include/power/regulator.h

   1 /*
   2  *  Copyright (C) 2014-2015 Samsung Electronics
   3  *  Przemyslaw Marczak <p.marczak@samsung.com>
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 #ifndef _INCLUDE_REGULATOR_H_
   9 #define _INCLUDE_REGULATOR_H_
  10
  11 /**
  12  * U-Boot Voltage/Current Regulator
  13  * ================================
  14  *
  15  * The regulator API is based on a driver model, with the device tree support.
  16  * And this header describes the functions and data types for the uclass id:
  17  * 'UCLASS_REGULATOR' and the regulator driver API.
  18  *
  19  * The regulator uclass - is based on uclass platform data which is allocated,
  20  * automatically for each regulator device on bind and 'dev->uclass_platdata'
  21  * points to it. The data type is: 'struct dm_regulator_uclass_platdata'.
  22  * The uclass file: 'drivers/power/regulator/regulator-uclass.c'
  23  *
  24  * The regulator device - is based on driver's model 'struct udevice'.
  25  * The API can use regulator name in two meanings:
  26  * - devname  - the regulator device's name: 'dev->name'
  27  * - platname - the device's platdata's name. So in the code it looks like:
  28  *              'uc_pdata = dev->uclass_platdata'; 'name = uc_pdata->name'.
  29  *
  30  * The regulator device driver - provide an implementation of uclass operations
  31  * pointed by 'dev->driver->ops' as a struct of type 'struct dm_regulator_ops'.
  32  *
  33  * To proper bind the regulator device, the device tree node should provide
  34  * regulator constraints, like in the example below:
  35  *
  36  * ldo1 {
  37  *      regulator-name = "VDD_MMC_1.8V";     (must be unique for proper bind)
  38  *      regulator-min-microvolt = <1000000>; (optional)
  39  *      regulator-max-microvolt = <1000000>; (optional)
  40  *      regulator-min-microamp = <1000>;     (optional)
  41  *      regulator-max-microamp = <1000>;     (optional)
  42  *      regulator-always-on;                 (optional)
  43  *      regulator-boot-on;                   (optional)
  44  * };
  45  *
  46  * Note: For the proper operation, at least name constraint is needed, since
  47  * it can be used when calling regulator_get_by_platname(). And the mandatory
  48  * rule for this name is, that it must be globally unique for the single dts.
  49  *
  50  * Regulator bind:
  51  * For each regulator device, the device_bind() should be called with passed
  52  * device tree offset. This is required for this uclass's '.post_bind' method,
  53  * which does the scan on the device node, for the 'regulator-name' constraint.
  54  * If the parent is not a PMIC device, and the child is not bind by function:
  55  * 'pmic_bind_childs()', then it's recommended to bind the device by call to
  56  * dm_scan_fdt_node() - this is usually done automatically for bus devices,
  57  * as a post bind method.
  58  *
  59  * Regulator get:
  60  * Having the device's name constraint, we can call regulator_by_platname(),
  61  * to find the required regulator. Before return, the regulator is probed,
  62  * and the rest of its constraints are put into the device's uclass platform
  63  * data, by the uclass regulator '.pre_probe' method.
  64  *
  65  * For more info about PMIC bind, please refer to file: 'include/power/pmic.h'
  66  *
  67  * Note:
  68  * Please do not use the device_bind_by_name() function, since it pass '-1' as
  69  * device node offset - and the bind will fail on uclass .post_bind method,
  70  * because of missing 'regulator-name' constraint.
  71  *
  72  *
  73  * Fixed Voltage/Current Regulator
  74  * ===============================
  75  *
  76  * When fixed voltage regulator is needed, then enable the config:
  77  * - CONFIG_DM_REGULATOR_FIXED
  78  *
  79  * The driver file: 'drivers/power/regulator/fixed.c', provides basic support
  80  * for control the GPIO, and return the device tree constraint values.
  81  *
  82  * To bind the fixed voltage regulator device, we usually use a 'simple-bus'
  83  * node as a parent. And 'regulator-fixed' for the driver compatible. This is
  84  * the same as in the kernel. The example node of fixed regulator:
  85  *
  86  * simple-bus {
  87  *     compatible = "simple-bus";
  88  *     #address-cells = <1>;
  89  *     #size-cells = <0>;
  90  *
  91  *     blue_led {
  92  *         compatible = "regulator-fixed";
  93  *         regulator-name = "VDD_LED_3.3V";
  94  *         regulator-min-microvolt = <3300000>;
  95  *         regulator-max-microvolt = <3300000>;
  96  *         gpio = <&gpc1 0 GPIO_ACTIVE_LOW>;
  97  *     };
  98  * };
  99  *
 100  * The fixed regulator devices also provide regulator uclass platform data. And
 101  * devices bound from such node, can use the regulator drivers API.
