drivers/clk/at91/sckc.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * drivers/clk/at91/sckc.c
   4  *
   5  *  Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
   6  */
   7
   8 #include <linux/clk-provider.h>
   9 #include <linux/clkdev.h>
  10 #include <linux/delay.h>
  11 #include <linux/of.h>
  12 #include <linux/of_address.h>
  13 #include <linux/io.h>
  14
  15 #define SLOW_CLOCK_FREQ         32768
  16 #define SLOWCK_SW_CYCLES        5
  17 #define SLOWCK_SW_TIME_USEC     ((SLOWCK_SW_CYCLES * USEC_PER_SEC) / \
  18                                  SLOW_CLOCK_FREQ)
  19
  20 #define AT91_SCKC_CR                    0x00
  21
  22 struct clk_slow_bits {
  23         u32 cr_rcen;
  24         u32 cr_osc32en;
  25         u32 cr_osc32byp;
  26         u32 cr_oscsel;
  27 };
  28
  29 struct clk_slow_osc {
  30         struct clk_hw hw;
  31         void __iomem *sckcr;
  32         const struct clk_slow_bits *bits;
  33         unsigned long startup_usec;
  34 };
  35
  36 #define to_clk_slow_osc(hw) container_of(hw, struct clk_slow_osc, hw)
  37
  38 struct clk_sama5d4_slow_osc {
  39         struct clk_hw hw;
  40         void __iomem *sckcr;
  41         const struct clk_slow_bits *bits;
  42         unsigned long startup_usec;
  43         bool prepared;
  44 };
  45
  46 #define to_clk_sama5d4_slow_osc(hw) container_of(hw, struct clk_sama5d4_slow_osc, hw)
  47
  48 struct clk_slow_rc_osc {
  49         struct clk_hw hw;
  50         void __iomem *sckcr;
  51         const struct clk_slow_bits *bits;
  52         unsigned long frequency;
  53         unsigned long accuracy;
  54         unsigned long startup_usec;
  55 };
  56
  57 #define to_clk_slow_rc_osc(hw) container_of(hw, struct clk_slow_rc_osc, hw)
  58
  59 struct clk_sam9x5_slow {
  60         struct clk_hw hw;
  61         void __iomem *sckcr;
  62         const struct clk_slow_bits *bits;
  63         u8 parent;
  64 };
  65
  66 #define to_clk_sam9x5_slow(hw) container_of(hw, struct clk_sam9x5_slow, hw)
  67
  68 static int clk_slow_osc_prepare(struct clk_hw *hw)
  69 {
  70         struct clk_slow_osc *osc = to_clk_slow_osc(hw);
  71         void __iomem *sckcr = osc->sckcr;
  72         u32 tmp = readl(sckcr);
  73
  74         if (tmp & (osc->bits->cr_osc32byp | osc->bits->cr_osc32en))
  75                 return 0;
  76
  77         writel(tmp | osc->bits->cr_osc32en, sckcr);
  78
  79         if (system_state < SYSTEM_RUNNING)
  80                 udelay(osc->startup_usec);
  81         else
  82                 usleep_range(osc->startup_usec, osc->startup_usec + 1);
  83
  84         return 0;
  85 }
  86
  87 static void clk_slow_osc_unprepare(struct clk_hw *hw)
  88 {
  89         struct clk_slow_osc *osc = to_clk_slow_osc(hw);
  90         void __iomem *sckcr = osc->sckcr;
  91         u32 tmp = readl(sckcr);
  92
  93         if (tmp & osc->bits->cr_osc32byp)
  94                 return;
  95
  96         writel(tmp & ~osc->bits->cr_osc32en, sckcr);
  97 }
  98
  99 static int clk_slow_osc_is_prepared(struct clk_hw *hw)
 100 {
 101         struct clk_slow_osc *osc = to_clk_slow_osc(hw);
 102         void __iomem *sckcr = osc->sckcr;
 103         u32 tmp = readl(sckcr);
 104
 105         if (tmp & osc->bits->cr_osc32byp)
 106                 return 1;
 107
 108         return !!(tmp & osc->bits->cr_osc32en);
 109 }
 110
 111 static const struct clk_ops slow_osc_ops = {
 112         .prepare = clk_slow_osc_prepare,
 113         .unprepare = clk_slow_osc_unprepare,
 114         .is_prepared = clk_slow_osc_is_prepared,
 115 };
 116
 117 static struct clk_hw * __init
 118 at91_clk_register_slow_osc(void __iomem *sckcr,
 119                            const char *name,
