drivers/clk/sifive/sifive-prci.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2020 SiFive, Inc.
   4  * Copyright (C) 2020 Zong Li
   5  */
   6
   7 #include <linux/clkdev.h>
   8 #include <linux/delay.h>
   9 #include <linux/io.h>
  10 #include <linux/of_device.h>
  11 #include "sifive-prci.h"
  12 #include "fu540-prci.h"
  13 #include "fu740-prci.h"
  14
  15 /*
  16  * Private functions
  17  */
  18
  19 /**
  20  * __prci_readl() - read from a PRCI register
  21  * @pd: PRCI context
  22  * @offs: register offset to read from (in bytes, from PRCI base address)
  23  *
  24  * Read the register located at offset @offs from the base virtual
  25  * address of the PRCI register target described by @pd, and return
  26  * the value to the caller.
  27  *
  28  * Context: Any context.
  29  *
  30  * Return: the contents of the register described by @pd and @offs.
  31  */
  32 static u32 __prci_readl(struct __prci_data *pd, u32 offs)
  33 {
  34         return readl_relaxed(pd->va + offs);
  35 }
  36
  37 static void __prci_writel(u32 v, u32 offs, struct __prci_data *pd)
  38 {
  39         writel_relaxed(v, pd->va + offs);
  40 }
  41
  42 /* WRPLL-related private functions */
  43
  44 /**
  45  * __prci_wrpll_unpack() - unpack WRPLL configuration registers into parameters
  46  * @c: ptr to a struct wrpll_cfg record to write config into
  47  * @r: value read from the PRCI PLL configuration register
  48  *
  49  * Given a value @r read from an FU740 PRCI PLL configuration register,
  50  * split it into fields and populate it into the WRPLL configuration record
  51  * pointed to by @c.
  52  *
  53  * The COREPLLCFG0 macros are used below, but the other *PLLCFG0 macros
  54  * have the same register layout.
  55  *
  56  * Context: Any context.
  57  */
  58 static void __prci_wrpll_unpack(struct wrpll_cfg *c, u32 r)
  59 {
  60         u32 v;
  61
  62         v = r & PRCI_COREPLLCFG0_DIVR_MASK;
  63         v >>= PRCI_COREPLLCFG0_DIVR_SHIFT;
  64         c->divr = v;
  65
  66         v = r & PRCI_COREPLLCFG0_DIVF_MASK;
  67         v >>= PRCI_COREPLLCFG0_DIVF_SHIFT;
  68         c->divf = v;
  69
  70         v = r & PRCI_COREPLLCFG0_DIVQ_MASK;
  71         v >>= PRCI_COREPLLCFG0_DIVQ_SHIFT;
  72         c->divq = v;
  73
  74         v = r & PRCI_COREPLLCFG0_RANGE_MASK;
  75         v >>= PRCI_COREPLLCFG0_RANGE_SHIFT;
  76         c->range = v;
  77
  78         c->flags &=
  79             (WRPLL_FLAGS_INT_FEEDBACK_MASK | WRPLL_FLAGS_EXT_FEEDBACK_MASK);
  80
  81         /* external feedback mode not supported */
  82         c->flags |= WRPLL_FLAGS_INT_FEEDBACK_MASK;
  83 }
  84
  85 /**
  86  * __prci_wrpll_pack() - pack PLL configuration parameters into a register value
  87  * @c: pointer to a struct wrpll_cfg record containing the PLL's cfg
  88  *
  89  * Using a set of WRPLL configuration values pointed to by @c,
  90  * assemble a PRCI PLL configuration register value, and return it to
  91  * the caller.
  92  *
  93  * Context: Any context.  Caller must ensure that the contents of the
  94  *          record pointed to by @c do not change during the execution
  95  *          of this function.
