drivers/staging/vme/devices/vme_pio2_core.c

   1 /*
   2  * GE PIO2 6U VME I/O Driver
   3  *
   4  * Author: Martyn Welch <martyn.welch@ge.com>
   5  * Copyright 2009 GE Intelligent Platforms Embedded Systems, Inc.
   6  *
   7  * This program is free software; you can redistribute  it and/or modify it
   8  * under  the terms of  the GNU General  Public License as published by the
   9  * Free Software Foundation;  either version 2 of the  License, or (at your
  10  * option) any later version.
  11  */
  12
  13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  14
  15 #include <linux/module.h>
  16 #include <linux/moduleparam.h>
  17 #include <linux/types.h>
  18 #include <linux/kernel.h>
  19 #include <linux/errno.h>
  20 #include <linux/device.h>
  21 #include <linux/ctype.h>
  22 #include <linux/gpio.h>
  23 #include <linux/slab.h>
  24 #include <linux/vme.h>
  25
  26 #include "vme_pio2.h"
  27
  28
  29 static const char driver_name[] = "pio2";
  30
  31 static int bus[PIO2_CARDS_MAX];
  32 static int bus_num;
  33 static long base[PIO2_CARDS_MAX];
  34 static int base_num;
  35 static int vector[PIO2_CARDS_MAX];
  36 static int vector_num;
  37 static int level[PIO2_CARDS_MAX];
  38 static int level_num;
  39 static char *variant[PIO2_CARDS_MAX];
  40 static int variant_num;
  41
  42 static bool loopback;
  43
  44 static int pio2_match(struct vme_dev *);
  45 static int pio2_probe(struct vme_dev *);
  46 static int pio2_remove(struct vme_dev *);
  47
  48 static int pio2_get_led(struct pio2_card *card)
  49 {
  50         /* Can't read hardware, state saved in structure */
  51         return card->led;
  52 }
  53
  54 static int pio2_set_led(struct pio2_card *card, int state)
  55 {
  56         u8 reg;
  57         int retval;
  58
  59         reg = card->irq_level;
  60
  61         /* Register state inverse of led state */
  62         if (!state)
  63                 reg |= PIO2_LED;
  64
  65         if (loopback)
  66                 reg |= PIO2_LOOP;
  67
  68         retval = vme_master_write(card->window, &reg, 1, PIO2_REGS_CTRL);
  69         if (retval < 0)
  70                 return retval;
  71
  72         card->led = state ? 1 : 0;
  73
  74         return 0;
  75 }
  76
  77 static void pio2_int(int level, int vector, void *ptr)
  78 {
  79         int vec, i, channel, retval;
  80         u8 reg;
  81         struct pio2_card *card  = ptr;
  82
  83         vec = vector & ~PIO2_VME_VECTOR_MASK;
  84
  85         switch (vec) {
  86         case 0:
  87                 dev_warn(&card->vdev->dev, "Spurious Interrupt\n");
  88                 break;
  89         case 1:
  90         case 2:
  91         case 3:
  92         case 4:
  93                 /* Channels 0 to 7 */
  94                 retval = vme_master_read(card->window, &reg, 1,
  95                         PIO2_REGS_INT_STAT[vec - 1]);
  96                 if (retval < 0) {
  97                         dev_err(&card->vdev->dev,
  98                                 "Unable to read IRQ status register\n");
  99                         return;
 100                 }
 101                 for (i = 0; i < 8; i++) {
 102                         channel = ((vec - 1) * 8) + i;
 103                         if (reg & PIO2_CHANNEL_BIT[channel])
 104                                 dev_info(&card->vdev->dev,
 105                                         "Interrupt on I/O channel %d\n",
 106                                         channel);
 107                 }
 108                 break;
 109         case 5:
 110         case 6:
 111         case 7:
 112         case 8:
 113         case 9:
 114         case 10:
 115                 /* Counters are dealt with by their own handler */
 116                 dev_err(&card->vdev->dev,
 117                         "Counter interrupt\n");
 118                 break;
 119         }
 120 }
 121
 122
 123 /*
 124  * We return whether this has been successful - this is used in the probe to
 125  * ensure we have a valid card.
