xref: /openbmc/linux/drivers/mtd/nand/raw/sunxi_nand.c (revision ae0be8de)
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_IO_DATA		0x0030
46 #define NFC_REG_ECC_CTL		0x0034
47 #define NFC_REG_ECC_ST		0x0038
48 #define NFC_REG_DEBUG		0x003C
49 #define NFC_REG_ECC_ERR_CNT(x)	((0x0040 + (x)) & ~0x3)
50 #define NFC_REG_USER_DATA(x)	(0x0050 + ((x) * 4))
51 #define NFC_REG_SPARE_AREA	0x00A0
52 #define NFC_REG_PAT_ID		0x00A4
53 #define NFC_RAM0_BASE		0x0400
54 #define NFC_RAM1_BASE		0x0800
55 
56 /* define bit use in NFC_CTL */
57 #define NFC_EN			BIT(0)
58 #define NFC_RESET		BIT(1)
59 #define NFC_BUS_WIDTH_MSK	BIT(2)
60 #define NFC_BUS_WIDTH_8		(0 << 2)
61 #define NFC_BUS_WIDTH_16	(1 << 2)
62 #define NFC_RB_SEL_MSK		BIT(3)
63 #define NFC_RB_SEL(x)		((x) << 3)
64 #define NFC_CE_SEL_MSK		GENMASK(26, 24)
65 #define NFC_CE_SEL(x)		((x) << 24)
66 #define NFC_CE_CTL		BIT(6)
67 #define NFC_PAGE_SHIFT_MSK	GENMASK(11, 8)
68 #define NFC_PAGE_SHIFT(x)	(((x) < 10 ? 0 : (x) - 10) << 8)
69 #define NFC_SAM			BIT(12)
70 #define NFC_RAM_METHOD		BIT(14)
71 #define NFC_DEBUG_CTL		BIT(31)
72 
73 /* define bit use in NFC_ST */
74 #define NFC_RB_B2R		BIT(0)
75 #define NFC_CMD_INT_FLAG	BIT(1)
76 #define NFC_DMA_INT_FLAG	BIT(2)
77 #define NFC_CMD_FIFO_STATUS	BIT(3)
78 #define NFC_STA			BIT(4)
79 #define NFC_NATCH_INT_FLAG	BIT(5)
80 #define NFC_RB_STATE(x)		BIT(x + 8)
81 
82 /* define bit use in NFC_INT */
83 #define NFC_B2R_INT_ENABLE	BIT(0)
84 #define NFC_CMD_INT_ENABLE	BIT(1)
85 #define NFC_DMA_INT_ENABLE	BIT(2)
86 #define NFC_INT_MASK		(NFC_B2R_INT_ENABLE | \
87 				 NFC_CMD_INT_ENABLE | \
88 				 NFC_DMA_INT_ENABLE)
89 
90 /* define bit use in NFC_TIMING_CTL */
91 #define NFC_TIMING_CTL_EDO	BIT(8)
92 
93 /* define NFC_TIMING_CFG register layout */
94 #define NFC_TIMING_CFG(tWB, tADL, tWHR, tRHW, tCAD)		\
95 	(((tWB) & 0x3) | (((tADL) & 0x3) << 2) |		\
96 	(((tWHR) & 0x3) << 4) | (((tRHW) & 0x3) << 6) |		\
97 	(((tCAD) & 0x7) << 8))
98 
99 /* define bit use in NFC_CMD */
100 #define NFC_CMD_LOW_BYTE_MSK	GENMASK(7, 0)
101 #define NFC_CMD_HIGH_BYTE_MSK	GENMASK(15, 8)
102 #define NFC_CMD(x)		(x)
103 #define NFC_ADR_NUM_MSK		GENMASK(18, 16)
104 #define NFC_ADR_NUM(x)		(((x) - 1) << 16)
105 #define NFC_SEND_ADR		BIT(19)
106 #define NFC_ACCESS_DIR		BIT(20)
107 #define NFC_DATA_TRANS		BIT(21)
108 #define NFC_SEND_CMD1		BIT(22)
109 #define NFC_WAIT_FLAG		BIT(23)
110 #define NFC_SEND_CMD2		BIT(24)
111 #define NFC_SEQ			BIT(25)
112 #define NFC_DATA_SWAP_METHOD	BIT(26)
113 #define NFC_ROW_AUTO_INC	BIT(27)
114 #define NFC_SEND_CMD3		BIT(28)
115 #define NFC_SEND_CMD4		BIT(29)
116 #define NFC_CMD_TYPE_MSK	GENMASK(31, 30)
117 #define NFC_NORMAL_OP		(0 << 30)
118 #define NFC_ECC_OP		(1 << 30)
119 #define NFC_PAGE_OP		(2U << 30)
120 
121 /* define bit use in NFC_RCMD_SET */
122 #define NFC_READ_CMD_MSK	GENMASK(7, 0)
123 #define NFC_RND_READ_CMD0_MSK	GENMASK(15, 8)
124 #define NFC_RND_READ_CMD1_MSK	GENMASK(23, 16)
125 
126 /* define bit use in NFC_WCMD_SET */
127 #define NFC_PROGRAM_CMD_MSK	GENMASK(7, 0)
128 #define NFC_RND_WRITE_CMD_MSK	GENMASK(15, 8)
129 #define NFC_READ_CMD0_MSK	GENMASK(23, 16)
130 #define NFC_READ_CMD1_MSK	GENMASK(31, 24)
131 
132 /* define bit use in NFC_ECC_CTL */
133 #define NFC_ECC_EN		BIT(0)
134 #define NFC_ECC_PIPELINE	BIT(3)
135 #define NFC_ECC_EXCEPTION	BIT(4)
136 #define NFC_ECC_BLOCK_SIZE_MSK	BIT(5)
137 #define NFC_ECC_BLOCK_512	BIT(5)
138 #define NFC_RANDOM_EN		BIT(9)
139 #define NFC_RANDOM_DIRECTION	BIT(10)
140 #define NFC_ECC_MODE_MSK	GENMASK(15, 12)
141 #define NFC_ECC_MODE(x)		((x) << 12)
142 #define NFC_RANDOM_SEED_MSK	GENMASK(30, 16)
143 #define NFC_RANDOM_SEED(x)	((x) << 16)
144 
145 /* define bit use in NFC_ECC_ST */
146 #define NFC_ECC_ERR(x)		BIT(x)
147 #define NFC_ECC_ERR_MSK		GENMASK(15, 0)
148 #define NFC_ECC_PAT_FOUND(x)	BIT(x + 16)
149 #define NFC_ECC_ERR_CNT(b, x)	(((x) >> (((b) % 4) * 8)) & 0xff)
150 
151 #define NFC_DEFAULT_TIMEOUT_MS	1000
152 
153 #define NFC_SRAM_SIZE		1024
154 
155 #define NFC_MAX_CS		7
156 
157 /**
158  * struct sunxi_nand_chip_sel - stores information related to NAND Chip Select
159  *
160  * @cs: the NAND CS id used to communicate with a NAND Chip
161  * @rb: the Ready/Busy pin ID. -1 means no R/B pin connected to the NFC
162  */
163 struct sunxi_nand_chip_sel {
164 	u8 cs;
165 	s8 rb;
166 };
167 
168 /**
169  * struct sunxi_nand_hw_ecc - stores information related to HW ECC support
170  *
171  * @mode: the sunxi ECC mode field deduced from ECC requirements
172  */
173 struct sunxi_nand_hw_ecc {
174 	int mode;
175 };
176 
177 /**
178  * struct sunxi_nand_chip - stores NAND chip device related information
179  *
180  * @node: used to store NAND chips into a list
181  * @nand: base NAND chip structure
182  * @clk_rate: clk_rate required for this NAND chip
183  * @timing_cfg: TIMING_CFG register value for this NAND chip
184  * @timing_ctl: TIMING_CTL register value for this NAND chip
185  * @nsels: number of CS lines required by the NAND chip
186  * @sels: array of CS lines descriptions
187  */
188 struct sunxi_nand_chip {
189 	struct list_head node;
190 	struct nand_chip nand;
191 	unsigned long clk_rate;
192 	u32 timing_cfg;
193 	u32 timing_ctl;
194 	int nsels;
195 	struct sunxi_nand_chip_sel sels[0];
196 };
197 
198 static inline struct sunxi_nand_chip *to_sunxi_nand(struct nand_chip *nand)
199 {
200 	return container_of(nand, struct sunxi_nand_chip, nand);
201 }
202 
203 /**
204  * struct sunxi_nfc - stores sunxi NAND controller information
205  *
206  * @controller: base controller structure
207  * @dev: parent device (used to print error messages)
208  * @regs: NAND controller registers
209  * @ahb_clk: NAND controller AHB clock
210  * @mod_clk: NAND controller mod clock
211  * @reset: NAND controller reset line
212  * @assigned_cs: bitmask describing already assigned CS lines
213  * @clk_rate: NAND controller current clock rate
214  * @chips: a list containing all the NAND chips attached to this NAND
215  *	   controller
216  * @complete: a completion object used to wait for NAND controller events
217  * @dmac: the DMA channel attached to the NAND controller
218  */
219 struct sunxi_nfc {
220 	struct nand_controller controller;
221 	struct device *dev;
222 	void __iomem *regs;
223 	struct clk *ahb_clk;
224 	struct clk *mod_clk;
225 	struct reset_control *reset;
226 	unsigned long assigned_cs;
227 	unsigned long clk_rate;
228 	struct list_head chips;
229 	struct completion complete;
230 	struct dma_chan *dmac;
231 };
232 
233 static inline struct sunxi_nfc *to_sunxi_nfc(struct nand_controller *ctrl)
234 {
235 	return container_of(ctrl, struct sunxi_nfc, controller);
236 }
237 
238 static irqreturn_t sunxi_nfc_interrupt(int irq, void *dev_id)
239 {
240 	struct sunxi_nfc *nfc = dev_id;
241 	u32 st = readl(nfc->regs + NFC_REG_ST);
242 	u32 ien = readl(nfc->regs + NFC_REG_INT);
243 
244 	if (!(ien & st))
245 		return IRQ_NONE;
246 
247 	if ((ien & st) == ien)
248 		complete(&nfc->complete);
249 
250 	writel(st & NFC_INT_MASK, nfc->regs + NFC_REG_ST);
251 	writel(~st & ien & NFC_INT_MASK, nfc->regs + NFC_REG_INT);
252 
253 	return IRQ_HANDLED;
254 }
255 
256 static int sunxi_nfc_wait_events(struct sunxi_nfc *nfc, u32 events,
257 				 bool use_polling, unsigned int timeout_ms)
258 {
259 	int ret;
260 
261 	if (events & ~NFC_INT_MASK)
262 		return -EINVAL;
263 
264 	if (!timeout_ms)
265 		timeout_ms = NFC_DEFAULT_TIMEOUT_MS;
266 
267 	if (!use_polling) {
268 		init_completion(&nfc->complete);
269 
270 		writel(events, nfc->regs + NFC_REG_INT);
271 
272 		ret = wait_for_completion_timeout(&nfc->complete,
