drivers/power/avs/smartreflex.c

   1 /*
   2  * OMAP SmartReflex Voltage Control
   3  *
   4  * Author: Thara Gopinath       <thara@ti.com>
   5  *
   6  * Copyright (C) 2012 Texas Instruments, Inc.
   7  * Thara Gopinath <thara@ti.com>
   8  *
   9  * Copyright (C) 2008 Nokia Corporation
  10  * Kalle Jokiniemi
  11  *
  12  * Copyright (C) 2007 Texas Instruments, Inc.
  13  * Lesly A M <x0080970@ti.com>
  14  *
  15  * This program is free software; you can redistribute it and/or modify
  16  * it under the terms of the GNU General Public License version 2 as
  17  * published by the Free Software Foundation.
  18  */
  19
  20 #include <linux/module.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/clk.h>
  23 #include <linux/io.h>
  24 #include <linux/debugfs.h>
  25 #include <linux/delay.h>
  26 #include <linux/slab.h>
  27 #include <linux/pm_runtime.h>
  28 #include <linux/power/smartreflex.h>
  29
  30 #define SMARTREFLEX_NAME_LEN    16
  31 #define NVALUE_NAME_LEN         40
  32 #define SR_DISABLE_TIMEOUT      200
  33
  34 /* sr_list contains all the instances of smartreflex module */
  35 static LIST_HEAD(sr_list);
  36
  37 static struct omap_sr_class_data *sr_class;
  38 static struct omap_sr_pmic_data *sr_pmic_data;
  39 static struct dentry            *sr_dbg_dir;
  40
  41 static inline void sr_write_reg(struct omap_sr *sr, unsigned offset, u32 value)
  42 {
  43         __raw_writel(value, (sr->base + offset));
  44 }
  45
  46 static inline void sr_modify_reg(struct omap_sr *sr, unsigned offset, u32 mask,
  47                                         u32 value)
  48 {
  49         u32 reg_val;
  50
  51         /*
  52          * Smartreflex error config register is special as it contains
  53          * certain status bits which if written a 1 into means a clear
  54          * of those bits. So in order to make sure no accidental write of
  55          * 1 happens to those status bits, do a clear of them in the read
  56          * value. This mean this API doesn't rewrite values in these bits
  57          * if they are currently set, but does allow the caller to write
  58          * those bits.
  59          */
  60         if (sr->ip_type == SR_TYPE_V1 && offset == ERRCONFIG_V1)
  61                 mask |= ERRCONFIG_STATUS_V1_MASK;
  62         else if (sr->ip_type == SR_TYPE_V2 && offset == ERRCONFIG_V2)
  63                 mask |= ERRCONFIG_VPBOUNDINTST_V2;
  64
  65         reg_val = __raw_readl(sr->base + offset);
  66         reg_val &= ~mask;
  67
  68         value &= mask;
  69
  70         reg_val |= value;
  71
  72         __raw_writel(reg_val, (sr->base + offset));
  73 }
  74
  75 static inline u32 sr_read_reg(struct omap_sr *sr, unsigned offset)
  76 {
  77         return __raw_readl(sr->base + offset);
  78 }
  79
  80 static struct omap_sr *_sr_lookup(struct voltagedomain *voltdm)
  81 {
  82         struct omap_sr *sr_info;
  83
  84         if (!voltdm) {
  85                 pr_err("%s: Null voltage domain passed!\n", __func__);
  86                 return ERR_PTR(-EINVAL);
  87         }
  88
  89         list_for_each_entry(sr_info, &sr_list, node) {
  90                 if (voltdm == sr_info->voltdm)
  91                         return sr_info;
  92         }
  93
  94         return ERR_PTR(-ENODATA);
  95 }
  96
  97 static irqreturn_t sr_interrupt(int irq, void *data)
  98 {
  99         struct omap_sr *sr_info = data;
 100         u32 status = 0;
 101
 102         switch (sr_info->ip_type) {
 103         case SR_TYPE_V1:
 104                 /* Read the status bits */
 105                 status = sr_read_reg(sr_info, ERRCONFIG_V1);
 106
 107                 /* Clear them by writing back */
 108                 sr_write_reg(sr_info, ERRCONFIG_V1, status);
 109                 break;
 110         case SR_TYPE_V2:
 111                 /* Read the status bits */
 112                 status = sr_read_reg(sr_info, IRQSTATUS);
 113
 114                 /* Clear them by writing back */
 115                 sr_write_reg(sr_info, IRQSTATUS, status);
 116                 break;
 117         default:
 118                 dev_err(&sr_info->pdev->dev, "UNKNOWN IP type %d\n",
 119                         sr_info->ip_type);
 120                 return IRQ_NONE;
 121         }
 122
 123         if (sr_class->notify)
 124                 sr_class->notify(sr_info, status);
 125
 126         return IRQ_HANDLED;
 127 }
 128
 129 static void sr_set_clk_length(struct omap_sr *sr)
 130 {
 131         struct clk *fck;
 132         u32 fclk_speed;
 133
 134         fck = clk_get(&sr->pdev->dev, "fck");
 135
 136         if (IS_ERR(fck)) {
 137                 dev_err(&sr->pdev->dev, "%s: unable to get fck for device %s\n",
 138                                 __func__, dev_name(&sr->pdev->dev));
 139                 return;
 140         }
 141
 142         fclk_speed = clk_get_rate(fck);
 143         clk_put(fck);
 144
 145         switch (fclk_speed) {
 146         case 12000000:
 147                 sr->clk_length = SRCLKLENGTH_12MHZ_SYSCLK;
 148                 break;
 149         case 13000000:
 150                 sr->clk_length = SRCLKLENGTH_13MHZ_SYSCLK;
 151                 break;
 152         case 19200000:
 153                 sr->clk_length = SRCLKLENGTH_19MHZ_SYSCLK;
 154                 break;
 155         case 26000000:
 156                 sr->clk_length = SRCLKLENGTH_26MHZ_SYSCLK;
 157                 break;
 158         case 38400000:
 159                 sr->clk_length = SRCLKLENGTH_38MHZ_SYSCLK;
 160                 break;
 161         default:
 162                 dev_err(&sr->pdev->dev, "%s: Invalid fclk rate: %d\n",
 163                         __func__, fclk_speed);
 164                 break;
 165         }
 166 }
 167
 168 static void sr_start_vddautocomp(struct omap_sr *sr)
 169 {
 170         if (!sr_class || !(sr_class->enable) || !(sr_class->configure)) {
 171                 dev_warn(&sr->pdev->dev,
 172                         "%s: smartreflex class driver not registered\n",
 173                         __func__);
 174                 return;
 175         }
 176
 177         if (!sr_class->enable(sr))
 178                 sr->autocomp_active = true;
 179 }
 180
 181 static void sr_stop_vddautocomp(struct omap_sr *sr)
 182 {
 183         if (!sr_class || !(sr_class->disable)) {
 184                 dev_warn(&sr->pdev->dev,
 185                         "%s: smartreflex class driver not registered\n",
 186                         __func__);
 187                 return;
 188         }
 189
 190         if (sr->autocomp_active) {
 191                 sr_class->disable(sr, 1);
 192                 sr->autocomp_active = false;
 193         }
 194 }
 195
 196 /*
 197  * This function handles the intializations which have to be done
 198  * only when both sr device and class driver regiter has
 199  * completed. This will be attempted to be called from both sr class
 200  * driver register and sr device intializtion API's. Only one call
 201  * will ultimately succeed.
