1/*
2 *  drivers/mtd/nand/rtc_from4.c
3 *
4 *  Copyright (C) 2004  Red Hat, Inc.
5 *
6 *  Derived from drivers/mtd/nand/spia.c
7 *       Copyright (C) 2000 Steven J. Hill (sjhill@realitydiluted.com)
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 *
13 * Overview:
14 *   This is a device driver for the AG-AND flash device found on the
15 *   Renesas Technology Corp. Flash ROM 4-slot interface board (FROM_BOARD4),
16 *   which utilizes the Renesas HN29V1G91T-30 part.
17 *   This chip is a 1 GBibit (128MiB x 8 bits) AG-AND flash device.
18 */
19
20#include <linux/delay.h>
21#include <linux/kernel.h>
22#include <linux/init.h>
23#include <linux/slab.h>
24#include <linux/rslib.h>
25#include <linux/bitrev.h>
26#include <linux/module.h>
27#include <linux/mtd/mtd.h>
28#include <linux/mtd/nand.h>
29#include <linux/mtd/partitions.h>
30#include <asm/io.h>
31
32/*
33 * MTD structure for Renesas board
34 */
35static struct mtd_info *rtc_from4_mtd = NULL;
36
37#define RTC_FROM4_MAX_CHIPS	2
38
39/* HS77x9 processor register defines */
40#define SH77X9_BCR1	((volatile unsigned short *)(0xFFFFFF60))
41#define SH77X9_BCR2	((volatile unsigned short *)(0xFFFFFF62))
42#define SH77X9_WCR1	((volatile unsigned short *)(0xFFFFFF64))
43#define SH77X9_WCR2	((volatile unsigned short *)(0xFFFFFF66))
44#define SH77X9_MCR	((volatile unsigned short *)(0xFFFFFF68))
45#define SH77X9_PCR	((volatile unsigned short *)(0xFFFFFF6C))
46#define SH77X9_FRQCR	((volatile unsigned short *)(0xFFFFFF80))
47
48/*
49 * Values specific to the Renesas Technology Corp. FROM_BOARD4 (used with HS77x9 processor)
50 */
51/* Address where flash is mapped */
52#define RTC_FROM4_FIO_BASE	0x14000000
53
54/* CLE and ALE are tied to address lines 5 & 4, respectively */
55#define RTC_FROM4_CLE		(1 << 5)
56#define RTC_FROM4_ALE		(1 << 4)
57
58/* address lines A24-A22 used for chip selection */
59#define RTC_FROM4_NAND_ADDR_SLOT3	(0x00800000)
60#define RTC_FROM4_NAND_ADDR_SLOT4	(0x00C00000)
61#define RTC_FROM4_NAND_ADDR_FPGA	(0x01000000)
62/* mask address lines A24-A22 used for chip selection */
63#define RTC_FROM4_NAND_ADDR_MASK	(RTC_FROM4_NAND_ADDR_SLOT3 | RTC_FROM4_NAND_ADDR_SLOT4 | RTC_FROM4_NAND_ADDR_FPGA)
64
65/* FPGA status register for checking device ready (bit zero) */
66#define RTC_FROM4_FPGA_SR		(RTC_FROM4_NAND_ADDR_FPGA | 0x00000002)
67#define RTC_FROM4_DEVICE_READY		0x0001
68
69/* FPGA Reed-Solomon ECC Control register */
70
71#define RTC_FROM4_RS_ECC_CTL		(RTC_FROM4_NAND_ADDR_FPGA | 0x00000050)
72#define RTC_FROM4_RS_ECC_CTL_CLR	(1 << 7)
73#define RTC_FROM4_RS_ECC_CTL_GEN	(1 << 6)
74#define RTC_FROM4_RS_ECC_CTL_FD_E	(1 << 5)
75
76/* FPGA Reed-Solomon ECC code base */
77#define RTC_FROM4_RS_ECC		(RTC_FROM4_NAND_ADDR_FPGA | 0x00000060)
78#define RTC_FROM4_RS_ECCN		(RTC_FROM4_NAND_ADDR_FPGA | 0x00000080)
79
80/* FPGA Reed-Solomon ECC check register */
81#define RTC_FROM4_RS_ECC_CHK		(RTC_FROM4_NAND_ADDR_FPGA | 0x00000070)
