xref: /openbmc/linux/drivers/mtd/nand/raw/sunxi_nand.c (revision fb799447)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2013 Boris BREZILLON <b.brezillon.dev@gmail.com>
4  *
5  * Derived from:
6  *	https://github.com/yuq/sunxi-nfc-mtd
7  *	Copyright (C) 2013 Qiang Yu <yuq825@gmail.com>
8  *
9  *	https://github.com/hno/Allwinner-Info
10  *	Copyright (C) 2013 Henrik Nordström <Henrik Nordström>
11  *
12  *	Copyright (C) 2013 Dmitriy B. <rzk333@gmail.com>
13  *	Copyright (C) 2013 Sergey Lapin <slapin@ossfans.org>
14  */
15 
16 #include <linux/dma-mapping.h>
17 #include <linux/slab.h>
18 #include <linux/module.h>
19 #include <linux/moduleparam.h>
20 #include <linux/platform_device.h>
21 #include <linux/of.h>
22 #include <linux/of_device.h>
23 #include <linux/mtd/mtd.h>
24 #include <linux/mtd/rawnand.h>
25 #include <linux/mtd/partitions.h>
26 #include <linux/clk.h>
27 #include <linux/delay.h>
28 #include <linux/dmaengine.h>
29 #include <linux/interrupt.h>
30 #include <linux/iopoll.h>
31 #include <linux/reset.h>
32 
33 #define NFC_REG_CTL		0x0000
34 #define NFC_REG_ST		0x0004
35 #define NFC_REG_INT		0x0008
36 #define NFC_REG_TIMING_CTL	0x000C
37 #define NFC_REG_TIMING_CFG	0x0010
38 #define NFC_REG_ADDR_LOW	0x0014
39 #define NFC_REG_ADDR_HIGH	0x0018
40 #define NFC_REG_SECTOR_NUM	0x001C
41 #define NFC_REG_CNT		0x0020
42 #define NFC_REG_CMD		0x0024
43 #define NFC_REG_RCMD_SET	0x0028
44 #define NFC_REG_WCMD_SET	0x002C
45 #define NFC_REG_A10_IO_DATA	0x0030
46 #define NFC_REG_A23_IO_DATA	0x0300
47 #define NFC_REG_ECC_CTL		0x0034
48 #define NFC_REG_ECC_ST		0x0038
49 #define NFC_REG_DEBUG		0x003C
50 #define NFC_REG_ECC_ERR_CNT(x)	((0x0040 + (x)) & ~0x3)
51 #define NFC_REG_USER_DATA(x)	(0x0050 + ((x) * 4))
52 #define NFC_REG_SPARE_AREA	0x00A0
53 #define NFC_REG_PAT_ID		0x00A4
54 #define NFC_REG_MDMA_ADDR	0x00C0
55 #define NFC_REG_MDMA_CNT	0x00C4
56 #define NFC_RAM0_BASE		0x0400
57 #define NFC_RAM1_BASE		0x0800
58 
59 /* define bit use in NFC_CTL */
60 #define NFC_EN			BIT(0)
61 #define NFC_RESET		BIT(1)
62 #define NFC_BUS_WIDTH_MSK	BIT(2)
63 #define NFC_BUS_WIDTH_8		(0 << 2)
64 #define NFC_BUS_WIDTH_16	(1 << 2)
65 #define NFC_RB_SEL_MSK		BIT(3)
66 #define NFC_RB_SEL(x)		((x) << 3)
67 #define NFC_CE_SEL_MSK		GENMASK(26, 24)
68 #define NFC_CE_SEL(x)		((x) << 24)
69 #define NFC_CE_CTL		BIT(6)
70 #define NFC_PAGE_SHIFT_MSK	GENMASK(11, 8)
71 #define NFC_PAGE_SHIFT(x)	(((x) < 10 ? 0 : (x) - 10) << 8)
72 #define NFC_SAM			BIT(12)
73 #define NFC_RAM_METHOD		BIT(14)
74 #define NFC_DMA_TYPE_NORMAL	BIT(15)
75 #define NFC_DEBUG_CTL		BIT(31)
76 
77 /* define bit use in NFC_ST */
78 #define NFC_RB_B2R		BIT(0)
79 #define NFC_CMD_INT_FLAG	BIT(1)
80 #define NFC_DMA_INT_FLAG	BIT(2)
81 #define NFC_CMD_FIFO_STATUS	BIT(3)
82 #define NFC_STA			BIT(4)
83 #define NFC_NATCH_INT_FLAG	BIT(5)
84 #define NFC_RB_STATE(x)		BIT(x + 8)
85 
86 /* define bit use in NFC_INT */
87 #define NFC_B2R_INT_ENABLE	BIT(0)
88 #define NFC_CMD_INT_ENABLE	BIT(1)
89 #define NFC_DMA_INT_ENABLE	BIT(2)
90 #define NFC_INT_MASK		(NFC_B2R_INT_ENABLE | \
91 				 NFC_CMD_INT_ENABLE | \
92 				 NFC_DMA_INT_ENABLE)
93 
94 /* define bit use in NFC_TIMING_CTL */
95 #define NFC_TIMING_CTL_EDO	BIT(8)
96 
97 /* define NFC_TIMING_CFG register layout */
98 #define NFC_TIMING_CFG(tWB, tADL, tWHR, tRHW, tCAD)		\
99 	(((tWB) & 0x3) | (((tADL) & 0x3) << 2) |		\
100 	(((tWHR) & 0x3) << 4) | (((tRHW) & 0x3) << 6) |		\
101 	(((tCAD) & 0x7) << 8))
102 
103 /* define bit use in NFC_CMD */
104 #define NFC_CMD_LOW_BYTE_MSK	GENMASK(7, 0)
105 #define NFC_CMD_HIGH_BYTE_MSK	GENMASK(15, 8)
106 #define NFC_CMD(x)		(x)
107 #define NFC_ADR_NUM_MSK		GENMASK(18, 16)
108 #define NFC_ADR_NUM(x)		(((x) - 1) << 16)
109 #define NFC_SEND_ADR		BIT(19)
110 #define NFC_ACCESS_DIR		BIT(20)
111 #define NFC_DATA_TRANS		BIT(21)
112 #define NFC_SEND_CMD1		BIT(22)
113 #define NFC_WAIT_FLAG		BIT(23)
114 #define NFC_SEND_CMD2		BIT(24)
115 #define NFC_SEQ			BIT(25)
116 #define NFC_DATA_SWAP_METHOD	BIT(26)
117 #define NFC_ROW_AUTO_INC	BIT(27)
118 #define NFC_SEND_CMD3		BIT(28)
119 #define NFC_SEND_CMD4		BIT(29)
120 #define NFC_CMD_TYPE_MSK	GENMASK(31, 30)
121 #define NFC_NORMAL_OP		(0 << 30)
122 #define NFC_ECC_OP		(1 << 30)
123 #define NFC_PAGE_OP		(2U << 30)
124 
125 /* define bit use in NFC_RCMD_SET */
126 #define NFC_READ_CMD_MSK	GENMASK(7, 0)
127 #define NFC_RND_READ_CMD0_MSK	GENMASK(15, 8)
128 #define NFC_RND_READ_CMD1_MSK	GENMASK(23, 16)
129 
130 /* define bit use in NFC_WCMD_SET */
131 #define NFC_PROGRAM_CMD_MSK	GENMASK(7, 0)
132 #define NFC_RND_WRITE_CMD_MSK	GENMASK(15, 8)
133 #define NFC_READ_CMD0_MSK	GENMASK(23, 16)
134 #define NFC_READ_CMD1_MSK	GENMASK(31, 24)
135 
136 /* define bit use in NFC_ECC_CTL */
137 #define NFC_ECC_EN		BIT(0)
138 #define NFC_ECC_PIPELINE	BIT(3)
139 #define NFC_ECC_EXCEPTION	BIT(4)
140 #define NFC_ECC_BLOCK_SIZE_MSK	BIT(5)
141 #define NFC_ECC_BLOCK_512	BIT(5)
142 #define NFC_RANDOM_EN		BIT(9)
143 #define NFC_RANDOM_DIRECTION	BIT(10)
144 #define NFC_ECC_MODE_MSK	GENMASK(15, 12)
145 #define NFC_ECC_MODE(x)		((x) << 12)
146 #define NFC_RANDOM_SEED_MSK	GENMASK(30, 16)
147 #define NFC_RANDOM_SEED(x)	((x) << 16)
148 
149 /* define bit use in NFC_ECC_ST */
150 #define NFC_ECC_ERR(x)		BIT(x)
151 #define NFC_ECC_ERR_MSK		GENMASK(15, 0)
152 #define NFC_ECC_PAT_FOUND(x)	BIT(x + 16)
153 #define NFC_ECC_ERR_CNT(b, x)	(((x) >> (((b) % 4) * 8)) & 0xff)
154 
155 #define NFC_DEFAULT_TIMEOUT_MS	1000
156 
157 #define NFC_SRAM_SIZE		1024
158 
159 #define NFC_MAX_CS		7
160 
161 /**
162  * struct sunxi_nand_chip_sel - stores information related to NAND Chip Select
163  *
164  * @cs: the NAND CS id used to communicate with a NAND Chip
165  * @rb: the Ready/Busy pin ID. -1 means no R/B pin connected to the NFC
166  */
167 struct sunxi_nand_chip_sel {
168 	u8 cs;
169 	s8 rb;
170 };
171 
172 /**
173  * struct sunxi_nand_hw_ecc - stores information related to HW ECC support
174  *
175  * @ecc_ctl: ECC_CTL register value for this NAND chip
176  */
177 struct sunxi_nand_hw_ecc {
178 	u32 ecc_ctl;
179 };
180 
181 /**
182  * struct sunxi_nand_chip - stores NAND chip device related information
183  *
184  * @node: used to store NAND chips into a list
185  * @nand: base NAND chip structure
186  * @ecc: ECC controller structure
187  * @clk_rate: clk_rate required for this NAND chip
188  * @timing_cfg: TIMING_CFG register value for this NAND chip
189  * @timing_ctl: TIMING_CTL register value for this NAND chip
190  * @nsels: number of CS lines required by the NAND chip
191  * @sels: array of CS lines descriptions
192  */
193 struct sunxi_nand_chip {
194 	struct list_head node;
195 	struct nand_chip nand;
196 	struct sunxi_nand_hw_ecc ecc;
197 	unsigned long clk_rate;
198 	u32 timing_cfg;
199 	u32 timing_ctl;
200 	int nsels;
201 	struct sunxi_nand_chip_sel sels[];
202 };
203 
204 static inline struct sunxi_nand_chip *to_sunxi_nand(struct nand_chip *nand)
205 {
206 	return container_of(nand, struct sunxi_nand_chip, nand);
207 }
208 
209 /*
210  * NAND Controller capabilities structure: stores NAND controller capabilities
211  * for distinction between compatible strings.
212  *
213  * @has_mdma:		Use mbus dma mode, otherwise general dma
214  *			through MBUS on A23/A33 needs extra configuration.
