xref: /openbmc/linux/drivers/mtd/nand/raw/cafe_nand.c (revision 045f77ba)
1 /*
2  * Driver for One Laptop Per Child ‘CAFÉ’ controller, aka Marvell 88ALP01
3  *
4  * The data sheet for this device can be found at:
5  *    http://wiki.laptop.org/go/Datasheets
6  *
7  * Copyright © 2006 Red Hat, Inc.
8  * Copyright © 2006 David Woodhouse <dwmw2@infradead.org>
9  */
10 
11 #define DEBUG
12 
13 #include <linux/device.h>
14 #undef DEBUG
15 #include <linux/mtd/mtd.h>
16 #include <linux/mtd/rawnand.h>
17 #include <linux/mtd/partitions.h>
18 #include <linux/rslib.h>
19 #include <linux/pci.h>
20 #include <linux/delay.h>
21 #include <linux/interrupt.h>
22 #include <linux/dma-mapping.h>
23 #include <linux/slab.h>
24 #include <linux/module.h>
25 #include <asm/io.h>
26 
27 #define CAFE_NAND_CTRL1		0x00
28 #define CAFE_NAND_CTRL2		0x04
29 #define CAFE_NAND_CTRL3		0x08
30 #define CAFE_NAND_STATUS	0x0c
31 #define CAFE_NAND_IRQ		0x10
32 #define CAFE_NAND_IRQ_MASK	0x14
33 #define CAFE_NAND_DATA_LEN	0x18
34 #define CAFE_NAND_ADDR1		0x1c
35 #define CAFE_NAND_ADDR2		0x20
36 #define CAFE_NAND_TIMING1	0x24
37 #define CAFE_NAND_TIMING2	0x28
38 #define CAFE_NAND_TIMING3	0x2c
39 #define CAFE_NAND_NONMEM	0x30
40 #define CAFE_NAND_ECC_RESULT	0x3C
41 #define CAFE_NAND_DMA_CTRL	0x40
42 #define CAFE_NAND_DMA_ADDR0	0x44
43 #define CAFE_NAND_DMA_ADDR1	0x48
44 #define CAFE_NAND_ECC_SYN01	0x50
45 #define CAFE_NAND_ECC_SYN23	0x54
46 #define CAFE_NAND_ECC_SYN45	0x58
47 #define CAFE_NAND_ECC_SYN67	0x5c
48 #define CAFE_NAND_READ_DATA	0x1000
49 #define CAFE_NAND_WRITE_DATA	0x2000
50 
51 #define CAFE_GLOBAL_CTRL	0x3004
52 #define CAFE_GLOBAL_IRQ		0x3008
53 #define CAFE_GLOBAL_IRQ_MASK	0x300c
54 #define CAFE_NAND_RESET		0x3034
55 
56 /* Missing from the datasheet: bit 19 of CTRL1 sets CE0 vs. CE1 */
57 #define CTRL1_CHIPSELECT	(1<<19)
58 
59 struct cafe_priv {
60 	struct nand_chip nand;
61 	struct pci_dev *pdev;
62 	void __iomem *mmio;
63 	struct rs_control *rs;
64 	uint32_t ctl1;
65 	uint32_t ctl2;
66 	int datalen;
67 	int nr_data;
68 	int data_pos;
69 	int page_addr;
70 	bool usedma;
71 	dma_addr_t dmaaddr;
72 	unsigned char *dmabuf;
73 };
74 
75 static int usedma = 1;
76 module_param(usedma, int, 0644);
77 
78 static int skipbbt = 0;
79 module_param(skipbbt, int, 0644);
80 
81 static int debug = 0;
82 module_param(debug, int, 0644);
83 
84 static int regdebug = 0;
85 module_param(regdebug, int, 0644);
86 
87 static int checkecc = 1;
88 module_param(checkecc, int, 0644);
89 
90 static unsigned int numtimings;
91 static int timing[3];
92 module_param_array(timing, int, &numtimings, 0644);
93 
94 static const char *part_probes[] = { "cmdlinepart", "RedBoot", NULL };
95 
96 /* Hrm. Why isn't this already conditional on something in the struct device? */
97 #define cafe_dev_dbg(dev, args...) do { if (debug) dev_dbg(dev, ##args); } while(0)
98 
99 /* Make it easier to switch to PIO if we need to */
100 #define cafe_readl(cafe, addr)			readl((cafe)->mmio + CAFE_##addr)
101 #define cafe_writel(cafe, datum, addr)		writel(datum, (cafe)->mmio + CAFE_##addr)
102 
103 static int cafe_device_ready(struct mtd_info *mtd)
104 {
105 	struct nand_chip *chip = mtd_to_nand(mtd);
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 mtd_info *mtd, const uint8_t *buf, int len)
121 {
122 	struct nand_chip *chip = mtd_to_nand(mtd);
123 	struct cafe_priv *cafe = nand_get_controller_data(chip);
124 
125 	if (cafe->usedma)
126 		memcpy(cafe->dmabuf + cafe->datalen, buf, len);
