1/* SPDX-License-Identifier: GPL-2.0+ */ 2/* 3 * Copyright (c) 2015 Google, Inc 4 * Written by Simon Glass <sjg@chromium.org> 5 * Copyright (c) 2016, NVIDIA CORPORATION. 6 */ 7 8#ifndef _CLK_H_ 9#define _CLK_H_ 10 11#include <dm/ofnode.h> 12#include <linux/errno.h> 13#include <linux/types.h> 14 15/** 16 * A clock is a hardware signal that oscillates autonomously at a specific 17 * frequency and duty cycle. Most hardware modules require one or more clock 18 * signal to drive their operation. Clock signals are typically generated 19 * externally to the HW module consuming them, by an entity this API calls a 20 * clock provider. This API provides a standard means for drivers to enable and 21 * disable clocks, and to set the rate at which they oscillate. 22 * 23 * A driver that implements UCLASS_CLK is a clock provider. A provider will 24 * often implement multiple separate clocks, since the hardware it manages 25 * often has this capability. clk-uclass.h describes the interface which 26 * clock providers must implement. 27 * 28 * Clock consumers/clients are the HW modules driven by the clock signals. This 29 * header file describes the API used by drivers for those HW modules. 30 */ 31 32struct udevice; 33 34/** 35 * struct clk - A handle to (allowing control of) a single clock. 36 * 37 * Clients provide storage for clock handles. The content of the structure is 38 * managed solely by the clock API and clock drivers. A clock struct is 39 * initialized by "get"ing the clock struct. The clock struct is passed to all 40 * other clock APIs to identify which clock signal to operate upon. 41 * 42 * @dev: The device which implements the clock signal. 43 * @rate: The clock rate (in HZ). 44 * @flags: Flags used across common clock structure (e.g. CLK_) 45 * Clock IP blocks specific flags (i.e. mux, div, gate, etc) are defined 46 * in struct's for those devices (e.g. struct clk_mux). 47 * @id: The clock signal ID within the provider. 48 * @data: An optional data field for scenarios where a single integer ID is not 49 * sufficient. If used, it can be populated through an .of_xlate op and 50 * processed during the various clock ops. 51 * 52 * Should additional information to identify and configure any clock signal 53 * for any provider be required in the future, the struct could be expanded to 54 * either (a) add more fields to allow clock providers to store additional 55 * information, or (b) replace the id field with an opaque pointer, which the 56 * provider would dynamically allocated during its .of_xlate op, and process 57 * during is .request op. This may require the addition of an extra op to clean 58 * up the allocation. 59 */ 60struct clk { 61 struct udevice *dev; 62 long long rate; /* in HZ */ 63 u32 flags; 64 int enable_count; 65 /* 66 * Written by of_xlate. In the future, we might add more fields here. 67 */ 68 unsigned long id; 69 unsigned long data; 70}; 71 72/** 73 * struct clk_bulk - A handle to (allowing control of) a bulk of clocks. 74 * 75 * Clients provide storage for the clock bulk. The content of the structure is 76 * managed solely by the clock API. A clock bulk struct is 77 * initialized by "get"ing the clock bulk struct. 78 * The clock bulk struct is passed to all other bulk clock APIs to apply 79 * the API to all the clock in the bulk struct. 80 * 81 * @clks: An array of clock handles. 82 * @count: The number of clock handles in the clks array. 83 */ 84struct clk_bulk { 85 struct clk *clks; 86 unsigned int count; 87}; 88 89#if CONFIG_IS_ENABLED(OF_CONTROL) && CONFIG_IS_ENABLED(CLK) 90struct phandle_1_arg; 91int clk_get_by_index_platdata(struct udevice *dev, int index, 92 struct phandle_1_arg *cells, struct clk *clk); 93 94/** 95 * clock_get_by_index - Get/request a clock by integer index. 