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/workqueue.h>
  26 #include <linux/i2c/sx150x.h>
  27
  28 #define NO_UPDATE_PENDING       -1
  29
  30 struct sx150x_device_data {
  31         u8 reg_pullup;
  32         u8 reg_pulldn;
  33         u8 reg_drain;
  34         u8 reg_polarity;
  35         u8 reg_dir;
  36         u8 reg_data;
  37         u8 reg_irq_mask;
  38         u8 reg_irq_src;
  39         u8 reg_sense;
  40         u8 reg_clock;
  41         u8 reg_misc;
  42         u8 reg_reset;
  43         u8 ngpios;
  44 };
  45
  46 struct sx150x_chip {
  47         struct gpio_chip                 gpio_chip;
  48         struct i2c_client               *client;
  49         const struct sx150x_device_data *dev_cfg;
  50         int                              irq_summary;
  51         int                              irq_base;
  52         int                              irq_update;
  53         u32                              irq_sense;
  54         u32                              irq_masked;
  55         u32                              dev_sense;
  56         u32                              dev_masked;
  57         struct irq_chip                  irq_chip;
  58         struct mutex                     lock;
  59 };
  60
  61 static const struct sx150x_device_data sx150x_devices[] = {
  62         [0] = { /* sx1508q */
  63                 .reg_pullup   = 0x03,
  64                 .reg_pulldn   = 0x04,
  65                 .reg_drain    = 0x05,
  66                 .reg_polarity = 0x06,
  67                 .reg_dir      = 0x07,
  68                 .reg_data     = 0x08,
  69                 .reg_irq_mask = 0x09,
  70                 .reg_irq_src  = 0x0c,
  71                 .reg_sense    = 0x0b,
  72                 .reg_clock    = 0x0f,
  73                 .reg_misc     = 0x10,
  74                 .reg_reset    = 0x7d,
  75                 .ngpios       = 8
  76         },
  77         [1] = { /* sx1509q */
  78                 .reg_pullup   = 0x07,
  79                 .reg_pulldn   = 0x09,
  80                 .reg_drain    = 0x0b,
  81                 .reg_polarity = 0x0d,
  82                 .reg_dir      = 0x0f,
  83                 .reg_data     = 0x11,
  84                 .reg_irq_mask = 0x13,
  85                 .reg_irq_src  = 0x19,
  86                 .reg_sense    = 0x17,
  87                 .reg_clock    = 0x1e,
  88                 .reg_misc     = 0x1f,
  89                 .reg_reset    = 0x7d,
  90                 .ngpios       = 16
  91         },
  92 };
  93
  94 static const struct i2c_device_id sx150x_id[] = {
  95         {"sx1508q", 0},
  96         {"sx1509q", 1},
  97         {}
  98 };
  99 MODULE_DEVICE_TABLE(i2c, sx150x_id);
 100
 101 static s32 sx150x_i2c_write(struct i2c_client *client, u8 reg, u8 val)
 102 {
 103         s32 err = i2c_smbus_write_byte_data(client, reg, val);
 104
 105         if (err < 0)
 106                 dev_warn(&client->dev,
 107                         "i2c write fail: can't write %02x to %02x: %d\n",
 108                         val, reg, err);
 109         return err;
 110 }
 111
 112 static s32 sx150x_i2c_read(struct i2c_client *client, u8 reg, u8 *val)
 113 {
 114         s32 err = i2c_smbus_read_byte_data(client, reg);
 115
 116         if (err >= 0)
 117                 *val = err;
 118         else
 119                 dev_warn(&client->dev,
 120                         "i2c read fail: can't read from %02x: %d\n",
 121                         reg, err);
 122         return err;
 123 }
 124
 125 static inline bool offset_is_oscio(struct sx150x_chip *chip, unsigned offset)
 126 {
 127         return (chip->dev_cfg->ngpios == offset);
 128 }
 129
 130 /*
 131  * These utility functions solve the common problem of locating and setting
 132  * configuration bits.  Configuration bits are grouped into registers
 133  * whose indexes increase downwards.  For example, with eight-bit registers,
 134  * sixteen gpios would have their config bits grouped in the following order:
 135  * REGISTER N-1 [ f e d c b a 9 8 ]
 136  *          N   [ 7 6 5 4 3 2 1 0 ]
 137  *
 138  * For multi-bit configurations, the pattern gets wider:
 139  * REGISTER N-3 [ f f e e d d c c ]
 140  *          N-2 [ b b a a 9 9 8 8 ]
 141  *          N-1 [ 7 7 6 6 5 5 4 4 ]
 142  *          N   [ 3 3 2 2 1 1 0 0 ]
 143  *
 144  * Given the address of the starting register 'N', the index of the gpio
 145  * whose configuration we seek to change, and the width in bits of that
 146  * configuration, these functions allow us to locate the correct
 147  * register and mask the correct bits.
