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 #include <linux/of.h>
  27 #include <linux/of_address.h>
  28 #include <linux/of_irq.h>
  29 #include <linux/of_gpio.h>
  30 #include <linux/of_device.h>
  31
  32 #define NO_UPDATE_PENDING       -1
  33
  34 /* The chip models of sx150x */
  35 #define SX150X_123 0
  36 #define SX150X_456 1
  37 #define SX150X_789 2
  38
  39 struct sx150x_123_pri {
  40         u8 reg_pld_mode;
  41         u8 reg_pld_table0;
  42         u8 reg_pld_table1;
  43         u8 reg_pld_table2;
  44         u8 reg_pld_table3;
  45         u8 reg_pld_table4;
  46         u8 reg_advance;
  47 };
  48
  49 struct sx150x_456_pri {
  50         u8 reg_pld_mode;
  51         u8 reg_pld_table0;
  52         u8 reg_pld_table1;
  53         u8 reg_pld_table2;
  54         u8 reg_pld_table3;
  55         u8 reg_pld_table4;
  56         u8 reg_advance;
  57 };
  58
  59 struct sx150x_789_pri {
  60         u8 reg_drain;
  61         u8 reg_polarity;
  62         u8 reg_clock;
  63         u8 reg_misc;
  64         u8 reg_reset;
  65         u8 ngpios;
  66 };
  67
  68 struct sx150x_device_data {
  69         u8 model;
  70         u8 reg_pullup;
  71         u8 reg_pulldn;
  72         u8 reg_dir;
  73         u8 reg_data;
  74         u8 reg_irq_mask;
  75         u8 reg_irq_src;
  76         u8 reg_sense;
  77         u8 ngpios;
  78         union {
  79                 struct sx150x_123_pri x123;
  80                 struct sx150x_456_pri x456;
  81                 struct sx150x_789_pri x789;
  82         } pri;
  83 };
  84
  85 struct sx150x_chip {
  86         struct gpio_chip                 gpio_chip;
  87         struct i2c_client               *client;
  88         const struct sx150x_device_data *dev_cfg;
  89         int                              irq_summary;
  90         int                              irq_base;
  91         int                              irq_update;
  92         u32                              irq_sense;
  93         u32                              irq_masked;
  94         u32                              dev_sense;
  95         u32                              dev_masked;
  96         struct irq_chip                  irq_chip;
  97         struct mutex                     lock;
  98 };
  99
 100 static const struct sx150x_device_data sx150x_devices[] = {
 101         [0] = { /* sx1508q */
 102                 .model = SX150X_789,
 103                 .reg_pullup     = 0x03,
 104                 .reg_pulldn     = 0x04,
 105                 .reg_dir        = 0x07,
 106                 .reg_data       = 0x08,
 107                 .reg_irq_mask   = 0x09,
 108                 .reg_irq_src    = 0x0c,
 109                 .reg_sense      = 0x0b,
 110                 .pri.x789 = {
 111                         .reg_drain      = 0x05,
 112                         .reg_polarity   = 0x06,
 113                         .reg_clock      = 0x0f,
 114                         .reg_misc       = 0x10,
 115                         .reg_reset      = 0x7d,
 116                 },
 117                 .ngpios = 8,
 118         },
 119         [1] = { /* sx1509q */
 120                 .model = SX150X_789,
 121                 .reg_pullup     = 0x07,
 122                 .reg_pulldn     = 0x09,
 123                 .reg_dir        = 0x0f,
 124                 .reg_data       = 0x11,
 125                 .reg_irq_mask   = 0x13,
 126                 .reg_irq_src    = 0x19,
 127                 .reg_sense      = 0x17,
 128                 .pri.x789 = {
 129                         .reg_drain      = 0x0b,
 130                         .reg_polarity   = 0x0d,
 131                         .reg_clock      = 0x1e,
 132                         .reg_misc       = 0x1f,
 133                         .reg_reset      = 0x7d,
 134                 },
 135                 .ngpios = 16
 136         },
 137         [2] = { /* sx1506q */
 138                 .model = SX150X_456,
 139                 .reg_pullup     = 0x05,
 140                 .reg_pulldn     = 0x07,
