xref: /openbmc/linux/drivers/mtd/nand/raw/sunxi_nand.c (revision 9c6d26df1fae6ad4718d51c48e6517913304ed27)
1 /*
2  * Copyright (C) 2013 Boris BREZILLON <b.brezillon.dev@gmail.com>
3  *
4  * Derived from:
5  *	https://github.com/yuq/sunxi-nfc-mtd
6  *	Copyright (C) 2013 Qiang Yu <yuq825@gmail.com>
7  *
8  *	https://github.com/hno/Allwinner-Info
9  *	Copyright (C) 2013 Henrik Nordström <Henrik Nordström>
10  *
11  *	Copyright (C) 2013 Dmitriy B. <rzk333@gmail.com>
12  *	Copyright (C) 2013 Sergey Lapin <slapin@ossfans.org>
13  *
14  * This program is free software; you can redistribute it and/or modify
15  * it under the terms of the GNU General Public License as published by
16  * the Free Software Foundation; either version 2 of the License, or
17  * (at your option) any later version.
18  *
19  * This program is distributed in the hope that it will be useful,
20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
22  * GNU General Public License for more details.
23  */
24 
25 #include <linux/dma-mapping.h>
26 #include <linux/slab.h>
27 #include <linux/module.h>
28 #include <linux/moduleparam.h>
29 #include <linux/platform_device.h>
30 #include <linux/of.h>
31 #include <linux/of_device.h>
32 #include <linux/of_gpio.h>
33 #include <linux/mtd/mtd.h>
34 #include <linux/mtd/rawnand.h>
35 #include <linux/mtd/partitions.h>
36 #include <linux/clk.h>
37 #include <linux/delay.h>
38 #include <linux/dmaengine.h>
39 #include <linux/gpio.h>
40 #include <linux/interrupt.h>
41 #include <linux/iopoll.h>
42 #include <linux/reset.h>
43 
44 #define NFC_REG_CTL		0x0000
45 #define NFC_REG_ST		0x0004
46 #define NFC_REG_INT		0x0008
47 #define NFC_REG_TIMING_CTL	0x000C
48 #define NFC_REG_TIMING_CFG	0x0010
49 #define NFC_REG_ADDR_LOW	0x0014
50 #define NFC_REG_ADDR_HIGH	0x0018
51 #define NFC_REG_SECTOR_NUM	0x001C
52 #define NFC_REG_CNT		0x0020
53 #define NFC_REG_CMD		0x0024
54 #define NFC_REG_RCMD_SET	0x0028
55 #define NFC_REG_WCMD_SET	0x002C
56 #define NFC_REG_IO_DATA		0x0030
57 #define NFC_REG_ECC_CTL		0x0034
58 #define NFC_REG_ECC_ST		0x0038
59 #define NFC_REG_DEBUG		0x003C
60 #define NFC_REG_ECC_ERR_CNT(x)	((0x0040 + (x)) & ~0x3)
61 #define NFC_REG_USER_DATA(x)	(0x0050 + ((x) * 4))
62 #define NFC_REG_SPARE_AREA	0x00A0
63 #define NFC_REG_PAT_ID		0x00A4
64 #define NFC_RAM0_BASE		0x0400
65 #define NFC_RAM1_BASE		0x0800
66 
67 /* define bit use in NFC_CTL */
68 #define NFC_EN			BIT(0)
69 #define NFC_RESET		BIT(1)
70 #define NFC_BUS_WIDTH_MSK	BIT(2)
71 #define NFC_BUS_WIDTH_8		(0 << 2)
72 #define NFC_BUS_WIDTH_16	(1 << 2)
73 #define NFC_RB_SEL_MSK		BIT(3)
74 #define NFC_RB_SEL(x)		((x) << 3)
75 #define NFC_CE_SEL_MSK		GENMASK(26, 24)
76 #define NFC_CE_SEL(x)		((x) << 24)
77 #define NFC_CE_CTL		BIT(6)
78 #define NFC_PAGE_SHIFT_MSK	GENMASK(11, 8)
79 #define NFC_PAGE_SHIFT(x)	(((x) < 10 ? 0 : (x) - 10) << 8)
80 #define NFC_SAM			BIT(12)
81 #define NFC_RAM_METHOD		BIT(14)
82 #define NFC_DEBUG_CTL		BIT(31)
83 
84 /* define bit use in NFC_ST */
85 #define NFC_RB_B2R		BIT(0)
86 #define NFC_CMD_INT_FLAG	BIT(1)
87 #define NFC_DMA_INT_FLAG	BIT(2)
88 #define NFC_CMD_FIFO_STATUS	BIT(3)
89 #define NFC_STA			BIT(4)
90 #define NFC_NATCH_INT_FLAG	BIT(5)
91 #define NFC_RB_STATE(x)		BIT(x + 8)
92 
