/drivers/mmc/host/atmel-mci.c

   1/*
   2 * Atmel MultiMedia Card Interface driver
   3 *
   4 * Copyright (C) 2004-2008 Atmel Corporation
   5 *
   6 * This program is free software; you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License version 2 as
   8 * published by the Free Software Foundation.
   9 */
  10#include <linux/blkdev.h>
  11#include <linux/clk.h>
  12#include <linux/debugfs.h>
  13#include <linux/device.h>
  14#include <linux/dmaengine.h>
  15#include <linux/dma-mapping.h>
  16#include <linux/err.h>
  17#include <linux/gpio.h>
  18#include <linux/init.h>
  19#include <linux/interrupt.h>
  20#include <linux/ioport.h>
  21#include <linux/module.h>
  22#include <linux/platform_device.h>
  23#include <linux/scatterlist.h>
  24#include <linux/seq_file.h>
  25#include <linux/slab.h>
  26#include <linux/stat.h>
  27
  28#include <linux/mmc/host.h>
  29#include <linux/mmc/sdio.h>
  30
  31#include <mach/atmel-mci.h>
  32#include <linux/atmel-mci.h>
  33
  34#include <asm/io.h>
  35#include <asm/unaligned.h>
  36
  37#include <mach/cpu.h>
  38#include <mach/board.h>
  39
  40#include "atmel-mci-regs.h"
  41
  42#define ATMCI_DATA_ERROR_FLAGS	(MCI_DCRCE | MCI_DTOE | MCI_OVRE | MCI_UNRE)
  43#define ATMCI_DMA_THRESHOLD	16
  44
  45enum {
  46	EVENT_CMD_COMPLETE = 0,
  47	EVENT_XFER_COMPLETE,
  48	EVENT_DATA_COMPLETE,
  49	EVENT_DATA_ERROR,
  50};
  51
  52enum atmel_mci_state {
  53	STATE_IDLE = 0,
  54	STATE_SENDING_CMD,
  55	STATE_SENDING_DATA,
  56	STATE_DATA_BUSY,
  57	STATE_SENDING_STOP,
  58	STATE_DATA_ERROR,
  59};
  60
  61struct atmel_mci_dma {
  62#ifdef CONFIG_MMC_ATMELMCI_DMA
  63	struct dma_chan			*chan;
  64	struct dma_async_tx_descriptor	*data_desc;
  65#endif
  66};
  67
  68/**
  69 * struct atmel_mci - MMC controller state shared between all slots
  70 * @lock: Spinlock protecting the queue and associated data.
  71 * @regs: Pointer to MMIO registers.
  72 * @sg: Scatterlist entry currently being processed by PIO code, if any.
  73 * @pio_offset: Offset into the current scatterlist entry.
  74 * @cur_slot: The slot which is currently using the controller.
  75 * @mrq: The request currently being processed on @cur_slot,
  76 *	or NULL if the controller is idle.
  77 * @cmd: The command currently being sent to the card, or NULL.
  78 * @data: The data currently being transferred, or NULL if no data
  79 *	transfer is in progress.
  80 * @dma: DMA client state.
  81 * @data_chan: DMA channel being used for the current data transfer.
  82 * @cmd_status: Snapshot of SR taken upon completion of the current
  83 *	command. Only valid when EVENT_CMD_COMPLETE is pending.
  84 * @data_status: Snapshot of SR taken upon completion of the current
  85 *	data transfer. Only valid when EVENT_DATA_COMPLETE or
  86 *	EVENT_DATA_ERROR is pending.
  87 * @stop_cmdr: Value to be loaded into CMDR when the stop command is
  88 *	to be sent.
  89 * @tasklet: Tasklet running the request state machine.
  90 * @pending_events: Bitmask of events flagged by the interrupt handler
  91 *	to be processed by the tasklet.
  92 * @completed_events: Bitmask of events which the state machine has
  93 *	processed.
  94 * @state: Tasklet state.
  95 * @queue: List of slots waiting for access to the controller.
  96 * @need_clock_update: Update the clock rate before the next request.
  97 * @need_reset: Reset controller before next request.
  98 * @mode_reg: Value of the MR register.
  99 * @cfg_reg: Value of the CFG register.
 100 * @bus_hz: The rate of @mck in Hz. This forms the basis for MMC bus
 101 *	rate and timeout calculations.
 102 * @mapbase: Physical address of the MMIO registers.
 103 * @mck: The peripheral bus clock hooked up to the MMC controller.
 104 * @pdev: Platform device associated with the MMC controller.
 105 * @slot: Slots sharing this MMC controller.
 106 *
 107 * Locking
 108 * =======
 109 *
 110 * @lock is a softirq-safe spinlock protecting @queue as well as
 111 * @cur_slot, @mrq and @state. These must always be updated
 112 * at the same time while holding @lock.
 113 *
 114 * @lock also protects mode_reg and need_clock_update since these are
 115 * used to synchronize mode register updates with the queue
 116 * processing.
 117 *
 118 * The @mrq field of struct atmel_mci_slot is also protected by @lock,
 119 * and must always be written at the same time as the slot is added to
 120 * @queue.
 121 *
 122 * @pending_events and @completed_events are accessed using atomic bit
 123 * operations, so they don't need any locking.
 124 *
 125 * None of the fields touched by the interrupt handler need any
 126 * locking. However, ordering is important: Before EVENT_DATA_ERROR or
 127 * EVENT_DATA_COMPLETE is set in @pending_events, all data-related
 128 * interrupts must be disabled and @data_status updated with a
 129 * snapshot of SR. Similarly, before EVENT_CMD_COMPLETE is set, the
 130 * CMDRDY interrupt must be disabled and @cmd_status updated with a
 131 * snapshot of SR, and before EVENT_XFER_COMPLETE can be set, the
 132 * bytes_xfered field of @data must be written. This is ensured by
 133 * using barriers.
 134 */
 135struct atmel_mci {
 136	spinlock_t		lock;
 137	void __iomem		*regs;
 138
 139	struct scatterlist	*sg;
 140	unsigned int		pio_offset;
 141
 142	struct atmel_mci_slot	*cur_slot;
 143	struct mmc_request	*mrq;
 144	struct mmc_command	*cmd;
 145	struct mmc_data		*data;
 146
 147	struct atmel_mci_dma	dma;
 148	struct dma_chan		*data_chan;
 149
 150	u32			cmd_status;
 151	u32			data_status;
 152	u32			stop_cmdr;
 153
 154	struct tasklet_struct	tasklet;
 155	unsigned long		pending_events;
 156	unsigned long		completed_events;
 157	enum atmel_mci_state	state;
 158	struct list_head	queue;
 159
 160	bool			need_clock_update;
 161	bool			need_reset;
 162	u32			mode_reg;
 163	u32			cfg_reg;
 164	unsigned long		bus_hz;
 165	unsigned long		mapbase;
 166	struct clk		*mck;
 167	struct platform_device	*pdev;
 168
 169	struct atmel_mci_slot	*slot[ATMEL_MCI_MAX_NR_SLOTS];
 170};
 171
 172/**
 173 * struct atmel_mci_slot - MMC slot state
 174 * @mmc: The mmc_host representing this slot.
 175 * @host: The MMC controller this slot is using.
 176 * @sdc_reg: Value of SDCR to be written before using this slot.
 177 * @sdio_irq: SDIO irq mask for this slot.
 178 * @mrq: mmc_request currently being processed or waiting to be
 179 *	processed, or NULL when the slot is idle.
 180 * @queue_node: List node for placing this node in the @queue list of
 181 *	&struct atmel_mci.
 182 * @clock: Clock rate configured by set_ios(). Protected by host->lock.
 183 * @flags: Random state bits associated with the slot.
 184 * @detect_pin: GPIO pin used for card detection, or negative if not
 185 *	available.
 186 * @wp_pin: GPIO pin used for card write protect sending, or negative
 187 *	if not available.
 188 * @detect_is_active_high: The state of the detect pin when it is active.
 189 * @detect_timer: Timer used for debouncing @detect_pin interrupts.
 190 */
 191struct atmel_mci_slot {
 192	struct mmc_host		*mmc;
 193	struct atmel_mci	*host;
 194
 195	u32			sdc_reg;
 196	u32			sdio_irq;
 197
 198	struct mmc_request	*mrq;
 199	struct list_head	queue_node;
 200
 201	unsigned int		clock;
 202	unsigned long		flags;
 203#define ATMCI_CARD_PRESENT	0
 204#define ATMCI_CARD_NEED_INIT	1
 205#define ATMCI_SHUTDOWN		2
 206
 207	int			detect_pin;
 208	int			wp_pin;
 209	bool			detect_is_active_high;
 210
 211	struct timer_list	detect_timer;
 212};
 213
 214#define atmci_test_and_clear_pending(host, event)		\
 215	test_and_clear_bit(event, &host->pending_events)
 216#define atmci_set_completed(host, event)			\
 217	set_bit(event, &host->completed_events)
 218#define atmci_set_pending(host, event)				\
 219	set_bit(event, &host->pending_events)
 220
 221/*
 222 * Enable or disable features/registers based on
 223 * whether the processor supports them
 224 */
 225static bool mci_has_rwproof(void)
 226{
 227	if (cpu_is_at91sam9261() || cpu_is_at91rm9200())
 228		return false;
 229	else
 230		return true;
 231}
 232
 233/*
 234 * The new MCI2 module isn't 100% compatible with the old MCI module,
 235 * and it has a few nice features which we want to use...
