drivers/gpio/gpio-sx150x.c

   1 /* Copyright (c) 2010, Code Aurora Forum. All rights reserved.
   2  *
   3  * Driver for Semtech SX150X I2C GPIO Expanders
   4  *
   5  * Author: Gregory Bean <gbean@codeaurora.org>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 and
   9  * only version 2 as published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19  * 02110-1301, USA.
  20  */
  21 #include <linux/gpio.h>
  22 #include <linux/i2c.h>
  23 #include <linux/init.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/irq.h>
  26 #include <linux/mutex.h>
  27 #include <linux/slab.h>
  28 #include <linux/of.h>
  29 #include <linux/of_address.h>
  30 #include <linux/of_irq.h>
  31 #include <linux/of_gpio.h>
  32 #include <linux/of_device.h>
  33
  34 #define NO_UPDATE_PENDING       -1
  35
  36 /* The chip models of sx150x */
  37 #define SX150X_123 0
  38 #define SX150X_456 1
  39 #define SX150X_789 2
  40
  41 struct sx150x_123_pri {
  42         u8 reg_pld_mode;
  43         u8 reg_pld_table0;
  44         u8 reg_pld_table1;
  45         u8 reg_pld_table2;
  46         u8 reg_pld_table3;
  47         u8 reg_pld_table4;
  48         u8 reg_advance;
  49 };
  50
  51 struct sx150x_456_pri {
  52         u8 reg_pld_mode;
  53         u8 reg_pld_table0;
  54         u8 reg_pld_table1;
  55         u8 reg_pld_table2;
  56         u8 reg_pld_table3;
  57         u8 reg_pld_table4;
  58         u8 reg_advance;
  59 };
  60
  61 struct sx150x_789_pri {
  62         u8 reg_drain;
  63         u8 reg_polarity;
  64         u8 reg_clock;
  65         u8 reg_misc;
  66         u8 reg_reset;
  67         u8 ngpios;
  68 };
  69
  70 struct sx150x_device_data {
  71         u8 model;
  72         u8 reg_pullup;
  73         u8 reg_pulldn;
  74         u8 reg_dir;
  75         u8 reg_data;
  76         u8 reg_irq_mask;
  77         u8 reg_irq_src;
  78         u8 reg_sense;
  79         u8 ngpios;
  80         union {
  81                 struct sx150x_123_pri x123;
  82                 struct sx150x_456_pri x456;
  83                 struct sx150x_789_pri x789;
  84         } pri;
  85 };
  86
  87 /**
  88  * struct sx150x_platform_data - config data for SX150x driver
  89  * @gpio_base: The index number of the first GPIO assigned to this
  90  *             GPIO expander.  The expander will create a block of
  91  *             consecutively numbered gpios beginning at the given base,
  92  *             with the size of the block depending on the model of the
  93  *             expander chip.
  94  * @oscio_is_gpo: If set to true, the driver will configure OSCIO as a GPO
  95  *                instead of as an oscillator, increasing the size of the
  96  *                GP(I)O pool created by this expander by one.  The
  97  *                output-only GPO pin will be added at the end of the block.
  98  * @io_pullup_ena: A bit-mask which enables or disables the pull-up resistor
  99  *                 for each IO line in the expander.  Setting the bit at
 100  *                 position n will enable the pull-up for the IO at
 101  *                 the corresponding offset.  For chips with fewer than
 102  *                 16 IO pins, high-end bits are ignored.
 103  * @io_pulldn_ena: A bit-mask which enables-or disables the pull-down
 104  *                 resistor for each IO line in the expander. Setting the
 105  *                 bit at position n will enable the pull-down for the IO at
 106  *                 the corresponding offset.  For chips with fewer than
 107  *                 16 IO pins, high-end bits are ignored.