215  * @reg_io_data:	I/O data register
216  * @dma_maxburst:	DMA maxburst
217  */
218 struct sunxi_nfc_caps {
219 	bool has_mdma;
220 	unsigned int reg_io_data;
221 	unsigned int dma_maxburst;
222 };
223 
224 /**
225  * struct sunxi_nfc - stores sunxi NAND controller information
226  *
227  * @controller: base controller structure
228  * @dev: parent device (used to print error messages)
229  * @regs: NAND controller registers
230  * @ahb_clk: NAND controller AHB clock
231  * @mod_clk: NAND controller mod clock
232  * @reset: NAND controller reset line
233  * @assigned_cs: bitmask describing already assigned CS lines
234  * @clk_rate: NAND controller current clock rate
235  * @chips: a list containing all the NAND chips attached to this NAND
236  *	   controller
237  * @complete: a completion object used to wait for NAND controller events
238  * @dmac: the DMA channel attached to the NAND controller
239  * @caps: NAND Controller capabilities
240  */
241 struct sunxi_nfc {
242 	struct nand_controller controller;
243 	struct device *dev;
244 	void __iomem *regs;
245 	struct clk *ahb_clk;
246 	struct clk *mod_clk;
247 	struct reset_control *reset;
248 	unsigned long assigned_cs;
249 	unsigned long clk_rate;
250 	struct list_head chips;
251 	struct completion complete;
252 	struct dma_chan *dmac;
253 	const struct sunxi_nfc_caps *caps;
254 };
255 
256 static inline struct sunxi_nfc *to_sunxi_nfc(struct nand_controller *ctrl)
257 {
258 	return container_of(ctrl, struct sunxi_nfc, controller);
259 }
260 
261 static irqreturn_t sunxi_nfc_interrupt(int irq, void *dev_id)
262 {
263 	struct sunxi_nfc *nfc = dev_id;
264 	u32 st = readl(nfc->regs + NFC_REG_ST);
265 	u32 ien = readl(nfc->regs + NFC_REG_INT);
266 
267 	if (!(ien & st))
268 		return IRQ_NONE;
269 
270 	if ((ien & st) == ien)
271 		complete(&nfc->complete);
272 
273 	writel(st & NFC_INT_MASK, nfc->regs + NFC_REG_ST);
274 	writel(~st & ien & NFC_INT_MASK, nfc->regs + NFC_REG_INT);
275 
276 	return IRQ_HANDLED;
277 }
278 
279 static int sunxi_nfc_wait_events(struct sunxi_nfc *nfc, u32 events,
280 				 bool use_polling, unsigned int timeout_ms)
281 {
282 	int ret;
283 
284 	if (events & ~NFC_INT_MASK)
285 		return -EINVAL;
286 
287 	if (!timeout_ms)
288 		timeout_ms = NFC_DEFAULT_TIMEOUT_MS;
289 
290 	if (!use_polling) {
291 		init_completion(&nfc->complete);
292 
293 		writel(events, nfc->regs + NFC_REG_INT);
294 
295 		ret = wait_for_completion_timeout(&nfc->complete,
296 						msecs_to_jiffies(timeout_ms));
297 		if (!ret)
298 			ret = -ETIMEDOUT;
299 		else
300 			ret = 0;
301 
302 		writel(0, nfc->regs + NFC_REG_INT);
303 	} else {
304 		u32 status;
305 
306 		ret = readl_poll_timeout(nfc->regs + NFC_REG_ST, status,
307 					 (status & events) == events, 1,
308 					 timeout_ms * 1000);
309 	}
310 
311 	writel(events & NFC_INT_MASK, nfc->regs + NFC_REG_ST);
312 
313 	if (ret)
314 		dev_err(nfc->dev, "wait interrupt timedout\n");
315 
316 	return ret;
317 }
318 
319 static int sunxi_nfc_wait_cmd_fifo_empty(struct sunxi_nfc *nfc)
320 {
321 	u32 status;
322 	int ret;
323 
324 	ret = readl_poll_timeout(nfc->regs + NFC_REG_ST, status,
325 				 !(status & NFC_CMD_FIFO_STATUS), 1,
326 				 NFC_DEFAULT_TIMEOUT_MS * 1000);
327 	if (ret)
328 		dev_err(nfc->dev, "wait for empty cmd FIFO timedout\n");
329 
330 	return ret;
331 }
332 
333 static int sunxi_nfc_rst(struct sunxi_nfc *nfc)
334 {
335 	u32 ctl;
336 	int ret;
337 
338 	writel(0, nfc->regs + NFC_REG_ECC_CTL);
339 	writel(NFC_RESET, nfc->regs + NFC_REG_CTL);
340 
341 	ret = readl_poll_timeout(nfc->regs + NFC_REG_CTL, ctl,
342 				 !(ctl & NFC_RESET), 1,
343 				 NFC_DEFAULT_TIMEOUT_MS * 1000);
344 	if (ret)
345 		dev_err(nfc->dev, "wait for NAND controller reset timedout\n");
346 
347 	return ret;
348 }
349 
350 static int sunxi_nfc_dma_op_prepare(struct sunxi_nfc *nfc, const void *buf,
351 				    int chunksize, int nchunks,
352 				    enum dma_data_direction ddir,
353 				    struct scatterlist *sg)
354 {
355 	struct dma_async_tx_descriptor *dmad;
356 	enum dma_transfer_direction tdir;
357 	dma_cookie_t dmat;
358 	int ret;
359 
360 	if (ddir == DMA_FROM_DEVICE)
361 		tdir = DMA_DEV_TO_MEM;
362 	else
363 		tdir = DMA_MEM_TO_DEV;
364 
365 	sg_init_one(sg, buf, nchunks * chunksize);
366 	ret = dma_map_sg(nfc->dev, sg, 1, ddir);
367 	if (!ret)
368 		return -ENOMEM;
369 
370 	if (!nfc->caps->has_mdma) {
371 		dmad = dmaengine_prep_slave_sg(nfc->dmac, sg, 1, tdir, DMA_CTRL_ACK);
372 		if (!dmad) {
373 			ret = -EINVAL;
374 			goto err_unmap_buf;
375 		}
376 	}
377 
378 	writel(readl(nfc->regs + NFC_REG_CTL) | NFC_RAM_METHOD,
379 	       nfc->regs + NFC_REG_CTL);
380 	writel(nchunks, nfc->regs + NFC_REG_SECTOR_NUM);
381 	writel(chunksize, nfc->regs + NFC_REG_CNT);
382 
383 	if (nfc->caps->has_mdma) {
384 		writel(readl(nfc->regs + NFC_REG_CTL) & ~NFC_DMA_TYPE_NORMAL,
385 		       nfc->regs + NFC_REG_CTL);
386 		writel(chunksize * nchunks, nfc->regs + NFC_REG_MDMA_CNT);
387 		writel(sg_dma_address(sg), nfc->regs + NFC_REG_MDMA_ADDR);
388 	} else {
389 		dmat = dmaengine_submit(dmad);
390 
391 		ret = dma_submit_error(dmat);
392 		if (ret)
393 			goto err_clr_dma_flag;
394 	}
395 
396 	return 0;
397 
398 err_clr_dma_flag:
399 	writel(readl(nfc->regs + NFC_REG_CTL) & ~NFC_RAM_METHOD,
400 	       nfc->regs + NFC_REG_CTL);
401 
402 err_unmap_buf:
403 	dma_unmap_sg(nfc->dev, sg, 1, ddir);
404 	return ret;
405 }
406 
407 static void sunxi_nfc_dma_op_cleanup(struct sunxi_nfc *nfc,
408 				     enum dma_data_direction ddir,
409 				     struct scatterlist *sg)
410 {
411 	dma_unmap_sg(nfc->dev, sg, 1, ddir);
412 	writel(readl(nfc->regs + NFC_REG_CTL) & ~NFC_RAM_METHOD,
413 	       nfc->regs + NFC_REG_CTL);
414 }
415 
416 static void sunxi_nfc_select_chip(struct nand_chip *nand, unsigned int cs)
417 {
418 	struct mtd_info *mtd = nand_to_mtd(nand);
419 	struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
420 	struct sunxi_nfc *nfc = to_sunxi_nfc(sunxi_nand->nand.controller);
421 	struct sunxi_nand_chip_sel *sel;
422 	u32 ctl;
423 
424 	if (cs >= sunxi_nand->nsels)
425 		return;
426 
427 	ctl = readl(nfc->regs + NFC_REG_CTL) &
428 	      ~(NFC_PAGE_SHIFT_MSK | NFC_CE_SEL_MSK | NFC_RB_SEL_MSK | NFC_EN);
429 
430 	sel = &sunxi_nand->sels[cs];
431 	ctl |= NFC_CE_SEL(sel->cs) | NFC_EN | NFC_PAGE_SHIFT(nand->page_shift);
432 	if (sel->rb >= 0)
433 		ctl |= NFC_RB_SEL(sel->rb);
434 
435 	writel(mtd->writesize, nfc->regs + NFC_REG_SPARE_AREA);
436 
437 	if (nfc->clk_rate != sunxi_nand->clk_rate) {
438 		clk_set_rate(nfc->mod_clk, sunxi_nand->clk_rate);
439 		nfc->clk_rate = sunxi_nand->clk_rate;
440 	}
441 
442 	writel(sunxi_nand->timing_ctl, nfc->regs + NFC_REG_TIMING_CTL);
443 	writel(sunxi_nand->timing_cfg, nfc->regs + NFC_REG_TIMING_CFG);
444 	writel(ctl, nfc->regs + NFC_REG_CTL);
445 }
446 
447 static void sunxi_nfc_read_buf(struct nand_chip *nand, uint8_t *buf, int len)
448 {
449 	struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
450 	struct sunxi_nfc *nfc = to_sunxi_nfc(sunxi_nand->nand.controller);
451 	int ret;
452 	int cnt;
453 	int offs = 0;
454 	u32 tmp;
455 
456 	while (len > offs) {
457 		bool poll = false;
458 
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 		tmp = NFC_DATA_TRANS | NFC_DATA_SWAP_METHOD;
467 		writel(tmp, nfc->regs + NFC_REG_CMD);
468 
469 		/* Arbitrary limit for polling mode */
470 		if (cnt < 64)
471 			poll = true;
472 
473 		ret = sunxi_nfc_wait_events(nfc, NFC_CMD_INT_FLAG, poll, 0);
474 		if (ret)
475 			break;
476 
477 		if (buf)
478 			memcpy_fromio(buf + offs, nfc->regs + NFC_RAM0_BASE,
479 				      cnt);
480 		offs += cnt;
481 	}
482 }
483 
484 static void sunxi_nfc_write_buf(struct nand_chip *nand, const uint8_t *buf,
485 				int len)
486 {
487 	struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
488 	struct sunxi_nfc *nfc = to_sunxi_nfc(sunxi_nand->nand.controller);
489 	int ret;
490 	int cnt;
491 	int offs = 0;
492 	u32 tmp;
493 
494 	while (len > offs) {
495 		bool poll = false;
496 
497 		cnt = min(len - offs, NFC_SRAM_SIZE);
498 
499 		ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
500 		if (ret)
501 			break;
502 
503 		writel(cnt, nfc->regs + NFC_REG_CNT);
504 		memcpy_toio(nfc->regs + NFC_RAM0_BASE, buf + offs, cnt);
505 		tmp = NFC_DATA_TRANS | NFC_DATA_SWAP_METHOD |
506 		      NFC_ACCESS_DIR;
507 		writel(tmp, nfc->regs + NFC_REG_CMD);
508 
509 		/* Arbitrary limit for polling mode */
510 		if (cnt < 64)
511 			poll = true;
512 
513 		ret = sunxi_nfc_wait_events(nfc, NFC_CMD_INT_FLAG, poll, 0);
514 		if (ret)
515 			break;
516 
517 		offs += cnt;
518 	}
519 }
520 
521 /* These seed values have been extracted from Allwinner's BSP */
522 static const u16 sunxi_nfc_randomizer_page_seeds[] = {
523 	0x2b75, 0x0bd0, 0x5ca3, 0x62d1, 0x1c93, 0x07e9, 0x2162, 0x3a72,
524 	0x0d67, 0x67f9, 0x1be7, 0x077d, 0x032f, 0x0dac, 0x2716, 0x2436,
525 	0x7922, 0x1510, 0x3860, 0x5287, 0x480f, 0x4252, 0x1789, 0x5a2d,
526 	0x2a49, 0x5e10, 0x437f, 0x4b4e, 0x2f45, 0x216e, 0x5cb7, 0x7130,
527 	0x2a3f, 0x60e4, 0x4dc9, 0x0ef0, 0x0f52, 0x1bb9, 0x6211, 0x7a56,
528 	0x226d, 0x4ea7, 0x6f36, 0x3692, 0x38bf, 0x0c62, 0x05eb, 0x4c55,
529 	0x60f4, 0x728c, 0x3b6f, 0x2037, 0x7f69, 0x0936, 0x651a, 0x4ceb,
530 	0x6218, 0x79f3, 0x383f, 0x18d9, 0x4f05, 0x5c82, 0x2912, 0x6f17,
531 	0x6856, 0x5938, 0x1007, 0x61ab, 0x3e7f, 0x57c2, 0x542f, 0x4f62,
532 	0x7454, 0x2eac, 0x7739, 0x42d4, 0x2f90, 0x435a, 0x2e52, 0x2064,
533 	0x637c, 0x66ad, 0x2c90, 0x0bad, 0x759c, 0x0029, 0x0986, 0x7126,
534 	0x1ca7, 0x1605, 0x386a, 0x27f5, 0x1380, 0x6d75, 0x24c3, 0x0f8e,
535 	0x2b7a, 0x1418, 0x1fd1, 0x7dc1, 0x2d8e, 0x43af, 0x2267, 0x7da3,
536 	0x4e3d, 0x1338, 0x50db, 0x454d, 0x764d, 0x40a3, 0x42e6, 0x262b,
537 	0x2d2e, 0x1aea, 0x2e17, 0x173d, 0x3a6e, 0x71bf, 0x25f9, 0x0a5d,
538 	0x7c57, 0x0fbe, 0x46ce, 0x4939, 0x6b17, 0x37bb, 0x3e91, 0x76db,
539 };
540 
541 /*
542  * sunxi_nfc_randomizer_ecc512_seeds and sunxi_nfc_randomizer_ecc1024_seeds
543  * have been generated using
544  * sunxi_nfc_randomizer_step(seed, (step_size * 8) + 15), which is what
545  * the randomizer engine does internally before de/scrambling OOB data.
