xref: /openbmc/linux/drivers/mtd/lpddr/lpddr_cmds.c (revision 1fa6ac37)
1 /*
2  * LPDDR flash memory device operations. This module provides read, write,
3  * erase, lock/unlock support for LPDDR flash memories
4  * (C) 2008 Korolev Alexey <akorolev@infradead.org>
5  * (C) 2008 Vasiliy Leonenko <vasiliy.leonenko@gmail.com>
6  * Many thanks to Roman Borisov for intial enabling
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License
10  * as published by the Free Software Foundation; either version 2
11  * of the License, or (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
21  * 02110-1301, USA.
22  * TODO:
23  * Implement VPP management
24  * Implement XIP support
25  * Implement OTP support
26  */
27 #include <linux/mtd/pfow.h>
28 #include <linux/mtd/qinfo.h>
29 #include <linux/slab.h>
30 
31 static int lpddr_read(struct mtd_info *mtd, loff_t adr, size_t len,
32 					size_t *retlen, u_char *buf);
33 static int lpddr_write_buffers(struct mtd_info *mtd, loff_t to,
34 				size_t len, size_t *retlen, const u_char *buf);
35 static int lpddr_writev(struct mtd_info *mtd, const struct kvec *vecs,
36 				unsigned long count, loff_t to, size_t *retlen);
37 static int lpddr_erase(struct mtd_info *mtd, struct erase_info *instr);
38 static int lpddr_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len);
39 static int lpddr_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len);
40 static int lpddr_point(struct mtd_info *mtd, loff_t adr, size_t len,
41 			size_t *retlen, void **mtdbuf, resource_size_t *phys);
42 static void lpddr_unpoint(struct mtd_info *mtd, loff_t adr, size_t len);
43 static int get_chip(struct map_info *map, struct flchip *chip, int mode);
44 static int chip_ready(struct map_info *map, struct flchip *chip, int mode);
45 static void put_chip(struct map_info *map, struct flchip *chip);
46 
47 struct mtd_info *lpddr_cmdset(struct map_info *map)
48 {
49 	struct lpddr_private *lpddr = map->fldrv_priv;
50 	struct flchip_shared *shared;
51 	struct flchip *chip;
52 	struct mtd_info *mtd;
53 	int numchips;
54 	int i, j;
55 
56 	mtd = kzalloc(sizeof(*mtd), GFP_KERNEL);
57 	if (!mtd) {
58 		printk(KERN_ERR "Failed to allocate memory for MTD device\n");
59 		return NULL;
60 	}
61 	mtd->priv = map;
62 	mtd->type = MTD_NORFLASH;
63 
64 	/* Fill in the default mtd operations */
65 	mtd->read = lpddr_read;
66 	mtd->type = MTD_NORFLASH;
67 	mtd->flags = MTD_CAP_NORFLASH;
68 	mtd->flags &= ~MTD_BIT_WRITEABLE;
69 	mtd->erase = lpddr_erase;
70 	mtd->write = lpddr_write_buffers;
71 	mtd->writev = lpddr_writev;
72 	mtd->read_oob = NULL;
73 	mtd->write_oob = NULL;
74 	mtd->sync = NULL;
75 	mtd->lock = lpddr_lock;
76 	mtd->unlock = lpddr_unlock;
77 	mtd->suspend = NULL;
78 	mtd->resume = NULL;
79 	if (map_is_linear(map)) {
80 		mtd->point = lpddr_point;
81 		mtd->unpoint = lpddr_unpoint;
82 	}
83 	mtd->block_isbad = NULL;
84 	mtd->block_markbad = NULL;
85 	mtd->size = 1 << lpddr->qinfo->DevSizeShift;
86 	mtd->erasesize = 1 << lpddr->qinfo->UniformBlockSizeShift;
87 	mtd->writesize = 1 << lpddr->qinfo->BufSizeShift;
88 
89 	shared = kmalloc(sizeof(struct flchip_shared) * lpddr->numchips,
90 						GFP_KERNEL);
91 	if (!shared) {
92 		kfree(lpddr);
93 		kfree(mtd);
94 		return NULL;
95 	}
96 
97 	chip = &lpddr->chips[0];
98 	numchips = lpddr->numchips / lpddr->qinfo->HWPartsNum;
99 	for (i = 0; i < numchips; i++) {
100 		shared[i].writing = shared[i].erasing = NULL;
101 		spin_lock_init(&shared[i].lock);
