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 Nordstr��m <Henrik Nordstr��m>
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_ERR_CNT(x)	((0x0040 + (x)) & ~0x3)
61#define NFC_REG_USER_DATA(x)	(0x0050 + ((x) * 4))
62#define NFC_REG_SPARE_AREA	0x00A0
63#define NFC_RAM0_BASE		0x0400
64#define NFC_RAM1_BASE		0x0800
65
66/* define bit use in NFC_CTL */
67#define NFC_EN			BIT(0)
68#define NFC_RESET		BIT(1)
69#define NFC_BUS_WIDTH_MSK	BIT(2)
70#define NFC_BUS_WIDTH_8		(0 << 2)
71#define NFC_BUS_WIDTH_16	(1 << 2)
72#define NFC_RB_SEL_MSK		BIT(3)
73#define NFC_RB_SEL(x)		((x) << 3)
74#define NFC_CE_SEL_MSK		GENMASK(26, 24)
75#define NFC_CE_SEL(x)		((x) << 24)
76#define NFC_CE_CTL		BIT(6)
77#define NFC_PAGE_SHIFT_MSK	GENMASK(11, 8)
78#define NFC_PAGE_SHIFT(x)	(((x) < 10 ? 0 : (x) - 10) << 8)
79#define NFC_SAM			BIT(12)
80#define NFC_RAM_METHOD		BIT(14)
81#define NFC_DEBUG_CTL		BIT(31)
82
83/* define bit use in NFC_ST */
84#define NFC_RB_B2R		BIT(0)
85#define NFC_CMD_INT_FLAG	BIT(1)
86#define NFC_DMA_INT_FLAG	BIT(2)
87#define NFC_CMD_FIFO_STATUS	BIT(3)
88#define NFC_STA			BIT(4)
89#define NFC_NATCH_INT_FLAG	BIT(5)
90#define NFC_RB_STATE(x)		BIT(x + 8)
91
92/* define bit use in NFC_INT */
93#define NFC_B2R_INT_ENABLE	BIT(0)
94#define NFC_CMD_INT_ENABLE	BIT(1)
95#define NFC_DMA_INT_ENABLE	BIT(2)
96#define NFC_INT_MASK		(NFC_B2R_INT_ENABLE | \
97				 NFC_CMD_INT_ENABLE | \
98				 NFC_DMA_INT_ENABLE)
99
100/* define bit use in NFC_TIMING_CTL */
101#define NFC_TIMING_CTL_EDO	BIT(8)
102
103/* define NFC_TIMING_CFG register layout */
104#define NFC_TIMING_CFG(tWB, tADL, tWHR, tRHW, tCAD)		\
105	(((tWB) & 0x3) | (((tADL) & 0x3) << 2) |		\
106	(((tWHR) & 0x3) << 4) | (((tRHW) & 0x3) << 6) |		\
107	(((tCAD) & 0x7) << 8))
108
109/* define bit use in NFC_CMD */
110#define NFC_CMD_LOW_BYTE_MSK	GENMASK(7, 0)
111#define NFC_CMD_HIGH_BYTE_MSK	GENMASK(15, 8)
112#define NFC_CMD(x)		(x)
113#define NFC_ADR_NUM_MSK		GENMASK(18, 16)
114#define NFC_ADR_NUM(x)		(((x) - 1) << 16)
115#define NFC_SEND_ADR		BIT(19)
116#define NFC_ACCESS_DIR		BIT(20)
117#define NFC_DATA_TRANS		BIT(21)
118#define NFC_SEND_CMD1		BIT(22)
119#define NFC_WAIT_FLAG		BIT(23)
120#define NFC_SEND_CMD2		BIT(24)
121#define NFC_SEQ			BIT(25)
122#define NFC_DATA_SWAP_METHOD	BIT(26)
123#define NFC_ROW_AUTO_INC	BIT(27)
124#define NFC_SEND_CMD3		BIT(28)
125#define NFC_SEND_CMD4		BIT(29)
126#define NFC_CMD_TYPE_MSK	GENMASK(31, 30)
127#define NFC_NORMAL_OP		(0 << 30)
128#define NFC_ECC_OP		(1 << 30)
129#define NFC_PAGE_OP		(2 << 30)
130
131/* define bit use in NFC_RCMD_SET */
132#define NFC_READ_CMD_MSK	GENMASK(7, 0)
133#define NFC_RND_READ_CMD0_MSK	GENMASK(15, 8)
134#define NFC_RND_READ_CMD1_MSK	GENMASK(23, 16)
135
136/* define bit use in NFC_WCMD_SET */
137#define NFC_PROGRAM_CMD_MSK	GENMASK(7, 0)
138#define NFC_RND_WRITE_CMD_MSK	GENMASK(15, 8)
139#define NFC_READ_CMD0_MSK	GENMASK(23, 16)
140#define NFC_READ_CMD1_MSK	GENMASK(31, 24)
141
142/* define bit use in NFC_ECC_CTL */
143#define NFC_ECC_EN		BIT(0)
144#define NFC_ECC_PIPELINE	BIT(3)
145#define NFC_ECC_EXCEPTION	BIT(4)
146#define NFC_ECC_BLOCK_SIZE_MSK	BIT(5)
147#define NFC_RANDOM_EN		BIT(9)
148#define NFC_RANDOM_DIRECTION	BIT(10)
149#define NFC_ECC_MODE_MSK	GENMASK(15, 12)
150#define NFC_ECC_MODE(x)		((x) << 12)
151#define NFC_RANDOM_SEED_MSK	GENMASK(30, 16)
152#define NFC_RANDOM_SEED(x)	((x) << 16)
153
154/* define bit use in NFC_ECC_ST */
155#define NFC_ECC_ERR(x)		BIT(x)
156#define NFC_ECC_PAT_FOUND(x)	BIT(x + 16)
157#define NFC_ECC_ERR_CNT(b, x)	(((x) >> ((b) * 8)) & 0xff)
158
159#define NFC_DEFAULT_TIMEOUT_MS	1000
160
161#define NFC_SRAM_SIZE		1024
162
163#define NFC_MAX_CS		7
164
165/*
166 * Ready/Busy detection type: describes the Ready/Busy detection modes
167 *
168 * @RB_NONE:	no external detection available, rely on STATUS command
169 *		and software timeouts
170 * @RB_NATIVE:	use sunxi NAND controller Ready/Busy support. The Ready/Busy
171 *		pin of the NAND flash chip must be connected to one of the
172 *		native NAND R/B pins (those which can be muxed to the NAND
173 *		Controller)
174 * @RB_GPIO:	use a simple GPIO to handle Ready/Busy status. The Ready/Busy
175 *		pin of the NAND flash chip must be connected to a GPIO capable
176 *		pin.
177 */
178enum sunxi_nand_rb_type {
179	RB_NONE,
180	RB_NATIVE,
181	RB_GPIO,
182};
183
184/*
185 * Ready/Busy structure: stores information related to Ready/Busy detection
186 *
187 * @type:	the Ready/Busy detection mode
188 * @info:	information related to the R/B detection mode. Either a gpio
189 *		id or a native R/B id (those supported by the NAND controller).