96 * 97 * This looks up and requests a clock. The index is relative to the client 98 * device; each device is assumed to have n clocks associated with it somehow, 99 * and this function finds and requests one of them. The mapping of client 100 * device clock indices to provider clocks may be via device-tree properties, 101 * board-provided mapping tables, or some other mechanism. 102 * 103 * @dev: The client device. 104 * @index: The index of the clock to request, within the client's list of 105 * clocks. 106 * @clock A pointer to a clock struct to initialize. 107 * @return 0 if OK, or a negative error code. 108 */ 109int clk_get_by_index(struct udevice *dev, int index, struct clk *clk); 110 111/** 112 * clock_get_by_index_nodev - Get/request a clock by integer index 113 * without a device. 114 * 115 * This is a version of clk_get_by_index() that does not use a device. 116 * 117 * @node: The client ofnode. 118 * @index: The index of the clock to request, within the client's list of 119 * clocks. 120 * @clock A pointer to a clock struct to initialize. 121 * @return 0 if OK, or a negative error code. 122 */ 123int clk_get_by_index_nodev(ofnode node, int index, struct clk *clk); 124 125/** 126 * clock_get_bulk - Get/request all clocks of a device. 127 * 128 * This looks up and requests all clocks of the client device; each device is 129 * assumed to have n clocks associated with it somehow, and this function finds 130 * and requests all of them in a separate structure. The mapping of client 131 * device clock indices to provider clocks may be via device-tree properties, 132 * board-provided mapping tables, or some other mechanism. 133 * 134 * @dev: The client device. 135 * @bulk A pointer to a clock bulk struct to initialize. 136 * @return 0 if OK, or a negative error code. 137 */ 138int clk_get_bulk(struct udevice *dev, struct clk_bulk *bulk); 139 140/** 141 * clock_get_by_name - Get/request a clock by name. 142 * 143 * This looks up and requests a clock. The name is relative to the client 144 * device; each device is assumed to have n clocks associated with it somehow, 145 * and this function finds and requests one of them. The mapping of client 146 * device clock names to provider clocks may be via device-tree properties, 147 * board-provided mapping tables, or some other mechanism. 148 * 149 * @dev: The client device. 150 * @name: The name of the clock to request, within the client's list of 151 * clocks. 152 * @clock: A pointer to a clock struct to initialize. 153 * @return 0 if OK, or a negative error code. 154 */ 155int clk_get_by_name(struct udevice *dev, const char *name, struct clk *clk); 156 157/** 158 * devm_clk_get - lookup and obtain a managed reference to a clock producer. 159 * @dev: device for clock "consumer" 160 * @id: clock consumer ID 161 * 162 * Returns a struct clk corresponding to the clock producer, or 163 * valid IS_ERR() condition containing errno. The implementation 164 * uses @dev and @id to determine the clock consumer, and thereby 165 * the clock producer. (IOW, @id may be identical strings, but 166 * clk_get may return different clock producers depending on @dev.) 167 * 168 * Drivers must assume that the clock source is not enabled. 169 * 170 * devm_clk_get should not be called from within interrupt context. 171 * 172 * The clock will automatically be freed when the device is unbound 173 * from the bus. 174 */ 175struct clk *devm_clk_get(struct udevice *dev, const char *id); 176 177/** 178 * devm_clk_get_optional - lookup and obtain a managed reference to an optional 179 * clock producer. 180 * @dev: device for clock "consumer" 181 * @id: clock consumer ID 182 * 183 * Behaves the same as devm_clk_get() except where there is no clock producer. 184 * In this case, instead of returning -ENOENT, the function returns NULL. 185 */ 186struct clk *devm_clk_get_optional(struct udevice *dev, const char *id); 187 188/** 189 * clk_release_all() - Disable (turn off)/Free an array of previously 190 * requested clocks. 