065fa818be5750a8b59dc7d12a53cb217933b5d0
[linux-2.6.git] / 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/stat.h>
26
27 #include <linux/mmc/host.h>
28 #include <linux/atmel-mci.h>
29
30 #include <asm/io.h>
31 #include <asm/unaligned.h>
32
33 #include <mach/cpu.h>
34 #include <mach/board.h>
35
36 #include "atmel-mci-regs.h"
37
38 #define ATMCI_DATA_ERROR_FLAGS  (MCI_DCRCE | MCI_DTOE | MCI_OVRE | MCI_UNRE)
39 #define ATMCI_DMA_THRESHOLD     16
40
41 enum {
42         EVENT_CMD_COMPLETE = 0,
43         EVENT_XFER_COMPLETE,
44         EVENT_DATA_COMPLETE,
45         EVENT_DATA_ERROR,
46 };
47
48 enum atmel_mci_state {
49         STATE_IDLE = 0,
50         STATE_SENDING_CMD,
51         STATE_SENDING_DATA,
52         STATE_DATA_BUSY,
53         STATE_SENDING_STOP,
54         STATE_DATA_ERROR,
55 };
56
57 struct atmel_mci_dma {
58 #ifdef CONFIG_MMC_ATMELMCI_DMA
59         struct dma_chan                 *chan;
60         struct dma_async_tx_descriptor  *data_desc;
61 #endif
62 };
63
64 /**
65  * struct atmel_mci - MMC controller state shared between all slots
66  * @lock: Spinlock protecting the queue and associated data.
67  * @regs: Pointer to MMIO registers.
68  * @sg: Scatterlist entry currently being processed by PIO code, if any.
69  * @pio_offset: Offset into the current scatterlist entry.
70  * @cur_slot: The slot which is currently using the controller.
71  * @mrq: The request currently being processed on @cur_slot,
72  *      or NULL if the controller is idle.
73  * @cmd: The command currently being sent to the card, or NULL.
74  * @data: The data currently being transferred, or NULL if no data
75  *      transfer is in progress.
76  * @dma: DMA client state.
77  * @data_chan: DMA channel being used for the current data transfer.
78  * @cmd_status: Snapshot of SR taken upon completion of the current
79  *      command. Only valid when EVENT_CMD_COMPLETE is pending.
80  * @data_status: Snapshot of SR taken upon completion of the current
81  *      data transfer. Only valid when EVENT_DATA_COMPLETE or
82  *      EVENT_DATA_ERROR is pending.
83  * @stop_cmdr: Value to be loaded into CMDR when the stop command is
84  *      to be sent.
85  * @tasklet: Tasklet running the request state machine.
86  * @pending_events: Bitmask of events flagged by the interrupt handler
87  *      to be processed by the tasklet.
88  * @completed_events: Bitmask of events which the state machine has
89  *      processed.
90  * @state: Tasklet state.
91  * @queue: List of slots waiting for access to the controller.
92  * @need_clock_update: Update the clock rate before the next request.
93  * @need_reset: Reset controller before next request.
94  * @mode_reg: Value of the MR register.
95  * @bus_hz: The rate of @mck in Hz. This forms the basis for MMC bus
96  *      rate and timeout calculations.
97  * @mapbase: Physical address of the MMIO registers.
98  * @mck: The peripheral bus clock hooked up to the MMC controller.
99  * @pdev: Platform device associated with the MMC controller.
100  * @slot: Slots sharing this MMC controller.
101  *
102  * Locking
103  * =======
104  *
105  * @lock is a softirq-safe spinlock protecting @queue as well as
106  * @cur_slot, @mrq and @state. These must always be updated
107  * at the same time while holding @lock.
108  *
109  * @lock also protects mode_reg and need_clock_update since these are
110  * used to synchronize mode register updates with the queue
111  * processing.
112  *
113  * The @mrq field of struct atmel_mci_slot is also protected by @lock,
114  * and must always be written at the same time as the slot is added to
115  * @queue.
116  *
117  * @pending_events and @completed_events are accessed using atomic bit
118  * operations, so they don't need any locking.
119  *
120  * None of the fields touched by the interrupt handler need any
121  * locking. However, ordering is important: Before EVENT_DATA_ERROR or
122  * EVENT_DATA_COMPLETE is set in @pending_events, all data-related
123  * interrupts must be disabled and @data_status updated with a
124  * snapshot of SR. Similarly, before EVENT_CMD_COMPLETE is set, the
125  * CMDRDY interupt must be disabled and @cmd_status updated with a
126  * snapshot of SR, and before EVENT_XFER_COMPLETE can be set, the
127  * bytes_xfered field of @data must be written. This is ensured by
128  * using barriers.
129  */
130 struct atmel_mci {
131         spinlock_t              lock;
132         void __iomem            *regs;
133
134         struct scatterlist      *sg;
135         unsigned int            pio_offset;
136
137         struct atmel_mci_slot   *cur_slot;
138         struct mmc_request      *mrq;
139         struct mmc_command      *cmd;
140         struct mmc_data         *data;
141
142         struct atmel_mci_dma    dma;
143         struct dma_chan         *data_chan;
144
145         u32                     cmd_status;
146         u32                     data_status;
147         u32                     stop_cmdr;
148
149         struct tasklet_struct   tasklet;
150         unsigned long           pending_events;
151         unsigned long           completed_events;
152         enum atmel_mci_state    state;
153         struct list_head        queue;
154
155         bool                    need_clock_update;
156         bool                    need_reset;
157         u32                     mode_reg;
158         unsigned long           bus_hz;
159         unsigned long           mapbase;
160         struct clk              *mck;
161         struct platform_device  *pdev;
162
163         struct atmel_mci_slot   *slot[ATMEL_MCI_MAX_NR_SLOTS];
164 };
165
166 /**
167  * struct atmel_mci_slot - MMC slot state
168  * @mmc: The mmc_host representing this slot.
169  * @host: The MMC controller this slot is using.
170  * @sdc_reg: Value of SDCR to be written before using this slot.
171  * @mrq: mmc_request currently being processed or waiting to be
172  *      processed, or NULL when the slot is idle.
173  * @queue_node: List node for placing this node in the @queue list of
174  *      &struct atmel_mci.
175  * @clock: Clock rate configured by set_ios(). Protected by host->lock.
176  * @flags: Random state bits associated with the slot.
177  * @detect_pin: GPIO pin used for card detection, or negative if not
178  *      available.
179  * @wp_pin: GPIO pin used for card write protect sending, or negative
180  *      if not available.
181  * @detect_is_active_high: The state of the detect pin when it is active.
182  * @detect_timer: Timer used for debouncing @detect_pin interrupts.
183  */
184 struct atmel_mci_slot {
185         struct mmc_host         *mmc;
186         struct atmel_mci        *host;
187
188         u32                     sdc_reg;
189
190         struct mmc_request      *mrq;
191         struct list_head        queue_node;
192
193         unsigned int            clock;
194         unsigned long           flags;
195 #define ATMCI_CARD_PRESENT      0
196 #define ATMCI_CARD_NEED_INIT    1
197 #define ATMCI_SHUTDOWN          2
198
199         int                     detect_pin;
200         int                     wp_pin;
201         bool                    detect_is_active_high;
202
203         struct timer_list       detect_timer;
204 };
205
206 #define atmci_test_and_clear_pending(host, event)               \
207         test_and_clear_bit(event, &host->pending_events)
208 #define atmci_set_completed(host, event)                        \
209         set_bit(event, &host->completed_events)
210 #define atmci_set_pending(host, event)                          \
211         set_bit(event, &host->pending_events)
212
213 /*
214  * Enable or disable features/registers based on
215  * whether the processor supports them
216  */
217 static bool mci_has_rwproof(void)
218 {
219         if (cpu_is_at91sam9261() || cpu_is_at91rm9200())
220                 return false;
221         else
222                 return true;
223 }
224
225 /*
226  * The debugfs stuff below is mostly optimized away when
227  * CONFIG_DEBUG_FS is not set.
