1/* 2 * htc-i2cpld.c 3 * Chip driver for an unknown CPLD chip found on omap850 HTC devices like 4 * the HTC Wizard and HTC Herald. 5 * The cpld is located on the i2c bus and acts as an input/output GPIO 6 * extender. 7 * 8 * Copyright (C) 2009 Cory Maccarrone <darkstar6262@gmail.com> 9 * 10 * Based on work done in the linwizard project 11 * Copyright (C) 2008-2009 Angelo Arrifano <miknix@gmail.com> 12 * 13 * This program is free software; you can redistribute it and/or modify 14 * it under the terms of the GNU General Public License as published by 15 * the Free Software Foundation; either version 2 of the License, or 16 * (at your option) any later version. 17 * 18 * This program is distributed in the hope that it will be useful, 19 * but WITHOUT ANY WARRANTY; without even the implied warranty of 20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 21 * GNU General Public License for more details. 22 * 23 * You should have received a copy of the GNU General Public License 24 * along with this program; if not, write to the Free Software 25 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 26 */ 27 28#include <linux/kernel.h> 29#include <linux/init.h> 30#include <linux/module.h> 31#include <linux/interrupt.h> 32#include <linux/platform_device.h> 33#include <linux/i2c.h> 34#include <linux/irq.h> 35#include <linux/spinlock.h> 36#include <linux/htcpld.h> 37#include <linux/gpio.h> 38#include <linux/slab.h> 39 40struct htcpld_chip { 41 spinlock_t lock; 42 43 /* chip info */ 44 u8 reset; 45 u8 addr; 46 struct device *dev; 47 struct i2c_client *client; 48 49 /* Output details */ 50 u8 cache_out; 51 struct gpio_chip chip_out; 52 53 /* Input details */ 54 u8 cache_in; 55 struct gpio_chip chip_in; 56 57 u16 irqs_enabled; 58 uint irq_start; 59 int nirqs; 60 61 unsigned int flow_type; 62 /* 63 * Work structure to allow for setting values outside of any 64 * possible interrupt context 65 */ 66 struct work_struct set_val_work; 67}; 68 69struct htcpld_data { 70 /* irq info */ 71 u16 irqs_enabled; 72 uint irq_start; 73 int nirqs; 74 uint chained_irq; 75 unsigned int int_reset_gpio_hi; 76 unsigned int int_reset_gpio_lo; 77 78 /* htcpld info */ 79 struct htcpld_chip *chip; 80 unsigned int nchips; 81}; 82 83/* There does not appear to be a way to proactively mask interrupts 84 * on the htcpld chip itself. So, we simply ignore interrupts that 85 * aren't desired. */ 86static void htcpld_mask(struct irq_data *data) 87{ 88 struct htcpld_chip *chip = irq_data_get_irq_chip_data(data); 89 chip->irqs_enabled &= ~(1 << (data->irq - chip->irq_start)); 90 pr_debug("HTCPLD mask %d %04x\n", data->irq, chip->irqs_enabled); 91} 92static void htcpld_unmask(struct irq_data *data) 93{ 94 struct htcpld_chip *chip = irq_data_get_irq_chip_data(data); 95 chip->irqs_enabled |= 1 << (data->irq - chip->irq_start); 96 pr_debug("HTCPLD unmask %d %04x\n", data->irq, chip->irqs_enabled); 97} 98 99static int htcpld_set_type(struct irq_data *data, unsigned int flags) 100{ 101 struct htcpld_chip *chip = irq_data_get_irq_chip_data(data); 102 103 if (flags & ~IRQ_TYPE_SENSE_MASK) 104 return -EINVAL; 105 106 /* We only allow edge triggering */ 107 if (flags & (IRQ_TYPE_LEVEL_LOW|IRQ_TYPE_LEVEL_HIGH)) 108 return -EINVAL; 109 110 chip->flow_type = flags; 111 return 