 108  * @io_polarity: A bit-mask which enables polarity inversion for each IO line
 109  *               in the expander.  Setting the bit at position n inverts
 110  *               the polarity of that IO line, while clearing it results
 111  *               in normal polarity. For chips with fewer than 16 IO pins,
 112  *               high-end bits are ignored.
 113  * @irq_summary: The 'summary IRQ' line to which the GPIO expander's INT line
 114  *               is connected, via which it reports interrupt events
 115  *               across all GPIO lines.  This must be a real,
 116  *               pre-existing IRQ line.
 117  *               Setting this value < 0 disables the irq_chip functionality
 118  *               of the driver.
 119  * @irq_base: The first 'virtual IRQ' line at which our block of GPIO-based
 120  *            IRQ lines will appear.  Similarly to gpio_base, the expander
 121  *            will create a block of irqs beginning at this number.
 122  *            This value is ignored if irq_summary is < 0.
 123  * @reset_during_probe: If set to true, the driver will trigger a full
 124  *                      reset of the chip at the beginning of the probe
 125  *                      in order to place it in a known state.
 126  */
 127 struct sx150x_platform_data {
 128         unsigned gpio_base;
 129         bool     oscio_is_gpo;
 130         u16      io_pullup_ena;
 131         u16      io_pulldn_ena;
 132         u16      io_polarity;
 133         int      irq_summary;
 134         unsigned irq_base;
 135         bool     reset_during_probe;
 136 };
 137
 138 struct sx150x_chip {
 139         struct gpio_chip                 gpio_chip;
 140         struct i2c_client               *client;
 141         const struct sx150x_device_data *dev_cfg;
 142         int                              irq_summary;
 143         int                              irq_base;
 144         int                              irq_update;
 145         u32                              irq_sense;
 146         u32                              irq_masked;
 147         u32                              dev_sense;
 148         u32                              dev_masked;
 149         struct irq_chip                  irq_chip;
 150         struct mutex                     lock;
 151 };
 152
 153 static const struct sx150x_device_data sx150x_devices[] = {
 154         [0] = { /* sx1508q */
 155                 .model = SX150X_789,
 156                 .reg_pullup     = 0x03,
 157                 .reg_pulldn     = 0x04,
 158                 .reg_dir        = 0x07,
 159                 .reg_data       = 0x08,
 160                 .reg_irq_mask   = 0x09,
 161                 .reg_irq_src    = 0x0c,
 162                 .reg_sense      = 0x0b,
 163                 .pri.x789 = {
 164                         .reg_drain      = 0x05,
 165                         .reg_polarity   = 0x06,
 166                         .reg_clock      = 0x0f,
 167                         .reg_misc       = 0x10,
 168                         .reg_reset      = 0x7d,
 169                 },
 170                 .ngpios = 8,
 171         },
 172         [1] = { /* sx1509q */
 173                 .model = SX150X_789,
 174                 .reg_pullup     = 0x07,
 175                 .reg_pulldn     = 0x09,
 176                 .reg_dir        = 0x0f,
 177                 .reg_data       = 0x11,
 178                 .reg_irq_mask   = 0x13,
 179                 .reg_irq_src    = 0x19,
 180                 .reg_sense      = 0x17,
 181                 .pri.x789 = {
 182                         .reg_drain      = 0x0b,
 183                         .reg_polarity   = 0x0d,
 184                         .reg_clock      = 0x1e,
 185                         .reg_misc       = 0x1f,
 186                         .reg_reset      = 0x7d,
 187                 },
 188                 .ngpios = 16
 189         },
 190         [2] = { /* sx1506q */
 191                 .model = SX150X_456,
 192                 .reg_pullup     = 0x05,
 193                 .reg_pulldn     = 0x07,