273 						msecs_to_jiffies(timeout_ms));
274 		if (!ret)
275 			ret = -ETIMEDOUT;
276 		else
277 			ret = 0;
278 
279 		writel(0, nfc->regs + NFC_REG_INT);
280 	} else {
281 		u32 status;
282 
283 		ret = readl_poll_timeout(nfc->regs + NFC_REG_ST, status,
284 					 (status & events) == events, 1,
285 					 timeout_ms * 1000);
286 	}
287 
288 	writel(events & NFC_INT_MASK, nfc->regs + NFC_REG_ST);
289 
290 	if (ret)
291 		dev_err(nfc->dev, "wait interrupt timedout\n");
292 
293 	return ret;
294 }
295 
296 static int sunxi_nfc_wait_cmd_fifo_empty(struct sunxi_nfc *nfc)
297 {
298 	u32 status;
299 	int ret;
300 
301 	ret = readl_poll_timeout(nfc->regs + NFC_REG_ST, status,
302 				 !(status & NFC_CMD_FIFO_STATUS), 1,
303 				 NFC_DEFAULT_TIMEOUT_MS * 1000);
304 	if (ret)
305 		dev_err(nfc->dev, "wait for empty cmd FIFO timedout\n");
306 
307 	return ret;
308 }
309 
310 static int sunxi_nfc_rst(struct sunxi_nfc *nfc)
311 {
312 	u32 ctl;
313 	int ret;
314 
315 	writel(0, nfc->regs + NFC_REG_ECC_CTL);
316 	writel(NFC_RESET, nfc->regs + NFC_REG_CTL);
317 
318 	ret = readl_poll_timeout(nfc->regs + NFC_REG_CTL, ctl,
319 				 !(ctl & NFC_RESET), 1,
320 				 NFC_DEFAULT_TIMEOUT_MS * 1000);
321 	if (ret)
322 		dev_err(nfc->dev, "wait for NAND controller reset timedout\n");
323 
324 	return ret;
325 }
326 
327 static int sunxi_nfc_dma_op_prepare(struct sunxi_nfc *nfc, const void *buf,
328 				    int chunksize, int nchunks,
329 				    enum dma_data_direction ddir,
330 				    struct scatterlist *sg)
331 {
332 	struct dma_async_tx_descriptor *dmad;
333 	enum dma_transfer_direction tdir;
334 	dma_cookie_t dmat;
335 	int ret;
336 
337 	if (ddir == DMA_FROM_DEVICE)
338 		tdir = DMA_DEV_TO_MEM;
339 	else
340 		tdir = DMA_MEM_TO_DEV;
341 
342 	sg_init_one(sg, buf, nchunks * chunksize);
343 	ret = dma_map_sg(nfc->dev, sg, 1, ddir);
344 	if (!ret)
345 		return -ENOMEM;
346 
347 	dmad = dmaengine_prep_slave_sg(nfc->dmac, sg, 1, tdir, DMA_CTRL_ACK);
348 	if (!dmad) {
349 		ret = -EINVAL;
350 		goto err_unmap_buf;
351 	}
352 
353 	writel(readl(nfc->regs + NFC_REG_CTL) | NFC_RAM_METHOD,
354 	       nfc->regs + NFC_REG_CTL);
355 	writel(nchunks, nfc->regs + NFC_REG_SECTOR_NUM);
356 	writel(chunksize, nfc->regs + NFC_REG_CNT);
357 	dmat = dmaengine_submit(dmad);
358 
359 	ret = dma_submit_error(dmat);
360 	if (ret)
361 		goto err_clr_dma_flag;
362 
363 	return 0;
364 
365 err_clr_dma_flag:
366 	writel(readl(nfc->regs + NFC_REG_CTL) & ~NFC_RAM_METHOD,
367 	       nfc->regs + NFC_REG_CTL);
368 
369 err_unmap_buf:
370 	dma_unmap_sg(nfc->dev, sg, 1, ddir);
371 	return ret;
372 }
373 
374 static void sunxi_nfc_dma_op_cleanup(struct sunxi_nfc *nfc,
375 				     enum dma_data_direction ddir,
376 				     struct scatterlist *sg)
377 {
378 	dma_unmap_sg(nfc->dev, sg, 1, ddir);
379 	writel(readl(nfc->regs + NFC_REG_CTL) & ~NFC_RAM_METHOD,
380 	       nfc->regs + NFC_REG_CTL);
381 }
382 
383 static void sunxi_nfc_select_chip(struct nand_chip *nand, unsigned int cs)
384 {
385 	struct mtd_info *mtd = nand_to_mtd(nand);
386 	struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
387 	struct sunxi_nfc *nfc = to_sunxi_nfc(sunxi_nand->nand.controller);
388 	struct sunxi_nand_chip_sel *sel;
389 	u32 ctl;
390 
391 	if (cs > 0 && cs >= sunxi_nand->nsels)
392 		return;
393 
394 	ctl = readl(nfc->regs + NFC_REG_CTL) &
395 	      ~(NFC_PAGE_SHIFT_MSK | NFC_CE_SEL_MSK | NFC_RB_SEL_MSK | NFC_EN);
396 
397 	sel = &sunxi_nand->sels[cs];
398 	ctl |= NFC_CE_SEL(sel->cs) | NFC_EN | NFC_PAGE_SHIFT(nand->page_shift);
399 	if (sel->rb >= 0)
400 		ctl |= NFC_RB_SEL(sel->rb);
401 
402 	writel(mtd->writesize, nfc->regs + NFC_REG_SPARE_AREA);
403 
404 	if (nfc->clk_rate != sunxi_nand->clk_rate) {
405 		clk_set_rate(nfc->mod_clk, sunxi_nand->clk_rate);
406 		nfc->clk_rate = sunxi_nand->clk_rate;
407 	}
408 
409 	writel(sunxi_nand->timing_ctl, nfc->regs + NFC_REG_TIMING_CTL);
410 	writel(sunxi_nand->timing_cfg, nfc->regs + NFC_REG_TIMING_CFG);
411 	writel(ctl, nfc->regs + NFC_REG_CTL);
412 }
413 
414 static void sunxi_nfc_read_buf(struct nand_chip *nand, uint8_t *buf, int len)
415 {
416 	struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
417 	struct sunxi_nfc *nfc = to_sunxi_nfc(sunxi_nand->nand.controller);
418 	int ret;
419 	int cnt;
420 	int offs = 0;
421 	u32 tmp;
422 
423 	while (len > offs) {
424 		bool poll = false;
425 
426 		cnt = min(len - offs, NFC_SRAM_SIZE);
427 
428 		ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
429 		if (ret)
430 			break;
431 
432 		writel(cnt, nfc->regs + NFC_REG_CNT);
433 		tmp = NFC_DATA_TRANS | NFC_DATA_SWAP_METHOD;
434 		writel(tmp, nfc->regs + NFC_REG_CMD);
435 
436 		/* Arbitrary limit for polling mode */
437 		if (cnt < 64)
438 			poll = true;
439 
440 		ret = sunxi_nfc_wait_events(nfc, NFC_CMD_INT_FLAG, poll, 0);
441 		if (ret)
442 			break;
443 
444 		if (buf)
445 			memcpy_fromio(buf + offs, nfc->regs + NFC_RAM0_BASE,
446 				      cnt);
447 		offs += cnt;
448 	}
449 }
450 
451 static void sunxi_nfc_write_buf(struct nand_chip *nand, const uint8_t *buf,
452 				int len)
453 {
454 	struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
455 	struct sunxi_nfc *nfc = to_sunxi_nfc(sunxi_nand->nand.controller);
456 	int ret;
457 	int cnt;
458 	int offs = 0;
459 	u32 tmp;
460 
461 	while (len > offs) {
462 		bool poll = false;
463 
464 		cnt = min(len - offs, NFC_SRAM_SIZE);
465 
466 		ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
467 		if (ret)
468 			break;
469 
470 		writel(cnt, nfc->regs + NFC_REG_CNT);
471 		memcpy_toio(nfc->regs + NFC_RAM0_BASE, buf + offs, cnt);
472 		tmp = NFC_DATA_TRANS | NFC_DATA_SWAP_METHOD |
473 		      NFC_ACCESS_DIR;
474 		writel(tmp, nfc->regs + NFC_REG_CMD);
475 
476 		/* Arbitrary limit for polling mode */
477 		if (cnt < 64)
478 			poll = true;
479 
480 		ret = sunxi_nfc_wait_events(nfc, NFC_CMD_INT_FLAG, poll, 0);
481 		if (ret)
482 			break;
483 
484 		offs += cnt;
485 	}
486 }
487 
488 /* These seed values have been extracted from Allwinner's BSP */
489 static const u16 sunxi_nfc_randomizer_page_seeds[] = {
490 	0x2b75, 0x0bd0, 0x5ca3, 0x62d1, 0x1c93, 0x07e9, 0x2162, 0x3a72,
491 	0x0d67, 0x67f9, 0x1be7, 0x077d, 0x032f, 0x0dac, 0x2716, 0x2436,
492 	0x7922, 0x1510, 0x3860, 0x5287, 0x480f, 0x4252, 0x1789, 0x5a2d,
493 	0x2a49, 0x5e10, 0x437f, 0x4b4e, 0x2f45, 0x216e, 0x5cb7, 0x7130,
494 	0x2a3f, 0x60e4, 0x4dc9, 0x0ef0, 0x0f52, 0x1bb9, 0x6211, 0x7a56,
495 	0x226d, 0x4ea7, 0x6f36, 0x3692, 0x38bf, 0x0c62, 0x05eb, 0x4c55,
496 	0x60f4, 0x728c, 0x3b6f, 0x2037, 0x7f69, 0x0936, 0x651a, 0x4ceb,
497 	0x6218, 0x79f3, 0x383f, 0x18d9, 0x4f05, 0x5c82, 0x2912, 0x6f17,
498 	0x6856, 0x5938, 0x1007, 0x61ab, 0x3e7f, 0x57c2, 0x542f, 0x4f62,
499 	0x7454, 0x2eac, 0x7739, 0x42d4, 0x2f90, 0x435a, 0x2e52, 0x2064,
500 	0x637c, 0x66ad, 0x2c90, 0x0bad, 0x759c, 0x0029, 0x0986, 0x7126,
501 	0x1ca7, 0x1605, 0x386a, 0x27f5, 0x1380, 0x6d75, 0x24c3, 0x0f8e,
502 	0x2b7a, 0x1418, 0x1fd1, 0x7dc1, 0x2d8e, 0x43af, 0x2267, 0x7da3,
503 	0x4e3d, 0x1338, 0x50db, 0x454d, 0x764d, 0x40a3, 0x42e6, 0x262b,
504 	0x2d2e, 0x1aea, 0x2e17, 0x173d, 0x3a6e, 0x71bf, 0x25f9, 0x0a5d,
505 	0x7c57, 0x0fbe, 0x46ce, 0x4939, 0x6b17, 0x37bb, 0x3e91, 0x76db,
506 };
507 
508 /*
509  * sunxi_nfc_randomizer_ecc512_seeds and sunxi_nfc_randomizer_ecc1024_seeds
510  * have been generated using
511  * sunxi_nfc_randomizer_step(seed, (step_size * 8) + 15), which is what
512  * the randomizer engine does internally before de/scrambling OOB data.
513  *
514  * Those tables are statically defined to avoid calculating randomizer state
515  * at runtime.