0; 112} 113 114static struct irq_chip htcpld_muxed_chip = { 115 .name = "htcpld", 116 .irq_mask = htcpld_mask, 117 .irq_unmask = htcpld_unmask, 118 .irq_set_type = htcpld_set_type, 119}; 120 121/* To properly dispatch IRQ events, we need to read from the 122 * chip. This is an I2C action that could possibly sleep 123 * (which is bad in interrupt context) -- so we use a threaded 124 * interrupt handler to get around that. 125 */ 126static irqreturn_t htcpld_handler(int irq, void *dev) 127{ 128 struct htcpld_data *htcpld = dev; 129 unsigned int i; 130 unsigned long flags; 131 int irqpin; 132 133 if (!htcpld) { 134 pr_debug("htcpld is null in ISR\n"); 135 return IRQ_HANDLED; 136 } 137 138 /* 139 * For each chip, do a read of the chip and trigger any interrupts 140 * desired. The interrupts will be triggered from LSB to MSB (i.e. 141 * bit 0 first, then bit 1, etc.) 142 * 143 * For chips that have no interrupt range specified, just skip 'em. 144 */ 145 for (i = 0; i < htcpld->nchips; i++) { 146 struct htcpld_chip *chip = &htcpld->chip[i]; 147 struct i2c_client *client; 148 int val; 149 unsigned long uval, old_val; 150 151 if (!chip) { 152 pr_debug("chip %d is null in ISR\n", i); 153 continue; 154 } 155 156 if (chip->nirqs == 0) 157 continue; 158 159 client = chip->client; 160 if (!client) { 161 pr_debug("client %d is null in ISR\n", i); 162 continue; 163 } 164 165 /* Scan the chip */ 166 val = i2c_smbus_read_byte_data(client, chip->cache_out); 167 if (val < 0) { 168 /* Throw a warning and skip this chip */ 169 dev_warn(chip->dev, "Unable to read from chip: %d\n", 170 val); 171 continue; 172 } 173 174 uval = (unsigned long)val; 175 176 spin_lock_irqsave(&chip->lock, flags); 177 178 /* Save away the old value so we can compare it */ 179 old_val = chip->cache_in; 180 181 /* Write the new value */ 182 chip->cache_in = uval; 183 184 spin_unlock_irqrestore(&chip->lock, flags); 185 186 /* 187 * For each bit in the data (starting at bit 0), trigger 188 * associated interrupts. 189 */ 190 for (irqpin = 0; irqpin < chip->nirqs; irqpin++) { 191 unsigned oldb, newb, type = chip->flow_type; 192 193 irq = chip->irq_start + irqpin; 194 195 /* Run the IRQ handler, but only if the bit value 196 * changed, and the proper flags are set */ 197 oldb = (old_val >> irqpin) & 1; 198 newb = (uval >> irqpin) & 1; 199 200 if ((!oldb && newb && (type & IRQ_TYPE_EDGE_RISING)) || 201 (oldb && !newb && (type & IRQ_TYPE_EDGE_FALLING))) { 202 pr_debug("fire IRQ %d\n", irqpin); 203 generic_handle_irq(irq); 204 } 205 } 206 } 207 208 /* 209 * In order to continue receiving interrupts, the int_reset_gpio must 210 * be asserted. 211 */ 212 if (htcpld->int_reset_gpio_hi) 213 gpio_set_value(htcpld->int_reset_gpio_hi, 1); 214 if (htcpld->int_reset_gpio_lo) 215 gpio_set_value(htcpld->int_reset_gpio_lo, 0); 216 217 return IRQ_HANDLED; 218} 219 220/* 221 * The GPIO set routines can be called from interrupt context, especially if, 222 * for example they're attached to the led-gpio framework and a trigger is 223 * enabled. As such, we declared work above in the htcpld_chip structure, 224 * and that work is scheduled in the set routine. The kernel can then run 225 * the I2C functions, which will sleep, in process context. 