xref: /linux/drivers/mtd/nand/raw/sunxi_nand.c (revision 9a6b55ac)
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_CNT	0x00C4
55 #define NFC_RAM0_BASE		0x0400
56 #define NFC_RAM1_BASE		0x0800
57 
58 /* define bit use in NFC_CTL */
59 #define NFC_EN			BIT(0)
60 #define NFC_RESET		BIT(1)
61 #define NFC_BUS_WIDTH_MSK	BIT(2)
62 #define NFC_BUS_WIDTH_8		(0 << 2)
63 #define NFC_BUS_WIDTH_16	(1 << 2)
64 #define NFC_RB_SEL_MSK		BIT(3)
65 #define NFC_RB_SEL(x)		((x) << 3)
66 #define NFC_CE_SEL_MSK		GENMASK(26, 24)
67 #define NFC_CE_SEL(x)		((x) << 24)
68 #define NFC_CE_CTL		BIT(6)
69 #define NFC_PAGE_SHIFT_MSK	GENMASK(11, 8)
70 #define NFC_PAGE_SHIFT(x)	(((x) < 10 ? 0 : (x) - 10) << 8)
71 #define NFC_SAM			BIT(12)
72 #define NFC_RAM_METHOD		BIT(14)
73 #define NFC_DMA_TYPE_NORMAL	BIT(15)
74 #define NFC_DEBUG_CTL		BIT(31)
75 
76 /* define bit use in NFC_ST */
77 #define NFC_RB_B2R		BIT(0)
78 #define NFC_CMD_INT_FLAG	BIT(1)
79 #define NFC_DMA_INT_FLAG	BIT(2)
80 #define NFC_CMD_FIFO_STATUS	BIT(3)
81 #define NFC_STA			BIT(4)
82 #define NFC_NATCH_INT_FLAG	BIT(5)
83 #define NFC_RB_STATE(x)		BIT(x + 8)
84 
85 /* define bit use in NFC_INT */
86 #define NFC_B2R_INT_ENABLE	BIT(0)
87 #define NFC_CMD_INT_ENABLE	BIT(1)
88 #define NFC_DMA_INT_ENABLE	BIT(2)
89 #define NFC_INT_MASK		(NFC_B2R_INT_ENABLE | \
90 				 NFC_CMD_INT_ENABLE | \
91 				 NFC_DMA_INT_ENABLE)
92 
93 /* define bit use in NFC_TIMING_CTL */
94 #define NFC_TIMING_CTL_EDO	BIT(8)
95 
96 /* define NFC_TIMING_CFG register layout */
97 #define NFC_TIMING_CFG(tWB, tADL, tWHR, tRHW, tCAD)		\
98 	(((tWB) & 0x3) | (((tADL) & 0x3) << 2) |		\
99 	(((tWHR) & 0x3) << 4) | (((tRHW) & 0x3) << 6) |		\
100 	(((tCAD) & 0x7) << 8))
101 
102 /* define bit use in NFC_CMD */
103 #define NFC_CMD_LOW_BYTE_MSK	GENMASK(7, 0)
104 #define NFC_CMD_HIGH_BYTE_MSK	GENMASK(15, 8)
105 #define NFC_CMD(x)		(x)
106 #define NFC_ADR_NUM_MSK		GENMASK(18, 16)
107 #define NFC_ADR_NUM(x)		(((x) - 1) << 16)
108 #define NFC_SEND_ADR		BIT(19)
109 #define NFC_ACCESS_DIR		BIT(20)
110 #define NFC_DATA_TRANS		BIT(21)
111 #define NFC_SEND_CMD1		BIT(22)
112 #define NFC_WAIT_FLAG		BIT(23)
113 #define NFC_SEND_CMD2		BIT(24)
114 #define NFC_SEQ			BIT(25)
115 #define NFC_DATA_SWAP_METHOD	BIT(26)
116 #define NFC_ROW_AUTO_INC	BIT(27)
117 #define NFC_SEND_CMD3		BIT(28)
118 #define NFC_SEND_CMD4		BIT(29)
119 #define NFC_CMD_TYPE_MSK	GENMASK(31, 30)
120 #define NFC_NORMAL_OP		(0 << 30)
121 #define NFC_ECC_OP		(1 << 30)
122 #define NFC_PAGE_OP		(2U << 30)
123 
124 /* define bit use in NFC_RCMD_SET */
125 #define NFC_READ_CMD_MSK	GENMASK(7, 0)
126 #define NFC_RND_READ_CMD0_MSK	GENMASK(15, 8)
127 #define NFC_RND_READ_CMD1_MSK	GENMASK(23, 16)
128 
129 /* define bit use in NFC_WCMD_SET */
130 #define NFC_PROGRAM_CMD_MSK	GENMASK(7, 0)
131 #define NFC_RND_WRITE_CMD_MSK	GENMASK(15, 8)
132 #define NFC_READ_CMD0_MSK	GENMASK(23, 16)
133 #define NFC_READ_CMD1_MSK	GENMASK(31, 24)
134 
135 /* define bit use in NFC_ECC_CTL */
136 #define NFC_ECC_EN		BIT(0)
137 #define NFC_ECC_PIPELINE	BIT(3)
138 #define NFC_ECC_EXCEPTION	BIT(4)
139 #define NFC_ECC_BLOCK_SIZE_MSK	BIT(5)
140 #define NFC_ECC_BLOCK_512	BIT(5)
141 #define NFC_RANDOM_EN		BIT(9)
142 #define NFC_RANDOM_DIRECTION	BIT(10)
143 #define NFC_ECC_MODE_MSK	GENMASK(15, 12)
144 #define NFC_ECC_MODE(x)		((x) << 12)
145 #define NFC_RANDOM_SEED_MSK	GENMASK(30, 16)
146 #define NFC_RANDOM_SEED(x)	((x) << 16)
147 
148 /* define bit use in NFC_ECC_ST */
149 #define NFC_ECC_ERR(x)		BIT(x)
150 #define NFC_ECC_ERR_MSK		GENMASK(15, 0)
151 #define NFC_ECC_PAT_FOUND(x)	BIT(x + 16)
152 #define NFC_ECC_ERR_CNT(b, x)	(((x) >> (((b) % 4) * 8)) & 0xff)
153 
154 #define NFC_DEFAULT_TIMEOUT_MS	1000
155 
156 #define NFC_SRAM_SIZE		1024
157 
158 #define NFC_MAX_CS		7
159 
160 /**
161  * struct sunxi_nand_chip_sel - stores information related to NAND Chip Select
162  *
163  * @cs: the NAND CS id used to communicate with a NAND Chip
164  * @rb: the Ready/Busy pin ID. -1 means no R/B pin connected to the NFC
165  */
166 struct sunxi_nand_chip_sel {
167 	u8 cs;
168 	s8 rb;
169 };
170 
171 /**
172  * struct sunxi_nand_hw_ecc - stores information related to HW ECC support
173  *
174  * @mode: the sunxi ECC mode field deduced from ECC requirements
175  */
176 struct sunxi_nand_hw_ecc {
177 	int mode;
178 };
179 
180 /**
181  * struct sunxi_nand_chip - stores NAND chip device related information
182  *
183  * @node: used to store NAND chips into a list
184  * @nand: base NAND chip structure
185  * @clk_rate: clk_rate required for this NAND chip
186  * @timing_cfg: TIMING_CFG register value for this NAND chip
187  * @timing_ctl: TIMING_CTL register value for this NAND chip
188  * @nsels: number of CS lines required by the NAND chip
189  * @sels: array of CS lines descriptions
190  */
191 struct sunxi_nand_chip {
192 	struct list_head node;
193 	struct nand_chip nand;
194 	unsigned long clk_rate;
195 	u32 timing_cfg;
196 	u32 timing_ctl;
197 	int nsels;
198 	struct sunxi_nand_chip_sel sels[0];
199 };
200 
201 static inline struct sunxi_nand_chip *to_sunxi_nand(struct nand_chip *nand)
202 {
203 	return container_of(nand, struct sunxi_nand_chip, nand);
204 }
205 
206 /*
207  * NAND Controller capabilities structure: stores NAND controller capabilities
208  * for distinction between compatible strings.
209  *
210  * @extra_mbus_conf:	Contrary to A10, A10s and A13, accessing internal RAM
211  *			through MBUS on A23/A33 needs extra configuration.
