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 */
28static 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 */
40static 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 */
52static 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 */
74static 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 */
86static 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 */
117static 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 */
130static 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 */
143static 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 */
159static 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 */
174static 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 */
193void 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}
211EXPORT_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 */
220static 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					false);
230		if (ret)
231			return;
232
233		if (status & NAND_STATUS_READY)
234			break;
235		touch_softlockup_watchdog();
236	} while (time_before(jiffies, timeo));
237};
238
239/**
240 * nand_command - [DEFAULT] Send command to NAND device
241 * @chip: NAND chip object
242 * @command: the command to be sent
243 * @column: the column address for this command, -1 if none
244 * @page_addr: the page address for this command, -1 if none
245 *
246 * Send command to NAND device. This function is used for small page devices
247 * (512 Bytes per page).
248 */
249static void nand_command(struct nand_chip *chip, unsigned int command,
250			 int column, int page_addr)
251{
252	struct mtd_info *mtd = nand_to_mtd(chip);
253	int ctrl = NAND_CTRL_CLE | NAND_CTRL_CHANGE;
254
255	/* Write out the command to the device */
256	if (command == NAND_CMD_SEQIN) {
257		int readcmd;
258
259		if (column >= mtd->writesize) {
260			/* OOB area */
261			column -= mtd->writesize;
262			readcmd = NAND_CMD_READOOB;
263		} else if (column < 256) {
264			/* First 256 bytes --> READ0 */
265			readcmd = NAND_CMD_READ0;
266		} else {
267			column -= 256;
268			readcmd = NAND_CMD_READ1;
269		}
270		chip->legacy.cmd_ctrl(chip, readcmd, ctrl);
271		ctrl &= ~NAND_CTRL_CHANGE;
272	}
273	if (command != NAND_CMD_NONE)
274		chip->legacy.cmd_ctrl(chip, command, ctrl);
275
276	/* Address cycle, when necessary */
277	ctrl = NAND_CTRL_ALE | NAND_CTRL_CHANGE;
278	/* Serially input address */
279	if (column != -1) {
280		/* Adjust columns for 16 bit buswidth */
281		if (chip->options & NAND_BUSWIDTH_16 &&
282				!nand_opcode_8bits(command))
283			column >>= 1;
284		chip->legacy.cmd_ctrl(chip, column, ctrl);
285		ctrl &= ~NAND_CTRL_CHANGE;
286	}
287	if (page_addr != -1) {
288		chip->legacy.cmd_ctrl(chip, page_addr, ctrl);
289		ctrl &= ~NAND_CTRL_CHANGE;
290		chip->legacy.cmd_ctrl(chip, page_addr >> 8, ctrl);
291		if (chip->options & NAND_ROW_ADDR_3)
292			chip->legacy.cmd_ctrl(chip, page_addr >> 16, ctrl);
293	}
294	chip->legacy.cmd_ctrl(chip, NAND_CMD_NONE,
295			      NAND_NCE | NAND_CTRL_CHANGE);
296
297	/*
298	 * Program and erase have their own busy handlers status and sequential
299	 * in needs no delay
300	 */
301	switch (command) {
302
303	case NAND_CMD_NONE:
304	case NAND_CMD_PAGEPROG:
305	case NAND_CMD_ERASE1:
306	case NAND_CMD_ERASE2:
307	case NAND_CMD_SEQIN:
308	case NAND_CMD_STATUS:
309	case NAND_CMD_READID:
310	case NAND_CMD_SET_FEATURES:
311		return;
312
313	case NAND_CMD_RESET:
314		if (chip->legacy.dev_ready)
315			break;
316		udelay(chip->legacy.chip_delay);
317		chip->legacy.cmd_ctrl(chip, NAND_CMD_STATUS,
318				      NAND_CTRL_CLE | NAND_CTRL_CHANGE);
319		chip->legacy.cmd_ctrl(chip, NAND_CMD_NONE,
320				      NAND_NCE | NAND_CTRL_CHANGE);
321		/* EZ-NAND can take upto 250ms as per ONFi v4.0 */
322		nand_wait_status_ready(chip, 250);
323		return;
324
325		/* This applies to read commands */
326	case NAND_CMD_READ0:
327		/*
328		 * READ0 is sometimes used to exit GET STATUS mode. When this
329		 * is the case no address cycles are requested, and we can use
330		 * this information to detect that we should not wait for the
331		 * device to be ready.
