drivers/gpio/gpio-sx150x.c

   1 /* Copyright (c) 2010, Code Aurora Forum. All rights reserved.
   2  *
   3  * This program is free software; you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License version 2 and
   5  * only version 2 as published by the Free Software Foundation.
   6  *
   7  * This program is distributed in the hope that it will be useful,
   8  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  10  * GNU General Public License for more details.
  11  *
  12  * You should have received a copy of the GNU General Public License
  13  * along with this program; if not, write to the Free Software
  14  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  15  * 02110-1301, USA.
  16  */
  17 #include <linux/gpio.h>
  18 #include <linux/i2c.h>
  19 #include <linux/init.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/irq.h>
  22 #include <linux/module.h>
  23 #include <linux/mutex.h>
  24 #include <linux/slab.h>
  25 #include <linux/i2c/sx150x.h>
  26
  27 #define NO_UPDATE_PENDING       -1
  28
  29 struct sx150x_device_data {
  30         u8 reg_pullup;
  31         u8 reg_pulldn;
  32         u8 reg_drain;
  33         u8 reg_polarity;
  34         u8 reg_dir;
  35         u8 reg_data;
  36         u8 reg_irq_mask;
  37         u8 reg_irq_src;
  38         u8 reg_sense;
  39         u8 reg_clock;
  40         u8 reg_misc;
  41         u8 reg_reset;
  42         u8 ngpios;
  43 };
  44
  45 struct sx150x_chip {
  46         struct gpio_chip                 gpio_chip;
  47         struct i2c_client               *client;
  48         const struct sx150x_device_data *dev_cfg;
  49         int                              irq_summary;
  50         int                              irq_base;
  51         int                              irq_update;
  52         u32                              irq_sense;
  53         u32                              irq_masked;
  54         u32                              dev_sense;
  55         u32                              dev_masked;
  56         struct irq_chip                  irq_chip;
  57         struct mutex                     lock;
  58 };
  59
  60 static const struct sx150x_device_data sx150x_devices[] = {
  61         [0] = { /* sx1508q */
  62                 .reg_pullup   = 0x03,
  63                 .reg_pulldn   = 0x04,
  64                 .reg_drain    = 0x05,
  65                 .reg_polarity = 0x06,
  66                 .reg_dir      = 0x07,
  67                 .reg_data     = 0x08,
  68                 .reg_irq_mask = 0x09,
  69                 .reg_irq_src  = 0x0c,
  70                 .reg_sense    = 0x0b,
  71                 .reg_clock    = 0x0f,
  72                 .reg_misc     = 0x10,
  73                 .reg_reset    = 0x7d,
  74                 .ngpios       = 8
  75         },
  76         [1] = { /* sx1509q */
  77                 .reg_pullup   = 0x07,
  78                 .reg_pulldn   = 0x09,
  79                 .reg_drain    = 0x0b,
  80                 .reg_polarity = 0x0d,
  81                 .reg_dir      = 0x0f,
  82                 .reg_data     = 0x11,
  83                 .reg_irq_mask = 0x13,
  84                 .reg_irq_src  = 0x19,
  85                 .reg_sense    = 0x17,
  86                 .reg_clock    = 0x1e,
  87                 .reg_misc     = 0x1f,
  88                 .reg_reset    = 0x7d,
  89                 .ngpios       = 16
  90         },
  91 };
  92
  93 static const struct i2c_device_id sx150x_id[] = {
  94         {"sx1508q", 0},
  95         {"sx1509q", 1},
  96         {}
  97 };
  98 MODULE_DEVICE_TABLE(i2c, sx150x_id);
  99
 100 static s32 sx150x_i2c_write(struct i2c_client *client, u8 reg, u8 val)
 101 {
 102         s32 err = i2c_smbus_write_byte_data(client, reg, val);
 103
 104         if (err < 0)
 105                 dev_warn(&client->dev,
 106                         "i2c write fail: can't write %02x to %02x: %d\n",
