Linux kernel & device driver programming

Cross-Referenced Linux and Device Driver Code

[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ]
Version: [ 2.6.11.8 ] [ 2.6.25 ] [ 2.6.25.8 ] [ 2.6.31.13 ] Architecture: [ i386 ]
  1 /*
  2  *  linux/drivers/mmc/host/at91_mci.c - ATMEL AT91 MCI Driver
  3  *
  4  *  Copyright (C) 2005 Cougar Creek Computing Devices Ltd, All Rights Reserved
  5  *
  6  *  Copyright (C) 2006 Malcolm Noyes
  7  *
  8  * This program is free software; you can redistribute it and/or modify
  9  * it under the terms of the GNU General Public License version 2 as
 10  * published by the Free Software Foundation.
 11  */
 12 
 13 /*
 14    This is the AT91 MCI driver that has been tested with both MMC cards
 15    and SD-cards.  Boards that support write protect are now supported.
 16    The CCAT91SBC001 board does not support SD cards.
 17 
 18    The three entry points are at91_mci_request, at91_mci_set_ios
 19    and at91_mci_get_ro.
 20 
 21    SET IOS
 22      This configures the device to put it into the correct mode and clock speed
 23      required.
 24 
 25    MCI REQUEST
 26      MCI request processes the commands sent in the mmc_request structure. This
 27      can consist of a processing command and a stop command in the case of
 28      multiple block transfers.
 29 
 30      There are three main types of request, commands, reads and writes.
 31 
 32      Commands are straight forward. The command is submitted to the controller and
 33      the request function returns. When the controller generates an interrupt to indicate
 34      the command is finished, the response to the command are read and the mmc_request_done
 35      function called to end the request.
 36 
 37      Reads and writes work in a similar manner to normal commands but involve the PDC (DMA)
 38      controller to manage the transfers.
 39 
 40      A read is done from the controller directly to the scatterlist passed in from the request.
 41      Due to a bug in the AT91RM9200 controller, when a read is completed, all the words are byte
 42      swapped in the scatterlist buffers.  AT91SAM926x are not affected by this bug.
 43 
 44      The sequence of read interrupts is: ENDRX, RXBUFF, CMDRDY
 45 
 46      A write is slightly different in that the bytes to write are read from the scatterlist
 47      into a dma memory buffer (this is in case the source buffer should be read only). The
 48      entire write buffer is then done from this single dma memory buffer.
 49 
 50      The sequence of write interrupts is: ENDTX, TXBUFE, NOTBUSY, CMDRDY
 51 
 52    GET RO
 53      Gets the status of the write protect pin, if available.
 54 */
 55 
 56 #include <linux/module.h>
 57 #include <linux/moduleparam.h>
 58 #include <linux/init.h>
 59 #include <linux/ioport.h>
 60 #include <linux/platform_device.h>
 61 #include <linux/interrupt.h>
 62 #include <linux/blkdev.h>
 63 #include <linux/delay.h>
 64 #include <linux/err.h>
 65 #include <linux/dma-mapping.h>
 66 #include <linux/clk.h>
 67 #include <linux/atmel_pdc.h>
 68 
 69 #include <linux/mmc/host.h>
 70 
 71 #include <asm/io.h>
 72 #include <asm/irq.h>
 73 #include <asm/gpio.h>
 74 
 75 #include <asm/mach/mmc.h>
 76 #include <mach/board.h>
 77 #include <mach/cpu.h>
 78 #include <mach/at91_mci.h>
 79 
 80 #define DRIVER_NAME "at91_mci"
 81 
 82 #define FL_SENT_COMMAND (1 << 0)
 83 #define FL_SENT_STOP    (1 << 1)
 84 
 85 #define AT91_MCI_ERRORS (AT91_MCI_RINDE | AT91_MCI_RDIRE | AT91_MCI_RCRCE       \
 86                 | AT91_MCI_RENDE | AT91_MCI_RTOE | AT91_MCI_DCRCE               \
 87                 | AT91_MCI_DTOE | AT91_MCI_OVRE | AT91_MCI_UNRE)
 88 
 89 #define at91_mci_read(host, reg)        __raw_readl((host)->baseaddr + (reg))
 90 #define at91_mci_write(host, reg, val)  __raw_writel((val), (host)->baseaddr + (reg))
 91 
 92 
 93 /*
 94  * Low level type for this driver
 95  */
 96 struct at91mci_host
 97 {
 98         struct mmc_host *mmc;
 99         struct mmc_command *cmd;
100         struct mmc_request *request;
101 
102         void __iomem *baseaddr;
103         int irq;
104 
105         struct at91_mmc_data *board;
106         int present;
107 
108         struct clk *mci_clk;
109 
110         /*
111          * Flag indicating when the command has been sent. This is used to
112          * work out whether or not to send the stop
113          */
114         unsigned int flags;
115         /* flag for current bus settings */
116         u32 bus_mode;
117 
118         /* DMA buffer used for transmitting */
119         unsigned int* buffer;
120         dma_addr_t physical_address;
121         unsigned int total_length;
122 
123         /* Latest in the scatterlist that has been enabled for transfer, but not freed */
124         int in_use_index;
125 
126         /* Latest in the scatterlist that has been enabled for transfer */
127         int transfer_index;
128 
129         /* Timer for timeouts */
130         struct timer_list timer;
131 };
132 
133 /*
134  * Reset the controller and restore most of the state
135  */
136 static void at91_reset_host(struct at91mci_host *host)
137 {
138         unsigned long flags;
139         u32 mr;
140         u32 sdcr;
141         u32 dtor;
142         u32 imr;
143 
144         local_irq_save(flags);
145         imr = at91_mci_read(host, AT91_MCI_IMR);
146 
147         at91_mci_write(host, AT91_MCI_IDR, 0xffffffff);
148 
149         /* save current state */
150         mr = at91_mci_read(host, AT91_MCI_MR) & 0x7fff;
151         sdcr = at91_mci_read(host, AT91_MCI_SDCR);
152         dtor = at91_mci_read(host, AT91_MCI_DTOR);
153 
154         /* reset the controller */
155         at91_mci_write(host, AT91_MCI_CR, AT91_MCI_MCIDIS | AT91_MCI_SWRST);
156 
157         /* restore state */
158         at91_mci_write(host, AT91_MCI_CR, AT91_MCI_MCIEN);
159         at91_mci_write(host, AT91_MCI_MR, mr);
160         at91_mci_write(host, AT91_MCI_SDCR, sdcr);
161         at91_mci_write(host, AT91_MCI_DTOR, dtor);
162         at91_mci_write(host, AT91_MCI_IER, imr);
163 
164         /* make sure sdio interrupts will fire */
165         at91_mci_read(host, AT91_MCI_SR);
166 
167         local_irq_restore(flags);
168 }
169 
