arch/arm/mach-omap2/voltage.c

   1 /*
   2  * OMAP3/OMAP4 Voltage Management Routines
   3  *
   4  * Author: Thara Gopinath       <thara@ti.com>
   5  *
   6  * Copyright (C) 2007 Texas Instruments, Inc.
   7  * Rajendra Nayak <rnayak@ti.com>
   8  * Lesly A M <x0080970@ti.com>
   9  *
  10  * Copyright (C) 2008, 2011 Nokia Corporation
  11  * Kalle Jokiniemi
  12  * Paul Walmsley
  13  *
  14  * Copyright (C) 2010 Texas Instruments, Inc.
  15  * Thara Gopinath <thara@ti.com>
  16  *
  17  * This program is free software; you can redistribute it and/or modify
  18  * it under the terms of the GNU General Public License version 2 as
  19  * published by the Free Software Foundation.
  20  */
  21
  22 #include <linux/delay.h>
  23 #include <linux/io.h>
  24 #include <linux/err.h>
  25 #include <linux/export.h>
  26 #include <linux/debugfs.h>
  27 #include <linux/slab.h>
  28 #include <linux/clk.h>
  29
  30 #include "common.h"
  31
  32 #include "prm-regbits-34xx.h"
  33 #include "prm-regbits-44xx.h"
  34 #include "prm44xx.h"
  35 #include "prcm44xx.h"
  36 #include "prminst44xx.h"
  37 #include "control.h"
  38
  39 #include "voltage.h"
  40 #include "powerdomain.h"
  41
  42 #include "vc.h"
  43 #include "vp.h"
  44
  45 static LIST_HEAD(voltdm_list);
  46
  47 /* Public functions */
  48 /**
  49  * voltdm_get_voltage() - Gets the current non-auto-compensated voltage
  50  * @voltdm:     pointer to the voltdm for which current voltage info is needed
  51  *
  52  * API to get the current non-auto-compensated voltage for a voltage domain.
  53  * Returns 0 in case of error else returns the current voltage.
  54  */
  55 unsigned long voltdm_get_voltage(struct voltagedomain *voltdm)
  56 {
  57         if (!voltdm || IS_ERR(voltdm)) {
  58                 pr_warning("%s: VDD specified does not exist!\n", __func__);
  59                 return 0;
  60         }
  61
  62         return voltdm->nominal_volt;
  63 }
  64
  65 /**
  66  * voltdm_scale() - API to scale voltage of a particular voltage domain.
  67  * @voltdm: pointer to the voltage domain which is to be scaled.
  68  * @target_volt: The target voltage of the voltage domain
  69  *
  70  * This API should be called by the kernel to do the voltage scaling
  71  * for a particular voltage domain during DVFS.
  72  */
  73 int voltdm_scale(struct voltagedomain *voltdm,
  74                  unsigned long target_volt)
  75 {
  76         int ret, i;
  77         unsigned long volt = 0;
  78
  79         if (!voltdm || IS_ERR(voltdm)) {
  80                 pr_warning("%s: VDD specified does not exist!\n", __func__);
  81                 return -EINVAL;
  82         }
  83
  84         if (!voltdm->scale) {
  85                 pr_err("%s: No voltage scale API registered for vdd_%s\n",
  86                         __func__, voltdm->name);
  87                 return -ENODATA;
  88         }
  89
  90         /* Adjust voltage to the exact voltage from the OPP table */
  91         for (i = 0; voltdm->volt_data[i].volt_nominal != 0; i++) {
  92                 if (voltdm->volt_data[i].volt_nominal >= target_volt) {
  93                         volt = voltdm->volt_data[i].volt_nominal;
  94                         break;
  95                 }
  96         }
  97
  98         if (!volt) {
  99                 pr_warning("%s: not scaling. OPP voltage for %lu, not found.\n",
 100                            __func__, target_volt);
 101                 return -EINVAL;
 102         }
 103
 104         ret = voltdm->scale(voltdm, volt);
 105         if (!ret)
 106                 voltdm->nominal_volt = volt;
 107
 108         return ret;
 109 }
 110
 111 /**
 112  * voltdm_reset() - Resets the voltage of a particular voltage domain
 113  *                  to that of the current OPP.