 148  */
 149 static inline void sx150x_find_cfg(u8 offset, u8 width,
 150                                 u8 *reg, u8 *mask, u8 *shift)
 151 {
 152         *reg   -= offset * width / 8;
 153         *mask   = (1 << width) - 1;
 154         *shift  = (offset * width) % 8;
 155         *mask <<= *shift;
 156 }
 157
 158 static s32 sx150x_write_cfg(struct sx150x_chip *chip,
 159                         u8 offset, u8 width, u8 reg, u8 val)
 160 {
 161         u8  mask;
 162         u8  data;
 163         u8  shift;
 164         s32 err;
 165
 166         sx150x_find_cfg(offset, width, &reg, &mask, &shift);
 167         err = sx150x_i2c_read(chip->client, reg, &data);
 168         if (err < 0)
 169                 return err;
 170
 171         data &= ~mask;
 172         data |= (val << shift) & mask;
 173         return sx150x_i2c_write(chip->client, reg, data);
 174 }
 175
 176 static int sx150x_get_io(struct sx150x_chip *chip, unsigned offset)
 177 {
 178         u8  reg = chip->dev_cfg->reg_data;
 179         u8  mask;
 180         u8  data;
 181         u8  shift;
 182         s32 err;
 183
 184         sx150x_find_cfg(offset, 1, &reg, &mask, &shift);
 185         err = sx150x_i2c_read(chip->client, reg, &data);
 186         if (err >= 0)
 187                 err = (data & mask) != 0 ? 1 : 0;
 188
 189         return err;
 190 }
 191
 192 static void sx150x_set_oscio(struct sx150x_chip *chip, int val)
 193 {
 194         sx150x_i2c_write(chip->client,
 195                         chip->dev_cfg->reg_clock,
 196                         (val ? 0x1f : 0x10));
 197 }
 198
 199 static void sx150x_set_io(struct sx150x_chip *chip, unsigned offset, int val)
 200 {
 201         sx150x_write_cfg(chip,
 202                         offset,
 203                         1,
 204                         chip->dev_cfg->reg_data,
 205                         (val ? 1 : 0));
 206 }
 207
 208 static int sx150x_io_input(struct sx150x_chip *chip, unsigned offset)
 209 {
 210         return sx150x_write_cfg(chip,
 211                                 offset,
 212                                 1,
 213                                 chip->dev_cfg->reg_dir,
 214                                 1);
 215 }
 216
 217 static int sx150x_io_output(struct sx150x_chip *chip, unsigned offset, int val)
 218 {
 219         int err;
 220
 221         err = sx150x_write_cfg(chip,
 222                         offset,
 223                         1,
 224                         chip->dev_cfg->reg_data,
 225                         (val ? 1 : 0));
 226         if (err >= 0)
 227                 err = sx150x_write_cfg(chip,
 228                                 offset,
 229                                 1,
 230                                 chip->dev_cfg->reg_dir,
 231                                 0);
 232         return err;
 233 }
 234
 235 static int sx150x_gpio_get(struct gpio_chip *gc, unsigned offset)
 236 {
 237         struct sx150x_chip *chip;
 238         int status = -EINVAL;
 239
 240         chip = container_of(gc, struct sx150x_chip, gpio_chip);
 241
 242         if (!offset_is_oscio(chip, offset)) {
 243                 mutex_lock(&chip->lock);
 244                 status = sx150x_get_io(chip, offset);
 245                 mutex_unlock(&chip->lock);
 246         }
 247
 248         return status;
 249 }
 250
 251 static void sx150x_gpio_set(struct gpio_chip *gc, unsigned offset, int val)
 252 {
 253         struct sx150x_chip *chip;
 254
 255         chip = container_of(gc, struct sx150x_chip, gpio_chip);
