1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Driver for the ICST307 VCO clock found in the ARM Reference designs. 4 * We wrap the custom interface from <asm/hardware/icst.h> into the generic 5 * clock framework. 6 * 7 * Copyright (C) 2012-2015 Linus Walleij 8 * 9 * TODO: when all ARM reference designs are migrated to generic clocks, the 10 * ICST clock code from the ARM tree should probably be merged into this 11 * file. 12 */ 13 #include <linux/kernel.h> 14 #include <linux/slab.h> 15 #include <linux/export.h> 16 #include <linux/err.h> 17 #include <linux/clk-provider.h> 18 #include <linux/io.h> 19 #include <linux/regmap.h> 20 #include <linux/mfd/syscon.h> 21 22 #include "icst.h" 23 #include "clk-icst.h" 24 25 /* Magic unlocking token used on all Versatile boards */ 26 #define VERSATILE_LOCK_VAL 0xA05F 27 28 #define VERSATILE_AUX_OSC_BITS 0x7FFFF 29 #define INTEGRATOR_AP_CM_BITS 0xFF 30 #define INTEGRATOR_AP_SYS_BITS 0xFF 31 #define INTEGRATOR_CP_CM_CORE_BITS 0x7FF 32 #define INTEGRATOR_CP_CM_MEM_BITS 0x7FF000 33 34 #define INTEGRATOR_AP_PCI_25_33_MHZ BIT(8) 35 36 /** 37 * struct clk_icst - ICST VCO clock wrapper 38 * @hw: corresponding clock hardware entry 39 * @map: register map 40 * @vcoreg_off: VCO register address 41 * @lockreg_off: VCO lock register address 42 * @params: parameters for this ICST instance 43 * @rate: current rate 44 * @ctype: the type of control register for the ICST 45 */ 46 struct clk_icst { 47 struct clk_hw hw; 48 struct regmap *map; 49 u32 vcoreg_off; 50 u32 lockreg_off; 51 struct icst_params *params; 52 unsigned long rate; 53 enum icst_control_type ctype; 54 }; 55 56 #define to_icst(_hw) container_of(_hw, struct clk_icst, hw) 57 58 /** 59 * vco_get() - get ICST VCO settings from a certain ICST 60 * @icst: the ICST clock to get 61 * @vco: the VCO struct to return the value in 62 */ 63 static int vco_get(struct clk_icst *icst, struct icst_vco *vco) 64 { 65 u32 val; 66 int ret; 67 68 ret = regmap_read(icst->map, icst->vcoreg_off, &val); 69 if (ret) 70 return ret; 71 72 /* 73 * The Integrator/AP core clock can only access the low eight 74 * bits of the v PLL divider. Bit 8 is tied low and always zero, 75 * r is hardwired to 22 and output divider s is hardwired to 1 76 * (divide by 2) according to the document 77 * "Integrator CM926EJ-S, CM946E-S, CM966E-S, CM1026EJ-S and 78 * CM1136JF-S User Guide" ARM DUI 0138E, page 3-13 thru 3-14. 79 */ 80 if (icst->ctype == ICST_INTEGRATOR_AP_CM) { 81 vco->v = val & INTEGRATOR_AP_CM_BITS; 82 vco->r = 22; 83 vco->s = 1; 84 return 0; 85 } 86 87 /* 88 * The Integrator/AP system clock on the base board can only 89 * access the low eight bits of the v PLL divider. Bit 8 is tied low 90 * and always zero, r is hardwired to 46, and the output divider is 91 * hardwired to 3 (divide by 4) according to the document 92 * "Integrator AP ASIC Development Motherboard" ARM DUI 0098B, 93 * page 3-16. 94 */ 95 if (icst->ctype == ICST_INTEGRATOR_AP_SYS) { 96 vco->v = val & INTEGRATOR_AP_SYS_BITS; 97 vco->r = 46; 98 vco->s = 3; 99 return 0; 100 } 101 102 /* 103 * The Integrator/AP PCI clock is using an odd pattern to create 104 * the child clock, basically a single bit called DIVX/Y is used 105 * to select between two different hardwired values: setting the 106 * bit to 0 yields v = 17, r = 22 and OD = 1, whereas setting the 107 * bit to 1 yields v = 14, r = 14 and OD = 1 giving the frequencies 108 * 33 or 25 MHz respectively. 