drivers/sh/pfc.c

   1 /*
   2  * Pinmuxed GPIO support for SuperH.
   3  *
   4  * Copyright (C) 2008 Magnus Damm
   5  *
   6  * This file is subject to the terms and conditions of the GNU General Public
   7  * License.  See the file "COPYING" in the main directory of this archive
   8  * for more details.
   9  */
  10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  11
  12 #include <linux/errno.h>
  13 #include <linux/kernel.h>
  14 #include <linux/list.h>
  15 #include <linux/module.h>
  16 #include <linux/clk.h>
  17 #include <linux/err.h>
  18 #include <linux/io.h>
  19 #include <linux/irq.h>
  20 #include <linux/bitops.h>
  21 #include <linux/gpio.h>
  22
  23 static int enum_in_range(pinmux_enum_t enum_id, struct pinmux_range *r)
  24 {
  25         if (enum_id < r->begin)
  26                 return 0;
  27
  28         if (enum_id > r->end)
  29                 return 0;
  30
  31         return 1;
  32 }
  33
  34 static unsigned long gpio_read_raw_reg(unsigned long reg,
  35                                        unsigned long reg_width)
  36 {
  37         switch (reg_width) {
  38         case 8:
  39                 return __raw_readb(reg);
  40         case 16:
  41                 return __raw_readw(reg);
  42         case 32:
  43                 return __raw_readl(reg);
  44         }
  45
  46         BUG();
  47         return 0;
  48 }
  49
  50 static void gpio_write_raw_reg(unsigned long reg,
  51                                unsigned long reg_width,
  52                                unsigned long data)
  53 {
  54         switch (reg_width) {
  55         case 8:
  56                 __raw_writeb(data, reg);
  57                 return;
  58         case 16:
  59                 __raw_writew(data, reg);
  60                 return;
  61         case 32:
  62                 __raw_writel(data, reg);
  63                 return;
  64         }
  65
  66         BUG();
  67 }
  68
  69 static void gpio_write_bit(struct pinmux_data_reg *dr,
  70                            unsigned long in_pos, unsigned long value)
  71 {
  72         unsigned long pos;
  73
  74         pos = dr->reg_width - (in_pos + 1);
  75
  76         pr_debug("write_bit addr = %lx, value = %d, pos = %ld, "
  77                  "r_width = %ld\n",
  78                  dr->reg, !!value, pos, dr->reg_width);
  79
  80         if (value)
  81                 set_bit(pos, &dr->reg_shadow);
  82         else
  83                 clear_bit(pos, &dr->reg_shadow);
  84
  85         gpio_write_raw_reg(dr->reg, dr->reg_width, dr->reg_shadow);
  86 }
  87
  88 static int gpio_read_reg(unsigned long reg, unsigned long reg_width,
  89                          unsigned long field_width, unsigned long in_pos)
  90 {
  91         unsigned long data, mask, pos;
  92
  93         data = 0;
  94         mask = (1 << field_width) - 1;
  95         pos = reg_width - ((in_pos + 1) * field_width);
  96
  97         pr_debug("read_reg: addr = %lx, pos = %ld, "
  98                  "r_width = %ld, f_width = %ld\n",
  99                  reg, pos, reg_width, field_width);
 100
 101         data = gpio_read_raw_reg(reg, reg_width);
 102         return (data >> pos) & mask;
 103 }
 104
 105 static void gpio_write_reg(unsigned long reg, unsigned long reg_width,
 106                            unsigned long field_width, unsigned long in_pos,
 107                            unsigned long value)
 108 {
 109         unsigned long mask, pos;
 110
 111         mask = (1 << field_width) - 1;
 112         pos = reg_width - ((in_pos + 1) * field_width);
 113
 114         pr_debug("write_reg addr = %lx, value = %ld, pos = %ld, "
 115                  "r_width = %ld, f_width = %ld\n",
 116                  reg, value, pos, reg_width, field_width);
 117
 118         mask = ~(mask << pos);
 119         value = value << pos;
 120
 121         switch (reg_width) {
 122         case 8:
 123                 __raw_writeb((__raw_readb(reg) & mask) | value, reg);
 124                 break;
 125         case 16:
 126                 __raw_writew((__raw_readw(reg) & mask) | value, reg);
 127                 break;
 128         case 32:
 129                 __raw_writel((__raw_readl(reg) & mask) | value, reg);
 130                 break;
 131         }
 132 }
 133
 134 static int setup_data_reg(struct pinmux_info *gpioc, unsigned gpio)