  96  *
  97  * Returns: a value suitable for writing into a PRCI PLL configuration
  98  *          register
  99  */
 100 static u32 __prci_wrpll_pack(const struct wrpll_cfg *c)
 101 {
 102         u32 r = 0;
 103
 104         r |= c->divr << PRCI_COREPLLCFG0_DIVR_SHIFT;
 105         r |= c->divf << PRCI_COREPLLCFG0_DIVF_SHIFT;
 106         r |= c->divq << PRCI_COREPLLCFG0_DIVQ_SHIFT;
 107         r |= c->range << PRCI_COREPLLCFG0_RANGE_SHIFT;
 108
 109         /* external feedback mode not supported */
 110         r |= PRCI_COREPLLCFG0_FSE_MASK;
 111
 112         return r;
 113 }
 114
 115 /**
 116  * __prci_wrpll_read_cfg0() - read the WRPLL configuration from the PRCI
 117  * @pd: PRCI context
 118  * @pwd: PRCI WRPLL metadata
 119  *
 120  * Read the current configuration of the PLL identified by @pwd from
 121  * the PRCI identified by @pd, and store it into the local configuration
 122  * cache in @pwd.
 123  *
 124  * Context: Any context.  Caller must prevent the records pointed to by
 125  *          @pd and @pwd from changing during execution.
 126  */
 127 static void __prci_wrpll_read_cfg0(struct __prci_data *pd,
 128                                    struct __prci_wrpll_data *pwd)
 129 {
 130         __prci_wrpll_unpack(&pwd->c, __prci_readl(pd, pwd->cfg0_offs));
 131 }
 132
 133 /**
 134  * __prci_wrpll_write_cfg0() - write WRPLL configuration into the PRCI
 135  * @pd: PRCI context
 136  * @pwd: PRCI WRPLL metadata
 137  * @c: WRPLL configuration record to write
 138  *
 139  * Write the WRPLL configuration described by @c into the WRPLL
 140  * configuration register identified by @pwd in the PRCI instance
 141  * described by @c.  Make a cached copy of the WRPLL's current
 142  * configuration so it can be used by other code.
 143  *
 144  * Context: Any context.  Caller must prevent the records pointed to by
 145  *          @pd and @pwd from changing during execution.
 146  */
 147 static void __prci_wrpll_write_cfg0(struct __prci_data *pd,
 148                                     struct __prci_wrpll_data *pwd,
 149                                     struct wrpll_cfg *c)
 150 {
 151         __prci_writel(__prci_wrpll_pack(c), pwd->cfg0_offs, pd);
 152
 153         memcpy(&pwd->c, c, sizeof(*c));
 154 }
 155
 156 /**
 157  * __prci_wrpll_write_cfg1() - write Clock enable/disable configuration
 158  * into the PRCI
 159  * @pd: PRCI context
 160  * @pwd: PRCI WRPLL metadata
 161  * @enable: Clock enable or disable value
 162  */
 163 static void __prci_wrpll_write_cfg1(struct __prci_data *pd,
 164                                     struct __prci_wrpll_data *pwd,
 165                                     u32 enable)
 166 {
 167         __prci_writel(enable, pwd->cfg1_offs, pd);
 168 }
 169
 170 /*
 171  * Linux clock framework integration
 172  *
 173  * See the Linux clock framework documentation for more information on
 174  * these functions.
