r592.c 21.3 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896
/*
 * Copyright (C) 2010 - Maxim Levitsky
 * driver for Ricoh memstick readers
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/freezer.h>
#include <linux/jiffies.h>
#include <linux/interrupt.h>
#include <linux/pci.h>
#include <linux/pci_ids.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/kthread.h>
#include <linux/sched.h>
#include <linux/highmem.h>
#include <asm/byteorder.h>
#include <linux/swab.h>
#include "r592.h"

static bool r592_enable_dma = 1;
static int debug;

static const char *tpc_names[] = {
	"MS_TPC_READ_MG_STATUS",
	"MS_TPC_READ_LONG_DATA",
	"MS_TPC_READ_SHORT_DATA",
	"MS_TPC_READ_REG",
	"MS_TPC_READ_QUAD_DATA",
	"INVALID",
	"MS_TPC_GET_INT",
	"MS_TPC_SET_RW_REG_ADRS",
	"MS_TPC_EX_SET_CMD",
	"MS_TPC_WRITE_QUAD_DATA",
	"MS_TPC_WRITE_REG",
	"MS_TPC_WRITE_SHORT_DATA",
	"MS_TPC_WRITE_LONG_DATA",
	"MS_TPC_SET_CMD",
};

/**
 * memstick_debug_get_tpc_name - debug helper that returns string for
 * a TPC number
 */
const char *memstick_debug_get_tpc_name(int tpc)
{
	return tpc_names[tpc-1];
}
EXPORT_SYMBOL(memstick_debug_get_tpc_name);


/* Read a register*/
static inline u32 r592_read_reg(struct r592_device *dev, int address)
{
	u32 value = readl(dev->mmio + address);
	dbg_reg("reg #%02d == 0x%08x", address, value);
	return value;
}

/* Write a register */
static inline void r592_write_reg(struct r592_device *dev,
							int address, u32 value)
{
	dbg_reg("reg #%02d <- 0x%08x", address, value);
	writel(value, dev->mmio + address);
}

/* Reads a big endian DWORD register */
static inline u32 r592_read_reg_raw_be(struct r592_device *dev, int address)
{
	u32 value = __raw_readl(dev->mmio + address);
	dbg_reg("reg #%02d == 0x%08x", address, value);
	return be32_to_cpu(value);
}

/* Writes a big endian DWORD register */
static inline void r592_write_reg_raw_be(struct r592_device *dev,
							int address, u32 value)
{
	dbg_reg("reg #%02d <- 0x%08x", address, value);
	__raw_writel(cpu_to_be32(value), dev->mmio + address);
}

/* Set specific bits in a register (little endian) */
static inline void r592_set_reg_mask(struct r592_device *dev,
							int address, u32 mask)
{
	u32 reg = readl(dev->mmio + address);
	dbg_reg("reg #%02d |= 0x%08x (old =0x%08x)", address, mask, reg);
	writel(reg | mask , dev->mmio + address);
}

/* Clear specific bits in a register (little endian) */
static inline void r592_clear_reg_mask(struct r592_device *dev,
						int address, u32 mask)
{
	u32 reg = readl(dev->mmio + address);
	dbg_reg("reg #%02d &= 0x%08x (old = 0x%08x, mask = 0x%08x)",
						address, ~mask, reg, mask);
	writel(reg & ~mask, dev->mmio + address);
}


/* Wait for status bits while checking for errors */
static int r592_wait_status(struct r592_device *dev, u32 mask, u32 wanted_mask)
{
	unsigned long timeout = jiffies + msecs_to_jiffies(1000);
	u32 reg = r592_read_reg(dev, R592_STATUS);

	if ((reg & mask) == wanted_mask)
		return 0;

	while (time_before(jiffies, timeout)) {

		reg = r592_read_reg(dev, R592_STATUS);

		if ((reg & mask) == wanted_mask)
			return 0;

		if (reg & (R592_STATUS_SEND_ERR | R592_STATUS_RECV_ERR))
			return -EIO;

		cpu_relax();
	}
	return -ETIME;
}


/* Enable/disable device */
static int r592_enable_device(struct r592_device *dev, bool enable)
{
	dbg("%sabling the device", enable ? "en" : "dis");

	if (enable) {

		/* Power up the card */
		r592_write_reg(dev, R592_POWER, R592_POWER_0 | R592_POWER_1);

