xref: /linux/drivers/mtd/nand/raw/cafe_nand.c (revision 249ebf3f65f8530beb2cbfb91bff1d83ba88d23c)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Driver for One Laptop Per Child ‘CAFÉ’ controller, aka Marvell 88ALP01
4  *
5  * The data sheet for this device can be found at:
6  *    http://wiki.laptop.org/go/Datasheets
7  *
8  * Copyright © 2006 Red Hat, Inc.
9  * Copyright © 2006 David Woodhouse <dwmw2@infradead.org>
10  */
11 
12 #define DEBUG
13 
14 #include <linux/device.h>
15 #undef DEBUG
16 #include <linux/mtd/mtd.h>
17 #include <linux/mtd/rawnand.h>
18 #include <linux/mtd/partitions.h>
19 #include <linux/rslib.h>
20 #include <linux/pci.h>
21 #include <linux/delay.h>
22 #include <linux/interrupt.h>
23 #include <linux/dma-mapping.h>
24 #include <linux/slab.h>
25 #include <linux/module.h>
26 #include <asm/io.h>
27 
28 #define CAFE_NAND_CTRL1		0x00
29 #define CAFE_NAND_CTRL2		0x04
30 #define CAFE_NAND_CTRL3		0x08
31 #define CAFE_NAND_STATUS	0x0c
32 #define CAFE_NAND_IRQ		0x10
33 #define CAFE_NAND_IRQ_MASK	0x14
34 #define CAFE_NAND_DATA_LEN	0x18
35 #define CAFE_NAND_ADDR1		0x1c
36 #define CAFE_NAND_ADDR2		0x20
37 #define CAFE_NAND_TIMING1	0x24
38 #define CAFE_NAND_TIMING2	0x28
39 #define CAFE_NAND_TIMING3	0x2c
40 #define CAFE_NAND_NONMEM	0x30
41 #define CAFE_NAND_ECC_RESULT	0x3C
42 #define CAFE_NAND_DMA_CTRL	0x40
43 #define CAFE_NAND_DMA_ADDR0	0x44
44 #define CAFE_NAND_DMA_ADDR1	0x48
45 #define CAFE_NAND_ECC_SYN01	0x50
46 #define CAFE_NAND_ECC_SYN23	0x54
47 #define CAFE_NAND_ECC_SYN45	0x58
48 #define CAFE_NAND_ECC_SYN67	0x5c
49 #define CAFE_NAND_READ_DATA	0x1000
50 #define CAFE_NAND_WRITE_DATA	0x2000
51 
52 #define CAFE_GLOBAL_CTRL	0x3004
53 #define CAFE_GLOBAL_IRQ		0x3008
54 #define CAFE_GLOBAL_IRQ_MASK	0x300c
55 #define CAFE_NAND_RESET		0x3034
56 
57 /* Missing from the datasheet: bit 19 of CTRL1 sets CE0 vs. CE1 */
58 #define CTRL1_CHIPSELECT	(1<<19)
59 
60 struct cafe_priv {
61 	struct nand_chip nand;
62 	struct pci_dev *pdev;
63 	void __iomem *mmio;
64 	struct rs_control *rs;
65 	uint32_t ctl1;
66 	uint32_t ctl2;
67 	int datalen;
68 	int nr_data;
69 	int data_pos;
70 	int page_addr;
71 	bool usedma;
72 	dma_addr_t dmaaddr;
73 	unsigned char *dmabuf;
74 };
75 
76 static int usedma = 1;
77 module_param(usedma, int, 0644);
78 
79 static int skipbbt = 0;
80 module_param(skipbbt, int, 0644);
81 
82 static int debug = 0;
83 module_param(debug, int, 0644);
84 
85 static int regdebug = 0;
86 module_param(regdebug, int, 0644);
87 
88 static int checkecc = 1;
89 module_param(checkecc, int, 0644);
90 
91 static unsigned int numtimings;
92 static int timing[3];
93 module_param_array(timing, int, &numtimings, 0644);
94 
95 static const char *part_probes[] = { "cmdlinepart", "RedBoot", NULL };
96 
97 /* Hrm. Why isn't this already conditional on something in the struct device? */
98 #define cafe_dev_dbg(dev, args...) do { if (debug) dev_dbg(dev, ##args); } while(0)
99 
100 /* Make it easier to switch to PIO if we need to */
101 #define cafe_readl(cafe, addr)			readl((cafe)->mmio + CAFE_##addr)
102 #define cafe_writel(cafe, datum, addr)		writel(datum, (cafe)->mmio + CAFE_##addr)
103 
104 static int cafe_device_ready(struct nand_chip *chip)
105 {
106 	struct cafe_priv *cafe = nand_get_controller_data(chip);
107 	int result = !!(cafe_readl(cafe, NAND_STATUS) & 0x40000000);
108 	uint32_t irqs = cafe_readl(cafe, NAND_IRQ);
109 
110 	cafe_writel(cafe, irqs, NAND_IRQ);
111 
112 	cafe_dev_dbg(&cafe->pdev->dev, "NAND device is%s ready, IRQ %x (%x) (%x,%x)\n",
113 		result?"":" not", irqs, cafe_readl(cafe, NAND_IRQ),