 107                         val, reg, err);
 108         return err;
 109 }
 110
 111 static s32 sx150x_i2c_read(struct i2c_client *client, u8 reg, u8 *val)
 112 {
 113         s32 err = i2c_smbus_read_byte_data(client, reg);
 114
 115         if (err >= 0)
 116                 *val = err;
 117         else
 118                 dev_warn(&client->dev,
 119                         "i2c read fail: can't read from %02x: %d\n",
 120                         reg, err);
 121         return err;
 122 }
 123
 124 static inline bool offset_is_oscio(struct sx150x_chip *chip, unsigned offset)
 125 {
 126         return (chip->dev_cfg->ngpios == offset);
 127 }
 128
 129 /*
 130  * These utility functions solve the common problem of locating and setting
 131  * configuration bits.  Configuration bits are grouped into registers
 132  * whose indexes increase downwards.  For example, with eight-bit registers,
 133  * sixteen gpios would have their config bits grouped in the following order:
 134  * REGISTER N-1 [ f e d c b a 9 8 ]
 135  *          N   [ 7 6 5 4 3 2 1 0 ]
 136  *
 137  * For multi-bit configurations, the pattern gets wider:
 138  * REGISTER N-3 [ f f e e d d c c ]
 139  *          N-2 [ b b a a 9 9 8 8 ]
 140  *          N-1 [ 7 7 6 6 5 5 4 4 ]
 141  *          N   [ 3 3 2 2 1 1 0 0 ]
 142  *
 143  * Given the address of the starting register 'N', the index of the gpio
 144  * whose configuration we seek to change, and the width in bits of that
 145  * configuration, these functions allow us to locate the correct
 146  * register and mask the correct bits.
 147  */
 148 static inline void sx150x_find_cfg(u8 offset, u8 width,
 149                                 u8 *reg, u8 *mask, u8 *shift)
 150 {
 151         *reg   -= offset * width / 8;
 152         *mask   = (1 << width) - 1;
 153         *shift  = (offset * width) % 8;
 154         *mask <<= *shift;
 155 }
 156
 157 static s32 sx150x_write_cfg(struct sx150x_chip *chip,
 158                         u8 offset, u8 width, u8 reg, u8 val)
 159 {
 160         u8  mask;
 161         u8  data;
 162         u8  shift;
 163         s32 err;
 164
 165         sx150x_find_cfg(offset, width, &reg, &mask, &shift);
 166         err = sx150x_i2c_read(chip->client, reg, &data);
 167         if (err < 0)
 168                 return err;
 169
 170         data &= ~mask;
 171         data |= (val << shift) & mask;
 172         return sx150x_i2c_write(chip->client, reg, data);
 173 }
 174
 175 static int sx150x_get_io(struct sx150x_chip *chip, unsigned offset)
 176 {
 177         u8  reg = chip->dev_cfg->reg_data;
 178         u8  mask;
 179         u8  data;
 180         u8  shift;
 181         s32 err;
 182
 183         sx150x_find_cfg(offset, 1, &reg, &mask, &shift);
 184         err = sx150x_i2c_read(chip->client, reg, &data);
 185         if (err >= 0)
 186                 err = (data & mask) != 0 ? 1 : 0;
 187
 188         return err;
 189 }
 190
 191 static void sx150x_set_oscio(struct sx150x_chip *chip, int val)
 192 {
 193         sx150x_i2c_write(chip->client,
 194                         chip->dev_cfg->reg_clock,
 195                         (val ? 0x1f : 0x10));
 196 }
 197
 198 static void sx150x_set_io(struct sx150x_chip *chip, unsigned offset, int val)
 199 {
 200         sx150x_write_cfg(chip,
 201                         offset,
 202                         1,
 203                         chip->dev_cfg->reg_data,
 204                         (val ? 1 : 0));
 205 }
 206
 207 static int sx150x_io_input(struct sx150x_chip *chip, unsigned offset)
 208 {
 209         return sx150x_write_cfg(chip,
 210                                 offset,
 211                                 1,
 212                                 chip->dev_cfg->reg_dir,
 213                                 1);
 214 }
 215
 216 static int sx150x_io_output(struct sx150x_chip *chip, unsigned offset, int val)
