xref: /openbmc/linux/drivers/mtd/devices/docg3.c (revision 6774def6)
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/platform_device.h>
26 #include <linux/string.h>
27 #include <linux/slab.h>
28 #include <linux/io.h>
29 #include <linux/delay.h>
30 #include <linux/mtd/mtd.h>
31 #include <linux/mtd/partitions.h>
32 #include <linux/bitmap.h>
33 #include <linux/bitrev.h>
34 #include <linux/bch.h>
35 
36 #include <linux/debugfs.h>
37 #include <linux/seq_file.h>
38 
39 #define CREATE_TRACE_POINTS
40 #include "docg3.h"
41 
42 /*
43  * This driver handles the DiskOnChip G3 flash memory.
44  *
45  * As no specification is available from M-Systems/Sandisk, this drivers lacks
46  * several functions available on the chip, as :
47  *  - IPL write
48  *
49  * The bus data width (8bits versus 16bits) is not handled (if_cfg flag), and
50  * the driver assumes a 16bits data bus.
51  *
52  * DocG3 relies on 2 ECC algorithms, which are handled in hardware :
53  *  - a 1 byte Hamming code stored in the OOB for each page
54  *  - a 7 bytes BCH code stored in the OOB for each page
55  * The BCH ECC is :
56  *  - BCH is in GF(2^14)
57  *  - BCH is over data of 520 bytes (512 page + 7 page_info bytes
58  *                                   + 1 hamming byte)
59  *  - BCH can correct up to 4 bits (t = 4)
60  *  - BCH syndroms are calculated in hardware, and checked in hardware as well
61  *
62  */
63 
64 static unsigned int reliable_mode;
65 module_param(reliable_mode, uint, 0);
66 MODULE_PARM_DESC(reliable_mode, "Set the docg3 mode (0=normal MLC, 1=fast, "
67 		 "2=reliable) : MLC normal operations are in normal mode");
68 
69 /**
70  * struct docg3_oobinfo - DiskOnChip G3 OOB layout
71  * @eccbytes: 8 bytes are used (1 for Hamming ECC, 7 for BCH ECC)
72  * @eccpos: ecc positions (byte 7 is Hamming ECC, byte 8-14 are BCH ECC)
73  * @oobfree: free pageinfo bytes (byte 0 until byte 6, byte 15
74  * @oobavail: 8 available bytes remaining after ECC toll
75  */
76 static struct nand_ecclayout docg3_oobinfo = {
77 	.eccbytes = 8,
78 	.eccpos = {7, 8, 9, 10, 11, 12, 13, 14},
79 	.oobfree = {{0, 7}, {15, 1} },
80 	.oobavail = 8,
81 };
82 
83 static inline u8 doc_readb(struct docg3 *docg3, u16 reg)
84 {
85 	u8 val = readb(docg3->cascade->base + reg);
86 
87 	trace_docg3_io(0, 8, reg, (int)val);
88 	return val;
89 }
90 
91 static inline u16 doc_readw(struct docg3 *docg3, u16 reg)
92 {
93 	u16 val = readw(docg3->cascade->base + reg);
94 
95 	trace_docg3_io(0, 16, reg, (int)val);
96 	return val;
97 }
98 
99 static inline void doc_writeb(struct docg3 *docg3, u8 val, u16 reg)
100 {
101 	writeb(val, docg3->cascade->base + reg);
102 	trace_docg3_io(1, 8, reg, val);
103 }
104 
105 static inline void doc_writew(struct docg3 *docg3, u16 val, u16 reg)
106 {
107 	writew(val, docg3->cascade->base + reg);
108 	trace_docg3_io(1, 16, reg, val);
109 }
110 
111 static inline void doc_flash_command(struct docg3 *docg3, u8 cmd)
112 {
113 	doc_writeb(docg3, cmd, DOC_FLASHCOMMAND);
114 }
115 
116 static inline void doc_flash_sequence(struct docg3 *docg3, u8 seq)
117 {
118 	doc_writeb(docg3, seq, DOC_FLASHSEQUENCE);
119 }
120 
121 static inline void doc_flash_address(struct docg3 *docg3, u8 addr)
122 {
123 	doc_writeb(docg3, addr, DOC_FLASHADDRESS);
124 }
125 
126 static char const * const part_probes[] = { "cmdlinepart", "saftlpart", NULL };
127 
128 static int doc_register_readb(struct docg3 *docg3, int reg)
129 {
130 	u8 val;
131 
132 	doc_writew(docg3, reg, DOC_READADDRESS);
133 	val = doc_readb(docg3, reg);
134 	doc_vdbg("Read register %04x : %02x\n", reg, val);
135 	return val;
136 }
137 
138 static int doc_register_readw(struct docg3 *docg3, int reg)
139 {
140 	u16 val;
141 
142 	doc_writew(docg3, reg, DOC_READADDRESS);
143 	val = doc_readw(docg3, reg);
144 	doc_vdbg("Read register %04x : %04x\n", reg, val);
145 	return val;
146 }
147 
148 /**
149  * doc_delay - delay docg3 operations
150  * @docg3: the device
151  * @nbNOPs: the number of NOPs to issue
152  *
153  * As no specification is available, the right timings between chip commands are
154  * unknown. The only available piece of information are the observed nops on a
155  * working docg3 chip.
156  * Therefore, doc_delay relies on a busy loop of NOPs, instead of scheduler
157  * friendlier msleep() functions or blocking mdelay().
158  */
159 static void doc_delay(struct docg3 *docg3, int nbNOPs)
160 {
161 	int i;
162 
163 	doc_vdbg("NOP x %d\n", nbNOPs);
164 	for (i = 0; i < nbNOPs; i++)
165 		doc_writeb(docg3, 0, DOC_NOP);
166 }
167 
168 static int is_prot_seq_error(struct docg3 *docg3)
169 {
170 	int ctrl;
171 
172 	ctrl = doc_register_readb(docg3, DOC_FLASHCONTROL);
173 	return ctrl & (DOC_CTRL_PROTECTION_ERROR | DOC_CTRL_SEQUENCE_ERROR);
174 }
175 
176 static int doc_is_ready(struct docg3 *docg3)
177 {
178 	int ctrl;
179 
180 	ctrl = doc_register_readb(docg3, DOC_FLASHCONTROL);
181 	return ctrl & DOC_CTRL_FLASHREADY;
182 }
183 
184 static int doc_wait_ready(struct docg3 *docg3)
185 {
186 	int maxWaitCycles = 100;
187 
188 	do {
189 		doc_delay(docg3, 4);
190 		cpu_relax();
191 	} while (!doc_is_ready(docg3) && maxWaitCycles--);
192 	doc_delay(docg3, 2);
193 	if (maxWaitCycles > 0)
194 		return 0;
195 	else
196 		return -EIO;
197 }
198 
199 static int doc_reset_seq(struct docg3 *docg3)
200 {
201 	int ret;
202 
203 	doc_writeb(docg3, 0x10, DOC_FLASHCONTROL);
204 	doc_flash_sequence(docg3, DOC_SEQ_RESET);
205 	doc_flash_command(docg3, DOC_CMD_RESET);
206 	doc_delay(docg3, 2);
207 	ret = doc_wait_ready(docg3);
208 
209 	doc_dbg("doc_reset_seq() -> isReady=%s\n", ret ? "false" : "true");
210 	return ret;
211 }
212 
213 /**
214  * doc_read_data_area - Read data from data area
215  * @docg3: the device
216  * @buf: the buffer to fill in (might be NULL is dummy reads)
217  * @len: the length to read
218  * @first: first time read, DOC_READADDRESS should be set
219  *
220  * Reads bytes from flash data. Handles the single byte / even bytes reads.
221  */
222 static void doc_read_data_area(struct docg3 *docg3, void *buf, int len,
223 			       int first)
224 {
225 	int i, cdr, len4;
226 	u16 data16, *dst16;
227 	u8 data8, *dst8;
228 
229 	doc_dbg("doc_read_data_area(buf=%p, len=%d)\n", buf, len);
230 	cdr = len & 0x1;
231 	len4 = len - cdr;
232 
233 	if (first)
234 		doc_writew(docg3, DOC_IOSPACE_DATA, DOC_READADDRESS);
235 	dst16 = buf;
236 	for (i = 0; i < len4; i += 2) {
237 		data16 = doc_readw(docg3, DOC_IOSPACE_DATA);
238 		if (dst16) {
239 			*dst16 = data16;
240 			dst16++;
241 		}
242 	}
243 
244 	if (cdr) {
245 		doc_writew(docg3, DOC_IOSPACE_DATA | DOC_READADDR_ONE_BYTE,
246 			   DOC_READADDRESS);
247 		doc_delay(docg3, 1);
248 		dst8 = (u8 *)dst16;
249 		for (i = 0; i < cdr; i++) {
250 			data8 = doc_readb(docg3, DOC_IOSPACE_DATA);
251 			if (dst8) {
252 				*dst8 = data8;
253 				dst8++;
254 			}
255 		}
256 	}
257 }
258 
259 /**
260  * doc_write_data_area - Write data into data area
261  * @docg3: the device
262  * @buf: the buffer to get input bytes from
263  * @len: the length to write
264  *
265  * Writes bytes into flash data. Handles the single byte / even bytes writes.
266  */
267 static void doc_write_data_area(struct docg3 *docg3, const void *buf, int len)
268 {
269 	int i, cdr, len4;
270 	u16 *src16;
271 	u8 *src8;
272 
273 	doc_dbg("doc_write_data_area(buf=%p, len=%d)\n", buf, len);
274 	cdr = len & 0x3;
275 	len4 = len - cdr;
276 
277 	doc_writew(docg3, DOC_IOSPACE_DATA, DOC_READADDRESS);
278 	src16 = (u16 *)buf;
279 	for (i = 0; i < len4; i += 2) {
280 		doc_writew(docg3, *src16, DOC_IOSPACE_DATA);
281 		src16++;
282 	}
283 
284 	src8 = (u8 *)src16;
285 	for (i = 0; i < cdr; i++) {
286 		doc_writew(docg3, DOC_IOSPACE_DATA | DOC_READADDR_ONE_BYTE,
287 			   DOC_READADDRESS);
288 		doc_writeb(docg3, *src8, DOC_IOSPACE_DATA);
289 		src8++;
290 	}
291 }
292 
293 /**
294  * doc_set_data_mode - Sets the flash to normal or reliable data mode
295  * @docg3: the device
296  *
297  * The reliable data mode is a bit slower than the fast mode, but less errors
298  * occur.  Entering the reliable mode cannot be done without entering the fast
299  * mode first.
300  *
301  * In reliable mode, pages 2*n and 2*n+1 are clones. Writing to page 0 of blocks
302  * (4,5) make the hardware write also to page 1 of blocks blocks(4,5). Reading
303  * from page 0 of blocks (4,5) or from page 1 of blocks (4,5) gives the same
304  * result, which is a logical and between bytes from page 0 and page 1 (which is
305  * consistent with the fact that writing to a page is _clearing_ bits of that
306  * page).