 202  *
 203  * Currently this function registers interrupt handler for a particular SR
 204  * if smartreflex class driver is already registered and has
 205  * requested for interrupts and the SR interrupt line in present.
 206  */
 207 static int sr_late_init(struct omap_sr *sr_info)
 208 {
 209         struct omap_sr_data *pdata = sr_info->pdev->dev.platform_data;
 210         struct resource *mem;
 211         int ret = 0;
 212
 213         if (sr_class->notify && sr_class->notify_flags && sr_info->irq) {
 214                 ret = request_irq(sr_info->irq, sr_interrupt,
 215                                   0, sr_info->name, sr_info);
 216                 if (ret)
 217                         goto error;
 218                 disable_irq(sr_info->irq);
 219         }
 220
 221         if (pdata && pdata->enable_on_init)
 222                 sr_start_vddautocomp(sr_info);
 223
 224         return ret;
 225
 226 error:
 227         iounmap(sr_info->base);
 228         mem = platform_get_resource(sr_info->pdev, IORESOURCE_MEM, 0);
 229         release_mem_region(mem->start, resource_size(mem));
 230         list_del(&sr_info->node);
 231         dev_err(&sr_info->pdev->dev, "%s: ERROR in registering"
 232                 "interrupt handler. Smartreflex will"
 233                 "not function as desired\n", __func__);
 234         kfree(sr_info);
 235
 236         return ret;
 237 }
 238
 239 static void sr_v1_disable(struct omap_sr *sr)
 240 {
 241         int timeout = 0;
 242         int errconf_val = ERRCONFIG_MCUACCUMINTST | ERRCONFIG_MCUVALIDINTST |
 243                         ERRCONFIG_MCUBOUNDINTST;
 244
 245         /* Enable MCUDisableAcknowledge interrupt */
 246         sr_modify_reg(sr, ERRCONFIG_V1,
 247                         ERRCONFIG_MCUDISACKINTEN, ERRCONFIG_MCUDISACKINTEN);
 248
 249         /* SRCONFIG - disable SR */
 250         sr_modify_reg(sr, SRCONFIG, SRCONFIG_SRENABLE, 0x0);
 251
 252         /* Disable all other SR interrupts and clear the status as needed */
 253         if (sr_read_reg(sr, ERRCONFIG_V1) & ERRCONFIG_VPBOUNDINTST_V1)
 254                 errconf_val |= ERRCONFIG_VPBOUNDINTST_V1;
 255         sr_modify_reg(sr, ERRCONFIG_V1,
 256                         (ERRCONFIG_MCUACCUMINTEN | ERRCONFIG_MCUVALIDINTEN |
 257                         ERRCONFIG_MCUBOUNDINTEN | ERRCONFIG_VPBOUNDINTEN_V1),
 258                         errconf_val);
 259
 260         /*
 261          * Wait for SR to be disabled.
 262          * wait until ERRCONFIG.MCUDISACKINTST = 1. Typical latency is 1us.
 263          */
 264         sr_test_cond_timeout((sr_read_reg(sr, ERRCONFIG_V1) &
 265                              ERRCONFIG_MCUDISACKINTST), SR_DISABLE_TIMEOUT,
 266                              timeout);
 267
 268         if (timeout >= SR_DISABLE_TIMEOUT)
 269                 dev_warn(&sr->pdev->dev, "%s: Smartreflex disable timedout\n",
 270                         __func__);
 271
 272         /* Disable MCUDisableAcknowledge interrupt & clear pending interrupt */
 273         sr_modify_reg(sr, ERRCONFIG_V1, ERRCONFIG_MCUDISACKINTEN,
 274                         ERRCONFIG_MCUDISACKINTST);
 275 }
 276
 277 static void sr_v2_disable(struct omap_sr *sr)
 278 {
 279         int timeout = 0;
 280
 281         /* Enable MCUDisableAcknowledge interrupt */
 282         sr_write_reg(sr, IRQENABLE_SET, IRQENABLE_MCUDISABLEACKINT);
 283
 284         /* SRCONFIG - disable SR */
 285         sr_modify_reg(sr, SRCONFIG, SRCONFIG_SRENABLE, 0x0);
 286
 287         /*
 288          * Disable all other SR interrupts and clear the status
 289          * write to status register ONLY on need basis - only if status
 290          * is set.