228  */
229 static int atmci_req_show(struct seq_file *s, void *v)
230 {
231         struct atmel_mci_slot   *slot = s->private;
232         struct mmc_request      *mrq;
233         struct mmc_command      *cmd;
234         struct mmc_command      *stop;
235         struct mmc_data         *data;
236
237         /* Make sure we get a consistent snapshot */
238         spin_lock_bh(&slot->host->lock);
239         mrq = slot->mrq;
240
241         if (mrq) {
242                 cmd = mrq->cmd;
243                 data = mrq->data;
244                 stop = mrq->stop;
245
246                 if (cmd)
247                         seq_printf(s,
248                                 "CMD%u(0x%x) flg %x rsp %x %x %x %x err %d\n",
249                                 cmd->opcode, cmd->arg, cmd->flags,
250                                 cmd->resp[0], cmd->resp[1], cmd->resp[2],
251                                 cmd->resp[2], cmd->error);
252                 if (data)
253                         seq_printf(s, "DATA %u / %u * %u flg %x err %d\n",
254                                 data->bytes_xfered, data->blocks,
255                                 data->blksz, data->flags, data->error);
256                 if (stop)
257                         seq_printf(s,
258                                 "CMD%u(0x%x) flg %x rsp %x %x %x %x err %d\n",
259                                 stop->opcode, stop->arg, stop->flags,
260                                 stop->resp[0], stop->resp[1], stop->resp[2],
261                                 stop->resp[2], stop->error);
262         }
263
264         spin_unlock_bh(&slot->host->lock);
265
266         return 0;
267 }
268
269 static int atmci_req_open(struct inode *inode, struct file *file)
270 {
271         return single_open(file, atmci_req_show, inode->i_private);
272 }
273
274 static const struct file_operations atmci_req_fops = {
275         .owner          = THIS_MODULE,
276         .open           = atmci_req_open,
277         .read           = seq_read,
278         .llseek         = seq_lseek,
279         .release        = single_release,
280 };
281
282 static void atmci_show_status_reg(struct seq_file *s,
283                 const char *regname, u32 value)
284 {
285         static const char       *sr_bit[] = {
286                 [0]     = "CMDRDY",
287                 [1]     = "RXRDY",
288                 [2]     = "TXRDY",
289                 [3]     = "BLKE",
290                 [4]     = "DTIP",
291                 [5]     = "NOTBUSY",
292                 [6]     = "ENDRX",
293                 [7]     = "ENDTX",
294                 [8]     = "SDIOIRQA",
295                 [9]     = "SDIOIRQB",
296                 [12]    = "SDIOWAIT",
297                 [14]    = "RXBUFF",
298                 [15]    = "TXBUFE",
299                 [16]    = "RINDE",
300                 [17]    = "RDIRE",
301                 [18]    = "RCRCE",
302                 [19]    = "RENDE",
303                 [20]    = "RTOE",
304                 [21]    = "DCRCE",
305                 [22]    = "DTOE",
306                 [23]    = "CSTOE",
307                 [24]    = "BLKOVRE",
308                 [25]    = "DMADONE",
309                 [26]    = "FIFOEMPTY",
310                 [27]    = "XFRDONE",
311                 [30]    = "OVRE",
312                 [31]    = "UNRE",
313         };
314         unsigned int            i;
315
316         seq_printf(s, "%s:\t0x%08x", regname, value);
317         for (i = 0; i < ARRAY_SIZE(sr_bit); i++) {
318                 if (value & (1 << i)) {
319                         if (sr_bit[i])
320                                 seq_printf(s, " %s", sr_bit[i]);
321                         else
322                                 seq_puts(s, " UNKNOWN");
323                 }
324         }
325         seq_putc(s, '\n');
326 }
327
328 static int atmci_regs_show(struct seq_file *s, void *v)
329 {
330         struct atmel_mci        *host = s->private;
331         u32                     *buf;
332
333         buf = kmalloc(MCI_REGS_SIZE, GFP_KERNEL);
334         if (!buf)
335                 return -ENOMEM;
336
337         /*
338          * Grab a more or less consistent snapshot. Note that we're
339          * not disabling interrupts, so IMR and SR may not be
340          * consistent.
341          */
342         spin_lock_bh(&host->lock);
343         clk_enable(host->mck);
344         memcpy_fromio(buf, host->regs, MCI_REGS_SIZE);
345         clk_disable(host->mck);
346         spin_unlock_bh(&host->lock);
347
348         seq_printf(s, "MR:\t0x%08x%s%s CLKDIV=%u\n",
349                         buf[MCI_MR / 4],
350                         buf[MCI_MR / 4] & MCI_MR_RDPROOF ? " RDPROOF" : "",
351                         buf[MCI_MR / 4] & MCI_MR_WRPROOF ? " WRPROOF" : "",
352                         buf[MCI_MR / 4] & 0xff);
353         seq_printf(s, "DTOR:\t0x%08x\n", buf[MCI_DTOR / 4]);
354         seq_printf(s, "SDCR:\t0x%08x\n", buf[MCI_SDCR / 4]);
355         seq_printf(s, "ARGR:\t0x%08x\n", buf[MCI_ARGR / 4]);
356         seq_printf(s, "BLKR:\t0x%08x BCNT=%u BLKLEN=%u\n",
357                         buf[MCI_BLKR / 4],
358                         buf[MCI_BLKR / 4] & 0xffff,
359                         (buf[MCI_BLKR / 4] >> 16) & 0xffff);
360
361         /* Don't read RSPR and RDR; it will consume the data there */
362
363         atmci_show_status_reg(s, "SR", buf[MCI_SR / 4]);
364         atmci_show_status_reg(s, "IMR", buf[MCI_IMR / 4]);
365
366         kfree(buf);
367
368         return 0;
369 }
370
371 static int atmci_regs_open(struct inode *inode, struct file *file)
372 {
373         return single_open(file, atmci_regs_show, inode->i_private);
374 }
375
376 static const struct file_operations atmci_regs_fops = {
377         .owner          = THIS_MODULE,
378         .open           = atmci_regs_open,
379         .read           = seq_read,
380         .llseek         = seq_lseek,
381         .release        = single_release,
382 };
383
384 static void atmci_init_debugfs(struct atmel_mci_slot *slot)
385 {
386         struct mmc_host         *mmc = slot->mmc;
387         struct atmel_mci        *host = slot->host;
388         struct dentry           *root;
389         struct dentry           *node;
390
391         root = mmc->debugfs_root;
392         if (!root)
393                 return;
394
395         node = debugfs_create_file("regs", S_IRUSR, root, host,
396                         &atmci_regs_fops);
397         if (IS_ERR(node))
398                 return;
399         if (!node)
400                 goto err;
401
402         node = debugfs_create_file("req", S_IRUSR, root, slot, &atmci_req_fops);
403         if (!node)
404                 goto err;
405
406         node = debugfs_create_u32("state", S_IRUSR, root, (u32 *)&host->state);
407         if (!node)
408                 goto err;
409
410         node = debugfs_create_x32("pending_events", S_IRUSR, root,
411                                      (u32 *)&host->pending_events);
412         if (!node)
413                 goto err;
414
415         node = debugfs_create_x32("completed_events", S_IRUSR, root,
416                                      (u32 *)&host->completed_events);
417         if (!node)
418                 goto err;
419
420         return;
421
422 err:
423         dev_err(&mmc->class_dev, "failed to initialize debugfs for slot\n");
424 }
425
426 static inline unsigned int ns_to_clocks(struct atmel_mci *host,
427                                         unsigned int ns)
428 {
429         return (ns * (host->bus_hz / 1000000) + 999) / 1000;
430 }
431
432 static void atmci_set_timeout(struct atmel_mci *host,
433                 struct atmel_mci_slot *slot, struct mmc_data *data)
434 {
435         static unsigned dtomul_to_shift[] = {
436                 0, 4, 7, 8, 10, 12, 16, 20
437         };
438         unsigned        timeout;
439         unsigned        dtocyc;
440         unsigned        dtomul;
441
442         timeout = ns_to_clocks(host, data->timeout_ns) + data->timeout_clks;
443
444         for (dtomul = 0; dtomul < 8; dtomul++) {
445                 unsigned shift = dtomul_to_shift[dtomul];
446                 dtocyc = (timeout + (1 << shift) - 1) >> shift;
447                 if (dtocyc < 15)
448                         break;
449         }
450
451         if (dtomul >= 8) {
452                 dtomul = 7;
453                 dtocyc = 15;
454         }
455
456         dev_vdbg(&slot->mmc->class_dev, "setting timeout to %u cycles\n",
457                         dtocyc << dtomul_to_shift[dtomul]);
458         mci_writel(host, DTOR, (MCI_DTOMUL(dtomul) | MCI_DTOCYC(dtocyc)));
459 }
460
461 /*
462  * Return mask with command flags to be enabled for this command.