 256
 257         mutex_lock(&chip->lock);
 258         if (offset_is_oscio(chip, offset))
 259                 sx150x_set_oscio(chip, val);
 260         else
 261                 sx150x_set_io(chip, offset, val);
 262         mutex_unlock(&chip->lock);
 263 }
 264
 265 static int sx150x_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
 266 {
 267         struct sx150x_chip *chip;
 268         int status = -EINVAL;
 269
 270         chip = container_of(gc, struct sx150x_chip, gpio_chip);
 271
 272         if (!offset_is_oscio(chip, offset)) {
 273                 mutex_lock(&chip->lock);
 274                 status = sx150x_io_input(chip, offset);
 275                 mutex_unlock(&chip->lock);
 276         }
 277         return status;
 278 }
 279
 280 static int sx150x_gpio_direction_output(struct gpio_chip *gc,
 281                                         unsigned offset,
 282                                         int val)
 283 {
 284         struct sx150x_chip *chip;
 285         int status = 0;
 286
 287         chip = container_of(gc, struct sx150x_chip, gpio_chip);
 288
 289         if (!offset_is_oscio(chip, offset)) {
 290                 mutex_lock(&chip->lock);
 291                 status = sx150x_io_output(chip, offset, val);
 292                 mutex_unlock(&chip->lock);
 293         }
 294         return status;
 295 }
 296
 297 static int sx150x_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
 298 {
 299         struct sx150x_chip *chip;
 300
 301         chip = container_of(gc, struct sx150x_chip, gpio_chip);
 302
 303         if (offset >= chip->dev_cfg->ngpios)
 304                 return -EINVAL;
 305
 306         if (chip->irq_base < 0)
 307                 return -EINVAL;
 308
 309         return chip->irq_base + offset;
 310 }
 311
 312 static void sx150x_irq_mask(struct irq_data *d)
 313 {
 314         struct sx150x_chip *chip = irq_data_get_irq_chip_data(d);
 315         unsigned n;
 316
 317         n = d->irq - chip->irq_base;
 318         chip->irq_masked |= (1 << n);
 319         chip->irq_update = n;
 320 }
 321
 322 static void sx150x_irq_unmask(struct irq_data *d)
 323 {
 324         struct sx150x_chip *chip = irq_data_get_irq_chip_data(d);
 325         unsigned n;
 326
 327         n = d->irq - chip->irq_base;
 328         chip->irq_masked &= ~(1 << n);
 329         chip->irq_update = n;
 330 }
 331
 332 static int sx150x_irq_set_type(struct irq_data *d, unsigned int flow_type)
 333 {
 334         struct sx150x_chip *chip = irq_data_get_irq_chip_data(d);
 335         unsigned n, val = 0;
 336
 337         if (flow_type & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW))
 338                 return -EINVAL;
 339
 340         n = d->irq - chip->irq_base;
 341
 342         if (flow_type & IRQ_TYPE_EDGE_RISING)
 343                 val |= 0x1;
 344         if (flow_type & IRQ_TYPE_EDGE_FALLING)
 345                 val |= 0x2;
 346
 347         chip->irq_sense &= ~(3UL << (n * 2));
 348         chip->irq_sense |= val << (n * 2);
 349         chip->irq_update = n;
 350         return 0;
 351 }
 352
 353 static irqreturn_t sx150x_irq_thread_fn(int irq, void *dev_id)
 354 {
 355         struct sx150x_chip *chip = (struct sx150x_chip *)dev_id;
 356         unsigned nhandled = 0;
 357         unsigned sub_irq;
 358         unsigned n;
 359         s32 err;
 360         u8 val;
 361         int i;
 362
 363         for (i = (chip->dev_cfg->ngpios / 8) - 1; i >= 0; --i) {