546  *
547  * Those tables are statically defined to avoid calculating randomizer state
548  * at runtime.
549  */
550 static const u16 sunxi_nfc_randomizer_ecc512_seeds[] = {
551 	0x3346, 0x367f, 0x1f18, 0x769a, 0x4f64, 0x068c, 0x2ef1, 0x6b64,
552 	0x28a9, 0x15d7, 0x30f8, 0x3659, 0x53db, 0x7c5f, 0x71d4, 0x4409,
553 	0x26eb, 0x03cc, 0x655d, 0x47d4, 0x4daa, 0x0877, 0x712d, 0x3617,
554 	0x3264, 0x49aa, 0x7f9e, 0x588e, 0x4fbc, 0x7176, 0x7f91, 0x6c6d,
555 	0x4b95, 0x5fb7, 0x3844, 0x4037, 0x0184, 0x081b, 0x0ee8, 0x5b91,
556 	0x293d, 0x1f71, 0x0e6f, 0x402b, 0x5122, 0x1e52, 0x22be, 0x3d2d,
557 	0x75bc, 0x7c60, 0x6291, 0x1a2f, 0x61d4, 0x74aa, 0x4140, 0x29ab,
558 	0x472d, 0x2852, 0x017e, 0x15e8, 0x5ec2, 0x17cf, 0x7d0f, 0x06b8,
559 	0x117a, 0x6b94, 0x789b, 0x3126, 0x6ac5, 0x5be7, 0x150f, 0x51f8,
560 	0x7889, 0x0aa5, 0x663d, 0x77e8, 0x0b87, 0x3dcb, 0x360d, 0x218b,
561 	0x512f, 0x7dc9, 0x6a4d, 0x630a, 0x3547, 0x1dd2, 0x5aea, 0x69a5,
562 	0x7bfa, 0x5e4f, 0x1519, 0x6430, 0x3a0e, 0x5eb3, 0x5425, 0x0c7a,
563 	0x5540, 0x3670, 0x63c1, 0x31e9, 0x5a39, 0x2de7, 0x5979, 0x2891,
564 	0x1562, 0x014b, 0x5b05, 0x2756, 0x5a34, 0x13aa, 0x6cb5, 0x2c36,
565 	0x5e72, 0x1306, 0x0861, 0x15ef, 0x1ee8, 0x5a37, 0x7ac4, 0x45dd,
566 	0x44c4, 0x7266, 0x2f41, 0x3ccc, 0x045e, 0x7d40, 0x7c66, 0x0fa0,
567 };
568 
569 static const u16 sunxi_nfc_randomizer_ecc1024_seeds[] = {
570 	0x2cf5, 0x35f1, 0x63a4, 0x5274, 0x2bd2, 0x778b, 0x7285, 0x32b6,
571 	0x6a5c, 0x70d6, 0x757d, 0x6769, 0x5375, 0x1e81, 0x0cf3, 0x3982,
572 	0x6787, 0x042a, 0x6c49, 0x1925, 0x56a8, 0x40a9, 0x063e, 0x7bd9,
573 	0x4dbf, 0x55ec, 0x672e, 0x7334, 0x5185, 0x4d00, 0x232a, 0x7e07,
574 	0x445d, 0x6b92, 0x528f, 0x4255, 0x53ba, 0x7d82, 0x2a2e, 0x3a4e,
575 	0x75eb, 0x450c, 0x6844, 0x1b5d, 0x581a, 0x4cc6, 0x0379, 0x37b2,
576 	0x419f, 0x0e92, 0x6b27, 0x5624, 0x01e3, 0x07c1, 0x44a5, 0x130c,
577 	0x13e8, 0x5910, 0x0876, 0x60c5, 0x54e3, 0x5b7f, 0x2269, 0x509f,
578 	0x7665, 0x36fd, 0x3e9a, 0x0579, 0x6295, 0x14ef, 0x0a81, 0x1bcc,
579 	0x4b16, 0x64db, 0x0514, 0x4f07, 0x0591, 0x3576, 0x6853, 0x0d9e,
580 	0x259f, 0x38b7, 0x64fb, 0x3094, 0x4693, 0x6ddd, 0x29bb, 0x0bc8,
581 	0x3f47, 0x490e, 0x0c0e, 0x7933, 0x3c9e, 0x5840, 0x398d, 0x3e68,
582 	0x4af1, 0x71f5, 0x57cf, 0x1121, 0x64eb, 0x3579, 0x15ac, 0x584d,
583 	0x5f2a, 0x47e2, 0x6528, 0x6eac, 0x196e, 0x6b96, 0x0450, 0x0179,
584 	0x609c, 0x06e1, 0x4626, 0x42c7, 0x273e, 0x486f, 0x0705, 0x1601,
585 	0x145b, 0x407e, 0x062b, 0x57a5, 0x53f9, 0x5659, 0x4410, 0x3ccd,
586 };
587 
588 static u16 sunxi_nfc_randomizer_step(u16 state, int count)
589 {
590 	state &= 0x7fff;
591 
592 	/*
593 	 * This loop is just a simple implementation of a Fibonacci LFSR using
594 	 * the x16 + x15 + 1 polynomial.
595 	 */
596 	while (count--)
597 		state = ((state >> 1) |
598 			 (((state ^ (state >> 1)) & 1) << 14)) & 0x7fff;
599 
600 	return state;
601 }
602 
603 static u16 sunxi_nfc_randomizer_state(struct nand_chip *nand, int page,
604 				      bool ecc)
605 {
606 	struct mtd_info *mtd = nand_to_mtd(nand);
607 	const u16 *seeds = sunxi_nfc_randomizer_page_seeds;
608 	int mod = mtd_div_by_ws(mtd->erasesize, mtd);
609 
610 	if (mod > ARRAY_SIZE(sunxi_nfc_randomizer_page_seeds))
611 		mod = ARRAY_SIZE(sunxi_nfc_randomizer_page_seeds);
612 
613 	if (ecc) {
614 		if (mtd->ecc_step_size == 512)
615 			seeds = sunxi_nfc_randomizer_ecc512_seeds;
616 		else
617 			seeds = sunxi_nfc_randomizer_ecc1024_seeds;
618 	}
619 
620 	return seeds[page % mod];
621 }
622 
623 static void sunxi_nfc_randomizer_config(struct nand_chip *nand, int page,
624 					bool ecc)
625 {
626 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
627 	u32 ecc_ctl = readl(nfc->regs + NFC_REG_ECC_CTL);
628 	u16 state;
629 
630 	if (!(nand->options & NAND_NEED_SCRAMBLING))
631 		return;
632 
633 	ecc_ctl = readl(nfc->regs + NFC_REG_ECC_CTL);
634 	state = sunxi_nfc_randomizer_state(nand, page, ecc);
635 	ecc_ctl = readl(nfc->regs + NFC_REG_ECC_CTL) & ~NFC_RANDOM_SEED_MSK;
636 	writel(ecc_ctl | NFC_RANDOM_SEED(state), nfc->regs + NFC_REG_ECC_CTL);
637 }
638 
639 static void sunxi_nfc_randomizer_enable(struct nand_chip *nand)
640 {
641 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
642 
643 	if (!(nand->options & NAND_NEED_SCRAMBLING))
644 		return;
645 
646 	writel(readl(nfc->regs + NFC_REG_ECC_CTL) | NFC_RANDOM_EN,
647 	       nfc->regs + NFC_REG_ECC_CTL);
648 }
649 
650 static void sunxi_nfc_randomizer_disable(struct nand_chip *nand)
651 {
652 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
653 
654 	if (!(nand->options & NAND_NEED_SCRAMBLING))
655 		return;
656 
657 	writel(readl(nfc->regs + NFC_REG_ECC_CTL) & ~NFC_RANDOM_EN,
658 	       nfc->regs + NFC_REG_ECC_CTL);
659 }
660 
661 static void sunxi_nfc_randomize_bbm(struct nand_chip *nand, int page, u8 *bbm)
662 {
663 	u16 state = sunxi_nfc_randomizer_state(nand, page, true);
664 
665 	bbm[0] ^= state;
666 	bbm[1] ^= sunxi_nfc_randomizer_step(state, 8);
667 }
668 
669 static void sunxi_nfc_randomizer_write_buf(struct nand_chip *nand,
670 					   const uint8_t *buf, int len,
671 					   bool ecc, int page)
672 {
673 	sunxi_nfc_randomizer_config(nand, page, ecc);
674 	sunxi_nfc_randomizer_enable(nand);
675 	sunxi_nfc_write_buf(nand, buf, len);
676 	sunxi_nfc_randomizer_disable(nand);
677 }
678 
679 static void sunxi_nfc_randomizer_read_buf(struct nand_chip *nand, uint8_t *buf,
680 					  int len, bool ecc, int page)
681 {
682 	sunxi_nfc_randomizer_config(nand, page, ecc);
683 	sunxi_nfc_randomizer_enable(nand);
684 	sunxi_nfc_read_buf(nand, buf, len);
685 	sunxi_nfc_randomizer_disable(nand);
686 }
687 
688 static void sunxi_nfc_hw_ecc_enable(struct nand_chip *nand)
689 {
690 	struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
691 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
692 
693 	writel(sunxi_nand->ecc.ecc_ctl, nfc->regs + NFC_REG_ECC_CTL);
694 }
695 
696 static void sunxi_nfc_hw_ecc_disable(struct nand_chip *nand)
697 {
698 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
699 
700 	writel(0, nfc->regs + NFC_REG_ECC_CTL);
701 }
702 
703 static inline void sunxi_nfc_user_data_to_buf(u32 user_data, u8 *buf)
704 {
705 	buf[0] = user_data;
706 	buf[1] = user_data >> 8;
707 	buf[2] = user_data >> 16;
708 	buf[3] = user_data >> 24;
709 }
710 
711 static inline u32 sunxi_nfc_buf_to_user_data(const u8 *buf)
712 {
713 	return buf[0] | (buf[1] << 8) | (buf[2] << 16) | (buf[3] << 24);
714 }
715 
716 static void sunxi_nfc_hw_ecc_get_prot_oob_bytes(struct nand_chip *nand, u8 *oob,
717 						int step, bool bbm, int page)
718 {
719 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
720 
721 	sunxi_nfc_user_data_to_buf(readl(nfc->regs + NFC_REG_USER_DATA(step)),
722 				   oob);
723 
724 	/* De-randomize the Bad Block Marker. */
725 	if (bbm && (nand->options & NAND_NEED_SCRAMBLING))
726 		sunxi_nfc_randomize_bbm(nand, page, oob);
727 }
728 
729 static void sunxi_nfc_hw_ecc_set_prot_oob_bytes(struct nand_chip *nand,
730 						const u8 *oob, int step,
731 						bool bbm, int page)
732 {
733 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
734 	u8 user_data[4];
735 
736 	/* Randomize the Bad Block Marker. */
737 	if (bbm && (nand->options & NAND_NEED_SCRAMBLING)) {
738 		memcpy(user_data, oob, sizeof(user_data));
739 		sunxi_nfc_randomize_bbm(nand, page, user_data);
740 		oob = user_data;
741 	}
742 
743 	writel(sunxi_nfc_buf_to_user_data(oob),
744 	       nfc->regs + NFC_REG_USER_DATA(step));
745 }
746 
747 static void sunxi_nfc_hw_ecc_update_stats(struct nand_chip *nand,
748 					  unsigned int *max_bitflips, int ret)
749 {
750 	struct mtd_info *mtd = nand_to_mtd(nand);
751 
752 	if (ret < 0) {
753 		mtd->ecc_stats.failed++;
754 	} else {
755 		mtd->ecc_stats.corrected += ret;
756 		*max_bitflips = max_t(unsigned int, *max_bitflips, ret);
757 	}
758 }
759 
760 static int sunxi_nfc_hw_ecc_correct(struct nand_chip *nand, u8 *data, u8 *oob,
761 				    int step, u32 status, bool *erased)
762 {
763 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
764 	struct nand_ecc_ctrl *ecc = &nand->ecc;
765 	u32 tmp;
766 
767 	*erased = false;
768 
769 	if (status & NFC_ECC_ERR(step))
770 		return -EBADMSG;
771 
772 	if (status & NFC_ECC_PAT_FOUND(step)) {
773 		u8 pattern;
774 
775 		if (unlikely(!(readl(nfc->regs + NFC_REG_PAT_ID) & 0x1))) {
776 			pattern = 0x0;
777 		} else {
778 			pattern = 0xff;
779 			*erased = true;
780 		}
781 
782 		if (data)
783 			memset(data, pattern, ecc->size);
784 
785 		if (oob)
786 			memset(oob, pattern, ecc->bytes + 4);
787 
788 		return 0;
789 	}
790 
791 	tmp = readl(nfc->regs + NFC_REG_ECC_ERR_CNT(step));
792 
793 	return NFC_ECC_ERR_CNT(step, tmp);
794 }
795 
796 static int sunxi_nfc_hw_ecc_read_chunk(struct nand_chip *nand,
797 				       u8 *data, int data_off,
798 				       u8 *oob, int oob_off,
799 				       int *cur_off,
800 				       unsigned int *max_bitflips,
801 				       bool bbm, bool oob_required, int page)
802 {
803 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
804 	struct nand_ecc_ctrl *ecc = &nand->ecc;
805 	int raw_mode = 0;
806 	bool erased;
807 	int ret;
808 
809 	if (*cur_off != data_off)
810 		nand_change_read_column_op(nand, data_off, NULL, 0, false);
811 
812 	sunxi_nfc_randomizer_read_buf(nand, NULL, ecc->size, false, page);
813 
814 	if (data_off + ecc->size != oob_off)
815 		nand_change_read_column_op(nand, oob_off, NULL, 0, false);
816 
817 	ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
818 	if (ret)
819 		return ret;
820 
821 	sunxi_nfc_randomizer_enable(nand);
822 	writel(NFC_DATA_TRANS | NFC_DATA_SWAP_METHOD | NFC_ECC_OP,
823 	       nfc->regs + NFC_REG_CMD);
824 
825 	ret = sunxi_nfc_wait_events(nfc, NFC_CMD_INT_FLAG, false, 0);
826 	sunxi_nfc_randomizer_disable(nand);
827 	if (ret)
828 		return ret;
829 
830 	*cur_off = oob_off + ecc->bytes + 4;
831 
832 	ret = sunxi_nfc_hw_ecc_correct(nand, data, oob_required ? oob : NULL, 0,
833 				       readl(nfc->regs + NFC_REG_ECC_ST),
834 				       &erased);
835 	if (erased)
836 		return 1;
837 
838 	if (ret < 0) {
839 		/*
840 		 * Re-read the data with the randomizer disabled to identify
841 		 * bitflips in erased pages.