516  */
517 static const u16 sunxi_nfc_randomizer_ecc512_seeds[] = {
518 	0x3346, 0x367f, 0x1f18, 0x769a, 0x4f64, 0x068c, 0x2ef1, 0x6b64,
519 	0x28a9, 0x15d7, 0x30f8, 0x3659, 0x53db, 0x7c5f, 0x71d4, 0x4409,
520 	0x26eb, 0x03cc, 0x655d, 0x47d4, 0x4daa, 0x0877, 0x712d, 0x3617,
521 	0x3264, 0x49aa, 0x7f9e, 0x588e, 0x4fbc, 0x7176, 0x7f91, 0x6c6d,
522 	0x4b95, 0x5fb7, 0x3844, 0x4037, 0x0184, 0x081b, 0x0ee8, 0x5b91,
523 	0x293d, 0x1f71, 0x0e6f, 0x402b, 0x5122, 0x1e52, 0x22be, 0x3d2d,
524 	0x75bc, 0x7c60, 0x6291, 0x1a2f, 0x61d4, 0x74aa, 0x4140, 0x29ab,
525 	0x472d, 0x2852, 0x017e, 0x15e8, 0x5ec2, 0x17cf, 0x7d0f, 0x06b8,
526 	0x117a, 0x6b94, 0x789b, 0x3126, 0x6ac5, 0x5be7, 0x150f, 0x51f8,
527 	0x7889, 0x0aa5, 0x663d, 0x77e8, 0x0b87, 0x3dcb, 0x360d, 0x218b,
528 	0x512f, 0x7dc9, 0x6a4d, 0x630a, 0x3547, 0x1dd2, 0x5aea, 0x69a5,
529 	0x7bfa, 0x5e4f, 0x1519, 0x6430, 0x3a0e, 0x5eb3, 0x5425, 0x0c7a,
530 	0x5540, 0x3670, 0x63c1, 0x31e9, 0x5a39, 0x2de7, 0x5979, 0x2891,
531 	0x1562, 0x014b, 0x5b05, 0x2756, 0x5a34, 0x13aa, 0x6cb5, 0x2c36,
532 	0x5e72, 0x1306, 0x0861, 0x15ef, 0x1ee8, 0x5a37, 0x7ac4, 0x45dd,
533 	0x44c4, 0x7266, 0x2f41, 0x3ccc, 0x045e, 0x7d40, 0x7c66, 0x0fa0,
534 };
535 
536 static const u16 sunxi_nfc_randomizer_ecc1024_seeds[] = {
537 	0x2cf5, 0x35f1, 0x63a4, 0x5274, 0x2bd2, 0x778b, 0x7285, 0x32b6,
538 	0x6a5c, 0x70d6, 0x757d, 0x6769, 0x5375, 0x1e81, 0x0cf3, 0x3982,
539 	0x6787, 0x042a, 0x6c49, 0x1925, 0x56a8, 0x40a9, 0x063e, 0x7bd9,
540 	0x4dbf, 0x55ec, 0x672e, 0x7334, 0x5185, 0x4d00, 0x232a, 0x7e07,
541 	0x445d, 0x6b92, 0x528f, 0x4255, 0x53ba, 0x7d82, 0x2a2e, 0x3a4e,
542 	0x75eb, 0x450c, 0x6844, 0x1b5d, 0x581a, 0x4cc6, 0x0379, 0x37b2,
543 	0x419f, 0x0e92, 0x6b27, 0x5624, 0x01e3, 0x07c1, 0x44a5, 0x130c,
544 	0x13e8, 0x5910, 0x0876, 0x60c5, 0x54e3, 0x5b7f, 0x2269, 0x509f,
545 	0x7665, 0x36fd, 0x3e9a, 0x0579, 0x6295, 0x14ef, 0x0a81, 0x1bcc,
546 	0x4b16, 0x64db, 0x0514, 0x4f07, 0x0591, 0x3576, 0x6853, 0x0d9e,
547 	0x259f, 0x38b7, 0x64fb, 0x3094, 0x4693, 0x6ddd, 0x29bb, 0x0bc8,
548 	0x3f47, 0x490e, 0x0c0e, 0x7933, 0x3c9e, 0x5840, 0x398d, 0x3e68,
549 	0x4af1, 0x71f5, 0x57cf, 0x1121, 0x64eb, 0x3579, 0x15ac, 0x584d,
550 	0x5f2a, 0x47e2, 0x6528, 0x6eac, 0x196e, 0x6b96, 0x0450, 0x0179,
551 	0x609c, 0x06e1, 0x4626, 0x42c7, 0x273e, 0x486f, 0x0705, 0x1601,
552 	0x145b, 0x407e, 0x062b, 0x57a5, 0x53f9, 0x5659, 0x4410, 0x3ccd,
553 };
554 
555 static u16 sunxi_nfc_randomizer_step(u16 state, int count)
556 {
557 	state &= 0x7fff;
558 
559 	/*
560 	 * This loop is just a simple implementation of a Fibonacci LFSR using
561 	 * the x16 + x15 + 1 polynomial.
562 	 */
563 	while (count--)
564 		state = ((state >> 1) |
565 			 (((state ^ (state >> 1)) & 1) << 14)) & 0x7fff;
566 
567 	return state;
568 }
569 
570 static u16 sunxi_nfc_randomizer_state(struct nand_chip *nand, int page,
571 				      bool ecc)
572 {
573 	struct mtd_info *mtd = nand_to_mtd(nand);
574 	const u16 *seeds = sunxi_nfc_randomizer_page_seeds;
575 	int mod = mtd_div_by_ws(mtd->erasesize, mtd);
576 
577 	if (mod > ARRAY_SIZE(sunxi_nfc_randomizer_page_seeds))
578 		mod = ARRAY_SIZE(sunxi_nfc_randomizer_page_seeds);
579 
580 	if (ecc) {
581 		if (mtd->ecc_step_size == 512)
582 			seeds = sunxi_nfc_randomizer_ecc512_seeds;
583 		else
584 			seeds = sunxi_nfc_randomizer_ecc1024_seeds;
585 	}
586 
587 	return seeds[page % mod];
588 }
589 
590 static void sunxi_nfc_randomizer_config(struct nand_chip *nand, int page,
591 					bool ecc)
592 {
593 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
594 	u32 ecc_ctl = readl(nfc->regs + NFC_REG_ECC_CTL);
595 	u16 state;
596 
597 	if (!(nand->options & NAND_NEED_SCRAMBLING))
598 		return;
599 
600 	ecc_ctl = readl(nfc->regs + NFC_REG_ECC_CTL);
601 	state = sunxi_nfc_randomizer_state(nand, page, ecc);
602 	ecc_ctl = readl(nfc->regs + NFC_REG_ECC_CTL) & ~NFC_RANDOM_SEED_MSK;
603 	writel(ecc_ctl | NFC_RANDOM_SEED(state), nfc->regs + NFC_REG_ECC_CTL);
604 }
605 
606 static void sunxi_nfc_randomizer_enable(struct nand_chip *nand)
607 {
608 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
609 
610 	if (!(nand->options & NAND_NEED_SCRAMBLING))
611 		return;
612 
613 	writel(readl(nfc->regs + NFC_REG_ECC_CTL) | NFC_RANDOM_EN,
614 	       nfc->regs + NFC_REG_ECC_CTL);
615 }
616 
617 static void sunxi_nfc_randomizer_disable(struct nand_chip *nand)
618 {
619 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
620 
621 	if (!(nand->options & NAND_NEED_SCRAMBLING))
622 		return;
623 
624 	writel(readl(nfc->regs + NFC_REG_ECC_CTL) & ~NFC_RANDOM_EN,
625 	       nfc->regs + NFC_REG_ECC_CTL);
626 }
627 
628 static void sunxi_nfc_randomize_bbm(struct nand_chip *nand, int page, u8 *bbm)
629 {
630 	u16 state = sunxi_nfc_randomizer_state(nand, page, true);
631 
632 	bbm[0] ^= state;
633 	bbm[1] ^= sunxi_nfc_randomizer_step(state, 8);
634 }
635 
636 static void sunxi_nfc_randomizer_write_buf(struct nand_chip *nand,
637 					   const uint8_t *buf, int len,
638 					   bool ecc, int page)
639 {
640 	sunxi_nfc_randomizer_config(nand, page, ecc);
641 	sunxi_nfc_randomizer_enable(nand);
642 	sunxi_nfc_write_buf(nand, buf, len);
643 	sunxi_nfc_randomizer_disable(nand);
644 }
645 
646 static void sunxi_nfc_randomizer_read_buf(struct nand_chip *nand, uint8_t *buf,
647 					  int len, bool ecc, int page)
648 {
649 	sunxi_nfc_randomizer_config(nand, page, ecc);
650 	sunxi_nfc_randomizer_enable(nand);
651 	sunxi_nfc_read_buf(nand, buf, len);
652 	sunxi_nfc_randomizer_disable(nand);
653 }
654 
655 static void sunxi_nfc_hw_ecc_enable(struct nand_chip *nand)
656 {
657 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
658 	struct sunxi_nand_hw_ecc *data = nand->ecc.priv;
659 	u32 ecc_ctl;
660 
661 	ecc_ctl = readl(nfc->regs + NFC_REG_ECC_CTL);
662 	ecc_ctl &= ~(NFC_ECC_MODE_MSK | NFC_ECC_PIPELINE |
663 		     NFC_ECC_BLOCK_SIZE_MSK);
664 	ecc_ctl |= NFC_ECC_EN | NFC_ECC_MODE(data->mode) | NFC_ECC_EXCEPTION |
665 		   NFC_ECC_PIPELINE;
666 
667 	if (nand->ecc.size == 512)
668 		ecc_ctl |= NFC_ECC_BLOCK_512;
669 
670 	writel(ecc_ctl, nfc->regs + NFC_REG_ECC_CTL);
671 }
672 
673 static void sunxi_nfc_hw_ecc_disable(struct nand_chip *nand)
674 {
675 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
676 
677 	writel(readl(nfc->regs + NFC_REG_ECC_CTL) & ~NFC_ECC_EN,
678 	       nfc->regs + NFC_REG_ECC_CTL);
679 }
680 
681 static inline void sunxi_nfc_user_data_to_buf(u32 user_data, u8 *buf)
682 {
683 	buf[0] = user_data;
684 	buf[1] = user_data >> 8;
685 	buf[2] = user_data >> 16;
686 	buf[3] = user_data >> 24;
687 }
688 
689 static inline u32 sunxi_nfc_buf_to_user_data(const u8 *buf)
690 {
691 	return buf[0] | (buf[1] << 8) | (buf[2] << 16) | (buf[3] << 24);
692 }
693 
694 static void sunxi_nfc_hw_ecc_get_prot_oob_bytes(struct nand_chip *nand, u8 *oob,
695 						int step, bool bbm, int page)
696 {
697 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
698 
699 	sunxi_nfc_user_data_to_buf(readl(nfc->regs + NFC_REG_USER_DATA(step)),
700 				   oob);
701 
702 	/* De-randomize the Bad Block Marker. */
703 	if (bbm && (nand->options & NAND_NEED_SCRAMBLING))
704 		sunxi_nfc_randomize_bbm(nand, page, oob);
705 }
706 
707 static void sunxi_nfc_hw_ecc_set_prot_oob_bytes(struct nand_chip *nand,
708 						const u8 *oob, int step,
709 						bool bbm, int page)
710 {
711 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
712 	u8 user_data[4];
713 
714 	/* Randomize the Bad Block Marker. */
715 	if (bbm && (nand->options & NAND_NEED_SCRAMBLING)) {
716 		memcpy(user_data, oob, sizeof(user_data));
717 		sunxi_nfc_randomize_bbm(nand, page, user_data);
718 		oob = user_data;
719 	}
720 
721 	writel(sunxi_nfc_buf_to_user_data(oob),
722 	       nfc->regs + NFC_REG_USER_DATA(step));
723 }
724 
725 static void sunxi_nfc_hw_ecc_update_stats(struct nand_chip *nand,
726 					  unsigned int *max_bitflips, int ret)
727 {
728 	struct mtd_info *mtd = nand_to_mtd(nand);
729 
730 	if (ret < 0) {
731 		mtd->ecc_stats.failed++;
732 	} else {
733 		mtd->ecc_stats.corrected += ret;
734 		*max_bitflips = max_t(unsigned int, *max_bitflips, ret);
735 	}
736 }
737 
738 static int sunxi_nfc_hw_ecc_correct(struct nand_chip *nand, u8 *data, u8 *oob,
739 				    int step, u32 status, bool *erased)
740 {
741 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
742 	struct nand_ecc_ctrl *ecc = &nand->ecc;
743 	u32 tmp;
744 
745 	*erased = false;
746 
747 	if (status & NFC_ECC_ERR(step))
748 		return -EBADMSG;
749 
750 	if (status & NFC_ECC_PAT_FOUND(step)) {
751 		u8 pattern;
752 
753 		if (unlikely(!(readl(nfc->regs + NFC_REG_PAT_ID) & 0x1))) {
754 			pattern = 0x0;
755 		} else {
756 			pattern = 0xff;
757 			*erased = true;
758 		}
759 
760 		if (data)
761 			memset(data, pattern, ecc->size);
762 
763 		if (oob)
764 			memset(oob, pattern, ecc->bytes + 4);
765 
766 		return 0;
767 	}
768 
769 	tmp = readl(nfc->regs + NFC_REG_ECC_ERR_CNT(step));
770 
771 	return NFC_ECC_ERR_CNT(step, tmp);
772 }
773 
774 static int sunxi_nfc_hw_ecc_read_chunk(struct nand_chip *nand,
775 				       u8 *data, int data_off,
776 				       u8 *oob, int oob_off,
777 				       int *cur_off,
778 				       unsigned int *max_bitflips,
779 				       bool bbm, bool oob_required, int page)
780 {
781 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
782 	struct nand_ecc_ctrl *ecc = &nand->ecc;
783 	int raw_mode = 0;
784 	bool erased;
785 	int ret;
786 
787 	if (*cur_off != data_off)
788 		nand_change_read_column_op(nand, data_off, NULL, 0, false);
789 
790 	sunxi_nfc_randomizer_read_buf(nand, NULL, ecc->size, false, page);
791 
792 	if (data_off + ecc->size != oob_off)
793 		nand_change_read_column_op(nand, oob_off, NULL, 0, false);
794 
795 	ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
796 	if (ret)
797 		return ret;
798 
799 	sunxi_nfc_randomizer_enable(nand);
800 	writel(NFC_DATA_TRANS | NFC_DATA_SWAP_METHOD | NFC_ECC_OP,
801 	       nfc->regs + NFC_REG_CMD);
802 
803 	ret = sunxi_nfc_wait_events(nfc, NFC_CMD_INT_FLAG, false, 0);
804 	sunxi_nfc_randomizer_disable(nand);
805 	if (ret)
806 		return ret;
807 
808 	*cur_off = oob_off + ecc->bytes + 4;
809 
810 	ret = sunxi_nfc_hw_ecc_correct(nand, data, oob_required ? oob : NULL, 0,
811 				       readl(nfc->regs + NFC_REG_ECC_ST),
812 				       &erased);
813 	if (erased)
814 		return 1;
815 
816 	if (ret < 0) {
817 		/*
818 		 * Re-read the data with the randomizer disabled to identify
819 		 * bitflips in erased pages.