127 	else
128 		memcpy_toio(cafe->mmio + CAFE_NAND_WRITE_DATA + cafe->datalen, buf, len);
129 
130 	cafe->datalen += len;
131 
132 	cafe_dev_dbg(&cafe->pdev->dev, "Copy 0x%x bytes to write buffer. datalen 0x%x\n",
133 		len, cafe->datalen);
134 }
135 
136 static void cafe_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
137 {
138 	struct nand_chip *chip = mtd_to_nand(mtd);
139 	struct cafe_priv *cafe = nand_get_controller_data(chip);
140 
141 	if (cafe->usedma)
142 		memcpy(buf, cafe->dmabuf + cafe->datalen, len);
143 	else
144 		memcpy_fromio(buf, cafe->mmio + CAFE_NAND_READ_DATA + cafe->datalen, len);
145 
146 	cafe_dev_dbg(&cafe->pdev->dev, "Copy 0x%x bytes from position 0x%x in read buffer.\n",
147 		  len, cafe->datalen);
148 	cafe->datalen += len;
149 }
150 
151 static uint8_t cafe_read_byte(struct mtd_info *mtd)
152 {
153 	struct nand_chip *chip = mtd_to_nand(mtd);
154 	struct cafe_priv *cafe = nand_get_controller_data(chip);
155 	uint8_t d;
156 
157 	cafe_read_buf(mtd, &d, 1);
158 	cafe_dev_dbg(&cafe->pdev->dev, "Read %02x\n", d);
159 
160 	return d;
161 }
162 
163 static void cafe_nand_cmdfunc(struct mtd_info *mtd, unsigned command,
164 			      int column, int page_addr)
165 {
166 	struct nand_chip *chip = mtd_to_nand(mtd);
167 	struct cafe_priv *cafe = nand_get_controller_data(chip);
168 	int adrbytes = 0;
169 	uint32_t ctl1;
170 	uint32_t doneint = 0x80000000;
171 
172 	cafe_dev_dbg(&cafe->pdev->dev, "cmdfunc %02x, 0x%x, 0x%x\n",
173 		command, column, page_addr);
174 
175 	if (command == NAND_CMD_ERASE2 || command == NAND_CMD_PAGEPROG) {
176 		/* Second half of a command we already calculated */
177 		cafe_writel(cafe, cafe->ctl2 | 0x100 | command, NAND_CTRL2);
178 		ctl1 = cafe->ctl1;
179 		cafe->ctl2 &= ~(1<<30);
180 		cafe_dev_dbg(&cafe->pdev->dev, "Continue command, ctl1 %08x, #data %d\n",
181 			  cafe->ctl1, cafe->nr_data);
182 		goto do_command;
183 	}
184 	/* Reset ECC engine */
185 	cafe_writel(cafe, 0, NAND_CTRL2);
186 
187 	/* Emulate NAND_CMD_READOOB on large-page chips */
188 	if (mtd->writesize > 512 &&
189 	    command == NAND_CMD_READOOB) {
190 		column += mtd->writesize;
191 		command = NAND_CMD_READ0;
192 	}
193 
194 	/* FIXME: Do we need to send read command before sending data
195 	   for small-page chips, to position the buffer correctly? */
196 
197 	if (column != -1) {
198 		cafe_writel(cafe, column, NAND_ADDR1);
199 		adrbytes = 2;
200 		if (page_addr != -1)
201 			goto write_adr2;
202 	} else if (page_addr != -1) {
203 		cafe_writel(cafe, page_addr & 0xffff, NAND_ADDR1);
204 		page_addr >>= 16;
205 	write_adr2:
206 		cafe_writel(cafe, page_addr, NAND_ADDR2);
207 		adrbytes += 2;
208 		if (mtd->size > mtd->writesize << 16)
209 			adrbytes++;
210 	}
211 
212 	cafe->data_pos = cafe->datalen = 0;
213 
214 	/* Set command valid bit, mask in the chip select bit  */
215 	ctl1 = 0x80000000 | command | (cafe->ctl1 & CTRL1_CHIPSELECT);
216 
217 	/* Set RD or WR bits as appropriate */
218 	if (command == NAND_CMD_READID || command == NAND_CMD_STATUS) {
219 		ctl1 |= (1<<26); /* rd */
220 		/* Always 5 bytes, for now */
221 		cafe->datalen = 4;
222 		/* And one address cycle -- even for STATUS, since the controller doesn't work without */
223 		adrbytes = 1;
224 	} else if (command == NAND_CMD_READ0 || command == NAND_CMD_READ1 ||
225 		   command == NAND_CMD_READOOB || command == NAND_CMD_RNDOUT) {
226 		ctl1 |= 1<<26; /* rd */
227 		/* For now, assume just read to end of page */