212  * @reg_io_data:	I/O data register
213  * @dma_maxburst:	DMA maxburst
214  */
215 struct sunxi_nfc_caps {
216 	bool extra_mbus_conf;
217 	unsigned int reg_io_data;
218 	unsigned int dma_maxburst;
219 };
220 
221 /**
222  * struct sunxi_nfc - stores sunxi NAND controller information
223  *
224  * @controller: base controller structure
225  * @dev: parent device (used to print error messages)
226  * @regs: NAND controller registers
227  * @ahb_clk: NAND controller AHB clock
228  * @mod_clk: NAND controller mod clock
229  * @reset: NAND controller reset line
230  * @assigned_cs: bitmask describing already assigned CS lines
231  * @clk_rate: NAND controller current clock rate
232  * @chips: a list containing all the NAND chips attached to this NAND
233  *	   controller
234  * @complete: a completion object used to wait for NAND controller events
235  * @dmac: the DMA channel attached to the NAND controller
236  */
237 struct sunxi_nfc {
238 	struct nand_controller controller;
239 	struct device *dev;
240 	void __iomem *regs;
241 	struct clk *ahb_clk;
242 	struct clk *mod_clk;
243 	struct reset_control *reset;
244 	unsigned long assigned_cs;
245 	unsigned long clk_rate;
246 	struct list_head chips;
247 	struct completion complete;
248 	struct dma_chan *dmac;
249 	const struct sunxi_nfc_caps *caps;
250 };
251 
252 static inline struct sunxi_nfc *to_sunxi_nfc(struct nand_controller *ctrl)
253 {
254 	return container_of(ctrl, struct sunxi_nfc, controller);
255 }
256 
257 static irqreturn_t sunxi_nfc_interrupt(int irq, void *dev_id)
258 {
259 	struct sunxi_nfc *nfc = dev_id;
260 	u32 st = readl(nfc->regs + NFC_REG_ST);
261 	u32 ien = readl(nfc->regs + NFC_REG_INT);
262 
263 	if (!(ien & st))
264 		return IRQ_NONE;
265 
266 	if ((ien & st) == ien)
267 		complete(&nfc->complete);
268 
269 	writel(st & NFC_INT_MASK, nfc->regs + NFC_REG_ST);
270 	writel(~st & ien & NFC_INT_MASK, nfc->regs + NFC_REG_INT);
271 
272 	return IRQ_HANDLED;
273 }
274 
275 static int sunxi_nfc_wait_events(struct sunxi_nfc *nfc, u32 events,
276 				 bool use_polling, unsigned int timeout_ms)
277 {
278 	int ret;
279 
280 	if (events & ~NFC_INT_MASK)
281 		return -EINVAL;
282 
283 	if (!timeout_ms)
284 		timeout_ms = NFC_DEFAULT_TIMEOUT_MS;
285 
286 	if (!use_polling) {
287 		init_completion(&nfc->complete);
288 
289 		writel(events, nfc->regs + NFC_REG_INT);
290 
291 		ret = wait_for_completion_timeout(&nfc->complete,
292 						msecs_to_jiffies(timeout_ms));
293 		if (!ret)
294 			ret = -ETIMEDOUT;
295 		else
296 			ret = 0;
297 
298 		writel(0, nfc->regs + NFC_REG_INT);
299 	} else {
300 		u32 status;
301 
302 		ret = readl_poll_timeout(nfc->regs + NFC_REG_ST, status,
303 					 (status & events) == events, 1,
304 					 timeout_ms * 1000);
305 	}
306 
307 	writel(events & NFC_INT_MASK, nfc->regs + NFC_REG_ST);
308 
309 	if (ret)
310 		dev_err(nfc->dev, "wait interrupt timedout\n");
311 
312 	return ret;
313 }
314 
315 static int sunxi_nfc_wait_cmd_fifo_empty(struct sunxi_nfc *nfc)
316 {
317 	u32 status;
318 	int ret;
319 
320 	ret = readl_poll_timeout(nfc->regs + NFC_REG_ST, status,
321 				 !(status & NFC_CMD_FIFO_STATUS), 1,
322 				 NFC_DEFAULT_TIMEOUT_MS * 1000);
323 	if (ret)
324 		dev_err(nfc->dev, "wait for empty cmd FIFO timedout\n");
325 
326 	return ret;
327 }
328 
329 static int sunxi_nfc_rst(struct sunxi_nfc *nfc)
330 {
331 	u32 ctl;
332 	int ret;
333 
334 	writel(0, nfc->regs + NFC_REG_ECC_CTL);
335 	writel(NFC_RESET, nfc->regs + NFC_REG_CTL);
336 
337 	ret = readl_poll_timeout(nfc->regs + NFC_REG_CTL, ctl,
338 				 !(ctl & NFC_RESET), 1,
339 				 NFC_DEFAULT_TIMEOUT_MS * 1000);
340 	if (ret)
341 		dev_err(nfc->dev, "wait for NAND controller reset timedout\n");
342 
343 	return ret;
344 }
345 
346 static int sunxi_nfc_dma_op_prepare(struct sunxi_nfc *nfc, const void *buf,
347 				    int chunksize, int nchunks,
348 				    enum dma_data_direction ddir,
349 				    struct scatterlist *sg)
350 {
351 	struct dma_async_tx_descriptor *dmad;
352 	enum dma_transfer_direction tdir;
353 	dma_cookie_t dmat;
354 	int ret;
355 
356 	if (ddir == DMA_FROM_DEVICE)
357 		tdir = DMA_DEV_TO_MEM;
358 	else
359 		tdir = DMA_MEM_TO_DEV;
360 
361 	sg_init_one(sg, buf, nchunks * chunksize);
362 	ret = dma_map_sg(nfc->dev, sg, 1, ddir);
363 	if (!ret)
364 		return -ENOMEM;
365 
366 	dmad = dmaengine_prep_slave_sg(nfc->dmac, sg, 1, tdir, DMA_CTRL_ACK);
367 	if (!dmad) {
368 		ret = -EINVAL;
369 		goto err_unmap_buf;
370 	}
371 
372 	writel(readl(nfc->regs + NFC_REG_CTL) | NFC_RAM_METHOD,
373 	       nfc->regs + NFC_REG_CTL);
374 	writel(nchunks, nfc->regs + NFC_REG_SECTOR_NUM);
375 	writel(chunksize, nfc->regs + NFC_REG_CNT);
376 	if (nfc->caps->extra_mbus_conf)
377 		writel(chunksize * nchunks, nfc->regs + NFC_REG_MDMA_CNT);
378 
379 	dmat = dmaengine_submit(dmad);
380 
381 	ret = dma_submit_error(dmat);
382 	if (ret)
383 		goto err_clr_dma_flag;
384 
385 	return 0;
386 
387 err_clr_dma_flag:
388 	writel(readl(nfc->regs + NFC_REG_CTL) & ~NFC_RAM_METHOD,
389 	       nfc->regs + NFC_REG_CTL);
390 
391 err_unmap_buf:
392 	dma_unmap_sg(nfc->dev, sg, 1, ddir);
393 	return ret;
394 }
395 
396 static void sunxi_nfc_dma_op_cleanup(struct sunxi_nfc *nfc,
397 				     enum dma_data_direction ddir,
398 				     struct scatterlist *sg)
399 {
400 	dma_unmap_sg(nfc->dev, sg, 1, ddir);
401 	writel(readl(nfc->regs + NFC_REG_CTL) & ~NFC_RAM_METHOD,
402 	       nfc->regs + NFC_REG_CTL);
403 }
404 
405 static void sunxi_nfc_select_chip(struct nand_chip *nand, unsigned int cs)
406 {
407 	struct mtd_info *mtd = nand_to_mtd(nand);
408 	struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
409 	struct sunxi_nfc *nfc = to_sunxi_nfc(sunxi_nand->nand.controller);
410 	struct sunxi_nand_chip_sel *sel;
411 	u32 ctl;
412 
413 	if (cs > 0 && cs >= sunxi_nand->nsels)
414 		return;
415 
416 	ctl = readl(nfc->regs + NFC_REG_CTL) &
417 	      ~(NFC_PAGE_SHIFT_MSK | NFC_CE_SEL_MSK | NFC_RB_SEL_MSK | NFC_EN);
418 
419 	sel = &sunxi_nand->sels[cs];
420 	ctl |= NFC_CE_SEL(sel->cs) | NFC_EN | NFC_PAGE_SHIFT(nand->page_shift);
421 	if (sel->rb >= 0)
422 		ctl |= NFC_RB_SEL(sel->rb);
423 
424 	writel(mtd->writesize, nfc->regs + NFC_REG_SPARE_AREA);
425 
426 	if (nfc->clk_rate != sunxi_nand->clk_rate) {
427 		clk_set_rate(nfc->mod_clk, sunxi_nand->clk_rate);
428 		nfc->clk_rate = sunxi_nand->clk_rate;
429 	}
430 
431 	writel(sunxi_nand->timing_ctl, nfc->regs + NFC_REG_TIMING_CTL);
432 	writel(sunxi_nand->timing_cfg, nfc->regs + NFC_REG_TIMING_CFG);
433 	writel(ctl, nfc->regs + NFC_REG_CTL);
434 }
435 
436 static void sunxi_nfc_read_buf(struct nand_chip *nand, uint8_t *buf, int len)
437 {
438 	struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
439 	struct sunxi_nfc *nfc = to_sunxi_nfc(sunxi_nand->nand.controller);
440 	int ret;
441 	int cnt;
442 	int offs = 0;
443 	u32 tmp;
444 
445 	while (len > offs) {
446 		bool poll = false;
447 
448 		cnt = min(len - offs, NFC_SRAM_SIZE);
449 
450 		ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
451 		if (ret)
452 			break;
453 
454 		writel(cnt, nfc->regs + NFC_REG_CNT);
455 		tmp = NFC_DATA_TRANS | NFC_DATA_SWAP_METHOD;
456 		writel(tmp, nfc->regs + NFC_REG_CMD);
457 
458 		/* Arbitrary limit for polling mode */
459 		if (cnt < 64)
460 			poll = true;
461 
462 		ret = sunxi_nfc_wait_events(nfc, NFC_CMD_INT_FLAG, poll, 0);
463 		if (ret)
464 			break;
465 
466 		if (buf)
467 			memcpy_fromio(buf + offs, nfc->regs + NFC_RAM0_BASE,
468 				      cnt);
469 		offs += cnt;
470 	}
471 }
472 
473 static void sunxi_nfc_write_buf(struct nand_chip *nand, const uint8_t *buf,
474 				int len)
475 {
476 	struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
477 	struct sunxi_nfc *nfc = to_sunxi_nfc(sunxi_nand->nand.controller);
478 	int ret;
479 	int cnt;
480 	int offs = 0;
481 	u32 tmp;
482 
483 	while (len > offs) {
484 		bool poll = false;
485 
486 		cnt = min(len - offs, NFC_SRAM_SIZE);
487 
488 		ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
489 		if (ret)
490 			break;
491 
492 		writel(cnt, nfc->regs + NFC_REG_CNT);
493 		memcpy_toio(nfc->regs + NFC_RAM0_BASE, buf + offs, cnt);
494 		tmp = NFC_DATA_TRANS | NFC_DATA_SWAP_METHOD |
495 		      NFC_ACCESS_DIR;
496 		writel(tmp, nfc->regs + NFC_REG_CMD);
497 
498 		/* Arbitrary limit for polling mode */
499 		if (cnt < 64)
500 			poll = true;
501 
502 		ret = sunxi_nfc_wait_events(nfc, NFC_CMD_INT_FLAG, poll, 0);
503 		if (ret)
504 			break;
505 
506 		offs += cnt;
507 	}
508 }
509 
510 /* These seed values have been extracted from Allwinner's BSP */
511 static const u16 sunxi_nfc_randomizer_page_seeds[] = {
512 	0x2b75, 0x0bd0, 0x5ca3, 0x62d1, 0x1c93, 0x07e9, 0x2162, 0x3a72,
513 	0x0d67, 0x67f9, 0x1be7, 0x077d, 0x032f, 0x0dac, 0x2716, 0x2436,
514 	0x7922, 0x1510, 0x3860, 0x5287, 0x480f, 0x4252, 0x1789, 0x5a2d,
515 	0x2a49, 0x5e10, 0x437f, 0x4b4e, 0x2f45, 0x216e, 0x5cb7, 0x7130,
516 	0x2a3f, 0x60e4, 0x4dc9, 0x0ef0, 0x0f52, 0x1bb9, 0x6211, 0x7a56,
517 	0x226d, 0x4ea7, 0x6f36, 0x3692, 0x38bf, 0x0c62, 0x05eb, 0x4c55,
518 	0x60f4, 0x728c, 0x3b6f, 0x2037, 0x7f69, 0x0936, 0x651a, 0x4ceb,
519 	0x6218, 0x79f3, 0x383f, 0x18d9, 0x4f05, 0x5c82, 0x2912, 0x6f17,
520 	0x6856, 0x5938, 0x1007, 0x61ab, 0x3e7f, 0x57c2, 0x542f, 0x4f62,
521 	0x7454, 0x2eac, 0x7739, 0x42d4, 0x2f90, 0x435a, 0x2e52, 0x2064,
522 	0x637c, 0x66ad, 0x2c90, 0x0bad, 0x759c, 0x0029, 0x0986, 0x7126,
523 	0x1ca7, 0x1605, 0x386a, 0x27f5, 0x1380, 0x6d75, 0x24c3, 0x0f8e,
524 	0x2b7a, 0x1418, 0x1fd1, 0x7dc1, 0x2d8e, 0x43af, 0x2267, 0x7da3,
525 	0x4e3d, 0x1338, 0x50db, 0x454d, 0x764d, 0x40a3, 0x42e6, 0x262b,
526 	0x2d2e, 0x1aea, 0x2e17, 0x173d, 0x3a6e, 0x71bf, 0x25f9, 0x0a5d,
527 	0x7c57, 0x0fbe, 0x46ce, 0x4939, 0x6b17, 0x37bb, 0x3e91, 0x76db,
528 };
529 
530 /*
531  * sunxi_nfc_randomizer_ecc512_seeds and sunxi_nfc_randomizer_ecc1024_seeds
532  * have been generated using
533  * sunxi_nfc_randomizer_step(seed, (step_size * 8) + 15), which is what
534  * the randomizer engine does internally before de/scrambling OOB data.