93 /* define bit use in NFC_INT */
94 #define NFC_B2R_INT_ENABLE	BIT(0)
95 #define NFC_CMD_INT_ENABLE	BIT(1)
96 #define NFC_DMA_INT_ENABLE	BIT(2)
97 #define NFC_INT_MASK		(NFC_B2R_INT_ENABLE | \
98 				 NFC_CMD_INT_ENABLE | \
99 				 NFC_DMA_INT_ENABLE)
100 
101 /* define bit use in NFC_TIMING_CTL */
102 #define NFC_TIMING_CTL_EDO	BIT(8)
103 
104 /* define NFC_TIMING_CFG register layout */
105 #define NFC_TIMING_CFG(tWB, tADL, tWHR, tRHW, tCAD)		\
106 	(((tWB) & 0x3) | (((tADL) & 0x3) << 2) |		\
107 	(((tWHR) & 0x3) << 4) | (((tRHW) & 0x3) << 6) |		\
108 	(((tCAD) & 0x7) << 8))
109 
110 /* define bit use in NFC_CMD */
111 #define NFC_CMD_LOW_BYTE_MSK	GENMASK(7, 0)
112 #define NFC_CMD_HIGH_BYTE_MSK	GENMASK(15, 8)
113 #define NFC_CMD(x)		(x)
114 #define NFC_ADR_NUM_MSK		GENMASK(18, 16)
115 #define NFC_ADR_NUM(x)		(((x) - 1) << 16)
116 #define NFC_SEND_ADR		BIT(19)
117 #define NFC_ACCESS_DIR		BIT(20)
118 #define NFC_DATA_TRANS		BIT(21)
119 #define NFC_SEND_CMD1		BIT(22)
120 #define NFC_WAIT_FLAG		BIT(23)
121 #define NFC_SEND_CMD2		BIT(24)
122 #define NFC_SEQ			BIT(25)
123 #define NFC_DATA_SWAP_METHOD	BIT(26)
124 #define NFC_ROW_AUTO_INC	BIT(27)
125 #define NFC_SEND_CMD3		BIT(28)
126 #define NFC_SEND_CMD4		BIT(29)
127 #define NFC_CMD_TYPE_MSK	GENMASK(31, 30)
128 #define NFC_NORMAL_OP		(0 << 30)
129 #define NFC_ECC_OP		(1 << 30)
130 #define NFC_PAGE_OP		(2 << 30)
131 
132 /* define bit use in NFC_RCMD_SET */
133 #define NFC_READ_CMD_MSK	GENMASK(7, 0)
134 #define NFC_RND_READ_CMD0_MSK	GENMASK(15, 8)
135 #define NFC_RND_READ_CMD1_MSK	GENMASK(23, 16)
136 
137 /* define bit use in NFC_WCMD_SET */
138 #define NFC_PROGRAM_CMD_MSK	GENMASK(7, 0)
139 #define NFC_RND_WRITE_CMD_MSK	GENMASK(15, 8)
140 #define NFC_READ_CMD0_MSK	GENMASK(23, 16)
141 #define NFC_READ_CMD1_MSK	GENMASK(31, 24)
142 
143 /* define bit use in NFC_ECC_CTL */
144 #define NFC_ECC_EN		BIT(0)
145 #define NFC_ECC_PIPELINE	BIT(3)
146 #define NFC_ECC_EXCEPTION	BIT(4)
147 #define NFC_ECC_BLOCK_SIZE_MSK	BIT(5)
148 #define NFC_ECC_BLOCK_512	BIT(5)
149 #define NFC_RANDOM_EN		BIT(9)
150 #define NFC_RANDOM_DIRECTION	BIT(10)
151 #define NFC_ECC_MODE_MSK	GENMASK(15, 12)
152 #define NFC_ECC_MODE(x)		((x) << 12)
153 #define NFC_RANDOM_SEED_MSK	GENMASK(30, 16)
154 #define NFC_RANDOM_SEED(x)	((x) << 16)
155 
156 /* define bit use in NFC_ECC_ST */
157 #define NFC_ECC_ERR(x)		BIT(x)
158 #define NFC_ECC_ERR_MSK		GENMASK(15, 0)
159 #define NFC_ECC_PAT_FOUND(x)	BIT(x + 16)
160 #define NFC_ECC_ERR_CNT(b, x)	(((x) >> (((b) % 4) * 8)) & 0xff)
161 
162 #define NFC_DEFAULT_TIMEOUT_MS	1000
163 
164 #define NFC_SRAM_SIZE		1024
165 
166 #define NFC_MAX_CS		7
167 
168 /*
169  * Ready/Busy detection type: describes the Ready/Busy detection modes
170  *
171  * @RB_NONE:	no external detection available, rely on STATUS command
172  *		and software timeouts
173  * @RB_NATIVE:	use sunxi NAND controller Ready/Busy support. The Ready/Busy
174  *		pin of the NAND flash chip must be connected to one of the
175  *		native NAND R/B pins (those which can be muxed to the NAND
176  *		Controller)
177  * @RB_GPIO:	use a simple GPIO to handle Ready/Busy status. The Ready/Busy
178  *		pin of the NAND flash chip must be connected to a GPIO capable
179  *		pin.