 135 {
 136         struct pinmux_gpio *gpiop = &gpioc->gpios[gpio];
 137         struct pinmux_data_reg *data_reg;
 138         int k, n;
 139
 140         if (!enum_in_range(gpiop->enum_id, &gpioc->data))
 141                 return -1;
 142
 143         k = 0;
 144         while (1) {
 145                 data_reg = gpioc->data_regs + k;
 146
 147                 if (!data_reg->reg_width)
 148                         break;
 149
 150                 for (n = 0; n < data_reg->reg_width; n++) {
 151                         if (data_reg->enum_ids[n] == gpiop->enum_id) {
 152                                 gpiop->flags &= ~PINMUX_FLAG_DREG;
 153                                 gpiop->flags |= (k << PINMUX_FLAG_DREG_SHIFT);
 154                                 gpiop->flags &= ~PINMUX_FLAG_DBIT;
 155                                 gpiop->flags |= (n << PINMUX_FLAG_DBIT_SHIFT);
 156                                 return 0;
 157                         }
 158                 }
 159                 k++;
 160         }
 161
 162         BUG();
 163
 164         return -1;
 165 }
 166
 167 static void setup_data_regs(struct pinmux_info *gpioc)
 168 {
 169         struct pinmux_data_reg *drp;
 170         int k;
 171
 172         for (k = gpioc->first_gpio; k <= gpioc->last_gpio; k++)
 173                 setup_data_reg(gpioc, k);
 174
 175         k = 0;
 176         while (1) {
 177                 drp = gpioc->data_regs + k;
 178
 179                 if (!drp->reg_width)
 180                         break;
 181
 182                 drp->reg_shadow = gpio_read_raw_reg(drp->reg, drp->reg_width);
 183                 k++;
 184         }
 185 }
 186
 187 static int get_data_reg(struct pinmux_info *gpioc, unsigned gpio,
 188                         struct pinmux_data_reg **drp, int *bitp)
 189 {
 190         struct pinmux_gpio *gpiop = &gpioc->gpios[gpio];
 191         int k, n;
 192
 193         if (!enum_in_range(gpiop->enum_id, &gpioc->data))
 194                 return -1;
 195
 196         k = (gpiop->flags & PINMUX_FLAG_DREG) >> PINMUX_FLAG_DREG_SHIFT;
 197         n = (gpiop->flags & PINMUX_FLAG_DBIT) >> PINMUX_FLAG_DBIT_SHIFT;
 198         *drp = gpioc->data_regs + k;
 199         *bitp = n;
 200         return 0;
 201 }
 202
 203 static int get_config_reg(struct pinmux_info *gpioc, pinmux_enum_t enum_id,
 204                           struct pinmux_cfg_reg **crp, int *indexp,
 205                           unsigned long **cntp)
 206 {
 207         struct pinmux_cfg_reg *config_reg;
 208         unsigned long r_width, f_width;
 209         int k, n;
 210
 211         k = 0;
 212         while (1) {
 213                 config_reg = gpioc->cfg_regs + k;
 214
 215                 r_width = config_reg->reg_width;
 216                 f_width = config_reg->field_width;
 217
 218                 if (!r_width)
 219                         break;
 220                 for (n = 0; n < (r_width / f_width) * 1 << f_width; n++) {
 221                         if (config_reg->enum_ids[n] == enum_id) {
 222                                 *crp = config_reg;
 223                                 *indexp = n;
 224                                 *cntp = &config_reg->cnt[n / (1 << f_width)];
 225                                 return 0;
 226                         }
 227                 }
 228                 k++;
 229         }
 230
 231         return -1;
 232 }
 233
 234 static int get_gpio_enum_id(struct pinmux_info *gpioc, unsigned gpio,
 235                             int pos, pinmux_enum_t *enum_idp)
 236 {
 237         pinmux_enum_t enum_id = gpioc->gpios[gpio].enum_id;
 238         pinmux_enum_t *data = gpioc->gpio_data;
 239         int k;
 240
 241         if (!enum_in_range(enum_id, &gpioc->data)) {
 242                 if (!enum_in_range(enum_id, &gpioc->mark)) {
 243                         pr_err("non data/mark enum_id for gpio %d\n", gpio);
 244                         return -1;
 245                 }
 246         }
 247
 248         if (pos) {
 249                 *enum_idp = data[pos + 1];
 250                 return pos + 1;
 251         }
 252
 253         for (k = 0; k < gpioc->gpio_data_size; k++) {
 254                 if (data[k] == enum_id) {
 255                         *enum_idp = data[k + 1];
 256                         return k + 1;
 257                 }
