arch/powerpc/platforms/52xx/mpc52xx_lpbfifo.c

   1 /*
   2  * LocalPlus Bus FIFO driver for the Freescale MPC52xx.
   3  *
   4  * Copyright (C) 2009 Secret Lab Technologies Ltd.
   5  *
   6  * This file is released under the GPLv2
   7  *
   8  * Todo:
   9  * - Add support for multiple requests to be queued.
  10  */
  11
  12 #include <linux/interrupt.h>
  13 #include <linux/kernel.h>
  14 #include <linux/of.h>
  15 #include <linux/of_platform.h>
  16 #include <linux/spinlock.h>
  17 #include <linux/module.h>
  18 #include <asm/io.h>
  19 #include <asm/prom.h>
  20 #include <asm/mpc52xx.h>
  21 #include <asm/time.h>
  22
  23 #include <linux/fsl/bestcomm/bestcomm.h>
  24 #include <linux/fsl/bestcomm/bestcomm_priv.h>
  25 #include <linux/fsl/bestcomm/gen_bd.h>
  26
  27 MODULE_AUTHOR("Grant Likely <grant.likely@secretlab.ca>");
  28 MODULE_DESCRIPTION("MPC5200 LocalPlus FIFO device driver");
  29 MODULE_LICENSE("GPL");
  30
  31 #define LPBFIFO_REG_PACKET_SIZE         (0x00)
  32 #define LPBFIFO_REG_START_ADDRESS       (0x04)
  33 #define LPBFIFO_REG_CONTROL             (0x08)
  34 #define LPBFIFO_REG_ENABLE              (0x0C)
  35 #define LPBFIFO_REG_BYTES_DONE_STATUS   (0x14)
  36 #define LPBFIFO_REG_FIFO_DATA           (0x40)
  37 #define LPBFIFO_REG_FIFO_STATUS         (0x44)
  38 #define LPBFIFO_REG_FIFO_CONTROL        (0x48)
  39 #define LPBFIFO_REG_FIFO_ALARM          (0x4C)
  40
  41 struct mpc52xx_lpbfifo {
  42         struct device *dev;
  43         phys_addr_t regs_phys;
  44         void __iomem *regs;
  45         int irq;
  46         spinlock_t lock;
  47
  48         struct bcom_task *bcom_tx_task;
  49         struct bcom_task *bcom_rx_task;
  50         struct bcom_task *bcom_cur_task;
  51
  52         /* Current state data */
  53         struct mpc52xx_lpbfifo_request *req;
  54         int dma_irqs_enabled;
  55 };
  56
  57 /* The MPC5200 has only one fifo, so only need one instance structure */
  58 static struct mpc52xx_lpbfifo lpbfifo;
  59
  60 /**
  61  * mpc52xx_lpbfifo_kick - Trigger the next block of data to be transferred
  62  */
  63 static void mpc52xx_lpbfifo_kick(struct mpc52xx_lpbfifo_request *req)
  64 {
  65         size_t transfer_size = req->size - req->pos;
  66         struct bcom_bd *bd;
  67         void __iomem *reg;
  68         u32 *data;
  69         int i;
  70         int bit_fields;
  71         int dma = !(req->flags & MPC52XX_LPBFIFO_FLAG_NO_DMA);
  72         int write = req->flags & MPC52XX_LPBFIFO_FLAG_WRITE;
  73         int poll_dma = req->flags & MPC52XX_LPBFIFO_FLAG_POLL_DMA;
  74
  75         /* Set and clear the reset bits; is good practice in User Manual */
  76         out_be32(lpbfifo.regs + LPBFIFO_REG_ENABLE, 0x01010000);
  77
  78         /* set master enable bit */
  79         out_be32(lpbfifo.regs + LPBFIFO_REG_ENABLE, 0x00000001);
  80         if (!dma) {
  81                 /* While the FIFO can be setup for transfer sizes as large as
  82                  * 16M-1, the FIFO itself is only 512 bytes deep and it does
  83                  * not generate interrupts for FIFO full events (only transfer
  84                  * complete will raise an IRQ).  Therefore when not using
  85                  * Bestcomm to drive the FIFO it needs to either be polled, or
  86                  * transfers need to constrained to the size of the fifo.
