xref: /openbmc/linux/drivers/mtd/nand/raw/nand_legacy.c (revision 15e3ae36)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  Copyright (C) 2000 Steven J. Hill (sjhill@realitydiluted.com)
4  *		  2002-2006 Thomas Gleixner (tglx@linutronix.de)
5  *
6  *  Credits:
7  *	David Woodhouse for adding multichip support
8  *
9  *	Aleph One Ltd. and Toby Churchill Ltd. for supporting the
10  *	rework for 2K page size chips
11  *
12  * This file contains all legacy helpers/code that should be removed
13  * at some point.
14  */
15 
16 #include <linux/delay.h>
17 #include <linux/io.h>
18 #include <linux/nmi.h>
19 
20 #include "internals.h"
21 
22 /**
23  * nand_read_byte - [DEFAULT] read one byte from the chip
24  * @chip: NAND chip object
25  *
26  * Default read function for 8bit buswidth
27  */
28 static uint8_t nand_read_byte(struct nand_chip *chip)
29 {
30 	return readb(chip->legacy.IO_ADDR_R);
31 }
32 
33 /**
34  * nand_read_byte16 - [DEFAULT] read one byte endianness aware from the chip
35  * @chip: NAND chip object
36  *
37  * Default read function for 16bit buswidth with endianness conversion.
38  *
39  */
40 static uint8_t nand_read_byte16(struct nand_chip *chip)
41 {
42 	return (uint8_t) cpu_to_le16(readw(chip->legacy.IO_ADDR_R));
43 }
44 
45 /**
46  * nand_select_chip - [DEFAULT] control CE line
47  * @chip: NAND chip object
48  * @chipnr: chipnumber to select, -1 for deselect
49  *
50  * Default select function for 1 chip devices.
51  */
52 static void nand_select_chip(struct nand_chip *chip, int chipnr)
53 {
54 	switch (chipnr) {
55 	case -1:
56 		chip->legacy.cmd_ctrl(chip, NAND_CMD_NONE,
57 				      0 | NAND_CTRL_CHANGE);
58 		break;
59 	case 0:
60 		break;
61 
62 	default:
63 		BUG();
64 	}
65 }
66 
67 /**
68  * nand_write_byte - [DEFAULT] write single byte to chip
69  * @chip: NAND chip object
70  * @byte: value to write
71  *
72  * Default function to write a byte to I/O[7:0]
73  */
74 static void nand_write_byte(struct nand_chip *chip, uint8_t byte)
75 {
76 	chip->legacy.write_buf(chip, &byte, 1);
77 }
78 
79 /**
80  * nand_write_byte16 - [DEFAULT] write single byte to a chip with width 16
81  * @chip: NAND chip object
82  * @byte: value to write
83  *
84  * Default function to write a byte to I/O[7:0] on a 16-bit wide chip.
85  */
86 static void nand_write_byte16(struct nand_chip *chip, uint8_t byte)
87 {
88 	uint16_t word = byte;
89 
90 	/*
91 	 * It's not entirely clear what should happen to I/O[15:8] when writing
92 	 * a byte. The ONFi spec (Revision 3.1; 2012-09-19, Section 2.16) reads:
93 	 *
94 	 *    When the host supports a 16-bit bus width, only data is
95 	 *    transferred at the 16-bit width. All address and command line
96 	 *    transfers shall use only the lower 8-bits of the data bus. During
97 	 *    command transfers, the host may place any value on the upper
98 	 *    8-bits of the data bus. During address transfers, the host shall
99 	 *    set the upper 8-bits of the data bus to 00h.
100 	 *
101 	 * One user of the write_byte callback is nand_set_features. The
102 	 * four parameters are specified to be written to I/O[7:0], but this is
103 	 * neither an address nor a command transfer. Let's assume a 0 on the
104 	 * upper I/O lines is OK.
105 	 */
106 	chip->legacy.write_buf(chip, (uint8_t *)&word, 2);
107 }
108 
109 /**
110  * nand_write_buf - [DEFAULT] write buffer to chip
111  * @chip: NAND chip object
112  * @buf: data buffer
113  * @len: number of bytes to write
114  *
115  * Default write function for 8bit buswidth.
