1 /* 2 * AXI clkgen driver 3 * 4 * Copyright 2012-2013 Analog Devices Inc. 5 * Author: Lars-Peter Clausen <lars@metafoo.de> 6 * 7 * Licensed under the GPL-2. 8 * 9 */ 10 11 #include <linux/platform_device.h> 12 #include <linux/clk-provider.h> 13 #include <linux/clk.h> 14 #include <linux/slab.h> 15 #include <linux/io.h> 16 #include <linux/of.h> 17 #include <linux/module.h> 18 #include <linux/err.h> 19 20 #define AXI_CLKGEN_V1_REG_UPDATE_ENABLE 0x04 21 #define AXI_CLKGEN_V1_REG_CLK_OUT1 0x08 22 #define AXI_CLKGEN_V1_REG_CLK_OUT2 0x0c 23 #define AXI_CLKGEN_V1_REG_CLK_DIV 0x10 24 #define AXI_CLKGEN_V1_REG_CLK_FB1 0x14 25 #define AXI_CLKGEN_V1_REG_CLK_FB2 0x18 26 #define AXI_CLKGEN_V1_REG_LOCK1 0x1c 27 #define AXI_CLKGEN_V1_REG_LOCK2 0x20 28 #define AXI_CLKGEN_V1_REG_LOCK3 0x24 29 #define AXI_CLKGEN_V1_REG_FILTER1 0x28 30 #define AXI_CLKGEN_V1_REG_FILTER2 0x2c 31 32 #define AXI_CLKGEN_V2_REG_RESET 0x40 33 #define AXI_CLKGEN_V2_REG_DRP_CNTRL 0x70 34 #define AXI_CLKGEN_V2_REG_DRP_STATUS 0x74 35 36 #define AXI_CLKGEN_V2_RESET_MMCM_ENABLE BIT(1) 37 #define AXI_CLKGEN_V2_RESET_ENABLE BIT(0) 38 39 #define AXI_CLKGEN_V2_DRP_CNTRL_SEL BIT(29) 40 #define AXI_CLKGEN_V2_DRP_CNTRL_READ BIT(28) 41 42 #define AXI_CLKGEN_V2_DRP_STATUS_BUSY BIT(16) 43 44 #define MMCM_REG_CLKOUT0_1 0x08 45 #define MMCM_REG_CLKOUT0_2 0x09 46 #define MMCM_REG_CLK_FB1 0x14 47 #define MMCM_REG_CLK_FB2 0x15 48 #define MMCM_REG_CLK_DIV 0x16 49 #define MMCM_REG_LOCK1 0x18 50 #define MMCM_REG_LOCK2 0x19 51 #define MMCM_REG_LOCK3 0x1a 52 #define MMCM_REG_FILTER1 0x4e 53 #define MMCM_REG_FILTER2 0x4f 54 55 struct axi_clkgen; 56 57 struct axi_clkgen_mmcm_ops { 58 void (*enable)(struct axi_clkgen *axi_clkgen, bool enable); 59 int (*write)(struct axi_clkgen *axi_clkgen, unsigned int reg, 60 unsigned int val, unsigned int mask); 61 int (*read)(struct axi_clkgen *axi_clkgen, unsigned int reg, 62 unsigned int *val); 63 }; 64 65 struct axi_clkgen { 66 void __iomem *base; 67 const struct axi_clkgen_mmcm_ops *mmcm_ops; 68 struct clk_hw clk_hw; 69 }; 70 71 static void axi_clkgen_mmcm_enable(struct axi_clkgen *axi_clkgen, 72 bool enable) 73 { 74 axi_clkgen->mmcm_ops->enable(axi_clkgen, enable); 75 } 76 77 static int axi_clkgen_mmcm_write(struct axi_clkgen *axi_clkgen, 78 unsigned int reg, unsigned int val, unsigned int mask) 79 { 80 return axi_clkgen->mmcm_ops->write(axi_clkgen, reg, val, mask); 81 } 82 83 static int axi_clkgen_mmcm_read(struct axi_clkgen *axi_clkgen, 84 unsigned int reg, unsigned int *val) 85 { 86 return axi_clkgen->mmcm_ops->read(axi_clkgen, reg, val); 87 } 88 89 static uint32_t axi_clkgen_lookup_filter(unsigned int m) 90 { 91 switch (m) { 92 case 0: 93 return 0x01001990; 94 case 1: 95 return 0x01001190; 96 case 2: 97 return 0x01009890; 98 case 3: 99 return 0x01001890; 100 case 4: 101 return 0x01008890; 102 case 5 ... 