Merge branch 'for-2.6.26' of master.kernel.org:/pub/scm/linux/kernel/git/olof/pasemi
[linux-2.6] / drivers / mtd / nand / bf5xx_nand.c
1 /* linux/drivers/mtd/nand/bf5xx_nand.c
2  *
3  * Copyright 2006-2007 Analog Devices Inc.
4  *      http://blackfin.uclinux.org/
5  *      Bryan Wu <bryan.wu@analog.com>
6  *
7  * Blackfin BF5xx on-chip NAND flash controller driver
8  *
9  * Derived from drivers/mtd/nand/s3c2410.c
10  * Copyright (c) 2007 Ben Dooks <ben@simtec.co.uk>
11  *
12  * Derived from drivers/mtd/nand/cafe.c
13  * Copyright © 2006 Red Hat, Inc.
14  * Copyright © 2006 David Woodhouse <dwmw2@infradead.org>
15  *
16  * Changelog:
17  *      12-Jun-2007  Bryan Wu:  Initial version
18  *      18-Jul-2007  Bryan Wu:
19  *              - ECC_HW and ECC_SW supported
20  *              - DMA supported in ECC_HW
21  *              - YAFFS tested as rootfs in both ECC_HW and ECC_SW
22  *
23  * TODO:
24  *      Enable JFFS2 over NAND as rootfs
25  *
26  * This program is free software; you can redistribute it and/or modify
27  * it under the terms of the GNU General Public License as published by
28  * the Free Software Foundation; either version 2 of the License, or
29  * (at your option) any later version.
30  *
31  * This program is distributed in the hope that it will be useful,
32  * but WITHOUT ANY WARRANTY; without even the implied warranty of
33  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
34  * GNU General Public License for more details.
35  *
36  * You should have received a copy of the GNU General Public License
37  * along with this program; if not, write to the Free Software
38  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
39 */
40
41 #include <linux/module.h>
42 #include <linux/types.h>
43 #include <linux/init.h>
44 #include <linux/kernel.h>
45 #include <linux/string.h>
46 #include <linux/ioport.h>
47 #include <linux/platform_device.h>
48 #include <linux/delay.h>
49 #include <linux/dma-mapping.h>
50 #include <linux/err.h>
51 #include <linux/slab.h>
52 #include <linux/io.h>
53 #include <linux/bitops.h>
54
55 #include <linux/mtd/mtd.h>
56 #include <linux/mtd/nand.h>
57 #include <linux/mtd/nand_ecc.h>
58 #include <linux/mtd/partitions.h>
59
60 #include <asm/blackfin.h>
61 #include <asm/dma.h>
62 #include <asm/cacheflush.h>
63 #include <asm/nand.h>
64 #include <asm/portmux.h>
65
66 #define DRV_NAME        "bf5xx-nand"
67 #define DRV_VERSION     "1.2"
68 #define DRV_AUTHOR      "Bryan Wu <bryan.wu@analog.com>"
69 #define DRV_DESC        "BF5xx on-chip NAND FLash Controller Driver"
70
71 #ifdef CONFIG_MTD_NAND_BF5XX_HWECC
72 static int hardware_ecc = 1;
73 #else
74 static int hardware_ecc;
75 #endif
76
77 static unsigned short bfin_nfc_pin_req[] =
78         {P_NAND_CE,
79          P_NAND_RB,
80          P_NAND_D0,
81          P_NAND_D1,
82          P_NAND_D2,
83          P_NAND_D3,
84          P_NAND_D4,
85          P_NAND_D5,
86          P_NAND_D6,
87          P_NAND_D7,
88          P_NAND_WE,
89          P_NAND_RE,
90          P_NAND_CLE,
91          P_NAND_ALE,
92          0};
93
94 /*
95  * Data structures for bf5xx nand flash controller driver
96  */
97
98 /* bf5xx nand info */
99 struct bf5xx_nand_info {
100         /* mtd info */
101         struct nand_hw_control          controller;
102         struct mtd_info                 mtd;
103         struct nand_chip                chip;
104
105         /* platform info */
106         struct bf5xx_nand_platform      *platform;
107
108         /* device info */
109         struct device                   *device;
110