 102 */
 103
 104 /* enum regulator_type - used for regulator_*() variant calls */
 105 enum regulator_type {
 106         REGULATOR_TYPE_LDO = 0,
 107         REGULATOR_TYPE_BUCK,
 108         REGULATOR_TYPE_DVS,
 109         REGULATOR_TYPE_FIXED,
 110         REGULATOR_TYPE_OTHER,
 111 };
 112
 113 /**
 114  * struct dm_regulator_mode - this structure holds an information about
 115  * each regulator operation mode. Probably in most cases - an array.
 116  * This will be probably a driver-static data, since it is device-specific.
 117  *
 118  * @id             - a driver-specific mode id
 119  * @register_value - a driver-specific value for its mode id
 120  * @name           - the name of mode - used for regulator command
 121  * Note:
 122  * The field 'id', should be always a positive number, since the negative values
 123  * are reserved for the errno numbers when returns the mode id.
 124  */
 125 struct dm_regulator_mode {
 126         int id; /* Set only as >= 0 (negative value is reserved for errno) */
 127         int register_value;
 128         const char *name;
 129 };
 130
 131 enum regulator_flag {
 132         REGULATOR_FLAG_AUTOSET_UV       = 1 << 0,
 133         REGULATOR_FLAG_AUTOSET_UA       = 1 << 1,
 134 };
 135
 136 /**
 137  * struct dm_regulator_uclass_platdata - pointed by dev->uclass_platdata, and
 138  * allocated on each regulator bind. This structure holds an information
 139  * about each regulator's constraints and supported operation modes.
 140  * There is no "step" voltage value - so driver should take care of this.
 141  *
 142  * @type       - one of 'enum regulator_type'
 143  * @mode       - pointer to the regulator mode (array if more than one)
 144  * @mode_count - number of '.mode' entries
 145  * @min_uV*    - minimum voltage (micro Volts)
 146  * @max_uV*    - maximum voltage (micro Volts)
 147  * @min_uA*    - minimum amperage (micro Amps)
 148  * @max_uA*    - maximum amperage (micro Amps)
 149  * @always_on* - bool type, true or false
 150  * @boot_on*   - bool type, true or false
 151  * TODO(sjg@chromium.org): Consider putting the above two into @flags
 152  * @flags:     - flags value (see REGULATOR_FLAG_...)
 153  * @name**     - fdt regulator name - should be taken from the device tree
 154  *
 155  * Note:
 156  * *  - set automatically on device probe by the uclass's '.pre_probe' method.
 157  * ** - set automatically on device bind by the uclass's '.post_bind' method.
 158  * The constraints: type, mode, mode_count, can be set by device driver, e.g.
 159  * by the driver '.probe' method.
 160  */
 161 struct dm_regulator_uclass_platdata {
 162         enum regulator_type type;
 163         struct dm_regulator_mode *mode;
 164         int mode_count;
 165         int min_uV;
 166         int max_uV;
 167         int min_uA;
 168         int max_uA;
 169         bool always_on;
 170         bool boot_on;
 171         const char *name;
 172         int flags;
 173 };
 174
 175 /* Regulator device operations */
 176 struct dm_regulator_ops {
 177         /**
 178          * The regulator output value function calls operates on a micro Volts.
 179          *
 180          * get/set_value - get/set output value of the given output number
 181          * @dev          - regulator device
 182          * Sets:
 183          * @uV           - set the output value [micro Volts]
 184          * @return output value [uV] on success or negative errno if fail.
 185          */
 186         int (*get_value)(struct udevice *dev);
 187         int (*set_value)(struct udevice *dev, int uV);
 188
 189         /**
 190          * The regulator output current function calls operates on a micro Amps.
 191          *
 192          * get/set_current - get/set output current of the given output number
 193          * @dev            - regulator device
 194          * Sets:
 195          * @uA           - set the output current [micro Amps]
 196          * @return output value [uA] on success or negative errno if fail.
 197          */
 198         int (*get_current)(struct udevice *dev);
 199         int (*set_current)(struct udevice *dev, int uA);
 200
 201         /**
 202          * The most basic feature of the regulator output is its enable state.
 203          *
 204          * get/set_enable - get/set enable state of the given output number
 205          * @dev           - regulator device
 206          * Sets:
 207          * @enable         - set true - enable or false - disable
 208          * @return true/false for get; or 0 / -errno for set.