  87                  *
  88                  * This driver restricts the size of the transfer
  89                  */
  90                 if (transfer_size > 512)
  91                         transfer_size = 512;
  92
  93                 /* Load the FIFO with data */
  94                 if (write) {
  95                         reg = lpbfifo.regs + LPBFIFO_REG_FIFO_DATA;
  96                         data = req->data + req->pos;
  97                         for (i = 0; i < transfer_size; i += 4)
  98                                 out_be32(reg, *data++);
  99                 }
 100
 101                 /* Unmask both error and completion irqs */
 102                 out_be32(lpbfifo.regs + LPBFIFO_REG_ENABLE, 0x00000301);
 103         } else {
 104                 /* Choose the correct direction
 105                  *
 106                  * Configure the watermarks so DMA will always complete correctly.
 107                  * It may be worth experimenting with the ALARM value to see if
 108                  * there is a performance impacit.  However, if it is wrong there
 109                  * is a risk of DMA not transferring the last chunk of data
 110                  */
 111                 if (write) {
 112                         out_be32(lpbfifo.regs + LPBFIFO_REG_FIFO_ALARM, 0x1e4);
 113                         out_8(lpbfifo.regs + LPBFIFO_REG_FIFO_CONTROL, 7);
 114                         lpbfifo.bcom_cur_task = lpbfifo.bcom_tx_task;
 115                 } else {
 116                         out_be32(lpbfifo.regs + LPBFIFO_REG_FIFO_ALARM, 0x1ff);
 117                         out_8(lpbfifo.regs + LPBFIFO_REG_FIFO_CONTROL, 0);
 118                         lpbfifo.bcom_cur_task = lpbfifo.bcom_rx_task;
 119
 120                         if (poll_dma) {
 121                                 if (lpbfifo.dma_irqs_enabled) {
 122                                         disable_irq(bcom_get_task_irq(lpbfifo.bcom_rx_task));
 123                                         lpbfifo.dma_irqs_enabled = 0;
 124                                 }
 125                         } else {
 126                                 if (!lpbfifo.dma_irqs_enabled) {
 127                                         enable_irq(bcom_get_task_irq(lpbfifo.bcom_rx_task));
 128                                         lpbfifo.dma_irqs_enabled = 1;
 129                                 }
 130                         }
 131                 }
 132
 133                 bd = bcom_prepare_next_buffer(lpbfifo.bcom_cur_task);
 134                 bd->status = transfer_size;
 135                 if (!write) {
 136                         /*
 137                          * In the DMA read case, the DMA doesn't complete,
 138                          * possibly due to incorrect watermarks in the ALARM
 139                          * and CONTROL regs. For now instead of trying to
 140                          * determine the right watermarks that will make this
 141                          * work, just increase the number of bytes the FIFO is
 142                          * expecting.
 143                          *
 144                          * When submitting another operation, the FIFO will get
 145                          * reset, so the condition of the FIFO waiting for a
 146                          * non-existent 4 bytes will get cleared.
 147                          */
 148                         transfer_size += 4; /* BLECH! */
 149                 }
 150                 bd->data[0] = req->data_phys + req->pos;
 151                 bcom_submit_next_buffer(lpbfifo.bcom_cur_task, NULL);
 152
 153                 /* error irq & master enabled bit */
 154                 bit_fields = 0x00000201;
 155
 156                 /* Unmask irqs */
 157                 if (write && (!poll_dma))
 158                         bit_fields |= 0x00000100; /* completion irq too */
 159                 out_be32(lpbfifo.regs + LPBFIFO_REG_ENABLE, bit_fields);
 160         }
 161
 162         /* Set transfer size, width, chip select and READ mode */
 163         out_be32(lpbfifo.regs + LPBFIFO_REG_START_ADDRESS,
 164                  req->offset + req->pos);
 165         out_be32(lpbfifo.regs + LPBFIFO_REG_PACKET_SIZE, transfer_size);
 166
 167         bit_fields = req->cs << 24 | 0x000008;
 168         if (!write)
 169                 bit_fields |= 0x010000; /* read mode */
 170         out_be32(lpbfifo.regs + LPBFIFO_REG_CONTROL, bit_fields);
 171
 172         /* Kick it off */
 173         if (!lpbfifo.req->defer_xfer_start)
 174                 out_8(lpbfifo.regs + LPBFIFO_REG_PACKET_SIZE, 0x01);
 175         if (dma)
 176                 bcom_enable(lpbfifo.bcom_cur_task);
 177 }
 178
 179 /**
 180  * mpc52xx_lpbfifo_irq - IRQ handler for LPB FIFO
 181  *
 182  * On transmit, the dma completion irq triggers before the fifo completion
 183  * triggers.  Handle the dma completion here instead of the LPB FIFO Bestcomm
 184  * task completion irq because everything is not really done until the LPB FIFO
 185  * completion irq triggers.