463  */
464 static u32 atmci_prepare_command(struct mmc_host *mmc,
465                                  struct mmc_command *cmd)
466 {
467         struct mmc_data *data;
468         u32             cmdr;
469
470         cmd->error = -EINPROGRESS;
471
472         cmdr = MCI_CMDR_CMDNB(cmd->opcode);
473
474         if (cmd->flags & MMC_RSP_PRESENT) {
475                 if (cmd->flags & MMC_RSP_136)
476                         cmdr |= MCI_CMDR_RSPTYP_136BIT;
477                 else
478                         cmdr |= MCI_CMDR_RSPTYP_48BIT;
479         }
480
481         /*
482          * This should really be MAXLAT_5 for CMD2 and ACMD41, but
483          * it's too difficult to determine whether this is an ACMD or
484          * not. Better make it 64.
485          */
486         cmdr |= MCI_CMDR_MAXLAT_64CYC;
487
488         if (mmc->ios.bus_mode == MMC_BUSMODE_OPENDRAIN)
489                 cmdr |= MCI_CMDR_OPDCMD;
490
491         data = cmd->data;
492         if (data) {
493                 cmdr |= MCI_CMDR_START_XFER;
494                 if (data->flags & MMC_DATA_STREAM)
495                         cmdr |= MCI_CMDR_STREAM;
496                 else if (data->blocks > 1)
497                         cmdr |= MCI_CMDR_MULTI_BLOCK;
498                 else
499                         cmdr |= MCI_CMDR_BLOCK;
500
501                 if (data->flags & MMC_DATA_READ)
502                         cmdr |= MCI_CMDR_TRDIR_READ;
503         }
504
505         return cmdr;
506 }
507
508 static void atmci_start_command(struct atmel_mci *host,
509                 struct mmc_command *cmd, u32 cmd_flags)
510 {
511         WARN_ON(host->cmd);
512         host->cmd = cmd;
513
514         dev_vdbg(&host->pdev->dev,
515                         "start command: ARGR=0x%08x CMDR=0x%08x\n",
516                         cmd->arg, cmd_flags);
517
518         mci_writel(host, ARGR, cmd->arg);
519         mci_writel(host, CMDR, cmd_flags);
520 }
521
522 static void send_stop_cmd(struct atmel_mci *host, struct mmc_data *data)
523 {
524         atmci_start_command(host, data->stop, host->stop_cmdr);
525         mci_writel(host, IER, MCI_CMDRDY);
526 }
527
528 #ifdef CONFIG_MMC_ATMELMCI_DMA
529 static void atmci_dma_cleanup(struct atmel_mci *host)
530 {
531         struct mmc_data                 *data = host->data;
532
533         dma_unmap_sg(&host->pdev->dev, data->sg, data->sg_len,
534                      ((data->flags & MMC_DATA_WRITE)
535                       ? DMA_TO_DEVICE : DMA_FROM_DEVICE));
536 }
537
538 static void atmci_stop_dma(struct atmel_mci *host)
539 {
540         struct dma_chan *chan = host->data_chan;
541
542         if (chan) {
543                 chan->device->device_terminate_all(chan);
544                 atmci_dma_cleanup(host);
545         } else {
546                 /* Data transfer was stopped by the interrupt handler */
547                 atmci_set_pending(host, EVENT_XFER_COMPLETE);
548                 mci_writel(host, IER, MCI_NOTBUSY);
549         }
550 }
551
552 /* This function is called by the DMA driver from tasklet context. */
553 static void atmci_dma_complete(void *arg)
554 {
555         struct atmel_mci        *host = arg;
556         struct mmc_data         *data = host->data;
557
558         dev_vdbg(&host->pdev->dev, "DMA complete\n");
559
560         atmci_dma_cleanup(host);
561
562         /*
563          * If the card was removed, data will be NULL. No point trying
564          * to send the stop command or waiting for NBUSY in this case.
565          */
566         if (data) {
567                 atmci_set_pending(host, EVENT_XFER_COMPLETE);
568                 tasklet_schedule(&host->tasklet);
569
570                 /*
571                  * Regardless of what the documentation says, we have
572                  * to wait for NOTBUSY even after block read
573                  * operations.
574                  *
575                  * When the DMA transfer is complete, the controller
576                  * may still be reading the CRC from the card, i.e.
577                  * the data transfer is still in progress and we
578                  * haven't seen all the potential error bits yet.
579                  *
580                  * The interrupt handler will schedule a different
581                  * tasklet to finish things up when the data transfer
582                  * is completely done.
583                  *
584                  * We may not complete the mmc request here anyway
585                  * because the mmc layer may call back and cause us to
586                  * violate the "don't submit new operations from the
587                  * completion callback" rule of the dma engine
588                  * framework.
589                  */
590                 mci_writel(host, IER, MCI_NOTBUSY);
591         }
592 }
593
594 static int
595 atmci_submit_data_dma(struct atmel_mci *host, struct mmc_data *data)
596 {
597         struct dma_chan                 *chan;
598         struct dma_async_tx_descriptor  *desc;
599         struct scatterlist              *sg;
600         unsigned int                    i;
601         enum dma_data_direction         direction;
602
603         /*
604          * We don't do DMA on "complex" transfers, i.e. with
605          * non-word-aligned buffers or lengths. Also, we don't bother
606          * with all the DMA setup overhead for short transfers.
607          */
608         if (data->blocks * data->blksz < ATMCI_DMA_THRESHOLD)
609                 return -EINVAL;
610         if (data->blksz & 3)
611                 return -EINVAL;
612
613         for_each_sg(data->sg, sg, data->sg_len, i) {
614                 if (sg->offset & 3 || sg->length & 3)
615                         return -EINVAL;
616         }
617
618         /* If we don't have a channel, we can't do DMA */
619         chan = host->dma.chan;
620         if (chan)
621                 host->data_chan = chan;
622
623         if (!chan)
624                 return -ENODEV;
625
626         if (data->flags & MMC_DATA_READ)
627                 direction = DMA_FROM_DEVICE;
628         else
629                 direction = DMA_TO_DEVICE;
630
631         desc = chan->device->device_prep_slave_sg(chan,
632                         data->sg, data->sg_len, direction,
633                         DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
634         if (!desc)
635                 return -ENOMEM;
636
637         host->dma.data_desc = desc;
638         desc->callback = atmci_dma_complete;
639         desc->callback_param = host;
640         desc->tx_submit(desc);
641
642         /* Go! */
643         chan->device->device_issue_pending(chan);
644
645         return 0;
646 }
647
648 #else /* CONFIG_MMC_ATMELMCI_DMA */
649
650 static int atmci_submit_data_dma(struct atmel_mci *host, struct mmc_data *data)
651 {
652         return -ENOSYS;
653 }
654
655 static void atmci_stop_dma(struct atmel_mci *host)
656 {
657         /* Data transfer was stopped by the interrupt handler */
658         atmci_set_pending(host, EVENT_XFER_COMPLETE);
659         mci_writel(host, IER, MCI_NOTBUSY);
660 }
661
662 #endif /* CONFIG_MMC_ATMELMCI_DMA */
663
664 /*
665  * Returns a mask of interrupt flags to be enabled after the whole
666  * request has been prepared.
667  */
668 static u32 atmci_submit_data(struct atmel_mci *host, struct mmc_data *data)
669 {
670         u32 iflags;
671
672         data->error = -EINPROGRESS;
673
674         WARN_ON(host->data);
675         host->sg = NULL;
676         host->data = data;
677
678         iflags = ATMCI_DATA_ERROR_FLAGS;
679         if (atmci_submit_data_dma(host, data)) {
680                 host->data_chan = NULL;
681
682                 /*
683                  * Errata: MMC data write operation with less than 12
684                  * bytes is impossible.