82#define RTC_FROM4_RS_ECC_CHK_ERROR	(1 << 7)
83
84#define ERR_STAT_ECC_AVAILABLE		0x20
85
86/* Undefine for software ECC */
87#define RTC_FROM4_HWECC	1
88
89/* Define as 1 for no virtual erase blocks (in JFFS2) */
90#define RTC_FROM4_NO_VIRTBLOCKS	0
91
92/*
93 * Module stuff
94 */
95static void __iomem *rtc_from4_fio_base = (void *)P2SEGADDR(RTC_FROM4_FIO_BASE);
96
97static const struct mtd_partition partition_info[] = {
98	{
99	 .name = "Renesas flash partition 1",
100	 .offset = 0,
101	 .size = MTDPART_SIZ_FULL},
102};
103
104#define NUM_PARTITIONS 1
105
106/*
107 *	hardware specific flash bbt decriptors
108 *	Note: this is to allow debugging by disabling
109 *		NAND_BBT_CREATE and/or NAND_BBT_WRITE
110 *
111 */
112static uint8_t bbt_pattern[] = { 'B', 'b', 't', '0' };
113static uint8_t mirror_pattern[] = { '1', 't', 'b', 'B' };
114
115static struct nand_bbt_descr rtc_from4_bbt_main_descr = {
116	.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
117		| NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
118	.offs = 40,
119	.len = 4,
120	.veroffs = 44,
121	.maxblocks = 4,
122	.pattern = bbt_pattern
123};
124
125static struct nand_bbt_descr rtc_from4_bbt_mirror_descr = {
126	.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
127		| NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
128	.offs = 40,
129	.len = 4,
130	.veroffs = 44,
131	.maxblocks = 4,
132	.pattern = mirror_pattern
133};
134
135#ifdef RTC_FROM4_HWECC
136
137/* the Reed Solomon control structure */
138static struct rs_control *rs_decoder;
139
140/*
141 *      hardware specific Out Of Band information
142 */
143static struct nand_ecclayout rtc_from4_nand_oobinfo = {
144	.eccbytes = 32,
145	.eccpos = {
146		   0, 1, 2, 3, 4, 5, 6, 7,
147		   8, 9, 10, 11, 12, 13, 14, 15,
148		   16, 17, 18, 19, 20, 21, 22, 23,
149		   24, 25, 26, 27, 28, 29, 30, 31},
150	.oobfree = {{32, 32}}
151};
152
153#endif
154
155/*
156 * rtc_from4_hwcontrol - hardware specific access to control-lines
157 * @mtd:	MTD device structure
158 * @cmd:	hardware control command
159 *
160 * Address lines (A5 and A4) are used to control Command and Address Latch
161 * Enable on this board, so set the read/write address appropriately.
162 *
163 * Chip Enable is also controlled by the Chip Select (CS5) and
164 * Address lines (A24-A22), so no action is required here.
165 *
166 */
167static void rtc_from4_hwcontrol(struct mtd_info *mtd, int cmd,
168				unsigned int ctrl)
169{
170	struct nand_chip *chip = (mtd->priv);
171
172	if (cmd == NAND_CMD_NONE)
173		return;
174
175	if (ctrl & NAND_CLE)
176		writeb(cmd, chip->IO_ADDR_W | RTC_FROM4_CLE);
177	else
178		writeb(cmd, chip->IO_ADDR_W | RTC_FROM4_ALE);
179}
180
181/*
182 * rtc_from4_nand_select_chip - hardware specific chip select
183 * @mtd:	MTD device structure
184 * @chip:	Chip to select (0 == slot 3, 1 == slot 4)
185 *
186 * The chip select is based on address lines A24-A22.
187 * This driver uses flash slots 3 and 4 (A23-A22).
