1/*
2 * Copyright (C) 2013 Boris BREZILLON <b.brezillon.dev@gmail.com>
3 *
4 * Derived from:
5 *	https://github.com/yuq/sunxi-nfc-mtd
6 *	Copyright (C) 2013 Qiang Yu <yuq825@gmail.com>
7 *
8 *	https://github.com/hno/Allwinner-Info
9 *	Copyright (C) 2013 Henrik Nordström <Henrik Nordström>
10 *
11 *	Copyright (C) 2013 Dmitriy B. <rzk333@gmail.com>
12 *	Copyright (C) 2013 Sergey Lapin <slapin@ossfans.org>
13 *
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or
17 * (at your option) any later version.
18 *
19 * This program is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
22 * GNU General Public License for more details.
23 */
24
25#include <linux/dma-mapping.h>
26#include <linux/slab.h>
27#include <linux/module.h>
28#include <linux/moduleparam.h>
29#include <linux/platform_device.h>
30#include <linux/of.h>
31#include <linux/of_device.h>
32#include <linux/of_gpio.h>
33#include <linux/of_mtd.h>
34#include <linux/mtd/mtd.h>
35#include <linux/mtd/nand.h>
36#include <linux/mtd/partitions.h>
37#include <linux/clk.h>
38#include <linux/delay.h>
39#include <linux/dmaengine.h>
40#include <linux/gpio.h>
41#include <linux/interrupt.h>
42#include <linux/io.h>
43
44#define NFC_REG_CTL		0x0000
45#define NFC_REG_ST		0x0004
46#define NFC_REG_INT		0x0008
47#define NFC_REG_TIMING_CTL	0x000C
48#define NFC_REG_TIMING_CFG	0x0010
49#define NFC_REG_ADDR_LOW	0x0014
50#define NFC_REG_ADDR_HIGH	0x0018
51#define NFC_REG_SECTOR_NUM	0x001C
52#define NFC_REG_CNT		0x0020
53#define NFC_REG_CMD		0x0024
54#define NFC_REG_RCMD_SET	0x0028
55#define NFC_REG_WCMD_SET	0x002C
56#define NFC_REG_IO_DATA		0x0030
57#define NFC_REG_ECC_CTL		0x0034
58#define NFC_REG_ECC_ST		0x0038
59#define NFC_REG_DEBUG		0x003C
60#define NFC_REG_ECC_CNT0	0x0040
61#define NFC_REG_ECC_CNT1	0x0044
62#define NFC_REG_ECC_CNT2	0x0048
63#define NFC_REG_ECC_CNT3	0x004c
64#define NFC_REG_USER_DATA_BASE	0x0050
65#define NFC_REG_SPARE_AREA	0x00A0
66#define NFC_RAM0_BASE		0x0400
67#define NFC_RAM1_BASE		0x0800
68
69/* define bit use in NFC_CTL */
70#define NFC_EN			BIT(0)
71#define NFC_RESET		BIT(1)
72#define NFC_BUS_WIDYH		BIT(2)
73#define NFC_RB_SEL		BIT(3)
74#define NFC_CE_SEL		GENMASK(26, 24)
75#define NFC_CE_CTL		BIT(6)
76#define NFC_CE_CTL1		BIT(7)
77#define NFC_PAGE_SIZE		GENMASK(11, 8)
78#define NFC_SAM			BIT(12)
79#define NFC_RAM_METHOD		BIT(14)
80#define NFC_DEBUG_CTL		BIT(31)
81
82/* define bit use in NFC_ST */
83#define NFC_RB_B2R		BIT(0)
84#define NFC_CMD_INT_FLAG	BIT(1)
85#define NFC_DMA_INT_FLAG	BIT(2)
86#define NFC_CMD_FIFO_STATUS	BIT(3)
87#define NFC_STA			BIT(4)
88#define NFC_NATCH_INT_FLAG	BIT(5)
89#define NFC_RB_STATE0		BIT(8)
90#define NFC_RB_STATE1		BIT(9)
91#define NFC_RB_STATE2		BIT(10)
92#define NFC_RB_STATE3		BIT(11)
93
94/* define bit use in NFC_INT */
95#define NFC_B2R_INT_ENABLE	BIT(0)
96#define NFC_CMD_INT_ENABLE	BIT(1)
97#define NFC_DMA_INT_ENABLE	BIT(2)
98#define NFC_INT_MASK		(NFC_B2R_INT_ENABLE | \
99				 NFC_CMD_INT_ENABLE | \
100				 NFC_DMA_INT_ENABLE)
101
102/* define bit use in NFC_CMD */
103#define NFC_CMD_LOW_BYTE	GENMASK(7, 0)
104#define NFC_CMD_HIGH_BYTE	GENMASK(15, 8)
105#define NFC_ADR_NUM		GENMASK(18, 16)
106#define NFC_SEND_ADR		BIT(19)
107#define NFC_ACCESS_DIR		BIT(20)
108#define NFC_DATA_TRANS		BIT(21)
109#define NFC_SEND_CMD1		BIT(22)
110#define NFC_WAIT_FLAG		BIT(23)
111#define NFC_SEND_CMD2		BIT(24)
112#define NFC_SEQ			BIT(25)
113#define NFC_DATA_SWAP_METHOD	BIT(26)
114#define NFC_ROW_AUTO_INC	BIT(27)
115#define NFC_SEND_CMD3		BIT(28)
116#define NFC_SEND_CMD4		BIT(29)
117#define NFC_CMD_TYPE		GENMASK(31, 30)
118
119/* define bit use in NFC_RCMD_SET */
120#define NFC_READ_CMD		GENMASK(7, 0)
121#define NFC_RANDOM_READ_CMD0	GENMASK(15, 8)
122#define NFC_RANDOM_READ_CMD1	GENMASK(23, 16)
123
124/* define bit use in NFC_WCMD_SET */
125#define NFC_PROGRAM_CMD		GENMASK(7, 0)
126#define NFC_RANDOM_WRITE_CMD	GENMASK(15, 8)
127#define NFC_READ_CMD0		GENMASK(23, 16)
128#define NFC_READ_CMD1		GENMASK(31, 24)
129
130/* define bit use in NFC_ECC_CTL */
131#define NFC_ECC_EN		BIT(0)
132#define NFC_ECC_PIPELINE	BIT(3)
133#define NFC_ECC_EXCEPTION	BIT(4)
134#define NFC_ECC_BLOCK_SIZE	BIT(5)
135#define NFC_RANDOM_EN		BIT(9)
136#define NFC_RANDOM_DIRECTION	BIT(10)
137#define NFC_ECC_MODE_SHIFT	12
138#define NFC_ECC_MODE		GENMASK(15, 12)
139#define NFC_RANDOM_SEED		GENMASK(30, 16)
140
141/* NFC_USER_DATA helper macros */
142#define NFC_BUF_TO_USER_DATA(buf)	((buf)[0] | ((buf)[1] << 8) | \
143					((buf)[2] << 16) | ((buf)[3] << 24))
144
145#define NFC_DEFAULT_TIMEOUT_MS	1000
146
147#define NFC_SRAM_SIZE		1024
148
149#define NFC_MAX_CS		7
150
151/*
152 * Ready/Busy detection type: describes the Ready/Busy detection modes
153 *
154 * @RB_NONE:	no external detection available, rely on STATUS command
155 *		and software timeouts
156 * @RB_NATIVE:	use sunxi NAND controller Ready/Busy support. The Ready/Busy
157 *		pin of the NAND flash chip must be connected to one of the
158 *		native NAND R/B pins (those which can be muxed to the NAND
159 *		Controller)
160 * @RB_GPIO:	use a simple GPIO to handle Ready/Busy status. The Ready/Busy
161 *		pin of the NAND flash chip must be connected to a GPIO capable
162 *		pin.