8: 103 return 0x01009090; 104 case 9 ... 11: 105 return 0x01000890; 106 case 12: 107 return 0x08009090; 108 case 13 ... 22: 109 return 0x01001090; 110 case 23 ... 36: 111 return 0x01008090; 112 case 37 ... 46: 113 return 0x08001090; 114 default: 115 return 0x08008090; 116 } 117 } 118 119 static const uint32_t axi_clkgen_lock_table[] = { 120 0x060603e8, 0x060603e8, 0x080803e8, 0x0b0b03e8, 121 0x0e0e03e8, 0x111103e8, 0x131303e8, 0x161603e8, 122 0x191903e8, 0x1c1c03e8, 0x1f1f0384, 0x1f1f0339, 123 0x1f1f02ee, 0x1f1f02bc, 0x1f1f028a, 0x1f1f0271, 124 0x1f1f023f, 0x1f1f0226, 0x1f1f020d, 0x1f1f01f4, 125 0x1f1f01db, 0x1f1f01c2, 0x1f1f01a9, 0x1f1f0190, 126 0x1f1f0190, 0x1f1f0177, 0x1f1f015e, 0x1f1f015e, 127 0x1f1f0145, 0x1f1f0145, 0x1f1f012c, 0x1f1f012c, 128 0x1f1f012c, 0x1f1f0113, 0x1f1f0113, 0x1f1f0113, 129 }; 130 131 static uint32_t axi_clkgen_lookup_lock(unsigned int m) 132 { 133 if (m < ARRAY_SIZE(axi_clkgen_lock_table)) 134 return axi_clkgen_lock_table[m]; 135 return 0x1f1f00fa; 136 } 137 138 static const unsigned int fpfd_min = 10000; 139 static const unsigned int fpfd_max = 300000; 140 static const unsigned int fvco_min = 600000; 141 static const unsigned int fvco_max = 1200000; 142 143 static void axi_clkgen_calc_params(unsigned long fin, unsigned long fout, 144 unsigned int *best_d, unsigned int *best_m, unsigned int *best_dout) 145 { 146 unsigned long d, d_min, d_max, _d_min, _d_max; 147 unsigned long m, m_min, m_max; 148 unsigned long f, dout, best_f, fvco; 149 150 fin /= 1000; 151 fout /= 1000; 152 153 best_f = ULONG_MAX; 154 *best_d = 0; 155 *best_m = 0; 156 *best_dout = 0; 157 158 d_min = max_t(unsigned long, DIV_ROUND_UP(fin, fpfd_max), 1); 159 d_max = min_t(unsigned long, fin / fpfd_min, 80); 160 161 m_min = max_t(unsigned long, DIV_ROUND_UP(fvco_min, fin) * d_min, 1); 162 m_max = min_t(unsigned long, fvco_max * d_max / fin, 64); 163 164 for (m = m_min; m <= m_max; m++) { 165 _d_min = max(d_min, DIV_ROUND_UP(fin * m, fvco_max)); 166 _d_max = min(d_max, fin * m / fvco_min); 167 168 for (d = _d_min; d <= _d_max; d++) { 169 fvco = fin * m / d; 170 171 dout = DIV_ROUND_CLOSEST(fvco, fout); 172 dout = clamp_t(unsigned long, dout, 1, 128); 173 f = fvco / dout; 174 if (abs(f - fout) < abs(best_f - fout)) { 175 best_f = f; 176 *best_d = d; 177 *best_m = m; 178 *best_dout = dout; 179 if (best_f == fout) 180 return; 181 } 182 } 183 } 184 } 185 186 