535  *
536  * Those tables are statically defined to avoid calculating randomizer state
537  * at runtime.
538  */
539 static const u16 sunxi_nfc_randomizer_ecc512_seeds[] = {
540 	0x3346, 0x367f, 0x1f18, 0x769a, 0x4f64, 0x068c, 0x2ef1, 0x6b64,
541 	0x28a9, 0x15d7, 0x30f8, 0x3659, 0x53db, 0x7c5f, 0x71d4, 0x4409,
542 	0x26eb, 0x03cc, 0x655d, 0x47d4, 0x4daa, 0x0877, 0x712d, 0x3617,
543 	0x3264, 0x49aa, 0x7f9e, 0x588e, 0x4fbc, 0x7176, 0x7f91, 0x6c6d,
544 	0x4b95, 0x5fb7, 0x3844, 0x4037, 0x0184, 0x081b, 0x0ee8, 0x5b91,
545 	0x293d, 0x1f71, 0x0e6f, 0x402b, 0x5122, 0x1e52, 0x22be, 0x3d2d,
546 	0x75bc, 0x7c60, 0x6291, 0x1a2f, 0x61d4, 0x74aa, 0x4140, 0x29ab,
547 	0x472d, 0x2852, 0x017e, 0x15e8, 0x5ec2, 0x17cf, 0x7d0f, 0x06b8,
548 	0x117a, 0x6b94, 0x789b, 0x3126, 0x6ac5, 0x5be7, 0x150f, 0x51f8,
549 	0x7889, 0x0aa5, 0x663d, 0x77e8, 0x0b87, 0x3dcb, 0x360d, 0x218b,
550 	0x512f, 0x7dc9, 0x6a4d, 0x630a, 0x3547, 0x1dd2, 0x5aea, 0x69a5,
551 	0x7bfa, 0x5e4f, 0x1519, 0x6430, 0x3a0e, 0x5eb3, 0x5425, 0x0c7a,
552 	0x5540, 0x3670, 0x63c1, 0x31e9, 0x5a39, 0x2de7, 0x5979, 0x2891,
553 	0x1562, 0x014b, 0x5b05, 0x2756, 0x5a34, 0x13aa, 0x6cb5, 0x2c36,
554 	0x5e72, 0x1306, 0x0861, 0x15ef, 0x1ee8, 0x5a37, 0x7ac4, 0x45dd,
555 	0x44c4, 0x7266, 0x2f41, 0x3ccc, 0x045e, 0x7d40, 0x7c66, 0x0fa0,
556 };
557 
558 static const u16 sunxi_nfc_randomizer_ecc1024_seeds[] = {
559 	0x2cf5, 0x35f1, 0x63a4, 0x5274, 0x2bd2, 0x778b, 0x7285, 0x32b6,
560 	0x6a5c, 0x70d6, 0x757d, 0x6769, 0x5375, 0x1e81, 0x0cf3, 0x3982,
561 	0x6787, 0x042a, 0x6c49, 0x1925, 0x56a8, 0x40a9, 0x063e, 0x7bd9,
562 	0x4dbf, 0x55ec, 0x672e, 0x7334, 0x5185, 0x4d00, 0x232a, 0x7e07,
563 	0x445d, 0x6b92, 0x528f, 0x4255, 0x53ba, 0x7d82, 0x2a2e, 0x3a4e,
564 	0x75eb, 0x450c, 0x6844, 0x1b5d, 0x581a, 0x4cc6, 0x0379, 0x37b2,
565 	0x419f, 0x0e92, 0x6b27, 0x5624, 0x01e3, 0x07c1, 0x44a5, 0x130c,
566 	0x13e8, 0x5910, 0x0876, 0x60c5, 0x54e3, 0x5b7f, 0x2269, 0x509f,
567 	0x7665, 0x36fd, 0x3e9a, 0x0579, 0x6295, 0x14ef, 0x0a81, 0x1bcc,
568 	0x4b16, 0x64db, 0x0514, 0x4f07, 0x0591, 0x3576, 0x6853, 0x0d9e,
569 	0x259f, 0x38b7, 0x64fb, 0x3094, 0x4693, 0x6ddd, 0x29bb, 0x0bc8,
570 	0x3f47, 0x490e, 0x0c0e, 0x7933, 0x3c9e, 0x5840, 0x398d, 0x3e68,
571 	0x4af1, 0x71f5, 0x57cf, 0x1121, 0x64eb, 0x3579, 0x15ac, 0x584d,
572 	0x5f2a, 0x47e2, 0x6528, 0x6eac, 0x196e, 0x6b96, 0x0450, 0x0179,
573 	0x609c, 0x06e1, 0x4626, 0x42c7, 0x273e, 0x486f, 0x0705, 0x1601,
574 	0x145b, 0x407e, 0x062b, 0x57a5, 0x53f9, 0x5659, 0x4410, 0x3ccd,
575 };
576 
577 static u16 sunxi_nfc_randomizer_step(u16 state, int count)
578 {
579 	state &= 0x7fff;
580 
581 	/*
582 	 * This loop is just a simple implementation of a Fibonacci LFSR using
583 	 * the x16 + x15 + 1 polynomial.
584 	 */
585 	while (count--)
586 		state = ((state >> 1) |
587 			 (((state ^ (state >> 1)) & 1) << 14)) & 0x7fff;
588 
589 	return state;
590 }
591 
592 static u16 sunxi_nfc_randomizer_state(struct nand_chip *nand, int page,
593 				      bool ecc)
594 {
595 	struct mtd_info *mtd = nand_to_mtd(nand);
596 	const u16 *seeds = sunxi_nfc_randomizer_page_seeds;
597 	int mod = mtd_div_by_ws(mtd->erasesize, mtd);
598 
599 	if (mod > ARRAY_SIZE(sunxi_nfc_randomizer_page_seeds))
600 		mod = ARRAY_SIZE(sunxi_nfc_randomizer_page_seeds);
601 
602 	if (ecc) {
603 		if (mtd->ecc_step_size == 512)
604 			seeds = sunxi_nfc_randomizer_ecc512_seeds;
605 		else
606 			seeds = sunxi_nfc_randomizer_ecc1024_seeds;
607 	}
608 
609 	return seeds[page % mod];
610 }
611 
612 static void sunxi_nfc_randomizer_config(struct nand_chip *nand, int page,
613 					bool ecc)
614 {
615 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
616 	u32 ecc_ctl = readl(nfc->regs + NFC_REG_ECC_CTL);
617 	u16 state;
618 
619 	if (!(nand->options & NAND_NEED_SCRAMBLING))
620 		return;
621 
622 	ecc_ctl = readl(nfc->regs + NFC_REG_ECC_CTL);
623 	state = sunxi_nfc_randomizer_state(nand, page, ecc);
624 	ecc_ctl = readl(nfc->regs + NFC_REG_ECC_CTL) & ~NFC_RANDOM_SEED_MSK;
625 	writel(ecc_ctl | NFC_RANDOM_SEED(state), nfc->regs + NFC_REG_ECC_CTL);
626 }
627 
628 static void sunxi_nfc_randomizer_enable(struct nand_chip *nand)
629 {
630 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
631 
632 	if (!(nand->options & NAND_NEED_SCRAMBLING))
633 		return;
634 
635 	writel(readl(nfc->regs + NFC_REG_ECC_CTL) | NFC_RANDOM_EN,
636 	       nfc->regs + NFC_REG_ECC_CTL);
637 }
638 
639 static void sunxi_nfc_randomizer_disable(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_randomize_bbm(struct nand_chip *nand, int page, u8 *bbm)
651 {
652 	u16 state = sunxi_nfc_randomizer_state(nand, page, true);
653 
654 	bbm[0] ^= state;
655 	bbm[1] ^= sunxi_nfc_randomizer_step(state, 8);
656 }
657 
658 static void sunxi_nfc_randomizer_write_buf(struct nand_chip *nand,
659 					   const uint8_t *buf, int len,
660 					   bool ecc, int page)
661 {
662 	sunxi_nfc_randomizer_config(nand, page, ecc);
663 	sunxi_nfc_randomizer_enable(nand);
664 	sunxi_nfc_write_buf(nand, buf, len);
665 	sunxi_nfc_randomizer_disable(nand);
666 }
667 
668 static void sunxi_nfc_randomizer_read_buf(struct nand_chip *nand, uint8_t *buf,
669 					  int len, bool ecc, int page)
670 {
671 	sunxi_nfc_randomizer_config(nand, page, ecc);
672 	sunxi_nfc_randomizer_enable(nand);
673 	sunxi_nfc_read_buf(nand, buf, len);
674 	sunxi_nfc_randomizer_disable(nand);
675 }
676 
677 static void sunxi_nfc_hw_ecc_enable(struct nand_chip *nand)
678 {
679 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
680 	struct sunxi_nand_hw_ecc *data = nand->ecc.priv;
681 	u32 ecc_ctl;
682 
683 	ecc_ctl = readl(nfc->regs + NFC_REG_ECC_CTL);
684 	ecc_ctl &= ~(NFC_ECC_MODE_MSK | NFC_ECC_PIPELINE |
685 		     NFC_ECC_BLOCK_SIZE_MSK);
686 	ecc_ctl |= NFC_ECC_EN | NFC_ECC_MODE(data->mode) | NFC_ECC_EXCEPTION |
687 		   NFC_ECC_PIPELINE;
688 
689 	if (nand->ecc.size == 512)
690 		ecc_ctl |= NFC_ECC_BLOCK_512;
691 
692 	writel(ecc_ctl, nfc->regs + NFC_REG_ECC_CTL);
693 }
694 
695 static void sunxi_nfc_hw_ecc_disable(struct nand_chip *nand)
696 {
697 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
698 
699 	writel(readl(nfc->regs + NFC_REG_ECC_CTL) & ~NFC_ECC_EN,
700 	       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;
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 	dma_async_issue_pending(nfc->dmac);
933 
934 	writel(NFC_PAGE_OP | NFC_DATA_SWAP_METHOD | NFC_DATA_TRANS,
935 	       nfc->regs + NFC_REG_CMD);
936 
937 	ret = sunxi_nfc_wait_events(nfc, NFC_CMD_INT_FLAG, false, 0);
938 	if (ret)
939 		dmaengine_terminate_all(nfc->dmac);
940 
941 	sunxi_nfc_randomizer_disable(nand);
942 	sunxi_nfc_hw_ecc_disable(nand);
943 
944 	sunxi_nfc_dma_op_cleanup(nfc, DMA_FROM_DEVICE, &sg);
945 
946 	if (ret)
947 		return ret;
948 
949 	status = readl(nfc->regs + NFC_REG_ECC_ST);
950 
951 	for (i = 0; i < nchunks; i++) {
952 		int data_off = i * ecc->size;
953 		int oob_off = i * (ecc->bytes + 4);
954 		u8 *data = buf + data_off;
955 		u8 *oob = nand->oob_poi + oob_off;
956 		bool erased;
957 
958 		ret = sunxi_nfc_hw_ecc_correct(nand, randomized ? data : NULL,
959 					       oob_required ? oob : NULL,
960 					       i, status, &erased);
961 
962 		/* ECC errors are handled in the second loop. */
963 		if (ret < 0)
964 			continue;
965 
966 		if (oob_required && !erased) {
967 			/* TODO: use DMA to retrieve OOB */
968 			nand_change_read_column_op(nand,
969 						   mtd->writesize + oob_off,
970 						   oob, ecc->bytes + 4, false);
971 
972 			sunxi_nfc_hw_ecc_get_prot_oob_bytes(nand, oob, i,
973 							    !i, page);
974 		}
975 
976 		if (erased)
977 			raw_mode = 1;
978 
979 		sunxi_nfc_hw_ecc_update_stats(nand, &max_bitflips, ret);
980 	}
981 
982 	if (status & NFC_ECC_ERR_MSK) {
983 		for (i = 0; i < nchunks; i++) {
984 			int data_off = i * ecc->size;
985 			int oob_off = i * (ecc->bytes + 4);
986 			u8 *data = buf + data_off;
987 			u8 *oob = nand->oob_poi + oob_off;
988 
989 			if (!(status & NFC_ECC_ERR(i)))
990 				continue;
991 
992 			/*
993 			 * Re-read the data with the randomizer disabled to
994 			 * identify bitflips in erased pages.