188 *
189 */
190static void rtc_from4_nand_select_chip(struct mtd_info *mtd, int chip)
191{
192	struct nand_chip *this = mtd->priv;
193
194	this->IO_ADDR_R = (void __iomem *)((unsigned long)this->IO_ADDR_R & ~RTC_FROM4_NAND_ADDR_MASK);
195	this->IO_ADDR_W = (void __iomem *)((unsigned long)this->IO_ADDR_W & ~RTC_FROM4_NAND_ADDR_MASK);
196
197	switch (chip) {
198
199	case 0:		/* select slot 3 chip */
200		this->IO_ADDR_R = (void __iomem *)((unsigned long)this->IO_ADDR_R | RTC_FROM4_NAND_ADDR_SLOT3);
201		this->IO_ADDR_W = (void __iomem *)((unsigned long)this->IO_ADDR_W | RTC_FROM4_NAND_ADDR_SLOT3);
202		break;
203	case 1:		/* select slot 4 chip */
204		this->IO_ADDR_R = (void __iomem *)((unsigned long)this->IO_ADDR_R | RTC_FROM4_NAND_ADDR_SLOT4);
205		this->IO_ADDR_W = (void __iomem *)((unsigned long)this->IO_ADDR_W | RTC_FROM4_NAND_ADDR_SLOT4);
206		break;
207
208	}
209}
210
211/*
212 * rtc_from4_nand_device_ready - hardware specific ready/busy check
213 * @mtd:	MTD device structure
214 *
215 * This board provides the Ready/Busy state in the status register
216 * of the FPGA.  Bit zero indicates the RDY(1)/BSY(0) signal.
217 *
218 */
219static int rtc_from4_nand_device_ready(struct mtd_info *mtd)
220{
221	unsigned short status;
222
223	status = *((volatile unsigned short *)(rtc_from4_fio_base + RTC_FROM4_FPGA_SR));
224
225	return (status & RTC_FROM4_DEVICE_READY);
226
227}
228
229/*
230 * deplete - code to perform device recovery in case there was a power loss
231 * @mtd:	MTD device structure
232 * @chip:	Chip to select (0 == slot 3, 1 == slot 4)
233 *
234 * If there was a sudden loss of power during an erase operation, a
235 * "device recovery" operation must be performed when power is restored
236 * to ensure correct operation.  This routine performs the required steps
237 * for the requested chip.
238 *
239 * See page 86 of the data sheet for details.
240 *
241 */
242static void deplete(struct mtd_info *mtd, int chip)
243{
244	struct nand_chip *this = mtd->priv;
245
246	/* wait until device is ready */
247	while (!this->dev_ready(mtd)) ;
248
249	this->select_chip(mtd, chip);
250
251	/* Send the commands for device recovery, phase 1 */
252	this->cmdfunc(mtd, NAND_CMD_DEPLETE1, 0x0000, 0x0000);
253	this->cmdfunc(mtd, NAND_CMD_DEPLETE2, -1, -1);
254
255	/* Send the commands for device recovery, phase 2 */
256	this->cmdfunc(mtd, NAND_CMD_DEPLETE1, 0x0000, 0x0004);
257	this->cmdfunc(mtd, NAND_CMD_DEPLETE2, -1, -1);
258
259}
260
261#ifdef RTC_FROM4_HWECC
262/*
263 * rtc_from4_enable_hwecc - hardware specific hardware ECC enable function
264 * @mtd:	MTD device structure
265 * @mode:	I/O mode; read or write
266 *
267 * enable hardware ECC for data read or write
268 *
269 */
270static void rtc_from4_enable_hwecc(struct mtd_info *mtd, int mode)
271{
272	volatile unsigned short *rs_ecc_ctl = (volatile unsigned short *)(rtc_from4_fio_base + RTC_FROM4_RS_ECC_CTL);
273	unsigned short status;
274
275	switch (mode) {
276	case NAND_ECC_READ:
277		status = RTC_FROM4_RS_ECC_CTL_CLR | RTC_FROM4_RS_ECC_CTL_FD_E;
278
279		*rs_ecc_ctl = status;
280		break;
281
282	case NAND_ECC_READSYN:
283		status = 0x00;
284
285		*rs_ecc_ctl = status;
286		break;
287
288	case NAND_ECC_WRITE:
289		status = RTC_FROM4_RS_ECC_CTL_CLR | RTC_FROM4_RS_ECC_CTL_GEN | RTC_FROM4_RS_ECC_CTL_FD_E;
290
291		*rs_ecc_ctl = status;
292		break;
293
294	default:
295		BUG();
296		break;
297	}
298
299}
300
301/*
302 * rtc_from4_calculate_ecc - hardware specific code to read ECC code
303 * @mtd:	MTD device structure
304 * @dat:	buffer containing the data to generate ECC codes
305 * @ecc_code	ECC codes calculated
306 *
307 * The ECC code is calculated by the FPGA.  All we have to do is read the values
308 * from the FPGA registers.