 291          */
 292         if (sr_read_reg(sr, ERRCONFIG_V2) & ERRCONFIG_VPBOUNDINTST_V2)
 293                 sr_modify_reg(sr, ERRCONFIG_V2, ERRCONFIG_VPBOUNDINTEN_V2,
 294                         ERRCONFIG_VPBOUNDINTST_V2);
 295         else
 296                 sr_modify_reg(sr, ERRCONFIG_V2, ERRCONFIG_VPBOUNDINTEN_V2,
 297                                 0x0);
 298         sr_write_reg(sr, IRQENABLE_CLR, (IRQENABLE_MCUACCUMINT |
 299                         IRQENABLE_MCUVALIDINT |
 300                         IRQENABLE_MCUBOUNDSINT));
 301         sr_write_reg(sr, IRQSTATUS, (IRQSTATUS_MCUACCUMINT |
 302                         IRQSTATUS_MCVALIDINT |
 303                         IRQSTATUS_MCBOUNDSINT));
 304
 305         /*
 306          * Wait for SR to be disabled.
 307          * wait until IRQSTATUS.MCUDISACKINTST = 1. Typical latency is 1us.
 308          */
 309         sr_test_cond_timeout((sr_read_reg(sr, IRQSTATUS) &
 310                              IRQSTATUS_MCUDISABLEACKINT), SR_DISABLE_TIMEOUT,
 311                              timeout);
 312
 313         if (timeout >= SR_DISABLE_TIMEOUT)
 314                 dev_warn(&sr->pdev->dev, "%s: Smartreflex disable timedout\n",
 315                         __func__);
 316
 317         /* Disable MCUDisableAcknowledge interrupt & clear pending interrupt */
 318         sr_write_reg(sr, IRQENABLE_CLR, IRQENABLE_MCUDISABLEACKINT);
 319         sr_write_reg(sr, IRQSTATUS, IRQSTATUS_MCUDISABLEACKINT);
 320 }
 321
 322 static struct omap_sr_nvalue_table *sr_retrieve_nvalue_row(
 323                                 struct omap_sr *sr, u32 efuse_offs)
 324 {
 325         int i;
 326
 327         if (!sr->nvalue_table) {
 328                 dev_warn(&sr->pdev->dev, "%s: Missing ntarget value table\n",
 329                         __func__);
 330                 return NULL;
 331         }
 332
 333         for (i = 0; i < sr->nvalue_count; i++) {
 334                 if (sr->nvalue_table[i].efuse_offs == efuse_offs)
 335                         return &sr->nvalue_table[i];
 336         }
 337
 338         return NULL;
 339 }
 340
 341 /* Public Functions */
 342
 343 /**
 344  * sr_configure_errgen() - Configures the smrtreflex to perform AVS using the
 345  *                       error generator module.
 346  * @voltdm:     VDD pointer to which the SR module to be configured belongs to.
 347  *
 348  * This API is to be called from the smartreflex class driver to
 349  * configure the error generator module inside the smartreflex module.
 350  * SR settings if using the ERROR module inside Smartreflex.
 351  * SR CLASS 3 by default uses only the ERROR module where as
 352  * SR CLASS 2 can choose between ERROR module and MINMAXAVG
 353  * module. Returns 0 on success and error value in case of failure.
 354  */
 355 int sr_configure_errgen(struct voltagedomain *voltdm)
 356 {
 357         u32 sr_config, sr_errconfig, errconfig_offs;
 358         u32 vpboundint_en, vpboundint_st;
 359         u32 senp_en = 0, senn_en = 0;
 360         u8 senp_shift, senn_shift;
 361         struct omap_sr *sr = _sr_lookup(voltdm);
 362
 363         if (IS_ERR(sr)) {
 364                 pr_warning("%s: omap_sr struct for voltdm not found\n", __func__);
 365                 return PTR_ERR(sr);
 366         }
 367
 368         if (!sr->clk_length)
 369                 sr_set_clk_length(sr);
 370
 371         senp_en = sr->senp_mod;
 372         senn_en = sr->senn_mod;
 373
 374         sr_config = (sr->clk_length << SRCONFIG_SRCLKLENGTH_SHIFT) |
 375                 SRCONFIG_SENENABLE | SRCONFIG_ERRGEN_EN;
 376
 377         switch (sr->ip_type) {
 378         case SR_TYPE_V1:
 379                 sr_config |= SRCONFIG_DELAYCTRL;
 380                 senn_shift = SRCONFIG_SENNENABLE_V1_SHIFT;
 381                 senp_shift = SRCONFIG_SENPENABLE_V1_SHIFT;
 382                 errconfig_offs = ERRCONFIG_V1;
 383                 vpboundint_en = ERRCONFIG_VPBOUNDINTEN_V1;
 384                 vpboundint_st = ERRCONFIG_VPBOUNDINTST_V1;
 385                 break;
 386         case SR_TYPE_V2:
 387                 senn_shift = SRCONFIG_SENNENABLE_V2_SHIFT;
 388                 senp_shift = SRCONFIG_SENPENABLE_V2_SHIFT;
 389                 errconfig_offs = ERRCONFIG_V2;
 390                 vpboundint_en = ERRCONFIG_VPBOUNDINTEN_V2;
 391                 vpboundint_st = ERRCONFIG_VPBOUNDINTST_V2;
 392                 break;
 393         default:
 394                 dev_err(&sr->pdev->dev, "%s: Trying to Configure smartreflex"
 395                         "module without specifying the ip\n", __func__);
 396                 return -EINVAL;
 397         }
 398
 399         sr_config |= ((senn_en << senn_shift) | (senp_en << senp_shift));
 400         sr_write_reg(sr, SRCONFIG, sr_config);
 401         sr_errconfig = (sr->err_weight << ERRCONFIG_ERRWEIGHT_SHIFT) |
 402                 (sr->err_maxlimit << ERRCONFIG_ERRMAXLIMIT_SHIFT) |
 403                 (sr->err_minlimit <<  ERRCONFIG_ERRMINLIMIT_SHIFT);
 404         sr_modify_reg(sr, errconfig_offs, (SR_ERRWEIGHT_MASK |
 405                 SR_ERRMAXLIMIT_MASK | SR_ERRMINLIMIT_MASK),
 406                 sr_errconfig);
 407
 408         /* Enabling the interrupts if the ERROR module is used */
 409         sr_modify_reg(sr, errconfig_offs, (vpboundint_en | vpboundint_st),
 410                       vpboundint_en);
 411
 412         return 0;
 413 }
 414
 415 /**
 416  * sr_disable_errgen() - Disables SmartReflex AVS module's errgen component
 417  * @voltdm:     VDD pointer to which the SR module to be configured belongs to.