163 */
164enum sunxi_nand_rb_type {
165	RB_NONE,
166	RB_NATIVE,
167	RB_GPIO,
168};
169
170/*
171 * Ready/Busy structure: stores information related to Ready/Busy detection
172 *
173 * @type:	the Ready/Busy detection mode
174 * @info:	information related to the R/B detection mode. Either a gpio
175 *		id or a native R/B id (those supported by the NAND controller).
176 */
177struct sunxi_nand_rb {
178	enum sunxi_nand_rb_type type;
179	union {
180		int gpio;
181		int nativeid;
182	} info;
183};
184
185/*
186 * Chip Select structure: stores information related to NAND Chip Select
187 *
188 * @cs:		the NAND CS id used to communicate with a NAND Chip
189 * @rb:		the Ready/Busy description
190 */
191struct sunxi_nand_chip_sel {
192	u8 cs;
193	struct sunxi_nand_rb rb;
194};
195
196/*
197 * sunxi HW ECC infos: stores information related to HW ECC support
198 *
199 * @mode:	the sunxi ECC mode field deduced from ECC requirements
200 * @layout:	the OOB layout depending on the ECC requirements and the
201 *		selected ECC mode
202 */
203struct sunxi_nand_hw_ecc {
204	int mode;
205	struct nand_ecclayout layout;
206};
207
208/*
209 * NAND chip structure: stores NAND chip device related information
210 *
211 * @node:		used to store NAND chips into a list
212 * @nand:		base NAND chip structure
213 * @mtd:		base MTD structure
214 * @clk_rate:		clk_rate required for this NAND chip
215 * @selected:		current active CS
216 * @nsels:		number of CS lines required by the NAND chip
217 * @sels:		array of CS lines descriptions
218 */
219struct sunxi_nand_chip {
220	struct list_head node;
221	struct nand_chip nand;
222	struct mtd_info mtd;
223	unsigned long clk_rate;
224	int selected;
225	int nsels;
226	struct sunxi_nand_chip_sel sels[0];
227};
228
229static inline struct sunxi_nand_chip *to_sunxi_nand(struct nand_chip *nand)
230{
231	return container_of(nand, struct sunxi_nand_chip, nand);
232}
233
234/*
235 * NAND Controller structure: stores sunxi NAND controller information
236 *
237 * @controller:		base controller structure
238 * @dev:		parent device (used to print error messages)
239 * @regs:		NAND controller registers
240 * @ahb_clk:		NAND Controller AHB clock
241 * @mod_clk:		NAND Controller mod clock
242 * @assigned_cs:	bitmask describing already assigned CS lines
243 * @clk_rate:		NAND controller current clock rate
244 * @chips:		a list containing all the NAND chips attached to
245 *			this NAND controller
246 * @complete:		a completion object used to wait for NAND
247 *			controller events
248 */
249struct sunxi_nfc {
250	struct nand_hw_control controller;
251	struct device *dev;
252	void __iomem *regs;
253	struct clk *ahb_clk;
254	struct clk *mod_clk;
255	unsigned long assigned_cs;
256	unsigned long clk_rate;
257	struct list_head chips;
258	struct completion complete;
259};
260
261static inline struct sunxi_nfc *to_sunxi_nfc(struct nand_hw_control *ctrl)
262{
263	return container_of(ctrl, struct sunxi_nfc, controller);
264}
265
266static irqreturn_t sunxi_nfc_interrupt(int irq, void *dev_id)
267{
268	struct sunxi_nfc *nfc = dev_id;
269	u32 st = readl(nfc->regs + NFC_REG_ST);
270	u32 ien = readl(nfc->regs + NFC_REG_INT);
271
272	if (!(ien & st))
273		return IRQ_NONE;
274
275	if ((ien & st) == ien)
276		complete(&nfc->complete);
277
278	writel(st & NFC_INT_MASK, nfc->regs + NFC_REG_ST);
279	writel(~st & ien & NFC_INT_MASK, nfc->regs + NFC_REG_INT);
280
281	return IRQ_HANDLED;
282}
283
284static int sunxi_nfc_wait_int(struct sunxi_nfc *nfc, u32 flags,
285			      unsigned int timeout_ms)
286{
287	init_completion(&nfc->complete);
288
289	writel(flags, nfc->regs + NFC_REG_INT);
290
291	if (!timeout_ms)
292		timeout_ms = NFC_DEFAULT_TIMEOUT_MS;
293
294	if (!wait_for_completion_timeout(&nfc->complete,
295					 msecs_to_jiffies(timeout_ms))) {
296		dev_err(nfc->dev, "wait interrupt timedout\n");
297		return -ETIMEDOUT;
298	}
299
300	return 0;
301}
302
303static int sunxi_nfc_wait_cmd_fifo_empty(struct sunxi_nfc *nfc)
304{
305	unsigned long timeout = jiffies +
306				msecs_to_jiffies(NFC_DEFAULT_TIMEOUT_MS);
307
308	do {
309		if (!(readl(nfc->regs + NFC_REG_ST) & NFC_CMD_FIFO_STATUS))
310			return 0;
311	} while (time_before(jiffies, timeout));
312
313	dev_err(nfc->dev, "wait for empty cmd FIFO timedout\n");
314	return -ETIMEDOUT;
315}
316
317static int sunxi_nfc_rst(struct sunxi_nfc *nfc)
318{
319	unsigned long timeout = jiffies +
320				msecs_to_jiffies(NFC_DEFAULT_TIMEOUT_MS);
321
322	writel(0, nfc->regs + NFC_REG_ECC_CTL);
323	writel(NFC_RESET, nfc->regs + NFC_REG_CTL);
324
325	do {
326		if (!(readl(nfc->regs + NFC_REG_CTL) & NFC_RESET))
327			return 0;
328	} while (time_before(jiffies, timeout));
329
