root/drivers/clk/ti/clk.c

DEFINITIONS

1. clk_memmap_writel
2. _clk_rmw
3. clk_memmap_rmw
4. clk_memmap_readl
5. ti_clk_setup_ll_ops
6. ti_dt_clocks_register
7. ti_clk_retry_init
8. ti_clk_get_reg_addr
9. ti_clk_latch
10. omap2_clk_provider_init
11. omap2_clk_legacy_provider_init
12. ti_dt_clk_init_retry_clks
13. ti_clk_add_aliases
14. ti_clk_setup_features
15. ti_clk_get_features
16. omap2_clk_enable_init_clocks
17. ti_clk_add_alias
18. ti_clk_register
19. ti_clk_register_omap_hw
20. omap2_clk_for_each
21. omap2_clk_is_hw_omap

   1 /*
   2  * TI clock support
   3  *
   4  * Copyright (C) 2013 Texas Instruments, Inc.
   5  *
   6  * Tero Kristo <t-kristo@ti.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  *
  12  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
  13  * kind, whether express or implied; without even the implied warranty
  14  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  */
  17 
  18 #include <linux/clk.h>
  19 #include <linux/clk-provider.h>
  20 #include <linux/clkdev.h>
  21 #include <linux/clk/ti.h>
  22 #include <linux/io.h>
  23 #include <linux/of.h>
  24 #include <linux/of_address.h>
  25 #include <linux/list.h>
  26 #include <linux/regmap.h>
  27 #include <linux/memblock.h>
  28 #include <linux/device.h>
  29 
  30 #include "clock.h"
  31 
  32 #undef pr_fmt
  33 #define pr_fmt(fmt) "%s: " fmt, __func__
  34 
  35 static LIST_HEAD(clk_hw_omap_clocks);
  36 struct ti_clk_ll_ops *ti_clk_ll_ops;
  37 static struct device_node *clocks_node_ptr[CLK_MAX_MEMMAPS];
  38 
  39 struct ti_clk_features ti_clk_features;
  40 
  41 struct clk_iomap {
  42         struct regmap *regmap;
  43         void __iomem *mem;
  44 };
  45 
  46 static struct clk_iomap *clk_memmaps[CLK_MAX_MEMMAPS];
  47 
  48 static void clk_memmap_writel(u32 val, const struct clk_omap_reg *reg)
  49 {
  50         struct clk_iomap *io = clk_memmaps[reg->index];
  51 
  52         if (reg->ptr)
  53                 writel_relaxed(val, reg->ptr);
  54         else if (io->regmap)
  55                 regmap_write(io->regmap, reg->offset, val);
  56         else
  57                 writel_relaxed(val, io->mem + reg->offset);
  58 }
  59 
  60 static void _clk_rmw(u32 val, u32 mask, void __iomem *ptr)
  61 {
  62         u32 v;
  63 
  64         v = readl_relaxed(ptr);
  65         v &= ~mask;
  66         v |= val;
  67         writel_relaxed(v, ptr);
  68 }
  69 
  70 static void clk_memmap_rmw(u32 val, u32 mask, const struct clk_omap_reg *reg)
  71 {
  72         struct clk_iomap *io = clk_memmaps[reg->index];
  73 
  74         if (reg->ptr) {
  75                 _clk_rmw(val, mask, reg->ptr);
  76         } else if (io->regmap) {
  77                 regmap_update_bits(io->regmap, reg->offset, mask, val);
  78         } else {
  79                 _clk_rmw(val, mask, io->mem + reg->offset);
  80         }
  81 }
  82 
  83 static u32 clk_memmap_readl(const struct clk_omap_reg *reg)
  84 {
  85         u32 val;
  86         struct clk_iomap *io = clk_memmaps[reg->index];
  87 
  88         if (reg->ptr)
  89                 val = readl_relaxed(reg->ptr);
  90         else if (io->regmap)
  91                 regmap_read(io->regmap, reg->offset, &val);
  92         else
  93                 val = readl_relaxed(io->mem + reg->offset);
  94 
  95         return val;
  96 }
  97 
  98 /**
  99  * ti_clk_setup_ll_ops - setup low level clock operations
 100  * @ops: low level clock ops descriptor
 101  *
 102  * Sets up low level clock operations for TI clock driver. This is used
 103  * to provide various callbacks for the clock driver towards platform
 104  * specific code. Returns 0 on success, -EBUSY if ll_ops have been
 105  * registered already.