 418  *
 419  * This API is to be called from the smartreflex class driver to
 420  * disable the error generator module inside the smartreflex module.
 421  *
 422  * Returns 0 on success and error value in case of failure.
 423  */
 424 int sr_disable_errgen(struct voltagedomain *voltdm)
 425 {
 426         u32 errconfig_offs;
 427         u32 vpboundint_en, vpboundint_st;
 428         struct omap_sr *sr = _sr_lookup(voltdm);
 429
 430         if (IS_ERR(sr)) {
 431                 pr_warning("%s: omap_sr struct for voltdm not found\n", __func__);
 432                 return PTR_ERR(sr);
 433         }
 434
 435         switch (sr->ip_type) {
 436         case SR_TYPE_V1:
 437                 errconfig_offs = ERRCONFIG_V1;
 438                 vpboundint_en = ERRCONFIG_VPBOUNDINTEN_V1;
 439                 vpboundint_st = ERRCONFIG_VPBOUNDINTST_V1;
 440                 break;
 441         case SR_TYPE_V2:
 442                 errconfig_offs = ERRCONFIG_V2;
 443                 vpboundint_en = ERRCONFIG_VPBOUNDINTEN_V2;
 444                 vpboundint_st = ERRCONFIG_VPBOUNDINTST_V2;
 445                 break;
 446         default:
 447                 dev_err(&sr->pdev->dev, "%s: Trying to Configure smartreflex"
 448                         "module without specifying the ip\n", __func__);
 449                 return -EINVAL;
 450         }
 451
 452         /* Disable the Sensor and errorgen */
 453         sr_modify_reg(sr, SRCONFIG, SRCONFIG_SENENABLE | SRCONFIG_ERRGEN_EN, 0);
 454
 455         /*
 456          * Disable the interrupts of ERROR module
 457          * NOTE: modify is a read, modify,write - an implicit OCP barrier
 458          * which is required is present here - sequencing is critical
 459          * at this point (after errgen is disabled, vpboundint disable)
 460          */
 461         sr_modify_reg(sr, errconfig_offs, vpboundint_en | vpboundint_st, 0);
 462
 463         return 0;
 464 }
 465
 466 /**
 467  * sr_configure_minmax() - Configures the smrtreflex to perform AVS using the
 468  *                       minmaxavg module.
 469  * @voltdm:     VDD pointer to which the SR module to be configured belongs to.
 470  *
 471  * This API is to be called from the smartreflex class driver to
 472  * configure the minmaxavg module inside the smartreflex module.
 473  * SR settings if using the ERROR module inside Smartreflex.
 474  * SR CLASS 3 by default uses only the ERROR module where as
 475  * SR CLASS 2 can choose between ERROR module and MINMAXAVG
 476  * module. Returns 0 on success and error value in case of failure.
 477  */
 478 int sr_configure_minmax(struct voltagedomain *voltdm)
 479 {
 480         u32 sr_config, sr_avgwt;
 481         u32 senp_en = 0, senn_en = 0;
 482         u8 senp_shift, senn_shift;
 483         struct omap_sr *sr = _sr_lookup(voltdm);
 484
 485         if (IS_ERR(sr)) {
 486                 pr_warning("%s: omap_sr struct for voltdm not found\n", __func__);
 487                 return PTR_ERR(sr);
 488         }
 489
 490         if (!sr->clk_length)
 491                 sr_set_clk_length(sr);
 492
 493         senp_en = sr->senp_mod;
 494         senn_en = sr->senn_mod;
 495
 496         sr_config = (sr->clk_length << SRCONFIG_SRCLKLENGTH_SHIFT) |
 497                 SRCONFIG_SENENABLE |
 498                 (sr->accum_data << SRCONFIG_ACCUMDATA_SHIFT);
 499
 500         switch (sr->ip_type) {
 501         case SR_TYPE_V1:
 502                 sr_config |= SRCONFIG_DELAYCTRL;
 503                 senn_shift = SRCONFIG_SENNENABLE_V1_SHIFT;
 504                 senp_shift = SRCONFIG_SENPENABLE_V1_SHIFT;
 505                 break;
 506         case SR_TYPE_V2:
 507                 senn_shift = SRCONFIG_SENNENABLE_V2_SHIFT;
 508                 senp_shift = SRCONFIG_SENPENABLE_V2_SHIFT;
 509                 break;
 510         default:
 511                 dev_err(&sr->pdev->dev, "%s: Trying to Configure smartreflex"
 512                         "module without specifying the ip\n", __func__);
 513                 return -EINVAL;
 514         }
 515
 516         sr_config |= ((senn_en << senn_shift) | (senp_en << senp_shift));
 517         sr_write_reg(sr, SRCONFIG, sr_config);
 518         sr_avgwt = (sr->senp_avgweight << AVGWEIGHT_SENPAVGWEIGHT_SHIFT) |
 519                 (sr->senn_avgweight << AVGWEIGHT_SENNAVGWEIGHT_SHIFT);
 520         sr_write_reg(sr, AVGWEIGHT, sr_avgwt);
 521
 522         /*
 523          * Enabling the interrupts if MINMAXAVG module is used.