114 		cafe_readl(cafe, GLOBAL_IRQ), cafe_readl(cafe, GLOBAL_IRQ_MASK));
115 
116 	return result;
117 }
118 
119 
120 static void cafe_write_buf(struct nand_chip *chip, const uint8_t *buf, int len)
121 {
122 	struct cafe_priv *cafe = nand_get_controller_data(chip);
123 
124 	if (cafe->usedma)
125 		memcpy(cafe->dmabuf + cafe->datalen, buf, len);
126 	else
127 		memcpy_toio(cafe->mmio + CAFE_NAND_WRITE_DATA + cafe->datalen, buf, len);
128 
129 	cafe->datalen += len;
130 
131 	cafe_dev_dbg(&cafe->pdev->dev, "Copy 0x%x bytes to write buffer. datalen 0x%x\n",
132 		len, cafe->datalen);
133 }
134 
135 static void cafe_read_buf(struct nand_chip *chip, uint8_t *buf, int len)
136 {
137 	struct cafe_priv *cafe = nand_get_controller_data(chip);
138 
139 	if (cafe->usedma)
140 		memcpy(buf, cafe->dmabuf + cafe->datalen, len);
141 	else
142 		memcpy_fromio(buf, cafe->mmio + CAFE_NAND_READ_DATA + cafe->datalen, len);
143 
144 	cafe_dev_dbg(&cafe->pdev->dev, "Copy 0x%x bytes from position 0x%x in read buffer.\n",
145 		  len, cafe->datalen);
146 	cafe->datalen += len;
147 }
148 
149 static uint8_t cafe_read_byte(struct nand_chip *chip)
150 {
151 	struct cafe_priv *cafe = nand_get_controller_data(chip);
152 	uint8_t d;
153 
154 	cafe_read_buf(chip, &d, 1);
155 	cafe_dev_dbg(&cafe->pdev->dev, "Read %02x\n", d);
156 
157 	return d;
158 }
159 
160 static void cafe_nand_cmdfunc(struct nand_chip *chip, unsigned command,
161 			      int column, int page_addr)
162 {
163 	struct mtd_info *mtd = nand_to_mtd(chip);
164 	struct cafe_priv *cafe = nand_get_controller_data(chip);
165 	int adrbytes = 0;
166 	uint32_t ctl1;
167 	uint32_t doneint = 0x80000000;
168 
169 	cafe_dev_dbg(&cafe->pdev->dev, "cmdfunc %02x, 0x%x, 0x%x\n",
170 		command, column, page_addr);
171 
172 	if (command == NAND_CMD_ERASE2 || command == NAND_CMD_PAGEPROG) {
173 		/* Second half of a command we already calculated */
174 		cafe_writel(cafe, cafe->ctl2 | 0x100 | command, NAND_CTRL2);
175 		ctl1 = cafe->ctl1;
176 		cafe->ctl2 &= ~(1<<30);
177 		cafe_dev_dbg(&cafe->pdev->dev, "Continue command, ctl1 %08x, #data %d\n",
178 			  cafe->ctl1, cafe->nr_data);
179 		goto do_command;
180 	}
181 	/* Reset ECC engine */
182 	cafe_writel(cafe, 0, NAND_CTRL2);
183 
184 	/* Emulate NAND_CMD_READOOB on large-page chips */
185 	if (mtd->writesize > 512 &&
186 	    command == NAND_CMD_READOOB) {
187 		column += mtd->writesize;
188 		command = NAND_CMD_READ0;
189 	}
190 
191 	/* FIXME: Do we need to send read command before sending data
192 	   for small-page chips, to position the buffer correctly? */
193 
194 	if (column != -1) {
195 		cafe_writel(cafe, column, NAND_ADDR1);
196 		adrbytes = 2;
197 		if (page_addr != -1)
198 			goto write_adr2;
199 	} else if (page_addr != -1) {
200 		cafe_writel(cafe, page_addr & 0xffff, NAND_ADDR1);
201 		page_addr >>= 16;
202 	write_adr2:
203 		cafe_writel(cafe, page_addr, NAND_ADDR2);
204 		adrbytes += 2;
205 		if (mtd->size > mtd->writesize << 16)
206 			adrbytes++;
207 	}
208 
209 	cafe->data_pos = cafe->datalen = 0;
210 
211 	/* Set command valid bit, mask in the chip select bit  */
212 	ctl1 = 0x80000000 | command | (cafe->ctl1 & CTRL1_CHIPSELECT);
213 
214 	/* Set RD or WR bits as appropriate */
215 	if (command == NAND_CMD_READID || command == NAND_CMD_STATUS) {
216 		ctl1 |= (1<<26); /* rd */
217 		/* Always 5 bytes, for now */
218 		cafe->datalen = 4;
219 		/* And one address cycle -- even for STATUS, since the controller doesn't work without */
220 		adrbytes = 1;
221 	} else if (command == NAND_CMD_READ0 || command == NAND_CMD_READ1 ||
