1/*
2 * Handles the M-Systems DiskOnChip G3 chip
3 *
4 * Copyright (C) 2011 Robert Jarzmik
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 as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
19 *
20 */
21
22#include <linux/kernel.h>
23#include <linux/module.h>
24#include <linux/errno.h>
25#include <linux/of.h>
26#include <linux/platform_device.h>
27#include <linux/string.h>
28#include <linux/slab.h>
29#include <linux/io.h>
30#include <linux/delay.h>
31#include <linux/mtd/mtd.h>
32#include <linux/mtd/partitions.h>
33#include <linux/bitmap.h>
34#include <linux/bitrev.h>
35#include <linux/bch.h>
36
37#include <linux/debugfs.h>
38#include <linux/seq_file.h>
39
40#define CREATE_TRACE_POINTS
41#include "docg3.h"
42
43/*
44 * This driver handles the DiskOnChip G3 flash memory.
45 *
46 * As no specification is available from M-Systems/Sandisk, this drivers lacks
47 * several functions available on the chip, as :
48 *  - IPL write
49 *
50 * The bus data width (8bits versus 16bits) is not handled (if_cfg flag), and
51 * the driver assumes a 16bits data bus.
52 *
53 * DocG3 relies on 2 ECC algorithms, which are handled in hardware :
54 *  - a 1 byte Hamming code stored in the OOB for each page
55 *  - a 7 bytes BCH code stored in the OOB for each page
56 * The BCH ECC is :
57 *  - BCH is in GF(2^14)
58 *  - BCH is over data of 520 bytes (512 page + 7 page_info bytes
59 *                                   + 1 hamming byte)
60 *  - BCH can correct up to 4 bits (t = 4)
61 *  - BCH syndroms are calculated in hardware, and checked in hardware as well
62 *
63 */
64
65static unsigned int reliable_mode;
66module_param(reliable_mode, uint, 0);
67MODULE_PARM_DESC(reliable_mode, "Set the docg3 mode (0=normal MLC, 1=fast, "
68		 "2=reliable) : MLC normal operations are in normal mode");
69
70/**
71 * struct docg3_oobinfo - DiskOnChip G3 OOB layout
72 * @eccbytes: 8 bytes are used (1 for Hamming ECC, 7 for BCH ECC)
73 * @eccpos: ecc positions (byte 7 is Hamming ECC, byte 8-14 are BCH ECC)
74 * @oobfree: free pageinfo bytes (byte 0 until byte 6, byte 15
75 * @oobavail: 8 available bytes remaining after ECC toll
76 */
77static struct nand_ecclayout docg3_oobinfo = {
78	.eccbytes = 8,
79	.eccpos = {7, 8, 9, 10, 11, 12, 13, 14},
80	.oobfree = {{0, 7}, {15, 1} },
81	.oobavail = 8,
82};
83
84static inline u8 doc_readb(struct docg3 *docg3, u16 reg)
85{
86	u8 val = readb(docg3->cascade->base + reg);
87
88	trace_docg3_io(0, 8, reg, (int)val);
89	return val;
90}
91
92static inline u16 doc_readw(struct docg3 *docg3, u16 reg)
93{
94	u16 val = readw(docg3->cascade->base + reg);
95
96	trace_docg3_io(0, 16, reg, (int)val);
97	return val;
98}
99
100static inline void doc_writeb(struct docg3 *docg3, u8 val, u16 reg)
101{
102	writeb(val, docg3->cascade->base + reg);
103	trace_docg3_io(1, 8, reg, val);
104}
105
106static inline void doc_writew(struct docg3 *docg3, u16 val, u16 reg)
107{
108	writew(val, docg3->cascade->base + reg);
109	trace_docg3_io(1, 16, reg, val);
110}
111
112static inline void doc_flash_command(struct docg3 *docg3, u8 cmd)
113{
114	doc_writeb(docg3, cmd, DOC_FLASHCOMMAND);
115}
116
117static inline void doc_flash_sequence(struct docg3 *docg3, u8 seq)
118{
119	doc_writeb(docg3, seq, DOC_FLASHSEQUENCE);
120}
121
122static inline void doc_flash_address(struct docg3 *docg3, u8 addr)
123{
124	doc_writeb(docg3, addr, DOC_FLASHADDRESS);
125}
126
127static char const * const part_probes[] = { "cmdlinepart", "saftlpart", NULL };
128
129static int doc_register_readb(struct docg3 *docg3, int reg)
130{
131	u8 val;
132
133	doc_writew(docg3, reg, DOC_READADDRESS);
134	val = doc_readb(docg3, reg);
135	doc_vdbg("Read register %04x : %02x\n", reg, val);
136	return val;
137}
138
139static int doc_register_readw(struct docg3 *docg3, int reg)
140{
141	u16 val;
142
143	doc_writew(docg3, reg, DOC_READADDRESS);
144	val = doc_readw(docg3, reg);
145	doc_vdbg("Read register %04x : %04x\n", reg, val);
146	return val;
147}
148
149/**
150 * doc_delay - delay docg3 operations
151 * @docg3: the device
152 * @nbNOPs: the number of NOPs to issue
153 *
154 * As no specification is available, the right timings between chip commands are
155 * unknown. The only available piece of information are the observed nops on a
156 * working docg3 chip.
157 * Therefore, doc_delay relies on a busy loop of NOPs, instead of scheduler
158 * friendlier msleep() functions or blocking mdelay().
159 */
160static void doc_delay(struct docg3 *docg3, int nbNOPs)
161{
162	int i;
163
164	doc_vdbg("NOP x %d\n", nbNOPs);
165	for (i = 0; i < nbNOPs; i++)
166		doc_writeb(docg3, 0, DOC_NOP);
167}
168
169static int is_prot_seq_error(struct docg3 *docg3)
170{
171	int ctrl;
172
173	ctrl = doc_register_readb(docg3, DOC_FLASHCONTROL);
174	return ctrl & (DOC_CTRL_PROTECTION_ERROR | DOC_CTRL_SEQUENCE_ERROR);
175}
176
177static int doc_is_ready(struct docg3 *docg3)
178{
179	int ctrl;
180
181	ctrl = doc_register_readb(docg3, DOC_FLASHCONTROL);
182	return ctrl & DOC_CTRL_FLASHREADY;
183}
184
185static int doc_wait_ready(struct docg3 *docg3)
186{
187	int maxWaitCycles = 100;
188
189	do {
190		doc_delay(docg3, 4);
191		cpu_relax();
192	} while (!doc_is_ready(docg3) && maxWaitCycles--);
193	doc_delay(docg3, 2);
194	if (maxWaitCycles > 0)
195		return 0;
196	else
197		return -EIO;
198}
199
200static int doc_reset_seq(struct docg3 *docg3)
201{
202	int ret;
203
204	doc_writeb(docg3, 0x10, DOC_FLASHCONTROL);
205	doc_flash_sequence(docg3, DOC_SEQ_RESET);
206	doc_flash_command(docg3, DOC_CMD_RESET);
207	doc_delay(docg3, 2);
208	ret = doc_wait_ready(docg3);
209
210	doc_dbg("doc_reset_seq() -> isReady=%s\n", ret ? "false" : "true");
211	return ret;
212}
213
214/**
215 * doc_read_data_area - Read data from data area
216 * @docg3: the device
217 * @buf: the buffer to fill in (might be NULL is dummy reads)
218 * @len: the length to read
219 * @first: first time read, DOC_READADDRESS should be set
220 *
221 * Reads bytes from flash data. Handles the single byte / even bytes reads.
222 */
223static void doc_read_data_area(struct docg3 *docg3, void *buf, int len,
224			       int first)
225{
226	int i, cdr, len4;
227	u16 data16, *dst16;
228	u8 data8, *dst8;
229
230	doc_dbg("doc_read_data_area(buf=%p, len=%d)\n", buf, len);
231	cdr = len & 0x1;
232	len4 = len - cdr;
233
234	if (first)
235		doc_writew(docg3, DOC_IOSPACE_DATA, DOC_READADDRESS);
236	dst16 = buf;
237	for (i = 0; i < len4; i += 2) {
238		data16 = doc_readw(docg3, DOC_IOSPACE_DATA);
239		if (dst16) {
240			*dst16 = data16;
241			dst16++;
242		}
243	}
244
245	if (cdr) {
246		doc_writew(docg3, DOC_IOSPACE_DATA | DOC_READADDR_ONE_BYTE,
247			   DOC_READADDRESS);
248		doc_delay(docg3, 1);
249		dst8 = (u8 *)dst16;
250		for (i = 0; i < cdr; i++) {
251			data8 = doc_readb(docg3, DOC_IOSPACE_DATA);
252			if (dst8) {
253				*dst8 = data8;
254				dst8++;
255			}
256		}
257	}
258}
259
260/**
261 * doc_write_data_area - Write data into data area
262 * @docg3: the device
263 * @buf: the buffer to get input bytes from
264 * @len: the length to write
265 *
266 * Writes bytes into flash data. Handles the single byte / even bytes writes.
267 */
268static void doc_write_data_area(struct docg3 *docg3, const void *buf, int len)
269{
270	int i, cdr, len4;
271	u16 *src16;
272	u8 *src8;
273
274	doc_dbg("doc_write_data_area(buf=%p, len=%d)\n", buf, len);
275	cdr = len & 0x3;
276	len4 = len - cdr;
277
278	doc_writew(docg3, DOC_IOSPACE_DATA, DOC_READADDRESS);
279	src16 = (u16 *)buf;
280	for (i = 0; i < len4; i += 2) {
281		doc_writew(docg3, *src16, DOC_IOSPACE_DATA);
282		src16++;
283	}
284
285	src8 = (u8 *)src16;
286	for (i = 0; i < cdr; i++) {
287		doc_writew(docg3, DOC_IOSPACE_DATA | DOC_READADDR_ONE_BYTE,
288			   DOC_READADDRESS);
289		doc_writeb(docg3, *src8, DOC_IOSPACE_DATA);
290		src8++;
291	}
292}
293
294/**
295 * doc_set_data_mode - Sets the flash to normal or reliable data mode
296 * @docg3: the device
297 *
298 * The reliable data mode is a bit slower than the fast mode, but less errors
299 * occur.  Entering the reliable mode cannot be done without entering the fast
300 * mode first.
301 *
302 * In reliable mode, pages 2*n and 2*n+1 are clones. Writing to page 0 of blocks
303 * (4,5) make the hardware write also to page 1 of blocks blocks(4,5). Reading
304 * from page 0 of blocks (4,5) or from page 1 of blocks (4,5) gives the same
305 * result, which is a logical and between bytes from page 0 and page 1 (which is
306 * consistent with the fact that writing to a page is _clearing_ bits of that
307 * page).