111         /* DMA stuff */
112         struct completion               dma_completion;
113 };
114
115 /*
116  * Conversion functions
117  */
118 static struct bf5xx_nand_info *mtd_to_nand_info(struct mtd_info *mtd)
119 {
120         return container_of(mtd, struct bf5xx_nand_info, mtd);
121 }
122
123 static struct bf5xx_nand_info *to_nand_info(struct platform_device *pdev)
124 {
125         return platform_get_drvdata(pdev);
126 }
127
128 static struct bf5xx_nand_platform *to_nand_plat(struct platform_device *pdev)
129 {
130         return pdev->dev.platform_data;
131 }
132
133 /*
134  * struct nand_chip interface function pointers
135  */
136
137 /*
138  * bf5xx_nand_hwcontrol
139  *
140  * Issue command and address cycles to the chip
141  */
142 static void bf5xx_nand_hwcontrol(struct mtd_info *mtd, int cmd,
143                                    unsigned int ctrl)
144 {
145         if (cmd == NAND_CMD_NONE)
146                 return;
147
148         while (bfin_read_NFC_STAT() & WB_FULL)
149                 cpu_relax();
150
151         if (ctrl & NAND_CLE)
152                 bfin_write_NFC_CMD(cmd);
153         else
154                 bfin_write_NFC_ADDR(cmd);
155         SSYNC();
156 }
157
158 /*
159  * bf5xx_nand_devready()
160  *
161  * returns 0 if the nand is busy, 1 if it is ready
162  */
163 static int bf5xx_nand_devready(struct mtd_info *mtd)
164 {
165         unsigned short val = bfin_read_NFC_IRQSTAT();
166
167         if ((val & NBUSYIRQ) == NBUSYIRQ)
168                 return 1;
169         else
170                 return 0;
171 }
172
173 /*
174  * ECC functions
175  * These allow the bf5xx to use the controller's ECC
176  * generator block to ECC the data as it passes through
177  */
178
179 /*
180  * ECC error correction function
181  */
182 static int bf5xx_nand_correct_data_256(struct mtd_info *mtd, u_char *dat,
183                                         u_char *read_ecc, u_char *calc_ecc)
184 {
185         struct bf5xx_nand_info *info = mtd_to_nand_info(mtd);
186         u32 syndrome[5];
187         u32 calced, stored;
188         int i;
189         unsigned short failing_bit, failing_byte;
190         u_char data;
191
192         calced = calc_ecc[0] | (calc_ecc[1] << 8) | (calc_ecc[2] << 16);
193         stored = read_ecc[0] | (read_ecc[1] << 8) | (read_ecc[2] << 16);
194
195         syndrome[0] = (calced ^ stored);
196
197         /*
198          * syndrome 0: all zero
199          * No error in data
200          * No action
201          */
202         if (!syndrome[0] || !calced || !stored)
203                 return 0;
204
205         /*
206          * sysdrome 0: only one bit is one
207          * ECC data was incorrect
208          * No action
209          */
210         if (hweight32(syndrome[0]) == 1) {
211                 dev_err(info->device, "ECC data was incorrect!\n");
212                 return 1;
213         }
214
215         syndrome[1] = (calced & 0x7FF) ^ (stored & 0x7FF);
216         syndrome[2] = (calced & 0x7FF) ^ ((calced >> 11) & 0x7FF);
217         syndrome[3] = (stored & 0x7FF) ^ ((stored >> 11) & 0x7FF);
218         syndrome[4] = syndrome[2] ^ syndrome[3];
219
220         for (i = 0; i < 5; i++)
221                 dev_info(info->device, "syndrome[%d] 0x%08x\n", i, syndrome[i]);
222
223         dev_info(info->device,
224                 "calced[0x%08x], stored[0x%08x]\n",
225                 calced, stored);
226
227         /*
228          * sysdrome 0: exactly 11 bits are one, each parity
229          * and parity' pair is 1 & 0 or 0 & 1.