102 		for (j = 0; j < lpddr->qinfo->HWPartsNum; j++) {
103 			*chip = lpddr->chips[i];
104 			chip->start += j << lpddr->chipshift;
105 			chip->oldstate = chip->state = FL_READY;
106 			chip->priv = &shared[i];
107 			/* those should be reset too since
108 			   they create memory references. */
109 			init_waitqueue_head(&chip->wq);
110 			mutex_init(&chip->mutex);
111 			chip++;
112 		}
113 	}
114 
115 	return mtd;
116 }
117 EXPORT_SYMBOL(lpddr_cmdset);
118 
119 static int wait_for_ready(struct map_info *map, struct flchip *chip,
120 		unsigned int chip_op_time)
121 {
122 	unsigned int timeo, reset_timeo, sleep_time;
123 	unsigned int dsr;
124 	flstate_t chip_state = chip->state;
125 	int ret = 0;
126 
127 	/* set our timeout to 8 times the expected delay */
128 	timeo = chip_op_time * 8;
129 	if (!timeo)
130 		timeo = 500000;
131 	reset_timeo = timeo;
132 	sleep_time = chip_op_time / 2;
133 
134 	for (;;) {
135 		dsr = CMDVAL(map_read(map, map->pfow_base + PFOW_DSR));
136 		if (dsr & DSR_READY_STATUS)
137 			break;
138 		if (!timeo) {
139 			printk(KERN_ERR "%s: Flash timeout error state %d \n",
140 							map->name, chip_state);
141 			ret = -ETIME;
142 			break;
143 		}
144 
145 		/* OK Still waiting. Drop the lock, wait a while and retry. */
146 		mutex_unlock(&chip->mutex);
147 		if (sleep_time >= 1000000/HZ) {
148 			/*
149 			 * Half of the normal delay still remaining
150 			 * can be performed with a sleeping delay instead
151 			 * of busy waiting.
152 			 */
153 			msleep(sleep_time/1000);
154 			timeo -= sleep_time;
155 			sleep_time = 1000000/HZ;
156 		} else {
157 			udelay(1);
158 			cond_resched();
159 			timeo--;
160 		}
161 		mutex_lock(&chip->mutex);
162 
163 		while (chip->state != chip_state) {
164 			/* Someone's suspended the operation: sleep */
165 			DECLARE_WAITQUEUE(wait, current);
166 			set_current_state(TASK_UNINTERRUPTIBLE);
167 			add_wait_queue(&chip->wq, &wait);
168 			mutex_unlock(&chip->mutex);
169 			schedule();
170 			remove_wait_queue(&chip->wq, &wait);
171 			mutex_lock(&chip->mutex);
172 		}
173 		if (chip->erase_suspended || chip->write_suspended)  {
174 			/* Suspend has occured while sleep: reset timeout */
175 			timeo = reset_timeo;
176 			chip->erase_suspended = chip->write_suspended = 0;
177 		}
178 	}
179 	/* check status for errors */
180 	if (dsr & DSR_ERR) {
181 		/* Clear DSR*/
182 		map_write(map, CMD(~(DSR_ERR)), map->pfow_base + PFOW_DSR);
183 		printk(KERN_WARNING"%s: Bad status on wait: 0x%x \n",
184 				map->name, dsr);
185 		print_drs_error(dsr);
186 		ret = -EIO;
187 	}
188 	chip->state = FL_READY;
189 	return ret;
190 }
191 
192 static int get_chip(struct map_info *map, struct flchip *chip, int mode)
193 {
194 	int ret;
195 	DECLARE_WAITQUEUE(wait, current);
196 
197  retry:
198 	if (chip->priv && (mode == FL_WRITING || mode == FL_ERASING)
199 		&& chip->state != FL_SYNCING) {
200 		/*
201 		 * OK. We have possibility for contension on the write/erase
202 		 * operations which are global to the real chip and not per
203 		 * partition.  So let's fight it over in the partition which
204 		 * currently has authority on the operation.
205 		 *
206 		 * The rules are as follows:
207 		 *
208 		 * - any write operation must own shared->writing.
209 		 *
210 		 * - any erase operation must own _both_ shared->writing and
211 		 *   shared->erasing.
212 		 *
213 		 * - contension arbitration is handled in the owner's context.