 126  */
 127 static int pio2_reset_card(struct pio2_card *card)
 128 {
 129         int retval = 0;
 130         u8 data = 0;
 131
 132         /* Clear main register*/
 133         retval = vme_master_write(card->window, &data, 1, PIO2_REGS_CTRL);
 134         if (retval < 0)
 135                 return retval;
 136
 137         /* Clear VME vector */
 138         retval = vme_master_write(card->window, &data, 1, PIO2_REGS_VME_VECTOR);
 139         if (retval < 0)
 140                 return retval;
 141
 142         /* Reset GPIO */
 143         retval = pio2_gpio_reset(card);
 144         if (retval < 0)
 145                 return retval;
 146
 147         /* Reset counters */
 148         retval = pio2_cntr_reset(card);
 149         if (retval < 0)
 150                 return retval;
 151
 152         return 0;
 153 }
 154
 155 static struct vme_driver pio2_driver = {
 156         .name = driver_name,
 157         .match = pio2_match,
 158         .probe = pio2_probe,
 159         .remove = pio2_remove,
 160 };
 161
 162
 163 static int __init pio2_init(void)
 164 {
 165         if (bus_num == 0) {
 166                 pr_err("No cards, skipping registration\n");
 167                 return -ENODEV;
 168         }
 169
 170         if (bus_num > PIO2_CARDS_MAX) {
 171                 pr_err("Driver only able to handle %d PIO2 Cards\n",
 172                        PIO2_CARDS_MAX);
 173                 bus_num = PIO2_CARDS_MAX;
 174         }
 175
 176         /* Register the PIO2 driver */
 177         return  vme_register_driver(&pio2_driver, bus_num);
 178 }
 179
 180 static int pio2_match(struct vme_dev *vdev)
 181 {
 182
 183         if (vdev->num >= bus_num) {
 184                 dev_err(&vdev->dev,
 185                         "The enumeration of the VMEbus to which the board is connected must be specified");
 186                 return 0;
 187         }
 188
 189         if (vdev->num >= base_num) {
 190                 dev_err(&vdev->dev,
 191                         "The VME address for the cards registers must be specified");
 192                 return 0;
 193         }
 194
 195         if (vdev->num >= vector_num) {
 196                 dev_err(&vdev->dev,
 197                         "The IRQ vector used by the card must be specified");
 198                 return 0;
 199         }
 200
 201         if (vdev->num >= level_num) {
 202                 dev_err(&vdev->dev,
 203                         "The IRQ level used by the card must be specified");
 204                 return 0;
 205         }
 206
 207         if (vdev->num >= variant_num) {
 208                 dev_err(&vdev->dev, "The variant of the card must be specified");
 209                 return 0;
 210         }
 211
 212         return 1;
 213 }
 214
 215 static int pio2_probe(struct vme_dev *vdev)
 216 {
 217         struct pio2_card *card;
 218         int retval;
 219         int i;
 220         u8 reg;
 221         int vec;
 222
 223         card = kzalloc(sizeof(struct pio2_card), GFP_KERNEL);
 224         if (card == NULL) {
 225                 retval = -ENOMEM;
 226                 goto err_struct;
 227         }
 228
 229         card->id = vdev->num;
 230         card->bus = bus[card->id];
 231         card->base = base[card->id];
 232         card->irq_vector = vector[card->id];
 233         card->irq_level = level[card->id] & PIO2_VME_INT_MASK;
 234         strncpy(card->variant, variant[card->id], PIO2_VARIANT_LENGTH);
 235         card->vdev = vdev;
 236
 237         for (i = 0; i < PIO2_VARIANT_LENGTH; i++) {
 238
 239                 if (isdigit(card->variant[i]) == 0) {
 240                         dev_err(&card->vdev->dev, "Variant invalid\n");
 241                         retval = -EINVAL;
 242                         goto err_variant;
 243                 }
 244         }
 245
 246         /*
 247          * Bottom 4 bits of VME interrupt vector used to determine source,
 248          * provided vector should only use upper 4 bits.
 249          */
 250         if (card->irq_vector & ~PIO2_VME_VECTOR_MASK) {
 251                 dev_err(&card->vdev->dev,
 252                         "Invalid VME IRQ Vector, vector must not use lower 4 bits\n");
 253                 retval = -EINVAL;
 254                 goto err_vector;
 255         }
 256
 257         /*
 258          * There is no way to determine the build variant or whether each bank
 259          * is input, output or both at run time. The inputs are also inverted
 260          * if configured as both.
 261          *
 262          * We pass in the board variant and use that to determine the
 263          * configuration of the banks.