190 */
191struct sunxi_nand_rb {
192	enum sunxi_nand_rb_type type;
193	union {
194		int gpio;
195		int nativeid;
196	} info;
197};
198
199/*
200 * Chip Select structure: stores information related to NAND Chip Select
201 *
202 * @cs:		the NAND CS id used to communicate with a NAND Chip
203 * @rb:		the Ready/Busy description
204 */
205struct sunxi_nand_chip_sel {
206	u8 cs;
207	struct sunxi_nand_rb rb;
208};
209
210/*
211 * sunxi HW ECC infos: stores information related to HW ECC support
212 *
213 * @mode:	the sunxi ECC mode field deduced from ECC requirements
214 * @layout:	the OOB layout depending on the ECC requirements and the
215 *		selected ECC mode
216 */
217struct sunxi_nand_hw_ecc {
218	int mode;
219	struct nand_ecclayout layout;
220};
221
222/*
223 * NAND chip structure: stores NAND chip device related information
224 *
225 * @node:		used to store NAND chips into a list
226 * @nand:		base NAND chip structure
227 * @mtd:		base MTD structure
228 * @clk_rate:		clk_rate required for this NAND chip
229 * @timing_cfg		TIMING_CFG register value for this NAND chip
230 * @selected:		current active CS
231 * @nsels:		number of CS lines required by the NAND chip
232 * @sels:		array of CS lines descriptions
233 */
234struct sunxi_nand_chip {
235	struct list_head node;
236	struct nand_chip nand;
237	struct mtd_info mtd;
238	unsigned long clk_rate;
239	u32 timing_cfg;
240	u32 timing_ctl;
241	int selected;
242	int nsels;
243	struct sunxi_nand_chip_sel sels[0];
244};
245
246static inline struct sunxi_nand_chip *to_sunxi_nand(struct nand_chip *nand)
247{
248	return container_of(nand, struct sunxi_nand_chip, nand);
249}
250
251/*
252 * NAND Controller structure: stores sunxi NAND controller information
253 *
254 * @controller:		base controller structure
255 * @dev:		parent device (used to print error messages)
256 * @regs:		NAND controller registers
257 * @ahb_clk:		NAND Controller AHB clock
258 * @mod_clk:		NAND Controller mod clock
259 * @assigned_cs:	bitmask describing already assigned CS lines
260 * @clk_rate:		NAND controller current clock rate
261 * @chips:		a list containing all the NAND chips attached to
262 *			this NAND controller
263 * @complete:		a completion object used to wait for NAND
264 *			controller events
265 */
266struct sunxi_nfc {
267	struct nand_hw_control controller;
268	struct device *dev;
269	void __iomem *regs;
270	struct clk *ahb_clk;
271	struct clk *mod_clk;
272	unsigned long assigned_cs;
273	unsigned long clk_rate;
274	struct list_head chips;
275	struct completion complete;
276};
277
278static inline struct sunxi_nfc *to_sunxi_nfc(struct nand_hw_control *ctrl)
279{
280	return container_of(ctrl, struct sunxi_nfc, controller);
281}
282
283static irqreturn_t sunxi_nfc_interrupt(int irq, void *dev_id)
284{
285	struct sunxi_nfc *nfc = dev_id;
286	u32 st = readl(nfc->regs + NFC_REG_ST);
287	u32 ien = readl(nfc->regs + NFC_REG_INT);
288
289	if (!(ien & st))
290		return IRQ_NONE;
291
292	if ((ien & st) == ien)
293		complete(&nfc->complete);
294
295	writel(st & NFC_INT_MASK, nfc->regs + NFC_REG_ST);
296	writel(~st & ien & NFC_INT_MASK, nfc->regs + NFC_REG_INT);
297
298	return IRQ_HANDLED;
299}
300
301static int sunxi_nfc_wait_int(struct sunxi_nfc *nfc, u32 flags,
302			      unsigned int timeout_ms)
303{
304	init_completion(&nfc->complete);
305
306	writel(flags, nfc->regs + NFC_REG_INT);
307
308	if (!timeout_ms)
309		timeout_ms = NFC_DEFAULT_TIMEOUT_MS;
310
311	if (!wait_for_completion_timeout(&nfc->complete,
312					 msecs_to_jiffies(timeout_ms))) {
313		dev_err(nfc->dev, "wait interrupt timedout\n");
314		return -ETIMEDOUT;
315	}
316
317	return 0;
318}
319
320static int sunxi_nfc_wait_cmd_fifo_empty(struct sunxi_nfc *nfc)
321{
322	unsigned long timeout = jiffies +
323				msecs_to_jiffies(NFC_DEFAULT_TIMEOUT_MS);
324
325	do {
326		if (!(readl(nfc->regs + NFC_REG_ST) & NFC_CMD_FIFO_STATUS))
327			return 0;
328	} while (time_before(jiffies, timeout));
329
330	dev_err(nfc->dev, "wait for empty cmd FIFO timedout\n");
331	return -ETIMEDOUT;
332}
333
334static int sunxi_nfc_rst(struct sunxi_nfc *nfc)
335{
336	unsigned long timeout = jiffies +
337				msecs_to_jiffies(NFC_DEFAULT_TIMEOUT_MS);
338
339	writel(0, nfc->regs + NFC_REG_ECC_CTL);
340	writel(NFC_RESET, nfc->regs + NFC_REG_CTL);
341
342	do {
343		if (!(readl(nfc->regs + NFC_REG_CTL) & NFC_RESET))
344			return 0;
345	} while (time_before(jiffies, timeout));
346
347	dev_err(nfc->dev, "wait for NAND controller reset timedout\n");
348	return -ETIMEDOUT;
349}
350
351static int sunxi_nfc_dev_ready(struct mtd_info *mtd)
352{
353	struct nand_chip *nand = mtd->priv;
354	struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
355	struct sunxi_nfc *nfc = to_sunxi_nfc(sunxi_nand->nand.controller);
356	struct sunxi_nand_rb *rb;
357	unsigned long timeo = (sunxi_nand->nand.state == FL_ERASING ? 400 : 20);
358	int ret;
359
360	if (sunxi_nand->selected < 0)
361		return 0;
362
363	rb = &sunxi_nand->sels[sunxi_nand->selected].rb;
364
365	switch (rb->type) {
366	case RB_NATIVE:
367		ret = !!(readl(nfc->regs + NFC_REG_ST) &
368			 NFC_RB_STATE(rb->info.nativeid));
369		if (ret)
370			break;
371
372		sunxi_nfc_wait_int(nfc, NFC_RB_B2R, timeo);
373		ret = !!(readl(nfc->regs + NFC_REG_ST) &
374			 NFC_RB_STATE(rb->info.nativeid));
375		break;
376	case RB_GPIO:
377		ret = gpio_get_value(rb->info.gpio);
378		break;
379	case RB_NONE:
380	default:
381		ret = 0;
382		dev_err(nfc->dev, "cannot check R/B NAND status!\n");
383		break;
384	}
385
386	return ret;
387}
388
389static void sunxi_nfc_select_chip(struct mtd_info *mtd, int chip)
390{
391	struct nand_chip *nand = mtd->priv;
392	struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
393	struct sunxi_nfc *nfc = to_sunxi_nfc(sunxi_nand->nand.controller);
394	struct sunxi_nand_chip_sel *sel;
395	u32 ctl;
396
397	if (chip > 0 && chip >= sunxi_nand->nsels)
398		return;
399
400	if (chip == sunxi_nand->selected)
401		return;
402
403	ctl = readl(nfc->regs + NFC_REG_CTL) &
404	      ~(NFC_PAGE_SHIFT_MSK | NFC_CE_SEL_MSK | NFC_RB_SEL_MSK | NFC_EN);