 120                            const char *parent_name,
 121                            unsigned long startup,
 122                            bool bypass,
 123                            const struct clk_slow_bits *bits)
 124 {
 125         struct clk_slow_osc *osc;
 126         struct clk_hw *hw;
 127         struct clk_init_data init;
 128         int ret;
 129
 130         if (!sckcr || !name || !parent_name)
 131                 return ERR_PTR(-EINVAL);
 132
 133         osc = kzalloc(sizeof(*osc), GFP_KERNEL);
 134         if (!osc)
 135                 return ERR_PTR(-ENOMEM);
 136
 137         init.name = name;
 138         init.ops = &slow_osc_ops;
 139         init.parent_names = &parent_name;
 140         init.num_parents = 1;
 141         init.flags = CLK_IGNORE_UNUSED;
 142
 143         osc->hw.init = &init;
 144         osc->sckcr = sckcr;
 145         osc->startup_usec = startup;
 146         osc->bits = bits;
 147
 148         if (bypass)
 149                 writel((readl(sckcr) & ~osc->bits->cr_osc32en) |
 150                                         osc->bits->cr_osc32byp, sckcr);
 151
 152         hw = &osc->hw;
 153         ret = clk_hw_register(NULL, &osc->hw);
 154         if (ret) {
 155                 kfree(osc);
 156                 hw = ERR_PTR(ret);
 157         }
 158
 159         return hw;
 160 }
 161
 162 static void at91_clk_unregister_slow_osc(struct clk_hw *hw)
 163 {
 164         struct clk_slow_osc *osc = to_clk_slow_osc(hw);
 165
 166         clk_hw_unregister(hw);
 167         kfree(osc);
 168 }
 169
 170 static unsigned long clk_slow_rc_osc_recalc_rate(struct clk_hw *hw,
 171                                                  unsigned long parent_rate)
 172 {
 173         struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
 174
 175         return osc->frequency;
 176 }
 177
 178 static unsigned long clk_slow_rc_osc_recalc_accuracy(struct clk_hw *hw,
 179                                                      unsigned long parent_acc)
 180 {
 181         struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
 182
 183         return osc->accuracy;
 184 }
 185
 186 static int clk_slow_rc_osc_prepare(struct clk_hw *hw)
 187 {
 188         struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
 189         void __iomem *sckcr = osc->sckcr;
 190
 191         writel(readl(sckcr) | osc->bits->cr_rcen, sckcr);
 192
 193         if (system_state < SYSTEM_RUNNING)
 194                 udelay(osc->startup_usec);
 195         else
 196                 usleep_range(osc->startup_usec, osc->startup_usec + 1);
 197
 198         return 0;
 199 }
 200
 201 static void clk_slow_rc_osc_unprepare(struct clk_hw *hw)
 202 {
 203         struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
 204         void __iomem *sckcr = osc->sckcr;
 205
 206         writel(readl(sckcr) & ~osc->bits->cr_rcen, sckcr);
 207 }
 208
 209 static int clk_slow_rc_osc_is_prepared(struct clk_hw *hw)
 210 {
 211         struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
 212
 213         return !!(readl(osc->sckcr) & osc->bits->cr_rcen);
 214 }
 215
 216 static const struct clk_ops slow_rc_osc_ops = {
 217         .prepare = clk_slow_rc_osc_prepare,
 218         .unprepare = clk_slow_rc_osc_unprepare,
 219         .is_prepared = clk_slow_rc_osc_is_prepared,
 220         .recalc_rate = clk_slow_rc_osc_recalc_rate,
 221         .recalc_accuracy = clk_slow_rc_osc_recalc_accuracy,
 222 };
 223
 224 static struct clk_hw * __init
 225 at91_clk_register_slow_rc_osc(void __iomem *sckcr,
 226                               const char *name,
 227                               unsigned long frequency,
 228                               unsigned long accuracy,