820 		 */
821 		if (nand->options & NAND_NEED_SCRAMBLING)
822 			nand_change_read_column_op(nand, data_off, data,
823 						   ecc->size, false);
824 		else
825 			memcpy_fromio(data, nfc->regs + NFC_RAM0_BASE,
826 				      ecc->size);
827 
828 		nand_change_read_column_op(nand, oob_off, oob, ecc->bytes + 4,
829 					   false);
830 
831 		ret = nand_check_erased_ecc_chunk(data,	ecc->size,
832 						  oob, ecc->bytes + 4,
833 						  NULL, 0, ecc->strength);
834 		if (ret >= 0)
835 			raw_mode = 1;
836 	} else {
837 		memcpy_fromio(data, nfc->regs + NFC_RAM0_BASE, ecc->size);
838 
839 		if (oob_required) {
840 			nand_change_read_column_op(nand, oob_off, NULL, 0,
841 						   false);
842 			sunxi_nfc_randomizer_read_buf(nand, oob, ecc->bytes + 4,
843 						      true, page);
844 
845 			sunxi_nfc_hw_ecc_get_prot_oob_bytes(nand, oob, 0,
846 							    bbm, page);
847 		}
848 	}
849 
850 	sunxi_nfc_hw_ecc_update_stats(nand, max_bitflips, ret);
851 
852 	return raw_mode;
853 }
854 
855 static void sunxi_nfc_hw_ecc_read_extra_oob(struct nand_chip *nand,
856 					    u8 *oob, int *cur_off,
857 					    bool randomize, int page)
858 {
859 	struct mtd_info *mtd = nand_to_mtd(nand);
860 	struct nand_ecc_ctrl *ecc = &nand->ecc;
861 	int offset = ((ecc->bytes + 4) * ecc->steps);
862 	int len = mtd->oobsize - offset;
863 
864 	if (len <= 0)
865 		return;
866 
867 	if (!cur_off || *cur_off != offset)
868 		nand_change_read_column_op(nand, mtd->writesize, NULL, 0,
869 					   false);
870 
871 	if (!randomize)
872 		sunxi_nfc_read_buf(nand, oob + offset, len);
873 	else
874 		sunxi_nfc_randomizer_read_buf(nand, oob + offset, len,
875 					      false, page);
876 
877 	if (cur_off)
878 		*cur_off = mtd->oobsize + mtd->writesize;
879 }
880 
881 static int sunxi_nfc_hw_ecc_read_chunks_dma(struct nand_chip *nand, uint8_t *buf,
882 					    int oob_required, int page,
883 					    int nchunks)
884 {
885 	bool randomized = nand->options & NAND_NEED_SCRAMBLING;
886 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
887 	struct mtd_info *mtd = nand_to_mtd(nand);
888 	struct nand_ecc_ctrl *ecc = &nand->ecc;
889 	unsigned int max_bitflips = 0;
890 	int ret, i, raw_mode = 0;
891 	struct scatterlist sg;
892 	u32 status;
893 
894 	ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
895 	if (ret)
896 		return ret;
897 
898 	ret = sunxi_nfc_dma_op_prepare(nfc, buf, ecc->size, nchunks,
899 				       DMA_FROM_DEVICE, &sg);
900 	if (ret)
901 		return ret;
902 
903 	sunxi_nfc_hw_ecc_enable(nand);
904 	sunxi_nfc_randomizer_config(nand, page, false);
905 	sunxi_nfc_randomizer_enable(nand);
906 
907 	writel((NAND_CMD_RNDOUTSTART << 16) | (NAND_CMD_RNDOUT << 8) |
908 	       NAND_CMD_READSTART, nfc->regs + NFC_REG_RCMD_SET);
909 
910 	dma_async_issue_pending(nfc->dmac);
911 
912 	writel(NFC_PAGE_OP | NFC_DATA_SWAP_METHOD | NFC_DATA_TRANS,
913 	       nfc->regs + NFC_REG_CMD);
914 
915 	ret = sunxi_nfc_wait_events(nfc, NFC_CMD_INT_FLAG, false, 0);
916 	if (ret)
917 		dmaengine_terminate_all(nfc->dmac);
918 
919 	sunxi_nfc_randomizer_disable(nand);
920 	sunxi_nfc_hw_ecc_disable(nand);
921 
922 	sunxi_nfc_dma_op_cleanup(nfc, DMA_FROM_DEVICE, &sg);
923 
924 	if (ret)
925 		return ret;
926 
927 	status = readl(nfc->regs + NFC_REG_ECC_ST);
928 
929 	for (i = 0; i < nchunks; i++) {
930 		int data_off = i * ecc->size;
931 		int oob_off = i * (ecc->bytes + 4);
932 		u8 *data = buf + data_off;
933 		u8 *oob = nand->oob_poi + oob_off;
934 		bool erased;
935 
936 		ret = sunxi_nfc_hw_ecc_correct(nand, randomized ? data : NULL,
937 					       oob_required ? oob : NULL,
938 					       i, status, &erased);
939 
940 		/* ECC errors are handled in the second loop. */
941 		if (ret < 0)
942 			continue;
943 
944 		if (oob_required && !erased) {
945 			/* TODO: use DMA to retrieve OOB */
946 			nand_change_read_column_op(nand,
947 						   mtd->writesize + oob_off,
948 						   oob, ecc->bytes + 4, false);
949 
950 			sunxi_nfc_hw_ecc_get_prot_oob_bytes(nand, oob, i,
951 							    !i, page);
952 		}
953 
954 		if (erased)
955 			raw_mode = 1;
956 
957 		sunxi_nfc_hw_ecc_update_stats(nand, &max_bitflips, ret);
958 	}
959 
960 	if (status & NFC_ECC_ERR_MSK) {
961 		for (i = 0; i < nchunks; i++) {
962 			int data_off = i * ecc->size;
963 			int oob_off = i * (ecc->bytes + 4);
964 			u8 *data = buf + data_off;
965 			u8 *oob = nand->oob_poi + oob_off;
966 
967 			if (!(status & NFC_ECC_ERR(i)))
968 				continue;
969 
970 			/*
971 			 * Re-read the data with the randomizer disabled to
972 			 * identify bitflips in erased pages.