static void axi_clkgen_calc_clk_params(unsigned int divider, unsigned int *low, 187 unsigned int *high, unsigned int *edge, unsigned int *nocount) 188 { 189 if (divider == 1) 190 *nocount = 1; 191 else 192 *nocount = 0; 193 194 *high = divider / 2; 195 *edge = divider % 2; 196 *low = divider - *high; 197 } 198 199 static void axi_clkgen_write(struct axi_clkgen *axi_clkgen, 200 unsigned int reg, unsigned int val) 201 { 202 writel(val, axi_clkgen->base + reg); 203 } 204 205 static void axi_clkgen_read(struct axi_clkgen *axi_clkgen, 206 unsigned int reg, unsigned int *val) 207 { 208 *val = readl(axi_clkgen->base + reg); 209 } 210 211 static unsigned int axi_clkgen_v1_map_mmcm_reg(unsigned int reg) 212 { 213 switch (reg) { 214 case MMCM_REG_CLKOUT0_1: 215 return AXI_CLKGEN_V1_REG_CLK_OUT1; 216 case MMCM_REG_CLKOUT0_2: 217 return AXI_CLKGEN_V1_REG_CLK_OUT2; 218 case MMCM_REG_CLK_FB1: 219 return AXI_CLKGEN_V1_REG_CLK_FB1; 220 case MMCM_REG_CLK_FB2: 221 return AXI_CLKGEN_V1_REG_CLK_FB2; 222 case MMCM_REG_CLK_DIV: 223 return AXI_CLKGEN_V1_REG_CLK_DIV; 224 case MMCM_REG_LOCK1: 225 return AXI_CLKGEN_V1_REG_LOCK1; 226 case MMCM_REG_LOCK2: 227 return AXI_CLKGEN_V1_REG_LOCK2; 228 case MMCM_REG_LOCK3: 229 return AXI_CLKGEN_V1_REG_LOCK3; 230 case MMCM_REG_FILTER1: 231 return AXI_CLKGEN_V1_REG_FILTER1; 232 case MMCM_REG_FILTER2: 233 return AXI_CLKGEN_V1_REG_FILTER2; 234 default: 235 return 0; 236 } 237 } 238 239 static int axi_clkgen_v1_mmcm_write(struct axi_clkgen *axi_clkgen, 240 unsigned int reg, unsigned int val, unsigned int mask) 241 { 242 reg = axi_clkgen_v1_map_mmcm_reg(reg); 243 if (reg == 0) 244 return -EINVAL; 245 246 axi_clkgen_write(axi_clkgen, reg, val); 247 248 return 0; 249 } 250 251 static int axi_clkgen_v1_mmcm_read(struct axi_clkgen *axi_clkgen, 252 unsigned int reg, unsigned int *val) 253 { 254 reg = axi_clkgen_v1_map_mmcm_reg(reg); 255 if (reg == 0) 256 return -EINVAL; 257 258 axi_clkgen_read(axi_clkgen, reg, val); 259 260 return 0; 261 } 262 263 static void axi_clkgen_v1_mmcm_enable(struct axi_clkgen *axi_clkgen, 264 bool enable) 265 { 266 axi_clkgen_write(axi_clkgen, AXI_CLKGEN_V1_REG_UPDATE_ENABLE, enable); 267 } 268 269 static const struct axi_clkgen_mmcm_ops axi_clkgen_v1_mmcm_ops = { 270 .write = axi_clkgen_v1_mmcm_write, 271 .read = axi_clkgen_v1_mmcm_read, 272 .enable = axi_clkgen_v1_mmcm_enable, 273 }; 274 275 static int axi_clkgen_wait_non_busy(struct axi_clkgen *axi_clkgen) 276 { 277 unsigned int timeout = 10000; 278 unsigned int val; 279 280 do { 281 axi_clkgen_read(axi_clkgen, AXI_CLKGEN_V2_REG_DRP_STATUS, &val); 282 } while ((val & AXI_CLKGEN_V2_DRP_STATUS_BUSY) && --timeout); 283 284 if (val & AXI_CLKGEN_V2_DRP_STATUS_BUSY) 285 return -EIO; 286 287 return val & 0xffff; 288 } 289 290 static int axi_clkgen_v2_mmcm_read(struct axi_clkgen *axi_clkgen, 291 unsigned int reg, unsigned int *val) 292 { 293 unsigned int reg_val; 294 int ret; 295 296 ret = axi_clkgen_wait_non_busy(axi_clkgen); 297 if (ret < 0) 298 return ret; 299 300 reg_val = AXI_CLKGEN_V2_DRP_CNTRL_SEL | AXI_CLKGEN_V2_DRP_CNTRL_READ; 301 reg_val |= (reg << 16); 302 303 axi_clkgen_write(axi_clkgen, AXI_CLKGEN_V2_REG_DRP_CNTRL, reg_val); 304 305 ret = axi_clkgen_wait_non_busy(axi_clkgen); 306 if (ret < 0) 307 return ret; 308 309 *val = ret; 310 311 return 0; 312 } 313 314 static int axi_clkgen_v2_mmcm_write(struct axi_clkgen *axi_clkgen, 315 unsigned int reg, unsigned int val, unsigned int mask) 316 { 317 unsigned int reg_val = 0; 318 int ret; 319 320 ret = axi_clkgen_wait_non_busy(axi_clkgen); 321 if (ret < 0) 322 return ret; 323 324 if (mask != 0xffff) { 325 axi_clkgen_v2_mmcm_read(axi_clkgen, reg, ®_val); 326 reg_val &= ~mask; 327 } 328 329 reg_val |= AXI_CLKGEN_V2_DRP_CNTRL_SEL | (reg << 16) | (val & mask); 330 331 axi_clkgen_write(axi_clkgen, AXI_CLKGEN_V2_REG_DRP_CNTRL, reg_val); 332 333 return 0; 334 } 335 336 static void axi_clkgen_v2_mmcm_enable(struct axi_clkgen *axi_clkgen, 337 bool enable) 338 { 339 unsigned int val = AXI_CLKGEN_V2_RESET_ENABLE; 340 341 if (enable) 342 val |= AXI_CLKGEN_V2_RESET_MMCM_ENABLE; 343 344 axi_clkgen_write(axi_clkgen, AXI_CLKGEN_V2_REG_RESET, val); 345 } 346 347 static const struct axi_clkgen_mmcm_ops axi_clkgen_v2_mmcm_ops = { 348 .write = axi_clkgen_v2_mmcm_write, 349 .read = axi_clkgen_v2_mmcm_read, 350 .enable = axi_clkgen_v2_mmcm_enable, 351 }; 352 353 static struct axi_clkgen *clk_hw_to_axi_clkgen(struct clk_hw *clk_hw) 354 { 355 return container_of(clk_hw, struct axi_clkgen, clk_hw); 356 } 357 358 static int axi_clkgen_set_rate(struct clk_hw *clk_hw, 359 unsigned long rate, unsigned long parent_rate) 360 { 361 struct axi_clkgen *axi_clkgen = clk_hw_to_axi_clkgen(clk_hw); 362 unsigned int d, m, dout; 363 unsigned int nocount; 364 unsigned int high; 365 unsigned int edge; 366 unsigned int low; 367 uint32_t filter; 368 uint32_t lock; 369 370 if (parent_rate == 0 || rate == 0) 371 return -EINVAL; 372 373 axi_clkgen_calc_params(parent_rate, rate, &d, &m, &dout); 374 375 if (d == 0 || dout == 0 || m == 0) 376 return -EINVAL; 377 378 filter = axi_clkgen_lookup_filter(m - 1); 379 lock = axi_clkgen_lookup_lock(m - 1); 380 381 axi_clkgen_calc_clk_params(dout, &low, &high, &edge, &nocount); 382 