685                  *
686                  * Errata: MCI Transmit Data Register (TDR) FIFO
687                  * corruption when length is not multiple of 4.
688                  */
689                 if (data->blocks * data->blksz < 12
690                                 || (data->blocks * data->blksz) & 3)
691                         host->need_reset = true;
692
693                 host->sg = data->sg;
694                 host->pio_offset = 0;
695                 if (data->flags & MMC_DATA_READ)
696                         iflags |= MCI_RXRDY;
697                 else
698                         iflags |= MCI_TXRDY;
699         }
700
701         return iflags;
702 }
703
704 static void atmci_start_request(struct atmel_mci *host,
705                 struct atmel_mci_slot *slot)
706 {
707         struct mmc_request      *mrq;
708         struct mmc_command      *cmd;
709         struct mmc_data         *data;
710         u32                     iflags;
711         u32                     cmdflags;
712
713         mrq = slot->mrq;
714         host->cur_slot = slot;
715         host->mrq = mrq;
716
717         host->pending_events = 0;
718         host->completed_events = 0;
719         host->data_status = 0;
720
721         if (host->need_reset) {
722                 mci_writel(host, CR, MCI_CR_SWRST);
723                 mci_writel(host, CR, MCI_CR_MCIEN);
724                 mci_writel(host, MR, host->mode_reg);
725                 host->need_reset = false;
726         }
727         mci_writel(host, SDCR, slot->sdc_reg);
728
729         iflags = mci_readl(host, IMR);
730         if (iflags)
731                 dev_warn(&slot->mmc->class_dev, "WARNING: IMR=0x%08x\n",
732                                 iflags);
733
734         if (unlikely(test_and_clear_bit(ATMCI_CARD_NEED_INIT, &slot->flags))) {
735                 /* Send init sequence (74 clock cycles) */
736                 mci_writel(host, CMDR, MCI_CMDR_SPCMD_INIT);
737                 while (!(mci_readl(host, SR) & MCI_CMDRDY))
738                         cpu_relax();
739         }
740         data = mrq->data;
741         if (data) {
742                 atmci_set_timeout(host, slot, data);
743
744                 /* Must set block count/size before sending command */
745                 mci_writel(host, BLKR, MCI_BCNT(data->blocks)
746                                 | MCI_BLKLEN(data->blksz));
747                 dev_vdbg(&slot->mmc->class_dev, "BLKR=0x%08x\n",
748                         MCI_BCNT(data->blocks) | MCI_BLKLEN(data->blksz));
749         }
750
751         iflags = MCI_CMDRDY;
752         cmd = mrq->cmd;
753         cmdflags = atmci_prepare_command(slot->mmc, cmd);
754         atmci_start_command(host, cmd, cmdflags);
755
756         if (data)
757                 iflags |= atmci_submit_data(host, data);
758
759         if (mrq->stop) {
760                 host->stop_cmdr = atmci_prepare_command(slot->mmc, mrq->stop);
761                 host->stop_cmdr |= MCI_CMDR_STOP_XFER;
762                 if (!(data->flags & MMC_DATA_WRITE))
763                         host->stop_cmdr |= MCI_CMDR_TRDIR_READ;
764                 if (data->flags & MMC_DATA_STREAM)
765                         host->stop_cmdr |= MCI_CMDR_STREAM;
766                 else
767                         host->stop_cmdr |= MCI_CMDR_MULTI_BLOCK;
768         }
769
770         /*
771          * We could have enabled interrupts earlier, but I suspect
772          * that would open up a nice can of interesting race
773          * conditions (e.g. command and data complete, but stop not
774          * prepared yet.)
775          */
776         mci_writel(host, IER, iflags);
777 }
778
779 static void atmci_queue_request(struct atmel_mci *host,
780                 struct atmel_mci_slot *slot, struct mmc_request *mrq)
781 {
782         dev_vdbg(&slot->mmc->class_dev, "queue request: state=%d\n",
783                         host->state);
784
785         spin_lock_bh(&host->lock);
786         slot->mrq = mrq;
787         if (host->state == STATE_IDLE) {
788                 host->state = STATE_SENDING_CMD;
789                 atmci_start_request(host, slot);
790         } else {
791                 list_add_tail(&slot->queue_node, &host->queue);
792         }
793         spin_unlock_bh(&host->lock);
794 }
795
796 static void atmci_request(struct mmc_host *mmc, struct mmc_request *mrq)
797 {
798         struct atmel_mci_slot   *slot = mmc_priv(mmc);
799         struct atmel_mci        *host = slot->host;
800         struct mmc_data         *data;
801
802         WARN_ON(slot->mrq);
803
804         /*
805          * We may "know" the card is gone even though there's still an
806          * electrical connection. If so, we really need to communicate
807          * this to the MMC core since there won't be any more
808          * interrupts as the card is completely removed. Otherwise,
809          * the MMC core might believe the card is still there even
810          * though the card was just removed very slowly.
811          */
812         if (!test_bit(ATMCI_CARD_PRESENT, &slot->flags)) {
813                 mrq->cmd->error = -ENOMEDIUM;
814                 mmc_request_done(mmc, mrq);
815                 return;
816         }
817
818         /* We don't support multiple blocks of weird lengths. */
819         data = mrq->data;
820         if (data && data->blocks > 1 && data->blksz & 3) {
821                 mrq->cmd->error = -EINVAL;
822                 mmc_request_done(mmc, mrq);
823         }
824
825         atmci_queue_request(host, slot, mrq);
826 }
827
828 static void atmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
829 {
830         struct atmel_mci_slot   *slot = mmc_priv(mmc);
831         struct atmel_mci        *host = slot->host;
832         unsigned int            i;
833
834         slot->sdc_reg &= ~MCI_SDCBUS_MASK;
835         switch (ios->bus_width) {
836         case MMC_BUS_WIDTH_1:
837                 slot->sdc_reg |= MCI_SDCBUS_1BIT;
838                 break;
839         case MMC_BUS_WIDTH_4:
840                 slot->sdc_reg |= MCI_SDCBUS_4BIT;
841                 break;
842         }
843
844         if (ios->clock) {
845                 unsigned int clock_min = ~0U;
846                 u32 clkdiv;
847
848                 spin_lock_bh(&host->lock);
849                 if (!host->mode_reg) {
850                         clk_enable(host->mck);
851                         mci_writel(host, CR, MCI_CR_SWRST);
852                         mci_writel(host, CR, MCI_CR_MCIEN);
853                 }
854
855                 /*
856                  * Use mirror of ios->clock to prevent race with mmc
857                  * core ios update when finding the minimum.
858                  */
859                 slot->clock = ios->clock;
860                 for (i = 0; i < ATMEL_MCI_MAX_NR_SLOTS; i++) {
861                         if (host->slot[i] && host->slot[i]->clock
862                                         && host->slot[i]->clock < clock_min)
863                                 clock_min = host->slot[i]->clock;
864                 }
865
866                 /* Calculate clock divider */
867                 clkdiv = DIV_ROUND_UP(host->bus_hz, 2 * clock_min) - 1;
868                 if (clkdiv > 255) {
869                         dev_warn(&mmc->class_dev,
870                                 "clock %u too slow; using %lu\n",
871                                 clock_min, host->bus_hz / (2 * 256));
872                         clkdiv = 255;
873                 }
874
875                 host->mode_reg = MCI_MR_CLKDIV(clkdiv);
876
877                 /*
878                  * WRPROOF and RDPROOF prevent overruns/underruns by
879                  * stopping the clock when the FIFO is full/empty.
880                  * This state is not expected to last for long.