973 			 * TODO: use DMA to read page in raw mode
974 			 */
975 			if (randomized)
976 				nand_change_read_column_op(nand, data_off,
977 							   data, ecc->size,
978 							   false);
979 
980 			/* TODO: use DMA to retrieve OOB */
981 			nand_change_read_column_op(nand,
982 						   mtd->writesize + oob_off,
983 						   oob, ecc->bytes + 4, false);
984 
985 			ret = nand_check_erased_ecc_chunk(data,	ecc->size,
986 							  oob, ecc->bytes + 4,
987 							  NULL, 0,
988 							  ecc->strength);
989 			if (ret >= 0)
990 				raw_mode = 1;
991 
992 			sunxi_nfc_hw_ecc_update_stats(nand, &max_bitflips, ret);
993 		}
994 	}
995 
996 	if (oob_required)
997 		sunxi_nfc_hw_ecc_read_extra_oob(nand, nand->oob_poi,
998 						NULL, !raw_mode,
999 						page);
1000 
1001 	return max_bitflips;
1002 }
1003 
1004 static int sunxi_nfc_hw_ecc_write_chunk(struct nand_chip *nand,
1005 					const u8 *data, int data_off,
1006 					const u8 *oob, int oob_off,
1007 					int *cur_off, bool bbm,
1008 					int page)
1009 {
1010 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
1011 	struct nand_ecc_ctrl *ecc = &nand->ecc;
1012 	int ret;
1013 
1014 	if (data_off != *cur_off)
1015 		nand_change_write_column_op(nand, data_off, NULL, 0, false);
1016 
1017 	sunxi_nfc_randomizer_write_buf(nand, data, ecc->size, false, page);
1018 
1019 	if (data_off + ecc->size != oob_off)
1020 		nand_change_write_column_op(nand, oob_off, NULL, 0, false);
1021 
1022 	ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
1023 	if (ret)
1024 		return ret;
1025 
1026 	sunxi_nfc_randomizer_enable(nand);
1027 	sunxi_nfc_hw_ecc_set_prot_oob_bytes(nand, oob, 0, bbm, page);
1028 
1029 	writel(NFC_DATA_TRANS | NFC_DATA_SWAP_METHOD |
1030 	       NFC_ACCESS_DIR | NFC_ECC_OP,
1031 	       nfc->regs + NFC_REG_CMD);
1032 
1033 	ret = sunxi_nfc_wait_events(nfc, NFC_CMD_INT_FLAG, false, 0);
1034 	sunxi_nfc_randomizer_disable(nand);
1035 	if (ret)
1036 		return ret;
1037 
1038 	*cur_off = oob_off + ecc->bytes + 4;
1039 
1040 	return 0;
1041 }
1042 
1043 static void sunxi_nfc_hw_ecc_write_extra_oob(struct nand_chip *nand,
1044 					     u8 *oob, int *cur_off,
1045 					     int page)
1046 {
1047 	struct mtd_info *mtd = nand_to_mtd(nand);
1048 	struct nand_ecc_ctrl *ecc = &nand->ecc;
1049 	int offset = ((ecc->bytes + 4) * ecc->steps);
1050 	int len = mtd->oobsize - offset;
1051 
1052 	if (len <= 0)
1053 		return;
1054 
1055 	if (!cur_off || *cur_off != offset)
1056 		nand_change_write_column_op(nand, offset + mtd->writesize,
1057 					    NULL, 0, false);
1058 
1059 	sunxi_nfc_randomizer_write_buf(nand, oob + offset, len, false, page);
1060 
1061 	if (cur_off)
1062 		*cur_off = mtd->oobsize + mtd->writesize;
1063 }
1064 
1065 static int sunxi_nfc_hw_ecc_read_page(struct nand_chip *nand, uint8_t *buf,
1066 				      int oob_required, int page)
1067 {
1068 	struct mtd_info *mtd = nand_to_mtd(nand);
1069 	struct nand_ecc_ctrl *ecc = &nand->ecc;
1070 	unsigned int max_bitflips = 0;
1071 	int ret, i, cur_off = 0;
1072 	bool raw_mode = false;
1073 
1074 	sunxi_nfc_select_chip(nand, nand->cur_cs);
1075 
1076 	nand_read_page_op(nand, page, 0, NULL, 0);
1077 
1078 	sunxi_nfc_hw_ecc_enable(nand);
1079 
1080 	for (i = 0; i < ecc->steps; i++) {
1081 		int data_off = i * ecc->size;
1082 		int oob_off = i * (ecc->bytes + 4);
1083 		u8 *data = buf + data_off;
1084 		u8 *oob = nand->oob_poi + oob_off;
1085 
1086 		ret = sunxi_nfc_hw_ecc_read_chunk(nand, data, data_off, oob,
1087 						  oob_off + mtd->writesize,
1088 						  &cur_off, &max_bitflips,
1089 						  !i, oob_required, page);
1090 		if (ret < 0)
1091 			return ret;
1092 		else if (ret)
1093 			raw_mode = true;
1094 	}
1095 
1096 	if (oob_required)
1097 		sunxi_nfc_hw_ecc_read_extra_oob(nand, nand->oob_poi, &cur_off,
1098 						!raw_mode, page);
1099 
1100 	sunxi_nfc_hw_ecc_disable(nand);
1101 
1102 	return max_bitflips;
1103 }
1104 
1105 static int sunxi_nfc_hw_ecc_read_page_dma(struct nand_chip *nand, u8 *buf,
1106 					  int oob_required, int page)
1107 {
1108 	int ret;
1109 
1110 	sunxi_nfc_select_chip(nand, nand->cur_cs);
1111 
1112 	nand_read_page_op(nand, page, 0, NULL, 0);
1113 
1114 	ret = sunxi_nfc_hw_ecc_read_chunks_dma(nand, buf, oob_required, page,
1115 					       nand->ecc.steps);
1116 	if (ret >= 0)
1117 		return ret;
1118 
1119 	/* Fallback to PIO mode */
1120 	return sunxi_nfc_hw_ecc_read_page(nand, buf, oob_required, page);
1121 }
1122 
1123 static int sunxi_nfc_hw_ecc_read_subpage(struct nand_chip *nand,
1124 					 u32 data_offs, u32 readlen,
1125 					 u8 *bufpoi, int page)
1126 {
1127 	struct mtd_info *mtd = nand_to_mtd(nand);
1128 	struct nand_ecc_ctrl *ecc = &nand->ecc;
1129 	int ret, i, cur_off = 0;
1130 	unsigned int max_bitflips = 0;
1131 
1132 	sunxi_nfc_select_chip(nand, nand->cur_cs);
1133 
1134 	nand_read_page_op(nand, page, 0, NULL, 0);
1135 
1136 	sunxi_nfc_hw_ecc_enable(nand);
1137 
1138 	for (i = data_offs / ecc->size;
1139 	     i < DIV_ROUND_UP(data_offs + readlen, ecc->size); i++) {
1140 		int data_off = i * ecc->size;
1141 		int oob_off = i * (ecc->bytes + 4);
1142 		u8 *data = bufpoi + data_off;
1143 		u8 *oob = nand->oob_poi + oob_off;
1144 
1145 		ret = sunxi_nfc_hw_ecc_read_chunk(nand, data, data_off,
1146 						  oob,
1147 						  oob_off + mtd->writesize,
1148 						  &cur_off, &max_bitflips, !i,
1149 						  false, page);
1150 		if (ret < 0)
1151 			return ret;
1152 	}
1153 
1154 	sunxi_nfc_hw_ecc_disable(nand);
1155 
1156 	return max_bitflips;
1157 }
1158 
1159 static int sunxi_nfc_hw_ecc_read_subpage_dma(struct nand_chip *nand,
1160 					     u32 data_offs, u32 readlen,
1161 					     u8 *buf, int page)
1162 {
1163 	int nchunks = DIV_ROUND_UP(data_offs + readlen, nand->ecc.size);
1164 	int ret;
1165 
1166 	sunxi_nfc_select_chip(nand, nand->cur_cs);
1167 
1168 	nand_read_page_op(nand, page, 0, NULL, 0);
1169 
1170 	ret = sunxi_nfc_hw_ecc_read_chunks_dma(nand, buf, false, page, nchunks);
1171 	if (ret >= 0)
1172 		return ret;
1173 
1174 	/* Fallback to PIO mode */
1175 	return sunxi_nfc_hw_ecc_read_subpage(nand, data_offs, readlen,
1176 					     buf, page);
1177 }
1178 
1179 static int sunxi_nfc_hw_ecc_write_page(struct nand_chip *nand,
1180 				       const uint8_t *buf, int oob_required,
1181 				       int page)
1182 {
1183 	struct mtd_info *mtd = nand_to_mtd(nand);
1184 	struct nand_ecc_ctrl *ecc = &nand->ecc;
1185 	int ret, i, cur_off = 0;
1186 
1187 	sunxi_nfc_select_chip(nand, nand->cur_cs);
1188 
1189 	nand_prog_page_begin_op(nand, page, 0, NULL, 0);
1190 
1191 	sunxi_nfc_hw_ecc_enable(nand);
1192 
1193 	for (i = 0; i < ecc->steps; i++) {
1194 		int data_off = i * ecc->size;
1195 		int oob_off = i * (ecc->bytes + 4);
1196 		const u8 *data = buf + data_off;
1197 		const u8 *oob = nand->oob_poi + oob_off;
1198 
1199 		ret = sunxi_nfc_hw_ecc_write_chunk(nand, data, data_off, oob,
1200 						   oob_off + mtd->writesize,
1201 						   &cur_off, !i, page);
1202 		if (ret)
1203 			return ret;
1204 	}
1205 
1206 	if (oob_required || (nand->options & NAND_NEED_SCRAMBLING))
1207 		sunxi_nfc_hw_ecc_write_extra_oob(nand, nand->oob_poi,
1208 						 &cur_off, page);
1209 
1210 	sunxi_nfc_hw_ecc_disable(nand);
1211 
1212 	return nand_prog_page_end_op(nand);
1213 }
1214 
1215 static int sunxi_nfc_hw_ecc_write_subpage(struct nand_chip *nand,
1216 					  u32 data_offs, u32 data_len,
1217 					  const u8 *buf, int oob_required,
1218 					  int page)
1219 {
1220 	struct mtd_info *mtd = nand_to_mtd(nand);
1221 	struct nand_ecc_ctrl *ecc = &nand->ecc;
1222 	int ret, i, cur_off = 0;
1223 
1224 	sunxi_nfc_select_chip(nand, nand->cur_cs);
1225 
1226 	nand_prog_page_begin_op(nand, page, 0, NULL, 0);
1227 
1228 	sunxi_nfc_hw_ecc_enable(nand);
1229 
1230 	for (i = data_offs / ecc->size;
1231 	     i < DIV_ROUND_UP(data_offs + data_len, ecc->size); i++) {
1232 		int data_off = i * ecc->size;
1233 		int oob_off = i * (ecc->bytes + 4);
1234 		const u8 *data = buf + data_off;
1235 		const u8 *oob = nand->oob_poi + oob_off;
1236 
1237 		ret = sunxi_nfc_hw_ecc_write_chunk(nand, data, data_off, oob,
1238 						   oob_off + mtd->writesize,
1239 						   &cur_off, !i, page);
1240 		if (ret)
1241 			return ret;
1242 	}
1243 
1244 	sunxi_nfc_hw_ecc_disable(nand);
1245 
1246 	return nand_prog_page_end_op(nand);
1247 }
1248 
1249 static int sunxi_nfc_hw_ecc_write_page_dma(struct nand_chip *nand,
1250 					   const u8 *buf,
1251 					   int oob_required,
1252 					   int page)
1253 {
1254 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
1255 	struct nand_ecc_ctrl *ecc = &nand->ecc;
1256 	struct scatterlist sg;
1257 	int ret, i;
1258 
1259 	sunxi_nfc_select_chip(nand, nand->cur_cs);
1260 
1261 	ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
1262 	if (ret)
1263 		return ret;
1264 
1265 	ret = sunxi_nfc_dma_op_prepare(nfc, buf, ecc->size, ecc->steps,
1266 				       DMA_TO_DEVICE, &sg);
1267 	if (ret)
1268 		goto pio_fallback;
1269 
1270 	for (i = 0; i < ecc->steps; i++) {
1271 		const u8 *oob = nand->oob_poi + (i * (ecc->bytes + 4));
1272 
1273 		sunxi_nfc_hw_ecc_set_prot_oob_bytes(nand, oob, i, !i, page);
1274 	}
1275 
1276 	nand_prog_page_begin_op(nand, page, 0, NULL, 0);
1277 
1278 	sunxi_nfc_hw_ecc_enable(nand);
1279 	sunxi_nfc_randomizer_config(nand, page, false);
1280 	sunxi_nfc_randomizer_enable(nand);
1281 
1282 	writel((NAND_CMD_RNDIN << 8) | NAND_CMD_PAGEPROG,
1283 	       nfc->regs + NFC_REG_WCMD_SET);
1284 
1285 	dma_async_issue_pending(nfc->dmac);
1286 
1287 	writel(NFC_PAGE_OP | NFC_DATA_SWAP_METHOD |
1288 	       NFC_DATA_TRANS | NFC_ACCESS_DIR,
1289 	       nfc->regs + NFC_REG_CMD);
1290 
1291 	ret = sunxi_nfc_wait_events(nfc, NFC_CMD_INT_FLAG, false, 0);
1292 	if (ret)
1293 		dmaengine_terminate_all(nfc->dmac);
1294 
1295 	sunxi_nfc_randomizer_disable(nand);
1296 	sunxi_nfc_hw_ecc_disable(nand);
1297 
1298 	sunxi_nfc_dma_op_cleanup(nfc, DMA_TO_DEVICE, &sg);
1299 
1300 	if (ret)
1301 		return ret;
1302 
1303 	if (oob_required || (nand->options & NAND_NEED_SCRAMBLING))
1304 		/* TODO: use DMA to transfer extra OOB bytes ? */
1305 		sunxi_nfc_hw_ecc_write_extra_oob(nand, nand->oob_poi,
1306 						 NULL, page);
1307 
1308 	return nand_prog_page_end_op(nand);
1309 
1310 pio_fallback:
1311 	return sunxi_nfc_hw_ecc_write_page(nand, buf, oob_required, page);
1312 }
1313 
