include/clk.h

   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
  32 struct 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  */
  60 struct clk {
  61         struct udevice *dev;
  62         long long rate; /* in HZ */
  63         u32 flags;
  64         /*
  65          * Written by of_xlate. In the future, we might add more fields here.
  66          */
  67         unsigned long id;
  68         unsigned long data;
  69 };
  70
  71 /**
  72  * struct clk_bulk - A handle to (allowing control of) a bulk of clocks.
  73  *
  74  * Clients provide storage for the clock bulk. The content of the structure is
  75  * managed solely by the clock API. A clock bulk struct is
  76  * initialized by "get"ing the clock bulk struct.
  77  * The clock bulk struct is passed to all other bulk clock APIs to apply
  78  * the API to all the clock in the bulk struct.
  79  *
  80  * @clks: An array of clock handles.
  81  * @count: The number of clock handles in the clks array.
  82  */
  83 struct clk_bulk {
  84         struct clk *clks;
  85         unsigned int count;
  86 };
  87
  88 #if CONFIG_IS_ENABLED(OF_CONTROL) && CONFIG_IS_ENABLED(CLK)
  89 struct phandle_1_arg;
  90 int clk_get_by_index_platdata(struct udevice *dev, int index,
  91                               struct phandle_1_arg *cells, struct clk *clk);
  92
  93 /**
  94  * clock_get_by_index - Get/request a clock by integer index.
  95  *
  96  * This looks up and requests a clock. The index is relative to the client
  97  * device; each device is assumed to have n clocks associated with it somehow,
  98  * and this function finds and requests one of them. The mapping of client
  99  * device clock indices to provider clocks may be via device-tree properties,
 100  * board-provided mapping tables, or some other mechanism.
 101  *
 102  * @dev:        The client device.
 103  * @index:      The index of the clock to request, within the client's list of
 104  *              clocks.
 105  * @clock       A pointer to a clock struct to initialize.
 106  * @return 0 if OK, or a negative error code.
 107  */
 108 int clk_get_by_index(struct udevice *dev, int index, struct clk *clk);
 109
 110 /**
 111  * clock_get_by_index_nodev - Get/request a clock by integer index
 112  * without a device.
 113  *
 114  * This is a version of clk_get_by_index() that does not use a device.
 115  *
 116  * @node:       The client ofnode.
 117  * @index:      The index of the clock to request, within the client's list of
 118  *              clocks.
 119  * @clock       A pointer to a clock struct to initialize.
 120  * @return 0 if OK, or a negative error code.
 121  */
 122 int clk_get_by_index_nodev(ofnode node, int index, struct clk *clk);
 123
 124 /**
 125  * clock_get_bulk - Get/request all clocks of a device.
 126  *
 127  * This looks up and requests all clocks of the client device; each device is
 128  * assumed to have n clocks associated with it somehow, and this function finds
 129  * and requests all of them in a separate structure. The mapping of client
 130  * device clock indices to provider clocks may be via device-tree properties,
 131  * board-provided mapping tables, or some other mechanism.
 132  *
 133  * @dev:        The client device.
 134  * @bulk        A pointer to a clock bulk struct to initialize.
 135  * @return 0 if OK, or a negative error code.
 136  */
 137 int clk_get_bulk(struct udevice *dev, struct clk_bulk *bulk);
 138
 139 /**
 140  * clock_get_by_name - Get/request a clock by name.
 141  *
 142  * This looks up and requests a clock. The name is relative to the client
 143  * device; each device is assumed to have n clocks associated with it somehow,
 144  * and this function finds and requests one of them. The mapping of client
 145  * device clock names to provider clocks may be via device-tree properties,
 146  * board-provided mapping tables, or some other mechanism.
 147  *
 148  * @dev:        The client device.
 149  * @name:       The name of the clock to request, within the client's list of
 150  *              clocks.
 151  * @clock:      A pointer to a clock struct to initialize.
 152  * @return 0 if OK, or a negative error code.