307  */
308 static void doc_set_reliable_mode(struct docg3 *docg3)
309 {
310 	static char *strmode[] = { "normal", "fast", "reliable", "invalid" };
311 
312 	doc_dbg("doc_set_reliable_mode(%s)\n", strmode[docg3->reliable]);
313 	switch (docg3->reliable) {
314 	case 0:
315 		break;
316 	case 1:
317 		doc_flash_sequence(docg3, DOC_SEQ_SET_FASTMODE);
318 		doc_flash_command(docg3, DOC_CMD_FAST_MODE);
319 		break;
320 	case 2:
321 		doc_flash_sequence(docg3, DOC_SEQ_SET_RELIABLEMODE);
322 		doc_flash_command(docg3, DOC_CMD_FAST_MODE);
323 		doc_flash_command(docg3, DOC_CMD_RELIABLE_MODE);
324 		break;
325 	default:
326 		doc_err("doc_set_reliable_mode(): invalid mode\n");
327 		break;
328 	}
329 	doc_delay(docg3, 2);
330 }
331 
332 /**
333  * doc_set_asic_mode - Set the ASIC mode
334  * @docg3: the device
335  * @mode: the mode
336  *
337  * The ASIC can work in 3 modes :
338  *  - RESET: all registers are zeroed
339  *  - NORMAL: receives and handles commands
340  *  - POWERDOWN: minimal poweruse, flash parts shut off
341  */
342 static void doc_set_asic_mode(struct docg3 *docg3, u8 mode)
343 {
344 	int i;
345 
346 	for (i = 0; i < 12; i++)
347 		doc_readb(docg3, DOC_IOSPACE_IPL);
348 
349 	mode |= DOC_ASICMODE_MDWREN;
350 	doc_dbg("doc_set_asic_mode(%02x)\n", mode);
351 	doc_writeb(docg3, mode, DOC_ASICMODE);
352 	doc_writeb(docg3, ~mode, DOC_ASICMODECONFIRM);
353 	doc_delay(docg3, 1);
354 }
355 
356 /**
357  * doc_set_device_id - Sets the devices id for cascaded G3 chips
358  * @docg3: the device
359  * @id: the chip to select (amongst 0, 1, 2, 3)
360  *
361  * There can be 4 cascaded G3 chips. This function selects the one which will
362  * should be the active one.
363  */
364 static void doc_set_device_id(struct docg3 *docg3, int id)
365 {
366 	u8 ctrl;
367 
368 	doc_dbg("doc_set_device_id(%d)\n", id);
369 	doc_writeb(docg3, id, DOC_DEVICESELECT);
370 	ctrl = doc_register_readb(docg3, DOC_FLASHCONTROL);
371 
372 	ctrl &= ~DOC_CTRL_VIOLATION;
373 	ctrl |= DOC_CTRL_CE;
374 	doc_writeb(docg3, ctrl, DOC_FLASHCONTROL);
375 }
376 
377 /**
378  * doc_set_extra_page_mode - Change flash page layout
379  * @docg3: the device
380  *
381  * Normally, the flash page is split into the data (512 bytes) and the out of
382  * band data (16 bytes). For each, 4 more bytes can be accessed, where the wear
383  * leveling counters are stored.  To access this last area of 4 bytes, a special
384  * mode must be input to the flash ASIC.
385  *
386  * Returns 0 if no error occurred, -EIO else.
387  */
388 static int doc_set_extra_page_mode(struct docg3 *docg3)
389 {
390 	int fctrl;
391 
392 	doc_dbg("doc_set_extra_page_mode()\n");
393 	doc_flash_sequence(docg3, DOC_SEQ_PAGE_SIZE_532);
394 	doc_flash_command(docg3, DOC_CMD_PAGE_SIZE_532);
395 	doc_delay(docg3, 2);
396 
397 	fctrl = doc_register_readb(docg3, DOC_FLASHCONTROL);
398 	if (fctrl & (DOC_CTRL_PROTECTION_ERROR | DOC_CTRL_SEQUENCE_ERROR))
399 		return -EIO;
400 	else
401 		return 0;
402 }
403 
404 /**
405  * doc_setup_addr_sector - Setup blocks/page/ofs address for one plane
406  * @docg3: the device
407  * @sector: the sector
408  */
409 static void doc_setup_addr_sector(struct docg3 *docg3, int sector)
410 {
411 	doc_delay(docg3, 1);
412 	doc_flash_address(docg3, sector & 0xff);
413 	doc_flash_address(docg3, (sector >> 8) & 0xff);
414 	doc_flash_address(docg3, (sector >> 16) & 0xff);
415 	doc_delay(docg3, 1);
416 }
417 
418 /**
419  * doc_setup_writeaddr_sector - Setup blocks/page/ofs address for one plane
420  * @docg3: the device
421  * @sector: the sector
422  * @ofs: the offset in the page, between 0 and (512 + 16 + 512)
423  */
424 static void doc_setup_writeaddr_sector(struct docg3 *docg3, int sector, int ofs)
425 {
426 	ofs = ofs >> 2;
427 	doc_delay(docg3, 1);
428 	doc_flash_address(docg3, ofs & 0xff);
429 	doc_flash_address(docg3, sector & 0xff);
430 	doc_flash_address(docg3, (sector >> 8) & 0xff);
431 	doc_flash_address(docg3, (sector >> 16) & 0xff);
432 	doc_delay(docg3, 1);
433 }
434 
435 /**
436  * doc_seek - Set both flash planes to the specified block, page for reading
437  * @docg3: the device
438  * @block0: the first plane block index
439  * @block1: the second plane block index
440  * @page: the page index within the block
441  * @wear: if true, read will occur on the 4 extra bytes of the wear area
442  * @ofs: offset in page to read
443  *
444  * Programs the flash even and odd planes to the specific block and page.
445  * Alternatively, programs the flash to the wear area of the specified page.
446  */
447 static int doc_read_seek(struct docg3 *docg3, int block0, int block1, int page,
448 			 int wear, int ofs)
449 {
450 	int sector, ret = 0;
451 
452 	doc_dbg("doc_seek(blocks=(%d,%d), page=%d, ofs=%d, wear=%d)\n",
453 		block0, block1, page, ofs, wear);
454 
455 	if (!wear && (ofs < 2 * DOC_LAYOUT_PAGE_SIZE)) {
456 		doc_flash_sequence(docg3, DOC_SEQ_SET_PLANE1);
457 		doc_flash_command(docg3, DOC_CMD_READ_PLANE1);
458 		doc_delay(docg3, 2);
459 	} else {
460 		doc_flash_sequence(docg3, DOC_SEQ_SET_PLANE2);
461 		doc_flash_command(docg3, DOC_CMD_READ_PLANE2);
462 		doc_delay(docg3, 2);
463 	}
464 
465 	doc_set_reliable_mode(docg3);
466 	if (wear)
467 		ret = doc_set_extra_page_mode(docg3);
468 	if (ret)
469 		goto out;
470 
471 	doc_flash_sequence(docg3, DOC_SEQ_READ);
472 	sector = (block0 << DOC_ADDR_BLOCK_SHIFT) + (page & DOC_ADDR_PAGE_MASK);
473 	doc_flash_command(docg3, DOC_CMD_PROG_BLOCK_ADDR);
474 	doc_setup_addr_sector(docg3, sector);
475 
476 	sector = (block1 << DOC_ADDR_BLOCK_SHIFT) + (page & DOC_ADDR_PAGE_MASK);
477 	doc_flash_command(docg3, DOC_CMD_PROG_BLOCK_ADDR);
478 	doc_setup_addr_sector(docg3, sector);
479 	doc_delay(docg3, 1);
480 
481 out:
482 	return ret;
483 }
484 
485 /**
486  * doc_write_seek - Set both flash planes to the specified block, page for writing
487  * @docg3: the device
488  * @block0: the first plane block index
489  * @block1: the second plane block index
490  * @page: the page index within the block
491  * @ofs: offset in page to write
492  *
493  * Programs the flash even and odd planes to the specific block and page.
494  * Alternatively, programs the flash to the wear area of the specified page.
495  */
496 static int doc_write_seek(struct docg3 *docg3, int block0, int block1, int page,
497 			 int ofs)
498 {
499 	int ret = 0, sector;
500 
501 	doc_dbg("doc_write_seek(blocks=(%d,%d), page=%d, ofs=%d)\n",
502 		block0, block1, page, ofs);
503 
504 	doc_set_reliable_mode(docg3);
505 
506 	if (ofs < 2 * DOC_LAYOUT_PAGE_SIZE) {
507 		doc_flash_sequence(docg3, DOC_SEQ_SET_PLANE1);
508 		doc_flash_command(docg3, DOC_CMD_READ_PLANE1);
509 		doc_delay(docg3, 2);
510 	} else {
511 		doc_flash_sequence(docg3, DOC_SEQ_SET_PLANE2);
512 		doc_flash_command(docg3, DOC_CMD_READ_PLANE2);
513 		doc_delay(docg3, 2);
514 	}
515 
516 	doc_flash_sequence(docg3, DOC_SEQ_PAGE_SETUP);
517 	doc_flash_command(docg3, DOC_CMD_PROG_CYCLE1);
518 
519 	sector = (block0 << DOC_ADDR_BLOCK_SHIFT) + (page & DOC_ADDR_PAGE_MASK);
520 	doc_setup_writeaddr_sector(docg3, sector, ofs);
521 
522 	doc_flash_command(docg3, DOC_CMD_PROG_CYCLE3);
523 	doc_delay(docg3, 2);
524 	ret = doc_wait_ready(docg3);
525 	if (ret)
526 		goto out;
527 
528 	doc_flash_command(docg3, DOC_CMD_PROG_CYCLE1);
529 	sector = (block1 << DOC_ADDR_BLOCK_SHIFT) + (page & DOC_ADDR_PAGE_MASK);
530 	doc_setup_writeaddr_sector(docg3, sector, ofs);
531 	doc_delay(docg3, 1);
532 
533 out:
534 	return ret;
535 }
536 
537 
538 /**
539  * doc_read_page_ecc_init - Initialize hardware ECC engine
540  * @docg3: the device
541  * @len: the number of bytes covered by the ECC (BCH covered)
542  *
543  * The function does initialize the hardware ECC engine to compute the Hamming
544  * ECC (on 1 byte) and the BCH hardware ECC (on 7 bytes).
545  *
546  * Return 0 if succeeded, -EIO on error
547  */
548 static int doc_read_page_ecc_init(struct docg3 *docg3, int len)
549 {
550 	doc_writew(docg3, DOC_ECCCONF0_READ_MODE
551 		   | DOC_ECCCONF0_BCH_ENABLE | DOC_ECCCONF0_HAMMING_ENABLE
552 		   | (len & DOC_ECCCONF0_DATA_BYTES_MASK),
553 		   DOC_ECCCONF0);
554 	doc_delay(docg3, 4);
555 	doc_register_readb(docg3, DOC_FLASHCONTROL);
556 	return doc_wait_ready(docg3);
557 }
558 
559 /**
560  * doc_write_page_ecc_init - Initialize hardware BCH ECC engine
561  * @docg3: the device
562  * @len: the number of bytes covered by the ECC (BCH covered)
563  *
564  * The function does initialize the hardware ECC engine to compute the Hamming
565  * ECC (on 1 byte) and the BCH hardware ECC (on 7 bytes).