 141                 .reg_dir        = 0x03,
 142                 .reg_data       = 0x01,
 143                 .reg_irq_mask   = 0x09,
 144                 .reg_irq_src    = 0x0f,
 145                 .reg_sense      = 0x0d,
 146                 .pri.x456 = {
 147                         .reg_pld_mode   = 0x21,
 148                         .reg_pld_table0 = 0x23,
 149                         .reg_pld_table1 = 0x25,
 150                         .reg_pld_table2 = 0x27,
 151                         .reg_pld_table3 = 0x29,
 152                         .reg_pld_table4 = 0x2b,
 153                         .reg_advance    = 0xad,
 154                 },
 155                 .ngpios = 16
 156         },
 157         [3] = { /* sx1502q */
 158                 .model = SX150X_123,
 159                 .reg_pullup     = 0x02,
 160                 .reg_pulldn     = 0x03,
 161                 .reg_dir        = 0x01,
 162                 .reg_data       = 0x00,
 163                 .reg_irq_mask   = 0x05,
 164                 .reg_irq_src    = 0x08,
 165                 .reg_sense      = 0x07,
 166                 .pri.x123 = {
 167                         .reg_pld_mode   = 0x10,
 168                         .reg_pld_table0 = 0x11,
 169                         .reg_pld_table1 = 0x12,
 170                         .reg_pld_table2 = 0x13,
 171                         .reg_pld_table3 = 0x14,
 172                         .reg_pld_table4 = 0x15,
 173                         .reg_advance    = 0xad,
 174                 },
 175                 .ngpios = 8,
 176         },
 177 };
 178
 179 static const struct i2c_device_id sx150x_id[] = {
 180         {"sx1508q", 0},
 181         {"sx1509q", 1},
 182         {"sx1506q", 2},
 183         {"sx1502q", 3},
 184         {}
 185 };
 186 MODULE_DEVICE_TABLE(i2c, sx150x_id);
 187
 188 static const struct of_device_id sx150x_of_match[] = {
 189         { .compatible = "semtech,sx1508q" },
 190         { .compatible = "semtech,sx1509q" },
 191         { .compatible = "semtech,sx1506q" },
 192         { .compatible = "semtech,sx1502q" },
 193         {},
 194 };
 195 MODULE_DEVICE_TABLE(of, sx150x_of_match);
 196
 197 static s32 sx150x_i2c_write(struct i2c_client *client, u8 reg, u8 val)
 198 {
 199         s32 err = i2c_smbus_write_byte_data(client, reg, val);
 200
 201         if (err < 0)
 202                 dev_warn(&client->dev,
 203                         "i2c write fail: can't write %02x to %02x: %d\n",
 204                         val, reg, err);
 205         return err;
 206 }
 207
 208 static s32 sx150x_i2c_read(struct i2c_client *client, u8 reg, u8 *val)
 209 {
 210         s32 err = i2c_smbus_read_byte_data(client, reg);
 211
 212         if (err >= 0)
 213                 *val = err;
 214         else
 215                 dev_warn(&client->dev,
 216                         "i2c read fail: can't read from %02x: %d\n",
 217                         reg, err);
 218         return err;
 219 }
 220
 221 static inline bool offset_is_oscio(struct sx150x_chip *chip, unsigned offset)
 222 {
 223         return (chip->dev_cfg->ngpios == offset);
 224 }
 225
 226 /*
 227  * These utility functions solve the common problem of locating and setting
 228  * configuration bits.  Configuration bits are grouped into registers
 229  * whose indexes increase downwards.  For example, with eight-bit registers,
 230  * sixteen gpios would have their config bits grouped in the following order:
 231  * REGISTER N-1 [ f e d c b a 9 8 ]
 232  *          N   [ 7 6 5 4 3 2 1 0 ]
 233  *
 234  * For multi-bit configurations, the pattern gets wider:
 235  * REGISTER N-3 [ f f e e d d c c ]
 236  *          N-2 [ b b a a 9 9 8 8 ]
 237  *          N-1 [ 7 7 6 6 5 5 4 4 ]
 238  *          N   [ 3 3 2 2 1 1 0 0 ]
 239  *
 240  * Given the address of the starting register 'N', the index of the gpio
 241  * whose configuration we seek to change, and the width in bits of that
 242  * configuration, these functions allow us to locate the correct
 243  * register and mask the correct bits.