308 */
309static void doc_set_reliable_mode(struct docg3 *docg3)
310{
311	static char *strmode[] = { "normal", "fast", "reliable", "invalid" };
312
313	doc_dbg("doc_set_reliable_mode(%s)\n", strmode[docg3->reliable]);
314	switch (docg3->reliable) {
315	case 0:
316		break;
317	case 1:
318		doc_flash_sequence(docg3, DOC_SEQ_SET_FASTMODE);
319		doc_flash_command(docg3, DOC_CMD_FAST_MODE);
320		break;
321	case 2:
322		doc_flash_sequence(docg3, DOC_SEQ_SET_RELIABLEMODE);
323		doc_flash_command(docg3, DOC_CMD_FAST_MODE);
324		doc_flash_command(docg3, DOC_CMD_RELIABLE_MODE);
325		break;
326	default:
327		doc_err("doc_set_reliable_mode(): invalid mode\n");
328		break;
329	}
330	doc_delay(docg3, 2);
331}
332
333/**
334 * doc_set_asic_mode - Set the ASIC mode
335 * @docg3: the device
336 * @mode: the mode
337 *
338 * The ASIC can work in 3 modes :
339 *  - RESET: all registers are zeroed
340 *  - NORMAL: receives and handles commands
341 *  - POWERDOWN: minimal poweruse, flash parts shut off
342 */
343static void doc_set_asic_mode(struct docg3 *docg3, u8 mode)
344{
345	int i;
346
347	for (i = 0; i < 12; i++)
348		doc_readb(docg3, DOC_IOSPACE_IPL);
349
350	mode |= DOC_ASICMODE_MDWREN;
351	doc_dbg("doc_set_asic_mode(%02x)\n", mode);
352	doc_writeb(docg3, mode, DOC_ASICMODE);
353	doc_writeb(docg3, ~mode, DOC_ASICMODECONFIRM);
354	doc_delay(docg3, 1);
355}
356
357/**
358 * doc_set_device_id - Sets the devices id for cascaded G3 chips
359 * @docg3: the device
360 * @id: the chip to select (amongst 0, 1, 2, 3)
361 *
362 * There can be 4 cascaded G3 chips. This function selects the one which will
363 * should be the active one.
364 */
365static void doc_set_device_id(struct docg3 *docg3, int id)
366{
367	u8 ctrl;
368
369	doc_dbg("doc_set_device_id(%d)\n", id);
370	doc_writeb(docg3, id, DOC_DEVICESELECT);
371	ctrl = doc_register_readb(docg3, DOC_FLASHCONTROL);
372
373	ctrl &= ~DOC_CTRL_VIOLATION;
374	ctrl |= DOC_CTRL_CE;
375	doc_writeb(docg3, ctrl, DOC_FLASHCONTROL);
376}
377
378/**
379 * doc_set_extra_page_mode - Change flash page layout
380 * @docg3: the device
381 *
382 * Normally, the flash page is split into the data (512 bytes) and the out of
383 * band data (16 bytes). For each, 4 more bytes can be accessed, where the wear
384 * leveling counters are stored.  To access this last area of 4 bytes, a special
385 * mode must be input to the flash ASIC.
386 *
387 * Returns 0 if no error occurred, -EIO else.
388 */
389static int doc_set_extra_page_mode(struct docg3 *docg3)
390{
391	int fctrl;
392
393	doc_dbg("doc_set_extra_page_mode()\n");
394	doc_flash_sequence(docg3, DOC_SEQ_PAGE_SIZE_532);
395	doc_flash_command(docg3, DOC_CMD_PAGE_SIZE_532);
396	doc_delay(docg3, 2);
397
398	fctrl = doc_register_readb(docg3, DOC_FLASHCONTROL);
399	if (fctrl & (DOC_CTRL_PROTECTION_ERROR | DOC_CTRL_SEQUENCE_ERROR))
400		return -EIO;
401	else
402		return 0;
403}
404
405/**
406 * doc_setup_addr_sector - Setup blocks/page/ofs address for one plane
407 * @docg3: the device
408 * @sector: the sector
409 */
410static void doc_setup_addr_sector(struct docg3 *docg3, int sector)
411{
412	doc_delay(docg3, 1);
413	doc_flash_address(docg3, sector & 0xff);
414	doc_flash_address(docg3, (sector >> 8) & 0xff);
415	doc_flash_address(docg3, (sector >> 16) & 0xff);
416	doc_delay(docg3, 1);
417}
418
419/**
420 * doc_setup_writeaddr_sector - Setup blocks/page/ofs address for one plane
421 * @docg3: the device
422 * @sector: the sector
423 * @ofs: the offset in the page, between 0 and (512 + 16 + 512)
424 */
425static void doc_setup_writeaddr_sector(struct docg3 *docg3, int sector, int ofs)
426{
427	ofs = ofs >> 2;
428	doc_delay(docg3, 1);
429	doc_flash_address(docg3, ofs & 0xff);
430	doc_flash_address(docg3, sector & 0xff);
431	doc_flash_address(docg3, (sector >> 8) & 0xff);
432	doc_flash_address(docg3, (sector >> 16) & 0xff);
433	doc_delay(docg3, 1);
434}
435
436/**
437 * doc_seek - Set both flash planes to the specified block, page for reading
438 * @docg3: the device
439 * @block0: the first plane block index
440 * @block1: the second plane block index
441 * @page: the page index within the block
442 * @wear: if true, read will occur on the 4 extra bytes of the wear area
443 * @ofs: offset in page to read
444 *
445 * Programs the flash even and odd planes to the specific block and page.
446 * Alternatively, programs the flash to the wear area of the specified page.
447 */
448static int doc_read_seek(struct docg3 *docg3, int block0, int block1, int page,
449			 int wear, int ofs)
450{
451	int sector, ret = 0;
452
453	doc_dbg("doc_seek(blocks=(%d,%d), page=%d, ofs=%d, wear=%d)\n",
454		block0, block1, page, ofs, wear);
455
456	if (!wear && (ofs < 2 * DOC_LAYOUT_PAGE_SIZE)) {
457		doc_flash_sequence(docg3, DOC_SEQ_SET_PLANE1);
458		doc_flash_command(docg3, DOC_CMD_READ_PLANE1);
459		doc_delay(docg3, 2);
460	} else {
461		doc_flash_sequence(docg3, DOC_SEQ_SET_PLANE2);
462		doc_flash_command(docg3, DOC_CMD_READ_PLANE2);
463		doc_delay(docg3, 2);
464	}
465
466	doc_set_reliable_mode(docg3);
467	if (wear)
468		ret = doc_set_extra_page_mode(docg3);
469	if (ret)
470		goto out;
471
472	doc_flash_sequence(docg3, DOC_SEQ_READ);
473	sector = (block0 << DOC_ADDR_BLOCK_SHIFT) + (page & DOC_ADDR_PAGE_MASK);
474	doc_flash_command(docg3, DOC_CMD_PROG_BLOCK_ADDR);
475	doc_setup_addr_sector(docg3, sector);
476
477	sector = (block1 << DOC_ADDR_BLOCK_SHIFT) + (page & DOC_ADDR_PAGE_MASK);
478	doc_flash_command(docg3, DOC_CMD_PROG_BLOCK_ADDR);
479	doc_setup_addr_sector(docg3, sector);
480	doc_delay(docg3, 1);
481
482out:
483	return ret;
484}
485
486/**
487 * doc_write_seek - Set both flash planes to the specified block, page for writing
488 * @docg3: the device
489 * @block0: the first plane block index
490 * @block1: the second plane block index
491 * @page: the page index within the block
492 * @ofs: offset in page to write
493 *
494 * Programs the flash even and odd planes to the specific block and page.
495 * Alternatively, programs the flash to the wear area of the specified page.
496 */
497static int doc_write_seek(struct docg3 *docg3, int block0, int block1, int page,
498			 int ofs)
499{
500	int ret = 0, sector;
501
502	doc_dbg("doc_write_seek(blocks=(%d,%d), page=%d, ofs=%d)\n",
503		block0, block1, page, ofs);
504
505	doc_set_reliable_mode(docg3);
506
507	if (ofs < 2 * DOC_LAYOUT_PAGE_SIZE) {
508		doc_flash_sequence(docg3, DOC_SEQ_SET_PLANE1);
509		doc_flash_command(docg3, DOC_CMD_READ_PLANE1);
510		doc_delay(docg3, 2);
511	} else {
512		doc_flash_sequence(docg3, DOC_SEQ_SET_PLANE2);
513		doc_flash_command(docg3, DOC_CMD_READ_PLANE2);
514		doc_delay(docg3, 2);
515	}
516
517	doc_flash_sequence(docg3, DOC_SEQ_PAGE_SETUP);
518	doc_flash_command(docg3, DOC_CMD_PROG_CYCLE1);
519
520	sector = (block0 << DOC_ADDR_BLOCK_SHIFT) + (page & DOC_ADDR_PAGE_MASK);
521	doc_setup_writeaddr_sector(docg3, sector, ofs);
522
523	doc_flash_command(docg3, DOC_CMD_PROG_CYCLE3);
524	doc_delay(docg3, 2);
525	ret = doc_wait_ready(docg3);
526	if (ret)
527		goto out;
528
529	doc_flash_command(docg3, DOC_CMD_PROG_CYCLE1);
530	sector = (block1 << DOC_ADDR_BLOCK_SHIFT) + (page & DOC_ADDR_PAGE_MASK);
531	doc_setup_writeaddr_sector(docg3, sector, ofs);
532	doc_delay(docg3, 1);
533
534out:
535	return ret;
536}
537
538
539/**
540 * doc_read_page_ecc_init - Initialize hardware ECC engine
541 * @docg3: the device
542 * @len: the number of bytes covered by the ECC (BCH covered)
543 *
544 * The function does initialize the hardware ECC engine to compute the Hamming
545 * ECC (on 1 byte) and the BCH hardware ECC (on 7 bytes).
546 *
547 * Return 0 if succeeded, -EIO on error
548 */
549static int doc_read_page_ecc_init(struct docg3 *docg3, int len)
550{
551	doc_writew(docg3, DOC_ECCCONF0_READ_MODE
552		   | DOC_ECCCONF0_BCH_ENABLE | DOC_ECCCONF0_HAMMING_ENABLE
553		   | (len & DOC_ECCCONF0_DATA_BYTES_MASK),
554		   DOC_ECCCONF0);
555	doc_delay(docg3, 4);
556	doc_register_readb(docg3, DOC_FLASHCONTROL);
557	return doc_wait_ready(docg3);
558}
559
560/**
561 * doc_write_page_ecc_init - Initialize hardware BCH ECC engine
562 * @docg3: the device
563 * @len: the number of bytes covered by the ECC (BCH covered)
564 *
565 * The function does initialize the hardware ECC engine to compute the Hamming
566 * ECC (on 1 byte) and the BCH hardware ECC (on 7 bytes).
567 *
568 * Return 0 if succeeded, -EIO on error
569 */
570static int doc_write_page_ecc_init(struct docg3 *docg3, int len)
571{
572	doc_writew(docg3, DOC_ECCCONF0_WRITE_MODE
573		   | DOC_ECCCONF0_BCH_ENABLE | DOC_ECCCONF0_HAMMING_ENABLE
574		   | (len & DOC_ECCCONF0_DATA_BYTES_MASK),
575		   DOC_ECCCONF0);
576	doc_delay(docg3, 4);
577	doc_register_readb(docg3, DOC_FLASHCONTROL);
578	return doc_wait_ready(docg3);
579}
580
581/**
582 * doc_ecc_disable - Disable Hamming and BCH ECC hardware calculator
583 * @docg3: the device
584 *
585 * Disables the hardware ECC generator and checker, for unchecked reads (as when
586 * reading OOB only or write status byte).