		/* Perform a reset */
		r592_set_reg_mask(dev, R592_IO, R592_IO_RESET);

		msleep(100);
	} else
		/* Power down the card */
		r592_write_reg(dev, R592_POWER, 0);

	return 0;
}

/* Set serial/parallel mode */
static int r592_set_mode(struct r592_device *dev, bool parallel_mode)
{
	if (!parallel_mode) {
		dbg("switching to serial mode");

		/* Set serial mode */
		r592_write_reg(dev, R592_IO_MODE, R592_IO_MODE_SERIAL);

		r592_clear_reg_mask(dev, R592_POWER, R592_POWER_20);

	} else {
		dbg("switching to parallel mode");

		/* This setting should be set _before_ switch TPC */
		r592_set_reg_mask(dev, R592_POWER, R592_POWER_20);

		r592_clear_reg_mask(dev, R592_IO,
			R592_IO_SERIAL1 | R592_IO_SERIAL2);

		/* Set the parallel mode now */
		r592_write_reg(dev, R592_IO_MODE, R592_IO_MODE_PARALLEL);
	}

	dev->parallel_mode = parallel_mode;
	return 0;
}

/* Perform a controller reset without powering down the card */
static void r592_host_reset(struct r592_device *dev)
{
	r592_set_reg_mask(dev, R592_IO, R592_IO_RESET);
	msleep(100);
	r592_set_mode(dev, dev->parallel_mode);
}

/* Disable all hardware interrupts */
static void r592_clear_interrupts(struct r592_device *dev)
{
	/* Disable & ACK all interrupts */
	r592_clear_reg_mask(dev, R592_REG_MSC, IRQ_ALL_ACK_MASK);
	r592_clear_reg_mask(dev, R592_REG_MSC, IRQ_ALL_EN_MASK);
}

/* Tests if there is an CRC error */
static int r592_test_io_error(struct r592_device *dev)
{
	if (!(r592_read_reg(dev, R592_STATUS) &
		(R592_STATUS_SEND_ERR | R592_STATUS_RECV_ERR)))
		return 0;

	return -EIO;
}

/* Ensure that FIFO is ready for use */
static int r592_test_fifo_empty(struct r592_device *dev)
{
	if (r592_read_reg(dev, R592_REG_MSC) & R592_REG_MSC_FIFO_EMPTY)
		return 0;

	dbg("FIFO not ready, trying to reset the device");
	r592_host_reset(dev);

	if (r592_read_reg(dev, R592_REG_MSC) & R592_REG_MSC_FIFO_EMPTY)
		return 0;

	message("FIFO still not ready, giving up");
	return -EIO;
}

/* Activates the DMA transfer from to FIFO */
static void r592_start_dma(struct r592_device *dev, bool is_write)
{
	unsigned long flags;
	u32 reg;
	spin_lock_irqsave(&dev->irq_lock, flags);

	/* Ack interrupts (just in case) + enable them */
	r592_clear_reg_mask(dev, R592_REG_MSC, DMA_IRQ_ACK_MASK);
	r592_set_reg_mask(dev, R592_REG_MSC, DMA_IRQ_EN_MASK);

	/* Set DMA address */
	r592_write_reg(dev, R592_FIFO_DMA, sg_dma_address(&dev->req->sg));

	/* Enable the DMA */
	reg = r592_read_reg(dev, R592_FIFO_DMA_SETTINGS);
	reg |= R592_FIFO_DMA_SETTINGS_EN;

	if (!is_write)
		reg |= R592_FIFO_DMA_SETTINGS_DIR;
	else
		reg &= ~R592_FIFO_DMA_SETTINGS_DIR;
	r592_write_reg(dev, R592_FIFO_DMA_SETTINGS, reg);

	spin_unlock_irqrestore(&dev->irq_lock, flags);
}

/* Cleanups DMA related settings */
static void r592_stop_dma(struct r592_device *dev, int error)
{
	r592_clear_reg_mask(dev, R592_FIFO_DMA_SETTINGS,
		R592_FIFO_DMA_SETTINGS_EN);