222 		   command == NAND_CMD_READOOB || command == NAND_CMD_RNDOUT) {
223 		ctl1 |= 1<<26; /* rd */
224 		/* For now, assume just read to end of page */
225 		cafe->datalen = mtd->writesize + mtd->oobsize - column;
226 	} else if (command == NAND_CMD_SEQIN)
227 		ctl1 |= 1<<25; /* wr */
228 
229 	/* Set number of address bytes */
230 	if (adrbytes)
231 		ctl1 |= ((adrbytes-1)|8) << 27;
232 
233 	if (command == NAND_CMD_SEQIN || command == NAND_CMD_ERASE1) {
234 		/* Ignore the first command of a pair; the hardware
235 		   deals with them both at once, later */
236 		cafe->ctl1 = ctl1;
237 		cafe_dev_dbg(&cafe->pdev->dev, "Setup for delayed command, ctl1 %08x, dlen %x\n",
238 			  cafe->ctl1, cafe->datalen);
239 		return;
240 	}
241 	/* RNDOUT and READ0 commands need a following byte */
242 	if (command == NAND_CMD_RNDOUT)
243 		cafe_writel(cafe, cafe->ctl2 | 0x100 | NAND_CMD_RNDOUTSTART, NAND_CTRL2);
244 	else if (command == NAND_CMD_READ0 && mtd->writesize > 512)
245 		cafe_writel(cafe, cafe->ctl2 | 0x100 | NAND_CMD_READSTART, NAND_CTRL2);
246 
247  do_command:
248 	cafe_dev_dbg(&cafe->pdev->dev, "dlen %x, ctl1 %x, ctl2 %x\n",
249 		cafe->datalen, ctl1, cafe_readl(cafe, NAND_CTRL2));
250 
251 	/* NB: The datasheet lies -- we really should be subtracting 1 here */
252 	cafe_writel(cafe, cafe->datalen, NAND_DATA_LEN);
253 	cafe_writel(cafe, 0x90000000, NAND_IRQ);
254 	if (cafe->usedma && (ctl1 & (3<<25))) {
255 		uint32_t dmactl = 0xc0000000 + cafe->datalen;
256 		/* If WR or RD bits set, set up DMA */
257 		if (ctl1 & (1<<26)) {
258 			/* It's a read */
259 			dmactl |= (1<<29);
260 			/* ... so it's done when the DMA is done, not just
261 			   the command. */
262 			doneint = 0x10000000;
263 		}
264 		cafe_writel(cafe, dmactl, NAND_DMA_CTRL);
265 	}
266 	cafe->datalen = 0;
267 
268 	if (unlikely(regdebug)) {
269 		int i;
270 		printk("About to write command %08x to register 0\n", ctl1);
271 		for (i=4; i< 0x5c; i+=4)
272 			printk("Register %x: %08x\n", i, readl(cafe->mmio + i));
273 	}
274 
275 	cafe_writel(cafe, ctl1, NAND_CTRL1);
276 	/* Apply this short delay always to ensure that we do wait tWB in
277 	 * any case on any machine. */
278 	ndelay(100);
279 
280 	if (1) {
281 		int c;
282 		uint32_t irqs;
283 
284 		for (c = 500000; c != 0; c--) {
285 			irqs = cafe_readl(cafe, NAND_IRQ);
286 			if (irqs & doneint)
287 				break;
288 			udelay(1);
289 			if (!(c % 100000))
290 				cafe_dev_dbg(&cafe->pdev->dev, "Wait for ready, IRQ %x\n", irqs);
291 			cpu_relax();
292 		}
293 		cafe_writel(cafe, doneint, NAND_IRQ);
294 		cafe_dev_dbg(&cafe->pdev->dev, "Command %x completed after %d usec, irqs %x (%x)\n",
295 			     command, 500000-c, irqs, cafe_readl(cafe, NAND_IRQ));
296 	}
297 
298 	WARN_ON(cafe->ctl2 & (1<<30));
299 
300 	switch (command) {
301 
302 	case NAND_CMD_CACHEDPROG:
303 	case NAND_CMD_PAGEPROG:
304 	case NAND_CMD_ERASE1:
305 	case NAND_CMD_ERASE2:
306 	case NAND_CMD_SEQIN:
307 	case NAND_CMD_RNDIN:
308 	case NAND_CMD_STATUS:
309 	case NAND_CMD_RNDOUT:
310 		cafe_writel(cafe, cafe->ctl2, NAND_CTRL2);
311 		return;
312 	}
313 	nand_wait_ready(chip);
314 	cafe_writel(cafe, cafe->ctl2, NAND_CTRL2);
315 }
316 
317 static void cafe_select_chip(struct nand_chip *chip, int chipnr)
318 {
319 	struct cafe_priv *cafe = nand_get_controller_data(chip);
320 
321 	cafe_dev_dbg(&cafe->pdev->dev, "select_chip %d\n", chipnr);
322 
323 	/* Mask the appropriate bit into the stored value of ctl1
324 	   which will be used by cafe_nand_cmdfunc() */
325 	if (chipnr)