 524          * TODO: check if all the interrupts are mandatory
 525          */
 526         switch (sr->ip_type) {
 527         case SR_TYPE_V1:
 528                 sr_modify_reg(sr, ERRCONFIG_V1,
 529                         (ERRCONFIG_MCUACCUMINTEN | ERRCONFIG_MCUVALIDINTEN |
 530                         ERRCONFIG_MCUBOUNDINTEN),
 531                         (ERRCONFIG_MCUACCUMINTEN | ERRCONFIG_MCUACCUMINTST |
 532                          ERRCONFIG_MCUVALIDINTEN | ERRCONFIG_MCUVALIDINTST |
 533                          ERRCONFIG_MCUBOUNDINTEN | ERRCONFIG_MCUBOUNDINTST));
 534                 break;
 535         case SR_TYPE_V2:
 536                 sr_write_reg(sr, IRQSTATUS,
 537                         IRQSTATUS_MCUACCUMINT | IRQSTATUS_MCVALIDINT |
 538                         IRQSTATUS_MCBOUNDSINT | IRQSTATUS_MCUDISABLEACKINT);
 539                 sr_write_reg(sr, IRQENABLE_SET,
 540                         IRQENABLE_MCUACCUMINT | IRQENABLE_MCUVALIDINT |
 541                         IRQENABLE_MCUBOUNDSINT | IRQENABLE_MCUDISABLEACKINT);
 542                 break;
 543         default:
 544                 dev_err(&sr->pdev->dev, "%s: Trying to Configure smartreflex"
 545                         "module without specifying the ip\n", __func__);
 546                 return -EINVAL;
 547         }
 548
 549         return 0;
 550 }
 551
 552 /**
 553  * sr_enable() - Enables the smartreflex module.
 554  * @voltdm:     VDD pointer to which the SR module to be configured belongs to.
 555  * @volt:       The voltage at which the Voltage domain associated with
 556  *              the smartreflex module is operating at.
 557  *              This is required only to program the correct Ntarget value.
 558  *
 559  * This API is to be called from the smartreflex class driver to
 560  * enable a smartreflex module. Returns 0 on success. Returns error
 561  * value if the voltage passed is wrong or if ntarget value is wrong.
 562  */
 563 int sr_enable(struct voltagedomain *voltdm, unsigned long volt)
 564 {
 565         struct omap_volt_data *volt_data;
 566         struct omap_sr *sr = _sr_lookup(voltdm);
 567         struct omap_sr_nvalue_table *nvalue_row;
 568         int ret;
 569
 570         if (IS_ERR(sr)) {
 571                 pr_warning("%s: omap_sr struct for voltdm not found\n", __func__);
 572                 return PTR_ERR(sr);
 573         }
 574
 575         volt_data = omap_voltage_get_voltdata(sr->voltdm, volt);
 576
 577         if (IS_ERR(volt_data)) {
 578                 dev_warn(&sr->pdev->dev, "%s: Unable to get voltage table"
 579                         "for nominal voltage %ld\n", __func__, volt);
 580                 return PTR_ERR(volt_data);
 581         }
 582
 583         nvalue_row = sr_retrieve_nvalue_row(sr, volt_data->sr_efuse_offs);
 584
 585         if (!nvalue_row) {
 586                 dev_warn(&sr->pdev->dev, "%s: failure getting SR data for this voltage %ld\n",
 587                          __func__, volt);
 588                 return -ENODATA;
 589         }
 590
 591         /* errminlimit is opp dependent and hence linked to voltage */
 592         sr->err_minlimit = nvalue_row->errminlimit;
 593
 594         pm_runtime_get_sync(&sr->pdev->dev);
 595
 596         /* Check if SR is already enabled. If yes do nothing */
 597         if (sr_read_reg(sr, SRCONFIG) & SRCONFIG_SRENABLE)
 598                 return 0;
 599
 600         /* Configure SR */
 601         ret = sr_class->configure(sr);
 602         if (ret)
 603                 return ret;
 604
 605         sr_write_reg(sr, NVALUERECIPROCAL, nvalue_row->nvalue);
 606
 607         /* SRCONFIG - enable SR */
 608         sr_modify_reg(sr, SRCONFIG, SRCONFIG_SRENABLE, SRCONFIG_SRENABLE);
 609         return 0;
 610 }
 611
 612 /**
 613  * sr_disable() - Disables the smartreflex module.
 614  * @voltdm:     VDD pointer to which the SR module to be configured belongs to.
 615  *
 616  * This API is to be called from the smartreflex class driver to
 617  * disable a smartreflex module.
 618  */
 619 void sr_disable(struct voltagedomain *voltdm)
 620 {
 621         struct omap_sr *sr = _sr_lookup(voltdm);
 622
 623         if (IS_ERR(sr)) {
 624                 pr_warning("%s: omap_sr struct for voltdm not found\n", __func__);
 625                 return;
 626         }
 627
 628         /* Check if SR clocks are already disabled. If yes do nothing */
 629         if (pm_runtime_suspended(&sr->pdev->dev))
 630                 return;
 631
 632         /*
 633          * Disable SR if only it is indeed enabled. Else just
 634          * disable the clocks.
 635          */
 636         if (sr_read_reg(sr, SRCONFIG) & SRCONFIG_SRENABLE) {
 637                 switch (sr->ip_type) {
 638                 case SR_TYPE_V1:
 639                         sr_v1_disable(sr);
 640                         break;
 641                 case SR_TYPE_V2:
 642                         sr_v2_disable(sr);
 643                         break;
 644                 default:
 645                         dev_err(&sr->pdev->dev, "UNKNOWN IP type %d\n",
 646                                 sr->ip_type);
 647                 }
 648         }
 649
 650         pm_runtime_put_sync_suspend(&sr->pdev->dev);
 651 }
 652
 653 /**
 654  * sr_register_class() - API to register a smartreflex class parameters.
