1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Handles the M-Systems DiskOnChip G3 chip
4 *
5 * Copyright (C) 2011 Robert Jarzmik
6 */
7
8#include <linux/kernel.h>
9#include <linux/module.h>
10#include <linux/errno.h>
11#include <linux/of.h>
12#include <linux/platform_device.h>
13#include <linux/string.h>
14#include <linux/slab.h>
15#include <linux/io.h>
16#include <linux/delay.h>
17#include <linux/mtd/mtd.h>
18#include <linux/mtd/partitions.h>
19#include <linux/bitmap.h>
20#include <linux/bitrev.h>
21#include <linux/bch.h>
22
23#include <linux/debugfs.h>
24#include <linux/seq_file.h>
25
26#define CREATE_TRACE_POINTS
27#include "docg3.h"
28
29/*
30 * This driver handles the DiskOnChip G3 flash memory.
31 *
32 * As no specification is available from M-Systems/Sandisk, this drivers lacks
33 * several functions available on the chip, as :
34 *  - IPL write
35 *
36 * The bus data width (8bits versus 16bits) is not handled (if_cfg flag), and
37 * the driver assumes a 16bits data bus.
38 *
39 * DocG3 relies on 2 ECC algorithms, which are handled in hardware :
40 *  - a 1 byte Hamming code stored in the OOB for each page
41 *  - a 7 bytes BCH code stored in the OOB for each page
42 * The BCH ECC is :
43 *  - BCH is in GF(2^14)
44 *  - BCH is over data of 520 bytes (512 page + 7 page_info bytes
45 *                                   + 1 hamming byte)
46 *  - BCH can correct up to 4 bits (t = 4)
47 *  - BCH syndroms are calculated in hardware, and checked in hardware as well
48 *
49 */
50
51static unsigned int reliable_mode;
52module_param(reliable_mode, uint, 0);
53MODULE_PARM_DESC(reliable_mode, "Set the docg3 mode (0=normal MLC, 1=fast, "
54		 "2=reliable) : MLC normal operations are in normal mode");
55
56static int docg3_ooblayout_ecc(struct mtd_info *mtd, int section,
57			       struct mtd_oob_region *oobregion)
58{
59	if (section)
60		return -ERANGE;
61
62	/* byte 7 is Hamming ECC, byte 8-14 are BCH ECC */
63	oobregion->offset = 7;
64	oobregion->length = 8;
65
66	return 0;
67}
68
69static int docg3_ooblayout_free(struct mtd_info *mtd, int section,
70				struct mtd_oob_region *oobregion)
71{
72	if (section > 1)
73		return -ERANGE;
74
75	/* free bytes: byte 0 until byte 6, byte 15 */
76	if (!section) {
77		oobregion->offset = 0;
78		oobregion->length = 7;
79	} else {
80		oobregion->offset = 15;
81		oobregion->length = 1;
82	}
83
84	return 0;
85}
86
87static const struct mtd_ooblayout_ops nand_ooblayout_docg3_ops = {
88	.ecc = docg3_ooblayout_ecc,
89	.free = docg3_ooblayout_free,
90};
91
92static inline u8 doc_readb(struct docg3 *docg3, u16 reg)
93{
94	u8 val = readb(docg3->cascade->base + reg);
95
96	trace_docg3_io(0, 8, reg, (int)val);
97	return val;
98}
99
100static inline u16 doc_readw(struct docg3 *docg3, u16 reg)
101{
102	u16 val = readw(docg3->cascade->base + reg);
103
104	trace_docg3_io(0, 16, reg, (int)val);
105	return val;
106}
107
108static inline void doc_writeb(struct docg3 *docg3, u8 val, u16 reg)
109{
110	writeb(val, docg3->cascade->base + reg);
111	trace_docg3_io(1, 8, reg, val);
112}
113
114static inline void doc_writew(struct docg3 *docg3, u16 val, u16 reg)
115{
116	writew(val, docg3->cascade->base + reg);
117	trace_docg3_io(1, 16, reg, val);
118}
119
120static inline void doc_flash_command(struct docg3 *docg3, u8 cmd)
121{
122	doc_writeb(docg3, cmd, DOC_FLASHCOMMAND);
123}
124
125static inline void doc_flash_sequence(struct docg3 *docg3, u8 seq)
126{
127	doc_writeb(docg3, seq, DOC_FLASHSEQUENCE);
128}
129
130static inline void doc_flash_address(struct docg3 *docg3, u8 addr)
131{
132	doc_writeb(docg3, addr, DOC_FLASHADDRESS);
133}
134
135static char const * const part_probes[] = { "cmdlinepart", "saftlpart", NULL };
136
137static int doc_register_readb(struct docg3 *docg3, int reg)
138{
139	u8 val;
140
141	doc_writew(docg3, reg, DOC_READADDRESS);
142	val = doc_readb(docg3, reg);
143	doc_vdbg("Read register %04x : %02x\n", reg, val);
144	return val;
145}
146
147static int doc_register_readw(struct docg3 *docg3, int reg)
148{
149	u16 val;
150
151	doc_writew(docg3, reg, DOC_READADDRESS);
152	val = doc_readw(docg3, reg);
153	doc_vdbg("Read register %04x : %04x\n", reg, val);
154	return val;
155}
156
157/**
158 * doc_delay - delay docg3 operations
159 * @docg3: the device
160 * @nbNOPs: the number of NOPs to issue
161 *
162 * As no specification is available, the right timings between chip commands are
163 * unknown. The only available piece of information are the observed nops on a
164 * working docg3 chip.
165 * Therefore, doc_delay relies on a busy loop of NOPs, instead of scheduler
166 * friendlier msleep() functions or blocking mdelay().
167 */
168static void doc_delay(struct docg3 *docg3, int nbNOPs)
169{
170	int i;
171
172	doc_vdbg("NOP x %d\n", nbNOPs);
173	for (i = 0; i < nbNOPs; i++)
174		doc_writeb(docg3, 0, DOC_NOP);
175}
176
177static int is_prot_seq_error(struct docg3 *docg3)
178{
179	int ctrl;
180
181	ctrl = doc_register_readb(docg3, DOC_FLASHCONTROL);
182	return ctrl & (DOC_CTRL_PROTECTION_ERROR | DOC_CTRL_SEQUENCE_ERROR);
183}
184
185static int doc_is_ready(struct docg3 *docg3)
186{
187	int ctrl;
188
189	ctrl = doc_register_readb(docg3, DOC_FLASHCONTROL);
190	return ctrl & DOC_CTRL_FLASHREADY;
191}
192
193static int doc_wait_ready(struct docg3 *docg3)
194{
195	int maxWaitCycles = 100;
196
197	do {
198		doc_delay(docg3, 4);
199		cpu_relax();
200	} while (!doc_is_ready(docg3) && maxWaitCycles--);
201	doc_delay(docg3, 2);
202	if (maxWaitCycles > 0)
203		return 0;
204	else
205		return -EIO;
206}
207
208static int doc_reset_seq(struct docg3 *docg3)
209{
210	int ret;
211
212	doc_writeb(docg3, 0x10, DOC_FLASHCONTROL);
213	doc_flash_sequence(docg3, DOC_SEQ_RESET);
214	doc_flash_command(docg3, DOC_CMD_RESET);
215	doc_delay(docg3, 2);
216	ret = doc_wait_ready(docg3);
217
218	doc_dbg("doc_reset_seq() -> isReady=%s\n", ret ? "false" : "true");
219	return ret;
220}
221
222/**
223 * doc_read_data_area - Read data from data area
224 * @docg3: the device
225 * @buf: the buffer to fill in (might be NULL is dummy reads)
226 * @len: the length to read
227 * @first: first time read, DOC_READADDRESS should be set
228 *
229 * Reads bytes from flash data. Handles the single byte / even bytes reads.
230 */
231static void doc_read_data_area(struct docg3 *docg3, void *buf, int len,
232			       int first)
233{
234	int i, cdr, len4;
235	u16 data16, *dst16;
236	u8 data8, *dst8;
237
238	doc_dbg("doc_read_data_area(buf=%p, len=%d)\n", buf, len);
239	cdr = len & 0x1;
240	len4 = len - cdr;
241
242	if (first)
243		doc_writew(docg3, DOC_IOSPACE_DATA, DOC_READADDRESS);
244	dst16 = buf;
245	for (i = 0; i < len4; i += 2) {
246		data16 = doc_readw(docg3, DOC_IOSPACE_DATA);
247		if (dst16) {
248			*dst16 = data16;
249			dst16++;
250		}
251	}
252
253	if (cdr) {
254		doc_writew(docg3, DOC_IOSPACE_DATA | DOC_READADDR_ONE_BYTE,
255			   DOC_READADDRESS);
256		doc_delay(docg3, 1);
257		dst8 = (u8 *)dst16;
258		for (i = 0; i < cdr; i++) {
259			data8 = doc_readb(docg3, DOC_IOSPACE_DATA);
260			if (dst8) {
261				*dst8 = data8;
262				dst8++;
263			}
264		}
265	}
266}
267
268/**
269 * doc_write_data_area - Write data into data area
270 * @docg3: the device
271 * @buf: the buffer to get input bytes from
272 * @len: the length to write
273 *
274 * Writes bytes into flash data. Handles the single byte / even bytes writes.
275 */
276static void doc_write_data_area(struct docg3 *docg3, const void *buf, int len)
277{
278	int i, cdr, len4;
279	u16 *src16;
280	u8 *src8;
281
282	doc_dbg("doc_write_data_area(buf=%p, len=%d)\n", buf, len);
283	cdr = len & 0x3;
284	len4 = len - cdr;
285
286	doc_writew(docg3, DOC_IOSPACE_DATA, DOC_READADDRESS);
287	src16 = (u16 *)buf;
288	for (i = 0; i < len4; i += 2) {
289		doc_writew(docg3, *src16, DOC_IOSPACE_DATA);
290		src16++;
291	}
292
293	src8 = (u8 *)src16;
294	for (i = 0; i < cdr; i++) {
295		doc_writew(docg3, DOC_IOSPACE_DATA | DOC_READADDR_ONE_BYTE,
296			   DOC_READADDRESS);
297		doc_writeb(docg3, *src8, DOC_IOSPACE_DATA);
298		src8++;
299	}
300}
301
302/**
303 * doc_set_data_mode - Sets the flash to normal or reliable data mode
304 * @docg3: the device
305 *
306 * The reliable data mode is a bit slower than the fast mode, but less errors
307 * occur.  Entering the reliable mode cannot be done without entering the fast
308 * mode first.
309 *
310 * In reliable mode, pages 2*n and 2*n+1 are clones. Writing to page 0 of blocks
311 * (4,5) make the hardware write also to page 1 of blocks blocks(4,5). Reading
312 * from page 0 of blocks (4,5) or from page 1 of blocks (4,5) gives the same
313 * result, which is a logical and between bytes from page 0 and page 1 (which is
314 * consistent with the fact that writing to a page is _clearing_ bits of that
315 * page).