330	dev_err(nfc->dev, "wait for NAND controller reset timedout\n");
331	return -ETIMEDOUT;
332}
333
334static int sunxi_nfc_dev_ready(struct mtd_info *mtd)
335{
336	struct nand_chip *nand = mtd->priv;
337	struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
338	struct sunxi_nfc *nfc = to_sunxi_nfc(sunxi_nand->nand.controller);
339	struct sunxi_nand_rb *rb;
340	unsigned long timeo = (sunxi_nand->nand.state == FL_ERASING ? 400 : 20);
341	int ret;
342
343	if (sunxi_nand->selected < 0)
344		return 0;
345
346	rb = &sunxi_nand->sels[sunxi_nand->selected].rb;
347
348	switch (rb->type) {
349	case RB_NATIVE:
350		ret = !!(readl(nfc->regs + NFC_REG_ST) &
351			 (NFC_RB_STATE0 << rb->info.nativeid));
352		if (ret)
353			break;
354
355		sunxi_nfc_wait_int(nfc, NFC_RB_B2R, timeo);
356		ret = !!(readl(nfc->regs + NFC_REG_ST) &
357			 (NFC_RB_STATE0 << rb->info.nativeid));
358		break;
359	case RB_GPIO:
360		ret = gpio_get_value(rb->info.gpio);
361		break;
362	case RB_NONE:
363	default:
364		ret = 0;
365		dev_err(nfc->dev, "cannot check R/B NAND status!\n");
366		break;
367	}
368
369	return ret;
370}
371
372static void sunxi_nfc_select_chip(struct mtd_info *mtd, int chip)
373{
374	struct nand_chip *nand = mtd->priv;
375	struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
376	struct sunxi_nfc *nfc = to_sunxi_nfc(sunxi_nand->nand.controller);
377	struct sunxi_nand_chip_sel *sel;
378	u32 ctl;
379
380	if (chip > 0 && chip >= sunxi_nand->nsels)
381		return;
382
383	if (chip == sunxi_nand->selected)
384		return;
385
386	ctl = readl(nfc->regs + NFC_REG_CTL) &
387	      ~(NFC_CE_SEL | NFC_RB_SEL | NFC_EN);
388
389	if (chip >= 0) {
390		sel = &sunxi_nand->sels[chip];
391
392		ctl |= (sel->cs << 24) | NFC_EN |
393		       (((nand->page_shift - 10) & 0xf) << 8);
394		if (sel->rb.type == RB_NONE) {
395			nand->dev_ready = NULL;
396		} else {
397			nand->dev_ready = sunxi_nfc_dev_ready;
398			if (sel->rb.type == RB_NATIVE)
399				ctl |= (sel->rb.info.nativeid << 3);
400		}
401
402		writel(mtd->writesize, nfc->regs + NFC_REG_SPARE_AREA);
403
404		if (nfc->clk_rate != sunxi_nand->clk_rate) {
405			clk_set_rate(nfc->mod_clk, sunxi_nand->clk_rate);
406			nfc->clk_rate = sunxi_nand->clk_rate;
407		}
408	}
409
410	writel(ctl, nfc->regs + NFC_REG_CTL);
411
412	sunxi_nand->selected = chip;
413}
414
415static void sunxi_nfc_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
416{
417	struct nand_chip *nand = mtd->priv;
418	struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
419	struct sunxi_nfc *nfc = to_sunxi_nfc(sunxi_nand->nand.controller);
420	int ret;
421	int cnt;
422	int offs = 0;
423	u32 tmp;
424
425	while (len > offs) {
426		cnt = min(len - offs, NFC_SRAM_SIZE);
427
428		ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
429		if (ret)
430			break;
431
432		writel(cnt, nfc->regs + NFC_REG_CNT);
433		tmp = NFC_DATA_TRANS | NFC_DATA_SWAP_METHOD;
434		writel(tmp, nfc->regs + NFC_REG_CMD);
435
436		ret = sunxi_nfc_wait_int(nfc, NFC_CMD_INT_FLAG, 0);
437		if (ret)
438			break;
439
440		if (buf)
441			memcpy_fromio(buf + offs, nfc->regs + NFC_RAM0_BASE,
442				      cnt);
443		offs += cnt;
444	}
445}
446
447static void sunxi_nfc_write_buf(struct mtd_info *mtd, const uint8_t *buf,
448				int len)
449{
450	struct nand_chip *nand = mtd->priv;
451	struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
452	struct sunxi_nfc *nfc = to_sunxi_nfc(sunxi_nand->nand.controller);
453	int ret;
454	int cnt;
455	int offs = 0;
456	u32 tmp;
457
458	while (len > offs) {
459		cnt = min(len - offs, NFC_SRAM_SIZE);
460
461		ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
462		if (ret)
463			break;
464
465		writel(cnt, nfc->regs + NFC_REG_CNT);
466		memcpy_toio(nfc->regs + NFC_RAM0_BASE, buf + offs, cnt);
467		tmp = NFC_DATA_TRANS | NFC_DATA_SWAP_METHOD |
468		      NFC_ACCESS_DIR;
469		writel(tmp, nfc->regs + NFC_REG_CMD);
470
471		ret = sunxi_nfc_wait_int(nfc, NFC_CMD_INT_FLAG, 0);
472		if (ret)
473			break;
474
475		offs += cnt;
476	}
477}
478
479static uint8_t sunxi_nfc_read_byte(struct mtd_info *mtd)
480{
481	uint8_t ret;
482
483	sunxi_nfc_read_buf(mtd, &ret, 1);
484
485	return ret;
486}
487
488static void sunxi_nfc_cmd_ctrl(struct mtd_info *mtd, int dat,
489			       unsigned int ctrl)
490{
491	struct nand_chip *nand = mtd->priv;
492	struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
493	struct sunxi_nfc *nfc = to_sunxi_nfc(sunxi_nand->nand.controller);
494	int ret;
495	u32 tmp;
496
497	ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
498	if (ret)
499		return;
500
501	if (ctrl & NAND_CTRL_CHANGE) {
502		tmp = readl(nfc->regs + NFC_REG_CTL);
503		if (ctrl & NAND_NCE)
504			tmp |= NFC_CE_CTL;
505		else
506			tmp &= ~NFC_CE_CTL;
507		writel(tmp, nfc->regs + NFC_REG_CTL);