 244  */
 245 static inline void sx150x_find_cfg(u8 offset, u8 width,
 246                                 u8 *reg, u8 *mask, u8 *shift)
 247 {
 248         *reg   -= offset * width / 8;
 249         *mask   = (1 << width) - 1;
 250         *shift  = (offset * width) % 8;
 251         *mask <<= *shift;
 252 }
 253
 254 static s32 sx150x_write_cfg(struct sx150x_chip *chip,
 255                         u8 offset, u8 width, u8 reg, u8 val)
 256 {
 257         u8  mask;
 258         u8  data;
 259         u8  shift;
 260         s32 err;
 261
 262         sx150x_find_cfg(offset, width, &reg, &mask, &shift);
 263         err = sx150x_i2c_read(chip->client, reg, &data);
 264         if (err < 0)
 265                 return err;
 266
 267         data &= ~mask;
 268         data |= (val << shift) & mask;
 269         return sx150x_i2c_write(chip->client, reg, data);
 270 }
 271
 272 static int sx150x_get_io(struct sx150x_chip *chip, unsigned offset)
 273 {
 274         u8  reg = chip->dev_cfg->reg_data;
 275         u8  mask;
 276         u8  data;
 277         u8  shift;
 278         s32 err;
 279
 280         sx150x_find_cfg(offset, 1, &reg, &mask, &shift);
 281         err = sx150x_i2c_read(chip->client, reg, &data);
 282         if (err >= 0)
 283                 err = (data & mask) != 0 ? 1 : 0;
 284
 285         return err;
 286 }
 287
 288 static void sx150x_set_oscio(struct sx150x_chip *chip, int val)
 289 {
 290         sx150x_i2c_write(chip->client,
 291                         chip->dev_cfg->pri.x789.reg_clock,
 292                         (val ? 0x1f : 0x10));
 293 }
 294
 295 static void sx150x_set_io(struct sx150x_chip *chip, unsigned offset, int val)
 296 {
 297         sx150x_write_cfg(chip,
 298                         offset,
 299                         1,
 300                         chip->dev_cfg->reg_data,
 301                         (val ? 1 : 0));
 302 }
 303
 304 static int sx150x_io_input(struct sx150x_chip *chip, unsigned offset)
 305 {
 306         return sx150x_write_cfg(chip,
 307                                 offset,
 308                                 1,
 309                                 chip->dev_cfg->reg_dir,
 310                                 1);
 311 }
 312
 313 static int sx150x_io_output(struct sx150x_chip *chip, unsigned offset, int val)
 314 {
 315         int err;
 316
 317         err = sx150x_write_cfg(chip,
 318                         offset,
 319                         1,
 320                         chip->dev_cfg->reg_data,
 321                         (val ? 1 : 0));
 322         if (err >= 0)
 323                 err = sx150x_write_cfg(chip,
 324                                 offset,
 325                                 1,
 326                                 chip->dev_cfg->reg_dir,
 327                                 0);
 328         return err;
 329 }
 330
 331 static int sx150x_gpio_get(struct gpio_chip *gc, unsigned offset)
 332 {
 333         struct sx150x_chip *chip = gpiochip_get_data(gc);
 334         int status = -EINVAL;
 335
 336         if (!offset_is_oscio(chip, offset)) {
 337                 mutex_lock(&chip->lock);
 338                 status = sx150x_get_io(chip, offset);
 339                 mutex_unlock(&chip->lock);
 340         }
 341
 342         return (status < 0) ? status : !!status;
 343 }
 344
 345 static void sx150x_gpio_set(struct gpio_chip *gc, unsigned offset, int val)
 346 {
 347         struct sx150x_chip *chip = gpiochip_get_data(gc);
 348
 349         mutex_lock(&chip->lock);
 350         if (offset_is_oscio(chip, offset))
 351                 sx150x_set_oscio(chip, val);