180  */
181 enum sunxi_nand_rb_type {
182 	RB_NONE,
183 	RB_NATIVE,
184 	RB_GPIO,
185 };
186 
187 /*
188  * Ready/Busy structure: stores information related to Ready/Busy detection
189  *
190  * @type:	the Ready/Busy detection mode
191  * @info:	information related to the R/B detection mode. Either a gpio
192  *		id or a native R/B id (those supported by the NAND controller).
193  */
194 struct sunxi_nand_rb {
195 	enum sunxi_nand_rb_type type;
196 	union {
197 		int gpio;
198 		int nativeid;
199 	} info;
200 };
201 
202 /*
203  * Chip Select structure: stores information related to NAND Chip Select
204  *
205  * @cs:		the NAND CS id used to communicate with a NAND Chip
206  * @rb:		the Ready/Busy description
207  */
208 struct sunxi_nand_chip_sel {
209 	u8 cs;
210 	struct sunxi_nand_rb rb;
211 };
212 
213 /*
214  * sunxi HW ECC infos: stores information related to HW ECC support
215  *
216  * @mode:	the sunxi ECC mode field deduced from ECC requirements
217  */
218 struct sunxi_nand_hw_ecc {
219 	int mode;
220 };
221 
222 /*
223  * NAND chip structure: stores NAND chip device related information
224  *
225  * @node:		used to store NAND chips into a list
226  * @nand:		base NAND chip structure
227  * @mtd:		base MTD structure
228  * @clk_rate:		clk_rate required for this NAND chip
229  * @timing_cfg		TIMING_CFG register value for this NAND chip
230  * @selected:		current active CS
231  * @nsels:		number of CS lines required by the NAND chip
232  * @sels:		array of CS lines descriptions
233  */
234 struct sunxi_nand_chip {
235 	struct list_head node;
236 	struct nand_chip nand;
237 	unsigned long clk_rate;
238 	u32 timing_cfg;
239 	u32 timing_ctl;
240 	int selected;
241 	int addr_cycles;
242 	u32 addr[2];
243 	int cmd_cycles;
244 	u8 cmd[2];
245 	int nsels;
246 	struct sunxi_nand_chip_sel sels[0];
247 };
248 
249 static inline struct sunxi_nand_chip *to_sunxi_nand(struct nand_chip *nand)
250 {
251 	return container_of(nand, struct sunxi_nand_chip, nand);
252 }
253 
254 /*
255  * NAND Controller structure: stores sunxi NAND controller information
256  *
257  * @controller:		base controller structure
258  * @dev:		parent device (used to print error messages)
259  * @regs:		NAND controller registers
260  * @ahb_clk:		NAND Controller AHB clock
261  * @mod_clk:		NAND Controller mod clock
262  * @assigned_cs:	bitmask describing already assigned CS lines
263  * @clk_rate:		NAND controller current clock rate
264  * @chips:		a list containing all the NAND chips attached to
265  *			this NAND controller
266  * @complete:		a completion object used to wait for NAND
267  *			controller events
268  */
269 struct sunxi_nfc {
270 	struct nand_hw_control controller;
271 	struct device *dev;
272 	void __iomem *regs;
273 	struct clk *ahb_clk;
274 	struct clk *mod_clk;
275 	struct reset_control *reset;
276 	unsigned long assigned_cs;
277 	unsigned long clk_rate;
278 	struct list_head chips;
279 	struct completion complete;