 655  * @class_data: The structure containing various sr class specific data.
 656  *
 657  * This API is to be called by the smartreflex class driver to register itself
 658  * with the smartreflex driver during init. Returns 0 on success else the
 659  * error value.
 660  */
 661 int sr_register_class(struct omap_sr_class_data *class_data)
 662 {
 663         struct omap_sr *sr_info;
 664
 665         if (!class_data) {
 666                 pr_warning("%s:, Smartreflex class data passed is NULL\n",
 667                         __func__);
 668                 return -EINVAL;
 669         }
 670
 671         if (sr_class) {
 672                 pr_warning("%s: Smartreflex class driver already registered\n",
 673                         __func__);
 674                 return -EBUSY;
 675         }
 676
 677         sr_class = class_data;
 678
 679         /*
 680          * Call into late init to do intializations that require
 681          * both sr driver and sr class driver to be initiallized.
 682          */
 683         list_for_each_entry(sr_info, &sr_list, node)
 684                 sr_late_init(sr_info);
 685
 686         return 0;
 687 }
 688
 689 /**
 690  * omap_sr_enable() -  API to enable SR clocks and to call into the
 691  *                      registered smartreflex class enable API.
 692  * @voltdm:     VDD pointer to which the SR module to be configured belongs to.
 693  *
 694  * This API is to be called from the kernel in order to enable
 695  * a particular smartreflex module. This API will do the initial
 696  * configurations to turn on the smartreflex module and in turn call
 697  * into the registered smartreflex class enable API.
 698  */
 699 void omap_sr_enable(struct voltagedomain *voltdm)
 700 {
 701         struct omap_sr *sr = _sr_lookup(voltdm);
 702
 703         if (IS_ERR(sr)) {
 704                 pr_warning("%s: omap_sr struct for voltdm not found\n", __func__);
 705                 return;
 706         }
 707
 708         if (!sr->autocomp_active)
 709                 return;
 710
 711         if (!sr_class || !(sr_class->enable) || !(sr_class->configure)) {
 712                 dev_warn(&sr->pdev->dev, "%s: smartreflex class driver not"
 713                         "registered\n", __func__);
 714                 return;
 715         }
 716
 717         sr_class->enable(sr);
 718 }
 719
 720 /**
 721  * omap_sr_disable() - API to disable SR without resetting the voltage
 722  *                      processor voltage
 723  * @voltdm:     VDD pointer to which the SR module to be configured belongs to.
 724  *
 725  * This API is to be called from the kernel in order to disable
 726  * a particular smartreflex module. This API will in turn call
 727  * into the registered smartreflex class disable API. This API will tell
 728  * the smartreflex class disable not to reset the VP voltage after
 729  * disabling smartreflex.
 730  */
 731 void omap_sr_disable(struct voltagedomain *voltdm)
 732 {
 733         struct omap_sr *sr = _sr_lookup(voltdm);
 734
 735         if (IS_ERR(sr)) {
 736                 pr_warning("%s: omap_sr struct for voltdm not found\n", __func__);
 737                 return;
 738         }
 739
 740         if (!sr->autocomp_active)
 741                 return;
 742
 743         if (!sr_class || !(sr_class->disable)) {
 744                 dev_warn(&sr->pdev->dev, "%s: smartreflex class driver not"
 745                         "registered\n", __func__);
 746                 return;
 747         }
 748
 749         sr_class->disable(sr, 0);
 750 }
 751
 752 /**
 753  * omap_sr_disable_reset_volt() - API to disable SR and reset the
 754  *                              voltage processor voltage
 755  * @voltdm:     VDD pointer to which the SR module to be configured belongs to.
 756  *
 757  * This API is to be called from the kernel in order to disable
 758  * a particular smartreflex module. This API will in turn call
 759  * into the registered smartreflex class disable API. This API will tell
 760  * the smartreflex class disable to reset the VP voltage after
 761  * disabling smartreflex.
 762  */
 763 void omap_sr_disable_reset_volt(struct voltagedomain *voltdm)
 764 {
 765         struct omap_sr *sr = _sr_lookup(voltdm);
 766
 767         if (IS_ERR(sr)) {
 768                 pr_warning("%s: omap_sr struct for voltdm not found\n", __func__);
 769                 return;
 770         }
 771
 772         if (!sr->autocomp_active)
 773                 return;
 774
 775         if (!sr_class || !(sr_class->disable)) {
 776                 dev_warn(&sr->pdev->dev, "%s: smartreflex class driver not"
 777                         "registered\n", __func__);
 778                 return;
 779         }
 780
 781         sr_class->disable(sr, 1);
 782 }
 783
 784 /**
 785  * omap_sr_register_pmic() - API to register pmic specific info.
 786  * @pmic_data:  The structure containing pmic specific data.
 787  *
 788  * This API is to be called from the PMIC specific code to register with
 789  * smartreflex driver pmic specific info. Currently the only info required
 790  * is the smartreflex init on the PMIC side.