405
406	if (chip >= 0) {
407		sel = &sunxi_nand->sels[chip];
408
409		ctl |= NFC_CE_SEL(sel->cs) | NFC_EN |
410		       NFC_PAGE_SHIFT(nand->page_shift - 10);
411		if (sel->rb.type == RB_NONE) {
412			nand->dev_ready = NULL;
413		} else {
414			nand->dev_ready = sunxi_nfc_dev_ready;
415			if (sel->rb.type == RB_NATIVE)
416				ctl |= NFC_RB_SEL(sel->rb.info.nativeid);
417		}
418
419		writel(mtd->writesize, nfc->regs + NFC_REG_SPARE_AREA);
420
421		if (nfc->clk_rate != sunxi_nand->clk_rate) {
422			clk_set_rate(nfc->mod_clk, sunxi_nand->clk_rate);
423			nfc->clk_rate = sunxi_nand->clk_rate;
424		}
425	}
426
427	writel(sunxi_nand->timing_ctl, nfc->regs + NFC_REG_TIMING_CTL);
428	writel(sunxi_nand->timing_cfg, nfc->regs + NFC_REG_TIMING_CFG);
429	writel(ctl, nfc->regs + NFC_REG_CTL);
430
431	sunxi_nand->selected = chip;
432}
433
434static void sunxi_nfc_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
435{
436	struct nand_chip *nand = mtd->priv;
437	struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
438	struct sunxi_nfc *nfc = to_sunxi_nfc(sunxi_nand->nand.controller);
439	int ret;
440	int cnt;
441	int offs = 0;
442	u32 tmp;
443
444	while (len > offs) {
445		cnt = min(len - offs, NFC_SRAM_SIZE);
446
447		ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
448		if (ret)
449			break;
450
451		writel(cnt, nfc->regs + NFC_REG_CNT);
452		tmp = NFC_DATA_TRANS | NFC_DATA_SWAP_METHOD;
453		writel(tmp, nfc->regs + NFC_REG_CMD);
454
455		ret = sunxi_nfc_wait_int(nfc, NFC_CMD_INT_FLAG, 0);
456		if (ret)
457			break;
458
459		if (buf)
460			memcpy_fromio(buf + offs, nfc->regs + NFC_RAM0_BASE,
461				      cnt);
462		offs += cnt;
463	}
464}
465
466static void sunxi_nfc_write_buf(struct mtd_info *mtd, const uint8_t *buf,
467				int len)
468{
469	struct nand_chip *nand = mtd->priv;
470	struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
471	struct sunxi_nfc *nfc = to_sunxi_nfc(sunxi_nand->nand.controller);
472	int ret;
473	int cnt;
474	int offs = 0;
475	u32 tmp;
476
477	while (len > offs) {
478		cnt = min(len - offs, NFC_SRAM_SIZE);
479
480		ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
481		if (ret)
482			break;
483
484		writel(cnt, nfc->regs + NFC_REG_CNT);
485		memcpy_toio(nfc->regs + NFC_RAM0_BASE, buf + offs, cnt);
486		tmp = NFC_DATA_TRANS | NFC_DATA_SWAP_METHOD |
487		      NFC_ACCESS_DIR;
488		writel(tmp, nfc->regs + NFC_REG_CMD);
489
490		ret = sunxi_nfc_wait_int(nfc, NFC_CMD_INT_FLAG, 0);
491		if (ret)
492			break;
493
494		offs += cnt;
495	}
496}
497
498static uint8_t sunxi_nfc_read_byte(struct mtd_info *mtd)
499{
500	uint8_t ret;
501
502	sunxi_nfc_read_buf(mtd, &ret, 1);
503
504	return ret;
505}
506
507static void sunxi_nfc_cmd_ctrl(struct mtd_info *mtd, int dat,
508			       unsigned int ctrl)
509{
510	struct nand_chip *nand = mtd->priv;
511	struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
512	struct sunxi_nfc *nfc = to_sunxi_nfc(sunxi_nand->nand.controller);
513	int ret;
514	u32 tmp;
515
516	ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
517	if (ret)
518		return;
519
520	if (ctrl & NAND_CTRL_CHANGE) {
521		tmp = readl(nfc->regs + NFC_REG_CTL);
522		if (ctrl & NAND_NCE)
523			tmp |= NFC_CE_CTL;
524		else
525			tmp &= ~NFC_CE_CTL;
526		writel(tmp, nfc->regs + NFC_REG_CTL);
527	}
528
529	if (dat == NAND_CMD_NONE)
530		return;
531
532	if (ctrl & NAND_CLE) {
533		writel(NFC_SEND_CMD1 | dat, nfc->regs + NFC_REG_CMD);
534	} else {
535		writel(dat, nfc->regs + NFC_REG_ADDR_LOW);
536		writel(NFC_SEND_ADR, nfc->regs + NFC_REG_CMD);
537	}
538
539	sunxi_nfc_wait_int(nfc, NFC_CMD_INT_FLAG, 0);
540}
541
542static void sunxi_nfc_hw_ecc_enable(struct mtd_info *mtd)
543{
544	struct nand_chip *nand = mtd->priv;
545	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
546	struct sunxi_nand_hw_ecc *data = nand->ecc.priv;
547	u32 ecc_ctl;
548
549	ecc_ctl = readl(nfc->regs + NFC_REG_ECC_CTL);
550	ecc_ctl &= ~(NFC_ECC_MODE_MSK | NFC_ECC_PIPELINE |
551		     NFC_ECC_BLOCK_SIZE_MSK);
552	ecc_ctl |= NFC_ECC_EN | NFC_ECC_MODE(data->mode) | NFC_ECC_EXCEPTION;
553
554	writel(ecc_ctl, nfc->regs + NFC_REG_ECC_CTL);
555}
556
557static void sunxi_nfc_hw_ecc_disable(struct mtd_info *mtd)
558{
559	struct nand_chip *nand = mtd->priv;
560	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
561
562	writel(readl(nfc->regs + NFC_REG_ECC_CTL) & ~NFC_ECC_EN,
563	       nfc->regs + NFC_REG_ECC_CTL);
564}
565
566static inline void sunxi_nfc_user_data_to_buf(u32 user_data, u8 *buf)
567{
568	buf[0] = user_data;
569	buf[1] = user_data >> 8;
570	buf[2] = user_data >> 16;
571	buf[3] = user_data >> 24;
572}
573
574static int sunxi_nfc_hw_ecc_read_chunk(struct mtd_info *mtd,
575				       u8 *data, int data_off,
576				       u8 *oob, int oob_off,
577				       int *cur_off,
578				       unsigned int *max_bitflips)
579{
580	struct nand_chip *nand = mtd->priv;
581	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
582	struct nand_ecc_ctrl *ecc = &nand->ecc;
583	u32 status;
584	int ret;
585
586	if (*cur_off != data_off)
587		nand->cmdfunc(mtd, NAND_CMD_RNDOUT, data_off, -1);
588
589	sunxi_nfc_read_buf(mtd, NULL, ecc->size);
590
591	if (data_off + ecc->size != oob_off)
592		nand->cmdfunc(mtd, NAND_CMD_RNDOUT, oob_off, -1);
593
594	ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
595	if (ret)
596		return ret;
597
598	writel(NFC_DATA_TRANS | NFC_DATA_SWAP_METHOD | NFC_ECC_OP,
599	       nfc->regs + NFC_REG_CMD);
600
601	ret = sunxi_nfc_wait_int(nfc, NFC_CMD_INT_FLAG, 0);
602	if (ret)
603		return ret;
604
605	status = readl(nfc->regs + NFC_REG_ECC_ST);
606	ret = NFC_ECC_ERR_CNT(0, readl(nfc->regs + NFC_REG_ECC_ERR_CNT(0)));
607
608	memcpy_fromio(data, nfc->regs + NFC_RAM0_BASE, ecc->size);
609
610	nand->cmdfunc(mtd, NAND_CMD_RNDOUT, oob_off, -1);
611	sunxi_nfc_read_buf(mtd, oob, ecc->bytes + 4);
612
613	if (status & NFC_ECC_ERR(0)) {
614		ret = nand_check_erased_ecc_chunk(data,	ecc->size,
615						  oob, ecc->bytes + 4,
616						  NULL, 0, ecc->strength);
617	} else {
618		/*
619		 * The engine protects 4 bytes of OOB data per chunk.