508	}
509
510	if (dat == NAND_CMD_NONE)
511		return;
512
513	if (ctrl & NAND_CLE) {
514		writel(NFC_SEND_CMD1 | dat, nfc->regs + NFC_REG_CMD);
515	} else {
516		writel(dat, nfc->regs + NFC_REG_ADDR_LOW);
517		writel(NFC_SEND_ADR, nfc->regs + NFC_REG_CMD);
518	}
519
520	sunxi_nfc_wait_int(nfc, NFC_CMD_INT_FLAG, 0);
521}
522
523static int sunxi_nfc_hw_ecc_read_page(struct mtd_info *mtd,
524				      struct nand_chip *chip, uint8_t *buf,
525				      int oob_required, int page)
526{
527	struct sunxi_nfc *nfc = to_sunxi_nfc(chip->controller);
528	struct nand_ecc_ctrl *ecc = &chip->ecc;
529	struct nand_ecclayout *layout = ecc->layout;
530	struct sunxi_nand_hw_ecc *data = ecc->priv;
531	unsigned int max_bitflips = 0;
532	int offset;
533	int ret;
534	u32 tmp;
535	int i;
536	int cnt;
537
538	tmp = readl(nfc->regs + NFC_REG_ECC_CTL);
539	tmp &= ~(NFC_ECC_MODE | NFC_ECC_PIPELINE | NFC_ECC_BLOCK_SIZE);
540	tmp |= NFC_ECC_EN | (data->mode << NFC_ECC_MODE_SHIFT) |
541	       NFC_ECC_EXCEPTION;
542
543	writel(tmp, nfc->regs + NFC_REG_ECC_CTL);
544
545	for (i = 0; i < ecc->steps; i++) {
546		if (i)
547			chip->cmdfunc(mtd, NAND_CMD_RNDOUT, i * ecc->size, -1);
548
549		offset = mtd->writesize + layout->eccpos[i * ecc->bytes] - 4;
550
551		chip->read_buf(mtd, NULL, ecc->size);
552
553		chip->cmdfunc(mtd, NAND_CMD_RNDOUT, offset, -1);
554
555		ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
556		if (ret)
557			return ret;
558
559		tmp = NFC_DATA_TRANS | NFC_DATA_SWAP_METHOD | (1 << 30);
560		writel(tmp, nfc->regs + NFC_REG_CMD);
561
562		ret = sunxi_nfc_wait_int(nfc, NFC_CMD_INT_FLAG, 0);
563		if (ret)
564			return ret;
565
566		memcpy_fromio(buf + (i * ecc->size),
567			      nfc->regs + NFC_RAM0_BASE, ecc->size);
568
569		if (readl(nfc->regs + NFC_REG_ECC_ST) & 0x1) {
570			mtd->ecc_stats.failed++;
571		} else {
572			tmp = readl(nfc->regs + NFC_REG_ECC_CNT0) & 0xff;
573			mtd->ecc_stats.corrected += tmp;
574			max_bitflips = max_t(unsigned int, max_bitflips, tmp);
575		}
576
577		if (oob_required) {
578			chip->cmdfunc(mtd, NAND_CMD_RNDOUT, offset, -1);
579
580			ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
581			if (ret)
582				return ret;
583
584			offset -= mtd->writesize;
585			chip->read_buf(mtd, chip->oob_poi + offset,
586				      ecc->bytes + 4);
587		}
588	}
589
590	if (oob_required) {
591		cnt = ecc->layout->oobfree[ecc->steps].length;
592		if (cnt > 0) {
593			offset = mtd->writesize +
594				 ecc->layout->oobfree[ecc->steps].offset;
595			chip->cmdfunc(mtd, NAND_CMD_RNDOUT, offset, -1);
596			offset -= mtd->writesize;
597			chip->read_buf(mtd, chip->oob_poi + offset, cnt);
598		}
599	}
600
601	tmp = readl(nfc->regs + NFC_REG_ECC_CTL);
602	tmp &= ~NFC_ECC_EN;
603
604	writel(tmp, nfc->regs + NFC_REG_ECC_CTL);
605
606	return max_bitflips;
607}
608
609static int sunxi_nfc_hw_ecc_write_page(struct mtd_info *mtd,
610				       struct nand_chip *chip,
611				       const uint8_t *buf, int oob_required)
612{
613	struct sunxi_nfc *nfc = to_sunxi_nfc(chip->controller);
614	struct nand_ecc_ctrl *ecc = &chip->ecc;
615	struct nand_ecclayout *layout = ecc->layout;
616	struct sunxi_nand_hw_ecc *data = ecc->priv;
617	int offset;
618	int ret;
619	u32 tmp;
620	int i;
621	int cnt;
622
623	tmp = readl(nfc->regs + NFC_REG_ECC_CTL);
624	tmp &= ~(NFC_ECC_MODE | NFC_ECC_PIPELINE | NFC_ECC_BLOCK_SIZE);
625	tmp |= NFC_ECC_EN | (data->mode << NFC_ECC_MODE_SHIFT) |
626	       NFC_ECC_EXCEPTION;
627
628	writel(tmp, nfc->regs + NFC_REG_ECC_CTL);
629
630	for (i = 0; i < ecc->steps; i++) {
631		if (i)
632			chip->cmdfunc(mtd, NAND_CMD_RNDIN, i * ecc->size, -1);
633
634		chip->write_buf(mtd, buf + (i * ecc->size), ecc->size);
635
636		offset = layout->eccpos[i * ecc->bytes] - 4 + mtd->writesize;
637
638		/* Fill OOB data in */
639		writel(NFC_BUF_TO_USER_DATA(chip->oob_poi +
640					    layout->oobfree[i].offset),
641		       nfc->regs + NFC_REG_USER_DATA_BASE);
642
643		chip->cmdfunc(mtd, NAND_CMD_RNDIN, offset, -1);
644
645		ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
646		if (ret)
647			return ret;
648
649		tmp = NFC_DATA_TRANS | NFC_DATA_SWAP_METHOD | NFC_ACCESS_DIR |
650		      (1 << 30);
651		writel(tmp, nfc->regs + NFC_REG_CMD);
652		ret = sunxi_nfc_wait_int(nfc, NFC_CMD_INT_FLAG, 0);
653		if (ret)
654			return ret;
655	}
656
657	if (oob_required) {
658		cnt = ecc->layout->oobfree[i].length;
659		if (cnt > 0) {
660			offset = mtd->writesize +
661				 ecc->layout->oobfree[i].offset;
662			chip->cmdfunc(mtd, NAND_CMD_RNDIN, offset, -1);
663			offset -= mtd->writesize;
664			chip->write_buf(mtd, chip->oob_poi + offset, cnt);
665		}
666	}
667
668	tmp = readl(nfc->regs + NFC_REG_ECC_CTL);