214 		 *
215 		 * The 'shared' struct can be read and/or written only when
216 		 * its lock is taken.
217 		 */
218 		struct flchip_shared *shared = chip->priv;
219 		struct flchip *contender;
220 		spin_lock(&shared->lock);
221 		contender = shared->writing;
222 		if (contender && contender != chip) {
223 			/*
224 			 * The engine to perform desired operation on this
225 			 * partition is already in use by someone else.
226 			 * Let's fight over it in the context of the chip
227 			 * currently using it.  If it is possible to suspend,
228 			 * that other partition will do just that, otherwise
229 			 * it'll happily send us to sleep.  In any case, when
230 			 * get_chip returns success we're clear to go ahead.
231 			 */
232 			ret = mutex_trylock(&contender->mutex);
233 			spin_unlock(&shared->lock);
234 			if (!ret)
235 				goto retry;
236 			mutex_unlock(&chip->mutex);
237 			ret = chip_ready(map, contender, mode);
238 			mutex_lock(&chip->mutex);
239 
240 			if (ret == -EAGAIN) {
241 				mutex_unlock(&contender->mutex);
242 				goto retry;
243 			}
244 			if (ret) {
245 				mutex_unlock(&contender->mutex);
246 				return ret;
247 			}
248 			spin_lock(&shared->lock);
249 
250 			/* We should not own chip if it is already in FL_SYNCING
251 			 * state. Put contender and retry. */
252 			if (chip->state == FL_SYNCING) {
253 				put_chip(map, contender);
254 				mutex_unlock(&contender->mutex);
255 				goto retry;
256 			}
257 			mutex_unlock(&contender->mutex);
258 		}
259 
260 		/* Check if we have suspended erase on this chip.
261 		   Must sleep in such a case. */
262 		if (mode == FL_ERASING && shared->erasing
263 		    && shared->erasing->oldstate == FL_ERASING) {
264 			spin_unlock(&shared->lock);
265 			set_current_state(TASK_UNINTERRUPTIBLE);
266 			add_wait_queue(&chip->wq, &wait);
267 			mutex_unlock(&chip->mutex);
268 			schedule();
269 			remove_wait_queue(&chip->wq, &wait);
270 			mutex_lock(&chip->mutex);
271 			goto retry;
272 		}
273 
274 		/* We now own it */
275 		shared->writing = chip;
276 		if (mode == FL_ERASING)
277 			shared->erasing = chip;
278 		spin_unlock(&shared->lock);
279 	}
280 
281 	ret = chip_ready(map, chip, mode);
282 	if (ret == -EAGAIN)
283 		goto retry;
284 
285 	return ret;
286 }
287 
288 static int chip_ready(struct map_info *map, struct flchip *chip, int mode)
289 {
290 	struct lpddr_private *lpddr = map->fldrv_priv;
291 	int ret = 0;
292 	DECLARE_WAITQUEUE(wait, current);
293 
294 	/* Prevent setting state FL_SYNCING for chip in suspended state. */
295 	if (FL_SYNCING == mode && FL_READY != chip->oldstate)
296 		goto sleep;
297 
298 	switch (chip->state) {
299 	case FL_READY:
300 	case FL_JEDEC_QUERY:
301 		return 0;
302 
303 	case FL_ERASING:
304 		if (!lpddr->qinfo->SuspEraseSupp ||
305 			!(mode == FL_READY || mode == FL_POINT))
306 			goto sleep;
307 
308 		map_write(map, CMD(LPDDR_SUSPEND),
309 			map->pfow_base + PFOW_PROGRAM_ERASE_SUSPEND);
310 		chip->oldstate = FL_ERASING;
311 		chip->state = FL_ERASE_SUSPENDING;
312 		ret = wait_for_ready(map, chip, 0);
313 		if (ret) {
314 			/* Oops. something got wrong. */
315 			/* Resume and pretend we weren't here.  */
316 			map_write(map, CMD(LPDDR_RESUME),
317 				map->pfow_base + PFOW_COMMAND_CODE);
318 			map_write(map, CMD(LPDDR_START_EXECUTION),
319 				map->pfow_base + PFOW_COMMAND_EXECUTE);
320 			chip->state = FL_ERASING;
321 			chip->oldstate = FL_READY;
322 			printk(KERN_ERR "%s: suspend operation failed."