 114  * @voltdm: pointer to the voltage domain whose voltage is to be reset.
 115  *
 116  * This API finds out the correct voltage the voltage domain is supposed
 117  * to be at and resets the voltage to that level. Should be used especially
 118  * while disabling any voltage compensation modules.
 119  */
 120 void voltdm_reset(struct voltagedomain *voltdm)
 121 {
 122         unsigned long target_volt;
 123
 124         if (!voltdm || IS_ERR(voltdm)) {
 125                 pr_warning("%s: VDD specified does not exist!\n", __func__);
 126                 return;
 127         }
 128
 129         target_volt = voltdm_get_voltage(voltdm);
 130         if (!target_volt) {
 131                 pr_err("%s: unable to find current voltage for vdd_%s\n",
 132                         __func__, voltdm->name);
 133                 return;
 134         }
 135
 136         voltdm_scale(voltdm, target_volt);
 137 }
 138
 139 /**
 140  * omap_voltage_get_volttable() - API to get the voltage table associated with a
 141  *                              particular voltage domain.
 142  * @voltdm:     pointer to the VDD for which the voltage table is required
 143  * @volt_data:  the voltage table for the particular vdd which is to be
 144  *              populated by this API
 145  *
 146  * This API populates the voltage table associated with a VDD into the
 147  * passed parameter pointer. Returns the count of distinct voltages
 148  * supported by this vdd.
 149  *
 150  */
 151 void omap_voltage_get_volttable(struct voltagedomain *voltdm,
 152                                 struct omap_volt_data **volt_data)
 153 {
 154         if (!voltdm || IS_ERR(voltdm)) {
 155                 pr_warning("%s: VDD specified does not exist!\n", __func__);
 156                 return;
 157         }
 158
 159         *volt_data = voltdm->volt_data;
 160 }
 161
 162 /**
 163  * omap_voltage_get_voltdata() - API to get the voltage table entry for a
 164  *                              particular voltage
 165  * @voltdm:     pointer to the VDD whose voltage table has to be searched
 166  * @volt:       the voltage to be searched in the voltage table
 167  *
 168  * This API searches through the voltage table for the required voltage
 169  * domain and tries to find a matching entry for the passed voltage volt.
 170  * If a matching entry is found volt_data is populated with that entry.
 171  * This API searches only through the non-compensated voltages int the
 172  * voltage table.
 173  * Returns pointer to the voltage table entry corresponding to volt on
 174  * success. Returns -ENODATA if no voltage table exisits for the passed voltage
 175  * domain or if there is no matching entry.
 176  */
 177 struct omap_volt_data *omap_voltage_get_voltdata(struct voltagedomain *voltdm,
 178                                                  unsigned long volt)
 179 {
 180         int i;
 181
 182         if (!voltdm || IS_ERR(voltdm)) {
 183                 pr_warning("%s: VDD specified does not exist!\n", __func__);
 184                 return ERR_PTR(-EINVAL);
 185         }
 186
 187         if (!voltdm->volt_data) {
 188                 pr_warning("%s: voltage table does not exist for vdd_%s\n",
 189                         __func__, voltdm->name);
 190                 return ERR_PTR(-ENODATA);
 191         }
 192
 193         for (i = 0; voltdm->volt_data[i].volt_nominal != 0; i++) {
 194                 if (voltdm->volt_data[i].volt_nominal == volt)
 195                         return &voltdm->volt_data[i];
 196         }
 197
 198         pr_notice("%s: Unable to match the current voltage with the voltage table for vdd_%s\n",
 199                   __func__, voltdm->name);
 200
 201         return ERR_PTR(-ENODATA);
 202 }
 203
 204 /**
 205  * omap_voltage_register_pmic() - API to register PMIC specific data
 206  * @voltdm:     pointer to the VDD for which the PMIC specific data is
 207  *              to be registered
 208  * @pmic:       the structure containing pmic info
 209  *
 210  * This API is to be called by the SOC/PMIC file to specify the
 211  * pmic specific info as present in omap_voltdm_pmic structure.