 106  */
 107 int ti_clk_setup_ll_ops(struct ti_clk_ll_ops *ops)
 108 {
 109         if (ti_clk_ll_ops) {
 110                 pr_err("Attempt to register ll_ops multiple times.\n");
 111                 return -EBUSY;
 112         }
 113 
 114         ti_clk_ll_ops = ops;
 115         ops->clk_readl = clk_memmap_readl;
 116         ops->clk_writel = clk_memmap_writel;
 117         ops->clk_rmw = clk_memmap_rmw;
 118 
 119         return 0;
 120 }
 121 
 122 /**
 123  * ti_dt_clocks_register - register DT alias clocks during boot
 124  * @oclks: list of clocks to register
 125  *
 126  * Register alias or non-standard DT clock entries during boot. By
 127  * default, DT clocks are found based on their node name. If any
 128  * additional con-id / dev-id -> clock mapping is required, use this
 129  * function to list these.
 130  */
 131 void __init ti_dt_clocks_register(struct ti_dt_clk oclks[])
 132 {
 133         struct ti_dt_clk *c;
 134         struct device_node *node, *parent;
 135         struct clk *clk;
 136         struct of_phandle_args clkspec;
 137         char buf[64];
 138         char *ptr;
 139         char *tags[2];
 140         int i;
 141         int num_args;
 142         int ret;
 143         static bool clkctrl_nodes_missing;
 144         static bool has_clkctrl_data;
 145         static bool compat_mode;
 146 
 147         compat_mode = ti_clk_get_features()->flags & TI_CLK_CLKCTRL_COMPAT;
 148 
 149         for (c = oclks; c->node_name != NULL; c++) {
 150                 strcpy(buf, c->node_name);
 151                 ptr = buf;
 152                 for (i = 0; i < 2; i++)
 153                         tags[i] = NULL;
 154                 num_args = 0;
 155                 while (*ptr) {
 156                         if (*ptr == ':') {
 157                                 if (num_args >= 2) {
 158                                         pr_warn("Bad number of tags on %s\n",
 159                                                 c->node_name);
 160                                         return;
 161                                 }
 162                                 tags[num_args++] = ptr + 1;
 163                                 *ptr = 0;
 164                         }
 165                         ptr++;
 166                 }
 167 
 168                 if (num_args && clkctrl_nodes_missing)
 169                         continue;
 170 
 171                 node = of_find_node_by_name(NULL, buf);
 172                 if (num_args && compat_mode) {
 173                         parent = node;
 174                         node = of_get_child_by_name(parent, "clk");
 175                         of_node_put(parent);
 176                 }
 177 
 178                 clkspec.np = node;
 179                 clkspec.args_count = num_args;
 180                 for (i = 0; i < num_args; i++) {
 181                         ret = kstrtoint(tags[i], i ? 10 : 16, clkspec.args + i);
 182                         if (ret) {
 183                                 pr_warn("Bad tag in %s at %d: %s\n",
 184                                         c->node_name, i, tags[i]);
 185                                 of_node_put(node);
 186                                 return;
 187                         }
 188                 }
 189                 clk = of_clk_get_from_provider(&clkspec);
 190                 of_node_put(node);
 191                 if (!IS_ERR(clk)) {
 192                         c->lk.clk = clk;
 193                         clkdev_add(&c->lk);
 194                 } else {
 195                         if (num_args && !has_clkctrl_data) {
 196                                 struct device_node *np;
 197 
 198                                 np = of_find_compatible_node(NULL, NULL,
 199                                                              "ti,clkctrl");
 200                                 if (np) {
 201                                         has_clkctrl_data = true;
 202                                         of_node_put(np);
 203                                 } else {
 204                                         clkctrl_nodes_missing = true;
 205 
 206                                         pr_warn("missing clkctrl nodes, please update your dts.\n");
 207                                         continue;
 208                                 }
 209                         }
 210 
 211                         pr_warn("failed to lookup clock node %s, ret=%ld\n",
 212                                 c->node_name, PTR_ERR(clk));
 213                 }
 214         }
 215 }
 216 
 217 struct clk_init_item {
 218         struct device_node *node;
 219         void *user;
 220         ti_of_clk_init_cb_t func;
 221         struct list_head link;
 222 };
 223 
 224 static LIST_HEAD(retry_list);
 225 
 226 /**
 227  * ti_clk_retry_init - retries a failed clock init at later phase
 228  * @node: device not for the clock
 229  * @user: user data pointer
 230  * @func: init function to be called for the clock
 231  *
 232  * Adds a failed clock init to the retry list. The retry list is parsed
 233  * once all the other clocks have been initialized.