326 		cafe->ctl1 |= CTRL1_CHIPSELECT;
327 	else
328 		cafe->ctl1 &= ~CTRL1_CHIPSELECT;
329 }
330 
331 static irqreturn_t cafe_nand_interrupt(int irq, void *id)
332 {
333 	struct mtd_info *mtd = id;
334 	struct nand_chip *chip = mtd_to_nand(mtd);
335 	struct cafe_priv *cafe = nand_get_controller_data(chip);
336 	uint32_t irqs = cafe_readl(cafe, NAND_IRQ);
337 	cafe_writel(cafe, irqs & ~0x90000000, NAND_IRQ);
338 	if (!irqs)
339 		return IRQ_NONE;
340 
341 	cafe_dev_dbg(&cafe->pdev->dev, "irq, bits %x (%x)\n", irqs, cafe_readl(cafe, NAND_IRQ));
342 	return IRQ_HANDLED;
343 }
344 
345 static int cafe_nand_write_oob(struct nand_chip *chip, int page)
346 {
347 	struct mtd_info *mtd = nand_to_mtd(chip);
348 
349 	return nand_prog_page_op(chip, page, mtd->writesize, chip->oob_poi,
350 				 mtd->oobsize);
351 }
352 
353 /* Don't use -- use nand_read_oob_std for now */
354 static int cafe_nand_read_oob(struct nand_chip *chip, int page)
355 {
356 	struct mtd_info *mtd = nand_to_mtd(chip);
357 
358 	return nand_read_oob_op(chip, page, 0, chip->oob_poi, mtd->oobsize);
359 }
360 /**
361  * cafe_nand_read_page - [REPLACEABLE] hardware ecc syndrome based page read
362  * @chip:	nand chip info structure
363  * @buf:	buffer to store read data
364  * @oob_required:	caller expects OOB data read to chip->oob_poi
365  * @page:	page number to read
366  *
367  * The hw generator calculates the error syndrome automatically. Therefore
368  * we need a special oob layout and handling.
369  */
370 static int cafe_nand_read_page(struct nand_chip *chip, uint8_t *buf,
371 			       int oob_required, int page)
372 {
373 	struct mtd_info *mtd = nand_to_mtd(chip);
374 	struct cafe_priv *cafe = nand_get_controller_data(chip);
375 	unsigned int max_bitflips = 0;
376 
377 	cafe_dev_dbg(&cafe->pdev->dev, "ECC result %08x SYN1,2 %08x\n",
378 		     cafe_readl(cafe, NAND_ECC_RESULT),
379 		     cafe_readl(cafe, NAND_ECC_SYN01));
380 
381 	nand_read_page_op(chip, page, 0, buf, mtd->writesize);
382 	chip->legacy.read_buf(chip, chip->oob_poi, mtd->oobsize);
383 
384 	if (checkecc && cafe_readl(cafe, NAND_ECC_RESULT) & (1<<18)) {
385 		unsigned short syn[8], pat[4];
386 		int pos[4];
387 		u8 *oob = chip->oob_poi;
388 		int i, n;
389 
390 		for (i=0; i<8; i+=2) {
391 			uint32_t tmp = cafe_readl(cafe, NAND_ECC_SYN01 + (i*2));
392 
393 			syn[i] = cafe->rs->codec->index_of[tmp & 0xfff];
394 			syn[i+1] = cafe->rs->codec->index_of[(tmp >> 16) & 0xfff];
395 		}
396 
397 		n = decode_rs16(cafe->rs, NULL, NULL, 1367, syn, 0, pos, 0,
398 				pat);
399 
400 		for (i = 0; i < n; i++) {
401 			int p = pos[i];
402 
403 			/* The 12-bit symbols are mapped to bytes here */
404 
405 			if (p > 1374) {
406 				/* out of range */
407 				n = -1374;
408 			} else if (p == 0) {
409 				/* high four bits do not correspond to data */
410 				if (pat[i] > 0xff)
411 					n = -2048;
412 				else
413 					buf[0] ^= pat[i];
414 			} else if (p == 1365) {
415 				buf[2047] ^= pat[i] >> 4;
416 				oob[0] ^= pat[i] << 4;
417 			} else if (p > 1365) {
418 				if ((p & 1) == 1) {
419 					oob[3*p/2 - 2048] ^= pat[i] >> 4;
420 					oob[3*p/2 - 2047] ^= pat[i] << 4;
421 				} else {
422 					oob[3*p/2 - 2049] ^= pat[i] >> 8;
423 					oob[3*p/2 - 2048] ^= pat[i];
424 				}
425 			} else if ((p & 1) == 1) {
426 				buf[3*p/2] ^= pat[i] >> 4;
427 				buf[3*p/2 + 1] ^= pat[i] << 4;
428 			} else {
429 				buf[3*p/2 - 1] ^= pat[i] >> 8;
430 				buf[3*p/2] ^= pat[i];
431 			}
432 		}
433 
434 		if (n < 0) {
435 			dev_dbg(&cafe->pdev->dev, "Failed to correct ECC at %08x\n",