669	tmp &= ~NFC_ECC_EN;
670
671	writel(tmp, nfc->regs + NFC_REG_ECC_CTL);
672
673	return 0;
674}
675
676static int sunxi_nfc_hw_syndrome_ecc_read_page(struct mtd_info *mtd,
677					       struct nand_chip *chip,
678					       uint8_t *buf, int oob_required,
679					       int page)
680{
681	struct sunxi_nfc *nfc = to_sunxi_nfc(chip->controller);
682	struct nand_ecc_ctrl *ecc = &chip->ecc;
683	struct sunxi_nand_hw_ecc *data = ecc->priv;
684	unsigned int max_bitflips = 0;
685	uint8_t *oob = chip->oob_poi;
686	int offset = 0;
687	int ret;
688	int cnt;
689	u32 tmp;
690	int i;
691
692	tmp = readl(nfc->regs + NFC_REG_ECC_CTL);
693	tmp &= ~(NFC_ECC_MODE | NFC_ECC_PIPELINE | NFC_ECC_BLOCK_SIZE);
694	tmp |= NFC_ECC_EN | (data->mode << NFC_ECC_MODE_SHIFT) |
695	       NFC_ECC_EXCEPTION;
696
697	writel(tmp, nfc->regs + NFC_REG_ECC_CTL);
698
699	for (i = 0; i < ecc->steps; i++) {
700		chip->read_buf(mtd, NULL, ecc->size);
701
702		tmp = NFC_DATA_TRANS | NFC_DATA_SWAP_METHOD | (1 << 30);
703		writel(tmp, nfc->regs + NFC_REG_CMD);
704
705		ret = sunxi_nfc_wait_int(nfc, NFC_CMD_INT_FLAG, 0);
706		if (ret)
707			return ret;
708
709		memcpy_fromio(buf, nfc->regs + NFC_RAM0_BASE, ecc->size);
710		buf += ecc->size;
711		offset += ecc->size;
712
713		if (readl(nfc->regs + NFC_REG_ECC_ST) & 0x1) {
714			mtd->ecc_stats.failed++;
715		} else {
716			tmp = readl(nfc->regs + NFC_REG_ECC_CNT0) & 0xff;
717			mtd->ecc_stats.corrected += tmp;
718			max_bitflips = max_t(unsigned int, max_bitflips, tmp);
719		}
720
721		if (oob_required) {
722			chip->cmdfunc(mtd, NAND_CMD_RNDOUT, offset, -1);
723			chip->read_buf(mtd, oob, ecc->bytes + ecc->prepad);
724			oob += ecc->bytes + ecc->prepad;
725		}
726
727		offset += ecc->bytes + ecc->prepad;
728	}
729
730	if (oob_required) {
731		cnt = mtd->oobsize - (oob - chip->oob_poi);
732		if (cnt > 0) {
733			chip->cmdfunc(mtd, NAND_CMD_RNDOUT, offset, -1);
734			chip->read_buf(mtd, oob, cnt);
735		}
736	}
737
738	writel(readl(nfc->regs + NFC_REG_ECC_CTL) & ~NFC_ECC_EN,
739	       nfc->regs + NFC_REG_ECC_CTL);
740
741	return max_bitflips;
742}
743
744static int sunxi_nfc_hw_syndrome_ecc_write_page(struct mtd_info *mtd,
745						struct nand_chip *chip,
746						const uint8_t *buf,
747						int oob_required)
748{
749	struct sunxi_nfc *nfc = to_sunxi_nfc(chip->controller);
750	struct nand_ecc_ctrl *ecc = &chip->ecc;
751	struct sunxi_nand_hw_ecc *data = ecc->priv;
752	uint8_t *oob = chip->oob_poi;
753	int offset = 0;
754	int ret;
755	int cnt;
756	u32 tmp;
757	int i;
758
759	tmp = readl(nfc->regs + NFC_REG_ECC_CTL);
760	tmp &= ~(NFC_ECC_MODE | NFC_ECC_PIPELINE | NFC_ECC_BLOCK_SIZE);
761	tmp |= NFC_ECC_EN | (data->mode << NFC_ECC_MODE_SHIFT) |
762	       NFC_ECC_EXCEPTION;
763
764	writel(tmp, nfc->regs + NFC_REG_ECC_CTL);
765
766	for (i = 0; i < ecc->steps; i++) {
767		chip->write_buf(mtd, buf + (i * ecc->size), ecc->size);
768		offset += ecc->size;
769
770		/* Fill OOB data in */
771		writel(NFC_BUF_TO_USER_DATA(oob),
772		       nfc->regs + NFC_REG_USER_DATA_BASE);
773
774		tmp = NFC_DATA_TRANS | NFC_DATA_SWAP_METHOD | NFC_ACCESS_DIR |
775		      (1 << 30);
776		writel(tmp, nfc->regs + NFC_REG_CMD);
777
778		ret = sunxi_nfc_wait_int(nfc, NFC_CMD_INT_FLAG, 0);
779		if (ret)
780			return ret;
781
782		offset += ecc->bytes + ecc->prepad;
783		oob += ecc->bytes + ecc->prepad;
784	}
785
786	if (oob_required) {
787		cnt = mtd->oobsize - (oob - chip->oob_poi);
788		if (cnt > 0) {
789			chip->cmdfunc(mtd, NAND_CMD_RNDIN, offset, -1);
790			chip->write_buf(mtd, oob, cnt);
791		}
792	}
793
794	tmp = readl(nfc->regs + NFC_REG_ECC_CTL);
795	tmp &= ~NFC_ECC_EN;
796
797	writel(tmp, nfc->regs + NFC_REG_ECC_CTL);
798
799	return 0;
800}
801
802static int sunxi_nand_chip_set_timings(struct sunxi_nand_chip *chip,
803				       const struct nand_sdr_timings *timings)
804{
805	u32 min_clk_period = 0;
806
807	/* T1 <=> tCLS */
808	if (timings->tCLS_min > min_clk_period)
809		min_clk_period = timings->tCLS_min;
810
811	/* T2 <=> tCLH */
812	if (timings->tCLH_min > min_clk_period)
813		min_clk_period = timings->tCLH_min;
814
815	/* T3 <=> tCS */
816	if (timings->tCS_min > min_clk_period)
817		min_clk_period = timings->tCS_min;
818
819	/* T4 <=> tCH */
820	if (timings->tCH_min > min_clk_period)
821		min_clk_period = timings->tCH_min;
822
823	/* T5 <=> tWP */
824	if (timings->tWP_min > min_clk_period)
825		min_clk_period = timings->tWP_min;
826
827	/* T6 <=> tWH */
828	if (timings->tWH_min > min_clk_period)
829		min_clk_period = timings->tWH_min;
830
831	/* T7 <=> tALS */
832	if (timings->tALS_min > min_clk_period)
833		min_clk_period = timings->tALS_min;
834
835	/* T8 <=> tDS */
836	if (timings->tDS_min > min_clk_period)