 234  */
 235 int __init ti_clk_retry_init(struct device_node *node, void *user,
 236                              ti_of_clk_init_cb_t func)
 237 {
 238         struct clk_init_item *retry;
 239 
 240         pr_debug("%pOFn: adding to retry list...\n", node);
 241         retry = kzalloc(sizeof(*retry), GFP_KERNEL);
 242         if (!retry)
 243                 return -ENOMEM;
 244 
 245         retry->node = node;
 246         retry->func = func;
 247         retry->user = user;
 248         list_add(&retry->link, &retry_list);
 249 
 250         return 0;
 251 }
 252 
 253 /**
 254  * ti_clk_get_reg_addr - get register address for a clock register
 255  * @node: device node for the clock
 256  * @index: register index from the clock node
 257  * @reg: pointer to target register struct
 258  *
 259  * Builds clock register address from device tree information, and returns
 260  * the data via the provided output pointer @reg. Returns 0 on success,
 261  * negative error value on failure.
 262  */
 263 int ti_clk_get_reg_addr(struct device_node *node, int index,
 264                         struct clk_omap_reg *reg)
 265 {
 266         u32 val;
 267         int i;
 268 
 269         for (i = 0; i < CLK_MAX_MEMMAPS; i++) {
 270                 if (clocks_node_ptr[i] == node->parent)
 271                         break;
 272         }
 273 
 274         if (i == CLK_MAX_MEMMAPS) {
 275                 pr_err("clk-provider not found for %pOFn!\n", node);
 276                 return -ENOENT;
 277         }
 278 
 279         reg->index = i;
 280 
 281         if (of_property_read_u32_index(node, "reg", index, &val)) {
 282                 pr_err("%pOFn must have reg[%d]!\n", node, index);
 283                 return -EINVAL;
 284         }
 285 
 286         reg->offset = val;
 287         reg->ptr = NULL;
 288 
 289         return 0;
 290 }
 291 
 292 void ti_clk_latch(struct clk_omap_reg *reg, s8 shift)
 293 {
 294         u32 latch;
 295 
 296         if (shift < 0)
 297                 return;
 298 
 299         latch = 1 << shift;
 300 
 301         ti_clk_ll_ops->clk_rmw(latch, latch, reg);
 302         ti_clk_ll_ops->clk_rmw(0, latch, reg);
 303         ti_clk_ll_ops->clk_readl(reg); /* OCP barrier */
 304 }
 305 
 306 /**
 307  * omap2_clk_provider_init - init master clock provider
 308  * @parent: master node
 309  * @index: internal index for clk_reg_ops
 310  * @syscon: syscon regmap pointer for accessing clock registers
 311  * @mem: iomem pointer for the clock provider memory area, only used if
 312  *       syscon is not provided
 313  *
 314  * Initializes a master clock IP block. This basically sets up the
 315  * mapping from clocks node to the memory map index. All the clocks
 316  * are then initialized through the common of_clk_init call, and the
 317  * clocks will access their memory maps based on the node layout.
 318  * Returns 0 in success.
 319  */
 320 int __init omap2_clk_provider_init(struct device_node *parent, int index,
 321                                    struct regmap *syscon, void __iomem *mem)
 322 {
 323         struct device_node *clocks;
 324         struct clk_iomap *io;
 325 
 326         /* get clocks for this parent */
 327         clocks = of_get_child_by_name(parent, "clocks");
 328         if (!clocks) {
 329                 pr_err("%pOFn missing 'clocks' child node.\n", parent);
 330                 return -EINVAL;
 331         }
 332 
 333         /* add clocks node info */
 334         clocks_node_ptr[index] = clocks;
 335 
 336         io = kzalloc(sizeof(*io), GFP_KERNEL);
 337         if (!io)
 338                 return -ENOMEM;
 339 
 340         io->regmap = syscon;
 341         io->mem = mem;
 342 
 343         clk_memmaps[index] = io;
 344 
 345         return 0;
 346 }
 347 
 348 /**
 349  * omap2_clk_legacy_provider_init - initialize a legacy clock provider
 350  * @index: index for the clock provider
 351  * @mem: iomem pointer for the clock provider memory area
 352  *
 353  * Initializes a legacy clock provider memory mapping.