228 		cafe->datalen = mtd->writesize + mtd->oobsize - column;
229 	} else if (command == NAND_CMD_SEQIN)
230 		ctl1 |= 1<<25; /* wr */
231 
232 	/* Set number of address bytes */
233 	if (adrbytes)
234 		ctl1 |= ((adrbytes-1)|8) << 27;
235 
236 	if (command == NAND_CMD_SEQIN || command == NAND_CMD_ERASE1) {
237 		/* Ignore the first command of a pair; the hardware
238 		   deals with them both at once, later */
239 		cafe->ctl1 = ctl1;
240 		cafe_dev_dbg(&cafe->pdev->dev, "Setup for delayed command, ctl1 %08x, dlen %x\n",
241 			  cafe->ctl1, cafe->datalen);
242 		return;
243 	}
244 	/* RNDOUT and READ0 commands need a following byte */
245 	if (command == NAND_CMD_RNDOUT)
246 		cafe_writel(cafe, cafe->ctl2 | 0x100 | NAND_CMD_RNDOUTSTART, NAND_CTRL2);
247 	else if (command == NAND_CMD_READ0 && mtd->writesize > 512)
248 		cafe_writel(cafe, cafe->ctl2 | 0x100 | NAND_CMD_READSTART, NAND_CTRL2);
249 
250  do_command:
251 	cafe_dev_dbg(&cafe->pdev->dev, "dlen %x, ctl1 %x, ctl2 %x\n",
252 		cafe->datalen, ctl1, cafe_readl(cafe, NAND_CTRL2));
253 
254 	/* NB: The datasheet lies -- we really should be subtracting 1 here */
255 	cafe_writel(cafe, cafe->datalen, NAND_DATA_LEN);
256 	cafe_writel(cafe, 0x90000000, NAND_IRQ);
257 	if (cafe->usedma && (ctl1 & (3<<25))) {
258 		uint32_t dmactl = 0xc0000000 + cafe->datalen;
259 		/* If WR or RD bits set, set up DMA */
260 		if (ctl1 & (1<<26)) {
261 			/* It's a read */
262 			dmactl |= (1<<29);
263 			/* ... so it's done when the DMA is done, not just
264 			   the command. */
265 			doneint = 0x10000000;
266 		}
267 		cafe_writel(cafe, dmactl, NAND_DMA_CTRL);
268 	}
269 	cafe->datalen = 0;
270 
271 	if (unlikely(regdebug)) {
272 		int i;
273 		printk("About to write command %08x to register 0\n", ctl1);
274 		for (i=4; i< 0x5c; i+=4)
275 			printk("Register %x: %08x\n", i, readl(cafe->mmio + i));
276 	}
277 
278 	cafe_writel(cafe, ctl1, NAND_CTRL1);
279 	/* Apply this short delay always to ensure that we do wait tWB in
280 	 * any case on any machine. */
281 	ndelay(100);
282 
283 	if (1) {
284 		int c;
285 		uint32_t irqs;
286 
287 		for (c = 500000; c != 0; c--) {
288 			irqs = cafe_readl(cafe, NAND_IRQ);
289 			if (irqs & doneint)
290 				break;
291 			udelay(1);
292 			if (!(c % 100000))
293 				cafe_dev_dbg(&cafe->pdev->dev, "Wait for ready, IRQ %x\n", irqs);
294 			cpu_relax();
295 		}
296 		cafe_writel(cafe, doneint, NAND_IRQ);
297 		cafe_dev_dbg(&cafe->pdev->dev, "Command %x completed after %d usec, irqs %x (%x)\n",
298 			     command, 500000-c, irqs, cafe_readl(cafe, NAND_IRQ));
299 	}
300 
301 	WARN_ON(cafe->ctl2 & (1<<30));
302 
303 	switch (command) {
304 
305 	case NAND_CMD_CACHEDPROG:
306 	case NAND_CMD_PAGEPROG:
307 	case NAND_CMD_ERASE1:
308 	case NAND_CMD_ERASE2:
309 	case NAND_CMD_SEQIN:
310 	case NAND_CMD_RNDIN:
311 	case NAND_CMD_STATUS:
312 	case NAND_CMD_RNDOUT:
313 		cafe_writel(cafe, cafe->ctl2, NAND_CTRL2);
314 		return;
315 	}
316 	nand_wait_ready(mtd);
317 	cafe_writel(cafe, cafe->ctl2, NAND_CTRL2);
318 }
319 
320 static void cafe_select_chip(struct mtd_info *mtd, int chipnr)
321 {
322 	struct nand_chip *chip = mtd_to_nand(mtd);
323 	struct cafe_priv *cafe = nand_get_controller_data(chip);
324 
325 	cafe_dev_dbg(&cafe->pdev->dev, "select_chip %d\n", chipnr);
326 
327 	/* Mask the appropriate bit into the stored value of ctl1
328 	   which will be used by cafe_nand_cmdfunc() */
329 	if (chipnr)
330 		cafe->ctl1 |= CTRL1_CHIPSELECT;