170 static void at91_timeout_timer(unsigned long data)
171 {
172         struct at91mci_host *host;
173 
174         host = (struct at91mci_host *)data;
175 
176         if (host->request) {
177                 dev_err(host->mmc->parent, "Timeout waiting end of packet\n");
178 
179                 if (host->cmd && host->cmd->data) {
180                         host->cmd->data->error = -ETIMEDOUT;
181                 } else {
182                         if (host->cmd)
183                                 host->cmd->error = -ETIMEDOUT;
184                         else
185                                 host->request->cmd->error = -ETIMEDOUT;
186                 }
187 
188                 at91_reset_host(host);
189                 mmc_request_done(host->mmc, host->request);
190         }
191 }
192 
193 /*
194  * Copy from sg to a dma block - used for transfers
195  */
196 static inline void at91_mci_sg_to_dma(struct at91mci_host *host, struct mmc_data *data)
197 {
198         unsigned int len, i, size;
199         unsigned *dmabuf = host->buffer;
200 
201         size = data->blksz * data->blocks;
202         len = data->sg_len;
203 
204         /* AT91SAM926[0/3] Data Write Operation and number of bytes erratum */
205         if (cpu_is_at91sam9260() || cpu_is_at91sam9263())
206                 if (host->total_length == 12)
207                         memset(dmabuf, 0, 12);
208 
209         /*
210          * Just loop through all entries. Size might not
211          * be the entire list though so make sure that
212          * we do not transfer too much.
213          */
214         for (i = 0; i < len; i++) {
215                 struct scatterlist *sg;
216                 int amount;
217                 unsigned int *sgbuffer;
218 
219                 sg = &data->sg[i];
220 
221                 sgbuffer = kmap_atomic(sg_page(sg), KM_BIO_SRC_IRQ) + sg->offset;
222                 amount = min(size, sg->length);
223                 size -= amount;
224 
225                 if (cpu_is_at91rm9200()) {      /* AT91RM9200 errata */
226                         int index;
227 
228                         for (index = 0; index < (amount / 4); index++)
229                                 *dmabuf++ = swab32(sgbuffer[index]);
230                 } else {
231                         memcpy(dmabuf, sgbuffer, amount);
232                         dmabuf += amount;
233                 }
234 
235                 kunmap_atomic(sgbuffer, KM_BIO_SRC_IRQ);
236 
237                 if (size == 0)
238                         break;
239         }
240 
241         /*
242          * Check that we didn't get a request to transfer
243          * more data than can fit into the SG list.
244          */
245         BUG_ON(size != 0);
246 }
247 
248 /*
249  * Prepare a dma read
250  */
251 static void at91_mci_pre_dma_read(struct at91mci_host *host)
252 {
253         int i;
254         struct scatterlist *sg;
255         struct mmc_command *cmd;
256         struct mmc_data *data;
257 
258         pr_debug("pre dma read\n");
259 
260         cmd = host->cmd;
261         if (!cmd) {
262                 pr_debug("no command\n");
263                 return;
264         }
265 
266         data = cmd->data;
267         if (!data) {
268                 pr_debug("no data\n");
269                 return;
270         }
271 
272         for (i = 0; i < 2; i++) {
273                 /* nothing left to transfer */
274                 if (host->transfer_index >= data->sg_len) {
275                         pr_debug("Nothing left to transfer (index = %d)\n", host->transfer_index);
276                         break;
277                 }
278 
279                 /* Check to see if this needs filling */
280                 if (i == 0) {
281                         if (at91_mci_read(host, ATMEL_PDC_RCR) != 0) {
282                                 pr_debug("Transfer active in current\n");
283                                 continue;
284                         }
285                 }
286                 else {
287                         if (at91_mci_read(host, ATMEL_PDC_RNCR) != 0) {
288                                 pr_debug("Transfer active in next\n");
289                                 continue;
290                         }
291                 }
292 
293                 /* Setup the next transfer */
294                 pr_debug("Using transfer index %d\n", host->transfer_index);
295 
296                 sg = &data->sg[host->transfer_index++];
297                 pr_debug("sg = %p\n", sg);
298 
299                 sg->dma_address = dma_map_page(NULL, sg_page(sg), sg->offset, sg->length, DMA_FROM_DEVICE);
300 
301                 pr_debug("dma address = %08X, length = %d\n", sg->dma_address, sg->length);
302 
303                 if (i == 0) {
304                         at91_mci_write(host, ATMEL_PDC_RPR, sg->dma_address);
305                         at91_mci_write(host, ATMEL_PDC_RCR, (data->blksz & 0x3) ? sg->length : sg->length / 4);
306                 }
307                 else {
308                         at91_mci_write(host, ATMEL_PDC_RNPR, sg->dma_address);
309                         at91_mci_write(host, ATMEL_PDC_RNCR, (data->blksz & 0x3) ? sg->length : sg->length / 4);
310                 }
311         }
312 
313         pr_debug("pre dma read done\n");
314 }
315 
316 /*
317  * Handle after a dma read
318  */
319 static void at91_mci_post_dma_read(struct at91mci_host *host)
320 {
321         struct mmc_command *cmd;
322         struct mmc_data *data;
323 
324         pr_debug("post dma read\n");
325 
326         cmd = host->cmd;
327         if (!cmd) {
328                 pr_debug("no command\n");
329                 return;
330         }
331 
332         data = cmd->data;
333         if (!data) {
334                 pr_debug("no data\n");
335                 return;
336         }
337 
338         while (host->in_use_index < host->transfer_index) {
339                 struct scatterlist *sg;
340 
341                 pr_debug("finishing index %d\n", host->in_use_index);
342 
343                 sg = &data->sg[host->in_use_index++];
344 
345                 pr_debug("Unmapping page %08X\n", sg->dma_address);
346 
347                 dma_unmap_page(NULL, sg->dma_address, sg->length, DMA_FROM_DEVICE);