842 		 */
843 		if (nand->options & NAND_NEED_SCRAMBLING)
844 			nand_change_read_column_op(nand, data_off, data,
845 						   ecc->size, false);
846 		else
847 			memcpy_fromio(data, nfc->regs + NFC_RAM0_BASE,
848 				      ecc->size);
849 
850 		nand_change_read_column_op(nand, oob_off, oob, ecc->bytes + 4,
851 					   false);
852 
853 		ret = nand_check_erased_ecc_chunk(data,	ecc->size,
854 						  oob, ecc->bytes + 4,
855 						  NULL, 0, ecc->strength);
856 		if (ret >= 0)
857 			raw_mode = 1;
858 	} else {
859 		memcpy_fromio(data, nfc->regs + NFC_RAM0_BASE, ecc->size);
860 
861 		if (oob_required) {
862 			nand_change_read_column_op(nand, oob_off, NULL, 0,
863 						   false);
864 			sunxi_nfc_randomizer_read_buf(nand, oob, ecc->bytes + 4,
865 						      true, page);
866 
867 			sunxi_nfc_hw_ecc_get_prot_oob_bytes(nand, oob, 0,
868 							    bbm, page);
869 		}
870 	}
871 
872 	sunxi_nfc_hw_ecc_update_stats(nand, max_bitflips, ret);
873 
874 	return raw_mode;
875 }
876 
877 static void sunxi_nfc_hw_ecc_read_extra_oob(struct nand_chip *nand,
878 					    u8 *oob, int *cur_off,
879 					    bool randomize, int page)
880 {
881 	struct mtd_info *mtd = nand_to_mtd(nand);
882 	struct nand_ecc_ctrl *ecc = &nand->ecc;
883 	int offset = ((ecc->bytes + 4) * ecc->steps);
884 	int len = mtd->oobsize - offset;
885 
886 	if (len <= 0)
887 		return;
888 
889 	if (!cur_off || *cur_off != offset)
890 		nand_change_read_column_op(nand, mtd->writesize, NULL, 0,
891 					   false);
892 
893 	if (!randomize)
894 		sunxi_nfc_read_buf(nand, oob + offset, len);
895 	else
896 		sunxi_nfc_randomizer_read_buf(nand, oob + offset, len,
897 					      false, page);
898 
899 	if (cur_off)
900 		*cur_off = mtd->oobsize + mtd->writesize;
901 }
902 
903 static int sunxi_nfc_hw_ecc_read_chunks_dma(struct nand_chip *nand, uint8_t *buf,
904 					    int oob_required, int page,
905 					    int nchunks)
906 {
907 	bool randomized = nand->options & NAND_NEED_SCRAMBLING;
908 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
909 	struct mtd_info *mtd = nand_to_mtd(nand);
910 	struct nand_ecc_ctrl *ecc = &nand->ecc;
911 	unsigned int max_bitflips = 0;
912 	int ret, i, raw_mode = 0;
913 	struct scatterlist sg;
914 	u32 status, wait;
915 
916 	ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
917 	if (ret)
918 		return ret;
919 
920 	ret = sunxi_nfc_dma_op_prepare(nfc, buf, ecc->size, nchunks,
921 				       DMA_FROM_DEVICE, &sg);
922 	if (ret)
923 		return ret;
924 
925 	sunxi_nfc_hw_ecc_enable(nand);
926 	sunxi_nfc_randomizer_config(nand, page, false);
927 	sunxi_nfc_randomizer_enable(nand);
928 
929 	writel((NAND_CMD_RNDOUTSTART << 16) | (NAND_CMD_RNDOUT << 8) |
930 	       NAND_CMD_READSTART, nfc->regs + NFC_REG_RCMD_SET);
931 
932 	wait = NFC_CMD_INT_FLAG;
933 
934 	if (nfc->caps->has_mdma)
935 		wait |= NFC_DMA_INT_FLAG;
936 	else
937 		dma_async_issue_pending(nfc->dmac);
938 
939 	writel(NFC_PAGE_OP | NFC_DATA_SWAP_METHOD | NFC_DATA_TRANS,
940 	       nfc->regs + NFC_REG_CMD);
941 
942 	ret = sunxi_nfc_wait_events(nfc, wait, false, 0);
943 	if (ret && !nfc->caps->has_mdma)
944 		dmaengine_terminate_all(nfc->dmac);
945 
946 	sunxi_nfc_randomizer_disable(nand);
947 	sunxi_nfc_hw_ecc_disable(nand);
948 
949 	sunxi_nfc_dma_op_cleanup(nfc, DMA_FROM_DEVICE, &sg);
950 
951 	if (ret)
952 		return ret;
953 
954 	status = readl(nfc->regs + NFC_REG_ECC_ST);
955 
956 	for (i = 0; i < nchunks; i++) {
957 		int data_off = i * ecc->size;
958 		int oob_off = i * (ecc->bytes + 4);
959 		u8 *data = buf + data_off;
960 		u8 *oob = nand->oob_poi + oob_off;
961 		bool erased;
962 
963 		ret = sunxi_nfc_hw_ecc_correct(nand, randomized ? data : NULL,
964 					       oob_required ? oob : NULL,
965 					       i, status, &erased);
966 
967 		/* ECC errors are handled in the second loop. */
968 		if (ret < 0)
969 			continue;
970 
971 		if (oob_required && !erased) {
972 			/* TODO: use DMA to retrieve OOB */
973 			nand_change_read_column_op(nand,
974 						   mtd->writesize + oob_off,
975 						   oob, ecc->bytes + 4, false);
976 
977 			sunxi_nfc_hw_ecc_get_prot_oob_bytes(nand, oob, i,
978 							    !i, page);
979 		}
980 
981 		if (erased)
982 			raw_mode = 1;
983 
984 		sunxi_nfc_hw_ecc_update_stats(nand, &max_bitflips, ret);
985 	}
986 
987 	if (status & NFC_ECC_ERR_MSK) {
988 		for (i = 0; i < nchunks; i++) {
989 			int data_off = i * ecc->size;
990 			int oob_off = i * (ecc->bytes + 4);
991 			u8 *data = buf + data_off;
992 			u8 *oob = nand->oob_poi + oob_off;
993 
994 			if (!(status & NFC_ECC_ERR(i)))
995 				continue;
996 
997 			/*
998 			 * Re-read the data with the randomizer disabled to
999 			 * identify bitflips in erased pages.