316 */
317static void doc_set_reliable_mode(struct docg3 *docg3)
318{
319	static char *strmode[] = { "normal", "fast", "reliable", "invalid" };
320
321	doc_dbg("doc_set_reliable_mode(%s)\n", strmode[docg3->reliable]);
322	switch (docg3->reliable) {
323	case 0:
324		break;
325	case 1:
326		doc_flash_sequence(docg3, DOC_SEQ_SET_FASTMODE);
327		doc_flash_command(docg3, DOC_CMD_FAST_MODE);
328		break;
329	case 2:
330		doc_flash_sequence(docg3, DOC_SEQ_SET_RELIABLEMODE);
331		doc_flash_command(docg3, DOC_CMD_FAST_MODE);
332		doc_flash_command(docg3, DOC_CMD_RELIABLE_MODE);
333		break;
334	default:
335		doc_err("doc_set_reliable_mode(): invalid mode\n");
336		break;
337	}
338	doc_delay(docg3, 2);
339}
340
341/**
342 * doc_set_asic_mode - Set the ASIC mode
343 * @docg3: the device
344 * @mode: the mode
345 *
346 * The ASIC can work in 3 modes :
347 *  - RESET: all registers are zeroed
348 *  - NORMAL: receives and handles commands
349 *  - POWERDOWN: minimal poweruse, flash parts shut off
350 */
351static void doc_set_asic_mode(struct docg3 *docg3, u8 mode)
352{
353	int i;
354
355	for (i = 0; i < 12; i++)
356		doc_readb(docg3, DOC_IOSPACE_IPL);
357
358	mode |= DOC_ASICMODE_MDWREN;
359	doc_dbg("doc_set_asic_mode(%02x)\n", mode);
360	doc_writeb(docg3, mode, DOC_ASICMODE);
361	doc_writeb(docg3, ~mode, DOC_ASICMODECONFIRM);
362	doc_delay(docg3, 1);
363}
364
365/**
366 * doc_set_device_id - Sets the devices id for cascaded G3 chips
367 * @docg3: the device
368 * @id: the chip to select (amongst 0, 1, 2, 3)
369 *
370 * There can be 4 cascaded G3 chips. This function selects the one which will
371 * should be the active one.
372 */
373static void doc_set_device_id(struct docg3 *docg3, int id)
374{
375	u8 ctrl;
376
377	doc_dbg("doc_set_device_id(%d)\n", id);
378	doc_writeb(docg3, id, DOC_DEVICESELECT);
379	ctrl = doc_register_readb(docg3, DOC_FLASHCONTROL);
380
381	ctrl &= ~DOC_CTRL_VIOLATION;
382	ctrl |= DOC_CTRL_CE;
383	doc_writeb(docg3, ctrl, DOC_FLASHCONTROL);
384}
385
386/**
387 * doc_set_extra_page_mode - Change flash page layout
388 * @docg3: the device
389 *
390 * Normally, the flash page is split into the data (512 bytes) and the out of
391 * band data (16 bytes). For each, 4 more bytes can be accessed, where the wear
392 * leveling counters are stored.  To access this last area of 4 bytes, a special
393 * mode must be input to the flash ASIC.
394 *
395 * Returns 0 if no error occurred, -EIO else.
396 */
397static int doc_set_extra_page_mode(struct docg3 *docg3)
398{
399	int fctrl;
400
401	doc_dbg("doc_set_extra_page_mode()\n");
402	doc_flash_sequence(docg3, DOC_SEQ_PAGE_SIZE_532);
403	doc_flash_command(docg3, DOC_CMD_PAGE_SIZE_532);
404	doc_delay(docg3, 2);
405
406	fctrl = doc_register_readb(docg3, DOC_FLASHCONTROL);
407	if (fctrl & (DOC_CTRL_PROTECTION_ERROR | DOC_CTRL_SEQUENCE_ERROR))
408		return -EIO;
409	else
410		return 0;
411}
412
413/**
414 * doc_setup_addr_sector - Setup blocks/page/ofs address for one plane
415 * @docg3: the device
416 * @sector: the sector
417 */
418static void doc_setup_addr_sector(struct docg3 *docg3, int sector)
419{
420	doc_delay(docg3, 1);
421	doc_flash_address(docg3, sector & 0xff);
422	doc_flash_address(docg3, (sector >> 8) & 0xff);
423	doc_flash_address(docg3, (sector >> 16) & 0xff);
424	doc_delay(docg3, 1);
425}
426
427/**
428 * doc_setup_writeaddr_sector - Setup blocks/page/ofs address for one plane
429 * @docg3: the device
430 * @sector: the sector
431 * @ofs: the offset in the page, between 0 and (512 + 16 + 512)
432 */
433static void doc_setup_writeaddr_sector(struct docg3 *docg3, int sector, int ofs)
434{
435	ofs = ofs >> 2;
436	doc_delay(docg3, 1);
437	doc_flash_address(docg3, ofs & 0xff);
438	doc_flash_address(docg3, sector & 0xff);
439	doc_flash_address(docg3, (sector >> 8) & 0xff);
440	doc_flash_address(docg3, (sector >> 16) & 0xff);
441	doc_delay(docg3, 1);
442}
443
444/**
445 * doc_seek - Set both flash planes to the specified block, page for reading
446 * @docg3: the device
447 * @block0: the first plane block index
448 * @block1: the second plane block index
449 * @page: the page index within the block
450 * @wear: if true, read will occur on the 4 extra bytes of the wear area
451 * @ofs: offset in page to read
452 *
453 * Programs the flash even and odd planes to the specific block and page.
454 * Alternatively, programs the flash to the wear area of the specified page.
455 */
456static int doc_read_seek(struct docg3 *docg3, int block0, int block1, int page,
457			 int wear, int ofs)
458{
459	int sector, ret = 0;
460
461	doc_dbg("doc_seek(blocks=(%d,%d), page=%d, ofs=%d, wear=%d)\n",
462		block0, block1, page, ofs, wear);
463
464	if (!wear && (ofs < 2 * DOC_LAYOUT_PAGE_SIZE)) {
465		doc_flash_sequence(docg3, DOC_SEQ_SET_PLANE1);
466		doc_flash_command(docg3, DOC_CMD_READ_PLANE1);
467		doc_delay(docg3, 2);
468	} else {
469		doc_flash_sequence(docg3, DOC_SEQ_SET_PLANE2);
470		doc_flash_command(docg3, DOC_CMD_READ_PLANE2);
471		doc_delay(docg3, 2);
472	}
473
474	doc_set_reliable_mode(docg3);
475	if (wear)
476		ret = doc_set_extra_page_mode(docg3);
477	if (ret)
478		goto out;
479
480	doc_flash_sequence(docg3, DOC_SEQ_READ);
481	sector = (block0 << DOC_ADDR_BLOCK_SHIFT) + (page & DOC_ADDR_PAGE_MASK);
482	doc_flash_command(docg3, DOC_CMD_PROG_BLOCK_ADDR);
483	doc_setup_addr_sector(docg3, sector);
484
485	sector = (block1 << DOC_ADDR_BLOCK_SHIFT) + (page & DOC_ADDR_PAGE_MASK);
486	doc_flash_command(docg3, DOC_CMD_PROG_BLOCK_ADDR);
487	doc_setup_addr_sector(docg3, sector);
488	doc_delay(docg3, 1);
489
490out:
491	return ret;
492}
493
494/**
495 * doc_write_seek - Set both flash planes to the specified block, page for writing
496 * @docg3: the device
497 * @block0: the first plane block index
498 * @block1: the second plane block index
499 * @page: the page index within the block
500 * @ofs: offset in page to write
501 *
502 * Programs the flash even and odd planes to the specific block and page.
503 * Alternatively, programs the flash to the wear area of the specified page.
504 */
505static int doc_write_seek(struct docg3 *docg3, int block0, int block1, int page,
506			 int ofs)
507{
508	int ret = 0, sector;
509
510	doc_dbg("doc_write_seek(blocks=(%d,%d), page=%d, ofs=%d)\n",
511		block0, block1, page, ofs);
512
513	doc_set_reliable_mode(docg3);
514
515	if (ofs < 2 * DOC_LAYOUT_PAGE_SIZE) {
516		doc_flash_sequence(docg3, DOC_SEQ_SET_PLANE1);
517		doc_flash_command(docg3, DOC_CMD_READ_PLANE1);
518		doc_delay(docg3, 2);
519	} else {
520		doc_flash_sequence(docg3, DOC_SEQ_SET_PLANE2);
521		doc_flash_command(docg3, DOC_CMD_READ_PLANE2);
522		doc_delay(docg3, 2);
523	}
524
525	doc_flash_sequence(docg3, DOC_SEQ_PAGE_SETUP);
526	doc_flash_command(docg3, DOC_CMD_PROG_CYCLE1);
527
528	sector = (block0 << DOC_ADDR_BLOCK_SHIFT) + (page & DOC_ADDR_PAGE_MASK);
529	doc_setup_writeaddr_sector(docg3, sector, ofs);
530
531	doc_flash_command(docg3, DOC_CMD_PROG_CYCLE3);
532	doc_delay(docg3, 2);
533	ret = doc_wait_ready(docg3);
534	if (ret)
535		goto out;
536
537	doc_flash_command(docg3, DOC_CMD_PROG_CYCLE1);
538	sector = (block1 << DOC_ADDR_BLOCK_SHIFT) + (page & DOC_ADDR_PAGE_MASK);
539	doc_setup_writeaddr_sector(docg3, sector, ofs);
540	doc_delay(docg3, 1);
541
542out:
543	return ret;
544}
545
546
547/**
548 * doc_read_page_ecc_init - Initialize hardware ECC engine
549 * @docg3: the device
550 * @len: the number of bytes covered by the ECC (BCH covered)
551 *
552 * The function does initialize the hardware ECC engine to compute the Hamming
553 * ECC (on 1 byte) and the BCH hardware ECC (on 7 bytes).
554 *
555 * Return 0 if succeeded, -EIO on error
556 */
557static int doc_read_page_ecc_init(struct docg3 *docg3, int len)
558{
559	doc_writew(docg3, DOC_ECCCONF0_READ_MODE
560		   | DOC_ECCCONF0_BCH_ENABLE | DOC_ECCCONF0_HAMMING_ENABLE
561		   | (len & DOC_ECCCONF0_DATA_BYTES_MASK),
562		   DOC_ECCCONF0);
563	doc_delay(docg3, 4);
564	doc_register_readb(docg3, DOC_FLASHCONTROL);
565	return doc_wait_ready(docg3);
566}
567
568/**
569 * doc_write_page_ecc_init - Initialize hardware BCH ECC engine
570 * @docg3: the device
571 * @len: the number of bytes covered by the ECC (BCH covered)
572 *
573 * The function does initialize the hardware ECC engine to compute the Hamming
574 * ECC (on 1 byte) and the BCH hardware ECC (on 7 bytes).