566  *
567  * Return 0 if succeeded, -EIO on error
568  */
569 static int doc_write_page_ecc_init(struct docg3 *docg3, int len)
570 {
571 	doc_writew(docg3, DOC_ECCCONF0_WRITE_MODE
572 		   | DOC_ECCCONF0_BCH_ENABLE | DOC_ECCCONF0_HAMMING_ENABLE
573 		   | (len & DOC_ECCCONF0_DATA_BYTES_MASK),
574 		   DOC_ECCCONF0);
575 	doc_delay(docg3, 4);
576 	doc_register_readb(docg3, DOC_FLASHCONTROL);
577 	return doc_wait_ready(docg3);
578 }
579 
580 /**
581  * doc_ecc_disable - Disable Hamming and BCH ECC hardware calculator
582  * @docg3: the device
583  *
584  * Disables the hardware ECC generator and checker, for unchecked reads (as when
585  * reading OOB only or write status byte).
586  */
587 static void doc_ecc_disable(struct docg3 *docg3)
588 {
589 	doc_writew(docg3, DOC_ECCCONF0_READ_MODE, DOC_ECCCONF0);
590 	doc_delay(docg3, 4);
591 }
592 
593 /**
594  * doc_hamming_ecc_init - Initialize hardware Hamming ECC engine
595  * @docg3: the device
596  * @nb_bytes: the number of bytes covered by the ECC (Hamming covered)
597  *
598  * This function programs the ECC hardware to compute the hamming code on the
599  * last provided N bytes to the hardware generator.
600  */
601 static void doc_hamming_ecc_init(struct docg3 *docg3, int nb_bytes)
602 {
603 	u8 ecc_conf1;
604 
605 	ecc_conf1 = doc_register_readb(docg3, DOC_ECCCONF1);
606 	ecc_conf1 &= ~DOC_ECCCONF1_HAMMING_BITS_MASK;
607 	ecc_conf1 |= (nb_bytes & DOC_ECCCONF1_HAMMING_BITS_MASK);
608 	doc_writeb(docg3, ecc_conf1, DOC_ECCCONF1);
609 }
610 
611 /**
612  * doc_ecc_bch_fix_data - Fix if need be read data from flash
613  * @docg3: the device
614  * @buf: the buffer of read data (512 + 7 + 1 bytes)
615  * @hwecc: the hardware calculated ECC.
616  *         It's in fact recv_ecc ^ calc_ecc, where recv_ecc was read from OOB
617  *         area data, and calc_ecc the ECC calculated by the hardware generator.
618  *
619  * Checks if the received data matches the ECC, and if an error is detected,
620  * tries to fix the bit flips (at most 4) in the buffer buf.  As the docg3
621  * understands the (data, ecc, syndroms) in an inverted order in comparison to
622  * the BCH library, the function reverses the order of bits (ie. bit7 and bit0,
623  * bit6 and bit 1, ...) for all ECC data.
624  *
625  * The hardware ecc unit produces oob_ecc ^ calc_ecc.  The kernel's bch
626  * algorithm is used to decode this.  However the hw operates on page
627  * data in a bit order that is the reverse of that of the bch alg,
628  * requiring that the bits be reversed on the result.  Thanks to Ivan
629  * Djelic for his analysis.
630  *
631  * Returns number of fixed bits (0, 1, 2, 3, 4) or -EBADMSG if too many bit
632  * errors were detected and cannot be fixed.
633  */
634 static int doc_ecc_bch_fix_data(struct docg3 *docg3, void *buf, u8 *hwecc)
635 {
636 	u8 ecc[DOC_ECC_BCH_SIZE];
637 	int errorpos[DOC_ECC_BCH_T], i, numerrs;
638 
639 	for (i = 0; i < DOC_ECC_BCH_SIZE; i++)
640 		ecc[i] = bitrev8(hwecc[i]);
641 	numerrs = decode_bch(docg3->cascade->bch, NULL,
642 			     DOC_ECC_BCH_COVERED_BYTES,
643 			     NULL, ecc, NULL, errorpos);
644 	BUG_ON(numerrs == -EINVAL);
645 	if (numerrs < 0)
646 		goto out;
647 
648 	for (i = 0; i < numerrs; i++)
649 		errorpos[i] = (errorpos[i] & ~7) | (7 - (errorpos[i] & 7));
650 	for (i = 0; i < numerrs; i++)
651 		if (errorpos[i] < DOC_ECC_BCH_COVERED_BYTES*8)
652 			/* error is located in data, correct it */
653 			change_bit(errorpos[i], buf);
654 out:
655 	doc_dbg("doc_ecc_bch_fix_data: flipped %d bits\n", numerrs);
656 	return numerrs;
657 }
658 
659 
660 /**
661  * doc_read_page_prepare - Prepares reading data from a flash page
662  * @docg3: the device
663  * @block0: the first plane block index on flash memory
664  * @block1: the second plane block index on flash memory
665  * @page: the page index in the block
666  * @offset: the offset in the page (must be a multiple of 4)
667  *
668  * Prepares the page to be read in the flash memory :
669  *   - tell ASIC to map the flash pages
670  *   - tell ASIC to be in read mode
671  *
672  * After a call to this method, a call to doc_read_page_finish is mandatory,
673  * to end the read cycle of the flash.
674  *
675  * Read data from a flash page. The length to be read must be between 0 and
676  * (page_size + oob_size + wear_size), ie. 532, and a multiple of 4 (because
677  * the extra bytes reading is not implemented).
678  *
679  * As pages are grouped by 2 (in 2 planes), reading from a page must be done
680  * in two steps:
681  *  - one read of 512 bytes at offset 0
682  *  - one read of 512 bytes at offset 512 + 16
683  *
684  * Returns 0 if successful, -EIO if a read error occurred.
685  */
686 static int doc_read_page_prepare(struct docg3 *docg3, int block0, int block1,
687 				 int page, int offset)
688 {
689 	int wear_area = 0, ret = 0;
690 
691 	doc_dbg("doc_read_page_prepare(blocks=(%d,%d), page=%d, ofsInPage=%d)\n",
692 		block0, block1, page, offset);
693 	if (offset >= DOC_LAYOUT_WEAR_OFFSET)
694 		wear_area = 1;
695 	if (!wear_area && offset > (DOC_LAYOUT_PAGE_OOB_SIZE * 2))
696 		return -EINVAL;
697 
698 	doc_set_device_id(docg3, docg3->device_id);
699 	ret = doc_reset_seq(docg3);
700 	if (ret)
701 		goto err;
702 
703 	/* Program the flash address block and page */
704 	ret = doc_read_seek(docg3, block0, block1, page, wear_area, offset);
705 	if (ret)
706 		goto err;
707 
708 	doc_flash_command(docg3, DOC_CMD_READ_ALL_PLANES);
709 	doc_delay(docg3, 2);
710 	doc_wait_ready(docg3);
711 
712 	doc_flash_command(docg3, DOC_CMD_SET_ADDR_READ);
713 	doc_delay(docg3, 1);
714 	if (offset >= DOC_LAYOUT_PAGE_SIZE * 2)
715 		offset -= 2 * DOC_LAYOUT_PAGE_SIZE;
716 	doc_flash_address(docg3, offset >> 2);
717 	doc_delay(docg3, 1);
718 	doc_wait_ready(docg3);
719 
720 	doc_flash_command(docg3, DOC_CMD_READ_FLASH);
721 
722 	return 0;
723 err:
724 	doc_writeb(docg3, 0, DOC_DATAEND);
725 	doc_delay(docg3, 2);
726 	return -EIO;
727 }
728 
729 /**
730  * doc_read_page_getbytes - Reads bytes from a prepared page
731  * @docg3: the device
732  * @len: the number of bytes to be read (must be a multiple of 4)
733  * @buf: the buffer to be filled in (or NULL is forget bytes)
734  * @first: 1 if first time read, DOC_READADDRESS should be set
735  * @last_odd: 1 if last read ended up on an odd byte
736  *
737  * Reads bytes from a prepared page. There is a trickery here : if the last read
738  * ended up on an odd offset in the 1024 bytes double page, ie. between the 2
739  * planes, the first byte must be read apart. If a word (16bit) read was used,
740  * the read would return the byte of plane 2 as low *and* high endian, which
741  * will mess the read.
742  *
743  */
744 static int doc_read_page_getbytes(struct docg3 *docg3, int len, u_char *buf,
745 				  int first, int last_odd)
746 {
747 	if (last_odd && len > 0) {
748 		doc_read_data_area(docg3, buf, 1, first);
749 		doc_read_data_area(docg3, buf ? buf + 1 : buf, len - 1, 0);
750 	} else {
751 		doc_read_data_area(docg3, buf, len, first);
752 	}
753 	doc_delay(docg3, 2);
754 	return len;
755 }
756 
757 /**
758  * doc_write_page_putbytes - Writes bytes into a prepared page
759  * @docg3: the device
760  * @len: the number of bytes to be written
761  * @buf: the buffer of input bytes
762  *
763  */
764 static void doc_write_page_putbytes(struct docg3 *docg3, int len,
765 				    const u_char *buf)
766 {
767 	doc_write_data_area(docg3, buf, len);
768 	doc_delay(docg3, 2);
769 }
770 
771 /**
772  * doc_get_bch_hw_ecc - Get hardware calculated BCH ECC
773  * @docg3: the device
774  * @hwecc:  the array of 7 integers where the hardware ecc will be stored
775  */
776 static void doc_get_bch_hw_ecc(struct docg3 *docg3, u8 *hwecc)
777 {
778 	int i;
779 
780 	for (i = 0; i < DOC_ECC_BCH_SIZE; i++)
781 		hwecc[i] = doc_register_readb(docg3, DOC_BCH_HW_ECC(i));
782 }
783 
784 /**
785  * doc_page_finish - Ends reading/writing of a flash page
786  * @docg3: the device
787  */
788 static void doc_page_finish(struct docg3 *docg3)
789 {
790 	doc_writeb(docg3, 0, DOC_DATAEND);
791 	doc_delay(docg3, 2);
792 }
793 
794 /**
795  * doc_read_page_finish - Ends reading of a flash page
796  * @docg3: the device
797  *
798  * As a side effect, resets the chip selector to 0. This ensures that after each
799  * read operation, the floor 0 is selected. Therefore, if the systems halts, the
800  * reboot will boot on floor 0, where the IPL is.
801  */
802 static void doc_read_page_finish(struct docg3 *docg3)
803 {
804 	doc_page_finish(docg3);
805 	doc_set_device_id(docg3, 0);
806 }
807 
808 /**
809  * calc_block_sector - Calculate blocks, pages and ofs.
810 
811  * @from: offset in flash
812  * @block0: first plane block index calculated
813  * @block1: second plane block index calculated
814  * @page: page calculated
815  * @ofs: offset in page
816  * @reliable: 0 if docg3 in normal mode, 1 if docg3 in fast mode, 2 if docg3 in
817  * reliable mode.
818  *
819  * The calculation is based on the reliable/normal mode. In normal mode, the 64
820  * pages of a block are available. In reliable mode, as pages 2*n and 2*n+1 are
821  * clones, only 32 pages per block are available.