1000 			 * TODO: use DMA to read page in raw mode
1001 			 */
1002 			if (randomized)
1003 				nand_change_read_column_op(nand, data_off,
1004 							   data, ecc->size,
1005 							   false);
1006 
1007 			/* TODO: use DMA to retrieve OOB */
1008 			nand_change_read_column_op(nand,
1009 						   mtd->writesize + oob_off,
1010 						   oob, ecc->bytes + 4, false);
1011 
1012 			ret = nand_check_erased_ecc_chunk(data,	ecc->size,
1013 							  oob, ecc->bytes + 4,
1014 							  NULL, 0,
1015 							  ecc->strength);
1016 			if (ret >= 0)
1017 				raw_mode = 1;
1018 
1019 			sunxi_nfc_hw_ecc_update_stats(nand, &max_bitflips, ret);
1020 		}
1021 	}
1022 
1023 	if (oob_required)
1024 		sunxi_nfc_hw_ecc_read_extra_oob(nand, nand->oob_poi,
1025 						NULL, !raw_mode,
1026 						page);
1027 
1028 	return max_bitflips;
1029 }
1030 
1031 static int sunxi_nfc_hw_ecc_write_chunk(struct nand_chip *nand,
1032 					const u8 *data, int data_off,
1033 					const u8 *oob, int oob_off,
1034 					int *cur_off, bool bbm,
1035 					int page)
1036 {
1037 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
1038 	struct nand_ecc_ctrl *ecc = &nand->ecc;
1039 	int ret;
1040 
1041 	if (data_off != *cur_off)
1042 		nand_change_write_column_op(nand, data_off, NULL, 0, false);
1043 
1044 	sunxi_nfc_randomizer_write_buf(nand, data, ecc->size, false, page);
1045 
1046 	if (data_off + ecc->size != oob_off)
1047 		nand_change_write_column_op(nand, oob_off, NULL, 0, false);
1048 
1049 	ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
1050 	if (ret)
1051 		return ret;
1052 
1053 	sunxi_nfc_randomizer_enable(nand);
1054 	sunxi_nfc_hw_ecc_set_prot_oob_bytes(nand, oob, 0, bbm, page);
1055 
1056 	writel(NFC_DATA_TRANS | NFC_DATA_SWAP_METHOD |
1057 	       NFC_ACCESS_DIR | NFC_ECC_OP,
1058 	       nfc->regs + NFC_REG_CMD);
1059 
1060 	ret = sunxi_nfc_wait_events(nfc, NFC_CMD_INT_FLAG, false, 0);
1061 	sunxi_nfc_randomizer_disable(nand);
1062 	if (ret)
1063 		return ret;
1064 
1065 	*cur_off = oob_off + ecc->bytes + 4;
1066 
1067 	return 0;
1068 }
1069 
1070 static void sunxi_nfc_hw_ecc_write_extra_oob(struct nand_chip *nand,
1071 					     u8 *oob, int *cur_off,
1072 					     int page)
1073 {
1074 	struct mtd_info *mtd = nand_to_mtd(nand);
1075 	struct nand_ecc_ctrl *ecc = &nand->ecc;
1076 	int offset = ((ecc->bytes + 4) * ecc->steps);
1077 	int len = mtd->oobsize - offset;
1078 
1079 	if (len <= 0)
1080 		return;
1081 
1082 	if (!cur_off || *cur_off != offset)
1083 		nand_change_write_column_op(nand, offset + mtd->writesize,
1084 					    NULL, 0, false);
1085 
1086 	sunxi_nfc_randomizer_write_buf(nand, oob + offset, len, false, page);
1087 
1088 	if (cur_off)
1089 		*cur_off = mtd->oobsize + mtd->writesize;
1090 }
1091 
1092 static int sunxi_nfc_hw_ecc_read_page(struct nand_chip *nand, uint8_t *buf,
1093 				      int oob_required, int page)
1094 {
1095 	struct mtd_info *mtd = nand_to_mtd(nand);
1096 	struct nand_ecc_ctrl *ecc = &nand->ecc;
1097 	unsigned int max_bitflips = 0;
1098 	int ret, i, cur_off = 0;
1099 	bool raw_mode = false;
1100 
1101 	sunxi_nfc_select_chip(nand, nand->cur_cs);
1102 
1103 	nand_read_page_op(nand, page, 0, NULL, 0);
1104 
1105 	sunxi_nfc_hw_ecc_enable(nand);
1106 
1107 	for (i = 0; i < ecc->steps; i++) {
1108 		int data_off = i * ecc->size;
1109 		int oob_off = i * (ecc->bytes + 4);
1110 		u8 *data = buf + data_off;
1111 		u8 *oob = nand->oob_poi + oob_off;
1112 
1113 		ret = sunxi_nfc_hw_ecc_read_chunk(nand, data, data_off, oob,
1114 						  oob_off + mtd->writesize,
1115 						  &cur_off, &max_bitflips,
1116 						  !i, oob_required, page);
1117 		if (ret < 0)
1118 			return ret;
1119 		else if (ret)
1120 			raw_mode = true;
1121 	}
1122 
1123 	if (oob_required)
1124 		sunxi_nfc_hw_ecc_read_extra_oob(nand, nand->oob_poi, &cur_off,
1125 						!raw_mode, page);
1126 
1127 	sunxi_nfc_hw_ecc_disable(nand);
1128 
1129 	return max_bitflips;
1130 }
1131 
1132 static int sunxi_nfc_hw_ecc_read_page_dma(struct nand_chip *nand, u8 *buf,
1133 					  int oob_required, int page)
1134 {
1135 	int ret;
1136 
1137 	sunxi_nfc_select_chip(nand, nand->cur_cs);
1138 
1139 	nand_read_page_op(nand, page, 0, NULL, 0);
1140 
1141 	ret = sunxi_nfc_hw_ecc_read_chunks_dma(nand, buf, oob_required, page,
1142 					       nand->ecc.steps);
1143 	if (ret >= 0)
1144 		return ret;
1145 
1146 	/* Fallback to PIO mode */
1147 	return sunxi_nfc_hw_ecc_read_page(nand, buf, oob_required, page);
1148 }
1149 
1150 static int sunxi_nfc_hw_ecc_read_subpage(struct nand_chip *nand,
1151 					 u32 data_offs, u32 readlen,
1152 					 u8 *bufpoi, int page)
1153 {
1154 	struct mtd_info *mtd = nand_to_mtd(nand);
1155 	struct nand_ecc_ctrl *ecc = &nand->ecc;
1156 	int ret, i, cur_off = 0;
1157 	unsigned int max_bitflips = 0;
1158 
1159 	sunxi_nfc_select_chip(nand, nand->cur_cs);
1160 
1161 	nand_read_page_op(nand, page, 0, NULL, 0);
1162 
1163 	sunxi_nfc_hw_ecc_enable(nand);
1164 
1165 	for (i = data_offs / ecc->size;
1166 	     i < DIV_ROUND_UP(data_offs + readlen, ecc->size); i++) {
1167 		int data_off = i * ecc->size;
1168 		int oob_off = i * (ecc->bytes + 4);
1169 		u8 *data = bufpoi + data_off;
1170 		u8 *oob = nand->oob_poi + oob_off;
1171 
1172 		ret = sunxi_nfc_hw_ecc_read_chunk(nand, data, data_off,
1173 						  oob,
1174 						  oob_off + mtd->writesize,
1175 						  &cur_off, &max_bitflips, !i,
1176 						  false, page);
1177 		if (ret < 0)
1178 			return ret;
1179 	}
1180 
1181 	sunxi_nfc_hw_ecc_disable(nand);
1182 
1183 	return max_bitflips;
1184 }
1185 
1186 static int sunxi_nfc_hw_ecc_read_subpage_dma(struct nand_chip *nand,
1187 					     u32 data_offs, u32 readlen,
1188 					     u8 *buf, int page)
1189 {
1190 	int nchunks = DIV_ROUND_UP(data_offs + readlen, nand->ecc.size);
1191 	int ret;
1192 
1193 	sunxi_nfc_select_chip(nand, nand->cur_cs);
1194 
1195 	nand_read_page_op(nand, page, 0, NULL, 0);
1196 
1197 	ret = sunxi_nfc_hw_ecc_read_chunks_dma(nand, buf, false, page, nchunks);
1198 	if (ret >= 0)
1199 		return ret;
1200 
1201 	/* Fallback to PIO mode */
1202 	return sunxi_nfc_hw_ecc_read_subpage(nand, data_offs, readlen,
1203 					     buf, page);
1204 }
1205 
1206 static int sunxi_nfc_hw_ecc_write_page(struct nand_chip *nand,
1207 				       const uint8_t *buf, int oob_required,
1208 				       int page)
1209 {
1210 	struct mtd_info *mtd = nand_to_mtd(nand);
1211 	struct nand_ecc_ctrl *ecc = &nand->ecc;
1212 	int ret, i, cur_off = 0;
1213 
1214 	sunxi_nfc_select_chip(nand, nand->cur_cs);
1215 
1216 	nand_prog_page_begin_op(nand, page, 0, NULL, 0);
1217 
1218 	sunxi_nfc_hw_ecc_enable(nand);
1219 
1220 	for (i = 0; i < ecc->steps; i++) {
1221 		int data_off = i * ecc->size;
1222 		int oob_off = i * (ecc->bytes + 4);
1223 		const u8 *data = buf + data_off;
1224 		const u8 *oob = nand->oob_poi + oob_off;
1225 
1226 		ret = sunxi_nfc_hw_ecc_write_chunk(nand, data, data_off, oob,
1227 						   oob_off + mtd->writesize,
1228 						   &cur_off, !i, page);
1229 		if (ret)
1230 			return ret;
1231 	}
1232 
1233 	if (oob_required || (nand->options & NAND_NEED_SCRAMBLING))
1234 		sunxi_nfc_hw_ecc_write_extra_oob(nand, nand->oob_poi,
1235 						 &cur_off, page);
1236 
1237 	sunxi_nfc_hw_ecc_disable(nand);
1238 
1239 	return nand_prog_page_end_op(nand);
1240 }
1241 
1242 static int sunxi_nfc_hw_ecc_write_subpage(struct nand_chip *nand,
1243 					  u32 data_offs, u32 data_len,
1244 					  const u8 *buf, int oob_required,
1245 					  int page)
1246 {
1247 	struct mtd_info *mtd = nand_to_mtd(nand);
1248 	struct nand_ecc_ctrl *ecc = &nand->ecc;
1249 	int ret, i, cur_off = 0;
1250 
1251 	sunxi_nfc_select_chip(nand, nand->cur_cs);
1252 
1253 	nand_prog_page_begin_op(nand, page, 0, NULL, 0);
1254 
1255 	sunxi_nfc_hw_ecc_enable(nand);
1256 
1257 	for (i = data_offs / ecc->size;
1258 	     i < DIV_ROUND_UP(data_offs + data_len, ecc->size); i++) {
1259 		int data_off = i * ecc->size;
1260 		int oob_off = i * (ecc->bytes + 4);
1261 		const u8 *data = buf + data_off;
1262 		const u8 *oob = nand->oob_poi + oob_off;
1263 
1264 		ret = sunxi_nfc_hw_ecc_write_chunk(nand, data, data_off, oob,
1265 						   oob_off + mtd->writesize,
1266 						   &cur_off, !i, page);
1267 		if (ret)
1268 			return ret;
1269 	}
1270 
1271 	sunxi_nfc_hw_ecc_disable(nand);
1272 
1273 	return nand_prog_page_end_op(nand);
1274 }
1275 
1276 static int sunxi_nfc_hw_ecc_write_page_dma(struct nand_chip *nand,
1277 					   const u8 *buf,
1278 					   int oob_required,
1279 					   int page)
1280 {
1281 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
1282 	struct nand_ecc_ctrl *ecc = &nand->ecc;
1283 	struct scatterlist sg;
1284 	u32 wait;
1285 	int ret, i;
1286 
1287 	sunxi_nfc_select_chip(nand, nand->cur_cs);
1288 
1289 	ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
1290 	if (ret)
1291 		return ret;
1292 
1293 	ret = sunxi_nfc_dma_op_prepare(nfc, buf, ecc->size, ecc->steps,
1294 				       DMA_TO_DEVICE, &sg);
1295 	if (ret)
1296 		goto pio_fallback;
1297 
1298 	for (i = 0; i < ecc->steps; i++) {
1299 		const u8 *oob = nand->oob_poi + (i * (ecc->bytes + 4));
1300 
1301 		sunxi_nfc_hw_ecc_set_prot_oob_bytes(nand, oob, i, !i, page);
1302 	}
1303 
1304 	nand_prog_page_begin_op(nand, page, 0, NULL, 0);
1305 
1306 	sunxi_nfc_hw_ecc_enable(nand);
1307 	sunxi_nfc_randomizer_config(nand, page, false);
1308 	sunxi_nfc_randomizer_enable(nand);
1309 
1310 	writel((NAND_CMD_RNDIN << 8) | NAND_CMD_PAGEPROG,
1311 	       nfc->regs + NFC_REG_WCMD_SET);
1312 
1313 	wait = NFC_CMD_INT_FLAG;
1314 
1315 	if (nfc->caps->has_mdma)
1316 		wait |= NFC_DMA_INT_FLAG;
1317 	else
1318 		dma_async_issue_pending(nfc->dmac);
1319 
1320 	writel(NFC_PAGE_OP | NFC_DATA_SWAP_METHOD |
1321 	       NFC_DATA_TRANS | NFC_ACCESS_DIR,
1322 	       nfc->regs + NFC_REG_CMD);
1323 
1324 	ret = sunxi_nfc_wait_events(nfc, wait, false, 0);
1325 	if (ret && !nfc->caps->has_mdma)
1326 		dmaengine_terminate_all(nfc->dmac);
1327 
1328 	sunxi_nfc_randomizer_disable(nand);
1329 	sunxi_nfc_hw_ecc_disable(nand);
1330 
1331 	sunxi_nfc_dma_op_cleanup(nfc, DMA_TO_DEVICE, &sg);
1332 
1333 	if (ret)
1334 		return ret;
1335 
1336 	if (oob_required || (nand->options & NAND_NEED_SCRAMBLING))
1337 		/* TODO: use DMA to transfer extra OOB bytes ? */
1338 		sunxi_nfc_hw_ecc_write_extra_oob(nand, nand->oob_poi,
1339 						 NULL, page);
1340 
1341 	return nand_prog_page_end_op(nand);
1342 
1343 pio_fallback:
1344 	return sunxi_nfc_hw_ecc_write_page(nand, buf, oob_required, page);
1345 }