 264          */
 265         for (i = 1; i < PIO2_VARIANT_LENGTH; i++) {
 266                 switch (card->variant[i]) {
 267                 case '0':
 268                         card->bank[i-1].config = NOFIT;
 269                         break;
 270                 case '1':
 271                 case '2':
 272                 case '3':
 273                 case '4':
 274                         card->bank[i-1].config = INPUT;
 275                         break;
 276                 case '5':
 277                         card->bank[i-1].config = OUTPUT;
 278                         break;
 279                 case '6':
 280                 case '7':
 281                 case '8':
 282                 case '9':
 283                         card->bank[i-1].config = BOTH;
 284                         break;
 285                 }
 286         }
 287
 288         /* Get a master window and position over regs */
 289         card->window = vme_master_request(vdev, VME_A24, VME_SCT, VME_D16);
 290         if (card->window == NULL) {
 291                 dev_err(&card->vdev->dev,
 292                         "Unable to assign VME master resource\n");
 293                 retval = -EIO;
 294                 goto err_window;
 295         }
 296
 297         retval = vme_master_set(card->window, 1, card->base, 0x10000, VME_A24,
 298                 (VME_SCT | VME_USER | VME_DATA), VME_D16);
 299         if (retval) {
 300                 dev_err(&card->vdev->dev,
 301                         "Unable to configure VME master resource\n");
 302                 goto err_set;
 303         }
 304
 305         /*
 306          * There is also no obvious register which we can probe to determine
 307          * whether the provided base is valid. If we can read the "ID Register"
 308          * offset and the reset function doesn't error, assume we have a valid
 309          * location.
 310          */
 311         retval = vme_master_read(card->window, &reg, 1, PIO2_REGS_ID);
 312         if (retval < 0) {
 313                 dev_err(&card->vdev->dev, "Unable to read from device\n");
 314                 goto err_read;
 315         }
 316
 317         dev_dbg(&card->vdev->dev, "ID Register:%x\n", reg);
 318
 319         /*
 320          * Ensure all the I/O is cleared. We can't read back the states, so
 321          * this is the only method we have to ensure that the I/O is in a known
 322          * state.
 323          */
 324         retval = pio2_reset_card(card);
 325         if (retval) {
 326                 dev_err(&card->vdev->dev,
 327                         "Failed to reset card, is location valid?");
 328                 retval = -ENODEV;
 329                 goto err_reset;
 330         }
 331
 332         /* Configure VME Interrupts */
 333         reg = card->irq_level;
 334         if (pio2_get_led(card))
 335                 reg |= PIO2_LED;
 336         if (loopback)
 337                 reg |= PIO2_LOOP;
 338         retval = vme_master_write(card->window, &reg, 1, PIO2_REGS_CTRL);
 339         if (retval < 0)
 340                 return retval;
 341
 342         /* Set VME vector */
 343         retval = vme_master_write(card->window, &card->irq_vector, 1,
 344                 PIO2_REGS_VME_VECTOR);
 345         if (retval < 0)
 346                 return retval;
 347
 348         /* Attach spurious interrupt handler. */
 349         vec = card->irq_vector | PIO2_VME_VECTOR_SPUR;
 350
 351         retval = vme_irq_request(vdev, card->irq_level, vec,
 352                 &pio2_int, (void *)card);
 353         if (retval < 0) {
 354                 dev_err(&card->vdev->dev,
 355                         "Unable to attach VME interrupt vector0x%x, level 0x%x\n",
 356                          vec, card->irq_level);
 357                 goto err_irq;
 358         }
 359
 360         /* Attach GPIO interrupt handlers. */
 361         for (i = 0; i < 4; i++) {
 362                 vec = card->irq_vector | PIO2_VECTOR_BANK[i];
 363
 364                 retval = vme_irq_request(vdev, card->irq_level, vec,
 365                         &pio2_int, (void *)card);
 366                 if (retval < 0) {
 367                         dev_err(&card->vdev->dev,
 368                                 "Unable to attach VME interrupt vector0x%x, level 0x%x\n",
 369                                  vec, card->irq_level);
 370                         goto err_gpio_irq;
 371                 }
 372         }
 373
 374         /* Attach counter interrupt handlers. */