 153  */
 154 int clk_get_by_name(struct udevice *dev, const char *name, struct clk *clk);
 155
 156 /**
 157  * clk_release_all() - Disable (turn off)/Free an array of previously
 158  * requested clocks.
 159  *
 160  * For each clock contained in the clock array, this function will check if
 161  * clock has been previously requested and then will disable and free it.
 162  *
 163  * @clk:        A clock struct array that was previously successfully
 164  *              requested by clk_request/get_by_*().
 165  * @count       Number of clock contained in the array
 166  * @return zero on success, or -ve error code.
 167  */
 168 int clk_release_all(struct clk *clk, int count);
 169
 170 #else
 171 static inline int clk_get_by_index(struct udevice *dev, int index,
 172                                    struct clk *clk)
 173 {
 174         return -ENOSYS;
 175 }
 176
 177 static inline int clk_get_bulk(struct udevice *dev, struct clk_bulk *bulk)
 178 {
 179         return -ENOSYS;
 180 }
 181
 182 static inline int clk_get_by_name(struct udevice *dev, const char *name,
 183                            struct clk *clk)
 184 {
 185         return -ENOSYS;
 186 }
 187
 188 static inline int clk_release_all(struct clk *clk, int count)
 189 {
 190         return -ENOSYS;
 191 }
 192 #endif
 193
 194 #if (CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)) && \
 195         CONFIG_IS_ENABLED(CLK)
 196 /**
 197  * clk_set_defaults - Process 'assigned-{clocks/clock-parents/clock-rates}'
 198  *                    properties to configure clocks
 199  *
 200  * @dev:        A device to process (the ofnode associated with this device
 201  *              will be processed).
 202  */
 203 int clk_set_defaults(struct udevice *dev);
 204 #else
 205 static inline int clk_set_defaults(struct udevice *dev)
 206 {
 207         return 0;
 208 }
 209 #endif
 210
 211 /**
 212  * clk_release_bulk() - Disable (turn off)/Free an array of previously
 213  * requested clocks in a clock bulk struct.
 214  *
 215  * For each clock contained in the clock bulk struct, this function will check
 216  * if clock has been previously requested and then will disable and free it.
 217  *
 218  * @clk:        A clock bulk struct that was previously successfully
 219  *              requested by clk_get_bulk().
 220  * @return zero on success, or -ve error code.
 221  */
 222 static inline int clk_release_bulk(struct clk_bulk *bulk)
 223 {
 224         return clk_release_all(bulk->clks, bulk->count);
 225 }
 226
 227 /**
 228  * clk_request - Request a clock by provider-specific ID.
 229  *
 230  * This requests a clock using a provider-specific ID. Generally, this function
 231  * should not be used, since clk_get_by_index/name() provide an interface that
 232  * better separates clients from intimate knowledge of clock providers.
 233  * However, this function may be useful in core SoC-specific code.
 234  *
 235  * @dev:        The clock provider device.
 236  * @clock:      A pointer to a clock struct to initialize. The caller must
 237  *              have already initialized any field in this struct which the
 238  *              clock provider uses to identify the clock.
 239  * @return 0 if OK, or a negative error code.
 240  */
 241 int clk_request(struct udevice *dev, struct clk *clk);
 242
 243 /**
 244  * clock_free - Free a previously requested clock.
 245  *
 246  * @clock:      A clock struct that was previously successfully requested by
 247  *              clk_request/get_by_*().
 248  * @return 0 if OK, or a negative error code.
 249  */
 250 int clk_free(struct clk *clk);
 251
 252 /**
 253  * clk_get_rate() - Get current clock rate.
 254  *
 255  * @clk:        A clock struct that was previously successfully requested by
 256  *              clk_request/get_by_*().
 257  * @return clock rate in Hz, or -ve error code.
 258  */
 259 ulong clk_get_rate(struct clk *clk);
 260
 261 /**
 262  * clk_get_parent() - Get current clock's parent.
 263  *
 264  * @clk:        A clock struct that was previously successfully requested by
 265  *              clk_request/get_by_*().