881                  */
882                 if (mci_has_rwproof())
883                         host->mode_reg |= (MCI_MR_WRPROOF | MCI_MR_RDPROOF);
884
885                 if (list_empty(&host->queue))
886                         mci_writel(host, MR, host->mode_reg);
887                 else
888                         host->need_clock_update = true;
889
890                 spin_unlock_bh(&host->lock);
891         } else {
892                 bool any_slot_active = false;
893
894                 spin_lock_bh(&host->lock);
895                 slot->clock = 0;
896                 for (i = 0; i < ATMEL_MCI_MAX_NR_SLOTS; i++) {
897                         if (host->slot[i] && host->slot[i]->clock) {
898                                 any_slot_active = true;
899                                 break;
900                         }
901                 }
902                 if (!any_slot_active) {
903                         mci_writel(host, CR, MCI_CR_MCIDIS);
904                         if (host->mode_reg) {
905                                 mci_readl(host, MR);
906                                 clk_disable(host->mck);
907                         }
908                         host->mode_reg = 0;
909                 }
910                 spin_unlock_bh(&host->lock);
911         }
912
913         switch (ios->power_mode) {
914         case MMC_POWER_UP:
915                 set_bit(ATMCI_CARD_NEED_INIT, &slot->flags);
916                 break;
917         default:
918                 /*
919                  * TODO: None of the currently available AVR32-based
920                  * boards allow MMC power to be turned off. Implement
921                  * power control when this can be tested properly.
922                  *
923                  * We also need to hook this into the clock management
924                  * somehow so that newly inserted cards aren't
925                  * subjected to a fast clock before we have a chance
926                  * to figure out what the maximum rate is. Currently,
927                  * there's no way to avoid this, and there never will
928                  * be for boards that don't support power control.
929                  */
930                 break;
931         }
932 }
933
934 static int atmci_get_ro(struct mmc_host *mmc)
935 {
936         int                     read_only = -ENOSYS;
937         struct atmel_mci_slot   *slot = mmc_priv(mmc);
938
939         if (gpio_is_valid(slot->wp_pin)) {
940                 read_only = gpio_get_value(slot->wp_pin);
941                 dev_dbg(&mmc->class_dev, "card is %s\n",
942                                 read_only ? "read-only" : "read-write");
943         }
944
945         return read_only;
946 }
947
948 static int atmci_get_cd(struct mmc_host *mmc)
949 {
950         int                     present = -ENOSYS;
951         struct atmel_mci_slot   *slot = mmc_priv(mmc);
952
953         if (gpio_is_valid(slot->detect_pin)) {
954                 present = !(gpio_get_value(slot->detect_pin) ^
955                             slot->detect_is_active_high);
956                 dev_dbg(&mmc->class_dev, "card is %spresent\n",
957                                 present ? "" : "not ");
958         }
959
960         return present;
961 }
962
963 static const struct mmc_host_ops atmci_ops = {
964         .request        = atmci_request,
965         .set_ios        = atmci_set_ios,
966         .get_ro         = atmci_get_ro,
967         .get_cd         = atmci_get_cd,
968 };
969
970 /* Called with host->lock held */
971 static void atmci_request_end(struct atmel_mci *host, struct mmc_request *mrq)
972         __releases(&host->lock)
973         __acquires(&host->lock)
974 {
975         struct atmel_mci_slot   *slot = NULL;
976         struct mmc_host         *prev_mmc = host->cur_slot->mmc;
977
978         WARN_ON(host->cmd || host->data);
979
980         /*
981          * Update the MMC clock rate if necessary. This may be
982          * necessary if set_ios() is called when a different slot is
983          * busy transfering data.
984          */
985         if (host->need_clock_update)
986                 mci_writel(host, MR, host->mode_reg);
987
988         host->cur_slot->mrq = NULL;
989         host->mrq = NULL;
990         if (!list_empty(&host->queue)) {
991                 slot = list_entry(host->queue.next,
992                                 struct atmel_mci_slot, queue_node);
993                 list_del(&slot->queue_node);
994                 dev_vdbg(&host->pdev->dev, "list not empty: %s is next\n",
995                                 mmc_hostname(slot->mmc));
996                 host->state = STATE_SENDING_CMD;
997                 atmci_start_request(host, slot);
998         } else {
999                 dev_vdbg(&host->pdev->dev, "list empty\n");
1000                 host->state = STATE_IDLE;
1001         }
1002
1003         spin_unlock(&host->lock);
1004         mmc_request_done(prev_mmc, mrq);
1005         spin_lock(&host->lock);
1006 }
1007
1008 static void atmci_command_complete(struct atmel_mci *host,
1009                         struct mmc_command *cmd)
1010 {
1011         u32             status = host->cmd_status;
1012
1013         /* Read the response from the card (up to 16 bytes) */
1014         cmd->resp[0] = mci_readl(host, RSPR);
1015         cmd->resp[1] = mci_readl(host, RSPR);
1016         cmd->resp[2] = mci_readl(host, RSPR);
1017         cmd->resp[3] = mci_readl(host, RSPR);
1018
1019         if (status & MCI_RTOE)
1020                 cmd->error = -ETIMEDOUT;
1021         else if ((cmd->flags & MMC_RSP_CRC) && (status & MCI_RCRCE))
1022                 cmd->error = -EILSEQ;
1023         else if (status & (MCI_RINDE | MCI_RDIRE | MCI_RENDE))
1024                 cmd->error = -EIO;
1025         else
1026                 cmd->error = 0;
1027
1028         if (cmd->error) {
1029                 dev_dbg(&host->pdev->dev,
1030                         "command error: status=0x%08x\n", status);
1031
1032                 if (cmd->data) {
1033                         host->data = NULL;
1034                         atmci_stop_dma(host);
1035                         mci_writel(host, IDR, MCI_NOTBUSY
1036                                         | MCI_TXRDY | MCI_RXRDY
1037                                         | ATMCI_DATA_ERROR_FLAGS);
1038                 }
1039         }
1040 }
1041
1042 static void atmci_detect_change(unsigned long data)
1043 {
1044         struct atmel_mci_slot   *slot = (struct atmel_mci_slot *)data;
1045         bool                    present;
1046         bool                    present_old;
1047
1048         /*
1049          * atmci_cleanup_slot() sets the ATMCI_SHUTDOWN flag before
1050          * freeing the interrupt. We must not re-enable the interrupt
1051          * if it has been freed, and if we're shutting down, it
1052          * doesn't really matter whether the card is present or not.
1053          */
1054         smp_rmb();
1055         if (test_bit(ATMCI_SHUTDOWN, &slot->flags))
1056                 return;
1057
1058         enable_irq(gpio_to_irq(slot->detect_pin));
1059         present = !(gpio_get_value(slot->detect_pin) ^
1060                     slot->detect_is_active_high);
1061         present_old = test_bit(ATMCI_CARD_PRESENT, &slot->flags);
1062
1063         dev_vdbg(&slot->mmc->class_dev, "detect change: %d (was %d)\n",
1064                         present, present_old);
1065
1066         if (present != present_old) {
1067                 struct atmel_mci        *host = slot->host;
1068                 struct mmc_request      *mrq;
1069
1070                 dev_dbg(&slot->mmc->class_dev, "card %s\n",
1071                         present ? "inserted" : "removed");
1072
1073                 spin_lock(&host->lock);
1074
1075                 if (!present)
1076                         clear_bit(ATMCI_CARD_PRESENT, &slot->flags);
1077                 else
1078                         set_bit(ATMCI_CARD_PRESENT, &slot->flags);
1079
1080                 /* Clean up queue if present */
1081                 mrq = slot->mrq;
1082                 if (mrq) {
1083                         if (mrq == host->mrq) {
1084                                 /*
1085                                  * Reset controller to terminate any ongoing
1086                                  * commands or data transfers.