587 */
588static void doc_ecc_disable(struct docg3 *docg3)
589{
590	doc_writew(docg3, DOC_ECCCONF0_READ_MODE, DOC_ECCCONF0);
591	doc_delay(docg3, 4);
592}
593
594/**
595 * doc_hamming_ecc_init - Initialize hardware Hamming ECC engine
596 * @docg3: the device
597 * @nb_bytes: the number of bytes covered by the ECC (Hamming covered)
598 *
599 * This function programs the ECC hardware to compute the hamming code on the
600 * last provided N bytes to the hardware generator.
601 */
602static void doc_hamming_ecc_init(struct docg3 *docg3, int nb_bytes)
603{
604	u8 ecc_conf1;
605
606	ecc_conf1 = doc_register_readb(docg3, DOC_ECCCONF1);
607	ecc_conf1 &= ~DOC_ECCCONF1_HAMMING_BITS_MASK;
608	ecc_conf1 |= (nb_bytes & DOC_ECCCONF1_HAMMING_BITS_MASK);
609	doc_writeb(docg3, ecc_conf1, DOC_ECCCONF1);
610}
611
612/**
613 * doc_ecc_bch_fix_data - Fix if need be read data from flash
614 * @docg3: the device
615 * @buf: the buffer of read data (512 + 7 + 1 bytes)
616 * @hwecc: the hardware calculated ECC.
617 *         It's in fact recv_ecc ^ calc_ecc, where recv_ecc was read from OOB
618 *         area data, and calc_ecc the ECC calculated by the hardware generator.
619 *
620 * Checks if the received data matches the ECC, and if an error is detected,
621 * tries to fix the bit flips (at most 4) in the buffer buf.  As the docg3
622 * understands the (data, ecc, syndroms) in an inverted order in comparison to
623 * the BCH library, the function reverses the order of bits (ie. bit7 and bit0,
624 * bit6 and bit 1, ...) for all ECC data.
625 *
626 * The hardware ecc unit produces oob_ecc ^ calc_ecc.  The kernel's bch
627 * algorithm is used to decode this.  However the hw operates on page
628 * data in a bit order that is the reverse of that of the bch alg,
629 * requiring that the bits be reversed on the result.  Thanks to Ivan
630 * Djelic for his analysis.
631 *
632 * Returns number of fixed bits (0, 1, 2, 3, 4) or -EBADMSG if too many bit
633 * errors were detected and cannot be fixed.
634 */
635static int doc_ecc_bch_fix_data(struct docg3 *docg3, void *buf, u8 *hwecc)
636{
637	u8 ecc[DOC_ECC_BCH_SIZE];
638	int errorpos[DOC_ECC_BCH_T], i, numerrs;
639
640	for (i = 0; i < DOC_ECC_BCH_SIZE; i++)
641		ecc[i] = bitrev8(hwecc[i]);
642	numerrs = decode_bch(docg3->cascade->bch, NULL,
643			     DOC_ECC_BCH_COVERED_BYTES,
644			     NULL, ecc, NULL, errorpos);
645	BUG_ON(numerrs == -EINVAL);
646	if (numerrs < 0)
647		goto out;
648
649	for (i = 0; i < numerrs; i++)
650		errorpos[i] = (errorpos[i] & ~7) | (7 - (errorpos[i] & 7));
651	for (i = 0; i < numerrs; i++)
652		if (errorpos[i] < DOC_ECC_BCH_COVERED_BYTES*8)
653			/* error is located in data, correct it */
654			change_bit(errorpos[i], buf);
655out:
656	doc_dbg("doc_ecc_bch_fix_data: flipped %d bits\n", numerrs);
657	return numerrs;
658}
659
660
661/**
662 * doc_read_page_prepare - Prepares reading data from a flash page
663 * @docg3: the device
664 * @block0: the first plane block index on flash memory
665 * @block1: the second plane block index on flash memory
666 * @page: the page index in the block
667 * @offset: the offset in the page (must be a multiple of 4)
668 *
669 * Prepares the page to be read in the flash memory :
670 *   - tell ASIC to map the flash pages
671 *   - tell ASIC to be in read mode
672 *
673 * After a call to this method, a call to doc_read_page_finish is mandatory,
674 * to end the read cycle of the flash.
675 *
676 * Read data from a flash page. The length to be read must be between 0 and
677 * (page_size + oob_size + wear_size), ie. 532, and a multiple of 4 (because
678 * the extra bytes reading is not implemented).
679 *
680 * As pages are grouped by 2 (in 2 planes), reading from a page must be done
681 * in two steps:
682 *  - one read of 512 bytes at offset 0
683 *  - one read of 512 bytes at offset 512 + 16
684 *
685 * Returns 0 if successful, -EIO if a read error occurred.
686 */
687static int doc_read_page_prepare(struct docg3 *docg3, int block0, int block1,
688				 int page, int offset)
689{
690	int wear_area = 0, ret = 0;
691
692	doc_dbg("doc_read_page_prepare(blocks=(%d,%d), page=%d, ofsInPage=%d)\n",
693		block0, block1, page, offset);
694	if (offset >= DOC_LAYOUT_WEAR_OFFSET)
695		wear_area = 1;
696	if (!wear_area && offset > (DOC_LAYOUT_PAGE_OOB_SIZE * 2))
697		return -EINVAL;
698
699	doc_set_device_id(docg3, docg3->device_id);
700	ret = doc_reset_seq(docg3);
701	if (ret)
702		goto err;
703
704	/* Program the flash address block and page */
705	ret = doc_read_seek(docg3, block0, block1, page, wear_area, offset);
706	if (ret)
707		goto err;
708
709	doc_flash_command(docg3, DOC_CMD_READ_ALL_PLANES);
710	doc_delay(docg3, 2);
711	doc_wait_ready(docg3);
712
713	doc_flash_command(docg3, DOC_CMD_SET_ADDR_READ);
714	doc_delay(docg3, 1);
715	if (offset >= DOC_LAYOUT_PAGE_SIZE * 2)
716		offset -= 2 * DOC_LAYOUT_PAGE_SIZE;
717	doc_flash_address(docg3, offset >> 2);
718	doc_delay(docg3, 1);
719	doc_wait_ready(docg3);
720
721	doc_flash_command(docg3, DOC_CMD_READ_FLASH);
722
723	return 0;
724err:
725	doc_writeb(docg3, 0, DOC_DATAEND);
726	doc_delay(docg3, 2);
727	return -EIO;
728}
729
730/**
731 * doc_read_page_getbytes - Reads bytes from a prepared page
732 * @docg3: the device
733 * @len: the number of bytes to be read (must be a multiple of 4)
734 * @buf: the buffer to be filled in (or NULL is forget bytes)
735 * @first: 1 if first time read, DOC_READADDRESS should be set
736 * @last_odd: 1 if last read ended up on an odd byte
737 *
738 * Reads bytes from a prepared page. There is a trickery here : if the last read
739 * ended up on an odd offset in the 1024 bytes double page, ie. between the 2
740 * planes, the first byte must be read apart. If a word (16bit) read was used,
741 * the read would return the byte of plane 2 as low *and* high endian, which
742 * will mess the read.
743 *
744 */
745static int doc_read_page_getbytes(struct docg3 *docg3, int len, u_char *buf,
746				  int first, int last_odd)
747{
748	if (last_odd && len > 0) {
749		doc_read_data_area(docg3, buf, 1, first);
750		doc_read_data_area(docg3, buf ? buf + 1 : buf, len - 1, 0);
751	} else {
752		doc_read_data_area(docg3, buf, len, first);
753	}
754	doc_delay(docg3, 2);
755	return len;
756}
757
758/**
759 * doc_write_page_putbytes - Writes bytes into a prepared page
760 * @docg3: the device
761 * @len: the number of bytes to be written
762 * @buf: the buffer of input bytes
763 *
764 */
765static void doc_write_page_putbytes(struct docg3 *docg3, int len,
766				    const u_char *buf)
767{
768	doc_write_data_area(docg3, buf, len);
769	doc_delay(docg3, 2);
770}
771
772/**
773 * doc_get_bch_hw_ecc - Get hardware calculated BCH ECC
774 * @docg3: the device
775 * @hwecc:  the array of 7 integers where the hardware ecc will be stored
776 */
777static void doc_get_bch_hw_ecc(struct docg3 *docg3, u8 *hwecc)
778{
779	int i;
780
781	for (i = 0; i < DOC_ECC_BCH_SIZE; i++)
782		hwecc[i] = doc_register_readb(docg3, DOC_BCH_HW_ECC(i));
783}
784
785/**
786 * doc_page_finish - Ends reading/writing of a flash page
787 * @docg3: the device
788 */
789static void doc_page_finish(struct docg3 *docg3)
790{
791	doc_writeb(docg3, 0, DOC_DATAEND);
792	doc_delay(docg3, 2);
793}
794
795/**
796 * doc_read_page_finish - Ends reading of a flash page
797 * @docg3: the device
798 *
799 * As a side effect, resets the chip selector to 0. This ensures that after each
800 * read operation, the floor 0 is selected. Therefore, if the systems halts, the
801 * reboot will boot on floor 0, where the IPL is.
802 */
803static void doc_read_page_finish(struct docg3 *docg3)
804{
805	doc_page_finish(docg3);
806	doc_set_device_id(docg3, 0);
807}
808
809/**
810 * calc_block_sector - Calculate blocks, pages and ofs.
811
812 * @from: offset in flash
813 * @block0: first plane block index calculated
814 * @block1: second plane block index calculated
815 * @page: page calculated
816 * @ofs: offset in page
817 * @reliable: 0 if docg3 in normal mode, 1 if docg3 in fast mode, 2 if docg3 in
818 * reliable mode.
819 *
820 * The calculation is based on the reliable/normal mode. In normal mode, the 64
821 * pages of a block are available. In reliable mode, as pages 2*n and 2*n+1 are
822 * clones, only 32 pages per block are available.
823 */
824static void calc_block_sector(loff_t from, int *block0, int *block1, int *page,
825			      int *ofs, int reliable)
826{
827	uint sector, pages_biblock;
828
829	pages_biblock = DOC_LAYOUT_PAGES_PER_BLOCK * DOC_LAYOUT_NBPLANES;
830	if (reliable == 1 || reliable == 2)
831		pages_biblock /= 2;
832
833	sector = from / DOC_LAYOUT_PAGE_SIZE;
834	*block0 = sector / pages_biblock * DOC_LAYOUT_NBPLANES;
835	*block1 = *block0 + 1;
836	*page = sector % pages_biblock;
837	*page /= DOC_LAYOUT_NBPLANES;
838	if (reliable == 1 || reliable == 2)
839		*page *= 2;
840	if (sector % 2)
841		*ofs = DOC_LAYOUT_PAGE_OOB_SIZE;
842	else
843		*ofs = 0;
844}
845
846/**
847 * doc_read_oob - Read out of band bytes from flash
848 * @mtd: the device
849 * @from: the offset from first block and first page, in bytes, aligned on page
850 *        size
851 * @ops: the mtd oob structure
852 *
853 * Reads flash memory OOB area of pages.