620		 * Retrieve the corrected OOB bytes.
621		 */
622		sunxi_nfc_user_data_to_buf(readl(nfc->regs + NFC_REG_USER_DATA(0)),
623					   oob);
624	}
625
626	if (ret < 0) {
627		mtd->ecc_stats.failed++;
628	} else {
629		mtd->ecc_stats.corrected += ret;
630		*max_bitflips = max_t(unsigned int, *max_bitflips, ret);
631	}
632
633	*cur_off = oob_off + ecc->bytes + 4;
634
635	return 0;
636}
637
638static void sunxi_nfc_hw_ecc_read_extra_oob(struct mtd_info *mtd,
639					    u8 *oob, int *cur_off)
640{
641	struct nand_chip *nand = mtd->priv;
642	struct nand_ecc_ctrl *ecc = &nand->ecc;
643	int offset = ((ecc->bytes + 4) * ecc->steps);
644	int len = mtd->oobsize - offset;
645
646	if (len <= 0)
647		return;
648
649	if (*cur_off != offset)
650		nand->cmdfunc(mtd, NAND_CMD_RNDOUT,
651			      offset + mtd->writesize, -1);
652
653	sunxi_nfc_read_buf(mtd, oob + offset, len);
654
655	*cur_off = mtd->oobsize + mtd->writesize;
656}
657
658static inline u32 sunxi_nfc_buf_to_user_data(const u8 *buf)
659{
660	return buf[0] | (buf[1] << 8) | (buf[2] << 16) | (buf[3] << 24);
661}
662
663static int sunxi_nfc_hw_ecc_write_chunk(struct mtd_info *mtd,
664					const u8 *data, int data_off,
665					const u8 *oob, int oob_off,
666					int *cur_off)
667{
668	struct nand_chip *nand = mtd->priv;
669	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
670	struct nand_ecc_ctrl *ecc = &nand->ecc;
671	int ret;
672
673	if (data_off != *cur_off)
674		nand->cmdfunc(mtd, NAND_CMD_RNDIN, data_off, -1);
675
676	sunxi_nfc_write_buf(mtd, data, ecc->size);
677
678	/* Fill OOB data in */
679	writel(sunxi_nfc_buf_to_user_data(oob),
680	       nfc->regs + NFC_REG_USER_DATA(0));
681
682	if (data_off + ecc->size != oob_off)
683		nand->cmdfunc(mtd, NAND_CMD_RNDIN, oob_off, -1);
684
685	ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
686	if (ret)
687		return ret;
688
689	writel(NFC_DATA_TRANS | NFC_DATA_SWAP_METHOD |
690	       NFC_ACCESS_DIR | NFC_ECC_OP,
691	       nfc->regs + NFC_REG_CMD);
692
693	ret = sunxi_nfc_wait_int(nfc, NFC_CMD_INT_FLAG, 0);
694	if (ret)
695		return ret;
696
697	*cur_off = oob_off + ecc->bytes + 4;
698
699	return 0;
700}
701
702static void sunxi_nfc_hw_ecc_write_extra_oob(struct mtd_info *mtd,
703					     u8 *oob, int *cur_off)
704{
705	struct nand_chip *nand = mtd->priv;
706	struct nand_ecc_ctrl *ecc = &nand->ecc;
707	int offset = ((ecc->bytes + 4) * ecc->steps);
708	int len = mtd->oobsize - offset;
709
710	if (len <= 0)
711		return;
712
713	if (*cur_off != offset)
714		nand->cmdfunc(mtd, NAND_CMD_RNDIN,
715			      offset + mtd->writesize, -1);
716
717	sunxi_nfc_write_buf(mtd, oob + offset, len);
718
719	*cur_off = mtd->oobsize + mtd->writesize;
720}
721
722static int sunxi_nfc_hw_ecc_read_page(struct mtd_info *mtd,
723				      struct nand_chip *chip, uint8_t *buf,
724				      int oob_required, int page)
725{
726	struct nand_ecc_ctrl *ecc = &chip->ecc;
727	unsigned int max_bitflips = 0;
728	int ret, i, cur_off = 0;
729
730	sunxi_nfc_hw_ecc_enable(mtd);
731
732	for (i = 0; i < ecc->steps; i++) {
733		int data_off = i * ecc->size;
734		int oob_off = i * (ecc->bytes + 4);
735		u8 *data = buf + data_off;
736		u8 *oob = chip->oob_poi + oob_off;
737
738		ret = sunxi_nfc_hw_ecc_read_chunk(mtd, data, data_off, oob,
739						  oob_off + mtd->writesize,
740						  &cur_off, &max_bitflips);
741		if (ret)
742			return ret;
743	}
744
745	if (oob_required)
746		sunxi_nfc_hw_ecc_read_extra_oob(mtd, chip->oob_poi, &cur_off);
747
748	sunxi_nfc_hw_ecc_disable(mtd);
749
750	return max_bitflips;
751}
752
753static int sunxi_nfc_hw_ecc_write_page(struct mtd_info *mtd,
754				       struct nand_chip *chip,
755				       const uint8_t *buf, int oob_required,
756				       int page)
757{
758	struct nand_ecc_ctrl *ecc = &chip->ecc;
759	int ret, i, cur_off = 0;
760
761	sunxi_nfc_hw_ecc_enable(mtd);
762
763	for (i = 0; i < ecc->steps; i++) {
764		int data_off = i * ecc->size;
765		int oob_off = i * (ecc->bytes + 4);
766		const u8 *data = buf + data_off;
767		const u8 *oob = chip->oob_poi + oob_off;
768
769		ret = sunxi_nfc_hw_ecc_write_chunk(mtd, data, data_off, oob,
770						   oob_off + mtd->writesize,
771						   &cur_off);
772		if (ret)
773			return ret;
774	}
775
776	if (oob_required)
777		sunxi_nfc_hw_ecc_write_extra_oob(mtd, chip->oob_poi, &cur_off);
778
779	sunxi_nfc_hw_ecc_disable(mtd);
780
781	return 0;
782}
783
784static int sunxi_nfc_hw_syndrome_ecc_read_page(struct mtd_info *mtd,
785					       struct nand_chip *chip,
786					       uint8_t *buf, int oob_required,
787					       int page)
788{
789	struct nand_ecc_ctrl *ecc = &chip->ecc;
790	unsigned int max_bitflips = 0;
791	int ret, i, cur_off = 0;
792
793	sunxi_nfc_hw_ecc_enable(mtd);
794
795	for (i = 0; i < ecc->steps; i++) {
