drivers/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 struct sx150x_device_data {
  29         u8 reg_pullup;
  30         u8 reg_pulldn;
  31         u8 reg_drain;
  32         u8 reg_polarity;
  33         u8 reg_dir;
  34         u8 reg_data;
  35         u8 reg_irq_mask;
  36         u8 reg_irq_src;
  37         u8 reg_sense;
  38         u8 reg_clock;
  39         u8 reg_misc;
  40         u8 reg_reset;
  41         u8 ngpios;
  42 };
  43
  44 struct sx150x_chip {
  45         struct gpio_chip                 gpio_chip;
  46         struct i2c_client               *client;
  47         const struct sx150x_device_data *dev_cfg;
  48         int                              irq_summary;
  49         int                              irq_base;
  50         u32                              irq_sense;
  51         unsigned long                    irq_set_type_pending;
  52         struct irq_chip                  irq_chip;
  53         struct mutex                     lock;
  54 };
  55
  56 static const struct sx150x_device_data sx150x_devices[] = {
  57         [0] = { /* sx1508q */
  58                 .reg_pullup   = 0x03,
  59                 .reg_pulldn   = 0x04,
  60                 .reg_drain    = 0x05,
  61                 .reg_polarity = 0x06,
  62                 .reg_dir      = 0x07,
  63                 .reg_data     = 0x08,
  64                 .reg_irq_mask = 0x09,
  65                 .reg_irq_src  = 0x0c,
  66                 .reg_sense    = 0x0b,
  67                 .reg_clock    = 0x0f,
  68                 .reg_misc     = 0x10,
  69                 .reg_reset    = 0x7d,
  70                 .ngpios       = 8
  71         },
  72         [1] = { /* sx1509q */
  73                 .reg_pullup   = 0x07,
  74                 .reg_pulldn   = 0x09,
  75                 .reg_drain    = 0x0b,
  76                 .reg_polarity = 0x0d,
  77                 .reg_dir      = 0x0f,
  78                 .reg_data     = 0x11,
  79                 .reg_irq_mask = 0x13,
  80                 .reg_irq_src  = 0x19,
  81                 .reg_sense    = 0x17,
  82                 .reg_clock    = 0x1e,
  83                 .reg_misc     = 0x1f,
  84                 .reg_reset    = 0x7d,
  85                 .ngpios       = 16
  86         },
  87 };
  88
  89 static const struct i2c_device_id sx150x_id[] = {
  90         {"sx1508q", 0},
  91         {"sx1509q", 1},
  92         {}
  93 };
  94 MODULE_DEVICE_TABLE(i2c, sx150x_id);
  95
  96 static s32 sx150x_i2c_write(struct i2c_client *client, u8 reg, u8 val)
  97 {
  98         s32 err = i2c_smbus_write_byte_data(client, reg, val);
  99
 100         if (err < 0)
 101                 dev_warn(&client->dev,
 102                         "i2c write fail: can't write %02x to %02x: %d\n",
 103                         val, reg, err);
 104         return err;
 105 }
 106
 107 static s32 sx150x_i2c_read(struct i2c_client *client, u8 reg, u8 *val)
 108 {
 109         s32 err = i2c_smbus_read_byte_data(client, reg);
 110
 111         if (err >= 0)
 112                 *val = err;
 113         else
 114                 dev_warn(&client->dev,
 115                         "i2c read fail: can't read from %02x: %d\n",
 116                         reg, err);
 117         return err;
 118 }
 119
 120 static inline bool offset_is_oscio(struct sx150x_chip *chip, unsigned offset)
 121 {
 122         return (chip->dev_cfg->ngpios == offset);
 123 }
 124
 125 /*
 126  * These utility functions solve the common problem of locating and setting
 127  * configuration bits.  Configuration bits are grouped into registers
 128  * whose indexes increase downwards.  For example, with eight-bit registers,
 129  * sixteen gpios would have their config bits grouped in the following order:
 130  * REGISTER N-1 [ f e d c b a 9 8 ]
 131  *          N   [ 7 6 5 4 3 2 1 0 ]
 132  *
 133  * For multi-bit configurations, the pattern gets wider:
 134  * REGISTER N-3 [ f f e e d d c c ]
 135  *          N-2 [ b b a a 9 9 8 8 ]
 136  *          N-1 [ 7 7 6 6 5 5 4 4 ]
 137  *          N   [ 3 3 2 2 1 1 0 0 ]
 138  *
 139  * Given the address of the starting register 'N', the index of the gpio
 140  * whose configuration we seek to change, and the width in bits of that
 141  * configuration, these functions allow us to locate the correct
 142  * register and mask the correct bits.
