xref: /linux/drivers/mtd/nand/raw/cafe_nand.c (revision 2359ccddc1c3f4752f43cc19b3db189710b15791)
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 	dma_addr_t dmaaddr;
71 	unsigned char *dmabuf;
72 };
73 
74 static int usedma = 1;
75 module_param(usedma, int, 0644);
76 
77 static int skipbbt = 0;
78 module_param(skipbbt, int, 0644);
79 
80 static int debug = 0;
81 module_param(debug, int, 0644);
82 
83 static int regdebug = 0;
84 module_param(regdebug, int, 0644);
85 
86 static int checkecc = 1;
87 module_param(checkecc, int, 0644);
88 
89 static unsigned int numtimings;
90 static int timing[3];
91 module_param_array(timing, int, &numtimings, 0644);
92 
93 static const char *part_probes[] = { "cmdlinepart", "RedBoot", NULL };
94 
95 /* Hrm. Why isn't this already conditional on something in the struct device? */
96 #define cafe_dev_dbg(dev, args...) do { if (debug) dev_dbg(dev, ##args); } while(0)
97 
98 /* Make it easier to switch to PIO if we need to */
99 #define cafe_readl(cafe, addr)			readl((cafe)->mmio + CAFE_##addr)
100 #define cafe_writel(cafe, datum, addr)		writel(datum, (cafe)->mmio + CAFE_##addr)
101 
102 static int cafe_device_ready(struct mtd_info *mtd)
103 {
104 	struct nand_chip *chip = mtd_to_nand(mtd);
105 	struct cafe_priv *cafe = nand_get_controller_data(chip);
106 	int result = !!(cafe_readl(cafe, NAND_STATUS) & 0x40000000);
107 	uint32_t irqs = cafe_readl(cafe, NAND_IRQ);
108 
109 	cafe_writel(cafe, irqs, NAND_IRQ);
110 
111 	cafe_dev_dbg(&cafe->pdev->dev, "NAND device is%s ready, IRQ %x (%x) (%x,%x)\n",
112 		result?"":" not", irqs, cafe_readl(cafe, NAND_IRQ),
113 		cafe_readl(cafe, GLOBAL_IRQ), cafe_readl(cafe, GLOBAL_IRQ_MASK));
114 
115 	return result;
116 }
117 
118 
119 static void cafe_write_buf(struct mtd_info *mtd, const uint8_t *buf, int len)
120 {
121 	struct nand_chip *chip = mtd_to_nand(mtd);
122 	struct cafe_priv *cafe = nand_get_controller_data(chip);
123 
124 	if (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 mtd_info *mtd, uint8_t *buf, int len)
136 {
137 	struct nand_chip *chip = mtd_to_nand(mtd);
138 	struct cafe_priv *cafe = nand_get_controller_data(chip);
139 
140 	if (usedma)
141 		memcpy(buf, cafe->dmabuf + cafe->datalen, len);
142 	else
143 		memcpy_fromio(buf, cafe->mmio + CAFE_NAND_READ_DATA + cafe->datalen, len);
144 
145 	cafe_dev_dbg(&cafe->pdev->dev, "Copy 0x%x bytes from position 0x%x in read buffer.\n",
146 		  len, cafe->datalen);
147 	cafe->datalen += len;
148 }
149 
150 static uint8_t cafe_read_byte(struct mtd_info *mtd)
151 {
152 	struct nand_chip *chip = mtd_to_nand(mtd);
153 	struct cafe_priv *cafe = nand_get_controller_data(chip);
154 	uint8_t d;
155 
156 	cafe_read_buf(mtd, &d, 1);
157 	cafe_dev_dbg(&cafe->pdev->dev, "Read %02x\n", d);
158 
159 	return d;
160 }
161 
162 static void cafe_nand_cmdfunc(struct mtd_info *mtd, unsigned command,
163 			      int column, int page_addr)
164 {
165 	struct nand_chip *chip = mtd_to_nand(mtd);
166 	struct cafe_priv *cafe = nand_get_controller_data(chip);
167 	int adrbytes = 0;
168 	uint32_t ctl1;
169 	uint32_t doneint = 0x80000000;
170 
171 	cafe_dev_dbg(&cafe->pdev->dev, "cmdfunc %02x, 0x%x, 0x%x\n",
172 		command, column, page_addr);
173 
174 	if (command == NAND_CMD_ERASE2 || command == NAND_CMD_PAGEPROG) {
175 		/* Second half of a command we already calculated */
176 		cafe_writel(cafe, cafe->ctl2 | 0x100 | command, NAND_CTRL2);