	/* This is only a precation */
	r592_write_reg(dev, R592_FIFO_DMA,
			dev->dummy_dma_page_physical_address);

	r592_clear_reg_mask(dev, R592_REG_MSC, DMA_IRQ_EN_MASK);
	r592_clear_reg_mask(dev, R592_REG_MSC, DMA_IRQ_ACK_MASK);
	dev->dma_error = error;
}

/* Test if hardware supports DMA */
static void r592_check_dma(struct r592_device *dev)
{
	dev->dma_capable = r592_enable_dma &&
		(r592_read_reg(dev, R592_FIFO_DMA_SETTINGS) &
			R592_FIFO_DMA_SETTINGS_CAP);
}

/* Transfers fifo contents in/out using DMA */
static int r592_transfer_fifo_dma(struct r592_device *dev)
{
	int len, sg_count;
	bool is_write;

	if (!dev->dma_capable || !dev->req->long_data)
		return -EINVAL;

	len = dev->req->sg.length;
	is_write = dev->req->data_dir == WRITE;

	if (len != R592_LFIFO_SIZE)
		return -EINVAL;

	dbg_verbose("doing dma transfer");

	dev->dma_error = 0;
	reinit_completion(&dev->dma_done);

	/* TODO: hidden assumption about nenth beeing always 1 */
	sg_count = dma_map_sg(&dev->pci_dev->dev, &dev->req->sg, 1, is_write ?
		PCI_DMA_TODEVICE : PCI_DMA_FROMDEVICE);

	if (sg_count != 1 ||
			(sg_dma_len(&dev->req->sg) < dev->req->sg.length)) {
		message("problem in dma_map_sg");
		return -EIO;
	}

	r592_start_dma(dev, is_write);

	/* Wait for DMA completion */
	if (!wait_for_completion_timeout(
			&dev->dma_done, msecs_to_jiffies(1000))) {
		message("DMA timeout");
		r592_stop_dma(dev, -ETIMEDOUT);
	}

	dma_unmap_sg(&dev->pci_dev->dev, &dev->req->sg, 1, is_write ?
		PCI_DMA_TODEVICE : PCI_DMA_FROMDEVICE);


	return dev->dma_error;
}

/*
 * Writes the FIFO in 4 byte chunks.
 * If length isn't 4 byte aligned, rest of the data if put to a fifo
 * to be written later
 * Use r592_flush_fifo_write to flush that fifo when writing for the
 * last time
 */
static void r592_write_fifo_pio(struct r592_device *dev,
					unsigned char *buffer, int len)
{
	/* flush spill from former write */
	if (!kfifo_is_empty(&dev->pio_fifo)) {

		u8 tmp[4] = {0};
		int copy_len = kfifo_in(&dev->pio_fifo, buffer, len);

		if (!kfifo_is_full(&dev->pio_fifo))
			return;
		len -= copy_len;
		buffer += copy_len;

		copy_len = kfifo_out(&dev->pio_fifo, tmp, 4);
		WARN_ON(copy_len != 4);
		r592_write_reg_raw_be(dev, R592_FIFO_PIO, *(u32 *)tmp);
	}

	WARN_ON(!kfifo_is_empty(&dev->pio_fifo));

	/* write full dwords */
	while (len >= 4) {
		r592_write_reg_raw_be(dev, R592_FIFO_PIO, *(u32 *)buffer);
		buffer += 4;
		len -= 4;
	}

	/* put remaining bytes to the spill */
	if (len)
		kfifo_in(&dev->pio_fifo, buffer, len);
}

/* Flushes the temporary FIFO used to make aligned DWORD writes */
static void r592_flush_fifo_write(struct r592_device *dev)
{
	u8 buffer[4] = { 0 };
	int len;

	if (kfifo_is_empty(&dev->pio_fifo))
		return;

	len = kfifo_out(&dev->pio_fifo, buffer, 4);
	r592_write_reg_raw_be(dev, R592_FIFO_PIO, *(u32 *)buffer);
}