109 */ 110 if (icst->ctype == ICST_INTEGRATOR_AP_PCI) { 111 bool divxy = !!(val & INTEGRATOR_AP_PCI_25_33_MHZ); 112 113 vco->v = divxy ? 17 : 14; 114 vco->r = divxy ? 22 : 14; 115 vco->s = 1; 116 return 0; 117 } 118 119 /* 120 * The Integrator/CP core clock can access the low eight bits 121 * of the v PLL divider. Bit 8 is tied low and always zero, 122 * r is hardwired to 22 and the output divider s is accessible 123 * in bits 8 thru 10 according to the document 124 * "Integrator/CM940T, CM920T, CM740T, and CM720T User Guide" 125 * ARM DUI 0157A, page 3-20 thru 3-23 and 4-10. 126 */ 127 if (icst->ctype == ICST_INTEGRATOR_CP_CM_CORE) { 128 vco->v = val & 0xFF; 129 vco->r = 22; 130 vco->s = (val >> 8) & 7; 131 return 0; 132 } 133 134 if (icst->ctype == ICST_INTEGRATOR_CP_CM_MEM) { 135 vco->v = (val >> 12) & 0xFF; 136 vco->r = 22; 137 vco->s = (val >> 20) & 7; 138 return 0; 139 } 140 141 vco->v = val & 0x1ff; 142 vco->r = (val >> 9) & 0x7f; 143 vco->s = (val >> 16) & 03; 144 return 0; 145 } 146 147 /** 148 * vco_set() - commit changes to an ICST VCO 149 * @icst: the ICST clock to set 150 * @vco: the VCO struct to set the changes from 151 */ 152 static int vco_set(struct clk_icst *icst, struct icst_vco vco) 153 { 154 u32 mask; 155 u32 val; 156 int ret; 157 158 /* Mask the bits used by the VCO */ 159 switch (icst->ctype) { 160 case ICST_INTEGRATOR_AP_CM: 161 mask = INTEGRATOR_AP_CM_BITS; 162 val = vco.v & 0xFF; 163 if (vco.v & 0x100) 164 pr_err("ICST error: tried to set bit 8 of VDW\n"); 165 if (vco.s != 1) 166 pr_err("ICST error: tried to use VOD != 1\n"); 167 if (vco.r != 22) 168 pr_err("ICST error: tried to use RDW != 22\n"); 169 break; 170 case ICST_INTEGRATOR_AP_SYS: 171 mask = INTEGRATOR_AP_SYS_BITS; 172 val = vco.v & 0xFF; 173 if (vco.v & 0x100) 174 pr_err("ICST error: tried to set bit 8 of VDW\n"); 175 if (vco.s != 3) 176 pr_err("ICST error: tried to use VOD != 1\n"); 177 if (vco.r != 46) 178 pr_err("ICST error: tried to use RDW != 22\n"); 179 break; 180 case ICST_INTEGRATOR_CP_CM_CORE: 181 mask = INTEGRATOR_CP_CM_CORE_BITS; /* Uses 12 bits */ 182 val = (vco.v & 0xFF) | vco.s << 8; 183 if (vco.v & 0x100) 184 pr_err("ICST error: tried to set bit 8 of VDW\n"); 185 if (vco.r != 22) 186 pr_err("ICST error: tried to use RDW != 22\n"); 187 break; 188 case ICST_INTEGRATOR_CP_CM_MEM: 189 mask = INTEGRATOR_CP_CM_MEM_BITS; /* Uses 12 bits */ 190 val = ((vco.v & 0xFF) << 12) | (vco.s << 20); 191 if (vco.v & 0x100) 192 pr_err("ICST error: tried to set bit 8 of VDW\n"); 193 if (vco.r != 22) 194 pr_err("ICST error: tried to use RDW != 22\n"); 195 break; 196 default: 197 /* Regular auxilary oscillator */ 198 mask = VERSATILE_AUX_OSC_BITS; 199 val = vco.v | (vco.r << 9) | (vco.s << 16); 200 break; 201 } 202 203 pr_debug("ICST: new val = 0x%08x\n", val); 204 205 /* This magic unlocks the VCO so it can be controlled */ 206 ret = regmap_write(icst->map, icst->lockreg_off, VERSATILE_LOCK_VAL); 207 if (ret) 208 return ret; 209 ret = regmap_update_bits(icst->map, icst->vcoreg_off, mask, val); 210 if (ret) 211 return ret; 212 /* This locks the VCO again */ 213 ret = regmap_write(icst->map, icst->lockreg_off, 0); 214 if (ret) 215 return ret; 216 return 0; 217 } 218 219 static unsigned long icst_recalc_rate(struct clk_hw *hw, 220 unsigned long parent_rate) 221 { 222 struct clk_icst *icst = to_icst(hw); 