822  */
823 static void calc_block_sector(loff_t from, int *block0, int *block1, int *page,
824 			      int *ofs, int reliable)
825 {
826 	uint sector, pages_biblock;
827 
828 	pages_biblock = DOC_LAYOUT_PAGES_PER_BLOCK * DOC_LAYOUT_NBPLANES;
829 	if (reliable == 1 || reliable == 2)
830 		pages_biblock /= 2;
831 
832 	sector = from / DOC_LAYOUT_PAGE_SIZE;
833 	*block0 = sector / pages_biblock * DOC_LAYOUT_NBPLANES;
834 	*block1 = *block0 + 1;
835 	*page = sector % pages_biblock;
836 	*page /= DOC_LAYOUT_NBPLANES;
837 	if (reliable == 1 || reliable == 2)
838 		*page *= 2;
839 	if (sector % 2)
840 		*ofs = DOC_LAYOUT_PAGE_OOB_SIZE;
841 	else
842 		*ofs = 0;
843 }
844 
845 /**
846  * doc_read_oob - Read out of band bytes from flash
847  * @mtd: the device
848  * @from: the offset from first block and first page, in bytes, aligned on page
849  *        size
850  * @ops: the mtd oob structure
851  *
852  * Reads flash memory OOB area of pages.
853  *
854  * Returns 0 if read successful, of -EIO, -EINVAL if an error occurred
855  */
856 static int doc_read_oob(struct mtd_info *mtd, loff_t from,
857 			struct mtd_oob_ops *ops)
858 {
859 	struct docg3 *docg3 = mtd->priv;
860 	int block0, block1, page, ret, skip, ofs = 0;
861 	u8 *oobbuf = ops->oobbuf;
862 	u8 *buf = ops->datbuf;
863 	size_t len, ooblen, nbdata, nboob;
864 	u8 hwecc[DOC_ECC_BCH_SIZE], eccconf1;
865 	int max_bitflips = 0;
866 
867 	if (buf)
868 		len = ops->len;
869 	else
870 		len = 0;
871 	if (oobbuf)
872 		ooblen = ops->ooblen;
873 	else
874 		ooblen = 0;
875 
876 	if (oobbuf && ops->mode == MTD_OPS_PLACE_OOB)
877 		oobbuf += ops->ooboffs;
878 
879 	doc_dbg("doc_read_oob(from=%lld, mode=%d, data=(%p:%zu), oob=(%p:%zu))\n",
880 		from, ops->mode, buf, len, oobbuf, ooblen);
881 	if (ooblen % DOC_LAYOUT_OOB_SIZE)
882 		return -EINVAL;
883 
884 	if (from + len > mtd->size)
885 		return -EINVAL;
886 
887 	ops->oobretlen = 0;
888 	ops->retlen = 0;
889 	ret = 0;
890 	skip = from % DOC_LAYOUT_PAGE_SIZE;
891 	mutex_lock(&docg3->cascade->lock);
892 	while (ret >= 0 && (len > 0 || ooblen > 0)) {
893 		calc_block_sector(from - skip, &block0, &block1, &page, &ofs,
894 			docg3->reliable);
895 		nbdata = min_t(size_t, len, DOC_LAYOUT_PAGE_SIZE - skip);
896 		nboob = min_t(size_t, ooblen, (size_t)DOC_LAYOUT_OOB_SIZE);
897 		ret = doc_read_page_prepare(docg3, block0, block1, page, ofs);
898 		if (ret < 0)
899 			goto out;
900 		ret = doc_read_page_ecc_init(docg3, DOC_ECC_BCH_TOTAL_BYTES);
901 		if (ret < 0)
902 			goto err_in_read;
903 		ret = doc_read_page_getbytes(docg3, skip, NULL, 1, 0);
904 		if (ret < skip)
905 			goto err_in_read;
906 		ret = doc_read_page_getbytes(docg3, nbdata, buf, 0, skip % 2);
907 		if (ret < nbdata)
908 			goto err_in_read;
909 		doc_read_page_getbytes(docg3,
910 				       DOC_LAYOUT_PAGE_SIZE - nbdata - skip,
911 				       NULL, 0, (skip + nbdata) % 2);
912 		ret = doc_read_page_getbytes(docg3, nboob, oobbuf, 0, 0);
913 		if (ret < nboob)
914 			goto err_in_read;
915 		doc_read_page_getbytes(docg3, DOC_LAYOUT_OOB_SIZE - nboob,
916 				       NULL, 0, nboob % 2);
917 
918 		doc_get_bch_hw_ecc(docg3, hwecc);
919 		eccconf1 = doc_register_readb(docg3, DOC_ECCCONF1);
920 
921 		if (nboob >= DOC_LAYOUT_OOB_SIZE) {
922 			doc_dbg("OOB - INFO: %*phC\n", 7, oobbuf);
923 			doc_dbg("OOB - HAMMING: %02x\n", oobbuf[7]);
924 			doc_dbg("OOB - BCH_ECC: %*phC\n", 7, oobbuf + 8);
925 			doc_dbg("OOB - UNUSED: %02x\n", oobbuf[15]);
926 		}
927 		doc_dbg("ECC checks: ECCConf1=%x\n", eccconf1);
928 		doc_dbg("ECC HW_ECC: %*phC\n", 7, hwecc);
929 
930 		ret = -EIO;
931 		if (is_prot_seq_error(docg3))
932 			goto err_in_read;
933 		ret = 0;
934 		if ((block0 >= DOC_LAYOUT_BLOCK_FIRST_DATA) &&
935 		    (eccconf1 & DOC_ECCCONF1_BCH_SYNDROM_ERR) &&
936 		    (eccconf1 & DOC_ECCCONF1_PAGE_IS_WRITTEN) &&
937 		    (ops->mode != MTD_OPS_RAW) &&
938 		    (nbdata == DOC_LAYOUT_PAGE_SIZE)) {
939 			ret = doc_ecc_bch_fix_data(docg3, buf, hwecc);
940 			if (ret < 0) {
941 				mtd->ecc_stats.failed++;
942 				ret = -EBADMSG;
943 			}
944 			if (ret > 0) {
945 				mtd->ecc_stats.corrected += ret;
946 				max_bitflips = max(max_bitflips, ret);
947 				ret = max_bitflips;
948 			}
949 		}
950 
951 		doc_read_page_finish(docg3);
952 		ops->retlen += nbdata;
953 		ops->oobretlen += nboob;
954 		buf += nbdata;
955 		oobbuf += nboob;
956 		len -= nbdata;
957 		ooblen -= nboob;
958 		from += DOC_LAYOUT_PAGE_SIZE;
959 		skip = 0;
960 	}
961 
962 out:
963 	mutex_unlock(&docg3->cascade->lock);
964 	return ret;
965 err_in_read:
966 	doc_read_page_finish(docg3);
967 	goto out;
968 }
969 
970 /**
971  * doc_read - Read bytes from flash
972  * @mtd: the device
973  * @from: the offset from first block and first page, in bytes, aligned on page
974  *        size
975  * @len: the number of bytes to read (must be a multiple of 4)
976  * @retlen: the number of bytes actually read
977  * @buf: the filled in buffer
978  *
979  * Reads flash memory pages. This function does not read the OOB chunk, but only
980  * the page data.
981  *
982  * Returns 0 if read successful, of -EIO, -EINVAL if an error occurred
983  */
984 static int doc_read(struct mtd_info *mtd, loff_t from, size_t len,
985 	     size_t *retlen, u_char *buf)
986 {
987 	struct mtd_oob_ops ops;
988 	size_t ret;
989 
990 	memset(&ops, 0, sizeof(ops));
991 	ops.datbuf = buf;
992 	ops.len = len;
993 	ops.mode = MTD_OPS_AUTO_OOB;
994 
995 	ret = doc_read_oob(mtd, from, &ops);
996 	*retlen = ops.retlen;
997 	return ret;
998 }
999 
1000 static int doc_reload_bbt(struct docg3 *docg3)
1001 {
1002 	int block = DOC_LAYOUT_BLOCK_BBT;
1003 	int ret = 0, nbpages, page;
1004 	u_char *buf = docg3->bbt;
1005 
1006 	nbpages = DIV_ROUND_UP(docg3->max_block + 1, 8 * DOC_LAYOUT_PAGE_SIZE);
1007 	for (page = 0; !ret && (page < nbpages); page++) {
1008 		ret = doc_read_page_prepare(docg3, block, block + 1,
1009 					    page + DOC_LAYOUT_PAGE_BBT, 0);
1010 		if (!ret)
1011 			ret = doc_read_page_ecc_init(docg3,
1012 						     DOC_LAYOUT_PAGE_SIZE);
1013 		if (!ret)
1014 			doc_read_page_getbytes(docg3, DOC_LAYOUT_PAGE_SIZE,
1015 					       buf, 1, 0);
1016 		buf += DOC_LAYOUT_PAGE_SIZE;
1017 	}
1018 	doc_read_page_finish(docg3);
1019 	return ret;
1020 }
1021 
1022 /**
1023  * doc_block_isbad - Checks whether a block is good or not
1024  * @mtd: the device
1025  * @from: the offset to find the correct block
1026  *
1027  * Returns 1 if block is bad, 0 if block is good
1028  */
1029 static int doc_block_isbad(struct mtd_info *mtd, loff_t from)
1030 {
1031 	struct docg3 *docg3 = mtd->priv;
1032 	int block0, block1, page, ofs, is_good;
1033 
1034 	calc_block_sector(from, &block0, &block1, &page, &ofs,
1035 		docg3->reliable);
1036 	doc_dbg("doc_block_isbad(from=%lld) => block=(%d,%d), page=%d, ofs=%d\n",
1037 		from, block0, block1, page, ofs);
1038 
1039 	if (block0 < DOC_LAYOUT_BLOCK_FIRST_DATA)
1040 		return 0;
1041 	if (block1 > docg3->max_block)
1042 		return -EINVAL;
1043 
1044 	is_good = docg3->bbt[block0 >> 3] & (1 << (block0 & 0x7));
1045 	return !is_good;
1046 }
1047 
1048 #if 0
1049 /**
1050  * doc_get_erase_count - Get block erase count
1051  * @docg3: the device
1052  * @from: the offset in which the block is.
1053  *
1054  * Get the number of times a block was erased. The number is the maximum of
1055  * erase times between first and second plane (which should be equal normally).
1056  *
1057  * Returns The number of erases, or -EINVAL or -EIO on error.
1058  */
1059 static int doc_get_erase_count(struct docg3 *docg3, loff_t from)
1060 {
1061 	u8 buf[DOC_LAYOUT_WEAR_SIZE];
1062 	int ret, plane1_erase_count, plane2_erase_count;
1063 	int block0, block1, page, ofs;
1064 
1065 	doc_dbg("doc_get_erase_count(from=%lld, buf=%p)\n", from, buf);
1066 	if (from % DOC_LAYOUT_PAGE_SIZE)
1067 		return -EINVAL;
1068 	calc_block_sector(from, &block0, &block1, &page, &ofs, docg3->reliable);
1069 	if (block1 > docg3->max_block)
1070 		return -EINVAL;
1071 
1072 	ret = doc_reset_seq(docg3);
1073 	if (!ret)
1074 		ret = doc_read_page_prepare(docg3, block0, block1, page,
1075 					    ofs + DOC_LAYOUT_WEAR_OFFSET, 0);
1076 	if (!ret)
1077 		ret = doc_read_page_getbytes(docg3, DOC_LAYOUT_WEAR_SIZE,
1078 					     buf, 1, 0);
1079 	doc_read_page_finish(docg3);
1080 
1081 	if (ret || (buf[0] != DOC_ERASE_MARK) || (buf[2] != DOC_ERASE_MARK))
1082 		return -EIO;
1083 	plane1_erase_count = (u8)(~buf[1]) | ((u8)(~buf[4]) << 8)
1084 		| ((u8)(~buf[5]) << 16);
1085 	plane2_erase_count = (u8)(~buf[3]) | ((u8)(~buf[6]) << 8)
1086 		| ((u8)(~buf[7]) << 16);
1087 
1088 	return max(plane1_erase_count, plane2_erase_count);
1089 }
1090 #endif
1091 
1092 /**
1093  * doc_get_op_status - get erase/write operation status
1094  * @docg3: the device
1095  *
1096  * Queries the status from the chip, and returns it
1097  *
1098  * Returns the status (bits DOC_PLANES_STATUS_*)
1099  */
1100 static int doc_get_op_status(struct docg3 *docg3)
1101 {
1102 	u8 status;
1103 
1104 	doc_flash_sequence(docg3, DOC_SEQ_PLANES_STATUS);
1105 	doc_flash_command(docg3, DOC_CMD_PLANES_STATUS);
1106 	doc_delay(docg3, 5);
1107 
1108 	doc_ecc_disable(docg3);
1109 	doc_read_data_area(docg3, &status, 1, 1);
1110 	return status;
1111 }
1112 
1113 /**
1114  * doc_write_erase_wait_status - wait for write or erase completion
1115  * @docg3: the device
1116  *
1117  * Wait for the chip to be ready again after erase or write operation, and check
1118  * erase/write status.