575 *
576 * Return 0 if succeeded, -EIO on error
577 */
578static int doc_write_page_ecc_init(struct docg3 *docg3, int len)
579{
580	doc_writew(docg3, DOC_ECCCONF0_WRITE_MODE
581		   | DOC_ECCCONF0_BCH_ENABLE | DOC_ECCCONF0_HAMMING_ENABLE
582		   | (len & DOC_ECCCONF0_DATA_BYTES_MASK),
583		   DOC_ECCCONF0);
584	doc_delay(docg3, 4);
585	doc_register_readb(docg3, DOC_FLASHCONTROL);
586	return doc_wait_ready(docg3);
587}
588
589/**
590 * doc_ecc_disable - Disable Hamming and BCH ECC hardware calculator
591 * @docg3: the device
592 *
593 * Disables the hardware ECC generator and checker, for unchecked reads (as when
594 * reading OOB only or write status byte).
595 */
596static void doc_ecc_disable(struct docg3 *docg3)
597{
598	doc_writew(docg3, DOC_ECCCONF0_READ_MODE, DOC_ECCCONF0);
599	doc_delay(docg3, 4);
600}
601
602/**
603 * doc_hamming_ecc_init - Initialize hardware Hamming ECC engine
604 * @docg3: the device
605 * @nb_bytes: the number of bytes covered by the ECC (Hamming covered)
606 *
607 * This function programs the ECC hardware to compute the hamming code on the
608 * last provided N bytes to the hardware generator.
609 */
610static void doc_hamming_ecc_init(struct docg3 *docg3, int nb_bytes)
611{
612	u8 ecc_conf1;
613
614	ecc_conf1 = doc_register_readb(docg3, DOC_ECCCONF1);
615	ecc_conf1 &= ~DOC_ECCCONF1_HAMMING_BITS_MASK;
616	ecc_conf1 |= (nb_bytes & DOC_ECCCONF1_HAMMING_BITS_MASK);
617	doc_writeb(docg3, ecc_conf1, DOC_ECCCONF1);
618}
619
620/**
621 * doc_ecc_bch_fix_data - Fix if need be read data from flash
622 * @docg3: the device
623 * @buf: the buffer of read data (512 + 7 + 1 bytes)
624 * @hwecc: the hardware calculated ECC.
625 *         It's in fact recv_ecc ^ calc_ecc, where recv_ecc was read from OOB
626 *         area data, and calc_ecc the ECC calculated by the hardware generator.
627 *
628 * Checks if the received data matches the ECC, and if an error is detected,
629 * tries to fix the bit flips (at most 4) in the buffer buf.  As the docg3
630 * understands the (data, ecc, syndroms) in an inverted order in comparison to
631 * the BCH library, the function reverses the order of bits (ie. bit7 and bit0,
632 * bit6 and bit 1, ...) for all ECC data.
633 *
634 * The hardware ecc unit produces oob_ecc ^ calc_ecc.  The kernel's bch
635 * algorithm is used to decode this.  However the hw operates on page
636 * data in a bit order that is the reverse of that of the bch alg,
637 * requiring that the bits be reversed on the result.  Thanks to Ivan
638 * Djelic for his analysis.
639 *
640 * Returns number of fixed bits (0, 1, 2, 3, 4) or -EBADMSG if too many bit
641 * errors were detected and cannot be fixed.
642 */
643static int doc_ecc_bch_fix_data(struct docg3 *docg3, void *buf, u8 *hwecc)
644{
645	u8 ecc[DOC_ECC_BCH_SIZE];
646	int errorpos[DOC_ECC_BCH_T], i, numerrs;
647
648	for (i = 0; i < DOC_ECC_BCH_SIZE; i++)
649		ecc[i] = bitrev8(hwecc[i]);
650	numerrs = bch_decode(docg3->cascade->bch, NULL,
651			     DOC_ECC_BCH_COVERED_BYTES,
652			     NULL, ecc, NULL, errorpos);
653	BUG_ON(numerrs == -EINVAL);
654	if (numerrs < 0)
655		goto out;
656
657	for (i = 0; i < numerrs; i++)
658		errorpos[i] = (errorpos[i] & ~7) | (7 - (errorpos[i] & 7));
659	for (i = 0; i < numerrs; i++)
660		if (errorpos[i] < DOC_ECC_BCH_COVERED_BYTES*8)
661			/* error is located in data, correct it */
662			change_bit(errorpos[i], buf);
663out:
664	doc_dbg("doc_ecc_bch_fix_data: flipped %d bits\n", numerrs);
665	return numerrs;
666}
667
668
669/**
670 * doc_read_page_prepare - Prepares reading data from a flash page
671 * @docg3: the device
672 * @block0: the first plane block index on flash memory
673 * @block1: the second plane block index on flash memory
674 * @page: the page index in the block
675 * @offset: the offset in the page (must be a multiple of 4)
676 *
677 * Prepares the page to be read in the flash memory :
678 *   - tell ASIC to map the flash pages
679 *   - tell ASIC to be in read mode
680 *
681 * After a call to this method, a call to doc_read_page_finish is mandatory,
682 * to end the read cycle of the flash.
683 *
684 * Read data from a flash page. The length to be read must be between 0 and
685 * (page_size + oob_size + wear_size), ie. 532, and a multiple of 4 (because
686 * the extra bytes reading is not implemented).
687 *
688 * As pages are grouped by 2 (in 2 planes), reading from a page must be done
689 * in two steps:
690 *  - one read of 512 bytes at offset 0
691 *  - one read of 512 bytes at offset 512 + 16
692 *
693 * Returns 0 if successful, -EIO if a read error occurred.
694 */
695static int doc_read_page_prepare(struct docg3 *docg3, int block0, int block1,
696				 int page, int offset)
697{
698	int wear_area = 0, ret = 0;
699
700	doc_dbg("doc_read_page_prepare(blocks=(%d,%d), page=%d, ofsInPage=%d)\n",
701		block0, block1, page, offset);
702	if (offset >= DOC_LAYOUT_WEAR_OFFSET)
703		wear_area = 1;
704	if (!wear_area && offset > (DOC_LAYOUT_PAGE_OOB_SIZE * 2))
705		return -EINVAL;
706
707	doc_set_device_id(docg3, docg3->device_id);
708	ret = doc_reset_seq(docg3);
709	if (ret)
710		goto err;
711
712	/* Program the flash address block and page */
713	ret = doc_read_seek(docg3, block0, block1, page, wear_area, offset);
714	if (ret)
715		goto err;
716
717	doc_flash_command(docg3, DOC_CMD_READ_ALL_PLANES);
718	doc_delay(docg3, 2);
719	doc_wait_ready(docg3);
720
721	doc_flash_command(docg3, DOC_CMD_SET_ADDR_READ);
722	doc_delay(docg3, 1);
723	if (offset >= DOC_LAYOUT_PAGE_SIZE * 2)
724		offset -= 2 * DOC_LAYOUT_PAGE_SIZE;
725	doc_flash_address(docg3, offset >> 2);
726	doc_delay(docg3, 1);
727	doc_wait_ready(docg3);
728
729	doc_flash_command(docg3, DOC_CMD_READ_FLASH);
730
731	return 0;
732err:
733	doc_writeb(docg3, 0, DOC_DATAEND);
734	doc_delay(docg3, 2);
735	return -EIO;
736}
737
738/**
739 * doc_read_page_getbytes - Reads bytes from a prepared page
740 * @docg3: the device
741 * @len: the number of bytes to be read (must be a multiple of 4)
742 * @buf: the buffer to be filled in (or NULL is forget bytes)
743 * @first: 1 if first time read, DOC_READADDRESS should be set
744 * @last_odd: 1 if last read ended up on an odd byte
745 *
746 * Reads bytes from a prepared page. There is a trickery here : if the last read
747 * ended up on an odd offset in the 1024 bytes double page, ie. between the 2
748 * planes, the first byte must be read apart. If a word (16bit) read was used,
749 * the read would return the byte of plane 2 as low *and* high endian, which
750 * will mess the read.
751 *
752 */
753static int doc_read_page_getbytes(struct docg3 *docg3, int len, u_char *buf,
754				  int first, int last_odd)
755{
756	if (last_odd && len > 0) {
757		doc_read_data_area(docg3, buf, 1, first);
758		doc_read_data_area(docg3, buf ? buf + 1 : buf, len - 1, 0);
759	} else {
760		doc_read_data_area(docg3, buf, len, first);
761	}
762	doc_delay(docg3, 2);
763	return len;
764}
765
766/**
767 * doc_write_page_putbytes - Writes bytes into a prepared page
768 * @docg3: the device
769 * @len: the number of bytes to be written
770 * @buf: the buffer of input bytes
771 *
772 */
773static void doc_write_page_putbytes(struct docg3 *docg3, int len,
774				    const u_char *buf)
775{
776	doc_write_data_area(docg3, buf, len);
777	doc_delay(docg3, 2);
778}
779
780/**
781 * doc_get_bch_hw_ecc - Get hardware calculated BCH ECC
782 * @docg3: the device
783 * @hwecc:  the array of 7 integers where the hardware ecc will be stored
784 */
785static void doc_get_bch_hw_ecc(struct docg3 *docg3, u8 *hwecc)
786{
787	int i;
788
789	for (i = 0; i < DOC_ECC_BCH_SIZE; i++)
790		hwecc[i] = doc_register_readb(docg3, DOC_BCH_HW_ECC(i));
791}
792
793/**
794 * doc_page_finish - Ends reading/writing of a flash page
795 * @docg3: the device
796 */
797static void doc_page_finish(struct docg3 *docg3)
798{
799	doc_writeb(docg3, 0, DOC_DATAEND);
800	doc_delay(docg3, 2);
801}
802
803/**
804 * doc_read_page_finish - Ends reading of a flash page
805 * @docg3: the device
806 *
807 * As a side effect, resets the chip selector to 0. This ensures that after each
808 * read operation, the floor 0 is selected. Therefore, if the systems halts, the
809 * reboot will boot on floor 0, where the IPL is.
810 */
811static void doc_read_page_finish(struct docg3 *docg3)
812{
813	doc_page_finish(docg3);
814	doc_set_device_id(docg3, 0);
815}
816
817/**
818 * calc_block_sector - Calculate blocks, pages and ofs.