280 	struct dma_chan *dmac;
281 };
282 
283 static inline struct sunxi_nfc *to_sunxi_nfc(struct nand_hw_control *ctrl)
284 {
285 	return container_of(ctrl, struct sunxi_nfc, controller);
286 }
287 
288 static irqreturn_t sunxi_nfc_interrupt(int irq, void *dev_id)
289 {
290 	struct sunxi_nfc *nfc = dev_id;
291 	u32 st = readl(nfc->regs + NFC_REG_ST);
292 	u32 ien = readl(nfc->regs + NFC_REG_INT);
293 
294 	if (!(ien & st))
295 		return IRQ_NONE;
296 
297 	if ((ien & st) == ien)
298 		complete(&nfc->complete);
299 
300 	writel(st & NFC_INT_MASK, nfc->regs + NFC_REG_ST);
301 	writel(~st & ien & NFC_INT_MASK, nfc->regs + NFC_REG_INT);
302 
303 	return IRQ_HANDLED;
304 }
305 
306 static int sunxi_nfc_wait_events(struct sunxi_nfc *nfc, u32 events,
307 				 bool use_polling, unsigned int timeout_ms)
308 {
309 	int ret;
310 
311 	if (events & ~NFC_INT_MASK)
312 		return -EINVAL;
313 
314 	if (!timeout_ms)
315 		timeout_ms = NFC_DEFAULT_TIMEOUT_MS;
316 
317 	if (!use_polling) {
318 		init_completion(&nfc->complete);
319 
320 		writel(events, nfc->regs + NFC_REG_INT);
321 
322 		ret = wait_for_completion_timeout(&nfc->complete,
323 						msecs_to_jiffies(timeout_ms));
324 		if (!ret)
325 			ret = -ETIMEDOUT;
326 		else
327 			ret = 0;
328 
329 		writel(0, nfc->regs + NFC_REG_INT);
330 	} else {
331 		u32 status;
332 
333 		ret = readl_poll_timeout(nfc->regs + NFC_REG_ST, status,
334 					 (status & events) == events, 1,
335 					 timeout_ms * 1000);
336 	}
337 
338 	writel(events & NFC_INT_MASK, nfc->regs + NFC_REG_ST);
339 
340 	if (ret)
341 		dev_err(nfc->dev, "wait interrupt timedout\n");
342 
343 	return ret;
344 }
345 
346 static int sunxi_nfc_wait_cmd_fifo_empty(struct sunxi_nfc *nfc)
347 {
348 	u32 status;
349 	int ret;
350 
351 	ret = readl_poll_timeout(nfc->regs + NFC_REG_ST, status,
352 				 !(status & NFC_CMD_FIFO_STATUS), 1,
353 				 NFC_DEFAULT_TIMEOUT_MS * 1000);
354 	if (ret)
355 		dev_err(nfc->dev, "wait for empty cmd FIFO timedout\n");
356 
357 	return ret;
358 }
359 
360 static int sunxi_nfc_rst(struct sunxi_nfc *nfc)
361 {
362 	u32 ctl;
363 	int ret;
364 
365 	writel(0, nfc->regs + NFC_REG_ECC_CTL);
366 	writel(NFC_RESET, nfc->regs + NFC_REG_CTL);
367 
368 	ret = readl_poll_timeout(nfc->regs + NFC_REG_CTL, ctl,
369 				 !(ctl & NFC_RESET), 1,
370 				 NFC_DEFAULT_TIMEOUT_MS * 1000);
371 	if (ret)
372 		dev_err(nfc->dev, "wait for NAND controller reset timedout\n");
373 
374 	return ret;
375 }
376 
377 static int sunxi_nfc_dma_op_prepare(struct mtd_info *mtd, const void *buf,
378 				    int chunksize, int nchunks,
379 				    enum dma_data_direction ddir,
380 				    struct scatterlist *sg)
381 {
382 	struct nand_chip *nand = mtd_to_nand(mtd);
383 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
384 	struct dma_async_tx_descriptor *dmad;
385 	enum dma_transfer_direction tdir;
386 	dma_cookie_t dmat;
387 	int ret;
388 
389 	if (ddir == DMA_FROM_DEVICE)
390 		tdir = DMA_DEV_TO_MEM;
391 	else
392 		tdir = DMA_MEM_TO_DEV;