309 *
310 * Note: We read from the inverted registers, since data is inverted before
311 * the code is calculated. So all 0xff data (blank page) results in all 0xff rs code
312 *
313 */
314static void rtc_from4_calculate_ecc(struct mtd_info *mtd, const u_char *dat, u_char *ecc_code)
315{
316	volatile unsigned short *rs_eccn = (volatile unsigned short *)(rtc_from4_fio_base + RTC_FROM4_RS_ECCN);
317	unsigned short value;
318	int i;
319
320	for (i = 0; i < 8; i++) {
321		value = *rs_eccn;
322		ecc_code[i] = (unsigned char)value;
323		rs_eccn++;
324	}
325	ecc_code[7] |= 0x0f;	/* set the last four bits (not used) */
326}
327
328/*
329 * rtc_from4_correct_data - hardware specific code to correct data using ECC code
330 * @mtd:	MTD device structure
331 * @buf:	buffer containing the data to generate ECC codes
332 * @ecc1	ECC codes read
333 * @ecc2	ECC codes calculated
334 *
335 * The FPGA tells us fast, if there's an error or not. If no, we go back happy
336 * else we read the ecc results from the fpga and call the rs library to decode
337 * and hopefully correct the error.
338 *
339 */
340static int rtc_from4_correct_data(struct mtd_info *mtd, const u_char *buf, u_char *ecc1, u_char *ecc2)
341{
342	int i, j, res;
343	unsigned short status;
344	uint16_t par[6], syn[6];
345	uint8_t ecc[8];
346	volatile unsigned short *rs_ecc;
347
348	status = *((volatile unsigned short *)(rtc_from4_fio_base + RTC_FROM4_RS_ECC_CHK));
349
350	if (!(status & RTC_FROM4_RS_ECC_CHK_ERROR)) {
351		return 0;
352	}
353
354	/* Read the syndrome pattern from the FPGA and correct the bitorder */
355	rs_ecc = (volatile unsigned short *)(rtc_from4_fio_base + RTC_FROM4_RS_ECC);
356	for (i = 0; i < 8; i++) {
357		ecc[i] = bitrev8(*rs_ecc);
358		rs_ecc++;
359	}
360
361	/* convert into 6 10bit syndrome fields */
362	par[5] = rs_decoder->index_of[(((uint16_t) ecc[0] >> 0) & 0x0ff) | (((uint16_t) ecc[1] << 8) & 0x300)];
363	par[4] = rs_decoder->index_of[(((uint16_t) ecc[1] >> 2) & 0x03f) | (((uint16_t) ecc[2] << 6) & 0x3c0)];
364	par[3] = rs_decoder->index_of[(((uint16_t) ecc[2] >> 4) & 0x00f) | (((uint16_t) ecc[3] << 4) & 0x3f0)];
365	par[2] = rs_decoder->index_of[(((uint16_t) ecc[3] >> 6) & 0x003) | (((uint16_t) ecc[4] << 2) & 0x3fc)];
366	par[1] = rs_decoder->index_of[(((uint16_t) ecc[5] >> 0) & 0x0ff) | (((uint16_t) ecc[6] << 8) & 0x300)];
367	par[0] = (((uint16_t) ecc[6] >> 2) & 0x03f) | (((uint16_t) ecc[7] << 6) & 0x3c0);
368
369	/* Convert to computable syndrome */
370	for (i = 0; i < 6; i++) {
371		syn[i] = par[0];
372		for (j = 1; j < 6; j++)
373			if (par[j] != rs_decoder->nn)
374				syn[i] ^= rs_decoder->alpha_to[rs_modnn(rs_decoder, par[j] + i * j)];
375
376		/* Convert to index form */
377		syn[i] = rs_decoder->index_of[syn[i]];
378	}
379
380	/* Let the library code do its magic. */
381	res = decode_rs8(rs_decoder, (uint8_t *) buf, par, 512, syn, 0, NULL, 0xff, NULL);
382	if (res > 0) {
383		pr_debug("rtc_from4_correct_data: " "ECC corrected %d errors on read\n", res);
384	}
385	return res;
386}
387
388/**
389 * rtc_from4_errstat - perform additional error status checks
390 * @mtd:	MTD device structure
391 * @this:	NAND chip structure
392 * @state:	state or the operation
393 * @status:	status code returned from read status
394 * @page:	startpage inside the chip, must be called with (page & this->pagemask)
395 *
396 * Perform additional error status checks on erase and write failures
397 * to determine if errors are correctable.  For this device, correctable
398 * 1-bit errors on erase and write are considered acceptable.