177 		ctl1 = cafe->ctl1;
178 		cafe->ctl2 &= ~(1<<30);
179 		cafe_dev_dbg(&cafe->pdev->dev, "Continue command, ctl1 %08x, #data %d\n",
180 			  cafe->ctl1, cafe->nr_data);
181 		goto do_command;
182 	}
183 	/* Reset ECC engine */
184 	cafe_writel(cafe, 0, NAND_CTRL2);
185 
186 	/* Emulate NAND_CMD_READOOB on large-page chips */
187 	if (mtd->writesize > 512 &&
188 	    command == NAND_CMD_READOOB) {
189 		column += mtd->writesize;
190 		command = NAND_CMD_READ0;
191 	}
192 
193 	/* FIXME: Do we need to send read command before sending data
194 	   for small-page chips, to position the buffer correctly? */
195 
196 	if (column != -1) {
197 		cafe_writel(cafe, column, NAND_ADDR1);
198 		adrbytes = 2;
199 		if (page_addr != -1)
200 			goto write_adr2;
201 	} else if (page_addr != -1) {
202 		cafe_writel(cafe, page_addr & 0xffff, NAND_ADDR1);
203 		page_addr >>= 16;
204 	write_adr2:
205 		cafe_writel(cafe, page_addr, NAND_ADDR2);
206 		adrbytes += 2;
207 		if (mtd->size > mtd->writesize << 16)
208 			adrbytes++;
209 	}
210 
211 	cafe->data_pos = cafe->datalen = 0;
212 
213 	/* Set command valid bit, mask in the chip select bit  */
214 	ctl1 = 0x80000000 | command | (cafe->ctl1 & CTRL1_CHIPSELECT);
215 
216 	/* Set RD or WR bits as appropriate */
217 	if (command == NAND_CMD_READID || command == NAND_CMD_STATUS) {
218 		ctl1 |= (1<<26); /* rd */
219 		/* Always 5 bytes, for now */
220 		cafe->datalen = 4;
221 		/* And one address cycle -- even for STATUS, since the controller doesn't work without */
222 		adrbytes = 1;
223 	} else if (command == NAND_CMD_READ0 || command == NAND_CMD_READ1 ||
224 		   command == NAND_CMD_READOOB || command == NAND_CMD_RNDOUT) {
225 		ctl1 |= 1<<26; /* rd */
226 		/* For now, assume just read to end of page */
227 		cafe->datalen = mtd->writesize + mtd->oobsize - column;
228 	} else if (command == NAND_CMD_SEQIN)
229 		ctl1 |= 1<<25; /* wr */
230 
231 	/* Set number of address bytes */
232 	if (adrbytes)
233 		ctl1 |= ((adrbytes-1)|8) << 27;
234 
235 	if (command == NAND_CMD_SEQIN || command == NAND_CMD_ERASE1) {
236 		/* Ignore the first command of a pair; the hardware
237 		   deals with them both at once, later */
238 		cafe->ctl1 = ctl1;
239 		cafe_dev_dbg(&cafe->pdev->dev, "Setup for delayed command, ctl1 %08x, dlen %x\n",
240 			  cafe->ctl1, cafe->datalen);
241 		return;
242 	}
243 	/* RNDOUT and READ0 commands need a following byte */
244 	if (command == NAND_CMD_RNDOUT)
245 		cafe_writel(cafe, cafe->ctl2 | 0x100 | NAND_CMD_RNDOUTSTART, NAND_CTRL2);
246 	else if (command == NAND_CMD_READ0 && mtd->writesize > 512)
247 		cafe_writel(cafe, cafe->ctl2 | 0x100 | NAND_CMD_READSTART, NAND_CTRL2);
248 
249  do_command:
250 	cafe_dev_dbg(&cafe->pdev->dev, "dlen %x, ctl1 %x, ctl2 %x\n",
251 		cafe->datalen, ctl1, cafe_readl(cafe, NAND_CTRL2));
252 
253 	/* NB: The datasheet lies -- we really should be subtracting 1 here */
254 	cafe_writel(cafe, cafe->datalen, NAND_DATA_LEN);
255 	cafe_writel(cafe, 0x90000000, NAND_IRQ);
256 	if (usedma && (ctl1 & (3<<25))) {
257 		uint32_t dmactl = 0xc0000000 + cafe->datalen;
258 		/* If WR or RD bits set, set up DMA */
259 		if (ctl1 & (1<<26)) {
260 			/* It's a read */
261 			dmactl |= (1<<29);
262 			/* ... so it's done when the DMA is done, not just
263 			   the command. */
264 			doneint = 0x10000000;
265 		}