116  */
117 static void nand_write_buf(struct nand_chip *chip, const uint8_t *buf, int len)
118 {
119 	iowrite8_rep(chip->legacy.IO_ADDR_W, buf, len);
120 }
121 
122 /**
123  * nand_read_buf - [DEFAULT] read chip data into buffer
124  * @chip: NAND chip object
125  * @buf: buffer to store date
126  * @len: number of bytes to read
127  *
128  * Default read function for 8bit buswidth.
129  */
130 static void nand_read_buf(struct nand_chip *chip, uint8_t *buf, int len)
131 {
132 	ioread8_rep(chip->legacy.IO_ADDR_R, buf, len);
133 }
134 
135 /**
136  * nand_write_buf16 - [DEFAULT] write buffer to chip
137  * @chip: NAND chip object
138  * @buf: data buffer
139  * @len: number of bytes to write
140  *
141  * Default write function for 16bit buswidth.
142  */
143 static void nand_write_buf16(struct nand_chip *chip, const uint8_t *buf,
144 			     int len)
145 {
146 	u16 *p = (u16 *) buf;
147 
148 	iowrite16_rep(chip->legacy.IO_ADDR_W, p, len >> 1);
149 }
150 
151 /**
152  * nand_read_buf16 - [DEFAULT] read chip data into buffer
153  * @chip: NAND chip object
154  * @buf: buffer to store date
155  * @len: number of bytes to read
156  *
157  * Default read function for 16bit buswidth.
158  */
159 static void nand_read_buf16(struct nand_chip *chip, uint8_t *buf, int len)
160 {
161 	u16 *p = (u16 *) buf;
162 
163 	ioread16_rep(chip->legacy.IO_ADDR_R, p, len >> 1);
164 }
165 
166 /**
167  * panic_nand_wait_ready - [GENERIC] Wait for the ready pin after commands.
168  * @chip: NAND chip object
169  * @timeo: Timeout
170  *
171  * Helper function for nand_wait_ready used when needing to wait in interrupt
172  * context.
173  */
174 static void panic_nand_wait_ready(struct nand_chip *chip, unsigned long timeo)
175 {
176 	int i;
177 
178 	/* Wait for the device to get ready */
179 	for (i = 0; i < timeo; i++) {
180 		if (chip->legacy.dev_ready(chip))
181 			break;
182 		touch_softlockup_watchdog();
183 		mdelay(1);
184 	}
185 }
186 
187 /**
188  * nand_wait_ready - [GENERIC] Wait for the ready pin after commands.
189  * @chip: NAND chip object
190  *
191  * Wait for the ready pin after a command, and warn if a timeout occurs.
192  */
193 void nand_wait_ready(struct nand_chip *chip)
194 {
195 	unsigned long timeo = 400;
196 
197 	if (in_interrupt() || oops_in_progress)
198 		return panic_nand_wait_ready(chip, timeo);
199 
200 	/* Wait until command is processed or timeout occurs */
201 	timeo = jiffies + msecs_to_jiffies(timeo);
202 	do {
203 		if (chip->legacy.dev_ready(chip))
204 			return;
205 		cond_resched();
206 	} while (time_before(jiffies, timeo));
207 
208 	if (!chip->legacy.dev_ready(chip))
209 		pr_warn_ratelimited("timeout while waiting for chip to become ready\n");
210 }
211 EXPORT_SYMBOL_GPL(nand_wait_ready);
212 
213 /**
214  * nand_wait_status_ready - [GENERIC] Wait for the ready status after commands.
215  * @chip: NAND chip object
216  * @timeo: Timeout in ms
217  *
218  * Wait for status ready (i.e. command done) or timeout.