 186  *
 187  * In other words:
 188  * For DMA, on receive, the "Fat Lady" is the bestcom completion irq. on
 189  * transmit, the fifo completion irq is the "Fat Lady". The opera (or in this
 190  * case the DMA/FIFO operation) is not finished until the "Fat Lady" sings.
 191  *
 192  * Reasons for entering this routine:
 193  * 1) PIO mode rx and tx completion irq
 194  * 2) DMA interrupt mode tx completion irq
 195  * 3) DMA polled mode tx
 196  *
 197  * Exit conditions:
 198  * 1) Transfer aborted
 199  * 2) FIFO complete without DMA; more data to do
 200  * 3) FIFO complete without DMA; all data transferred
 201  * 4) FIFO complete using DMA
 202  *
 203  * Condition 1 can occur regardless of whether or not DMA is used.
 204  * It requires executing the callback to report the error and exiting
 205  * immediately.
 206  *
 207  * Condition 2 requires programming the FIFO with the next block of data
 208  *
 209  * Condition 3 requires executing the callback to report completion
 210  *
 211  * Condition 4 means the same as 3, except that we also retrieve the bcom
 212  * buffer so DMA doesn't get clogged up.
 213  *
 214  * To make things trickier, the spinlock must be dropped before
 215  * executing the callback, otherwise we could end up with a deadlock
 216  * or nested spinlock condition.  The out path is non-trivial, so
 217  * extra fiddling is done to make sure all paths lead to the same
 218  * outbound code.
 219  */
 220 static irqreturn_t mpc52xx_lpbfifo_irq(int irq, void *dev_id)
 221 {
 222         struct mpc52xx_lpbfifo_request *req;
 223         u32 status = in_8(lpbfifo.regs + LPBFIFO_REG_BYTES_DONE_STATUS);
 224         void __iomem *reg;
 225         u32 *data;
 226         int count, i;
 227         int do_callback = 0;
 228         u32 ts;
 229         unsigned long flags;
 230         int dma, write, poll_dma;
 231
 232         spin_lock_irqsave(&lpbfifo.lock, flags);
 233         ts = get_tbl();
 234
 235         req = lpbfifo.req;
 236         if (!req) {
 237                 spin_unlock_irqrestore(&lpbfifo.lock, flags);
 238                 pr_err("bogus LPBFIFO IRQ\n");
 239                 return IRQ_HANDLED;
 240         }
 241
 242         dma = !(req->flags & MPC52XX_LPBFIFO_FLAG_NO_DMA);
 243         write = req->flags & MPC52XX_LPBFIFO_FLAG_WRITE;
 244         poll_dma = req->flags & MPC52XX_LPBFIFO_FLAG_POLL_DMA;
 245
 246         if (dma && !write) {
 247                 spin_unlock_irqrestore(&lpbfifo.lock, flags);
 248                 pr_err("bogus LPBFIFO IRQ (dma and not writing)\n");
 249                 return IRQ_HANDLED;
 250         }
 251
 252         if ((status & 0x01) == 0) {
 253                 goto out;
 254         }
 255
 256         /* check abort bit */
 257         if (status & 0x10) {
 258                 out_be32(lpbfifo.regs + LPBFIFO_REG_ENABLE, 0x01010000);
 259                 do_callback = 1;
 260                 goto out;
 261         }
 262
 263         /* Read result from hardware */
 264         count = in_be32(lpbfifo.regs + LPBFIFO_REG_BYTES_DONE_STATUS);
 265         count &= 0x00ffffff;
 266
 267         if (!dma && !write) {
 268                 /* copy the data out of the FIFO */
 269                 reg = lpbfifo.regs + LPBFIFO_REG_FIFO_DATA;
 270                 data = req->data + req->pos;
 271                 for (i = 0; i < count; i += 4)
 272                         *data++ = in_be32(reg);
 273         }
 274
 275         /* Update transfer position and count */
 276         req->pos += count;
 277
 278         /* Decide what to do next */
 279         if (req->size - req->pos)
 280                 mpc52xx_lpbfifo_kick(req); /* more work to do */
 281         else
 282                 do_callback = 1;
 283
 284  out:
 285         /* Clear the IRQ */
 286         out_8(lpbfifo.regs + LPBFIFO_REG_BYTES_DONE_STATUS, 0x01);
 287
 288         if (dma && (status & 0x11)) {
 289                 /*
 290                  * Count the DMA as complete only when the FIFO completion
 291                  * status or abort bits are set.