348 
349                 if (cpu_is_at91rm9200()) {      /* AT91RM9200 errata */
350                         unsigned int *buffer;
351                         int index;
352 
353                         /* Swap the contents of the buffer */
354                         buffer = kmap_atomic(sg_page(sg), KM_BIO_SRC_IRQ) + sg->offset;
355                         pr_debug("buffer = %p, length = %d\n", buffer, sg->length);
356 
357                         for (index = 0; index < (sg->length / 4); index++)
358                                 buffer[index] = swab32(buffer[index]);
359 
360                         kunmap_atomic(buffer, KM_BIO_SRC_IRQ);
361                 }
362 
363                 flush_dcache_page(sg_page(sg));
364 
365                 data->bytes_xfered += sg->length;
366         }
367 
368         /* Is there another transfer to trigger? */
369         if (host->transfer_index < data->sg_len)
370                 at91_mci_pre_dma_read(host);
371         else {
372                 at91_mci_write(host, AT91_MCI_IDR, AT91_MCI_ENDRX);
373                 at91_mci_write(host, AT91_MCI_IER, AT91_MCI_RXBUFF);
374         }
375 
376         pr_debug("post dma read done\n");
377 }
378 
379 /*
380  * Handle transmitted data
381  */
382 static void at91_mci_handle_transmitted(struct at91mci_host *host)
383 {
384         struct mmc_command *cmd;
385         struct mmc_data *data;
386 
387         pr_debug("Handling the transmit\n");
388 
389         /* Disable the transfer */
390         at91_mci_write(host, ATMEL_PDC_PTCR, ATMEL_PDC_RXTDIS | ATMEL_PDC_TXTDIS);
391 
392         /* Now wait for cmd ready */
393         at91_mci_write(host, AT91_MCI_IDR, AT91_MCI_TXBUFE);
394 
395         cmd = host->cmd;
396         if (!cmd) return;
397 
398         data = cmd->data;
399         if (!data) return;
400 
401         if (cmd->data->blocks > 1) {
402                 pr_debug("multiple write : wait for BLKE...\n");
403                 at91_mci_write(host, AT91_MCI_IER, AT91_MCI_BLKE);
404         } else
405                 at91_mci_write(host, AT91_MCI_IER, AT91_MCI_NOTBUSY);
406 }
407 
408 /*
409  * Update bytes tranfered count during a write operation
410  */
411 static void at91_mci_update_bytes_xfered(struct at91mci_host *host)
412 {
413         struct mmc_data *data;
414 
415         /* always deal with the effective request (and not the current cmd) */
416 
417         if (host->request->cmd && host->request->cmd->error != 0)
418                 return;
419 
420         if (host->request->data) {
421                 data = host->request->data;
422                 if (data->flags & MMC_DATA_WRITE) {
423                         /* card is in IDLE mode now */
424                         pr_debug("-> bytes_xfered %d, total_length = %d\n",
425                                 data->bytes_xfered, host->total_length);
426                         data->bytes_xfered = data->blksz * data->blocks;
427                 }
428         }
429 }
430 
431 
432 /*Handle after command sent ready*/
433 static int at91_mci_handle_cmdrdy(struct at91mci_host *host)
434 {
435         if (!host->cmd)
436                 return 1;
437         else if (!host->cmd->data) {
438                 if (host->flags & FL_SENT_STOP) {
439                         /*After multi block write, we must wait for NOTBUSY*/
440                         at91_mci_write(host, AT91_MCI_IER, AT91_MCI_NOTBUSY);
441                 } else return 1;
442         } else if (host->cmd->data->flags & MMC_DATA_WRITE) {
443                 /*After sendding multi-block-write command, start DMA transfer*/
444                 at91_mci_write(host, AT91_MCI_IER, AT91_MCI_TXBUFE | AT91_MCI_BLKE);
445                 at91_mci_write(host, ATMEL_PDC_PTCR, ATMEL_PDC_TXTEN);
446         }
447 
448         /* command not completed, have to wait */
449         return 0;
450 }
451 
452 
453 /*
454  * Enable the controller
455  */
456 static void at91_mci_enable(struct at91mci_host *host)
457 {
458         unsigned int mr;
459 
460         at91_mci_write(host, AT91_MCI_CR, AT91_MCI_MCIEN);
461         at91_mci_write(host, AT91_MCI_IDR, 0xffffffff);
462         at91_mci_write(host, AT91_MCI_DTOR, AT91_MCI_DTOMUL_1M | AT91_MCI_DTOCYC);
463         mr = AT91_MCI_PDCMODE | 0x34a;
464 
465         if (cpu_is_at91sam9260() || cpu_is_at91sam9263())
466                 mr |= AT91_MCI_RDPROOF | AT91_MCI_WRPROOF;
467 
468         at91_mci_write(host, AT91_MCI_MR, mr);
469 
470         /* use Slot A or B (only one at same time) */
471         at91_mci_write(host, AT91_MCI_SDCR, host->board->slot_b);
472 }
473 
474 /*
475  * Disable the controller
476  */
477 static void at91_mci_disable(struct at91mci_host *host)
478 {
479         at91_mci_write(host, AT91_MCI_CR, AT91_MCI_MCIDIS | AT91_MCI_SWRST);
480 }
481 
482 /*
483  * Send a command
484  */
485 static void at91_mci_send_command(struct at91mci_host *host, struct mmc_command *cmd)
486 {
487         unsigned int cmdr, mr;
488         unsigned int block_length;
489         struct mmc_data *data = cmd->data;
490 
491         unsigned int blocks;
492         unsigned int ier = 0;
493 
494         host->cmd = cmd;
495 
496         /* Needed for leaving busy state before CMD1 */
497         if ((at91_mci_read(host, AT91_MCI_SR) & AT91_MCI_RTOE) && (cmd->opcode == 1)) {
498                 pr_debug("Clearing timeout\n");
499                 at91_mci_write(host, AT91_MCI_ARGR, 0);
500                 at91_mci_write(host, AT91_MCI_CMDR, AT91_MCI_OPDCMD);
501                 while (!(at91_mci_read(host, AT91_MCI_SR) & AT91_MCI_CMDRDY)) {
502                         /* spin */
503                         pr_debug("Clearing: SR = %08X\n", at91_mci_read(host, AT91_MCI_SR));
504                 }
505         }
506 
507         cmdr = cmd->opcode;
508 
509         if (mmc_resp_type(cmd) == MMC_RSP_NONE)
510                 cmdr |= AT91_MCI_RSPTYP_NONE;
511         else {
512                 /* if a response is expected then allow maximum response latancy */
513                 cmdr |= AT91_MCI_MAXLAT;
514                 /* set 136 bit response for R2, 48 bit response otherwise */
515                 if (mmc_resp_type(cmd) == MMC_RSP_R2)
