1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Versatile Express Serial Power Controller (SPC) support 4 * 5 * Copyright (C) 2013 ARM Ltd. 6 * 7 * Authors: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com> 8 * Achin Gupta <achin.gupta@arm.com> 9 * Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> 10 */ 11 12 #include <linux/clk-provider.h> 13 #include <linux/clkdev.h> 14 #include <linux/cpu.h> 15 #include <linux/delay.h> 16 #include <linux/err.h> 17 #include <linux/interrupt.h> 18 #include <linux/io.h> 19 #include <linux/platform_device.h> 20 #include <linux/pm_opp.h> 21 #include <linux/slab.h> 22 #include <linux/semaphore.h> 23 24 #include <asm/cacheflush.h> 25 26 #include "spc.h" 27 28 #define SPCLOG "vexpress-spc: " 29 30 #define PERF_LVL_A15 0x00 31 #define PERF_REQ_A15 0x04 32 #define PERF_LVL_A7 0x08 33 #define PERF_REQ_A7 0x0c 34 #define COMMS 0x10 35 #define COMMS_REQ 0x14 36 #define PWC_STATUS 0x18 37 #define PWC_FLAG 0x1c 38 39 /* SPC wake-up IRQs status and mask */ 40 #define WAKE_INT_MASK 0x24 41 #define WAKE_INT_RAW 0x28 42 #define WAKE_INT_STAT 0x2c 43 /* SPC power down registers */ 44 #define A15_PWRDN_EN 0x30 45 #define A7_PWRDN_EN 0x34 46 /* SPC per-CPU mailboxes */ 47 #define A15_BX_ADDR0 0x68 48 #define A7_BX_ADDR0 0x78 49 50 /* SPC CPU/cluster reset statue */ 51 #define STANDBYWFI_STAT 0x3c 52 #define STANDBYWFI_STAT_A15_CPU_MASK(cpu) (1 << (cpu)) 53 #define STANDBYWFI_STAT_A7_CPU_MASK(cpu) (1 << (3 + (cpu))) 54 55 /* SPC system config interface registers */ 56 #define SYSCFG_WDATA 0x70 57 #define SYSCFG_RDATA 0x74 58 59 /* A15/A7 OPP virtual register base */ 60 #define A15_PERFVAL_BASE 0xC10 61 #define A7_PERFVAL_BASE 0xC30 62 63 /* Config interface control bits */ 64 #define SYSCFG_START BIT(31) 65 #define SYSCFG_SCC (6 << 20) 66 #define SYSCFG_STAT (14 << 20) 67 68 /* wake-up interrupt masks */ 69 #define GBL_WAKEUP_INT_MSK (0x3 << 10) 70 71 /* TC2 static dual-cluster configuration */ 72 #define MAX_CLUSTERS 2 73 74 /* 75 * Even though the SPC takes max 3-5 ms to complete any OPP/COMMS 76 * operation, the operation could start just before jiffie is about 77 * to be incremented. So setting timeout value of 20ms = 2jiffies@100Hz 78 */ 79 #define TIMEOUT_US 20000 80 81 #define MAX_OPPS 8 82 #define CA15_DVFS 0 83 #define CA7_DVFS 1 84 #define SPC_SYS_CFG 2 85 #define STAT_COMPLETE(type) ((1 << 0) << (type << 2)) 86 #define STAT_ERR(type) ((1 << 1) << (type << 2)) 87 #define RESPONSE_MASK(type) (STAT_COMPLETE(type) | STAT_ERR(type)) 88 89 struct ve_spc_opp { 90 unsigned long freq; 91 unsigned long u_volt; 92 }; 93 94 struct ve_spc_drvdata { 95 void __iomem *baseaddr; 96 /* 97 * A15s cluster identifier 98 * It corresponds to A15 processors MPIDR[15:8] bitfield 99 */ 100 u32 a15_clusid; 101 uint32_t cur_rsp_mask; 102 uint32_t cur_rsp_stat; 103 struct semaphore sem; 104 struct completion done; 105 struct ve_spc_opp *opps[MAX_CLUSTERS]; 106 int num_opps[MAX_CLUSTERS]; 107 }; 108 109 static struct ve_spc_drvdata *info; 110 111 static inline bool cluster_is_a15(u32 cluster) 112 { 113 return cluster == info->a15_clusid; 114 } 115 116 /** 117 * ve_spc_global_wakeup_irq() - sets/clears global wakeup IRQs 118 * 119 * @set: if true, global wake-up IRQs are set, if false they are cleared 120 * 121 * Function to set/clear global wakeup IRQs. Not protected by locking since 122 * it might be used in code paths where normal cacheable locks are not 123 * working. Locking must be provided by the caller to ensure atomicity. 