399 *
400 * note: see pages 34..37 of data sheet for details.
401 *
402 */
403static int rtc_from4_errstat(struct mtd_info *mtd, struct nand_chip *this,
404			     int state, int status, int page)
405{
406	int er_stat = 0;
407	int rtn, retlen;
408	size_t len;
409	uint8_t *buf;
410	int i;
411
412	this->cmdfunc(mtd, NAND_CMD_STATUS_CLEAR, -1, -1);
413
414	if (state == FL_ERASING) {
415
416		for (i = 0; i < 4; i++) {
417			if (!(status & 1 << (i + 1)))
418				continue;
419			this->cmdfunc(mtd, (NAND_CMD_STATUS_ERROR + i + 1),
420				      -1, -1);
421			rtn = this->read_byte(mtd);
422			this->cmdfunc(mtd, NAND_CMD_STATUS_RESET, -1, -1);
423
424			/* err_ecc_not_avail */
425			if (!(rtn & ERR_STAT_ECC_AVAILABLE))
426				er_stat |= 1 << (i + 1);
427		}
428
429	} else if (state == FL_WRITING) {
430
431		unsigned long corrected = mtd->ecc_stats.corrected;
432
433		/* single bank write logic */
434		this->cmdfunc(mtd, NAND_CMD_STATUS_ERROR, -1, -1);
435		rtn = this->read_byte(mtd);
436		this->cmdfunc(mtd, NAND_CMD_STATUS_RESET, -1, -1);
437
438		if (!(rtn & ERR_STAT_ECC_AVAILABLE)) {
439			/* err_ecc_not_avail */
440			er_stat |= 1 << 1;
441			goto out;
442		}
443
444		len = mtd->writesize;
445		buf = kmalloc(len, GFP_KERNEL);
446		if (!buf) {
447			er_stat = 1;
448			goto out;
449		}
450
451		/* recovery read */
452		rtn = nand_do_read(mtd, page, len, &retlen, buf);
453
454		/* if read failed or > 1-bit error corrected */
455		if (rtn || (mtd->ecc_stats.corrected - corrected) > 1)
456			er_stat |= 1 << 1;
457		kfree(buf);
458	}
459out:
460	rtn = status;
461	if (er_stat == 0) {	/* if ECC is available   */
462		rtn = (status & ~NAND_STATUS_FAIL);	/*   clear the error bit */
463	}
464
465	return rtn;
466}
467#endif
468
469/*
470 * Main initialization routine
471 */
472static int __init rtc_from4_init(void)
473{
474	struct nand_chip *this;
475	unsigned short bcr1, bcr2, wcr2;
476	int i;
477	int ret;
478
479	/* Allocate memory for MTD device structure and private data */
480	rtc_from4_mtd = kmalloc(sizeof(struct mtd_info) + sizeof(struct nand_chip), GFP_KERNEL);
481	if (!rtc_from4_mtd) {
482		printk("Unable to allocate Renesas NAND MTD device structure.\n");
483		return -ENOMEM;
484	}
485
486	/* Get pointer to private data */
487	this = (struct nand_chip *)(&rtc_from4_mtd[1]);
488
489	/* Initialize structures */
490	memset(rtc_from4_mtd, 0, sizeof(struct mtd_info));
491	memset(this, 0, sizeof(struct nand_chip));
492
493	/* Link the private data with the MTD structure */
494	rtc_from4_mtd->priv = this;
495	rtc_from4_mtd->owner = THIS_MODULE;
496
497	/* set area 5 as PCMCIA mode to clear the spec of tDH(Data hold time;9ns min) */
498	bcr1 = *SH77X9_BCR1 & ~0x0002;
499	bcr1 |= 0x0002;
500	*SH77X9_BCR1 = bcr1;
501
502	/* set */
503	bcr2 = *SH77X9_BCR2 & ~0x0c00;
504	bcr2 |= 0x0800;
505	*SH77X9_BCR2 = bcr2;
506
507	/* set area 5 wait states */
508	wcr2 = *SH77X9_WCR2 & ~0x1c00;
509	wcr2 |= 0x1c00;
510	*SH77X9_WCR2 = wcr2;
511
512	/* Set address of NAND IO lines */
513	this->IO_ADDR_R = rtc_from4_fio_base;
514	this->IO_ADDR_W = rtc_from4_fio_base;
515	/* Set address of hardware control function */
516	this->cmd_ctrl = rtc_from4_hwcontrol;