516                         cmdr |= AT91_MCI_RSPTYP_136;
517                 else
518                         cmdr |= AT91_MCI_RSPTYP_48;
519         }
520 
521         if (data) {
522 
523                 if (cpu_is_at91rm9200() || cpu_is_at91sam9261()) {
524                         if (data->blksz & 0x3) {
525                                 pr_debug("Unsupported block size\n");
526                                 cmd->error = -EINVAL;
527                                 mmc_request_done(host->mmc, host->request);
528                                 return;
529                         }
530                         if (data->flags & MMC_DATA_STREAM) {
531                                 pr_debug("Stream commands not supported\n");
532                                 cmd->error = -EINVAL;
533                                 mmc_request_done(host->mmc, host->request);
534                                 return;
535                         }
536                 }
537 
538                 block_length = data->blksz;
539                 blocks = data->blocks;
540 
541                 /* always set data start - also set direction flag for read */
542                 if (data->flags & MMC_DATA_READ)
543                         cmdr |= (AT91_MCI_TRDIR | AT91_MCI_TRCMD_START);
544                 else if (data->flags & MMC_DATA_WRITE)
545                         cmdr |= AT91_MCI_TRCMD_START;
546 
547                 if (data->flags & MMC_DATA_STREAM)
548                         cmdr |= AT91_MCI_TRTYP_STREAM;
549                 if (data->blocks > 1)
550                         cmdr |= AT91_MCI_TRTYP_MULTIPLE;
551         }
552         else {
553                 block_length = 0;
554                 blocks = 0;
555         }
556 
557         if (host->flags & FL_SENT_STOP)
558                 cmdr |= AT91_MCI_TRCMD_STOP;
559 
560         if (host->bus_mode == MMC_BUSMODE_OPENDRAIN)
561                 cmdr |= AT91_MCI_OPDCMD;
562 
563         /*
564          * Set the arguments and send the command
565          */
566         pr_debug("Sending command %d as %08X, arg = %08X, blocks = %d, length = %d (MR = %08X)\n",
567                 cmd->opcode, cmdr, cmd->arg, blocks, block_length, at91_mci_read(host, AT91_MCI_MR));
568 
569         if (!data) {
570                 at91_mci_write(host, ATMEL_PDC_PTCR, ATMEL_PDC_TXTDIS | ATMEL_PDC_RXTDIS);
571                 at91_mci_write(host, ATMEL_PDC_RPR, 0);
572                 at91_mci_write(host, ATMEL_PDC_RCR, 0);
573                 at91_mci_write(host, ATMEL_PDC_RNPR, 0);
574                 at91_mci_write(host, ATMEL_PDC_RNCR, 0);
575                 at91_mci_write(host, ATMEL_PDC_TPR, 0);
576                 at91_mci_write(host, ATMEL_PDC_TCR, 0);
577                 at91_mci_write(host, ATMEL_PDC_TNPR, 0);
578                 at91_mci_write(host, ATMEL_PDC_TNCR, 0);
579                 ier = AT91_MCI_CMDRDY;
580         } else {
581                 /* zero block length and PDC mode */
582                 mr = at91_mci_read(host, AT91_MCI_MR) & 0x5fff;
583                 mr |= (data->blksz & 0x3) ? AT91_MCI_PDCFBYTE : 0;
584                 mr |= (block_length << 16);
585                 mr |= AT91_MCI_PDCMODE;
586                 at91_mci_write(host, AT91_MCI_MR, mr);
587 
588                 if (!(cpu_is_at91rm9200() || cpu_is_at91sam9261()))
589                         at91_mci_write(host, AT91_MCI_BLKR,
590                                 AT91_MCI_BLKR_BCNT(blocks) |
591                                 AT91_MCI_BLKR_BLKLEN(block_length));
592 
593                 /*
594                  * Disable the PDC controller
595                  */
596                 at91_mci_write(host, ATMEL_PDC_PTCR, ATMEL_PDC_RXTDIS | ATMEL_PDC_TXTDIS);
597 
598                 if (cmdr & AT91_MCI_TRCMD_START) {
599                         data->bytes_xfered = 0;
600                         host->transfer_index = 0;
601                         host->in_use_index = 0;
602                         if (cmdr & AT91_MCI_TRDIR) {
603                                 /*
604                                  * Handle a read
605                                  */
606                                 host->buffer = NULL;
607                                 host->total_length = 0;
608 
609                                 at91_mci_pre_dma_read(host);
610                                 ier = AT91_MCI_ENDRX /* | AT91_MCI_RXBUFF */;
611                         }
612                         else {
613                                 /*
614                                  * Handle a write
615                                  */
616                                 host->total_length = block_length * blocks;
617                                 /*
618                                  * AT91SAM926[0/3] Data Write Operation and
619                                  * number of bytes erratum
620                                  */
621                                 if (cpu_is_at91sam9260 () || cpu_is_at91sam9263())
622                                         if (host->total_length < 12)
623                                                 host->total_length = 12;
624 
625                                 host->buffer = kmalloc(host->total_length, GFP_KERNEL);
626                                 if (!host->buffer) {
627                                         pr_debug("Can't alloc tx buffer\n");
628                                         cmd->error = -ENOMEM;
629                                         mmc_request_done(host->mmc, host->request);
630                                         return;
631                                 }
632 
633                                 at91_mci_sg_to_dma(host, data);
634 
635                                 host->physical_address = dma_map_single(NULL,
636                                                 host->buffer, host->total_length,
637                                                 DMA_TO_DEVICE);
638 
639                                 pr_debug("Transmitting %d bytes\n", host->total_length);
640 
641                                 at91_mci_write(host, ATMEL_PDC_TPR, host->physical_address);
642                                 at91_mci_write(host, ATMEL_PDC_TCR, (data->blksz & 0x3) ?