 236 */
 237static inline bool atmci_is_mci2(void)
 238{
 239	if (cpu_is_at91sam9g45())
 240		return true;
 241
 242	return false;
 243}
 244
 245
 246/*
 247 * The debugfs stuff below is mostly optimized away when
 248 * CONFIG_DEBUG_FS is not set.
 249 */
 250static int atmci_req_show(struct seq_file *s, void *v)
 251{
 252	struct atmel_mci_slot	*slot = s->private;
 253	struct mmc_request	*mrq;
 254	struct mmc_command	*cmd;
 255	struct mmc_command	*stop;
 256	struct mmc_data		*data;
 257
 258	/* Make sure we get a consistent snapshot */
 259	spin_lock_bh(&slot->host->lock);
 260	mrq = slot->mrq;
 261
 262	if (mrq) {
 263		cmd = mrq->cmd;
 264		data = mrq->data;
 265		stop = mrq->stop;
 266
 267		if (cmd)
 268			seq_printf(s,
 269				"CMD%u(0x%x) flg %x rsp %x %x %x %x err %d\n",
 270				cmd->opcode, cmd->arg, cmd->flags,
 271				cmd->resp[0], cmd->resp[1], cmd->resp[2],
 272				cmd->resp[3], cmd->error);
 273		if (data)
 274			seq_printf(s, "DATA %u / %u * %u flg %x err %d\n",
 275				data->bytes_xfered, data->blocks,
 276				data->blksz, data->flags, data->error);
 277		if (stop)
 278			seq_printf(s,
 279				"CMD%u(0x%x) flg %x rsp %x %x %x %x err %d\n",
 280				stop->opcode, stop->arg, stop->flags,
 281				stop->resp[0], stop->resp[1], stop->resp[2],
 282				stop->resp[3], stop->error);
 283	}
 284
 285	spin_unlock_bh(&slot->host->lock);
 286
 287	return 0;
 288}
 289
 290static int atmci_req_open(struct inode *inode, struct file *file)
 291{
 292	return single_open(file, atmci_req_show, inode->i_private);
 293}
 294
 295static const struct file_operations atmci_req_fops = {
 296	.owner		= THIS_MODULE,
 297	.open		= atmci_req_open,
 298	.read		= seq_read,
 299	.llseek		= seq_lseek,
 300	.release	= single_release,
 301};
 302
 303static void atmci_show_status_reg(struct seq_file *s,
 304		const char *regname, u32 value)
 305{
 306	static const char	*sr_bit[] = {
 307		[0]	= "CMDRDY",
 308		[1]	= "RXRDY",
 309		[2]	= "TXRDY",
 310		[3]	= "BLKE",
 311		[4]	= "DTIP",
 312		[5]	= "NOTBUSY",
 313		[6]	= "ENDRX",
 314		[7]	= "ENDTX",
 315		[8]	= "SDIOIRQA",
 316		[9]	= "SDIOIRQB",
 317		[12]	= "SDIOWAIT",
 318		[14]	= "RXBUFF",
 319		[15]	= "TXBUFE",
 320		[16]	= "RINDE",
 321		[17]	= "RDIRE",
 322		[18]	= "RCRCE",
 323		[19]	= "RENDE",
 324		[20]	= "RTOE",
 325		[21]	= "DCRCE",
 326		[22]	= "DTOE",
 327		[23]	= "CSTOE",
 328		[24]	= "BLKOVRE",
 329		[25]	= "DMADONE",
 330		[26]	= "FIFOEMPTY",
 331		[27]	= "XFRDONE",
 332		[30]	= "OVRE",
 333		[31]	= "UNRE",
 334	};
 335	unsigned int		i;
 336
 337	seq_printf(s, "%s:\t0x%08x", regname, value);
 338	for (i = 0; i < ARRAY_SIZE(sr_bit); i++) {
 339		if (value & (1 << i)) {
 340			if (sr_bit[i])
 341				seq_printf(s, " %s", sr_bit[i]);
 342			else
 343				seq_puts(s, " UNKNOWN");
 344		}
 345	}
 346	seq_putc(s, '\n');
 347}
 348
 349static int atmci_regs_show(struct seq_file *s, void *v)
 350{
 351	struct atmel_mci	*host = s->private;
 352	u32			*buf;
 353
 354	buf = kmalloc(MCI_REGS_SIZE, GFP_KERNEL);
 355	if (!buf)
 356		return -ENOMEM;
 357
 358	/*
 359	 * Grab a more or less consistent snapshot. Note that we're
 360	 * not disabling interrupts, so IMR and SR may not be
 361	 * consistent.
 362	 */
 363	spin_lock_bh(&host->lock);
 364	clk_enable(host->mck);
 365	memcpy_fromio(buf, host->regs, MCI_REGS_SIZE);
 366	clk_disable(host->mck);
 367	spin_unlock_bh(&host->lock);
 368
 369	seq_printf(s, "MR:\t0x%08x%s%s CLKDIV=%u\n",
 370			buf[MCI_MR / 4],
 371			buf[MCI_MR / 4] & MCI_MR_RDPROOF ? " RDPROOF" : "",
 372			buf[MCI_MR / 4] & MCI_MR_WRPROOF ? " WRPROOF" : "",
 373			buf[MCI_MR / 4] & 0xff);
 374	seq_printf(s, "DTOR:\t0x%08x\n", buf[MCI_DTOR / 4]);
 375	seq_printf(s, "SDCR:\t0x%08x\n", buf[MCI_SDCR / 4]);
 376	seq_printf(s, "ARGR:\t0x%08x\n", buf[MCI_ARGR / 4]);
 377	seq_printf(s, "BLKR:\t0x%08x BCNT=%u BLKLEN=%u\n",
 378			buf[MCI_BLKR / 4],
 379			buf[MCI_BLKR / 4] & 0xffff,
 380			(buf[MCI_BLKR / 4] >> 16) & 0xffff);
 381	if (atmci_is_mci2())
 382		seq_printf(s, "CSTOR:\t0x%08x\n", buf[MCI_CSTOR / 4]);
 383
 384	/* Don't read RSPR and RDR; it will consume the data there */
 385
 386	atmci_show_status_reg(s, "SR", buf[MCI_SR / 4]);
 387	atmci_show_status_reg(s, "IMR", buf[MCI_IMR / 4]);
 388
 389	if (atmci_is_mci2()) {
 390		u32 val;
 391
 392		val = buf[MCI_DMA / 4];
 393		seq_printf(s, "DMA:\t0x%08x OFFSET=%u CHKSIZE=%u%s\n",
 394				val, val & 3,
 395				((val >> 4) & 3) ?
 396					1 << (((val >> 4) & 3) + 1) : 1,
 397				val & MCI_DMAEN ? " DMAEN" : "");
 398
 399		val = buf[MCI_CFG / 4];
 400		seq_printf(s, "CFG:\t0x%08x%s%s%s%s\n",
 401				val,
 402				val & MCI_CFG_FIFOMODE_1DATA ? " FIFOMODE_ONE_DATA" : "",
 403				val & MCI_CFG_FERRCTRL_COR ? " FERRCTRL_CLEAR_ON_READ" : "",
 404				val & MCI_CFG_HSMODE ? " HSMODE" : "",
 405				val & MCI_CFG_LSYNC ? " LSYNC" : "");
 406	}
 407
 408	kfree(buf);
 409
 410	return 0;
 411}
 412
 413static int atmci_regs_open(struct inode *inode, struct file *file)
 414{
 415	return single_open(file, atmci_regs_show, inode->i_private);
 416}
 417
 418static const struct file_operations atmci_regs_fops = {
 419	.owner		= THIS_MODULE,
 420	.open		= atmci_regs_open,
 421	.read		= seq_read,
 422	.llseek		= seq_lseek,
 423	.release	= single_release,
 424};
 425
 426static void atmci_init_debugfs(struct atmel_mci_slot *slot)
 427{
 428	struct mmc_host		*mmc = slot->mmc;
 429	struct atmel_mci	*host = slot->host;
 430	struct dentry		*root;
 431	struct dentry		*node;
 432
 433	root = mmc->debugfs_root;
 434	if (!root)
 435		return;
 436
 437	node = debugfs_create_file("regs", S_IRUSR, root, host,
 438			&atmci_regs_fops);
 439	if (IS_ERR(node))
 440		return;
 441	if (!node)
 442		goto err;
 443
 444	node = debugfs_create_file("req", S_IRUSR, root, slot, &atmci_req_fops);
 445	if (!node)
 446		goto err;
 447
 448	node = debugfs_create_u32("state", S_IRUSR, root, (u32 *)&host->state);
 449	if (!node)
 450		goto err;
 451
 452	node = debugfs_create_x32("pending_events", S_IRUSR, root,
 453				     (u32 *)&host->pending_events);
 454	if (!node)
 455		goto err;
 456
 457	node = debugfs_create_x32("completed_events", S_IRUSR, root,
 458				     (u32 *)&host->completed_events);
 459	if (!node)
 460		goto err;
 461
 462	return;
 463
 464err:
 465	dev_err(&mmc->class_dev, "failed to initialize debugfs for slot\n");
 466}
 467
 468static inline unsigned int ns_to_clocks(struct atmel_mci *host,
 469					unsigned int ns)
 470{
 471	/*
 472	 * It is easier here to use us instead of ns for the timeout,
 473	 * it prevents from overflows during calculation.