 209          */
 210         bool (*get_enable)(struct udevice *dev);
 211         int (*set_enable)(struct udevice *dev, bool enable);
 212
 213         /**
 214          * The 'get/set_mode()' function calls should operate on a driver-
 215          * specific mode id definitions, which should be found in:
 216          * field 'id' of struct dm_regulator_mode.
 217          *
 218          * get/set_mode - get/set operation mode of the given output number
 219          * @dev         - regulator device
 220          * Sets
 221          * @mode_id     - set output mode id (struct dm_regulator_mode->id)
 222          * @return id/0 for get/set on success or negative errno if fail.
 223          * Note:
 224          * The field 'id' of struct type 'dm_regulator_mode', should be always
 225          * a positive number, since the negative is reserved for the error.
 226          */
 227         int (*get_mode)(struct udevice *dev);
 228         int (*set_mode)(struct udevice *dev, int mode_id);
 229 };
 230
 231 /**
 232  * regulator_mode: returns a pointer to the array of regulator mode info
 233  *
 234  * @dev        - pointer to the regulator device
 235  * @modep      - pointer to the returned mode info array
 236  * @return     - count of modep entries on success or negative errno if fail.
 237  */
 238 int regulator_mode(struct udevice *dev, struct dm_regulator_mode **modep);
 239
 240 /**
 241  * regulator_get_value: get microvoltage voltage value of a given regulator
 242  *
 243  * @dev    - pointer to the regulator device
 244  * @return - positive output value [uV] on success or negative errno if fail.
 245  */
 246 int regulator_get_value(struct udevice *dev);
 247
 248 /**
 249  * regulator_set_value: set the microvoltage value of a given regulator.
 250  *
 251  * @dev    - pointer to the regulator device
 252  * @uV     - the output value to set [micro Volts]
 253  * @return - 0 on success or -errno val if fails
 254  */
 255 int regulator_set_value(struct udevice *dev, int uV);
 256
 257 /**
 258  * regulator_get_current: get microampere value of a given regulator
 259  *
 260  * @dev    - pointer to the regulator device
 261  * @return - positive output current [uA] on success or negative errno if fail.
 262  */
 263 int regulator_get_current(struct udevice *dev);
 264
 265 /**
 266  * regulator_set_current: set the microampere value of a given regulator.
 267  *
 268  * @dev    - pointer to the regulator device
 269  * @uA     - set the output current [micro Amps]
 270  * @return - 0 on success or -errno val if fails
 271  */
 272 int regulator_set_current(struct udevice *dev, int uA);
 273
 274 /**
 275  * regulator_get_enable: get regulator device enable state.
 276  *
 277  * @dev    - pointer to the regulator device
 278  * @return - true/false of enable state
 279  */
 280 bool regulator_get_enable(struct udevice *dev);
 281
 282 /**
 283  * regulator_set_enable: set regulator enable state
 284  *
 285  * @dev    - pointer to the regulator device
 286  * @enable - set true or false
 287  * @return - 0 on success or -errno val if fails
 288  */
 289 int regulator_set_enable(struct udevice *dev, bool enable);
 290
 291 /**
 292  * regulator_get_mode: get active operation mode id of a given regulator
 293  *
 294  * @dev    - pointer to the regulator device
 295  * @return - positive mode 'id' number on success or -errno val if fails
 296  * Note:
 297  * The device can provide an array of operating modes, which is type of struct
 298  * dm_regulator_mode. Each mode has it's own 'id', which should be unique inside
 299  * that array. By calling this function, the driver should return an active mode
 300  * id of the given regulator device.
 301  */
 302 int regulator_get_mode(struct udevice *dev);
 303
 304 /**
 305  * regulator_set_mode: set the given regulator's, active mode id
 306  *
 307  * @dev     - pointer to the regulator device
 308  * @mode_id - mode id to set ('id' field of struct type dm_regulator_mode)
 309  * @return  - 0 on success or -errno value if fails
 310  * Note:
 311  * The device can provide an array of operating modes, which is type of struct
 312  * dm_regulator_mode. Each mode has it's own 'id', which should be unique inside
 313  * that array. By calling this function, the driver should set the active mode
 314  * of a given regulator to given by "mode_id" argument.
 315  */
 316 int regulator_set_mode(struct udevice *dev, int mode_id);
 317
 318 /**
 319  * regulators_enable_boot_on() - enable regulators needed for boot
 320  *
 321  * This enables all regulators which are marked to be on at boot time. This
 322  * only works for regulators which don't have a range for voltage/current,
 323  * since in that case it is not possible to know which value to use.