323 					"State may be wrong \n", map->name);
324 			return -EIO;
325 		}
326 		chip->erase_suspended = 1;
327 		chip->state = FL_READY;
328 		return 0;
329 		/* Erase suspend */
330 	case FL_POINT:
331 		/* Only if there's no operation suspended... */
332 		if (mode == FL_READY && chip->oldstate == FL_READY)
333 			return 0;
334 
335 	default:
336 sleep:
337 		set_current_state(TASK_UNINTERRUPTIBLE);
338 		add_wait_queue(&chip->wq, &wait);
339 		mutex_unlock(&chip->mutex);
340 		schedule();
341 		remove_wait_queue(&chip->wq, &wait);
342 		mutex_lock(&chip->mutex);
343 		return -EAGAIN;
344 	}
345 }
346 
347 static void put_chip(struct map_info *map, struct flchip *chip)
348 {
349 	if (chip->priv) {
350 		struct flchip_shared *shared = chip->priv;
351 		spin_lock(&shared->lock);
352 		if (shared->writing == chip && chip->oldstate == FL_READY) {
353 			/* We own the ability to write, but we're done */
354 			shared->writing = shared->erasing;
355 			if (shared->writing && shared->writing != chip) {
356 				/* give back the ownership */
357 				struct flchip *loaner = shared->writing;
358 				mutex_lock(&loaner->mutex);
359 				spin_unlock(&shared->lock);
360 				mutex_unlock(&chip->mutex);
361 				put_chip(map, loaner);
362 				mutex_lock(&chip->mutex);
363 				mutex_unlock(&loaner->mutex);
364 				wake_up(&chip->wq);
365 				return;
366 			}
367 			shared->erasing = NULL;
368 			shared->writing = NULL;
369 		} else if (shared->erasing == chip && shared->writing != chip) {
370 			/*
371 			 * We own the ability to erase without the ability
372 			 * to write, which means the erase was suspended
373 			 * and some other partition is currently writing.
374 			 * Don't let the switch below mess things up since
375 			 * we don't have ownership to resume anything.
376 			 */
377 			spin_unlock(&shared->lock);
378 			wake_up(&chip->wq);
379 			return;
380 		}
381 		spin_unlock(&shared->lock);
382 	}
383 
384 	switch (chip->oldstate) {
385 	case FL_ERASING:
386 		chip->state = chip->oldstate;
387 		map_write(map, CMD(LPDDR_RESUME),
388 				map->pfow_base + PFOW_COMMAND_CODE);
389 		map_write(map, CMD(LPDDR_START_EXECUTION),
390 				map->pfow_base + PFOW_COMMAND_EXECUTE);
391 		chip->oldstate = FL_READY;
392 		chip->state = FL_ERASING;
393 		break;
394 	case FL_READY:
395 		break;
396 	default:
397 		printk(KERN_ERR "%s: put_chip() called with oldstate %d!\n",
398 				map->name, chip->oldstate);
399 	}
400 	wake_up(&chip->wq);
401 }
402 
403 int do_write_buffer(struct map_info *map, struct flchip *chip,
404 			unsigned long adr, const struct kvec **pvec,
405 			unsigned long *pvec_seek, int len)
406 {
407 	struct lpddr_private *lpddr = map->fldrv_priv;
408 	map_word datum;
409 	int ret, wbufsize, word_gap, words;
410 	const struct kvec *vec;
411 	unsigned long vec_seek;
412 	unsigned long prog_buf_ofs;
413 
414 	wbufsize = 1 << lpddr->qinfo->BufSizeShift;
415 
416 	mutex_lock(&chip->mutex);
417 	ret = get_chip(map, chip, FL_WRITING);
418 	if (ret) {
419 		mutex_unlock(&chip->mutex);
420 		return ret;
421 	}
422 	/* Figure out the number of words to write */
423 	word_gap = (-adr & (map_bankwidth(map)-1));
424 	words = (len - word_gap + map_bankwidth(map) - 1) / map_bankwidth(map);
425 	if (!word_gap) {
426 		words--;
427 	} else {
428 		word_gap = map_bankwidth(map) - word_gap;