 217 {
 218         int err;
 219
 220         err = sx150x_write_cfg(chip,
 221                         offset,
 222                         1,
 223                         chip->dev_cfg->reg_data,
 224                         (val ? 1 : 0));
 225         if (err >= 0)
 226                 err = sx150x_write_cfg(chip,
 227                                 offset,
 228                                 1,
 229                                 chip->dev_cfg->reg_dir,
 230                                 0);
 231         return err;
 232 }
 233
 234 static int sx150x_gpio_get(struct gpio_chip *gc, unsigned offset)
 235 {
 236         struct sx150x_chip *chip;
 237         int status = -EINVAL;
 238
 239         chip = container_of(gc, struct sx150x_chip, gpio_chip);
 240
 241         if (!offset_is_oscio(chip, offset)) {
 242                 mutex_lock(&chip->lock);
 243                 status = sx150x_get_io(chip, offset);
 244                 mutex_unlock(&chip->lock);
 245         }
 246
 247         return status;
 248 }
 249
 250 static void sx150x_gpio_set(struct gpio_chip *gc, unsigned offset, int val)
 251 {
 252         struct sx150x_chip *chip;
 253
 254         chip = container_of(gc, struct sx150x_chip, gpio_chip);
 255
 256         mutex_lock(&chip->lock);
 257         if (offset_is_oscio(chip, offset))
 258                 sx150x_set_oscio(chip, val);
 259         else
 260                 sx150x_set_io(chip, offset, val);
 261         mutex_unlock(&chip->lock);
 262 }
 263
 264 static int sx150x_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
 265 {
 266         struct sx150x_chip *chip;
 267         int status = -EINVAL;
 268
 269         chip = container_of(gc, struct sx150x_chip, gpio_chip);
 270
 271         if (!offset_is_oscio(chip, offset)) {
 272                 mutex_lock(&chip->lock);
 273                 status = sx150x_io_input(chip, offset);
 274                 mutex_unlock(&chip->lock);
 275         }
 276         return status;
 277 }
 278
 279 static int sx150x_gpio_direction_output(struct gpio_chip *gc,
 280                                         unsigned offset,
 281                                         int val)
 282 {
 283         struct sx150x_chip *chip;
 284         int status = 0;
 285
 286         chip = container_of(gc, struct sx150x_chip, gpio_chip);
 287
 288         if (!offset_is_oscio(chip, offset)) {
 289                 mutex_lock(&chip->lock);
 290                 status = sx150x_io_output(chip, offset, val);
 291                 mutex_unlock(&chip->lock);
 292         }
 293         return status;
 294 }
 295
 296 static int sx150x_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
 297 {
 298         struct sx150x_chip *chip;
 299
 300         chip = container_of(gc, struct sx150x_chip, gpio_chip);
 301
 302         if (offset >= chip->dev_cfg->ngpios)
 303                 return -EINVAL;
 304
 305         if (chip->irq_base < 0)
 306                 return -EINVAL;
 307
 308         return chip->irq_base + offset;
 309 }
 310
 311 static void sx150x_irq_mask(struct irq_data *d)
 312 {
 313         struct sx150x_chip *chip = irq_data_get_irq_chip_data(d);
 314         unsigned n;
 315
 316         n = d->irq - chip->irq_base;
 317         chip->irq_masked |= (1 << n);
 318         chip->irq_update = n;
 319 }
 320
 321 static void sx150x_irq_unmask(struct irq_data *d)
 322 {
 323         struct sx150x_chip *chip = irq_data_get_irq_chip_data(d);
 324         unsigned n;
 325
 326         n = d->irq - chip->irq_base;
 327         chip->irq_masked &= ~(1 << n);
 328         chip->irq_update = n;
 329 }
 330
 331 static int sx150x_irq_set_type(struct irq_data *d, unsigned int flow_type)
 332 {
 333         struct sx150x_chip *chip = irq_data_get_irq_chip_data(d);
 334         unsigned n, val = 0;
 335
 336         if (flow_type & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW))