 258         }
 259
 260         pr_err("cannot locate data/mark enum_id for gpio %d\n", gpio);
 261         return -1;
 262 }
 263
 264 static void write_config_reg(struct pinmux_info *gpioc,
 265                              struct pinmux_cfg_reg *crp,
 266                              int index)
 267 {
 268         unsigned long ncomb, pos, value;
 269
 270         ncomb = 1 << crp->field_width;
 271         pos = index / ncomb;
 272         value = index % ncomb;
 273
 274         gpio_write_reg(crp->reg, crp->reg_width, crp->field_width, pos, value);
 275 }
 276
 277 static int check_config_reg(struct pinmux_info *gpioc,
 278                             struct pinmux_cfg_reg *crp,
 279                             int index)
 280 {
 281         unsigned long ncomb, pos, value;
 282
 283         ncomb = 1 << crp->field_width;
 284         pos = index / ncomb;
 285         value = index % ncomb;
 286
 287         if (gpio_read_reg(crp->reg, crp->reg_width,
 288                           crp->field_width, pos) == value)
 289                 return 0;
 290
 291         return -1;
 292 }
 293
 294 enum { GPIO_CFG_DRYRUN, GPIO_CFG_REQ, GPIO_CFG_FREE };
 295
 296 static int pinmux_config_gpio(struct pinmux_info *gpioc, unsigned gpio,
 297                               int pinmux_type, int cfg_mode)
 298 {
 299         struct pinmux_cfg_reg *cr = NULL;
 300         pinmux_enum_t enum_id;
 301         struct pinmux_range *range;
 302         int in_range, pos, index;
 303         unsigned long *cntp;
 304
 305         switch (pinmux_type) {
 306
 307         case PINMUX_TYPE_FUNCTION:
 308                 range = NULL;
 309                 break;
 310
 311         case PINMUX_TYPE_OUTPUT:
 312                 range = &gpioc->output;
 313                 break;
 314
 315         case PINMUX_TYPE_INPUT:
 316                 range = &gpioc->input;
 317                 break;
 318
 319         case PINMUX_TYPE_INPUT_PULLUP:
 320                 range = &gpioc->input_pu;
 321                 break;
 322
 323         case PINMUX_TYPE_INPUT_PULLDOWN:
 324                 range = &gpioc->input_pd;
 325                 break;
 326
 327         default:
 328                 goto out_err;
 329         }
 330
 331         pos = 0;
 332         enum_id = 0;
 333         index = 0;
 334         while (1) {
 335                 pos = get_gpio_enum_id(gpioc, gpio, pos, &enum_id);
 336                 if (pos <= 0)
 337                         goto out_err;
 338
 339                 if (!enum_id)
 340                         break;
 341
 342                 /* first check if this is a function enum */
 343                 in_range = enum_in_range(enum_id, &gpioc->function);
 344                 if (!in_range) {
 345                         /* not a function enum */
 346                         if (range) {
 347                                 /*
 348                                  * other range exists, so this pin is
 349                                  * a regular GPIO pin that now is being
 350                                  * bound to a specific direction.
 351                                  *
 352                                  * for this case we only allow function enums
 353                                  * and the enums that match the other range.
 354                                  */
 355                                 in_range = enum_in_range(enum_id, range);
 356
 357                                 /*
 358                                  * special case pass through for fixed
 359                                  * input-only or output-only pins without
 360                                  * function enum register association.
 361                                  */
 362                                 if (in_range && enum_id == range->force)
 363                                         continue;
 364                         } else {
 365                                 /*
 366                                  * no other range exists, so this pin
 367                                  * must then be of the function type.
 368                                  *
 369                                  * allow function type pins to select
 370                                  * any combination of function/in/out
 371                                  * in their MARK lists.