124 */ 125 void ve_spc_global_wakeup_irq(bool set) 126 { 127 u32 reg; 128 129 reg = readl_relaxed(info->baseaddr + WAKE_INT_MASK); 130 131 if (set) 132 reg |= GBL_WAKEUP_INT_MSK; 133 else 134 reg &= ~GBL_WAKEUP_INT_MSK; 135 136 writel_relaxed(reg, info->baseaddr + WAKE_INT_MASK); 137 } 138 139 /** 140 * ve_spc_cpu_wakeup_irq() - sets/clears per-CPU wake-up IRQs 141 * 142 * @cluster: mpidr[15:8] bitfield describing cluster affinity level 143 * @cpu: mpidr[7:0] bitfield describing cpu affinity level 144 * @set: if true, wake-up IRQs are set, if false they are cleared 145 * 146 * Function to set/clear per-CPU wake-up IRQs. Not protected by locking since 147 * it might be used in code paths where normal cacheable locks are not 148 * working. Locking must be provided by the caller to ensure atomicity. 149 */ 150 void ve_spc_cpu_wakeup_irq(u32 cluster, u32 cpu, bool set) 151 { 152 u32 mask, reg; 153 154 if (cluster >= MAX_CLUSTERS) 155 return; 156 157 mask = BIT(cpu); 158 159 if (!cluster_is_a15(cluster)) 160 mask <<= 4; 161 162 reg = readl_relaxed(info->baseaddr + WAKE_INT_MASK); 163 164 if (set) 165 reg |= mask; 166 else 167 reg &= ~mask; 168 169 writel_relaxed(reg, info->baseaddr + WAKE_INT_MASK); 170 } 171 172 /** 173 * ve_spc_set_resume_addr() - set the jump address used for warm boot 174 * 175 * @cluster: mpidr[15:8] bitfield describing cluster affinity level 176 * @cpu: mpidr[7:0] bitfield describing cpu affinity level 177 * @addr: physical resume address 178 */ 179 void ve_spc_set_resume_addr(u32 cluster, u32 cpu, u32 addr) 180 { 181 void __iomem *baseaddr; 182 183 if (cluster >= MAX_CLUSTERS) 184 return; 185 186 if (cluster_is_a15(cluster)) 187 baseaddr = info->baseaddr + A15_BX_ADDR0 + (cpu << 2); 188 else 189 baseaddr = info->baseaddr + A7_BX_ADDR0 + (cpu << 2); 190 191 writel_relaxed(addr, baseaddr); 192 } 193 194 /** 195 * ve_spc_powerdown() - enables/disables cluster powerdown 196 * 197 * @cluster: mpidr[15:8] bitfield describing cluster affinity level 198 * @enable: if true enables powerdown, if false disables it 199 * 200 * Function to enable/disable cluster powerdown. Not protected by locking 201 * since it might be used in code paths where normal cacheable locks are not 202 * working. Locking must be provided by the caller to ensure atomicity. 203 */ 204 void ve_spc_powerdown(u32 cluster, bool enable) 205 { 206 u32 pwdrn_reg; 207 208 if (cluster >= MAX_CLUSTERS) 209 return; 210 211 pwdrn_reg = cluster_is_a15(cluster) ? A15_PWRDN_EN : A7_PWRDN_EN; 212 writel_relaxed(enable, info->baseaddr + pwdrn_reg); 213 } 214 215 static u32 standbywfi_cpu_mask(u32 cpu, u32 cluster) 216 { 217 return cluster_is_a15(cluster) ? 