 143  */
 144 static inline void sx150x_find_cfg(u8 offset, u8 width,
 145                                 u8 *reg, u8 *mask, u8 *shift)
 146 {
 147         *reg   -= offset * width / 8;
 148         *mask   = (1 << width) - 1;
 149         *shift  = (offset * width) % 8;
 150         *mask <<= *shift;
 151 }
 152
 153 static s32 sx150x_write_cfg(struct sx150x_chip *chip,
 154                         u8 offset, u8 width, u8 reg, u8 val)
 155 {
 156         u8  mask;
 157         u8  data;
 158         u8  shift;
 159         s32 err;
 160
 161         sx150x_find_cfg(offset, width, &reg, &mask, &shift);
 162         err = sx150x_i2c_read(chip->client, reg, &data);
 163         if (err < 0)
 164                 return err;
 165
 166         data &= ~mask;
 167         data |= (val << shift) & mask;
 168         return sx150x_i2c_write(chip->client, reg, data);
 169 }
 170
 171 static int sx150x_get_io(struct sx150x_chip *chip, unsigned offset)
 172 {
 173         u8  reg = chip->dev_cfg->reg_data;
 174         u8  mask;
 175         u8  data;
 176         u8  shift;
 177         s32 err;
 178
 179         sx150x_find_cfg(offset, 1, &reg, &mask, &shift);
 180         err = sx150x_i2c_read(chip->client, reg, &data);
 181         if (err >= 0)
 182                 err = (data & mask) != 0 ? 1 : 0;
 183
 184         return err;
 185 }
 186
 187 static void sx150x_set_oscio(struct sx150x_chip *chip, int val)
 188 {
 189         sx150x_i2c_write(chip->client,
 190                         chip->dev_cfg->reg_clock,
 191                         (val ? 0x1f : 0x10));
 192 }
 193
 194 static void sx150x_set_io(struct sx150x_chip *chip, unsigned offset, int val)
 195 {
 196         sx150x_write_cfg(chip,
 197                         offset,
 198                         1,
 199                         chip->dev_cfg->reg_data,
 200                         (val ? 1 : 0));
 201 }
 202
 203 static int sx150x_io_input(struct sx150x_chip *chip, unsigned offset)
 204 {
 205         return sx150x_write_cfg(chip,
 206                                 offset,
 207                                 1,
 208                                 chip->dev_cfg->reg_dir,
 209                                 1);
 210 }
 211
 212 static int sx150x_io_output(struct sx150x_chip *chip, unsigned offset, int val)
 213 {
 214         int err;
 215
 216         err = sx150x_write_cfg(chip,
 217                         offset,
 218                         1,
 219                         chip->dev_cfg->reg_data,
 220                         (val ? 1 : 0));
 221         if (err >= 0)
 222                 err = sx150x_write_cfg(chip,
 223                                 offset,
 224                                 1,
 225                                 chip->dev_cfg->reg_dir,
 226                                 0);
 227         return err;
 228 }
 229
 230 static int sx150x_gpio_get(struct gpio_chip *gc, unsigned offset)
 231 {
 232         struct sx150x_chip *chip;
 233         int status = -EINVAL;
 234
 235         chip = container_of(gc, struct sx150x_chip, gpio_chip);
 236
 237         if (!offset_is_oscio(chip, offset)) {
 238                 mutex_lock(&chip->lock);
 239                 status = sx150x_get_io(chip, offset);
 240                 mutex_unlock(&chip->lock);
 241         }
 242
 243         return status;
 244 }
 245
 246 static void sx150x_gpio_set(struct gpio_chip *gc, unsigned offset, int val)
 247 {
 248         struct sx150x_chip *chip;
 249
 250         chip = container_of(gc, struct sx150x_chip, gpio_chip);