995 			 * TODO: use DMA to read page in raw mode
996 			 */
997 			if (randomized)
998 				nand_change_read_column_op(nand, data_off,
999 							   data, ecc->size,
1000 							   false);
1001 
1002 			/* TODO: use DMA to retrieve OOB */
1003 			nand_change_read_column_op(nand,
1004 						   mtd->writesize + oob_off,
1005 						   oob, ecc->bytes + 4, false);
1006 
1007 			ret = nand_check_erased_ecc_chunk(data,	ecc->size,
1008 							  oob, ecc->bytes + 4,
1009 							  NULL, 0,
1010 							  ecc->strength);
1011 			if (ret >= 0)
1012 				raw_mode = 1;
1013 
1014 			sunxi_nfc_hw_ecc_update_stats(nand, &max_bitflips, ret);
1015 		}
1016 	}
1017 
1018 	if (oob_required)
1019 		sunxi_nfc_hw_ecc_read_extra_oob(nand, nand->oob_poi,
1020 						NULL, !raw_mode,
1021 						page);
1022 
1023 	return max_bitflips;
1024 }
1025 
1026 static int sunxi_nfc_hw_ecc_write_chunk(struct nand_chip *nand,
1027 					const u8 *data, int data_off,
1028 					const u8 *oob, int oob_off,
1029 					int *cur_off, bool bbm,
1030 					int page)
1031 {
1032 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
1033 	struct nand_ecc_ctrl *ecc = &nand->ecc;
1034 	int ret;
1035 
1036 	if (data_off != *cur_off)
1037 		nand_change_write_column_op(nand, data_off, NULL, 0, false);
1038 
1039 	sunxi_nfc_randomizer_write_buf(nand, data, ecc->size, false, page);
1040 
1041 	if (data_off + ecc->size != oob_off)
1042 		nand_change_write_column_op(nand, oob_off, NULL, 0, false);
1043 
1044 	ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
1045 	if (ret)
1046 		return ret;
1047 
1048 	sunxi_nfc_randomizer_enable(nand);
1049 	sunxi_nfc_hw_ecc_set_prot_oob_bytes(nand, oob, 0, bbm, page);
1050 
1051 	writel(NFC_DATA_TRANS | NFC_DATA_SWAP_METHOD |
1052 	       NFC_ACCESS_DIR | NFC_ECC_OP,
1053 	       nfc->regs + NFC_REG_CMD);
1054 
1055 	ret = sunxi_nfc_wait_events(nfc, NFC_CMD_INT_FLAG, false, 0);
1056 	sunxi_nfc_randomizer_disable(nand);
1057 	if (ret)
1058 		return ret;
1059 
1060 	*cur_off = oob_off + ecc->bytes + 4;
1061 
1062 	return 0;
1063 }
1064 
1065 static void sunxi_nfc_hw_ecc_write_extra_oob(struct nand_chip *nand,
1066 					     u8 *oob, int *cur_off,
1067 					     int page)
1068 {
1069 	struct mtd_info *mtd = nand_to_mtd(nand);
1070 	struct nand_ecc_ctrl *ecc = &nand->ecc;
1071 	int offset = ((ecc->bytes + 4) * ecc->steps);
1072 	int len = mtd->oobsize - offset;
1073 
1074 	if (len <= 0)
1075 		return;
1076 
1077 	if (!cur_off || *cur_off != offset)
1078 		nand_change_write_column_op(nand, offset + mtd->writesize,
1079 					    NULL, 0, false);
1080 
1081 	sunxi_nfc_randomizer_write_buf(nand, oob + offset, len, false, page);
1082 
1083 	if (cur_off)
1084 		*cur_off = mtd->oobsize + mtd->writesize;
1085 }
1086 
1087 static int sunxi_nfc_hw_ecc_read_page(struct nand_chip *nand, uint8_t *buf,
1088 				      int oob_required, int page)
1089 {
1090 	struct mtd_info *mtd = nand_to_mtd(nand);
1091 	struct nand_ecc_ctrl *ecc = &nand->ecc;
1092 	unsigned int max_bitflips = 0;
1093 	int ret, i, cur_off = 0;
1094 	bool raw_mode = false;
1095 
1096 	sunxi_nfc_select_chip(nand, nand->cur_cs);
1097 
1098 	nand_read_page_op(nand, page, 0, NULL, 0);
1099 
1100 	sunxi_nfc_hw_ecc_enable(nand);
1101 
1102 	for (i = 0; i < ecc->steps; i++) {
1103 		int data_off = i * ecc->size;
1104 		int oob_off = i * (ecc->bytes + 4);
1105 		u8 *data = buf + data_off;
1106 		u8 *oob = nand->oob_poi + oob_off;
1107 
1108 		ret = sunxi_nfc_hw_ecc_read_chunk(nand, data, data_off, oob,
1109 						  oob_off + mtd->writesize,
1110 						  &cur_off, &max_bitflips,
1111 						  !i, oob_required, page);
1112 		if (ret < 0)
1113 			return ret;
1114 		else if (ret)
1115 			raw_mode = true;
1116 	}
1117 
1118 	if (oob_required)
1119 		sunxi_nfc_hw_ecc_read_extra_oob(nand, nand->oob_poi, &cur_off,
1120 						!raw_mode, page);
1121 
1122 	sunxi_nfc_hw_ecc_disable(nand);
1123 
1124 	return max_bitflips;
1125 }
1126 
1127 static int sunxi_nfc_hw_ecc_read_page_dma(struct nand_chip *nand, u8 *buf,
1128 					  int oob_required, int page)
1129 {
1130 	int ret;
1131 
1132 	sunxi_nfc_select_chip(nand, nand->cur_cs);
1133 
1134 	nand_read_page_op(nand, page, 0, NULL, 0);
1135 
1136 	ret = sunxi_nfc_hw_ecc_read_chunks_dma(nand, buf, oob_required, page,
1137 					       nand->ecc.steps);
1138 	if (ret >= 0)
1139 		return ret;
1140 
1141 	/* Fallback to PIO mode */
1142 	return sunxi_nfc_hw_ecc_read_page(nand, buf, oob_required, page);
1143 }
1144 
1145 static int sunxi_nfc_hw_ecc_read_subpage(struct nand_chip *nand,
1146 					 u32 data_offs, u32 readlen,
1147 					 u8 *bufpoi, int page)
1148 {
1149 	struct mtd_info *mtd = nand_to_mtd(nand);
1150 	struct nand_ecc_ctrl *ecc = &nand->ecc;
1151 	int ret, i, cur_off = 0;
1152 	unsigned int max_bitflips = 0;
1153 
1154 	sunxi_nfc_select_chip(nand, nand->cur_cs);
1155 
1156 	nand_read_page_op(nand, page, 0, NULL, 0);
1157 
1158 	sunxi_nfc_hw_ecc_enable(nand);
1159 
1160 	for (i = data_offs / ecc->size;
1161 	     i < DIV_ROUND_UP(data_offs + readlen, ecc->size); i++) {
1162 		int data_off = i * ecc->size;
1163 		int oob_off = i * (ecc->bytes + 4);
1164 		u8 *data = bufpoi + data_off;
1165 		u8 *oob = nand->oob_poi + oob_off;
1166 
1167 		ret = sunxi_nfc_hw_ecc_read_chunk(nand, data, data_off,
1168 						  oob,
1169 						  oob_off + mtd->writesize,
1170 						  &cur_off, &max_bitflips, !i,
1171 						  false, page);
1172 		if (ret < 0)
1173 			return ret;
1174 	}
1175 
1176 	sunxi_nfc_hw_ecc_disable(nand);
1177 
1178 	return max_bitflips;
1179 }
1180 
1181 static int sunxi_nfc_hw_ecc_read_subpage_dma(struct nand_chip *nand,
1182 					     u32 data_offs, u32 readlen,
1183 					     u8 *buf, int page)
1184 {
1185 	int nchunks = DIV_ROUND_UP(data_offs + readlen, nand->ecc.size);
1186 	int ret;
1187 
1188 	sunxi_nfc_select_chip(nand, nand->cur_cs);
1189 
1190 	nand_read_page_op(nand, page, 0, NULL, 0);
1191 
1192 	ret = sunxi_nfc_hw_ecc_read_chunks_dma(nand, buf, false, page, nchunks);
1193 	if (ret >= 0)
1194 		return ret;
1195 
1196 	/* Fallback to PIO mode */
1197 	return sunxi_nfc_hw_ecc_read_subpage(nand, data_offs, readlen,
1198 					     buf, page);
1199 }
1200 
1201 static int sunxi_nfc_hw_ecc_write_page(struct nand_chip *nand,
1202 				       const uint8_t *buf, int oob_required,
1203 				       int page)
1204 {
1205 	struct mtd_info *mtd = nand_to_mtd(nand);
1206 	struct nand_ecc_ctrl *ecc = &nand->ecc;
1207 	int ret, i, cur_off = 0;
1208 
1209 	sunxi_nfc_select_chip(nand, nand->cur_cs);
1210 
1211 	nand_prog_page_begin_op(nand, page, 0, NULL, 0);
1212 
1213 	sunxi_nfc_hw_ecc_enable(nand);
1214 
1215 	for (i = 0; i < ecc->steps; i++) {
1216 		int data_off = i * ecc->size;
1217 		int oob_off = i * (ecc->bytes + 4);
1218 		const u8 *data = buf + data_off;
1219 		const u8 *oob = nand->oob_poi + oob_off;
1220 
1221 		ret = sunxi_nfc_hw_ecc_write_chunk(nand, data, data_off, oob,
1222 						   oob_off + mtd->writesize,
1223 						   &cur_off, !i, page);
1224 		if (ret)
1225 			return ret;
1226 	}
1227 
1228 	if (oob_required || (nand->options & NAND_NEED_SCRAMBLING))
1229 		sunxi_nfc_hw_ecc_write_extra_oob(nand, nand->oob_poi,
1230 						 &cur_off, page);
1231 
1232 	sunxi_nfc_hw_ecc_disable(nand);
1233 
1234 	return nand_prog_page_end_op(nand);
1235 }
1236 
1237 static int sunxi_nfc_hw_ecc_write_subpage(struct nand_chip *nand,