 194                 .reg_dir        = 0x03,
 195                 .reg_data       = 0x01,
 196                 .reg_irq_mask   = 0x09,
 197                 .reg_irq_src    = 0x0f,
 198                 .reg_sense      = 0x0d,
 199                 .pri.x456 = {
 200                         .reg_pld_mode   = 0x21,
 201                         .reg_pld_table0 = 0x23,
 202                         .reg_pld_table1 = 0x25,
 203                         .reg_pld_table2 = 0x27,
 204                         .reg_pld_table3 = 0x29,
 205                         .reg_pld_table4 = 0x2b,
 206                         .reg_advance    = 0xad,
 207                 },
 208                 .ngpios = 16
 209         },
 210         [3] = { /* sx1502q */
 211                 .model = SX150X_123,
 212                 .reg_pullup     = 0x02,
 213                 .reg_pulldn     = 0x03,
 214                 .reg_dir        = 0x01,
 215                 .reg_data       = 0x00,
 216                 .reg_irq_mask   = 0x05,
 217                 .reg_irq_src    = 0x08,
 218                 .reg_sense      = 0x07,
 219                 .pri.x123 = {
 220                         .reg_pld_mode   = 0x10,
 221                         .reg_pld_table0 = 0x11,
 222                         .reg_pld_table1 = 0x12,
 223                         .reg_pld_table2 = 0x13,
 224                         .reg_pld_table3 = 0x14,
 225                         .reg_pld_table4 = 0x15,
 226                         .reg_advance    = 0xad,
 227                 },
 228                 .ngpios = 8,
 229         },
 230 };
 231
 232 static const struct i2c_device_id sx150x_id[] = {
 233         {"sx1508q", 0},
 234         {"sx1509q", 1},
 235         {"sx1506q", 2},
 236         {"sx1502q", 3},
 237         {}
 238 };
 239 MODULE_DEVICE_TABLE(i2c, sx150x_id);
 240
 241 static const struct of_device_id sx150x_of_match[] = {
 242         { .compatible = "semtech,sx1508q" },
 243         { .compatible = "semtech,sx1509q" },
 244         { .compatible = "semtech,sx1506q" },
 245         { .compatible = "semtech,sx1502q" },
 246         {},
 247 };
 248 MODULE_DEVICE_TABLE(of, sx150x_of_match);
 249
 250 static s32 sx150x_i2c_write(struct i2c_client *client, u8 reg, u8 val)
 251 {
 252         s32 err = i2c_smbus_write_byte_data(client, reg, val);
 253
 254         if (err < 0)
 255                 dev_warn(&client->dev,
 256                         "i2c write fail: can't write %02x to %02x: %d\n",
 257                         val, reg, err);
 258         return err;
 259 }
 260
 261 static s32 sx150x_i2c_read(struct i2c_client *client, u8 reg, u8 *val)
 262 {
 263         s32 err = i2c_smbus_read_byte_data(client, reg);
 264
 265         if (err >= 0)
 266                 *val = err;
 267         else
 268                 dev_warn(&client->dev,
 269                         "i2c read fail: can't read from %02x: %d\n",
 270                         reg, err);
 271         return err;
 272 }
 273
 274 static inline bool offset_is_oscio(struct sx150x_chip *chip, unsigned offset)
 275 {
 276         return (chip->dev_cfg->ngpios == offset);
 277 }
 278
 279 /*
 280  * These utility functions solve the common problem of locating and setting
 281  * configuration bits.  Configuration bits are grouped into registers
 282  * whose indexes increase downwards.  For example, with eight-bit registers,
 283  * sixteen gpios would have their config bits grouped in the following order:
 284  * REGISTER N-1 [ f e d c b a 9 8 ]
 285  *          N   [ 7 6 5 4 3 2 1 0 ]
 286  *
 287  * For multi-bit configurations, the pattern gets wider:
 288  * REGISTER N-3 [ f f e e d d c c ]
 289  *          N-2 [ b b a a 9 9 8 8 ]
 290  *          N-1 [ 7 7 6 6 5 5 4 4 ]
 291  *          N   [ 3 3 2 2 1 1 0 0 ]
 292  *
 293  * Given the address of the starting register 'N', the index of the gpio
 294  * whose configuration we seek to change, and the width in bits of that
 295  * configuration, these functions allow us to locate the correct
 296  * register and mask the correct bits.