226 */ 227static void htcpld_chip_set(struct gpio_chip *chip, unsigned offset, int val) 228{ 229 struct i2c_client *client; 230 struct htcpld_chip *chip_data; 231 unsigned long flags; 232 233 chip_data = container_of(chip, struct htcpld_chip, chip_out); 234 if (!chip_data) 235 return; 236 237 client = chip_data->client; 238 if (client == NULL) 239 return; 240 241 spin_lock_irqsave(&chip_data->lock, flags); 242 if (val) 243 chip_data->cache_out |= (1 << offset); 244 else 245 chip_data->cache_out &= ~(1 << offset); 246 spin_unlock_irqrestore(&chip_data->lock, flags); 247 248 schedule_work(&(chip_data->set_val_work)); 249} 250 251static void htcpld_chip_set_ni(struct work_struct *work) 252{ 253 struct htcpld_chip *chip_data; 254 struct i2c_client *client; 255 256 chip_data = container_of(work, struct htcpld_chip, set_val_work); 257 client = chip_data->client; 258 i2c_smbus_read_byte_data(client, chip_data->cache_out); 259} 260 261static int htcpld_chip_get(struct gpio_chip *chip, unsigned offset) 262{ 263 struct htcpld_chip *chip_data; 264 int val = 0; 265 int is_input = 0; 266 267 /* Try out first */ 268 chip_data = container_of(chip, struct htcpld_chip, chip_out); 269 if (!chip_data) { 270 /* Try in */ 271 is_input = 1; 272 chip_data = container_of(chip, struct htcpld_chip, chip_in); 273 if (!chip_data) 274 return -EINVAL; 275 } 276 277 /* Determine if this is an input or output GPIO */ 278 if (!is_input) 279 /* Use the output cache */ 280 val = (chip_data->cache_out >> offset) & 1; 281 else 282 /* Use the input cache */ 283 val = (chip_data->cache_in >> offset) & 1; 284 285 if (val) 286 return 1; 287 else 288 return 0; 289} 290 291static int htcpld_direction_output(struct gpio_chip *chip, 292 unsigned offset, int value) 293{ 294 htcpld_chip_set(chip, offset, value); 295 return 0; 296} 297 298static int htcpld_direction_input(struct gpio_chip *chip, 299 unsigned offset) 300{ 301 /* 302 * No-op: this function can only be called on the input chip. 303 * We do however make sure the offset is within range. 304 */ 305 return (offset < chip->ngpio) ? 0 : -EINVAL; 306} 307 308static int htcpld_chip_to_irq(struct gpio_chip *chip, unsigned offset) 309{ 310 struct htcpld_chip *chip_data; 311 312 chip_data = container_of(chip, struct htcpld_chip, chip_in); 313 314 if (offset < chip_data->nirqs) 315 return chip_data->irq_start + offset; 316 else 317 return -EINVAL; 318} 319 320static void htcpld_chip_reset(struct i2c_client *client) 321{ 322 struct htcpld_chip *chip_data = i2c_get_clientdata(client); 323 if (!chip_data) 324 return; 325 326 i2c_smbus_read_byte_data( 327 client, (chip_data->cache_out = chip_data->reset)); 328} 329 330static int __devinit htcpld_setup_chip_irq( 331 struct platform_device *pdev, 332 int chip_index) 333{ 334 struct htcpld_data *htcpld; 335 struct device *dev = &pdev->dev; 336 struct htcpld_core_platform_data *pdata; 337 struct htcpld_chip *chip; 338 struct htcpld_chip_platform_data *plat_chip_data; 339 unsigned int irq, irq_end; 340 int ret = 0; 341 342 /* Get the platform and driver data */ 343 pdata = dev->platform_data; 344 htcpld = platform_get_drvdata(pdev); 345 chip = &htcpld->chip[chip_index]; 346 plat_chip_data = &pdata->chip[chip_index]; 347 348 /* Setup irq handlers */ 349 irq_end = chip->irq_start + chip->nirqs; 350 for (irq = chip->irq_start; irq < irq_end; irq++) { 351 irq_set_chip_and_handler(irq, &htcpld_muxed_chip, 352 handle_simple_irq); 353 irq_set_chip_data(irq, chip); 354#ifdef CONFIG_ARM 355 set_irq_flags(irq, IRQF_VALID | IRQF_PROBE); 356#else 357 irq_set_probe(irq); 358#endif 359 } 360 361 return ret; 362} 363 364static int __devinit htcpld_register_chip_i2c( 365 struct platform_device *pdev, 366 int chip_index) 367{ 368 struct htcpld_data *htcpld; 369 struct device *dev = &pdev->dev; 370 struct htcpld_core_platform_data *pdata; 371 struct htcpld_chip *chip; 372 struct htcpld_chip_platform_data *plat_chip_data; 373 struct i2c_adapter *adapter; 374 struct i2c_client *client; 375 struct i2c_board_info info; 376 377 /* Get the platform and driver data */ 378 pdata = dev->platform_data; 379 htcpld = platform_get_drvdata(pdev); 380 chip = &htcpld->chip[chip_index]; 381 plat_chip_data = &pdata->chip[chip_index]; 382 383 adapter = i2c_get_adapter(pdata->i2c_adapter_id); 384 if (adapter == NULL) { 385 /* Eek, no such I2C adapter! Bail out. */ 386 dev_warn(dev, "Chip at i2c address 0x%x: Invalid i2c adapter %d\n", 387 plat_chip_data->addr, pdata->i2c_adapter_id); 388 return -ENODEV; 389 } 390 391 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_BYTE_DATA)) { 392 dev_warn(dev, "i2c adapter %d non-functional\n", 393 pdata->i2c_adapter_id); 394 return -EINVAL; 395 } 396 397 memset(&info, 0, sizeof(struct i2c_board_info)); 398 info.addr = plat_chip_data->addr; 399 strlcpy(info.type, "htcpld-chip", I2C_NAME_SIZE); 400 info.platform_data = chip; 401 402 /* Add the I2C device. This calls the probe() function. */ 403 client = i2c_new_device(adapter, &info); 404 if (!client) { 405 /* I2C device registration failed, contineu with the next */ 406 dev_warn(dev, "Unable to add I2C device for 0x%x\n", 407 plat_chip_data->addr); 408 return -ENODEV; 409 } 410 411 i2c_set_clientdata(client, chip); 412 snprintf(client->name, I2C_NAME_SIZE, "Chip_0x%d", client->addr); 413 chip->client = client; 414 415 /* Reset the chip */ 416 htcpld_chip_reset(client); 417 chip->cache_in = i2c_smbus_read_byte_data(client, chip->cache_out); 418 419 return 0; 420} 421 422static void __devinit htcpld_unregister_chip_i2c( 423 struct platform_device *pdev, 424 int chip_index) 425{ 426 struct htcpld_data *htcpld; 427 struct htcpld_chip *chip; 428 429 /* Get the platform and driver data */ 430 htcpld = platform_get_drvdata(pdev); 431 chip = &htcpld->chip[chip_index]; 432 433 if (chip->client) 434 i2c_unregister_device(chip->client); 435} 436 437static int __devinit htcpld_register_chip_gpio( 438 struct platform_device *pdev, 439 int chip_index) 440{ 441 struct htcpld_data *htcpld; 442 struct device *dev = &pdev->dev; 443 struct htcpld_core_platform_data *pdata; 444 struct htcpld_chip *chip; 445 struct htcpld_chip_platform_data *plat_chip_data; 446 struct gpio_chip *gpio_chip; 447 int ret = 0; 448 449 /* Get the platform and driver data */ 450 pdata = dev->platform_data; 451 htcpld = platform_get_drvdata(pdev); 452 chip = &htcpld->chip[chip_index]; 453 plat_chip_data = &pdata->chip[chip_index]; 454 455 /* Setup the GPIO chips */ 456 gpio_chip = &(chip->chip_out); 457 gpio_chip->label = "htcpld-out"; 458 gpio_chip->dev = dev; 459 gpio_chip->owner = THIS_MODULE; 460 gpio_chip->get = htcpld_chip_get; 461 gpio_chip->set = htcpld_chip_set; 462 gpio_chip->direction_input = NULL; 463 gpio_chip->direction_output = htcpld_direction_output; 464 gpio_chip->base = plat_chip_data->gpio_out_base; 465 gpio_chip->ngpio = plat_chip_data->num_gpios; 466 467 gpio_chip = &(chip->chip_in); 468 gpio_chip->label = "htcpld-in"; 469 gpio_chip->dev = dev; 470 gpio_chip->owner = THIS_MODULE; 471 gpio_chip->get = htcpld_chip_get; 472 gpio_chip->set = NULL; 473 gpio_chip->direction_input = htcpld_direction_input; 474 gpio_chip->direction_output = NULL; 475 gpio_chip->to_irq = htcpld_chip_to_irq; 476 gpio_chip->base = plat_chip_data->gpio_in_base; 477 gpio_chip->ngpio = plat_chip_data->num_gpios; 478 479 /* Add the GPIO chips */ 480 ret = gpiochip_add(&(chip->chip_out)); 481 if (ret) { 482 dev_warn(dev, "Unable to register output GPIOs for 0x%x: %d\n", 483 plat_chip_data->addr, ret); 484 return ret; 485 } 486 487 ret = gpiochip_add(&(chip->chip_in)); 488 if (ret) { 489 int error; 490 491 dev_warn(dev, "Unable to register input GPIOs for 0x%x: %d\n", 492 plat_chip_data->addr, ret); 493 494 error = gpiochip_remove(&(chip->chip_out)); 495 if (error) 496 dev_warn(dev, "Error while trying to unregister gpio chip: %d\n", error); 497 498 return ret; 499 } 500 501 return 0; 502} 503 504static int __devinit htcpld_setup_chips(struct platform_device *pdev) 505{ 506 struct htcpld_data *htcpld; 507 struct device *dev = &pdev->dev; 508 struct htcpld_core_platform_data *pdata; 509 int i; 510 511 /* Get the platform and driver data */ 512 pdata = dev->platform_data; 513 htcpld = platform_get_drvdata(pdev); 514 515 /* Setup each chip's output GPIOs */ 516 htcpld->nchips = pdata->num_chip; 517 htcpld->chip = kzalloc(sizeof(struct htcpld_chip) * htcpld->nchips, 518 GFP_KERNEL); 519 if (!htcpld->chip) { 520 dev_warn(dev, "Unable to allocate memory for chips\n"); 521 return -ENOMEM; 522 } 523 524 /* Add the chips as best we can */ 525 for (i = 0; i < htcpld->nchips; i++) { 526 int ret; 527 528 /* Setup the HTCPLD chips */ 529 htcpld->chip[i].reset = pdata->chip[i].reset; 530 htcpld->chip[i].cache_out = pdata->chip[i].reset; 531 htcpld->chip[i].cache_in = 0; 532 htcpld->chip[i].dev = dev; 533 htcpld->chip[i].irq_start = pdata->chip[i].irq_base; 534 htcpld->chip[i].nirqs = pdata->chip[i].num_irqs; 535 536 INIT_WORK(&(htcpld->chip[i].set_val_work), &htcpld_chip_set_ni); 537 spin_lock_init(&(htcpld->chip[i].lock)); 538 539 /* Setup the interrupts for the chip */ 540 if (htcpld->chained_irq) { 541 ret = htcpld_setup_chip_irq(pdev, i); 542 if (ret) 543 continue; 544 } 545 546 /* Register the chip with I2C */ 547 ret = htcpld_register_chip_i2c(pdev, i); 548 if (ret) 549 continue; 550 551 552 /* Register the chips with the GPIO subsystem */ 553 ret = htcpld_register_chip_gpio(pdev, i); 554 if (ret) { 555 /* Unregister the chip from i2c and continue */ 556 htcpld_unregister_chip_i2c(pdev, i); 557 continue; 558 } 559 560 dev_info(dev, "Registered chip at 0x%x\n", pdata->chip[i].addr); 561 } 562 563 return 0; 564} 565 566static int __devinit htcpld_core_probe(struct platform_device *pdev) 567{ 568 struct htcpld_data *htcpld; 569 struct device *dev = &pdev->dev; 570 struct htcpld_core_platform_data *pdata; 571 struct resource *res; 572 int ret = 0; 573 574 if (!dev) 575 return -ENODEV; 576 577 pdata = dev->platform_data; 578 if (!pdata) { 579 dev_warn(dev, "Platform data not found for htcpld core!