854 *
855 * Returns 0 if read successful, of -EIO, -EINVAL if an error occurred
856 */
857static int doc_read_oob(struct mtd_info *mtd, loff_t from,
858			struct mtd_oob_ops *ops)
859{
860	struct docg3 *docg3 = mtd->priv;
861	int block0, block1, page, ret, skip, ofs = 0;
862	u8 *oobbuf = ops->oobbuf;
863	u8 *buf = ops->datbuf;
864	size_t len, ooblen, nbdata, nboob;
865	u8 hwecc[DOC_ECC_BCH_SIZE], eccconf1;
866	int max_bitflips = 0;
867
868	if (buf)
869		len = ops->len;
870	else
871		len = 0;
872	if (oobbuf)
873		ooblen = ops->ooblen;
874	else
875		ooblen = 0;
876
877	if (oobbuf && ops->mode == MTD_OPS_PLACE_OOB)
878		oobbuf += ops->ooboffs;
879
880	doc_dbg("doc_read_oob(from=%lld, mode=%d, data=(%p:%zu), oob=(%p:%zu))\n",
881		from, ops->mode, buf, len, oobbuf, ooblen);
882	if (ooblen % DOC_LAYOUT_OOB_SIZE)
883		return -EINVAL;
884
885	if (from + len > mtd->size)
886		return -EINVAL;
887
888	ops->oobretlen = 0;
889	ops->retlen = 0;
890	ret = 0;
891	skip = from % DOC_LAYOUT_PAGE_SIZE;
892	mutex_lock(&docg3->cascade->lock);
893	while (ret >= 0 && (len > 0 || ooblen > 0)) {
894		calc_block_sector(from - skip, &block0, &block1, &page, &ofs,
895			docg3->reliable);
896		nbdata = min_t(size_t, len, DOC_LAYOUT_PAGE_SIZE - skip);
897		nboob = min_t(size_t, ooblen, (size_t)DOC_LAYOUT_OOB_SIZE);
898		ret = doc_read_page_prepare(docg3, block0, block1, page, ofs);
899		if (ret < 0)
900			goto out;
901		ret = doc_read_page_ecc_init(docg3, DOC_ECC_BCH_TOTAL_BYTES);
902		if (ret < 0)
903			goto err_in_read;
904		ret = doc_read_page_getbytes(docg3, skip, NULL, 1, 0);
905		if (ret < skip)
906			goto err_in_read;
907		ret = doc_read_page_getbytes(docg3, nbdata, buf, 0, skip % 2);
908		if (ret < nbdata)
909			goto err_in_read;
910		doc_read_page_getbytes(docg3,
911				       DOC_LAYOUT_PAGE_SIZE - nbdata - skip,
912				       NULL, 0, (skip + nbdata) % 2);
913		ret = doc_read_page_getbytes(docg3, nboob, oobbuf, 0, 0);
914		if (ret < nboob)
915			goto err_in_read;
916		doc_read_page_getbytes(docg3, DOC_LAYOUT_OOB_SIZE - nboob,
917				       NULL, 0, nboob % 2);
918
919		doc_get_bch_hw_ecc(docg3, hwecc);
920		eccconf1 = doc_register_readb(docg3, DOC_ECCCONF1);
921
922		if (nboob >= DOC_LAYOUT_OOB_SIZE) {
923			doc_dbg("OOB - INFO: %*phC\n", 7, oobbuf);
924			doc_dbg("OOB - HAMMING: %02x\n", oobbuf[7]);
925			doc_dbg("OOB - BCH_ECC: %*phC\n", 7, oobbuf + 8);
926			doc_dbg("OOB - UNUSED: %02x\n", oobbuf[15]);
927		}
928		doc_dbg("ECC checks: ECCConf1=%x\n", eccconf1);
929		doc_dbg("ECC HW_ECC: %*phC\n", 7, hwecc);
930
931		ret = -EIO;
932		if (is_prot_seq_error(docg3))
933			goto err_in_read;
934		ret = 0;
935		if ((block0 >= DOC_LAYOUT_BLOCK_FIRST_DATA) &&
936		    (eccconf1 & DOC_ECCCONF1_BCH_SYNDROM_ERR) &&
937		    (eccconf1 & DOC_ECCCONF1_PAGE_IS_WRITTEN) &&
938		    (ops->mode != MTD_OPS_RAW) &&
939		    (nbdata == DOC_LAYOUT_PAGE_SIZE)) {
940			ret = doc_ecc_bch_fix_data(docg3, buf, hwecc);
941			if (ret < 0) {
942				mtd->ecc_stats.failed++;
943				ret = -EBADMSG;
944			}
945			if (ret > 0) {
946				mtd->ecc_stats.corrected += ret;
947				max_bitflips = max(max_bitflips, ret);
948				ret = max_bitflips;
949			}
950		}
951
952		doc_read_page_finish(docg3);
953		ops->retlen += nbdata;
954		ops->oobretlen += nboob;
955		buf += nbdata;
956		oobbuf += nboob;
957		len -= nbdata;
958		ooblen -= nboob;
959		from += DOC_LAYOUT_PAGE_SIZE;
960		skip = 0;
961	}
962
963out:
964	mutex_unlock(&docg3->cascade->lock);
965	return ret;
966err_in_read:
967	doc_read_page_finish(docg3);
968	goto out;
969}
970
971/**
972 * doc_read - Read bytes from flash
973 * @mtd: the device
974 * @from: the offset from first block and first page, in bytes, aligned on page
975 *        size
976 * @len: the number of bytes to read (must be a multiple of 4)
977 * @retlen: the number of bytes actually read
978 * @buf: the filled in buffer
979 *
980 * Reads flash memory pages. This function does not read the OOB chunk, but only
981 * the page data.
982 *
983 * Returns 0 if read successful, of -EIO, -EINVAL if an error occurred
984 */
985static int doc_read(struct mtd_info *mtd, loff_t from, size_t len,
986	     size_t *retlen, u_char *buf)
987{
988	struct mtd_oob_ops ops;
989	size_t ret;
990
991	memset(&ops, 0, sizeof(ops));
992	ops.datbuf = buf;
993	ops.len = len;
994	ops.mode = MTD_OPS_AUTO_OOB;
995
996	ret = doc_read_oob(mtd, from, &ops);
997	*retlen = ops.retlen;
998	return ret;
999}
1000
1001static int doc_reload_bbt(struct docg3 *docg3)
1002{
1003	int block = DOC_LAYOUT_BLOCK_BBT;
1004	int ret = 0, nbpages, page;
1005	u_char *buf = docg3->bbt;
1006
1007	nbpages = DIV_ROUND_UP(docg3->max_block + 1, 8 * DOC_LAYOUT_PAGE_SIZE);
1008	for (page = 0; !ret && (page < nbpages); page++) {
1009		ret = doc_read_page_prepare(docg3, block, block + 1,
1010					    page + DOC_LAYOUT_PAGE_BBT, 0);
1011		if (!ret)
1012			ret = doc_read_page_ecc_init(docg3,
1013						     DOC_LAYOUT_PAGE_SIZE);
1014		if (!ret)
1015			doc_read_page_getbytes(docg3, DOC_LAYOUT_PAGE_SIZE,
1016					       buf, 1, 0);
1017		buf += DOC_LAYOUT_PAGE_SIZE;
1018	}
1019	doc_read_page_finish(docg3);
1020	return ret;
1021}
1022
1023/**
1024 * doc_block_isbad - Checks whether a block is good or not
1025 * @mtd: the device
1026 * @from: the offset to find the correct block
1027 *
1028 * Returns 1 if block is bad, 0 if block is good
1029 */
1030static int doc_block_isbad(struct mtd_info *mtd, loff_t from)
1031{
1032	struct docg3 *docg3 = mtd->priv;
1033	int block0, block1, page, ofs, is_good;
1034
1035	calc_block_sector(from, &block0, &block1, &page, &ofs,
1036		docg3->reliable);
1037	doc_dbg("doc_block_isbad(from=%lld) => block=(%d,%d), page=%d, ofs=%d\n",
1038		from, block0, block1, page, ofs);
1039
1040	if (block0 < DOC_LAYOUT_BLOCK_FIRST_DATA)
1041		return 0;
1042	if (block1 > docg3->max_block)
1043		return -EINVAL;
1044
1045	is_good = docg3->bbt[block0 >> 3] & (1 << (block0 & 0x7));
1046	return !is_good;
1047}
1048
1049#if 0
1050/**
1051 * doc_get_erase_count - Get block erase count
1052 * @docg3: the device
1053 * @from: the offset in which the block is.
1054 *
1055 * Get the number of times a block was erased. The number is the maximum of
1056 * erase times between first and second plane (which should be equal normally).
1057 *
1058 * Returns The number of erases, or -EINVAL or -EIO on error.
1059 */
1060static int doc_get_erase_count(struct docg3 *docg3, loff_t from)
1061{
1062	u8 buf[DOC_LAYOUT_WEAR_SIZE];
1063	int ret, plane1_erase_count, plane2_erase_count;
1064	int block0, block1, page, ofs;
1065
1066	doc_dbg("doc_get_erase_count(from=%lld, buf=%p)\n", from, buf);
1067	if (from % DOC_LAYOUT_PAGE_SIZE)
1068		return -EINVAL;
1069	calc_block_sector(from, &block0, &block1, &page, &ofs, docg3->reliable);
1070	if (block1 > docg3->max_block)
1071		return -EINVAL;
1072
1073	ret = doc_reset_seq(docg3);
1074	if (!ret)
1075		ret = doc_read_page_prepare(docg3, block0, block1, page,
1076					    ofs + DOC_LAYOUT_WEAR_OFFSET, 0);
1077	if (!ret)
1078		ret = doc_read_page_getbytes(docg3, DOC_LAYOUT_WEAR_SIZE,
1079					     buf, 1, 0);
1080	doc_read_page_finish(docg3);
1081
1082	if (ret || (buf[0] != DOC_ERASE_MARK) || (buf[2] != DOC_ERASE_MARK))
1083		return -EIO;
1084	plane1_erase_count = (u8)(~buf[1]) | ((u8)(~buf[4]) << 8)
1085		| ((u8)(~buf[5]) << 16);
1086	plane2_erase_count = (u8)(~buf[3]) | ((u8)(~buf[6]) << 8)
1087		| ((u8)(~buf[7]) << 16);
1088
1089	return max(plane1_erase_count, plane2_erase_count);
1090}
1091#endif
1092
1093/**
1094 * doc_get_op_status - get erase/write operation status
1095 * @docg3: the device
1096 *
1097 * Queries the status from the chip, and returns it
1098 *
1099 * Returns the status (bits DOC_PLANES_STATUS_*)
1100 */
1101static int doc_get_op_status(struct docg3 *docg3)
1102{
1103	u8 status;
1104
1105	doc_flash_sequence(docg3, DOC_SEQ_PLANES_STATUS);
1106	doc_flash_command(docg3, DOC_CMD_PLANES_STATUS);
1107	doc_delay(docg3, 5);
1108
1109	doc_ecc_disable(docg3);
1110	doc_read_data_area(docg3, &status, 1, 1);
1111	return status;
1112}
1113
1114/**
1115 * doc_write_erase_wait_status - wait for write or erase completion
1116 * @docg3: the device
1117 *
1118 * Wait for the chip to be ready again after erase or write operation, and check
1119 * erase/write status.