837		min_clk_period = timings->tDS_min;
838
839	/* T9 <=> tDH */
840	if (timings->tDH_min > min_clk_period)
841		min_clk_period = timings->tDH_min;
842
843	/* T10 <=> tRR */
844	if (timings->tRR_min > (min_clk_period * 3))
845		min_clk_period = DIV_ROUND_UP(timings->tRR_min, 3);
846
847	/* T11 <=> tALH */
848	if (timings->tALH_min > min_clk_period)
849		min_clk_period = timings->tALH_min;
850
851	/* T12 <=> tRP */
852	if (timings->tRP_min > min_clk_period)
853		min_clk_period = timings->tRP_min;
854
855	/* T13 <=> tREH */
856	if (timings->tREH_min > min_clk_period)
857		min_clk_period = timings->tREH_min;
858
859	/* T14 <=> tRC */
860	if (timings->tRC_min > (min_clk_period * 2))
861		min_clk_period = DIV_ROUND_UP(timings->tRC_min, 2);
862
863	/* T15 <=> tWC */
864	if (timings->tWC_min > (min_clk_period * 2))
865		min_clk_period = DIV_ROUND_UP(timings->tWC_min, 2);
866
867
868	/* Convert min_clk_period from picoseconds to nanoseconds */
869	min_clk_period = DIV_ROUND_UP(min_clk_period, 1000);
870
871	/*
872	 * Convert min_clk_period into a clk frequency, then get the
873	 * appropriate rate for the NAND controller IP given this formula
874	 * (specified in the datasheet):
875	 * nand clk_rate = 2 * min_clk_rate
876	 */
877	chip->clk_rate = (2 * NSEC_PER_SEC) / min_clk_period;
878
879	/* TODO: configure T16-T19 */
880
881	return 0;
882}
883
884static int sunxi_nand_chip_init_timings(struct sunxi_nand_chip *chip,
885					struct device_node *np)
886{
887	const struct nand_sdr_timings *timings;
888	int ret;
889	int mode;
890
891	mode = onfi_get_async_timing_mode(&chip->nand);
892	if (mode == ONFI_TIMING_MODE_UNKNOWN) {
893		mode = chip->nand.onfi_timing_mode_default;
894	} else {
895		uint8_t feature[ONFI_SUBFEATURE_PARAM_LEN] = {};
896
897		mode = fls(mode) - 1;
898		if (mode < 0)
899			mode = 0;
900
901		feature[0] = mode;
902		ret = chip->nand.onfi_set_features(&chip->mtd, &chip->nand,
903						ONFI_FEATURE_ADDR_TIMING_MODE,
904						feature);
905		if (ret)
906			return ret;
907	}
908
909	timings = onfi_async_timing_mode_to_sdr_timings(mode);
910	if (IS_ERR(timings))
911		return PTR_ERR(timings);
912
913	return sunxi_nand_chip_set_timings(chip, timings);
914}
915
916static int sunxi_nand_hw_common_ecc_ctrl_init(struct mtd_info *mtd,
917					      struct nand_ecc_ctrl *ecc,
918					      struct device_node *np)
919{
920	static const u8 strengths[] = { 16, 24, 28, 32, 40, 48, 56, 60, 64 };
921	struct nand_chip *nand = mtd->priv;
922	struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
923	struct sunxi_nfc *nfc = to_sunxi_nfc(sunxi_nand->nand.controller);
924	struct sunxi_nand_hw_ecc *data;
925	struct nand_ecclayout *layout;
926	int nsectors;
927	int ret;
928	int i;
929
930	data = kzalloc(sizeof(*data), GFP_KERNEL);
931	if (!data)
932		return -ENOMEM;
933
934	/* Add ECC info retrieval from DT */
935	for (i = 0; i < ARRAY_SIZE(strengths); i++) {
936		if (ecc->strength <= strengths[i])
937			break;
938	}
939
940	if (i >= ARRAY_SIZE(strengths)) {
941		dev_err(nfc->dev, "unsupported strength\n");
942		ret = -ENOTSUPP;
943		goto err;
944	}
945
946	data->mode = i;
947
948	/* HW ECC always request ECC bytes for 1024 bytes blocks */
949	ecc->bytes = DIV_ROUND_UP(ecc->strength * fls(8 * 1024), 8);
950
951	/* HW ECC always work with even numbers of ECC bytes */
952	ecc->bytes = ALIGN(ecc->bytes, 2);
953
954	layout = &data->layout;
955	nsectors = mtd->writesize / ecc->size;
956
957	if (mtd->oobsize < ((ecc->bytes + 4) * nsectors)) {
958		ret = -EINVAL;
959		goto err;
960	}
961
962	layout->eccbytes = (ecc->bytes * nsectors);
963
964	ecc->layout = layout;
965	ecc->priv = data;
966
967	return 0;
968
969err:
970	kfree(data);
971
972	return ret;
973}
974
975static void sunxi_nand_hw_common_ecc_ctrl_cleanup(struct nand_ecc_ctrl *ecc)
976{
977	kfree(ecc->priv);
978}
979
980static int sunxi_nand_hw_ecc_ctrl_init(struct mtd_info *mtd,
981				       struct nand_ecc_ctrl *ecc,
982				       struct device_node *np)
983{
984	struct nand_ecclayout *layout;
985	int nsectors;
986	int i, j;
987	int ret;
988
989	ret = sunxi_nand_hw_common_ecc_ctrl_init(mtd, ecc, np);
990	if (ret)
991		return ret;
992
993	ecc->read_page = sunxi_nfc_hw_ecc_read_page;
994	ecc->write_page = sunxi_nfc_hw_ecc_write_page;
995	layout = ecc->layout;
996	nsectors = mtd->writesize / ecc->size;
997
998	for (i = 0; i < nsectors; i++) {
999		if (i) {
1000			layout->oobfree[i].offset =
1001				layout->oobfree[i - 1].offset +
1002				layout->oobfree[i - 1].length +
1003				ecc->bytes;
1004			layout->oobfree[i].length = 4;
1005		} else {
1006			/*
1007			 * The first 2 bytes are used for BB markers, hence we
1008			 * only have 2 bytes available in the first user data
1009			 * section.