 352         else
 353                 sx150x_set_io(chip, offset, val);
 354         mutex_unlock(&chip->lock);
 355 }
 356
 357 static int sx150x_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
 358 {
 359         struct sx150x_chip *chip = gpiochip_get_data(gc);
 360         int status = -EINVAL;
 361
 362         if (!offset_is_oscio(chip, offset)) {
 363                 mutex_lock(&chip->lock);
 364                 status = sx150x_io_input(chip, offset);
 365                 mutex_unlock(&chip->lock);
 366         }
 367         return status;
 368 }
 369
 370 static int sx150x_gpio_direction_output(struct gpio_chip *gc,
 371                                         unsigned offset,
 372                                         int val)
 373 {
 374         struct sx150x_chip *chip = gpiochip_get_data(gc);
 375         int status = 0;
 376
 377         if (!offset_is_oscio(chip, offset)) {
 378                 mutex_lock(&chip->lock);
 379                 status = sx150x_io_output(chip, offset, val);
 380                 mutex_unlock(&chip->lock);
 381         }
 382         return status;
 383 }
 384
 385 static void sx150x_irq_mask(struct irq_data *d)
 386 {
 387         struct sx150x_chip *chip = gpiochip_get_data(irq_data_get_irq_chip_data(d));
 388         unsigned n = d->hwirq;
 389
 390         chip->irq_masked |= (1 << n);
 391         chip->irq_update = n;
 392 }
 393
 394 static void sx150x_irq_unmask(struct irq_data *d)
 395 {
 396         struct sx150x_chip *chip = gpiochip_get_data(irq_data_get_irq_chip_data(d));
 397         unsigned n = d->hwirq;
 398
 399         chip->irq_masked &= ~(1 << n);
 400         chip->irq_update = n;
 401 }
 402
 403 static int sx150x_irq_set_type(struct irq_data *d, unsigned int flow_type)
 404 {
 405         struct sx150x_chip *chip = gpiochip_get_data(irq_data_get_irq_chip_data(d));
 406         unsigned n, val = 0;
 407
 408         if (flow_type & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW))
 409                 return -EINVAL;
 410
 411         n = d->hwirq;
 412
 413         if (flow_type & IRQ_TYPE_EDGE_RISING)
 414                 val |= 0x1;
 415         if (flow_type & IRQ_TYPE_EDGE_FALLING)
 416                 val |= 0x2;
 417
 418         chip->irq_sense &= ~(3UL << (n * 2));
 419         chip->irq_sense |= val << (n * 2);
 420         chip->irq_update = n;
 421         return 0;
 422 }
 423
 424 static irqreturn_t sx150x_irq_thread_fn(int irq, void *dev_id)
 425 {
 426         struct sx150x_chip *chip = (struct sx150x_chip *)dev_id;
 427         unsigned nhandled = 0;
 428         unsigned sub_irq;
 429         unsigned n;
 430         s32 err;
 431         u8 val;
 432         int i;
 433
 434         for (i = (chip->dev_cfg->ngpios / 8) - 1; i >= 0; --i) {
 435                 err = sx150x_i2c_read(chip->client,
 436                                       chip->dev_cfg->reg_irq_src - i,
 437                                       &val);
 438                 if (err < 0)
 439                         continue;
 440
 441                 sx150x_i2c_write(chip->client,
 442                                 chip->dev_cfg->reg_irq_src - i,
 443                                 val);
 444                 for (n = 0; n < 8; ++n) {
 445                         if (val & (1 << n)) {
 446                                 sub_irq = irq_find_mapping(
 447                                         chip->gpio_chip.irqdomain,
 448                                         (i * 8) + n);
 449                                 handle_nested_irq(sub_irq);
 450                                 ++nhandled;