1314 static int sunxi_nfc_hw_ecc_read_oob(struct nand_chip *nand, int page)
1315 {
1316 	nand->pagebuf = -1;
1317 
1318 	return nand->ecc.read_page(nand, nand->data_buf, 1, page);
1319 }
1320 
1321 static int sunxi_nfc_hw_ecc_write_oob(struct nand_chip *nand, int page)
1322 {
1323 	struct mtd_info *mtd = nand_to_mtd(nand);
1324 	int ret;
1325 
1326 	nand->pagebuf = -1;
1327 
1328 	memset(nand->data_buf, 0xff, mtd->writesize);
1329 	ret = nand->ecc.write_page(nand, nand->data_buf, 1, page);
1330 	if (ret)
1331 		return ret;
1332 
1333 	/* Send command to program the OOB data */
1334 	return nand_prog_page_end_op(nand);
1335 }
1336 
1337 static const s32 tWB_lut[] = {6, 12, 16, 20};
1338 static const s32 tRHW_lut[] = {4, 8, 12, 20};
1339 
1340 static int _sunxi_nand_lookup_timing(const s32 *lut, int lut_size, u32 duration,
1341 		u32 clk_period)
1342 {
1343 	u32 clk_cycles = DIV_ROUND_UP(duration, clk_period);
1344 	int i;
1345 
1346 	for (i = 0; i < lut_size; i++) {
1347 		if (clk_cycles <= lut[i])
1348 			return i;
1349 	}
1350 
1351 	/* Doesn't fit */
1352 	return -EINVAL;
1353 }
1354 
1355 #define sunxi_nand_lookup_timing(l, p, c) \
1356 			_sunxi_nand_lookup_timing(l, ARRAY_SIZE(l), p, c)
1357 
1358 static int sunxi_nfc_setup_data_interface(struct nand_chip *nand, int csline,
1359 					const struct nand_data_interface *conf)
1360 {
1361 	struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
1362 	struct sunxi_nfc *nfc = to_sunxi_nfc(sunxi_nand->nand.controller);
1363 	const struct nand_sdr_timings *timings;
1364 	u32 min_clk_period = 0;
1365 	s32 tWB, tADL, tWHR, tRHW, tCAD;
1366 	long real_clk_rate;
1367 
1368 	timings = nand_get_sdr_timings(conf);
1369 	if (IS_ERR(timings))
1370 		return -ENOTSUPP;
1371 
1372 	/* T1 <=> tCLS */
1373 	if (timings->tCLS_min > min_clk_period)
1374 		min_clk_period = timings->tCLS_min;
1375 
1376 	/* T2 <=> tCLH */
1377 	if (timings->tCLH_min > min_clk_period)
1378 		min_clk_period = timings->tCLH_min;
1379 
1380 	/* T3 <=> tCS */
1381 	if (timings->tCS_min > min_clk_period)
1382 		min_clk_period = timings->tCS_min;
1383 
1384 	/* T4 <=> tCH */
1385 	if (timings->tCH_min > min_clk_period)
1386 		min_clk_period = timings->tCH_min;
1387 
1388 	/* T5 <=> tWP */
1389 	if (timings->tWP_min > min_clk_period)
1390 		min_clk_period = timings->tWP_min;
1391 
1392 	/* T6 <=> tWH */
1393 	if (timings->tWH_min > min_clk_period)
1394 		min_clk_period = timings->tWH_min;
1395 
1396 	/* T7 <=> tALS */
1397 	if (timings->tALS_min > min_clk_period)
1398 		min_clk_period = timings->tALS_min;
1399 
1400 	/* T8 <=> tDS */
1401 	if (timings->tDS_min > min_clk_period)
1402 		min_clk_period = timings->tDS_min;
1403 
1404 	/* T9 <=> tDH */
1405 	if (timings->tDH_min > min_clk_period)
1406 		min_clk_period = timings->tDH_min;
1407 
1408 	/* T10 <=> tRR */
1409 	if (timings->tRR_min > (min_clk_period * 3))
1410 		min_clk_period = DIV_ROUND_UP(timings->tRR_min, 3);
1411 
1412 	/* T11 <=> tALH */
1413 	if (timings->tALH_min > min_clk_period)
1414 		min_clk_period = timings->tALH_min;
1415 
1416 	/* T12 <=> tRP */
1417 	if (timings->tRP_min > min_clk_period)
1418 		min_clk_period = timings->tRP_min;
1419 
1420 	/* T13 <=> tREH */
1421 	if (timings->tREH_min > min_clk_period)
1422 		min_clk_period = timings->tREH_min;
1423 
1424 	/* T14 <=> tRC */
1425 	if (timings->tRC_min > (min_clk_period * 2))
1426 		min_clk_period = DIV_ROUND_UP(timings->tRC_min, 2);
1427 
1428 	/* T15 <=> tWC */
1429 	if (timings->tWC_min > (min_clk_period * 2))
1430 		min_clk_period = DIV_ROUND_UP(timings->tWC_min, 2);
1431 
1432 	/* T16 - T19 + tCAD */
1433 	if (timings->tWB_max > (min_clk_period * 20))
1434 		min_clk_period = DIV_ROUND_UP(timings->tWB_max, 20);
1435 
1436 	if (timings->tADL_min > (min_clk_period * 32))
1437 		min_clk_period = DIV_ROUND_UP(timings->tADL_min, 32);
1438 
1439 	if (timings->tWHR_min > (min_clk_period * 32))
1440 		min_clk_period = DIV_ROUND_UP(timings->tWHR_min, 32);
1441 
1442 	if (timings->tRHW_min > (min_clk_period * 20))
1443 		min_clk_period = DIV_ROUND_UP(timings->tRHW_min, 20);
1444 
1445 	/*
1446 	 * In non-EDO, tREA should be less than tRP to guarantee that the
1447 	 * controller does not sample the IO lines too early. Unfortunately,
1448 	 * the sunxi NAND controller does not allow us to have different
1449 	 * values for tRP and tREH (tRP = tREH = tRW / 2).
1450 	 *
1451 	 * We have 2 options to overcome this limitation:
1452 	 *
1453 	 * 1/ Extend tRC to fulfil the tREA <= tRC / 2 constraint
1454 	 * 2/ Use EDO mode (only works if timings->tRLOH > 0)
1455 	 */
1456 	if (timings->tREA_max > min_clk_period && !timings->tRLOH_min)
1457 		min_clk_period = timings->tREA_max;
1458 
1459 	tWB  = sunxi_nand_lookup_timing(tWB_lut, timings->tWB_max,
1460 					min_clk_period);
1461 	if (tWB < 0) {
1462 		dev_err(nfc->dev, "unsupported tWB\n");
1463 		return tWB;
1464 	}
1465 
1466 	tADL = DIV_ROUND_UP(timings->tADL_min, min_clk_period) >> 3;
1467 	if (tADL > 3) {
1468 		dev_err(nfc->dev, "unsupported tADL\n");
1469 		return -EINVAL;
1470 	}
1471 
1472 	tWHR = DIV_ROUND_UP(timings->tWHR_min, min_clk_period) >> 3;
1473 	if (tWHR > 3) {
1474 		dev_err(nfc->dev, "unsupported tWHR\n");
1475 		return -EINVAL;
1476 	}
1477 
1478 	tRHW = sunxi_nand_lookup_timing(tRHW_lut, timings->tRHW_min,
1479 					min_clk_period);
1480 	if (tRHW < 0) {
1481 		dev_err(nfc->dev, "unsupported tRHW\n");
1482 		return tRHW;
1483 	}
1484 
1485 	if (csline == NAND_DATA_IFACE_CHECK_ONLY)
1486 		return 0;
1487 
1488 	/*
1489 	 * TODO: according to ONFI specs this value only applies for DDR NAND,
1490 	 * but Allwinner seems to set this to 0x7. Mimic them for now.
1491 	 */
1492 	tCAD = 0x7;
1493 
1494 	/* TODO: A83 has some more bits for CDQSS, CS, CLHZ, CCS, WC */
1495 	sunxi_nand->timing_cfg = NFC_TIMING_CFG(tWB, tADL, tWHR, tRHW, tCAD);
1496 
1497 	/* Convert min_clk_period from picoseconds to nanoseconds */
1498 	min_clk_period = DIV_ROUND_UP(min_clk_period, 1000);
1499 
1500 	/*
1501 	 * Unlike what is stated in Allwinner datasheet, the clk_rate should
1502 	 * be set to (1 / min_clk_period), and not (2 / min_clk_period).
1503 	 * This new formula was verified with a scope and validated by
1504 	 * Allwinner engineers.
1505 	 */
1506 	sunxi_nand->clk_rate = NSEC_PER_SEC / min_clk_period;
1507 	real_clk_rate = clk_round_rate(nfc->mod_clk, sunxi_nand->clk_rate);
1508 	if (real_clk_rate <= 0) {
1509 		dev_err(nfc->dev, "Unable to round clk %lu\n",
1510 			sunxi_nand->clk_rate);
1511 		return -EINVAL;
1512 	}
1513 
1514 	sunxi_nand->timing_ctl = 0;
1515 
1516 	/*
1517 	 * ONFI specification 3.1, paragraph 4.15.2 dictates that EDO data
1518 	 * output cycle timings shall be used if the host drives tRC less than
1519 	 * 30 ns. We should also use EDO mode if tREA is bigger than tRP.
1520 	 */
1521 	min_clk_period = NSEC_PER_SEC / real_clk_rate;
1522 	if (min_clk_period * 2 < 30 || min_clk_period * 1000 < timings->tREA_max)
1523 		sunxi_nand->timing_ctl = NFC_TIMING_CTL_EDO;
1524 
1525 	return 0;
1526 }
1527 
1528 static int sunxi_nand_ooblayout_ecc(struct mtd_info *mtd, int section,
1529 				    struct mtd_oob_region *oobregion)
1530 {
1531 	struct nand_chip *nand = mtd_to_nand(mtd);
1532 	struct nand_ecc_ctrl *ecc = &nand->ecc;
1533 
1534 	if (section >= ecc->steps)
1535 		return -ERANGE;
1536 
1537 	oobregion->offset = section * (ecc->bytes + 4) + 4;
1538 	oobregion->length = ecc->bytes;
1539 
1540 	return 0;
1541 }
1542 
1543 static int sunxi_nand_ooblayout_free(struct mtd_info *mtd, int section,
1544 				     struct mtd_oob_region *oobregion)
1545 {
1546 	struct nand_chip *nand = mtd_to_nand(mtd);
1547 	struct nand_ecc_ctrl *ecc = &nand->ecc;
1548 
1549 	if (section > ecc->steps)
1550 		return -ERANGE;
1551 
1552 	/*
1553 	 * The first 2 bytes are used for BB markers, hence we
1554 	 * only have 2 bytes available in the first user data
1555 	 * section.
1556 	 */
1557 	if (!section && ecc->mode == NAND_ECC_HW) {
1558 		oobregion->offset = 2;
1559 		oobregion->length = 2;
1560 
1561 		return 0;
1562 	}
1563 
1564 	oobregion->offset = section * (ecc->bytes + 4);
1565 
1566 	if (section < ecc->steps)
1567 		oobregion->length = 4;
1568 	else
1569 		oobregion->offset = mtd->oobsize - oobregion->offset;
1570 
1571 	return 0;
1572 }
1573 
1574 static const struct mtd_ooblayout_ops sunxi_nand_ooblayout_ops = {
1575 	.ecc = sunxi_nand_ooblayout_ecc,
1576 	.free = sunxi_nand_ooblayout_free,
1577 };
1578 
1579 static void sunxi_nand_hw_ecc_ctrl_cleanup(struct nand_ecc_ctrl *ecc)
1580 {
1581 	kfree(ecc->priv);
1582 }
1583 
1584 static int sunxi_nand_hw_ecc_ctrl_init(struct nand_chip *nand,
1585 				       struct nand_ecc_ctrl *ecc,
1586 				       struct device_node *np)
1587 {
1588 	static const u8 strengths[] = { 16, 24, 28, 32, 40, 48, 56, 60, 64 };
1589 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
1590 	struct mtd_info *mtd = nand_to_mtd(nand);
1591 	struct sunxi_nand_hw_ecc *data;
1592 	int nsectors;
1593 	int ret;
1594 	int i;
1595 
1596 	if (ecc->options & NAND_ECC_MAXIMIZE) {
1597 		int bytes;
1598 
1599 		ecc->size = 1024;
1600 		nsectors = mtd->writesize / ecc->size;
1601 
1602 		/* Reserve 2 bytes for the BBM */
1603 		bytes = (mtd->oobsize - 2) / nsectors;
1604 
1605 		/* 4 non-ECC bytes are added before each ECC bytes section */
1606 		bytes -= 4;
1607 
1608 		/* and bytes has to be even. */
1609 		if (bytes % 2)
1610 			bytes--;
1611 
1612 		ecc->strength = bytes * 8 / fls(8 * ecc->size);
1613 
1614 		for (i = 0; i < ARRAY_SIZE(strengths); i++) {
1615 			if (strengths[i] > ecc->strength)
1616 				break;
1617 		}
1618 
1619 		if (!i)
1620 			ecc->strength = 0;
1621 		else
1622 			ecc->strength = strengths[i - 1];
1623 	}
1624 
1625 	if (ecc->size != 512 && ecc->size != 1024)
1626 		return -EINVAL;
1627 
1628 	data = kzalloc(sizeof(*data), GFP_KERNEL);
1629 	if (!data)
1630 		return -ENOMEM;
1631 
1632 	/* Prefer 1k ECC chunk over 512 ones */
1633 	if (ecc->size == 512 && mtd->writesize > 512) {
1634 		ecc->size = 1024;
1635 		ecc->strength *= 2;
1636 	}
1637 
1638 	/* Add ECC info retrieval from DT */
1639 	for (i = 0; i < ARRAY_SIZE(strengths); i++) {
1640 		if (ecc->strength <= strengths[i]) {
1641 			/*
1642 			 * Update ecc->strength value with the actual strength
1643 			 * that will be used by the ECC engine.
