h> 35 #include <asm/time.h> 36 #include <asm/smp.h> 37 38 #define SDCASR_REG 0x0100 39 #define SDCASR_REG_STRIDE 0x1000 40 #define SDCPWR_CFGA0_REG 0x0100 41 #define SDCPWR_PWST0_REG 0x0000 42 #define SDCPWR_GIZTIME_REG 0x0440 43 44 /* SDCPWR_GIZTIME_REG fields */ 45 #define SDCPWR_GIZTIME_GR 0x80000000 46 #define SDCPWR_GIZTIME_LONGLOCK 0x000000ff 47 48 /* Offset of ASR registers from SDC base */ 49 #define SDCASR_OFFSET 0x120000 50 51 static void __iomem *sdcpwr_mapbase; 52 static void __iomem *sdcasr_mapbase; 53 54 static DEFINE_MUTEX(pas_switch_mutex); 55 56 /* Current astate, is used when waking up from power savings on 57 * one core, in case the other core has switched states during 58 * the idle time. 59 */ 60 static int current_astate; 61 62 /* We support 5(A0-A4) power states excluding turbo(A5-A6) modes */ 63 static struct cpufreq_frequency_table pas_freqs[] = { 64 {0, 0}, 65 {1, 0}, 66 {2, 0}, 67 {3, 0}, 68 {4, 0}, 69 {0, CPUFREQ_TABLE_END}, 70 }; 71 72 static struct freq_attr *pas_cpu_freqs_attr[] = { 73 &cpufreq_freq_attr_scaling_available_freqs, 74 NULL, 75 }; 76 77 /* 78 * hardware specific functions 79 */ 80 81 static int get_astate_freq(int astate) 82 { 83 u32 ret; 84 ret = in_le32(sdcpwr_mapbase + SDCPWR_CFGA0_REG + (astate * 0x10)); 85 86 return ret & 0x3f; 87 } 88 89 static int get_cur_astate(int cpu) 90 { 91 u32 ret; 92 93 ret = in_le32(sdcpwr_mapbase + SDCPWR_PWST0_REG); 94 ret = (ret >> (cpu * 4)) & 0x7; 95 96 return ret; 97 } 98 99 static int get_gizmo_latency(void) 100 { 101 u32 giztime, ret; 102 103 giztime = in_le32(sdcpwr_mapbase + SDCPWR_GIZTIME_REG); 104 105 /* just provide the upper bound */ 106 if (giztime & SDCPWR_GIZTIME_GR) 107 ret = (giztime & SDCPWR_GIZTIME_LONGLOCK) * 128000; 108 else 109 ret = (giztime & SDCPWR_GIZTIME_LONGLOCK) * 1000; 110 111 return ret; 112 } 113 114 static void set_astate(int cpu, unsigned int astate) 115 { 116 unsigned long flags; 117 118 /* Return if called before init has run */ 119 if (unlikely(!sdcasr_mapbase)) 120 return; 121 122 local_irq_save(flags); 123 124 out_le32(sdcasr_mapbase + SDCASR_REG + SDCASR_REG_STRIDE*cpu, astate); 125 126 local_irq_restore(flags); 127 } 128 129 int check_astate(void) 130 { 131 return get_cur_astate(hard_smp_processor_id()); 132 } 133 134 void restore_astate(int cpu) 135 { 136 set_astate(cpu, current_astate); 137 } 138 139 /* 140 * cpufreq functions 141 */ 142 143 static int pas_cpufreq_cpu_init(struct cpufreq_policy *policy) 144 { 145 const u32 *max_freqp; 146 u32 max_freq; 147 int i, cur_astate; 148 struct resource res; 149 struct device_node *cpu, *dn; 150 int err = -ENODEV; 151 152 cpu = of_get_cpu_node(policy->cpu, NULL); 153 154 if (!cpu) 155 goto out; 156 157 dn = of_find_compatible_node(NULL, NULL, "1682m-sdc"); 158 if (!dn) 159 dn = of_find_compatible_node(NULL, NULL, 160 "pasemi,pwrficient-sdc"); 161 if (!dn) 162 goto out; 163 err = of_address_to_resource(dn, 0, &res); 164 of_node_put(dn); 165 if (err) 166 goto out; 167 sdcasr_mapbase = ioremap(res.start + SDCASR_OFFSET, 0x2000); 168 if (!sdcasr_mapbase) { 169 err = -EINVAL; 170 goto out; 171 } 172 173 dn = of_find_compatible_node(NULL, NULL, "1682m-gizmo"); 174 if (!dn) 175 dn = of_find_compatible_node(NULL, NULL, 176 "pasemi,pwrficient-gizmo"); 177 if (!dn) { 178 err = -ENODEV; 179 goto out_unmap_sdcasr; 180 } 181 err = of_address_to_resource(dn, 0, &res); 182 of_node_put(dn); 183 if (err) 184 goto out_unmap_sdcasr; 185 sdcpwr_mapbase = ioremap(res.start, 0x1000); 186 if (!sdcpwr_mapbase) { 187 err = -EINVAL; 188 goto out_unmap_sdcasr; 189 } 190 191 pr_debug("init cpufreq on CPU %d\n", policy->cpu); 192 193 max_freqp = of_get_property(cpu, "clock-frequency", NULL); 194 if (!max_freqp) { 195 err = -EINVAL; 196 goto out_unmap_sdcpwr; 197 } 198 199 /* we need the freq in kHz */ 200 max_freq = *max_freqp / 1000; 201 202 pr_debug("max clock-frequency is at %u kHz\n", max_freq); 203 pr_debug("initializing frequency table\n"); 204 205 /* initialize frequency table */ 206 for (i=0; pas_freqs[i].frequency!