819
820 * @from: offset in flash
821 * @block0: first plane block index calculated
822 * @block1: second plane block index calculated
823 * @page: page calculated
824 * @ofs: offset in page
825 * @reliable: 0 if docg3 in normal mode, 1 if docg3 in fast mode, 2 if docg3 in
826 * reliable mode.
827 *
828 * The calculation is based on the reliable/normal mode. In normal mode, the 64
829 * pages of a block are available. In reliable mode, as pages 2*n and 2*n+1 are
830 * clones, only 32 pages per block are available.
831 */
832static void calc_block_sector(loff_t from, int *block0, int *block1, int *page,
833			      int *ofs, int reliable)
834{
835	uint sector, pages_biblock;
836
837	pages_biblock = DOC_LAYOUT_PAGES_PER_BLOCK * DOC_LAYOUT_NBPLANES;
838	if (reliable == 1 || reliable == 2)
839		pages_biblock /= 2;
840
841	sector = from / DOC_LAYOUT_PAGE_SIZE;
842	*block0 = sector / pages_biblock * DOC_LAYOUT_NBPLANES;
843	*block1 = *block0 + 1;
844	*page = sector % pages_biblock;
845	*page /= DOC_LAYOUT_NBPLANES;
846	if (reliable == 1 || reliable == 2)
847		*page *= 2;
848	if (sector % 2)
849		*ofs = DOC_LAYOUT_PAGE_OOB_SIZE;
850	else
851		*ofs = 0;
852}
853
854/**
855 * doc_read_oob - Read out of band bytes from flash
856 * @mtd: the device
857 * @from: the offset from first block and first page, in bytes, aligned on page
858 *        size
859 * @ops: the mtd oob structure
860 *
861 * Reads flash memory OOB area of pages.
862 *
863 * Returns 0 if read successful, of -EIO, -EINVAL if an error occurred
864 */
865static int doc_read_oob(struct mtd_info *mtd, loff_t from,
866			struct mtd_oob_ops *ops)
867{
868	struct docg3 *docg3 = mtd->priv;
869	int block0, block1, page, ret, skip, ofs = 0;
870	u8 *oobbuf = ops->oobbuf;
871	u8 *buf = ops->datbuf;
872	size_t len, ooblen, nbdata, nboob;
873	u8 hwecc[DOC_ECC_BCH_SIZE], eccconf1;
874	int max_bitflips = 0;
875
876	if (buf)
877		len = ops->len;
878	else
879		len = 0;
880	if (oobbuf)
881		ooblen = ops->ooblen;
882	else
883		ooblen = 0;
884
885	if (oobbuf && ops->mode == MTD_OPS_PLACE_OOB)
886		oobbuf += ops->ooboffs;
887
888	doc_dbg("doc_read_oob(from=%lld, mode=%d, data=(%p:%zu), oob=(%p:%zu))\n",
889		from, ops->mode, buf, len, oobbuf, ooblen);
890	if (ooblen % DOC_LAYOUT_OOB_SIZE)
891		return -EINVAL;
892
893	ops->oobretlen = 0;
894	ops->retlen = 0;
895	ret = 0;
896	skip = from % DOC_LAYOUT_PAGE_SIZE;
897	mutex_lock(&docg3->cascade->lock);
898	while (ret >= 0 && (len > 0 || ooblen > 0)) {
899		calc_block_sector(from - skip, &block0, &block1, &page, &ofs,
900			docg3->reliable);
901		nbdata = min_t(size_t, len, DOC_LAYOUT_PAGE_SIZE - skip);
902		nboob = min_t(size_t, ooblen, (size_t)DOC_LAYOUT_OOB_SIZE);
903		ret = doc_read_page_prepare(docg3, block0, block1, page, ofs);
904		if (ret < 0)
905			goto out;
906		ret = doc_read_page_ecc_init(docg3, DOC_ECC_BCH_TOTAL_BYTES);
907		if (ret < 0)
908			goto err_in_read;
909		ret = doc_read_page_getbytes(docg3, skip, NULL, 1, 0);
910		if (ret < skip)
911			goto err_in_read;
912		ret = doc_read_page_getbytes(docg3, nbdata, buf, 0, skip % 2);
913		if (ret < nbdata)
914			goto err_in_read;
915		doc_read_page_getbytes(docg3,
916				       DOC_LAYOUT_PAGE_SIZE - nbdata - skip,
917				       NULL, 0, (skip + nbdata) % 2);
918		ret = doc_read_page_getbytes(docg3, nboob, oobbuf, 0, 0);
919		if (ret < nboob)
920			goto err_in_read;
921		doc_read_page_getbytes(docg3, DOC_LAYOUT_OOB_SIZE - nboob,
922				       NULL, 0, nboob % 2);
923
924		doc_get_bch_hw_ecc(docg3, hwecc);
925		eccconf1 = doc_register_readb(docg3, DOC_ECCCONF1);
926
927		if (nboob >= DOC_LAYOUT_OOB_SIZE) {
928			doc_dbg("OOB - INFO: %*phC\n", 7, oobbuf);
929			doc_dbg("OOB - HAMMING: %02x\n", oobbuf[7]);
930			doc_dbg("OOB - BCH_ECC: %*phC\n", 7, oobbuf + 8);
931			doc_dbg("OOB - UNUSED: %02x\n", oobbuf[15]);
932		}
933		doc_dbg("ECC checks: ECCConf1=%x\n", eccconf1);
934		doc_dbg("ECC HW_ECC: %*phC\n", 7, hwecc);
935
936		ret = -EIO;
937		if (is_prot_seq_error(docg3))
938			goto err_in_read;
939		ret = 0;
940		if ((block0 >= DOC_LAYOUT_BLOCK_FIRST_DATA) &&
941		    (eccconf1 & DOC_ECCCONF1_BCH_SYNDROM_ERR) &&
942		    (eccconf1 & DOC_ECCCONF1_PAGE_IS_WRITTEN) &&
943		    (ops->mode != MTD_OPS_RAW) &&
944		    (nbdata == DOC_LAYOUT_PAGE_SIZE)) {
945			ret = doc_ecc_bch_fix_data(docg3, buf, hwecc);
946			if (ret < 0) {
947				mtd->ecc_stats.failed++;
948				ret = -EBADMSG;
949			}
950			if (ret > 0) {
951				mtd->ecc_stats.corrected += ret;
952				max_bitflips = max(max_bitflips, ret);
953				ret = max_bitflips;
954			}
955		}
956
957		doc_read_page_finish(docg3);
958		ops->retlen += nbdata;
959		ops->oobretlen += nboob;
960		buf += nbdata;
961		oobbuf += nboob;
962		len -= nbdata;
963		ooblen -= nboob;
964		from += DOC_LAYOUT_PAGE_SIZE;
965		skip = 0;
966	}
967
968out:
969	mutex_unlock(&docg3->cascade->lock);
970	return ret;
971err_in_read:
972	doc_read_page_finish(docg3);
973	goto out;
974}
975
976static int doc_reload_bbt(struct docg3 *docg3)
977{
978	int block = DOC_LAYOUT_BLOCK_BBT;
979	int ret = 0, nbpages, page;
980	u_char *buf = docg3->bbt;
981
982	nbpages = DIV_ROUND_UP(docg3->max_block + 1, 8 * DOC_LAYOUT_PAGE_SIZE);
983	for (page = 0; !ret && (page < nbpages); page++) {
984		ret = doc_read_page_prepare(docg3, block, block + 1,
985					    page + DOC_LAYOUT_PAGE_BBT, 0);
986		if (!ret)
987			ret = doc_read_page_ecc_init(docg3,
988						     DOC_LAYOUT_PAGE_SIZE);
989		if (!ret)
990			doc_read_page_getbytes(docg3, DOC_LAYOUT_PAGE_SIZE,
991					       buf, 1, 0);
992		buf += DOC_LAYOUT_PAGE_SIZE;
993	}
994	doc_read_page_finish(docg3);
995	return ret;
996}
997
998/**
999 * doc_block_isbad - Checks whether a block is good or not
1000 * @mtd: the device
1001 * @from: the offset to find the correct block
1002 *
1003 * Returns 1 if block is bad, 0 if block is good
1004 */
1005static int doc_block_isbad(struct mtd_info *mtd, loff_t from)
1006{
1007	struct docg3 *docg3 = mtd->priv;
1008	int block0, block1, page, ofs, is_good;
1009
1010	calc_block_sector(from, &block0, &block1, &page, &ofs,
1011		docg3->reliable);
1012	doc_dbg("doc_block_isbad(from=%lld) => block=(%d,%d), page=%d, ofs=%d\n",
1013		from, block0, block1, page, ofs);
1014
1015	if (block0 < DOC_LAYOUT_BLOCK_FIRST_DATA)
1016		return 0;
1017	if (block1 > docg3->max_block)
1018		return -EINVAL;
1019
1020	is_good = docg3->bbt[block0 >> 3] & (1 << (block0 & 0x7));
1021	return !is_good;
1022}
1023
1024#if 0
1025/**
1026 * doc_get_erase_count - Get block erase count
1027 * @docg3: the device
1028 * @from: the offset in which the block is.
1029 *
1030 * Get the number of times a block was erased. The number is the maximum of
1031 * erase times between first and second plane (which should be equal normally).
1032 *
1033 * Returns The number of erases, or -EINVAL or -EIO on error.
1034 */
1035static int doc_get_erase_count(struct docg3 *docg3, loff_t from)
1036{
1037	u8 buf[DOC_LAYOUT_WEAR_SIZE];
1038	int ret, plane1_erase_count, plane2_erase_count;
1039	int block0, block1, page, ofs;
1040
1041	doc_dbg("doc_get_erase_count(from=%lld, buf=%p)\n", from, buf);
1042	if (from % DOC_LAYOUT_PAGE_SIZE)
1043		return -EINVAL;
1044	calc_block_sector(from, &block0, &block1, &page, &ofs, docg3->reliable);
1045	if (block1 > docg3->max_block)
1046		return -EINVAL;
1047
1048	ret = doc_reset_seq(docg3);
1049	if (!ret)
1050		ret = doc_read_page_prepare(docg3, block0, block1, page,
1051					    ofs + DOC_LAYOUT_WEAR_OFFSET, 0);
1052	if (!ret)
1053		ret = doc_read_page_getbytes(docg3, DOC_LAYOUT_WEAR_SIZE,
1054					     buf, 1, 0);
1055	doc_read_page_finish(docg3);
1056
1057	if (ret || (buf[0] != DOC_ERASE_MARK) || (buf[2] != DOC_ERASE_MARK))
1058		return -EIO;
1059	plane1_erase_count = (u8)(~buf[1]) | ((u8)(~buf[4]) << 8)
1060		| ((u8)(~buf[5]) << 16);
1061	plane2_erase_count = (u8)(~buf[3]) | ((u8)(~buf[6]) << 8)
1062		| ((u8)(~buf[7]) << 16);
1063
1064	return max(plane1_erase_count, plane2_erase_count);
1065}
1066#endif
1067
1068/**
1069 * doc_get_op_status - get erase/write operation status
1070 * @docg3: the device
1071 *
1072 * Queries the status from the chip, and returns it
1073 *
1074 * Returns the status (bits DOC_PLANES_STATUS_*)
1075 */
1076static int doc_get_op_status(struct docg3 *docg3)
1077{
1078	u8 status;
1079
1080	doc_flash_sequence(docg3, DOC_SEQ_PLANES_STATUS);
1081	doc_flash_command(docg3, DOC_CMD_PLANES_STATUS);
1082	doc_delay(docg3, 5);
1083
1084	doc_ecc_disable(docg3);
1085	doc_read_data_area(docg3, &status, 1, 1);
1086	return status;
1087}
1088
1089/**
1090 * doc_write_erase_wait_status - wait for write or erase completion
1091 * @docg3: the device
1092 *
1093 * Wait for the chip to be ready again after erase or write operation, and check
1094 * erase/write status.