 364                 err = sx150x_i2c_read(chip->client,
 365                                       chip->dev_cfg->reg_irq_src - i,
 366                                       &val);
 367                 if (err < 0)
 368                         continue;
 369
 370                 sx150x_i2c_write(chip->client,
 371                                 chip->dev_cfg->reg_irq_src - i,
 372                                 val);
 373                 for (n = 0; n < 8; ++n) {
 374                         if (val & (1 << n)) {
 375                                 sub_irq = chip->irq_base + (i * 8) + n;
 376                                 handle_nested_irq(sub_irq);
 377                                 ++nhandled;
 378                         }
 379                 }
 380         }
 381
 382         return (nhandled > 0 ? IRQ_HANDLED : IRQ_NONE);
 383 }
 384
 385 static void sx150x_irq_bus_lock(struct irq_data *d)
 386 {
 387         struct sx150x_chip *chip = irq_data_get_irq_chip_data(d);
 388
 389         mutex_lock(&chip->lock);
 390 }
 391
 392 static void sx150x_irq_bus_sync_unlock(struct irq_data *d)
 393 {
 394         struct sx150x_chip *chip = irq_data_get_irq_chip_data(d);
 395         unsigned n;
 396
 397         if (chip->irq_update == NO_UPDATE_PENDING)
 398                 goto out;
 399
 400         n = chip->irq_update;
 401         chip->irq_update = NO_UPDATE_PENDING;
 402
 403         /* Avoid updates if nothing changed */
 404         if (chip->dev_sense == chip->irq_sense &&
 405             chip->dev_sense == chip->irq_masked)
 406                 goto out;
 407
 408         chip->dev_sense = chip->irq_sense;
 409         chip->dev_masked = chip->irq_masked;
 410
 411         if (chip->irq_masked & (1 << n)) {
 412                 sx150x_write_cfg(chip, n, 1, chip->dev_cfg->reg_irq_mask, 1);
 413                 sx150x_write_cfg(chip, n, 2, chip->dev_cfg->reg_sense, 0);
 414         } else {
 415                 sx150x_write_cfg(chip, n, 1, chip->dev_cfg->reg_irq_mask, 0);
 416                 sx150x_write_cfg(chip, n, 2, chip->dev_cfg->reg_sense,
 417                                  chip->irq_sense >> (n * 2));
 418         }
 419 out:
 420         mutex_unlock(&chip->lock);
 421 }
 422
 423 static void sx150x_init_chip(struct sx150x_chip *chip,
 424                         struct i2c_client *client,
 425                         kernel_ulong_t driver_data,
 426                         struct sx150x_platform_data *pdata)
 427 {
 428         mutex_init(&chip->lock);
 429
 430         chip->client                     = client;
 431         chip->dev_cfg                    = &sx150x_devices[driver_data];
 432         chip->gpio_chip.label            = client->name;
 433         chip->gpio_chip.direction_input  = sx150x_gpio_direction_input;
 434         chip->gpio_chip.direction_output = sx150x_gpio_direction_output;
 435         chip->gpio_chip.get              = sx150x_gpio_get;
 436         chip->gpio_chip.set              = sx150x_gpio_set;
 437         chip->gpio_chip.to_irq           = sx150x_gpio_to_irq;
 438         chip->gpio_chip.base             = pdata->gpio_base;
 439         chip->gpio_chip.can_sleep        = 1;
 440         chip->gpio_chip.ngpio            = chip->dev_cfg->ngpios;
 441         if (pdata->oscio_is_gpo)
 442                 ++chip->gpio_chip.ngpio;
 443
 444         chip->irq_chip.name                = client->name;
 445         chip->irq_chip.irq_mask            = sx150x_irq_mask;
 446         chip->irq_chip.irq_unmask          = sx150x_irq_unmask;