=CPUFREQ_TABLE_END; i++) { 207 pas_freqs[i].frequency = 208 get_astate_freq(pas_freqs[i].driver_data) * 100000; 209 pr_debug("%d: %d\n", i, pas_freqs[i].frequency); 210 } 211 212 policy->cpuinfo.transition_latency = get_gizmo_latency(); 213 214 cur_astate = get_cur_astate(policy->cpu); 215 pr_debug("current astate is at %d\n",cur_astate); 216 217 policy->cur = pas_freqs[cur_astate].frequency; 218 cpumask_copy(policy->cpus, cpu_online_mask); 219 220 ppc_proc_freq = policy->cur * 1000ul; 221 222 cpufreq_frequency_table_get_attr(pas_freqs, policy->cpu); 223 224 /* this ensures that policy->cpuinfo_min and policy->cpuinfo_max 225 * are set correctly 226 */ 227 return cpufreq_frequency_table_cpuinfo(policy, pas_freqs); 228 229 out_unmap_sdcpwr: 230 iounmap(sdcpwr_mapbase); 231 232 out_unmap_sdcasr: 233 iounmap(sdcasr_mapbase); 234 out: 235 return err; 236 } 237 238 static int pas_cpufreq_cpu_exit(struct cpufreq_policy *policy) 239 { 240 /* 241 * We don't support CPU hotplug. Don't unmap after the system 242 * has already made it to a running state. 243 */ 244 if (system_state != SYSTEM_BOOTING) 245 return 0; 246 247 if (sdcasr_mapbase) 248 iounmap(sdcasr_mapbase); 249 if (sdcpwr_mapbase) 250 iounmap(sdcpwr_mapbase); 251 252 cpufreq_frequency_table_put_attr(policy->cpu); 253 return 0; 254 } 255 256 static int pas_cpufreq_verify(struct cpufreq_policy *policy) 257 { 258 return cpufreq_frequency_table_verify(policy, pas_freqs); 259 } 260 261 static int pas_cpufreq_target(struct cpufreq_policy *policy, 262 unsigned int target_freq, 263 unsigned int relation) 264 { 265 struct cpufreq_freqs freqs; 266 int pas_astate_new; 267 int i; 268 269 cpufreq_frequency_table_target(policy, 270 pas_freqs, 271 target_freq, 272 relation, 273 &pas_astate_new); 274 275 freqs.old = policy->cur; 276 freqs.new = pas_freqs[pas_astate_new].frequency; 277 278 mutex_lock(&pas_switch_mutex); 279 cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE); 280 281 pr_debug("setting frequency for cpu %d to %d kHz, 1/%d of max frequency\n", 282 policy->cpu, 283 pas_freqs[pas_astate_new].frequency, 284 pas_freqs[pas_astate_new].driver_data); 285 286 current_astate = pas_astate_new; 287 288 for_each_online_cpu(i) 289 set_astate(i, pas_astate_new); 290 291 cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE); 292 mutex_unlock(&pas_switch_mutex); 293 294 ppc_proc_freq = freqs.new * 1000ul; 295 return 0; 296 } 297 298 static struct cpufreq_driver pas_cpufreq_driver = { 299 .name = "pas-cpufreq", 300 .flags = CPUFREQ_CONST_LOOPS, 301 .init = pas_cpufreq_cpu_init, 302 .exit = pas_cpufreq_cpu_exit, 303 .verify = pas_cpufreq_verify, 304 .target = pas_cpufreq_target, 305 .attr = pas_cpu_freqs_attr, 306 }; 307 308 /* 309 * module init and destoy 310 */ 311 312 static int __init pas_cpufreq_init(void) 313 { 314 if (!of_machine_is_compatible("PA6T-1682M") && 315 !of_machine_is_compatible("pasemi,pwrficient")) 316 return -ENODEV; 317 318 return cpufreq_register_driver(&pas_cpufreq_driver); 319 } 320 321 static void __exit pas_cpufreq_exit(void) 322 { 323 cpufreq_unregister_driver(&pas_cpufreq_driver); 324 } 325 326 module_init(pas_cpufreq_init); 327 module_exit(pas_cpufreq_exit); 328 329 MODULE_LICENSE("GPL"); 330 MODULE_AUTHOR("Egor Martovetsky <egor@pasemi.com>, Olof Johansson <olof@lixom.net>"); 331