436 				cafe_readl(cafe, NAND_ADDR2) * 2048);
437 			for (i = 0; i < 0x5c; i += 4)
438 				printk("Register %x: %08x\n", i, readl(cafe->mmio + i));
439 			mtd->ecc_stats.failed++;
440 		} else {
441 			dev_dbg(&cafe->pdev->dev, "Corrected %d symbol errors\n", n);
442 			mtd->ecc_stats.corrected += n;
443 			max_bitflips = max_t(unsigned int, max_bitflips, n);
444 		}
445 	}
446 
447 	return max_bitflips;
448 }
449 
450 static int cafe_ooblayout_ecc(struct mtd_info *mtd, int section,
451 			      struct mtd_oob_region *oobregion)
452 {
453 	struct nand_chip *chip = mtd_to_nand(mtd);
454 
455 	if (section)
456 		return -ERANGE;
457 
458 	oobregion->offset = 0;
459 	oobregion->length = chip->ecc.total;
460 
461 	return 0;
462 }
463 
464 static int cafe_ooblayout_free(struct mtd_info *mtd, int section,
465 			       struct mtd_oob_region *oobregion)
466 {
467 	struct nand_chip *chip = mtd_to_nand(mtd);
468 
469 	if (section)
470 		return -ERANGE;
471 
472 	oobregion->offset = chip->ecc.total;
473 	oobregion->length = mtd->oobsize - chip->ecc.total;
474 
475 	return 0;
476 }
477 
478 static const struct mtd_ooblayout_ops cafe_ooblayout_ops = {
479 	.ecc = cafe_ooblayout_ecc,
480 	.free = cafe_ooblayout_free,
481 };
482 
483 /* Ick. The BBT code really ought to be able to work this bit out
484    for itself from the above, at least for the 2KiB case */
485 static uint8_t cafe_bbt_pattern_2048[] = { 'B', 'b', 't', '0' };
486 static uint8_t cafe_mirror_pattern_2048[] = { '1', 't', 'b', 'B' };
487 
488 static uint8_t cafe_bbt_pattern_512[] = { 0xBB };
489 static uint8_t cafe_mirror_pattern_512[] = { 0xBC };
490 
491 
492 static struct nand_bbt_descr cafe_bbt_main_descr_2048 = {
493 	.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
494 		| NAND_BBT_2BIT | NAND_BBT_VERSION,
495 	.offs =	14,
496 	.len = 4,
497 	.veroffs = 18,
498 	.maxblocks = 4,
499 	.pattern = cafe_bbt_pattern_2048
500 };
501 
502 static struct nand_bbt_descr cafe_bbt_mirror_descr_2048 = {
503 	.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
504 		| NAND_BBT_2BIT | NAND_BBT_VERSION,
505 	.offs =	14,
506 	.len = 4,
507 	.veroffs = 18,
508 	.maxblocks = 4,
509 	.pattern = cafe_mirror_pattern_2048
510 };
511 
512 static struct nand_bbt_descr cafe_bbt_main_descr_512 = {
513 	.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
514 		| NAND_BBT_2BIT | NAND_BBT_VERSION,
515 	.offs =	14,
516 	.len = 1,
517 	.veroffs = 15,
518 	.maxblocks = 4,
519 	.pattern = cafe_bbt_pattern_512
520 };
521 
522 static struct nand_bbt_descr cafe_bbt_mirror_descr_512 = {
523 	.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
524 		| NAND_BBT_2BIT | NAND_BBT_VERSION,
525 	.offs =	14,
526 	.len = 1,
527 	.veroffs = 15,
528 	.maxblocks = 4,
529 	.pattern = cafe_mirror_pattern_512
530 };
531 
532 
533 static int cafe_nand_write_page_lowlevel(struct nand_chip *chip,
534 					 const uint8_t *buf, int oob_required,
535 					 int page)
536 {
537 	struct mtd_info *mtd = nand_to_mtd(chip);
538 	struct cafe_priv *cafe = nand_get_controller_data(chip);
539 
540 	nand_prog_page_begin_op(chip, page, 0, buf, mtd->writesize);
541 	chip->legacy.write_buf(chip, chip->oob_poi, mtd->oobsize);
542 
543 	/* Set up ECC autogeneration */
544 	cafe->ctl2 |= (1<<30);
545 
546 	return nand_prog_page_end_op(chip);
547 }
548 
549 /* F_2[X]/(X**6+X+1)  */
550 static unsigned short gf64_mul(u8 a, u8 b)
551 {
552 	u8 c;
553 	unsigned int i;
554 
555 	c = 0;
556 	for (i = 0; i < 6; i++) {
557 		if (a & 1)
558 			c ^= b;
559 		a >>= 1;
560 		b <<= 1;
561 		if ((b & 0x40) != 0)
562 			b ^= 0x43;