266 		cafe_writel(cafe, dmactl, NAND_DMA_CTRL);
267 	}
268 	cafe->datalen = 0;
269 
270 	if (unlikely(regdebug)) {
271 		int i;
272 		printk("About to write command %08x to register 0\n", ctl1);
273 		for (i=4; i< 0x5c; i+=4)
274 			printk("Register %x: %08x\n", i, readl(cafe->mmio + i));
275 	}
276 
277 	cafe_writel(cafe, ctl1, NAND_CTRL1);
278 	/* Apply this short delay always to ensure that we do wait tWB in
279 	 * any case on any machine. */
280 	ndelay(100);
281 
282 	if (1) {
283 		int c;
284 		uint32_t irqs;
285 
286 		for (c = 500000; c != 0; c--) {
287 			irqs = cafe_readl(cafe, NAND_IRQ);
288 			if (irqs & doneint)
289 				break;
290 			udelay(1);
291 			if (!(c % 100000))
292 				cafe_dev_dbg(&cafe->pdev->dev, "Wait for ready, IRQ %x\n", irqs);
293 			cpu_relax();
294 		}
295 		cafe_writel(cafe, doneint, NAND_IRQ);
296 		cafe_dev_dbg(&cafe->pdev->dev, "Command %x completed after %d usec, irqs %x (%x)\n",
297 			     command, 500000-c, irqs, cafe_readl(cafe, NAND_IRQ));
298 	}
299 
300 	WARN_ON(cafe->ctl2 & (1<<30));
301 
302 	switch (command) {
303 
304 	case NAND_CMD_CACHEDPROG:
305 	case NAND_CMD_PAGEPROG:
306 	case NAND_CMD_ERASE1:
307 	case NAND_CMD_ERASE2:
308 	case NAND_CMD_SEQIN:
309 	case NAND_CMD_RNDIN:
310 	case NAND_CMD_STATUS:
311 	case NAND_CMD_RNDOUT:
312 		cafe_writel(cafe, cafe->ctl2, NAND_CTRL2);
313 		return;
314 	}
315 	nand_wait_ready(mtd);
316 	cafe_writel(cafe, cafe->ctl2, NAND_CTRL2);
317 }
318 
319 static void cafe_select_chip(struct mtd_info *mtd, int chipnr)
320 {
321 	struct nand_chip *chip = mtd_to_nand(mtd);
322 	struct cafe_priv *cafe = nand_get_controller_data(chip);
323 
324 	cafe_dev_dbg(&cafe->pdev->dev, "select_chip %d\n", chipnr);
325 
326 	/* Mask the appropriate bit into the stored value of ctl1
327 	   which will be used by cafe_nand_cmdfunc() */
328 	if (chipnr)
329 		cafe->ctl1 |= CTRL1_CHIPSELECT;
330 	else
331 		cafe->ctl1 &= ~CTRL1_CHIPSELECT;
332 }
333 
334 static irqreturn_t cafe_nand_interrupt(int irq, void *id)
335 {
336 	struct mtd_info *mtd = id;
337 	struct nand_chip *chip = mtd_to_nand(mtd);
338 	struct cafe_priv *cafe = nand_get_controller_data(chip);
339 	uint32_t irqs = cafe_readl(cafe, NAND_IRQ);
340 	cafe_writel(cafe, irqs & ~0x90000000, NAND_IRQ);
341 	if (!irqs)
342 		return IRQ_NONE;
343 
344 	cafe_dev_dbg(&cafe->pdev->dev, "irq, bits %x (%x)\n", irqs, cafe_readl(cafe, NAND_IRQ));
345 	return IRQ_HANDLED;
346 }
347 
348 static void cafe_nand_bug(struct mtd_info *mtd)
349 {
350 	BUG();
351 }
352 
353 static int cafe_nand_write_oob(struct mtd_info *mtd,
354 			       struct nand_chip *chip, int page)
355 {
356 	return nand_prog_page_op(chip, page, mtd->writesize, chip->oob_poi,
357 				 mtd->oobsize);
358 }
359 
360 /* Don't use -- use nand_read_oob_std for now */
361 static int cafe_nand_read_oob(struct mtd_info *mtd, struct nand_chip *chip,
362 			      int page)
363 {
364 	return nand_read_oob_op(chip, page, 0, chip->oob_poi, mtd->oobsize);
365 }
366 /**
367  * cafe_nand_read_page_syndrome - [REPLACEABLE] hardware ecc syndrome based page read
368  * @mtd:	mtd info structure
369  * @chip:	nand chip info structure
370  * @buf:	buffer to store read data
371  * @oob_required:	caller expects OOB data read to chip->oob_poi
372  *
373  * The hw generator calculates the error syndrome automatically. Therefore
374  * we need a special oob layout and handling.