 354  */
 355 void __init omap2_clk_legacy_provider_init(int index, void __iomem *mem)
 356 {
 357         struct clk_iomap *io;
 358 
 359         io = memblock_alloc(sizeof(*io), SMP_CACHE_BYTES);
 360         if (!io)
 361                 panic("%s: Failed to allocate %zu bytes\n", __func__,
 362                       sizeof(*io));
 363 
 364         io->mem = mem;
 365 
 366         clk_memmaps[index] = io;
 367 }
 368 
 369 /**
 370  * ti_dt_clk_init_retry_clks - init clocks from the retry list
 371  *
 372  * Initializes any clocks that have failed to initialize before,
 373  * reasons being missing parent node(s) during earlier init. This
 374  * typically happens only for DPLLs which need to have both of their
 375  * parent clocks ready during init.
 376  */
 377 void ti_dt_clk_init_retry_clks(void)
 378 {
 379         struct clk_init_item *retry;
 380         struct clk_init_item *tmp;
 381         int retries = 5;
 382 
 383         while (!list_empty(&retry_list) && retries) {
 384                 list_for_each_entry_safe(retry, tmp, &retry_list, link) {
 385                         pr_debug("retry-init: %pOFn\n", retry->node);
 386                         retry->func(retry->user, retry->node);
 387                         list_del(&retry->link);
 388                         kfree(retry);
 389                 }
 390                 retries--;
 391         }
 392 }
 393 
 394 static const struct of_device_id simple_clk_match_table[] __initconst = {
 395         { .compatible = "fixed-clock" },
 396         { .compatible = "fixed-factor-clock" },
 397         { }
 398 };
 399 
 400 /**
 401  * ti_clk_add_aliases - setup clock aliases
 402  *
 403  * Sets up any missing clock aliases. No return value.
 404  */
 405 void __init ti_clk_add_aliases(void)
 406 {
 407         struct device_node *np;
 408         struct clk *clk;
 409 
 410         for_each_matching_node(np, simple_clk_match_table) {
 411                 struct of_phandle_args clkspec;
 412 
 413                 clkspec.np = np;
 414                 clk = of_clk_get_from_provider(&clkspec);
 415 
 416                 ti_clk_add_alias(NULL, clk, np->name);
 417         }
 418 }
 419 
 420 /**
 421  * ti_clk_setup_features - setup clock features flags
 422  * @features: features definition to use
 423  *
 424  * Initializes the clock driver features flags based on platform
 425  * provided data. No return value.
 426  */
 427 void __init ti_clk_setup_features(struct ti_clk_features *features)
 428 {
 429         memcpy(&ti_clk_features, features, sizeof(*features));
 430 }
 431 
 432 /**
 433  * ti_clk_get_features - get clock driver features flags
 434  *
 435  * Get TI clock driver features description. Returns a pointer
 436  * to the current feature setup.
 437  */
 438 const struct ti_clk_features *ti_clk_get_features(void)
 439 {
 440         return &ti_clk_features;
 441 }
 442 
 443 /**
 444  * omap2_clk_enable_init_clocks - prepare & enable a list of clocks
 445  * @clk_names: ptr to an array of strings of clock names to enable
 446  * @num_clocks: number of clock names in @clk_names
 447  *
 448  * Prepare and enable a list of clocks, named by @clk_names.  No
 449  * return value. XXX Deprecated; only needed until these clocks are
 450  * properly claimed and enabled by the drivers or core code that uses
 451  * them.  XXX What code disables & calls clk_put on these clocks?
 452  */
 453 void omap2_clk_enable_init_clocks(const char **clk_names, u8 num_clocks)
 454 {
 455         struct clk *init_clk;
 456         int i;
 457 
 458         for (i = 0; i < num_clocks; i++) {
 459                 init_clk = clk_get(NULL, clk_names[i]);
 460                 if (WARN(IS_ERR(init_clk), "could not find init clock %s\n",
 461                          clk_names[i]))
 462                         continue;
 463                 clk_prepare_enable(init_clk);
 464         }
 465 }
 466 
 467 /**
 468  * ti_clk_add_alias - add a clock alias for a TI clock
 469  * @dev: device alias for this clock
 470  * @clk: clock handle to create alias for
 471  * @con: connection ID for this clock
 472  *
 473  * Creates a clock alias for a TI clock. Allocates the clock lookup entry
 474  * and assigns the data to it. Returns 0 if successful, negative error
 475  * value otherwise.