1346 
1347 static int sunxi_nfc_hw_ecc_read_oob(struct nand_chip *nand, int page)
1348 {
1349 	u8 *buf = nand_get_data_buf(nand);
1350 
1351 	return nand->ecc.read_page(nand, buf, 1, page);
1352 }
1353 
1354 static int sunxi_nfc_hw_ecc_write_oob(struct nand_chip *nand, int page)
1355 {
1356 	struct mtd_info *mtd = nand_to_mtd(nand);
1357 	u8 *buf = nand_get_data_buf(nand);
1358 	int ret;
1359 
1360 	memset(buf, 0xff, mtd->writesize);
1361 	ret = nand->ecc.write_page(nand, buf, 1, page);
1362 	if (ret)
1363 		return ret;
1364 
1365 	/* Send command to program the OOB data */
1366 	return nand_prog_page_end_op(nand);
1367 }
1368 
1369 static const s32 tWB_lut[] = {6, 12, 16, 20};
1370 static const s32 tRHW_lut[] = {4, 8, 12, 20};
1371 
1372 static int _sunxi_nand_lookup_timing(const s32 *lut, int lut_size, u32 duration,
1373 		u32 clk_period)
1374 {
1375 	u32 clk_cycles = DIV_ROUND_UP(duration, clk_period);
1376 	int i;
1377 
1378 	for (i = 0; i < lut_size; i++) {
1379 		if (clk_cycles <= lut[i])
1380 			return i;
1381 	}
1382 
1383 	/* Doesn't fit */
1384 	return -EINVAL;
1385 }
1386 
1387 #define sunxi_nand_lookup_timing(l, p, c) \
1388 			_sunxi_nand_lookup_timing(l, ARRAY_SIZE(l), p, c)
1389 
1390 static int sunxi_nfc_setup_interface(struct nand_chip *nand, int csline,
1391 				     const struct nand_interface_config *conf)
1392 {
1393 	struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
1394 	struct sunxi_nfc *nfc = to_sunxi_nfc(sunxi_nand->nand.controller);
1395 	const struct nand_sdr_timings *timings;
1396 	u32 min_clk_period = 0;
1397 	s32 tWB, tADL, tWHR, tRHW, tCAD;
1398 	long real_clk_rate;
1399 
1400 	timings = nand_get_sdr_timings(conf);
1401 	if (IS_ERR(timings))
1402 		return -ENOTSUPP;
1403 
1404 	/* T1 <=> tCLS */
1405 	if (timings->tCLS_min > min_clk_period)
1406 		min_clk_period = timings->tCLS_min;
1407 
1408 	/* T2 <=> tCLH */
1409 	if (timings->tCLH_min > min_clk_period)
1410 		min_clk_period = timings->tCLH_min;
1411 
1412 	/* T3 <=> tCS */
1413 	if (timings->tCS_min > min_clk_period)
1414 		min_clk_period = timings->tCS_min;
1415 
1416 	/* T4 <=> tCH */
1417 	if (timings->tCH_min > min_clk_period)
1418 		min_clk_period = timings->tCH_min;
1419 
1420 	/* T5 <=> tWP */
1421 	if (timings->tWP_min > min_clk_period)
1422 		min_clk_period = timings->tWP_min;
1423 
1424 	/* T6 <=> tWH */
1425 	if (timings->tWH_min > min_clk_period)
1426 		min_clk_period = timings->tWH_min;
1427 
1428 	/* T7 <=> tALS */
1429 	if (timings->tALS_min > min_clk_period)
1430 		min_clk_period = timings->tALS_min;
1431 
1432 	/* T8 <=> tDS */
1433 	if (timings->tDS_min > min_clk_period)
1434 		min_clk_period = timings->tDS_min;
1435 
1436 	/* T9 <=> tDH */
1437 	if (timings->tDH_min > min_clk_period)
1438 		min_clk_period = timings->tDH_min;
1439 
1440 	/* T10 <=> tRR */
1441 	if (timings->tRR_min > (min_clk_period * 3))
1442 		min_clk_period = DIV_ROUND_UP(timings->tRR_min, 3);
1443 
1444 	/* T11 <=> tALH */
1445 	if (timings->tALH_min > min_clk_period)
1446 		min_clk_period = timings->tALH_min;
1447 
1448 	/* T12 <=> tRP */
1449 	if (timings->tRP_min > min_clk_period)
1450 		min_clk_period = timings->tRP_min;
1451 
1452 	/* T13 <=> tREH */
1453 	if (timings->tREH_min > min_clk_period)
1454 		min_clk_period = timings->tREH_min;
1455 
1456 	/* T14 <=> tRC */
1457 	if (timings->tRC_min > (min_clk_period * 2))
1458 		min_clk_period = DIV_ROUND_UP(timings->tRC_min, 2);
1459 
1460 	/* T15 <=> tWC */
1461 	if (timings->tWC_min > (min_clk_period * 2))
1462 		min_clk_period = DIV_ROUND_UP(timings->tWC_min, 2);
1463 
1464 	/* T16 - T19 + tCAD */
1465 	if (timings->tWB_max > (min_clk_period * 20))
1466 		min_clk_period = DIV_ROUND_UP(timings->tWB_max, 20);
1467 
1468 	if (timings->tADL_min > (min_clk_period * 32))
1469 		min_clk_period = DIV_ROUND_UP(timings->tADL_min, 32);
1470 
1471 	if (timings->tWHR_min > (min_clk_period * 32))
1472 		min_clk_period = DIV_ROUND_UP(timings->tWHR_min, 32);
1473 
1474 	if (timings->tRHW_min > (min_clk_period * 20))
1475 		min_clk_period = DIV_ROUND_UP(timings->tRHW_min, 20);
1476 
1477 	/*
1478 	 * In non-EDO, tREA should be less than tRP to guarantee that the
1479 	 * controller does not sample the IO lines too early. Unfortunately,
1480 	 * the sunxi NAND controller does not allow us to have different
1481 	 * values for tRP and tREH (tRP = tREH = tRW / 2).
1482 	 *
1483 	 * We have 2 options to overcome this limitation:
1484 	 *
1485 	 * 1/ Extend tRC to fulfil the tREA <= tRC / 2 constraint
1486 	 * 2/ Use EDO mode (only works if timings->tRLOH > 0)
1487 	 */
1488 	if (timings->tREA_max > min_clk_period && !timings->tRLOH_min)
1489 		min_clk_period = timings->tREA_max;
1490 
1491 	tWB  = sunxi_nand_lookup_timing(tWB_lut, timings->tWB_max,
1492 					min_clk_period);
1493 	if (tWB < 0) {
1494 		dev_err(nfc->dev, "unsupported tWB\n");
1495 		return tWB;
1496 	}
1497 
1498 	tADL = DIV_ROUND_UP(timings->tADL_min, min_clk_period) >> 3;
1499 	if (tADL > 3) {
1500 		dev_err(nfc->dev, "unsupported tADL\n");
1501 		return -EINVAL;
1502 	}
1503 
1504 	tWHR = DIV_ROUND_UP(timings->tWHR_min, min_clk_period) >> 3;
1505 	if (tWHR > 3) {
1506 		dev_err(nfc->dev, "unsupported tWHR\n");
1507 		return -EINVAL;
1508 	}
1509 
1510 	tRHW = sunxi_nand_lookup_timing(tRHW_lut, timings->tRHW_min,
1511 					min_clk_period);
1512 	if (tRHW < 0) {
1513 		dev_err(nfc->dev, "unsupported tRHW\n");
1514 		return tRHW;
1515 	}
1516 
1517 	if (csline == NAND_DATA_IFACE_CHECK_ONLY)
1518 		return 0;
1519 
1520 	/*
1521 	 * TODO: according to ONFI specs this value only applies for DDR NAND,
1522 	 * but Allwinner seems to set this to 0x7. Mimic them for now.
1523 	 */
1524 	tCAD = 0x7;
1525 
1526 	/* TODO: A83 has some more bits for CDQSS, CS, CLHZ, CCS, WC */
1527 	sunxi_nand->timing_cfg = NFC_TIMING_CFG(tWB, tADL, tWHR, tRHW, tCAD);
1528 
1529 	/* Convert min_clk_period from picoseconds to nanoseconds */
1530 	min_clk_period = DIV_ROUND_UP(min_clk_period, 1000);
1531 
1532 	/*
1533 	 * Unlike what is stated in Allwinner datasheet, the clk_rate should
1534 	 * be set to (1 / min_clk_period), and not (2 / min_clk_period).
1535 	 * This new formula was verified with a scope and validated by
1536 	 * Allwinner engineers.
1537 	 */
1538 	sunxi_nand->clk_rate = NSEC_PER_SEC / min_clk_period;
1539 	real_clk_rate = clk_round_rate(nfc->mod_clk, sunxi_nand->clk_rate);
1540 	if (real_clk_rate <= 0) {
1541 		dev_err(nfc->dev, "Unable to round clk %lu\n",
1542 			sunxi_nand->clk_rate);
1543 		return -EINVAL;
1544 	}
1545 
1546 	sunxi_nand->timing_ctl = 0;
1547 
1548 	/*
1549 	 * ONFI specification 3.1, paragraph 4.15.2 dictates that EDO data
1550 	 * output cycle timings shall be used if the host drives tRC less than
1551 	 * 30 ns. We should also use EDO mode if tREA is bigger than tRP.
1552 	 */
1553 	min_clk_period = NSEC_PER_SEC / real_clk_rate;
1554 	if (min_clk_period * 2 < 30 || min_clk_period * 1000 < timings->tREA_max)
1555 		sunxi_nand->timing_ctl = NFC_TIMING_CTL_EDO;
1556 
1557 	return 0;
1558 }
1559 
1560 static int sunxi_nand_ooblayout_ecc(struct mtd_info *mtd, int section,
1561 				    struct mtd_oob_region *oobregion)
1562 {
1563 	struct nand_chip *nand = mtd_to_nand(mtd);
1564 	struct nand_ecc_ctrl *ecc = &nand->ecc;
1565 
1566 	if (section >= ecc->steps)
1567 		return -ERANGE;
1568 
1569 	oobregion->offset = section * (ecc->bytes + 4) + 4;
1570 	oobregion->length = ecc->bytes;
1571 
1572 	return 0;
1573 }
1574 
1575 static int sunxi_nand_ooblayout_free(struct mtd_info *mtd, int section,
1576 				     struct mtd_oob_region *oobregion)
1577 {
1578 	struct nand_chip *nand = mtd_to_nand(mtd);
1579 	struct nand_ecc_ctrl *ecc = &nand->ecc;
1580 
1581 	if (section > ecc->steps)
1582 		return -ERANGE;
1583 
1584 	/*
1585 	 * The first 2 bytes are used for BB markers, hence we
1586 	 * only have 2 bytes available in the first user data
1587 	 * section.
1588 	 */
1589 	if (!section && ecc->engine_type == NAND_ECC_ENGINE_TYPE_ON_HOST) {
1590 		oobregion->offset = 2;
1591 		oobregion->length = 2;
1592 
1593 		return 0;
1594 	}
1595 
1596 	/*
1597 	 * The controller does not provide access to OOB bytes
1598 	 * past the end of the ECC data.
1599 	 */
1600 	if (section == ecc->steps && ecc->engine_type == NAND_ECC_ENGINE_TYPE_ON_HOST)
1601 		return -ERANGE;
1602 
1603 	oobregion->offset = section * (ecc->bytes + 4);
1604 
1605 	if (section < ecc->steps)
1606 		oobregion->length = 4;
1607 	else
1608 		oobregion->length = mtd->oobsize - oobregion->offset;
1609 
1610 	return 0;
1611 }
1612 
1613 static const struct mtd_ooblayout_ops sunxi_nand_ooblayout_ops = {
1614 	.ecc = sunxi_nand_ooblayout_ecc,
1615 	.free = sunxi_nand_ooblayout_free,
1616 };
1617 
1618 static int sunxi_nand_hw_ecc_ctrl_init(struct nand_chip *nand,
1619 				       struct nand_ecc_ctrl *ecc,
1620 				       struct device_node *np)
1621 {
1622 	static const u8 strengths[] = { 16, 24, 28, 32, 40, 48, 56, 60, 64 };
1623 	struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
1624 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
1625 	struct mtd_info *mtd = nand_to_mtd(nand);
1626 	struct nand_device *nanddev = mtd_to_nanddev(mtd);
1627 	int nsectors;
1628 	int i;
1629 
1630 	if (nanddev->ecc.user_conf.flags & NAND_ECC_MAXIMIZE_STRENGTH) {
1631 		int bytes;
1632 
1633 		ecc->size = 1024;
1634 		nsectors = mtd->writesize / ecc->size;
1635 
1636 		/* Reserve 2 bytes for the BBM */
1637 		bytes = (mtd->oobsize - 2) / nsectors;
1638 
1639 		/* 4 non-ECC bytes are added before each ECC bytes section */
1640 		bytes -= 4;
1641 
1642 		/* and bytes has to be even. */
1643 		if (bytes % 2)
1644 			bytes--;
1645 
1646 		ecc->strength = bytes * 8 / fls(8 * ecc->size);
1647 
1648 		for (i = 0; i < ARRAY_SIZE(strengths); i++) {
1649 			if (strengths[i] > ecc->strength)
1650 				break;
1651 		}
1652 
1653 		if (!i)
1654 			ecc->strength = 0;
1655 		else
1656 			ecc->strength = strengths[i - 1];
1657 	}
1658 
1659 	if (ecc->size != 512 && ecc->size != 1024)
1660 		return -EINVAL;
1661 
1662 	/* Prefer 1k ECC chunk over 512 ones */
1663 	if (ecc->size == 512 && mtd->writesize > 512) {
1664 		ecc->size = 1024;
1665 		ecc->strength *= 2;
1666 	}
1667 
1668 	/* Add ECC info retrieval from DT */
1669 	for (i = 0; i < ARRAY_SIZE(strengths); i++) {
1670 		if (ecc->strength <= strengths[i]) {
1671 			/*
1672 			 * Update ecc->strength value with the actual strength
1673 			 * that will be used by the ECC engine.