1644 			 */
1645 			ecc->strength = strengths[i];
1646 			break;
1647 		}
1648 	}
1649 
1650 	if (i >= ARRAY_SIZE(strengths)) {
1651 		dev_err(nfc->dev, "unsupported strength\n");
1652 		ret = -ENOTSUPP;
1653 		goto err;
1654 	}
1655 
1656 	data->mode = i;
1657 
1658 	/* HW ECC always request ECC bytes for 1024 bytes blocks */
1659 	ecc->bytes = DIV_ROUND_UP(ecc->strength * fls(8 * 1024), 8);
1660 
1661 	/* HW ECC always work with even numbers of ECC bytes */
1662 	ecc->bytes = ALIGN(ecc->bytes, 2);
1663 
1664 	nsectors = mtd->writesize / ecc->size;
1665 
1666 	if (mtd->oobsize < ((ecc->bytes + 4) * nsectors)) {
1667 		ret = -EINVAL;
1668 		goto err;
1669 	}
1670 
1671 	ecc->read_oob = sunxi_nfc_hw_ecc_read_oob;
1672 	ecc->write_oob = sunxi_nfc_hw_ecc_write_oob;
1673 	mtd_set_ooblayout(mtd, &sunxi_nand_ooblayout_ops);
1674 	ecc->priv = data;
1675 
1676 	if (nfc->dmac) {
1677 		ecc->read_page = sunxi_nfc_hw_ecc_read_page_dma;
1678 		ecc->read_subpage = sunxi_nfc_hw_ecc_read_subpage_dma;
1679 		ecc->write_page = sunxi_nfc_hw_ecc_write_page_dma;
1680 		nand->options |= NAND_USE_BOUNCE_BUFFER;
1681 	} else {
1682 		ecc->read_page = sunxi_nfc_hw_ecc_read_page;
1683 		ecc->read_subpage = sunxi_nfc_hw_ecc_read_subpage;
1684 		ecc->write_page = sunxi_nfc_hw_ecc_write_page;
1685 	}
1686 
1687 	/* TODO: support DMA for raw accesses and subpage write */
1688 	ecc->write_subpage = sunxi_nfc_hw_ecc_write_subpage;
1689 	ecc->read_oob_raw = nand_read_oob_std;
1690 	ecc->write_oob_raw = nand_write_oob_std;
1691 
1692 	return 0;
1693 
1694 err:
1695 	kfree(data);
1696 
1697 	return ret;
1698 }
1699 
1700 static void sunxi_nand_ecc_cleanup(struct nand_ecc_ctrl *ecc)
1701 {
1702 	switch (ecc->mode) {
1703 	case NAND_ECC_HW:
1704 		sunxi_nand_hw_ecc_ctrl_cleanup(ecc);
1705 		break;
1706 	case NAND_ECC_NONE:
1707 	default:
1708 		break;
1709 	}
1710 }
1711 
1712 static int sunxi_nand_attach_chip(struct nand_chip *nand)
1713 {
1714 	struct nand_ecc_ctrl *ecc = &nand->ecc;
1715 	struct device_node *np = nand_get_flash_node(nand);
1716 	int ret;
1717 
1718 	if (nand->bbt_options & NAND_BBT_USE_FLASH)
1719 		nand->bbt_options |= NAND_BBT_NO_OOB;
1720 
1721 	if (nand->options & NAND_NEED_SCRAMBLING)
1722 		nand->options |= NAND_NO_SUBPAGE_WRITE;
1723 
1724 	nand->options |= NAND_SUBPAGE_READ;
1725 
1726 	if (!ecc->size) {
1727 		ecc->size = nand->ecc_step_ds;
1728 		ecc->strength = nand->ecc_strength_ds;
1729 	}
1730 
1731 	if (!ecc->size || !ecc->strength)
1732 		return -EINVAL;
1733 
1734 	switch (ecc->mode) {
1735 	case NAND_ECC_HW:
1736 		ret = sunxi_nand_hw_ecc_ctrl_init(nand, ecc, np);
1737 		if (ret)
1738 			return ret;
1739 		break;
1740 	case NAND_ECC_NONE:
1741 	case NAND_ECC_SOFT:
1742 		break;
1743 	default:
1744 		return -EINVAL;
1745 	}
1746 
1747 	return 0;
1748 }
1749 
1750 static int sunxi_nfc_exec_subop(struct nand_chip *nand,
1751 				const struct nand_subop *subop)
1752 {
1753 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
1754 	u32 cmd = 0, extcmd = 0, cnt = 0, addrs[2] = { };
1755 	unsigned int i, j, remaining, start;
1756 	void *inbuf = NULL;
1757 	int ret;
1758 
1759 	for (i = 0; i < subop->ninstrs; i++) {
1760 		const struct nand_op_instr *instr = &subop->instrs[i];
1761 
1762 		switch (instr->type) {
1763 		case NAND_OP_CMD_INSTR:
1764 			if (cmd & NFC_SEND_CMD1) {
1765 				if (WARN_ON(cmd & NFC_SEND_CMD2))
1766 					return -EINVAL;
1767 
1768 				cmd |= NFC_SEND_CMD2;
1769 				extcmd |= instr->ctx.cmd.opcode;
1770 			} else {
1771 				cmd |= NFC_SEND_CMD1 |
1772 				       NFC_CMD(instr->ctx.cmd.opcode);
1773 			}
1774 			break;
1775 
1776 		case NAND_OP_ADDR_INSTR:
1777 			remaining = nand_subop_get_num_addr_cyc(subop, i);
1778 			start = nand_subop_get_addr_start_off(subop, i);
1779 			for (j = 0; j < 8 && j + start < remaining; j++) {
1780 				u32 addr = instr->ctx.addr.addrs[j + start];
1781 
1782 				addrs[j / 4] |= addr << (j % 4) * 8;
1783 			}
1784 
1785 			if (j)
1786 				cmd |= NFC_SEND_ADR | NFC_ADR_NUM(j);
1787 
1788 			break;
1789 
1790 		case NAND_OP_DATA_IN_INSTR:
1791 		case NAND_OP_DATA_OUT_INSTR:
1792 			start = nand_subop_get_data_start_off(subop, i);
1793 			remaining = nand_subop_get_data_len(subop, i);
1794 			cnt = min_t(u32, remaining, NFC_SRAM_SIZE);
1795 			cmd |= NFC_DATA_TRANS | NFC_DATA_SWAP_METHOD;
1796 
1797 			if (instr->type == NAND_OP_DATA_OUT_INSTR) {
1798 				cmd |= NFC_ACCESS_DIR;
1799 				memcpy_toio(nfc->regs + NFC_RAM0_BASE,
1800 					    instr->ctx.data.buf.out + start,
1801 					    cnt);
1802 			} else {
1803 				inbuf = instr->ctx.data.buf.in + start;
1804 			}
1805 
1806 			break;
1807 
1808 		case NAND_OP_WAITRDY_INSTR:
1809 			cmd |= NFC_WAIT_FLAG;
1810 			break;
1811 		}
1812 	}
1813 
1814 	ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
1815 	if (ret)
1816 		return ret;
1817 
1818 	if (cmd & NFC_SEND_ADR) {
1819 		writel(addrs[0], nfc->regs + NFC_REG_ADDR_LOW);
1820 		writel(addrs[1], nfc->regs + NFC_REG_ADDR_HIGH);
1821 	}
1822 
1823 	if (cmd & NFC_SEND_CMD2)
1824 		writel(extcmd,
1825 		       nfc->regs +
1826 		       (cmd & NFC_ACCESS_DIR ?