1087                                  */
1088                                 mci_writel(host, CR, MCI_CR_SWRST);
1089                                 mci_writel(host, CR, MCI_CR_MCIEN);
1090                                 mci_writel(host, MR, host->mode_reg);
1091
1092                                 host->data = NULL;
1093                                 host->cmd = NULL;
1094
1095                                 switch (host->state) {
1096                                 case STATE_IDLE:
1097                                         break;
1098                                 case STATE_SENDING_CMD:
1099                                         mrq->cmd->error = -ENOMEDIUM;
1100                                         if (!mrq->data)
1101                                                 break;
1102                                         /* fall through */
1103                                 case STATE_SENDING_DATA:
1104                                         mrq->data->error = -ENOMEDIUM;
1105                                         atmci_stop_dma(host);
1106                                         break;
1107                                 case STATE_DATA_BUSY:
1108                                 case STATE_DATA_ERROR:
1109                                         if (mrq->data->error == -EINPROGRESS)
1110                                                 mrq->data->error = -ENOMEDIUM;
1111                                         if (!mrq->stop)
1112                                                 break;
1113                                         /* fall through */
1114                                 case STATE_SENDING_STOP:
1115                                         mrq->stop->error = -ENOMEDIUM;
1116                                         break;
1117                                 }
1118
1119                                 atmci_request_end(host, mrq);
1120                         } else {
1121                                 list_del(&slot->queue_node);
1122                                 mrq->cmd->error = -ENOMEDIUM;
1123                                 if (mrq->data)
1124                                         mrq->data->error = -ENOMEDIUM;
1125                                 if (mrq->stop)
1126                                         mrq->stop->error = -ENOMEDIUM;
1127
1128                                 spin_unlock(&host->lock);
1129                                 mmc_request_done(slot->mmc, mrq);
1130                                 spin_lock(&host->lock);
1131                         }
1132                 }
1133                 spin_unlock(&host->lock);
1134
1135                 mmc_detect_change(slot->mmc, 0);
1136         }
1137 }
1138
1139 static void atmci_tasklet_func(unsigned long priv)
1140 {
1141         struct atmel_mci        *host = (struct atmel_mci *)priv;
1142         struct mmc_request      *mrq = host->mrq;
1143         struct mmc_data         *data = host->data;
1144         struct mmc_command      *cmd = host->cmd;
1145         enum atmel_mci_state    state = host->state;
1146         enum atmel_mci_state    prev_state;
1147         u32                     status;
1148
1149         spin_lock(&host->lock);
1150
1151         state = host->state;
1152
1153         dev_vdbg(&host->pdev->dev,
1154                 "tasklet: state %u pending/completed/mask %lx/%lx/%x\n",
1155                 state, host->pending_events, host->completed_events,
1156                 mci_readl(host, IMR));
1157
1158         do {
1159                 prev_state = state;
1160
1161                 switch (state) {
1162                 case STATE_IDLE:
1163                         break;
1164
1165                 case STATE_SENDING_CMD:
1166                         if (!atmci_test_and_clear_pending(host,
1167                                                 EVENT_CMD_COMPLETE))
1168                                 break;
1169
1170                         host->cmd = NULL;
1171                         atmci_set_completed(host, EVENT_CMD_COMPLETE);
1172                         atmci_command_complete(host, mrq->cmd);
1173                         if (!mrq->data || cmd->error) {
1174                                 atmci_request_end(host, host->mrq);
1175                                 goto unlock;
1176                         }
1177
1178                         prev_state = state = STATE_SENDING_DATA;
1179                         /* fall through */
1180
1181                 case STATE_SENDING_DATA:
1182                         if (atmci_test_and_clear_pending(host,
1183                                                 EVENT_DATA_ERROR)) {
1184                                 atmci_stop_dma(host);
1185                                 if (data->stop)
1186                                         send_stop_cmd(host, data);
1187                                 state = STATE_DATA_ERROR;
1188                                 break;
1189                         }
1190
1191                         if (!atmci_test_and_clear_pending(host,
1192                                                 EVENT_XFER_COMPLETE))
1193                                 break;
1194
1195                         atmci_set_completed(host, EVENT_XFER_COMPLETE);
1196                         prev_state = state = STATE_DATA_BUSY;
1197                         /* fall through */
1198
1199                 case STATE_DATA_BUSY:
1200                         if (!atmci_test_and_clear_pending(host,
1201                                                 EVENT_DATA_COMPLETE))
1202                                 break;
1203
1204                         host->data = NULL;
1205                         atmci_set_completed(host, EVENT_DATA_COMPLETE);
1206                         status = host->data_status;
1207                         if (unlikely(status & ATMCI_DATA_ERROR_FLAGS)) {
1208                                 if (status & MCI_DTOE) {
1209                                         dev_dbg(&host->pdev->dev,
1210                                                         "data timeout error\n");
1211                                         data->error = -ETIMEDOUT;
1212                                 } else if (status & MCI_DCRCE) {
1213                                         dev_dbg(&host->pdev->dev,
1214                                                         "data CRC error\n");
1215                                         data->error = -EILSEQ;
1216                                 } else {
1217                                         dev_dbg(&host->pdev->dev,
1218                                                 "data FIFO error (status=%08x)\n",
1219                                                 status);
1220                                         data->error = -EIO;
1221                                 }
1222                         } else {
1223                                 data->bytes_xfered = data->blocks * data->blksz;
1224                                 data->error = 0;
1225                         }
1226
1227                         if (!data->stop) {
1228                                 atmci_request_end(host, host->mrq);
1229                                 goto unlock;
1230                         }
1231
1232                         prev_state = state = STATE_SENDING_STOP;
1233                         if (!data->error)
1234                                 send_stop_cmd(host, data);
1235                         /* fall through */
1236
1237                 case STATE_SENDING_STOP:
1238                         if (!atmci_test_and_clear_pending(host,
1239                                                 EVENT_CMD_COMPLETE))
1240                                 break;
1241
1242                         host->cmd = NULL;
1243                         atmci_command_complete(host, mrq->stop);
1244                         atmci_request_end(host, host->mrq);
1245                         goto unlock;
1246
1247                 case STATE_DATA_ERROR:
1248                         if (!atmci_test_and_clear_pending(host,
1249                                                 EVENT_XFER_COMPLETE))
1250                                 break;
1251
1252                         state = STATE_DATA_BUSY;
1253                         break;
1254                 }
1255         } while (state != prev_state);
1256
1257         host->state = state;
1258
1259 unlock:
1260         spin_unlock(&host->lock);
1261 }
1262
1263 static void atmci_read_data_pio(struct atmel_mci *host)
1264 {
1265         struct scatterlist      *sg = host->sg;
1266         void                    *buf = sg_virt(sg);
1267         unsigned int            offset = host->pio_offset;
1268         struct mmc_data         *data = host->data;
1269         u32                     value;
1270         u32                     status;
1271         unsigned int            nbytes = 0;
1272
1273         do {
1274                 value = mci_readl(host, RDR);
1275                 if (likely(offset + 4 <= sg->length)) {
1276                         put_unaligned(value, (u32 *)(buf + offset));
1277
1278                         offset += 4;