1120 *
1121 * Returns 0 if erase successful, -EIO if erase/write issue, -ETIMEOUT if
1122 * timeout
1123 */
1124static int doc_write_erase_wait_status(struct docg3 *docg3)
1125{
1126	int i, status, ret = 0;
1127
1128	for (i = 0; !doc_is_ready(docg3) && i < 5; i++)
1129		msleep(20);
1130	if (!doc_is_ready(docg3)) {
1131		doc_dbg("Timeout reached and the chip is still not ready\n");
1132		ret = -EAGAIN;
1133		goto out;
1134	}
1135
1136	status = doc_get_op_status(docg3);
1137	if (status & DOC_PLANES_STATUS_FAIL) {
1138		doc_dbg("Erase/Write failed on (a) plane(s), status = %x\n",
1139			status);
1140		ret = -EIO;
1141	}
1142
1143out:
1144	doc_page_finish(docg3);
1145	return ret;
1146}
1147
1148/**
1149 * doc_erase_block - Erase a couple of blocks
1150 * @docg3: the device
1151 * @block0: the first block to erase (leftmost plane)
1152 * @block1: the second block to erase (rightmost plane)
1153 *
1154 * Erase both blocks, and return operation status
1155 *
1156 * Returns 0 if erase successful, -EIO if erase issue, -ETIMEOUT if chip not
1157 * ready for too long
1158 */
1159static int doc_erase_block(struct docg3 *docg3, int block0, int block1)
1160{
1161	int ret, sector;
1162
1163	doc_dbg("doc_erase_block(blocks=(%d,%d))\n", block0, block1);
1164	ret = doc_reset_seq(docg3);
1165	if (ret)
1166		return -EIO;
1167
1168	doc_set_reliable_mode(docg3);
1169	doc_flash_sequence(docg3, DOC_SEQ_ERASE);
1170
1171	sector = block0 << DOC_ADDR_BLOCK_SHIFT;
1172	doc_flash_command(docg3, DOC_CMD_PROG_BLOCK_ADDR);
1173	doc_setup_addr_sector(docg3, sector);
1174	sector = block1 << DOC_ADDR_BLOCK_SHIFT;
1175	doc_flash_command(docg3, DOC_CMD_PROG_BLOCK_ADDR);
1176	doc_setup_addr_sector(docg3, sector);
1177	doc_delay(docg3, 1);
1178
1179	doc_flash_command(docg3, DOC_CMD_ERASECYCLE2);
1180	doc_delay(docg3, 2);
1181
1182	if (is_prot_seq_error(docg3)) {
1183		doc_err("Erase blocks %d,%d error\n", block0, block1);
1184		return -EIO;
1185	}
1186
1187	return doc_write_erase_wait_status(docg3);
1188}
1189
1190/**
1191 * doc_erase - Erase a portion of the chip
1192 * @mtd: the device
1193 * @info: the erase info
1194 *
1195 * Erase a bunch of contiguous blocks, by pairs, as a "mtd" page of 1024 is
1196 * split into 2 pages of 512 bytes on 2 contiguous blocks.
1197 *
1198 * Returns 0 if erase successful, -EINVAL if addressing error, -EIO if erase
1199 * issue
1200 */
1201static int doc_erase(struct mtd_info *mtd, struct erase_info *info)
1202{
1203	struct docg3 *docg3 = mtd->priv;
1204	uint64_t len;
1205	int block0, block1, page, ret, ofs = 0;
1206
1207	doc_dbg("doc_erase(from=%lld, len=%lld\n", info->addr, info->len);
1208
1209	info->state = MTD_ERASE_PENDING;
1210	calc_block_sector(info->addr + info->len, &block0, &block1, &page,
1211			  &ofs, docg3->reliable);
1212	ret = -EINVAL;
1213	if (info->addr + info->len > mtd->size || page || ofs)
1214		goto reset_err;
1215
1216	ret = 0;
1217	calc_block_sector(info->addr, &block0, &block1, &page, &ofs,
1218			  docg3->reliable);
1219	mutex_lock(&docg3->cascade->lock);
1220	doc_set_device_id(docg3, docg3->device_id);
1221	doc_set_reliable_mode(docg3);
1222	for (len = info->len; !ret && len > 0; len -= mtd->erasesize) {
1223		info->state = MTD_ERASING;
1224		ret = doc_erase_block(docg3, block0, block1);
1225		block0 += 2;
1226		block1 += 2;
1227	}
1228	mutex_unlock(&docg3->cascade->lock);
1229
1230	if (ret)
1231		goto reset_err;
1232
1233	info->state = MTD_ERASE_DONE;
1234	return 0;
1235
1236reset_err:
1237	info->state = MTD_ERASE_FAILED;
1238	return ret;
1239}
1240
1241/**
1242 * doc_write_page - Write a single page to the chip
1243 * @docg3: the device
1244 * @to: the offset from first block and first page, in bytes, aligned on page
1245 *      size
1246 * @buf: buffer to get bytes from
1247 * @oob: buffer to get out of band bytes from (can be NULL if no OOB should be
1248 *       written)
1249 * @autoecc: if 0, all 16 bytes from OOB are taken, regardless of HW Hamming or
1250 *           BCH computations. If 1, only bytes 0-7 and byte 15 are taken,
1251 *           remaining ones are filled with hardware Hamming and BCH
1252 *           computations. Its value is not meaningfull is oob == NULL.
1253 *
1254 * Write one full page (ie. 1 page split on two planes), of 512 bytes, with the
1255 * OOB data. The OOB ECC is automatically computed by the hardware Hamming and
1256 * BCH generator if autoecc is not null.
1257 *
1258 * Returns 0 if write successful, -EIO if write error, -EAGAIN if timeout
1259 */
1260static int doc_write_page(struct docg3 *docg3, loff_t to, const u_char *buf,
1261			  const u_char *oob, int autoecc)
1262{
1263	int block0, block1, page, ret, ofs = 0;
1264	u8 hwecc[DOC_ECC_BCH_SIZE], hamming;
1265
1266	doc_dbg("doc_write_page(to=%lld)\n", to);
1267	calc_block_sector(to, &block0, &block1, &page, &ofs, docg3->reliable);
1268
1269	doc_set_device_id(docg3, docg3->device_id);
1270	ret = doc_reset_seq(docg3);
1271	if (ret)
1272		goto err;
1273
1274	/* Program the flash address block and page */
1275	ret = doc_write_seek(docg3, block0, block1, page, ofs);
1276	if (ret)
1277		goto err;
1278
1279	doc_write_page_ecc_init(docg3, DOC_ECC_BCH_TOTAL_BYTES);
1280	doc_delay(docg3, 2);
1281	doc_write_page_putbytes(docg3, DOC_LAYOUT_PAGE_SIZE, buf);
1282
1283	if (oob && autoecc) {
1284		doc_write_page_putbytes(docg3, DOC_LAYOUT_OOB_PAGEINFO_SZ, oob);
1285		doc_delay(docg3, 2);
1286		oob += DOC_LAYOUT_OOB_UNUSED_OFS;
1287
1288		hamming = doc_register_readb(docg3, DOC_HAMMINGPARITY);
1289		doc_delay(docg3, 2);
1290		doc_write_page_putbytes(docg3, DOC_LAYOUT_OOB_HAMMING_SZ,
1291					&hamming);
1292		doc_delay(docg3, 2);
1293
1294		doc_get_bch_hw_ecc(docg3, hwecc);
1295		doc_write_page_putbytes(docg3, DOC_LAYOUT_OOB_BCH_SZ, hwecc);
1296		doc_delay(docg3, 2);
1297
1298		doc_write_page_putbytes(docg3, DOC_LAYOUT_OOB_UNUSED_SZ, oob);
1299	}
1300	if (oob && !autoecc)
1301		doc_write_page_putbytes(docg3, DOC_LAYOUT_OOB_SIZE, oob);
1302
1303	doc_delay(docg3, 2);
1304	doc_page_finish(docg3);
1305	doc_delay(docg3, 2);
1306	doc_flash_command(docg3, DOC_CMD_PROG_CYCLE2);
1307	doc_delay(docg3, 2);
1308
1309	/*
1310	 * The wait status will perform another doc_page_finish() call, but that
1311	 * seems to please the docg3, so leave it.
1312	 */
1313	ret = doc_write_erase_wait_status(docg3);
1314	return ret;
1315err:
1316	doc_read_page_finish(docg3);
1317	return ret;
1318}
1319
1320/**
1321 * doc_guess_autoecc - Guess autoecc mode from mbd_oob_ops
1322 * @ops: the oob operations
1323 *
1324 * Returns 0 or 1 if success, -EINVAL if invalid oob mode
1325 */
1326static int doc_guess_autoecc(struct mtd_oob_ops *ops)
1327{
1328	int autoecc;
1329
1330	switch (ops->mode) {
1331	case MTD_OPS_PLACE_OOB:
1332	case MTD_OPS_AUTO_OOB:
1333		autoecc = 1;
1334		break;
1335	case MTD_OPS_RAW:
1336		autoecc = 0;
1337		break;
1338	default:
1339		autoecc = -EINVAL;
1340	}
1341	return autoecc;
1342}
1343
1344/**
1345 * doc_fill_autooob - Fill a 16 bytes OOB from 8 non-ECC bytes
1346 * @dst: the target 16 bytes OOB buffer
1347 * @oobsrc: the source 8 bytes non-ECC OOB buffer
1348 *
1349 */
1350static void doc_fill_autooob(u8 *dst, u8 *oobsrc)
1351{
1352	memcpy(dst, oobsrc, DOC_LAYOUT_OOB_PAGEINFO_SZ);
1353	dst[DOC_LAYOUT_OOB_UNUSED_OFS] = oobsrc[DOC_LAYOUT_OOB_PAGEINFO_SZ];
1354}
1355
1356/**
1357 * doc_backup_oob - Backup OOB into docg3 structure
1358 * @docg3: the device
1359 * @to: the page offset in the chip
1360 * @ops: the OOB size and buffer
1361 *
1362 * As the docg3 should write a page with its OOB in one pass, and some userland
1363 * applications do write_oob() to setup the OOB and then write(), store the OOB
1364 * into a temporary storage. This is very dangerous, as 2 concurrent
1365 * applications could store an OOB, and then write their pages (which will
1366 * result into one having its OOB corrupted).
1367 *
1368 * The only reliable way would be for userland to call doc_write_oob() with both
1369 * the page data _and_ the OOB area.