 791  */
 792 void omap_sr_register_pmic(struct omap_sr_pmic_data *pmic_data)
 793 {
 794         if (!pmic_data) {
 795                 pr_warning("%s: Trying to register NULL PMIC data structure"
 796                         "with smartreflex\n", __func__);
 797                 return;
 798         }
 799
 800         sr_pmic_data = pmic_data;
 801 }
 802
 803 /* PM Debug FS entries to enable and disable smartreflex. */
 804 static int omap_sr_autocomp_show(void *data, u64 *val)
 805 {
 806         struct omap_sr *sr_info = data;
 807
 808         if (!sr_info) {
 809                 pr_warning("%s: omap_sr struct not found\n", __func__);
 810                 return -EINVAL;
 811         }
 812
 813         *val = sr_info->autocomp_active;
 814
 815         return 0;
 816 }
 817
 818 static int omap_sr_autocomp_store(void *data, u64 val)
 819 {
 820         struct omap_sr *sr_info = data;
 821
 822         if (!sr_info) {
 823                 pr_warning("%s: omap_sr struct not found\n", __func__);
 824                 return -EINVAL;
 825         }
 826
 827         /* Sanity check */
 828         if (val > 1) {
 829                 pr_warning("%s: Invalid argument %lld\n", __func__, val);
 830                 return -EINVAL;
 831         }
 832
 833         /* control enable/disable only if there is a delta in value */
 834         if (sr_info->autocomp_active != val) {
 835                 if (!val)
 836                         sr_stop_vddautocomp(sr_info);
 837                 else
 838                         sr_start_vddautocomp(sr_info);
 839         }
 840
 841         return 0;
 842 }
 843
 844 DEFINE_SIMPLE_ATTRIBUTE(pm_sr_fops, omap_sr_autocomp_show,
 845                         omap_sr_autocomp_store, "%llu\n");
 846
 847 static int __init omap_sr_probe(struct platform_device *pdev)
 848 {
 849         struct omap_sr *sr_info;
 850         struct omap_sr_data *pdata = pdev->dev.platform_data;
 851         struct resource *mem, *irq;
 852         struct dentry *nvalue_dir;
 853         int i, ret = 0;
 854
 855         sr_info = kzalloc(sizeof(struct omap_sr), GFP_KERNEL);
 856         if (!sr_info) {
 857                 dev_err(&pdev->dev, "%s: unable to allocate sr_info\n",
 858                         __func__);
 859                 return -ENOMEM;
 860         }
 861
 862         platform_set_drvdata(pdev, sr_info);
 863
 864         if (!pdata) {
 865                 dev_err(&pdev->dev, "%s: platform data missing\n", __func__);
 866                 ret = -EINVAL;
 867                 goto err_free_devinfo;
 868         }
 869
 870         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 871         if (!mem) {
 872                 dev_err(&pdev->dev, "%s: no mem resource\n", __func__);
 873                 ret = -ENODEV;
 874                 goto err_free_devinfo;
 875         }
 876
 877         mem = request_mem_region(mem->start, resource_size(mem),
 878                                         dev_name(&pdev->dev));
 879         if (!mem) {
 880                 dev_err(&pdev->dev, "%s: no mem region\n", __func__);
 881                 ret = -EBUSY;
 882                 goto err_free_devinfo;
 883         }
 884
 885         irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 886
 887         pm_runtime_enable(&pdev->dev);
 888         pm_runtime_irq_safe(&pdev->dev);
 889
 890         sr_info->name = kasprintf(GFP_KERNEL, "%s", pdata->name);
 891         if (!sr_info->name) {
 892                 dev_err(&pdev->dev, "%s: Unable to alloc SR instance name\n",
 893                         __func__);
 894                 ret = -ENOMEM;
 895                 goto err_release_region;
 896         }
 897
 898         sr_info->pdev = pdev;
 899         sr_info->srid = pdev->id;
 900         sr_info->voltdm = pdata->voltdm;
 901         sr_info->nvalue_table = pdata->nvalue_table;
 902         sr_info->nvalue_count = pdata->nvalue_count;
 903         sr_info->senn_mod = pdata->senn_mod;
 904         sr_info->senp_mod = pdata->senp_mod;
 905         sr_info->err_weight = pdata->err_weight;
 906         sr_info->err_maxlimit = pdata->err_maxlimit;
 907         sr_info->accum_data = pdata->accum_data;
 908         sr_info->senn_avgweight = pdata->senn_avgweight;
 909         sr_info->senp_avgweight = pdata->senp_avgweight;
 910         sr_info->autocomp_active = false;
 911         sr_info->ip_type = pdata->ip_type;
 912
 913         sr_info->base = ioremap(mem->start, resource_size(mem));
 914         if (!sr_info->base) {
 915                 dev_err(&pdev->dev, "%s: ioremap fail\n", __func__);
 916                 ret = -ENOMEM;
 917                 goto err_free_name;
 918         }
 919
 920         if (irq)
 921                 sr_info->irq = irq->start;
 922
 923         sr_set_clk_length(sr_info);
 924
 925         list_add(&sr_info->node, &sr_list);
 926
 927         /*
 928          * Call into late init to do intializations that require
 929          * both sr driver and sr class driver to be initiallized.