393 
394 	sg_init_one(sg, buf, nchunks * chunksize);
395 	ret = dma_map_sg(nfc->dev, sg, 1, ddir);
396 	if (!ret)
397 		return -ENOMEM;
398 
399 	dmad = dmaengine_prep_slave_sg(nfc->dmac, sg, 1, tdir, DMA_CTRL_ACK);
400 	if (!dmad) {
401 		ret = -EINVAL;
402 		goto err_unmap_buf;
403 	}
404 
405 	writel(readl(nfc->regs + NFC_REG_CTL) | NFC_RAM_METHOD,
406 	       nfc->regs + NFC_REG_CTL);
407 	writel(nchunks, nfc->regs + NFC_REG_SECTOR_NUM);
408 	writel(chunksize, nfc->regs + NFC_REG_CNT);
409 	dmat = dmaengine_submit(dmad);
410 
411 	ret = dma_submit_error(dmat);
412 	if (ret)
413 		goto err_clr_dma_flag;
414 
415 	return 0;
416 
417 err_clr_dma_flag:
418 	writel(readl(nfc->regs + NFC_REG_CTL) & ~NFC_RAM_METHOD,
419 	       nfc->regs + NFC_REG_CTL);
420 
421 err_unmap_buf:
422 	dma_unmap_sg(nfc->dev, sg, 1, ddir);
423 	return ret;
424 }
425 
426 static void sunxi_nfc_dma_op_cleanup(struct mtd_info *mtd,
427 				     enum dma_data_direction ddir,
428 				     struct scatterlist *sg)
429 {
430 	struct nand_chip *nand = mtd_to_nand(mtd);
431 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
432 
433 	dma_unmap_sg(nfc->dev, sg, 1, ddir);
434 	writel(readl(nfc->regs + NFC_REG_CTL) & ~NFC_RAM_METHOD,
435 	       nfc->regs + NFC_REG_CTL);
436 }
437 
438 static int sunxi_nfc_dev_ready(struct mtd_info *mtd)
439 {
440 	struct nand_chip *nand = mtd_to_nand(mtd);
441 	struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
442 	struct sunxi_nfc *nfc = to_sunxi_nfc(sunxi_nand->nand.controller);
443 	struct sunxi_nand_rb *rb;
444 	int ret;
445 
446 	if (sunxi_nand->selected < 0)
447 		return 0;
448 
449 	rb = &sunxi_nand->sels[sunxi_nand->selected].rb;
450 
451 	switch (rb->type) {
452 	case RB_NATIVE:
453 		ret = !!(readl(nfc->regs + NFC_REG_ST) &
454 			 NFC_RB_STATE(rb->info.nativeid));
455 		break;
456 	case RB_GPIO:
457 		ret = gpio_get_value(rb->info.gpio);
458 		break;
459 	case RB_NONE:
460 	default:
461 		ret = 0;
462 		dev_err(nfc->dev, "cannot check R/B NAND status!\n");
463 		break;
464 	}
465 
466 	return ret;
467 }
468 
469 static void sunxi_nfc_select_chip(struct mtd_info *mtd, int chip)
470 {
471 	struct nand_chip *nand = mtd_to_nand(mtd);
472 	struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
473 	struct sunxi_nfc *nfc = to_sunxi_nfc(sunxi_nand->nand.controller);
474 	struct sunxi_nand_chip_sel *sel;
475 	u32 ctl;
476 
477 	if (chip > 0 && chip >= sunxi_nand->nsels)
478 		return;
479 
480 	if (chip == sunxi_nand->selected)
481 		return;
482 
483 	ctl = readl(nfc->regs + NFC_REG_CTL) &
484 	      ~(NFC_PAGE_SHIFT_MSK | NFC_CE_SEL_MSK | NFC_RB_SEL_MSK | NFC_EN);
485 
486 	if (chip >= 0) {
487 		sel = &sunxi_nand->sels[chip];
488 
489 		ctl |= NFC_CE_SEL(sel->cs) | NFC_EN |
490 		       NFC_PAGE_SHIFT(nand->page_shift);
491 		if (sel->rb.type == RB_NONE) {
492 			nand->dev_ready = NULL;
493 		} else {
494 			nand->dev_ready = sunxi_nfc_dev_ready;
495 			if (sel->rb.type == RB_NATIVE)