796		int data_off = i * (ecc->size + ecc->bytes + 4);
797		int oob_off = data_off + ecc->size;
798		u8 *data = buf + (i * ecc->size);
799		u8 *oob = chip->oob_poi + (i * (ecc->bytes + 4));
800
801		ret = sunxi_nfc_hw_ecc_read_chunk(mtd, data, data_off, oob,
802						  oob_off, &cur_off,
803						  &max_bitflips);
804		if (ret)
805			return ret;
806	}
807
808	if (oob_required)
809		sunxi_nfc_hw_ecc_read_extra_oob(mtd, chip->oob_poi, &cur_off);
810
811	sunxi_nfc_hw_ecc_disable(mtd);
812
813	return max_bitflips;
814}
815
816static int sunxi_nfc_hw_syndrome_ecc_write_page(struct mtd_info *mtd,
817						struct nand_chip *chip,
818						const uint8_t *buf,
819						int oob_required, int page)
820{
821	struct nand_ecc_ctrl *ecc = &chip->ecc;
822	int ret, i, cur_off = 0;
823
824	sunxi_nfc_hw_ecc_enable(mtd);
825
826	for (i = 0; i < ecc->steps; i++) {
827		int data_off = i * (ecc->size + ecc->bytes + 4);
828		int oob_off = data_off + ecc->size;
829		const u8 *data = buf + (i * ecc->size);
830		const u8 *oob = chip->oob_poi + (i * (ecc->bytes + 4));
831
832		ret = sunxi_nfc_hw_ecc_write_chunk(mtd, data, data_off,
833						   oob, oob_off, &cur_off);
834		if (ret)
835			return ret;
836	}
837
838	if (oob_required)
839		sunxi_nfc_hw_ecc_write_extra_oob(mtd, chip->oob_poi, &cur_off);
840
841	sunxi_nfc_hw_ecc_disable(mtd);
842
843	return 0;
844}
845
846static const s32 tWB_lut[] = {6, 12, 16, 20};
847static const s32 tRHW_lut[] = {4, 8, 12, 20};
848
849static int _sunxi_nand_lookup_timing(const s32 *lut, int lut_size, u32 duration,
850		u32 clk_period)
851{
852	u32 clk_cycles = DIV_ROUND_UP(duration, clk_period);
853	int i;
854
855	for (i = 0; i < lut_size; i++) {
856		if (clk_cycles <= lut[i])
857			return i;
858	}
859
860	/* Doesn't fit */
861	return -EINVAL;
862}
863
864#define sunxi_nand_lookup_timing(l, p, c) \
865			_sunxi_nand_lookup_timing(l, ARRAY_SIZE(l), p, c)
866
867static int sunxi_nand_chip_set_timings(struct sunxi_nand_chip *chip,
868				       const struct nand_sdr_timings *timings)
869{
870	struct sunxi_nfc *nfc = to_sunxi_nfc(chip->nand.controller);
871	u32 min_clk_period = 0;
872	s32 tWB, tADL, tWHR, tRHW, tCAD;
873
874	/* T1 <=> tCLS */
875	if (timings->tCLS_min > min_clk_period)
876		min_clk_period = timings->tCLS_min;
877
878	/* T2 <=> tCLH */
879	if (timings->tCLH_min > min_clk_period)
880		min_clk_period = timings->tCLH_min;
881
882	/* T3 <=> tCS */
883	if (timings->tCS_min > min_clk_period)
884		min_clk_period = timings->tCS_min;
885
886	/* T4 <=> tCH */
887	if (timings->tCH_min > min_clk_period)
888		min_clk_period = timings->tCH_min;
889
890	/* T5 <=> tWP */
891	if (timings->tWP_min > min_clk_period)
892		min_clk_period = timings->tWP_min;
893
894	/* T6 <=> tWH */
895	if (timings->tWH_min > min_clk_period)
896		min_clk_period = timings->tWH_min;
897
898	/* T7 <=> tALS */
899	if (timings->tALS_min > min_clk_period)
900		min_clk_period = timings->tALS_min;
901
902	/* T8 <=> tDS */
903	if (timings->tDS_min > min_clk_period)
904		min_clk_period = timings->tDS_min;
905
906	/* T9 <=> tDH */
907	if (timings->tDH_min > min_clk_period)
908		min_clk_period = timings->tDH_min;
909
910	/* T10 <=> tRR */
911	if (timings->tRR_min > (min_clk_period * 3))
912		min_clk_period = DIV_ROUND_UP(timings->tRR_min, 3);
913
914	/* T11 <=> tALH */
915	if (timings->tALH_min > min_clk_period)
916		min_clk_period = timings->tALH_min;
917
918	/* T12 <=> tRP */
919	if (timings->tRP_min > min_clk_period)
920		min_clk_period = timings->tRP_min;
921
922	/* T13 <=> tREH */
923	if (timings->tREH_min > min_clk_period)
924		min_clk_period = timings->tREH_min;
925
926	/* T14 <=> tRC */
927	if (timings->tRC_min > (min_clk_period * 2))
928		min_clk_period = DIV_ROUND_UP(timings->tRC_min, 2);
929
930	/* T15 <=> tWC */
931	if (timings->tWC_min > (min_clk_period * 2))
932		min_clk_period = DIV_ROUND_UP(timings->tWC_min, 2);
933
934	/* T16 - T19 + tCAD */
935	tWB  = sunxi_nand_lookup_timing(tWB_lut, timings->tWB_max,
936					min_clk_period);
937	if (tWB < 0) {
938		dev_err(nfc->dev, "unsupported tWB\n");
939		return tWB;
940	}
941
942	tADL = DIV_ROUND_UP(timings->tADL_min, min_clk_period) >> 3;
943	if (tADL > 3) {
944		dev_err(nfc->dev, "unsupported tADL\n");
945		return -EINVAL;
946	}
947
948	tWHR = DIV_ROUND_UP(timings->tWHR_min, min_clk_period) >> 3;
949	if (tWHR > 3) {
950		dev_err(nfc->dev, "unsupported tWHR\n");
951		return -EINVAL;
952	}
953
954	tRHW = sunxi_nand_lookup_timing(tRHW_lut, timings->tRHW_min,
955					min_clk_period);
956	if (tRHW < 0) {
957		dev_err(nfc->dev, "unsupported tRHW\n");
958		return tRHW;
959	}
960
961	/*
962	 * TODO: according to ONFI specs this value only applies for DDR NAND,
963	 * but Allwinner seems to set this to 0x7. Mimic them for now.