 297  */
 298 static inline void sx150x_find_cfg(u8 offset, u8 width,
 299                                 u8 *reg, u8 *mask, u8 *shift)
 300 {
 301         *reg   -= offset * width / 8;
 302         *mask   = (1 << width) - 1;
 303         *shift  = (offset * width) % 8;
 304         *mask <<= *shift;
 305 }
 306
 307 static s32 sx150x_write_cfg(struct sx150x_chip *chip,
 308                         u8 offset, u8 width, u8 reg, u8 val)
 309 {
 310         u8  mask;
 311         u8  data;
 312         u8  shift;
 313         s32 err;
 314
 315         sx150x_find_cfg(offset, width, &reg, &mask, &shift);
 316         err = sx150x_i2c_read(chip->client, reg, &data);
 317         if (err < 0)
 318                 return err;
 319
 320         data &= ~mask;
 321         data |= (val << shift) & mask;
 322         return sx150x_i2c_write(chip->client, reg, data);
 323 }
 324
 325 static int sx150x_get_io(struct sx150x_chip *chip, unsigned offset)
 326 {
 327         u8  reg = chip->dev_cfg->reg_data;
 328         u8  mask;
 329         u8  data;
 330         u8  shift;
 331         s32 err;
 332
 333         sx150x_find_cfg(offset, 1, &reg, &mask, &shift);
 334         err = sx150x_i2c_read(chip->client, reg, &data);
 335         if (err >= 0)
 336                 err = (data & mask) != 0 ? 1 : 0;
 337
 338         return err;
 339 }
 340
 341 static void sx150x_set_oscio(struct sx150x_chip *chip, int val)
 342 {
 343         sx150x_i2c_write(chip->client,
 344                         chip->dev_cfg->pri.x789.reg_clock,
 345                         (val ? 0x1f : 0x10));
 346 }
 347
 348 static void sx150x_set_io(struct sx150x_chip *chip, unsigned offset, int val)
 349 {
 350         sx150x_write_cfg(chip,
 351                         offset,
 352                         1,
 353                         chip->dev_cfg->reg_data,
 354                         (val ? 1 : 0));
 355 }
 356
 357 static int sx150x_io_input(struct sx150x_chip *chip, unsigned offset)
 358 {
 359         return sx150x_write_cfg(chip,
 360                                 offset,
 361                                 1,
 362                                 chip->dev_cfg->reg_dir,
 363                                 1);
 364 }
 365
 366 static int sx150x_io_output(struct sx150x_chip *chip, unsigned offset, int val)
 367 {
 368         int err;
 369
 370         err = sx150x_write_cfg(chip,
 371                         offset,
 372                         1,
 373                         chip->dev_cfg->reg_data,
 374                         (val ? 1 : 0));
 375         if (err >= 0)
 376                 err = sx150x_write_cfg(chip,
 377                                 offset,
 378                                 1,
 379                                 chip->dev_cfg->reg_dir,
 380                                 0);
 381         return err;
 382 }
 383
 384 static int sx150x_gpio_get(struct gpio_chip *gc, unsigned offset)
 385 {
 386         struct sx150x_chip *chip = gpiochip_get_data(gc);
 387         int status = -EINVAL;
 388
 389         if (!offset_is_oscio(chip, offset)) {
 390                 mutex_lock(&chip->lock);
 391                 status = sx150x_get_io(chip, offset);
 392                 mutex_unlock(&chip->lock);
 393         }
 394
 395         return (status < 0) ? status : !!status;
 396 }
 397
 398 static void sx150x_gpio_set(struct gpio_chip *gc, unsigned offset, int val)
 399 {
 400         struct sx150x_chip *chip = gpiochip_get_data(gc);
 401
 402         mutex_lock(&chip->lock);
 403         if (offset_is_oscio(chip, offset))
 404                 sx150x_set_oscio(chip, val);
 405         else
 406                 sx150x_set_io(chip, offset, val);
 407         mutex_unlock(&chip->lock);
 408 }