496 				ctl |= NFC_RB_SEL(sel->rb.info.nativeid);
497 		}
498 
499 		writel(mtd->writesize, nfc->regs + NFC_REG_SPARE_AREA);
500 
501 		if (nfc->clk_rate != sunxi_nand->clk_rate) {
502 			clk_set_rate(nfc->mod_clk, sunxi_nand->clk_rate);
503 			nfc->clk_rate = sunxi_nand->clk_rate;
504 		}
505 	}
506 
507 	writel(sunxi_nand->timing_ctl, nfc->regs + NFC_REG_TIMING_CTL);
508 	writel(sunxi_nand->timing_cfg, nfc->regs + NFC_REG_TIMING_CFG);
509 	writel(ctl, nfc->regs + NFC_REG_CTL);
510 
511 	sunxi_nand->selected = chip;
512 }
513 
514 static void sunxi_nfc_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
515 {
516 	struct nand_chip *nand = mtd_to_nand(mtd);
517 	struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
518 	struct sunxi_nfc *nfc = to_sunxi_nfc(sunxi_nand->nand.controller);
519 	int ret;
520 	int cnt;
521 	int offs = 0;
522 	u32 tmp;
523 
524 	while (len > offs) {
525 		bool poll = false;
526 
527 		cnt = min(len - offs, NFC_SRAM_SIZE);
528 
529 		ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
530 		if (ret)
531 			break;
532 
533 		writel(cnt, nfc->regs + NFC_REG_CNT);
534 		tmp = NFC_DATA_TRANS | NFC_DATA_SWAP_METHOD;
535 		writel(tmp, nfc->regs + NFC_REG_CMD);
536 
537 		/* Arbitrary limit for polling mode */
538 		if (cnt < 64)
539 			poll = true;
540 
541 		ret = sunxi_nfc_wait_events(nfc, NFC_CMD_INT_FLAG, poll, 0);
542 		if (ret)
543 			break;
544 
545 		if (buf)
546 			memcpy_fromio(buf + offs, nfc->regs + NFC_RAM0_BASE,
547 				      cnt);
548 		offs += cnt;
549 	}
550 }
551 
552 static void sunxi_nfc_write_buf(struct mtd_info *mtd, const uint8_t *buf,
553 				int len)
554 {
555 	struct nand_chip *nand = mtd_to_nand(mtd);
556 	struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
557 	struct sunxi_nfc *nfc = to_sunxi_nfc(sunxi_nand->nand.controller);
558 	int ret;
559 	int cnt;
560 	int offs = 0;
561 	u32 tmp;
562 
563 	while (len > offs) {
564 		bool poll = false;
565 
566 		cnt = min(len - offs, NFC_SRAM_SIZE);
567 
568 		ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
569 		if (ret)
570 			break;
571 
572 		writel(cnt, nfc->regs + NFC_REG_CNT);
573 		memcpy_toio(nfc->regs + NFC_RAM0_BASE, buf + offs, cnt);
574 		tmp = NFC_DATA_TRANS | NFC_DATA_SWAP_METHOD |
575 		      NFC_ACCESS_DIR;
576 		writel(tmp, nfc->regs + NFC_REG_CMD);
577 
578 		/* Arbitrary limit for polling mode */
579 		if (cnt < 64)
580 			poll = true;
581 
582 		ret = sunxi_nfc_wait_events(nfc, NFC_CMD_INT_FLAG, poll, 0);
583 		if (ret)
584 			break;
585 
586 		offs += cnt;
587 	}
588 }
589 
590 static uint8_t sunxi_nfc_read_byte(struct mtd_info *mtd)
591 {
592 	uint8_t ret;
593 
594 	sunxi_nfc_read_buf(mtd, &ret, 1);
595 
596 	return ret;
597 }
598 
599 static void sunxi_nfc_cmd_ctrl(struct mtd_info *mtd, int dat,
600 			       unsigned int ctrl)
601 {
602 	struct nand_chip *nand = mtd_to_nand(mtd);
603 	struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
604 	struct sunxi_nfc *nfc = to_sunxi_nfc(sunxi_nand->nand.controller);