1674 			 */
1675 			ecc->strength = strengths[i];
1676 			break;
1677 		}
1678 	}
1679 
1680 	if (i >= ARRAY_SIZE(strengths)) {
1681 		dev_err(nfc->dev, "unsupported strength\n");
1682 		return -ENOTSUPP;
1683 	}
1684 
1685 	/* HW ECC always request ECC bytes for 1024 bytes blocks */
1686 	ecc->bytes = DIV_ROUND_UP(ecc->strength * fls(8 * 1024), 8);
1687 
1688 	/* HW ECC always work with even numbers of ECC bytes */
1689 	ecc->bytes = ALIGN(ecc->bytes, 2);
1690 
1691 	nsectors = mtd->writesize / ecc->size;
1692 
1693 	if (mtd->oobsize < ((ecc->bytes + 4) * nsectors))
1694 		return -EINVAL;
1695 
1696 	ecc->read_oob = sunxi_nfc_hw_ecc_read_oob;
1697 	ecc->write_oob = sunxi_nfc_hw_ecc_write_oob;
1698 	mtd_set_ooblayout(mtd, &sunxi_nand_ooblayout_ops);
1699 
1700 	if (nfc->dmac || nfc->caps->has_mdma) {
1701 		ecc->read_page = sunxi_nfc_hw_ecc_read_page_dma;
1702 		ecc->read_subpage = sunxi_nfc_hw_ecc_read_subpage_dma;
1703 		ecc->write_page = sunxi_nfc_hw_ecc_write_page_dma;
1704 		nand->options |= NAND_USES_DMA;
1705 	} else {
1706 		ecc->read_page = sunxi_nfc_hw_ecc_read_page;
1707 		ecc->read_subpage = sunxi_nfc_hw_ecc_read_subpage;
1708 		ecc->write_page = sunxi_nfc_hw_ecc_write_page;
1709 	}
1710 
1711 	/* TODO: support DMA for raw accesses and subpage write */
1712 	ecc->write_subpage = sunxi_nfc_hw_ecc_write_subpage;
1713 	ecc->read_oob_raw = nand_read_oob_std;
1714 	ecc->write_oob_raw = nand_write_oob_std;
1715 
1716 	sunxi_nand->ecc.ecc_ctl = NFC_ECC_MODE(i) | NFC_ECC_EXCEPTION |
1717 				  NFC_ECC_PIPELINE | NFC_ECC_EN;
1718 
1719 	if (ecc->size == 512)
1720 		sunxi_nand->ecc.ecc_ctl |= NFC_ECC_BLOCK_512;
1721 
1722 	return 0;
1723 }
1724 
1725 static int sunxi_nand_attach_chip(struct nand_chip *nand)
1726 {
1727 	const struct nand_ecc_props *requirements =
1728 		nanddev_get_ecc_requirements(&nand->base);
1729 	struct nand_ecc_ctrl *ecc = &nand->ecc;
1730 	struct device_node *np = nand_get_flash_node(nand);
1731 	int ret;
1732 
1733 	if (nand->bbt_options & NAND_BBT_USE_FLASH)
1734 		nand->bbt_options |= NAND_BBT_NO_OOB;
1735 
1736 	if (nand->options & NAND_NEED_SCRAMBLING)
1737 		nand->options |= NAND_NO_SUBPAGE_WRITE;
1738 
1739 	nand->options |= NAND_SUBPAGE_READ;
1740 
1741 	if (!ecc->size) {
1742 		ecc->size = requirements->step_size;
1743 		ecc->strength = requirements->strength;
1744 	}
1745 
1746 	if (!ecc->size || !ecc->strength)
1747 		return -EINVAL;
1748 
1749 	switch (ecc->engine_type) {
1750 	case NAND_ECC_ENGINE_TYPE_ON_HOST:
1751 		ret = sunxi_nand_hw_ecc_ctrl_init(nand, ecc, np);
1752 		if (ret)
1753 			return ret;
1754 		break;
1755 	case NAND_ECC_ENGINE_TYPE_NONE:
1756 	case NAND_ECC_ENGINE_TYPE_SOFT:
1757 		break;
1758 	default:
1759 		return -EINVAL;
1760 	}
1761 
1762 	return 0;
1763 }
1764 
1765 static int sunxi_nfc_exec_subop(struct nand_chip *nand,
1766 				const struct nand_subop *subop)
1767 {
1768 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
1769 	u32 cmd = 0, extcmd = 0, cnt = 0, addrs[2] = { };
1770 	unsigned int i, j, remaining, start;
1771 	void *inbuf = NULL;
1772 	int ret;
1773 
1774 	for (i = 0; i < subop->ninstrs; i++) {
1775 		const struct nand_op_instr *instr = &subop->instrs[i];
1776 
1777 		switch (instr->type) {
1778 		case NAND_OP_CMD_INSTR:
1779 			if (cmd & NFC_SEND_CMD1) {
1780 				if (WARN_ON(cmd & NFC_SEND_CMD2))
1781 					return -EINVAL;
1782 
1783 				cmd |= NFC_SEND_CMD2;
1784 				extcmd |= instr->ctx.cmd.opcode;
1785 			} else {
1786 				cmd |= NFC_SEND_CMD1 |
1787 				       NFC_CMD(instr->ctx.cmd.opcode);
1788 			}
1789 			break;
1790 
1791 		case NAND_OP_ADDR_INSTR:
1792 			remaining = nand_subop_get_num_addr_cyc(subop, i);
1793 			start = nand_subop_get_addr_start_off(subop, i);
1794 			for (j = 0; j < 8 && j + start < remaining; j++) {
1795 				u32 addr = instr->ctx.addr.addrs[j + start];
1796 
1797 				addrs[j / 4] |= addr << (j % 4) * 8;
1798 			}
1799 
1800 			if (j)
1801 				cmd |= NFC_SEND_ADR | NFC_ADR_NUM(j);
1802 
1803 			break;
1804 
1805 		case NAND_OP_DATA_IN_INSTR:
1806 		case NAND_OP_DATA_OUT_INSTR:
1807 			start = nand_subop_get_data_start_off(subop, i);
1808 			remaining = nand_subop_get_data_len(subop, i);
1809 			cnt = min_t(u32, remaining, NFC_SRAM_SIZE);
1810 			cmd |= NFC_DATA_TRANS | NFC_DATA_SWAP_METHOD;
1811 
1812 			if (instr->type == NAND_OP_DATA_OUT_INSTR) {
1813 				cmd |= NFC_ACCESS_DIR;
1814 				memcpy_toio(nfc->regs + NFC_RAM0_BASE,
1815 					    instr->ctx.data.buf.out + start,
1816 					    cnt);
1817 			} else {
1818 				inbuf = instr->ctx.data.buf.in + start;
1819 			}
1820 
1821 			break;
1822 
1823 		case NAND_OP_WAITRDY_INSTR:
1824 			cmd |= NFC_WAIT_FLAG;
1825 			break;
1826 		}
1827 	}
1828 
1829 	ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
1830 	if (ret)
1831 		return ret;
1832 
1833 	if (cmd & NFC_SEND_ADR) {
1834 		writel(addrs[0], nfc->regs + NFC_REG_ADDR_LOW);
1835 		writel(addrs[1], nfc->regs + NFC_REG_ADDR_HIGH);
1836 	}
1837 
1838 	if (cmd & NFC_SEND_CMD2)
1839 		writel(extcmd,
1840 		       nfc->regs +
1841 		       (cmd & NFC_ACCESS_DIR ?
1842 			NFC_REG_WCMD_SET : NFC_REG_RCMD_SET));
1843 
1844 	if (cmd & NFC_DATA_TRANS)
1845 		writel(cnt, nfc->regs + NFC_REG_CNT);
1846 
1847 	writel(cmd, nfc->regs + NFC_REG_CMD);
1848 
1849 	ret = sunxi_nfc_wait_events(nfc, NFC_CMD_INT_FLAG,
1850 				    !(cmd & NFC_WAIT_FLAG) && cnt < 64,
1851 				    0);
1852 	if (ret)
1853 		return ret;
1854 
1855 	if (inbuf)
1856 		memcpy_fromio(inbuf, nfc->regs + NFC_RAM0_BASE, cnt);
1857 
1858 	return 0;
1859 }
1860 
1861 static int sunxi_nfc_soft_waitrdy(struct nand_chip *nand,
1862 				  const struct nand_subop *subop)
1863 {
1864 	return nand_soft_waitrdy(nand,
1865 				 subop->instrs[0].ctx.waitrdy.timeout_ms);
1866 }
1867 
1868 static const struct nand_op_parser sunxi_nfc_op_parser = NAND_OP_PARSER(
1869 	NAND_OP_PARSER_PATTERN(sunxi_nfc_exec_subop,
1870 			       NAND_OP_PARSER_PAT_CMD_ELEM(true),
1871 			       NAND_OP_PARSER_PAT_ADDR_ELEM(true, 8),
1872 			       NAND_OP_PARSER_PAT_CMD_ELEM(true),
1873 			       NAND_OP_PARSER_PAT_WAITRDY_ELEM(true),
1874 			       NAND_OP_PARSER_PAT_DATA_IN_ELEM(true, 1024)),
1875 	NAND_OP_PARSER_PATTERN(sunxi_nfc_exec_subop,
1876 			       NAND_OP_PARSER_PAT_CMD_ELEM(true),
1877 			       NAND_OP_PARSER_PAT_ADDR_ELEM(true, 8),
1878 			       NAND_OP_PARSER_PAT_DATA_OUT_ELEM(true, 1024),
1879 			       NAND_OP_PARSER_PAT_CMD_ELEM(true),
1880 			       NAND_OP_PARSER_PAT_WAITRDY_ELEM(true)),
1881 );
1882 
1883 static const struct nand_op_parser sunxi_nfc_norb_op_parser = NAND_OP_PARSER(
1884 	NAND_OP_PARSER_PATTERN(sunxi_nfc_exec_subop,
1885 			       NAND_OP_PARSER_PAT_CMD_ELEM(true),
1886 			       NAND_OP_PARSER_PAT_ADDR_ELEM(true, 8),
1887 			       NAND_OP_PARSER_PAT_CMD_ELEM(true),
1888 			       NAND_OP_PARSER_PAT_DATA_IN_ELEM(true, 1024)),
1889 	NAND_OP_PARSER_PATTERN(sunxi_nfc_exec_subop,
1890 			       NAND_OP_PARSER_PAT_CMD_ELEM(true),
1891 			       NAND_OP_PARSER_PAT_ADDR_ELEM(true, 8),
1892 			       NAND_OP_PARSER_PAT_DATA_OUT_ELEM(true, 1024),
1893 			       NAND_OP_PARSER_PAT_CMD_ELEM(true)),
1894 	NAND_OP_PARSER_PATTERN(sunxi_nfc_soft_waitrdy,
1895 			       NAND_OP_PARSER_PAT_WAITRDY_ELEM(false)),
1896 );
1897 
1898 static int sunxi_nfc_exec_op(struct nand_chip *nand,
1899 			     const struct nand_operation *op, bool check_only)
1900 {
1901 	struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
1902 	const struct nand_op_parser *parser;
1903 
1904 	if (!check_only)
1905 		sunxi_nfc_select_chip(nand, op->cs);
1906 
1907 	if (sunxi_nand->sels[op->cs].rb >= 0)
1908 		parser = &sunxi_nfc_op_parser;
1909 	else
1910 		parser = &sunxi_nfc_norb_op_parser;
1911 
1912 	return nand_op_parser_exec_op(nand, parser, op, check_only);
1913 }
1914 
1915 static const struct nand_controller_ops sunxi_nand_controller_ops = {
1916 	.attach_chip = sunxi_nand_attach_chip,
1917 	.setup_interface = sunxi_nfc_setup_interface,
1918 	.exec_op = sunxi_nfc_exec_op,
1919 };
1920 
1921 static void sunxi_nand_chips_cleanup(struct sunxi_nfc *nfc)
1922 {
1923 	struct sunxi_nand_chip *sunxi_nand;
1924 	struct nand_chip *chip;
1925 	int ret;
1926 
1927 	while (!list_empty(&nfc->chips)) {
1928 		sunxi_nand = list_first_entry(&nfc->chips,
1929 					      struct sunxi_nand_chip,
1930 					      node);
1931 		chip = &sunxi_nand->nand;
1932 		ret = mtd_device_unregister(nand_to_mtd(chip));
1933 		WARN_ON(ret);
1934 		nand_cleanup(chip);
1935 		list_del(&sunxi_nand->node);
1936 	}
1937 }
1938 
1939 static int sunxi_nand_chip_init(struct device *dev, struct sunxi_nfc *nfc,
1940 				struct device_node *np)
1941 {
1942 	struct sunxi_nand_chip *sunxi_nand;
1943 	struct mtd_info *mtd;
1944 	struct nand_chip *nand;
1945 	int nsels;
1946 	int ret;
1947 	int i;
1948 	u32 tmp;
1949 
1950 	if (!of_get_property(np, "reg", &nsels))
1951 		return -EINVAL;
1952 
1953 	nsels /= sizeof(u32);
1954 	if (!nsels) {
1955 		dev_err(dev, "invalid reg property size\n");
1956 		return -EINVAL;
1957 	}
1958 
1959 	sunxi_nand = devm_kzalloc(dev, struct_size(sunxi_nand, sels, nsels),
1960 				  GFP_KERNEL);
1961 	if (!sunxi_nand)
1962 		return -ENOMEM;
1963 
1964 	sunxi_nand->nsels = nsels;
1965 
1966 	for (i = 0; i < nsels; i++) {
1967 		ret = of_property_read_u32_index(np, "reg", i, &tmp);
1968 		if (ret) {
1969 			dev_err(dev, "could not retrieve reg property: %d\n",
1970 				ret);
1971 			return ret;
1972 		}
1973 
1974 		if (tmp > NFC_MAX_CS) {
1975 			dev_err(dev,
1976 				"invalid reg value: %u (max CS = 7)\n",
1977 				tmp);
1978 			return -EINVAL;
1979 		}
1980 
1981 		if (test_and_set_bit(tmp, &nfc->assigned_cs)) {
1982 			dev_err(dev, "CS %d already assigned\n", tmp);
1983 			return -EINVAL;
1984 		}
1985 
1986 		sunxi_nand->sels[i].cs = tmp;
1987 
1988 		if (!of_property_read_u32_index(np, "allwinner,rb", i, &tmp) &&
1989 		    tmp < 2)
1990 			sunxi_nand->sels[i].rb = tmp;
1991 		else
1992 			sunxi_nand->sels[i].rb = -1;
1993 	}
1994 
1995 	nand = &sunxi_nand->nand;
1996 	/* Default tR value specified in the ONFI spec (chapter 4.15.1) */
1997 	nand->controller = &nfc->controller;
1998 	nand->controller->ops = &sunxi_nand_controller_ops;
1999 
2000 	/*
2001 	 * Set the ECC mode to the default value in case nothing is specified
2002 	 * in the DT.