331 	else
332 		cafe->ctl1 &= ~CTRL1_CHIPSELECT;
333 }
334 
335 static irqreturn_t cafe_nand_interrupt(int irq, void *id)
336 {
337 	struct mtd_info *mtd = id;
338 	struct nand_chip *chip = mtd_to_nand(mtd);
339 	struct cafe_priv *cafe = nand_get_controller_data(chip);
340 	uint32_t irqs = cafe_readl(cafe, NAND_IRQ);
341 	cafe_writel(cafe, irqs & ~0x90000000, NAND_IRQ);
342 	if (!irqs)
343 		return IRQ_NONE;
344 
345 	cafe_dev_dbg(&cafe->pdev->dev, "irq, bits %x (%x)\n", irqs, cafe_readl(cafe, NAND_IRQ));
346 	return IRQ_HANDLED;
347 }
348 
349 static int cafe_nand_write_oob(struct mtd_info *mtd,
350 			       struct nand_chip *chip, int page)
351 {
352 	return nand_prog_page_op(chip, page, mtd->writesize, chip->oob_poi,
353 				 mtd->oobsize);
354 }
355 
356 /* Don't use -- use nand_read_oob_std for now */
357 static int cafe_nand_read_oob(struct mtd_info *mtd, struct nand_chip *chip,
358 			      int page)
359 {
360 	return nand_read_oob_op(chip, page, 0, chip->oob_poi, mtd->oobsize);
361 }
362 /**
363  * cafe_nand_read_page_syndrome - [REPLACEABLE] hardware ecc syndrome based page read
364  * @mtd:	mtd info structure
365  * @chip:	nand chip info structure
366  * @buf:	buffer to store read data
367  * @oob_required:	caller expects OOB data read to chip->oob_poi
368  *
369  * The hw generator calculates the error syndrome automatically. Therefore
370  * we need a special oob layout and handling.
371  */
372 static int cafe_nand_read_page(struct mtd_info *mtd, struct nand_chip *chip,
373 			       uint8_t *buf, int oob_required, int page)
374 {
375 	struct cafe_priv *cafe = nand_get_controller_data(chip);
376 	unsigned int max_bitflips = 0;
377 
378 	cafe_dev_dbg(&cafe->pdev->dev, "ECC result %08x SYN1,2 %08x\n",
379 		     cafe_readl(cafe, NAND_ECC_RESULT),
380 		     cafe_readl(cafe, NAND_ECC_SYN01));
381 
382 	nand_read_page_op(chip, page, 0, buf, mtd->writesize);
383 	chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
384 
385 	if (checkecc && cafe_readl(cafe, NAND_ECC_RESULT) & (1<<18)) {
386 		unsigned short syn[8], pat[4];
387 		int pos[4];
388 		u8 *oob = chip->oob_poi;
389 		int i, n;
390 
391 		for (i=0; i<8; i+=2) {
392 			uint32_t tmp = cafe_readl(cafe, NAND_ECC_SYN01 + (i*2));
393 
394 			syn[i] = cafe->rs->codec->index_of[tmp & 0xfff];
395 			syn[i+1] = cafe->rs->codec->index_of[(tmp >> 16) & 0xfff];
396 		}
397 
398 		n = decode_rs16(cafe->rs, NULL, NULL, 1367, syn, 0, pos, 0,
399 				pat);
400 
401 		for (i = 0; i < n; i++) {
402 			int p = pos[i];
403 
404 			/* The 12-bit symbols are mapped to bytes here */
405 
406 			if (p > 1374) {
407 				/* out of range */
408 				n = -1374;
409 			} else if (p == 0) {
410 				/* high four bits do not correspond to data */
411 				if (pat[i] > 0xff)
412 					n = -2048;
413 				else
414 					buf[0] ^= pat[i];
415 			} else if (p == 1365) {
416 				buf[2047] ^= pat[i] >> 4;
417 				oob[0] ^= pat[i] << 4;
418 			} else if (p > 1365) {
419 				if ((p & 1) == 1) {
420 					oob[3*p/2 - 2048] ^= pat[i] >> 4;
421 					oob[3*p/2 - 2047] ^= pat[i] << 4;
422 				} else {
423 					oob[3*p/2 - 2049] ^= pat[i] >> 8;
424 					oob[3*p/2 - 2048] ^= pat[i];
425 				}
426 			} else if ((p & 1) == 1) {
427 				buf[3*p/2] ^= pat[i] >> 4;
428 				buf[3*p/2 + 1] ^= pat[i] << 4;
429 			} else {
430 				buf[3*p/2 - 1] ^= pat[i] >> 8;
431 				buf[3*p/2] ^= pat[i];
432 			}
433 		}
434 
435 		if (n < 0) {
436 			dev_dbg(&cafe->pdev->dev, "Failed to correct ECC at %08x\n",