 229                               unsigned long startup,
 230                               const struct clk_slow_bits *bits)
 231 {
 232         struct clk_slow_rc_osc *osc;
 233         struct clk_hw *hw;
 234         struct clk_init_data init;
 235         int ret;
 236
 237         if (!sckcr || !name)
 238                 return ERR_PTR(-EINVAL);
 239
 240         osc = kzalloc(sizeof(*osc), GFP_KERNEL);
 241         if (!osc)
 242                 return ERR_PTR(-ENOMEM);
 243
 244         init.name = name;
 245         init.ops = &slow_rc_osc_ops;
 246         init.parent_names = NULL;
 247         init.num_parents = 0;
 248         init.flags = CLK_IGNORE_UNUSED;
 249
 250         osc->hw.init = &init;
 251         osc->sckcr = sckcr;
 252         osc->bits = bits;
 253         osc->frequency = frequency;
 254         osc->accuracy = accuracy;
 255         osc->startup_usec = startup;
 256
 257         hw = &osc->hw;
 258         ret = clk_hw_register(NULL, &osc->hw);
 259         if (ret) {
 260                 kfree(osc);
 261                 hw = ERR_PTR(ret);
 262         }
 263
 264         return hw;
 265 }
 266
 267 static void at91_clk_unregister_slow_rc_osc(struct clk_hw *hw)
 268 {
 269         struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
 270
 271         clk_hw_unregister(hw);
 272         kfree(osc);
 273 }
 274
 275 static int clk_sam9x5_slow_set_parent(struct clk_hw *hw, u8 index)
 276 {
 277         struct clk_sam9x5_slow *slowck = to_clk_sam9x5_slow(hw);
 278         void __iomem *sckcr = slowck->sckcr;
 279         u32 tmp;
 280
 281         if (index > 1)
 282                 return -EINVAL;
 283
 284         tmp = readl(sckcr);
 285
 286         if ((!index && !(tmp & slowck->bits->cr_oscsel)) ||
 287             (index && (tmp & slowck->bits->cr_oscsel)))
 288                 return 0;
 289
 290         if (index)
 291                 tmp |= slowck->bits->cr_oscsel;
 292         else
 293                 tmp &= ~slowck->bits->cr_oscsel;
 294
 295         writel(tmp, sckcr);
 296
 297         if (system_state < SYSTEM_RUNNING)
 298                 udelay(SLOWCK_SW_TIME_USEC);
 299         else
 300                 usleep_range(SLOWCK_SW_TIME_USEC, SLOWCK_SW_TIME_USEC + 1);
 301
 302         return 0;
 303 }
 304
 305 static u8 clk_sam9x5_slow_get_parent(struct clk_hw *hw)
 306 {
 307         struct clk_sam9x5_slow *slowck = to_clk_sam9x5_slow(hw);
 308
 309         return !!(readl(slowck->sckcr) & slowck->bits->cr_oscsel);
 310 }
 311
 312 static const struct clk_ops sam9x5_slow_ops = {
 313         .set_parent = clk_sam9x5_slow_set_parent,
 314         .get_parent = clk_sam9x5_slow_get_parent,
 315 };
 316
 317 static struct clk_hw * __init
 318 at91_clk_register_sam9x5_slow(void __iomem *sckcr,
 319                               const char *name,
 320                               const char **parent_names,
 321                               int num_parents,
 322                               const struct clk_slow_bits *bits)
 323 {
 324         struct clk_sam9x5_slow *slowck;
 325         struct clk_hw *hw;
 326         struct clk_init_data init;
 327         int ret;
 328
 329         if (!sckcr || !name || !parent_names || !num_parents)
 330                 return ERR_PTR(-EINVAL);
 331
 332         slowck = kzalloc(sizeof(*slowck), GFP_KERNEL);
 333         if (!slowck)
 334                 return ERR_PTR(-ENOMEM);
 335
 336         init.name = name;
 337         init.ops = &sam9x5_slow_ops;
 338         init.parent_names = parent_names;
 339         init.num_parents = num_parents;
 340         init.flags = 0;
 341
 342         slowck->hw.init = &init;
 343         slowck->sckcr = sckcr;