 451                         }
 452                 }
 453         }
 454
 455         return (nhandled > 0 ? IRQ_HANDLED : IRQ_NONE);
 456 }
 457
 458 static void sx150x_irq_bus_lock(struct irq_data *d)
 459 {
 460         struct sx150x_chip *chip = gpiochip_get_data(irq_data_get_irq_chip_data(d));
 461
 462         mutex_lock(&chip->lock);
 463 }
 464
 465 static void sx150x_irq_bus_sync_unlock(struct irq_data *d)
 466 {
 467         struct sx150x_chip *chip = gpiochip_get_data(irq_data_get_irq_chip_data(d));
 468         unsigned n;
 469
 470         if (chip->irq_update == NO_UPDATE_PENDING)
 471                 goto out;
 472
 473         n = chip->irq_update;
 474         chip->irq_update = NO_UPDATE_PENDING;
 475
 476         /* Avoid updates if nothing changed */
 477         if (chip->dev_sense == chip->irq_sense &&
 478             chip->dev_masked == chip->irq_masked)
 479                 goto out;
 480
 481         chip->dev_sense = chip->irq_sense;
 482         chip->dev_masked = chip->irq_masked;
 483
 484         if (chip->irq_masked & (1 << n)) {
 485                 sx150x_write_cfg(chip, n, 1, chip->dev_cfg->reg_irq_mask, 1);
 486                 sx150x_write_cfg(chip, n, 2, chip->dev_cfg->reg_sense, 0);
 487         } else {
 488                 sx150x_write_cfg(chip, n, 1, chip->dev_cfg->reg_irq_mask, 0);
 489                 sx150x_write_cfg(chip, n, 2, chip->dev_cfg->reg_sense,
 490                                  chip->irq_sense >> (n * 2));
 491         }
 492 out:
 493         mutex_unlock(&chip->lock);
 494 }
 495
 496 static void sx150x_init_chip(struct sx150x_chip *chip,
 497                         struct i2c_client *client,
 498                         kernel_ulong_t driver_data,
 499                         struct sx150x_platform_data *pdata)
 500 {
 501         mutex_init(&chip->lock);
 502
 503         chip->client                     = client;
 504         chip->dev_cfg                    = &sx150x_devices[driver_data];
 505         chip->gpio_chip.parent              = &client->dev;
 506         chip->gpio_chip.label            = client->name;
 507         chip->gpio_chip.direction_input  = sx150x_gpio_direction_input;
 508         chip->gpio_chip.direction_output = sx150x_gpio_direction_output;
 509         chip->gpio_chip.get              = sx150x_gpio_get;
 510         chip->gpio_chip.set              = sx150x_gpio_set;
 511         chip->gpio_chip.base             = pdata->gpio_base;
 512         chip->gpio_chip.can_sleep        = true;
 513         chip->gpio_chip.ngpio            = chip->dev_cfg->ngpios;
 514 #ifdef CONFIG_OF_GPIO
 515         chip->gpio_chip.of_node          = client->dev.of_node;
 516         chip->gpio_chip.of_gpio_n_cells  = 2;
 517 #endif
 518         if (pdata->oscio_is_gpo)
 519                 ++chip->gpio_chip.ngpio;
 520
 521         chip->irq_chip.name                = client->name;
 522         chip->irq_chip.irq_mask            = sx150x_irq_mask;
 523         chip->irq_chip.irq_unmask          = sx150x_irq_unmask;
 524         chip->irq_chip.irq_set_type        = sx150x_irq_set_type;
 525         chip->irq_chip.irq_bus_lock        = sx150x_irq_bus_lock;
 526         chip->irq_chip.irq_bus_sync_unlock = sx150x_irq_bus_sync_unlock;
 527         chip->irq_summary                  = -1;
 528         chip->irq_base                     = -1;
 529         chip->irq_masked                   = ~0;
 530         chip->irq_sense                    = 0;
 531         chip->dev_masked                   = ~0;
 532         chip->dev_sense                    = 0;