/*
 * Read a fifo in 4 bytes chunks.
 * If input doesn't fit the buffer, it places bytes of last dword in spill
 * buffer, so that they don't get lost on last read, just throw these away.
 */
static void r592_read_fifo_pio(struct r592_device *dev,
						unsigned char *buffer, int len)
{
	u8 tmp[4];

	/* Read from last spill */
	if (!kfifo_is_empty(&dev->pio_fifo)) {
		int bytes_copied =
			kfifo_out(&dev->pio_fifo, buffer, min(4, len));
		buffer += bytes_copied;
		len -= bytes_copied;

		if (!kfifo_is_empty(&dev->pio_fifo))
			return;
	}

	/* Reads dwords from FIFO */
	while (len >= 4) {
		*(u32 *)buffer = r592_read_reg_raw_be(dev, R592_FIFO_PIO);
		buffer += 4;
		len -= 4;
	}

	if (len) {
		*(u32 *)tmp = r592_read_reg_raw_be(dev, R592_FIFO_PIO);
		kfifo_in(&dev->pio_fifo, tmp, 4);
		len -= kfifo_out(&dev->pio_fifo, buffer, len);
	}

	WARN_ON(len);
	return;
}

/* Transfers actual data using PIO. */
static int r592_transfer_fifo_pio(struct r592_device *dev)
{
	unsigned long flags;

	bool is_write = dev->req->tpc >= MS_TPC_SET_RW_REG_ADRS;
	struct sg_mapping_iter miter;

	kfifo_reset(&dev->pio_fifo);

	if (!dev->req->long_data) {
		if (is_write) {
			r592_write_fifo_pio(dev, dev->req->data,
							dev->req->data_len);
			r592_flush_fifo_write(dev);
		} else
			r592_read_fifo_pio(dev, dev->req->data,
							dev->req->data_len);
		return 0;
	}

	local_irq_save(flags);
	sg_miter_start(&miter, &dev->req->sg, 1, SG_MITER_ATOMIC |
		(is_write ? SG_MITER_FROM_SG : SG_MITER_TO_SG));

	/* Do the transfer fifo<->memory*/
	while (sg_miter_next(&miter))
		if (is_write)
			r592_write_fifo_pio(dev, miter.addr, miter.length);
		else
			r592_read_fifo_pio(dev, miter.addr, miter.length);


	/* Write last few non aligned bytes*/
	if (is_write)
		r592_flush_fifo_write(dev);

	sg_miter_stop(&miter);
	local_irq_restore(flags);
	return 0;
}

/* Executes one TPC (data is read/written from small or large fifo) */
static void r592_execute_tpc(struct r592_device *dev)
{
	bool is_write;
	int len, error;
	u32 status, reg;

	if (!dev->req) {
		message("BUG: tpc execution without request!");
		return;
	}

	is_write = dev->req->tpc >= MS_TPC_SET_RW_REG_ADRS;
	len = dev->req->long_data ?
		dev->req->sg.length : dev->req->data_len;

	/* Ensure that FIFO can hold the input data */
	if (len > R592_LFIFO_SIZE) {
		message("IO: hardware doesn't support TPCs longer that 512");
		error = -ENOSYS;
		goto out;
	}

	if (!(r592_read_reg(dev, R592_REG_MSC) & R592_REG_MSC_PRSNT)) {
		dbg("IO: refusing to send TPC because card is absent");
		error = -ENODEV;
		goto out;
	}

	dbg("IO: executing %s LEN=%d",
			memstick_debug_get_tpc_name(dev->req->tpc), len);

	/* Set IO direction */
	if (is_write)
		r592_set_reg_mask(dev, R592_IO, R592_IO_DIRECTION);
	else
		r592_clear_reg_mask(dev, R592_IO, R592_IO_DIRECTION);


	error = r592_test_fifo_empty(dev);
	if (error)
		goto out;

	/* Transfer write data */
	if (is_write) {
		error = r592_transfer_fifo_dma(dev);
		if (error == -EINVAL)
			error = r592_transfer_fifo_pio(dev);
	}

	if (error)
		goto out;