1010			 */
1011			layout->oobfree[i].length = 2;
1012			layout->oobfree[i].offset = 2;
1013		}
1014
1015		for (j = 0; j < ecc->bytes; j++)
1016			layout->eccpos[(ecc->bytes * i) + j] =
1017					layout->oobfree[i].offset +
1018					layout->oobfree[i].length + j;
1019	}
1020
1021	if (mtd->oobsize > (ecc->bytes + 4) * nsectors) {
1022		layout->oobfree[nsectors].offset =
1023				layout->oobfree[nsectors - 1].offset +
1024				layout->oobfree[nsectors - 1].length +
1025				ecc->bytes;
1026		layout->oobfree[nsectors].length = mtd->oobsize -
1027				((ecc->bytes + 4) * nsectors);
1028	}
1029
1030	return 0;
1031}
1032
1033static int sunxi_nand_hw_syndrome_ecc_ctrl_init(struct mtd_info *mtd,
1034						struct nand_ecc_ctrl *ecc,
1035						struct device_node *np)
1036{
1037	struct nand_ecclayout *layout;
1038	int nsectors;
1039	int i;
1040	int ret;
1041
1042	ret = sunxi_nand_hw_common_ecc_ctrl_init(mtd, ecc, np);
1043	if (ret)
1044		return ret;
1045
1046	ecc->prepad = 4;
1047	ecc->read_page = sunxi_nfc_hw_syndrome_ecc_read_page;
1048	ecc->write_page = sunxi_nfc_hw_syndrome_ecc_write_page;
1049
1050	layout = ecc->layout;
1051	nsectors = mtd->writesize / ecc->size;
1052
1053	for (i = 0; i < (ecc->bytes * nsectors); i++)
1054		layout->eccpos[i] = i;
1055
1056	layout->oobfree[0].length = mtd->oobsize - i;
1057	layout->oobfree[0].offset = i;
1058
1059	return 0;
1060}
1061
1062static void sunxi_nand_ecc_cleanup(struct nand_ecc_ctrl *ecc)
1063{
1064	switch (ecc->mode) {
1065	case NAND_ECC_HW:
1066	case NAND_ECC_HW_SYNDROME:
1067		sunxi_nand_hw_common_ecc_ctrl_cleanup(ecc);
1068		break;
1069	case NAND_ECC_NONE:
1070		kfree(ecc->layout);
1071	default:
1072		break;
1073	}
1074}
1075
1076static int sunxi_nand_ecc_init(struct mtd_info *mtd, struct nand_ecc_ctrl *ecc,
1077			       struct device_node *np)
1078{
1079	struct nand_chip *nand = mtd->priv;
1080	int strength;
1081	int blk_size;
1082	int ret;
1083
1084	blk_size = of_get_nand_ecc_step_size(np);
1085	strength = of_get_nand_ecc_strength(np);
1086	if (blk_size > 0 && strength > 0) {
1087		ecc->size = blk_size;
1088		ecc->strength = strength;
1089	} else {
1090		ecc->size = nand->ecc_step_ds;
1091		ecc->strength = nand->ecc_strength_ds;
1092	}
1093
1094	if (!ecc->size || !ecc->strength)
1095		return -EINVAL;
1096
1097	ecc->mode = NAND_ECC_HW;
1098
1099	ret = of_get_nand_ecc_mode(np);
1100	if (ret >= 0)
1101		ecc->mode = ret;
1102
1103	switch (ecc->mode) {
1104	case NAND_ECC_SOFT_BCH:
1105		break;
1106	case NAND_ECC_HW:
1107		ret = sunxi_nand_hw_ecc_ctrl_init(mtd, ecc, np);
1108		if (ret)
1109			return ret;
1110		break;
1111	case NAND_ECC_HW_SYNDROME:
1112		ret = sunxi_nand_hw_syndrome_ecc_ctrl_init(mtd, ecc, np);
1113		if (ret)
1114			return ret;
1115		break;
1116	case NAND_ECC_NONE:
1117		ecc->layout = kzalloc(sizeof(*ecc->layout), GFP_KERNEL);
1118		if (!ecc->layout)
1119			return -ENOMEM;
1120		ecc->layout->oobfree[0].length = mtd->oobsize;
1121	case NAND_ECC_SOFT:
1122		break;
1123	default:
1124		return -EINVAL;
1125	}
1126
1127	return 0;
1128}
1129
1130static int sunxi_nand_chip_init(struct device *dev, struct sunxi_nfc *nfc,
1131				struct device_node *np)
1132{
1133	const struct nand_sdr_timings *timings;
1134	struct sunxi_nand_chip *chip;
1135	struct mtd_part_parser_data ppdata;
1136	struct mtd_info *mtd;
1137	struct nand_chip *nand;
1138	int nsels;
1139	int ret;
1140	int i;
1141	u32 tmp;
1142
1143	if (!of_get_property(np, "reg", &nsels))
1144		return -EINVAL;
1145
1146	nsels /= sizeof(u32);
1147	if (!nsels) {
1148		dev_err(dev, "invalid reg property size\n");
1149		return -EINVAL;
1150	}
1151
1152	chip = devm_kzalloc(dev,
1153			    sizeof(*chip) +
1154			    (nsels * sizeof(struct sunxi_nand_chip_sel)),
1155			    GFP_KERNEL);
1156	if (!chip) {
1157		dev_err(dev, "could not allocate chip\n");
1158		return -ENOMEM;
1159	}
1160
1161	chip->nsels = nsels;
1162	chip->selected = -1;
1163
1164	for (i = 0; i < nsels; i++) {
1165		ret = of_property_read_u32_index(np, "reg", i, &tmp);
1166		if (ret) {
1167			dev_err(dev, "could not retrieve reg property: %d\n",
1168				ret);
1169			return ret;
1170		}
1171
1172		if (tmp > NFC_MAX_CS) {
1173			dev_err(dev,
1174				"invalid reg value: %u (max CS = 7)\n",
1175				tmp);
1176			return -EINVAL;
1177		}
1178
1179		if (test_and_set_bit(tmp, &nfc->assigned_cs)) {
1180			dev_err(dev, "CS %d already assigned\n", tmp);
1181			return -EINVAL;
1182		}
1183
1184		chip->sels[i].cs = tmp;
1185
1186		if (!of_property_read_u32_index(np, "allwinner,rb", i, &tmp) &&
1187		    tmp < 2) {
1188			chip->sels[i].rb.type = RB_NATIVE;
1189			chip->sels[i].rb.info.nativeid = tmp;
1190		} else {
1191			ret = of_get_named_gpio(np, "rb-gpios", i);
1192			if (ret >= 0) {
1193				tmp = ret;
1194				chip->sels[i].rb.type = RB_GPIO;
1195				chip->sels[i].rb.info.gpio = tmp;
1196				ret = devm_gpio_request(dev, tmp, "nand-rb");
1197				if (ret)
1198					return ret;
1199
1200				ret = gpio_direction_input(tmp);
1201				if (ret)
1202					return ret;
1203			} else {
1204				chip->sels[i].rb.type = RB_NONE;
1205			}
1206		}
1207	}
1208
1209	timings = onfi_async_timing_mode_to_sdr_timings(0);
1210	if (IS_ERR(timings)) {
1211		ret = PTR_ERR(timings);
1212		dev_err(dev,
1213			"could not retrieve timings for ONFI mode 0: %d\n",
1214			ret);
1215		return ret;
1216	}
1217
1218	ret = sunxi_nand_chip_set_timings(chip, timings);
1219	if (ret) {
1220		dev_err(dev, "could not configure chip timings: %d\n", ret);