\n"); 580 return -ENXIO; 581 } 582 583 htcpld = kzalloc(sizeof(struct htcpld_data), GFP_KERNEL); 584 if (!htcpld) 585 return -ENOMEM; 586 587 /* Find chained irq */ 588 ret = -EINVAL; 589 res = platform_get_resource(pdev, IORESOURCE_IRQ, 0); 590 if (res) { 591 int flags; 592 htcpld->chained_irq = res->start; 593 594 /* Setup the chained interrupt handler */ 595 flags = IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING; 596 ret = request_threaded_irq(htcpld->chained_irq, 597 NULL, htcpld_handler, 598 flags, pdev->name, htcpld); 599 if (ret) { 600 dev_warn(dev, "Unable to setup chained irq handler: %d\n", ret); 601 goto fail; 602 } else 603 device_init_wakeup(dev, 0); 604 } 605 606 /* Set the driver data */ 607 platform_set_drvdata(pdev, htcpld); 608 609 /* Setup the htcpld chips */ 610 ret = htcpld_setup_chips(pdev); 611 if (ret) 612 goto fail; 613 614 /* Request the GPIO(s) for the int reset and set them up */ 615 if (pdata->int_reset_gpio_hi) { 616 ret = gpio_request(pdata->int_reset_gpio_hi, "htcpld-core"); 617 if (ret) { 618 /* 619 * If it failed, that sucks, but we can probably 620 * continue on without it. 621 */ 622 dev_warn(dev, "Unable to request int_reset_gpio_hi -- interrupts may not work\n"); 623 htcpld->int_reset_gpio_hi = 0; 624 } else { 625 htcpld->int_reset_gpio_hi = pdata->int_reset_gpio_hi; 626 gpio_set_value(htcpld->int_reset_gpio_hi, 1); 627 } 628 } 629 630 if (pdata->int_reset_gpio_lo) { 631 ret = gpio_request(pdata->int_reset_gpio_lo, "htcpld-core"); 632 if (ret) { 633 /* 634 * If it failed, that sucks, but we can probably 635 * continue on without it. 636 */ 637 dev_warn(dev, "Unable to request int_reset_gpio_lo -- interrupts may not work\n"); 638 htcpld->int_reset_gpio_lo = 0; 639 } else { 640 htcpld->int_reset_gpio_lo = pdata->int_reset_gpio_lo; 641 gpio_set_value(htcpld->int_reset_gpio_lo, 0); 642 } 643 } 644 645 dev_info(dev, "Initialized successfully\n"); 646 return 0; 647 648fail: 649 kfree(htcpld); 650 return ret; 651} 652 653/* The I2C Driver -- used internally */ 654static const struct i2c_device_id htcpld_chip_id[] = { 655 { "htcpld-chip", 0 }, 656 { } 657}; 658MODULE_DEVICE_TABLE(i2c, htcpld_chip_id); 659 660 661static struct i2c_driver htcpld_chip_driver = { 662 .driver = { 663 .name = "htcpld-chip", 664 }, 665 .id_table = htcpld_chip_id, 666}; 667 668/* The Core Driver */ 669static struct platform_driver htcpld_core_driver = { 670 .driver = { 671 .name = "i2c-htcpld", 672 }, 673}; 674 675static int __init htcpld_core_init(void) 676{ 677 int ret; 678 679 /* Register the I2C Chip driver */ 680 ret = i2c_add_driver(&htcpld_chip_driver); 681 if (ret) 682 return ret; 683 684 /* Probe for our chips */ 685 return platform_driver_probe(&htcpld_core_driver, htcpld_core_probe); 686} 687 688static void __exit htcpld_core_exit(void) 689{ 690 i2c_del_driver(&htcpld_chip_driver); 691 platform_driver_unregister(&htcpld_core_driver); 692} 693 694module_init(htcpld_core_init); 695module_exit(htcpld_core_exit); 696 697MODULE_AUTHOR("Cory Maccarrone <darkstar6262@gmail.com>"); 698MODULE_DESCRIPTION("I2C HTC PLD Driver"); 699MODULE_LICENSE("GPL"); 700 701