191 * 192 * For each clock contained in the clock array, this function will check if 193 * clock has been previously requested and then will disable and free it. 194 * 195 * @clk: A clock struct array that was previously successfully 196 * requested by clk_request/get_by_*(). 197 * @count Number of clock contained in the array 198 * @return zero on success, or -ve error code. 199 */ 200int clk_release_all(struct clk *clk, int count); 201 202/** 203 * devm_clk_put - "free" a managed clock source 204 * @dev: device used to acquire the clock 205 * @clk: clock source acquired with devm_clk_get() 206 * 207 * Note: drivers must ensure that all clk_enable calls made on this 208 * clock source are balanced by clk_disable calls prior to calling 209 * this function. 210 * 211 * clk_put should not be called from within interrupt context. 212 */ 213void devm_clk_put(struct udevice *dev, struct clk *clk); 214 215#else 216static inline int clk_get_by_index(struct udevice *dev, int index, 217 struct clk *clk) 218{ 219 return -ENOSYS; 220} 221 222static inline int clk_get_bulk(struct udevice *dev, struct clk_bulk *bulk) 223{ 224 return -ENOSYS; 225} 226 227static inline int clk_get_by_name(struct udevice *dev, const char *name, 228 struct clk *clk) 229{ 230 return -ENOSYS; 231} 232 233static inline int clk_release_all(struct clk *clk, int count) 234{ 235 return -ENOSYS; 236} 237#endif 238 239#if (CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)) && \ 240 CONFIG_IS_ENABLED(CLK) 241/** 242 * clk_set_defaults - Process 'assigned-{clocks/clock-parents/clock-rates}' 243 * properties to configure clocks 244 * 245 * @dev: A device to process (the ofnode associated with this device 246 * will be processed). 247 * @stage: A integer. 0 indicates that this is called before the device 248 * is probed. 1 indicates that this is called just after the 249 * device has been probed 250 */ 251int clk_set_defaults(struct udevice *dev, int stage); 252#else 253static inline int clk_set_defaults(struct udevice *dev, int stage) 254{ 255 return 0; 256} 257#endif 258 259/** 260 * clk_release_bulk() - Disable (turn off)/Free an array of previously 261 * requested clocks in a clock bulk struct. 262 * 263 * For each clock contained in the clock bulk struct, this function will check 264 * if clock has been previously requested and then will disable and free it. 265 * 266 * @clk: A clock bulk struct that was previously successfully 267 * requested by clk_get_bulk(). 268 * @return zero on success, or -ve error code. 269 */ 270static inline int clk_release_bulk(struct clk_bulk *bulk) 271{ 272 return clk_release_all(bulk->clks, bulk->count); 273} 274 275/** 276 * clk_request - Request a clock by provider-specific ID. 277 * 278 * This requests a clock using a provider-specific ID. Generally, this function 279 * should not be used, since clk_get_by_index/name() provide an interface that 280 * better separates clients from intimate knowledge of clock providers. 281 * However, this function may be useful in core SoC-specific code. 282 * 283 * @dev: The clock provider device. 284 * @clock: A pointer to a clock struct to initialize. The caller must 285 * have already initialized any field in this struct which the 286 * clock provider uses to identify the clock. 287 * @return 0 if OK, or a negative error code. 288 */ 289int clk_request(struct udevice *dev, struct clk *clk); 290 291/** 292 * clock_free - Free a previously requested clock. 293 * 294 * @clock: A clock struct that was previously successfully requested by 295 * clk_request/get_by_*(). 296 * @return 0 if OK, or a negative error code. 297 */ 298int clk_free(struct clk *clk); 299 300/** 301 * clk_get_rate() - Get current clock rate. 302 * 303 * @clk: A clock struct that was previously successfully requested by 304 * clk_request/get_by_*(). 