429 		adr -= word_gap;
430 		datum = map_word_ff(map);
431 	}
432 	/* Write data */
433 	/* Get the program buffer offset from PFOW register data first*/
434 	prog_buf_ofs = map->pfow_base + CMDVAL(map_read(map,
435 				map->pfow_base + PFOW_PROGRAM_BUFFER_OFFSET));
436 	vec = *pvec;
437 	vec_seek = *pvec_seek;
438 	do {
439 		int n = map_bankwidth(map) - word_gap;
440 
441 		if (n > vec->iov_len - vec_seek)
442 			n = vec->iov_len - vec_seek;
443 		if (n > len)
444 			n = len;
445 
446 		if (!word_gap && (len < map_bankwidth(map)))
447 			datum = map_word_ff(map);
448 
449 		datum = map_word_load_partial(map, datum,
450 				vec->iov_base + vec_seek, word_gap, n);
451 
452 		len -= n;
453 		word_gap += n;
454 		if (!len || word_gap == map_bankwidth(map)) {
455 			map_write(map, datum, prog_buf_ofs);
456 			prog_buf_ofs += map_bankwidth(map);
457 			word_gap = 0;
458 		}
459 
460 		vec_seek += n;
461 		if (vec_seek == vec->iov_len) {
462 			vec++;
463 			vec_seek = 0;
464 		}
465 	} while (len);
466 	*pvec = vec;
467 	*pvec_seek = vec_seek;
468 
469 	/* GO GO GO */
470 	send_pfow_command(map, LPDDR_BUFF_PROGRAM, adr, wbufsize, NULL);
471 	chip->state = FL_WRITING;
472 	ret = wait_for_ready(map, chip, (1<<lpddr->qinfo->ProgBufferTime));
473 	if (ret)	{
474 		printk(KERN_WARNING"%s Buffer program error: %d at %lx; \n",
475 			map->name, ret, adr);
476 		goto out;
477 	}
478 
479  out:	put_chip(map, chip);
480 	mutex_unlock(&chip->mutex);
481 	return ret;
482 }
483 
484 int do_erase_oneblock(struct mtd_info *mtd, loff_t adr)
485 {
486 	struct map_info *map = mtd->priv;
487 	struct lpddr_private *lpddr = map->fldrv_priv;
488 	int chipnum = adr >> lpddr->chipshift;
489 	struct flchip *chip = &lpddr->chips[chipnum];
490 	int ret;
491 
492 	mutex_lock(&chip->mutex);
493 	ret = get_chip(map, chip, FL_ERASING);
494 	if (ret) {
495 		mutex_unlock(&chip->mutex);
496 		return ret;
497 	}
498 	send_pfow_command(map, LPDDR_BLOCK_ERASE, adr, 0, NULL);
499 	chip->state = FL_ERASING;
500 	ret = wait_for_ready(map, chip, (1<<lpddr->qinfo->BlockEraseTime)*1000);
501 	if (ret) {
502 		printk(KERN_WARNING"%s Erase block error %d at : %llx\n",
503 			map->name, ret, adr);
504 		goto out;
505 	}
506  out:	put_chip(map, chip);
507 	mutex_unlock(&chip->mutex);
508 	return ret;
509 }
510 
511 static int lpddr_read(struct mtd_info *mtd, loff_t adr, size_t len,
512 			size_t *retlen, u_char *buf)
513 {
514 	struct map_info *map = mtd->priv;
515 	struct lpddr_private *lpddr = map->fldrv_priv;
516 	int chipnum = adr >> lpddr->chipshift;
517 	struct flchip *chip = &lpddr->chips[chipnum];
518 	int ret = 0;
519 
520 	mutex_lock(&chip->mutex);
521 	ret = get_chip(map, chip, FL_READY);
522 	if (ret) {
523 		mutex_unlock(&chip->mutex);
524 		return ret;
525 	}
526 
527 	map_copy_from(map, buf, adr, len);
528 	*retlen = len;
529 
530 	put_chip(map, chip);
531 	mutex_unlock(&chip->mutex);
532 	return ret;
533 }
534 
535 static int lpddr_point(struct mtd_info *mtd, loff_t adr, size_t len,
536 			size_t *retlen, void **mtdbuf, resource_size_t *phys)
537 {
538 	struct map_info *map = mtd->priv;
539 	struct lpddr_private *lpddr = map->fldrv_priv;
540 	int chipnum = adr >> lpddr->chipshift;
541 	unsigned long ofs, last_end = 0;
542 	struct flchip *chip = &lpddr->chips[chipnum];
543 	int ret = 0;
544 