964	 */
965	tCAD = 0x7;
966
967	/* TODO: A83 has some more bits for CDQSS, CS, CLHZ, CCS, WC */
968	chip->timing_cfg = NFC_TIMING_CFG(tWB, tADL, tWHR, tRHW, tCAD);
969
970	/*
971	 * ONFI specification 3.1, paragraph 4.15.2 dictates that EDO data
972	 * output cycle timings shall be used if the host drives tRC less than
973	 * 30 ns.
974	 */
975	chip->timing_ctl = (timings->tRC_min < 30000) ? NFC_TIMING_CTL_EDO : 0;
976
977	/* Convert min_clk_period from picoseconds to nanoseconds */
978	min_clk_period = DIV_ROUND_UP(min_clk_period, 1000);
979
980	/*
981	 * Convert min_clk_period into a clk frequency, then get the
982	 * appropriate rate for the NAND controller IP given this formula
983	 * (specified in the datasheet):
984	 * nand clk_rate = 2 * min_clk_rate
985	 */
986	chip->clk_rate = (2 * NSEC_PER_SEC) / min_clk_period;
987
988	return 0;
989}
990
991static int sunxi_nand_chip_init_timings(struct sunxi_nand_chip *chip,
992					struct device_node *np)
993{
994	const struct nand_sdr_timings *timings;
995	int ret;
996	int mode;
997
998	mode = onfi_get_async_timing_mode(&chip->nand);
999	if (mode == ONFI_TIMING_MODE_UNKNOWN) {
1000		mode = chip->nand.onfi_timing_mode_default;
1001	} else {
1002		uint8_t feature[ONFI_SUBFEATURE_PARAM_LEN] = {};
1003		int i;
1004
1005		mode = fls(mode) - 1;
1006		if (mode < 0)
1007			mode = 0;
1008
1009		feature[0] = mode;
1010		for (i = 0; i < chip->nsels; i++) {
1011			chip->nand.select_chip(&chip->mtd, i);
1012			ret = chip->nand.onfi_set_features(&chip->mtd,
1013						&chip->nand,
1014						ONFI_FEATURE_ADDR_TIMING_MODE,
1015						feature);
1016			chip->nand.select_chip(&chip->mtd, -1);
1017			if (ret)
1018				return ret;
1019		}
1020	}
1021
1022	timings = onfi_async_timing_mode_to_sdr_timings(mode);
1023	if (IS_ERR(timings))
1024		return PTR_ERR(timings);
1025
1026	return sunxi_nand_chip_set_timings(chip, timings);
1027}
1028
1029static int sunxi_nand_hw_common_ecc_ctrl_init(struct mtd_info *mtd,
1030					      struct nand_ecc_ctrl *ecc,
1031					      struct device_node *np)
1032{
1033	static const u8 strengths[] = { 16, 24, 28, 32, 40, 48, 56, 60, 64 };
1034	struct nand_chip *nand = mtd->priv;
1035	struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
1036	struct sunxi_nfc *nfc = to_sunxi_nfc(sunxi_nand->nand.controller);
1037	struct sunxi_nand_hw_ecc *data;
1038	struct nand_ecclayout *layout;
1039	int nsectors;
1040	int ret;
1041	int i;
1042
1043	data = kzalloc(sizeof(*data), GFP_KERNEL);
1044	if (!data)
1045		return -ENOMEM;
1046
1047	/* Add ECC info retrieval from DT */
1048	for (i = 0; i < ARRAY_SIZE(strengths); i++) {
1049		if (ecc->strength <= strengths[i])
1050			break;
1051	}
1052
1053	if (i >= ARRAY_SIZE(strengths)) {
1054		dev_err(nfc->dev, "unsupported strength\n");
1055		ret = -ENOTSUPP;
1056		goto err;
1057	}
1058
1059	data->mode = i;
1060
1061	/* HW ECC always request ECC bytes for 1024 bytes blocks */
1062	ecc->bytes = DIV_ROUND_UP(ecc->strength * fls(8 * 1024), 8);
1063
1064	/* HW ECC always work with even numbers of ECC bytes */
1065	ecc->bytes = ALIGN(ecc->bytes, 2);
1066
1067	layout = &data->layout;
1068	nsectors = mtd->writesize / ecc->size;
1069
1070	if (mtd->oobsize < ((ecc->bytes + 4) * nsectors)) {
1071		ret = -EINVAL;
1072		goto err;
1073	}
1074
1075	layout->eccbytes = (ecc->bytes * nsectors);
1076
1077	ecc->layout = layout;
1078	ecc->priv = data;
1079
1080	return 0;
1081
1082err:
1083	kfree(data);
1084
1085	return ret;
1086}
1087
1088static void sunxi_nand_hw_common_ecc_ctrl_cleanup(struct nand_ecc_ctrl *ecc)
1089{
1090	kfree(ecc->priv);
1091}
1092
1093static int sunxi_nand_hw_ecc_ctrl_init(struct mtd_info *mtd,
1094				       struct nand_ecc_ctrl *ecc,
1095				       struct device_node *np)
1096{
1097	struct nand_ecclayout *layout;
1098	int nsectors;
1099	int i, j;
1100	int ret;
1101
1102	ret = sunxi_nand_hw_common_ecc_ctrl_init(mtd, ecc, np);
1103	if (ret)
1104		return ret;
1105
1106	ecc->read_page = sunxi_nfc_hw_ecc_read_page;
1107	ecc->write_page = sunxi_nfc_hw_ecc_write_page;
1108	layout = ecc->layout;
1109	nsectors = mtd->writesize / ecc->size;
1110
1111	for (i = 0; i < nsectors; i++) {
1112		if (i) {
1113			layout->oobfree[i].offset =
1114				layout->oobfree[i - 1].offset +
1115				layout->oobfree[i - 1].length +
1116				ecc->bytes;
1117			layout->oobfree[i].length = 4;
1118		} else {
1119			/*
1120			 * The first 2 bytes are used for BB markers, hence we
1121			 * only have 2 bytes available in the first user data
1122			 * section.