1119  *
1120  * Returns 0 if erase successful, -EIO if erase/write issue, -ETIMEOUT if
1121  * timeout
1122  */
1123 static int doc_write_erase_wait_status(struct docg3 *docg3)
1124 {
1125 	int i, status, ret = 0;
1126 
1127 	for (i = 0; !doc_is_ready(docg3) && i < 5; i++)
1128 		msleep(20);
1129 	if (!doc_is_ready(docg3)) {
1130 		doc_dbg("Timeout reached and the chip is still not ready\n");
1131 		ret = -EAGAIN;
1132 		goto out;
1133 	}
1134 
1135 	status = doc_get_op_status(docg3);
1136 	if (status & DOC_PLANES_STATUS_FAIL) {
1137 		doc_dbg("Erase/Write failed on (a) plane(s), status = %x\n",
1138 			status);
1139 		ret = -EIO;
1140 	}
1141 
1142 out:
1143 	doc_page_finish(docg3);
1144 	return ret;
1145 }
1146 
1147 /**
1148  * doc_erase_block - Erase a couple of blocks
1149  * @docg3: the device
1150  * @block0: the first block to erase (leftmost plane)
1151  * @block1: the second block to erase (rightmost plane)
1152  *
1153  * Erase both blocks, and return operation status
1154  *
1155  * Returns 0 if erase successful, -EIO if erase issue, -ETIMEOUT if chip not
1156  * ready for too long
1157  */
1158 static int doc_erase_block(struct docg3 *docg3, int block0, int block1)
1159 {
1160 	int ret, sector;
1161 
1162 	doc_dbg("doc_erase_block(blocks=(%d,%d))\n", block0, block1);
1163 	ret = doc_reset_seq(docg3);
1164 	if (ret)
1165 		return -EIO;
1166 
1167 	doc_set_reliable_mode(docg3);
1168 	doc_flash_sequence(docg3, DOC_SEQ_ERASE);
1169 
1170 	sector = block0 << DOC_ADDR_BLOCK_SHIFT;
1171 	doc_flash_command(docg3, DOC_CMD_PROG_BLOCK_ADDR);
1172 	doc_setup_addr_sector(docg3, sector);
1173 	sector = block1 << DOC_ADDR_BLOCK_SHIFT;
1174 	doc_flash_command(docg3, DOC_CMD_PROG_BLOCK_ADDR);
1175 	doc_setup_addr_sector(docg3, sector);
1176 	doc_delay(docg3, 1);
1177 
1178 	doc_flash_command(docg3, DOC_CMD_ERASECYCLE2);
1179 	doc_delay(docg3, 2);
1180 
1181 	if (is_prot_seq_error(docg3)) {
1182 		doc_err("Erase blocks %d,%d error\n", block0, block1);
1183 		return -EIO;
1184 	}
1185 
1186 	return doc_write_erase_wait_status(docg3);
1187 }
1188 
1189 /**
1190  * doc_erase - Erase a portion of the chip
1191  * @mtd: the device
1192  * @info: the erase info
1193  *
1194  * Erase a bunch of contiguous blocks, by pairs, as a "mtd" page of 1024 is
1195  * split into 2 pages of 512 bytes on 2 contiguous blocks.
1196  *
1197  * Returns 0 if erase successful, -EINVAL if addressing error, -EIO if erase
1198  * issue
1199  */
1200 static int doc_erase(struct mtd_info *mtd, struct erase_info *info)
1201 {
1202 	struct docg3 *docg3 = mtd->priv;
1203 	uint64_t len;
1204 	int block0, block1, page, ret, ofs = 0;
1205 
1206 	doc_dbg("doc_erase(from=%lld, len=%lld\n", info->addr, info->len);
1207 
1208 	info->state = MTD_ERASE_PENDING;
1209 	calc_block_sector(info->addr + info->len, &block0, &block1, &page,
1210 			  &ofs, docg3->reliable);
1211 	ret = -EINVAL;
1212 	if (info->addr + info->len > mtd->size || page || ofs)
1213 		goto reset_err;
1214 
1215 	ret = 0;
1216 	calc_block_sector(info->addr, &block0, &block1, &page, &ofs,
1217 			  docg3->reliable);
1218 	mutex_lock(&docg3->cascade->lock);
1219 	doc_set_device_id(docg3, docg3->device_id);
1220 	doc_set_reliable_mode(docg3);
1221 	for (len = info->len; !ret && len > 0; len -= mtd->erasesize) {
1222 		info->state = MTD_ERASING;
1223 		ret = doc_erase_block(docg3, block0, block1);
1224 		block0 += 2;
1225 		block1 += 2;
1226 	}
1227 	mutex_unlock(&docg3->cascade->lock);
1228 
1229 	if (ret)
1230 		goto reset_err;
1231 
1232 	info->state = MTD_ERASE_DONE;
1233 	return 0;
1234 
1235 reset_err:
1236 	info->state = MTD_ERASE_FAILED;
1237 	return ret;
1238 }
1239 
1240 /**
1241  * doc_write_page - Write a single page to the chip
1242  * @docg3: the device
1243  * @to: the offset from first block and first page, in bytes, aligned on page
1244  *      size
1245  * @buf: buffer to get bytes from
1246  * @oob: buffer to get out of band bytes from (can be NULL if no OOB should be
1247  *       written)
1248  * @autoecc: if 0, all 16 bytes from OOB are taken, regardless of HW Hamming or
1249  *           BCH computations. If 1, only bytes 0-7 and byte 15 are taken,
1250  *           remaining ones are filled with hardware Hamming and BCH
1251  *           computations. Its value is not meaningfull is oob == NULL.
1252  *
1253  * Write one full page (ie. 1 page split on two planes), of 512 bytes, with the
1254  * OOB data. The OOB ECC is automatically computed by the hardware Hamming and
1255  * BCH generator if autoecc is not null.
1256  *
1257  * Returns 0 if write successful, -EIO if write error, -EAGAIN if timeout
1258  */
1259 static int doc_write_page(struct docg3 *docg3, loff_t to, const u_char *buf,
1260 			  const u_char *oob, int autoecc)
1261 {
1262 	int block0, block1, page, ret, ofs = 0;
1263 	u8 hwecc[DOC_ECC_BCH_SIZE], hamming;
1264 
1265 	doc_dbg("doc_write_page(to=%lld)\n", to);
1266 	calc_block_sector(to, &block0, &block1, &page, &ofs, docg3->reliable);
1267 
1268 	doc_set_device_id(docg3, docg3->device_id);
1269 	ret = doc_reset_seq(docg3);
1270 	if (ret)
1271 		goto err;
1272 
1273 	/* Program the flash address block and page */
1274 	ret = doc_write_seek(docg3, block0, block1, page, ofs);
1275 	if (ret)
1276 		goto err;
1277 
1278 	doc_write_page_ecc_init(docg3, DOC_ECC_BCH_TOTAL_BYTES);
1279 	doc_delay(docg3, 2);
1280 	doc_write_page_putbytes(docg3, DOC_LAYOUT_PAGE_SIZE, buf);
1281 
1282 	if (oob && autoecc) {
1283 		doc_write_page_putbytes(docg3, DOC_LAYOUT_OOB_PAGEINFO_SZ, oob);
1284 		doc_delay(docg3, 2);
1285 		oob += DOC_LAYOUT_OOB_UNUSED_OFS;
1286 
1287 		hamming = doc_register_readb(docg3, DOC_HAMMINGPARITY);
1288 		doc_delay(docg3, 2);
1289 		doc_write_page_putbytes(docg3, DOC_LAYOUT_OOB_HAMMING_SZ,
1290 					&hamming);
1291 		doc_delay(docg3, 2);
1292 
1293 		doc_get_bch_hw_ecc(docg3, hwecc);
1294 		doc_write_page_putbytes(docg3, DOC_LAYOUT_OOB_BCH_SZ, hwecc);
1295 		doc_delay(docg3, 2);
1296 
1297 		doc_write_page_putbytes(docg3, DOC_LAYOUT_OOB_UNUSED_SZ, oob);
1298 	}
1299 	if (oob && !autoecc)
1300 		doc_write_page_putbytes(docg3, DOC_LAYOUT_OOB_SIZE, oob);
1301 
1302 	doc_delay(docg3, 2);
1303 	doc_page_finish(docg3);
1304 	doc_delay(docg3, 2);
1305 	doc_flash_command(docg3, DOC_CMD_PROG_CYCLE2);
1306 	doc_delay(docg3, 2);
1307 
1308 	/*
1309 	 * The wait status will perform another doc_page_finish() call, but that
1310 	 * seems to please the docg3, so leave it.
1311 	 */
1312 	ret = doc_write_erase_wait_status(docg3);
1313 	return ret;
1314 err:
1315 	doc_read_page_finish(docg3);
1316 	return ret;
1317 }
1318 
1319 /**
1320  * doc_guess_autoecc - Guess autoecc mode from mbd_oob_ops
1321  * @ops: the oob operations
1322  *
1323  * Returns 0 or 1 if success, -EINVAL if invalid oob mode
1324  */
1325 static int doc_guess_autoecc(struct mtd_oob_ops *ops)
1326 {
1327 	int autoecc;
1328 
1329 	switch (ops->mode) {
1330 	case MTD_OPS_PLACE_OOB:
1331 	case MTD_OPS_AUTO_OOB:
1332 		autoecc = 1;
1333 		break;
1334 	case MTD_OPS_RAW:
1335 		autoecc = 0;
1336 		break;
1337 	default:
1338 		autoecc = -EINVAL;
1339 	}
1340 	return autoecc;
1341 }
1342 
1343 /**
1344  * doc_fill_autooob - Fill a 16 bytes OOB from 8 non-ECC bytes
1345  * @dst: the target 16 bytes OOB buffer
1346  * @oobsrc: the source 8 bytes non-ECC OOB buffer
1347  *
1348  */
1349 static void doc_fill_autooob(u8 *dst, u8 *oobsrc)
1350 {
1351 	memcpy(dst, oobsrc, DOC_LAYOUT_OOB_PAGEINFO_SZ);
1352 	dst[DOC_LAYOUT_OOB_UNUSED_OFS] = oobsrc[DOC_LAYOUT_OOB_PAGEINFO_SZ];
1353 }
1354 
1355 /**
1356  * doc_backup_oob - Backup OOB into docg3 structure
1357  * @docg3: the device
1358  * @to: the page offset in the chip
1359  * @ops: the OOB size and buffer
1360  *
1361  * As the docg3 should write a page with its OOB in one pass, and some userland
1362  * applications do write_oob() to setup the OOB and then write(), store the OOB
1363  * into a temporary storage. This is very dangerous, as 2 concurrent
1364  * applications could store an OOB, and then write their pages (which will
1365  * result into one having its OOB corrupted).