1370 *
1371 * Returns 0 if success, -EINVAL if ops content invalid
1372 */
1373static int doc_backup_oob(struct docg3 *docg3, loff_t to,
1374			  struct mtd_oob_ops *ops)
1375{
1376	int ooblen = ops->ooblen, autoecc;
1377
1378	if (ooblen != DOC_LAYOUT_OOB_SIZE)
1379		return -EINVAL;
1380	autoecc = doc_guess_autoecc(ops);
1381	if (autoecc < 0)
1382		return autoecc;
1383
1384	docg3->oob_write_ofs = to;
1385	docg3->oob_autoecc = autoecc;
1386	if (ops->mode == MTD_OPS_AUTO_OOB) {
1387		doc_fill_autooob(docg3->oob_write_buf, ops->oobbuf);
1388		ops->oobretlen = 8;
1389	} else {
1390		memcpy(docg3->oob_write_buf, ops->oobbuf, DOC_LAYOUT_OOB_SIZE);
1391		ops->oobretlen = DOC_LAYOUT_OOB_SIZE;
1392	}
1393	return 0;
1394}
1395
1396/**
1397 * doc_write_oob - Write out of band bytes to flash
1398 * @mtd: the device
1399 * @ofs: the offset from first block and first page, in bytes, aligned on page
1400 *       size
1401 * @ops: the mtd oob structure
1402 *
1403 * Either write OOB data into a temporary buffer, for the subsequent write
1404 * page. The provided OOB should be 16 bytes long. If a data buffer is provided
1405 * as well, issue the page write.
1406 * Or provide data without OOB, and then a all zeroed OOB will be used (ECC will
1407 * still be filled in if asked for).
1408 *
1409 * Returns 0 is successful, EINVAL if length is not 14 bytes
1410 */
1411static int doc_write_oob(struct mtd_info *mtd, loff_t ofs,
1412			 struct mtd_oob_ops *ops)
1413{
1414	struct docg3 *docg3 = mtd->priv;
1415	int ret, autoecc, oobdelta;
1416	u8 *oobbuf = ops->oobbuf;
1417	u8 *buf = ops->datbuf;
1418	size_t len, ooblen;
1419	u8 oob[DOC_LAYOUT_OOB_SIZE];
1420
1421	if (buf)
1422		len = ops->len;
1423	else
1424		len = 0;
1425	if (oobbuf)
1426		ooblen = ops->ooblen;
1427	else
1428		ooblen = 0;
1429
1430	if (oobbuf && ops->mode == MTD_OPS_PLACE_OOB)
1431		oobbuf += ops->ooboffs;
1432
1433	doc_dbg("doc_write_oob(from=%lld, mode=%d, data=(%p:%zu), oob=(%p:%zu))\n",
1434		ofs, ops->mode, buf, len, oobbuf, ooblen);
1435	switch (ops->mode) {
1436	case MTD_OPS_PLACE_OOB:
1437	case MTD_OPS_RAW:
1438		oobdelta = mtd->oobsize;
1439		break;
1440	case MTD_OPS_AUTO_OOB:
1441		oobdelta = mtd->ecclayout->oobavail;
1442		break;
1443	default:
1444		return -EINVAL;
1445	}
1446	if ((len % DOC_LAYOUT_PAGE_SIZE) || (ooblen % oobdelta) ||
1447	    (ofs % DOC_LAYOUT_PAGE_SIZE))
1448		return -EINVAL;
1449	if (len && ooblen &&
1450	    (len / DOC_LAYOUT_PAGE_SIZE) != (ooblen / oobdelta))
1451		return -EINVAL;
1452	if (ofs + len > mtd->size)
1453		return -EINVAL;
1454
1455	ops->oobretlen = 0;
1456	ops->retlen = 0;
1457	ret = 0;
1458	if (len == 0 && ooblen == 0)
1459		return -EINVAL;
1460	if (len == 0 && ooblen > 0)
1461		return doc_backup_oob(docg3, ofs, ops);
1462
1463	autoecc = doc_guess_autoecc(ops);
1464	if (autoecc < 0)
1465		return autoecc;
1466
1467	mutex_lock(&docg3->cascade->lock);
1468	while (!ret && len > 0) {
1469		memset(oob, 0, sizeof(oob));
1470		if (ofs == docg3->oob_write_ofs)
1471			memcpy(oob, docg3->oob_write_buf, DOC_LAYOUT_OOB_SIZE);
1472		else if (ooblen > 0 && ops->mode == MTD_OPS_AUTO_OOB)
1473			doc_fill_autooob(oob, oobbuf);
1474		else if (ooblen > 0)
1475			memcpy(oob, oobbuf, DOC_LAYOUT_OOB_SIZE);
1476		ret = doc_write_page(docg3, ofs, buf, oob, autoecc);
1477
1478		ofs += DOC_LAYOUT_PAGE_SIZE;
1479		len -= DOC_LAYOUT_PAGE_SIZE;
1480		buf += DOC_LAYOUT_PAGE_SIZE;
1481		if (ooblen) {
1482			oobbuf += oobdelta;
1483			ooblen -= oobdelta;
1484			ops->oobretlen += oobdelta;
1485		}
1486		ops->retlen += DOC_LAYOUT_PAGE_SIZE;
1487	}
1488
1489	doc_set_device_id(docg3, 0);
1490	mutex_unlock(&docg3->cascade->lock);
1491	return ret;
1492}
1493
1494/**
1495 * doc_write - Write a buffer to the chip
1496 * @mtd: the device
1497 * @to: the offset from first block and first page, in bytes, aligned on page
1498 *      size
1499 * @len: the number of bytes to write (must be a full page size, ie. 512)
1500 * @retlen: the number of bytes actually written (0 or 512)
1501 * @buf: the buffer to get bytes from
1502 *
1503 * Writes data to the chip.
1504 *
1505 * Returns 0 if write successful, -EIO if write error
1506 */
1507static int doc_write(struct mtd_info *mtd, loff_t to, size_t len,
1508		     size_t *retlen, const u_char *buf)
1509{
1510	struct docg3 *docg3 = mtd->priv;
1511	int ret;
1512	struct mtd_oob_ops ops;
1513
1514	doc_dbg("doc_write(to=%lld, len=%zu)\n", to, len);
1515	ops.datbuf = (char *)buf;
1516	ops.len = len;
1517	ops.mode = MTD_OPS_PLACE_OOB;
1518	ops.oobbuf = NULL;
1519	ops.ooblen = 0;
1520	ops.ooboffs = 0;
1521
1522	ret = doc_write_oob(mtd, to, &ops);
1523	*retlen = ops.retlen;
1524	return ret;
1525}
1526
1527static struct docg3 *sysfs_dev2docg3(struct device *dev,
1528				     struct device_attribute *attr)
1529{
1530	int floor;
1531	struct platform_device *pdev = to_platform_device(dev);
1532	struct mtd_info **docg3_floors = platform_get_drvdata(pdev);
1533
1534	floor = attr->attr.name[1] - '0';
1535	if (floor < 0 || floor >= DOC_MAX_NBFLOORS)
1536		return NULL;
1537	else
1538		return docg3_floors[floor]->priv;
1539}
1540
1541static ssize_t dps0_is_key_locked(struct device *dev,
1542				  struct device_attribute *attr, char *buf)
1543{
1544	struct docg3 *docg3 = sysfs_dev2docg3(dev, attr);
1545	int dps0;
1546
1547	mutex_lock(&docg3->cascade->lock);
1548	doc_set_device_id(docg3, docg3->device_id);
1549	dps0 = doc_register_readb(docg3, DOC_DPS0_STATUS);
1550	doc_set_device_id(docg3, 0);
1551	mutex_unlock(&docg3->cascade->lock);
1552
1553	return sprintf(buf, "%d\n", !(dps0 & DOC_DPS_KEY_OK));
1554}
1555
1556static ssize_t dps1_is_key_locked(struct device *dev,
1557				  struct device_attribute *attr, char *buf)
1558{
1559	struct docg3 *docg3 = sysfs_dev2docg3(dev, attr);
1560	int dps1;
1561
1562	mutex_lock(&docg3->cascade->lock);
1563	doc_set_device_id(docg3, docg3->device_id);
1564	dps1 = doc_register_readb(docg3, DOC_DPS1_STATUS);
1565	doc_set_device_id(docg3, 0);
1566	mutex_unlock(&docg3->cascade->lock);
1567
1568	return sprintf(buf, "%d\n", !(dps1 & DOC_DPS_KEY_OK));
1569}
1570
1571static ssize_t dps0_insert_key(struct device *dev,
1572			       struct device_attribute *attr,
1573			       const char *buf, size_t count)
1574{
1575	struct docg3 *docg3 = sysfs_dev2docg3(dev, attr);
1576	int i;
1577
1578	if (count != DOC_LAYOUT_DPS_KEY_LENGTH)
1579		return -EINVAL;
1580
1581	mutex_lock(&docg3->cascade->lock);
1582	doc_set_device_id(docg3, docg3->device_id);
1583	for (i = 0; i < DOC_LAYOUT_DPS_KEY_LENGTH; i++)
1584		doc_writeb(docg3, buf[i], DOC_DPS0_KEY);
1585	doc_set_device_id(docg3, 0);
1586	mutex_unlock(&docg3->cascade->lock);
1587	return count;
1588}
1589
1590static ssize_t dps1_insert_key(struct device *dev,
1591			       struct device_attribute *attr,
1592			       const char *buf, size_t count)
1593{
1594	struct docg3 *docg3 = sysfs_dev2docg3(dev, attr);
1595	int i;
1596
1597	if (count != DOC_LAYOUT_DPS_KEY_LENGTH)
1598		return -EINVAL;
1599
1600	mutex_lock(&docg3->cascade->lock);
1601	doc_set_device_id(docg3, docg3->device_id);
1602	for (i = 0; i < DOC_LAYOUT_DPS_KEY_LENGTH; i++)
1603		doc_writeb(docg3, buf[i], DOC_DPS1_KEY);
1604	doc_set_device_id(docg3, 0);
1605	mutex_unlock(&docg3->cascade->lock);
1606	return count;
1607}
1608
1609#define FLOOR_SYSFS(id) { \
1610	__ATTR(f##id##_dps0_is_keylocked, S_IRUGO, dps0_is_key_locked, NULL), \
1611	__ATTR(f##id##_dps1_is_keylocked, S_IRUGO, dps1_is_key_locked, NULL), \
1612	__ATTR(f##id##_dps0_protection_key, S_IWUSR|S_IWGRP, NULL, dps0_insert_key), \
1613	__ATTR(f##id##_dps1_protection_key, S_IWUSR|S_IWGRP, NULL, dps1_insert_key), \
1614}
1615
1616static struct device_attribute doc_sys_attrs[DOC_MAX_NBFLOORS][4] = {
1617	FLOOR_SYSFS(0), FLOOR_SYSFS(1), FLOOR_SYSFS(2), FLOOR_SYSFS(3)
1618};
1619
1620static int doc_register_sysfs(struct platform_device *pdev,
1621			      struct docg3_cascade *cascade)
1622{
1623	int ret = 0, floor, i = 0;
1624	struct device *dev = &pdev->dev;
1625
1626	for (floor = 0; !ret && floor < DOC_MAX_NBFLOORS &&