219  */
220 static void nand_wait_status_ready(struct nand_chip *chip, unsigned long timeo)
221 {
222 	int ret;
223 
224 	timeo = jiffies + msecs_to_jiffies(timeo);
225 	do {
226 		u8 status;
227 
228 		ret = nand_read_data_op(chip, &status, sizeof(status), true);
229 		if (ret)
230 			return;
231 
232 		if (status & NAND_STATUS_READY)
233 			break;
234 		touch_softlockup_watchdog();
235 	} while (time_before(jiffies, timeo));
236 };
237 
238 /**
239  * nand_command - [DEFAULT] Send command to NAND device
240  * @chip: NAND chip object
241  * @command: the command to be sent
242  * @column: the column address for this command, -1 if none
243  * @page_addr: the page address for this command, -1 if none
244  *
245  * Send command to NAND device. This function is used for small page devices
246  * (512 Bytes per page).
247  */
248 static void nand_command(struct nand_chip *chip, unsigned int command,
249 			 int column, int page_addr)
250 {
251 	struct mtd_info *mtd = nand_to_mtd(chip);
252 	int ctrl = NAND_CTRL_CLE | NAND_CTRL_CHANGE;
253 
254 	/* Write out the command to the device */
255 	if (command == NAND_CMD_SEQIN) {
256 		int readcmd;
257 
258 		if (column >= mtd->writesize) {
259 			/* OOB area */
260 			column -= mtd->writesize;
261 			readcmd = NAND_CMD_READOOB;
262 		} else if (column < 256) {
263 			/* First 256 bytes --> READ0 */
264 			readcmd = NAND_CMD_READ0;
265 		} else {
266 			column -= 256;
267 			readcmd = NAND_CMD_READ1;
268 		}
269 		chip->legacy.cmd_ctrl(chip, readcmd, ctrl);
270 		ctrl &= ~NAND_CTRL_CHANGE;
271 	}
272 	if (command != NAND_CMD_NONE)
273 		chip->legacy.cmd_ctrl(chip, command, ctrl);
274 
275 	/* Address cycle, when necessary */
276 	ctrl = NAND_CTRL_ALE | NAND_CTRL_CHANGE;
277 	/* Serially input address */
278 	if (column != -1) {
279 		/* Adjust columns for 16 bit buswidth */
280 		if (chip->options & NAND_BUSWIDTH_16 &&
281 				!nand_opcode_8bits(command))
282 			column >>= 1;
283 		chip->legacy.cmd_ctrl(chip, column, ctrl);
284 		ctrl &= ~NAND_CTRL_CHANGE;
285 	}
286 	if (page_addr != -1) {
287 		chip->legacy.cmd_ctrl(chip, page_addr, ctrl);
288 		ctrl &= ~NAND_CTRL_CHANGE;
289 		chip->legacy.cmd_ctrl(chip, page_addr >> 8, ctrl);
290 		if (chip->options & NAND_ROW_ADDR_3)
291 			chip->legacy.cmd_ctrl(chip, page_addr >> 16, ctrl);
292 	}
293 	chip->legacy.cmd_ctrl(chip, NAND_CMD_NONE,
294 			      NAND_NCE | NAND_CTRL_CHANGE);
295 
296 	/*
297 	 * Program and erase have their own busy handlers status and sequential
298 	 * in needs no delay
299 	 */
300 	switch (command) {
301 
302 	case NAND_CMD_NONE:
303 	case NAND_CMD_PAGEPROG:
304 	case NAND_CMD_ERASE1:
305 	case NAND_CMD_ERASE2:
306 	case NAND_CMD_SEQIN:
307 	case NAND_CMD_STATUS:
308 	case NAND_CMD_READID:
309 	case NAND_CMD_SET_FEATURES:
310 		return;
311 
312 	case NAND_CMD_RESET:
313 		if (chip->legacy.dev_ready)
314 			break;
315 		udelay(chip->legacy.chip_delay);
316 		chip->legacy.cmd_ctrl(chip, NAND_CMD_STATUS,
317 				      NAND_CTRL_CLE | NAND_CTRL_CHANGE);
318 		chip->legacy.cmd_ctrl(chip, NAND_CMD_NONE,
319 				      NAND_NCE | NAND_CTRL_CHANGE);
320 		/* EZ-NAND can take upto 250ms as per ONFi v4.0 */
321 		nand_wait_status_ready(chip, 250);
322 		return;
323 
324 		/* This applies to read commands */
325 	case NAND_CMD_READ0:
326 		/*
327 		 * READ0 is sometimes used to exit GET STATUS mode. When this
328 		 * is the case no address cycles are requested, and we can use
329 		 * this information to detect that we should not wait for the
330 		 * device to be ready.