1123			 */
1124			layout->oobfree[i].length = 2;
1125			layout->oobfree[i].offset = 2;
1126		}
1127
1128		for (j = 0; j < ecc->bytes; j++)
1129			layout->eccpos[(ecc->bytes * i) + j] =
1130					layout->oobfree[i].offset +
1131					layout->oobfree[i].length + j;
1132	}
1133
1134	if (mtd->oobsize > (ecc->bytes + 4) * nsectors) {
1135		layout->oobfree[nsectors].offset =
1136				layout->oobfree[nsectors - 1].offset +
1137				layout->oobfree[nsectors - 1].length +
1138				ecc->bytes;
1139		layout->oobfree[nsectors].length = mtd->oobsize -
1140				((ecc->bytes + 4) * nsectors);
1141	}
1142
1143	return 0;
1144}
1145
1146static int sunxi_nand_hw_syndrome_ecc_ctrl_init(struct mtd_info *mtd,
1147						struct nand_ecc_ctrl *ecc,
1148						struct device_node *np)
1149{
1150	struct nand_ecclayout *layout;
1151	int nsectors;
1152	int i;
1153	int ret;
1154
1155	ret = sunxi_nand_hw_common_ecc_ctrl_init(mtd, ecc, np);
1156	if (ret)
1157		return ret;
1158
1159	ecc->prepad = 4;
1160	ecc->read_page = sunxi_nfc_hw_syndrome_ecc_read_page;
1161	ecc->write_page = sunxi_nfc_hw_syndrome_ecc_write_page;
1162
1163	layout = ecc->layout;
1164	nsectors = mtd->writesize / ecc->size;
1165
1166	for (i = 0; i < (ecc->bytes * nsectors); i++)
1167		layout->eccpos[i] = i;
1168
1169	layout->oobfree[0].length = mtd->oobsize - i;
1170	layout->oobfree[0].offset = i;
1171
1172	return 0;
1173}
1174
1175static void sunxi_nand_ecc_cleanup(struct nand_ecc_ctrl *ecc)
1176{
1177	switch (ecc->mode) {
1178	case NAND_ECC_HW:
1179	case NAND_ECC_HW_SYNDROME:
1180		sunxi_nand_hw_common_ecc_ctrl_cleanup(ecc);
1181		break;
1182	case NAND_ECC_NONE:
1183		kfree(ecc->layout);
1184	default:
1185		break;
1186	}
1187}
1188
1189static int sunxi_nand_ecc_init(struct mtd_info *mtd, struct nand_ecc_ctrl *ecc,
1190			       struct device_node *np)
1191{
1192	struct nand_chip *nand = mtd->priv;
1193	int ret;
1194
1195	if (!ecc->size) {
1196		ecc->size = nand->ecc_step_ds;
1197		ecc->strength = nand->ecc_strength_ds;
1198	}
1199
1200	if (!ecc->size || !ecc->strength)
1201		return -EINVAL;
1202
1203	switch (ecc->mode) {
1204	case NAND_ECC_SOFT_BCH:
1205		break;
1206	case NAND_ECC_HW:
1207		ret = sunxi_nand_hw_ecc_ctrl_init(mtd, ecc, np);
1208		if (ret)
1209			return ret;
1210		break;
1211	case NAND_ECC_HW_SYNDROME:
1212		ret = sunxi_nand_hw_syndrome_ecc_ctrl_init(mtd, ecc, np);
1213		if (ret)
1214			return ret;
1215		break;
1216	case NAND_ECC_NONE:
1217		ecc->layout = kzalloc(sizeof(*ecc->layout), GFP_KERNEL);
1218		if (!ecc->layout)
1219			return -ENOMEM;
1220		ecc->layout->oobfree[0].length = mtd->oobsize;
1221	case NAND_ECC_SOFT:
1222		break;
1223	default:
1224		return -EINVAL;
1225	}
1226
1227	return 0;
1228}
1229
1230static int sunxi_nand_chip_init(struct device *dev, struct sunxi_nfc *nfc,
1231				struct device_node *np)
1232{
1233	const struct nand_sdr_timings *timings;
1234	struct sunxi_nand_chip *chip;
1235	struct mtd_part_parser_data ppdata;
1236	struct mtd_info *mtd;
1237	struct nand_chip *nand;
1238	int nsels;
1239	int ret;
1240	int i;
1241	u32 tmp;
1242
1243	if (!of_get_property(np, "reg", &nsels))
1244		return -EINVAL;
1245
1246	nsels /= sizeof(u32);
1247	if (!nsels) {
1248		dev_err(dev, "invalid reg property size\n");
1249		return -EINVAL;
1250	}
1251
1252	chip = devm_kzalloc(dev,
1253			    sizeof(*chip) +
1254			    (nsels * sizeof(struct sunxi_nand_chip_sel)),
1255			    GFP_KERNEL);
1256	if (!chip) {
1257		dev_err(dev, "could not allocate chip\n");
1258		return -ENOMEM;
1259	}
1260
1261	chip->nsels = nsels;
1262	chip->selected = -1;
1263
1264	for (i = 0; i < nsels; i++) {
1265		ret = of_property_read_u32_index(np, "reg", i, &tmp);
1266		if (ret) {
1267			dev_err(dev, "could not retrieve reg property: %d\n",
1268				ret);
1269			return ret;
1270		}
1271
1272		if (tmp > NFC_MAX_CS) {
1273			dev_err(dev,
1274				"invalid reg value: %u (max CS = 7)\n",
1275				tmp);
1276			return -EINVAL;
1277		}
1278
1279		if (test_and_set_bit(tmp, &nfc->assigned_cs)) {
1280			dev_err(dev, "CS %d already assigned\n", tmp);
1281			return -EINVAL;
1282		}
1283
1284		chip->sels[i].cs = tmp;
1285
1286		if (!of_property_read_u32_index(np, "allwinner,rb", i, &tmp) &&
1287		    tmp < 2) {
1288			chip->sels[i].rb.type = RB_NATIVE;
1289			chip->sels[i].rb.info.nativeid = tmp;
1290		} else {
1291			ret = of_get_named_gpio(np, "rb-gpios", i);
1292			if (ret >= 0) {
1293				tmp = ret;
1294				chip->sels[i].rb.type = RB_GPIO;
1295				chip->sels[i].rb.info.gpio = tmp;
1296				ret = devm_gpio_request(dev, tmp, "nand-rb");
1297				if (ret)
1298					return ret;
1299
1300				ret = gpio_direction_input(tmp);
1301				if (ret)
1302					return ret;
1303			} else {
1304				chip->sels[i].rb.type = RB_NONE;
1305			}
1306		}
1307	}
1308
1309	timings = onfi_async_timing_mode_to_sdr_timings(0);
1310	if (IS_ERR(timings)) {
1311		ret = PTR_ERR(timings);
1312		dev_err(dev,
1313			"could not retrieve timings for ONFI mode 0: %d\n",
1314			ret);
1315		return ret;
1316	}
1317
1318	ret = sunxi_nand_chip_set_timings(chip, timings);
1319	if (ret) {
1320		dev_err(dev, "could not configure chip timings: %d\n", ret);
1321		return ret;
1322	}
1323
1324	nand = &chip->nand;
1325	/* Default tR value specified in the ONFI spec (chapter 4.15.1) */
1326	nand->chip_delay = 200;
1327	nand->controller = &nfc->controller;
1328	/*
1329	 * Set the ECC mode to the default value in case nothing is specified
1330	 * in the DT.