 344         slowck->bits = bits;
 345         slowck->parent = !!(readl(sckcr) & slowck->bits->cr_oscsel);
 346
 347         hw = &slowck->hw;
 348         ret = clk_hw_register(NULL, &slowck->hw);
 349         if (ret) {
 350                 kfree(slowck);
 351                 hw = ERR_PTR(ret);
 352         }
 353
 354         return hw;
 355 }
 356
 357 static void at91_clk_unregister_sam9x5_slow(struct clk_hw *hw)
 358 {
 359         struct clk_sam9x5_slow *slowck = to_clk_sam9x5_slow(hw);
 360
 361         clk_hw_unregister(hw);
 362         kfree(slowck);
 363 }
 364
 365 static void __init at91sam9x5_sckc_register(struct device_node *np,
 366                                             unsigned int rc_osc_startup_us,
 367                                             const struct clk_slow_bits *bits)
 368 {
 369         const char *parent_names[2] = { "slow_rc_osc", "slow_osc" };
 370         void __iomem *regbase = of_iomap(np, 0);
 371         struct device_node *child = NULL;
 372         const char *xtal_name;
 373         struct clk_hw *slow_rc, *slow_osc, *slowck;
 374         bool bypass;
 375         int ret;
 376
 377         if (!regbase)
 378                 return;
 379
 380         slow_rc = at91_clk_register_slow_rc_osc(regbase, parent_names[0],
 381                                                 32768, 50000000,
 382                                                 rc_osc_startup_us, bits);
 383         if (IS_ERR(slow_rc))
 384                 return;
 385
 386         xtal_name = of_clk_get_parent_name(np, 0);
 387         if (!xtal_name) {
 388                 /* DT backward compatibility */
 389                 child = of_get_compatible_child(np, "atmel,at91sam9x5-clk-slow-osc");
 390                 if (!child)
 391                         goto unregister_slow_rc;
 392
 393                 xtal_name = of_clk_get_parent_name(child, 0);
 394                 bypass = of_property_read_bool(child, "atmel,osc-bypass");
 395
 396                 child =  of_get_compatible_child(np, "atmel,at91sam9x5-clk-slow");
 397         } else {
 398                 bypass = of_property_read_bool(np, "atmel,osc-bypass");
 399         }
 400
 401         if (!xtal_name)
 402                 goto unregister_slow_rc;
 403
 404         slow_osc = at91_clk_register_slow_osc(regbase, parent_names[1],
 405                                               xtal_name, 1200000, bypass, bits);
 406         if (IS_ERR(slow_osc))
 407                 goto unregister_slow_rc;
 408
 409         slowck = at91_clk_register_sam9x5_slow(regbase, "slowck", parent_names,
 410                                                2, bits);
 411         if (IS_ERR(slowck))
 412                 goto unregister_slow_osc;
 413
 414         /* DT backward compatibility */
 415         if (child)
 416                 ret = of_clk_add_hw_provider(child, of_clk_hw_simple_get,
 417                                              slowck);
 418         else
 419                 ret = of_clk_add_hw_provider(np, of_clk_hw_simple_get, slowck);
 420
 421         if (WARN_ON(ret))
 422                 goto unregister_slowck;
 423
 424         return;
 425
 426 unregister_slowck:
 427         at91_clk_unregister_sam9x5_slow(slowck);
 428 unregister_slow_osc:
 429         at91_clk_unregister_slow_osc(slow_osc);
 430 unregister_slow_rc:
 431         at91_clk_unregister_slow_rc_osc(slow_rc);
 432 }
 433
 434 static const struct clk_slow_bits at91sam9x5_bits = {
 435         .cr_rcen = BIT(0),
 436         .cr_osc32en = BIT(1),
 437         .cr_osc32byp = BIT(2),
 438         .cr_oscsel = BIT(3),
 439 };
 440
 441 static void __init of_at91sam9x5_sckc_setup(struct device_node *np)
 442 {