643                                                 host->total_length : host->total_length / 4);
644 
645                                 ier = AT91_MCI_CMDRDY;
646                         }
647                 }
648         }
649 
650         /*
651          * Send the command and then enable the PDC - not the other way round as
652          * the data sheet says
653          */
654 
655         at91_mci_write(host, AT91_MCI_ARGR, cmd->arg);
656         at91_mci_write(host, AT91_MCI_CMDR, cmdr);
657 
658         if (cmdr & AT91_MCI_TRCMD_START) {
659                 if (cmdr & AT91_MCI_TRDIR)
660                         at91_mci_write(host, ATMEL_PDC_PTCR, ATMEL_PDC_RXTEN);
661         }
662 
663         /* Enable selected interrupts */
664         at91_mci_write(host, AT91_MCI_IER, AT91_MCI_ERRORS | ier);
665 }
666 
667 /*
668  * Process the next step in the request
669  */
670 static void at91_mci_process_next(struct at91mci_host *host)
671 {
672         if (!(host->flags & FL_SENT_COMMAND)) {
673                 host->flags |= FL_SENT_COMMAND;
674                 at91_mci_send_command(host, host->request->cmd);
675         }
676         else if ((!(host->flags & FL_SENT_STOP)) && host->request->stop) {
677                 host->flags |= FL_SENT_STOP;
678                 at91_mci_send_command(host, host->request->stop);
679         } else {
680                 del_timer(&host->timer);
681                 /* the at91rm9200 mci controller hangs after some transfers,
682                  * and the workaround is to reset it after each transfer.
683                  */
684                 if (cpu_is_at91rm9200())
685                         at91_reset_host(host);
686                 mmc_request_done(host->mmc, host->request);
687         }
688 }
689 
690 /*
691  * Handle a command that has been completed
692  */
693 static void at91_mci_completed_command(struct at91mci_host *host, unsigned int status)
694 {
695         struct mmc_command *cmd = host->cmd;
696         struct mmc_data *data = cmd->data;
697 
698         at91_mci_write(host, AT91_MCI_IDR, 0xffffffff & ~(AT91_MCI_SDIOIRQA | AT91_MCI_SDIOIRQB));
699 
700         cmd->resp[0] = at91_mci_read(host, AT91_MCI_RSPR(0));
701         cmd->resp[1] = at91_mci_read(host, AT91_MCI_RSPR(1));
702         cmd->resp[2] = at91_mci_read(host, AT91_MCI_RSPR(2));
703         cmd->resp[3] = at91_mci_read(host, AT91_MCI_RSPR(3));
704 
705         if (host->buffer) {
706                 dma_unmap_single(NULL,
707                                 host->physical_address, host->total_length,
708                                 DMA_TO_DEVICE);
709                 kfree(host->buffer);
710                 host->buffer = NULL;
711         }
712 
713         pr_debug("Status = %08X/%08x [%08X %08X %08X %08X]\n",
714                  status, at91_mci_read(host, AT91_MCI_SR),
715                  cmd->resp[0], cmd->resp[1], cmd->resp[2], cmd->resp[3]);
716 
717         if (status & AT91_MCI_ERRORS) {
718                 if ((status & AT91_MCI_RCRCE) && !(mmc_resp_type(cmd) & MMC_RSP_CRC)) {
719                         cmd->error = 0;
720                 }
721                 else {
722                         if (status & (AT91_MCI_DTOE | AT91_MCI_DCRCE)) {
723                                 if (data) {
724                                         if (status & AT91_MCI_DTOE)
725                                                 data->error = -ETIMEDOUT;
726                                         else if (status & AT91_MCI_DCRCE)
727                                                 data->error = -EILSEQ;
728                                 }
729                         } else {
730                                 if (status & AT91_MCI_RTOE)
731                                         cmd->error = -ETIMEDOUT;
732                                 else if (status & AT91_MCI_RCRCE)
733                                         cmd->error = -EILSEQ;
734                                 else
735                                         cmd->error = -EIO;
736                         }
737 
738                         pr_debug("Error detected and set to %d/%d (cmd = %d, retries = %d)\n",
739                                 cmd->error, data ? data->error : 0,
740                                  cmd->opcode, cmd->retries);
741                 }
742         }
743         else
744                 cmd->error = 0;
745 
746         at91_mci_process_next(host);
747 }
748 
749 /*
750  * Handle an MMC request
751  */
752 static void at91_mci_request(struct mmc_host *mmc, struct mmc_request *mrq)
753 {
754         struct at91mci_host *host = mmc_priv(mmc);
755         host->request = mrq;
756         host->flags = 0;
757 
758         mod_timer(&host->timer, jiffies +  HZ);
759 
760         at91_mci_process_next(host);
761 }
762 
763 /*
764  * Set the IOS
765  */
766 static void at91_mci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
767 {
768         int clkdiv;
769         struct at91mci_host *host = mmc_priv(mmc);
770         unsigned long at91_master_clock = clk_get_rate(host->mci_clk);
771 
772         host->bus_mode = ios->bus_mode;
773 
774         if (ios->clock == 0) {
775                 /* Disable the MCI controller */
776                 at91_mci_write(host, AT91_MCI_CR, AT91_MCI_MCIDIS);
777                 clkdiv = 0;
778         }
779         else {
780                 /* Enable the MCI controller */
781                 at91_mci_write(host, AT91_MCI_CR, AT91_MCI_MCIEN);
782 
783                 if ((at91_master_clock % (ios->clock * 2)) == 0)
784                         clkdiv = ((at91_master_clock / ios->clock) / 2) - 1;
785                 else
786                         clkdiv = (at91_master_clock / ios->clock) / 2;
787 
788                 pr_debug("clkdiv = %d. mcck = %ld\n", clkdiv,
789                         at91_master_clock / (2 * (clkdiv + 1)));
790         }
791         if (ios->bus_width == MMC_BUS_WIDTH_4 && host->board->wire4) {
792                 pr_debug("MMC: Setting controller bus width to 4\n");
793                 at91_mci_write(host, AT91_MCI_SDCR, at91_mci_read(host, AT91_MCI_SDCR) | AT91_MCI_SDCBUS);
794         }