 409
 410 static int sx150x_gpio_set_single_ended(struct gpio_chip *gc,
 411                                         unsigned offset,
 412                                         enum single_ended_mode mode)
 413 {
 414         struct sx150x_chip *chip = gpiochip_get_data(gc);
 415
 416         /* On the SX160X 789 we can set open drain */
 417         if (chip->dev_cfg->model != SX150X_789)
 418                 return -ENOTSUPP;
 419
 420         if (mode == LINE_MODE_PUSH_PULL)
 421                 return sx150x_write_cfg(chip,
 422                                         offset,
 423                                         1,
 424                                         chip->dev_cfg->pri.x789.reg_drain,
 425                                         0);
 426
 427         if (mode == LINE_MODE_OPEN_DRAIN)
 428                 return sx150x_write_cfg(chip,
 429                                         offset,
 430                                         1,
 431                                         chip->dev_cfg->pri.x789.reg_drain,
 432                                         1);
 433         return -ENOTSUPP;
 434 }
 435
 436 static int sx150x_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
 437 {
 438         struct sx150x_chip *chip = gpiochip_get_data(gc);
 439         int status = -EINVAL;
 440
 441         if (!offset_is_oscio(chip, offset)) {
 442                 mutex_lock(&chip->lock);
 443                 status = sx150x_io_input(chip, offset);
 444                 mutex_unlock(&chip->lock);
 445         }
 446         return status;
 447 }
 448
 449 static int sx150x_gpio_direction_output(struct gpio_chip *gc,
 450                                         unsigned offset,
 451                                         int val)
 452 {
 453         struct sx150x_chip *chip = gpiochip_get_data(gc);
 454         int status = 0;
 455
 456         if (!offset_is_oscio(chip, offset)) {
 457                 mutex_lock(&chip->lock);
 458                 status = sx150x_io_output(chip, offset, val);
 459                 mutex_unlock(&chip->lock);
 460         }
 461         return status;
 462 }
 463
 464 static void sx150x_irq_mask(struct irq_data *d)
 465 {
 466         struct sx150x_chip *chip = gpiochip_get_data(irq_data_get_irq_chip_data(d));
 467         unsigned n = d->hwirq;
 468
 469         chip->irq_masked |= (1 << n);
 470         chip->irq_update = n;
 471 }
 472
 473 static void sx150x_irq_unmask(struct irq_data *d)
 474 {
 475         struct sx150x_chip *chip = gpiochip_get_data(irq_data_get_irq_chip_data(d));
 476         unsigned n = d->hwirq;
 477
 478         chip->irq_masked &= ~(1 << n);
 479         chip->irq_update = n;
 480 }
 481
 482 static int sx150x_irq_set_type(struct irq_data *d, unsigned int flow_type)
 483 {
 484         struct sx150x_chip *chip = gpiochip_get_data(irq_data_get_irq_chip_data(d));
 485         unsigned n, val = 0;
 486
 487         if (flow_type & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW))
 488                 return -EINVAL;
 489
 490         n = d->hwirq;
 491
 492         if (flow_type & IRQ_TYPE_EDGE_RISING)
 493                 val |= 0x1;
 494         if (flow_type & IRQ_TYPE_EDGE_FALLING)
 495                 val |= 0x2;
 496
 497         chip->irq_sense &= ~(3UL << (n * 2));
 498         chip->irq_sense |= val << (n * 2);
 499         chip->irq_update = n;
 500         return 0;
 501 }
 502
 503 static irqreturn_t sx150x_irq_thread_fn(int irq, void *dev_id)
 504 {
 505         struct sx150x_chip *chip = (struct sx150x_chip *)dev_id;
 506         unsigned nhandled = 0;
 507         unsigned sub_irq;
 508         unsigned n;
 509         s32 err;
 510         u8 val;
 511         int i;
 512