 372                                  */
 373                                 in_range = 1;
 374                         }
 375                 }
 376
 377                 if (!in_range)
 378                         continue;
 379
 380                 if (get_config_reg(gpioc, enum_id, &cr, &index, &cntp) != 0)
 381                         goto out_err;
 382
 383                 switch (cfg_mode) {
 384                 case GPIO_CFG_DRYRUN:
 385                         if (!*cntp || !check_config_reg(gpioc, cr, index))
 386                                 continue;
 387                         break;
 388
 389                 case GPIO_CFG_REQ:
 390                         write_config_reg(gpioc, cr, index);
 391                         *cntp = *cntp + 1;
 392                         break;
 393
 394                 case GPIO_CFG_FREE:
 395                         *cntp = *cntp - 1;
 396                         break;
 397                 }
 398         }
 399
 400         return 0;
 401  out_err:
 402         return -1;
 403 }
 404
 405 static DEFINE_SPINLOCK(gpio_lock);
 406
 407 static struct pinmux_info *chip_to_pinmux(struct gpio_chip *chip)
 408 {
 409         return container_of(chip, struct pinmux_info, chip);
 410 }
 411
 412 static int sh_gpio_request(struct gpio_chip *chip, unsigned offset)
 413 {
 414         struct pinmux_info *gpioc = chip_to_pinmux(chip);
 415         struct pinmux_data_reg *dummy;
 416         unsigned long flags;
 417         int i, ret, pinmux_type;
 418
 419         ret = -EINVAL;
 420
 421         if (!gpioc)
 422                 goto err_out;
 423
 424         spin_lock_irqsave(&gpio_lock, flags);
 425
 426         if ((gpioc->gpios[offset].flags & PINMUX_FLAG_TYPE) != PINMUX_TYPE_NONE)
 427                 goto err_unlock;
 428
 429         /* setup pin function here if no data is associated with pin */
 430
 431         if (get_data_reg(gpioc, offset, &dummy, &i) != 0)
 432                 pinmux_type = PINMUX_TYPE_FUNCTION;
 433         else
 434                 pinmux_type = PINMUX_TYPE_GPIO;
 435
 436         if (pinmux_type == PINMUX_TYPE_FUNCTION) {
 437                 if (pinmux_config_gpio(gpioc, offset,
 438                                        pinmux_type,
 439                                        GPIO_CFG_DRYRUN) != 0)
 440                         goto err_unlock;
 441
 442                 if (pinmux_config_gpio(gpioc, offset,
 443                                        pinmux_type,
 444                                        GPIO_CFG_REQ) != 0)
 445                         BUG();
 446         }
 447
 448         gpioc->gpios[offset].flags &= ~PINMUX_FLAG_TYPE;
 449         gpioc->gpios[offset].flags |= pinmux_type;
 450
 451         ret = 0;
 452  err_unlock:
 453         spin_unlock_irqrestore(&gpio_lock, flags);
 454  err_out:
 455         return ret;
 456 }
 457
 458 static void sh_gpio_free(struct gpio_chip *chip, unsigned offset)
 459 {
 460         struct pinmux_info *gpioc = chip_to_pinmux(chip);
 461         unsigned long flags;
 462         int pinmux_type;
 463
 464         if (!gpioc)
 465                 return;
 466
 467         spin_lock_irqsave(&gpio_lock, flags);
 468
 469         pinmux_type = gpioc->gpios[offset].flags & PINMUX_FLAG_TYPE;
 470         pinmux_config_gpio(gpioc, offset, pinmux_type, GPIO_CFG_FREE);
 471         gpioc->gpios[offset].flags &= ~PINMUX_FLAG_TYPE;
 472         gpioc->gpios[offset].flags |= PINMUX_TYPE_NONE;
 473
 474         spin_unlock_irqrestore(&gpio_lock, flags);
 475 }
 476
 477 static int pinmux_direction(struct pinmux_info *gpioc,
 478                             unsigned gpio, int new_pinmux_type)
 479 {
 480         int pinmux_type;
 481         int ret = -EINVAL;
 482
 483         if (!gpioc)
 484                 goto err_out;
 485
 486         pinmux_type = gpioc->gpios[gpio].flags & PINMUX_FLAG_TYPE;
 487
 488         switch (pinmux_type) {
 489         case PINMUX_TYPE_GPIO:
 490                 break;