332		 */
333		if (column == -1 && page_addr == -1)
334			return;
335		fallthrough;
336	default:
337		/*
338		 * If we don't have access to the busy pin, we apply the given
339		 * command delay
340		 */
341		if (!chip->legacy.dev_ready) {
342			udelay(chip->legacy.chip_delay);
343			return;
344		}
345	}
346	/*
347	 * Apply this short delay always to ensure that we do wait tWB in
348	 * any case on any machine.
349	 */
350	ndelay(100);
351
352	nand_wait_ready(chip);
353}
354
355static void nand_ccs_delay(struct nand_chip *chip)
356{
357	const struct nand_sdr_timings *sdr =
358		nand_get_sdr_timings(nand_get_interface_config(chip));
359
360	/*
361	 * The controller already takes care of waiting for tCCS when the RNDIN
362	 * or RNDOUT command is sent, return directly.
363	 */
364	if (!(chip->options & NAND_WAIT_TCCS))
365		return;
366
367	/*
368	 * Wait tCCS_min if it is correctly defined, otherwise wait 500ns
369	 * (which should be safe for all NANDs).
370	 */
371	if (nand_controller_can_setup_interface(chip))
372		ndelay(sdr->tCCS_min / 1000);
373	else
374		ndelay(500);
375}
376
377/**
378 * nand_command_lp - [DEFAULT] Send command to NAND large page device
379 * @chip: NAND chip object
380 * @command: the command to be sent
381 * @column: the column address for this command, -1 if none
382 * @page_addr: the page address for this command, -1 if none
383 *
384 * Send command to NAND device. This is the version for the new large page
385 * devices. We don't have the separate regions as we have in the small page
386 * devices. We must emulate NAND_CMD_READOOB to keep the code compatible.
387 */
388static void nand_command_lp(struct nand_chip *chip, unsigned int command,
389			    int column, int page_addr)
390{
391	struct mtd_info *mtd = nand_to_mtd(chip);
392
393	/* Emulate NAND_CMD_READOOB */
394	if (command == NAND_CMD_READOOB) {
395		column += mtd->writesize;
396		command = NAND_CMD_READ0;
397	}
398
399	/* Command latch cycle */
400	if (command != NAND_CMD_NONE)
401		chip->legacy.cmd_ctrl(chip, command,
402				      NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
403
404	if (column != -1 || page_addr != -1) {
405		int ctrl = NAND_CTRL_CHANGE | NAND_NCE | NAND_ALE;
406
407		/* Serially input address */
408		if (column != -1) {
409			/* Adjust columns for 16 bit buswidth */
410			if (chip->options & NAND_BUSWIDTH_16 &&
411					!nand_opcode_8bits(command))
412				column >>= 1;
413			chip->legacy.cmd_ctrl(chip, column, ctrl);
414			ctrl &= ~NAND_CTRL_CHANGE;
415
416			/* Only output a single addr cycle for 8bits opcodes. */
417			if (!nand_opcode_8bits(command))
418				chip->legacy.cmd_ctrl(chip, column >> 8, ctrl);
419		}
420		if (page_addr != -1) {
421			chip->legacy.cmd_ctrl(chip, page_addr, ctrl);
422			chip->legacy.cmd_ctrl(chip, page_addr >> 8,
423					     NAND_NCE | NAND_ALE);
424			if (chip->options & NAND_ROW_ADDR_3)
425				chip->legacy.cmd_ctrl(chip, page_addr >> 16,
426						      NAND_NCE | NAND_ALE);
427		}
428	}
429	chip->legacy.cmd_ctrl(chip, NAND_CMD_NONE,
430			      NAND_NCE | NAND_CTRL_CHANGE);
431
432	/*
433	 * Program and erase have their own busy handlers status, sequential
434	 * in and status need no delay.