437 				cafe_readl(cafe, NAND_ADDR2) * 2048);
438 			for (i = 0; i < 0x5c; i += 4)
439 				printk("Register %x: %08x\n", i, readl(cafe->mmio + i));
440 			mtd->ecc_stats.failed++;
441 		} else {
442 			dev_dbg(&cafe->pdev->dev, "Corrected %d symbol errors\n", n);
443 			mtd->ecc_stats.corrected += n;
444 			max_bitflips = max_t(unsigned int, max_bitflips, n);
445 		}
446 	}
447 
448 	return max_bitflips;
449 }
450 
451 static int cafe_ooblayout_ecc(struct mtd_info *mtd, int section,
452 			      struct mtd_oob_region *oobregion)
453 {
454 	struct nand_chip *chip = mtd_to_nand(mtd);
455 
456 	if (section)
457 		return -ERANGE;
458 
459 	oobregion->offset = 0;
460 	oobregion->length = chip->ecc.total;
461 
462 	return 0;
463 }
464 
465 static int cafe_ooblayout_free(struct mtd_info *mtd, int section,
466 			       struct mtd_oob_region *oobregion)
467 {
468 	struct nand_chip *chip = mtd_to_nand(mtd);
469 
470 	if (section)
471 		return -ERANGE;
472 
473 	oobregion->offset = chip->ecc.total;
474 	oobregion->length = mtd->oobsize - chip->ecc.total;
475 
476 	return 0;
477 }
478 
479 static const struct mtd_ooblayout_ops cafe_ooblayout_ops = {
480 	.ecc = cafe_ooblayout_ecc,
481 	.free = cafe_ooblayout_free,
482 };
483 
484 /* Ick. The BBT code really ought to be able to work this bit out
485    for itself from the above, at least for the 2KiB case */
486 static uint8_t cafe_bbt_pattern_2048[] = { 'B', 'b', 't', '0' };
487 static uint8_t cafe_mirror_pattern_2048[] = { '1', 't', 'b', 'B' };
488 
489 static uint8_t cafe_bbt_pattern_512[] = { 0xBB };
490 static uint8_t cafe_mirror_pattern_512[] = { 0xBC };
491 
492 
493 static struct nand_bbt_descr cafe_bbt_main_descr_2048 = {
494 	.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
495 		| NAND_BBT_2BIT | NAND_BBT_VERSION,
496 	.offs =	14,
497 	.len = 4,
498 	.veroffs = 18,
499 	.maxblocks = 4,
500 	.pattern = cafe_bbt_pattern_2048
501 };
502 
503 static struct nand_bbt_descr cafe_bbt_mirror_descr_2048 = {
504 	.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
505 		| NAND_BBT_2BIT | NAND_BBT_VERSION,
506 	.offs =	14,
507 	.len = 4,
508 	.veroffs = 18,
509 	.maxblocks = 4,
510 	.pattern = cafe_mirror_pattern_2048
511 };
512 
513 static struct nand_bbt_descr cafe_bbt_main_descr_512 = {
514 	.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
515 		| NAND_BBT_2BIT | NAND_BBT_VERSION,
516 	.offs =	14,
517 	.len = 1,
518 	.veroffs = 15,
519 	.maxblocks = 4,
520 	.pattern = cafe_bbt_pattern_512
521 };
522 
523 static struct nand_bbt_descr cafe_bbt_mirror_descr_512 = {
524 	.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
525 		| NAND_BBT_2BIT | NAND_BBT_VERSION,
526 	.offs =	14,
527 	.len = 1,
528 	.veroffs = 15,
529 	.maxblocks = 4,
530 	.pattern = cafe_mirror_pattern_512
531 };
532 
533 
534 static int cafe_nand_write_page_lowlevel(struct mtd_info *mtd,
535 					  struct nand_chip *chip,
536 					  const uint8_t *buf, int oob_required,
537 					  int page)
538 {
539 	struct cafe_priv *cafe = nand_get_controller_data(chip);
540 
541 	nand_prog_page_begin_op(chip, page, 0, buf, mtd->writesize);
542 	chip->write_buf(mtd, chip->oob_poi, mtd->oobsize);
543 
544 	/* Set up ECC autogeneration */
545 	cafe->ctl2 |= (1<<30);
546 
547 	return nand_prog_page_end_op(chip);
548 }
549 
550 static int cafe_nand_block_bad(struct mtd_info *mtd, loff_t ofs)
551 {
552 	return 0;
553 }
554 
555 /* F_2[X]/(X**6+X+1)  */
556 static unsigned short gf64_mul(u8 a, u8 b)
