xref: /openbmc/linux/drivers/mtd/devices/docg3.c (revision ca55b2fe)
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 
65 static unsigned int reliable_mode;
66 module_param(reliable_mode, uint, 0);
67 MODULE_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  */
77 static 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 
84 static 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 
92 static 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 
100 static 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 
106 static 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 
112 static inline void doc_flash_command(struct docg3 *docg3, u8 cmd)
113 {
114 	doc_writeb(docg3, cmd, DOC_FLASHCOMMAND);
115 }
116 
117 static inline void doc_flash_sequence(struct docg3 *docg3, u8 seq)
118 {
119 	doc_writeb(docg3, seq, DOC_FLASHSEQUENCE);
120 }
121 
122 static inline void doc_flash_address(struct docg3 *docg3, u8 addr)
123 {
124 	doc_writeb(docg3, addr, DOC_FLASHADDRESS);
125 }
126 
127 static char const * const part_probes[] = { "cmdlinepart", "saftlpart", NULL };
128 
129 static 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 
139 static 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  */
160 static 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 
169 static 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 
177 static 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 
185 static 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 
200 static 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  */
223 static 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  */
268 static 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  */
309 static 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  */
343 static 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  */
365 static 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  */
389 static 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  */
410 static 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  */
425 static 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  */
448 static 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 
482 out:
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  */
497 static 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 
534 out:
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  */
549 static 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  */
570 static 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  */
588 static 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  */
602 static 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  */
635 static 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);
655 out:
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  */
687 static 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;
724 err:
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  */
745 static 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  */
765 static 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  */
777 static 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  */
789 static 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  */
803 static 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  */
824 static 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  */
857 static 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 
963 out:
964 	mutex_unlock(&docg3->cascade->lock);
965 	return ret;
966 err_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  */
985 static 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 
1001 static 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  */
1030 static 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  */
1060 static 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  */
1101 static 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  */
1124 static 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 
1143 out:
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  */
1159 static 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  */
1201 static 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 
1236 reset_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  */
1260 static 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;
1315 err:
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  */
1326 static 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  */
1350 static 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  */
1373 static 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  */
1411 static 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  */
1507 static 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 
1527 static 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 
1541 static 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 
1556 static 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 
1571 static 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 
1590 static 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 
1616 static 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 
1620 static 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 
1640 static 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  */
1655 static 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 }
1675 DEBUGFS_RO_ATTR(flashcontrol, dbg_flashctrl_show);
1676 
1677 static 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 }
1712 DEBUGFS_RO_ATTR(asic_mode, dbg_asicmode_show);
1713 
1714 static 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 }
1726 DEBUGFS_RO_ATTR(device_id, dbg_device_id_show);
1727 
1728 static 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 }
1778 DEBUGFS_RO_ATTR(protection, dbg_protection_show);
1779 
1780 static 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 
1808 static 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  */
1818 static int __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 		if (!mtd->name)
1832 			return -ENOMEM;
1833 		docg3->max_block = 2047;
1834 		break;
1835 	}
1836 	mtd->type = MTD_NANDFLASH;
1837 	mtd->flags = MTD_CAP_NANDFLASH;
1838 	mtd->size = (docg3->max_block + 1) * DOC_LAYOUT_BLOCK_SIZE;
1839 	if (docg3->reliable == 2)
1840 		mtd->size /= 2;
1841 	mtd->erasesize = DOC_LAYOUT_BLOCK_SIZE * DOC_LAYOUT_NBPLANES;
1842 	if (docg3->reliable == 2)
1843 		mtd->erasesize /= 2;
1844 	mtd->writebufsize = mtd->writesize = DOC_LAYOUT_PAGE_SIZE;
1845 	mtd->oobsize = DOC_LAYOUT_OOB_SIZE;
1846 	mtd->owner = THIS_MODULE;
1847 	mtd->_erase = doc_erase;
1848 	mtd->_read = doc_read;
1849 	mtd->_write = doc_write;
1850 	mtd->_read_oob = doc_read_oob;
1851 	mtd->_write_oob = doc_write_oob;
1852 	mtd->_block_isbad = doc_block_isbad;
1853 	mtd->ecclayout = &docg3_oobinfo;
1854 	mtd->ecc_strength = DOC_ECC_BCH_T;
1855 
1856 	return 0;
1857 }
1858 
1859 /**
1860  * doc_probe_device - Check if a device is available
1861  * @base: the io space where the device is probed
1862  * @floor: the floor of the probed device
1863  * @dev: the device
1864  * @cascade: the cascade of chips this devices will belong to
1865  *
1866  * Checks whether a device at the specified IO range, and floor is available.