axi_clkgen_mmcm_write(axi_clkgen, MMCM_REG_CLKOUT0_1, 383 (high << 6) | low, 0xefff); 384 axi_clkgen_mmcm_write(axi_clkgen, MMCM_REG_CLKOUT0_2, 385 (edge << 7) | (nocount << 6), 0x03ff); 386 387 axi_clkgen_calc_clk_params(d, &low, &high, &edge, &nocount); 388 axi_clkgen_mmcm_write(axi_clkgen, MMCM_REG_CLK_DIV, 389 (edge << 13) | (nocount << 12) | (high << 6) | low, 0x3fff); 390 391 axi_clkgen_calc_clk_params(m, &low, &high, &edge, &nocount); 392 axi_clkgen_mmcm_write(axi_clkgen, MMCM_REG_CLK_FB1, 393 (high << 6) | low, 0xefff); 394 axi_clkgen_mmcm_write(axi_clkgen, MMCM_REG_CLK_FB2, 395 (edge << 7) | (nocount << 6), 0x03ff); 396 397 axi_clkgen_mmcm_write(axi_clkgen, MMCM_REG_LOCK1, lock & 0x3ff, 0x3ff); 398 axi_clkgen_mmcm_write(axi_clkgen, MMCM_REG_LOCK2, 399 (((lock >> 16) & 0x1f) << 10) | 0x1, 0x7fff); 400 axi_clkgen_mmcm_write(axi_clkgen, MMCM_REG_LOCK3, 401 (((lock >> 24) & 0x1f) << 10) | 0x3e9, 0x7fff); 402 axi_clkgen_mmcm_write(axi_clkgen, MMCM_REG_FILTER1, filter >> 16, 0x9900); 403 axi_clkgen_mmcm_write(axi_clkgen, MMCM_REG_FILTER2, filter, 0x9900); 404 405 return 0; 406 } 407 408 static long axi_clkgen_round_rate(struct clk_hw *hw, unsigned long rate, 409 unsigned long *parent_rate) 410 { 411 unsigned int d, m, dout; 412 413 axi_clkgen_calc_params(*parent_rate, rate, &d, &m, &dout); 414 415 if (d == 0 || dout == 0 || m == 0) 416 return -EINVAL; 417 418 return *parent_rate / d * m / dout; 419 } 420 421 static unsigned long axi_clkgen_recalc_rate(struct clk_hw *clk_hw, 422 unsigned long parent_rate) 423 { 424 struct axi_clkgen *axi_clkgen = clk_hw_to_axi_clkgen(clk_hw); 425 unsigned int d, m, dout; 426 unsigned int reg; 427 unsigned long long tmp; 428 429 axi_clkgen_mmcm_read(axi_clkgen, MMCM_REG_CLKOUT0_1, ®); 430 dout = (reg & 0x3f) + ((reg >> 6) & 0x3f); 431 axi_clkgen_mmcm_read(axi_clkgen, MMCM_REG_CLK_DIV, ®); 432 d = (reg & 0x3f) + ((reg >> 6) & 0x3f); 433 axi_clkgen_mmcm_read(axi_clkgen, MMCM_REG_CLK_FB1, ®); 434 m = (reg & 0x3f) + ((reg >> 6) & 0x3f); 435 436 if (d == 0 || dout == 0) 437 return 0; 438 439 tmp = (unsigned long long)(parent_rate / d) * m; 440 do_div(tmp, dout); 441 442 if (tmp > ULONG_MAX) 443 return ULONG_MAX; 444 445 return tmp; 446 } 447 448 static int axi_clkgen_enable(struct clk_hw *clk_hw) 449 { 450 struct axi_clkgen *axi_clkgen = clk_hw_to_axi_clkgen(clk_hw); 451 452 axi_clkgen_mmcm_enable(axi_clkgen, true); 453 454 return 0; 455 } 456 457 static void axi_clkgen_disable(struct clk_hw *clk_hw) 458 { 459 struct axi_clkgen *axi_clkgen = clk_hw_to_axi_clkgen(clk_hw); 460 461 axi_clkgen_mmcm_enable(axi_clkgen, false); 462 } 463 464 static const