331 		 */
332 		if (column == -1 && page_addr == -1)
333 			return;
334 		fallthrough;
335 	default:
336 		/*
337 		 * If we don't have access to the busy pin, we apply the given
338 		 * command delay
339 		 */
340 		if (!chip->legacy.dev_ready) {
341 			udelay(chip->legacy.chip_delay);
342 			return;
343 		}
344 	}
345 	/*
346 	 * Apply this short delay always to ensure that we do wait tWB in
347 	 * any case on any machine.
348 	 */
349 	ndelay(100);
350 
351 	nand_wait_ready(chip);
352 }
353 
354 static void nand_ccs_delay(struct nand_chip *chip)
355 {
356 	/*
357 	 * The controller already takes care of waiting for tCCS when the RNDIN
358 	 * or RNDOUT command is sent, return directly.
359 	 */
360 	if (!(chip->options & NAND_WAIT_TCCS))
361 		return;
362 
363 	/*
364 	 * Wait tCCS_min if it is correctly defined, otherwise wait 500ns
365 	 * (which should be safe for all NANDs).
366 	 */
367 	if (nand_has_setup_data_iface(chip))
368 		ndelay(chip->data_interface.timings.sdr.tCCS_min / 1000);
369 	else
370 		ndelay(500);
371 }
372 
373 /**
374  * nand_command_lp - [DEFAULT] Send command to NAND large page device
375  * @chip: NAND chip object
376  * @command: the command to be sent
377  * @column: the column address for this command, -1 if none
378  * @page_addr: the page address for this command, -1 if none
379  *
380  * Send command to NAND device. This is the version for the new large page
381  * devices. We don't have the separate regions as we have in the small page
382  * devices. We must emulate NAND_CMD_READOOB to keep the code compatible.
383  */
384 static void nand_command_lp(struct nand_chip *chip, unsigned int command,
385 			    int column, int page_addr)
386 {
387 	struct mtd_info *mtd = nand_to_mtd(chip);
388 
389 	/* Emulate NAND_CMD_READOOB */
390 	if (command == NAND_CMD_READOOB) {
391 		column += mtd->writesize;
392 		command = NAND_CMD_READ0;
393 	}
394 
395 	/* Command latch cycle */
396 	if (command != NAND_CMD_NONE)
397 		chip->legacy.cmd_ctrl(chip, command,
398 				      NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
399 
400 	if (column != -1 || page_addr != -1) {
401 		int ctrl = NAND_CTRL_CHANGE | NAND_NCE | NAND_ALE;
402 
403 		/* Serially input address */
404 		if (column != -1) {
405 			/* Adjust columns for 16 bit buswidth */
406 			if (chip->options & NAND_BUSWIDTH_16 &&
407 					!nand_opcode_8bits(command))
408 				column >>= 1;
409 			chip->legacy.cmd_ctrl(chip, column, ctrl);
410 			ctrl &= ~NAND_CTRL_CHANGE;
411 
412 			/* Only output a single addr cycle for 8bits opcodes. */
413 			if (!nand_opcode_8bits(command))
414 				chip->legacy.cmd_ctrl(chip, column >> 8, ctrl);
415 		}
416 		if (page_addr != -1) {
417 			chip->legacy.cmd_ctrl(chip, page_addr, ctrl);
418 			chip->legacy.cmd_ctrl(chip, page_addr >> 8,
419 					     NAND_NCE | NAND_ALE);
420 			if (chip->options & NAND_ROW_ADDR_3)
421 				chip->legacy.cmd_ctrl(chip, page_addr >> 16,
422 						      NAND_NCE | NAND_ALE);
423 		}
424 	}
425 	chip->legacy.cmd_ctrl(chip, NAND_CMD_NONE,
426 			      NAND_NCE | NAND_CTRL_CHANGE);
427 
428 	/*
429 	 * Program and erase have their own busy handlers status, sequential
430 	 * in and status need no delay.