 175  */
 176
 177 unsigned long sifive_prci_wrpll_recalc_rate(struct clk_hw *hw,
 178                                             unsigned long parent_rate)
 179 {
 180         struct __prci_clock *pc = clk_hw_to_prci_clock(hw);
 181         struct __prci_wrpll_data *pwd = pc->pwd;
 182
 183         return wrpll_calc_output_rate(&pwd->c, parent_rate);
 184 }
 185
 186 long sifive_prci_wrpll_round_rate(struct clk_hw *hw,
 187                                   unsigned long rate,
 188                                   unsigned long *parent_rate)
 189 {
 190         struct __prci_clock *pc = clk_hw_to_prci_clock(hw);
 191         struct __prci_wrpll_data *pwd = pc->pwd;
 192         struct wrpll_cfg c;
 193
 194         memcpy(&c, &pwd->c, sizeof(c));
 195
 196         wrpll_configure_for_rate(&c, rate, *parent_rate);
 197
 198         return wrpll_calc_output_rate(&c, *parent_rate);
 199 }
 200
 201 int sifive_prci_wrpll_set_rate(struct clk_hw *hw,
 202                                unsigned long rate, unsigned long parent_rate)
 203 {
 204         struct __prci_clock *pc = clk_hw_to_prci_clock(hw);
 205         struct __prci_wrpll_data *pwd = pc->pwd;
 206         struct __prci_data *pd = pc->pd;
 207         int r;
 208
 209         r = wrpll_configure_for_rate(&pwd->c, rate, parent_rate);
 210         if (r)
 211                 return r;
 212
 213         if (pwd->enable_bypass)
 214                 pwd->enable_bypass(pd);
 215
 216         __prci_wrpll_write_cfg0(pd, pwd, &pwd->c);
 217
 218         udelay(wrpll_calc_max_lock_us(&pwd->c));
 219
 220         return 0;
 221 }
 222
 223 int sifive_clk_is_enabled(struct clk_hw *hw)
 224 {
 225         struct __prci_clock *pc = clk_hw_to_prci_clock(hw);
 226         struct __prci_wrpll_data *pwd = pc->pwd;
 227         struct __prci_data *pd = pc->pd;
 228         u32 r;
 229
 230         r = __prci_readl(pd, pwd->cfg1_offs);
 231
 232         if (r & PRCI_COREPLLCFG1_CKE_MASK)
 233                 return 1;
 234         else
 235                 return 0;
 236 }
 237
 238 int sifive_prci_clock_enable(struct clk_hw *hw)
 239 {
 240         struct __prci_clock *pc = clk_hw_to_prci_clock(hw);
 241         struct __prci_wrpll_data *pwd = pc->pwd;
 242         struct __prci_data *pd = pc->pd;
 243
 244         if (sifive_clk_is_enabled(hw))
 245                 return 0;
 246
 247         __prci_wrpll_write_cfg1(pd, pwd, PRCI_COREPLLCFG1_CKE_MASK);
 248
 249         if (pwd->disable_bypass)
 250                 pwd->disable_bypass(pd);
 251
 252         return 0;
 253 }
 254
 255 void sifive_prci_clock_disable(struct clk_hw *hw)
 256 {
 257         struct __prci_clock *pc = clk_hw_to_prci_clock(hw);
 258         struct __prci_wrpll_data *pwd = pc->pwd;
 259         struct __prci_data *pd = pc->pd;
 260         u32 r;
 261
 262         if (pwd->enable_bypass)
 263                 pwd->enable_bypass(pd);
 264
 265         r = __prci_readl(pd, pwd->cfg1_offs);
 266         r &= ~PRCI_COREPLLCFG1_CKE_MASK;
 267
 268         __prci_wrpll_write_cfg1(pd, pwd, r);
 269 }
 270
 271 /* TLCLKSEL clock integration */
 272
 273 unsigned long sifive_prci_tlclksel_recalc_rate(struct clk_hw *hw,
 274                                                unsigned long parent_rate)
 275 {
 276         struct __prci_clock *pc = clk_hw_to_prci_clock(hw);
 277         struct __prci_data *pd = pc->pd;
 278         u32 v;
 279         u8 div;
 280
 281         v = __prci_readl(pd, PRCI_CLKMUXSTATUSREG_OFFSET);
 282         v &= PRCI_CLKMUXSTATUSREG_TLCLKSEL_STATUS_MASK;
 283         div = v ? 1 : 2;
 284
 285         return div_u64(parent_rate, div);
 286 }
 287
 288 /* HFPCLK clock integration */
 289
 290 unsigned long sifive_prci_hfpclkplldiv_recalc_rate(struct clk_hw *hw,
 291                                                    unsigned long parent_rate)
 292 {
 293         struct __prci_clock *pc = clk_hw_to_prci_clock(hw);
 294         struct __prci_data *pd = pc->pd;
 295         u32 div = __prci_readl(pd, PRCI_HFPCLKPLLDIV_OFFSET);
 296
 297         return div_u64(parent_rate, div + 2);
 298 }
 299
 300 /*
 301  * Core clock mux control
 302  */
 303
 304 /**
 305  * sifive_prci_coreclksel_use_hfclk() - switch the CORECLK mux to output HFCLK
 306  * @pd: struct __prci_data * for the PRCI containing the CORECLK mux reg
 307  *
 308  * Switch the CORECLK mux to the HFCLK input source; return once complete.