605 	int ret;
606 
607 	if (dat == NAND_CMD_NONE && (ctrl & NAND_NCE) &&
608 	    !(ctrl & (NAND_CLE | NAND_ALE))) {
609 		u32 cmd = 0;
610 
611 		if (!sunxi_nand->addr_cycles && !sunxi_nand->cmd_cycles)
612 			return;
613 
614 		if (sunxi_nand->cmd_cycles--)
615 			cmd |= NFC_SEND_CMD1 | sunxi_nand->cmd[0];
616 
617 		if (sunxi_nand->cmd_cycles--) {
618 			cmd |= NFC_SEND_CMD2;
619 			writel(sunxi_nand->cmd[1],
620 			       nfc->regs + NFC_REG_RCMD_SET);
621 		}
622 
623 		sunxi_nand->cmd_cycles = 0;
624 
625 		if (sunxi_nand->addr_cycles) {
626 			cmd |= NFC_SEND_ADR |
627 			       NFC_ADR_NUM(sunxi_nand->addr_cycles);
628 			writel(sunxi_nand->addr[0],
629 			       nfc->regs + NFC_REG_ADDR_LOW);
630 		}
631 
632 		if (sunxi_nand->addr_cycles > 4)
633 			writel(sunxi_nand->addr[1],
634 			       nfc->regs + NFC_REG_ADDR_HIGH);
635 
636 		ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
637 		if (ret)
638 			return;
639 
640 		writel(cmd, nfc->regs + NFC_REG_CMD);
641 		sunxi_nand->addr[0] = 0;
642 		sunxi_nand->addr[1] = 0;
643 		sunxi_nand->addr_cycles = 0;
644 		sunxi_nfc_wait_events(nfc, NFC_CMD_INT_FLAG, true, 0);
645 	}
646 
647 	if (ctrl & NAND_CLE) {
648 		sunxi_nand->cmd[sunxi_nand->cmd_cycles++] = dat;
649 	} else if (ctrl & NAND_ALE) {
650 		sunxi_nand->addr[sunxi_nand->addr_cycles / 4] |=
651 				dat << ((sunxi_nand->addr_cycles % 4) * 8);
652 		sunxi_nand->addr_cycles++;
653 	}
654 }
655 
656 /* These seed values have been extracted from Allwinner's BSP */
657 static const u16 sunxi_nfc_randomizer_page_seeds[] = {
658 	0x2b75, 0x0bd0, 0x5ca3, 0x62d1, 0x1c93, 0x07e9, 0x2162, 0x3a72,
659 	0x0d67, 0x67f9, 0x1be7, 0x077d, 0x032f, 0x0dac, 0x2716, 0x2436,
660 	0x7922, 0x1510, 0x3860, 0x5287, 0x480f, 0x4252, 0x1789, 0x5a2d,
661 	0x2a49, 0x5e10, 0x437f, 0x4b4e, 0x2f45, 0x216e, 0x5cb7, 0x7130,
662 	0x2a3f, 0x60e4, 0x4dc9, 0x0ef0, 0x0f52, 0x1bb9, 0x6211, 0x7a56,
663 	0x226d, 0x4ea7, 0x6f36, 0x3692, 0x38bf, 0x0c62, 0x05eb, 0x4c55,
664 	0x60f4, 0x728c, 0x3b6f, 0x2037, 0x7f69, 0x0936, 0x651a, 0x4ceb,
665 	0x6218, 0x79f3, 0x383f, 0x18d9, 0x4f05, 0x5c82, 0x2912, 0x6f17,
666 	0x6856, 0x5938, 0x1007, 0x61ab, 0x3e7f, 0x57c2, 0x542f, 0x4f62,
667 	0x7454, 0x2eac, 0x7739, 0x42d4, 0x2f90, 0x435a, 0x2e52, 0x2064,
668 	0x637c, 0x66ad, 0x2c90, 0x0bad, 0x759c, 0x0029, 0x0986, 0x7126,
669 	0x1ca7, 0x1605, 0x386a, 0x27f5, 0x1380, 0x6d75, 0x24c3, 0x0f8e,
670 	0x2b7a, 0x1418, 0x1fd1, 0x7dc1, 0x2d8e, 0x43af, 0x2267, 0x7da3,
671 	0x4e3d, 0x1338, 0x50db, 0x454d, 0x764d, 0x40a3, 0x42e6, 0x262b,
672 	0x2d2e, 0x1aea, 0x2e17, 0x173d, 0x3a6e, 0x71bf, 0x25f9, 0x0a5d,
673 	0x7c57, 0x0fbe, 0x46ce, 0x4939, 0x6b17, 0x37bb, 0x3e91, 0x76db,
674 };
675 
676 /*
677  * sunxi_nfc_randomizer_ecc512_seeds and sunxi_nfc_randomizer_ecc1024_seeds
678  * have been generated using
679  * sunxi_nfc_randomizer_step(seed, (step_size * 8) + 15), which is what
680  * the randomizer engine does internally before de/scrambling OOB data.