1827 			NFC_REG_WCMD_SET : NFC_REG_RCMD_SET));
1828 
1829 	if (cmd & NFC_DATA_TRANS)
1830 		writel(cnt, nfc->regs + NFC_REG_CNT);
1831 
1832 	writel(cmd, nfc->regs + NFC_REG_CMD);
1833 
1834 	ret = sunxi_nfc_wait_events(nfc, NFC_CMD_INT_FLAG,
1835 				    !(cmd & NFC_WAIT_FLAG) && cnt < 64,
1836 				    0);
1837 	if (ret)
1838 		return ret;
1839 
1840 	if (inbuf)
1841 		memcpy_fromio(inbuf, nfc->regs + NFC_RAM0_BASE, cnt);
1842 
1843 	return 0;
1844 }
1845 
1846 static int sunxi_nfc_soft_waitrdy(struct nand_chip *nand,
1847 				  const struct nand_subop *subop)
1848 {
1849 	return nand_soft_waitrdy(nand,
1850 				 subop->instrs[0].ctx.waitrdy.timeout_ms);
1851 }
1852 
1853 static const struct nand_op_parser sunxi_nfc_op_parser = NAND_OP_PARSER(
1854 	NAND_OP_PARSER_PATTERN(sunxi_nfc_exec_subop,
1855 			       NAND_OP_PARSER_PAT_CMD_ELEM(true),
1856 			       NAND_OP_PARSER_PAT_ADDR_ELEM(true, 8),
1857 			       NAND_OP_PARSER_PAT_CMD_ELEM(true),
1858 			       NAND_OP_PARSER_PAT_WAITRDY_ELEM(true),
1859 			       NAND_OP_PARSER_PAT_DATA_IN_ELEM(true, 1024)),
1860 	NAND_OP_PARSER_PATTERN(sunxi_nfc_exec_subop,
1861 			       NAND_OP_PARSER_PAT_CMD_ELEM(true),
1862 			       NAND_OP_PARSER_PAT_ADDR_ELEM(true, 8),
1863 			       NAND_OP_PARSER_PAT_DATA_OUT_ELEM(true, 1024),
1864 			       NAND_OP_PARSER_PAT_CMD_ELEM(true),
1865 			       NAND_OP_PARSER_PAT_WAITRDY_ELEM(true)),
1866 );
1867 
1868 static const struct nand_op_parser sunxi_nfc_norb_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_DATA_IN_ELEM(true, 1024)),
1874 	NAND_OP_PARSER_PATTERN(sunxi_nfc_exec_subop,
1875 			       NAND_OP_PARSER_PAT_CMD_ELEM(true),
1876 			       NAND_OP_PARSER_PAT_ADDR_ELEM(true, 8),
1877 			       NAND_OP_PARSER_PAT_DATA_OUT_ELEM(true, 1024),
1878 			       NAND_OP_PARSER_PAT_CMD_ELEM(true)),
1879 	NAND_OP_PARSER_PATTERN(sunxi_nfc_soft_waitrdy,
1880 			       NAND_OP_PARSER_PAT_WAITRDY_ELEM(false)),
1881 );
1882 
1883 static int sunxi_nfc_exec_op(struct nand_chip *nand,
1884 			     const struct nand_operation *op, bool check_only)
1885 {
1886 	struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
1887 	const struct nand_op_parser *parser;
1888 
1889 	sunxi_nfc_select_chip(nand, op->cs);
1890 
1891 	if (sunxi_nand->sels[op->cs].rb >= 0)
1892 		parser = &sunxi_nfc_op_parser;
1893 	else
1894 		parser = &sunxi_nfc_norb_op_parser;
1895 
1896 	return nand_op_parser_exec_op(nand, parser, op, check_only);
1897 }
1898 
1899 static const struct nand_controller_ops sunxi_nand_controller_ops = {
1900 	.attach_chip = sunxi_nand_attach_chip,
1901 	.setup_data_interface = sunxi_nfc_setup_data_interface,
1902 	.exec_op = sunxi_nfc_exec_op,
1903 };
1904 
1905 static int sunxi_nand_chip_init(struct device *dev, struct sunxi_nfc *nfc,
1906 				struct device_node *np)
1907 {
1908 	struct sunxi_nand_chip *sunxi_nand;
1909 	struct mtd_info *mtd;
1910 	struct nand_chip *nand;
1911 	int nsels;
1912 	int ret;
1913 	int i;
1914 	u32 tmp;
1915 
1916 	if (!of_get_property(np, "reg", &nsels))
1917 		return -EINVAL;
1918 
1919 	nsels /= sizeof(u32);
1920 	if (!nsels) {
1921 		dev_err(dev, "invalid reg property size\n");
1922 		return -EINVAL;
1923 	}
1924 
1925 	sunxi_nand = devm_kzalloc(dev, struct_size(sunxi_nand, sels, nsels),
1926 				  GFP_KERNEL);
1927 	if (!sunxi_nand) {
1928 		dev_err(dev, "could not allocate chip\n");
1929 		return -ENOMEM;
1930 	}
1931 
1932 	sunxi_nand->nsels = nsels;
1933 
1934 	for (i = 0; i < nsels; i++) {
1935 		ret = of_property_read_u32_index(np, "reg", i, &tmp);
1936 		if (ret) {
1937 			dev_err(dev, "could not retrieve reg property: %d\n",
1938 				ret);
1939 			return ret;
1940 		}
1941 
1942 		if (tmp > NFC_MAX_CS) {
1943 			dev_err(dev,
1944 				"invalid reg value: %u (max CS = 7)\n",
1945 				tmp);
1946 			return -EINVAL;
1947 		}
1948 
1949 		if (test_and_set_bit(tmp, &nfc->assigned_cs)) {
1950 			dev_err(dev, "CS %d already assigned\n", tmp);
1951 			return -EINVAL;
1952 		}
1953 
1954 		sunxi_nand->sels[i].cs = tmp;
1955 
1956 		if (!of_property_read_u32_index(np, "allwinner,rb", i, &tmp) &&
1957 		    tmp < 2)
1958 			sunxi_nand->sels[i].rb = tmp;
1959 		else
1960 			sunxi_nand->sels[i].rb = -1;
1961 	}
1962 
1963 	nand = &sunxi_nand->nand;
1964 	/* Default tR value specified in the ONFI spec (chapter 4.15.1) */
1965 	nand->controller = &nfc->controller;
1966 	nand->controller->ops = &sunxi_nand_controller_ops;
1967 
1968 	/*
1969 	 * Set the ECC mode to the default value in case nothing is specified
1970 	 * in the DT.
1971 	 */
1972 	nand->ecc.mode = NAND_ECC_HW;
1973 	nand_set_flash_node(nand, np);
1974 
1975 	mtd = nand_to_mtd(nand);
1976 	mtd->dev.parent = dev;
1977 
1978 	ret = nand_scan(nand, nsels);
1979 	if (ret)
1980 		return ret;
1981 
1982 	ret = mtd_device_register(mtd, NULL, 0);
1983 	if (ret) {
1984 		dev_err(dev, "failed to register mtd device: %d\n", ret);
1985 		nand_release(nand);
1986 		return ret;
1987 	}
1988 
1989 	list_add_tail(&sunxi_nand->node, &nfc->chips);
1990 
1991 	return 0;
1992 }
1993 
1994 static int sunxi_nand_chips_init(struct device *dev, struct sunxi_nfc *nfc)
1995 {
1996 	struct device_node *np = dev->of_node;
1997 	struct device_node *nand_np;
1998 	int nchips = of_get_child_count(np);
1999 	int ret;
2000 
2001 	if (nchips > 8) {
2002 		dev_err(dev, "too many NAND chips: %d (max = 8)\n", nchips);
2003 		return -EINVAL;
2004 	}
2005 
2006 	for_each_child_of_node(np, nand_np) {
2007 		ret = sunxi_nand_chip_init(dev, nfc, nand_np);
2008 		if (ret) {
2009 			of_node_put(nand_np);
2010 			return ret;
2011 		}
2012 	}
2013 
2014 	return 0;
2015 }
2016 
2017 static void sunxi_nand_chips_cleanup(struct sunxi_nfc *nfc)
2018 {
2019 	struct sunxi_nand_chip *sunxi_nand;
2020 
2021 	while (!list_empty(&nfc->chips)) {
2022 		sunxi_nand = list_first_entry(&nfc->chips,
2023 					      struct sunxi_nand_chip,
2024 					      node);
2025 		nand_release(&sunxi_nand->nand);
2026 		sunxi_nand_ecc_cleanup(&sunxi_nand->nand.ecc);
2027 		list_del(&sunxi_nand->node);
2028 	}
2029 }
2030 
2031 static int sunxi_nfc_probe(struct platform_device *pdev)
2032 {
2033 	struct device *dev = &pdev->dev;
2034 	struct resource *r;
2035 	struct sunxi_nfc *nfc;
2036 	int irq;
2037 	int ret;
2038 
2039 	nfc = devm_kzalloc(dev, sizeof(*nfc), GFP_KERNEL);
2040 	if (!nfc)
2041 		return -ENOMEM;
2042 
2043 	nfc->dev = dev;
2044 	nand_controller_init(&nfc->controller);
2045 	INIT_LIST_HEAD(&nfc->chips);
2046 
2047 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
2048 	nfc->regs = devm_ioremap_resource(dev, r);
2049 	if (IS_ERR(nfc->regs))
2050 		return PTR_ERR(nfc->regs);
2051 
2052 	irq = platform_get_irq(pdev, 0);
2053 	if (irq < 0) {
2054 		dev_err(dev, "failed to retrieve irq\n");
2055 		return irq;
2056 	}
2057 
2058 	nfc->ahb_clk = devm_clk_get(dev, "ahb");
2059 	if (IS_ERR(nfc->ahb_clk)) {
2060 		dev_err(dev, "failed to retrieve ahb clk\n");
2061 		return PTR_ERR(nfc->ahb_clk);
2062 	}
2063 
2064 	ret = clk_prepare_enable(nfc->ahb_clk);
2065 	if (ret)
2066 		return ret;
2067 
2068 	nfc->mod_clk = devm_clk_get(dev, "mod");
2069 	if (IS_ERR(nfc->mod_clk)) {
2070 		dev_err(dev, "failed to retrieve mod clk\n");
2071 		ret = PTR_ERR(nfc->mod_clk);
2072 		goto out_ahb_clk_unprepare;
2073 	}
2074 
2075 	ret = clk_prepare_enable(nfc->mod_clk);
2076 	if (ret)
2077 		goto out_ahb_clk_unprepare;
2078 
2079 	nfc->reset = devm_reset_control_get_optional_exclusive(dev, "ahb");
2080 	if (IS_ERR(nfc->reset)) {
2081 		ret = PTR_ERR(nfc->reset);
2082 		goto out_mod_clk_unprepare;
2083 	}
2084 
2085 	ret = reset_control_deassert(nfc->reset);
2086 	if (ret) {
2087 		dev_err(dev, "reset err %d\n", ret);
2088 		goto out_mod_clk_unprepare;
2089 	}
2090 
2091 	ret = sunxi_nfc_rst(nfc);
2092 	if (ret)
2093 		goto out_ahb_reset_reassert;
2094 
2095 	writel(0, nfc->regs + NFC_REG_INT);
2096 	ret = devm_request_irq(dev, irq, sunxi_nfc_interrupt,
2097 			       0, "sunxi-nand", nfc);
2098 	if (ret)
2099 		goto out_ahb_reset_reassert;
2100 
2101 	nfc->dmac = dma_request_slave_channel(dev, "rxtx");
2102 	if (nfc->dmac) {
2103 		struct dma_slave_config dmac_cfg = { };
2104 
2105 		dmac_cfg.src_addr = r->start + NFC_REG_IO_DATA;
2106 		dmac_cfg.dst_addr = dmac_cfg.src_addr;
2107 		dmac_cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
2108 		dmac_cfg.dst_addr_width = dmac_cfg.src_addr_width;
2109 		dmac_cfg.src_maxburst = 4;
2110 		dmac_cfg.dst_maxburst = 4;
2111 		dmaengine_slave_config(nfc->dmac, &dmac_cfg);
2112 	} else {
2113 		dev_warn(dev, "failed to request rxtx DMA channel\n");
2114 	}
2115 
2116 	platform_set_drvdata(pdev, nfc);
2117 
2118 	ret = sunxi_nand_chips_init(dev, nfc);
2119 	if (ret) {
2120 		dev_err(dev, "failed to init nand chips\n");
2121 		goto out_release_dmac;
2122 	}
2123 
2124 	return 0;
2125 
2126 out_release_dmac:
2127 	if (nfc->dmac)
2128 		dma_release_channel(nfc->dmac);
2129 out_ahb_reset_reassert:
2130 	reset_control_assert(nfc->reset);
2131 out_mod_clk_unprepare:
2132 	clk_disable_unprepare(nfc->mod_clk);
2133 out_ahb_clk_unprepare:
2134 	clk_disable_unprepare(nfc->ahb_clk);
2135 
2136 	return ret;
2137 }
2138 
2139 static int sunxi_nfc_remove(struct platform_device *pdev)
2140 {
2141 	struct sunxi_nfc *nfc = platform_get_drvdata(pdev);
2142 
2143 	sunxi_nand_chips_cleanup(nfc);
2144 
2145 	reset_control_assert(nfc->reset);
2146 
2147 	if (nfc->dmac)
2148 		dma_release_channel(nfc->dmac);
2149 	clk_disable_unprepare(nfc->mod_clk);
2150 	clk_disable_unprepare(nfc->ahb_clk);
2151 
2152 	return 0;
2153 }
2154 
2155 static const struct of_device_id sunxi_nfc_ids[] = {
2156 	{ .compatible = "allwinner,sun4i-a10-nand" },
2157 	{ /* sentinel */ }
2158 };
2159 MODULE_DEVICE_TABLE(of, sunxi_nfc_ids);
2160 
2161 static struct platform_driver sunxi_nfc_driver = {
2162 	.driver = {
2163 		.name = "sunxi_nand",
2164 		.of_match_table = sunxi_nfc_ids,
2165 	},
2166 	.probe = sunxi_nfc_probe,
2167 	.remove = sunxi_nfc_remove,
2168 };
2169 module_platform_driver(sunxi_nfc_driver);
2170 
2171 MODULE_LICENSE("GPL");
2172 MODULE_AUTHOR("Boris BREZILLON");
2173 MODULE_DESCRIPTION("Allwinner NAND Flash Controller driver");
2174 MODULE_ALIAS("platform:sunxi_nand");
2175