 375         for (i = 0; i < 6; i++) {
 376                 vec = card->irq_vector | PIO2_VECTOR_CNTR[i];
 377
 378                 retval = vme_irq_request(vdev, card->irq_level, vec,
 379                         &pio2_int, (void *)card);
 380                 if (retval < 0) {
 381                         dev_err(&card->vdev->dev,
 382                                 "Unable to attach VME interrupt vector0x%x, level 0x%x\n",
 383                                 vec, card->irq_level);
 384                         goto err_cntr_irq;
 385                 }
 386         }
 387
 388         /* Register IO */
 389         retval = pio2_gpio_init(card);
 390         if (retval < 0) {
 391                 dev_err(&card->vdev->dev,
 392                         "Unable to register with GPIO framework\n");
 393                 goto err_gpio;
 394         }
 395
 396         /* Set LED - This also sets interrupt level */
 397         retval = pio2_set_led(card, 0);
 398         if (retval < 0) {
 399                 dev_err(&card->vdev->dev, "Unable to set LED\n");
 400                 goto err_led;
 401         }
 402
 403         dev_set_drvdata(&card->vdev->dev, card);
 404
 405         dev_info(&card->vdev->dev,
 406                 "PIO2 (variant %s) configured at 0x%lx\n", card->variant,
 407                 card->base);
 408
 409         return 0;
 410
 411 err_led:
 412         pio2_gpio_exit(card);
 413 err_gpio:
 414         i = 6;
 415 err_cntr_irq:
 416         while (i > 0) {
 417                 i--;
 418                 vec = card->irq_vector | PIO2_VECTOR_CNTR[i];
 419                 vme_irq_free(vdev, card->irq_level, vec);
 420         }
 421
 422         i = 4;
 423 err_gpio_irq:
 424         while (i > 0) {
 425                 i--;
 426                 vec = card->irq_vector | PIO2_VECTOR_BANK[i];
 427                 vme_irq_free(vdev, card->irq_level, vec);
 428         }
 429
 430         vec = (card->irq_vector & PIO2_VME_VECTOR_MASK) | PIO2_VME_VECTOR_SPUR;
 431         vme_irq_free(vdev, card->irq_level, vec);
 432 err_irq:
 433          pio2_reset_card(card);
 434 err_reset:
 435 err_read:
 436         vme_master_set(card->window, 0, 0, 0, VME_A16, 0, VME_D16);
 437 err_set:
 438         vme_master_free(card->window);
 439 err_window:
 440 err_vector:
 441 err_variant:
 442         kfree(card);
 443 err_struct:
 444         return retval;
 445 }
 446
 447 static int pio2_remove(struct vme_dev *vdev)
 448 {
 449         int vec;
 450         int i;
 451
 452         struct pio2_card *card = dev_get_drvdata(&vdev->dev);
 453
 454         pio2_gpio_exit(card);
 455
 456         for (i = 0; i < 6; i++) {
 457                 vec = card->irq_vector | PIO2_VECTOR_CNTR[i];
 458                 vme_irq_free(vdev, card->irq_level, vec);
 459         }
 460
 461         for (i = 0; i < 4; i++) {
 462                 vec = card->irq_vector | PIO2_VECTOR_BANK[i];
 463                 vme_irq_free(vdev, card->irq_level, vec);
 464         }
 465
 466         vec = (card->irq_vector & PIO2_VME_VECTOR_MASK) | PIO2_VME_VECTOR_SPUR;
 467         vme_irq_free(vdev, card->irq_level, vec);
 468
 469         pio2_reset_card(card);
 470
 471         vme_master_set(card->window, 0, 0, 0, VME_A16, 0, VME_D16);
 472
 473         vme_master_free(card->window);
 474
 475         kfree(card);
 476
 477         return 0;
 478 }
 479
 480 static void __exit pio2_exit(void)
 481 {
 482         vme_unregister_driver(&pio2_driver);
 483 }
 484
 485
 486 /* These are required for each board */
 487 MODULE_PARM_DESC(bus, "Enumeration of VMEbus to which the board is connected");
 488 module_param_array(bus, int, &bus_num, S_IRUGO);
 489
 490 MODULE_PARM_DESC(base, "Base VME address for PIO2 Registers");
 491 module_param_array(base, long, &base_num, S_IRUGO);
 492
 493 MODULE_PARM_DESC(vector, "VME IRQ Vector (Lower 4 bits masked)");
 494 module_param_array(vector, int, &vector_num, S_IRUGO);
 495
 496 MODULE_PARM_DESC(level, "VME IRQ Level");
 497 module_param_array(level, int, &level_num, S_IRUGO);
 498
 499 MODULE_PARM_DESC(variant, "Last 4 characters of PIO2 board variant");
 500 module_param_array(variant, charp, &variant_num, S_IRUGO);
 501
 502 /* This is for debugging */
 503 MODULE_PARM_DESC(loopback, "Enable loopback mode on all cards");
 504 module_param(loopback, bool, S_IRUGO);
 505
 506 MODULE_DESCRIPTION("GE PIO2 6U VME I/O Driver");
 507 MODULE_AUTHOR("Martyn Welch <martyn.welch@ge.com");
 508 MODULE_LICENSE("GPL");
 509
 510 module_init(pio2_init);
 511 module_exit(pio2_exit);
 512