563 	}
564 
565 	return c;
566 }
567 
568 /* F_64[X]/(X**2+X+A**-1) with A the generator of F_64[X]  */
569 static u16 gf4096_mul(u16 a, u16 b)
570 {
571 	u8 ah, al, bh, bl, ch, cl;
572 
573 	ah = a >> 6;
574 	al = a & 0x3f;
575 	bh = b >> 6;
576 	bl = b & 0x3f;
577 
578 	ch = gf64_mul(ah ^ al, bh ^ bl) ^ gf64_mul(al, bl);
579 	cl = gf64_mul(gf64_mul(ah, bh), 0x21) ^ gf64_mul(al, bl);
580 
581 	return (ch << 6) ^ cl;
582 }
583 
584 static int cafe_mul(int x)
585 {
586 	if (x == 0)
587 		return 1;
588 	return gf4096_mul(x, 0xe01);
589 }
590 
591 static int cafe_nand_attach_chip(struct nand_chip *chip)
592 {
593 	struct mtd_info *mtd = nand_to_mtd(chip);
594 	struct cafe_priv *cafe = nand_get_controller_data(chip);
595 	int err = 0;
596 
597 	cafe->dmabuf = dma_alloc_coherent(&cafe->pdev->dev, 2112,
598 					  &cafe->dmaaddr, GFP_KERNEL);
599 	if (!cafe->dmabuf)
600 		return -ENOMEM;
601 
602 	/* Set up DMA address */
603 	cafe_writel(cafe, lower_32_bits(cafe->dmaaddr), NAND_DMA_ADDR0);
604 	cafe_writel(cafe, upper_32_bits(cafe->dmaaddr), NAND_DMA_ADDR1);
605 
606 	cafe_dev_dbg(&cafe->pdev->dev, "Set DMA address to %x (virt %p)\n",
607 		     cafe_readl(cafe, NAND_DMA_ADDR0), cafe->dmabuf);
608 
609 	/* Restore the DMA flag */
610 	cafe->usedma = usedma;
611 
612 	cafe->ctl2 = BIT(27); /* Reed-Solomon ECC */
613 	if (mtd->writesize == 2048)
614 		cafe->ctl2 |= BIT(29); /* 2KiB page size */
615 
616 	/* Set up ECC according to the type of chip we found */
617 	mtd_set_ooblayout(mtd, &cafe_ooblayout_ops);
618 	if (mtd->writesize == 2048) {
619 		cafe->nand.bbt_td = &cafe_bbt_main_descr_2048;
620 		cafe->nand.bbt_md = &cafe_bbt_mirror_descr_2048;
621 	} else if (mtd->writesize == 512) {
622 		cafe->nand.bbt_td = &cafe_bbt_main_descr_512;
623 		cafe->nand.bbt_md = &cafe_bbt_mirror_descr_512;
624 	} else {
625 		dev_warn(&cafe->pdev->dev,
626 			 "Unexpected NAND flash writesize %d. Aborting\n",
627 			 mtd->writesize);
628 		err = -ENOTSUPP;
629 		goto out_free_dma;
630 	}
631 
632 	cafe->nand.ecc.engine_type = NAND_ECC_ENGINE_TYPE_ON_HOST;
633 	cafe->nand.ecc.placement = NAND_ECC_PLACEMENT_INTERLEAVED;
634 	cafe->nand.ecc.size = mtd->writesize;
635 	cafe->nand.ecc.bytes = 14;
636 	cafe->nand.ecc.strength = 4;
637 	cafe->nand.ecc.write_page = cafe_nand_write_page_lowlevel;
638 	cafe->nand.ecc.write_oob = cafe_nand_write_oob;
639 	cafe->nand.ecc.read_page = cafe_nand_read_page;
640 	cafe->nand.ecc.read_oob = cafe_nand_read_oob;
641 
642 	return 0;
643 
644  out_free_dma:
645 	dma_free_coherent(&cafe->pdev->dev, 2112, cafe->dmabuf, cafe->dmaaddr);
646 
647 	return err;
648 }
649 
650 static void cafe_nand_detach_chip(struct nand_chip *chip)
651 {
652 	struct cafe_priv *cafe = nand_get_controller_data(chip);
653 
654 	dma_free_coherent(&cafe->pdev->dev, 2112, cafe->dmabuf, cafe->dmaaddr);
655 }
656 
657 static const struct nand_controller_ops cafe_nand_controller_ops = {
658 	.attach_chip = cafe_nand_attach_chip,
659 	.detach_chip = cafe_nand_detach_chip,
660 };
661 
662 static int cafe_nand_probe(struct pci_dev *pdev,
663 				     const struct pci_device_id *ent)
664 {
665 	struct mtd_info *mtd;
666 	struct cafe_priv *cafe;
667 	uint32_t ctrl;
668 	int err = 0;
669 
670 	/* Very old versions shared the same PCI ident for all three
671 	   functions on the chip. Verify the class too... */
672 	if ((pdev->class >> 8) != PCI_CLASS_MEMORY_FLASH)
673 		return -ENODEV;
674 
675 	err = pci_enable_device(pdev);
676 	if (err)
677 		return err;
678 
679 	pci_set_master(pdev);
680 
681 	cafe = kzalloc(sizeof(*cafe), GFP_KERNEL);