795         else {
796                 pr_debug("MMC: Setting controller bus width to 1\n");
797                 at91_mci_write(host, AT91_MCI_SDCR, at91_mci_read(host, AT91_MCI_SDCR) & ~AT91_MCI_SDCBUS);
798         }
799 
800         /* Set the clock divider */
801         at91_mci_write(host, AT91_MCI_MR, (at91_mci_read(host, AT91_MCI_MR) & ~AT91_MCI_CLKDIV) | clkdiv);
802 
803         /* maybe switch power to the card */
804         if (host->board->vcc_pin) {
805                 switch (ios->power_mode) {
806                         case MMC_POWER_OFF:
807                                 gpio_set_value(host->board->vcc_pin, 0);
808                                 break;
809                         case MMC_POWER_UP:
810                                 gpio_set_value(host->board->vcc_pin, 1);
811                                 break;
812                         case MMC_POWER_ON:
813                                 break;
814                         default:
815                                 WARN_ON(1);
816                 }
817         }
818 }
819 
820 /*
821  * Handle an interrupt
822  */
823 static irqreturn_t at91_mci_irq(int irq, void *devid)
824 {
825         struct at91mci_host *host = devid;
826         int completed = 0;
827         unsigned int int_status, int_mask;
828 
829         int_status = at91_mci_read(host, AT91_MCI_SR);
830         int_mask = at91_mci_read(host, AT91_MCI_IMR);
831 
832         pr_debug("MCI irq: status = %08X, %08X, %08X\n", int_status, int_mask,
833                 int_status & int_mask);
834 
835         int_status = int_status & int_mask;
836 
837         if (int_status & AT91_MCI_ERRORS) {
838                 completed = 1;
839 
840                 if (int_status & AT91_MCI_UNRE)
841                         pr_debug("MMC: Underrun error\n");
842                 if (int_status & AT91_MCI_OVRE)
843                         pr_debug("MMC: Overrun error\n");
844                 if (int_status & AT91_MCI_DTOE)
845                         pr_debug("MMC: Data timeout\n");
846                 if (int_status & AT91_MCI_DCRCE)
847                         pr_debug("MMC: CRC error in data\n");
848                 if (int_status & AT91_MCI_RTOE)
849                         pr_debug("MMC: Response timeout\n");
850                 if (int_status & AT91_MCI_RENDE)
851                         pr_debug("MMC: Response end bit error\n");
852                 if (int_status & AT91_MCI_RCRCE)
853                         pr_debug("MMC: Response CRC error\n");
854                 if (int_status & AT91_MCI_RDIRE)
855                         pr_debug("MMC: Response direction error\n");
856                 if (int_status & AT91_MCI_RINDE)
857                         pr_debug("MMC: Response index error\n");
858         } else {
859                 /* Only continue processing if no errors */
860 
861                 if (int_status & AT91_MCI_TXBUFE) {
862                         pr_debug("TX buffer empty\n");
863                         at91_mci_handle_transmitted(host);
864                 }
865 
866                 if (int_status & AT91_MCI_ENDRX) {
867                         pr_debug("ENDRX\n");
868                         at91_mci_post_dma_read(host);
869                 }
870 
871                 if (int_status & AT91_MCI_RXBUFF) {
872                         pr_debug("RX buffer full\n");
873                         at91_mci_write(host, ATMEL_PDC_PTCR, ATMEL_PDC_RXTDIS | ATMEL_PDC_TXTDIS);
874                         at91_mci_write(host, AT91_MCI_IDR, AT91_MCI_RXBUFF | AT91_MCI_ENDRX);
875                         completed = 1;
876                 }
877 
878                 if (int_status & AT91_MCI_ENDTX)
879                         pr_debug("Transmit has ended\n");
880 
881                 if (int_status & AT91_MCI_NOTBUSY) {
882                         pr_debug("Card is ready\n");
883                         at91_mci_update_bytes_xfered(host);
884                         completed = 1;
885                 }
886 
887                 if (int_status & AT91_MCI_DTIP)
888                         pr_debug("Data transfer in progress\n");
889 
890                 if (int_status & AT91_MCI_BLKE) {
891                         pr_debug("Block transfer has ended\n");
892                         if (host->request->data && host->request->data->blocks > 1) {
893                                 /* multi block write : complete multi write
894                                  * command and send stop */
895                                 completed = 1;
896                         } else {
897                                 at91_mci_write(host, AT91_MCI_IER, AT91_MCI_NOTBUSY);
898                         }
899                 }
900 
901                 if (int_status & AT91_MCI_SDIOIRQA)
902                         mmc_signal_sdio_irq(host->mmc);
903 
904                 if (int_status & AT91_MCI_SDIOIRQB)
905                         mmc_signal_sdio_irq(host->mmc);
906 
907                 if (int_status & AT91_MCI_TXRDY)
908                         pr_debug("Ready to transmit\n");
909 
910                 if (int_status & AT91_MCI_RXRDY)
911                         pr_debug("Ready to receive\n");
912 
913                 if (int_status & AT91_MCI_CMDRDY) {
914                         pr_debug("Command ready\n");
915                         completed = at91_mci_handle_cmdrdy(host);
916                 }
917         }
918 
919         if (completed) {
920                 pr_debug("Completed command\n");
921                 at91_mci_write(host, AT91_MCI_IDR, 0xffffffff & ~(AT91_MCI_SDIOIRQA | AT91_MCI_SDIOIRQB));
922                 at91_mci_completed_command(host, int_status);
923         } else
924                 at91_mci_write(host, AT91_MCI_IDR, int_status & ~(AT91_MCI_SDIOIRQA | AT91_MCI_SDIOIRQB));
925 
926         return IRQ_HANDLED;
927 }
928 
929 static irqreturn_t at91_mmc_det_irq(int irq, void *_host)
930 {
931         struct at91mci_host *host = _host;
932         int present = !gpio_get_value(irq_to_gpio(irq));
933 
934         /*
935          * we expect this irq on both insert and remove,
936          * and use a short delay to debounce.