517	/* Set address of chip select function */
518	this->select_chip = rtc_from4_nand_select_chip;
519	/* command delay time (in us) */
520	this->chip_delay = 100;
521	/* return the status of the Ready/Busy line */
522	this->dev_ready = rtc_from4_nand_device_ready;
523
524#ifdef RTC_FROM4_HWECC
525	printk(KERN_INFO "rtc_from4_init: using hardware ECC detection.\n");
526
527	this->ecc.mode = NAND_ECC_HW_SYNDROME;
528	this->ecc.size = 512;
529	this->ecc.bytes = 8;
530	/* return the status of extra status and ECC checks */
531	this->errstat = rtc_from4_errstat;
532	/* set the nand_oobinfo to support FPGA H/W error detection */
533	this->ecc.layout = &rtc_from4_nand_oobinfo;
534	this->ecc.hwctl = rtc_from4_enable_hwecc;
535	this->ecc.calculate = rtc_from4_calculate_ecc;
536	this->ecc.correct = rtc_from4_correct_data;
537
538	/* We could create the decoder on demand, if memory is a concern.
539	 * This way we have it handy, if an error happens
540	 *
541	 * Symbolsize is 10 (bits)
542	 * Primitve polynomial is x^10+x^3+1
543	 * first consecutive root is 0
544	 * primitve element to generate roots = 1
545	 * generator polinomial degree = 6
546	 */
547	rs_decoder = init_rs(10, 0x409, 0, 1, 6);
548	if (!rs_decoder) {
549		printk(KERN_ERR "Could not create a RS decoder\n");
550		ret = -ENOMEM;
551		goto err_1;
552	}
553#else
554	printk(KERN_INFO "rtc_from4_init: using software ECC detection.\n");
555
556	this->ecc.mode = NAND_ECC_SOFT;
557#endif
558
559	/* set the bad block tables to support debugging */
560	this->bbt_td = &rtc_from4_bbt_main_descr;
561	this->bbt_md = &rtc_from4_bbt_mirror_descr;
562
563	/* Scan to find existence of the device */
564	if (nand_scan(rtc_from4_mtd, RTC_FROM4_MAX_CHIPS)) {
565		ret = -ENXIO;
566		goto err_2;
567	}
568
569	/* Perform 'device recovery' for each chip in case there was a power loss. */
570	for (i = 0; i < this->numchips; i++) {
571		deplete(rtc_from4_mtd, i);
572	}
573
574#if RTC_FROM4_NO_VIRTBLOCKS
575	/* use a smaller erase block to minimize wasted space when a block is bad */
576	/* note: this uses eight times as much RAM as using the default and makes */
577	/*       mounts take four times as long. */
578	rtc_from4_mtd->flags |= MTD_NO_VIRTBLOCKS;
579#endif
580
581	/* Register the partitions */
582	ret = mtd_device_register(rtc_from4_mtd, partition_info,
583				  NUM_PARTITIONS);
584	if (ret)
585		goto err_3;
586
587	/* Return happy */
588	return 0;
589err_3:
590	nand_release(rtc_from4_mtd);
591err_2:
592	free_rs(rs_decoder);
593err_1:
594	kfree(rtc_from4_mtd);
595	return ret;
596}
597
598module_init(rtc_from4_init);
599
600/*
601 * Clean up routine
602 */
603static void __exit rtc_from4_cleanup(void)
604{
605	/* Release resource, unregister partitions */
606	nand_release(rtc_from4_mtd);
607
608	/* Free the MTD device structure */
609	kfree(rtc_from4_mtd);
610
611#ifdef RTC_FROM4_HWECC
612	/* Free the reed solomon resources */
613	if (rs_decoder) {
614		free_rs(rs_decoder);
615	}
616#endif
617}
618
619module_exit(rtc_from4_cleanup);
620
621MODULE_LICENSE("GPL");
622MODULE_AUTHOR("d.marlin <dmarlin@redhat.com");
623MODULE_DESCRIPTION("Board-specific glue layer for AG-AND flash on Renesas FROM_BOARD4");
624