 251
 252         mutex_lock(&chip->lock);
 253         if (offset_is_oscio(chip, offset))
 254                 sx150x_set_oscio(chip, val);
 255         else
 256                 sx150x_set_io(chip, offset, val);
 257         mutex_unlock(&chip->lock);
 258 }
 259
 260 static int sx150x_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
 261 {
 262         struct sx150x_chip *chip;
 263         int status = -EINVAL;
 264
 265         chip = container_of(gc, struct sx150x_chip, gpio_chip);
 266
 267         if (!offset_is_oscio(chip, offset)) {
 268                 mutex_lock(&chip->lock);
 269                 status = sx150x_io_input(chip, offset);
 270                 mutex_unlock(&chip->lock);
 271         }
 272         return status;
 273 }
 274
 275 static int sx150x_gpio_direction_output(struct gpio_chip *gc,
 276                                         unsigned offset,
 277                                         int val)
 278 {
 279         struct sx150x_chip *chip;
 280         int status = 0;
 281
 282         chip = container_of(gc, struct sx150x_chip, gpio_chip);
 283
 284         if (!offset_is_oscio(chip, offset)) {
 285                 mutex_lock(&chip->lock);
 286                 status = sx150x_io_output(chip, offset, val);
 287                 mutex_unlock(&chip->lock);
 288         }
 289         return status;
 290 }
 291
 292 static int sx150x_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
 293 {
 294         struct sx150x_chip *chip;
 295
 296         chip = container_of(gc, struct sx150x_chip, gpio_chip);
 297
 298         if (offset >= chip->dev_cfg->ngpios)
 299                 return -EINVAL;
 300
 301         if (chip->irq_base < 0)
 302                 return -EINVAL;
 303
 304         return chip->irq_base + offset;
 305 }
 306
 307 static void sx150x_irq_mask(unsigned int irq)
 308 {
 309         struct irq_chip *ic = get_irq_chip(irq);
 310         struct sx150x_chip *chip;
 311         unsigned n;
 312
 313         chip = container_of(ic, struct sx150x_chip, irq_chip);
 314         n = irq - chip->irq_base;
 315
 316         sx150x_write_cfg(chip, n, 1, chip->dev_cfg->reg_irq_mask, 1);
 317         sx150x_write_cfg(chip, n, 2, chip->dev_cfg->reg_sense, 0);
 318 }
 319
 320 static void sx150x_irq_unmask(unsigned int irq)
 321 {
 322         struct irq_chip *ic = get_irq_chip(irq);
 323         struct sx150x_chip *chip;
 324         unsigned n;
 325
 326         chip = container_of(ic, struct sx150x_chip, irq_chip);
 327         n = irq - chip->irq_base;
 328
 329         sx150x_write_cfg(chip, n, 1, chip->dev_cfg->reg_irq_mask, 0);
 330         sx150x_write_cfg(chip, n, 2, chip->dev_cfg->reg_sense,
 331                          chip->irq_sense >> (n * 2));
 332 }
 333
 334 static int sx150x_irq_set_type(unsigned int irq, unsigned int flow_type)
 335 {
 336         struct irq_chip *ic = get_irq_chip(irq);
 337         struct sx150x_chip *chip;
 338         unsigned n, val = 0;
 339
 340         if (flow_type & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW))
 341                 return -EINVAL;
 342
 343         chip = container_of(ic, struct sx150x_chip, irq_chip);
 344         n = irq - chip->irq_base;
 345
 346         if (flow_type & IRQ_TYPE_EDGE_RISING)
 347                 val |= 0x1;
 348         if (flow_type & IRQ_TYPE_EDGE_FALLING)
 349                 val |= 0x2;
 350
 351         chip->irq_sense &= ~(3UL << (n * 2));
 352         chip->irq_sense |= val << (n * 2);