375  */
376 static int cafe_nand_read_page(struct mtd_info *mtd, struct nand_chip *chip,
377 			       uint8_t *buf, int oob_required, int page)
378 {
379 	struct cafe_priv *cafe = nand_get_controller_data(chip);
380 	unsigned int max_bitflips = 0;
381 
382 	cafe_dev_dbg(&cafe->pdev->dev, "ECC result %08x SYN1,2 %08x\n",
383 		     cafe_readl(cafe, NAND_ECC_RESULT),
384 		     cafe_readl(cafe, NAND_ECC_SYN01));
385 
386 	nand_read_page_op(chip, page, 0, buf, mtd->writesize);
387 	chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
388 
389 	if (checkecc && cafe_readl(cafe, NAND_ECC_RESULT) & (1<<18)) {
390 		unsigned short syn[8], pat[4];
391 		int pos[4];
392 		u8 *oob = chip->oob_poi;
393 		int i, n;
394 
395 		for (i=0; i<8; i+=2) {
396 			uint32_t tmp = cafe_readl(cafe, NAND_ECC_SYN01 + (i*2));
397 			syn[i] = cafe->rs->index_of[tmp & 0xfff];
398 			syn[i+1] = cafe->rs->index_of[(tmp >> 16) & 0xfff];
399 		}
400 
401 		n = decode_rs16(cafe->rs, NULL, NULL, 1367, syn, 0, pos, 0,
402 		                pat);
403 
404 		for (i = 0; i < n; i++) {
405 			int p = pos[i];
406 
407 			/* The 12-bit symbols are mapped to bytes here */
408 
409 			if (p > 1374) {
410 				/* out of range */
411 				n = -1374;
412 			} else if (p == 0) {
413 				/* high four bits do not correspond to data */
414 				if (pat[i] > 0xff)
415 					n = -2048;
416 				else
417 					buf[0] ^= pat[i];
418 			} else if (p == 1365) {
419 				buf[2047] ^= pat[i] >> 4;
420 				oob[0] ^= pat[i] << 4;
421 			} else if (p > 1365) {
422 				if ((p & 1) == 1) {
423 					oob[3*p/2 - 2048] ^= pat[i] >> 4;
424 					oob[3*p/2 - 2047] ^= pat[i] << 4;
425 				} else {
426 					oob[3*p/2 - 2049] ^= pat[i] >> 8;
427 					oob[3*p/2 - 2048] ^= pat[i];
428 				}
429 			} else if ((p & 1) == 1) {
430 				buf[3*p/2] ^= pat[i] >> 4;
431 				buf[3*p/2 + 1] ^= pat[i] << 4;
432 			} else {
433 				buf[3*p/2 - 1] ^= pat[i] >> 8;
434 				buf[3*p/2] ^= pat[i];
435 			}
436 		}
437 
438 		if (n < 0) {
439 			dev_dbg(&cafe->pdev->dev, "Failed to correct ECC at %08x\n",
440 				cafe_readl(cafe, NAND_ADDR2) * 2048);
441 			for (i = 0; i < 0x5c; i += 4)
442 				printk("Register %x: %08x\n", i, readl(cafe->mmio + i));
443 			mtd->ecc_stats.failed++;
444 		} else {
445 			dev_dbg(&cafe->pdev->dev, "Corrected %d symbol errors\n", n);
446 			mtd->ecc_stats.corrected += n;
447 			max_bitflips = max_t(unsigned int, max_bitflips, n);
448 		}
449 	}
450 
451 	return max_bitflips;
452 }
453 
454 static int cafe_ooblayout_ecc(struct mtd_info *mtd, int section,
455 			      struct mtd_oob_region *oobregion)
456 {
457 	struct nand_chip *chip = mtd_to_nand(mtd);
458 
459 	if (section)
460 		return -ERANGE;
461 
462 	oobregion->offset = 0;
463 	oobregion->length = chip->ecc.total;
464 
465 	return 0;
466 }
467 
468 static int cafe_ooblayout_free(struct mtd_info *mtd, int section,
469 			       struct mtd_oob_region *oobregion)
470 {
471 	struct nand_chip *chip = mtd_to_nand(mtd);
472 
473 	if (section)
474 		return -ERANGE;
475 
476 	oobregion->offset = chip->ecc.total;
477 	oobregion->length = mtd->oobsize - chip->ecc.total;
478 