1279                         nbytes += 4;
1280
1281                         if (offset == sg->length) {
1282                                 flush_dcache_page(sg_page(sg));
1283                                 host->sg = sg = sg_next(sg);
1284                                 if (!sg)
1285                                         goto done;
1286
1287                                 offset = 0;
1288                                 buf = sg_virt(sg);
1289                         }
1290                 } else {
1291                         unsigned int remaining = sg->length - offset;
1292                         memcpy(buf + offset, &value, remaining);
1293                         nbytes += remaining;
1294
1295                         flush_dcache_page(sg_page(sg));
1296                         host->sg = sg = sg_next(sg);
1297                         if (!sg)
1298                                 goto done;
1299
1300                         offset = 4 - remaining;
1301                         buf = sg_virt(sg);
1302                         memcpy(buf, (u8 *)&value + remaining, offset);
1303                         nbytes += offset;
1304                 }
1305
1306                 status = mci_readl(host, SR);
1307                 if (status & ATMCI_DATA_ERROR_FLAGS) {
1308                         mci_writel(host, IDR, (MCI_NOTBUSY | MCI_RXRDY
1309                                                 | ATMCI_DATA_ERROR_FLAGS));
1310                         host->data_status = status;
1311                         data->bytes_xfered += nbytes;
1312                         smp_wmb();
1313                         atmci_set_pending(host, EVENT_DATA_ERROR);
1314                         tasklet_schedule(&host->tasklet);
1315                         return;
1316                 }
1317         } while (status & MCI_RXRDY);
1318
1319         host->pio_offset = offset;
1320         data->bytes_xfered += nbytes;
1321
1322         return;
1323
1324 done:
1325         mci_writel(host, IDR, MCI_RXRDY);
1326         mci_writel(host, IER, MCI_NOTBUSY);
1327         data->bytes_xfered += nbytes;
1328         smp_wmb();
1329         atmci_set_pending(host, EVENT_XFER_COMPLETE);
1330 }
1331
1332 static void atmci_write_data_pio(struct atmel_mci *host)
1333 {
1334         struct scatterlist      *sg = host->sg;
1335         void                    *buf = sg_virt(sg);
1336         unsigned int            offset = host->pio_offset;
1337         struct mmc_data         *data = host->data;
1338         u32                     value;
1339         u32                     status;
1340         unsigned int            nbytes = 0;
1341
1342         do {
1343                 if (likely(offset + 4 <= sg->length)) {
1344                         value = get_unaligned((u32 *)(buf + offset));
1345                         mci_writel(host, TDR, value);
1346
1347                         offset += 4;
1348                         nbytes += 4;
1349                         if (offset == sg->length) {
1350                                 host->sg = sg = sg_next(sg);
1351                                 if (!sg)
1352                                         goto done;
1353
1354                                 offset = 0;
1355                                 buf = sg_virt(sg);
1356                         }
1357                 } else {
1358                         unsigned int remaining = sg->length - offset;
1359
1360                         value = 0;
1361                         memcpy(&value, buf + offset, remaining);
1362                         nbytes += remaining;
1363
1364                         host->sg = sg = sg_next(sg);
1365                         if (!sg) {
1366                                 mci_writel(host, TDR, value);
1367                                 goto done;
1368                         }
1369
1370                         offset = 4 - remaining;
1371                         buf = sg_virt(sg);
1372                         memcpy((u8 *)&value + remaining, buf, offset);
1373                         mci_writel(host, TDR, value);
1374                         nbytes += offset;
1375                 }
1376
1377                 status = mci_readl(host, SR);
1378                 if (status & ATMCI_DATA_ERROR_FLAGS) {
1379                         mci_writel(host, IDR, (MCI_NOTBUSY | MCI_TXRDY
1380                                                 | ATMCI_DATA_ERROR_FLAGS));
1381                         host->data_status = status;
1382                         data->bytes_xfered += nbytes;
1383                         smp_wmb();
1384                         atmci_set_pending(host, EVENT_DATA_ERROR);
1385                         tasklet_schedule(&host->tasklet);
1386                         return;
1387                 }
1388         } while (status & MCI_TXRDY);
1389
1390         host->pio_offset = offset;
1391         data->bytes_xfered += nbytes;
1392
1393         return;
1394
1395 done:
1396         mci_writel(host, IDR, MCI_TXRDY);
1397         mci_writel(host, IER, MCI_NOTBUSY);
1398         data->bytes_xfered += nbytes;
1399         smp_wmb();
1400         atmci_set_pending(host, EVENT_XFER_COMPLETE);
1401 }
1402
1403 static void atmci_cmd_interrupt(struct atmel_mci *host, u32 status)
1404 {
1405         mci_writel(host, IDR, MCI_CMDRDY);
1406
1407         host->cmd_status = status;
1408         smp_wmb();
1409         atmci_set_pending(host, EVENT_CMD_COMPLETE);
1410         tasklet_schedule(&host->tasklet);
1411 }
1412
1413 static irqreturn_t atmci_interrupt(int irq, void *dev_id)
1414 {
1415         struct atmel_mci        *host = dev_id;
1416         u32                     status, mask, pending;
1417         unsigned int            pass_count = 0;
1418
1419         do {
1420                 status = mci_readl(host, SR);
1421                 mask = mci_readl(host, IMR);
1422                 pending = status & mask;
1423                 if (!pending)
1424                         break;
1425
1426                 if (pending & ATMCI_DATA_ERROR_FLAGS) {
1427                         mci_writel(host, IDR, ATMCI_DATA_ERROR_FLAGS
1428                                         | MCI_RXRDY | MCI_TXRDY);
1429                         pending &= mci_readl(host, IMR);
1430
1431                         host->data_status = status;
1432                         smp_wmb();
1433                         atmci_set_pending(host, EVENT_DATA_ERROR);
1434                         tasklet_schedule(&host->tasklet);
1435                 }
1436                 if (pending & MCI_NOTBUSY) {
1437                         mci_writel(host, IDR,
1438                                         ATMCI_DATA_ERROR_FLAGS | MCI_NOTBUSY);
1439                         if (!host->data_status)
1440                                 host->data_status = status;
1441                         smp_wmb();
1442                         atmci_set_pending(host, EVENT_DATA_COMPLETE);
1443                         tasklet_schedule(&host->tasklet);
1444                 }
1445                 if (pending & MCI_RXRDY)
1446                         atmci_read_data_pio(host);
1447                 if (pending & MCI_TXRDY)
1448                         atmci_write_data_pio(host);
1449
1450                 if (pending & MCI_CMDRDY)
1451                         atmci_cmd_interrupt(host, status);
1452         } while (pass_count++ < 5);
1453
1454         return pass_count ? IRQ_HANDLED : IRQ_NONE;
1455 }
1456
1457 static irqreturn_t atmci_detect_interrupt(int irq, void *dev_id)
1458 {
1459         struct atmel_mci_slot   *slot = dev_id;
1460
1461         /*
1462          * Disable interrupts until the pin has stabilized and check
1463          * the state then. Use mod_timer() since we may be in the
1464          * middle of the timer routine when this interrupt triggers.
1465          */
1466         disable_irq_nosync(irq);
1467         mod_timer(&slot->detect_timer, jiffies + msecs_to_jiffies(20));
1468
1469         return IRQ_HANDLED;
1470 }
1471
1472 static int __init atmci_init_slot(struct atmel_mci *host,
1473                 struct mci_slot_pdata *slot_data, unsigned int id,
1474                 u32 sdc_reg)
1475 {
1476         struct mmc_host                 *mmc;
1477         struct atmel_mci_slot           *slot;
1478
1479         mmc = mmc_alloc_host(sizeof(struct atmel_mci_slot), &host->pdev->dev);
1480         if (!mmc)
1481                 return -ENOMEM;
1482
1483         slot = mmc_priv(mmc);
1484         slot->mmc = mmc;
1485         slot->host = host;
1486         slot->detect_pin = slot_data->detect_pin;
1487         slot->wp_pin = slot_data->wp_pin;
1488         slot->detect_is_active_high = slot_data->detect_is_active_high;
1489         slot->sdc_reg = sdc_reg;
1490
1491         mmc->ops = &atmci_ops;
1492         mmc->f_min = DIV_ROUND_UP(host->bus_hz, 512);
1493         mmc->f_max = host->bus_hz / 2;
1494         mmc->ocr_avail  = MMC_VDD_32_33 | MMC_VDD_33_34;
1495         if (slot_data->bus_width >= 4)
1496                 mmc->caps |= MMC_CAP_4_BIT_DATA;
1497
1498         mmc->max_hw_segs = 64;