1867  *
1868  * Returns a mtd_info struct if there is a device, ENODEV if none found, ENOMEM
1869  * if a memory allocation failed. If floor 0 is checked, a reset of the ASIC is
1870  * launched.
1871  */
1872 static struct mtd_info * __init
1873 doc_probe_device(struct docg3_cascade *cascade, int floor, struct device *dev)
1874 {
1875 	int ret, bbt_nbpages;
1876 	u16 chip_id, chip_id_inv;
1877 	struct docg3 *docg3;
1878 	struct mtd_info *mtd;
1879 
1880 	ret = -ENOMEM;
1881 	docg3 = kzalloc(sizeof(struct docg3), GFP_KERNEL);
1882 	if (!docg3)
1883 		goto nomem1;
1884 	mtd = kzalloc(sizeof(struct mtd_info), GFP_KERNEL);
1885 	if (!mtd)
1886 		goto nomem2;
1887 	mtd->priv = docg3;
1888 	bbt_nbpages = DIV_ROUND_UP(docg3->max_block + 1,
1889 				   8 * DOC_LAYOUT_PAGE_SIZE);
1890 	docg3->bbt = kzalloc(bbt_nbpages * DOC_LAYOUT_PAGE_SIZE, GFP_KERNEL);
1891 	if (!docg3->bbt)
1892 		goto nomem3;
1893 
1894 	docg3->dev = dev;
1895 	docg3->device_id = floor;
1896 	docg3->cascade = cascade;
1897 	doc_set_device_id(docg3, docg3->device_id);
1898 	if (!floor)
1899 		doc_set_asic_mode(docg3, DOC_ASICMODE_RESET);
1900 	doc_set_asic_mode(docg3, DOC_ASICMODE_NORMAL);
1901 
1902 	chip_id = doc_register_readw(docg3, DOC_CHIPID);
1903 	chip_id_inv = doc_register_readw(docg3, DOC_CHIPID_INV);
1904 
1905 	ret = 0;
1906 	if (chip_id != (u16)(~chip_id_inv)) {
1907 		goto nomem4;
1908 	}
1909 
1910 	switch (chip_id) {
1911 	case DOC_CHIPID_G3:
1912 		doc_info("Found a G3 DiskOnChip at addr %p, floor %d\n",
1913 			 docg3->cascade->base, floor);
1914 		break;
1915 	default:
1916 		doc_err("Chip id %04x is not a DiskOnChip G3 chip\n", chip_id);
1917 		goto nomem4;
1918 	}
1919 
1920 	ret = doc_set_driver_info(chip_id, mtd);
1921 	if (ret)
1922 		goto nomem4;
1923 
1924 	doc_hamming_ecc_init(docg3, DOC_LAYOUT_OOB_PAGEINFO_SZ);
1925 	doc_reload_bbt(docg3);
1926 	return mtd;
1927 
1928 nomem4:
1929 	kfree(docg3->bbt);
1930 nomem3:
1931 	kfree(mtd);
1932 nomem2:
1933 	kfree(docg3);
1934 nomem1:
1935 	return ERR_PTR(ret);
1936 }
1937 
1938 /**
1939  * doc_release_device - Release a docg3 floor
1940  * @mtd: the device
1941  */
1942 static void doc_release_device(struct mtd_info *mtd)
1943 {
1944 	struct docg3 *docg3 = mtd->priv;
1945 
1946 	mtd_device_unregister(mtd);
1947 	kfree(docg3->bbt);
1948 	kfree(docg3);
1949 	kfree(mtd->name);
1950 	kfree(mtd);
1951 }
1952 
1953 /**
1954  * docg3_resume - Awakens docg3 floor
1955  * @pdev: platfrom device
1956  *
1957  * Returns 0 (always successful)
1958  */
1959 static int docg3_resume(struct platform_device *pdev)
1960 {
1961 	int i;
1962 	struct docg3_cascade *cascade;
1963 	struct mtd_info **docg3_floors, *mtd;
1964 	struct docg3 *docg3;
1965 
1966 	cascade = platform_get_drvdata(pdev);
1967 	docg3_floors = cascade->floors;
1968 	mtd = docg3_floors[0];
1969 	docg3 = mtd->priv;
1970 
1971 	doc_dbg("docg3_resume()\n");
1972 	for (i = 0; i < 12; i++)
1973 		doc_readb(docg3, DOC_IOSPACE_IPL);
1974 	return 0;
1975 }
1976 
1977 /**
1978  * docg3_suspend - Put in low power mode the docg3 floor
1979  * @pdev: platform device
1980  * @state: power state
1981  *
1982  * Shuts off most of docg3 circuitery to lower power consumption.