 337                 return -EINVAL;
 338
 339         n = d->irq - chip->irq_base;
 340
 341         if (flow_type & IRQ_TYPE_EDGE_RISING)
 342                 val |= 0x1;
 343         if (flow_type & IRQ_TYPE_EDGE_FALLING)
 344                 val |= 0x2;
 345
 346         chip->irq_sense &= ~(3UL << (n * 2));
 347         chip->irq_sense |= val << (n * 2);
 348         chip->irq_update = n;
 349         return 0;
 350 }
 351
 352 static irqreturn_t sx150x_irq_thread_fn(int irq, void *dev_id)
 353 {
 354         struct sx150x_chip *chip = (struct sx150x_chip *)dev_id;
 355         unsigned nhandled = 0;
 356         unsigned sub_irq;
 357         unsigned n;
 358         s32 err;
 359         u8 val;
 360         int i;
 361
 362         for (i = (chip->dev_cfg->ngpios / 8) - 1; i >= 0; --i) {
 363                 err = sx150x_i2c_read(chip->client,
 364                                       chip->dev_cfg->reg_irq_src - i,
 365                                       &val);
 366                 if (err < 0)
 367                         continue;
 368
 369                 sx150x_i2c_write(chip->client,
 370                                 chip->dev_cfg->reg_irq_src - i,
 371                                 val);
 372                 for (n = 0; n < 8; ++n) {
 373                         if (val & (1 << n)) {
 374                                 sub_irq = chip->irq_base + (i * 8) + n;
 375                                 handle_nested_irq(sub_irq);
 376                                 ++nhandled;
 377                         }
 378                 }
 379         }
 380
 381         return (nhandled > 0 ? IRQ_HANDLED : IRQ_NONE);
 382 }
 383
 384 static void sx150x_irq_bus_lock(struct irq_data *d)
 385 {
 386         struct sx150x_chip *chip = irq_data_get_irq_chip_data(d);
 387
 388         mutex_lock(&chip->lock);
 389 }
 390
 391 static void sx150x_irq_bus_sync_unlock(struct irq_data *d)
 392 {
 393         struct sx150x_chip *chip = irq_data_get_irq_chip_data(d);
 394         unsigned n;
 395
 396         if (chip->irq_update == NO_UPDATE_PENDING)
 397                 goto out;
 398
 399         n = chip->irq_update;
 400         chip->irq_update = NO_UPDATE_PENDING;
 401
 402         /* Avoid updates if nothing changed */
 403         if (chip->dev_sense == chip->irq_sense &&
 404             chip->dev_sense == chip->irq_masked)
 405                 goto out;
 406
 407         chip->dev_sense = chip->irq_sense;
 408         chip->dev_masked = chip->irq_masked;
 409
 410         if (chip->irq_masked & (1 << n)) {
 411                 sx150x_write_cfg(chip, n, 1, chip->dev_cfg->reg_irq_mask, 1);
 412                 sx150x_write_cfg(chip, n, 2, chip->dev_cfg->reg_sense, 0);
 413         } else {
 414                 sx150x_write_cfg(chip, n, 1, chip->dev_cfg->reg_irq_mask, 0);
 415                 sx150x_write_cfg(chip, n, 2, chip->dev_cfg->reg_sense,
 416                                  chip->irq_sense >> (n * 2));
 417         }
 418 out:
 419         mutex_unlock(&chip->lock);
 420 }
 421
 422 static void sx150x_init_chip(struct sx150x_chip *chip,
 423                         struct i2c_client *client,
 424                         kernel_ulong_t driver_data,
 425                         struct sx150x_platform_data *pdata)
 426 {
 427         mutex_init(&chip->lock);
 428
 429         chip->client                     = client;
 430         chip->dev_cfg                    = &sx150x_devices[driver_data];
 431         chip->gpio_chip.label            = client->name;
 432         chip->gpio_chip.direction_input  = sx150x_gpio_direction_input;
 433         chip->gpio_chip.direction_output = sx150x_gpio_direction_output;
 434         chip->gpio_chip.get              = sx150x_gpio_get;
 435         chip->gpio_chip.set              = sx150x_gpio_set;
 436         chip->gpio_chip.to_irq           = sx150x_gpio_to_irq;