545 	if (!map->virt || (adr + len > mtd->size))
546 		return -EINVAL;
547 
548 	/* ofs: offset within the first chip that the first read should start */
549 	ofs = adr - (chipnum << lpddr->chipshift);
550 
551 	*mtdbuf = (void *)map->virt + chip->start + ofs;
552 	*retlen = 0;
553 
554 	while (len) {
555 		unsigned long thislen;
556 
557 		if (chipnum >= lpddr->numchips)
558 			break;
559 
560 		/* We cannot point across chips that are virtually disjoint */
561 		if (!last_end)
562 			last_end = chip->start;
563 		else if (chip->start != last_end)
564 			break;
565 
566 		if ((len + ofs - 1) >> lpddr->chipshift)
567 			thislen = (1<<lpddr->chipshift) - ofs;
568 		else
569 			thislen = len;
570 		/* get the chip */
571 		mutex_lock(&chip->mutex);
572 		ret = get_chip(map, chip, FL_POINT);
573 		mutex_unlock(&chip->mutex);
574 		if (ret)
575 			break;
576 
577 		chip->state = FL_POINT;
578 		chip->ref_point_counter++;
579 		*retlen += thislen;
580 		len -= thislen;
581 
582 		ofs = 0;
583 		last_end += 1 << lpddr->chipshift;
584 		chipnum++;
585 		chip = &lpddr->chips[chipnum];
586 	}
587 	return 0;
588 }
589 
590 static void lpddr_unpoint (struct mtd_info *mtd, loff_t adr, size_t len)
591 {
592 	struct map_info *map = mtd->priv;
593 	struct lpddr_private *lpddr = map->fldrv_priv;
594 	int chipnum = adr >> lpddr->chipshift;
595 	unsigned long ofs;
596 
597 	/* ofs: offset within the first chip that the first read should start */
598 	ofs = adr - (chipnum << lpddr->chipshift);
599 
600 	while (len) {
601 		unsigned long thislen;
602 		struct flchip *chip;
603 
604 		chip = &lpddr->chips[chipnum];
605 		if (chipnum >= lpddr->numchips)
606 			break;
607 
608 		if ((len + ofs - 1) >> lpddr->chipshift)
609 			thislen = (1<<lpddr->chipshift) - ofs;
610 		else
611 			thislen = len;
612 
613 		mutex_lock(&chip->mutex);
614 		if (chip->state == FL_POINT) {
615 			chip->ref_point_counter--;
616 			if (chip->ref_point_counter == 0)
617 				chip->state = FL_READY;
618 		} else
619 			printk(KERN_WARNING "%s: Warning: unpoint called on non"
620 					"pointed region\n", map->name);
621 
622 		put_chip(map, chip);
623 		mutex_unlock(&chip->mutex);
624 
625 		len -= thislen;
626 		ofs = 0;
627 		chipnum++;
628 	}
629 }
630 
631 static int lpddr_write_buffers(struct mtd_info *mtd, loff_t to, size_t len,
632 				size_t *retlen, const u_char *buf)
633 {
634 	struct kvec vec;
635 
636 	vec.iov_base = (void *) buf;
637 	vec.iov_len = len;
638 
639 	return lpddr_writev(mtd, &vec, 1, to, retlen);
640 }
641 
642 
643 static int lpddr_writev(struct mtd_info *mtd, const struct kvec *vecs,
644 				unsigned long count, loff_t to, size_t *retlen)
645 {
646 	struct map_info *map = mtd->priv;
647 	struct lpddr_private *lpddr = map->fldrv_priv;
648 	int ret = 0;
649 	int chipnum;
650 	unsigned long ofs, vec_seek, i;
651 	int wbufsize = 1 << lpddr->qinfo->BufSizeShift;
652 
653 	size_t len = 0;
654 
655 	for (i = 0; i < count; i++)
656 		len += vecs[i].iov_len;
657 
658 	*retlen = 0;
659 	if (!len)
660 		return 0;
661 
662 	chipnum = to >> lpddr->chipshift;
663 
664 	ofs = to;
665 	vec_seek = 0;
666 
667 	do {
668 		/* We must not cross write block boundaries */
669 		int size = wbufsize - (ofs & (wbufsize-1));
670 
671 		if (size > len)
672 			size = len;
673 
674 		ret = do_write_buffer(map, &lpddr->chips[chipnum],