230          * 1-bit correctable error
231          * Correct the error
232          */
233         if (hweight32(syndrome[0]) == 11 && syndrome[4] == 0x7FF) {
234                 dev_info(info->device,
235                         "1-bit correctable error, correct it.\n");
236                 dev_info(info->device,
237                         "syndrome[1] 0x%08x\n", syndrome[1]);
238
239                 failing_bit = syndrome[1] & 0x7;
240                 failing_byte = syndrome[1] >> 0x3;
241                 data = *(dat + failing_byte);
242                 data = data ^ (0x1 << failing_bit);
243                 *(dat + failing_byte) = data;
244
245                 return 0;
246         }
247
248         /*
249          * sysdrome 0: random data
250          * More than 1-bit error, non-correctable error
251          * Discard data, mark bad block
252          */
253         dev_err(info->device,
254                 "More than 1-bit error, non-correctable error.\n");
255         dev_err(info->device,
256                 "Please discard data, mark bad block\n");
257
258         return 1;
259 }
260
261 static int bf5xx_nand_correct_data(struct mtd_info *mtd, u_char *dat,
262                                         u_char *read_ecc, u_char *calc_ecc)
263 {
264         struct bf5xx_nand_info *info = mtd_to_nand_info(mtd);
265         struct bf5xx_nand_platform *plat = info->platform;
266         unsigned short page_size = (plat->page_size ? 512 : 256);
267         int ret;
268
269         ret = bf5xx_nand_correct_data_256(mtd, dat, read_ecc, calc_ecc);
270
271         /* If page size is 512, correct second 256 bytes */
272         if (page_size == 512) {
273                 dat += 256;
274                 read_ecc += 8;
275                 calc_ecc += 8;
276                 ret = bf5xx_nand_correct_data_256(mtd, dat, read_ecc, calc_ecc);
277         }
278
279         return ret;
280 }
281
282 static void bf5xx_nand_enable_hwecc(struct mtd_info *mtd, int mode)
283 {
284         return;
285 }
286
287 static int bf5xx_nand_calculate_ecc(struct mtd_info *mtd,
288                 const u_char *dat, u_char *ecc_code)
289 {
290         struct bf5xx_nand_info *info = mtd_to_nand_info(mtd);
291         struct bf5xx_nand_platform *plat = info->platform;
292         u16 page_size = (plat->page_size ? 512 : 256);
293         u16 ecc0, ecc1;
294         u32 code[2];
295         u8 *p;
296
297         /* first 4 bytes ECC code for 256 page size */
298         ecc0 = bfin_read_NFC_ECC0();
299         ecc1 = bfin_read_NFC_ECC1();
300
301         code[0] = (ecc0 & 0x3FF) | ((ecc1 & 0x3FF) << 11);
302
303         dev_dbg(info->device, "returning ecc 0x%08x\n", code[0]);
304
305         /* first 3 bytes in ecc_code for 256 page size */
306         p = (u8 *) code;
307         memcpy(ecc_code, p, 3);
308
309         /* second 4 bytes ECC code for 512 page size */
310         if (page_size == 512) {
311                 ecc0 = bfin_read_NFC_ECC2();
312                 ecc1 = bfin_read_NFC_ECC3();
313                 code[1] = (ecc0 & 0x3FF) | ((ecc1 & 0x3FF) << 11);
314
315                 /* second 3 bytes in ecc_code for second 256
316                  * bytes of 512 page size
317                  */
318                 p = (u8 *) (code + 1);
319                 memcpy((ecc_code + 3), p, 3);
320                 dev_dbg(info->device, "returning ecc 0x%08x\n", code[1]);
321         }
322
323         return 0;
324 }
325
326 /*
327  * PIO mode for buffer writing and reading
328  */
329 static void bf5xx_nand_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
330 {
331         int i;
332         unsigned short val;
333
334         /*
335          * Data reads are requested by first writing to NFC_DATA_RD
336          * and then reading back from NFC_READ.