218 STANDBYWFI_STAT_A15_CPU_MASK(cpu) 219 : STANDBYWFI_STAT_A7_CPU_MASK(cpu); 220 } 221 222 /** 223 * ve_spc_cpu_in_wfi() - Checks if the specified CPU is in WFI or not 224 * 225 * @cpu: mpidr[7:0] bitfield describing CPU affinity level within cluster 226 * @cluster: mpidr[15:8] bitfield describing cluster affinity level 227 * 228 * @return: non-zero if and only if the specified CPU is in WFI 229 * 230 * Take care when interpreting the result of this function: a CPU might 231 * be in WFI temporarily due to idle, and is not necessarily safely 232 * parked. 233 */ 234 int ve_spc_cpu_in_wfi(u32 cpu, u32 cluster) 235 { 236 int ret; 237 u32 mask = standbywfi_cpu_mask(cpu, cluster); 238 239 if (cluster >= MAX_CLUSTERS) 240 return 1; 241 242 ret = readl_relaxed(info->baseaddr + STANDBYWFI_STAT); 243 244 pr_debug("%s: PCFGREG[0x%X] = 0x%08X, mask = 0x%X\n", 245 __func__, STANDBYWFI_STAT, ret, mask); 246 247 return ret & mask; 248 } 249 250 static int ve_spc_get_performance(int cluster, u32 *freq) 251 { 252 struct ve_spc_opp *opps = info->opps[cluster]; 253 u32 perf_cfg_reg = 0; 254 u32 perf; 255 256 perf_cfg_reg = cluster_is_a15(cluster) ? PERF_LVL_A15 : PERF_LVL_A7; 257 258 perf = readl_relaxed(info->baseaddr + perf_cfg_reg); 259 if (perf >= info->num_opps[cluster]) 260 return -EINVAL; 261 262 opps += perf; 263 *freq = opps->freq; 264 265 return 0; 266 } 267 268 /* find closest match to given frequency in OPP table */ 269 static int ve_spc_round_performance(int cluster, u32 freq) 270 { 271 int idx, max_opp = info->num_opps[cluster]; 272 struct ve_spc_opp *opps = info->opps[cluster]; 273 u32 fmin = 0, fmax = ~0, ftmp; 274 275 freq /= 1000; /* OPP entries in kHz */ 276 for (idx = 0; idx < max_opp; idx++, opps++) { 277 ftmp = opps->freq; 278 if (ftmp >= freq) { 279 if (ftmp <= fmax) 280 fmax = ftmp; 281 } else { 282 if (ftmp >= fmin) 283 fmin = ftmp; 284 } 285 } 286 if (fmax != ~0) 287 return fmax * 1000; 288 else 289 return fmin * 1000; 290 } 291 292 static int ve_spc_find_performance_index(int cluster, u32 freq) 293 { 294 int idx, max_opp = info->num_opps[cluster]; 295 struct ve_spc_opp *opps = info->opps[cluster]; 296 297 for (idx = 0; idx < max_opp; idx++, opps++) 298 if (opps->freq == freq) 299 break; 300 return (idx == max_opp) ? -EINVAL : idx; 301 } 302 303 static int ve_spc_waitforcompletion(int req_type) 304 { 305 int ret = wait_for_completion_interruptible_timeout( 306 &info->done, usecs_to_jiffies(TIMEOUT_US)); 307 if (ret == 0) 308 ret = -ETIMEDOUT; 309 else if (ret > 0) 310 ret = info->cur_rsp_stat & STAT_COMPLETE(req_type) ? 0 : -EIO; 311 return ret; 312 } 313 314 static int ve_spc_set_performance(int cluster, u32 freq) 315 { 316 u32 perf_cfg_reg; 317 int ret, perf, req_type; 318 319 if (cluster_is_a15(cluster)) { 320 req_type = CA15_DVFS; 321 perf_cfg_reg = PERF_LVL_A15; 322 } else { 323 req_type = CA7_DVFS; 324 perf_cfg_reg = PERF_LVL_A7; 325 } 326 327 perf = ve_spc_find_performance_index(cluster, freq); 328 329 if (perf < 0) 330 return perf; 331 332 if (down_timeout(&info->sem, usecs_to_jiffies(TIMEOUT_US))) 333 return -ETIME; 334 335 init_completion(&info->done); 336 info->cur_rsp_mask = RESPONSE_MASK(req_type); 337 338 writel(perf, info->baseaddr + perf_cfg_reg); 339 ret = ve_spc_waitforcompletion(req_type); 340 341 info->cur_rsp_mask = 0; 342 up(&info->sem); 343 344 