 437         chip->gpio_chip.base             = pdata->gpio_base;
 438         chip->gpio_chip.can_sleep        = true;
 439         chip->gpio_chip.ngpio            = chip->dev_cfg->ngpios;
 440         if (pdata->oscio_is_gpo)
 441                 ++chip->gpio_chip.ngpio;
 442
 443         chip->irq_chip.name                = client->name;
 444         chip->irq_chip.irq_mask            = sx150x_irq_mask;
 445         chip->irq_chip.irq_unmask          = sx150x_irq_unmask;
 446         chip->irq_chip.irq_set_type        = sx150x_irq_set_type;
 447         chip->irq_chip.irq_bus_lock        = sx150x_irq_bus_lock;
 448         chip->irq_chip.irq_bus_sync_unlock = sx150x_irq_bus_sync_unlock;
 449         chip->irq_summary                  = -1;
 450         chip->irq_base                     = -1;
 451         chip->irq_masked                   = ~0;
 452         chip->irq_sense                    = 0;
 453         chip->dev_masked                   = ~0;
 454         chip->dev_sense                    = 0;
 455         chip->irq_update                   = NO_UPDATE_PENDING;
 456 }
 457
 458 static int sx150x_init_io(struct sx150x_chip *chip, u8 base, u16 cfg)
 459 {
 460         int err = 0;
 461         unsigned n;
 462
 463         for (n = 0; err >= 0 && n < (chip->dev_cfg->ngpios / 8); ++n)
 464                 err = sx150x_i2c_write(chip->client, base - n, cfg >> (n * 8));
 465         return err;
 466 }
 467
 468 static int sx150x_reset(struct sx150x_chip *chip)
 469 {
 470         int err;
 471
 472         err = i2c_smbus_write_byte_data(chip->client,
 473                                         chip->dev_cfg->reg_reset,
 474                                         0x12);
 475         if (err < 0)
 476                 return err;
 477
 478         err = i2c_smbus_write_byte_data(chip->client,
 479                                         chip->dev_cfg->reg_reset,
 480                                         0x34);
 481         return err;
 482 }
 483
 484 static int sx150x_init_hw(struct sx150x_chip *chip,
 485                         struct sx150x_platform_data *pdata)
 486 {
 487         int err = 0;
 488
 489         if (pdata->reset_during_probe) {
 490                 err = sx150x_reset(chip);
 491                 if (err < 0)
 492                         return err;
 493         }
 494
 495         err = sx150x_i2c_write(chip->client,
 496                         chip->dev_cfg->reg_misc,
 497                         0x01);
 498         if (err < 0)
 499                 return err;
 500
 501         err = sx150x_init_io(chip, chip->dev_cfg->reg_pullup,
 502                         pdata->io_pullup_ena);
 503         if (err < 0)
 504                 return err;
 505
 506         err = sx150x_init_io(chip, chip->dev_cfg->reg_pulldn,
 507                         pdata->io_pulldn_ena);
 508         if (err < 0)
 509                 return err;
 510
 511         err = sx150x_init_io(chip, chip->dev_cfg->reg_drain,
 512                         pdata->io_open_drain_ena);
 513         if (err < 0)
 514                 return err;
 515
 516         err = sx150x_init_io(chip, chip->dev_cfg->reg_polarity,
 517                         pdata->io_polarity);
 518         if (err < 0)
 519                 return err;
 520
 521         if (pdata->oscio_is_gpo)
 522                 sx150x_set_oscio(chip, 0);
 523
 524         return err;
 525 }
 526
 527 static int sx150x_install_irq_chip(struct sx150x_chip *chip,
 528                                 int irq_summary,
 529                                 int irq_base)
 530 {
 531         int err;
 532         unsigned n;
 533         unsigned irq;
 534
 535         chip->irq_summary = irq_summary;
 536         chip->irq_base    = irq_base;
 537
 538         for (n = 0; n < chip->dev_cfg->ngpios; ++n) {
 539                 irq = irq_base + n;
 540                 irq_set_chip_data(irq, chip);