337          */
338         for (i = 0; i < len; i++) {
339                 while (bfin_read_NFC_STAT() & WB_FULL)
340                         cpu_relax();
341
342                 /* Contents do not matter */
343                 bfin_write_NFC_DATA_RD(0x0000);
344                 SSYNC();
345
346                 while ((bfin_read_NFC_IRQSTAT() & RD_RDY) != RD_RDY)
347                         cpu_relax();
348
349                 buf[i] = bfin_read_NFC_READ();
350
351                 val = bfin_read_NFC_IRQSTAT();
352                 val |= RD_RDY;
353                 bfin_write_NFC_IRQSTAT(val);
354                 SSYNC();
355         }
356 }
357
358 static uint8_t bf5xx_nand_read_byte(struct mtd_info *mtd)
359 {
360         uint8_t val;
361
362         bf5xx_nand_read_buf(mtd, &val, 1);
363
364         return val;
365 }
366
367 static void bf5xx_nand_write_buf(struct mtd_info *mtd,
368                                 const uint8_t *buf, int len)
369 {
370         int i;
371
372         for (i = 0; i < len; i++) {
373                 while (bfin_read_NFC_STAT() & WB_FULL)
374                         cpu_relax();
375
376                 bfin_write_NFC_DATA_WR(buf[i]);
377                 SSYNC();
378         }
379 }
380
381 static void bf5xx_nand_read_buf16(struct mtd_info *mtd, uint8_t *buf, int len)
382 {
383         int i;
384         u16 *p = (u16 *) buf;
385         len >>= 1;
386
387         /*
388          * Data reads are requested by first writing to NFC_DATA_RD
389          * and then reading back from NFC_READ.
390          */
391         bfin_write_NFC_DATA_RD(0x5555);
392
393         SSYNC();
394
395         for (i = 0; i < len; i++)
396                 p[i] = bfin_read_NFC_READ();
397 }
398
399 static void bf5xx_nand_write_buf16(struct mtd_info *mtd,
400                                 const uint8_t *buf, int len)
401 {
402         int i;
403         u16 *p = (u16 *) buf;
404         len >>= 1;
405
406         for (i = 0; i < len; i++)
407                 bfin_write_NFC_DATA_WR(p[i]);
408
409         SSYNC();
410 }
411
412 /*
413  * DMA functions for buffer writing and reading
414  */
415 static irqreturn_t bf5xx_nand_dma_irq(int irq, void *dev_id)
416 {
417         struct bf5xx_nand_info *info = dev_id;
418
419         clear_dma_irqstat(CH_NFC);
420         disable_dma(CH_NFC);
421         complete(&info->dma_completion);
422
423         return IRQ_HANDLED;
424 }
425
426 static int bf5xx_nand_dma_rw(struct mtd_info *mtd,
427                                 uint8_t *buf, int is_read)
428 {
429         struct bf5xx_nand_info *info = mtd_to_nand_info(mtd);
430         struct bf5xx_nand_platform *plat = info->platform;
431         unsigned short page_size = (plat->page_size ? 512 : 256);
432         unsigned short val;
433
434         dev_dbg(info->device, " mtd->%p, buf->%p, is_read %d\n",
435                         mtd, buf, is_read);
436
437         /*
438          * Before starting a dma transfer, be sure to invalidate/flush
439          * the cache over the address range of your DMA buffer to
440          * prevent cache coherency problems. Otherwise very subtle bugs
441          * can be introduced to your driver.
442          */
443         if (is_read)
444                 invalidate_dcache_range((unsigned int)buf,
445                                 (unsigned int)(buf + page_size));
446         else
447                 flush_dcache_range((unsigned int)buf,
448                                 (unsigned int)(buf + page_size));
449
450         /*
451          * This register must be written before each page is
452          * transferred to generate the correct ECC register
453          * values.