435	 */
436	switch (command) {
437
438	case NAND_CMD_NONE:
439	case NAND_CMD_CACHEDPROG:
440	case NAND_CMD_PAGEPROG:
441	case NAND_CMD_ERASE1:
442	case NAND_CMD_ERASE2:
443	case NAND_CMD_SEQIN:
444	case NAND_CMD_STATUS:
445	case NAND_CMD_READID:
446	case NAND_CMD_SET_FEATURES:
447		return;
448
449	case NAND_CMD_RNDIN:
450		nand_ccs_delay(chip);
451		return;
452
453	case NAND_CMD_RESET:
454		if (chip->legacy.dev_ready)
455			break;
456		udelay(chip->legacy.chip_delay);
457		chip->legacy.cmd_ctrl(chip, NAND_CMD_STATUS,
458				      NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
459		chip->legacy.cmd_ctrl(chip, NAND_CMD_NONE,
460				      NAND_NCE | NAND_CTRL_CHANGE);
461		/* EZ-NAND can take upto 250ms as per ONFi v4.0 */
462		nand_wait_status_ready(chip, 250);
463		return;
464
465	case NAND_CMD_RNDOUT:
466		/* No ready / busy check necessary */
467		chip->legacy.cmd_ctrl(chip, NAND_CMD_RNDOUTSTART,
468				      NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
469		chip->legacy.cmd_ctrl(chip, NAND_CMD_NONE,
470				      NAND_NCE | NAND_CTRL_CHANGE);
471
472		nand_ccs_delay(chip);
473		return;
474
475	case NAND_CMD_READ0:
476		/*
477		 * READ0 is sometimes used to exit GET STATUS mode. When this
478		 * is the case no address cycles are requested, and we can use
479		 * this information to detect that READSTART should not be
480		 * issued.
481		 */
482		if (column == -1 && page_addr == -1)
483			return;
484
485		chip->legacy.cmd_ctrl(chip, NAND_CMD_READSTART,
486				      NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
487		chip->legacy.cmd_ctrl(chip, NAND_CMD_NONE,
488				      NAND_NCE | NAND_CTRL_CHANGE);
489		fallthrough;	/* This applies to read commands */
490	default:
491		/*
492		 * If we don't have access to the busy pin, we apply the given
493		 * command delay.
494		 */
495		if (!chip->legacy.dev_ready) {
496			udelay(chip->legacy.chip_delay);
497			return;
498		}
499	}
500
501	/*
502	 * Apply this short delay always to ensure that we do wait tWB in
503	 * any case on any machine.
504	 */
505	ndelay(100);
506
507	nand_wait_ready(chip);
508}
509
510/**
511 * nand_get_set_features_notsupp - set/get features stub returning -ENOTSUPP
512 * @chip: nand chip info structure
513 * @addr: feature address.
514 * @subfeature_param: the subfeature parameters, a four bytes array.
515 *
516 * Should be used by NAND controller drivers that do not support the SET/GET
517 * FEATURES operations.
518 */
519int nand_get_set_features_notsupp(struct nand_chip *chip, int addr,
520				  u8 *subfeature_param)
521{
522	return -ENOTSUPP;
523}
524EXPORT_SYMBOL(nand_get_set_features_notsupp);
525
526/**
527 * nand_wait - [DEFAULT] wait until the command is done
528 * @chip: NAND chip structure
529 *
530 * Wait for command done. This applies to erase and program only.
531 */
532static int nand_wait(struct nand_chip *chip)
533{
534
535	unsigned long timeo = 400;
536	u8 status;
537	int ret;
538
539	/*
540	 * Apply this short delay always to ensure that we do wait tWB in any
541	 * case on any machine.