	/* Trigger the TPC */
	reg = (len << R592_TPC_EXEC_LEN_SHIFT) |
		(dev->req->tpc << R592_TPC_EXEC_TPC_SHIFT) |
			R592_TPC_EXEC_BIG_FIFO;

	r592_write_reg(dev, R592_TPC_EXEC, reg);

	/* Wait for TPC completion */
	status = R592_STATUS_RDY;
	if (dev->req->need_card_int)
		status |= R592_STATUS_CED;

	error = r592_wait_status(dev, status, status);
	if (error) {
		message("card didn't respond");
		goto out;
	}

	/* Test IO errors */
	error = r592_test_io_error(dev);
	if (error) {
		dbg("IO error");
		goto out;
	}

	/* Read data from FIFO */
	if (!is_write) {
		error = r592_transfer_fifo_dma(dev);
		if (error == -EINVAL)
			error = r592_transfer_fifo_pio(dev);
	}

	/* read INT reg. This can be shortened with shifts, but that way
		its more readable */
	if (dev->parallel_mode && dev->req->need_card_int) {

		dev->req->int_reg = 0;
		status = r592_read_reg(dev, R592_STATUS);

		if (status & R592_STATUS_P_CMDNACK)
			dev->req->int_reg |= MEMSTICK_INT_CMDNAK;
		if (status & R592_STATUS_P_BREQ)
			dev->req->int_reg |= MEMSTICK_INT_BREQ;
		if (status & R592_STATUS_P_INTERR)
			dev->req->int_reg |= MEMSTICK_INT_ERR;
		if (status & R592_STATUS_P_CED)
			dev->req->int_reg |= MEMSTICK_INT_CED;
	}

	if (error)
		dbg("FIFO read error");
out:
	dev->req->error = error;
	r592_clear_reg_mask(dev, R592_REG_MSC, R592_REG_MSC_LED);
	return;
}

/* Main request processing thread */
static int r592_process_thread(void *data)
{
	int error;
	struct r592_device *dev = (struct r592_device *)data;
	unsigned long flags;

	while (!kthread_should_stop()) {
		spin_lock_irqsave(&dev->io_thread_lock, flags);
		set_current_state(TASK_INTERRUPTIBLE);
		error = memstick_next_req(dev->host, &dev->req);
		spin_unlock_irqrestore(&dev->io_thread_lock, flags);

		if (error) {
			if (error == -ENXIO || error == -EAGAIN) {
				dbg_verbose("IO: done IO, sleeping");
			} else {
				dbg("IO: unknown error from "
					"memstick_next_req %d", error);
			}

			if (kthread_should_stop())
				set_current_state(TASK_RUNNING);

			schedule();
		} else {
			set_current_state(TASK_RUNNING);
			r592_execute_tpc(dev);
		}
	}
	return 0;
}

/* Reprogram chip to detect change in card state */
/* eg, if card is detected, arm it to detect removal, and vice versa */
static void r592_update_card_detect(struct r592_device *dev)
{
	u32 reg = r592_read_reg(dev, R592_REG_MSC);
	bool card_detected = reg & R592_REG_MSC_PRSNT;

	dbg("update card detect. card state: %s", card_detected ?
		"present" : "absent");

	reg &= ~((R592_REG_MSC_IRQ_REMOVE | R592_REG_MSC_IRQ_INSERT) << 16);

	if (card_detected)
		reg |= (R592_REG_MSC_IRQ_REMOVE << 16);
	else
		reg |= (R592_REG_MSC_IRQ_INSERT << 16);

	r592_write_reg(dev, R592_REG_MSC, reg);
}

/* Timer routine that fires 1 second after last card detection event, */
static void r592_detect_timer(long unsigned int data)
{
	struct r592_device *dev = (struct r592_device *)data;
	r592_update_card_detect(dev);
	memstick_detect_change(dev->host);
}