1366  *
1367  * The only reliable way would be for userland to call doc_write_oob() with both
1368  * the page data _and_ the OOB area.
1369  *
1370  * Returns 0 if success, -EINVAL if ops content invalid
1371  */
1372 static int doc_backup_oob(struct docg3 *docg3, loff_t to,
1373 			  struct mtd_oob_ops *ops)
1374 {
1375 	int ooblen = ops->ooblen, autoecc;
1376 
1377 	if (ooblen != DOC_LAYOUT_OOB_SIZE)
1378 		return -EINVAL;
1379 	autoecc = doc_guess_autoecc(ops);
1380 	if (autoecc < 0)
1381 		return autoecc;
1382 
1383 	docg3->oob_write_ofs = to;
1384 	docg3->oob_autoecc = autoecc;
1385 	if (ops->mode == MTD_OPS_AUTO_OOB) {
1386 		doc_fill_autooob(docg3->oob_write_buf, ops->oobbuf);
1387 		ops->oobretlen = 8;
1388 	} else {
1389 		memcpy(docg3->oob_write_buf, ops->oobbuf, DOC_LAYOUT_OOB_SIZE);
1390 		ops->oobretlen = DOC_LAYOUT_OOB_SIZE;
1391 	}
1392 	return 0;
1393 }
1394 
1395 /**
1396  * doc_write_oob - Write out of band bytes to flash
1397  * @mtd: the device
1398  * @ofs: the offset from first block and first page, in bytes, aligned on page
1399  *       size
1400  * @ops: the mtd oob structure
1401  *
1402  * Either write OOB data into a temporary buffer, for the subsequent write
1403  * page. The provided OOB should be 16 bytes long. If a data buffer is provided
1404  * as well, issue the page write.
1405  * Or provide data without OOB, and then a all zeroed OOB will be used (ECC will
1406  * still be filled in if asked for).
1407  *
1408  * Returns 0 is successful, EINVAL if length is not 14 bytes
1409  */
1410 static int doc_write_oob(struct mtd_info *mtd, loff_t ofs,
1411 			 struct mtd_oob_ops *ops)
1412 {
1413 	struct docg3 *docg3 = mtd->priv;
1414 	int ret, autoecc, oobdelta;
1415 	u8 *oobbuf = ops->oobbuf;
1416 	u8 *buf = ops->datbuf;
1417 	size_t len, ooblen;
1418 	u8 oob[DOC_LAYOUT_OOB_SIZE];
1419 
1420 	if (buf)
1421 		len = ops->len;
1422 	else
1423 		len = 0;
1424 	if (oobbuf)
1425 		ooblen = ops->ooblen;
1426 	else
1427 		ooblen = 0;
1428 
1429 	if (oobbuf && ops->mode == MTD_OPS_PLACE_OOB)
1430 		oobbuf += ops->ooboffs;
1431 
1432 	doc_dbg("doc_write_oob(from=%lld, mode=%d, data=(%p:%zu), oob=(%p:%zu))\n",
1433 		ofs, ops->mode, buf, len, oobbuf, ooblen);
1434 	switch (ops->mode) {
1435 	case MTD_OPS_PLACE_OOB:
1436 	case MTD_OPS_RAW:
1437 		oobdelta = mtd->oobsize;
1438 		break;
1439 	case MTD_OPS_AUTO_OOB:
1440 		oobdelta = mtd->ecclayout->oobavail;
1441 		break;
1442 	default:
1443 		return -EINVAL;
1444 	}
1445 	if ((len % DOC_LAYOUT_PAGE_SIZE) || (ooblen % oobdelta) ||
1446 	    (ofs % DOC_LAYOUT_PAGE_SIZE))
1447 		return -EINVAL;
1448 	if (len && ooblen &&
1449 	    (len / DOC_LAYOUT_PAGE_SIZE) != (ooblen / oobdelta))
1450 		return -EINVAL;
1451 	if (ofs + len > mtd->size)
1452 		return -EINVAL;
1453 
1454 	ops->oobretlen = 0;
1455 	ops->retlen = 0;
1456 	ret = 0;
1457 	if (len == 0 && ooblen == 0)
1458 		return -EINVAL;
1459 	if (len == 0 && ooblen > 0)
1460 		return doc_backup_oob(docg3, ofs, ops);
1461 
1462 	autoecc = doc_guess_autoecc(ops);
1463 	if (autoecc < 0)
1464 		return autoecc;
1465 
1466 	mutex_lock(&docg3->cascade->lock);
1467 	while (!ret && len > 0) {
1468 		memset(oob, 0, sizeof(oob));
1469 		if (ofs == docg3->oob_write_ofs)
1470 			memcpy(oob, docg3->oob_write_buf, DOC_LAYOUT_OOB_SIZE);
1471 		else if (ooblen > 0 && ops->mode == MTD_OPS_AUTO_OOB)
1472 			doc_fill_autooob(oob, oobbuf);
1473 		else if (ooblen > 0)
1474 			memcpy(oob, oobbuf, DOC_LAYOUT_OOB_SIZE);
1475 		ret = doc_write_page(docg3, ofs, buf, oob, autoecc);
1476 
1477 		ofs += DOC_LAYOUT_PAGE_SIZE;
1478 		len -= DOC_LAYOUT_PAGE_SIZE;
1479 		buf += DOC_LAYOUT_PAGE_SIZE;
1480 		if (ooblen) {
1481 			oobbuf += oobdelta;
1482 			ooblen -= oobdelta;
1483 			ops->oobretlen += oobdelta;
1484 		}
1485 		ops->retlen += DOC_LAYOUT_PAGE_SIZE;
1486 	}
1487 
1488 	doc_set_device_id(docg3, 0);
1489 	mutex_unlock(&docg3->cascade->lock);
1490 	return ret;
1491 }
1492 
1493 /**
1494  * doc_write - Write a buffer to the chip
1495  * @mtd: the device
1496  * @to: the offset from first block and first page, in bytes, aligned on page
1497  *      size
1498  * @len: the number of bytes to write (must be a full page size, ie. 512)
1499  * @retlen: the number of bytes actually written (0 or 512)
1500  * @buf: the buffer to get bytes from
1501  *
1502  * Writes data to the chip.
1503  *
1504  * Returns 0 if write successful, -EIO if write error
1505  */
1506 static int doc_write(struct mtd_info *mtd, loff_t to, size_t len,
1507 		     size_t *retlen, const u_char *buf)
1508 {
1509 	struct docg3 *docg3 = mtd->priv;
1510 	int ret;
1511 	struct mtd_oob_ops ops;
1512 
1513 	doc_dbg("doc_write(to=%lld, len=%zu)\n", to, len);
1514 	ops.datbuf = (char *)buf;
1515 	ops.len = len;
1516 	ops.mode = MTD_OPS_PLACE_OOB;
1517 	ops.oobbuf = NULL;
1518 	ops.ooblen = 0;
1519 	ops.ooboffs = 0;
1520 
1521 	ret = doc_write_oob(mtd, to, &ops);
1522 	*retlen = ops.retlen;
1523 	return ret;
1524 }
1525 
1526 static struct docg3 *sysfs_dev2docg3(struct device *dev,
1527 				     struct device_attribute *attr)
1528 {
1529 	int floor;
1530 	struct platform_device *pdev = to_platform_device(dev);
1531 	struct mtd_info **docg3_floors = platform_get_drvdata(pdev);
1532 
1533 	floor = attr->attr.name[1] - '0';
1534 	if (floor < 0 || floor >= DOC_MAX_NBFLOORS)
1535 		return NULL;
1536 	else
1537 		return docg3_floors[floor]->priv;
1538 }
1539 
1540 static ssize_t dps0_is_key_locked(struct device *dev,
1541 				  struct device_attribute *attr, char *buf)
1542 {
1543 	struct docg3 *docg3 = sysfs_dev2docg3(dev, attr);
1544 	int dps0;
1545 
1546 	mutex_lock(&docg3->cascade->lock);
1547 	doc_set_device_id(docg3, docg3->device_id);
1548 	dps0 = doc_register_readb(docg3, DOC_DPS0_STATUS);
1549 	doc_set_device_id(docg3, 0);
1550 	mutex_unlock(&docg3->cascade->lock);
1551 
1552 	return sprintf(buf, "%d\n", !(dps0 & DOC_DPS_KEY_OK));
1553 }
1554 
1555 static ssize_t dps1_is_key_locked(struct device *dev,
1556 				  struct device_attribute *attr, char *buf)
1557 {
1558 	struct docg3 *docg3 = sysfs_dev2docg3(dev, attr);
1559 	int dps1;
1560 
1561 	mutex_lock(&docg3->cascade->lock);
1562 	doc_set_device_id(docg3, docg3->device_id);
1563 	dps1 = doc_register_readb(docg3, DOC_DPS1_STATUS);
1564 	doc_set_device_id(docg3, 0);
1565 	mutex_unlock(&docg3->cascade->lock);
1566 
1567 	return sprintf(buf, "%d\n", !(dps1 & DOC_DPS_KEY_OK));
1568 }
1569 
1570 static ssize_t dps0_insert_key(struct device *dev,
1571 			       struct device_attribute *attr,
1572 			       const char *buf, size_t count)
1573 {
1574 	struct docg3 *docg3 = sysfs_dev2docg3(dev, attr);
1575 	int i;
1576 
1577 	if (count != DOC_LAYOUT_DPS_KEY_LENGTH)
1578 		return -EINVAL;
1579 
1580 	mutex_lock(&docg3->cascade->lock);
1581 	doc_set_device_id(docg3, docg3->device_id);
1582 	for (i = 0; i < DOC_LAYOUT_DPS_KEY_LENGTH; i++)
1583 		doc_writeb(docg3, buf[i], DOC_DPS0_KEY);
1584 	doc_set_device_id(docg3, 0);
1585 	mutex_unlock(&docg3->cascade->lock);
1586 	return count;
1587 }
1588 
1589 static ssize_t dps1_insert_key(struct device *dev,
1590 			       struct device_attribute *attr,
1591 			       const char *buf, size_t count)
1592 {
1593 	struct docg3 *docg3 = sysfs_dev2docg3(dev, attr);
1594 	int i;
1595 
1596 	if (count != DOC_LAYOUT_DPS_KEY_LENGTH)
1597 		return -EINVAL;
1598 
1599 	mutex_lock(&docg3->cascade->lock);
1600 	doc_set_device_id(docg3, docg3->device_id);
1601 	for (i = 0; i < DOC_LAYOUT_DPS_KEY_LENGTH; i++)
1602 		doc_writeb(docg3, buf[i], DOC_DPS1_KEY);
1603 	doc_set_device_id(docg3, 0);
1604 	mutex_unlock(&docg3->cascade->lock);
1605 	return count;
1606 }
1607 
1608 #define FLOOR_SYSFS(id) { \
1609 	__ATTR(f##id##_dps0_is_keylocked, S_IRUGO, dps0_is_key_locked, NULL), \
1610 	__ATTR(f##id##_dps1_is_keylocked, S_IRUGO, dps1_is_key_locked, NULL), \
1611 	__ATTR(f##id##_dps0_protection_key, S_IWUSR|S_IWGRP, NULL, dps0_insert_key), \