479 	return 0;
480 }
481 
482 static const struct mtd_ooblayout_ops cafe_ooblayout_ops = {
483 	.ecc = cafe_ooblayout_ecc,
484 	.free = cafe_ooblayout_free,
485 };
486 
487 /* Ick. The BBT code really ought to be able to work this bit out
488    for itself from the above, at least for the 2KiB case */
489 static uint8_t cafe_bbt_pattern_2048[] = { 'B', 'b', 't', '0' };
490 static uint8_t cafe_mirror_pattern_2048[] = { '1', 't', 'b', 'B' };
491 
492 static uint8_t cafe_bbt_pattern_512[] = { 0xBB };
493 static uint8_t cafe_mirror_pattern_512[] = { 0xBC };
494 
495 
496 static struct nand_bbt_descr cafe_bbt_main_descr_2048 = {
497 	.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
498 		| NAND_BBT_2BIT | NAND_BBT_VERSION,
499 	.offs =	14,
500 	.len = 4,
501 	.veroffs = 18,
502 	.maxblocks = 4,
503 	.pattern = cafe_bbt_pattern_2048
504 };
505 
506 static struct nand_bbt_descr cafe_bbt_mirror_descr_2048 = {
507 	.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
508 		| NAND_BBT_2BIT | NAND_BBT_VERSION,
509 	.offs =	14,
510 	.len = 4,
511 	.veroffs = 18,
512 	.maxblocks = 4,
513 	.pattern = cafe_mirror_pattern_2048
514 };
515 
516 static struct nand_bbt_descr cafe_bbt_main_descr_512 = {
517 	.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
518 		| NAND_BBT_2BIT | NAND_BBT_VERSION,
519 	.offs =	14,
520 	.len = 1,
521 	.veroffs = 15,
522 	.maxblocks = 4,
523 	.pattern = cafe_bbt_pattern_512
524 };
525 
526 static struct nand_bbt_descr cafe_bbt_mirror_descr_512 = {
527 	.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
528 		| NAND_BBT_2BIT | NAND_BBT_VERSION,
529 	.offs =	14,
530 	.len = 1,
531 	.veroffs = 15,
532 	.maxblocks = 4,
533 	.pattern = cafe_mirror_pattern_512
534 };
535 
536 
537 static int cafe_nand_write_page_lowlevel(struct mtd_info *mtd,
538 					  struct nand_chip *chip,
539 					  const uint8_t *buf, int oob_required,
540 					  int page)
541 {
542 	struct cafe_priv *cafe = nand_get_controller_data(chip);
543 
544 	nand_prog_page_begin_op(chip, page, 0, buf, mtd->writesize);
545 	chip->write_buf(mtd, chip->oob_poi, mtd->oobsize);
546 
547 	/* Set up ECC autogeneration */
548 	cafe->ctl2 |= (1<<30);
549 
550 	return nand_prog_page_end_op(chip);
551 }
552 
553 static int cafe_nand_block_bad(struct mtd_info *mtd, loff_t ofs)
554 {
555 	return 0;
556 }
557 
558 /* F_2[X]/(X**6+X+1)  */
559 static unsigned short gf64_mul(u8 a, u8 b)
560 {
561 	u8 c;
562 	unsigned int i;
563 
564 	c = 0;
565 	for (i = 0; i < 6; i++) {
566 		if (a & 1)
567 			c ^= b;
568 		a >>= 1;
569 		b <<= 1;
570 		if ((b & 0x40) != 0)
571 			b ^= 0x43;
572 	}
573 
574 	return c;
575 }
576 
577 /* F_64[X]/(X**2+X+A**-1) with A the generator of F_64[X]  */
578 static u16 gf4096_mul(u16 a, u16 b)
579 {
580 	u8 ah, al, bh, bl, ch, cl;
581 
582 	ah = a >> 6;
583 	al = a & 0x3f;
584 	bh = b >> 6;
585 	bl = b & 0x3f;
586 
587 	ch = gf64_mul(ah ^ al, bh ^ bl) ^ gf64_mul(al, bl);
588 	cl = gf64_mul(gf64_mul(ah, bh), 0x21) ^ gf64_mul(al, bl);
589 
590 	return (ch << 6) ^ cl;
591 }
592 
593 static int cafe_mul(int x)
594 {
595 	if (x == 0)
596 		return 1;