1238 					  u32 data_offs, u32 data_len,
1239 					  const u8 *buf, int oob_required,
1240 					  int page)
1241 {
1242 	struct mtd_info *mtd = nand_to_mtd(nand);
1243 	struct nand_ecc_ctrl *ecc = &nand->ecc;
1244 	int ret, i, cur_off = 0;
1245 
1246 	sunxi_nfc_select_chip(nand, nand->cur_cs);
1247 
1248 	nand_prog_page_begin_op(nand, page, 0, NULL, 0);
1249 
1250 	sunxi_nfc_hw_ecc_enable(nand);
1251 
1252 	for (i = data_offs / ecc->size;
1253 	     i < DIV_ROUND_UP(data_offs + data_len, ecc->size); i++) {
1254 		int data_off = i * ecc->size;
1255 		int oob_off = i * (ecc->bytes + 4);
1256 		const u8 *data = buf + data_off;
1257 		const u8 *oob = nand->oob_poi + oob_off;
1258 
1259 		ret = sunxi_nfc_hw_ecc_write_chunk(nand, data, data_off, oob,
1260 						   oob_off + mtd->writesize,
1261 						   &cur_off, !i, page);
1262 		if (ret)
1263 			return ret;
1264 	}
1265 
1266 	sunxi_nfc_hw_ecc_disable(nand);
1267 
1268 	return nand_prog_page_end_op(nand);
1269 }
1270 
1271 static int sunxi_nfc_hw_ecc_write_page_dma(struct nand_chip *nand,
1272 					   const u8 *buf,
1273 					   int oob_required,
1274 					   int page)
1275 {
1276 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
1277 	struct nand_ecc_ctrl *ecc = &nand->ecc;
1278 	struct scatterlist sg;
1279 	int ret, i;
1280 
1281 	sunxi_nfc_select_chip(nand, nand->cur_cs);
1282 
1283 	ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
1284 	if (ret)
1285 		return ret;
1286 
1287 	ret = sunxi_nfc_dma_op_prepare(nfc, buf, ecc->size, ecc->steps,
1288 				       DMA_TO_DEVICE, &sg);
1289 	if (ret)
1290 		goto pio_fallback;
1291 
1292 	for (i = 0; i < ecc->steps; i++) {
1293 		const u8 *oob = nand->oob_poi + (i * (ecc->bytes + 4));
1294 
1295 		sunxi_nfc_hw_ecc_set_prot_oob_bytes(nand, oob, i, !i, page);
1296 	}
1297 
1298 	nand_prog_page_begin_op(nand, page, 0, NULL, 0);
1299 
1300 	sunxi_nfc_hw_ecc_enable(nand);
1301 	sunxi_nfc_randomizer_config(nand, page, false);
1302 	sunxi_nfc_randomizer_enable(nand);
1303 
1304 	writel((NAND_CMD_RNDIN << 8) | NAND_CMD_PAGEPROG,
1305 	       nfc->regs + NFC_REG_WCMD_SET);
1306 
1307 	dma_async_issue_pending(nfc->dmac);
1308 
1309 	writel(NFC_PAGE_OP | NFC_DATA_SWAP_METHOD |
1310 	       NFC_DATA_TRANS | NFC_ACCESS_DIR,
1311 	       nfc->regs + NFC_REG_CMD);
1312 
1313 	ret = sunxi_nfc_wait_events(nfc, NFC_CMD_INT_FLAG, false, 0);
1314 	if (ret)
1315 		dmaengine_terminate_all(nfc->dmac);
1316 
1317 	sunxi_nfc_randomizer_disable(nand);
1318 	sunxi_nfc_hw_ecc_disable(nand);
1319 
1320 	sunxi_nfc_dma_op_cleanup(nfc, DMA_TO_DEVICE, &sg);
1321 
1322 	if (ret)
1323 		return ret;
1324 
1325 	if (oob_required || (nand->options & NAND_NEED_SCRAMBLING))
1326 		/* TODO: use DMA to transfer extra OOB bytes ? */
1327 		sunxi_nfc_hw_ecc_write_extra_oob(nand, nand->oob_poi,
1328 						 NULL, page);
1329 
1330 	return nand_prog_page_end_op(nand);
1331 
1332 pio_fallback:
1333 	return sunxi_nfc_hw_ecc_write_page(nand, buf, oob_required, page);
1334 }
1335 
1336 static int sunxi_nfc_hw_ecc_read_oob(struct nand_chip *nand, int page)
1337 {
1338 	u8 *buf = nand_get_data_buf(nand);
1339 
1340 	return nand->ecc.read_page(nand, buf, 1, page);
1341 }
1342 
1343 static int sunxi_nfc_hw_ecc_write_oob(struct nand_chip *nand, int page)
1344 {
1345 	struct mtd_info *mtd = nand_to_mtd(nand);
1346 	u8 *buf = nand_get_data_buf(nand);
1347 	int ret;
1348 
1349 	memset(buf, 0xff, mtd->writesize);
1350 	ret = nand->ecc.write_page(nand, buf, 1, page);
1351 	if (ret)
1352 		return ret;
1353 
1354 	/* Send command to program the OOB data */
1355 	return nand_prog_page_end_op(nand);
1356 }
1357 
1358 static const s32 tWB_lut[] = {6, 12, 16, 20};
1359 static const s32 tRHW_lut[] = {4, 8, 12, 20};
1360 
1361 static int _sunxi_nand_lookup_timing(const s32 *lut, int lut_size, u32 duration,
1362 		u32 clk_period)
1363 {
1364 	u32 clk_cycles = DIV_ROUND_UP(duration, clk_period);
1365 	int i;
1366 
1367 	for (i = 0; i < lut_size; i++) {
1368 		if (clk_cycles <= lut[i])
1369 			return i;
1370 	}
1371 
1372 	/* Doesn't fit */
1373 	return -EINVAL;
1374 }
1375 
1376 #define sunxi_nand_lookup_timing(l, p, c) \
1377 			_sunxi_nand_lookup_timing(l, ARRAY_SIZE(l), p, c)
1378 
1379 static int sunxi_nfc_setup_data_interface(struct nand_chip *nand, int csline,
1380 					const struct nand_data_interface *conf)
1381 {
1382 	struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
1383 	struct sunxi_nfc *nfc = to_sunxi_nfc(sunxi_nand->nand.controller);
1384 	const struct nand_sdr_timings *timings;
1385 	u32 min_clk_period = 0;
1386 	s32 tWB, tADL, tWHR, tRHW, tCAD;
1387 	long real_clk_rate;
1388 
1389 	timings = nand_get_sdr_timings(conf);
1390 	if (IS_ERR(timings))
1391 		return -ENOTSUPP;
1392 
1393 	/* T1 <=> tCLS */
1394 	if (timings->tCLS_min > min_clk_period)
1395 		min_clk_period = timings->tCLS_min;
1396 
1397 	/* T2 <=> tCLH */
1398 	if (timings->tCLH_min > min_clk_period)
1399 		min_clk_period = timings->tCLH_min;
1400 
1401 	/* T3 <=> tCS */
1402 	if (timings->tCS_min > min_clk_period)
1403 		min_clk_period = timings->tCS_min;
1404 
1405 	/* T4 <=> tCH */
1406 	if (timings->tCH_min > min_clk_period)
1407 		min_clk_period = timings->tCH_min;
1408 
1409 	/* T5 <=> tWP */
1410 	if (timings->tWP_min > min_clk_period)
1411 		min_clk_period = timings->tWP_min;
1412 
1413 	/* T6 <=> tWH */
1414 	if (timings->tWH_min > min_clk_period)
1415 		min_clk_period = timings->tWH_min;
1416 
1417 	/* T7 <=> tALS */
1418 	if (timings->tALS_min > min_clk_period)
1419 		min_clk_period = timings->tALS_min;
1420 
1421 	/* T8 <=> tDS */
1422 	if (timings->tDS_min > min_clk_period)
1423 		min_clk_period = timings->tDS_min;
1424 
1425 	/* T9 <=> tDH */
1426 	if (timings->tDH_min > min_clk_period)
1427 		min_clk_period = timings->tDH_min;
1428 
1429 	/* T10 <=> tRR */
1430 	if (timings->tRR_min > (min_clk_period * 3))
1431 		min_clk_period = DIV_ROUND_UP(timings->tRR_min, 3);
1432 
1433 	/* T11 <=> tALH */
1434 	if (timings->tALH_min > min_clk_period)
1435 		min_clk_period = timings->tALH_min;
1436 
1437 	/* T12 <=> tRP */
1438 	if (timings->tRP_min > min_clk_period)
1439 		min_clk_period = timings->tRP_min;
1440 
1441 	/* T13 <=> tREH */
1442 	if (timings->tREH_min > min_clk_period)
1443 		min_clk_period = timings->tREH_min;
1444 
1445 	/* T14 <=> tRC */
1446 	if (timings->tRC_min > (min_clk_period * 2))
1447 		min_clk_period = DIV_ROUND_UP(timings->tRC_min, 2);
1448 
1449 	/* T15 <=> tWC */
1450 	if (timings->tWC_min > (min_clk_period * 2))
1451 		min_clk_period = DIV_ROUND_UP(timings->tWC_min, 2);
1452 
1453 	/* T16 - T19 + tCAD */
1454 	if (timings->tWB_max > (min_clk_period * 20))
1455 		min_clk_period = DIV_ROUND_UP(timings->tWB_max, 20);
1456 
1457 	if (timings->tADL_min > (min_clk_period * 32))
1458 		min_clk_period = DIV_ROUND_UP(timings->tADL_min, 32);
1459 
1460 	if (timings->tWHR_min > (min_clk_period * 32))
1461 		min_clk_period = DIV_ROUND_UP(timings->tWHR_min, 32);
1462 
1463 	if (timings->tRHW_min > (min_clk_period * 20))
1464 		min_clk_period = DIV_ROUND_UP(timings->tRHW_min, 20);
1465 
1466 	/*
1467 	 * In non-EDO, tREA should be less than tRP to guarantee that the
1468 	 * controller does not sample the IO lines too early. Unfortunately,
1469 	 * the sunxi NAND controller does not allow us to have different
1470 	 * values for tRP and tREH (tRP = tREH = tRW / 2).