682 	if (!cafe) {
683 		err = -ENOMEM;
684 		goto out_disable_device;
685 	}
686 
687 	mtd = nand_to_mtd(&cafe->nand);
688 	mtd->dev.parent = &pdev->dev;
689 	nand_set_controller_data(&cafe->nand, cafe);
690 
691 	cafe->pdev = pdev;
692 	cafe->mmio = pci_iomap(pdev, 0, 0);
693 	if (!cafe->mmio) {
694 		dev_warn(&pdev->dev, "failed to iomap\n");
695 		err = -ENOMEM;
696 		goto out_free_mtd;
697 	}
698 
699 	cafe->rs = init_rs_non_canonical(12, &cafe_mul, 0, 1, 8);
700 	if (!cafe->rs) {
701 		err = -ENOMEM;
702 		goto out_ior;
703 	}
704 
705 	cafe->nand.legacy.cmdfunc = cafe_nand_cmdfunc;
706 	cafe->nand.legacy.dev_ready = cafe_device_ready;
707 	cafe->nand.legacy.read_byte = cafe_read_byte;
708 	cafe->nand.legacy.read_buf = cafe_read_buf;
709 	cafe->nand.legacy.write_buf = cafe_write_buf;
710 	cafe->nand.legacy.select_chip = cafe_select_chip;
711 	cafe->nand.legacy.set_features = nand_get_set_features_notsupp;
712 	cafe->nand.legacy.get_features = nand_get_set_features_notsupp;
713 
714 	cafe->nand.legacy.chip_delay = 0;
715 
716 	/* Enable the following for a flash based bad block table */
717 	cafe->nand.bbt_options = NAND_BBT_USE_FLASH;
718 
719 	if (skipbbt)
720 		cafe->nand.options |= NAND_SKIP_BBTSCAN | NAND_NO_BBM_QUIRK;
721 
722 	if (numtimings && numtimings != 3) {
723 		dev_warn(&cafe->pdev->dev, "%d timing register values ignored; precisely three are required\n", numtimings);
724 	}
725 
726 	if (numtimings == 3) {
727 		cafe_dev_dbg(&cafe->pdev->dev, "Using provided timings (%08x %08x %08x)\n",
728 			     timing[0], timing[1], timing[2]);
729 	} else {
730 		timing[0] = cafe_readl(cafe, NAND_TIMING1);
731 		timing[1] = cafe_readl(cafe, NAND_TIMING2);
732 		timing[2] = cafe_readl(cafe, NAND_TIMING3);
733 
734 		if (timing[0] | timing[1] | timing[2]) {
735 			cafe_dev_dbg(&cafe->pdev->dev, "Timing registers already set (%08x %08x %08x)\n",
736 				     timing[0], timing[1], timing[2]);
737 		} else {
738 			dev_warn(&cafe->pdev->dev, "Timing registers unset; using most conservative defaults\n");
739 			timing[0] = timing[1] = timing[2] = 0xffffffff;
740 		}
741 	}
742 
743 	/* Start off by resetting the NAND controller completely */
744 	cafe_writel(cafe, 1, NAND_RESET);
745 	cafe_writel(cafe, 0, NAND_RESET);
746 
747 	cafe_writel(cafe, timing[0], NAND_TIMING1);
748 	cafe_writel(cafe, timing[1], NAND_TIMING2);
749 	cafe_writel(cafe, timing[2], NAND_TIMING3);
750 
751 	cafe_writel(cafe, 0xffffffff, NAND_IRQ_MASK);
752 	err = request_irq(pdev->irq, &cafe_nand_interrupt, IRQF_SHARED,
753 			  "CAFE NAND", mtd);
754 	if (err) {
755 		dev_warn(&pdev->dev, "Could not register IRQ %d\n", pdev->irq);
756 		goto out_free_rs;
757 	}
758 
759 	/* Disable master reset, enable NAND clock */
760 	ctrl = cafe_readl(cafe, GLOBAL_CTRL);
761 	ctrl &= 0xffffeff0;
762 	ctrl |= 0x00007000;
763 	cafe_writel(cafe, ctrl | 0x05, GLOBAL_CTRL);
764 	cafe_writel(cafe, ctrl | 0x0a, GLOBAL_CTRL);
765 	cafe_writel(cafe, 0, NAND_DMA_CTRL);
766 
767 	cafe_writel(cafe, 0x7006, GLOBAL_CTRL);
768 	cafe_writel(cafe, 0x700a, GLOBAL_CTRL);
769 
770 	/* Enable NAND IRQ in global IRQ mask register */
771 	cafe_writel(cafe, 0x80000007, GLOBAL_IRQ_MASK);
772 	cafe_dev_dbg(&cafe->pdev->dev, "Control %x, IRQ mask %x\n",
773 		cafe_readl(cafe, GLOBAL_CTRL),
774 		cafe_readl(cafe, GLOBAL_IRQ_MASK));
775 
776 	/* Do not use the DMA during the NAND identification */
777 	cafe->usedma = 0;
778 
779 	/* Scan to find existence of the device */
780 	cafe->nand.legacy.dummy_controller.ops = &cafe_nand_controller_ops;