937          */
938         if (present != host->present) {
939                 host->present = present;
940                 pr_debug("%s: card %s\n", mmc_hostname(host->mmc),
941                         present ? "insert" : "remove");
942                 if (!present) {
943                         pr_debug("****** Resetting SD-card bus width ******\n");
944                         at91_mci_write(host, AT91_MCI_SDCR, at91_mci_read(host, AT91_MCI_SDCR) & ~AT91_MCI_SDCBUS);
945                 }
946                 mmc_detect_change(host->mmc, msecs_to_jiffies(100));
947         }
948         return IRQ_HANDLED;
949 }
950 
951 static int at91_mci_get_ro(struct mmc_host *mmc)
952 {
953         struct at91mci_host *host = mmc_priv(mmc);
954 
955         if (host->board->wp_pin)
956                 return !!gpio_get_value(host->board->wp_pin);
957         /*
958          * Board doesn't support read only detection; let the mmc core
959          * decide what to do.
960          */
961         return -ENOSYS;
962 }
963 
964 static void at91_mci_enable_sdio_irq(struct mmc_host *mmc, int enable)
965 {
966         struct at91mci_host *host = mmc_priv(mmc);
967 
968         pr_debug("%s: sdio_irq %c : %s\n", mmc_hostname(host->mmc),
969                 host->board->slot_b ? 'B':'A', enable ? "enable" : "disable");
970         at91_mci_write(host, enable ? AT91_MCI_IER : AT91_MCI_IDR,
971                 host->board->slot_b ? AT91_MCI_SDIOIRQB : AT91_MCI_SDIOIRQA);
972 
973 }
974 
975 static const struct mmc_host_ops at91_mci_ops = {
976         .request        = at91_mci_request,
977         .set_ios        = at91_mci_set_ios,
978         .get_ro         = at91_mci_get_ro,
979         .enable_sdio_irq = at91_mci_enable_sdio_irq,
980 };
981 
982 /*
983  * Probe for the device
984  */
985 static int __init at91_mci_probe(struct platform_device *pdev)
986 {
987         struct mmc_host *mmc;
988         struct at91mci_host *host;
989         struct resource *res;
990         int ret;
991 
992         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
993         if (!res)
994                 return -ENXIO;
995 
996         if (!request_mem_region(res->start, res->end - res->start + 1, DRIVER_NAME))
997                 return -EBUSY;
998 
999         mmc = mmc_alloc_host(sizeof(struct at91mci_host), &pdev->dev);
1000         if (!mmc) {
1001                 ret = -ENOMEM;
1002                 dev_dbg(&pdev->dev, "couldn't allocate mmc host\n");
1003                 goto fail6;
1004         }
1005 
1006         mmc->ops = &at91_mci_ops;
1007         mmc->f_min = 375000;
1008         mmc->f_max = 25000000;
1009         mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
1010         mmc->caps = MMC_CAP_SDIO_IRQ;
1011 
1012         mmc->max_blk_size = 4095;
1013         mmc->max_blk_count = mmc->max_req_size;
1014 
1015         host = mmc_priv(mmc);
1016         host->mmc = mmc;
1017         host->buffer = NULL;
1018         host->bus_mode = 0;
1019         host->board = pdev->dev.platform_data;
1020         if (host->board->wire4) {
1021                 if (cpu_is_at91sam9260() || cpu_is_at91sam9263())
1022                         mmc->caps |= MMC_CAP_4_BIT_DATA;
1023                 else
1024                         dev_warn(&pdev->dev, "4 wire bus mode not supported"
1025                                 " - using 1 wire\n");
1026         }
1027 
1028         /*
1029          * Reserve GPIOs ... board init code makes sure these pins are set
1030          * up as GPIOs with the right direction (input, except for vcc)
1031          */
1032         if (host->board->det_pin) {
1033                 ret = gpio_request(host->board->det_pin, "mmc_detect");
1034                 if (ret < 0) {
1035                         dev_dbg(&pdev->dev, "couldn't claim card detect pin\n");
1036                         goto fail5;
1037                 }
1038         }
1039         if (host->board->wp_pin) {
1040                 ret = gpio_request(host->board->wp_pin, "mmc_wp");
1041                 if (ret < 0) {
1042                         dev_dbg(&pdev->dev, "couldn't claim wp sense pin\n");
1043                         goto fail4;
1044                 }
1045         }
1046         if (host->board->vcc_pin) {
1047                 ret = gpio_request(host->board->vcc_pin, "mmc_vcc");
1048                 if (ret < 0) {
1049                         dev_dbg(&pdev->dev, "couldn't claim vcc switch pin\n");
1050                         goto fail3;
1051                 }
1052         }
1053 
1054         /*
1055          * Get Clock
1056          */
1057         host->mci_clk = clk_get(&pdev->dev, "mci_clk");
1058         if (IS_ERR(host->mci_clk)) {
1059                 ret = -ENODEV;
1060                 dev_dbg(&pdev->dev, "no mci_clk?\n");
1061                 goto fail2;
1062         }
1063 
1064         /*
1065          * Map I/O region
1066          */
1067         host->baseaddr = ioremap(res->start, res->end - res->start + 1);
1068         if (!host->baseaddr) {
1069                 ret = -ENOMEM;
1070                 goto fail1;
1071         }
1072 
1073         /*
1074          * Reset hardware
1075          */
1076         clk_enable(host->mci_clk);              /* Enable the peripheral clock */
1077         at91_mci_disable(host);
1078         at91_mci_enable(host);
1079 
1080         /*
1081          * Allocate the MCI interrupt
1082          */
1083         host->irq = platform_get_irq(pdev, 0);
1084         ret = request_irq(host->irq, at91_mci_irq, IRQF_SHARED,