454          */
455         bfin_write_NFC_RST(0x1);
456         SSYNC();
457
458         disable_dma(CH_NFC);
459         clear_dma_irqstat(CH_NFC);
460
461         /* setup DMA register with Blackfin DMA API */
462         set_dma_config(CH_NFC, 0x0);
463         set_dma_start_addr(CH_NFC, (unsigned long) buf);
464         set_dma_x_count(CH_NFC, (page_size >> 2));
465         set_dma_x_modify(CH_NFC, 4);
466
467         /* setup write or read operation */
468         val = DI_EN | WDSIZE_32;
469         if (is_read)
470                 val |= WNR;
471         set_dma_config(CH_NFC, val);
472         enable_dma(CH_NFC);
473
474         /* Start PAGE read/write operation */
475         if (is_read)
476                 bfin_write_NFC_PGCTL(0x1);
477         else
478                 bfin_write_NFC_PGCTL(0x2);
479         wait_for_completion(&info->dma_completion);
480
481         return 0;
482 }
483
484 static void bf5xx_nand_dma_read_buf(struct mtd_info *mtd,
485                                         uint8_t *buf, int len)
486 {
487         struct bf5xx_nand_info *info = mtd_to_nand_info(mtd);
488         struct bf5xx_nand_platform *plat = info->platform;
489         unsigned short page_size = (plat->page_size ? 512 : 256);
490
491         dev_dbg(info->device, "mtd->%p, buf->%p, int %d\n", mtd, buf, len);
492
493         if (len == page_size)
494                 bf5xx_nand_dma_rw(mtd, buf, 1);
495         else
496                 bf5xx_nand_read_buf(mtd, buf, len);
497 }
498
499 static void bf5xx_nand_dma_write_buf(struct mtd_info *mtd,
500                                 const uint8_t *buf, int len)
501 {
502         struct bf5xx_nand_info *info = mtd_to_nand_info(mtd);
503         struct bf5xx_nand_platform *plat = info->platform;
504         unsigned short page_size = (plat->page_size ? 512 : 256);
505
506         dev_dbg(info->device, "mtd->%p, buf->%p, len %d\n", mtd, buf, len);
507
508         if (len == page_size)
509                 bf5xx_nand_dma_rw(mtd, (uint8_t *)buf, 0);
510         else
511                 bf5xx_nand_write_buf(mtd, buf, len);
512 }
513
514 /*
515  * System initialization functions
516  */
517
518 static int bf5xx_nand_dma_init(struct bf5xx_nand_info *info)
519 {
520         int ret;
521         unsigned short val;
522
523         /* Do not use dma */
524         if (!hardware_ecc)
525                 return 0;
526
527         init_completion(&info->dma_completion);
528
529 #ifdef CONFIG_BF54x
530         /* Setup DMAC1 channel mux for NFC which shared with SDH */
531         val = bfin_read_DMAC1_PERIMUX();
532         val &= 0xFFFE;
533         bfin_write_DMAC1_PERIMUX(val);
534         SSYNC();
535 #endif
536         /* Request NFC DMA channel */
537         ret = request_dma(CH_NFC, "BF5XX NFC driver");
538         if (ret < 0) {
539                 dev_err(info->device, " unable to get DMA channel\n");
540                 return ret;
541         }
542
543         set_dma_callback(CH_NFC, (void *) bf5xx_nand_dma_irq, (void *) info);
544
545         /* Turn off the DMA channel first */
546         disable_dma(CH_NFC);
547         return 0;
548 }
549
550 /*
551  * BF5XX NFC hardware initialization
552  *  - pin mux setup
553  *  - clear interrupt status
554  */
555 static int bf5xx_nand_hw_init(struct bf5xx_nand_info *info)
556 {
557         int err = 0;
558         unsigned short val;
559         struct bf5xx_nand_platform *plat = info->platform;
560
561         /* setup NFC_CTL register */
562         dev_info(info->device,
563                 "page_size=%d, data_width=%d, wr_dly=%d, rd_dly=%d\n",
564                 (plat->page_size ? 512 : 256),
565                 (plat->data_width ? 16 : 8),
566                 plat->wr_dly, plat->rd_dly);
567