 309  *
 310  * Context: Any context.  Caller must prevent concurrent changes to the
 311  *          PRCI_CORECLKSEL_OFFSET register.
 312  */
 313 void sifive_prci_coreclksel_use_hfclk(struct __prci_data *pd)
 314 {
 315         u32 r;
 316
 317         r = __prci_readl(pd, PRCI_CORECLKSEL_OFFSET);
 318         r |= PRCI_CORECLKSEL_CORECLKSEL_MASK;
 319         __prci_writel(r, PRCI_CORECLKSEL_OFFSET, pd);
 320
 321         r = __prci_readl(pd, PRCI_CORECLKSEL_OFFSET);   /* barrier */
 322 }
 323
 324 /**
 325  * sifive_prci_coreclksel_use_corepll() - switch the CORECLK mux to output
 326  * COREPLL
 327  * @pd: struct __prci_data * for the PRCI containing the CORECLK mux reg
 328  *
 329  * Switch the CORECLK mux to the COREPLL output clock; return once complete.
 330  *
 331  * Context: Any context.  Caller must prevent concurrent changes to the
 332  *          PRCI_CORECLKSEL_OFFSET register.
 333  */
 334 void sifive_prci_coreclksel_use_corepll(struct __prci_data *pd)
 335 {
 336         u32 r;
 337
 338         r = __prci_readl(pd, PRCI_CORECLKSEL_OFFSET);
 339         r &= ~PRCI_CORECLKSEL_CORECLKSEL_MASK;
 340         __prci_writel(r, PRCI_CORECLKSEL_OFFSET, pd);
 341
 342         r = __prci_readl(pd, PRCI_CORECLKSEL_OFFSET);   /* barrier */
 343 }
 344
 345 /**
 346  * sifive_prci_coreclksel_use_final_corepll() - switch the CORECLK mux to output
 347  * FINAL_COREPLL
 348  * @pd: struct __prci_data * for the PRCI containing the CORECLK mux reg
 349  *
 350  * Switch the CORECLK mux to the final COREPLL output clock; return once
 351  * complete.
 352  *
 353  * Context: Any context.  Caller must prevent concurrent changes to the
 354  *          PRCI_CORECLKSEL_OFFSET register.
 355  */
 356 void sifive_prci_coreclksel_use_final_corepll(struct __prci_data *pd)
 357 {
 358         u32 r;
 359
 360         r = __prci_readl(pd, PRCI_CORECLKSEL_OFFSET);
 361         r &= ~PRCI_CORECLKSEL_CORECLKSEL_MASK;
 362         __prci_writel(r, PRCI_CORECLKSEL_OFFSET, pd);
 363
 364         r = __prci_readl(pd, PRCI_CORECLKSEL_OFFSET);   /* barrier */
 365 }
 366
 367 /**
 368  * sifive_prci_corepllsel_use_dvfscorepll() - switch the COREPLL mux to
 369  * output DVFS_COREPLL
 370  * @pd: struct __prci_data * for the PRCI containing the COREPLL mux reg
 371  *
 372  * Switch the COREPLL mux to the DVFSCOREPLL output clock; return once complete.
 373  *
 374  * Context: Any context.  Caller must prevent concurrent changes to the
 375  *          PRCI_COREPLLSEL_OFFSET register.