 513         for (i = (chip->dev_cfg->ngpios / 8) - 1; i >= 0; --i) {
 514                 err = sx150x_i2c_read(chip->client,
 515                                       chip->dev_cfg->reg_irq_src - i,
 516                                       &val);
 517                 if (err < 0)
 518                         continue;
 519
 520                 sx150x_i2c_write(chip->client,
 521                                 chip->dev_cfg->reg_irq_src - i,
 522                                 val);
 523                 for (n = 0; n < 8; ++n) {
 524                         if (val & (1 << n)) {
 525                                 sub_irq = irq_find_mapping(
 526                                         chip->gpio_chip.irqdomain,
 527                                         (i * 8) + n);
 528                                 handle_nested_irq(sub_irq);
 529                                 ++nhandled;
 530                         }
 531                 }
 532         }
 533
 534         return (nhandled > 0 ? IRQ_HANDLED : IRQ_NONE);
 535 }
 536
 537 static void sx150x_irq_bus_lock(struct irq_data *d)
 538 {
 539         struct sx150x_chip *chip = gpiochip_get_data(irq_data_get_irq_chip_data(d));
 540
 541         mutex_lock(&chip->lock);
 542 }
 543
 544 static void sx150x_irq_bus_sync_unlock(struct irq_data *d)
 545 {
 546         struct sx150x_chip *chip = gpiochip_get_data(irq_data_get_irq_chip_data(d));
 547         unsigned n;
 548
 549         if (chip->irq_update == NO_UPDATE_PENDING)
 550                 goto out;
 551
 552         n = chip->irq_update;
 553         chip->irq_update = NO_UPDATE_PENDING;
 554
 555         /* Avoid updates if nothing changed */
 556         if (chip->dev_sense == chip->irq_sense &&
 557             chip->dev_masked == chip->irq_masked)
 558                 goto out;
 559
 560         chip->dev_sense = chip->irq_sense;
 561         chip->dev_masked = chip->irq_masked;
 562
 563         if (chip->irq_masked & (1 << n)) {
 564                 sx150x_write_cfg(chip, n, 1, chip->dev_cfg->reg_irq_mask, 1);
 565                 sx150x_write_cfg(chip, n, 2, chip->dev_cfg->reg_sense, 0);
 566         } else {
 567                 sx150x_write_cfg(chip, n, 1, chip->dev_cfg->reg_irq_mask, 0);
 568                 sx150x_write_cfg(chip, n, 2, chip->dev_cfg->reg_sense,
 569                                  chip->irq_sense >> (n * 2));
 570         }
 571 out:
 572         mutex_unlock(&chip->lock);
 573 }
 574
 575 static void sx150x_init_chip(struct sx150x_chip *chip,
 576                         struct i2c_client *client,
 577                         kernel_ulong_t driver_data,
 578                         struct sx150x_platform_data *pdata)
 579 {
 580         mutex_init(&chip->lock);
 581
 582         chip->client                     = client;
 583         chip->dev_cfg                    = &sx150x_devices[driver_data];
 584         chip->gpio_chip.parent              = &client->dev;
 585         chip->gpio_chip.label            = client->name;
 586         chip->gpio_chip.direction_input  = sx150x_gpio_direction_input;
 587         chip->gpio_chip.direction_output = sx150x_gpio_direction_output;
 588         chip->gpio_chip.get              = sx150x_gpio_get;
 589         chip->gpio_chip.set              = sx150x_gpio_set;
 590         chip->gpio_chip.set_single_ended = sx150x_gpio_set_single_ended;
 591         chip->gpio_chip.base             = pdata->gpio_base;
 592         chip->gpio_chip.can_sleep        = true;
 593         chip->gpio_chip.ngpio            = chip->dev_cfg->ngpios;
 594 #ifdef CONFIG_OF_GPIO
 595         chip->gpio_chip.of_node          = client->dev.of_node;
 596         chip->gpio_chip.of_gpio_n_cells  = 2;
 597 #endif
 598         if (pdata->oscio_is_gpo)
