| 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 | } |