 474	 */
 475	unsigned int us = DIV_ROUND_UP(ns, 1000);
 476
 477	/* Maximum clock frequency is host->bus_hz/2 */
 478	return us * (DIV_ROUND_UP(host->bus_hz, 2000000));
 479}
 480
 481static void atmci_set_timeout(struct atmel_mci *host,
 482		struct atmel_mci_slot *slot, struct mmc_data *data)
 483{
 484	static unsigned	dtomul_to_shift[] = {
 485		0, 4, 7, 8, 10, 12, 16, 20
 486	};
 487	unsigned	timeout;
 488	unsigned	dtocyc;
 489	unsigned	dtomul;
 490
 491	timeout = ns_to_clocks(host, data->timeout_ns) + data->timeout_clks;
 492
 493	for (dtomul = 0; dtomul < 8; dtomul++) {
 494		unsigned shift = dtomul_to_shift[dtomul];
 495		dtocyc = (timeout + (1 << shift) - 1) >> shift;
 496		if (dtocyc < 15)
 497			break;
 498	}
 499
 500	if (dtomul >= 8) {
 501		dtomul = 7;
 502		dtocyc = 15;
 503	}
 504
 505	dev_vdbg(&slot->mmc->class_dev, "setting timeout to %u cycles\n",
 506			dtocyc << dtomul_to_shift[dtomul]);
 507	mci_writel(host, DTOR, (MCI_DTOMUL(dtomul) | MCI_DTOCYC(dtocyc)));
 508}
 509
 510/*
 511 * Return mask with command flags to be enabled for this command.
 512 */
 513static u32 atmci_prepare_command(struct mmc_host *mmc,
 514				 struct mmc_command *cmd)
 515{
 516	struct mmc_data	*data;
 517	u32		cmdr;
 518
 519	cmd->error = -EINPROGRESS;
 520
 521	cmdr = MCI_CMDR_CMDNB(cmd->opcode);
 522
 523	if (cmd->flags & MMC_RSP_PRESENT) {
 524		if (cmd->flags & MMC_RSP_136)
 525			cmdr |= MCI_CMDR_RSPTYP_136BIT;
 526		else
 527			cmdr |= MCI_CMDR_RSPTYP_48BIT;
 528	}
 529
 530	/*
 531	 * This should really be MAXLAT_5 for CMD2 and ACMD41, but
 532	 * it's too difficult to determine whether this is an ACMD or
 533	 * not. Better make it 64.
 534	 */
 535	cmdr |= MCI_CMDR_MAXLAT_64CYC;
 536
 537	if (mmc->ios.bus_mode == MMC_BUSMODE_OPENDRAIN)
 538		cmdr |= MCI_CMDR_OPDCMD;
 539
 540	data = cmd->data;
 541	if (data) {
 542		cmdr |= MCI_CMDR_START_XFER;
 543
 544		if (cmd->opcode == SD_IO_RW_EXTENDED) {
 545			cmdr |= MCI_CMDR_SDIO_BLOCK;
 546		} else {
 547			if (data->flags & MMC_DATA_STREAM)
 548				cmdr |= MCI_CMDR_STREAM;
 549			else if (data->blocks > 1)
 550				cmdr |= MCI_CMDR_MULTI_BLOCK;
 551			else
 552				cmdr |= MCI_CMDR_BLOCK;
 553		}
 554
 555		if (data->flags & MMC_DATA_READ)
 556			cmdr |= MCI_CMDR_TRDIR_READ;
 557	}
 558
 559	return cmdr;
 560}
 561
 562static void atmci_start_command(struct atmel_mci *host,
 563		struct mmc_command *cmd, u32 cmd_flags)
 564{
 565	WARN_ON(host->cmd);
 566	host->cmd = cmd;
 567
 568	dev_vdbg(&host->pdev->dev,
 569			"start command: ARGR=0x%08x CMDR=0x%08x\n",
 570			cmd->arg, cmd_flags);
 571
 572	mci_writel(host, ARGR, cmd->arg);
 573	mci_writel(host, CMDR, cmd_flags);
 574}
 575
 576static void send_stop_cmd(struct atmel_mci *host, struct mmc_data *data)
 577{
 578	atmci_start_command(host, data->stop, host->stop_cmdr);
 579	mci_writel(host, IER, MCI_CMDRDY);
 580}
 581
 582#ifdef CONFIG_MMC_ATMELMCI_DMA
 583static void atmci_dma_cleanup(struct atmel_mci *host)
 584{
 585	struct mmc_data			*data = host->data;
 586
 587	if (data)
 588		dma_unmap_sg(host->dma.chan->device->dev,
 589			     data->sg, data->sg_len,
 590			     ((data->flags & MMC_DATA_WRITE)
 591			      ? DMA_TO_DEVICE : DMA_FROM_DEVICE));
 592}
 593
 594static void atmci_stop_dma(struct atmel_mci *host)
 595{
 596	struct dma_chan *chan = host->data_chan;
 597
 598	if (chan) {
 599		dmaengine_terminate_all(chan);
 600		atmci_dma_cleanup(host);
 601	} else {
 602		/* Data transfer was stopped by the interrupt handler */
 603		atmci_set_pending(host, EVENT_XFER_COMPLETE);
 604		mci_writel(host, IER, MCI_NOTBUSY);
 605	}
 606}
 607
 608/* This function is called by the DMA driver from tasklet context. */
 609static void atmci_dma_complete(void *arg)
 610{
 611	struct atmel_mci	*host = arg;
 612	struct mmc_data		*data = host->data;
 613
 614	dev_vdbg(&host->pdev->dev, "DMA complete\n");
 615
 616	if (atmci_is_mci2())
 617		/* Disable DMA hardware handshaking on MCI */
 618		mci_writel(host, DMA, mci_readl(host, DMA) & ~MCI_DMAEN);
 619
 620	atmci_dma_cleanup(host);
 621
 622	/*
 623	 * If the card was removed, data will be NULL. No point trying
 624	 * to send the stop command or waiting for NBUSY in this case.
 625	 */
 626	if (data) {
 627		atmci_set_pending(host, EVENT_XFER_COMPLETE);
 628		tasklet_schedule(&host->tasklet);
 629
 630		/*
 631		 * Regardless of what the documentation says, we have
 632		 * to wait for NOTBUSY even after block read
 633		 * operations.
 634		 *
 635		 * When the DMA transfer is complete, the controller
 636		 * may still be reading the CRC from the card, i.e.
 637		 * the data transfer is still in progress and we
 638		 * haven't seen all the potential error bits yet.
 639		 *
 640		 * The interrupt handler will schedule a different
 641		 * tasklet to finish things up when the data transfer
 642		 * is completely done.
 643		 *
 644		 * We may not complete the mmc request here anyway
 645		 * because the mmc layer may call back and cause us to
 646		 * violate the "don't submit new operations from the
 647		 * completion callback" rule of the dma engine
 648		 * framework.
 649		 */
 650		mci_writel(host, IER, MCI_NOTBUSY);
 651	}
 652}
 653
 654static int
 655atmci_prepare_data_dma(struct atmel_mci *host, struct mmc_data *data)
 656{
 657	struct dma_chan			*chan;
 658	struct dma_async_tx_descriptor	*desc;
 659	struct scatterlist		*sg;
 660	unsigned int			i;
 661	enum dma_data_direction		direction;
 662	unsigned int			sglen;
 663
 664	/*
 665	 * We don't do DMA on "complex" transfers, i.e. with
 666	 * non-word-aligned buffers or lengths. Also, we don't bother
 667	 * with all the DMA setup overhead for short transfers.