 353         chip->irq_set_type_pending |= BIT(n);
 354         return 0;
 355 }
 356
 357 static irqreturn_t sx150x_irq_thread_fn(int irq, void *dev_id)
 358 {
 359         struct sx150x_chip *chip = (struct sx150x_chip *)dev_id;
 360         unsigned nhandled = 0;
 361         unsigned sub_irq;
 362         unsigned n;
 363         s32 err;
 364         u8 val;
 365         int i;
 366
 367         for (i = (chip->dev_cfg->ngpios / 8) - 1; i >= 0; --i) {
 368                 err = sx150x_i2c_read(chip->client,
 369                                       chip->dev_cfg->reg_irq_src - i,
 370                                       &val);
 371                 if (err < 0)
 372                         continue;
 373
 374                 sx150x_i2c_write(chip->client,
 375                                 chip->dev_cfg->reg_irq_src - i,
 376                                 val);
 377                 for (n = 0; n < 8; ++n) {
 378                         if (val & (1 << n)) {
 379                                 sub_irq = chip->irq_base + (i * 8) + n;
 380                                 handle_nested_irq(sub_irq);
 381                                 ++nhandled;
 382                         }
 383                 }
 384         }
 385
 386         return (nhandled > 0 ? IRQ_HANDLED : IRQ_NONE);
 387 }
 388
 389 static void sx150x_irq_bus_lock(unsigned int irq)
 390 {
 391         struct irq_chip *ic = get_irq_chip(irq);
 392         struct sx150x_chip *chip;
 393
 394         chip = container_of(ic, struct sx150x_chip, irq_chip);
 395
 396         mutex_lock(&chip->lock);
 397 }
 398
 399 static void sx150x_irq_bus_sync_unlock(unsigned int irq)
 400 {
 401         struct irq_chip *ic = get_irq_chip(irq);
 402         struct sx150x_chip *chip;
 403         unsigned n;
 404
 405         chip = container_of(ic, struct sx150x_chip, irq_chip);
 406
 407         while (chip->irq_set_type_pending) {
 408                 n = __ffs(chip->irq_set_type_pending);
 409                 chip->irq_set_type_pending &= ~BIT(n);
 410                 if (!(irq_to_desc(n + chip->irq_base)->status & IRQ_MASKED))
 411                         sx150x_write_cfg(chip, n, 2,
 412                                         chip->dev_cfg->reg_sense,
 413                                         chip->irq_sense >> (n * 2));
 414         }
 415
 416         mutex_unlock(&chip->lock);
 417 }
 418
 419 static void sx150x_init_chip(struct sx150x_chip *chip,
 420                         struct i2c_client *client,
 421                         kernel_ulong_t driver_data,
 422                         struct sx150x_platform_data *pdata)
 423 {
 424         mutex_init(&chip->lock);
 425
 426         chip->client                     = client;
 427         chip->dev_cfg                    = &sx150x_devices[driver_data];
 428         chip->gpio_chip.label            = client->name;
 429         chip->gpio_chip.direction_input  = sx150x_gpio_direction_input;
 430         chip->gpio_chip.direction_output = sx150x_gpio_direction_output;
 431         chip->gpio_chip.get              = sx150x_gpio_get;
 432         chip->gpio_chip.set              = sx150x_gpio_set;
 433         chip->gpio_chip.to_irq           = sx150x_gpio_to_irq;
 434         chip->gpio_chip.base             = pdata->gpio_base;
 435         chip->gpio_chip.can_sleep        = 1;
 436         chip->gpio_chip.ngpio            = chip->dev_cfg->ngpios;
 437         if (pdata->oscio_is_gpo)
 438                 ++chip->gpio_chip.ngpio;
 439