 443         at91sam9x5_sckc_register(np, 75, &at91sam9x5_bits);
 444 }
 445 CLK_OF_DECLARE(at91sam9x5_clk_sckc, "atmel,at91sam9x5-sckc",
 446                of_at91sam9x5_sckc_setup);
 447
 448 static void __init of_sama5d3_sckc_setup(struct device_node *np)
 449 {
 450         at91sam9x5_sckc_register(np, 500, &at91sam9x5_bits);
 451 }
 452 CLK_OF_DECLARE(sama5d3_clk_sckc, "atmel,sama5d3-sckc",
 453                of_sama5d3_sckc_setup);
 454
 455 static const struct clk_slow_bits at91sam9x60_bits = {
 456         .cr_osc32en = BIT(1),
 457         .cr_osc32byp = BIT(2),
 458         .cr_oscsel = BIT(24),
 459 };
 460
 461 static void __init of_sam9x60_sckc_setup(struct device_node *np)
 462 {
 463         void __iomem *regbase = of_iomap(np, 0);
 464         struct clk_hw_onecell_data *clk_data;
 465         struct clk_hw *slow_rc, *slow_osc;
 466         const char *xtal_name;
 467         const char *parent_names[2] = { "slow_rc_osc", "slow_osc" };
 468         bool bypass;
 469         int ret;
 470
 471         if (!regbase)
 472                 return;
 473
 474         slow_rc = clk_hw_register_fixed_rate(NULL, parent_names[0], NULL, 0,
 475                                              32768);
 476         if (IS_ERR(slow_rc))
 477                 return;
 478
 479         xtal_name = of_clk_get_parent_name(np, 0);
 480         if (!xtal_name)
 481                 goto unregister_slow_rc;
 482
 483         bypass = of_property_read_bool(np, "atmel,osc-bypass");
 484         slow_osc = at91_clk_register_slow_osc(regbase, parent_names[1],
 485                                               xtal_name, 5000000, bypass,
 486                                               &at91sam9x60_bits);
 487         if (IS_ERR(slow_osc))
 488                 goto unregister_slow_rc;
 489
 490         clk_data = kzalloc(struct_size(clk_data, hws, 2), GFP_KERNEL);
 491         if (!clk_data)
 492                 goto unregister_slow_osc;
 493
 494         /* MD_SLCK and TD_SLCK. */
 495         clk_data->num = 2;
 496         clk_data->hws[0] = clk_hw_register_fixed_rate(NULL, "md_slck",
 497                                                       parent_names[0],
 498                                                       0, 32768);
 499         if (IS_ERR(clk_data->hws[0]))
 500                 goto clk_data_free;
 501
 502         clk_data->hws[1] = at91_clk_register_sam9x5_slow(regbase, "td_slck",
 503                                                          parent_names, 2,
 504                                                          &at91sam9x60_bits);
 505         if (IS_ERR(clk_data->hws[1]))
 506                 goto unregister_md_slck;
 507
 508         ret = of_clk_add_hw_provider(np, of_clk_hw_onecell_get, clk_data);
 509         if (WARN_ON(ret))
 510                 goto unregister_td_slck;
 511
 512         return;
 513
 514 unregister_td_slck:
 515         at91_clk_unregister_sam9x5_slow(clk_data->hws[1]);
 516 unregister_md_slck:
 517         clk_hw_unregister(clk_data->hws[0]);
 518 clk_data_free:
 519         kfree(clk_data);
 520 unregister_slow_osc:
 521         at91_clk_unregister_slow_osc(slow_osc);
 522 unregister_slow_rc:
 523         clk_hw_unregister(slow_rc);
 524 }
 525 CLK_OF_DECLARE(sam9x60_clk_sckc, "microchip,sam9x60-sckc",
 526                of_sam9x60_sckc_setup);
 527
 528 static int clk_sama5d4_slow_osc_prepare(struct clk_hw *hw)
 529 {
 530         struct clk_sama5d4_slow_osc *osc = to_clk_sama5d4_slow_osc(hw);
 531
 532         if (osc->prepared)
 533                 return 0;
 534
 535         /*
 536          * Assume that if it has already been selected (for example by the
 537          * bootloader), enough time has aready passed.