1085                         mmc_hostname(mmc), host);
1086         if (ret) {
1087                 dev_dbg(&pdev->dev, "request MCI interrupt failed\n");
1088                 goto fail0;
1089         }
1090 
1091         setup_timer(&host->timer, at91_timeout_timer, (unsigned long)host);
1092 
1093         platform_set_drvdata(pdev, mmc);
1094 
1095         /*
1096          * Add host to MMC layer
1097          */
1098         if (host->board->det_pin) {
1099                 host->present = !gpio_get_value(host->board->det_pin);
1100         }
1101         else
1102                 host->present = -1;
1103 
1104         mmc_add_host(mmc);
1105 
1106         /*
1107          * monitor card insertion/removal if we can
1108          */
1109         if (host->board->det_pin) {
1110                 ret = request_irq(gpio_to_irq(host->board->det_pin),
1111                                 at91_mmc_det_irq, 0, mmc_hostname(mmc), host);
1112                 if (ret)
1113                         dev_warn(&pdev->dev, "request MMC detect irq failed\n");
1114                 else
1115                         device_init_wakeup(&pdev->dev, 1);
1116         }
1117 
1118         pr_debug("Added MCI driver\n");
1119 
1120         return 0;
1121 
1122 fail0:
1123         clk_disable(host->mci_clk);
1124         iounmap(host->baseaddr);
1125 fail1:
1126         clk_put(host->mci_clk);
1127 fail2:
1128         if (host->board->vcc_pin)
1129                 gpio_free(host->board->vcc_pin);
1130 fail3:
1131         if (host->board->wp_pin)
1132                 gpio_free(host->board->wp_pin);
1133 fail4:
1134         if (host->board->det_pin)
1135                 gpio_free(host->board->det_pin);
1136 fail5:
1137         mmc_free_host(mmc);
1138 fail6:
1139         release_mem_region(res->start, res->end - res->start + 1);
1140         dev_err(&pdev->dev, "probe failed, err %d\n", ret);
1141         return ret;
1142 }
1143 
1144 /*
1145  * Remove a device
1146  */
1147 static int __exit at91_mci_remove(struct platform_device *pdev)
1148 {
1149         struct mmc_host *mmc = platform_get_drvdata(pdev);
1150         struct at91mci_host *host;
1151         struct resource *res;
1152 
1153         if (!mmc)
1154                 return -1;
1155 
1156         host = mmc_priv(mmc);
1157 
1158         if (host->board->det_pin) {
1159                 if (device_can_wakeup(&pdev->dev))
1160                         free_irq(gpio_to_irq(host->board->det_pin), host);
1161                 device_init_wakeup(&pdev->dev, 0);
1162                 gpio_free(host->board->det_pin);
1163         }
1164 
1165         at91_mci_disable(host);
1166         del_timer_sync(&host->timer);
1167         mmc_remove_host(mmc);
1168         free_irq(host->irq, host);
1169 
1170         clk_disable(host->mci_clk);                     /* Disable the peripheral clock */
1171         clk_put(host->mci_clk);
1172 
1173         if (host->board->vcc_pin)
1174                 gpio_free(host->board->vcc_pin);
1175         if (host->board->wp_pin)
1176                 gpio_free(host->board->wp_pin);
1177 
1178         iounmap(host->baseaddr);
1179         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1180         release_mem_region(res->start, res->end - res->start + 1);
1181 
1182         mmc_free_host(mmc);
1183         platform_set_drvdata(pdev, NULL);
1184         pr_debug("MCI Removed\n");
1185 
1186         return 0;
1187 }
1188 
1189 #ifdef CONFIG_PM
1190 static int at91_mci_suspend(struct platform_device *pdev, pm_message_t state)
1191 {
1192         struct mmc_host *mmc = platform_get_drvdata(pdev);
1193         struct at91mci_host *host = mmc_priv(mmc);
1194         int ret = 0;
1195 
1196         if (host->board->det_pin && device_may_wakeup(&pdev->dev))
1197                 enable_irq_wake(host->board->det_pin);
1198 
1199         if (mmc)
1200                 ret = mmc_suspend_host(mmc, state);
1201 
1202         return ret;
1203 }
1204 
1205 static int at91_mci_resume(struct platform_device *pdev)
1206 {
1207         struct mmc_host *mmc = platform_get_drvdata(pdev);
1208         struct at91mci_host *host = mmc_priv(mmc);
1209         int ret = 0;
1210 
1211         if (host->board->det_pin && device_may_wakeup(&pdev->dev))
1212                 disable_irq_wake(host->board->det_pin);
1213 
1214         if (mmc)
1215                 ret = mmc_resume_host(mmc);
1216 
1217         return ret;
1218 }
1219 #else
1220 #define at91_mci_suspend        NULL
1221 #define at91_mci_resume         NULL
1222 #endif
1223 
1224 static struct platform_driver at91_mci_driver = {
1225         .remove         = __exit_p(at91_mci_remove),
1226         .suspend        = at91_mci_suspend,
1227         .resume         = at91_mci_resume,
1228         .driver         = {
1229                 .name   = DRIVER_NAME,
1230                 .owner  = THIS_MODULE,
1231         },
1232 };
1233 
1234 static int __init at91_mci_init(void)
1235 {
1236         return platform_driver_probe(&at91_mci_driver, at91_mci_probe);
1237 }
1238 
1239 static void __exit at91_mci_exit(void)
1240 {
1241         platform_driver_unregister(&at91_mci_driver);
1242 }
1243 
1244 module_init(at91_mci_init);
1245 module_exit(at91_mci_exit);
1246 
1247 MODULE_DESCRIPTION("AT91 Multimedia Card Interface driver");
1248 MODULE_AUTHOR("Nick Randell");
1249 MODULE_LICENSE("GPL");
1250 MODULE_ALIAS("platform:at91_mci");
1251 
  This page was automatically generated by the LXR engine.