 292                  *
 293                  * (status & 0x01) should always be the case except sometimes
 294                  * when using polled DMA.
 295                  *
 296                  * (status & 0x10) {transfer aborted}: This case needs more
 297                  * testing.
 298                  */
 299                 bcom_retrieve_buffer(lpbfifo.bcom_cur_task, &status, NULL);
 300         }
 301         req->last_byte = ((u8 *)req->data)[req->size - 1];
 302
 303         /* When the do_callback flag is set; it means the transfer is finished
 304          * so set the FIFO as idle */
 305         if (do_callback)
 306                 lpbfifo.req = NULL;
 307
 308         if (irq != 0) /* don't increment on polled case */
 309                 req->irq_count++;
 310
 311         req->irq_ticks += get_tbl() - ts;
 312         spin_unlock_irqrestore(&lpbfifo.lock, flags);
 313
 314         /* Spinlock is released; it is now safe to call the callback */
 315         if (do_callback && req->callback)
 316                 req->callback(req);
 317
 318         return IRQ_HANDLED;
 319 }
 320
 321 /**
 322  * mpc52xx_lpbfifo_bcom_irq - IRQ handler for LPB FIFO Bestcomm task
 323  *
 324  * Only used when receiving data.
 325  */
 326 static irqreturn_t mpc52xx_lpbfifo_bcom_irq(int irq, void *dev_id)
 327 {
 328         struct mpc52xx_lpbfifo_request *req;
 329         unsigned long flags;
 330         u32 status;
 331         u32 ts;
 332
 333         spin_lock_irqsave(&lpbfifo.lock, flags);
 334         ts = get_tbl();
 335
 336         req = lpbfifo.req;
 337         if (!req || (req->flags & MPC52XX_LPBFIFO_FLAG_NO_DMA)) {
 338                 spin_unlock_irqrestore(&lpbfifo.lock, flags);
 339                 return IRQ_HANDLED;
 340         }
 341
 342         if (irq != 0) /* don't increment on polled case */
 343                 req->irq_count++;
 344
 345         if (!bcom_buffer_done(lpbfifo.bcom_cur_task)) {
 346                 spin_unlock_irqrestore(&lpbfifo.lock, flags);
 347
 348                 req->buffer_not_done_cnt++;
 349                 if ((req->buffer_not_done_cnt % 1000) == 0)
 350                         pr_err("transfer stalled\n");
 351
 352                 return IRQ_HANDLED;
 353         }
 354
 355         bcom_retrieve_buffer(lpbfifo.bcom_cur_task, &status, NULL);
 356
 357         req->last_byte = ((u8 *)req->data)[req->size - 1];
 358
 359         req->pos = status & 0x00ffffff;
 360
 361         /* Mark the FIFO as idle */
 362         lpbfifo.req = NULL;
 363
 364         /* Release the lock before calling out to the callback. */
 365         req->irq_ticks += get_tbl() - ts;
 366         spin_unlock_irqrestore(&lpbfifo.lock, flags);
 367
 368         if (req->callback)
 369                 req->callback(req);
 370
 371         return IRQ_HANDLED;
 372 }
 373
 374 /**
 375  * mpc52xx_lpbfifo_bcom_poll - Poll for DMA completion
 376  */
 377 void mpc52xx_lpbfifo_poll(void)
 378 {
 379         struct mpc52xx_lpbfifo_request *req = lpbfifo.req;
 380         int dma = !(req->flags & MPC52XX_LPBFIFO_FLAG_NO_DMA);
 381         int write = req->flags & MPC52XX_LPBFIFO_FLAG_WRITE;
 382
 383         /*
 384          * For more information, see comments on the "Fat Lady"
 385          */
 386         if (dma && write)
 387                 mpc52xx_lpbfifo_irq(0, NULL);
 388         else
 389                 mpc52xx_lpbfifo_bcom_irq(0, NULL);
 390 }
 391 EXPORT_SYMBOL(mpc52xx_lpbfifo_poll);
 392
 393 /**
 394  * mpc52xx_lpbfifo_submit - Submit an LPB FIFO transfer request.