223 struct icst_vco vco; 224 int ret; 225 226 if (parent_rate) 227 icst->params->ref = parent_rate; 228 ret = vco_get(icst, &vco); 229 if (ret) { 230 pr_err("ICST: could not get VCO setting\n"); 231 return 0; 232 } 233 icst->rate = icst_hz(icst->params, vco); 234 return icst->rate; 235 } 236 237 static long icst_round_rate(struct clk_hw *hw, unsigned long rate, 238 unsigned long *prate) 239 { 240 struct clk_icst *icst = to_icst(hw); 241 struct icst_vco vco; 242 243 if (icst->ctype == ICST_INTEGRATOR_AP_CM || 244 icst->ctype == ICST_INTEGRATOR_CP_CM_CORE) { 245 if (rate <= 12000000) 246 return 12000000; 247 if (rate >= 160000000) 248 return 160000000; 249 /* Slam to closest megahertz */ 250 return DIV_ROUND_CLOSEST(rate, 1000000) * 1000000; 251 } 252 253 if (icst->ctype == ICST_INTEGRATOR_CP_CM_MEM) { 254 if (rate <= 6000000) 255 return 6000000; 256 if (rate >= 66000000) 257 return 66000000; 258 /* Slam to closest 0.5 megahertz */ 259 return DIV_ROUND_CLOSEST(rate, 500000) * 500000; 260 } 261 262 if (icst->ctype == ICST_INTEGRATOR_AP_SYS) { 263 /* Divides between 3 and 50 MHz in steps of 0.25 MHz */ 264 if (rate <= 3000000) 265 return 3000000; 266 if (rate >= 50000000) 267 return 5000000; 268 /* Slam to closest 0.25 MHz */ 269 return DIV_ROUND_CLOSEST(rate, 250000) * 250000; 270 } 271 272 if (icst->ctype == ICST_INTEGRATOR_AP_PCI) { 273 /* 274 * If we're below or less than halfway from 25 to 33 MHz 275 * select 25 MHz 276 */ 277 if (rate <= 25000000 || rate < 29000000) 278 return 25000000; 279 /* Else just return the default frequency */ 280 return 33000000; 281 } 282 283 vco = icst_hz_to_vco(icst->params, rate); 284 return icst_hz(icst->params, vco); 285 } 286 287 static int icst_set_rate(struct clk_hw *hw, unsigned long rate, 288 unsigned long parent_rate) 289 { 290 struct clk_icst *icst = to_icst(hw); 291 struct icst_vco vco; 292 293 if (icst->ctype == ICST_INTEGRATOR_AP_PCI) { 294 /* This clock is especially primitive */ 295 unsigned int val; 296 int ret; 297 298 if (rate == 25000000) { 299 val = 0; 300 } else if (rate == 33000000) { 301 val = INTEGRATOR_AP_PCI_25_33_MHZ; 302 } else { 303 pr_err("ICST: cannot set PCI frequency %lu\n", 304 rate); 305 return -EINVAL; 306 } 307 ret = regmap_write(icst->map, icst->lockreg_off, 308 VERSATILE_LOCK_VAL); 309 if (ret) 310 return ret; 311 ret = regmap_update_bits(icst->map, icst->vcoreg_off, 312 INTEGRATOR_AP_PCI_25_33_MHZ, 313 val); 314 if (ret) 315 return ret; 316 /* This locks the VCO again */ 317 ret = regmap_write(icst->map, icst->lockreg_off, 0); 318 if (ret) 319 return ret; 320 return 0; 321 } 322 323 if (parent_rate) 324 icst->params->ref = parent_rate; 325 vco = icst_hz_to_vco(icst->params, rate); 326 icst->rate = icst_hz(icst->params, vco); 327 return vco_set(icst, vco); 328 } 329 330 static const struct clk_ops icst_ops = { 331 .recalc_rate = icst_recalc_rate, 332 .round_rate = icst_round_rate, 333 .set_rate = icst_set_rate, 334 }; 335 336 struct clk *icst_clk_setup(struct device *dev, 337 const struct clk_icst_desc *desc, 338 const char *name, 339 const char *parent_name, 340 struct regmap *map, 341 enum icst_control_type ctype) 342 { 343 struct clk *clk; 344 struct clk_icst *icst; 345 struct clk_init_data init; 346 struct icst_params *pclone; 347 348 icst = kzalloc(sizeof(*icst), GFP_KERNEL); 349 if (!icst) 350 return ERR_PTR(-ENOMEM); 351 352 pclone = kmemdup(desc->params, sizeof(*pclone), GFP_KERNEL); 353 if (!pclone) { 354 kfree(icst); 355 return ERR_PTR(-ENOMEM); 356 } 357 358 init.name = name; 359 init.ops = &icst_ops; 360 init.flags = 0; 361 init.parent_names = (parent_name ? &parent_name : NULL); 362 init.num_parents = (parent_name ? 