 476  */
 477 int ti_clk_add_alias(struct device *dev, struct clk *clk, const char *con)
 478 {
 479         struct clk_lookup *cl;
 480 
 481         if (!clk)
 482                 return 0;
 483 
 484         if (IS_ERR(clk))
 485                 return PTR_ERR(clk);
 486 
 487         cl = kzalloc(sizeof(*cl), GFP_KERNEL);
 488         if (!cl)
 489                 return -ENOMEM;
 490 
 491         if (dev)
 492                 cl->dev_id = dev_name(dev);
 493         cl->con_id = con;
 494         cl->clk = clk;
 495 
 496         clkdev_add(cl);
 497 
 498         return 0;
 499 }
 500 
 501 /**
 502  * ti_clk_register - register a TI clock to the common clock framework
 503  * @dev: device for this clock
 504  * @hw: hardware clock handle
 505  * @con: connection ID for this clock
 506  *
 507  * Registers a TI clock to the common clock framework, and adds a clock
 508  * alias for it. Returns a handle to the registered clock if successful,
 509  * ERR_PTR value in failure.
 510  */
 511 struct clk *ti_clk_register(struct device *dev, struct clk_hw *hw,
 512                             const char *con)
 513 {
 514         struct clk *clk;
 515         int ret;
 516 
 517         clk = clk_register(dev, hw);
 518         if (IS_ERR(clk))
 519                 return clk;
 520 
 521         ret = ti_clk_add_alias(dev, clk, con);
 522         if (ret) {
 523                 clk_unregister(clk);
 524                 return ERR_PTR(ret);
 525         }
 526 
 527         return clk;
 528 }
 529 
 530 /**
 531  * ti_clk_register_omap_hw - register a clk_hw_omap to the clock framework
 532  * @dev: device for this clock
 533  * @hw: hardware clock handle
 534  * @con: connection ID for this clock
 535  *
 536  * Registers a clk_hw_omap clock to the clock framewor, adds a clock alias
 537  * for it, and adds the list to the available clk_hw_omap type clocks.
 538  * Returns a handle to the registered clock if successful, ERR_PTR value
 539  * in failure.
 540  */
 541 struct clk *ti_clk_register_omap_hw(struct device *dev, struct clk_hw *hw,
 542                                     const char *con)
 543 {
 544         struct clk *clk;
 545         struct clk_hw_omap *oclk;
 546 
 547         clk = ti_clk_register(dev, hw, con);
 548         if (IS_ERR(clk))
 549                 return clk;
 550 
 551         oclk = to_clk_hw_omap(hw);
 552 
 553         list_add(&oclk->node, &clk_hw_omap_clocks);
 554 
 555         return clk;
 556 }
 557 
 558 /**
 559  * omap2_clk_for_each - call function for each registered clk_hw_omap
 560  * @fn: pointer to a callback function
 561  *
 562  * Call @fn for each registered clk_hw_omap, passing @hw to each
 563  * function.  @fn must return 0 for success or any other value for
 564  * failure.  If @fn returns non-zero, the iteration across clocks
 565  * will stop and the non-zero return value will be passed to the
 566  * caller of omap2_clk_for_each().
 567  */
 568 int omap2_clk_for_each(int (*fn)(struct clk_hw_omap *hw))
 569 {
 570         int ret;
 571         struct clk_hw_omap *hw;
 572 
 573         list_for_each_entry(hw, &clk_hw_omap_clocks, node) {
 574                 ret = (*fn)(hw);
 575                 if (ret)
 576                         break;
 577         }
 578 
 579         return ret;
 580 }
 581 
 582 /**
 583  * omap2_clk_is_hw_omap - check if the provided clk_hw is OMAP clock
 584  * @hw: clk_hw to check if it is an omap clock or not
 585  *
 586  * Checks if the provided clk_hw is OMAP clock or not. Returns true if
 587  * it is, false otherwise.
 588  */
 589 bool omap2_clk_is_hw_omap(struct clk_hw *hw)
 590 {
 591         struct clk_hw_omap *oclk;
 592 
 593         list_for_each_entry(oclk, &clk_hw_omap_clocks, node) {
 594                 if (&oclk->hw == hw)
 595                         return true;
 596         }
 597 
 598         return false;
 599 }