 395  * @req: Pointer to request structure
 396  */
 397 int mpc52xx_lpbfifo_submit(struct mpc52xx_lpbfifo_request *req)
 398 {
 399         unsigned long flags;
 400
 401         if (!lpbfifo.regs)
 402                 return -ENODEV;
 403
 404         spin_lock_irqsave(&lpbfifo.lock, flags);
 405
 406         /* If the req pointer is already set, then a transfer is in progress */
 407         if (lpbfifo.req) {
 408                 spin_unlock_irqrestore(&lpbfifo.lock, flags);
 409                 return -EBUSY;
 410         }
 411
 412         /* Setup the transfer */
 413         lpbfifo.req = req;
 414         req->irq_count = 0;
 415         req->irq_ticks = 0;
 416         req->buffer_not_done_cnt = 0;
 417         req->pos = 0;
 418
 419         mpc52xx_lpbfifo_kick(req);
 420         spin_unlock_irqrestore(&lpbfifo.lock, flags);
 421         return 0;
 422 }
 423 EXPORT_SYMBOL(mpc52xx_lpbfifo_submit);
 424
 425 int mpc52xx_lpbfifo_start_xfer(struct mpc52xx_lpbfifo_request *req)
 426 {
 427         unsigned long flags;
 428
 429         if (!lpbfifo.regs)
 430                 return -ENODEV;
 431
 432         spin_lock_irqsave(&lpbfifo.lock, flags);
 433
 434         /*
 435          * If the req pointer is already set and a transfer was
 436          * started on submit, then this transfer is in progress
 437          */
 438         if (lpbfifo.req && !lpbfifo.req->defer_xfer_start) {
 439                 spin_unlock_irqrestore(&lpbfifo.lock, flags);
 440                 return -EBUSY;
 441         }
 442
 443         /*
 444          * If the req was previously submitted but not
 445          * started, start it now
 446          */
 447         if (lpbfifo.req && lpbfifo.req == req &&
 448             lpbfifo.req->defer_xfer_start) {
 449                 out_8(lpbfifo.regs + LPBFIFO_REG_PACKET_SIZE, 0x01);
 450         }
 451
 452         spin_unlock_irqrestore(&lpbfifo.lock, flags);
 453         return 0;
 454 }
 455 EXPORT_SYMBOL(mpc52xx_lpbfifo_start_xfer);
 456
 457 void mpc52xx_lpbfifo_abort(struct mpc52xx_lpbfifo_request *req)
 458 {
 459         unsigned long flags;
 460
 461         spin_lock_irqsave(&lpbfifo.lock, flags);
 462         if (lpbfifo.req == req) {
 463                 /* Put it into reset and clear the state */
 464                 bcom_gen_bd_rx_reset(lpbfifo.bcom_rx_task);
 465                 bcom_gen_bd_tx_reset(lpbfifo.bcom_tx_task);
 466                 out_be32(lpbfifo.regs + LPBFIFO_REG_ENABLE, 0x01010000);
 467                 lpbfifo.req = NULL;
 468         }
 469         spin_unlock_irqrestore(&lpbfifo.lock, flags);
 470 }
 471 EXPORT_SYMBOL(mpc52xx_lpbfifo_abort);
 472
 473 static int mpc52xx_lpbfifo_probe(struct platform_device *op)
 474 {
 475         struct resource res;
 476         int rc = -ENOMEM;
 477
 478         if (lpbfifo.dev != NULL)
 479                 return -ENOSPC;
 480
 481         lpbfifo.irq = irq_of_parse_and_map(op->dev.of_node, 0);
 482         if (!lpbfifo.irq)
 483                 return -ENODEV;
 484
 485         if (of_address_to_resource(op->dev.of_node, 0, &res))
 486                 return -ENODEV;
 487         lpbfifo.regs_phys = res.start;
 488         lpbfifo.regs = of_iomap(op->dev.of_node, 0);
 489         if (!lpbfifo.regs)
 490                 return -ENOMEM;
 491