2003 	 */
2004 	nand->ecc.engine_type = NAND_ECC_ENGINE_TYPE_ON_HOST;
2005 	nand_set_flash_node(nand, np);
2006 
2007 	mtd = nand_to_mtd(nand);
2008 	mtd->dev.parent = dev;
2009 
2010 	ret = nand_scan(nand, nsels);
2011 	if (ret)
2012 		return ret;
2013 
2014 	ret = mtd_device_register(mtd, NULL, 0);
2015 	if (ret) {
2016 		dev_err(dev, "failed to register mtd device: %d\n", ret);
2017 		nand_cleanup(nand);
2018 		return ret;
2019 	}
2020 
2021 	list_add_tail(&sunxi_nand->node, &nfc->chips);
2022 
2023 	return 0;
2024 }
2025 
2026 static int sunxi_nand_chips_init(struct device *dev, struct sunxi_nfc *nfc)
2027 {
2028 	struct device_node *np = dev->of_node;
2029 	struct device_node *nand_np;
2030 	int ret;
2031 
2032 	for_each_child_of_node(np, nand_np) {
2033 		ret = sunxi_nand_chip_init(dev, nfc, nand_np);
2034 		if (ret) {
2035 			of_node_put(nand_np);
2036 			sunxi_nand_chips_cleanup(nfc);
2037 			return ret;
2038 		}
2039 	}
2040 
2041 	return 0;
2042 }
2043 
2044 static int sunxi_nfc_dma_init(struct sunxi_nfc *nfc, struct resource *r)
2045 {
2046 	int ret;
2047 
2048 	if (nfc->caps->has_mdma)
2049 		return 0;
2050 
2051 	nfc->dmac = dma_request_chan(nfc->dev, "rxtx");
2052 	if (IS_ERR(nfc->dmac)) {
2053 		ret = PTR_ERR(nfc->dmac);
2054 		if (ret == -EPROBE_DEFER)
2055 			return ret;
2056 
2057 		/* Ignore errors to fall back to PIO mode */
2058 		dev_warn(nfc->dev, "failed to request rxtx DMA channel: %d\n", ret);
2059 		nfc->dmac = NULL;
2060 	} else {
2061 		struct dma_slave_config dmac_cfg = { };
2062 
2063 		dmac_cfg.src_addr = r->start + nfc->caps->reg_io_data;
2064 		dmac_cfg.dst_addr = dmac_cfg.src_addr;
2065 		dmac_cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
2066 		dmac_cfg.dst_addr_width = dmac_cfg.src_addr_width;
2067 		dmac_cfg.src_maxburst = nfc->caps->dma_maxburst;
2068 		dmac_cfg.dst_maxburst = nfc->caps->dma_maxburst;
2069 		dmaengine_slave_config(nfc->dmac, &dmac_cfg);
2070 	}
2071 	return 0;
2072 }
2073 
2074 static int sunxi_nfc_probe(struct platform_device *pdev)
2075 {
2076 	struct device *dev = &pdev->dev;
2077 	struct resource *r;
2078 	struct sunxi_nfc *nfc;
2079 	int irq;
2080 	int ret;
2081 
2082 	nfc = devm_kzalloc(dev, sizeof(*nfc), GFP_KERNEL);
2083 	if (!nfc)
2084 		return -ENOMEM;
2085 
2086 	nfc->dev = dev;
2087 	nand_controller_init(&nfc->controller);
2088 	INIT_LIST_HEAD(&nfc->chips);
2089 
2090 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
2091 	nfc->regs = devm_ioremap_resource(dev, r);
2092 	if (IS_ERR(nfc->regs))
2093 		return PTR_ERR(nfc->regs);
2094 
2095 	irq = platform_get_irq(pdev, 0);
2096 	if (irq < 0)
2097 		return irq;
2098 
2099 	nfc->ahb_clk = devm_clk_get(dev, "ahb");
2100 	if (IS_ERR(nfc->ahb_clk)) {
2101 		dev_err(dev, "failed to retrieve ahb clk\n");
2102 		return PTR_ERR(nfc->ahb_clk);
2103 	}
2104 
2105 	ret = clk_prepare_enable(nfc->ahb_clk);
2106 	if (ret)
2107 		return ret;
2108 
2109 	nfc->mod_clk = devm_clk_get(dev, "mod");
2110 	if (IS_ERR(nfc->mod_clk)) {
2111 		dev_err(dev, "failed to retrieve mod clk\n");
2112 		ret = PTR_ERR(nfc->mod_clk);
2113 		goto out_ahb_clk_unprepare;
2114 	}
2115 
2116 	ret = clk_prepare_enable(nfc->mod_clk);
2117 	if (ret)
2118 		goto out_ahb_clk_unprepare;
2119 
2120 	nfc->reset = devm_reset_control_get_optional_exclusive(dev, "ahb");
2121 	if (IS_ERR(nfc->reset)) {
2122 		ret = PTR_ERR(nfc->reset);
2123 		goto out_mod_clk_unprepare;
2124 	}
2125 
2126 	ret = reset_control_deassert(nfc->reset);
2127 	if (ret) {
2128 		dev_err(dev, "reset err %d\n", ret);
2129 		goto out_mod_clk_unprepare;
2130 	}
2131 
2132 	nfc->caps = of_device_get_match_data(&pdev->dev);
2133 	if (!nfc->caps) {
2134 		ret = -EINVAL;
2135 		goto out_ahb_reset_reassert;
2136 	}
2137 
2138 	ret = sunxi_nfc_rst(nfc);
2139 	if (ret)
2140 		goto out_ahb_reset_reassert;
2141 
2142 	writel(0, nfc->regs + NFC_REG_INT);
2143 	ret = devm_request_irq(dev, irq, sunxi_nfc_interrupt,
2144 			       0, "sunxi-nand", nfc);
2145 	if (ret)
2146 		goto out_ahb_reset_reassert;
2147 
2148 	ret = sunxi_nfc_dma_init(nfc, r);
2149 
2150 	if (ret)
2151 		goto out_ahb_reset_reassert;
2152 
2153 	platform_set_drvdata(pdev, nfc);
2154 
2155 	ret = sunxi_nand_chips_init(dev, nfc);
2156 	if (ret) {
2157 		dev_err(dev, "failed to init nand chips\n");
2158 		goto out_release_dmac;
2159 	}
2160 
2161 	return 0;
2162 
2163 out_release_dmac:
2164 	if (nfc->dmac)
2165 		dma_release_channel(nfc->dmac);
2166 out_ahb_reset_reassert:
2167 	reset_control_assert(nfc->reset);
2168 out_mod_clk_unprepare:
2169 	clk_disable_unprepare(nfc->mod_clk);
2170 out_ahb_clk_unprepare:
2171 	clk_disable_unprepare(nfc->ahb_clk);
2172 
2173 	return ret;
2174 }
2175 
2176 static int sunxi_nfc_remove(struct platform_device *pdev)
2177 {
2178 	struct sunxi_nfc *nfc = platform_get_drvdata(pdev);
2179 
2180 	sunxi_nand_chips_cleanup(nfc);
2181 
2182 	reset_control_assert(nfc->reset);
2183 
2184 	if (nfc->dmac)
2185 		dma_release_channel(nfc->dmac);
2186 	clk_disable_unprepare(nfc->mod_clk);
2187 	clk_disable_unprepare(nfc->ahb_clk);
2188 
2189 	return 0;
2190 }
2191 
2192 static const struct sunxi_nfc_caps sunxi_nfc_a10_caps = {
2193 	.reg_io_data = NFC_REG_A10_IO_DATA,
2194 	.dma_maxburst = 4,
2195 };
2196 
2197 static const struct sunxi_nfc_caps sunxi_nfc_a23_caps = {
2198 	.has_mdma = true,
2199 	.reg_io_data = NFC_REG_A23_IO_DATA,
2200 	.dma_maxburst = 8,
2201 };
2202 
2203 static const struct of_device_id sunxi_nfc_ids[] = {
2204 	{
2205 		.compatible = "allwinner,sun4i-a10-nand",
2206 		.data = &sunxi_nfc_a10_caps,
2207 	},
2208 	{
2209 		.compatible = "allwinner,sun8i-a23-nand-controller",
2210 		.data = &sunxi_nfc_a23_caps,
2211 	},
2212 	{ /* sentinel */ }
2213 };
2214 MODULE_DEVICE_TABLE(of, sunxi_nfc_ids);
2215 
2216 static struct platform_driver sunxi_nfc_driver = {
2217 	.driver = {
2218 		.name = "sunxi_nand",
2219 		.of_match_table = sunxi_nfc_ids,
2220 	},
2221 	.probe = sunxi_nfc_probe,
2222 	.remove = sunxi_nfc_remove,
2223 };
2224 module_platform_driver(sunxi_nfc_driver);
2225 
2226 MODULE_LICENSE("GPL");
2227 MODULE_AUTHOR("Boris BREZILLON");
2228 MODULE_DESCRIPTION("Allwinner NAND Flash Controller driver");
2229 MODULE_ALIAS("platform:sunxi_nand");
2230