 668	 */
 669	if (data->blocks * data->blksz < ATMCI_DMA_THRESHOLD)
 670		return -EINVAL;
 671	if (data->blksz & 3)
 672		return -EINVAL;
 673
 674	for_each_sg(data->sg, sg, data->sg_len, i) {
 675		if (sg->offset & 3 || sg->length & 3)
 676			return -EINVAL;
 677	}
 678
 679	/* If we don't have a channel, we can't do DMA */
 680	chan = host->dma.chan;
 681	if (chan)
 682		host->data_chan = chan;
 683
 684	if (!chan)
 685		return -ENODEV;
 686
 687	if (atmci_is_mci2())
 688		mci_writel(host, DMA, MCI_DMA_CHKSIZE(3) | MCI_DMAEN);
 689
 690	if (data->flags & MMC_DATA_READ)
 691		direction = DMA_FROM_DEVICE;
 692	else
 693		direction = DMA_TO_DEVICE;
 694
 695	sglen = dma_map_sg(chan->device->dev, data->sg,
 696			   data->sg_len, direction);
 697
 698	desc = chan->device->device_prep_slave_sg(chan,
 699			data->sg, sglen, direction,
 700			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 701	if (!desc)
 702		goto unmap_exit;
 703
 704	host->dma.data_desc = desc;
 705	desc->callback = atmci_dma_complete;
 706	desc->callback_param = host;
 707
 708	return 0;
 709unmap_exit:
 710	dma_unmap_sg(chan->device->dev, data->sg, data->sg_len, direction);
 711	return -ENOMEM;
 712}
 713
 714static void atmci_submit_data(struct atmel_mci *host)
 715{
 716	struct dma_chan			*chan = host->data_chan;
 717	struct dma_async_tx_descriptor	*desc = host->dma.data_desc;
 718
 719	if (chan) {
 720		dmaengine_submit(desc);
 721		dma_async_issue_pending(chan);
 722	}
 723}
 724
 725#else /* CONFIG_MMC_ATMELMCI_DMA */
 726
 727static int atmci_prepare_data_dma(struct atmel_mci *host, struct mmc_data *data)
 728{
 729	return -ENOSYS;
 730}
 731
 732static void atmci_submit_data(struct atmel_mci *host) {}
 733
 734static void atmci_stop_dma(struct atmel_mci *host)
 735{
 736	/* Data transfer was stopped by the interrupt handler */
 737	atmci_set_pending(host, EVENT_XFER_COMPLETE);
 738	mci_writel(host, IER, MCI_NOTBUSY);
 739}
 740
 741#endif /* CONFIG_MMC_ATMELMCI_DMA */
 742
 743/*
 744 * Returns a mask of interrupt flags to be enabled after the whole
 745 * request has been prepared.
 746 */
 747static u32 atmci_prepare_data(struct atmel_mci *host, struct mmc_data *data)
 748{
 749	u32 iflags;
 750
 751	data->error = -EINPROGRESS;
 752
 753	WARN_ON(host->data);
 754	host->sg = NULL;
 755	host->data = data;
 756
 757	iflags = ATMCI_DATA_ERROR_FLAGS;
 758	if (atmci_prepare_data_dma(host, data)) {
 759		host->data_chan = NULL;
 760
 761		/*
 762		 * Errata: MMC data write operation with less than 12
 763		 * bytes is impossible.
 764		 *
 765		 * Errata: MCI Transmit Data Register (TDR) FIFO
 766		 * corruption when length is not multiple of 4.
 767		 */
 768		if (data->blocks * data->blksz < 12
 769				|| (data->blocks * data->blksz) & 3)
 770			host->need_reset = true;
 771
 772		host->sg = data->sg;
 773		host->pio_offset = 0;
 774		if (data->flags & MMC_DATA_READ)
 775			iflags |= MCI_RXRDY;
 776		else
 777			iflags |= MCI_TXRDY;
 778	}
 779
 780	return iflags;
 781}
 782
 783static void atmci_start_request(struct atmel_mci *host,
 784		struct atmel_mci_slot *slot)
 785{
 786	struct mmc_request	*mrq;
 787	struct mmc_command	*cmd;
 788	struct mmc_data		*data;
 789	u32			iflags;
 790	u32			cmdflags;
 791
 792	mrq = slot->mrq;
 793	host->cur_slot = slot;
 794	host->mrq = mrq;
 795
 796	host->pending_events = 0;
 797	host->completed_events = 0;
 798	host->data_status = 0;
 799
 800	if (host->need_reset) {
 801		mci_writel(host, CR, MCI_CR_SWRST);
 802		mci_writel(host, CR, MCI_CR_MCIEN);
 803		mci_writel(host, MR, host->mode_reg);
 804		if (atmci_is_mci2())
 805			mci_writel(host, CFG, host->cfg_reg);
 806		host->need_reset = false;
 807	}
 808	mci_writel(host, SDCR, slot->sdc_reg);
 809
 810	iflags = mci_readl(host, IMR);
 811	if (iflags & ~(MCI_SDIOIRQA | MCI_SDIOIRQB))
 812		dev_warn(&slot->mmc->class_dev, "WARNING: IMR=0x%08x\n",
 813				iflags);
 814
 815	if (unlikely(test_and_clear_bit(ATMCI_CARD_NEED_INIT, &slot->flags))) {
 816		/* Send init sequence (74 clock cycles) */
 817		mci_writel(host, CMDR, MCI_CMDR_SPCMD_INIT);
 818		while (!(mci_readl(host, SR) & MCI_CMDRDY))
 819			cpu_relax();
 820	}
 821	iflags = 0;
 822	data = mrq->data;
 823	if (data) {
 824		atmci_set_timeout(host, slot, data);
 825
 826		/* Must set block count/size before sending command */
 827		mci_writel(host, BLKR, MCI_BCNT(data->blocks)
 828				| MCI_BLKLEN(data->blksz));
 829		dev_vdbg(&slot->mmc->class_dev, "BLKR=0x%08x\n",
 830			MCI_BCNT(data->blocks) | MCI_BLKLEN(data->blksz));
 831
 832		iflags |= atmci_prepare_data(host, data);
 833	}
 834
 835	iflags |= MCI_CMDRDY;
 836	cmd = mrq->cmd;
 837	cmdflags = atmci_prepare_command(slot->mmc, cmd);
 838	atmci_start_command(host, cmd, cmdflags);
 839
 840	if (data)
 841		atmci_submit_data(host);
 842
 843	if (mrq->stop) {
 844		host->stop_cmdr = atmci_prepare_command(slot->mmc, mrq->stop);
 845		host->stop_cmdr |= MCI_CMDR_STOP_XFER;
 846		if (!(data->flags & MMC_DATA_WRITE))
 847			host->stop_cmdr |= MCI_CMDR_TRDIR_READ;
 848		if (data->flags & MMC_DATA_STREAM)
 849			host->stop_cmdr |= MCI_CMDR_STREAM;
 850		else
 851			host->stop_cmdr |= MCI_CMDR_MULTI_BLOCK;
 852	}
 853
 854	/*
 855	 * We could have enabled interrupts earlier, but I suspect
 856	 * that would open up a nice can of interesting race
 857	 * conditions (e.g. command and data complete, but stop not
 858	 * prepared yet.)
 859	 */
 860	mci_writel(host, IER, iflags);
 861}
 862
 863static void atmci_queue_request(struct atmel_mci *host,
 864		struct atmel_mci_slot *slot, struct mmc_request *mrq)
 865{
 866	dev_vdbg(&slot->mmc->class_dev, "queue request: state=%d\n",
 867			host->state);
 868
 869	spin_lock_bh(&host->lock);
 870	slot->mrq = mrq;
 871	if (host->state == STATE_IDLE) {
 872		host->state = STATE_SENDING_CMD;
 873		atmci_start_request(host, slot);
 874	} else {
 875		list_add_tail(&slot->queue_node, &host->queue);
 876	}
 877	spin_unlock_bh(&host->lock);
 878}
 879
 880static void atmci_request(struct mmc_host *mmc, struct mmc_request *mrq)
 881{
 882	struct atmel_mci_slot	*slot = mmc_priv(mmc);
 883	struct atmel_mci	*host = slot->host;
 884	struct mmc_data		*data;
 885
 886	WARN_ON(slot->mrq);
 887
 888	/*
 889	 * We may "know" the card is gone even though there's still an
 890	 * electrical connection. If so, we really need to communicate
 891	 * this to the MMC core since there won't be any more
 892	 * interrupts as the card is completely removed. Otherwise,
 893	 * the MMC core might believe the card is still there even
 894	 * though the card was just removed very slowly.
 895	 */
 896	if (!test_bit(ATMCI_CARD_PRESENT, &slot->flags)) {
 897		mrq->cmd->error = -ENOMEDIUM;
 898		mmc_request_done(mmc, mrq);
 899		return;
 900	}
 901
 902	/* We don't support multiple blocks of weird lengths. */
 903	data = mrq->data;
 904	if (data && data->blocks > 1 && data->blksz & 3) {
 905		mrq->cmd->error = -EINVAL;
 906		mmc_request_done(mmc, mrq);
 907	}
 908
 909	atmci_queue_request(host, slot, mrq);
 910}
 911
 912static void atmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 913{
 914	struct atmel_mci_slot	*slot = mmc_priv(mmc);
 915	struct atmel_mci	*host = slot->host;
 916	unsigned int		i;
 917
 918	slot->sdc_reg &= ~MCI_SDCBUS_MASK;
 919	switch (ios->bus_width) {
 920	case MMC_BUS_WIDTH_1:
 921		slot->sdc_reg |= MCI_SDCBUS_1BIT;
 922		break;
 923	case MMC_BUS_WIDTH_4:
 924		slot->sdc_reg |= MCI_SDCBUS_4BIT;
 925		break;
 926	}
 927
 928	if (ios->clock) {
 929		unsigned int clock_min = ~0U;
 930		u32 clkdiv;
 931
 932		spin_lock_bh(&host->lock);
 933		if (!host->mode_reg) {
 934			clk_enable(host->mck);
 935			mci_writel(host, CR, MCI_CR_SWRST);
 936			mci_writel(host, CR, MCI_CR_MCIEN);
 937			if (atmci_is_mci2())
 938				mci_writel(host, CFG, host->cfg_reg);
 939		}
 940
 941		/*
 942		 * Use mirror of ios->clock to prevent race with mmc
 943		 * core ios update when finding the minimum.