1 : 0); 363 icst->map = map; 364 icst->hw.init = &init; 365 icst->params = pclone; 366 icst->vcoreg_off = desc->vco_offset; 367 icst->lockreg_off = desc->lock_offset; 368 icst->ctype = ctype; 369 370 clk = clk_register(dev, &icst->hw); 371 if (IS_ERR(clk)) { 372 kfree(pclone); 373 kfree(icst); 374 } 375 376 return clk; 377 } 378 EXPORT_SYMBOL_GPL(icst_clk_setup); 379 380 struct clk *icst_clk_register(struct device *dev, 381 const struct clk_icst_desc *desc, 382 const char *name, 383 const char *parent_name, 384 void __iomem *base) 385 { 386 struct regmap_config icst_regmap_conf = { 387 .reg_bits = 32, 388 .val_bits = 32, 389 .reg_stride = 4, 390 }; 391 struct regmap *map; 392 393 map = regmap_init_mmio(dev, base, &icst_regmap_conf); 394 if (IS_ERR(map)) { 395 pr_err("could not initialize ICST regmap\n"); 396 return ERR_CAST(map); 397 } 398 return icst_clk_setup(dev, desc, name, parent_name, map, 399 ICST_VERSATILE); 400 } 401 EXPORT_SYMBOL_GPL(icst_clk_register); 402 403 #ifdef CONFIG_OF 404 /* 405 * In a device tree, an memory-mapped ICST clock appear as a child 406 * of a syscon node. Assume this and probe it only as a child of a 407 * syscon. 408 */ 409 410 static const struct icst_params icst525_params = { 411 .vco_max = ICST525_VCO_MAX_5V, 412 .vco_min = ICST525_VCO_MIN, 413 .vd_min = 8, 414 .vd_max = 263, 415 .rd_min = 3, 416 .rd_max = 65, 417 .s2div = icst525_s2div, 418 .idx2s = icst525_idx2s, 419 }; 420 421 static const struct icst_params icst307_params = { 422 .vco_max = ICST307_VCO_MAX, 423 .vco_min = ICST307_VCO_MIN, 424 .vd_min = 4 + 8, 425 .vd_max = 511 + 8, 426 .rd_min = 1 + 2, 427 .rd_max = 127 + 2, 428 .s2div = icst307_s2div, 429 .idx2s = icst307_idx2s, 430 }; 431 432 /* 433 * The core modules on the Integrator/AP and Integrator/CP have 434 * especially crippled ICST525 control. 435 */ 436 static const struct icst_params icst525_apcp_cm_params = { 437 .vco_max = ICST525_VCO_MAX_5V, 438 .vco_min = ICST525_VCO_MIN, 439 /* Minimum 12 MHz, VDW = 4 */ 440 .vd_min = 12, 441 /* 442 * Maximum 160 MHz, VDW = 152 for all core modules, but 443 * CM926EJ-S, CM1026EJ-S and CM1136JF-S can actually 444 * go to 200 MHz (max VDW = 192). 445 */ 446 .vd_max = 192, 447 /* r is hardcoded to 22 and this is the actual divisor, +2 */ 448 .rd_min = 24, 449 .rd_max = 24, 450 .s2div = icst525_s2div, 451 .idx2s = icst525_idx2s, 452 }; 453 454 static const struct icst_params icst525_ap_sys_params = { 455 .vco_max = ICST525_VCO_MAX_5V, 456 .vco_min = ICST525_VCO_MIN, 457 /* Minimum 3 MHz, VDW = 4 */ 458 .vd_min = 3, 459 /* Maximum 50 MHz, VDW = 192 */ 460 .vd_max = 50, 461 /* r is hardcoded to 46 and this is the actual divisor, +2 */ 462 .rd_min = 48, 463 .rd_max = 48, 464 .s2div = icst525_s2div, 465 .idx2s = icst525_idx2s, 466 }; 467 468 static const struct icst_params icst525_ap_pci_params = { 469 .vco_max = ICST525_VCO_MAX_5V, 470 .vco_min = ICST525_VCO_MIN, 471 /* Minimum 25 MHz */ 472 .vd_min = 25, 473 /* Maximum 33 MHz */ 474 .vd_max = 33, 475 /* r is hardcoded to 14 or 22 and this is the actual divisors +2 */ 476 .rd_min = 16, 477 .rd_max = 24, 478 .s2div = icst525_s2div, 