1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (C) 2007 PA Semi, Inc 4 * 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 2005 12 */ 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/prom.h> 22 #include <asm/time.h> 23 #include <asm/smp.h> 24 25 #include <platforms/pasemi/pasemi.h> 26 27 #define SDCASR_REG 0x0100 28 #define SDCASR_REG_STRIDE 0x1000 29 #define SDCPWR_CFGA0_REG 0x0100 30 #define SDCPWR_PWST0_REG 0x0000 31 #define SDCPWR_GIZTIME_REG 0x0440 32 33 /* SDCPWR_GIZTIME_REG fields */ 34 #define SDCPWR_GIZTIME_GR 0x80000000 35 #define SDCPWR_GIZTIME_LONGLOCK 0x000000ff 36 37 /* Offset of ASR registers from SDC base */ 38 #define SDCASR_OFFSET 0x120000 39 40 static void __iomem *sdcpwr_mapbase; 41 static void __iomem *sdcasr_mapbase; 42 43 /* Current astate, is used when waking up from power savings on 44 * one core, in case the other core has switched states during 45 * the idle time. 46 */ 47 static int current_astate; 48 49 /* We support 5(A0-A4) power states excluding turbo(A5-A6) modes */ 50 static struct cpufreq_frequency_table pas_freqs[] = { 51 {0, 0, 0}, 52 {0, 1, 0}, 53 {0, 2, 0}, 54 {0, 3, 0}, 55 {0, 4, 0}, 56 {0, 0, CPUFREQ_TABLE_END}, 57 }; 58 59 /* 60 * hardware specific functions 61 */ 62 63 static int get_astate_freq(int astate) 64 { 65 u32 ret; 66 ret = in_le32(sdcpwr_mapbase + SDCPWR_CFGA0_REG + (astate * 0x10)); 67 68 return ret & 0x3f; 69 } 70 71 static int get_cur_astate(int cpu) 72 { 73 u32 ret; 74 75 ret = in_le32(sdcpwr_mapbase + SDCPWR_PWST0_REG); 76 ret = (ret >> (cpu * 4)) & 0x7; 77 78 return ret; 79 } 80 81 static int get_gizmo_latency(void) 82 { 83 u32 giztime, ret; 84 85 giztime = in_le32(sdcpwr_mapbase + SDCPWR_GIZTIME_REG); 86 87 /* just provide the upper bound */ 88 if (giztime & SDCPWR_GIZTIME_GR) 89 ret = (giztime & SDCPWR_GIZTIME_LONGLOCK) * 128000; 90 else 91 ret = (giztime & SDCPWR_GIZTIME_LONGLOCK) * 1000; 92 93 return ret; 94 } 95 96 static void set_astate(int cpu, unsigned int astate) 97 { 98 unsigned long flags; 99 100 /* Return if called before init has run */ 101 if (unlikely(!sdcasr_mapbase)) 102 return; 103 104 local_irq_save(flags); 105 106 out_le32(sdcasr_mapbase + SDCASR_REG + SDCASR_REG_STRIDE*cpu, astate); 107 108 local_irq_restore(flags); 109 } 110 111 int check_astate(void) 112 { 113 return get_cur_astate(hard_smp_processor_id()); 114 } 115 116 void restore_astate(int cpu) 117 { 118 set_astate(cpu, current_astate); 119 } 120 121 /* 122 * cpufreq functions 123 */ 124 125 static int pas_cpufreq_cpu_init(struct cpufreq_policy *policy) 126 { 127 struct cpufreq_frequency_table *pos; 128 const u32 *max_freqp; 129 u32 max_freq; 130 int cur_astate, idx; 131 struct resource res; 132 struct device_node *cpu, *dn; 133 int err = -ENODEV; 134 135 cpu = of_get_cpu_node(policy->cpu, NULL); 136 if (!cpu) 137 goto out; 138 139 max_freqp = of_get_property(cpu, "clock-frequency", NULL); 140 of_node_put(cpu); 141 if (!max_freqp) { 142 err = -EINVAL; 143 goto out; 144 } 145 146 /* we need the freq in kHz */ 147 max_freq = *max_freqp / 1000; 148 149 dn = of_find_compatible_node(NULL, NULL, "1682m-sdc"); 150 if (!dn) 151 dn = of_find_compatible_node(NULL, NULL, 152 "pasemi,pwrficient-sdc"); 153 if (!dn) 154 goto out; 155 err = of_address_to_resource(dn, 0, &res); 156 of_node_put(dn); 157 if (err) 158 goto out; 159 sdcasr_mapbase = ioremap(res.start + SDCASR_OFFSET, 0x2000); 160 if (!sdcasr_mapbase) { 161 err = -EINVAL; 162 goto out; 163 } 164 165 dn = of_find_compatible_node(NULL, NULL, "1682m-gizmo"); 166 if (!dn) 167 dn = of_find_compatible_node(NULL, NULL, 168 "pasemi,pwrficient-gizmo"); 169 if (!dn) { 170 err = -ENODEV; 171 goto out_unmap_sdcasr; 172 } 173 err = of_address_to_resource(dn, 0, &res); 174 of_node_put(dn); 175 if (err) 176 goto out_unmap_sdcasr; 177 sdcpwr_mapbase = ioremap(res.start, 0x1000); 178 if (!sdcpwr_mapbase) { 179 err = -EINVAL; 180 goto out_unmap_sdcasr; 181 } 182 183 pr_debug("init cpufreq on CPU %d\n", policy->cpu); 184 pr_debug("max clock-frequency is at %u kHz\n", max_freq); 185 pr_debug("initializing frequency table\n"); 186 187 /* initialize frequency table */ 188 cpufreq_for_each_entry_idx(pos, pas_freqs, idx) { 189 pos->frequency = get_astate_freq(pos->driver_data) * 100000; 190 pr_debug("%d: %d\n", idx, pos->frequency); 191 } 192 193 cur_astate = get_cur_astate(policy->cpu); 194 pr_debug("current astate is at %d\n",cur_astate); 195 196 policy->cur = pas_freqs[cur_astate].frequency; 197 ppc_proc_freq = policy->cur * 1000ul; 198 199 cpufreq_generic_init(policy, pas_freqs, get_gizmo_latency()); 200 return 0; 201 202 out_unmap_sdcasr: 203 iounmap(sdcasr_mapbase); 204 out: 205 return err; 206 } 207 208 static int pas_cpufreq_cpu_exit(struct cpufreq_policy *policy) 209 { 210 /* 211 * We don't support CPU hotplug. Don't unmap after the system 212 * has already made it to a running state. 213 */ 214 if (system_state >= SYSTEM_RUNNING) 215 return 0; 216 217 if (sdcasr_mapbase) 218 iounmap(sdcasr_mapbase); 219 if (sdcpwr_mapbase) 220 iounmap(sdcpwr_mapbase); 221 222 return 0; 223 } 224 225 static int pas_cpufreq_target(struct cpufreq_policy *policy, 226 unsigned int pas_astate_new) 227 { 228 int i; 229 230 pr_debug("setting frequency for cpu %d to %d kHz, 1/%d of max frequency\n", 231 policy->cpu, 232 pas_freqs[pas_astate_new].frequency, 233 pas_freqs[pas_astate_new].driver_data); 234 235 current_astate = pas_astate_new; 236 237 for_each_online_cpu(i) 238 set_astate(i, pas_astate_new); 239 240 ppc_proc_freq = pas_freqs[pas_astate_new].frequency * 1000ul; 241 return 0; 242 } 243 244 static struct cpufreq_driver pas_cpufreq_driver = { 245 .name = "pas-cpufreq", 246 .flags = CPUFREQ_CONST_LOOPS, 247 .init = pas_cpufreq_cpu_init, 248 .exit = pas_cpufreq_cpu_exit, 249 .verify = cpufreq_generic_frequency_table_verify, 250 .target_index = pas_cpufreq_target, 251 .attr = cpufreq_generic_attr, 252 }; 253 254 /* 255 * module init and destoy 256 */ 257 258 static int __init pas_cpufreq_init(void) 259 { 260 if (!of_machine_is_compatible("PA6T-1682M") && 261 !of_machine_is_compatible("pasemi,pwrficient")) 262 return -ENODEV; 263 264 return cpufreq_register_driver(&pas_cpufreq_driver); 265 } 266 267 static void __exit pas_cpufreq_exit(void) 268 { 269 cpufreq_unregister_driver(&pas_cpufreq_driver); 270 } 271 272 module_init(pas_cpufreq_init); 273 module_exit(pas_cpufreq_exit); 274 275 MODULE_LICENSE("GPL"); 276 MODULE_AUTHOR("Egor Martovetsky <egor@pasemi.com>, Olof Johansson <olof@lixom.net>"); 277