 944		 */
 945		slot->clock = ios->clock;
 946		for (i = 0; i < ATMEL_MCI_MAX_NR_SLOTS; i++) {
 947			if (host->slot[i] && host->slot[i]->clock
 948					&& host->slot[i]->clock < clock_min)
 949				clock_min = host->slot[i]->clock;
 950		}
 951
 952		/* Calculate clock divider */
 953		clkdiv = DIV_ROUND_UP(host->bus_hz, 2 * clock_min) - 1;
 954		if (clkdiv > 255) {
 955			dev_warn(&mmc->class_dev,
 956				"clock %u too slow; using %lu\n",
 957				clock_min, host->bus_hz / (2 * 256));
 958			clkdiv = 255;
 959		}
 960
 961		host->mode_reg = MCI_MR_CLKDIV(clkdiv);
 962
 963		/*
 964		 * WRPROOF and RDPROOF prevent overruns/underruns by
 965		 * stopping the clock when the FIFO is full/empty.
 966		 * This state is not expected to last for long.
 967		 */
 968		if (mci_has_rwproof())
 969			host->mode_reg |= (MCI_MR_WRPROOF | MCI_MR_RDPROOF);
 970
 971		if (atmci_is_mci2()) {
 972			/* setup High Speed mode in relation with card capacity */
 973			if (ios->timing == MMC_TIMING_SD_HS)
 974				host->cfg_reg |= MCI_CFG_HSMODE;
 975			else
 976				host->cfg_reg &= ~MCI_CFG_HSMODE;
 977		}
 978
 979		if (list_empty(&host->queue)) {
 980			mci_writel(host, MR, host->mode_reg);
 981			if (atmci_is_mci2())
 982				mci_writel(host, CFG, host->cfg_reg);
 983		} else {
 984			host->need_clock_update = true;
 985		}
 986
 987		spin_unlock_bh(&host->lock);
 988	} else {
 989		bool any_slot_active = false;
 990
 991		spin_lock_bh(&host->lock);
 992		slot->clock = 0;
 993		for (i = 0; i < ATMEL_MCI_MAX_NR_SLOTS; i++) {
 994			if (host->slot[i] && host->slot[i]->clock) {
 995				any_slot_active = true;
 996				break;
 997			}
 998		}
 999		if (!any_slot_active) {
1000			mci_writel(host, CR, MCI_CR_MCIDIS);
1001			if (host->mode_reg) {
1002				mci_readl(host, MR);
1003				clk_disable(host->mck);
1004			}
1005			host->mode_reg = 0;
1006		}
1007		spin_unlock_bh(&host->lock);
1008	}
1009
1010	switch (ios->power_mode) {
1011	case MMC_POWER_UP:
1012		set_bit(ATMCI_CARD_NEED_INIT, &slot->flags);
1013		break;
1014	default:
1015		/*
1016		 * TODO: None of the currently available AVR32-based
1017		 * boards allow MMC power to be turned off. Implement
1018		 * power control when this can be tested properly.
1019		 *
1020		 * We also need to hook this into the clock management
1021		 * somehow so that newly inserted cards aren't
1022		 * subjected to a fast clock before we have a chance
1023		 * to figure out what the maximum rate is. Currently,
1024		 * there's no way to avoid this, and there never will
1025		 * be for boards that don't support power control.
1026		 */
1027		break;
1028	}
1029}
1030
1031static int atmci_get_ro(struct mmc_host *mmc)
1032{
1033	int			read_only = -ENOSYS;
1034	struct atmel_mci_slot	*slot = mmc_priv(mmc);
1035
1036	if (gpio_is_valid(slot->wp_pin)) {
1037		read_only = gpio_get_value(slot->wp_pin);
1038		dev_dbg(&mmc->class_dev, "card is %s\n",
1039				read_only ? "read-only" : "read-write");
1040	}
1041
1042	return read_only;
1043}
1044
1045static int atmci_get_cd(struct mmc_host *mmc)
1046{
1047	int			present = -ENOSYS;
1048	struct atmel_mci_slot	*slot = mmc_priv(mmc);
1049
1050	if (gpio_is_valid(slot->detect_pin)) {
1051		present = !(gpio_get_value(slot->detect_pin) ^
1052			    slot->detect_is_active_high);
1053		dev_dbg(&mmc->class_dev, "card is %spresent\n",
1054				present ? "" : "not ");
1055	}
1056
1057	return present;
1058}
1059
1060static void atmci_enable_sdio_irq(struct mmc_host *mmc, int enable)
1061{
1062	struct atmel_mci_slot	*slot = mmc_priv(mmc);
1063	struct atmel_mci	*host = slot->host;
1064
1065	if (enable)
1066		mci_writel(host, IER, slot->sdio_irq);
1067	else
1068		mci_writel(host, IDR, slot->sdio_irq);
1069}
1070
1071static const struct mmc_host_ops atmci_ops = {
1072	.request	= atmci_request,
1073	.set_ios	= atmci_set_ios,
1074	.get_ro		= atmci_get_ro,
1075	.get_cd		= atmci_get_cd,
1076	.enable_sdio_irq = atmci_enable_sdio_irq,
1077};
1078
1079/* Called with host->lock held */
1080static void atmci_request_end(struct atmel_mci *host, struct mmc_request *mrq)
1081	__releases(&host->lock)
1082	__acquires(&host->lock)
1083{
1084	struct atmel_mci_slot	*slot = NULL;
1085	struct mmc_host		*prev_mmc = host->cur_slot->mmc;
1086
1087	WARN_ON(host->cmd || host->data);
1088
1089	/*
1090	 * Update the MMC clock rate if necessary. This may be
1091	 * necessary if set_ios() is called when a different slot is
1092	 * busy transferring data.
1093	 */
1094	if (host->need_clock_update) {
1095		mci_writel(host, MR, host->mode_reg);
1096		if (atmci_is_mci2())
1097			mci_writel(host, CFG, host->cfg_reg);
1098	}
1099
1100	host->cur_slot->mrq = NULL;
1101	host->mrq = NULL;
1102	if (!list_empty(&host->queue)) {
1103		slot = list_entry(host->queue.next,
1104				struct atmel_mci_slot, queue_node);
1105		list_del(&slot->queue_node);
1106		dev_vdbg(&host->pdev->dev, "list not empty: %s is next\n",
1107				mmc_hostname(slot->mmc));
1108		host->state = STATE_SENDING_CMD;
1109		atmci_start_request(host, slot);
1110	} else {
1111		dev_vdbg(&host->pdev->dev, "list empty\n");
1112		host->state = STATE_IDLE;
1113	}
1114
1115	spin_unlock(&host->lock);
1116	mmc_request_done(prev_mmc, mrq);
1117	spin_lock(&host->lock);
1118}
1119
1120static void atmci_command_complete(struct atmel_mci *host,
1121			struct mmc_command *cmd)
1122{
1123	u32		status = host->cmd_status;
1124
1125	/* Read the response from the card (up to 16 bytes) */
1126	cmd->resp[0] = mci_readl(host, RSPR);
1127	cmd->resp[1] = mci_readl(host, RSPR);
1128	cmd->resp[2] = mci_readl(host, RSPR);
1129	cmd->resp[3] = mci_readl(host, RSPR);
1130
1131	if (status & MCI_RTOE)
1132		cmd->error = -ETIMEDOUT;
1133	else if ((cmd->flags & MMC_RSP_CRC) && (status & MCI_RCRCE))
1134		cmd->error = -EILSEQ;
1135	else if (status & (MCI_RINDE | MCI_RDIRE | MCI_RENDE))
1136		cmd->error = -EIO;
1137	else
1138		cmd->error = 0;
1139
1140	if (cmd->error) {
1141		dev_dbg(&host->pdev->dev,
1142			"command error: status=0x%08x\n", status);
1143
1144		if (cmd->data) {
1145			atmci_stop_dma(host);
1146			host->data = NULL;
1147			mci_writel(host, IDR, MCI_NOTBUSY
1148					| MCI_TXRDY | MCI_RXRDY
1149					| ATMCI_DATA_ERROR_FLAGS);
1150		}
1151	}
1152}
1153
1154static void atmci_detect_change(unsigned long data)
1155{
1156	struct atmel_mci_slot	*slot = (struct atmel_mci_slot *)data;
1157	bool			present;
1158	bool			present_old;
1159
1160	/*
1161	 * atmci_cleanup_slot() sets the ATMCI_SHUTDOWN flag before
1162	 * freeing the interrupt. We must not re-enable the interrupt
1163	 * if it has been freed, and if we're shutting down, it
1164	 * doesn't really matter whether the card is present or not.