1095 *
1096 * Returns 0 if erase successful, -EIO if erase/write issue, -ETIMEOUT if
1097 * timeout
1098 */
1099static int doc_write_erase_wait_status(struct docg3 *docg3)
1100{
1101	int i, status, ret = 0;
1102
1103	for (i = 0; !doc_is_ready(docg3) && i < 5; i++)
1104		msleep(20);
1105	if (!doc_is_ready(docg3)) {
1106		doc_dbg("Timeout reached and the chip is still not ready\n");
1107		ret = -EAGAIN;
1108		goto out;
1109	}
1110
1111	status = doc_get_op_status(docg3);
1112	if (status & DOC_PLANES_STATUS_FAIL) {
1113		doc_dbg("Erase/Write failed on (a) plane(s), status = %x\n",
1114			status);
1115		ret = -EIO;
1116	}
1117
1118out:
1119	doc_page_finish(docg3);
1120	return ret;
1121}
1122
1123/**
1124 * doc_erase_block - Erase a couple of blocks
1125 * @docg3: the device
1126 * @block0: the first block to erase (leftmost plane)
1127 * @block1: the second block to erase (rightmost plane)
1128 *
1129 * Erase both blocks, and return operation status
1130 *
1131 * Returns 0 if erase successful, -EIO if erase issue, -ETIMEOUT if chip not
1132 * ready for too long
1133 */
1134static int doc_erase_block(struct docg3 *docg3, int block0, int block1)
1135{
1136	int ret, sector;
1137
1138	doc_dbg("doc_erase_block(blocks=(%d,%d))\n", block0, block1);
1139	ret = doc_reset_seq(docg3);
1140	if (ret)
1141		return -EIO;
1142
1143	doc_set_reliable_mode(docg3);
1144	doc_flash_sequence(docg3, DOC_SEQ_ERASE);
1145
1146	sector = block0 << DOC_ADDR_BLOCK_SHIFT;
1147	doc_flash_command(docg3, DOC_CMD_PROG_BLOCK_ADDR);
1148	doc_setup_addr_sector(docg3, sector);
1149	sector = block1 << DOC_ADDR_BLOCK_SHIFT;
1150	doc_flash_command(docg3, DOC_CMD_PROG_BLOCK_ADDR);
1151	doc_setup_addr_sector(docg3, sector);
1152	doc_delay(docg3, 1);
1153
1154	doc_flash_command(docg3, DOC_CMD_ERASECYCLE2);
1155	doc_delay(docg3, 2);
1156
1157	if (is_prot_seq_error(docg3)) {
1158		doc_err("Erase blocks %d,%d error\n", block0, block1);
1159		return -EIO;
1160	}
1161
1162	return doc_write_erase_wait_status(docg3);
1163}
1164
1165/**
1166 * doc_erase - Erase a portion of the chip
1167 * @mtd: the device
1168 * @info: the erase info
1169 *
1170 * Erase a bunch of contiguous blocks, by pairs, as a "mtd" page of 1024 is
1171 * split into 2 pages of 512 bytes on 2 contiguous blocks.
1172 *
1173 * Returns 0 if erase successful, -EINVAL if addressing error, -EIO if erase
1174 * issue
1175 */
1176static int doc_erase(struct mtd_info *mtd, struct erase_info *info)
1177{
1178	struct docg3 *docg3 = mtd->priv;
1179	uint64_t len;
1180	int block0, block1, page, ret = 0, ofs = 0;
1181
1182	doc_dbg("doc_erase(from=%lld, len=%lld\n", info->addr, info->len);
1183
1184	calc_block_sector(info->addr + info->len, &block0, &block1, &page,
1185			  &ofs, docg3->reliable);
1186	if (info->addr + info->len > mtd->size || page || ofs)
1187		return -EINVAL;
1188
1189	calc_block_sector(info->addr, &block0, &block1, &page, &ofs,
1190			  docg3->reliable);
1191	mutex_lock(&docg3->cascade->lock);
1192	doc_set_device_id(docg3, docg3->device_id);
1193	doc_set_reliable_mode(docg3);
1194	for (len = info->len; !ret && len > 0; len -= mtd->erasesize) {
1195		ret = doc_erase_block(docg3, block0, block1);
1196		block0 += 2;
1197		block1 += 2;
1198	}
1199	mutex_unlock(&docg3->cascade->lock);
1200
1201	return ret;
1202}
1203
1204/**
1205 * doc_write_page - Write a single page to the chip
1206 * @docg3: the device
1207 * @to: the offset from first block and first page, in bytes, aligned on page
1208 *      size
1209 * @buf: buffer to get bytes from
1210 * @oob: buffer to get out of band bytes from (can be NULL if no OOB should be
1211 *       written)
1212 * @autoecc: if 0, all 16 bytes from OOB are taken, regardless of HW Hamming or
1213 *           BCH computations. If 1, only bytes 0-7 and byte 15 are taken,
1214 *           remaining ones are filled with hardware Hamming and BCH
1215 *           computations. Its value is not meaningfull is oob == NULL.
1216 *
1217 * Write one full page (ie. 1 page split on two planes), of 512 bytes, with the
1218 * OOB data. The OOB ECC is automatically computed by the hardware Hamming and
1219 * BCH generator if autoecc is not null.
1220 *
1221 * Returns 0 if write successful, -EIO if write error, -EAGAIN if timeout
1222 */
1223static int doc_write_page(struct docg3 *docg3, loff_t to, const u_char *buf,
1224			  const u_char *oob, int autoecc)
1225{
1226	int block0, block1, page, ret, ofs = 0;
1227	u8 hwecc[DOC_ECC_BCH_SIZE], hamming;
1228
1229	doc_dbg("doc_write_page(to=%lld)\n", to);
1230	calc_block_sector(to, &block0, &block1, &page, &ofs, docg3->reliable);
1231
1232	doc_set_device_id(docg3, docg3->device_id);
1233	ret = doc_reset_seq(docg3);
1234	if (ret)
1235		goto err;
1236
1237	/* Program the flash address block and page */
1238	ret = doc_write_seek(docg3, block0, block1, page, ofs);
1239	if (ret)
1240		goto err;
1241
1242	doc_write_page_ecc_init(docg3, DOC_ECC_BCH_TOTAL_BYTES);
1243	doc_delay(docg3, 2);
1244	doc_write_page_putbytes(docg3, DOC_LAYOUT_PAGE_SIZE, buf);
1245
1246	if (oob && autoecc) {
1247		doc_write_page_putbytes(docg3, DOC_LAYOUT_OOB_PAGEINFO_SZ, oob);
1248		doc_delay(docg3, 2);
1249		oob += DOC_LAYOUT_OOB_UNUSED_OFS;
1250
1251		hamming = doc_register_readb(docg3, DOC_HAMMINGPARITY);
1252		doc_delay(docg3, 2);
1253		doc_write_page_putbytes(docg3, DOC_LAYOUT_OOB_HAMMING_SZ,
1254					&hamming);
1255		doc_delay(docg3, 2);
1256
1257		doc_get_bch_hw_ecc(docg3, hwecc);
1258		doc_write_page_putbytes(docg3, DOC_LAYOUT_OOB_BCH_SZ, hwecc);
1259		doc_delay(docg3, 2);
1260
1261		doc_write_page_putbytes(docg3, DOC_LAYOUT_OOB_UNUSED_SZ, oob);
1262	}
1263	if (oob && !autoecc)
1264		doc_write_page_putbytes(docg3, DOC_LAYOUT_OOB_SIZE, oob);
1265
1266	doc_delay(docg3, 2);
1267	doc_page_finish(docg3);
1268	doc_delay(docg3, 2);
1269	doc_flash_command(docg3, DOC_CMD_PROG_CYCLE2);
1270	doc_delay(docg3, 2);
1271
1272	/*
1273	 * The wait status will perform another doc_page_finish() call, but that
1274	 * seems to please the docg3, so leave it.
1275	 */
1276	ret = doc_write_erase_wait_status(docg3);
1277	return ret;
1278err:
1279	doc_read_page_finish(docg3);
1280	return ret;
1281}
1282
1283/**
1284 * doc_guess_autoecc - Guess autoecc mode from mbd_oob_ops
1285 * @ops: the oob operations
1286 *
1287 * Returns 0 or 1 if success, -EINVAL if invalid oob mode
1288 */
1289static int doc_guess_autoecc(struct mtd_oob_ops *ops)
1290{
1291	int autoecc;
1292
1293	switch (ops->mode) {
1294	case MTD_OPS_PLACE_OOB:
1295	case MTD_OPS_AUTO_OOB:
1296		autoecc = 1;
1297		break;
1298	case MTD_OPS_RAW:
1299		autoecc = 0;
1300		break;
1301	default:
1302		autoecc = -EINVAL;
1303	}
1304	return autoecc;
1305}
1306
1307/**
1308 * doc_fill_autooob - Fill a 16 bytes OOB from 8 non-ECC bytes
1309 * @dst: the target 16 bytes OOB buffer
1310 * @oobsrc: the source 8 bytes non-ECC OOB buffer
1311 *
1312 */
1313static void doc_fill_autooob(u8 *dst, u8 *oobsrc)
1314{
1315	memcpy(dst, oobsrc, DOC_LAYOUT_OOB_PAGEINFO_SZ);
1316	dst[DOC_LAYOUT_OOB_UNUSED_OFS] = oobsrc[DOC_LAYOUT_OOB_PAGEINFO_SZ];
1317}
1318
1319/**
1320 * doc_backup_oob - Backup OOB into docg3 structure
1321 * @docg3: the device
1322 * @to: the page offset in the chip
1323 * @ops: the OOB size and buffer
1324 *
1325 * As the docg3 should write a page with its OOB in one pass, and some userland
1326 * applications do write_oob() to setup the OOB and then write(), store the OOB
1327 * into a temporary storage. This is very dangerous, as 2 concurrent
1328 * applications could store an OOB, and then write their pages (which will
1329 * result into one having its OOB corrupted).