 212  */
 213 int omap_voltage_register_pmic(struct voltagedomain *voltdm,
 214                                struct omap_voltdm_pmic *pmic)
 215 {
 216         if (!voltdm || IS_ERR(voltdm)) {
 217                 pr_warning("%s: VDD specified does not exist!\n", __func__);
 218                 return -EINVAL;
 219         }
 220
 221         voltdm->pmic = pmic;
 222
 223         return 0;
 224 }
 225
 226 /**
 227  * omap_change_voltscale_method() - API to change the voltage scaling method.
 228  * @voltdm:     pointer to the VDD whose voltage scaling method
 229  *              has to be changed.
 230  * @voltscale_method:   the method to be used for voltage scaling.
 231  *
 232  * This API can be used by the board files to change the method of voltage
 233  * scaling between vpforceupdate and vcbypass. The parameter values are
 234  * defined in voltage.h
 235  */
 236 void omap_change_voltscale_method(struct voltagedomain *voltdm,
 237                                   int voltscale_method)
 238 {
 239         if (!voltdm || IS_ERR(voltdm)) {
 240                 pr_warning("%s: VDD specified does not exist!\n", __func__);
 241                 return;
 242         }
 243
 244         switch (voltscale_method) {
 245         case VOLTSCALE_VPFORCEUPDATE:
 246                 voltdm->scale = omap_vp_forceupdate_scale;
 247                 return;
 248         case VOLTSCALE_VCBYPASS:
 249                 voltdm->scale = omap_vc_bypass_scale;
 250                 return;
 251         default:
 252                 pr_warn("%s: Trying to change the method of voltage scaling to an unsupported one!\n",
 253                         __func__);
 254         }
 255 }
 256
 257 /**
 258  * omap_voltage_late_init() - Init the various voltage parameters
 259  *
 260  * This API is to be called in the later stages of the
 261  * system boot to init the voltage controller and
 262  * voltage processors.
 263  */
 264 int __init omap_voltage_late_init(void)
 265 {
 266         struct voltagedomain *voltdm;
 267
 268         if (list_empty(&voltdm_list)) {
 269                 pr_err("%s: Voltage driver support not added\n",
 270                         __func__);
 271                 return -EINVAL;
 272         }
 273
 274         list_for_each_entry(voltdm, &voltdm_list, node) {
 275                 struct clk *sys_ck;
 276
 277                 if (!voltdm->scalable)
 278                         continue;
 279
 280                 sys_ck = clk_get(NULL, voltdm->sys_clk.name);
 281                 if (IS_ERR(sys_ck)) {
 282                         pr_warning("%s: Could not get sys clk.\n", __func__);
 283                         return -EINVAL;
 284                 }
 285                 voltdm->sys_clk.rate = clk_get_rate(sys_ck);
 286                 WARN_ON(!voltdm->sys_clk.rate);
 287                 clk_put(sys_ck);
 288
 289                 if (voltdm->vc) {
 290                         voltdm->scale = omap_vc_bypass_scale;
 291                         omap_vc_init_channel(voltdm);
 292                 }
 293
 294                 if (voltdm->vp) {
 295                         voltdm->scale = omap_vp_forceupdate_scale;
 296                         omap_vp_init(voltdm);
 297                 }
 298         }
 299
 300         return 0;
 301 }
 302
 303 static struct voltagedomain *_voltdm_lookup(const char *name)
 304 {
 305         struct voltagedomain *voltdm, *temp_voltdm;
 306
 307         voltdm = NULL;
 308
 309         list_for_each_entry(temp_voltdm, &voltdm_list, node) {
 310                 if (!strcmp(name, temp_voltdm->name)) {
 311                         voltdm = temp_voltdm;
 312                         break;
 313                 }
 314         }
 315
 316         return voltdm;
 317 }
 318
 319 /**
 320  * voltdm_add_pwrdm - add a powerdomain to a voltagedomain
 321  * @voltdm: struct voltagedomain * to add the powerdomain to
 322  * @pwrdm: struct powerdomain * to associate with a voltagedomain
 323  *
 324  * Associate the powerdomain @pwrdm with a voltagedomain @voltdm.  This
 325  * enables the use of voltdm_for_each_pwrdm().  Returns -EINVAL if
 326  * presented with invalid pointers; -ENOMEM if memory could not be allocated;
 327  * or 0 upon success.