 599                 ++chip->gpio_chip.ngpio;
 600
 601         chip->irq_chip.name                = client->name;
 602         chip->irq_chip.irq_mask            = sx150x_irq_mask;
 603         chip->irq_chip.irq_unmask          = sx150x_irq_unmask;
 604         chip->irq_chip.irq_set_type        = sx150x_irq_set_type;
 605         chip->irq_chip.irq_bus_lock        = sx150x_irq_bus_lock;
 606         chip->irq_chip.irq_bus_sync_unlock = sx150x_irq_bus_sync_unlock;
 607         chip->irq_summary                  = -1;
 608         chip->irq_base                     = -1;
 609         chip->irq_masked                   = ~0;
 610         chip->irq_sense                    = 0;
 611         chip->dev_masked                   = ~0;
 612         chip->dev_sense                    = 0;
 613         chip->irq_update                   = NO_UPDATE_PENDING;
 614 }
 615
 616 static int sx150x_init_io(struct sx150x_chip *chip, u8 base, u16 cfg)
 617 {
 618         int err = 0;
 619         unsigned n;
 620
 621         for (n = 0; err >= 0 && n < (chip->dev_cfg->ngpios / 8); ++n)
 622                 err = sx150x_i2c_write(chip->client, base - n, cfg >> (n * 8));
 623         return err;
 624 }
 625
 626 static int sx150x_reset(struct sx150x_chip *chip)
 627 {
 628         int err;
 629
 630         err = i2c_smbus_write_byte_data(chip->client,
 631                                         chip->dev_cfg->pri.x789.reg_reset,
 632                                         0x12);
 633         if (err < 0)
 634                 return err;
 635
 636         err = i2c_smbus_write_byte_data(chip->client,
 637                                         chip->dev_cfg->pri.x789.reg_reset,
 638                                         0x34);
 639         return err;
 640 }
 641
 642 static int sx150x_init_hw(struct sx150x_chip *chip,
 643                         struct sx150x_platform_data *pdata)
 644 {
 645         int err = 0;
 646
 647         if (pdata->reset_during_probe) {
 648                 err = sx150x_reset(chip);
 649                 if (err < 0)
 650                         return err;
 651         }
 652
 653         if (chip->dev_cfg->model == SX150X_789)
 654                 err = sx150x_i2c_write(chip->client,
 655                                 chip->dev_cfg->pri.x789.reg_misc,
 656                                 0x01);
 657         else if (chip->dev_cfg->model == SX150X_456)
 658                 err = sx150x_i2c_write(chip->client,
 659                                 chip->dev_cfg->pri.x456.reg_advance,
 660                                 0x04);
 661         else
 662                 err = sx150x_i2c_write(chip->client,
 663                                 chip->dev_cfg->pri.x123.reg_advance,
 664                                 0x00);
 665         if (err < 0)
 666                 return err;
 667
 668         err = sx150x_init_io(chip, chip->dev_cfg->reg_pullup,
 669                         pdata->io_pullup_ena);
 670         if (err < 0)
 671                 return err;
 672
 673         err = sx150x_init_io(chip, chip->dev_cfg->reg_pulldn,
 674                         pdata->io_pulldn_ena);
 675         if (err < 0)
 676                 return err;
 677
 678         if (chip->dev_cfg->model == SX150X_789) {
 679                 err = sx150x_init_io(chip,
 680                                 chip->dev_cfg->pri.x789.reg_polarity,
 681                                 pdata->io_polarity);
 682                 if (err < 0)
 683                         return err;
 684         } else if (chip->dev_cfg->model == SX150X_456) {
 685                 /* Set all pins to work in normal mode */
 686                 err = sx150x_init_io(chip,