1330 *
1331 * The only reliable way would be for userland to call doc_write_oob() with both
1332 * the page data _and_ the OOB area.
1333 *
1334 * Returns 0 if success, -EINVAL if ops content invalid
1335 */
1336static int doc_backup_oob(struct docg3 *docg3, loff_t to,
1337			  struct mtd_oob_ops *ops)
1338{
1339	int ooblen = ops->ooblen, autoecc;
1340
1341	if (ooblen != DOC_LAYOUT_OOB_SIZE)
1342		return -EINVAL;
1343	autoecc = doc_guess_autoecc(ops);
1344	if (autoecc < 0)
1345		return autoecc;
1346
1347	docg3->oob_write_ofs = to;
1348	docg3->oob_autoecc = autoecc;
1349	if (ops->mode == MTD_OPS_AUTO_OOB) {
1350		doc_fill_autooob(docg3->oob_write_buf, ops->oobbuf);
1351		ops->oobretlen = 8;
1352	} else {
1353		memcpy(docg3->oob_write_buf, ops->oobbuf, DOC_LAYOUT_OOB_SIZE);
1354		ops->oobretlen = DOC_LAYOUT_OOB_SIZE;
1355	}
1356	return 0;
1357}
1358
1359/**
1360 * doc_write_oob - Write out of band bytes to flash
1361 * @mtd: the device
1362 * @ofs: the offset from first block and first page, in bytes, aligned on page
1363 *       size
1364 * @ops: the mtd oob structure
1365 *
1366 * Either write OOB data into a temporary buffer, for the subsequent write
1367 * page. The provided OOB should be 16 bytes long. If a data buffer is provided
1368 * as well, issue the page write.
1369 * Or provide data without OOB, and then a all zeroed OOB will be used (ECC will
1370 * still be filled in if asked for).
1371 *
1372 * Returns 0 is successful, EINVAL if length is not 14 bytes
1373 */
1374static int doc_write_oob(struct mtd_info *mtd, loff_t ofs,
1375			 struct mtd_oob_ops *ops)
1376{
1377	struct docg3 *docg3 = mtd->priv;
1378	int ret, autoecc, oobdelta;
1379	u8 *oobbuf = ops->oobbuf;
1380	u8 *buf = ops->datbuf;
1381	size_t len, ooblen;
1382	u8 oob[DOC_LAYOUT_OOB_SIZE];
1383
1384	if (buf)
1385		len = ops->len;
1386	else
1387		len = 0;
1388	if (oobbuf)
1389		ooblen = ops->ooblen;
1390	else
1391		ooblen = 0;
1392
1393	if (oobbuf && ops->mode == MTD_OPS_PLACE_OOB)
1394		oobbuf += ops->ooboffs;
1395
1396	doc_dbg("doc_write_oob(from=%lld, mode=%d, data=(%p:%zu), oob=(%p:%zu))\n",
1397		ofs, ops->mode, buf, len, oobbuf, ooblen);
1398	switch (ops->mode) {
1399	case MTD_OPS_PLACE_OOB:
1400	case MTD_OPS_RAW:
1401		oobdelta = mtd->oobsize;
1402		break;
1403	case MTD_OPS_AUTO_OOB:
1404		oobdelta = mtd->oobavail;
1405		break;
1406	default:
1407		return -EINVAL;
1408	}
1409	if ((len % DOC_LAYOUT_PAGE_SIZE) || (ooblen % oobdelta) ||
1410	    (ofs % DOC_LAYOUT_PAGE_SIZE))
1411		return -EINVAL;
1412	if (len && ooblen &&
1413	    (len / DOC_LAYOUT_PAGE_SIZE) != (ooblen / oobdelta))
1414		return -EINVAL;
1415
1416	ops->oobretlen = 0;
1417	ops->retlen = 0;
1418	ret = 0;
1419	if (len == 0 && ooblen == 0)
1420		return -EINVAL;
1421	if (len == 0 && ooblen > 0)
1422		return doc_backup_oob(docg3, ofs, ops);
1423
1424	autoecc = doc_guess_autoecc(ops);
1425	if (autoecc < 0)
1426		return autoecc;
1427
1428	mutex_lock(&docg3->cascade->lock);
1429	while (!ret && len > 0) {
1430		memset(oob, 0, sizeof(oob));
1431		if (ofs == docg3->oob_write_ofs)
1432			memcpy(oob, docg3->oob_write_buf, DOC_LAYOUT_OOB_SIZE);
1433		else if (ooblen > 0 && ops->mode == MTD_OPS_AUTO_OOB)
1434			doc_fill_autooob(oob, oobbuf);
1435		else if (ooblen > 0)
1436			memcpy(oob, oobbuf, DOC_LAYOUT_OOB_SIZE);
1437		ret = doc_write_page(docg3, ofs, buf, oob, autoecc);
1438
1439		ofs += DOC_LAYOUT_PAGE_SIZE;
1440		len -= DOC_LAYOUT_PAGE_SIZE;
1441		buf += DOC_LAYOUT_PAGE_SIZE;
1442		if (ooblen) {
1443			oobbuf += oobdelta;
1444			ooblen -= oobdelta;
1445			ops->oobretlen += oobdelta;
1446		}
1447		ops->retlen += DOC_LAYOUT_PAGE_SIZE;
1448	}
1449
1450	doc_set_device_id(docg3, 0);
1451	mutex_unlock(&docg3->cascade->lock);
1452	return ret;
1453}
1454
1455static struct docg3 *sysfs_dev2docg3(struct device *dev,
1456				     struct device_attribute *attr)
1457{
1458	int floor;
1459	struct mtd_info **docg3_floors = dev_get_drvdata(dev);
1460
1461	floor = attr->attr.name[1] - '0';
1462	if (floor < 0 || floor >= DOC_MAX_NBFLOORS)
1463		return NULL;
1464	else
1465		return docg3_floors[floor]->priv;
1466}
1467
1468static ssize_t dps0_is_key_locked(struct device *dev,
1469				  struct device_attribute *attr, char *buf)
1470{
1471	struct docg3 *docg3 = sysfs_dev2docg3(dev, attr);
1472	int dps0;
1473
1474	mutex_lock(&docg3->cascade->lock);
1475	doc_set_device_id(docg3, docg3->device_id);
1476	dps0 = doc_register_readb(docg3, DOC_DPS0_STATUS);
1477	doc_set_device_id(docg3, 0);
1478	mutex_unlock(&docg3->cascade->lock);
1479
1480	return sprintf(buf, "%d\n", !(dps0 & DOC_DPS_KEY_OK));
1481}
1482
1483static ssize_t dps1_is_key_locked(struct device *dev,
1484				  struct device_attribute *attr, char *buf)
1485{
1486	struct docg3 *docg3 = sysfs_dev2docg3(dev, attr);
1487	int dps1;
1488
1489	mutex_lock(&docg3->cascade->lock);
1490	doc_set_device_id(docg3, docg3->device_id);
1491	dps1 = doc_register_readb(docg3, DOC_DPS1_STATUS);
1492	doc_set_device_id(docg3, 0);
1493	mutex_unlock(&docg3->cascade->lock);
1494
1495	return sprintf(buf, "%d\n", !(dps1 & DOC_DPS_KEY_OK));
1496}
1497
1498static ssize_t dps0_insert_key(struct device *dev,
1499			       struct device_attribute *attr,
1500			       const char *buf, size_t count)
1501{
1502	struct docg3 *docg3 = sysfs_dev2docg3(dev, attr);
1503	int i;
1504
1505	if (count != DOC_LAYOUT_DPS_KEY_LENGTH)
1506		return -EINVAL;
1507
1508	mutex_lock(&docg3->cascade->lock);
1509	doc_set_device_id(docg3, docg3->device_id);
1510	for (i = 0; i < DOC_LAYOUT_DPS_KEY_LENGTH; i++)
1511		doc_writeb(docg3, buf[i], DOC_DPS0_KEY);
1512	doc_set_device_id(docg3, 0);
1513	mutex_unlock(&docg3->cascade->lock);
1514	return count;
1515}
1516
1517static ssize_t dps1_insert_key(struct device *dev,
1518			       struct device_attribute *attr,
1519			       const char *buf, size_t count)
1520{
1521	struct docg3 *docg3 = sysfs_dev2docg3(dev, attr);
1522	int i;
1523
1524	if (count != DOC_LAYOUT_DPS_KEY_LENGTH)
1525		return -EINVAL;
1526
1527	mutex_lock(&docg3->cascade->lock);
1528	doc_set_device_id(docg3, docg3->device_id);
1529	for (i = 0; i < DOC_LAYOUT_DPS_KEY_LENGTH; i++)
1530		doc_writeb(docg3, buf[i], DOC_DPS1_KEY);
1531	doc_set_device_id(docg3, 0);
1532	mutex_unlock(&docg3->cascade->lock);
1533	return count;
1534}
1535
1536#define FLOOR_SYSFS(id) { \
1537	__ATTR(f##id##_dps0_is_keylocked, S_IRUGO, dps0_is_key_locked, NULL), \
1538	__ATTR(f##id##_dps1_is_keylocked, S_IRUGO, dps1_is_key_locked, NULL), \
1539	__ATTR(f##id##_dps0_protection_key, S_IWUSR|S_IWGRP, NULL, dps0_insert_key), \
1540	__ATTR(f##id##_dps1_protection_key, S_IWUSR|S_IWGRP, NULL, dps1_insert_key), \
1541}
1542
1543static struct device_attribute doc_sys_attrs[DOC_MAX_NBFLOORS][4] = {
1544	FLOOR_SYSFS(0), FLOOR_SYSFS(1), FLOOR_SYSFS(2), FLOOR_SYSFS(3)
1545};
1546
1547static int doc_register_sysfs(struct platform_device *pdev,
1548			      struct docg3_cascade *cascade)
1549{
1550	struct device *dev = &pdev->dev;
1551	int floor;
1552	int ret;
1553	int i;
1554
1555	for (floor = 0;
1556	     floor < DOC_MAX_NBFLOORS && cascade->floors[floor];
1557	     floor++) {
1558		for (i = 0; i < 4; i++) {
1559			ret = device_create_file(dev, &doc_sys_attrs[floor][i]);
1560			if (ret)
1561				goto remove_files;
1562		}
1563	}
1564
1565	return 0;
1566
1567remove_files:
1568	do {
1569		while (--i >= 0)
1570			device_remove_file(dev, &doc_sys_attrs[floor][i]);
1571		i = 4;
1572	} while (--floor >= 0);
1573