568         val = (plat->page_size << NFC_PG_SIZE_OFFSET) |
569                 (plat->data_width << NFC_NWIDTH_OFFSET) |
570                 (plat->rd_dly << NFC_RDDLY_OFFSET) |
571                 (plat->rd_dly << NFC_WRDLY_OFFSET);
572         dev_dbg(info->device, "NFC_CTL is 0x%04x\n", val);
573
574         bfin_write_NFC_CTL(val);
575         SSYNC();
576
577         /* clear interrupt status */
578         bfin_write_NFC_IRQMASK(0x0);
579         SSYNC();
580         val = bfin_read_NFC_IRQSTAT();
581         bfin_write_NFC_IRQSTAT(val);
582         SSYNC();
583
584         if (peripheral_request_list(bfin_nfc_pin_req, DRV_NAME)) {
585                 printk(KERN_ERR DRV_NAME
586                 ": Requesting Peripherals failed\n");
587                 return -EFAULT;
588         }
589
590         /* DMA initialization  */
591         if (bf5xx_nand_dma_init(info))
592                 err = -ENXIO;
593
594         return err;
595 }
596
597 /*
598  * Device management interface
599  */
600 static int bf5xx_nand_add_partition(struct bf5xx_nand_info *info)
601 {
602         struct mtd_info *mtd = &info->mtd;
603
604 #ifdef CONFIG_MTD_PARTITIONS
605         struct mtd_partition *parts = info->platform->partitions;
606         int nr = info->platform->nr_partitions;
607
608         return add_mtd_partitions(mtd, parts, nr);
609 #else
610         return add_mtd_device(mtd);
611 #endif
612 }
613
614 static int bf5xx_nand_remove(struct platform_device *pdev)
615 {
616         struct bf5xx_nand_info *info = to_nand_info(pdev);
617         struct mtd_info *mtd = NULL;
618
619         platform_set_drvdata(pdev, NULL);
620
621         /* first thing we need to do is release all our mtds
622          * and their partitions, then go through freeing the
623          * resources used
624          */
625         mtd = &info->mtd;
626         if (mtd) {
627                 nand_release(mtd);
628                 kfree(mtd);
629         }
630
631         peripheral_free_list(bfin_nfc_pin_req);
632
633         /* free the common resources */
634         kfree(info);
635
636         return 0;
637 }
638
639 /*
640  * bf5xx_nand_probe
641  *
642  * called by device layer when it finds a device matching
643  * one our driver can handled. This code checks to see if
644  * it can allocate all necessary resources then calls the
645  * nand layer to look for devices
646  */
647 static int bf5xx_nand_probe(struct platform_device *pdev)
648 {
649         struct bf5xx_nand_platform *plat = to_nand_plat(pdev);
650         struct bf5xx_nand_info *info = NULL;
651         struct nand_chip *chip = NULL;
652         struct mtd_info *mtd = NULL;
653         int err = 0;
654
655         dev_dbg(&pdev->dev, "(%p)\n", pdev);
656
657         if (!plat) {
658                 dev_err(&pdev->dev, "no platform specific information\n");
659                 goto exit_error;
660         }
661
662         info = kzalloc(sizeof(*info), GFP_KERNEL);
663         if (info == NULL) {
664                 dev_err(&pdev->dev, "no memory for flash info\n");
665                 err = -ENOMEM;
666                 goto exit_error;
667         }
668
669         platform_set_drvdata(pdev, info);
670
671         spin_lock_init(&info->controller.lock);
672         init_waitqueue_head(&info->controller.wq);
673
674         info->device     = &pdev->dev;
675         info->platform   = plat;
676
677         /* initialise chip data struct */
678         chip = &info->chip;
679
680         if (plat->data_width)
681                 chip->options |= NAND_BUSWIDTH_16;
682
683         chip->options |= NAND_CACHEPRG | NAND_SKIP_BBTSCAN;
684
685         chip->read_buf = (plat->data_width) ?
686                 bf5xx_nand_read_buf16 : bf5xx_nand_read_buf;
687         chip->write_buf = (plat->data_width) ?