1499         mmc->max_phys_segs = 64;
1500         mmc->max_req_size = 32768 * 512;
1501         mmc->max_blk_size = 32768;
1502         mmc->max_blk_count = 512;
1503
1504         /* Assume card is present initially */
1505         set_bit(ATMCI_CARD_PRESENT, &slot->flags);
1506         if (gpio_is_valid(slot->detect_pin)) {
1507                 if (gpio_request(slot->detect_pin, "mmc_detect")) {
1508                         dev_dbg(&mmc->class_dev, "no detect pin available\n");
1509                         slot->detect_pin = -EBUSY;
1510                 } else if (gpio_get_value(slot->detect_pin) ^
1511                                 slot->detect_is_active_high) {
1512                         clear_bit(ATMCI_CARD_PRESENT, &slot->flags);
1513                 }
1514         }
1515
1516         if (!gpio_is_valid(slot->detect_pin))
1517                 mmc->caps |= MMC_CAP_NEEDS_POLL;
1518
1519         if (gpio_is_valid(slot->wp_pin)) {
1520                 if (gpio_request(slot->wp_pin, "mmc_wp")) {
1521                         dev_dbg(&mmc->class_dev, "no WP pin available\n");
1522                         slot->wp_pin = -EBUSY;
1523                 }
1524         }
1525
1526         host->slot[id] = slot;
1527         mmc_add_host(mmc);
1528
1529         if (gpio_is_valid(slot->detect_pin)) {
1530                 int ret;
1531
1532                 setup_timer(&slot->detect_timer, atmci_detect_change,
1533                                 (unsigned long)slot);
1534
1535                 ret = request_irq(gpio_to_irq(slot->detect_pin),
1536                                 atmci_detect_interrupt,
1537                                 IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
1538                                 "mmc-detect", slot);
1539                 if (ret) {
1540                         dev_dbg(&mmc->class_dev,
1541                                 "could not request IRQ %d for detect pin\n",
1542                                 gpio_to_irq(slot->detect_pin));
1543                         gpio_free(slot->detect_pin);
1544                         slot->detect_pin = -EBUSY;
1545                 }
1546         }
1547
1548         atmci_init_debugfs(slot);
1549
1550         return 0;
1551 }
1552
1553 static void __exit atmci_cleanup_slot(struct atmel_mci_slot *slot,
1554                 unsigned int id)
1555 {
1556         /* Debugfs stuff is cleaned up by mmc core */
1557
1558         set_bit(ATMCI_SHUTDOWN, &slot->flags);
1559         smp_wmb();
1560
1561         mmc_remove_host(slot->mmc);
1562
1563         if (gpio_is_valid(slot->detect_pin)) {
1564                 int pin = slot->detect_pin;
1565
1566                 free_irq(gpio_to_irq(pin), slot);
1567                 del_timer_sync(&slot->detect_timer);
1568                 gpio_free(pin);
1569         }
1570         if (gpio_is_valid(slot->wp_pin))
1571                 gpio_free(slot->wp_pin);
1572
1573         slot->host->slot[id] = NULL;
1574         mmc_free_host(slot->mmc);
1575 }
1576
1577 #ifdef CONFIG_MMC_ATMELMCI_DMA
1578 static bool filter(struct dma_chan *chan, void *slave)
1579 {
1580         struct dw_dma_slave *dws = slave;
1581
1582         if (dws->dma_dev == chan->device->dev) {
1583                 chan->private = dws;
1584                 return true;
1585         } else
1586                 return false;
1587 }
1588 #endif
1589
1590 static int __init atmci_probe(struct platform_device *pdev)
1591 {
1592         struct mci_platform_data        *pdata;
1593         struct atmel_mci                *host;
1594         struct resource                 *regs;
1595         unsigned int                    nr_slots;
1596         int                             irq;
1597         int                             ret;
1598
1599         regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1600         if (!regs)
1601                 return -ENXIO;
1602         pdata = pdev->dev.platform_data;
1603         if (!pdata)
1604                 return -ENXIO;
1605         irq = platform_get_irq(pdev, 0);
1606         if (irq < 0)
1607                 return irq;
1608
1609         host = kzalloc(sizeof(struct atmel_mci), GFP_KERNEL);
1610         if (!host)
1611                 return -ENOMEM;
1612
1613         host->pdev = pdev;
1614         spin_lock_init(&host->lock);
1615         INIT_LIST_HEAD(&host->queue);
1616
1617         host->mck = clk_get(&pdev->dev, "mci_clk");
1618         if (IS_ERR(host->mck)) {
1619                 ret = PTR_ERR(host->mck);
1620                 goto err_clk_get;
1621         }
1622
1623         ret = -ENOMEM;
1624         host->regs = ioremap(regs->start, regs->end - regs->start + 1);
1625         if (!host->regs)
1626                 goto err_ioremap;
1627
1628         clk_enable(host->mck);
1629         mci_writel(host, CR, MCI_CR_SWRST);
1630         host->bus_hz = clk_get_rate(host->mck);
1631         clk_disable(host->mck);
1632
1633         host->mapbase = regs->start;
1634
1635         tasklet_init(&host->tasklet, atmci_tasklet_func, (unsigned long)host);
1636
1637         ret = request_irq(irq, atmci_interrupt, 0, dev_name(&pdev->dev), host);
1638         if (ret)
1639                 goto err_request_irq;
1640
1641 #ifdef CONFIG_MMC_ATMELMCI_DMA
1642         if (pdata->dma_slave.dma_dev) {
1643                 struct dw_dma_slave *dws = &pdata->dma_slave;
1644                 dma_cap_mask_t mask;
1645
1646                 dws->tx_reg = regs->start + MCI_TDR;
1647                 dws->rx_reg = regs->start + MCI_RDR;
1648
1649                 /* Try to grab a DMA channel */
1650                 dma_cap_zero(mask);
1651                 dma_cap_set(DMA_SLAVE, mask);
1652                 host->dma.chan = dma_request_channel(mask, filter, dws);
1653         }
1654         if (!host->dma.chan)
1655                 dev_notice(&pdev->dev, "DMA not available, using PIO\n");
1656 #endif /* CONFIG_MMC_ATMELMCI_DMA */
1657
1658         platform_set_drvdata(pdev, host);
1659
1660         /* We need at least one slot to succeed */
1661         nr_slots = 0;
1662         ret = -ENODEV;
1663         if (pdata->slot[0].bus_width) {
1664                 ret = atmci_init_slot(host, &pdata->slot[0],
1665                                 MCI_SDCSEL_SLOT_A, 0);
1666                 if (!ret)
1667                         nr_slots++;
1668         }
1669         if (pdata->slot[1].bus_width) {
1670                 ret = atmci_init_slot(host, &pdata->slot[1],
1671                                 MCI_SDCSEL_SLOT_B, 1);
1672                 if (!ret)
1673                         nr_slots++;
1674         }
1675
1676         if (!nr_slots) {
1677                 dev_err(&pdev->dev, "init failed: no slot defined\n");
1678                 goto err_init_slot;
1679         }
1680
1681         dev_info(&pdev->dev,
1682                         "Atmel MCI controller at 0x%08lx irq %d, %u slots\n",
1683                         host->mapbase, irq, nr_slots);
1684
1685         return 0;
1686
1687 err_init_slot:
1688 #ifdef CONFIG_MMC_ATMELMCI_DMA
1689         if (host->dma.chan)
1690                 dma_release_channel(host->dma.chan);
1691 #endif
1692         free_irq(irq, host);
1693 err_request_irq:
1694         iounmap(host->regs);
1695 err_ioremap:
1696         clk_put(host->mck);
1697 err_clk_get:
1698         kfree(host);
1699         return ret;
1700 }
1701
1702 static int __exit atmci_remove(struct platform_device *pdev)
1703 {
1704         struct atmel_mci        *host = platform_get_drvdata(pdev);
1705         unsigned int            i;
1706
1707         platform_set_drvdata(pdev, NULL);
1708
1709         for (i = 0; i < ATMEL_MCI_MAX_NR_SLOTS; i++) {
1710                 if (host->slot[i])
1711                         atmci_cleanup_slot(host->slot[i], i);
1712         }
1713
1714         clk_enable(host->mck);
1715         mci_writel(host, IDR, ~0UL);
1716         mci_writel(host, CR, MCI_CR_MCIDIS);
1717         mci_readl(host, SR);
1718         clk_disable(host->mck);
1719
1720 #ifdef CONFIG_MMC_ATMELMCI_DMA
1721         if (host->dma.chan)
1722                 dma_release_channel(host->dma.chan);
1723 #endif
1724
1725         free_irq(platform_get_irq(pdev, 0), host);
1726         iounmap(host->regs);
1727
1728         clk_put(host->mck);
1729         kfree(host);
1730
1731         return 0;
1732 }
1733
1734 static struct platform_driver atmci_driver = {
1735         .remove         = __exit_p(atmci_remove),
1736         .driver         = {
1737                 .name           = "atmel_mci",
1738         },
1739 };
1740
1741 static int __init atmci_init(void)
1742 {
1743         return platform_driver_probe(&atmci_driver, atmci_probe);
1744 }
1745
1746 static void __exit atmci_exit(void)
1747 {
1748         platform_driver_unregister(&atmci_driver);
1749 }
1750
1751 late_initcall(atmci_init); /* try to load after dma driver when built-in */
1752 module_exit(atmci_exit);
1753
1754 MODULE_DESCRIPTION("Atmel Multimedia Card Interface driver");
1755 MODULE_AUTHOR("Haavard Skinnemoen <haavard.skinnemoen@atmel.com>");
1756 MODULE_LICENSE("GPL v2");