 376  */
 377 void sifive_prci_corepllsel_use_dvfscorepll(struct __prci_data *pd)
 378 {
 379         u32 r;
 380
 381         r = __prci_readl(pd, PRCI_COREPLLSEL_OFFSET);
 382         r |= PRCI_COREPLLSEL_COREPLLSEL_MASK;
 383         __prci_writel(r, PRCI_COREPLLSEL_OFFSET, pd);
 384
 385         r = __prci_readl(pd, PRCI_COREPLLSEL_OFFSET);   /* barrier */
 386 }
 387
 388 /**
 389  * sifive_prci_corepllsel_use_corepll() - switch the COREPLL mux to
 390  * output COREPLL
 391  * @pd: struct __prci_data * for the PRCI containing the COREPLL mux reg
 392  *
 393  * Switch the COREPLL mux to the COREPLL output clock; return once complete.
 394  *
 395  * Context: Any context.  Caller must prevent concurrent changes to the
 396  *          PRCI_COREPLLSEL_OFFSET register.
 397  */
 398 void sifive_prci_corepllsel_use_corepll(struct __prci_data *pd)
 399 {
 400         u32 r;
 401
 402         r = __prci_readl(pd, PRCI_COREPLLSEL_OFFSET);
 403         r &= ~PRCI_COREPLLSEL_COREPLLSEL_MASK;
 404         __prci_writel(r, PRCI_COREPLLSEL_OFFSET, pd);
 405
 406         r = __prci_readl(pd, PRCI_COREPLLSEL_OFFSET);   /* barrier */
 407 }
 408
 409 /**
 410  * sifive_prci_hfpclkpllsel_use_hfclk() - switch the HFPCLKPLL mux to
 411  * output HFCLK
 412  * @pd: struct __prci_data * for the PRCI containing the HFPCLKPLL mux reg
 413  *
 414  * Switch the HFPCLKPLL mux to the HFCLK input source; return once complete.
 415  *
 416  * Context: Any context.  Caller must prevent concurrent changes to the
 417  *          PRCI_HFPCLKPLLSEL_OFFSET register.
 418  */
 419 void sifive_prci_hfpclkpllsel_use_hfclk(struct __prci_data *pd)
 420 {
 421         u32 r;
 422
 423         r = __prci_readl(pd, PRCI_HFPCLKPLLSEL_OFFSET);
 424         r |= PRCI_HFPCLKPLLSEL_HFPCLKPLLSEL_MASK;
 425         __prci_writel(r, PRCI_HFPCLKPLLSEL_OFFSET, pd);
 426
 427         r = __prci_readl(pd, PRCI_HFPCLKPLLSEL_OFFSET); /* barrier */
 428 }
 429
 430 /**
 431  * sifive_prci_hfpclkpllsel_use_hfpclkpll() - switch the HFPCLKPLL mux to
 432  * output HFPCLKPLL
 433  * @pd: struct __prci_data * for the PRCI containing the HFPCLKPLL mux reg
 434  *
 435  * Switch the HFPCLKPLL mux to the HFPCLKPLL output clock; return once complete.
 436  *
 437  * Context: Any context.  Caller must prevent concurrent changes to the
 438  *          PRCI_HFPCLKPLLSEL_OFFSET register.
 439  */
 440 void sifive_prci_hfpclkpllsel_use_hfpclkpll(struct __prci_data *pd)
 441 {
 442         u32 r;
 443
 444         r = __prci_readl(pd, PRCI_HFPCLKPLLSEL_OFFSET);
 445         r &= ~PRCI_HFPCLKPLLSEL_HFPCLKPLLSEL_MASK;
 446         __prci_writel(r, PRCI_HFPCLKPLLSEL_OFFSET, pd);
 447
 448         r = __prci_readl(pd, PRCI_HFPCLKPLLSEL_OFFSET); /* barrier */
 449 }
 450
 451 /**
 452  * __prci_register_clocks() - register clock controls in the PRCI
 453  * @dev: Linux struct device
 454  * @pd: The pointer for PRCI per-device instance data
 455  * @desc: The pointer for the information of clocks of each SoCs
 456  *
 457  * Register the list of clock controls described in __prci_init_clocks[] with
 458  * the Linux clock framework.
 459  *
 460  * Return: 0 upon success or a negative error code upon failure.