struct clk_ops axi_clkgen_ops = { 465 .recalc_rate = axi_clkgen_recalc_rate, 466 .round_rate = axi_clkgen_round_rate, 467 .set_rate = axi_clkgen_set_rate, 468 .enable = axi_clkgen_enable, 469 .disable = axi_clkgen_disable, 470 }; 471 472 static const struct of_device_id axi_clkgen_ids[] = { 473 { 474 .compatible = "adi,axi-clkgen-1.00.a", 475 .data = &axi_clkgen_v1_mmcm_ops 476 }, { 477 .compatible = "adi,axi-clkgen-2.00.a", 478 .data = &axi_clkgen_v2_mmcm_ops, 479 }, 480 { }, 481 }; 482 MODULE_DEVICE_TABLE(of, axi_clkgen_ids); 483 484 static int axi_clkgen_probe(struct platform_device *pdev) 485 { 486 const struct of_device_id *id; 487 struct axi_clkgen *axi_clkgen; 488 struct clk_init_data init; 489 const char *parent_name; 490 const char *clk_name; 491 struct resource *mem; 492 struct clk *clk; 493 494 if (!pdev->dev.of_node) 495 return -ENODEV; 496 497 id = of_match_node(axi_clkgen_ids, pdev->dev.of_node); 498 if (!id) 499 return -ENODEV; 500 501 axi_clkgen = devm_kzalloc(&pdev->dev, sizeof(*axi_clkgen), GFP_KERNEL); 502 if (!axi_clkgen) 503 return -ENOMEM; 504 505 axi_clkgen->mmcm_ops = id->data; 506 507 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 508 axi_clkgen->base = devm_ioremap_resource(&pdev->dev, mem); 509 if (IS_ERR(axi_clkgen->base)) 510 return PTR_ERR(axi_clkgen->base); 511 512 parent_name = of_clk_get_parent_name(pdev->dev.of_node, 0); 513 if (!parent_name) 514 return -EINVAL; 515 516 clk_name = pdev->dev.of_node->name; 517 of_property_read_string(pdev->dev.of_node, "clock-output-names", 518 &clk_name); 519 520 init.name = clk_name; 521 init.ops = &axi_clkgen_ops; 522 init.flags = CLK_SET_RATE_GATE; 523 init.parent_names = &parent_name; 524 init.num_parents = 1; 525 526 axi_clkgen_mmcm_enable(axi_clkgen, false); 527 528 axi_clkgen->clk_hw.init = &init; 529 clk = devm_clk_register(&pdev->dev, &axi_clkgen->clk_hw); 530 if (IS_ERR(clk)) 531 return PTR_ERR(clk); 532 533 return of_clk_add_provider(pdev->dev.of_node, of_clk_src_simple_get, 534 clk); 535 } 536 537 static int axi_clkgen_remove(struct platform_device *pdev) 538 { 539 of_clk_del_provider(pdev->dev.of_node); 540 541 return 0; 542 } 543 544 static struct platform_driver axi_clkgen_driver = { 545 .driver = { 546 .name = "adi-axi-clkgen", 547 .of_match_table = axi_clkgen_ids, 548 }, 549 .probe = axi_clkgen_probe, 550 .remove = axi_clkgen_remove, 551 }; 552 module_platform_driver(axi_clkgen_driver); 553 554 MODULE_LICENSE("GPL v2"); 555 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); 556 MODULE_DESCRIPTION("Driver for the Analog Devices' AXI clkgen pcore clock generator"); 557