return ret; 345 } 346 347 static int ve_spc_read_sys_cfg(int func, int offset, uint32_t *data) 348 { 349 int ret; 350 351 if (down_timeout(&info->sem, usecs_to_jiffies(TIMEOUT_US))) 352 return -ETIME; 353 354 init_completion(&info->done); 355 info->cur_rsp_mask = RESPONSE_MASK(SPC_SYS_CFG); 356 357 /* Set the control value */ 358 writel(SYSCFG_START | func | offset >> 2, info->baseaddr + COMMS); 359 ret = ve_spc_waitforcompletion(SPC_SYS_CFG); 360 361 if (ret == 0) 362 *data = readl(info->baseaddr + SYSCFG_RDATA); 363 364 info->cur_rsp_mask = 0; 365 up(&info->sem); 366 367 return ret; 368 } 369 370 static irqreturn_t ve_spc_irq_handler(int irq, void *data) 371 { 372 struct ve_spc_drvdata *drv_data = data; 373 uint32_t status = readl_relaxed(drv_data->baseaddr + PWC_STATUS); 374 375 if (info->cur_rsp_mask & status) { 376 info->cur_rsp_stat = status; 377 complete(&drv_data->done); 378 } 379 380 return IRQ_HANDLED; 381 } 382 383 /* 384 * +--------------------------+ 385 * | 31 20 | 19 0 | 386 * +--------------------------+ 387 * | m_volt | freq(kHz) | 388 * +--------------------------+ 389 */ 390 #define MULT_FACTOR 20 391 #define VOLT_SHIFT 20 392 #define FREQ_MASK (0xFFFFF) 393 static int ve_spc_populate_opps(uint32_t cluster) 394 { 395 uint32_t data = 0, off, ret, idx; 396 struct ve_spc_opp *opps; 397 398 opps = kcalloc(MAX_OPPS, sizeof(*opps), GFP_KERNEL); 399 if (!opps) 400 return -ENOMEM; 401 402 info->opps[cluster] = opps; 403 404 off = cluster_is_a15(cluster) ? A15_PERFVAL_BASE : A7_PERFVAL_BASE; 405 for (idx = 0; idx < MAX_OPPS; idx++, off += 4, opps++) { 406 ret = ve_spc_read_sys_cfg(SYSCFG_SCC, off, &data); 407 if (!ret) { 408 opps->freq = (data & FREQ_MASK) * MULT_FACTOR; 409 opps->u_volt = (data >> VOLT_SHIFT) * 1000; 410 } else { 411 break; 412 } 413 } 414 info->num_opps[cluster] = idx; 415 416 return ret; 417 } 418 419 static int ve_init_opp_table(struct device *cpu_dev) 420 { 421 int cluster; 422 int idx, ret = 0, max_opp; 423 struct ve_spc_opp *opps; 424 425 cluster = topology_physical_package_id(cpu_dev->id); 426 cluster = cluster < 0 ? 0 : cluster; 427 428 max_opp = info->num_opps[cluster]; 429 opps = info->opps[cluster]; 430 431 for (idx = 0; idx < max_opp; idx++, opps++) { 432 ret = dev_pm_opp_add(cpu_dev, opps->freq * 1000, opps->u_volt); 433 if (ret) { 434 dev_warn(cpu_dev, "failed to add opp %lu %lu\n", 435 opps->freq, opps->u_volt); 436 return ret; 437 } 438 } 439 return ret; 440 } 441 442 int __init ve_spc_init(void __iomem *baseaddr, u32 a15_clusid, int irq) 443 { 444 int ret; 445 info = kzalloc(sizeof(*info), GFP_KERNEL); 446 if (!info) 447 return -ENOMEM; 448 449 info->baseaddr = baseaddr; 450 info->a15_clusid = a15_clusid; 451 452 if (irq <= 0) { 453 pr_err(SPCLOG "Invalid IRQ %d\n", irq); 454 kfree(info); 455 return -EINVAL; 456 } 457 458 init_completion(&info->done); 459 460 readl_relaxed(info->baseaddr + PWC_STATUS); 461 462 ret = request_irq(irq, ve_spc_irq_handler, IRQF_TRIGGER_HIGH 463 | IRQF_ONESHOT, "vexpress-spc", info); 464 if (ret) { 465 pr_err(SPCLOG "IRQ %d request failed\n", irq); 466 kfree(info); 467 return -ENODEV; 468 } 469 470 sema_init(&info->sem, 1); 471 /* 472 * Multi-cluster systems may need this data when non-coherent, during 473 * cluster power-up/power-down. Make sure driver info reaches main 474 * memory. 