 328  */
 329 int voltdm_add_pwrdm(struct voltagedomain *voltdm, struct powerdomain *pwrdm)
 330 {
 331         if (!voltdm || !pwrdm)
 332                 return -EINVAL;
 333
 334         pr_debug("voltagedomain: %s: associating powerdomain %s\n",
 335                  voltdm->name, pwrdm->name);
 336
 337         list_add(&pwrdm->voltdm_node, &voltdm->pwrdm_list);
 338
 339         return 0;
 340 }
 341
 342 /**
 343  * voltdm_for_each_pwrdm - call function for each pwrdm in a voltdm
 344  * @voltdm: struct voltagedomain * to iterate over
 345  * @fn: callback function *
 346  *
 347  * Call the supplied function @fn for each powerdomain in the
 348  * voltagedomain @voltdm.  Returns -EINVAL if presented with invalid
 349  * pointers; or passes along the last return value of the callback
 350  * function, which should be 0 for success or anything else to
 351  * indicate failure.
 352  */
 353 int voltdm_for_each_pwrdm(struct voltagedomain *voltdm,
 354                           int (*fn)(struct voltagedomain *voltdm,
 355                                     struct powerdomain *pwrdm))
 356 {
 357         struct powerdomain *pwrdm;
 358         int ret = 0;
 359
 360         if (!fn)
 361                 return -EINVAL;
 362
 363         list_for_each_entry(pwrdm, &voltdm->pwrdm_list, voltdm_node)
 364                 ret = (*fn)(voltdm, pwrdm);
 365
 366         return ret;
 367 }
 368
 369 /**
 370  * voltdm_for_each - call function on each registered voltagedomain
 371  * @fn: callback function *
 372  *
 373  * Call the supplied function @fn for each registered voltagedomain.
 374  * The callback function @fn can return anything but 0 to bail out
 375  * early from the iterator.  Returns the last return value of the
 376  * callback function, which should be 0 for success or anything else
 377  * to indicate failure; or -EINVAL if the function pointer is null.
 378  */
 379 int voltdm_for_each(int (*fn)(struct voltagedomain *voltdm, void *user),
 380                     void *user)
 381 {
 382         struct voltagedomain *temp_voltdm;
 383         int ret = 0;
 384
 385         if (!fn)
 386                 return -EINVAL;
 387
 388         list_for_each_entry(temp_voltdm, &voltdm_list, node) {
 389                 ret = (*fn)(temp_voltdm, user);
 390                 if (ret)
 391                         break;
 392         }
 393
 394         return ret;
 395 }
 396
 397 static int _voltdm_register(struct voltagedomain *voltdm)
 398 {
 399         if (!voltdm || !voltdm->name)
 400                 return -EINVAL;
 401
 402         INIT_LIST_HEAD(&voltdm->pwrdm_list);
 403         list_add(&voltdm->node, &voltdm_list);
 404
 405         pr_debug("voltagedomain: registered %s\n", voltdm->name);
 406
 407         return 0;
 408 }
 409
 410 /**
 411  * voltdm_lookup - look up a voltagedomain by name, return a pointer
 412  * @name: name of voltagedomain
 413  *
 414  * Find a registered voltagedomain by its name @name.  Returns a pointer
 415  * to the struct voltagedomain if found, or NULL otherwise.
 416  */
 417 struct voltagedomain *voltdm_lookup(const char *name)
 418 {
 419         struct voltagedomain *voltdm ;
 420
 421         if (!name)
 422                 return NULL;
 423
 424         voltdm = _voltdm_lookup(name);
 425
 426         return voltdm;
 427 }
 428
 429 /**
 430  * voltdm_init - set up the voltagedomain layer
 431  * @voltdm_list: array of struct voltagedomain pointers to register
 432  *
 433  * Loop through the array of voltagedomains @voltdm_list, registering all
 434  * that are available on the current CPU. If voltdm_list is supplied
 435  * and not null, all of the referenced voltagedomains will be
 436  * registered.  No return value.
 437  */
 438 void voltdm_init(struct voltagedomain **voltdms)
 439 {
 440         struct voltagedomain **v;
 441
 442         if (voltdms) {
 443                 for (v = voltdms; *v; v++)
 444                         _voltdm_register(*v);
 445         }
 446 }