597 	return gf4096_mul(x, 0xe01);
598 }
599 
600 static int cafe_nand_probe(struct pci_dev *pdev,
601 				     const struct pci_device_id *ent)
602 {
603 	struct mtd_info *mtd;
604 	struct cafe_priv *cafe;
605 	uint32_t ctrl;
606 	int err = 0;
607 	int old_dma;
608 
609 	/* Very old versions shared the same PCI ident for all three
610 	   functions on the chip. Verify the class too... */
611 	if ((pdev->class >> 8) != PCI_CLASS_MEMORY_FLASH)
612 		return -ENODEV;
613 
614 	err = pci_enable_device(pdev);
615 	if (err)
616 		return err;
617 
618 	pci_set_master(pdev);
619 
620 	cafe = kzalloc(sizeof(*cafe), GFP_KERNEL);
621 	if (!cafe)
622 		return  -ENOMEM;
623 
624 	mtd = nand_to_mtd(&cafe->nand);
625 	mtd->dev.parent = &pdev->dev;
626 	nand_set_controller_data(&cafe->nand, cafe);
627 
628 	cafe->pdev = pdev;
629 	cafe->mmio = pci_iomap(pdev, 0, 0);
630 	if (!cafe->mmio) {
631 		dev_warn(&pdev->dev, "failed to iomap\n");
632 		err = -ENOMEM;
633 		goto out_free_mtd;
634 	}
635 
636 	cafe->rs = init_rs_non_canonical(12, &cafe_mul, 0, 1, 8);
637 	if (!cafe->rs) {
638 		err = -ENOMEM;
639 		goto out_ior;
640 	}
641 
642 	cafe->nand.cmdfunc = cafe_nand_cmdfunc;
643 	cafe->nand.dev_ready = cafe_device_ready;
644 	cafe->nand.read_byte = cafe_read_byte;
645 	cafe->nand.read_buf = cafe_read_buf;
646 	cafe->nand.write_buf = cafe_write_buf;
647 	cafe->nand.select_chip = cafe_select_chip;
648 	cafe->nand.set_features = nand_get_set_features_notsupp;
649 	cafe->nand.get_features = nand_get_set_features_notsupp;
650 
651 	cafe->nand.chip_delay = 0;
652 
653 	/* Enable the following for a flash based bad block table */
654 	cafe->nand.bbt_options = NAND_BBT_USE_FLASH;
655 
656 	if (skipbbt) {
657 		cafe->nand.options |= NAND_SKIP_BBTSCAN;
658 		cafe->nand.block_bad = cafe_nand_block_bad;
659 	}
660 
661 	if (numtimings && numtimings != 3) {
662 		dev_warn(&cafe->pdev->dev, "%d timing register values ignored; precisely three are required\n", numtimings);
663 	}
664 
665 	if (numtimings == 3) {
666 		cafe_dev_dbg(&cafe->pdev->dev, "Using provided timings (%08x %08x %08x)\n",
667 			     timing[0], timing[1], timing[2]);
668 	} else {
669 		timing[0] = cafe_readl(cafe, NAND_TIMING1);
670 		timing[1] = cafe_readl(cafe, NAND_TIMING2);
671 		timing[2] = cafe_readl(cafe, NAND_TIMING3);
672 
673 		if (timing[0] | timing[1] | timing[2]) {
674 			cafe_dev_dbg(&cafe->pdev->dev, "Timing registers already set (%08x %08x %08x)\n",
675 				     timing[0], timing[1], timing[2]);
676 		} else {
677 			dev_warn(&cafe->pdev->dev, "Timing registers unset; using most conservative defaults\n");
678 			timing[0] = timing[1] = timing[2] = 0xffffffff;
679 		}
680 	}
681 
682 	/* Start off by resetting the NAND controller completely */
683 	cafe_writel(cafe, 1, NAND_RESET);
684 	cafe_writel(cafe, 0, NAND_RESET);
685 
686 	cafe_writel(cafe, timing[0], NAND_TIMING1);
687 	cafe_writel(cafe, timing[1], NAND_TIMING2);
688 	cafe_writel(cafe, timing[2], NAND_TIMING3);
689 
690 	cafe_writel(cafe, 0xffffffff, NAND_IRQ_MASK);
691 	err = request_irq(pdev->irq, &cafe_nand_interrupt, IRQF_SHARED,
692 			  "CAFE NAND", mtd);