1221		return ret;
1222	}
1223
1224	nand = &chip->nand;
1225	/* Default tR value specified in the ONFI spec (chapter 4.15.1) */
1226	nand->chip_delay = 200;
1227	nand->controller = &nfc->controller;
1228	nand->select_chip = sunxi_nfc_select_chip;
1229	nand->cmd_ctrl = sunxi_nfc_cmd_ctrl;
1230	nand->read_buf = sunxi_nfc_read_buf;
1231	nand->write_buf = sunxi_nfc_write_buf;
1232	nand->read_byte = sunxi_nfc_read_byte;
1233
1234	if (of_get_nand_on_flash_bbt(np))
1235		nand->bbt_options |= NAND_BBT_USE_FLASH | NAND_BBT_NO_OOB;
1236
1237	mtd = &chip->mtd;
1238	mtd->dev.parent = dev;
1239	mtd->priv = nand;
1240	mtd->owner = THIS_MODULE;
1241
1242	ret = nand_scan_ident(mtd, nsels, NULL);
1243	if (ret)
1244		return ret;
1245
1246	ret = sunxi_nand_chip_init_timings(chip, np);
1247	if (ret) {
1248		dev_err(dev, "could not configure chip timings: %d\n", ret);
1249		return ret;
1250	}
1251
1252	ret = sunxi_nand_ecc_init(mtd, &nand->ecc, np);
1253	if (ret) {
1254		dev_err(dev, "ECC init failed: %d\n", ret);
1255		return ret;
1256	}
1257
1258	ret = nand_scan_tail(mtd);
1259	if (ret) {
1260		dev_err(dev, "nand_scan_tail failed: %d\n", ret);
1261		return ret;
1262	}
1263
1264	ppdata.of_node = np;
1265	ret = mtd_device_parse_register(mtd, NULL, &ppdata, NULL, 0);
1266	if (ret) {
1267		dev_err(dev, "failed to register mtd device: %d\n", ret);
1268		nand_release(mtd);
1269		return ret;
1270	}
1271
1272	list_add_tail(&chip->node, &nfc->chips);
1273
1274	return 0;
1275}
1276
1277static int sunxi_nand_chips_init(struct device *dev, struct sunxi_nfc *nfc)
1278{
1279	struct device_node *np = dev->of_node;
1280	struct device_node *nand_np;
1281	int nchips = of_get_child_count(np);
1282	int ret;
1283
1284	if (nchips > 8) {
1285		dev_err(dev, "too many NAND chips: %d (max = 8)\n", nchips);
1286		return -EINVAL;
1287	}
1288
1289	for_each_child_of_node(np, nand_np) {
1290		ret = sunxi_nand_chip_init(dev, nfc, nand_np);
1291		if (ret)
1292			return ret;
1293	}
1294
1295	return 0;
1296}
1297
1298static void sunxi_nand_chips_cleanup(struct sunxi_nfc *nfc)
1299{
1300	struct sunxi_nand_chip *chip;
1301
1302	while (!list_empty(&nfc->chips)) {
1303		chip = list_first_entry(&nfc->chips, struct sunxi_nand_chip,
1304					node);
1305		nand_release(&chip->mtd);
1306		sunxi_nand_ecc_cleanup(&chip->nand.ecc);
1307		list_del(&chip->node);
1308	}
1309}
1310
1311static int sunxi_nfc_probe(struct platform_device *pdev)
1312{
1313	struct device *dev = &pdev->dev;
1314	struct resource *r;
1315	struct sunxi_nfc *nfc;
1316	int irq;
1317	int ret;
1318
1319	nfc = devm_kzalloc(dev, sizeof(*nfc), GFP_KERNEL);
1320	if (!nfc)
1321		return -ENOMEM;
1322
1323	nfc->dev = dev;
1324	spin_lock_init(&nfc->controller.lock);
1325	init_waitqueue_head(&nfc->controller.wq);
1326	INIT_LIST_HEAD(&nfc->chips);
1327
1328	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1329	nfc->regs = devm_ioremap_resource(dev, r);
1330	if (IS_ERR(nfc->regs))
1331		return PTR_ERR(nfc->regs);
1332
1333	irq = platform_get_irq(pdev, 0);
1334	if (irq < 0) {
1335		dev_err(dev, "failed to retrieve irq\n");
1336		return irq;
1337	}
1338
1339	nfc->ahb_clk = devm_clk_get(dev, "ahb");
1340	if (IS_ERR(nfc->ahb_clk)) {
1341		dev_err(dev, "failed to retrieve ahb clk\n");
1342		return PTR_ERR(nfc->ahb_clk);
1343	}
1344
1345	ret = clk_prepare_enable(nfc->ahb_clk);
1346	if (ret)
1347		return ret;
1348
1349	nfc->mod_clk = devm_clk_get(dev, "mod");
1350	if (IS_ERR(nfc->mod_clk)) {
1351		dev_err(dev, "failed to retrieve mod clk\n");
1352		ret = PTR_ERR(nfc->mod_clk);
1353		goto out_ahb_clk_unprepare;
1354	}
1355
1356	ret = clk_prepare_enable(nfc->mod_clk);
1357	if (ret)
1358		goto out_ahb_clk_unprepare;
1359
1360	ret = sunxi_nfc_rst(nfc);
1361	if (ret)
1362		goto out_mod_clk_unprepare;
1363
1364	writel(0, nfc->regs + NFC_REG_INT);
1365	ret = devm_request_irq(dev, irq, sunxi_nfc_interrupt,
1366			       0, "sunxi-nand", nfc);
1367	if (ret)
1368		goto out_mod_clk_unprepare;
1369
1370	platform_set_drvdata(pdev, nfc);
1371
1372	/*
1373	 * TODO: replace these magic values with proper flags as soon as we
1374	 * know what they are encoding.
1375	 */
1376	writel(0x100, nfc->regs + NFC_REG_TIMING_CTL);
1377	writel(0x7ff, nfc->regs + NFC_REG_TIMING_CFG);
1378
1379	ret = sunxi_nand_chips_init(dev, nfc);
1380	if (ret) {
1381		dev_err(dev, "failed to init nand chips\n");
1382		goto out_mod_clk_unprepare;
1383	}
1384
1385	return 0;
1386
1387out_mod_clk_unprepare:
1388	clk_disable_unprepare(nfc->mod_clk);
1389out_ahb_clk_unprepare:
1390	clk_disable_unprepare(nfc->ahb_clk);
1391
1392	return ret;
1393}
1394
1395static int sunxi_nfc_remove(struct platform_device *pdev)
1396{
1397	struct sunxi_nfc *nfc = platform_get_drvdata(pdev);
1398
1399	sunxi_nand_chips_cleanup(nfc);
1400
1401	return 0;
1402}
1403
1404static const struct of_device_id sunxi_nfc_ids[] = {
1405	{ .compatible = "allwinner,sun4i-a10-nand" },
1406	{ /* sentinel */ }
1407};
1408MODULE_DEVICE_TABLE(of, sunxi_nfc_ids);
1409
1410static struct platform_driver sunxi_nfc_driver = {
1411	.driver = {
1412		.name = "sunxi_nand",
1413		.of_match_table = sunxi_nfc_ids,
1414	},
1415	.probe = sunxi_nfc_probe,
1416	.remove = sunxi_nfc_remove,
1417};
1418module_platform_driver(sunxi_nfc_driver);
1419
1420MODULE_LICENSE("GPL v2");
1421MODULE_AUTHOR("Boris BREZILLON");
1422MODULE_DESCRIPTION("Allwinner NAND Flash Controller driver");
1423MODULE_ALIAS("platform:sunxi_nand");
1424