 533         chip->irq_update                   = NO_UPDATE_PENDING;
 534 }
 535
 536 static int sx150x_init_io(struct sx150x_chip *chip, u8 base, u16 cfg)
 537 {
 538         int err = 0;
 539         unsigned n;
 540
 541         for (n = 0; err >= 0 && n < (chip->dev_cfg->ngpios / 8); ++n)
 542                 err = sx150x_i2c_write(chip->client, base - n, cfg >> (n * 8));
 543         return err;
 544 }
 545
 546 static int sx150x_reset(struct sx150x_chip *chip)
 547 {
 548         int err;
 549
 550         err = i2c_smbus_write_byte_data(chip->client,
 551                                         chip->dev_cfg->pri.x789.reg_reset,
 552                                         0x12);
 553         if (err < 0)
 554                 return err;
 555
 556         err = i2c_smbus_write_byte_data(chip->client,
 557                                         chip->dev_cfg->pri.x789.reg_reset,
 558                                         0x34);
 559         return err;
 560 }
 561
 562 static int sx150x_init_hw(struct sx150x_chip *chip,
 563                         struct sx150x_platform_data *pdata)
 564 {
 565         int err = 0;
 566
 567         if (pdata->reset_during_probe) {
 568                 err = sx150x_reset(chip);
 569                 if (err < 0)
 570                         return err;
 571         }
 572
 573         if (chip->dev_cfg->model == SX150X_789)
 574                 err = sx150x_i2c_write(chip->client,
 575                                 chip->dev_cfg->pri.x789.reg_misc,
 576                                 0x01);
 577         else if (chip->dev_cfg->model == SX150X_456)
 578                 err = sx150x_i2c_write(chip->client,
 579                                 chip->dev_cfg->pri.x456.reg_advance,
 580                                 0x04);
 581         else
 582                 err = sx150x_i2c_write(chip->client,
 583                                 chip->dev_cfg->pri.x123.reg_advance,
 584                                 0x00);
 585         if (err < 0)
 586                 return err;
 587
 588         err = sx150x_init_io(chip, chip->dev_cfg->reg_pullup,
 589                         pdata->io_pullup_ena);
 590         if (err < 0)
 591                 return err;
 592
 593         err = sx150x_init_io(chip, chip->dev_cfg->reg_pulldn,
 594                         pdata->io_pulldn_ena);
 595         if (err < 0)
 596                 return err;
 597
 598         if (chip->dev_cfg->model == SX150X_789) {
 599                 err = sx150x_init_io(chip,
 600                                 chip->dev_cfg->pri.x789.reg_drain,
 601                                 pdata->io_open_drain_ena);
 602                 if (err < 0)
 603                         return err;
 604
 605                 err = sx150x_init_io(chip,
 606                                 chip->dev_cfg->pri.x789.reg_polarity,
 607                                 pdata->io_polarity);
 608                 if (err < 0)
 609                         return err;
 610         } else if (chip->dev_cfg->model == SX150X_456) {
 611                 /* Set all pins to work in normal mode */
 612                 err = sx150x_init_io(chip,
 613                                 chip->dev_cfg->pri.x456.reg_pld_mode,
 614                                 0);
 615                 if (err < 0)
 616                         return err;
 617         } else {
 618                 /* Set all pins to work in normal mode */
 619                 err = sx150x_init_io(chip,
 620                                 chip->dev_cfg->pri.x123.reg_pld_mode,
 621                                 0);
 622                 if (err < 0)