557 {
558 	u8 c;
559 	unsigned int i;
560 
561 	c = 0;
562 	for (i = 0; i < 6; i++) {
563 		if (a & 1)
564 			c ^= b;
565 		a >>= 1;
566 		b <<= 1;
567 		if ((b & 0x40) != 0)
568 			b ^= 0x43;
569 	}
570 
571 	return c;
572 }
573 
574 /* F_64[X]/(X**2+X+A**-1) with A the generator of F_64[X]  */
575 static u16 gf4096_mul(u16 a, u16 b)
576 {
577 	u8 ah, al, bh, bl, ch, cl;
578 
579 	ah = a >> 6;
580 	al = a & 0x3f;
581 	bh = b >> 6;
582 	bl = b & 0x3f;
583 
584 	ch = gf64_mul(ah ^ al, bh ^ bl) ^ gf64_mul(al, bl);
585 	cl = gf64_mul(gf64_mul(ah, bh), 0x21) ^ gf64_mul(al, bl);
586 
587 	return (ch << 6) ^ cl;
588 }
589 
590 static int cafe_mul(int x)
591 {
592 	if (x == 0)
593 		return 1;
594 	return gf4096_mul(x, 0xe01);
595 }
596 
597 static int cafe_nand_attach_chip(struct nand_chip *chip)
598 {
599 	struct mtd_info *mtd = nand_to_mtd(chip);
600 	struct cafe_priv *cafe = nand_get_controller_data(chip);
601 	int err = 0;
602 
603 	cafe->dmabuf = dma_alloc_coherent(&cafe->pdev->dev, 2112,
604 					  &cafe->dmaaddr, GFP_KERNEL);
605 	if (!cafe->dmabuf)
606 		return -ENOMEM;
607 
608 	/* Set up DMA address */
609 	cafe_writel(cafe, lower_32_bits(cafe->dmaaddr), NAND_DMA_ADDR0);
610 	cafe_writel(cafe, upper_32_bits(cafe->dmaaddr), NAND_DMA_ADDR1);
611 
612 	cafe_dev_dbg(&cafe->pdev->dev, "Set DMA address to %x (virt %p)\n",
613 		     cafe_readl(cafe, NAND_DMA_ADDR0), cafe->dmabuf);
614 
615 	/* Restore the DMA flag */
616 	cafe->usedma = usedma;
617 
618 	cafe->ctl2 = BIT(27); /* Reed-Solomon ECC */
619 	if (mtd->writesize == 2048)
620 		cafe->ctl2 |= BIT(29); /* 2KiB page size */
621 
622 	/* Set up ECC according to the type of chip we found */
623 	mtd_set_ooblayout(mtd, &cafe_ooblayout_ops);
624 	if (mtd->writesize == 2048) {
625 		cafe->nand.bbt_td = &cafe_bbt_main_descr_2048;
626 		cafe->nand.bbt_md = &cafe_bbt_mirror_descr_2048;
627 	} else if (mtd->writesize == 512) {
628 		cafe->nand.bbt_td = &cafe_bbt_main_descr_512;
629 		cafe->nand.bbt_md = &cafe_bbt_mirror_descr_512;
630 	} else {
631 		dev_warn(&cafe->pdev->dev,
632 			 "Unexpected NAND flash writesize %d. Aborting\n",
633 			 mtd->writesize);
634 		err = -ENOTSUPP;
635 		goto out_free_dma;
636 	}
637 
638 	cafe->nand.ecc.mode = NAND_ECC_HW_SYNDROME;
639 	cafe->nand.ecc.size = mtd->writesize;
640 	cafe->nand.ecc.bytes = 14;
641 	cafe->nand.ecc.strength = 4;
642 	cafe->nand.ecc.write_page = cafe_nand_write_page_lowlevel;
643 	cafe->nand.ecc.write_oob = cafe_nand_write_oob;
644 	cafe->nand.ecc.read_page = cafe_nand_read_page;
645 	cafe->nand.ecc.read_oob = cafe_nand_read_oob;
646 
647 	return 0;
648 
649  out_free_dma:
650 	dma_free_coherent(&cafe->pdev->dev, 2112, cafe->dmabuf, cafe->dmaaddr);
651 
652 	return err;
653 }
654 
655 static void cafe_nand_detach_chip(struct nand_chip *chip)
656 {
657 	struct cafe_priv *cafe = nand_get_controller_data(chip);
658 
659 	dma_free_coherent(&cafe->pdev->dev, 2112, cafe->dmabuf, cafe->dmaaddr);
660 }
661 
662 static const struct nand_controller_ops cafe_nand_controller_ops = {
663 	.attach_chip = cafe_nand_attach_chip,
664 	.detach_chip = cafe_nand_detach_chip,
665 };
666 
667 static int cafe_nand_probe(struct pci_dev *pdev,
668 				     const struct pci_device_id *ent)
669 {
670 	struct mtd_info *mtd;
671 	struct cafe_priv *cafe;
672 	uint32_t ctrl;
673 	int err = 0;
674 
675 	/* Very old versions shared the same PCI ident for all three
676 	   functions on the chip. Verify the class too... */