1331	 */
1332	nand->ecc.mode = NAND_ECC_HW;
1333	nand->flash_node = np;
1334	nand->select_chip = sunxi_nfc_select_chip;
1335	nand->cmd_ctrl = sunxi_nfc_cmd_ctrl;
1336	nand->read_buf = sunxi_nfc_read_buf;
1337	nand->write_buf = sunxi_nfc_write_buf;
1338	nand->read_byte = sunxi_nfc_read_byte;
1339
1340	mtd = &chip->mtd;
1341	mtd->dev.parent = dev;
1342	mtd->priv = nand;
1343
1344	ret = nand_scan_ident(mtd, nsels, NULL);
1345	if (ret)
1346		return ret;
1347
1348	if (nand->bbt_options & NAND_BBT_USE_FLASH)
1349		nand->bbt_options |= NAND_BBT_NO_OOB;
1350
1351	ret = sunxi_nand_chip_init_timings(chip, np);
1352	if (ret) {
1353		dev_err(dev, "could not configure chip timings: %d\n", ret);
1354		return ret;
1355	}
1356
1357	ret = sunxi_nand_ecc_init(mtd, &nand->ecc, np);
1358	if (ret) {
1359		dev_err(dev, "ECC init failed: %d\n", ret);
1360		return ret;
1361	}
1362
1363	ret = nand_scan_tail(mtd);
1364	if (ret) {
1365		dev_err(dev, "nand_scan_tail failed: %d\n", ret);
1366		return ret;
1367	}
1368
1369	ppdata.of_node = np;
1370	ret = mtd_device_parse_register(mtd, NULL, &ppdata, NULL, 0);
1371	if (ret) {
1372		dev_err(dev, "failed to register mtd device: %d\n", ret);
1373		nand_release(mtd);
1374		return ret;
1375	}
1376
1377	list_add_tail(&chip->node, &nfc->chips);
1378
1379	return 0;
1380}
1381
1382static int sunxi_nand_chips_init(struct device *dev, struct sunxi_nfc *nfc)
1383{
1384	struct device_node *np = dev->of_node;
1385	struct device_node *nand_np;
1386	int nchips = of_get_child_count(np);
1387	int ret;
1388
1389	if (nchips > 8) {
1390		dev_err(dev, "too many NAND chips: %d (max = 8)\n", nchips);
1391		return -EINVAL;
1392	}
1393
1394	for_each_child_of_node(np, nand_np) {
1395		ret = sunxi_nand_chip_init(dev, nfc, nand_np);
1396		if (ret)
1397			return ret;
1398	}
1399
1400	return 0;
1401}
1402
1403static void sunxi_nand_chips_cleanup(struct sunxi_nfc *nfc)
1404{
1405	struct sunxi_nand_chip *chip;
1406
1407	while (!list_empty(&nfc->chips)) {
1408		chip = list_first_entry(&nfc->chips, struct sunxi_nand_chip,
1409					node);
1410		nand_release(&chip->mtd);
1411		sunxi_nand_ecc_cleanup(&chip->nand.ecc);
1412		list_del(&chip->node);
1413	}
1414}
1415
1416static int sunxi_nfc_probe(struct platform_device *pdev)
1417{
1418	struct device *dev = &pdev->dev;
1419	struct resource *r;
1420	struct sunxi_nfc *nfc;
1421	int irq;
1422	int ret;
1423
1424	nfc = devm_kzalloc(dev, sizeof(*nfc), GFP_KERNEL);
1425	if (!nfc)
1426		return -ENOMEM;
1427
1428	nfc->dev = dev;
1429	spin_lock_init(&nfc->controller.lock);
1430	init_waitqueue_head(&nfc->controller.wq);
1431	INIT_LIST_HEAD(&nfc->chips);
1432
1433	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1434	nfc->regs = devm_ioremap_resource(dev, r);
1435	if (IS_ERR(nfc->regs))
1436		return PTR_ERR(nfc->regs);
1437
1438	irq = platform_get_irq(pdev, 0);
1439	if (irq < 0) {
1440		dev_err(dev, "failed to retrieve irq\n");
1441		return irq;
1442	}
1443
1444	nfc->ahb_clk = devm_clk_get(dev, "ahb");
1445	if (IS_ERR(nfc->ahb_clk)) {
1446		dev_err(dev, "failed to retrieve ahb clk\n");
1447		return PTR_ERR(nfc->ahb_clk);
1448	}
1449
1450	ret = clk_prepare_enable(nfc->ahb_clk);
1451	if (ret)
1452		return ret;
1453
1454	nfc->mod_clk = devm_clk_get(dev, "mod");
1455	if (IS_ERR(nfc->mod_clk)) {
1456		dev_err(dev, "failed to retrieve mod clk\n");
1457		ret = PTR_ERR(nfc->mod_clk);
1458		goto out_ahb_clk_unprepare;
1459	}
1460
1461	ret = clk_prepare_enable(nfc->mod_clk);
1462	if (ret)
1463		goto out_ahb_clk_unprepare;
1464
1465	ret = sunxi_nfc_rst(nfc);
1466	if (ret)
1467		goto out_mod_clk_unprepare;
1468
1469	writel(0, nfc->regs + NFC_REG_INT);
1470	ret = devm_request_irq(dev, irq, sunxi_nfc_interrupt,
1471			       0, "sunxi-nand", nfc);
1472	if (ret)
1473		goto out_mod_clk_unprepare;
1474
1475	platform_set_drvdata(pdev, nfc);
1476
1477	ret = sunxi_nand_chips_init(dev, nfc);
1478	if (ret) {
1479		dev_err(dev, "failed to init nand chips\n");
1480		goto out_mod_clk_unprepare;
1481	}
1482
1483	return 0;
1484
1485out_mod_clk_unprepare:
1486	clk_disable_unprepare(nfc->mod_clk);
1487out_ahb_clk_unprepare:
1488	clk_disable_unprepare(nfc->ahb_clk);
1489
1490	return ret;
1491}
1492
1493static int sunxi_nfc_remove(struct platform_device *pdev)
1494{
1495	struct sunxi_nfc *nfc = platform_get_drvdata(pdev);
1496
1497	sunxi_nand_chips_cleanup(nfc);
1498
1499	return 0;
1500}
1501
1502static const struct of_device_id sunxi_nfc_ids[] = {
1503	{ .compatible = "allwinner,sun4i-a10-nand" },
1504	{ /* sentinel */ }
1505};
1506MODULE_DEVICE_TABLE(of, sunxi_nfc_ids);
1507
1508static struct platform_driver sunxi_nfc_driver = {
1509	.driver = {
1510		.name = "sunxi_nand",
1511		.of_match_table = sunxi_nfc_ids,
1512	},
1513	.probe = sunxi_nfc_probe,
1514	.remove = sunxi_nfc_remove,
1515};
1516module_platform_driver(sunxi_nfc_driver);
1517
1518MODULE_LICENSE("GPL v2");
1519MODULE_AUTHOR("Boris BREZILLON");
1520MODULE_DESCRIPTION("Allwinner NAND Flash Controller driver");
1521MODULE_ALIAS("platform:sunxi_nand");
1522