/* Interrupt handler */
static irqreturn_t r592_irq(int irq, void *data)
{
	struct r592_device *dev = (struct r592_device *)data;
	irqreturn_t ret = IRQ_NONE;
	u32 reg;
	u16 irq_enable, irq_status;
	unsigned long flags;
	int error;

	spin_lock_irqsave(&dev->irq_lock, flags);

	reg = r592_read_reg(dev, R592_REG_MSC);
	irq_enable = reg >> 16;
	irq_status = reg & 0xFFFF;

	/* Ack the interrupts */
	reg &= ~irq_status;
	r592_write_reg(dev, R592_REG_MSC, reg);

	/* Get the IRQ status minus bits that aren't enabled */
	irq_status &= (irq_enable);

	/* Due to limitation of memstick core, we don't look at bits that
		indicate that card was removed/inserted and/or present */
	if (irq_status & (R592_REG_MSC_IRQ_INSERT | R592_REG_MSC_IRQ_REMOVE)) {

		bool card_was_added = irq_status & R592_REG_MSC_IRQ_INSERT;
		ret = IRQ_HANDLED;

		message("IRQ: card %s", card_was_added ? "added" : "removed");

		mod_timer(&dev->detect_timer,
			jiffies + msecs_to_jiffies(card_was_added ? 500 : 50));
	}

	if (irq_status &
		(R592_REG_MSC_FIFO_DMA_DONE | R592_REG_MSC_FIFO_DMA_ERR)) {
		ret = IRQ_HANDLED;

		if (irq_status & R592_REG_MSC_FIFO_DMA_ERR) {
			message("IRQ: DMA error");
			error = -EIO;
		} else {
			dbg_verbose("IRQ: dma done");
			error = 0;
		}

		r592_stop_dma(dev, error);
		complete(&dev->dma_done);
	}

	spin_unlock_irqrestore(&dev->irq_lock, flags);
	return ret;
}

/* External inteface: set settings */
static int r592_set_param(struct memstick_host *host,
			enum memstick_param param, int value)
{
	struct r592_device *dev = memstick_priv(host);

	switch (param) {
	case MEMSTICK_POWER:
		switch (value) {
		case MEMSTICK_POWER_ON:
			return r592_enable_device(dev, true);
		case MEMSTICK_POWER_OFF:
			return r592_enable_device(dev, false);
		default:
			return -EINVAL;
		}
	case MEMSTICK_INTERFACE:
		switch (value) {
		case MEMSTICK_SERIAL:
			return r592_set_mode(dev, 0);
		case MEMSTICK_PAR4:
			return r592_set_mode(dev, 1);
		default:
			return -EINVAL;
		}
	default:
		return -EINVAL;
	}
}

/* External interface: submit requests */
static void r592_submit_req(struct memstick_host *host)
{
	struct r592_device *dev = memstick_priv(host);
	unsigned long flags;

	if (dev->req)
		return;

	spin_lock_irqsave(&dev->io_thread_lock, flags);
	if (wake_up_process(dev->io_thread))
		dbg_verbose("IO thread woken to process requests");
	spin_unlock_irqrestore(&dev->io_thread_lock, flags);
}

static const struct pci_device_id r592_pci_id_tbl[] = {

	{ PCI_VDEVICE(RICOH, 0x0592), },
	{ },
};

/* Main entry */
static int r592_probe(struct pci_dev *pdev, const struct pci_device_id *id)
{
	int error = -ENOMEM;
	struct memstick_host *host;
	struct r592_device *dev;

	/* Allocate memory */
	host = memstick_alloc_host(sizeof(struct r592_device), &pdev->dev);
	if (!host)
		goto error1;

	dev = memstick_priv(host);
	dev->host = host;
	dev->pci_dev = pdev;
	pci_set_drvdata(pdev, dev);

	/* pci initialization */
	error = pci_enable_device(pdev);
	if (error)
		goto error2;

	pci_set_master(pdev);
	error = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
	if (error)
		goto error3;

	error = pci_request_regions(pdev, DRV_NAME);
	if (error)
		goto error3;

	dev->mmio = pci_ioremap_bar(pdev, 0);
	if (!dev->mmio)
		goto error4;

	dev->irq = pdev->irq;
	spin_lock_init(&dev->irq_lock);
	spin_lock_init(&dev->io_thread_lock);
	init_completion(&dev->dma_done);
	INIT_KFIFO(dev->pio_fifo);
	setup_timer(&dev->detect_timer,
		r592_detect_timer, (long unsigned int)dev);

