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         if (!voltdm->volt_data) {
  91                 pr_err("%s: No voltage data defined for vdd_%s\n",
  92                         __func__, voltdm->name);
  93                 return -ENODATA;
  94         }
  95
  96         /* Adjust voltage to the exact voltage from the OPP table */
  97         for (i = 0; voltdm->volt_data[i].volt_nominal != 0; i++) {
  98                 if (voltdm->volt_data[i].volt_nominal >= target_volt) {
  99                         volt = voltdm->volt_data[i].volt_nominal;
 100                         break;
 101                 }
 102         }
 103
 104         if (!volt) {
 105                 pr_warn("%s: not scaling. OPP voltage for %lu, not found.\n",
 106                         __func__, target_volt);
 107                 return -EINVAL;
 108         }
 109
 110         ret = voltdm->scale(voltdm, volt);
 111         if (!ret)
 112                 voltdm->nominal_volt = volt;
 113
 114         return ret;
 115 }
 116
 117 /**
 118  * voltdm_reset() - Resets the voltage of a particular voltage domain
 119  *                  to that of the current OPP.
 120  * @voltdm: pointer to the voltage domain whose voltage is to be reset.
 121  *
 122  * This API finds out the correct voltage the voltage domain is supposed
 123  * to be at and resets the voltage to that level. Should be used especially
 124  * while disabling any voltage compensation modules.
 125  */
 126 void voltdm_reset(struct voltagedomain *voltdm)
 127 {
 128         unsigned long target_volt;
 129
 130         if (!voltdm || IS_ERR(voltdm)) {
 131                 pr_warn("%s: VDD specified does not exist!\n", __func__);
 132                 return;
 133         }
 134
 135         target_volt = voltdm_get_voltage(voltdm);
 136         if (!target_volt) {
 137                 pr_err("%s: unable to find current voltage for vdd_%s\n",
 138                         __func__, voltdm->name);
 139                 return;
 140         }
 141
 142         voltdm_scale(voltdm, target_volt);
 143 }
 144
 145 /**
 146  * omap_voltage_get_volttable() - API to get the voltage table associated with a
 147  *                              particular voltage domain.
 148  * @voltdm:     pointer to the VDD for which the voltage table is required
 149  * @volt_data:  the voltage table for the particular vdd which is to be
 150  *              populated by this API
 151  *
 152  * This API populates the voltage table associated with a VDD into the
 153  * passed parameter pointer. Returns the count of distinct voltages
 154  * supported by this vdd.
 155  *
 156  */
 157 void omap_voltage_get_volttable(struct voltagedomain *voltdm,
 158                                 struct omap_volt_data **volt_data)
 159 {
 160         if (!voltdm || IS_ERR(voltdm)) {
 161                 pr_warn("%s: VDD specified does not exist!\n", __func__);
 162                 return;
 163         }
 164
 165         *volt_data = voltdm->volt_data;
 166 }
 167
 168 /**
 169  * omap_voltage_get_voltdata() - API to get the voltage table entry for a
 170  *                              particular voltage
 171  * @voltdm:     pointer to the VDD whose voltage table has to be searched
 172  * @volt:       the voltage to be searched in the voltage table
 173  *
 174  * This API searches through the voltage table for the required voltage
 175  * domain and tries to find a matching entry for the passed voltage volt.
 176  * If a matching entry is found volt_data is populated with that entry.
 177  * This API searches only through the non-compensated voltages int the
 178  * voltage table.
 179  * Returns pointer to the voltage table entry corresponding to volt on
 180  * success. Returns -ENODATA if no voltage table exisits for the passed voltage
 181  * domain or if there is no matching entry.
 182  */
 183 struct omap_volt_data *omap_voltage_get_voltdata(struct voltagedomain *voltdm,
 184                                                  unsigned long volt)
 185 {
 186         int i;
 187
 188         if (!voltdm || IS_ERR(voltdm)) {
 189                 pr_warn("%s: VDD specified does not exist!\n", __func__);
 190                 return ERR_PTR(-EINVAL);
 191         }
 192
 193         if (!voltdm->volt_data) {
 194                 pr_warn("%s: voltage table does not exist for vdd_%s\n",
 195                         __func__, voltdm->name);
 196                 return ERR_PTR(-ENODATA);
 197         }
 198
 199         for (i = 0; voltdm->volt_data[i].volt_nominal != 0; i++) {
 200                 if (voltdm->volt_data[i].volt_nominal == volt)
 201                         return &voltdm->volt_data[i];
 202         }
 203
 204         pr_notice("%s: Unable to match the current voltage with the voltage table for vdd_%s\n",
 205                   __func__, voltdm->name);
 206
 207         return ERR_PTR(-ENODATA);
 208 }
 209
 210 /**
 211  * omap_voltage_register_pmic() - API to register PMIC specific data
 212  * @voltdm:     pointer to the VDD for which the PMIC specific data is
 213  *              to be registered
 214  * @pmic:       the structure containing pmic info
 215  *
 216  * This API is to be called by the SOC/PMIC file to specify the
 217  * pmic specific info as present in omap_voltdm_pmic structure.