1574	return ret;
1575}
1576
1577static void doc_unregister_sysfs(struct platform_device *pdev,
1578				 struct docg3_cascade *cascade)
1579{
1580	struct device *dev = &pdev->dev;
1581	int floor, i;
1582
1583	for (floor = 0; floor < DOC_MAX_NBFLOORS && cascade->floors[floor];
1584	     floor++)
1585		for (i = 0; i < 4; i++)
1586			device_remove_file(dev, &doc_sys_attrs[floor][i]);
1587}
1588
1589/*
1590 * Debug sysfs entries
1591 */
1592static int flashcontrol_show(struct seq_file *s, void *p)
1593{
1594	struct docg3 *docg3 = (struct docg3 *)s->private;
1595
1596	u8 fctrl;
1597
1598	mutex_lock(&docg3->cascade->lock);
1599	fctrl = doc_register_readb(docg3, DOC_FLASHCONTROL);
1600	mutex_unlock(&docg3->cascade->lock);
1601
1602	seq_printf(s, "FlashControl : 0x%02x (%s,CE# %s,%s,%s,flash %s)\n",
1603		   fctrl,
1604		   fctrl & DOC_CTRL_VIOLATION ? "protocol violation" : "-",
1605		   fctrl & DOC_CTRL_CE ? "active" : "inactive",
1606		   fctrl & DOC_CTRL_PROTECTION_ERROR ? "protection error" : "-",
1607		   fctrl & DOC_CTRL_SEQUENCE_ERROR ? "sequence error" : "-",
1608		   fctrl & DOC_CTRL_FLASHREADY ? "ready" : "not ready");
1609
1610	return 0;
1611}
1612DEFINE_SHOW_ATTRIBUTE(flashcontrol);
1613
1614static int asic_mode_show(struct seq_file *s, void *p)
1615{
1616	struct docg3 *docg3 = (struct docg3 *)s->private;
1617
1618	int pctrl, mode;
1619
1620	mutex_lock(&docg3->cascade->lock);
1621	pctrl = doc_register_readb(docg3, DOC_ASICMODE);
1622	mode = pctrl & 0x03;
1623	mutex_unlock(&docg3->cascade->lock);
1624
1625	seq_printf(s,
1626		   "%04x : RAM_WE=%d,RSTIN_RESET=%d,BDETCT_RESET=%d,WRITE_ENABLE=%d,POWERDOWN=%d,MODE=%d%d (",
1627		   pctrl,
1628		   pctrl & DOC_ASICMODE_RAM_WE ? 1 : 0,
1629		   pctrl & DOC_ASICMODE_RSTIN_RESET ? 1 : 0,
1630		   pctrl & DOC_ASICMODE_BDETCT_RESET ? 1 : 0,
1631		   pctrl & DOC_ASICMODE_MDWREN ? 1 : 0,
1632		   pctrl & DOC_ASICMODE_POWERDOWN ? 1 : 0,
1633		   mode >> 1, mode & 0x1);
1634
1635	switch (mode) {
1636	case DOC_ASICMODE_RESET:
1637		seq_puts(s, "reset");
1638		break;
1639	case DOC_ASICMODE_NORMAL:
1640		seq_puts(s, "normal");
1641		break;
1642	case DOC_ASICMODE_POWERDOWN:
1643		seq_puts(s, "powerdown");
1644		break;
1645	}
1646	seq_puts(s, ")\n");
1647	return 0;
1648}
1649DEFINE_SHOW_ATTRIBUTE(asic_mode);
1650
1651static int device_id_show(struct seq_file *s, void *p)
1652{
1653	struct docg3 *docg3 = (struct docg3 *)s->private;
1654	int id;
1655
1656	mutex_lock(&docg3->cascade->lock);
1657	id = doc_register_readb(docg3, DOC_DEVICESELECT);
1658	mutex_unlock(&docg3->cascade->lock);
1659
1660	seq_printf(s, "DeviceId = %d\n", id);
1661	return 0;
1662}
1663DEFINE_SHOW_ATTRIBUTE(device_id);
1664
1665static int protection_show(struct seq_file *s, void *p)
1666{
1667	struct docg3 *docg3 = (struct docg3 *)s->private;
1668	int protect, dps0, dps0_low, dps0_high, dps1, dps1_low, dps1_high;
1669
1670	mutex_lock(&docg3->cascade->lock);
1671	protect = doc_register_readb(docg3, DOC_PROTECTION);
1672	dps0 = doc_register_readb(docg3, DOC_DPS0_STATUS);
1673	dps0_low = doc_register_readw(docg3, DOC_DPS0_ADDRLOW);
1674	dps0_high = doc_register_readw(docg3, DOC_DPS0_ADDRHIGH);
1675	dps1 = doc_register_readb(docg3, DOC_DPS1_STATUS);
1676	dps1_low = doc_register_readw(docg3, DOC_DPS1_ADDRLOW);
1677	dps1_high = doc_register_readw(docg3, DOC_DPS1_ADDRHIGH);
1678	mutex_unlock(&docg3->cascade->lock);
1679
1680	seq_printf(s, "Protection = 0x%02x (", protect);
1681	if (protect & DOC_PROTECT_FOUNDRY_OTP_LOCK)
1682		seq_puts(s, "FOUNDRY_OTP_LOCK,");
1683	if (protect & DOC_PROTECT_CUSTOMER_OTP_LOCK)
1684		seq_puts(s, "CUSTOMER_OTP_LOCK,");
1685	if (protect & DOC_PROTECT_LOCK_INPUT)
1686		seq_puts(s, "LOCK_INPUT,");
1687	if (protect & DOC_PROTECT_STICKY_LOCK)
1688		seq_puts(s, "STICKY_LOCK,");
1689	if (protect & DOC_PROTECT_PROTECTION_ENABLED)
1690		seq_puts(s, "PROTECTION ON,");
1691	if (protect & DOC_PROTECT_IPL_DOWNLOAD_LOCK)
1692		seq_puts(s, "IPL_DOWNLOAD_LOCK,");
1693	if (protect & DOC_PROTECT_PROTECTION_ERROR)
1694		seq_puts(s, "PROTECT_ERR,");
1695	else
1696		seq_puts(s, "NO_PROTECT_ERR");
1697	seq_puts(s, ")\n");
1698
1699	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",
1700		   dps0, dps0_low, dps0_high,
1701		   !!(dps0 & DOC_DPS_OTP_PROTECTED),
1702		   !!(dps0 & DOC_DPS_READ_PROTECTED),
1703		   !!(dps0 & DOC_DPS_WRITE_PROTECTED),
1704		   !!(dps0 & DOC_DPS_HW_LOCK_ENABLED),
1705		   !!(dps0 & DOC_DPS_KEY_OK));
1706	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",
1707		   dps1, dps1_low, dps1_high,
1708		   !!(dps1 & DOC_DPS_OTP_PROTECTED),
1709		   !!(dps1 & DOC_DPS_READ_PROTECTED),
1710		   !!(dps1 & DOC_DPS_WRITE_PROTECTED),
1711		   !!(dps1 & DOC_DPS_HW_LOCK_ENABLED),
1712		   !!(dps1 & DOC_DPS_KEY_OK));
1713	return 0;
1714}
1715DEFINE_SHOW_ATTRIBUTE(protection);
1716
1717static void __init doc_dbg_register(struct mtd_info *floor)
1718{
1719	struct dentry *root = floor->dbg.dfs_dir;
1720	struct docg3 *docg3 = floor->priv;
1721
1722	if (IS_ERR_OR_NULL(root)) {
1723		if (IS_ENABLED(CONFIG_DEBUG_FS) &&
1724		    !IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER))
1725			dev_warn(floor->dev.parent,
1726				 "CONFIG_MTD_PARTITIONED_MASTER must be enabled to expose debugfs stuff\n");
1727		return;
1728	}
1729
1730	debugfs_create_file("docg3_flashcontrol", S_IRUSR, root, docg3,
1731			    &flashcontrol_fops);
1732	debugfs_create_file("docg3_asic_mode", S_IRUSR, root, docg3,
1733			    &asic_mode_fops);
1734	debugfs_create_file("docg3_device_id", S_IRUSR, root, docg3,
1735			    &device_id_fops);
1736	debugfs_create_file("docg3_protection", S_IRUSR, root, docg3,
1737			    &protection_fops);
1738}
1739
1740/**
1741 * doc_set_driver_info - Fill the mtd_info structure and docg3 structure
1742 * @chip_id: The chip ID of the supported chip
1743 * @mtd: The structure to fill
1744 */
1745static int __init doc_set_driver_info(int chip_id, struct mtd_info *mtd)
1746{
1747	struct docg3 *docg3 = mtd->priv;
1748	int cfg;
1749
1750	cfg = doc_register_readb(docg3, DOC_CONFIGURATION);
1751	docg3->if_cfg = (cfg & DOC_CONF_IF_CFG ? 1 : 0);
1752	docg3->reliable = reliable_mode;
1753
1754	switch (chip_id) {
1755	case DOC_CHIPID_G3:
1756		mtd->name = devm_kasprintf(docg3->dev, GFP_KERNEL, "docg3.%d",
1757					   docg3->device_id);
1758		if (!mtd->name)
1759			return -ENOMEM;
1760		docg3->max_block = 2047;
1761		break;
1762	}
1763	mtd->type = MTD_NANDFLASH;
1764	mtd->flags = MTD_CAP_NANDFLASH;
1765	mtd->size = (docg3->max_block + 1) * DOC_LAYOUT_BLOCK_SIZE;
1766	if (docg3->reliable == 2)
1767		mtd->size /= 2;
1768	mtd->erasesize = DOC_LAYOUT_BLOCK_SIZE * DOC_LAYOUT_NBPLANES;
1769	if (docg3->reliable == 2)
1770		mtd->erasesize /= 2;
1771	mtd->writebufsize = mtd->writesize = DOC_LAYOUT_PAGE_SIZE;
1772	mtd->oobsize = DOC_LAYOUT_OOB_SIZE;
1773	mtd->_erase = doc_erase;
1774	mtd->_read_oob = doc_read_oob;
1775	mtd->_write_oob = doc_write_oob;
1776	mtd->_block_isbad = doc_block_isbad;
1777	mtd_set_ooblayout(mtd, &nand_ooblayout_docg3_ops);
1778	mtd->oobavail = 8;
1779	mtd->ecc_strength = DOC_ECC_BCH_T;
1780
1781	return 0;
1782}
1783
1784/**
1785 * doc_probe_device - Check if a device is available
1786 * @base: the io space where the device is probed
1787 * @floor: the floor of the probed device
1788 * @dev: the device
1789 * @cascade: the cascade of chips this devices will belong to
1790 *
1791 * Checks whether a device at the specified IO range, and floor is available.