	/* Host initialization */
	host->caps = MEMSTICK_CAP_PAR4;
	host->request = r592_submit_req;
	host->set_param = r592_set_param;
	r592_check_dma(dev);

	dev->io_thread = kthread_run(r592_process_thread, dev, "r592_io");
	if (IS_ERR(dev->io_thread)) {
		error = PTR_ERR(dev->io_thread);
		goto error5;
	}

	/* This is just a precation, so don't fail */
	dev->dummy_dma_page = pci_alloc_consistent(pdev, PAGE_SIZE,
		&dev->dummy_dma_page_physical_address);
	r592_stop_dma(dev , 0);

	if (request_irq(dev->irq, &r592_irq, IRQF_SHARED,
			  DRV_NAME, dev))
		goto error6;

	r592_update_card_detect(dev);
	if (memstick_add_host(host))
		goto error7;

	message("driver successfully loaded");
	return 0;
error7:
	free_irq(dev->irq, dev);
error6:
	if (dev->dummy_dma_page)
		pci_free_consistent(pdev, PAGE_SIZE, dev->dummy_dma_page,
			dev->dummy_dma_page_physical_address);

	kthread_stop(dev->io_thread);
error5:
	iounmap(dev->mmio);
error4:
	pci_release_regions(pdev);
error3:
	pci_disable_device(pdev);
error2:
	memstick_free_host(host);
error1:
	return error;
}

static void r592_remove(struct pci_dev *pdev)
{
	int error = 0;
	struct r592_device *dev = pci_get_drvdata(pdev);

	/* Stop the processing thread.
	That ensures that we won't take any more requests */
	kthread_stop(dev->io_thread);

	r592_enable_device(dev, false);

	while (!error && dev->req) {
		dev->req->error = -ETIME;
		error = memstick_next_req(dev->host, &dev->req);
	}
	memstick_remove_host(dev->host);

	free_irq(dev->irq, dev);
	iounmap(dev->mmio);
	pci_release_regions(pdev);
	pci_disable_device(pdev);
	memstick_free_host(dev->host);

	if (dev->dummy_dma_page)
		pci_free_consistent(pdev, PAGE_SIZE, dev->dummy_dma_page,
			dev->dummy_dma_page_physical_address);
}

#ifdef CONFIG_PM_SLEEP
static int r592_suspend(struct device *core_dev)
{
	struct pci_dev *pdev = to_pci_dev(core_dev);
	struct r592_device *dev = pci_get_drvdata(pdev);

	r592_clear_interrupts(dev);
	memstick_suspend_host(dev->host);
	del_timer_sync(&dev->detect_timer);
	return 0;
}

static int r592_resume(struct device *core_dev)
{
	struct pci_dev *pdev = to_pci_dev(core_dev);
	struct r592_device *dev = pci_get_drvdata(pdev);

	r592_clear_interrupts(dev);
	r592_enable_device(dev, false);
	memstick_resume_host(dev->host);
	r592_update_card_detect(dev);
	return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(r592_pm_ops, r592_suspend, r592_resume);

MODULE_DEVICE_TABLE(pci, r592_pci_id_tbl);

static struct pci_driver r852_pci_driver = {
	.name		= DRV_NAME,
	.id_table	= r592_pci_id_tbl,
	.probe		= r592_probe,
	.remove		= r592_remove,
	.driver.pm	= &r592_pm_ops,
};

module_pci_driver(r852_pci_driver);

module_param_named(enable_dma, r592_enable_dma, bool, S_IRUGO);
MODULE_PARM_DESC(enable_dma, "Enable usage of the DMA (default)");
module_param(debug, int, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(debug, "Debug level (0-3)");

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Maxim Levitsky <maximlevitsky@gmail.com>");
MODULE_DESCRIPTION("Ricoh R5C592 Memstick/Memstick PRO card reader driver");