781 	err = nand_scan(&cafe->nand, 2);
782 	if (err)
783 		goto out_irq;
784 
785 	pci_set_drvdata(pdev, mtd);
786 
787 	mtd->name = "cafe_nand";
788 	err = mtd_device_parse_register(mtd, part_probes, NULL, NULL, 0);
789 	if (err)
790 		goto out_cleanup_nand;
791 
792 	goto out;
793 
794  out_cleanup_nand:
795 	nand_cleanup(&cafe->nand);
796  out_irq:
797 	/* Disable NAND IRQ in global IRQ mask register */
798 	cafe_writel(cafe, ~1 & cafe_readl(cafe, GLOBAL_IRQ_MASK), GLOBAL_IRQ_MASK);
799 	free_irq(pdev->irq, mtd);
800  out_free_rs:
801 	free_rs(cafe->rs);
802  out_ior:
803 	pci_iounmap(pdev, cafe->mmio);
804  out_free_mtd:
805 	kfree(cafe);
806  out_disable_device:
807 	pci_disable_device(pdev);
808  out:
809 	return err;
810 }
811 
812 static void cafe_nand_remove(struct pci_dev *pdev)
813 {
814 	struct mtd_info *mtd = pci_get_drvdata(pdev);
815 	struct nand_chip *chip = mtd_to_nand(mtd);
816 	struct cafe_priv *cafe = nand_get_controller_data(chip);
817 	int ret;
818 
819 	/* Disable NAND IRQ in global IRQ mask register */
820 	cafe_writel(cafe, ~1 & cafe_readl(cafe, GLOBAL_IRQ_MASK), GLOBAL_IRQ_MASK);
821 	free_irq(pdev->irq, mtd);
822 	ret = mtd_device_unregister(mtd);
823 	WARN_ON(ret);
824 	nand_cleanup(chip);
825 	free_rs(cafe->rs);
826 	pci_iounmap(pdev, cafe->mmio);
827 	dma_free_coherent(&cafe->pdev->dev, 2112, cafe->dmabuf, cafe->dmaaddr);
828 	kfree(cafe);
829 	pci_disable_device(pdev);
830 }
831 
832 static const struct pci_device_id cafe_nand_tbl[] = {
833 	{ PCI_VENDOR_ID_MARVELL, PCI_DEVICE_ID_MARVELL_88ALP01_NAND,
834 	  PCI_ANY_ID, PCI_ANY_ID },
835 	{ }
836 };
837 
838 MODULE_DEVICE_TABLE(pci, cafe_nand_tbl);
839 
840 static int cafe_nand_resume(struct pci_dev *pdev)
841 {
842 	uint32_t ctrl;
843 	struct mtd_info *mtd = pci_get_drvdata(pdev);
844 	struct nand_chip *chip = mtd_to_nand(mtd);
845 	struct cafe_priv *cafe = nand_get_controller_data(chip);
846 
847        /* Start off by resetting the NAND controller completely */
848 	cafe_writel(cafe, 1, NAND_RESET);
849 	cafe_writel(cafe, 0, NAND_RESET);
850 	cafe_writel(cafe, 0xffffffff, NAND_IRQ_MASK);
851 
852 	/* Restore timing configuration */
853 	cafe_writel(cafe, timing[0], NAND_TIMING1);
854 	cafe_writel(cafe, timing[1], NAND_TIMING2);
855 	cafe_writel(cafe, timing[2], NAND_TIMING3);
856 
857         /* Disable master reset, enable NAND clock */
858 	ctrl = cafe_readl(cafe, GLOBAL_CTRL);
859 	ctrl &= 0xffffeff0;
860 	ctrl |= 0x00007000;
861 	cafe_writel(cafe, ctrl | 0x05, GLOBAL_CTRL);
862 	cafe_writel(cafe, ctrl | 0x0a, GLOBAL_CTRL);
863 	cafe_writel(cafe, 0, NAND_DMA_CTRL);
864 	cafe_writel(cafe, 0x7006, GLOBAL_CTRL);
865 	cafe_writel(cafe, 0x700a, GLOBAL_CTRL);
866 
867 	/* Set up DMA address */
868 	cafe_writel(cafe, cafe->dmaaddr & 0xffffffff, NAND_DMA_ADDR0);
869 	if (sizeof(cafe->dmaaddr) > 4)
870 	/* Shift in two parts to shut the compiler up */
871 		cafe_writel(cafe, (cafe->dmaaddr >> 16) >> 16, NAND_DMA_ADDR1);
872 	else
873 		cafe_writel(cafe, 0, NAND_DMA_ADDR1);
874 
875 	/* Enable NAND IRQ in global IRQ mask register */
876 	cafe_writel(cafe, 0x80000007, GLOBAL_IRQ_MASK);
877 	return 0;
878 }
879 
880 static struct pci_driver cafe_nand_pci_driver = {
881 	.name = "CAFÉ NAND",
882 	.id_table = cafe_nand_tbl,
883 	.probe = cafe_nand_probe,
884 	.remove = cafe_nand_remove,
885 	.resume = cafe_nand_resume,
886 };
887 
888 module_pci_driver(cafe_nand_pci_driver);
889 
890 MODULE_LICENSE("GPL");
891 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
892 MODULE_DESCRIPTION("NAND flash driver for OLPC CAFÉ chip");
893