688                 bf5xx_nand_write_buf16 : bf5xx_nand_write_buf;
689
690         chip->read_byte    = bf5xx_nand_read_byte;
691
692         chip->cmd_ctrl     = bf5xx_nand_hwcontrol;
693         chip->dev_ready    = bf5xx_nand_devready;
694
695         chip->priv         = &info->mtd;
696         chip->controller   = &info->controller;
697
698         chip->IO_ADDR_R    = (void __iomem *) NFC_READ;
699         chip->IO_ADDR_W    = (void __iomem *) NFC_DATA_WR;
700
701         chip->chip_delay   = 0;
702
703         /* initialise mtd info data struct */
704         mtd             = &info->mtd;
705         mtd->priv       = chip;
706         mtd->owner      = THIS_MODULE;
707
708         /* initialise the hardware */
709         err = bf5xx_nand_hw_init(info);
710         if (err != 0)
711                 goto exit_error;
712
713         /* setup hardware ECC data struct */
714         if (hardware_ecc) {
715                 if (plat->page_size == NFC_PG_SIZE_256) {
716                         chip->ecc.bytes = 3;
717                         chip->ecc.size = 256;
718                 } else if (plat->page_size == NFC_PG_SIZE_512) {
719                         chip->ecc.bytes = 6;
720                         chip->ecc.size = 512;
721                 }
722
723                 chip->read_buf      = bf5xx_nand_dma_read_buf;
724                 chip->write_buf     = bf5xx_nand_dma_write_buf;
725                 chip->ecc.calculate = bf5xx_nand_calculate_ecc;
726                 chip->ecc.correct   = bf5xx_nand_correct_data;
727                 chip->ecc.mode      = NAND_ECC_HW;
728                 chip->ecc.hwctl     = bf5xx_nand_enable_hwecc;
729         } else {
730                 chip->ecc.mode      = NAND_ECC_SOFT;
731         }
732
733         /* scan hardware nand chip and setup mtd info data struct */
734         if (nand_scan(mtd, 1)) {
735                 err = -ENXIO;
736                 goto exit_error;
737         }
738
739         /* add NAND partition */
740         bf5xx_nand_add_partition(info);
741
742         dev_dbg(&pdev->dev, "initialised ok\n");
743         return 0;
744
745 exit_error:
746         bf5xx_nand_remove(pdev);
747
748         if (err == 0)
749                 err = -EINVAL;
750         return err;
751 }
752
753 /* PM Support */
754 #ifdef CONFIG_PM
755
756 static int bf5xx_nand_suspend(struct platform_device *dev, pm_message_t pm)
757 {
758         struct bf5xx_nand_info *info = platform_get_drvdata(dev);
759
760         return 0;
761 }
762
763 static int bf5xx_nand_resume(struct platform_device *dev)
764 {
765         struct bf5xx_nand_info *info = platform_get_drvdata(dev);
766
767         return 0;
768 }
769
770 #else
771 #define bf5xx_nand_suspend NULL
772 #define bf5xx_nand_resume NULL
773 #endif
774
775 /* driver device registration */
776 static struct platform_driver bf5xx_nand_driver = {
777         .probe          = bf5xx_nand_probe,
778         .remove         = bf5xx_nand_remove,
779         .suspend        = bf5xx_nand_suspend,
780         .resume         = bf5xx_nand_resume,
781         .driver         = {
782                 .name   = DRV_NAME,
783                 .owner  = THIS_MODULE,
784         },
785 };
786
787 static int __init bf5xx_nand_init(void)
788 {
789         printk(KERN_INFO "%s, Version %s (c) 2007 Analog Devices, Inc.\n",
790                 DRV_DESC, DRV_VERSION);
791
792         return platform_driver_register(&bf5xx_nand_driver);
793 }
794
795 static void __exit bf5xx_nand_exit(void)
796 {
797         platform_driver_unregister(&bf5xx_nand_driver);
798 }
799
800 module_init(bf5xx_nand_init);
801 module_exit(bf5xx_nand_exit);
802
803 MODULE_LICENSE("GPL");
804 MODULE_AUTHOR(DRV_AUTHOR);
805 MODULE_DESCRIPTION(DRV_DESC);