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_warn("%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_warn("%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_warn("%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_warn("%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_warn("%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_warn("%s: VDD specified does not exist!\n", __func__);
 184                 return ERR_PTR(-EINVAL);
 185         }
 186
 187         if (!voltdm->volt_data) {
 188                 pr_warn("%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_warn("%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_voltage_late_init() - Init the various voltage parameters
 228  *
 229  * This API is to be called in the later stages of the
 230  * system boot to init the voltage controller and
 231  * voltage processors.
 232  */
 233 int __init omap_voltage_late_init(void)
 234 {
 235         struct voltagedomain *voltdm;
 236
 237         if (list_empty(&voltdm_list)) {
 238                 pr_err("%s: Voltage driver support not added\n",
 239                         __func__);
 240                 return -EINVAL;
 241         }
 242
 243         list_for_each_entry(voltdm, &voltdm_list, node) {
 244                 struct clk *sys_ck;
 245
 246                 if (!voltdm->scalable)
 247                         continue;
 248
 249                 sys_ck = clk_get(NULL, voltdm->sys_clk.name);
 250                 if (IS_ERR(sys_ck)) {
 251                         pr_warn("%s: Could not get sys clk.\n", __func__);
 252                         return -EINVAL;
 253                 }
 254                 voltdm->sys_clk.rate = clk_get_rate(sys_ck);
 255                 WARN_ON(!voltdm->sys_clk.rate);
 256                 clk_put(sys_ck);
 257
 258                 if (voltdm->vc) {
 259                         voltdm->scale = omap_vc_bypass_scale;
 260                         omap_vc_init_channel(voltdm);
 261                 }
 262
 263                 if (voltdm->vp) {
 264                         voltdm->scale = omap_vp_forceupdate_scale;
 265                         omap_vp_init(voltdm);
 266                 }
 267         }
 268
 269         return 0;
 270 }
 271
 272 static struct voltagedomain *_voltdm_lookup(const char *name)
 273 {
 274         struct voltagedomain *voltdm, *temp_voltdm;
 275
 276         voltdm = NULL;
 277
 278         list_for_each_entry(temp_voltdm, &voltdm_list, node) {
 279                 if (!strcmp(name, temp_voltdm->name)) {
 280                         voltdm = temp_voltdm;
 281                         break;
 282                 }
 283         }
 284
 285         return voltdm;
 286 }
 287
 288 static int _voltdm_register(struct voltagedomain *voltdm)
 289 {
 290         if (!voltdm || !voltdm->name)
 291                 return -EINVAL;
 292
 293         list_add(&voltdm->node, &voltdm_list);
 294
 295         pr_debug("voltagedomain: registered %s\n", voltdm->name);
 296
 297         return 0;
 298 }
 299
 300 /**
 301  * voltdm_lookup - look up a voltagedomain by name, return a pointer
 302  * @name: name of voltagedomain
 303  *
 304  * Find a registered voltagedomain by its name @name.  Returns a pointer
 305  * to the struct voltagedomain if found, or NULL otherwise.
 306  */
 307 struct voltagedomain *voltdm_lookup(const char *name)
 308 {
 309         struct voltagedomain *voltdm ;
 310
 311         if (!name)
 312                 return NULL;
 313
 314         voltdm = _voltdm_lookup(name);
 315
 316         return voltdm;
 317 }
 318
 319 /**
 320  * voltdm_init - set up the voltagedomain layer
 321  * @voltdm_list: array of struct voltagedomain pointers to register
 322  *
 323  * Loop through the array of voltagedomains @voltdm_list, registering all
 324  * that are available on the current CPU. If voltdm_list is supplied
 325  * and not null, all of the referenced voltagedomains will be
 326  * registered.  No return value.
 327  */
 328 void voltdm_init(struct voltagedomain **voltdms)
 329 {
 330         struct voltagedomain **v;
 331
 332         if (voltdms) {
 333                 for (v = voltdms; *v; v++)
 334                         _voltdm_register(*v);
 335         }
 336 }