431 	 */
432 	switch (command) {
433 
434 	case NAND_CMD_NONE:
435 	case NAND_CMD_CACHEDPROG:
436 	case NAND_CMD_PAGEPROG:
437 	case NAND_CMD_ERASE1:
438 	case NAND_CMD_ERASE2:
439 	case NAND_CMD_SEQIN:
440 	case NAND_CMD_STATUS:
441 	case NAND_CMD_READID:
442 	case NAND_CMD_SET_FEATURES:
443 		return;
444 
445 	case NAND_CMD_RNDIN:
446 		nand_ccs_delay(chip);
447 		return;
448 
449 	case NAND_CMD_RESET:
450 		if (chip->legacy.dev_ready)
451 			break;
452 		udelay(chip->legacy.chip_delay);
453 		chip->legacy.cmd_ctrl(chip, NAND_CMD_STATUS,
454 				      NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
455 		chip->legacy.cmd_ctrl(chip, NAND_CMD_NONE,
456 				      NAND_NCE | NAND_CTRL_CHANGE);
457 		/* EZ-NAND can take upto 250ms as per ONFi v4.0 */
458 		nand_wait_status_ready(chip, 250);
459 		return;
460 
461 	case NAND_CMD_RNDOUT:
462 		/* No ready / busy check necessary */
463 		chip->legacy.cmd_ctrl(chip, NAND_CMD_RNDOUTSTART,
464 				      NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
465 		chip->legacy.cmd_ctrl(chip, NAND_CMD_NONE,
466 				      NAND_NCE | NAND_CTRL_CHANGE);
467 
468 		nand_ccs_delay(chip);
469 		return;
470 
471 	case NAND_CMD_READ0:
472 		/*
473 		 * READ0 is sometimes used to exit GET STATUS mode. When this
474 		 * is the case no address cycles are requested, and we can use
475 		 * this information to detect that READSTART should not be
476 		 * issued.
477 		 */
478 		if (column == -1 && page_addr == -1)
479 			return;
480 
481 		chip->legacy.cmd_ctrl(chip, NAND_CMD_READSTART,
482 				      NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
483 		chip->legacy.cmd_ctrl(chip, NAND_CMD_NONE,
484 				      NAND_NCE | NAND_CTRL_CHANGE);
485 		fallthrough;	/* This applies to read commands */
486 	default:
487 		/*
488 		 * If we don't have access to the busy pin, we apply the given
489 		 * command delay.
490 		 */
491 		if (!chip->legacy.dev_ready) {
492 			udelay(chip->legacy.chip_delay);
493 			return;
494 		}
495 	}
496 
497 	/*
498 	 * Apply this short delay always to ensure that we do wait tWB in
499 	 * any case on any machine.
500 	 */
501 	ndelay(100);
502 
503 	nand_wait_ready(chip);
504 }
505 
506 /**
507  * nand_get_set_features_notsupp - set/get features stub returning -ENOTSUPP
508  * @chip: nand chip info structure
509  * @addr: feature address.
510  * @subfeature_param: the subfeature parameters, a four bytes array.
511  *
512  * Should be used by NAND controller drivers that do not support the SET/GET
513  * FEATURES operations.
514  */
515 int nand_get_set_features_notsupp(struct nand_chip *chip, int addr,
516 				  u8 *subfeature_param)
517 {
518 	return -ENOTSUPP;
519 }
520 EXPORT_SYMBOL(nand_get_set_features_notsupp);
521 
522 /**
523  * nand_wait - [DEFAULT] wait until the command is done
524  * @chip: NAND chip structure
525  *
526  * Wait for command done. This applies to erase and program only.
527  */
528 static int nand_wait(struct nand_chip *chip)
529 {
530 
531 	unsigned long timeo = 400;
532 	u8 status;
533 	int ret;
534 
535 	/*
536 	 * Apply this short delay always to ensure that we do wait tWB in any
537 	 * case on any machine.