 440         chip->irq_chip.name            = client->name;
 441         chip->irq_chip.mask            = sx150x_irq_mask;
 442         chip->irq_chip.unmask          = sx150x_irq_unmask;
 443         chip->irq_chip.set_type        = sx150x_irq_set_type;
 444         chip->irq_chip.bus_lock        = sx150x_irq_bus_lock;
 445         chip->irq_chip.bus_sync_unlock = sx150x_irq_bus_sync_unlock;
 446         chip->irq_summary              = -1;
 447         chip->irq_base                 = -1;
 448         chip->irq_sense                = 0;
 449         chip->irq_set_type_pending     = 0;
 450 }
 451
 452 static int sx150x_init_io(struct sx150x_chip *chip, u8 base, u16 cfg)
 453 {
 454         int err = 0;
 455         unsigned n;
 456
 457         for (n = 0; err >= 0 && n < (chip->dev_cfg->ngpios / 8); ++n)
 458                 err = sx150x_i2c_write(chip->client, base - n, cfg >> (n * 8));
 459         return err;
 460 }
 461
 462 static int sx150x_init_hw(struct sx150x_chip *chip,
 463                         struct sx150x_platform_data *pdata)
 464 {
 465         int err = 0;
 466
 467         err = i2c_smbus_write_word_data(chip->client,
 468                                         chip->dev_cfg->reg_reset,
 469                                         0x3412);
 470         if (err < 0)
 471                 return err;
 472
 473         err = sx150x_i2c_write(chip->client,
 474                         chip->dev_cfg->reg_misc,
 475                         0x01);
 476         if (err < 0)
 477                 return err;
 478
 479         err = sx150x_init_io(chip, chip->dev_cfg->reg_pullup,
 480                         pdata->io_pullup_ena);
 481         if (err < 0)
 482                 return err;
 483
 484         err = sx150x_init_io(chip, chip->dev_cfg->reg_pulldn,
 485                         pdata->io_pulldn_ena);
 486         if (err < 0)
 487                 return err;
 488
 489         err = sx150x_init_io(chip, chip->dev_cfg->reg_drain,
 490                         pdata->io_open_drain_ena);
 491         if (err < 0)
 492                 return err;
 493
 494         err = sx150x_init_io(chip, chip->dev_cfg->reg_polarity,
 495                         pdata->io_polarity);
 496         if (err < 0)
 497                 return err;
 498
 499         if (pdata->oscio_is_gpo)
 500                 sx150x_set_oscio(chip, 0);
 501
 502         return err;
 503 }
 504
 505 static int sx150x_install_irq_chip(struct sx150x_chip *chip,
 506                                 int irq_summary,
 507                                 int irq_base)
 508 {
 509         int err;
 510         unsigned n;
 511         unsigned irq;
 512
 513         chip->irq_summary = irq_summary;
 514         chip->irq_base    = irq_base;
 515
 516         for (n = 0; n < chip->dev_cfg->ngpios; ++n) {
 517                 irq = irq_base + n;
 518                 set_irq_chip_and_handler(irq, &chip->irq_chip, handle_edge_irq);
 519                 set_irq_nested_thread(irq, 1);
 520 #ifdef CONFIG_ARM
 521                 set_irq_flags(irq, IRQF_VALID);
 522 #else
 523                 set_irq_noprobe(irq);
 524 #endif
 525         }
 526
 527         err = request_threaded_irq(irq_summary,
 528                                 NULL,
 529                                 sx150x_irq_thread_fn,
 530                                 IRQF_SHARED | IRQF_TRIGGER_FALLING,
 531                                 chip->irq_chip.name,
 532                                 chip);
 533         if (err < 0) {