 491         case PINMUX_TYPE_OUTPUT:
 492         case PINMUX_TYPE_INPUT:
 493         case PINMUX_TYPE_INPUT_PULLUP:
 494         case PINMUX_TYPE_INPUT_PULLDOWN:
 495                 pinmux_config_gpio(gpioc, gpio, pinmux_type, GPIO_CFG_FREE);
 496                 break;
 497         default:
 498                 goto err_out;
 499         }
 500
 501         if (pinmux_config_gpio(gpioc, gpio,
 502                                new_pinmux_type,
 503                                GPIO_CFG_DRYRUN) != 0)
 504                 goto err_out;
 505
 506         if (pinmux_config_gpio(gpioc, gpio,
 507                                new_pinmux_type,
 508                                GPIO_CFG_REQ) != 0)
 509                 BUG();
 510
 511         gpioc->gpios[gpio].flags &= ~PINMUX_FLAG_TYPE;
 512         gpioc->gpios[gpio].flags |= new_pinmux_type;
 513
 514         ret = 0;
 515  err_out:
 516         return ret;
 517 }
 518
 519 static int sh_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
 520 {
 521         struct pinmux_info *gpioc = chip_to_pinmux(chip);
 522         unsigned long flags;
 523         int ret;
 524
 525         spin_lock_irqsave(&gpio_lock, flags);
 526         ret = pinmux_direction(gpioc, offset, PINMUX_TYPE_INPUT);
 527         spin_unlock_irqrestore(&gpio_lock, flags);
 528
 529         return ret;
 530 }
 531
 532 static void sh_gpio_set_value(struct pinmux_info *gpioc,
 533                              unsigned gpio, int value)
 534 {
 535         struct pinmux_data_reg *dr = NULL;
 536         int bit = 0;
 537
 538         if (!gpioc || get_data_reg(gpioc, gpio, &dr, &bit) != 0)
 539                 BUG();
 540         else
 541                 gpio_write_bit(dr, bit, value);
 542 }
 543
 544 static int sh_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
 545                                     int value)
 546 {
 547         struct pinmux_info *gpioc = chip_to_pinmux(chip);
 548         unsigned long flags;
 549         int ret;
 550
 551         sh_gpio_set_value(gpioc, offset, value);
 552         spin_lock_irqsave(&gpio_lock, flags);
 553         ret = pinmux_direction(gpioc, offset, PINMUX_TYPE_OUTPUT);
 554         spin_unlock_irqrestore(&gpio_lock, flags);
 555
 556         return ret;
 557 }
 558
 559 static int sh_gpio_get_value(struct pinmux_info *gpioc, unsigned gpio)
 560 {
 561         struct pinmux_data_reg *dr = NULL;
 562         int bit = 0;
 563
 564         if (!gpioc || get_data_reg(gpioc, gpio, &dr, &bit) != 0)
 565                 return -EINVAL;
 566
 567         return gpio_read_reg(dr->reg, dr->reg_width, 1, bit);
 568 }
 569
 570 static int sh_gpio_get(struct gpio_chip *chip, unsigned offset)
 571 {
 572         return sh_gpio_get_value(chip_to_pinmux(chip), offset);
 573 }
 574
 575 static void sh_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
 576 {
 577         sh_gpio_set_value(chip_to_pinmux(chip), offset, value);
 578 }
 579
 580 int register_pinmux(struct pinmux_info *pip)
 581 {
 582         struct gpio_chip *chip = &pip->chip;
 583
 584         pr_info("%s handling gpio %d -> %d\n",
 585                 pip->name, pip->first_gpio, pip->last_gpio);
 586
 587         setup_data_regs(pip);
 588
 589         chip->request = sh_gpio_request;
 590         chip->free = sh_gpio_free;
 591         chip->direction_input = sh_gpio_direction_input;
 592         chip->get = sh_gpio_get;
 593         chip->direction_output = sh_gpio_direction_output;
 594         chip->set = sh_gpio_set;
 595
 596         WARN_ON(pip->first_gpio != 0); /* needs testing */
 597
 598         chip->label = pip->name;
 599         chip->owner = THIS_MODULE;
 600         chip->base = pip->first_gpio;
 601         chip->ngpio = (pip->last_gpio - pip->first_gpio) + 1;
 602
 603         return gpiochip_add(chip);
 604 }
 605
 606 int unregister_pinmux(struct pinmux_info *pip)
 607 {
 608         pr_info("%s deregistering\n", pip->name);
 609
 610         return gpiochip_remove(&pip->chip);
 611 }