675 					  ofs, &vecs, &vec_seek, size);
676 		if (ret)
677 			return ret;
678 
679 		ofs += size;
680 		(*retlen) += size;
681 		len -= size;
682 
683 		/* Be nice and reschedule with the chip in a usable
684 		 * state for other processes */
685 		cond_resched();
686 
687 	} while (len);
688 
689 	return 0;
690 }
691 
692 static int lpddr_erase(struct mtd_info *mtd, struct erase_info *instr)
693 {
694 	unsigned long ofs, len;
695 	int ret;
696 	struct map_info *map = mtd->priv;
697 	struct lpddr_private *lpddr = map->fldrv_priv;
698 	int size = 1 << lpddr->qinfo->UniformBlockSizeShift;
699 
700 	ofs = instr->addr;
701 	len = instr->len;
702 
703 	if (ofs > mtd->size || (len + ofs) > mtd->size)
704 		return -EINVAL;
705 
706 	while (len > 0) {
707 		ret = do_erase_oneblock(mtd, ofs);
708 		if (ret)
709 			return ret;
710 		ofs += size;
711 		len -= size;
712 	}
713 	instr->state = MTD_ERASE_DONE;
714 	mtd_erase_callback(instr);
715 
716 	return 0;
717 }
718 
719 #define DO_XXLOCK_LOCK		1
720 #define DO_XXLOCK_UNLOCK	2
721 int do_xxlock(struct mtd_info *mtd, loff_t adr, uint32_t len, int thunk)
722 {
723 	int ret = 0;
724 	struct map_info *map = mtd->priv;
725 	struct lpddr_private *lpddr = map->fldrv_priv;
726 	int chipnum = adr >> lpddr->chipshift;
727 	struct flchip *chip = &lpddr->chips[chipnum];
728 
729 	mutex_lock(&chip->mutex);
730 	ret = get_chip(map, chip, FL_LOCKING);
731 	if (ret) {
732 		mutex_unlock(&chip->mutex);
733 		return ret;
734 	}
735 
736 	if (thunk == DO_XXLOCK_LOCK) {
737 		send_pfow_command(map, LPDDR_LOCK_BLOCK, adr, adr + len, NULL);
738 		chip->state = FL_LOCKING;
739 	} else if (thunk == DO_XXLOCK_UNLOCK) {
740 		send_pfow_command(map, LPDDR_UNLOCK_BLOCK, adr, adr + len, NULL);
741 		chip->state = FL_UNLOCKING;
742 	} else
743 		BUG();
744 
745 	ret = wait_for_ready(map, chip, 1);
746 	if (ret)	{
747 		printk(KERN_ERR "%s: block unlock error status %d \n",
748 				map->name, ret);
749 		goto out;
750 	}
751 out:	put_chip(map, chip);
752 	mutex_unlock(&chip->mutex);
753 	return ret;
754 }
755 
756 static int lpddr_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
757 {
758 	return do_xxlock(mtd, ofs, len, DO_XXLOCK_LOCK);
759 }
760 
761 static int lpddr_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
762 {
763 	return do_xxlock(mtd, ofs, len, DO_XXLOCK_UNLOCK);
764 }
765 
766 int word_program(struct map_info *map, loff_t adr, uint32_t curval)
767 {
768     int ret;
769 	struct lpddr_private *lpddr = map->fldrv_priv;
770 	int chipnum = adr >> lpddr->chipshift;
771 	struct flchip *chip = &lpddr->chips[chipnum];
772 
773 	mutex_lock(&chip->mutex);
774 	ret = get_chip(map, chip, FL_WRITING);
775 	if (ret) {
776 		mutex_unlock(&chip->mutex);
777 		return ret;
778 	}
779 
780 	send_pfow_command(map, LPDDR_WORD_PROGRAM, adr, 0x00, (map_word *)&curval);
781 
782 	ret = wait_for_ready(map, chip, (1<<lpddr->qinfo->SingleWordProgTime));
783 	if (ret)	{
784 		printk(KERN_WARNING"%s word_program error at: %llx; val: %x\n",
785 			map->name, adr, curval);
786 		goto out;
787 	}
788 
789 out:	put_chip(map, chip);
790 	mutex_unlock(&chip->mutex);
791 	return ret;
792 }
793 
794 MODULE_LICENSE("GPL");
795 MODULE_AUTHOR("Alexey Korolev <akorolev@infradead.org>");
796 MODULE_DESCRIPTION("MTD driver for LPDDR flash chips");
797