 447         chip->irq_chip.irq_set_type        = sx150x_irq_set_type;
 448         chip->irq_chip.irq_bus_lock        = sx150x_irq_bus_lock;
 449         chip->irq_chip.irq_bus_sync_unlock = sx150x_irq_bus_sync_unlock;
 450         chip->irq_summary                  = -1;
 451         chip->irq_base                     = -1;
 452         chip->irq_masked                   = ~0;
 453         chip->irq_sense                    = 0;
 454         chip->dev_masked                   = ~0;
 455         chip->dev_sense                    = 0;
 456         chip->irq_update                   = NO_UPDATE_PENDING;
 457 }
 458
 459 static int sx150x_init_io(struct sx150x_chip *chip, u8 base, u16 cfg)
 460 {
 461         int err = 0;
 462         unsigned n;
 463
 464         for (n = 0; err >= 0 && n < (chip->dev_cfg->ngpios / 8); ++n)
 465                 err = sx150x_i2c_write(chip->client, base - n, cfg >> (n * 8));
 466         return err;
 467 }
 468
 469 static int sx150x_reset(struct sx150x_chip *chip)
 470 {
 471         int err;
 472
 473         err = i2c_smbus_write_byte_data(chip->client,
 474                                         chip->dev_cfg->reg_reset,
 475                                         0x12);
 476         if (err < 0)
 477                 return err;
 478
 479         err = i2c_smbus_write_byte_data(chip->client,
 480                                         chip->dev_cfg->reg_reset,
 481                                         0x34);
 482         return err;
 483 }
 484
 485 static int sx150x_init_hw(struct sx150x_chip *chip,
 486                         struct sx150x_platform_data *pdata)
 487 {
 488         int err = 0;
 489
 490         if (pdata->reset_during_probe) {
 491                 err = sx150x_reset(chip);
 492                 if (err < 0)
 493                         return err;
 494         }
 495
 496         err = sx150x_i2c_write(chip->client,
 497                         chip->dev_cfg->reg_misc,
 498                         0x01);
 499         if (err < 0)
 500                 return err;
 501
 502         err = sx150x_init_io(chip, chip->dev_cfg->reg_pullup,
 503                         pdata->io_pullup_ena);
 504         if (err < 0)
 505                 return err;
 506
 507         err = sx150x_init_io(chip, chip->dev_cfg->reg_pulldn,
 508                         pdata->io_pulldn_ena);
 509         if (err < 0)
 510                 return err;
 511
 512         err = sx150x_init_io(chip, chip->dev_cfg->reg_drain,
 513                         pdata->io_open_drain_ena);
 514         if (err < 0)
 515                 return err;
 516
 517         err = sx150x_init_io(chip, chip->dev_cfg->reg_polarity,
 518                         pdata->io_polarity);
 519         if (err < 0)
 520                 return err;
 521
 522         if (pdata->oscio_is_gpo)
 523                 sx150x_set_oscio(chip, 0);
 524
 525         return err;
 526 }
 527
 528 static int sx150x_install_irq_chip(struct sx150x_chip *chip,
 529                                 int irq_summary,
 530                                 int irq_base)
 531 {
 532         int err;
 533         unsigned n;
 534         unsigned irq;
 535
 536         chip->irq_summary = irq_summary;
 537         chip->irq_base    = irq_base;
 538
 539         for (n = 0; n < chip->dev_cfg->ngpios; ++n) {
 540                 irq = irq_base + n;
 541                 irq_set_chip_data(irq, chip);
 542                 irq_set_chip_and_handler(irq, &chip->irq_chip, handle_edge_irq);