 461  */
 462 static int __prci_register_clocks(struct device *dev, struct __prci_data *pd,
 463                                   const struct prci_clk_desc *desc)
 464 {
 465         struct clk_init_data init = { };
 466         struct __prci_clock *pic;
 467         int parent_count, i, r;
 468
 469         parent_count = of_clk_get_parent_count(dev->of_node);
 470         if (parent_count != EXPECTED_CLK_PARENT_COUNT) {
 471                 dev_err(dev, "expected only two parent clocks, found %d\n",
 472                         parent_count);
 473                 return -EINVAL;
 474         }
 475
 476         /* Register PLLs */
 477         for (i = 0; i < desc->num_clks; ++i) {
 478                 pic = &(desc->clks[i]);
 479
 480                 init.name = pic->name;
 481                 init.parent_names = &pic->parent_name;
 482                 init.num_parents = 1;
 483                 init.ops = pic->ops;
 484                 pic->hw.init = &init;
 485
 486                 pic->pd = pd;
 487
 488                 if (pic->pwd)
 489                         __prci_wrpll_read_cfg0(pd, pic->pwd);
 490
 491                 r = devm_clk_hw_register(dev, &pic->hw);
 492                 if (r) {
 493                         dev_warn(dev, "Failed to register clock %s: %d\n",
 494                                  init.name, r);
 495                         return r;
 496                 }
 497
 498                 r = clk_hw_register_clkdev(&pic->hw, pic->name, dev_name(dev));
 499                 if (r) {
 500                         dev_warn(dev, "Failed to register clkdev for %s: %d\n",
 501                                  init.name, r);
 502                         return r;
 503                 }
 504
 505                 pd->hw_clks.hws[i] = &pic->hw;
 506         }
 507
 508         pd->hw_clks.num = i;
 509
 510         r = devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get,
 511                                         &pd->hw_clks);
 512         if (r) {
 513                 dev_err(dev, "could not add hw_provider: %d\n", r);
 514                 return r;
 515         }
 516
 517         return 0;
 518 }
 519
 520 /**
 521  * sifive_prci_init() - initialize prci data and check parent count
 522  * @pdev: platform device pointer for the prci
 523  *
 524  * Return: 0 upon success or a negative error code upon failure.
 525  */
 526 static int sifive_prci_probe(struct platform_device *pdev)
 527 {
 528         struct device *dev = &pdev->dev;
 529         struct resource *res;
 530         struct __prci_data *pd;
 531         const struct prci_clk_desc *desc;
 532         int r;
 533
 534         desc = of_device_get_match_data(&pdev->dev);
 535
 536         pd = devm_kzalloc(dev, struct_size(pd, hw_clks.hws, desc->num_clks), GFP_KERNEL);
 537         if (!pd)
 538                 return -ENOMEM;
 539
 540         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 541         pd->va = devm_ioremap_resource(dev, res);
 542         if (IS_ERR(pd->va))
 543                 return PTR_ERR(pd->va);
 544
 545         r = __prci_register_clocks(dev, pd, desc);
 546         if (r) {
 547                 dev_err(dev, "could not register clocks: %d\n", r);
 548                 return r;
 549         }
 550
 551         dev_dbg(dev, "SiFive PRCI probed\n");
 552
 553         return 0;
 554 }
 555
 556 static const struct of_device_id sifive_prci_of_match[] = {
 557         {.compatible = "sifive,fu540-c000-prci", .data = &prci_clk_fu540},
 558         {.compatible = "sifive,fu740-c000-prci", .data = &prci_clk_fu740},
 559         {}
 560 };
 561
 562 static struct platform_driver sifive_prci_driver = {
 563         .driver = {
 564                 .name = "sifive-clk-prci",
 565                 .of_match_table = sifive_prci_of_match,
 566         },
 567         .probe = sifive_prci_probe,
 568 };
 569
 570 static int __init sifive_prci_init(void)
 571 {
 572         return platform_driver_register(&sifive_prci_driver);
 573 }
 574 core_initcall(sifive_prci_init);