1627		     cascade->floors[floor]; floor++)
1628		for (i = 0; !ret && i < 4; i++)
1629			ret = device_create_file(dev, &doc_sys_attrs[floor][i]);
1630	if (!ret)
1631		return 0;
1632	do {
1633		while (--i >= 0)
1634			device_remove_file(dev, &doc_sys_attrs[floor][i]);
1635		i = 4;
1636	} while (--floor >= 0);
1637	return ret;
1638}
1639
1640static void doc_unregister_sysfs(struct platform_device *pdev,
1641				 struct docg3_cascade *cascade)
1642{
1643	struct device *dev = &pdev->dev;
1644	int floor, i;
1645
1646	for (floor = 0; floor < DOC_MAX_NBFLOORS && cascade->floors[floor];
1647	     floor++)
1648		for (i = 0; i < 4; i++)
1649			device_remove_file(dev, &doc_sys_attrs[floor][i]);
1650}
1651
1652/*
1653 * Debug sysfs entries
1654 */
1655static int dbg_flashctrl_show(struct seq_file *s, void *p)
1656{
1657	struct docg3 *docg3 = (struct docg3 *)s->private;
1658
1659	u8 fctrl;
1660
1661	mutex_lock(&docg3->cascade->lock);
1662	fctrl = doc_register_readb(docg3, DOC_FLASHCONTROL);
1663	mutex_unlock(&docg3->cascade->lock);
1664
1665	seq_printf(s, "FlashControl : 0x%02x (%s,CE# %s,%s,%s,flash %s)\n",
1666		   fctrl,
1667		   fctrl & DOC_CTRL_VIOLATION ? "protocol violation" : "-",
1668		   fctrl & DOC_CTRL_CE ? "active" : "inactive",
1669		   fctrl & DOC_CTRL_PROTECTION_ERROR ? "protection error" : "-",
1670		   fctrl & DOC_CTRL_SEQUENCE_ERROR ? "sequence error" : "-",
1671		   fctrl & DOC_CTRL_FLASHREADY ? "ready" : "not ready");
1672
1673	return 0;
1674}
1675DEBUGFS_RO_ATTR(flashcontrol, dbg_flashctrl_show);
1676
1677static int dbg_asicmode_show(struct seq_file *s, void *p)
1678{
1679	struct docg3 *docg3 = (struct docg3 *)s->private;
1680
1681	int pctrl, mode;
1682
1683	mutex_lock(&docg3->cascade->lock);
1684	pctrl = doc_register_readb(docg3, DOC_ASICMODE);
1685	mode = pctrl & 0x03;
1686	mutex_unlock(&docg3->cascade->lock);
1687
1688	seq_printf(s,
1689		   "%04x : RAM_WE=%d,RSTIN_RESET=%d,BDETCT_RESET=%d,WRITE_ENABLE=%d,POWERDOWN=%d,MODE=%d%d (",
1690		   pctrl,
1691		   pctrl & DOC_ASICMODE_RAM_WE ? 1 : 0,
1692		   pctrl & DOC_ASICMODE_RSTIN_RESET ? 1 : 0,
1693		   pctrl & DOC_ASICMODE_BDETCT_RESET ? 1 : 0,
1694		   pctrl & DOC_ASICMODE_MDWREN ? 1 : 0,
1695		   pctrl & DOC_ASICMODE_POWERDOWN ? 1 : 0,
1696		   mode >> 1, mode & 0x1);
1697
1698	switch (mode) {
1699	case DOC_ASICMODE_RESET:
1700		seq_puts(s, "reset");
1701		break;
1702	case DOC_ASICMODE_NORMAL:
1703		seq_puts(s, "normal");
1704		break;
1705	case DOC_ASICMODE_POWERDOWN:
1706		seq_puts(s, "powerdown");
1707		break;
1708	}
1709	seq_puts(s, ")\n");
1710	return 0;
1711}
1712DEBUGFS_RO_ATTR(asic_mode, dbg_asicmode_show);
1713
1714static int dbg_device_id_show(struct seq_file *s, void *p)
1715{
1716	struct docg3 *docg3 = (struct docg3 *)s->private;
1717	int id;
1718
1719	mutex_lock(&docg3->cascade->lock);
1720	id = doc_register_readb(docg3, DOC_DEVICESELECT);
1721	mutex_unlock(&docg3->cascade->lock);
1722
1723	seq_printf(s, "DeviceId = %d\n", id);
1724	return 0;
1725}
1726DEBUGFS_RO_ATTR(device_id, dbg_device_id_show);
1727
1728static int dbg_protection_show(struct seq_file *s, void *p)
1729{
1730	struct docg3 *docg3 = (struct docg3 *)s->private;
1731	int protect, dps0, dps0_low, dps0_high, dps1, dps1_low, dps1_high;
1732
1733	mutex_lock(&docg3->cascade->lock);
1734	protect = doc_register_readb(docg3, DOC_PROTECTION);
1735	dps0 = doc_register_readb(docg3, DOC_DPS0_STATUS);
1736	dps0_low = doc_register_readw(docg3, DOC_DPS0_ADDRLOW);
1737	dps0_high = doc_register_readw(docg3, DOC_DPS0_ADDRHIGH);
1738	dps1 = doc_register_readb(docg3, DOC_DPS1_STATUS);
1739	dps1_low = doc_register_readw(docg3, DOC_DPS1_ADDRLOW);
1740	dps1_high = doc_register_readw(docg3, DOC_DPS1_ADDRHIGH);
1741	mutex_unlock(&docg3->cascade->lock);
1742
1743	seq_printf(s, "Protection = 0x%02x (", protect);
1744	if (protect & DOC_PROTECT_FOUNDRY_OTP_LOCK)
1745		seq_puts(s, "FOUNDRY_OTP_LOCK,");
1746	if (protect & DOC_PROTECT_CUSTOMER_OTP_LOCK)
1747		seq_puts(s, "CUSTOMER_OTP_LOCK,");
1748	if (protect & DOC_PROTECT_LOCK_INPUT)
1749		seq_puts(s, "LOCK_INPUT,");
1750	if (protect & DOC_PROTECT_STICKY_LOCK)
1751		seq_puts(s, "STICKY_LOCK,");
1752	if (protect & DOC_PROTECT_PROTECTION_ENABLED)
1753		seq_puts(s, "PROTECTION ON,");
1754	if (protect & DOC_PROTECT_IPL_DOWNLOAD_LOCK)
1755		seq_puts(s, "IPL_DOWNLOAD_LOCK,");
1756	if (protect & DOC_PROTECT_PROTECTION_ERROR)
1757		seq_puts(s, "PROTECT_ERR,");
1758	else
1759		seq_puts(s, "NO_PROTECT_ERR");
1760	seq_puts(s, ")\n");
1761
1762	seq_printf(s, "DPS0 = 0x%02x : Protected area [0x%x - 0x%x] : OTP=%d, READ=%d, WRITE=%d, HW_LOCK=%d, KEY_OK=%d\n",
1763		   dps0, dps0_low, dps0_high,
1764		   !!(dps0 & DOC_DPS_OTP_PROTECTED),
1765		   !!(dps0 & DOC_DPS_READ_PROTECTED),
1766		   !!(dps0 & DOC_DPS_WRITE_PROTECTED),
1767		   !!(dps0 & DOC_DPS_HW_LOCK_ENABLED),
1768		   !!(dps0 & DOC_DPS_KEY_OK));
1769	seq_printf(s, "DPS1 = 0x%02x : Protected area [0x%x - 0x%x] : OTP=%d, READ=%d, WRITE=%d, HW_LOCK=%d, KEY_OK=%d\n",
1770		   dps1, dps1_low, dps1_high,
1771		   !!(dps1 & DOC_DPS_OTP_PROTECTED),
1772		   !!(dps1 & DOC_DPS_READ_PROTECTED),
1773		   !!(dps1 & DOC_DPS_WRITE_PROTECTED),
1774		   !!(dps1 & DOC_DPS_HW_LOCK_ENABLED),
1775		   !!(dps1 & DOC_DPS_KEY_OK));
1776	return 0;
1777}
1778DEBUGFS_RO_ATTR(protection, dbg_protection_show);
1779
1780static int __init doc_dbg_register(struct docg3 *docg3)
1781{
1782	struct dentry *root, *entry;
1783
1784	root = debugfs_create_dir("docg3", NULL);
1785	if (!root)
1786		return -ENOMEM;
1787
1788	entry = debugfs_create_file("flashcontrol", S_IRUSR, root, docg3,
1789				  &flashcontrol_fops);
1790	if (entry)
1791		entry = debugfs_create_file("asic_mode", S_IRUSR, root,
1792					    docg3, &asic_mode_fops);
1793	if (entry)
1794		entry = debugfs_create_file("device_id", S_IRUSR, root,
1795					    docg3, &device_id_fops);
1796	if (entry)
1797		entry = debugfs_create_file("protection", S_IRUSR, root,
1798					    docg3, &protection_fops);
1799	if (entry) {
1800		docg3->debugfs_root = root;
1801		return 0;
1802	} else {
1803		debugfs_remove_recursive(root);
1804		return -ENOMEM;
1805	}
1806}
1807
1808static void doc_dbg_unregister(struct docg3 *docg3)
1809{
1810	debugfs_remove_recursive(docg3->debugfs_root);
1811}
1812
1813/**
1814 * doc_set_driver_info - Fill the mtd_info structure and docg3 structure
1815 * @chip_id: The chip ID of the supported chip
1816 * @mtd: The structure to fill
1817 */
1818static void __init doc_set_driver_info(int chip_id, struct mtd_info *mtd)
1819{
1820	struct docg3 *docg3 = mtd->priv;
1821	int cfg;
1822
1823	cfg = doc_register_readb(docg3, DOC_CONFIGURATION);
1824	docg3->if_cfg = (cfg & DOC_CONF_IF_CFG ? 1 : 0);
1825	docg3->reliable = reliable_mode;
1826
1827	switch (chip_id) {
1828	case DOC_CHIPID_G3:
1829		mtd->name = kasprintf(GFP_KERNEL, "docg3.%d",
1830				      docg3->device_id);
1831		docg3->max_block = 2047;
1832		break;
1833	}
1834	mtd->type = MTD_NANDFLASH;
1835	mtd->flags = MTD_CAP_NANDFLASH;
1836	mtd->size = (docg3->max_block + 1) * DOC_LAYOUT_BLOCK_SIZE;
1837	if (docg3->reliable == 2)
1838		mtd->size /= 2;
1839	mtd->erasesize = DOC_LAYOUT_BLOCK_SIZE * DOC_LAYOUT_NBPLANES;
1840	if (docg3->reliable == 2)
1841		mtd->erasesize /= 2;
1842	mtd->writebufsize = mtd->writesize = DOC_LAYOUT_PAGE_SIZE;
1843	mtd->oobsize = DOC_LAYOUT_OOB_SIZE;
1844	mtd->owner = THIS_MODULE;
1845	mtd->_erase = doc_erase;
1846	mtd->_read = doc_read;
1847	mtd->_write = doc_write;
1848	mtd->_read_oob = doc_read_oob;
1849	mtd->_write_oob = doc_write_oob;
1850	mtd->_block_isbad = doc_block_isbad;
1851	mtd->ecclayout = &docg3_oobinfo;
1852	mtd->ecc_strength = DOC_ECC_BCH_T;
1853}
1854
1855/**
1856 * doc_probe_device - Check if a device is available
1857 * @base: the io space where the device is probed
1858 * @floor: the floor of the probed device
1859 * @dev: the device
1860 * @cascade: the cascade of chips this devices will belong to
1861 *
1862 * Checks whether a device at the specified IO range, and floor is available.