479 .idx2s = icst525_idx2s, 480 }; 481 482 static void __init of_syscon_icst_setup(struct device_node *np) 483 { 484 struct device_node *parent; 485 struct regmap *map; 486 struct clk_icst_desc icst_desc; 487 const char *name = np->name; 488 const char *parent_name; 489 struct clk *regclk; 490 enum icst_control_type ctype; 491 492 /* We do not release this reference, we are using it perpetually */ 493 parent = of_get_parent(np); 494 if (!parent) { 495 pr_err("no parent node for syscon ICST clock\n"); 496 return; 497 } 498 map = syscon_node_to_regmap(parent); 499 if (IS_ERR(map)) { 500 pr_err("no regmap for syscon ICST clock parent\n"); 501 return; 502 } 503 504 if (of_property_read_u32(np, "vco-offset", &icst_desc.vco_offset)) { 505 pr_err("no VCO register offset for ICST clock\n"); 506 return; 507 } 508 if (of_property_read_u32(np, "lock-offset", &icst_desc.lock_offset)) { 509 pr_err("no lock register offset for ICST clock\n"); 510 return; 511 } 512 513 if (of_device_is_compatible(np, "arm,syscon-icst525")) { 514 icst_desc.params = &icst525_params; 515 ctype = ICST_VERSATILE; 516 } else if (of_device_is_compatible(np, "arm,syscon-icst307")) { 517 icst_desc.params = &icst307_params; 518 ctype = ICST_VERSATILE; 519 } else if (of_device_is_compatible(np, "arm,syscon-icst525-integratorap-cm")) { 520 icst_desc.params = &icst525_apcp_cm_params; 521 ctype = ICST_INTEGRATOR_AP_CM; 522 } else if (of_device_is_compatible(np, "arm,syscon-icst525-integratorap-sys")) { 523 icst_desc.params = &icst525_ap_sys_params; 524 ctype = ICST_INTEGRATOR_AP_SYS; 525 } else if (of_device_is_compatible(np, "arm,syscon-icst525-integratorap-pci")) { 526 icst_desc.params = &icst525_ap_pci_params; 527 ctype = ICST_INTEGRATOR_AP_PCI; 528 } else if (of_device_is_compatible(np, "arm,syscon-icst525-integratorcp-cm-core")) { 529 icst_desc.params = &icst525_apcp_cm_params; 530 ctype = ICST_INTEGRATOR_CP_CM_CORE; 531 } else if (of_device_is_compatible(np, "arm,syscon-icst525-integratorcp-cm-mem")) { 532 icst_desc.params = &icst525_apcp_cm_params; 533 ctype = ICST_INTEGRATOR_CP_CM_MEM; 534 } else { 535 pr_err("unknown ICST clock %s\n", name); 536 return; 537 } 538 539 /* Parent clock name is not the same as node parent */ 540 parent_name = of_clk_get_parent_name(np, 0); 541 542 regclk = icst_clk_setup(NULL, &icst_desc, name, parent_name, map, ctype); 543 if (IS_ERR(regclk)) { 544 pr_err("error setting up syscon ICST clock %s\n", name); 545 return; 546 } 547 of_clk_add_provider(np, of_clk_src_simple_get, regclk); 548 pr_debug("registered syscon ICST clock %s\n", name); 549 } 550 551 CLK_OF_DECLARE(arm_syscon_icst525_clk, 552 "arm,syscon-icst525", of_syscon_icst_setup); 553 CLK_OF_DECLARE(arm_syscon_icst307_clk, 554 "arm,syscon-icst307", of_syscon_icst_setup); 555 CLK_OF_DECLARE(arm_syscon_integratorap_cm_clk, 556 "arm,syscon-icst525-integratorap-cm", of_syscon_icst_setup); 557 CLK_OF_DECLARE(arm_syscon_integratorap_sys_clk, 558 "arm,syscon-icst525-integratorap-sys", of_syscon_icst_setup); 559 CLK_OF_DECLARE(arm_syscon_integratorap_pci_clk, 560 "arm,syscon-icst525-integratorap-pci", of_syscon_icst_setup); 561 CLK_OF_DECLARE(arm_syscon_integratorcp_cm_core_clk, 562 "arm,syscon-icst525-integratorcp-cm-core", of_syscon_icst_setup); 563 CLK_OF_DECLARE(arm_syscon_integratorcp_cm_mem_clk, 564 "arm,syscon-icst525-integratorcp-cm-mem", of_syscon_icst_setup); 565 #endif 566