693 	if (err) {
694 		dev_warn(&pdev->dev, "Could not register IRQ %d\n", pdev->irq);
695 		goto out_ior;
696 	}
697 
698 	/* Disable master reset, enable NAND clock */
699 	ctrl = cafe_readl(cafe, GLOBAL_CTRL);
700 	ctrl &= 0xffffeff0;
701 	ctrl |= 0x00007000;
702 	cafe_writel(cafe, ctrl | 0x05, GLOBAL_CTRL);
703 	cafe_writel(cafe, ctrl | 0x0a, GLOBAL_CTRL);
704 	cafe_writel(cafe, 0, NAND_DMA_CTRL);
705 
706 	cafe_writel(cafe, 0x7006, GLOBAL_CTRL);
707 	cafe_writel(cafe, 0x700a, GLOBAL_CTRL);
708 
709 	/* Enable NAND IRQ in global IRQ mask register */
710 	cafe_writel(cafe, 0x80000007, GLOBAL_IRQ_MASK);
711 	cafe_dev_dbg(&cafe->pdev->dev, "Control %x, IRQ mask %x\n",
712 		cafe_readl(cafe, GLOBAL_CTRL),
713 		cafe_readl(cafe, GLOBAL_IRQ_MASK));
714 
715 	/* Do not use the DMA for the nand_scan_ident() */
716 	old_dma = usedma;
717 	usedma = 0;
718 
719 	/* Scan to find existence of the device */
720 	err = nand_scan_ident(mtd, 2, NULL);
721 	if (err)
722 		goto out_irq;
723 
724 	cafe->dmabuf = dma_alloc_coherent(&cafe->pdev->dev, 2112,
725 					  &cafe->dmaaddr, GFP_KERNEL);
726 	if (!cafe->dmabuf) {
727 		err = -ENOMEM;
728 		goto out_irq;
729 	}
730 
731 	/* Set up DMA address */
732 	cafe_writel(cafe, lower_32_bits(cafe->dmaaddr), NAND_DMA_ADDR0);
733 	cafe_writel(cafe, upper_32_bits(cafe->dmaaddr), NAND_DMA_ADDR1);
734 
735 	cafe_dev_dbg(&cafe->pdev->dev, "Set DMA address to %x (virt %p)\n",
736 		cafe_readl(cafe, NAND_DMA_ADDR0), cafe->dmabuf);
737 
738 	/* Restore the DMA flag */
739 	usedma = old_dma;
740 
741 	cafe->ctl2 = 1<<27; /* Reed-Solomon ECC */
742 	if (mtd->writesize == 2048)
743 		cafe->ctl2 |= 1<<29; /* 2KiB page size */
744 
745 	/* Set up ECC according to the type of chip we found */
746 	mtd_set_ooblayout(mtd, &cafe_ooblayout_ops);
747 	if (mtd->writesize == 2048) {
748 		cafe->nand.bbt_td = &cafe_bbt_main_descr_2048;
749 		cafe->nand.bbt_md = &cafe_bbt_mirror_descr_2048;
750 	} else if (mtd->writesize == 512) {
751 		cafe->nand.bbt_td = &cafe_bbt_main_descr_512;
752 		cafe->nand.bbt_md = &cafe_bbt_mirror_descr_512;
753 	} else {
754 		pr_warn("Unexpected NAND flash writesize %d. Aborting\n",
755 			mtd->writesize);
756 		goto out_free_dma;
757 	}
758 	cafe->nand.ecc.mode = NAND_ECC_HW_SYNDROME;
759 	cafe->nand.ecc.size = mtd->writesize;
760 	cafe->nand.ecc.bytes = 14;
761 	cafe->nand.ecc.strength = 4;
762 	cafe->nand.ecc.hwctl  = (void *)cafe_nand_bug;
763 	cafe->nand.ecc.calculate = (void *)cafe_nand_bug;
764 	cafe->nand.ecc.correct  = (void *)cafe_nand_bug;
765 	cafe->nand.ecc.write_page = cafe_nand_write_page_lowlevel;
766 	cafe->nand.ecc.write_oob = cafe_nand_write_oob;
767 	cafe->nand.ecc.read_page = cafe_nand_read_page;
768 	cafe->nand.ecc.read_oob = cafe_nand_read_oob;
769 
770 	err = nand_scan_tail(mtd);
771 	if (err)
772 		goto out_free_dma;
773 
774 	pci_set_drvdata(pdev, mtd);
775 
776 	mtd->name = "cafe_nand";
777 	err = mtd_device_parse_register(mtd, part_probes, NULL, NULL, 0);
778 	if (err)
779 		goto out_cleanup_nand;
780 
781 	goto out;
782 
783  out_cleanup_nand:
784 	nand_cleanup(&cafe->nand);
785  out_free_dma:
786 	dma_free_coherent(&cafe->pdev->dev, 2112, cafe->dmabuf, cafe->dmaaddr);
787  out_irq:
788 	/* Disable NAND IRQ in global IRQ mask register */
789 	cafe_writel(cafe, ~1 & cafe_readl(cafe, GLOBAL_IRQ_MASK), GLOBAL_IRQ_MASK);
790 	free_irq(pdev->irq, mtd);
791  out_ior:
792 	pci_iounmap(pdev, cafe->mmio);
793  out_free_mtd:
794 	kfree(cafe);
795  out:
796 	return err;
797 }
798 
799 static void cafe_nand_remove(struct pci_dev *pdev)
800 {
801 	struct mtd_info *mtd = pci_get_drvdata(pdev);
802 	struct nand_chip *chip = mtd_to_nand(mtd);
803 	struct cafe_priv *cafe = nand_get_controller_data(chip);
804 
805 	/* Disable NAND IRQ in global IRQ mask register */
806 	cafe_writel(cafe, ~1 & cafe_readl(cafe, GLOBAL_IRQ_MASK), GLOBAL_IRQ_MASK);
807 	free_irq(pdev->irq, mtd);
808 	nand_release(mtd);
809 	free_rs(cafe->rs);
810 	pci_iounmap(pdev, cafe->mmio);
811 	dma_free_coherent(&cafe->pdev->dev, 2112, cafe->dmabuf, cafe->dmaaddr);
812 	kfree(cafe);
813 }
814 
815 static const struct pci_device_id cafe_nand_tbl[] = {
816 	{ PCI_VENDOR_ID_MARVELL, PCI_DEVICE_ID_MARVELL_88ALP01_NAND,
817 	  PCI_ANY_ID, PCI_ANY_ID },
818 	{ }
819 };
820 
821 MODULE_DEVICE_TABLE(pci, cafe_nand_tbl);
822 
823 static int cafe_nand_resume(struct pci_dev *pdev)
824 {
825 	uint32_t ctrl;
826 	struct mtd_info *mtd = pci_get_drvdata(pdev);
827 	struct nand_chip *chip = mtd_to_nand(mtd);
828 	struct cafe_priv *cafe = nand_get_controller_data(chip);
829 
830        /* Start off by resetting the NAND controller completely */
831 	cafe_writel(cafe, 1, NAND_RESET);
832 	cafe_writel(cafe, 0, NAND_RESET);
833 	cafe_writel(cafe, 0xffffffff, NAND_IRQ_MASK);
834 
835 	/* Restore timing configuration */
836 	cafe_writel(cafe, timing[0], NAND_TIMING1);
837 	cafe_writel(cafe, timing[1], NAND_TIMING2);
838 	cafe_writel(cafe, timing[2], NAND_TIMING3);
839 
840         /* Disable master reset, enable NAND clock */
841 	ctrl = cafe_readl(cafe, GLOBAL_CTRL);
842 	ctrl &= 0xffffeff0;
843 	ctrl |= 0x00007000;
844 	cafe_writel(cafe, ctrl | 0x05, GLOBAL_CTRL);
845 	cafe_writel(cafe, ctrl | 0x0a, GLOBAL_CTRL);
846 	cafe_writel(cafe, 0, NAND_DMA_CTRL);
847 	cafe_writel(cafe, 0x7006, GLOBAL_CTRL);
848 	cafe_writel(cafe, 0x700a, GLOBAL_CTRL);
849 
850 	/* Set up DMA address */
851 	cafe_writel(cafe, cafe->dmaaddr & 0xffffffff, NAND_DMA_ADDR0);
852 	if (sizeof(cafe->dmaaddr) > 4)
853 	/* Shift in two parts to shut the compiler up */
854 		cafe_writel(cafe, (cafe->dmaaddr >> 16) >> 16, NAND_DMA_ADDR1);
855 	else
856 		cafe_writel(cafe, 0, NAND_DMA_ADDR1);
857 
858 	/* Enable NAND IRQ in global IRQ mask register */
859 	cafe_writel(cafe, 0x80000007, GLOBAL_IRQ_MASK);
860 	return 0;
861 }
862 
863 static struct pci_driver cafe_nand_pci_driver = {
864 	.name = "CAFÉ NAND",
865 	.id_table = cafe_nand_tbl,
866 	.probe = cafe_nand_probe,
867 	.remove = cafe_nand_remove,
868 	.resume = cafe_nand_resume,
869 };
870 
871 module_pci_driver(cafe_nand_pci_driver);
872 
873 MODULE_LICENSE("GPL");
874 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
875 MODULE_DESCRIPTION("NAND flash driver for OLPC CAFÉ chip");
876