1165	 */
1166	smp_rmb();
1167	if (test_bit(ATMCI_SHUTDOWN, &slot->flags))
1168		return;
1169
1170	enable_irq(gpio_to_irq(slot->detect_pin));
1171	present = !(gpio_get_value(slot->detect_pin) ^
1172		    slot->detect_is_active_high);
1173	present_old = test_bit(ATMCI_CARD_PRESENT, &slot->flags);
1174
1175	dev_vdbg(&slot->mmc->class_dev, "detect change: %d (was %d)\n",
1176			present, present_old);
1177
1178	if (present != present_old) {
1179		struct atmel_mci	*host = slot->host;
1180		struct mmc_request	*mrq;
1181
1182		dev_dbg(&slot->mmc->class_dev, "card %s\n",
1183			present ? "inserted" : "removed");
1184
1185		spin_lock(&host->lock);
1186
1187		if (!present)
1188			clear_bit(ATMCI_CARD_PRESENT, &slot->flags);
1189		else
1190			set_bit(ATMCI_CARD_PRESENT, &slot->flags);
1191
1192		/* Clean up queue if present */
1193		mrq = slot->mrq;
1194		if (mrq) {
1195			if (mrq == host->mrq) {
1196				/*
1197				 * Reset controller to terminate any ongoing
1198				 * commands or data transfers.
1199				 */
1200				mci_writel(host, CR, MCI_CR_SWRST);
1201				mci_writel(host, CR, MCI_CR_MCIEN);
1202				mci_writel(host, MR, host->mode_reg);
1203				if (atmci_is_mci2())
1204					mci_writel(host, CFG, host->cfg_reg);
1205
1206				host->data = NULL;
1207				host->cmd = NULL;
1208
1209				switch (host->state) {
1210				case STATE_IDLE:
1211					break;
1212				case STATE_SENDING_CMD:
1213					mrq->cmd->error = -ENOMEDIUM;
1214					if (!mrq->data)
1215						break;
1216					/* fall through */
1217				case STATE_SENDING_DATA:
1218					mrq->data->error = -ENOMEDIUM;
1219					atmci_stop_dma(host);
1220					break;
1221				case STATE_DATA_BUSY:
1222				case STATE_DATA_ERROR:
1223					if (mrq->data->error == -EINPROGRESS)
1224						mrq->data->error = -ENOMEDIUM;
1225					if (!mrq->stop)
1226						break;
1227					/* fall through */
1228				case STATE_SENDING_STOP:
1229					mrq->stop->error = -ENOMEDIUM;
1230					break;
1231				}
1232
1233				atmci_request_end(host, mrq);
1234			} else {
1235				list_del(&slot->queue_node);
1236				mrq->cmd->error = -ENOMEDIUM;
1237				if (mrq->data)
1238					mrq->data->error = -ENOMEDIUM;
1239				if (mrq->stop)
1240					mrq->stop->error = -ENOMEDIUM;
1241
1242				spin_unlock(&host->lock);
1243				mmc_request_done(slot->mmc, mrq);
1244				spin_lock(&host->lock);
1245			}
1246		}
1247		spin_unlock(&host->lock);
1248
1249		mmc_detect_change(slot->mmc, 0);
1250	}
1251}
1252
1253static void atmci_tasklet_func(unsigned long priv)
1254{
1255	struct atmel_mci	*host = (struct atmel_mci *)priv;
1256	struct mmc_request	*mrq = host->mrq;
1257	struct mmc_data		*data = host->data;
1258	struct mmc_command	*cmd = host->cmd;
1259	enum atmel_mci_state	state = host->state;
1260	enum atmel_mci_state	prev_state;
1261	u32			status;
1262
1263	spin_lock(&host->lock);
1264
1265	state = host->state;
1266
1267	dev_vdbg(&host->pdev->dev,
1268		"tasklet: state %u pending/completed/mask %lx/%lx/%x\n",
1269		state, host->pending_events, host->completed_events,
1270		mci_readl(host, IMR));
1271
1272	do {
1273		prev_state = state;
1274
1275		switch (state) {
1276		case STATE_IDLE:
1277			break;
1278
1279		case STATE_SENDING_CMD:
1280			if (!atmci_test_and_clear_pending(host,
1281						EVENT_CMD_COMPLETE))
1282				break;
1283
1284			host->cmd = NULL;
1285			atmci_set_completed(host, EVENT_CMD_COMPLETE);
1286			atmci_command_complete(host, mrq->cmd);
1287			if (!mrq->data || cmd->error) {
1288				atmci_request_end(host, host->mrq);
1289				goto unlock;
1290			}
1291
1292			prev_state = state = STATE_SENDING_DATA;
1293			/* fall through */
1294
1295		case STATE_SENDING_DATA:
1296			if (atmci_test_and_clear_pending(host,
1297						EVENT_DATA_ERROR)) {
1298				atmci_stop_dma(host);
1299				if (data->stop)
1300					send_stop_cmd(host, data);
1301				state = STATE_DATA_ERROR;
1302				break;
1303			}
1304
1305			if (!atmci_test_and_clear_pending(host,
1306						EVENT_XFER_COMPLETE))
1307				break;
1308
1309			atmci_set_completed(host, EVENT_XFER_COMPLETE);
1310			prev_state = state = STATE_DATA_BUSY;
1311			/* fall through */
1312
1313		case STATE_DATA_BUSY:
1314			if (!atmci_test_and_clear_pending(host,
1315						EVENT_DATA_COMPLETE))
1316				break;
1317
1318			host->data = NULL;
1319			atmci_set_completed(host, EVENT_DATA_COMPLETE);
1320			status = host->data_status;
1321			if (unlikely(status & ATMCI_DATA_ERROR_FLAGS)) {
1322				if (status & MCI_DTOE) {
1323					dev_dbg(&host->pdev->dev,
1324							"data timeout error\n");
1325					data->error = -ETIMEDOUT;
1326				} else if (status & MCI_DCRCE) {
1327					dev_dbg(&host->pdev->dev,
1328							"data CRC error\n");
1329					data->error = -EILSEQ;
1330				} else {
1331					dev_dbg(&host->pdev->dev,
1332						"data FIFO error (status=%08x)\n",
1333						status);
1334					data->error = -EIO;
1335				}
1336			} else {
1337				data->bytes_xfered = data->blocks * data->blksz;
1338				data->error = 0;
1339				mci_writel(host, IDR, ATMCI_DATA_ERROR_FLAGS);
1340			}
1341
1342			if (!data->stop) {
1343				atmci_request_end(host, host->mrq);
1344				goto unlock;
1345			}
1346
1347			prev_state = state = STATE_SENDING_STOP;
1348			if (!data->error)
1349				send_stop_cmd(host, data);
1350			/* fall through */
1351
1352		case STATE_SENDING_STOP:
1353			if (!atmci_test_and_clear_pending(host,
1354						EVENT_CMD_COMPLETE))
1355				break;
1356
1357			host->cmd = NULL;
1358			atmci_command_complete(host, mrq->stop);
1359			atmci_request_end(host, host->mrq);
1360			goto unlock;
1361
1362		case STATE_DATA_ERROR:
1363			if (!atmci_test_and_clear_pending(host,
1364						EVENT_XFER_COMPLETE))
1365				break;
1366
1367			state = STATE_DATA_BUSY;
1368			break;
1369		}
1370	} while (state != prev_state);
1371
1372	host->state = state;
1373
1374unlock:
1375	spin_unlock(&host->lock);
1376}
1377
1378static void atmci_read_data_pio(struct atmel_mci *host)
1379{