 930          */
 931         if (sr_class) {
 932                 ret = sr_late_init(sr_info);
 933                 if (ret) {
 934                         pr_warning("%s: Error in SR late init\n", __func__);
 935                         goto err_iounmap;
 936                 }
 937         }
 938
 939         dev_info(&pdev->dev, "%s: SmartReflex driver initialized\n", __func__);
 940         if (!sr_dbg_dir) {
 941                 sr_dbg_dir = debugfs_create_dir("smartreflex", NULL);
 942                 if (IS_ERR_OR_NULL(sr_dbg_dir)) {
 943                         ret = PTR_ERR(sr_dbg_dir);
 944                         pr_err("%s:sr debugfs dir creation failed(%d)\n",
 945                                 __func__, ret);
 946                         goto err_iounmap;
 947                 }
 948         }
 949
 950         sr_info->dbg_dir = debugfs_create_dir(sr_info->name, sr_dbg_dir);
 951         if (IS_ERR_OR_NULL(sr_info->dbg_dir)) {
 952                 dev_err(&pdev->dev, "%s: Unable to create debugfs directory\n",
 953                         __func__);
 954                 ret = PTR_ERR(sr_info->dbg_dir);
 955                 goto err_debugfs;
 956         }
 957
 958         (void) debugfs_create_file("autocomp", S_IRUGO | S_IWUSR,
 959                         sr_info->dbg_dir, (void *)sr_info, &pm_sr_fops);
 960         (void) debugfs_create_x32("errweight", S_IRUGO, sr_info->dbg_dir,
 961                         &sr_info->err_weight);
 962         (void) debugfs_create_x32("errmaxlimit", S_IRUGO, sr_info->dbg_dir,
 963                         &sr_info->err_maxlimit);
 964
 965         nvalue_dir = debugfs_create_dir("nvalue", sr_info->dbg_dir);
 966         if (IS_ERR_OR_NULL(nvalue_dir)) {
 967                 dev_err(&pdev->dev, "%s: Unable to create debugfs directory"
 968                         "for n-values\n", __func__);
 969                 ret = PTR_ERR(nvalue_dir);
 970                 goto err_debugfs;
 971         }
 972
 973         if (sr_info->nvalue_count == 0 || !sr_info->nvalue_table) {
 974                 dev_warn(&pdev->dev, "%s: %s: No Voltage table for the corresponding vdd. Cannot create debugfs entries for n-values\n",
 975                          __func__, sr_info->name);
 976
 977                 ret = -ENODATA;
 978                 goto err_debugfs;
 979         }
 980
 981         for (i = 0; i < sr_info->nvalue_count; i++) {
 982                 char name[NVALUE_NAME_LEN + 1];
 983
 984                 snprintf(name, sizeof(name), "volt_%lu",
 985                                 sr_info->nvalue_table[i].volt_nominal);
 986                 (void) debugfs_create_x32(name, S_IRUGO | S_IWUSR, nvalue_dir,
 987                                 &(sr_info->nvalue_table[i].nvalue));
 988                 snprintf(name, sizeof(name), "errminlimit_%lu",
 989                          sr_info->nvalue_table[i].volt_nominal);
 990                 (void) debugfs_create_x32(name, S_IRUGO | S_IWUSR, nvalue_dir,
 991                                 &(sr_info->nvalue_table[i].errminlimit));
 992
 993         }
 994
 995         return ret;
 996
 997 err_debugfs:
 998         debugfs_remove_recursive(sr_info->dbg_dir);
 999 err_iounmap:
1000         list_del(&sr_info->node);
1001         iounmap(sr_info->base);
1002 err_free_name:
1003         kfree(sr_info->name);
1004 err_release_region:
1005         release_mem_region(mem->start, resource_size(mem));
1006 err_free_devinfo:
1007         kfree(sr_info);
1008
1009         return ret;
1010 }
1011
1012 static int omap_sr_remove(struct platform_device *pdev)
1013 {
1014         struct omap_sr_data *pdata = pdev->dev.platform_data;
1015         struct omap_sr *sr_info;
1016         struct resource *mem;
1017
1018         if (!pdata) {
1019                 dev_err(&pdev->dev, "%s: platform data missing\n", __func__);
1020                 return -EINVAL;
1021         }
1022
1023         sr_info = _sr_lookup(pdata->voltdm);
1024         if (IS_ERR(sr_info)) {
1025                 dev_warn(&pdev->dev, "%s: omap_sr struct not found\n",
1026                         __func__);
1027                 return PTR_ERR(sr_info);
1028         }
1029
1030         if (sr_info->autocomp_active)
1031                 sr_stop_vddautocomp(sr_info);
1032         if (sr_info->dbg_dir)
1033                 debugfs_remove_recursive(sr_info->dbg_dir);
1034
1035         list_del(&sr_info->node);
1036         iounmap(sr_info->base);
1037         kfree(sr_info->name);
1038         kfree(sr_info);
1039         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1040         release_mem_region(mem->start, resource_size(mem));
1041
1042         return 0;
1043 }
1044
1045 static void omap_sr_shutdown(struct platform_device *pdev)
1046 {
1047         struct omap_sr_data *pdata = pdev->dev.platform_data;
1048         struct omap_sr *sr_info;
1049
1050         if (!pdata) {
1051                 dev_err(&pdev->dev, "%s: platform data missing\n", __func__);
1052                 return;
1053         }
1054
1055         sr_info = _sr_lookup(pdata->voltdm);
1056         if (IS_ERR(sr_info)) {
1057                 dev_warn(&pdev->dev, "%s: omap_sr struct not found\n",
1058                         __func__);
1059                 return;
1060         }
1061
1062         if (sr_info->autocomp_active)
1063                 sr_stop_vddautocomp(sr_info);
1064
1065         return;
1066 }
1067
1068 static struct platform_driver smartreflex_driver = {
1069         .remove         = omap_sr_remove,
1070         .shutdown       = omap_sr_shutdown,
1071         .driver         = {
1072                 .name   = "smartreflex",
1073         },
1074 };
1075
1076 static int __init sr_init(void)
1077 {
1078         int ret = 0;
1079
1080         /*
1081          * sr_init is a late init. If by then a pmic specific API is not
1082          * registered either there is no need for anything to be done on
1083          * the PMIC side or somebody has forgotten to register a PMIC
1084          * handler. Warn for the second condition.
1085          */
1086         if (sr_pmic_data && sr_pmic_data->sr_pmic_init)
1087                 sr_pmic_data->sr_pmic_init();
1088         else
1089                 pr_warning("%s: No PMIC hook to init smartreflex\n", __func__);
1090
1091         ret = platform_driver_probe(&smartreflex_driver, omap_sr_probe);
1092         if (ret) {
1093                 pr_err("%s: platform driver register failed for SR\n",
1094                         __func__);
1095                 return ret;
1096         }
1097
1098         return 0;
1099 }
1100 late_initcall(sr_init);
1101
1102 static void __exit sr_exit(void)
1103 {
1104         platform_driver_unregister(&smartreflex_driver);
1105 }
1106 module_exit(sr_exit);
1107
1108 MODULE_DESCRIPTION("OMAP Smartreflex Driver");
1109 MODULE_LICENSE("GPL");
1110 MODULE_ALIAS("platform:" DRIVER_NAME);
1111 MODULE_AUTHOR("Texas Instruments Inc");