305 * @return clock rate in Hz, or -ve error code. 306 */ 307ulong clk_get_rate(struct clk *clk); 308 309/** 310 * clk_get_parent() - Get current clock's parent. 311 * 312 * @clk: A clock struct that was previously successfully requested by 313 * clk_request/get_by_*(). 314 * @return pointer to parent's struct clk, or error code passed as pointer 315 */ 316struct clk *clk_get_parent(struct clk *clk); 317 318/** 319 * clk_get_parent_rate() - Get parent of current clock rate. 320 * 321 * @clk: A clock struct that was previously successfully requested by 322 * clk_request/get_by_*(). 323 * @return clock rate in Hz, or -ve error code. 324 */ 325long long clk_get_parent_rate(struct clk *clk); 326 327/** 328 * clk_set_rate() - Set current clock rate. 329 * 330 * @clk: A clock struct that was previously successfully requested by 331 * clk_request/get_by_*(). 332 * @rate: New clock rate in Hz. 333 * @return new rate, or -ve error code. 334 */ 335ulong clk_set_rate(struct clk *clk, ulong rate); 336 337/** 338 * clk_set_parent() - Set current clock parent. 339 * 340 * @clk: A clock struct that was previously successfully requested by 341 * clk_request/get_by_*(). 342 * @parent: A clock struct that was previously successfully requested by 343 * clk_request/get_by_*(). 344 * @return new rate, or -ve error code. 345 */ 346int clk_set_parent(struct clk *clk, struct clk *parent); 347 348/** 349 * clk_enable() - Enable (turn on) a clock. 350 * 351 * @clk: A clock struct that was previously successfully requested by 352 * clk_request/get_by_*(). 353 * @return zero on success, or -ve error code. 354 */ 355int clk_enable(struct clk *clk); 356 357/** 358 * clk_enable_bulk() - Enable (turn on) all clocks in a clock bulk struct. 359 * 360 * @bulk: A clock bulk struct that was previously successfully requested 361 * by clk_get_bulk(). 362 * @return zero on success, or -ve error code. 363 */ 364int clk_enable_bulk(struct clk_bulk *bulk); 365 366/** 367 * clk_disable() - Disable (turn off) a clock. 368 * 369 * @clk: A clock struct that was previously successfully requested by 370 * clk_request/get_by_*(). 371 * @return zero on success, or -ve error code. 372 */ 373int clk_disable(struct clk *clk); 374 375/** 376 * clk_disable_bulk() - Disable (turn off) all clocks in a clock bulk struct. 377 * 378 * @bulk: A clock bulk struct that was previously successfully requested 379 * by clk_get_bulk(). 380 * @return zero on success, or -ve error code. 381 */ 382int clk_disable_bulk(struct clk_bulk *bulk); 383 384/** 385 * clk_is_match - check if two clk's point to the same hardware clock 386 * @p: clk compared against q 387 * @q: clk compared against p 388 * 389 * Returns true if the two struct clk pointers both point to the same hardware 390 * clock node. 391 * 392 * Returns false otherwise. Note that two NULL clks are treated as matching. 393 */ 394bool clk_is_match(const struct clk *p, const struct clk *q); 395 396int soc_clk_dump(void); 397 398/** 399 * clk_valid() - check if clk is valid 400 * 401 * @clk: the clock to check 402 * @return true if valid, or false 403 */ 404static inline bool clk_valid(struct clk *clk) 405{ 406 return clk && !!clk->dev; 407} 408 409/** 410 * clk_get_by_id() - Get the clock by its ID 411 * 412 * @id: The clock ID to search for 413 * 414 * @clkp: A pointer to clock struct that has been found among added clocks 415 * to UCLASS_CLK 416 * @return zero on success, or -ENOENT on error 417 */ 418int clk_get_by_id(ulong id, struct clk **clkp); 419 420/** 421 * clk_dev_binded() - Check whether the clk has a device binded 422 * 423 * @clk A pointer to the clk 424 * 425 * @return true on binded, or false on no 426 */ 427bool clk_dev_binded(struct clk *clk); 428#endif 429 430#define clk_prepare_enable(clk) clk_enable(clk) 431#define clk_disable_unprepare(clk) clk_disable(clk) 432