1471 	 *
1472 	 * We have 2 options to overcome this limitation:
1473 	 *
1474 	 * 1/ Extend tRC to fulfil the tREA <= tRC / 2 constraint
1475 	 * 2/ Use EDO mode (only works if timings->tRLOH > 0)
1476 	 */
1477 	if (timings->tREA_max > min_clk_period && !timings->tRLOH_min)
1478 		min_clk_period = timings->tREA_max;
1479 
1480 	tWB  = sunxi_nand_lookup_timing(tWB_lut, timings->tWB_max,
1481 					min_clk_period);
1482 	if (tWB < 0) {
1483 		dev_err(nfc->dev, "unsupported tWB\n");
1484 		return tWB;
1485 	}
1486 
1487 	tADL = DIV_ROUND_UP(timings->tADL_min, min_clk_period) >> 3;
1488 	if (tADL > 3) {
1489 		dev_err(nfc->dev, "unsupported tADL\n");
1490 		return -EINVAL;
1491 	}
1492 
1493 	tWHR = DIV_ROUND_UP(timings->tWHR_min, min_clk_period) >> 3;
1494 	if (tWHR > 3) {
1495 		dev_err(nfc->dev, "unsupported tWHR\n");
1496 		return -EINVAL;
1497 	}
1498 
1499 	tRHW = sunxi_nand_lookup_timing(tRHW_lut, timings->tRHW_min,
1500 					min_clk_period);
1501 	if (tRHW < 0) {
1502 		dev_err(nfc->dev, "unsupported tRHW\n");
1503 		return tRHW;
1504 	}
1505 
1506 	if (csline == NAND_DATA_IFACE_CHECK_ONLY)
1507 		return 0;
1508 
1509 	/*
1510 	 * TODO: according to ONFI specs this value only applies for DDR NAND,
1511 	 * but Allwinner seems to set this to 0x7. Mimic them for now.
1512 	 */
1513 	tCAD = 0x7;
1514 
1515 	/* TODO: A83 has some more bits for CDQSS, CS, CLHZ, CCS, WC */
1516 	sunxi_nand->timing_cfg = NFC_TIMING_CFG(tWB, tADL, tWHR, tRHW, tCAD);
1517 
1518 	/* Convert min_clk_period from picoseconds to nanoseconds */
1519 	min_clk_period = DIV_ROUND_UP(min_clk_period, 1000);
1520 
1521 	/*
1522 	 * Unlike what is stated in Allwinner datasheet, the clk_rate should
1523 	 * be set to (1 / min_clk_period), and not (2 / min_clk_period).
1524 	 * This new formula was verified with a scope and validated by
1525 	 * Allwinner engineers.
1526 	 */
1527 	sunxi_nand->clk_rate = NSEC_PER_SEC / min_clk_period;
1528 	real_clk_rate = clk_round_rate(nfc->mod_clk, sunxi_nand->clk_rate);
1529 	if (real_clk_rate <= 0) {
1530 		dev_err(nfc->dev, "Unable to round clk %lu\n",
1531 			sunxi_nand->clk_rate);
1532 		return -EINVAL;
1533 	}
1534 
1535 	sunxi_nand->timing_ctl = 0;
1536 
1537 	/*
1538 	 * ONFI specification 3.1, paragraph 4.15.2 dictates that EDO data
1539 	 * output cycle timings shall be used if the host drives tRC less than
1540 	 * 30 ns. We should also use EDO mode if tREA is bigger than tRP.
1541 	 */
1542 	min_clk_period = NSEC_PER_SEC / real_clk_rate;
1543 	if (min_clk_period * 2 < 30 || min_clk_period * 1000 < timings->tREA_max)
1544 		sunxi_nand->timing_ctl = NFC_TIMING_CTL_EDO;
1545 
1546 	return 0;
1547 }
1548 
1549 static int sunxi_nand_ooblayout_ecc(struct mtd_info *mtd, int section,
1550 				    struct mtd_oob_region *oobregion)
1551 {
1552 	struct nand_chip *nand = mtd_to_nand(mtd);
1553 	struct nand_ecc_ctrl *ecc = &nand->ecc;
1554 
1555 	if (section >= ecc->steps)
1556 		return -ERANGE;
1557 
1558 	oobregion->offset = section * (ecc->bytes + 4) + 4;
1559 	oobregion->length = ecc->bytes;
1560 
1561 	return 0;
1562 }
1563 
1564 static int sunxi_nand_ooblayout_free(struct mtd_info *mtd, int section,
1565 				     struct mtd_oob_region *oobregion)
1566 {
1567 	struct nand_chip *nand = mtd_to_nand(mtd);
1568 	struct nand_ecc_ctrl *ecc = &nand->ecc;
1569 
1570 	if (section > ecc->steps)
1571 		return -ERANGE;
1572 
1573 	/*
1574 	 * The first 2 bytes are used for BB markers, hence we
1575 	 * only have 2 bytes available in the first user data
1576 	 * section.
1577 	 */
1578 	if (!section && ecc->mode == NAND_ECC_HW) {
1579 		oobregion->offset = 2;
1580 		oobregion->length = 2;
1581 
1582 		return 0;
1583 	}
1584 
1585 	oobregion->offset = section * (ecc->bytes + 4);
1586 
1587 	if (section < ecc->steps)
1588 		oobregion->length = 4;
1589 	else
1590 		oobregion->offset = mtd->oobsize - oobregion->offset;
1591 
1592 	return 0;
1593 }
1594 
1595 static const struct mtd_ooblayout_ops sunxi_nand_ooblayout_ops = {
1596 	.ecc = sunxi_nand_ooblayout_ecc,
1597 	.free = sunxi_nand_ooblayout_free,
1598 };
1599 
1600 static void sunxi_nand_hw_ecc_ctrl_cleanup(struct nand_ecc_ctrl *ecc)
1601 {
1602 	kfree(ecc->priv);
1603 }
1604 
1605 static int sunxi_nand_hw_ecc_ctrl_init(struct nand_chip *nand,
1606 				       struct nand_ecc_ctrl *ecc,
1607 				       struct device_node *np)
1608 {
1609 	static const u8 strengths[] = { 16, 24, 28, 32, 40, 48, 56, 60, 64 };
1610 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
1611 	struct mtd_info *mtd = nand_to_mtd(nand);
1612 	struct sunxi_nand_hw_ecc *data;
1613 	int nsectors;
1614 	int ret;
1615 	int i;
1616 
1617 	if (ecc->options & NAND_ECC_MAXIMIZE) {
1618 		int bytes;
1619 
1620 		ecc->size = 1024;
1621 		nsectors = mtd->writesize / ecc->size;
1622 
1623 		/* Reserve 2 bytes for the BBM */
1624 		bytes = (mtd->oobsize - 2) / nsectors;
1625 
1626 		/* 4 non-ECC bytes are added before each ECC bytes section */
1627 		bytes -= 4;
1628 
1629 		/* and bytes has to be even. */
1630 		if (bytes % 2)
1631 			bytes--;
1632 
1633 		ecc->strength = bytes * 8 / fls(8 * ecc->size);
1634 
1635 		for (i = 0; i < ARRAY_SIZE(strengths); i++) {
1636 			if (strengths[i] > ecc->strength)
1637 				break;
1638 		}
1639 
1640 		if (!i)
1641 			ecc->strength = 0;
1642 		else
1643 			ecc->strength = strengths[i - 1];
1644 	}
1645 
1646 	if (ecc->size != 512 && ecc->size != 1024)
1647 		return -EINVAL;
1648 
1649 	data = kzalloc(sizeof(*data), GFP_KERNEL);
1650 	if (!data)
1651 		return -ENOMEM;
1652 
1653 	/* Prefer 1k ECC chunk over 512 ones */
1654 	if (ecc->size == 512 && mtd->writesize > 512) {
1655 		ecc->size = 1024;
1656 		ecc->strength *= 2;
1657 	}
1658 
1659 	/* Add ECC info retrieval from DT */
1660 	for (i = 0; i < ARRAY_SIZE(strengths); i++) {
1661 		if (ecc->strength <= strengths[i]) {
1662 			/*
1663 			 * Update ecc->strength value with the actual strength
1664 			 * that will be used by the ECC engine.