 687                                 chip->dev_cfg->pri.x456.reg_pld_mode,
 688                                 0);
 689                 if (err < 0)
 690                         return err;
 691         } else {
 692                 /* Set all pins to work in normal mode */
 693                 err = sx150x_init_io(chip,
 694                                 chip->dev_cfg->pri.x123.reg_pld_mode,
 695                                 0);
 696                 if (err < 0)
 697                         return err;
 698         }
 699
 700
 701         if (pdata->oscio_is_gpo)
 702                 sx150x_set_oscio(chip, 0);
 703
 704         return err;
 705 }
 706
 707 static int sx150x_install_irq_chip(struct sx150x_chip *chip,
 708                                 int irq_summary,
 709                                 int irq_base)
 710 {
 711         int err;
 712
 713         chip->irq_summary = irq_summary;
 714         chip->irq_base    = irq_base;
 715
 716         /* Add gpio chip to irq subsystem */
 717         err = gpiochip_irqchip_add(&chip->gpio_chip,
 718                 &chip->irq_chip, chip->irq_base,
 719                 handle_edge_irq, IRQ_TYPE_EDGE_BOTH);
 720         if (err) {
 721                 dev_err(&chip->client->dev,
 722                         "could not connect irqchip to gpiochip\n");
 723                 return  err;
 724         }
 725
 726         err = devm_request_threaded_irq(&chip->client->dev,
 727                         irq_summary, NULL, sx150x_irq_thread_fn,
 728                         IRQF_ONESHOT | IRQF_SHARED | IRQF_TRIGGER_FALLING,
 729                         chip->irq_chip.name, chip);
 730         if (err < 0) {
 731                 chip->irq_summary = -1;
 732                 chip->irq_base    = -1;
 733         }
 734
 735         return err;
 736 }
 737
 738 static int sx150x_probe(struct i2c_client *client,
 739                                 const struct i2c_device_id *id)
 740 {
 741         static const u32 i2c_funcs = I2C_FUNC_SMBUS_BYTE_DATA |
 742                                      I2C_FUNC_SMBUS_WRITE_WORD_DATA;
 743         struct sx150x_platform_data *pdata;
 744         struct sx150x_chip *chip;
 745         int rc;
 746
 747         pdata = dev_get_platdata(&client->dev);
 748         if (!pdata)
 749                 return -EINVAL;
 750
 751         if (!i2c_check_functionality(client->adapter, i2c_funcs))
 752                 return -ENOSYS;
 753
 754         chip = devm_kzalloc(&client->dev,
 755                 sizeof(struct sx150x_chip), GFP_KERNEL);
 756         if (!chip)
 757                 return -ENOMEM;
 758
 759         sx150x_init_chip(chip, client, id->driver_data, pdata);
 760         rc = sx150x_init_hw(chip, pdata);
 761         if (rc < 0)
 762                 return rc;
 763
 764         rc = devm_gpiochip_add_data(&client->dev, &chip->gpio_chip, chip);
 765         if (rc)
 766                 return rc;
 767
 768         if (pdata->irq_summary >= 0) {
 769                 rc = sx150x_install_irq_chip(chip,
 770                                         pdata->irq_summary,
 771                                         pdata->irq_base);
 772                 if (rc < 0)
 773                         return rc;
 774         }
 775
 776         i2c_set_clientdata(client, chip);
 777
 778         return 0;
 779 }
 780
 781 static struct i2c_driver sx150x_driver = {
 782         .driver = {
 783                 .name = "sx150x",
 784                 .of_match_table = of_match_ptr(sx150x_of_match),
 785         },
 786         .probe    = sx150x_probe,
 787         .id_table = sx150x_id,
 788 };
 789
 790 static int __init sx150x_init(void)
 791 {
 792         return i2c_add_driver(&sx150x_driver);
 793 }
 794 subsys_initcall(sx150x_init);