1792 *
1793 * Returns a mtd_info struct if there is a device, ENODEV if none found, ENOMEM
1794 * if a memory allocation failed. If floor 0 is checked, a reset of the ASIC is
1795 * launched.
1796 */
1797static struct mtd_info * __init
1798doc_probe_device(struct docg3_cascade *cascade, int floor, struct device *dev)
1799{
1800	int ret, bbt_nbpages;
1801	u16 chip_id, chip_id_inv;
1802	struct docg3 *docg3;
1803	struct mtd_info *mtd;
1804
1805	ret = -ENOMEM;
1806	docg3 = kzalloc(sizeof(struct docg3), GFP_KERNEL);
1807	if (!docg3)
1808		goto nomem1;
1809	mtd = kzalloc(sizeof(struct mtd_info), GFP_KERNEL);
1810	if (!mtd)
1811		goto nomem2;
1812	mtd->priv = docg3;
1813	mtd->dev.parent = dev;
1814	bbt_nbpages = DIV_ROUND_UP(docg3->max_block + 1,
1815				   8 * DOC_LAYOUT_PAGE_SIZE);
1816	docg3->bbt = kcalloc(DOC_LAYOUT_PAGE_SIZE, bbt_nbpages, GFP_KERNEL);
1817	if (!docg3->bbt)
1818		goto nomem3;
1819
1820	docg3->dev = dev;
1821	docg3->device_id = floor;
1822	docg3->cascade = cascade;
1823	doc_set_device_id(docg3, docg3->device_id);
1824	if (!floor)
1825		doc_set_asic_mode(docg3, DOC_ASICMODE_RESET);
1826	doc_set_asic_mode(docg3, DOC_ASICMODE_NORMAL);
1827
1828	chip_id = doc_register_readw(docg3, DOC_CHIPID);
1829	chip_id_inv = doc_register_readw(docg3, DOC_CHIPID_INV);
1830
1831	ret = 0;
1832	if (chip_id != (u16)(~chip_id_inv)) {
1833		goto nomem4;
1834	}
1835
1836	switch (chip_id) {
1837	case DOC_CHIPID_G3:
1838		doc_info("Found a G3 DiskOnChip at addr %p, floor %d\n",
1839			 docg3->cascade->base, floor);
1840		break;
1841	default:
1842		doc_err("Chip id %04x is not a DiskOnChip G3 chip\n", chip_id);
1843		goto nomem4;
1844	}
1845
1846	ret = doc_set_driver_info(chip_id, mtd);
1847	if (ret)
1848		goto nomem4;
1849
1850	doc_hamming_ecc_init(docg3, DOC_LAYOUT_OOB_PAGEINFO_SZ);
1851	doc_reload_bbt(docg3);
1852	return mtd;
1853
1854nomem4:
1855	kfree(docg3->bbt);
1856nomem3:
1857	kfree(mtd);
1858nomem2:
1859	kfree(docg3);
1860nomem1:
1861	return ret ? ERR_PTR(ret) : NULL;
1862}
1863
1864/**
1865 * doc_release_device - Release a docg3 floor
1866 * @mtd: the device
1867 */
1868static void doc_release_device(struct mtd_info *mtd)
1869{
1870	struct docg3 *docg3 = mtd->priv;
1871
1872	mtd_device_unregister(mtd);
1873	kfree(docg3->bbt);
1874	kfree(docg3);
1875	kfree(mtd);
1876}
1877
1878/**
1879 * docg3_resume - Awakens docg3 floor
1880 * @pdev: platfrom device
1881 *
1882 * Returns 0 (always successful)
1883 */
1884static int docg3_resume(struct platform_device *pdev)
1885{
1886	int i;
1887	struct docg3_cascade *cascade;
1888	struct mtd_info **docg3_floors, *mtd;
1889	struct docg3 *docg3;
1890
1891	cascade = platform_get_drvdata(pdev);
1892	docg3_floors = cascade->floors;
1893	mtd = docg3_floors[0];
1894	docg3 = mtd->priv;
1895
1896	doc_dbg("docg3_resume()\n");
1897	for (i = 0; i < 12; i++)
1898		doc_readb(docg3, DOC_IOSPACE_IPL);
1899	return 0;
1900}
1901
1902/**
1903 * docg3_suspend - Put in low power mode the docg3 floor
1904 * @pdev: platform device
1905 * @state: power state
1906 *
1907 * Shuts off most of docg3 circuitery to lower power consumption.
1908 *
1909 * Returns 0 if suspend succeeded, -EIO if chip refused suspend
1910 */
1911static int docg3_suspend(struct platform_device *pdev, pm_message_t state)
1912{
1913	int floor, i;
1914	struct docg3_cascade *cascade;
1915	struct mtd_info **docg3_floors, *mtd;
1916	struct docg3 *docg3;
1917	u8 ctrl, pwr_down;
1918
1919	cascade = platform_get_drvdata(pdev);
1920	docg3_floors = cascade->floors;
1921	for (floor = 0; floor < DOC_MAX_NBFLOORS; floor++) {
1922		mtd = docg3_floors[floor];
1923		if (!mtd)
1924			continue;
1925		docg3 = mtd->priv;
1926
1927		doc_writeb(docg3, floor, DOC_DEVICESELECT);
1928		ctrl = doc_register_readb(docg3, DOC_FLASHCONTROL);
1929		ctrl &= ~DOC_CTRL_VIOLATION & ~DOC_CTRL_CE;
1930		doc_writeb(docg3, ctrl, DOC_FLASHCONTROL);
1931
1932		for (i = 0; i < 10; i++) {
1933			usleep_range(3000, 4000);
1934			pwr_down = doc_register_readb(docg3, DOC_POWERMODE);
1935			if (pwr_down & DOC_POWERDOWN_READY)
1936				break;
1937		}
1938		if (pwr_down & DOC_POWERDOWN_READY) {
1939			doc_dbg("docg3_suspend(): floor %d powerdown ok\n",
1940				floor);
1941		} else {
1942			doc_err("docg3_suspend(): floor %d powerdown failed\n",
1943				floor);
1944			return -EIO;
1945		}
1946	}
1947
1948	mtd = docg3_floors[0];
1949	docg3 = mtd->priv;
1950	doc_set_asic_mode(docg3, DOC_ASICMODE_POWERDOWN);
1951	return 0;
1952}
1953
1954/**
1955 * doc_probe - Probe the IO space for a DiskOnChip G3 chip
1956 * @pdev: platform device
1957 *
1958 * Probes for a G3 chip at the specified IO space in the platform data
1959 * ressources. The floor 0 must be available.
1960 *
1961 * Returns 0 on success, -ENOMEM, -ENXIO on error
1962 */
1963static int __init docg3_probe(struct platform_device *pdev)
1964{
1965	struct device *dev = &pdev->dev;
1966	struct mtd_info *mtd;
1967	struct resource *ress;
1968	void __iomem *base;
1969	int ret, floor;
1970	struct docg3_cascade *cascade;
1971
1972	ret = -ENXIO;
1973	ress = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1974	if (!ress) {
1975		dev_err(dev, "No I/O memory resource defined\n");
1976		return ret;
1977	}
1978
1979	ret = -ENOMEM;
1980	base = devm_ioremap(dev, ress->start, DOC_IOSPACE_SIZE);
1981	if (!base) {
1982		dev_err(dev, "devm_ioremap dev failed\n");
1983		return ret;
1984	}
1985
1986	cascade = devm_kcalloc(dev, DOC_MAX_NBFLOORS, sizeof(*cascade),
1987			       GFP_KERNEL);
1988	if (!cascade)
1989		return ret;
1990	cascade->base = base;
1991	mutex_init(&cascade->lock);
1992	cascade->bch = bch_init(DOC_ECC_BCH_M, DOC_ECC_BCH_T,
1993				DOC_ECC_BCH_PRIMPOLY, false);
1994	if (!cascade->bch)
1995		return ret;
1996
1997	for (floor = 0; floor < DOC_MAX_NBFLOORS; floor++) {
1998		mtd = doc_probe_device(cascade, floor, dev);
1999		if (IS_ERR(mtd)) {
2000			ret = PTR_ERR(mtd);
2001			goto err_probe;
2002		}
2003		if (!mtd) {
2004			if (floor == 0)
2005				goto notfound;
2006			else
2007				continue;
2008		}
2009		cascade->floors[floor] = mtd;
2010		ret = mtd_device_parse_register(mtd, part_probes, NULL, NULL,
2011						0);
2012		if (ret)
2013			goto err_probe;
2014
2015		doc_dbg_register(cascade->floors[floor]);
2016	}
2017
2018	ret = doc_register_sysfs(pdev, cascade);
2019	if (ret)
2020		goto err_probe;
2021
2022	platform_set_drvdata(pdev, cascade);
2023	return 0;
2024
2025notfound:
2026	ret = -ENODEV;
2027	dev_info(dev, "No supported DiskOnChip found\n");
2028err_probe:
2029	bch_free(cascade->bch);
2030	for (floor = 0; floor < DOC_MAX_NBFLOORS; floor++)
2031		if (cascade->floors[floor])
2032			doc_release_device(cascade->floors[floor]);
2033	return ret;
2034}
2035
2036/**
2037 * docg3_release - Release the driver
2038 * @pdev: the platform device
2039 *
2040 * Returns 0
2041 */
2042static int docg3_release(struct platform_device *pdev)
2043{
2044	struct docg3_cascade *cascade = platform_get_drvdata(pdev);
2045	struct docg3 *docg3 = cascade->floors[0]->priv;
2046	int floor;
2047
2048	doc_unregister_sysfs(pdev, cascade);
2049	for (floor = 0; floor < DOC_MAX_NBFLOORS; floor++)
2050		if (cascade->floors[floor])
2051			doc_release_device(cascade->floors[floor]);
2052
2053	bch_free(docg3->cascade->bch);
2054	return 0;
2055}
2056
2057#ifdef CONFIG_OF
2058static const struct of_device_id docg3_dt_ids[] = {
2059	{ .compatible = "m-systems,diskonchip-g3" },
2060	{}
2061};
2062MODULE_DEVICE_TABLE(of, docg3_dt_ids);
2063#endif
2064
2065static struct platform_driver g3_driver = {
2066	.driver		= {
2067		.name	= "docg3",
2068		.of_match_table = of_match_ptr(docg3_dt_ids),
2069	},
2070	.suspend	= docg3_suspend,
2071	.resume		= docg3_resume,
2072	.remove		= docg3_release,
2073};
2074
2075module_platform_driver_probe(g3_driver, docg3_probe);
2076
2077MODULE_LICENSE("GPL");
2078MODULE_AUTHOR("Robert Jarzmik <robert.jarzmik@free.fr>");
2079MODULE_DESCRIPTION("MTD driver for DiskOnChip G3");
2080