1665 			 */
1666 			ecc->strength = strengths[i];
1667 			break;
1668 		}
1669 	}
1670 
1671 	if (i >= ARRAY_SIZE(strengths)) {
1672 		dev_err(nfc->dev, "unsupported strength\n");
1673 		ret = -ENOTSUPP;
1674 		goto err;
1675 	}
1676 
1677 	data->mode = i;
1678 
1679 	/* HW ECC always request ECC bytes for 1024 bytes blocks */
1680 	ecc->bytes = DIV_ROUND_UP(ecc->strength * fls(8 * 1024), 8);
1681 
1682 	/* HW ECC always work with even numbers of ECC bytes */
1683 	ecc->bytes = ALIGN(ecc->bytes, 2);
1684 
1685 	nsectors = mtd->writesize / ecc->size;
1686 
1687 	if (mtd->oobsize < ((ecc->bytes + 4) * nsectors)) {
1688 		ret = -EINVAL;
1689 		goto err;
1690 	}
1691 
1692 	ecc->read_oob = sunxi_nfc_hw_ecc_read_oob;
1693 	ecc->write_oob = sunxi_nfc_hw_ecc_write_oob;
1694 	mtd_set_ooblayout(mtd, &sunxi_nand_ooblayout_ops);
1695 	ecc->priv = data;
1696 
1697 	if (nfc->dmac) {
1698 		ecc->read_page = sunxi_nfc_hw_ecc_read_page_dma;
1699 		ecc->read_subpage = sunxi_nfc_hw_ecc_read_subpage_dma;
1700 		ecc->write_page = sunxi_nfc_hw_ecc_write_page_dma;
1701 		nand->options |= NAND_USE_BOUNCE_BUFFER;
1702 	} else {
1703 		ecc->read_page = sunxi_nfc_hw_ecc_read_page;
1704 		ecc->read_subpage = sunxi_nfc_hw_ecc_read_subpage;
1705 		ecc->write_page = sunxi_nfc_hw_ecc_write_page;
1706 	}
1707 
1708 	/* TODO: support DMA for raw accesses and subpage write */
1709 	ecc->write_subpage = sunxi_nfc_hw_ecc_write_subpage;
1710 	ecc->read_oob_raw = nand_read_oob_std;
1711 	ecc->write_oob_raw = nand_write_oob_std;
1712 
1713 	return 0;
1714 
1715 err:
1716 	kfree(data);
1717 
1718 	return ret;
1719 }
1720 
1721 static void sunxi_nand_ecc_cleanup(struct nand_ecc_ctrl *ecc)
1722 {
1723 	switch (ecc->mode) {
1724 	case NAND_ECC_HW:
1725 		sunxi_nand_hw_ecc_ctrl_cleanup(ecc);
1726 		break;
1727 	case NAND_ECC_NONE:
1728 	default:
1729 		break;
1730 	}
1731 }
1732 
1733 static int sunxi_nand_attach_chip(struct nand_chip *nand)
1734 {
1735 	struct nand_ecc_ctrl *ecc = &nand->ecc;
1736 	struct device_node *np = nand_get_flash_node(nand);
1737 	int ret;
1738 
1739 	if (nand->bbt_options & NAND_BBT_USE_FLASH)
1740 		nand->bbt_options |= NAND_BBT_NO_OOB;
1741 
1742 	if (nand->options & NAND_NEED_SCRAMBLING)
1743 		nand->options |= NAND_NO_SUBPAGE_WRITE;
1744 
1745 	nand->options |= NAND_SUBPAGE_READ;
1746 
1747 	if (!ecc->size) {
1748 		ecc->size = nand->base.eccreq.step_size;
1749 		ecc->strength = nand->base.eccreq.strength;
1750 	}
1751 
1752 	if (!ecc->size || !ecc->strength)
1753 		return -EINVAL;
1754 
1755 	switch (ecc->mode) {
1756 	case NAND_ECC_HW:
1757 		ret = sunxi_nand_hw_ecc_ctrl_init(nand, ecc, np);
1758 		if (ret)
1759 			return ret;
1760 		break;
1761 	case NAND_ECC_NONE:
1762 	case NAND_ECC_SOFT:
1763 		break;
1764 	default:
1765 		return -EINVAL;
1766 	}
1767 
1768 	return 0;
1769 }
1770 
1771 static int sunxi_nfc_exec_subop(struct nand_chip *nand,
1772 				const struct nand_subop *subop)
1773 {
1774 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
1775 	u32 cmd = 0, extcmd = 0, cnt = 0, addrs[2] = { };
1776 	unsigned int i, j, remaining, start;
1777 	void *inbuf = NULL;
1778 	int ret;
1779 
1780 	for (i = 0; i < subop->ninstrs; i++) {
1781 		const struct nand_op_instr *instr = &subop->instrs[i];
1782 
1783 		switch (instr->type) {
1784 		case NAND_OP_CMD_INSTR:
1785 			if (cmd & NFC_SEND_CMD1) {
1786 				if (WARN_ON(cmd & NFC_SEND_CMD2))
1787 					return -EINVAL;
1788 
1789 				cmd |= NFC_SEND_CMD2;
1790 				extcmd |= instr->ctx.cmd.opcode;
1791 			} else {
1792 				cmd |= NFC_SEND_CMD1 |
1793 				       NFC_CMD(instr->ctx.cmd.opcode);
1794 			}
1795 			break;
1796 
1797 		case NAND_OP_ADDR_INSTR:
1798 			remaining = nand_subop_get_num_addr_cyc(subop, i);
1799 			start = nand_subop_get_addr_start_off(subop, i);
1800 			for (j = 0; j < 8 && j + start < remaining; j++) {
1801 				u32 addr = instr->ctx.addr.addrs[j + start];
1802 
1803 				addrs[j / 4] |= addr << (j % 4) * 8;
1804 			}
1805 
1806 			if (j)
1807 				cmd |= NFC_SEND_ADR | NFC_ADR_NUM(j);
1808 
1809 			break;
1810 
1811 		case NAND_OP_DATA_IN_INSTR:
1812 		case NAND_OP_DATA_OUT_INSTR:
1813 			start = nand_subop_get_data_start_off(subop, i);
1814 			remaining = nand_subop_get_data_len(subop, i);
1815 			cnt = min_t(u32, remaining, NFC_SRAM_SIZE);
1816 			cmd |= NFC_DATA_TRANS | NFC_DATA_SWAP_METHOD;
1817 
1818 			if (instr->type == NAND_OP_DATA_OUT_INSTR) {
1819 				cmd |= NFC_ACCESS_DIR;
1820 				memcpy_toio(nfc->regs + NFC_RAM0_BASE,
1821 					    instr->ctx.data.buf.out + start,
1822 					    cnt);
1823 			} else {
1824 				inbuf = instr->ctx.data.buf.in + start;
1825 			}
1826 
1827 			break;
1828 
1829 		case NAND_OP_WAITRDY_INSTR:
1830 			cmd |= NFC_WAIT_FLAG;
1831 			break;
1832 		}
1833 	}
1834 
1835 	ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
1836 	if (ret)
1837 		return ret;
1838 
1839 	if (cmd & NFC_SEND_ADR) {
1840 		writel(addrs[0], nfc->regs + NFC_REG_ADDR_LOW);
1841 		writel(addrs[1], nfc->regs + NFC_REG_ADDR_HIGH);
1842 	}
1843 
1844 	if (cmd & NFC_SEND_CMD2)
1845 		writel(extcmd,
1846 		       nfc->regs +
1847 		       (cmd & NFC_ACCESS_DIR ?
1848 			NFC_REG_WCMD_SET : NFC_REG_RCMD_SET));
1849 
1850 	if (cmd & NFC_DATA_TRANS)
1851 		writel(cnt, nfc->regs + NFC_REG_CNT);
1852 
1853 	writel(cmd, nfc->regs + NFC_REG_CMD);
1854 
1855 	ret = sunxi_nfc_wait_events(nfc, NFC_CMD_INT_FLAG,
1856 				    !(cmd & NFC_WAIT_FLAG) && cnt < 64,
1857 				    0);
1858 	if (ret)
1859 		return ret;
1860 
1861 	if (inbuf)
1862 		memcpy_fromio(inbuf, nfc->regs + NFC_RAM0_BASE, cnt);
1863 
1864 	return 0;
1865 }
1866 
1867 static int sunxi_nfc_soft_waitrdy(struct nand_chip *nand,
1868 				  const struct nand_subop *subop)
1869 {
1870 	return nand_soft_waitrdy(nand,
1871 				 subop->instrs[0].ctx.waitrdy.timeout_ms);
1872 }
1873 
1874 static const struct nand_op_parser sunxi_nfc_op_parser = NAND_OP_PARSER(
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_CMD_ELEM(true),
1879 			       NAND_OP_PARSER_PAT_WAITRDY_ELEM(true),
1880 			       NAND_OP_PARSER_PAT_DATA_IN_ELEM(true, 1024)),
1881 	NAND_OP_PARSER_PATTERN(sunxi_nfc_exec_subop,
1882 			       NAND_OP_PARSER_PAT_CMD_ELEM(true),
1883 			       NAND_OP_PARSER_PAT_ADDR_ELEM(true, 8),
1884 			       NAND_OP_PARSER_PAT_DATA_OUT_ELEM(true, 1024),
1885 			       NAND_OP_PARSER_PAT_CMD_ELEM(true),
1886 			       NAND_OP_PARSER_PAT_WAITRDY_ELEM(true)),
1887 );
1888 
1889 static const struct nand_op_parser sunxi_nfc_norb_op_parser = NAND_OP_PARSER(
1890 	NAND_OP_PARSER_PATTERN(sunxi_nfc_exec_subop,
1891 			       NAND_OP_PARSER_PAT_CMD_ELEM(true),
1892 			       NAND_OP_PARSER_PAT_ADDR_ELEM(true, 8),
1893 			       NAND_OP_PARSER_PAT_CMD_ELEM(true),
1894 			       NAND_OP_PARSER_PAT_DATA_IN_ELEM(true, 1024)),
1895 	NAND_OP_PARSER_PATTERN(sunxi_nfc_exec_subop,
1896 			       NAND_OP_PARSER_PAT_CMD_ELEM(true),
1897 			       NAND_OP_PARSER_PAT_ADDR_ELEM(true, 8),
1898 			       NAND_OP_PARSER_PAT_DATA_OUT_ELEM(true, 1024),
1899 			       NAND_OP_PARSER_PAT_CMD_ELEM(true)),
1900 	NAND_OP_PARSER_PATTERN(sunxi_nfc_soft_waitrdy,
1901 			       NAND_OP_PARSER_PAT_WAITRDY_ELEM(false)),
1902 );
1903 
1904 static int sunxi_nfc_exec_op(struct nand_chip *nand,
1905 			     const struct nand_operation *op, bool check_only)
1906 {
1907 	struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
1908 	const struct nand_op_parser *parser;
1909 
1910 	sunxi_nfc_select_chip(nand, op->cs);
1911 
1912 	if (sunxi_nand->sels[op->cs].rb >= 0)
1913 		parser = &sunxi_nfc_op_parser;
1914 	else
1915 		parser = &sunxi_nfc_norb_op_parser;
1916 
1917 	return nand_op_parser_exec_op(nand, parser, op, check_only);
1918 }
1919 
1920 static const struct nand_controller_ops sunxi_nand_controller_ops = {
1921 	.attach_chip = sunxi_nand_attach_chip,
1922 	.setup_data_interface = sunxi_nfc_setup_data_interface,
1923 	.exec_op = sunxi_nfc_exec_op,
1924 };
1925 
1926 static int sunxi_nand_chip_init(struct device *dev, struct sunxi_nfc *nfc,
1927 				struct device_node *np)
1928 {
1929 	struct sunxi_nand_chip *sunxi_nand;
1930 	struct mtd_info *mtd;
1931 	struct nand_chip *nand;
1932 	int nsels;
1933 	int ret;
1934 	int i;
1935 	u32 tmp;
1936 
1937 	if (!of_get_property(np, "reg", &nsels))
1938 		return -EINVAL;
1939 
1940 	nsels /= sizeof(u32);
1941 	if (!nsels) {
1942 		dev_err(dev, "invalid reg property size\n");
1943 		return -EINVAL;
1944 	}
1945 
1946 	sunxi_nand = devm_kzalloc(dev, struct_size(sunxi_nand, sels, nsels),
1947 				  GFP_KERNEL);
1948 	if (!sunxi_nand) {
1949 		dev_err(dev, "could not allocate chip\n");
1950 		return -ENOMEM;
1951 	}
1952 
1953 	sunxi_nand->nsels = nsels;
1954 
1955 	for (i = 0; i < nsels; i++) {
1956 		ret = of_property_read_u32_index(np, "reg", i, &tmp);
1957 		if (ret) {
1958 			dev_err(dev, "could not retrieve reg property: %d\n",
1959 				ret);
1960 			return ret;
1961 		}
1962 
1963 		if (tmp > NFC_MAX_CS) {
1964 			dev_err(dev,
1965 				"invalid reg value: %u (max CS = 7)\n",
1966 				tmp);
1967 			return -EINVAL;
1968 		}
1969 
1970 		if (test_and_set_bit(tmp, &nfc->assigned_cs)) {
1971 			dev_err(dev, "CS %d already assigned\n", tmp);
1972 			return -EINVAL;
1973 		}
1974 
1975 		sunxi_nand->sels[i].cs = tmp;
1976 
1977 		if (!of_property_read_u32_index(np, "allwinner,rb", i, &tmp) &&
1978 		    tmp < 2)
1979 			sunxi_nand->sels[i].rb = tmp;
1980 		else
1981 			sunxi_nand->sels[i].rb = -1;
1982 	}
1983 
1984 	nand = &sunxi_nand->nand;
1985 	/* Default tR value specified in the ONFI spec (chapter 4.15.1) */
1986 	nand->controller = &nfc->controller;
1987 	nand->controller->ops = &sunxi_nand_controller_ops;
1988 
1989 	/*
1990 	 * Set the ECC mode to the default value in case nothing is specified
1991 	 * in the DT.