1983  *
1984  * Returns 0 if suspend succeeded, -EIO if chip refused suspend
1985  */
1986 static int docg3_suspend(struct platform_device *pdev, pm_message_t state)
1987 {
1988 	int floor, i;
1989 	struct docg3_cascade *cascade;
1990 	struct mtd_info **docg3_floors, *mtd;
1991 	struct docg3 *docg3;
1992 	u8 ctrl, pwr_down;
1993 
1994 	cascade = platform_get_drvdata(pdev);
1995 	docg3_floors = cascade->floors;
1996 	for (floor = 0; floor < DOC_MAX_NBFLOORS; floor++) {
1997 		mtd = docg3_floors[floor];
1998 		if (!mtd)
1999 			continue;
2000 		docg3 = mtd->priv;
2001 
2002 		doc_writeb(docg3, floor, DOC_DEVICESELECT);
2003 		ctrl = doc_register_readb(docg3, DOC_FLASHCONTROL);
2004 		ctrl &= ~DOC_CTRL_VIOLATION & ~DOC_CTRL_CE;
2005 		doc_writeb(docg3, ctrl, DOC_FLASHCONTROL);
2006 
2007 		for (i = 0; i < 10; i++) {
2008 			usleep_range(3000, 4000);
2009 			pwr_down = doc_register_readb(docg3, DOC_POWERMODE);
2010 			if (pwr_down & DOC_POWERDOWN_READY)
2011 				break;
2012 		}
2013 		if (pwr_down & DOC_POWERDOWN_READY) {
2014 			doc_dbg("docg3_suspend(): floor %d powerdown ok\n",
2015 				floor);
2016 		} else {
2017 			doc_err("docg3_suspend(): floor %d powerdown failed\n",
2018 				floor);
2019 			return -EIO;
2020 		}
2021 	}
2022 
2023 	mtd = docg3_floors[0];
2024 	docg3 = mtd->priv;
2025 	doc_set_asic_mode(docg3, DOC_ASICMODE_POWERDOWN);
2026 	return 0;
2027 }
2028 
2029 /**
2030  * doc_probe - Probe the IO space for a DiskOnChip G3 chip
2031  * @pdev: platform device
2032  *
2033  * Probes for a G3 chip at the specified IO space in the platform data
2034  * ressources. The floor 0 must be available.