538 	 */
539 	ndelay(100);
540 
541 	ret = nand_status_op(chip, NULL);
542 	if (ret)
543 		return ret;
544 
545 	if (in_interrupt() || oops_in_progress)
546 		panic_nand_wait(chip, timeo);
547 	else {
548 		timeo = jiffies + msecs_to_jiffies(timeo);
549 		do {
550 			if (chip->legacy.dev_ready) {
551 				if (chip->legacy.dev_ready(chip))
552 					break;
553 			} else {
554 				ret = nand_read_data_op(chip, &status,
555 							sizeof(status), true);
556 				if (ret)
557 					return ret;
558 
559 				if (status & NAND_STATUS_READY)
560 					break;
561 			}
562 			cond_resched();
563 		} while (time_before(jiffies, timeo));
564 	}
565 
566 	ret = nand_read_data_op(chip, &status, sizeof(status), true);
567 	if (ret)
568 		return ret;
569 
570 	/* This can happen if in case of timeout or buggy dev_ready */
571 	WARN_ON(!(status & NAND_STATUS_READY));
572 	return status;
573 }
574 
575 void nand_legacy_set_defaults(struct nand_chip *chip)
576 {
577 	unsigned int busw = chip->options & NAND_BUSWIDTH_16;
578 
579 	if (nand_has_exec_op(chip))
580 		return;
581 
582 	/* check for proper chip_delay setup, set 20us if not */
583 	if (!chip->legacy.chip_delay)
584 		chip->legacy.chip_delay = 20;
585 
586 	/* check, if a user supplied command function given */
587 	if (!chip->legacy.cmdfunc)
588 		chip->legacy.cmdfunc = nand_command;
589 
590 	/* check, if a user supplied wait function given */
591 	if (chip->legacy.waitfunc == NULL)
592 		chip->legacy.waitfunc = nand_wait;
593 
594 	if (!chip->legacy.select_chip)
595 		chip->legacy.select_chip = nand_select_chip;
596 
597 	/* If called twice, pointers that depend on busw may need to be reset */
598 	if (!chip->legacy.read_byte || chip->legacy.read_byte == nand_read_byte)
599 		chip->legacy.read_byte = busw ? nand_read_byte16 : nand_read_byte;
600 	if (!chip->legacy.write_buf || chip->legacy.write_buf == nand_write_buf)
601 		chip->legacy.write_buf = busw ? nand_write_buf16 : nand_write_buf;
602 	if (!chip->legacy.write_byte || chip->legacy.write_byte == nand_write_byte)
603 		chip->legacy.write_byte = busw ? nand_write_byte16 : nand_write_byte;
604 	if (!chip->legacy.read_buf || chip->legacy.read_buf == nand_read_buf)
605 		chip->legacy.read_buf = busw ? nand_read_buf16 : nand_read_buf;
606 }
607 
608 void nand_legacy_adjust_cmdfunc(struct nand_chip *chip)
609 {
610 	struct mtd_info *mtd = nand_to_mtd(chip);
611 
612 	/* Do not replace user supplied command function! */
613 	if (mtd->writesize > 512 && chip->legacy.cmdfunc == nand_command)
614 		chip->legacy.cmdfunc = nand_command_lp;
615 }
616 
617 int nand_legacy_check_hooks(struct nand_chip *chip)
618 {
619 	/*
620 	 * ->legacy.cmdfunc() is legacy and will only be used if ->exec_op() is
621 	 * not populated.
622 	 */
623 	if (nand_has_exec_op(chip))
624 		return 0;
625 
626 	/*
627 	 * Default functions assigned for ->legacy.cmdfunc() and
628 	 * ->legacy.select_chip() both expect ->legacy.cmd_ctrl() to be
629 	 *  populated.
630 	 */
631 	if ((!chip->legacy.cmdfunc || !chip->legacy.select_chip) &&
632 	    !chip->legacy.cmd_ctrl) {
633 		pr_err("->legacy.cmd_ctrl() should be provided\n");
634 		return -EINVAL;
635 	}
636 
637 	return 0;
638 }
639