1612 	__ATTR(f##id##_dps1_protection_key, S_IWUSR|S_IWGRP, NULL, dps1_insert_key), \
1613 }
1614 
1615 static struct device_attribute doc_sys_attrs[DOC_MAX_NBFLOORS][4] = {
1616 	FLOOR_SYSFS(0), FLOOR_SYSFS(1), FLOOR_SYSFS(2), FLOOR_SYSFS(3)
1617 };
1618 
1619 static int doc_register_sysfs(struct platform_device *pdev,
1620 			      struct docg3_cascade *cascade)
1621 {
1622 	int ret = 0, floor, i = 0;
1623 	struct device *dev = &pdev->dev;
1624 
1625 	for (floor = 0; !ret && floor < DOC_MAX_NBFLOORS &&
1626 		     cascade->floors[floor]; floor++)
1627 		for (i = 0; !ret && i < 4; i++)
1628 			ret = device_create_file(dev, &doc_sys_attrs[floor][i]);
1629 	if (!ret)
1630 		return 0;
1631 	do {
1632 		while (--i >= 0)
1633 			device_remove_file(dev, &doc_sys_attrs[floor][i]);
1634 		i = 4;
1635 	} while (--floor >= 0);
1636 	return ret;
1637 }
1638 
1639 static void doc_unregister_sysfs(struct platform_device *pdev,
1640 				 struct docg3_cascade *cascade)
1641 {
1642 	struct device *dev = &pdev->dev;
1643 	int floor, i;
1644 
1645 	for (floor = 0; floor < DOC_MAX_NBFLOORS && cascade->floors[floor];
1646 	     floor++)
1647 		for (i = 0; i < 4; i++)
1648 			device_remove_file(dev, &doc_sys_attrs[floor][i]);
1649 }
1650 
1651 /*
1652  * Debug sysfs entries
1653  */
1654 static int dbg_flashctrl_show(struct seq_file *s, void *p)
1655 {
1656 	struct docg3 *docg3 = (struct docg3 *)s->private;
1657 
1658 	int pos = 0;
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 	pos += seq_printf(s,
1666 		 "FlashControl : 0x%02x (%s,CE# %s,%s,%s,flash %s)\n",
1667 		 fctrl,
1668 		 fctrl & DOC_CTRL_VIOLATION ? "protocol violation" : "-",
1669 		 fctrl & DOC_CTRL_CE ? "active" : "inactive",
1670 		 fctrl & DOC_CTRL_PROTECTION_ERROR ? "protection error" : "-",
1671 		 fctrl & DOC_CTRL_SEQUENCE_ERROR ? "sequence error" : "-",
1672 		 fctrl & DOC_CTRL_FLASHREADY ? "ready" : "not ready");
1673 	return pos;
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 pos = 0, 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 	pos += 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 		pos += seq_puts(s, "reset");
1701 		break;
1702 	case DOC_ASICMODE_NORMAL:
1703 		pos += seq_puts(s, "normal");
1704 		break;
1705 	case DOC_ASICMODE_POWERDOWN:
1706 		pos += seq_puts(s, "powerdown");
1707 		break;
1708 	}
1709 	pos += seq_puts(s, ")\n");
1710 	return pos;
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 pos = 0;
1718 	int id;
1719 
1720 	mutex_lock(&docg3->cascade->lock);
1721 	id = doc_register_readb(docg3, DOC_DEVICESELECT);
1722 	mutex_unlock(&docg3->cascade->lock);
1723 
1724 	pos += seq_printf(s, "DeviceId = %d\n", id);
1725 	return pos;
1726 }
1727 DEBUGFS_RO_ATTR(device_id, dbg_device_id_show);
1728 
1729 static int dbg_protection_show(struct seq_file *s, void *p)
1730 {
1731 	struct docg3 *docg3 = (struct docg3 *)s->private;
1732 	int pos = 0;
1733 	int protect, dps0, dps0_low, dps0_high, dps1, dps1_low, dps1_high;
1734 
1735 	mutex_lock(&docg3->cascade->lock);
1736 	protect = doc_register_readb(docg3, DOC_PROTECTION);
1737 	dps0 = doc_register_readb(docg3, DOC_DPS0_STATUS);
1738 	dps0_low = doc_register_readw(docg3, DOC_DPS0_ADDRLOW);
1739 	dps0_high = doc_register_readw(docg3, DOC_DPS0_ADDRHIGH);
1740 	dps1 = doc_register_readb(docg3, DOC_DPS1_STATUS);
1741 	dps1_low = doc_register_readw(docg3, DOC_DPS1_ADDRLOW);
1742 	dps1_high = doc_register_readw(docg3, DOC_DPS1_ADDRHIGH);
1743 	mutex_unlock(&docg3->cascade->lock);
1744 
1745 	pos += seq_printf(s, "Protection = 0x%02x (",
1746 			 protect);
1747 	if (protect & DOC_PROTECT_FOUNDRY_OTP_LOCK)
1748 		pos += seq_puts(s, "FOUNDRY_OTP_LOCK,");
1749 	if (protect & DOC_PROTECT_CUSTOMER_OTP_LOCK)
1750 		pos += seq_puts(s, "CUSTOMER_OTP_LOCK,");
1751 	if (protect & DOC_PROTECT_LOCK_INPUT)
1752 		pos += seq_puts(s, "LOCK_INPUT,");
1753 	if (protect & DOC_PROTECT_STICKY_LOCK)
1754 		pos += seq_puts(s, "STICKY_LOCK,");
1755 	if (protect & DOC_PROTECT_PROTECTION_ENABLED)
1756 		pos += seq_puts(s, "PROTECTION ON,");
1757 	if (protect & DOC_PROTECT_IPL_DOWNLOAD_LOCK)
1758 		pos += seq_puts(s, "IPL_DOWNLOAD_LOCK,");
1759 	if (protect & DOC_PROTECT_PROTECTION_ERROR)
1760 		pos += seq_puts(s, "PROTECT_ERR,");
1761 	else
1762 		pos += seq_puts(s, "NO_PROTECT_ERR");
1763 	pos += seq_puts(s, ")\n");
1764 
1765 	pos += seq_printf(s, "DPS0 = 0x%02x : "
1766 			 "Protected area [0x%x - 0x%x] : OTP=%d, READ=%d, "
1767 			 "WRITE=%d, HW_LOCK=%d, KEY_OK=%d\n",
1768 			 dps0, dps0_low, dps0_high,
1769 			 !!(dps0 & DOC_DPS_OTP_PROTECTED),
1770 			 !!(dps0 & DOC_DPS_READ_PROTECTED),
1771 			 !!(dps0 & DOC_DPS_WRITE_PROTECTED),
1772 			 !!(dps0 & DOC_DPS_HW_LOCK_ENABLED),
1773 			 !!(dps0 & DOC_DPS_KEY_OK));
1774 	pos += seq_printf(s, "DPS1 = 0x%02x : "
1775 			 "Protected area [0x%x - 0x%x] : OTP=%d, READ=%d, "
1776 			 "WRITE=%d, HW_LOCK=%d, KEY_OK=%d\n",
1777 			 dps1, dps1_low, dps1_high,
1778 			 !!(dps1 & DOC_DPS_OTP_PROTECTED),
1779 			 !!(dps1 & DOC_DPS_READ_PROTECTED),
1780 			 !!(dps1 & DOC_DPS_WRITE_PROTECTED),
1781 			 !!(dps1 & DOC_DPS_HW_LOCK_ENABLED),
1782 			 !!(dps1 & DOC_DPS_KEY_OK));
1783 	return pos;
1784 }
1785 DEBUGFS_RO_ATTR(protection, dbg_protection_show);
1786 
1787 static int __init doc_dbg_register(struct docg3 *docg3)
1788 {
1789 	struct dentry *root, *entry;
1790 
1791 	root = debugfs_create_dir("docg3", NULL);
1792 	if (!root)
1793 		return -ENOMEM;
1794 
1795 	entry = debugfs_create_file("flashcontrol", S_IRUSR, root, docg3,
1796 				  &flashcontrol_fops);
1797 	if (entry)
1798 		entry = debugfs_create_file("asic_mode", S_IRUSR, root,
1799 					    docg3, &asic_mode_fops);
1800 	if (entry)
1801 		entry = debugfs_create_file("device_id", S_IRUSR, root,
1802 					    docg3, &device_id_fops);
1803 	if (entry)
1804 		entry = debugfs_create_file("protection", S_IRUSR, root,
1805 					    docg3, &protection_fops);
1806 	if (entry) {
1807 		docg3->debugfs_root = root;
1808 		return 0;
1809 	} else {
1810 		debugfs_remove_recursive(root);
1811 		return -ENOMEM;
1812 	}
1813 }
1814 
1815 static void __exit doc_dbg_unregister(struct docg3 *docg3)
1816 {
1817 	debugfs_remove_recursive(docg3->debugfs_root);
1818 }
1819 
1820 /**
1821  * doc_set_driver_info - Fill the mtd_info structure and docg3 structure
1822  * @chip_id: The chip ID of the supported chip
1823  * @mtd: The structure to fill
1824  */
1825 static void __init doc_set_driver_info(int chip_id, struct mtd_info *mtd)
1826 {
1827 	struct docg3 *docg3 = mtd->priv;
1828 	int cfg;
1829 
1830 	cfg = doc_register_readb(docg3, DOC_CONFIGURATION);
1831 	docg3->if_cfg = (cfg & DOC_CONF_IF_CFG ? 1 : 0);
1832 	docg3->reliable = reliable_mode;
1833 
1834 	switch (chip_id) {
1835 	case DOC_CHIPID_G3:
1836 		mtd->name = kasprintf(GFP_KERNEL, "docg3.%d",
1837 				      docg3->device_id);
1838 		docg3->max_block = 2047;
1839 		break;
1840 	}
1841 	mtd->type = MTD_NANDFLASH;
1842 	mtd->flags = MTD_CAP_NANDFLASH;
1843 	mtd->size = (docg3->max_block + 1) * DOC_LAYOUT_BLOCK_SIZE;
1844 	if (docg3->reliable == 2)
1845 		mtd->size /= 2;
1846 	mtd->erasesize = DOC_LAYOUT_BLOCK_SIZE * DOC_LAYOUT_NBPLANES;
1847 	if (docg3->reliable == 2)
1848 		mtd->erasesize /= 2;
1849 	mtd->writebufsize = mtd->writesize = DOC_LAYOUT_PAGE_SIZE;
1850 	mtd->oobsize = DOC_LAYOUT_OOB_SIZE;
1851 	mtd->owner = THIS_MODULE;
1852 	mtd->_erase = doc_erase;
1853 	mtd->_read = doc_read;
1854 	mtd->_write = doc_write;
1855 	mtd->_read_oob = doc_read_oob;
1856 	mtd->_write_oob = doc_write_oob;
1857 	mtd->_block_isbad = doc_block_isbad;
1858 	mtd->ecclayout = &docg3_oobinfo;
1859 	mtd->ecc_strength = DOC_ECC_BCH_T;
1860 }
1861 
1862 /**
1863  * doc_probe_device - Check if a device is available
1864  * @base: the io space where the device is probed
1865  * @floor: the floor of the probed device
1866  * @dev: the device
1867  * @cascade: the cascade of chips this devices will belong to
1868  *
1869  * Checks whether a device at the specified IO range, and floor is available.