1380	struct scatterlist	*sg = host->sg;
1381	void			*buf = sg_virt(sg);
1382	unsigned int		offset = host->pio_offset;
1383	struct mmc_data		*data = host->data;
1384	u32			value;
1385	u32			status;
1386	unsigned int		nbytes = 0;
1387
1388	do {
1389		value = mci_readl(host, RDR);
1390		if (likely(offset + 4 <= sg->length)) {
1391			put_unaligned(value, (u32 *)(buf + offset));
1392
1393			offset += 4;
1394			nbytes += 4;
1395
1396			if (offset == sg->length) {
1397				flush_dcache_page(sg_page(sg));
1398				host->sg = sg = sg_next(sg);
1399				if (!sg)
1400					goto done;
1401
1402				offset = 0;
1403				buf = sg_virt(sg);
1404			}
1405		} else {
1406			unsigned int remaining = sg->length - offset;
1407			memcpy(buf + offset, &value, remaining);
1408			nbytes += remaining;
1409
1410			flush_dcache_page(sg_page(sg));
1411			host->sg = sg = sg_next(sg);
1412			if (!sg)
1413				goto done;
1414
1415			offset = 4 - remaining;
1416			buf = sg_virt(sg);
1417			memcpy(buf, (u8 *)&value + remaining, offset);
1418			nbytes += offset;
1419		}
1420
1421		status = mci_readl(host, SR);
1422		if (status & ATMCI_DATA_ERROR_FLAGS) {
1423			mci_writel(host, IDR, (MCI_NOTBUSY | MCI_RXRDY
1424						| ATMCI_DATA_ERROR_FLAGS));
1425			host->data_status = status;
1426			data->bytes_xfered += nbytes;
1427			smp_wmb();
1428			atmci_set_pending(host, EVENT_DATA_ERROR);
1429			tasklet_schedule(&host->tasklet);
1430			return;
1431		}
1432	} while (status & MCI_RXRDY);
1433
1434	host->pio_offset = offset;
1435	data->bytes_xfered += nbytes;
1436
1437	return;
1438
1439done:
1440	mci_writel(host, IDR, MCI_RXRDY);
1441	mci_writel(host, IER, MCI_NOTBUSY);
1442	data->bytes_xfered += nbytes;
1443	smp_wmb();
1444	atmci_set_pending(host, EVENT_XFER_COMPLETE);
1445}
1446
1447static void atmci_write_data_pio(struct atmel_mci *host)
1448{
1449	struct scatterlist	*sg = host->sg;
1450	void			*buf = sg_virt(sg);
1451	unsigned int		offset = host->pio_offset;
1452	struct mmc_data		*data = host->data;
1453	u32			value;
1454	u32			status;
1455	unsigned int		nbytes = 0;
1456
1457	do {
1458		if (likely(offset + 4 <= sg->length)) {
1459			value = get_unaligned((u32 *)(buf + offset));
1460			mci_writel(host, TDR, value);
1461
1462			offset += 4;
1463			nbytes += 4;
1464			if (offset == sg->length) {
1465				host->sg = sg = sg_next(sg);
1466				if (!sg)
1467					goto done;
1468
1469				offset = 0;
1470				buf = sg_virt(sg);
1471			}
1472		} else {
1473			unsigned int remaining = sg->length - offset;
1474
1475			value = 0;
1476			memcpy(&value, buf + offset, remaining);
1477			nbytes += remaining;
1478
1479			host->sg = sg = sg_next(sg);
1480			if (!sg) {
1481				mci_writel(host, TDR, value);
1482				goto done;
1483			}
1484
1485			offset = 4 - remaining;
1486			buf = sg_virt(sg);
1487			memcpy((u8 *)&value + remaining, buf, offset);
1488			mci_writel(host, TDR, value);
1489			nbytes += offset;
1490		}
1491
1492		status = mci_readl(host, SR);
1493		if (status & ATMCI_DATA_ERROR_FLAGS) {
1494			mci_writel(host, IDR, (MCI_NOTBUSY | MCI_TXRDY
1495						| ATMCI_DATA_ERROR_FLAGS));
1496			host->data_status = status;
1497			data->bytes_xfered += nbytes;
1498			smp_wmb();
1499			atmci_set_pending(host, EVENT_DATA_ERROR);
1500			tasklet_schedule(&host->tasklet);
1501			return;
1502		}
1503	} while (status & MCI_TXRDY);
1504
1505	host->pio_offset = offset;
1506	data->bytes_xfered += nbytes;
1507
1508	return;
1509
1510done:
1511	mci_writel(host, IDR, MCI_TXRDY);
1512	mci_writel(host, IER, MCI_NOTBUSY);
1513	data->bytes_xfered += nbytes;
1514	smp_wmb();
1515	atmci_set_pending(host, EVENT_XFER_COMPLETE);
1516}
1517
1518static void atmci_cmd_interrupt(struct atmel_mci *host, u32 status)
1519{
1520	mci_writel(host, IDR, MCI_CMDRDY);
1521
1522	host->cmd_status = status;
1523	smp_wmb();
1524	atmci_set_pending(host, EVENT_CMD_COMPLETE);
1525	tasklet_schedule(&host->tasklet);
1526}
1527
1528static void atmci_sdio_interrupt(struct atmel_mci *host, u32 status)
1529{
1530	int	i;
1531
1532	for (i = 0; i < ATMEL_MCI_MAX_NR_SLOTS; i++) {
1533		struct atmel_mci_slot *slot = host->slot[i];
1534		if (slot && (status & slot->sdio_irq)) {
1535			mmc_signal_sdio_irq(slot->mmc);
1536		}
1537	}
1538}
1539
1540
1541static irqreturn_t atmci_interrupt(int irq, void *dev_id)
1542{
1543	struct atmel_mci	*host = dev_id;
1544	u32			status, mask, pending;
1545	unsigned int		pass_count = 0;
1546
1547	do {
1548		status = mci_readl(host, SR);
1549		mask = mci_readl(host, IMR);
1550		pending = status & mask;
1551		if (!pending)
1552			break;
1553
1554		if (pending & ATMCI_DATA_ERROR_FLAGS) {
1555			mci_writel(host, IDR, ATMCI_DATA_ERROR_FLAGS
1556					| MCI_RXRDY | MCI_TXRDY);
1557			pending &= mci_readl(host, IMR);
1558
1559			host->data_status = status;
1560			smp_wmb();
1561			atmci_set_pending(host, EVENT_DATA_ERROR);
1562			tasklet_schedule(&host->tasklet);
1563		}
1564		if (pending & MCI_NOTBUSY) {
1565			mci_writel(host, IDR,
1566					ATMCI_DATA_ERROR_FLAGS | MCI_NOTBUSY);
1567			if (!host->data_status)
1568				host->data_status = status;
1569			smp_wmb();
1570			atmci_set_pending(host, EVENT_DATA_COMPLETE);
1571			tasklet_schedule(&host->tasklet);
1572		}
1573		if (pending & MCI_RXRDY)
1574			atmci_read_data_pio(host);
1575		if (pending & MCI_TXRDY)
1576			atmci_write_data_pio(host);
1577
1578		if (pending & MCI_CMDRDY)
1579			atmci_cmd_interrupt(host, status);
1580
1581		if (pending & (MCI_SDIOIRQA | MCI_SDIOIRQB))
1582			atmci_sdio_interrupt(host, status);
1583
1584	} while (pass_count++ < 5);
1585
1586	return pass_count ? IRQ_HANDLED : IRQ_NONE;
1587}
1588
1589static irqreturn_t atmci_detect_interrupt(int irq, void *dev_id)
1590{
1591	struct atmel_mci_slot	*slot = dev_id;
1592
1593	/*
1594	 * Disable interrupts until the pin has stabilized and check
1595	 * the state then. Use mod_timer() since we may be in the
1596	 * middle of the timer routine when this interrupt triggers.