1992 	 */
1993 	nand->ecc.mode = NAND_ECC_HW;
1994 	nand_set_flash_node(nand, np);
1995 
1996 	mtd = nand_to_mtd(nand);
1997 	mtd->dev.parent = dev;
1998 
1999 	ret = nand_scan(nand, nsels);
2000 	if (ret)
2001 		return ret;
2002 
2003 	ret = mtd_device_register(mtd, NULL, 0);
2004 	if (ret) {
2005 		dev_err(dev, "failed to register mtd device: %d\n", ret);
2006 		nand_release(nand);
2007 		return ret;
2008 	}
2009 
2010 	list_add_tail(&sunxi_nand->node, &nfc->chips);
2011 
2012 	return 0;
2013 }
2014 
2015 static int sunxi_nand_chips_init(struct device *dev, struct sunxi_nfc *nfc)
2016 {
2017 	struct device_node *np = dev->of_node;
2018 	struct device_node *nand_np;
2019 	int nchips = of_get_child_count(np);
2020 	int ret;
2021 
2022 	if (nchips > 8) {
2023 		dev_err(dev, "too many NAND chips: %d (max = 8)\n", nchips);
2024 		return -EINVAL;
2025 	}
2026 
2027 	for_each_child_of_node(np, nand_np) {
2028 		ret = sunxi_nand_chip_init(dev, nfc, nand_np);
2029 		if (ret) {
2030 			of_node_put(nand_np);
2031 			return ret;
2032 		}
2033 	}
2034 
2035 	return 0;
2036 }
2037 
2038 static void sunxi_nand_chips_cleanup(struct sunxi_nfc *nfc)
2039 {
2040 	struct sunxi_nand_chip *sunxi_nand;
2041 
2042 	while (!list_empty(&nfc->chips)) {
2043 		sunxi_nand = list_first_entry(&nfc->chips,
2044 					      struct sunxi_nand_chip,
2045 					      node);
2046 		nand_release(&sunxi_nand->nand);
2047 		sunxi_nand_ecc_cleanup(&sunxi_nand->nand.ecc);
2048 		list_del(&sunxi_nand->node);
2049 	}
2050 }
2051 
2052 static int sunxi_nfc_probe(struct platform_device *pdev)
2053 {
2054 	struct device *dev = &pdev->dev;
2055 	struct resource *r;
2056 	struct sunxi_nfc *nfc;
2057 	int irq;
2058 	int ret;
2059 
2060 	nfc = devm_kzalloc(dev, sizeof(*nfc), GFP_KERNEL);
2061 	if (!nfc)
2062 		return -ENOMEM;
2063 
2064 	nfc->dev = dev;
2065 	nand_controller_init(&nfc->controller);
2066 	INIT_LIST_HEAD(&nfc->chips);
2067 
2068 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
2069 	nfc->regs = devm_ioremap_resource(dev, r);
2070 	if (IS_ERR(nfc->regs))
2071 		return PTR_ERR(nfc->regs);
2072 
2073 	irq = platform_get_irq(pdev, 0);
2074 	if (irq < 0)
2075 		return irq;
2076 
2077 	nfc->ahb_clk = devm_clk_get(dev, "ahb");
2078 	if (IS_ERR(nfc->ahb_clk)) {
2079 		dev_err(dev, "failed to retrieve ahb clk\n");
2080 		return PTR_ERR(nfc->ahb_clk);
2081 	}
2082 
2083 	ret = clk_prepare_enable(nfc->ahb_clk);
2084 	if (ret)
2085 		return ret;
2086 
2087 	nfc->mod_clk = devm_clk_get(dev, "mod");
2088 	if (IS_ERR(nfc->mod_clk)) {
2089 		dev_err(dev, "failed to retrieve mod clk\n");
2090 		ret = PTR_ERR(nfc->mod_clk);
2091 		goto out_ahb_clk_unprepare;
2092 	}
2093 
2094 	ret = clk_prepare_enable(nfc->mod_clk);
2095 	if (ret)
2096 		goto out_ahb_clk_unprepare;
2097 
2098 	nfc->reset = devm_reset_control_get_optional_exclusive(dev, "ahb");
2099 	if (IS_ERR(nfc->reset)) {
2100 		ret = PTR_ERR(nfc->reset);
2101 		goto out_mod_clk_unprepare;
2102 	}
2103 
2104 	ret = reset_control_deassert(nfc->reset);
2105 	if (ret) {
2106 		dev_err(dev, "reset err %d\n", ret);
2107 		goto out_mod_clk_unprepare;
2108 	}
2109 
2110 	nfc->caps = of_device_get_match_data(&pdev->dev);
2111 	if (!nfc->caps) {
2112 		ret = -EINVAL;
2113 		goto out_ahb_reset_reassert;
2114 	}
2115 
2116 	ret = sunxi_nfc_rst(nfc);
2117 	if (ret)
2118 		goto out_ahb_reset_reassert;
2119 
2120 	writel(0, nfc->regs + NFC_REG_INT);
2121 	ret = devm_request_irq(dev, irq, sunxi_nfc_interrupt,
2122 			       0, "sunxi-nand", nfc);
2123 	if (ret)
2124 		goto out_ahb_reset_reassert;
2125 
2126 	nfc->dmac = dma_request_slave_channel(dev, "rxtx");
2127 	if (nfc->dmac) {
2128 		struct dma_slave_config dmac_cfg = { };
2129 
2130 		dmac_cfg.src_addr = r->start + nfc->caps->reg_io_data;
2131 		dmac_cfg.dst_addr = dmac_cfg.src_addr;
2132 		dmac_cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
2133 		dmac_cfg.dst_addr_width = dmac_cfg.src_addr_width;
2134 		dmac_cfg.src_maxburst = nfc->caps->dma_maxburst;
2135 		dmac_cfg.dst_maxburst = nfc->caps->dma_maxburst;
2136 		dmaengine_slave_config(nfc->dmac, &dmac_cfg);
2137 
2138 		if (nfc->caps->extra_mbus_conf)
2139 			writel(readl(nfc->regs + NFC_REG_CTL) |
2140 			       NFC_DMA_TYPE_NORMAL, nfc->regs + NFC_REG_CTL);
2141 
2142 	} else {
2143 		dev_warn(dev, "failed to request rxtx DMA channel\n");
2144 	}
2145 
2146 	platform_set_drvdata(pdev, nfc);
2147 
2148 	ret = sunxi_nand_chips_init(dev, nfc);
2149 	if (ret) {
2150 		dev_err(dev, "failed to init nand chips\n");
2151 		goto out_release_dmac;
2152 	}
2153 
2154 	return 0;
2155 
2156 out_release_dmac:
2157 	if (nfc->dmac)
2158 		dma_release_channel(nfc->dmac);
2159 out_ahb_reset_reassert:
2160 	reset_control_assert(nfc->reset);
2161 out_mod_clk_unprepare:
2162 	clk_disable_unprepare(nfc->mod_clk);
2163 out_ahb_clk_unprepare:
2164 	clk_disable_unprepare(nfc->ahb_clk);
2165 
2166 	return ret;
2167 }
2168 
2169 static int sunxi_nfc_remove(struct platform_device *pdev)
2170 {
2171 	struct sunxi_nfc *nfc = platform_get_drvdata(pdev);
2172 
2173 	sunxi_nand_chips_cleanup(nfc);
2174 
2175 	reset_control_assert(nfc->reset);
2176 
2177 	if (nfc->dmac)
2178 		dma_release_channel(nfc->dmac);
2179 	clk_disable_unprepare(nfc->mod_clk);
2180 	clk_disable_unprepare(nfc->ahb_clk);
2181 
2182 	return 0;
2183 }
2184 
2185 static const struct sunxi_nfc_caps sunxi_nfc_a10_caps = {
2186 	.reg_io_data = NFC_REG_A10_IO_DATA,
2187 	.dma_maxburst = 4,
2188 };
2189 
2190 static const struct sunxi_nfc_caps sunxi_nfc_a23_caps = {
2191 	.extra_mbus_conf = true,
2192 	.reg_io_data = NFC_REG_A23_IO_DATA,
2193 	.dma_maxburst = 8,
2194 };
2195 
2196 static const struct of_device_id sunxi_nfc_ids[] = {
2197 	{
2198 		.compatible = "allwinner,sun4i-a10-nand",
2199 		.data = &sunxi_nfc_a10_caps,
2200 	},
2201 	{
2202 		.compatible = "allwinner,sun8i-a23-nand-controller",
2203 		.data = &sunxi_nfc_a23_caps,
2204 	},
2205 	{ /* sentinel */ }
2206 };
2207 MODULE_DEVICE_TABLE(of, sunxi_nfc_ids);
2208 
2209 static struct platform_driver sunxi_nfc_driver = {
2210 	.driver = {
2211 		.name = "sunxi_nand",
2212 		.of_match_table = sunxi_nfc_ids,
2213 	},
2214 	.probe = sunxi_nfc_probe,
2215 	.remove = sunxi_nfc_remove,
2216 };
2217 module_platform_driver(sunxi_nfc_driver);
2218 
2219 MODULE_LICENSE("GPL");
2220 MODULE_AUTHOR("Boris BREZILLON");
2221 MODULE_DESCRIPTION("Allwinner NAND Flash Controller driver");
2222 MODULE_ALIAS("platform:sunxi_nand");
2223