 541                 irq_set_chip_and_handler(irq, &chip->irq_chip, handle_edge_irq);
 542                 irq_set_nested_thread(irq, 1);
 543 #ifdef CONFIG_ARM
 544                 set_irq_flags(irq, IRQF_VALID);
 545 #else
 546                 irq_set_noprobe(irq);
 547 #endif
 548         }
 549
 550         err = devm_request_threaded_irq(&chip->client->dev,
 551                                 irq_summary,
 552                                 NULL,
 553                                 sx150x_irq_thread_fn,
 554                                 IRQF_SHARED | IRQF_TRIGGER_FALLING,
 555                                 chip->irq_chip.name,
 556                                 chip);
 557         if (err < 0) {
 558                 chip->irq_summary = -1;
 559                 chip->irq_base    = -1;
 560         }
 561
 562         return err;
 563 }
 564
 565 static void sx150x_remove_irq_chip(struct sx150x_chip *chip)
 566 {
 567         unsigned n;
 568         unsigned irq;
 569
 570         for (n = 0; n < chip->dev_cfg->ngpios; ++n) {
 571                 irq = chip->irq_base + n;
 572                 irq_set_chip_and_handler(irq, NULL, NULL);
 573         }
 574 }
 575
 576 static int sx150x_probe(struct i2c_client *client,
 577                                 const struct i2c_device_id *id)
 578 {
 579         static const u32 i2c_funcs = I2C_FUNC_SMBUS_BYTE_DATA |
 580                                      I2C_FUNC_SMBUS_WRITE_WORD_DATA;
 581         struct sx150x_platform_data *pdata;
 582         struct sx150x_chip *chip;
 583         int rc;
 584
 585         pdata = dev_get_platdata(&client->dev);
 586         if (!pdata)
 587                 return -EINVAL;
 588
 589         if (!i2c_check_functionality(client->adapter, i2c_funcs))
 590                 return -ENOSYS;
 591
 592         chip = devm_kzalloc(&client->dev,
 593                 sizeof(struct sx150x_chip), GFP_KERNEL);
 594         if (!chip)
 595                 return -ENOMEM;
 596
 597         sx150x_init_chip(chip, client, id->driver_data, pdata);
 598         rc = sx150x_init_hw(chip, pdata);
 599         if (rc < 0)
 600                 return rc;
 601
 602         rc = gpiochip_add(&chip->gpio_chip);
 603         if (rc)
 604                 return rc;
 605
 606         if (pdata->irq_summary >= 0) {
 607                 rc = sx150x_install_irq_chip(chip,
 608                                         pdata->irq_summary,
 609                                         pdata->irq_base);
 610                 if (rc < 0)
 611                         goto probe_fail_post_gpiochip_add;
 612         }
 613
 614         i2c_set_clientdata(client, chip);
 615
 616         return 0;
 617 probe_fail_post_gpiochip_add:
 618         gpiochip_remove(&chip->gpio_chip);
 619         return rc;
 620 }
 621
 622 static int sx150x_remove(struct i2c_client *client)
 623 {
 624         struct sx150x_chip *chip;
 625
 626         chip = i2c_get_clientdata(client);
 627         gpiochip_remove(&chip->gpio_chip);
 628
 629         if (chip->irq_summary >= 0)
 630                 sx150x_remove_irq_chip(chip);
 631
 632         return 0;
 633 }
 634
 635 static struct i2c_driver sx150x_driver = {
 636         .driver = {
 637                 .name = "sx150x",
 638                 .owner = THIS_MODULE
 639         },
 640         .probe    = sx150x_probe,
 641         .remove   = sx150x_remove,
 642         .id_table = sx150x_id,
 643 };
 644
 645 static int __init sx150x_init(void)
 646 {
 647         return i2c_add_driver(&sx150x_driver);
 648 }
 649 subsys_initcall(sx150x_init);
 650
 651 static void __exit sx150x_exit(void)
 652 {
 653         return i2c_del_driver(&sx150x_driver);
 654 }
 655 module_exit(sx150x_exit);
 656
 657 MODULE_AUTHOR("Gregory Bean <gbean@codeaurora.org>");
 658 MODULE_DESCRIPTION("Driver for Semtech SX150X I2C GPIO Expanders");
 659 MODULE_LICENSE("GPL v2");
 660 MODULE_ALIAS("i2c:sx150x");