 218  */
 219 int omap_voltage_register_pmic(struct voltagedomain *voltdm,
 220                                struct omap_voltdm_pmic *pmic)
 221 {
 222         if (!voltdm || IS_ERR(voltdm)) {
 223                 pr_warn("%s: VDD specified does not exist!\n", __func__);
 224                 return -EINVAL;
 225         }
 226
 227         voltdm->pmic = pmic;
 228
 229         return 0;
 230 }
 231
 232 /**
 233  * omap_voltage_late_init() - Init the various voltage parameters
 234  *
 235  * This API is to be called in the later stages of the
 236  * system boot to init the voltage controller and
 237  * voltage processors.
 238  */
 239 int __init omap_voltage_late_init(void)
 240 {
 241         struct voltagedomain *voltdm;
 242
 243         if (list_empty(&voltdm_list)) {
 244                 pr_err("%s: Voltage driver support not added\n",
 245                         __func__);
 246                 return -EINVAL;
 247         }
 248
 249         list_for_each_entry(voltdm, &voltdm_list, node) {
 250                 struct clk *sys_ck;
 251
 252                 if (!voltdm->scalable)
 253                         continue;
 254
 255                 sys_ck = clk_get(NULL, voltdm->sys_clk.name);
 256                 if (IS_ERR(sys_ck)) {
 257                         pr_warn("%s: Could not get sys clk.\n", __func__);
 258                         return -EINVAL;
 259                 }
 260                 voltdm->sys_clk.rate = clk_get_rate(sys_ck);
 261                 WARN_ON(!voltdm->sys_clk.rate);
 262                 clk_put(sys_ck);
 263
 264                 if (voltdm->vc) {
 265                         voltdm->scale = omap_vc_bypass_scale;
 266                         omap_vc_init_channel(voltdm);
 267                 }
 268
 269                 if (voltdm->vp) {
 270                         voltdm->scale = omap_vp_forceupdate_scale;
 271                         omap_vp_init(voltdm);
 272                 }
 273         }
 274
 275         return 0;
 276 }
 277
 278 static struct voltagedomain *_voltdm_lookup(const char *name)
 279 {
 280         struct voltagedomain *voltdm, *temp_voltdm;
 281
 282         voltdm = NULL;
 283
 284         list_for_each_entry(temp_voltdm, &voltdm_list, node) {
 285                 if (!strcmp(name, temp_voltdm->name)) {
 286                         voltdm = temp_voltdm;
 287                         break;
 288                 }
 289         }
 290
 291         return voltdm;
 292 }
 293
 294 static int _voltdm_register(struct voltagedomain *voltdm)
 295 {
 296         if (!voltdm || !voltdm->name)
 297                 return -EINVAL;
 298
 299         list_add(&voltdm->node, &voltdm_list);
 300
 301         pr_debug("voltagedomain: registered %s\n", voltdm->name);
 302
 303         return 0;
 304 }
 305
 306 /**
 307  * voltdm_lookup - look up a voltagedomain by name, return a pointer
 308  * @name: name of voltagedomain
 309  *
 310  * Find a registered voltagedomain by its name @name.  Returns a pointer
 311  * to the struct voltagedomain if found, or NULL otherwise.
 312  */
 313 struct voltagedomain *voltdm_lookup(const char *name)
 314 {
 315         struct voltagedomain *voltdm ;
 316
 317         if (!name)
 318                 return NULL;
 319
 320         voltdm = _voltdm_lookup(name);
 321
 322         return voltdm;
 323 }
 324
 325 /**
 326  * voltdm_init - set up the voltagedomain layer
 327  * @voltdm_list: array of struct voltagedomain pointers to register
 328  *
 329  * Loop through the array of voltagedomains @voltdm_list, registering all
 330  * that are available on the current CPU. If voltdm_list is supplied
 331  * and not null, all of the referenced voltagedomains will be
 332  * registered.  No return value.
 333  */
 334 void voltdm_init(struct voltagedomain **voltdms)
 335 {
 336         struct voltagedomain **v;
 337
 338         if (voltdms) {
 339                 for (v = voltdms; *v; v++)
 340                         _voltdm_register(*v);
 341         }
 342 }