 324  *
 325  * This effectively calls regulator_autoset() for every regulator.
 326  */
 327 int regulators_enable_boot_on(bool verbose);
 328
 329 /**
 330  * regulator_autoset: setup the voltage/current on a regulator
 331  *
 332  * The setup depends on constraints found in device's uclass's platform data
 333  * (struct dm_regulator_uclass_platdata):
 334  *
 335  * - Enable - will set - if any of: 'always_on' or 'boot_on' is set to true,
 336  *   or if both are unset, then the function returns
 337  * - Voltage value - will set - if '.min_uV' and '.max_uV' values are equal
 338  * - Current limit - will set - if '.min_uA' and '.max_uA' values are equal
 339  *
 340  * The function returns on the first-encountered error.
 341  *
 342  * @platname - expected string for dm_regulator_uclass_platdata .name field
 343  * @devp     - returned pointer to the regulator device - if non-NULL passed
 344  * @return: 0 on success or negative value of errno.
 345  */
 346 int regulator_autoset(struct udevice *dev);
 347
 348 /**
 349  * regulator_autoset_by_name: setup the regulator given by its uclass's
 350  * platform data name field. The setup depends on constraints found in device's
 351  * uclass's platform data (struct dm_regulator_uclass_platdata):
 352  * - Enable - will set - if any of: 'always_on' or 'boot_on' is set to true,
 353  *   or if both are unset, then the function returns
 354  * - Voltage value - will set - if '.min_uV' and '.max_uV' values are equal
 355  * - Current limit - will set - if '.min_uA' and '.max_uA' values are equal
 356  *
 357  * The function returns on first encountered error.
 358  *
 359  * @platname - expected string for dm_regulator_uclass_platdata .name field
 360  * @devp     - returned pointer to the regulator device - if non-NULL passed
 361  * @return: 0 on success or negative value of errno.
 362  *
 363  * The returned 'regulator' device can be used with:
 364  * - regulator_get/set_*
 365  */
 366 int regulator_autoset_by_name(const char *platname, struct udevice **devp);
 367
 368 /**
 369  * regulator_list_autoset: setup the regulators given by list of their uclass's
 370  * platform data name field. The setup depends on constraints found in device's
 371  * uclass's platform data. The function loops with calls to:
 372  * regulator_autoset_by_name() for each name from the list.
 373  *
 374  * @list_platname - an array of expected strings for .name field of each
 375  *                  regulator's uclass platdata
 376  * @list_devp     - an array of returned pointers to the successfully setup
 377  *                  regulator devices if non-NULL passed
 378  * @verbose       - (true/false) print each regulator setup info, or be quiet
 379  * @return 0 on successfully setup of all list entries, otherwise first error.
 380  *
 381  * The returned 'regulator' devices can be used with:
 382  * - regulator_get/set_*
 383  *
 384  * Note: The list must ends with NULL entry, like in the "platname" list below:
 385  * char *my_regulators[] = {
 386  *     "VCC_3.3V",
 387  *     "VCC_1.8V",
 388  *     NULL,
 389  * };
 390  */
 391 int regulator_list_autoset(const char *list_platname[],
 392                            struct udevice *list_devp[],
 393                            bool verbose);
 394
 395 /**
 396  * regulator_get_by_devname: returns the pointer to the pmic regulator device.
 397  * Search by name, found in regulator device's name.
 398  *
 399  * @devname - expected string for 'dev->name' of regulator device
 400  * @devp    - returned pointer to the regulator device
 401  * @return 0 on success or negative value of errno.
 402  *
 403  * The returned 'regulator' device is probed and can be used with:
 404  * - regulator_get/set_*
 405  */
 406 int regulator_get_by_devname(const char *devname, struct udevice **devp);
 407
 408 /**
 409  * regulator_get_by_platname: returns the pointer to the pmic regulator device.
 410  * Search by name, found in regulator uclass platdata.
 411  *
 412  * @platname - expected string for uc_pdata->name of regulator uclass platdata
 413  * @devp     - returns pointer to the regulator device or NULL on error
 414  * @return 0 on success or negative value of errno.
 415  *
 416  * The returned 'regulator' device is probed and can be used with:
 417  * - regulator_get/set_*
 418  */
 419 int regulator_get_by_platname(const char *platname, struct udevice **devp);
 420
 421 #endif /* _INCLUDE_REGULATOR_H_ */