677 	if ((pdev->class >> 8) != PCI_CLASS_MEMORY_FLASH)
678 		return -ENODEV;
679 
680 	err = pci_enable_device(pdev);
681 	if (err)
682 		return err;
683 
684 	pci_set_master(pdev);
685 
686 	cafe = kzalloc(sizeof(*cafe), GFP_KERNEL);
687 	if (!cafe)
688 		return  -ENOMEM;
689 
690 	mtd = nand_to_mtd(&cafe->nand);
691 	mtd->dev.parent = &pdev->dev;
692 	nand_set_controller_data(&cafe->nand, cafe);
693 
694 	cafe->pdev = pdev;
695 	cafe->mmio = pci_iomap(pdev, 0, 0);
696 	if (!cafe->mmio) {
697 		dev_warn(&pdev->dev, "failed to iomap\n");
698 		err = -ENOMEM;
699 		goto out_free_mtd;
700 	}
701 
702 	cafe->rs = init_rs_non_canonical(12, &cafe_mul, 0, 1, 8);
703 	if (!cafe->rs) {
704 		err = -ENOMEM;
705 		goto out_ior;
706 	}
707 
708 	cafe->nand.cmdfunc = cafe_nand_cmdfunc;
709 	cafe->nand.dev_ready = cafe_device_ready;
710 	cafe->nand.read_byte = cafe_read_byte;
711 	cafe->nand.read_buf = cafe_read_buf;
712 	cafe->nand.write_buf = cafe_write_buf;
713 	cafe->nand.select_chip = cafe_select_chip;
714 	cafe->nand.set_features = nand_get_set_features_notsupp;
715 	cafe->nand.get_features = nand_get_set_features_notsupp;
716 
717 	cafe->nand.chip_delay = 0;
718 
719 	/* Enable the following for a flash based bad block table */
720 	cafe->nand.bbt_options = NAND_BBT_USE_FLASH;
721 
722 	if (skipbbt) {
723 		cafe->nand.options |= NAND_SKIP_BBTSCAN;
724 		cafe->nand.block_bad = cafe_nand_block_bad;
725 	}
726 
727 	if (numtimings && numtimings != 3) {
728 		dev_warn(&cafe->pdev->dev, "%d timing register values ignored; precisely three are required\n", numtimings);
729 	}
730 
731 	if (numtimings == 3) {
732 		cafe_dev_dbg(&cafe->pdev->dev, "Using provided timings (%08x %08x %08x)\n",
733 			     timing[0], timing[1], timing[2]);
734 	} else {
735 		timing[0] = cafe_readl(cafe, NAND_TIMING1);
736 		timing[1] = cafe_readl(cafe, NAND_TIMING2);
737 		timing[2] = cafe_readl(cafe, NAND_TIMING3);
738 
739 		if (timing[0] | timing[1] | timing[2]) {
740 			cafe_dev_dbg(&cafe->pdev->dev, "Timing registers already set (%08x %08x %08x)\n",
741 				     timing[0], timing[1], timing[2]);
742 		} else {
743 			dev_warn(&cafe->pdev->dev, "Timing registers unset; using most conservative defaults\n");
744 			timing[0] = timing[1] = timing[2] = 0xffffffff;
745 		}
746 	}
747 
748 	/* Start off by resetting the NAND controller completely */
749 	cafe_writel(cafe, 1, NAND_RESET);
750 	cafe_writel(cafe, 0, NAND_RESET);
751 
752 	cafe_writel(cafe, timing[0], NAND_TIMING1);
753 	cafe_writel(cafe, timing[1], NAND_TIMING2);
754 	cafe_writel(cafe, timing[2], NAND_TIMING3);
755 
756 	cafe_writel(cafe, 0xffffffff, NAND_IRQ_MASK);
757 	err = request_irq(pdev->irq, &cafe_nand_interrupt, IRQF_SHARED,
758 			  "CAFE NAND", mtd);
759 	if (err) {
760 		dev_warn(&pdev->dev, "Could not register IRQ %d\n", pdev->irq);
761 		goto out_ior;
762 	}
763 
764 	/* Disable master reset, enable NAND clock */
765 	ctrl = cafe_readl(cafe, GLOBAL_CTRL);
766 	ctrl &= 0xffffeff0;
767 	ctrl |= 0x00007000;
768 	cafe_writel(cafe, ctrl | 0x05, GLOBAL_CTRL);
769 	cafe_writel(cafe, ctrl | 0x0a, GLOBAL_CTRL);
770 	cafe_writel(cafe, 0, NAND_DMA_CTRL);
771 
772 	cafe_writel(cafe, 0x7006, GLOBAL_CTRL);
773 	cafe_writel(cafe, 0x700a, GLOBAL_CTRL);
774 
775 	/* Enable NAND IRQ in global IRQ mask register */
776 	cafe_writel(cafe, 0x80000007, GLOBAL_IRQ_MASK);
777 	cafe_dev_dbg(&cafe->pdev->dev, "Control %x, IRQ mask %x\n",
778 		cafe_readl(cafe, GLOBAL_CTRL),