475 */ 476 sync_cache_w(info); 477 sync_cache_w(&info); 478 479 return 0; 480 } 481 482 struct clk_spc { 483 struct clk_hw hw; 484 int cluster; 485 }; 486 487 #define to_clk_spc(spc) container_of(spc, struct clk_spc, hw) 488 static unsigned long spc_recalc_rate(struct clk_hw *hw, 489 unsigned long parent_rate) 490 { 491 struct clk_spc *spc = to_clk_spc(hw); 492 u32 freq; 493 494 if (ve_spc_get_performance(spc->cluster, &freq)) 495 return -EIO; 496 497 return freq * 1000; 498 } 499 500 static long spc_round_rate(struct clk_hw *hw, unsigned long drate, 501 unsigned long *parent_rate) 502 { 503 struct clk_spc *spc = to_clk_spc(hw); 504 505 return ve_spc_round_performance(spc->cluster, drate); 506 } 507 508 static int spc_set_rate(struct clk_hw *hw, unsigned long rate, 509 unsigned long parent_rate) 510 { 511 struct clk_spc *spc = to_clk_spc(hw); 512 513 return ve_spc_set_performance(spc->cluster, rate / 1000); 514 } 515 516 static struct clk_ops clk_spc_ops = { 517 .recalc_rate = spc_recalc_rate, 518 .round_rate = spc_round_rate, 519 .set_rate = spc_set_rate, 520 }; 521 522 static struct clk *ve_spc_clk_register(struct device *cpu_dev) 523 { 524 struct clk_init_data init; 525 struct clk_spc *spc; 526 527 spc = kzalloc(sizeof(*spc), GFP_KERNEL); 528 if (!spc) 529 return ERR_PTR(-ENOMEM); 530 531 spc->hw.init = &init; 532 spc->cluster = topology_physical_package_id(cpu_dev->id); 533 534 spc->cluster = spc->cluster < 0 ? 0 : spc->cluster; 535 536 init.name = dev_name(cpu_dev); 537 init.ops = &clk_spc_ops; 538 init.flags = CLK_GET_RATE_NOCACHE; 539 init.num_parents = 0; 540 541 return devm_clk_register(cpu_dev, &spc->hw); 542 } 543 544 static int __init ve_spc_clk_init(void) 545 { 546 int cpu, cluster; 547 struct clk *clk; 548 bool init_opp_table[MAX_CLUSTERS] = { false }; 549 550 if (!info) 551 return 0; /* Continue only if SPC is initialised */ 552 553 if (ve_spc_populate_opps(0) || ve_spc_populate_opps(1)) { 554 pr_err("failed to build OPP table\n"); 555 return -ENODEV; 556 } 557 558 for_each_possible_cpu(cpu) { 559 struct device *cpu_dev = get_cpu_device(cpu); 560 if (!cpu_dev) { 561 pr_warn("failed to get cpu%d device\n", cpu); 562 continue; 563 } 564 clk = ve_spc_clk_register(cpu_dev); 565 if (IS_ERR(clk)) { 566 pr_warn("failed to register cpu%d clock\n", cpu); 567 continue; 568 } 569 if (clk_register_clkdev(clk, NULL, dev_name(cpu_dev))) { 570 pr_warn("failed to register cpu%d clock lookup\n", cpu); 571 continue; 572 } 573 574 cluster = topology_physical_package_id(cpu_dev->id); 575 if (cluster < 0 || init_opp_table[cluster]) 576 continue; 577 578 if (ve_init_opp_table(cpu_dev)) 579 pr_warn("failed to initialise cpu%d opp table\n", cpu); 580 else if (dev_pm_opp_set_sharing_cpus(cpu_dev, 581 topology_core_cpumask(cpu_dev->id))) 582 pr_warn("failed to mark OPPs shared for cpu%d\n", cpu); 583 else 584 init_opp_table[cluster] = true; 585 } 586 587 platform_device_register_simple("vexpress-spc-cpufreq", -1, NULL, 0); 588 return 0; 589 } 590 device_initcall(ve_spc_clk_init); 591