1870  *
1871  * Returns a mtd_info struct if there is a device, ENODEV if none found, ENOMEM
1872  * if a memory allocation failed. If floor 0 is checked, a reset of the ASIC is
1873  * launched.
1874  */
1875 static struct mtd_info * __init
1876 doc_probe_device(struct docg3_cascade *cascade, int floor, struct device *dev)
1877 {
1878 	int ret, bbt_nbpages;
1879 	u16 chip_id, chip_id_inv;
1880 	struct docg3 *docg3;
1881 	struct mtd_info *mtd;
1882 
1883 	ret = -ENOMEM;
1884 	docg3 = kzalloc(sizeof(struct docg3), GFP_KERNEL);
1885 	if (!docg3)
1886 		goto nomem1;
1887 	mtd = kzalloc(sizeof(struct mtd_info), GFP_KERNEL);
1888 	if (!mtd)
1889 		goto nomem2;
1890 	mtd->priv = docg3;
1891 	bbt_nbpages = DIV_ROUND_UP(docg3->max_block + 1,
1892 				   8 * DOC_LAYOUT_PAGE_SIZE);
1893 	docg3->bbt = kzalloc(bbt_nbpages * DOC_LAYOUT_PAGE_SIZE, GFP_KERNEL);
1894 	if (!docg3->bbt)
1895 		goto nomem3;
1896 
1897 	docg3->dev = dev;
1898 	docg3->device_id = floor;
1899 	docg3->cascade = cascade;
1900 	doc_set_device_id(docg3, docg3->device_id);
1901 	if (!floor)
1902 		doc_set_asic_mode(docg3, DOC_ASICMODE_RESET);
1903 	doc_set_asic_mode(docg3, DOC_ASICMODE_NORMAL);
1904 
1905 	chip_id = doc_register_readw(docg3, DOC_CHIPID);
1906 	chip_id_inv = doc_register_readw(docg3, DOC_CHIPID_INV);
1907 
1908 	ret = 0;
1909 	if (chip_id != (u16)(~chip_id_inv)) {
1910 		goto nomem3;
1911 	}
1912 
1913 	switch (chip_id) {
1914 	case DOC_CHIPID_G3:
1915 		doc_info("Found a G3 DiskOnChip at addr %p, floor %d\n",
1916 			 docg3->cascade->base, floor);
1917 		break;
1918 	default:
1919 		doc_err("Chip id %04x is not a DiskOnChip G3 chip\n", chip_id);
1920 		goto nomem3;
1921 	}
1922 
1923 	doc_set_driver_info(chip_id, mtd);
1924 
1925 	doc_hamming_ecc_init(docg3, DOC_LAYOUT_OOB_PAGEINFO_SZ);
1926 	doc_reload_bbt(docg3);
1927 	return mtd;
1928 
1929 nomem3:
1930 	kfree(mtd);
1931 nomem2:
1932 	kfree(docg3);
1933 nomem1:
1934 	return ERR_PTR(ret);
1935 }
1936 
1937 /**
1938  * doc_release_device - Release a docg3 floor
1939  * @mtd: the device
1940  */
1941 static void doc_release_device(struct mtd_info *mtd)
1942 {
1943 	struct docg3 *docg3 = mtd->priv;
1944 
1945 	mtd_device_unregister(mtd);
1946 	kfree(docg3->bbt);
1947 	kfree(docg3);
1948 	kfree(mtd->name);
1949 	kfree(mtd);
1950 }
1951 
1952 /**
1953  * docg3_resume - Awakens docg3 floor
1954  * @pdev: platfrom device
1955  *
1956  * Returns 0 (always successful)
1957  */
1958 static int docg3_resume(struct platform_device *pdev)
1959 {
1960 	int i;
1961 	struct docg3_cascade *cascade;
1962 	struct mtd_info **docg3_floors, *mtd;
1963 	struct docg3 *docg3;
1964 
1965 	cascade = platform_get_drvdata(pdev);
1966 	docg3_floors = cascade->floors;
1967 	mtd = docg3_floors[0];
1968 	docg3 = mtd->priv;
1969 
1970 	doc_dbg("docg3_resume()\n");
1971 	for (i = 0; i < 12; i++)
1972 		doc_readb(docg3, DOC_IOSPACE_IPL);
1973 	return 0;
1974 }
1975 
1976 /**
1977  * docg3_suspend - Put in low power mode the docg3 floor
1978  * @pdev: platform device
1979  * @state: power state
1980  *
1981  * Shuts off most of docg3 circuitery to lower power consumption.
1982  *
1983  * Returns 0 if suspend succeeded, -EIO if chip refused suspend
1984  */
1985 static int docg3_suspend(struct platform_device *pdev, pm_message_t state)
1986 {
1987 	int floor, i;
1988 	struct docg3_cascade *cascade;
1989 	struct mtd_info **docg3_floors, *mtd;
1990 	struct docg3 *docg3;
1991 	u8 ctrl, pwr_down;
1992 
1993 	cascade = platform_get_drvdata(pdev);
1994 	docg3_floors = cascade->floors;
1995 	for (floor = 0; floor < DOC_MAX_NBFLOORS; floor++) {
1996 		mtd = docg3_floors[floor];
1997 		if (!mtd)
1998 			continue;
1999 		docg3 = mtd->priv;
2000 
2001 		doc_writeb(docg3, floor, DOC_DEVICESELECT);
2002 		ctrl = doc_register_readb(docg3, DOC_FLASHCONTROL);
2003 		ctrl &= ~DOC_CTRL_VIOLATION & ~DOC_CTRL_CE;
2004 		doc_writeb(docg3, ctrl, DOC_FLASHCONTROL);
2005 
2006 		for (i = 0; i < 10; i++) {
2007 			usleep_range(3000, 4000);
2008 			pwr_down = doc_register_readb(docg3, DOC_POWERMODE);
2009 			if (pwr_down & DOC_POWERDOWN_READY)
2010 				break;
2011 		}
2012 		if (pwr_down & DOC_POWERDOWN_READY) {
2013 			doc_dbg("docg3_suspend(): floor %d powerdown ok\n",
2014 				floor);
2015 		} else {
2016 			doc_err("docg3_suspend(): floor %d powerdown failed\n",
2017 				floor);
2018 			return -EIO;
2019 		}
2020 	}
2021 
2022 	mtd = docg3_floors[0];
2023 	docg3 = mtd->priv;
2024 	doc_set_asic_mode(docg3, DOC_ASICMODE_POWERDOWN);
2025 	return 0;
2026 }
2027 
2028 /**
2029  * doc_probe - Probe the IO space for a DiskOnChip G3 chip
2030  * @pdev: platform device
2031  *
2032  * Probes for a G3 chip at the specified IO space in the platform data
2033  * ressources. The floor 0 must be available.
2034  *
2035  * Returns 0 on success, -ENOMEM, -ENXIO on error
2036  */
2037 static int __init docg3_probe(struct platform_device *pdev)
2038 {
2039 	struct device *dev = &pdev->dev;
2040 	struct mtd_info *mtd;
2041 	struct resource *ress;
2042 	void __iomem *base;
2043 	int ret, floor, found = 0;
2044 	struct docg3_cascade *cascade;
2045 
2046 	ret = -ENXIO;
2047 	ress = platform_get_resource(pdev, IORESOURCE_MEM, 0);
2048 	if (!ress) {
2049 		dev_err(dev, "No I/O memory resource defined\n");
2050 		return ret;
2051 	}
2052 	base = devm_ioremap(dev, ress->start, DOC_IOSPACE_SIZE);
2053 
2054 	ret = -ENOMEM;
2055 	cascade = devm_kzalloc(dev, sizeof(*cascade) * DOC_MAX_NBFLOORS,
2056 			       GFP_KERNEL);
2057 	if (!cascade)
2058 		return ret;
2059 	cascade->base = base;
2060 	mutex_init(&cascade->lock);
2061 	cascade->bch = init_bch(DOC_ECC_BCH_M, DOC_ECC_BCH_T,
2062 			     DOC_ECC_BCH_PRIMPOLY);
2063 	if (!cascade->bch)
2064 		return ret;
2065 
2066 	for (floor = 0; floor < DOC_MAX_NBFLOORS; floor++) {
2067 		mtd = doc_probe_device(cascade, floor, dev);
2068 		if (IS_ERR(mtd)) {
2069 			ret = PTR_ERR(mtd);
2070 			goto err_probe;
2071 		}
2072 		if (!mtd) {
2073 			if (floor == 0)
2074 				goto notfound;
2075 			else
2076 				continue;
2077 		}
2078 		cascade->floors[floor] = mtd;
2079 		ret = mtd_device_parse_register(mtd, part_probes, NULL, NULL,
2080 						0);
2081 		if (ret)
2082 			goto err_probe;
2083 		found++;
2084 	}
2085 
2086 	ret = doc_register_sysfs(pdev, cascade);
2087 	if (ret)
2088 		goto err_probe;
2089 	if (!found)
2090 		goto notfound;
2091 
2092 	platform_set_drvdata(pdev, cascade);
2093 	doc_dbg_register(cascade->floors[0]->priv);
2094 	return 0;
2095 
2096 notfound:
2097 	ret = -ENODEV;
2098 	dev_info(dev, "No supported DiskOnChip found\n");
2099 err_probe:
2100 	free_bch(cascade->bch);
2101 	for (floor = 0; floor < DOC_MAX_NBFLOORS; floor++)
2102 		if (cascade->floors[floor])
2103 			doc_release_device(cascade->floors[floor]);
2104 	return ret;
2105 }
2106 
2107 /**
2108  * docg3_release - Release the driver
2109  * @pdev: the platform device
2110  *
2111  * Returns 0
2112  */
2113 static int __exit docg3_release(struct platform_device *pdev)
2114 {
2115 	struct docg3_cascade *cascade = platform_get_drvdata(pdev);
2116 	struct docg3 *docg3 = cascade->floors[0]->priv;
2117 	int floor;
2118 
2119 	doc_unregister_sysfs(pdev, cascade);
2120 	doc_dbg_unregister(docg3);
2121 	for (floor = 0; floor < DOC_MAX_NBFLOORS; floor++)
2122 		if (cascade->floors[floor])
2123 			doc_release_device(cascade->floors[floor]);
2124 
2125 	free_bch(docg3->cascade->bch);
2126 	return 0;
2127 }
2128 
2129 static struct platform_driver g3_driver = {
2130 	.driver		= {
2131 		.name	= "docg3",
2132 		.owner	= THIS_MODULE,
2133 	},
2134 	.suspend	= docg3_suspend,
2135 	.resume		= docg3_resume,
2136 	.remove		= __exit_p(docg3_release),
2137 };
2138 
2139 module_platform_driver_probe(g3_driver, docg3_probe);
2140 
2141 MODULE_LICENSE("GPL");
2142 MODULE_AUTHOR("Robert Jarzmik <robert.jarzmik@free.fr>");
2143 MODULE_DESCRIPTION("MTD driver for DiskOnChip G3");
2144