 534                 chip->irq_summary = -1;
 535                 chip->irq_base    = -1;
 536         }
 537
 538         return err;
 539 }
 540
 541 static void sx150x_remove_irq_chip(struct sx150x_chip *chip)
 542 {
 543         unsigned n;
 544         unsigned irq;
 545
 546         free_irq(chip->irq_summary, chip);
 547
 548         for (n = 0; n < chip->dev_cfg->ngpios; ++n) {
 549                 irq = chip->irq_base + n;
 550                 set_irq_handler(irq, NULL);
 551                 set_irq_chip(irq, NULL);
 552         }
 553 }
 554
 555 static int __devinit sx150x_probe(struct i2c_client *client,
 556                                 const struct i2c_device_id *id)
 557 {
 558         static const u32 i2c_funcs = I2C_FUNC_SMBUS_BYTE_DATA |
 559                                      I2C_FUNC_SMBUS_WRITE_WORD_DATA;
 560         struct sx150x_platform_data *pdata;
 561         struct sx150x_chip *chip;
 562         int rc;
 563
 564         pdata = client->dev.platform_data;
 565         if (!pdata)
 566                 return -EINVAL;
 567
 568         if (!i2c_check_functionality(client->adapter, i2c_funcs))
 569                 return -ENOSYS;
 570
 571         chip = kzalloc(sizeof(struct sx150x_chip), GFP_KERNEL);
 572         if (!chip)
 573                 return -ENOMEM;
 574
 575         sx150x_init_chip(chip, client, id->driver_data, pdata);
 576         rc = sx150x_init_hw(chip, pdata);
 577         if (rc < 0)
 578                 goto probe_fail_pre_gpiochip_add;
 579
 580         rc = gpiochip_add(&chip->gpio_chip);
 581         if (rc < 0)
 582                 goto probe_fail_pre_gpiochip_add;
 583
 584         if (pdata->irq_summary >= 0) {
 585                 rc = sx150x_install_irq_chip(chip,
 586                                         pdata->irq_summary,
 587                                         pdata->irq_base);
 588                 if (rc < 0)
 589                         goto probe_fail_post_gpiochip_add;
 590         }
 591
 592         i2c_set_clientdata(client, chip);
 593
 594         return 0;
 595 probe_fail_post_gpiochip_add:
 596         WARN_ON(gpiochip_remove(&chip->gpio_chip) < 0);
 597 probe_fail_pre_gpiochip_add:
 598         kfree(chip);
 599         return rc;
 600 }
 601
 602 static int __devexit sx150x_remove(struct i2c_client *client)
 603 {
 604         struct sx150x_chip *chip;
 605         int rc;
 606
 607         chip = i2c_get_clientdata(client);
 608         rc = gpiochip_remove(&chip->gpio_chip);
 609         if (rc < 0)
 610                 return rc;
 611
 612         if (chip->irq_summary >= 0)
 613                 sx150x_remove_irq_chip(chip);
 614
 615         kfree(chip);
 616
 617         return 0;
 618 }
 619
 620 static struct i2c_driver sx150x_driver = {
 621         .driver = {
 622                 .name = "sx150x",
 623                 .owner = THIS_MODULE
 624         },
 625         .probe    = sx150x_probe,
 626         .remove   = __devexit_p(sx150x_remove),
 627         .id_table = sx150x_id,
 628 };
 629
 630 static int __init sx150x_init(void)
 631 {
 632         return i2c_add_driver(&sx150x_driver);
 633 }
 634 subsys_initcall(sx150x_init);
 635
 636 static void __exit sx150x_exit(void)
 637 {
 638         return i2c_del_driver(&sx150x_driver);
 639 }
 640 module_exit(sx150x_exit);
 641
 642 MODULE_AUTHOR("Gregory Bean <gbean@codeaurora.org>");
 643 MODULE_DESCRIPTION("Driver for Semtech SX150X I2C GPIO Expanders");
 644 MODULE_LICENSE("GPL v2");
 645 MODULE_ALIAS("i2c:sx150x");