 538          */
 539         if ((readl(osc->sckcr) & osc->bits->cr_oscsel)) {
 540                 osc->prepared = true;
 541                 return 0;
 542         }
 543
 544         if (system_state < SYSTEM_RUNNING)
 545                 udelay(osc->startup_usec);
 546         else
 547                 usleep_range(osc->startup_usec, osc->startup_usec + 1);
 548         osc->prepared = true;
 549
 550         return 0;
 551 }
 552
 553 static int clk_sama5d4_slow_osc_is_prepared(struct clk_hw *hw)
 554 {
 555         struct clk_sama5d4_slow_osc *osc = to_clk_sama5d4_slow_osc(hw);
 556
 557         return osc->prepared;
 558 }
 559
 560 static const struct clk_ops sama5d4_slow_osc_ops = {
 561         .prepare = clk_sama5d4_slow_osc_prepare,
 562         .is_prepared = clk_sama5d4_slow_osc_is_prepared,
 563 };
 564
 565 static const struct clk_slow_bits at91sama5d4_bits = {
 566         .cr_oscsel = BIT(3),
 567 };
 568
 569 static void __init of_sama5d4_sckc_setup(struct device_node *np)
 570 {
 571         void __iomem *regbase = of_iomap(np, 0);
 572         struct clk_hw *slow_rc, *slowck;
 573         struct clk_sama5d4_slow_osc *osc;
 574         struct clk_init_data init;
 575         const char *xtal_name;
 576         const char *parent_names[2] = { "slow_rc_osc", "slow_osc" };
 577         int ret;
 578
 579         if (!regbase)
 580                 return;
 581
 582         slow_rc = clk_hw_register_fixed_rate_with_accuracy(NULL,
 583                                                            parent_names[0],
 584                                                            NULL, 0, 32768,
 585                                                            250000000);
 586         if (IS_ERR(slow_rc))
 587                 return;
 588
 589         xtal_name = of_clk_get_parent_name(np, 0);
 590
 591         osc = kzalloc(sizeof(*osc), GFP_KERNEL);
 592         if (!osc)
 593                 goto unregister_slow_rc;
 594
 595         init.name = parent_names[1];
 596         init.ops = &sama5d4_slow_osc_ops;
 597         init.parent_names = &xtal_name;
 598         init.num_parents = 1;
 599         init.flags = CLK_IGNORE_UNUSED;
 600
 601         osc->hw.init = &init;
 602         osc->sckcr = regbase;
 603         osc->startup_usec = 1200000;
 604         osc->bits = &at91sama5d4_bits;
 605
 606         ret = clk_hw_register(NULL, &osc->hw);
 607         if (ret)
 608                 goto free_slow_osc_data;
 609
 610         slowck = at91_clk_register_sam9x5_slow(regbase, "slowck",
 611                                                parent_names, 2,
 612                                                &at91sama5d4_bits);
 613         if (IS_ERR(slowck))
 614                 goto unregister_slow_osc;
 615
 616         ret = of_clk_add_hw_provider(np, of_clk_hw_simple_get, slowck);
 617         if (WARN_ON(ret))
 618                 goto unregister_slowck;
 619
 620         return;
 621
 622 unregister_slowck:
 623         at91_clk_unregister_sam9x5_slow(slowck);
 624 unregister_slow_osc:
 625         clk_hw_unregister(&osc->hw);
 626 free_slow_osc_data:
 627         kfree(osc);
 628 unregister_slow_rc:
 629         clk_hw_unregister(slow_rc);
 630 }
 631 CLK_OF_DECLARE(sama5d4_clk_sckc, "atmel,sama5d4-sckc",
 632                of_sama5d4_sckc_setup);