 623                         return err;
 624         }
 625
 626
 627         if (pdata->oscio_is_gpo)
 628                 sx150x_set_oscio(chip, 0);
 629
 630         return err;
 631 }
 632
 633 static int sx150x_install_irq_chip(struct sx150x_chip *chip,
 634                                 int irq_summary,
 635                                 int irq_base)
 636 {
 637         int err;
 638
 639         chip->irq_summary = irq_summary;
 640         chip->irq_base    = irq_base;
 641
 642         /* Add gpio chip to irq subsystem */
 643         err = gpiochip_irqchip_add(&chip->gpio_chip,
 644                 &chip->irq_chip, chip->irq_base,
 645                 handle_edge_irq, IRQ_TYPE_EDGE_BOTH);
 646         if (err) {
 647                 dev_err(&chip->client->dev,
 648                         "could not connect irqchip to gpiochip\n");
 649                 return  err;
 650         }
 651
 652         err = devm_request_threaded_irq(&chip->client->dev,
 653                         irq_summary, NULL, sx150x_irq_thread_fn,
 654                         IRQF_ONESHOT | IRQF_SHARED | IRQF_TRIGGER_FALLING,
 655                         chip->irq_chip.name, chip);
 656         if (err < 0) {
 657                 chip->irq_summary = -1;
 658                 chip->irq_base    = -1;
 659         }
 660
 661         return err;
 662 }
 663
 664 static int sx150x_probe(struct i2c_client *client,
 665                                 const struct i2c_device_id *id)
 666 {
 667         static const u32 i2c_funcs = I2C_FUNC_SMBUS_BYTE_DATA |
 668                                      I2C_FUNC_SMBUS_WRITE_WORD_DATA;
 669         struct sx150x_platform_data *pdata;
 670         struct sx150x_chip *chip;
 671         int rc;
 672
 673         pdata = dev_get_platdata(&client->dev);
 674         if (!pdata)
 675                 return -EINVAL;
 676
 677         if (!i2c_check_functionality(client->adapter, i2c_funcs))
 678                 return -ENOSYS;
 679
 680         chip = devm_kzalloc(&client->dev,
 681                 sizeof(struct sx150x_chip), GFP_KERNEL);
 682         if (!chip)
 683                 return -ENOMEM;
 684
 685         sx150x_init_chip(chip, client, id->driver_data, pdata);
 686         rc = sx150x_init_hw(chip, pdata);
 687         if (rc < 0)
 688                 return rc;
 689
 690         rc = devm_gpiochip_add_data(&client->dev, &chip->gpio_chip, chip);
 691         if (rc)
 692                 return rc;
 693
 694         if (pdata->irq_summary >= 0) {
 695                 rc = sx150x_install_irq_chip(chip,
 696                                         pdata->irq_summary,
 697                                         pdata->irq_base);
 698                 if (rc < 0)
 699                         return rc;
 700         }
 701
 702         i2c_set_clientdata(client, chip);
 703
 704         return 0;
 705 }
 706
 707 static struct i2c_driver sx150x_driver = {
 708         .driver = {
 709                 .name = "sx150x",
 710                 .of_match_table = of_match_ptr(sx150x_of_match),
 711         },
 712         .probe    = sx150x_probe,
 713         .id_table = sx150x_id,
 714 };
 715
 716 static int __init sx150x_init(void)
 717 {
 718         return i2c_add_driver(&sx150x_driver);
 719 }
 720 subsys_initcall(sx150x_init);
 721
 722 static void __exit sx150x_exit(void)
 723 {
 724         return i2c_del_driver(&sx150x_driver);
 725 }
 726 module_exit(sx150x_exit);
 727
 728 MODULE_AUTHOR("Gregory Bean <[email protected]>");
 729 MODULE_DESCRIPTION("Driver for Semtech SX150X I2C GPIO Expanders");
 730 MODULE_LICENSE("GPL v2");