2035  *
2036  * Returns 0 on success, -ENOMEM, -ENXIO on error
2037  */
2038 static int __init docg3_probe(struct platform_device *pdev)
2039 {
2040 	struct device *dev = &pdev->dev;
2041 	struct mtd_info *mtd;
2042 	struct resource *ress;
2043 	void __iomem *base;
2044 	int ret, floor;
2045 	struct docg3_cascade *cascade;
2046 
2047 	ret = -ENXIO;
2048 	ress = platform_get_resource(pdev, IORESOURCE_MEM, 0);
2049 	if (!ress) {
2050 		dev_err(dev, "No I/O memory resource defined\n");
2051 		return ret;
2052 	}
2053 	base = devm_ioremap(dev, ress->start, DOC_IOSPACE_SIZE);
2054 
2055 	ret = -ENOMEM;
2056 	cascade = devm_kzalloc(dev, sizeof(*cascade) * DOC_MAX_NBFLOORS,
2057 			       GFP_KERNEL);
2058 	if (!cascade)
2059 		return ret;
2060 	cascade->base = base;
2061 	mutex_init(&cascade->lock);
2062 	cascade->bch = init_bch(DOC_ECC_BCH_M, DOC_ECC_BCH_T,
2063 			     DOC_ECC_BCH_PRIMPOLY);
2064 	if (!cascade->bch)
2065 		return ret;
2066 
2067 	for (floor = 0; floor < DOC_MAX_NBFLOORS; floor++) {
2068 		mtd = doc_probe_device(cascade, floor, dev);
2069 		if (IS_ERR(mtd)) {
2070 			ret = PTR_ERR(mtd);
2071 			goto err_probe;
2072 		}
2073 		if (!mtd) {
2074 			if (floor == 0)
2075 				goto notfound;
2076 			else
2077 				continue;
2078 		}
2079 		cascade->floors[floor] = mtd;
2080 		ret = mtd_device_parse_register(mtd, part_probes, NULL, NULL,
2081 						0);
2082 		if (ret)
2083 			goto err_probe;
2084 	}
2085 
2086 	ret = doc_register_sysfs(pdev, cascade);
2087 	if (ret)
2088 		goto err_probe;
2089 
2090 	platform_set_drvdata(pdev, cascade);
2091 	doc_dbg_register(cascade->floors[0]->priv);
2092 	return 0;
2093 
2094 notfound:
2095 	ret = -ENODEV;
2096 	dev_info(dev, "No supported DiskOnChip found\n");
2097 err_probe:
2098 	free_bch(cascade->bch);
2099 	for (floor = 0; floor < DOC_MAX_NBFLOORS; floor++)
2100 		if (cascade->floors[floor])
2101 			doc_release_device(cascade->floors[floor]);
2102 	return ret;
2103 }
2104 
2105 /**
2106  * docg3_release - Release the driver
2107  * @pdev: the platform device
2108  *
2109  * Returns 0
2110  */
2111 static int docg3_release(struct platform_device *pdev)
2112 {
2113 	struct docg3_cascade *cascade = platform_get_drvdata(pdev);
2114 	struct docg3 *docg3 = cascade->floors[0]->priv;
2115 	int floor;
2116 
2117 	doc_unregister_sysfs(pdev, cascade);
2118 	doc_dbg_unregister(docg3);
2119 	for (floor = 0; floor < DOC_MAX_NBFLOORS; floor++)
2120 		if (cascade->floors[floor])
2121 			doc_release_device(cascade->floors[floor]);
2122 
2123 	free_bch(docg3->cascade->bch);
2124 	return 0;
2125 }
2126 
2127 #ifdef CONFIG_OF
2128 static const struct of_device_id docg3_dt_ids[] = {
2129 	{ .compatible = "m-systems,diskonchip-g3" },
2130 	{}
2131 };
2132 MODULE_DEVICE_TABLE(of, docg3_dt_ids);
2133 #endif
2134 
2135 static struct platform_driver g3_driver = {
2136 	.driver		= {
2137 		.name	= "docg3",
2138 		.of_match_table = of_match_ptr(docg3_dt_ids),
2139 	},
2140 	.suspend	= docg3_suspend,
2141 	.resume		= docg3_resume,
2142 	.remove		= docg3_release,
2143 };
2144 
2145 module_platform_driver_probe(g3_driver, docg3_probe);
2146 
2147 MODULE_LICENSE("GPL");
2148 MODULE_AUTHOR("Robert Jarzmik <robert.jarzmik@free.fr>");
2149 MODULE_DESCRIPTION("MTD driver for DiskOnChip G3");
2150