 266  * @return pointer to parent's struct clk, or error code passed as pointer
 267  */
 268 struct clk *clk_get_parent(struct clk *clk);
 269
 270 /**
 271  * clk_get_parent_rate() - Get parent of current clock rate.
 272  *
 273  * @clk:        A clock struct that was previously successfully requested by
 274  *              clk_request/get_by_*().
 275  * @return clock rate in Hz, or -ve error code.
 276  */
 277 long long clk_get_parent_rate(struct clk *clk);
 278
 279 /**
 280  * clk_set_rate() - Set current clock rate.
 281  *
 282  * @clk:        A clock struct that was previously successfully requested by
 283  *              clk_request/get_by_*().
 284  * @rate:       New clock rate in Hz.
 285  * @return new rate, or -ve error code.
 286  */
 287 ulong clk_set_rate(struct clk *clk, ulong rate);
 288
 289 /**
 290  * clk_set_parent() - Set current clock parent.
 291  *
 292  * @clk:        A clock struct that was previously successfully requested by
 293  *              clk_request/get_by_*().
 294  * @parent:     A clock struct that was previously successfully requested by
 295  *              clk_request/get_by_*().
 296  * @return new rate, or -ve error code.
 297  */
 298 int clk_set_parent(struct clk *clk, struct clk *parent);
 299
 300 /**
 301  * clk_enable() - Enable (turn on) a clock.
 302  *
 303  * @clk:        A clock struct that was previously successfully requested by
 304  *              clk_request/get_by_*().
 305  * @return zero on success, or -ve error code.
 306  */
 307 int clk_enable(struct clk *clk);
 308
 309 /**
 310  * clk_enable_bulk() - Enable (turn on) all clocks in a clock bulk struct.
 311  *
 312  * @bulk:       A clock bulk struct that was previously successfully requested
 313  *              by clk_get_bulk().
 314  * @return zero on success, or -ve error code.
 315  */
 316 int clk_enable_bulk(struct clk_bulk *bulk);
 317
 318 /**
 319  * clk_disable() - Disable (turn off) a clock.
 320  *
 321  * @clk:        A clock struct that was previously successfully requested by
 322  *              clk_request/get_by_*().
 323  * @return zero on success, or -ve error code.
 324  */
 325 int clk_disable(struct clk *clk);
 326
 327 /**
 328  * clk_disable_bulk() - Disable (turn off) all clocks in a clock bulk struct.
 329  *
 330  * @bulk:       A clock bulk struct that was previously successfully requested
 331  *              by clk_get_bulk().
 332  * @return zero on success, or -ve error code.
 333  */
 334 int clk_disable_bulk(struct clk_bulk *bulk);
 335
 336 /**
 337  * clk_is_match - check if two clk's point to the same hardware clock
 338  * @p: clk compared against q
 339  * @q: clk compared against p
 340  *
 341  * Returns true if the two struct clk pointers both point to the same hardware
 342  * clock node.
 343  *
 344  * Returns false otherwise. Note that two NULL clks are treated as matching.
 345  */
 346 bool clk_is_match(const struct clk *p, const struct clk *q);
 347
 348 int soc_clk_dump(void);
 349
 350 /**
 351  * clk_valid() - check if clk is valid
 352  *
 353  * @clk:        the clock to check
 354  * @return true if valid, or false
 355  */
 356 static inline bool clk_valid(struct clk *clk)
 357 {
 358         return !!clk->dev;
 359 }
 360
 361 /**
 362  * clk_get_by_id() - Get the clock by its ID
 363  *
 364  * @id: The clock ID to search for
 365  *
 366  * @clkp:       A pointer to clock struct that has been found among added clocks
 367  *              to UCLASS_CLK
 368  * @return zero on success, or -ENOENT on error
 369  */
 370 int clk_get_by_id(ulong id, struct clk **clkp);
 371
 372 /**
 373  * clk_dev_binded() - Check whether the clk has a device binded
 374  *
 375  * @clk         A pointer to the clk
 376  *
 377  * @return true on binded, or false on no
 378  */
 379 bool clk_dev_binded(struct clk *clk);
 380 #endif