 492         spin_lock_init(&lpbfifo.lock);
 493
 494         /* Put FIFO into reset */
 495         out_be32(lpbfifo.regs + LPBFIFO_REG_ENABLE, 0x01010000);
 496
 497         /* Register the interrupt handler */
 498         rc = request_irq(lpbfifo.irq, mpc52xx_lpbfifo_irq, 0,
 499                          "mpc52xx-lpbfifo", &lpbfifo);
 500         if (rc)
 501                 goto err_irq;
 502
 503         /* Request the Bestcomm receive (fifo --> memory) task and IRQ */
 504         lpbfifo.bcom_rx_task =
 505                 bcom_gen_bd_rx_init(2, res.start + LPBFIFO_REG_FIFO_DATA,
 506                                     BCOM_INITIATOR_SCLPC, BCOM_IPR_SCLPC,
 507                                     16*1024*1024);
 508         if (!lpbfifo.bcom_rx_task)
 509                 goto err_bcom_rx;
 510
 511         rc = request_irq(bcom_get_task_irq(lpbfifo.bcom_rx_task),
 512                          mpc52xx_lpbfifo_bcom_irq, 0,
 513                          "mpc52xx-lpbfifo-rx", &lpbfifo);
 514         if (rc)
 515                 goto err_bcom_rx_irq;
 516
 517         lpbfifo.dma_irqs_enabled = 1;
 518
 519         /* Request the Bestcomm transmit (memory --> fifo) task and IRQ */
 520         lpbfifo.bcom_tx_task =
 521                 bcom_gen_bd_tx_init(2, res.start + LPBFIFO_REG_FIFO_DATA,
 522                                     BCOM_INITIATOR_SCLPC, BCOM_IPR_SCLPC);
 523         if (!lpbfifo.bcom_tx_task)
 524                 goto err_bcom_tx;
 525
 526         lpbfifo.dev = &op->dev;
 527         return 0;
 528
 529  err_bcom_tx:
 530         free_irq(bcom_get_task_irq(lpbfifo.bcom_rx_task), &lpbfifo);
 531  err_bcom_rx_irq:
 532         bcom_gen_bd_rx_release(lpbfifo.bcom_rx_task);
 533  err_bcom_rx:
 534  err_irq:
 535         iounmap(lpbfifo.regs);
 536         lpbfifo.regs = NULL;
 537
 538         dev_err(&op->dev, "mpc52xx_lpbfifo_probe() failed\n");
 539         return -ENODEV;
 540 }
 541
 542
 543 static int mpc52xx_lpbfifo_remove(struct platform_device *op)
 544 {
 545         if (lpbfifo.dev != &op->dev)
 546                 return 0;
 547
 548         /* Put FIFO in reset */
 549         out_be32(lpbfifo.regs + LPBFIFO_REG_ENABLE, 0x01010000);
 550
 551         /* Release the bestcomm transmit task */
 552         free_irq(bcom_get_task_irq(lpbfifo.bcom_tx_task), &lpbfifo);
 553         bcom_gen_bd_tx_release(lpbfifo.bcom_tx_task);
 554
 555         /* Release the bestcomm receive task */
 556         free_irq(bcom_get_task_irq(lpbfifo.bcom_rx_task), &lpbfifo);
 557         bcom_gen_bd_rx_release(lpbfifo.bcom_rx_task);
 558
 559         free_irq(lpbfifo.irq, &lpbfifo);
 560         iounmap(lpbfifo.regs);
 561         lpbfifo.regs = NULL;
 562         lpbfifo.dev = NULL;
 563
 564         return 0;
 565 }
 566
 567 static const struct of_device_id mpc52xx_lpbfifo_match[] = {
 568         { .compatible = "fsl,mpc5200-lpbfifo", },
 569         {},
 570 };
 571 MODULE_DEVICE_TABLE(of, mpc52xx_lpbfifo_match);
 572
 573 static struct platform_driver mpc52xx_lpbfifo_driver = {
 574         .driver = {
 575                 .name = "mpc52xx-lpbfifo",
 576                 .of_match_table = mpc52xx_lpbfifo_match,
 577         },
 578         .probe = mpc52xx_lpbfifo_probe,
 579         .remove = mpc52xx_lpbfifo_remove,
 580 };
 581 module_platform_driver(mpc52xx_lpbfifo_driver);