542	 */
543	ndelay(100);
544
545	ret = nand_status_op(chip, NULL);
546	if (ret)
547		return ret;
548
549	if (in_interrupt() || oops_in_progress)
550		panic_nand_wait(chip, timeo);
551	else {
552		timeo = jiffies + msecs_to_jiffies(timeo);
553		do {
554			if (chip->legacy.dev_ready) {
555				if (chip->legacy.dev_ready(chip))
556					break;
557			} else {
558				ret = nand_read_data_op(chip, &status,
559							sizeof(status), true,
560							false);
561				if (ret)
562					return ret;
563
564				if (status & NAND_STATUS_READY)
565					break;
566			}
567			cond_resched();
568		} while (time_before(jiffies, timeo));
569	}
570
571	ret = nand_read_data_op(chip, &status, sizeof(status), true, false);
572	if (ret)
573		return ret;
574
575	/* This can happen if in case of timeout or buggy dev_ready */
576	WARN_ON(!(status & NAND_STATUS_READY));
577	return status;
578}
579
580void nand_legacy_set_defaults(struct nand_chip *chip)
581{
582	unsigned int busw = chip->options & NAND_BUSWIDTH_16;
583
584	if (nand_has_exec_op(chip))
585		return;
586
587	/* check for proper chip_delay setup, set 20us if not */
588	if (!chip->legacy.chip_delay)
589		chip->legacy.chip_delay = 20;
590
591	/* check, if a user supplied command function given */
592	if (!chip->legacy.cmdfunc)
593		chip->legacy.cmdfunc = nand_command;
594
595	/* check, if a user supplied wait function given */
596	if (chip->legacy.waitfunc == NULL)
597		chip->legacy.waitfunc = nand_wait;
598
599	if (!chip->legacy.select_chip)
600		chip->legacy.select_chip = nand_select_chip;
601
602	/* If called twice, pointers that depend on busw may need to be reset */
603	if (!chip->legacy.read_byte || chip->legacy.read_byte == nand_read_byte)
604		chip->legacy.read_byte = busw ? nand_read_byte16 : nand_read_byte;
605	if (!chip->legacy.write_buf || chip->legacy.write_buf == nand_write_buf)
606		chip->legacy.write_buf = busw ? nand_write_buf16 : nand_write_buf;
607	if (!chip->legacy.write_byte || chip->legacy.write_byte == nand_write_byte)
608		chip->legacy.write_byte = busw ? nand_write_byte16 : nand_write_byte;
609	if (!chip->legacy.read_buf || chip->legacy.read_buf == nand_read_buf)
610		chip->legacy.read_buf = busw ? nand_read_buf16 : nand_read_buf;
611}
612
613void nand_legacy_adjust_cmdfunc(struct nand_chip *chip)
614{
615	struct mtd_info *mtd = nand_to_mtd(chip);
616
617	/* Do not replace user supplied command function! */
618	if (mtd->writesize > 512 && chip->legacy.cmdfunc == nand_command)
619		chip->legacy.cmdfunc = nand_command_lp;
620}
621
622int nand_legacy_check_hooks(struct nand_chip *chip)
623{
624	/*
625	 * ->legacy.cmdfunc() is legacy and will only be used if ->exec_op() is
626	 * not populated.
627	 */
628	if (nand_has_exec_op(chip))
629		return 0;
630
631	/*
632	 * Default functions assigned for ->legacy.cmdfunc() and
633	 * ->legacy.select_chip() both expect ->legacy.cmd_ctrl() to be
634	 *  populated.
635	 */
636	if ((!chip->legacy.cmdfunc || !chip->legacy.select_chip) &&
637	    !chip->legacy.cmd_ctrl) {
638		pr_err("->legacy.cmd_ctrl() should be provided\n");
639		return -EINVAL;
640	}
641
642	return 0;
643}
644