779 		cafe_readl(cafe, GLOBAL_IRQ_MASK));
780 
781 	/* Do not use the DMA during the NAND identification */
782 	cafe->usedma = 0;
783 
784 	/* Scan to find existence of the device */
785 	cafe->nand.dummy_controller.ops = &cafe_nand_controller_ops;
786 	err = nand_scan(mtd, 2);
787 	if (err)
788 		goto out_irq;
789 
790 	pci_set_drvdata(pdev, mtd);
791 
792 	mtd->name = "cafe_nand";
793 	err = mtd_device_parse_register(mtd, part_probes, NULL, NULL, 0);
794 	if (err)
795 		goto out_cleanup_nand;
796 
797 	goto out;
798 
799  out_cleanup_nand:
800 	nand_cleanup(&cafe->nand);
801  out_irq:
802 	/* Disable NAND IRQ in global IRQ mask register */
803 	cafe_writel(cafe, ~1 & cafe_readl(cafe, GLOBAL_IRQ_MASK), GLOBAL_IRQ_MASK);
804 	free_irq(pdev->irq, mtd);
805  out_ior:
806 	pci_iounmap(pdev, cafe->mmio);
807  out_free_mtd:
808 	kfree(cafe);
809  out:
810 	return err;
811 }
812 
813 static void cafe_nand_remove(struct pci_dev *pdev)
814 {
815 	struct mtd_info *mtd = pci_get_drvdata(pdev);
816 	struct nand_chip *chip = mtd_to_nand(mtd);
817 	struct cafe_priv *cafe = nand_get_controller_data(chip);
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 	nand_release(mtd);
823 	free_rs(cafe->rs);
824 	pci_iounmap(pdev, cafe->mmio);
825 	dma_free_coherent(&cafe->pdev->dev, 2112, cafe->dmabuf, cafe->dmaaddr);
826 	kfree(cafe);
827 }
828 
829 static const struct pci_device_id cafe_nand_tbl[] = {
830 	{ PCI_VENDOR_ID_MARVELL, PCI_DEVICE_ID_MARVELL_88ALP01_NAND,
831 	  PCI_ANY_ID, PCI_ANY_ID },
832 	{ }
833 };
834 
835 MODULE_DEVICE_TABLE(pci, cafe_nand_tbl);
836 
837 static int cafe_nand_resume(struct pci_dev *pdev)
838 {
839 	uint32_t ctrl;
840 	struct mtd_info *mtd = pci_get_drvdata(pdev);
841 	struct nand_chip *chip = mtd_to_nand(mtd);
842 	struct cafe_priv *cafe = nand_get_controller_data(chip);
843 
844        /* Start off by resetting the NAND controller completely */
845 	cafe_writel(cafe, 1, NAND_RESET);
846 	cafe_writel(cafe, 0, NAND_RESET);
847 	cafe_writel(cafe, 0xffffffff, NAND_IRQ_MASK);
848 
849 	/* Restore timing configuration */
850 	cafe_writel(cafe, timing[0], NAND_TIMING1);
851 	cafe_writel(cafe, timing[1], NAND_TIMING2);
852 	cafe_writel(cafe, timing[2], NAND_TIMING3);
853 
854         /* Disable master reset, enable NAND clock */
855 	ctrl = cafe_readl(cafe, GLOBAL_CTRL);
856 	ctrl &= 0xffffeff0;
857 	ctrl |= 0x00007000;
858 	cafe_writel(cafe, ctrl | 0x05, GLOBAL_CTRL);
859 	cafe_writel(cafe, ctrl | 0x0a, GLOBAL_CTRL);
860 	cafe_writel(cafe, 0, NAND_DMA_CTRL);
861 	cafe_writel(cafe, 0x7006, GLOBAL_CTRL);
862 	cafe_writel(cafe, 0x700a, GLOBAL_CTRL);
863 
864 	/* Set up DMA address */
865 	cafe_writel(cafe, cafe->dmaaddr & 0xffffffff, NAND_DMA_ADDR0);
866 	if (sizeof(cafe->dmaaddr) > 4)
867 	/* Shift in two parts to shut the compiler up */
868 		cafe_writel(cafe, (cafe->dmaaddr >> 16) >> 16, NAND_DMA_ADDR1);
869 	else
870 		cafe_writel(cafe, 0, NAND_DMA_ADDR1);
871 
872 	/* Enable NAND IRQ in global IRQ mask register */
873 	cafe_writel(cafe, 0x80000007, GLOBAL_IRQ_MASK);
874 	return 0;
875 }
876 
877 static struct pci_driver cafe_nand_pci_driver = {
878 	.name = "CAFÉ NAND",
879 	.id_table = cafe_nand_tbl,
880 	.probe = cafe_nand_probe,
881 	.remove = cafe_nand_remove,
882 	.resume = cafe_nand_resume,
883 };
884 
885 module_pci_driver(cafe_nand_pci_driver);
886 
887 MODULE_LICENSE("GPL");
888 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
889 MODULE_DESCRIPTION("NAND flash driver for OLPC CAFÉ chip");
890