 543                 irq_set_nested_thread(irq, 1);
 544 #ifdef CONFIG_ARM
 545                 set_irq_flags(irq, IRQF_VALID);
 546 #else
 547                 irq_set_noprobe(irq);
 548 #endif
 549         }
 550
 551         err = request_threaded_irq(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         free_irq(chip->irq_summary, chip);
 571
 572         for (n = 0; n < chip->dev_cfg->ngpios; ++n) {
 573                 irq = chip->irq_base + n;
 574                 irq_set_chip_and_handler(irq, NULL, NULL);
 575         }
 576 }
 577
 578 static int sx150x_probe(struct i2c_client *client,
 579                                 const struct i2c_device_id *id)
 580 {
 581         static const u32 i2c_funcs = I2C_FUNC_SMBUS_BYTE_DATA |
 582                                      I2C_FUNC_SMBUS_WRITE_WORD_DATA;
 583         struct sx150x_platform_data *pdata;
 584         struct sx150x_chip *chip;
 585         int rc;
 586
 587         pdata = client->dev.platform_data;
 588         if (!pdata)
 589                 return -EINVAL;
 590
 591         if (!i2c_check_functionality(client->adapter, i2c_funcs))
 592                 return -ENOSYS;
 593
 594         chip = kzalloc(sizeof(struct sx150x_chip), GFP_KERNEL);
 595         if (!chip)
 596                 return -ENOMEM;
 597
 598         sx150x_init_chip(chip, client, id->driver_data, pdata);
 599         rc = sx150x_init_hw(chip, pdata);
 600         if (rc < 0)
 601                 goto probe_fail_pre_gpiochip_add;
 602
 603         rc = gpiochip_add(&chip->gpio_chip);
 604         if (rc < 0)
 605                 goto probe_fail_pre_gpiochip_add;
 606
 607         if (pdata->irq_summary >= 0) {
 608                 rc = sx150x_install_irq_chip(chip,
 609                                         pdata->irq_summary,
 610                                         pdata->irq_base);
 611                 if (rc < 0)
 612                         goto probe_fail_post_gpiochip_add;
 613         }
 614
 615         i2c_set_clientdata(client, chip);
 616
 617         return 0;
 618 probe_fail_post_gpiochip_add:
 619         WARN_ON(gpiochip_remove(&chip->gpio_chip) < 0);
 620 probe_fail_pre_gpiochip_add:
 621         kfree(chip);
 622         return rc;
 623 }
 624
 625 static int sx150x_remove(struct i2c_client *client)
 626 {
 627         struct sx150x_chip *chip;
 628         int rc;
 629
 630         chip = i2c_get_clientdata(client);
 631         rc = gpiochip_remove(&chip->gpio_chip);
 632         if (rc < 0)
 633                 return rc;
 634
 635         if (chip->irq_summary >= 0)
 636                 sx150x_remove_irq_chip(chip);
 637
 638         kfree(chip);
 639
 640         return 0;
 641 }
 642
 643 static struct i2c_driver sx150x_driver = {
 644         .driver = {
 645                 .name = "sx150x",
 646                 .owner = THIS_MODULE
 647         },
 648         .probe    = sx150x_probe,
 649         .remove   = sx150x_remove,
 650         .id_table = sx150x_id,
 651 };
 652
 653 static int __init sx150x_init(void)
 654 {
 655         return i2c_add_driver(&sx150x_driver);
 656 }
 657 subsys_initcall(sx150x_init);
 658
 659 static void __exit sx150x_exit(void)
 660 {
 661         return i2c_del_driver(&sx150x_driver);
 662 }
 663 module_exit(sx150x_exit);
 664
 665 MODULE_AUTHOR("Gregory Bean <[email protected]>");
 666 MODULE_DESCRIPTION("Driver for Semtech SX150X I2C GPIO Expanders");
 667 MODULE_LICENSE("GPL v2");
 668 MODULE_ALIAS("i2c:sx150x");