1863 *
1864 * Returns a mtd_info struct if there is a device, ENODEV if none found, ENOMEM
1865 * if a memory allocation failed. If floor 0 is checked, a reset of the ASIC is
1866 * launched.
1867 */
1868static struct mtd_info * __init
1869doc_probe_device(struct docg3_cascade *cascade, int floor, struct device *dev)
1870{
1871	int ret, bbt_nbpages;
1872	u16 chip_id, chip_id_inv;
1873	struct docg3 *docg3;
1874	struct mtd_info *mtd;
1875
1876	ret = -ENOMEM;
1877	docg3 = kzalloc(sizeof(struct docg3), GFP_KERNEL);
1878	if (!docg3)
1879		goto nomem1;
1880	mtd = kzalloc(sizeof(struct mtd_info), GFP_KERNEL);
1881	if (!mtd)
1882		goto nomem2;
1883	mtd->priv = docg3;
1884	bbt_nbpages = DIV_ROUND_UP(docg3->max_block + 1,
1885				   8 * DOC_LAYOUT_PAGE_SIZE);
1886	docg3->bbt = kzalloc(bbt_nbpages * DOC_LAYOUT_PAGE_SIZE, GFP_KERNEL);
1887	if (!docg3->bbt)
1888		goto nomem3;
1889
1890	docg3->dev = dev;
1891	docg3->device_id = floor;
1892	docg3->cascade = cascade;
1893	doc_set_device_id(docg3, docg3->device_id);
1894	if (!floor)
1895		doc_set_asic_mode(docg3, DOC_ASICMODE_RESET);
1896	doc_set_asic_mode(docg3, DOC_ASICMODE_NORMAL);
1897
1898	chip_id = doc_register_readw(docg3, DOC_CHIPID);
1899	chip_id_inv = doc_register_readw(docg3, DOC_CHIPID_INV);
1900
1901	ret = 0;
1902	if (chip_id != (u16)(~chip_id_inv)) {
1903		goto nomem3;
1904	}
1905
1906	switch (chip_id) {
1907	case DOC_CHIPID_G3:
1908		doc_info("Found a G3 DiskOnChip at addr %p, floor %d\n",
1909			 docg3->cascade->base, floor);
1910		break;
1911	default:
1912		doc_err("Chip id %04x is not a DiskOnChip G3 chip\n", chip_id);
1913		goto nomem3;
1914	}
1915
1916	doc_set_driver_info(chip_id, mtd);
1917
1918	doc_hamming_ecc_init(docg3, DOC_LAYOUT_OOB_PAGEINFO_SZ);
1919	doc_reload_bbt(docg3);
1920	return mtd;
1921
1922nomem3:
1923	kfree(mtd);
1924nomem2:
1925	kfree(docg3);
1926nomem1:
1927	return ERR_PTR(ret);
1928}
1929
1930/**
1931 * doc_release_device - Release a docg3 floor
1932 * @mtd: the device
1933 */
1934static void doc_release_device(struct mtd_info *mtd)
1935{
1936	struct docg3 *docg3 = mtd->priv;
1937
1938	mtd_device_unregister(mtd);
1939	kfree(docg3->bbt);
1940	kfree(docg3);
1941	kfree(mtd->name);
1942	kfree(mtd);
1943}
1944
1945/**
1946 * docg3_resume - Awakens docg3 floor
1947 * @pdev: platfrom device
1948 *
1949 * Returns 0 (always successful)
1950 */
1951static int docg3_resume(struct platform_device *pdev)
1952{
1953	int i;
1954	struct docg3_cascade *cascade;
1955	struct mtd_info **docg3_floors, *mtd;
1956	struct docg3 *docg3;
1957
1958	cascade = platform_get_drvdata(pdev);
1959	docg3_floors = cascade->floors;
1960	mtd = docg3_floors[0];
1961	docg3 = mtd->priv;
1962
1963	doc_dbg("docg3_resume()\n");
1964	for (i = 0; i < 12; i++)
1965		doc_readb(docg3, DOC_IOSPACE_IPL);
1966	return 0;
1967}
1968
1969/**
1970 * docg3_suspend - Put in low power mode the docg3 floor
1971 * @pdev: platform device
1972 * @state: power state
1973 *
1974 * Shuts off most of docg3 circuitery to lower power consumption.
1975 *
1976 * Returns 0 if suspend succeeded, -EIO if chip refused suspend
1977 */
1978static int docg3_suspend(struct platform_device *pdev, pm_message_t state)
1979{
1980	int floor, i;
1981	struct docg3_cascade *cascade;
1982	struct mtd_info **docg3_floors, *mtd;
1983	struct docg3 *docg3;
1984	u8 ctrl, pwr_down;
1985
1986	cascade = platform_get_drvdata(pdev);
1987	docg3_floors = cascade->floors;
1988	for (floor = 0; floor < DOC_MAX_NBFLOORS; floor++) {
1989		mtd = docg3_floors[floor];
1990		if (!mtd)
1991			continue;
1992		docg3 = mtd->priv;
1993
1994		doc_writeb(docg3, floor, DOC_DEVICESELECT);
1995		ctrl = doc_register_readb(docg3, DOC_FLASHCONTROL);
1996		ctrl &= ~DOC_CTRL_VIOLATION & ~DOC_CTRL_CE;
1997		doc_writeb(docg3, ctrl, DOC_FLASHCONTROL);
1998
1999		for (i = 0; i < 10; i++) {
2000			usleep_range(3000, 4000);
2001			pwr_down = doc_register_readb(docg3, DOC_POWERMODE);
2002			if (pwr_down & DOC_POWERDOWN_READY)
2003				break;
2004		}
2005		if (pwr_down & DOC_POWERDOWN_READY) {
2006			doc_dbg("docg3_suspend(): floor %d powerdown ok\n",
2007				floor);
2008		} else {
2009			doc_err("docg3_suspend(): floor %d powerdown failed\n",
2010				floor);
2011			return -EIO;
2012		}
2013	}
2014
2015	mtd = docg3_floors[0];
2016	docg3 = mtd->priv;
2017	doc_set_asic_mode(docg3, DOC_ASICMODE_POWERDOWN);
2018	return 0;
2019}
2020
2021/**
2022 * doc_probe - Probe the IO space for a DiskOnChip G3 chip
2023 * @pdev: platform device
2024 *
2025 * Probes for a G3 chip at the specified IO space in the platform data
2026 * ressources. The floor 0 must be available.
2027 *
2028 * Returns 0 on success, -ENOMEM, -ENXIO on error
2029 */
2030static int __init docg3_probe(struct platform_device *pdev)
2031{
2032	struct device *dev = &pdev->dev;
2033	struct mtd_info *mtd;
2034	struct resource *ress;
2035	void __iomem *base;
2036	int ret, floor;
2037	struct docg3_cascade *cascade;
2038
2039	ret = -ENXIO;
2040	ress = platform_get_resource(pdev, IORESOURCE_MEM, 0);
2041	if (!ress) {
2042		dev_err(dev, "No I/O memory resource defined\n");
2043		return ret;
2044	}
2045	base = devm_ioremap(dev, ress->start, DOC_IOSPACE_SIZE);
2046
2047	ret = -ENOMEM;
2048	cascade = devm_kzalloc(dev, sizeof(*cascade) * DOC_MAX_NBFLOORS,
2049			       GFP_KERNEL);
2050	if (!cascade)
2051		return ret;
2052	cascade->base = base;
2053	mutex_init(&cascade->lock);
2054	cascade->bch = init_bch(DOC_ECC_BCH_M, DOC_ECC_BCH_T,
2055			     DOC_ECC_BCH_PRIMPOLY);
2056	if (!cascade->bch)
2057		return ret;
2058
2059	for (floor = 0; floor < DOC_MAX_NBFLOORS; floor++) {
2060		mtd = doc_probe_device(cascade, floor, dev);
2061		if (IS_ERR(mtd)) {
2062			ret = PTR_ERR(mtd);
2063			goto err_probe;
2064		}
2065		if (!mtd) {
2066			if (floor == 0)
2067				goto notfound;
2068			else
2069				continue;
2070		}
2071		cascade->floors[floor] = mtd;
2072		ret = mtd_device_parse_register(mtd, part_probes, NULL, NULL,
2073						0);
2074		if (ret)
2075			goto err_probe;
2076	}
2077
2078	ret = doc_register_sysfs(pdev, cascade);
2079	if (ret)
2080		goto err_probe;
2081
2082	platform_set_drvdata(pdev, cascade);
2083	doc_dbg_register(cascade->floors[0]->priv);
2084	return 0;
2085
2086notfound:
2087	ret = -ENODEV;
2088	dev_info(dev, "No supported DiskOnChip found\n");
2089err_probe:
2090	free_bch(cascade->bch);
2091	for (floor = 0; floor < DOC_MAX_NBFLOORS; floor++)
2092		if (cascade->floors[floor])
2093			doc_release_device(cascade->floors[floor]);
2094	return ret;
2095}
2096
2097/**
2098 * docg3_release - Release the driver
2099 * @pdev: the platform device
2100 *
2101 * Returns 0
2102 */
2103static int docg3_release(struct platform_device *pdev)
2104{
2105	struct docg3_cascade *cascade = platform_get_drvdata(pdev);
2106	struct docg3 *docg3 = cascade->floors[0]->priv;
2107	int floor;
2108
2109	doc_unregister_sysfs(pdev, cascade);
2110	doc_dbg_unregister(docg3);
2111	for (floor = 0; floor < DOC_MAX_NBFLOORS; floor++)
2112		if (cascade->floors[floor])
2113			doc_release_device(cascade->floors[floor]);
2114
2115	free_bch(docg3->cascade->bch);
2116	return 0;
2117}
2118
2119#ifdef CONFIG_OF
2120static struct of_device_id docg3_dt_ids[] = {
2121	{ .compatible = "m-systems,diskonchip-g3" },
2122	{}
2123};
2124MODULE_DEVICE_TABLE(of, docg3_dt_ids);
2125#endif
2126
2127static struct platform_driver g3_driver = {
2128	.driver		= {
2129		.name	= "docg3",
2130		.of_match_table = of_match_ptr(docg3_dt_ids),
2131	},
2132	.suspend	= docg3_suspend,
2133	.resume		= docg3_resume,
2134	.remove		= docg3_release,
2135};
2136
2137module_platform_driver_probe(g3_driver, docg3_probe);
2138
2139MODULE_LICENSE("GPL");
2140MODULE_AUTHOR("Robert Jarzmik <robert.jarzmik@free.fr>");
2141MODULE_DESCRIPTION("MTD driver for DiskOnChip G3");
2142