1597	 */
1598	disable_irq_nosync(irq);
1599	mod_timer(&slot->detect_timer, jiffies + msecs_to_jiffies(20));
1600
1601	return IRQ_HANDLED;
1602}
1603
1604static int __init atmci_init_slot(struct atmel_mci *host,
1605		struct mci_slot_pdata *slot_data, unsigned int id,
1606		u32 sdc_reg, u32 sdio_irq)
1607{
1608	struct mmc_host			*mmc;
1609	struct atmel_mci_slot		*slot;
1610
1611	mmc = mmc_alloc_host(sizeof(struct atmel_mci_slot), &host->pdev->dev);
1612	if (!mmc)
1613		return -ENOMEM;
1614
1615	slot = mmc_priv(mmc);
1616	slot->mmc = mmc;
1617	slot->host = host;
1618	slot->detect_pin = slot_data->detect_pin;
1619	slot->wp_pin = slot_data->wp_pin;
1620	slot->detect_is_active_high = slot_data->detect_is_active_high;
1621	slot->sdc_reg = sdc_reg;
1622	slot->sdio_irq = sdio_irq;
1623
1624	mmc->ops = &atmci_ops;
1625	mmc->f_min = DIV_ROUND_UP(host->bus_hz, 512);
1626	mmc->f_max = host->bus_hz / 2;
1627	mmc->ocr_avail	= MMC_VDD_32_33 | MMC_VDD_33_34;
1628	if (sdio_irq)
1629		mmc->caps |= MMC_CAP_SDIO_IRQ;
1630	if (atmci_is_mci2())
1631		mmc->caps |= MMC_CAP_SD_HIGHSPEED;
1632	if (slot_data->bus_width >= 4)
1633		mmc->caps |= MMC_CAP_4_BIT_DATA;
1634
1635	mmc->max_segs = 64;
1636	mmc->max_req_size = 32768 * 512;
1637	mmc->max_blk_size = 32768;
1638	mmc->max_blk_count = 512;
1639
1640	/* Assume card is present initially */
1641	set_bit(ATMCI_CARD_PRESENT, &slot->flags);
1642	if (gpio_is_valid(slot->detect_pin)) {
1643		if (gpio_request(slot->detect_pin, "mmc_detect")) {
1644			dev_dbg(&mmc->class_dev, "no detect pin available\n");
1645			slot->detect_pin = -EBUSY;
1646		} else if (gpio_get_value(slot->detect_pin) ^
1647				slot->detect_is_active_high) {
1648			clear_bit(ATMCI_CARD_PRESENT, &slot->flags);
1649		}
1650	}
1651
1652	if (!gpio_is_valid(slot->detect_pin))
1653		mmc->caps |= MMC_CAP_NEEDS_POLL;
1654
1655	if (gpio_is_valid(slot->wp_pin)) {
1656		if (gpio_request(slot->wp_pin, "mmc_wp")) {
1657			dev_dbg(&mmc->class_dev, "no WP pin available\n");
1658			slot->wp_pin = -EBUSY;
1659		}
1660	}
1661
1662	host->slot[id] = slot;
1663	mmc_add_host(mmc);
1664
1665	if (gpio_is_valid(slot->detect_pin)) {
1666		int ret;
1667
1668		setup_timer(&slot->detect_timer, atmci_detect_change,
1669				(unsigned long)slot);
1670
1671		ret = request_irq(gpio_to_irq(slot->detect_pin),
1672				atmci_detect_interrupt,
1673				IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
1674				"mmc-detect", slot);
1675		if (ret) {
1676			dev_dbg(&mmc->class_dev,
1677				"could not request IRQ %d for detect pin\n",
1678				gpio_to_irq(slot->detect_pin));
1679			gpio_free(slot->detect_pin);
1680			slot->detect_pin = -EBUSY;
1681		}
1682	}
1683
1684	atmci_init_debugfs(slot);
1685
1686	return 0;
1687}
1688
1689static void __exit atmci_cleanup_slot(struct atmel_mci_slot *slot,
1690		unsigned int id)
1691{
1692	/* Debugfs stuff is cleaned up by mmc core */
1693
1694	set_bit(ATMCI_SHUTDOWN, &slot->flags);
1695	smp_wmb();
1696
1697	mmc_remove_host(slot->mmc);
1698
1699	if (gpio_is_valid(slot->detect_pin)) {
1700		int pin = slot->detect_pin;
1701
1702		free_irq(gpio_to_irq(pin), slot);
1703		del_timer_sync(&slot->detect_timer);
1704		gpio_free(pin);
1705	}
1706	if (gpio_is_valid(slot->wp_pin))
1707		gpio_free(slot->wp_pin);
1708
1709	slot->host->slot[id] = NULL;
1710	mmc_free_host(slot->mmc);
1711}
1712
1713#ifdef CONFIG_MMC_ATMELMCI_DMA
1714static bool filter(struct dma_chan *chan, void *slave)
1715{
1716	struct mci_dma_data	*sl = slave;
1717
1718	if (sl && find_slave_dev(sl) == chan->device->dev) {
1719		chan->private = slave_data_ptr(sl);
1720		return true;
1721	} else {
1722		return false;
1723	}
1724}
1725
1726static void atmci_configure_dma(struct atmel_mci *host)
1727{
1728	struct mci_platform_data	*pdata;
1729
1730	if (host == NULL)
1731		return;
1732
1733	pdata = host->pdev->dev.platform_data;
1734
1735	if (pdata && find_slave_dev(pdata->dma_slave)) {
1736		dma_cap_mask_t mask;
1737
1738		setup_dma_addr(pdata->dma_slave,
1739			       host->mapbase + MCI_TDR,
1740			       host->mapbase + MCI_RDR);
1741
1742		/* Try to grab a DMA channel */
1743		dma_cap_zero(mask);
1744		dma_cap_set(DMA_SLAVE, mask);
1745		host->dma.chan =
1746			dma_request_channel(mask, filter, pdata->dma_slave);
1747	}
1748	if (!host->dma.chan)
1749		dev_notice(&host->pdev->dev, "DMA not available, using PIO\n");
1750	else
1751		dev_info(&host->pdev->dev,
1752					"Using %s for DMA transfers\n",
1753					dma_chan_name(host->dma.chan));
1754}
1755#else
1756static void atmci_configure_dma(struct atmel_mci *host) {}
1757#endif
1758
1759static int __init atmci_probe(struct platform_device *pdev)
1760{
1761	struct mci_platform_data	*pdata;
1762	struct atmel_mci		*host;
1763	struct resource			*regs;
1764	unsigned int			nr_slots;
1765	int				irq;
1766	int				ret;
1767
1768	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1769	if (!regs)
1770		return -ENXIO;
1771	pdata = pdev->dev.platform_data;
1772	if (!pdata)
1773		return -ENXIO;
1774	irq = platform_get_irq(pdev, 0);
1775	if (irq < 0)
1776		return irq;
1777
1778	host = kzalloc(sizeof(struct atmel_mci), GFP_KERNEL);
1779	if (!host)
1780		return -ENOMEM;
1781
1782	host->pdev = pdev;
1783	spin_lock_init(&host->lock);
1784	INIT_LIST_HEAD(&host->queue);
1785
1786	host->mck = clk_get(&pdev->dev, "mci_clk");
1787	if (IS_ERR(host->mck)) {
1788		ret = PTR_ERR(host->mck);
1789		goto err_clk_get;
1790	}
1791
1792	ret = -ENOMEM;
1793	host->regs = ioremap(regs->start, resource_size(regs));
1794	if (!host->regs)
1795		goto err_ioremap;
1796
1797	clk_enable(host->mck);
1798	mci_writel(host, CR, MCI_CR_SWRST);
1799	host->bus_hz = clk_get_rate(host->mck);
1800	clk_disable(host->mck);
1801
1802	host->mapbase = regs->start;
1803
1804	tasklet_init(&host->tasklet, atmci_tasklet_func, (unsigned long)host);
1805
1806	ret = request_irq(irq, atmci_interrupt, 0, dev_name(&pdev->dev), host);
1807	if (ret)
1808		goto err_request_irq;
1809
1810	atmci_configure_dma(host);
1811
1812	platform_set_drvdata(pdev, host);
1813
1814	/* We need at least one slot to succeed */
1815	nr_slots = 0;
1816	ret = -ENODEV;
1817	if (pdata->slot[0].bus_width) {
1818		ret = atmci_init_slot(host, &pdata->slot[0],
1819				0, MCI_SDCSEL_SLOT_A, MCI_SDIOIRQA);
1820		if (!ret)
1821			nr_slots++;
1822	}
1823	if (pdata->slot[1].bus_width) {
1824		ret = atmci_init_slot(host, &pdata->slot[1],
1825				1, MCI_SDCSEL_SLOT_B, MCI_SDIOIRQB);
1826		if (!ret)
1827			nr_slots++;
1828	}
1829
1830	if (!nr_slots) {
1831		dev_err(&pdev->dev, "init failed: no slot defined\n");
1832		goto err_init_slot;
1833	}
1834
1835	dev_info(&pdev->dev,
1836			"Atmel MCI controller at 0x%08lx irq %d, %u slots\n",
1837			host->mapbase, irq, nr_slots);
1838
1839	return 0;
1840
1841err_init_slot:
1842#ifdef CONFIG_MMC_ATMELMCI_DMA
1843	if (host->dma.chan)
1844		dma_release_channel(host->dma.chan);
1845#endif
1846	free_irq(irq, host);
1847err_request_irq:
1848	iounmap(host->regs);
1849err_ioremap:
1850	clk_put(host->mck);
1851err_clk_get:
1852	kfree(host);
1853	return ret;
1854}
1855
1856static int __exit atmci_remove(struct platform_device *pdev)
1857{
1858	struct atmel_mci	*host = platform_get_drvdata(pdev);
1859	unsigned int		i;
1860
1861	platform_set_drvdata(pdev, NULL);
1862
1863	for (i = 0; i < ATMEL_MCI_MAX_NR_SLOTS; i++) {
1864		if (host->slot[i])
1865			atmci_cleanup_slot(host->slot[i], i);
1866	}
1867
1868	clk_enable(host->mck);
1869	mci_writel(host, IDR, ~0UL);
1870	mci_writel(host, CR, MCI_CR_MCIDIS);
1871	mci_readl(host, SR);
1872	clk_disable(host->mck);
1873
1874#ifdef CONFIG_MMC_ATMELMCI_DMA
1875	if (host->dma.chan)
1876		dma_release_channel(host->dma.chan);
1877#endif
1878
1879	free_irq(platform_get_irq(pdev, 0), host);
1880	iounmap(host->regs);
1881
1882	clk_put(host->mck);
1883	kfree(host);
1884
1885	return 0;
1886}
1887
1888static struct platform_driver atmci_driver = {
1889	.remove		= __exit_p(atmci_remove),
1890	.driver		= {
1891		.name		= "atmel_mci",
1892	},
1893};
1894
1895static int __init atmci_init(void)
1896{
1897	return platform_driver_probe(&atmci_driver, atmci_probe);
1898}
1899
1900static void __exit atmci_exit(void)
1901{
1902	platform_driver_unregister(&atmci_driver);
1903}
1904
1905late_initcall(atmci_init); /* try to load after dma driver when built-in */
1906module_exit(atmci_exit);
1907
1908MODULE_DESCRIPTION("Atmel Multimedia Card Interface driver");
1909MODULE_AUTHOR("Haavard Skinnemoen (Atmel)");
1910MODULE_LICENSE("GPL v2");