681  *
682  * Those tables are statically defined to avoid calculating randomizer state
683  * at runtime.
684  */
685 static const u16 sunxi_nfc_randomizer_ecc512_seeds[] = {
686 	0x3346, 0x367f, 0x1f18, 0x769a, 0x4f64, 0x068c, 0x2ef1, 0x6b64,
687 	0x28a9, 0x15d7, 0x30f8, 0x3659, 0x53db, 0x7c5f, 0x71d4, 0x4409,
688 	0x26eb, 0x03cc, 0x655d, 0x47d4, 0x4daa, 0x0877, 0x712d, 0x3617,
689 	0x3264, 0x49aa, 0x7f9e, 0x588e, 0x4fbc, 0x7176, 0x7f91, 0x6c6d,
690 	0x4b95, 0x5fb7, 0x3844, 0x4037, 0x0184, 0x081b, 0x0ee8, 0x5b91,
691 	0x293d, 0x1f71, 0x0e6f, 0x402b, 0x5122, 0x1e52, 0x22be, 0x3d2d,
692 	0x75bc, 0x7c60, 0x6291, 0x1a2f, 0x61d4, 0x74aa, 0x4140, 0x29ab,
693 	0x472d, 0x2852, 0x017e, 0x15e8, 0x5ec2, 0x17cf, 0x7d0f, 0x06b8,
694 	0x117a, 0x6b94, 0x789b, 0x3126, 0x6ac5, 0x5be7, 0x150f, 0x51f8,
695 	0x7889, 0x0aa5, 0x663d, 0x77e8, 0x0b87, 0x3dcb, 0x360d, 0x218b,
696 	0x512f, 0x7dc9, 0x6a4d, 0x630a, 0x3547, 0x1dd2, 0x5aea, 0x69a5,
697 	0x7bfa, 0x5e4f, 0x1519, 0x6430, 0x3a0e, 0x5eb3, 0x5425, 0x0c7a,
698 	0x5540, 0x3670, 0x63c1, 0x31e9, 0x5a39, 0x2de7, 0x5979, 0x2891,
699 	0x1562, 0x014b, 0x5b05, 0x2756, 0x5a34, 0x13aa, 0x6cb5, 0x2c36,
700 	0x5e72, 0x1306, 0x0861, 0x15ef, 0x1ee8, 0x5a37, 0x7ac4, 0x45dd,
701 	0x44c4, 0x7266, 0x2f41, 0x3ccc, 0x045e, 0x7d40, 0x7c66, 0x0fa0,
702 };
703 
704 static const u16 sunxi_nfc_randomizer_ecc1024_seeds[] = {
705 	0x2cf5, 0x35f1, 0x63a4, 0x5274, 0x2bd2, 0x778b, 0x7285, 0x32b6,
706 	0x6a5c, 0x70d6, 0x757d, 0x6769, 0x5375, 0x1e81, 0x0cf3, 0x3982,
707 	0x6787, 0x042a, 0x6c49, 0x1925, 0x56a8, 0x40a9, 0x063e, 0x7bd9,
708 	0x4dbf, 0x55ec, 0x672e, 0x7334, 0x5185, 0x4d00, 0x232a, 0x7e07,
709 	0x445d, 0x6b92, 0x528f, 0x4255, 0x53ba, 0x7d82, 0x2a2e, 0x3a4e,
710 	0x75eb, 0x450c, 0x6844, 0x1b5d, 0x581a, 0x4cc6, 0x0379, 0x37b2,
711 	0x419f, 0x0e92, 0x6b27, 0x5624, 0x01e3, 0x07c1, 0x44a5, 0x130c,
712 	0x13e8, 0x5910, 0x0876, 0x60c5, 0x54e3, 0x5b7f, 0x2269, 0x509f,
713 	0x7665, 0x36fd, 0x3e9a, 0x0579, 0x6295, 0x14ef, 0x0a81, 0x1bcc,
714 	0x4b16, 0x64db, 0x0514, 0x4f07, 0x0591, 0x3576, 0x6853, 0x0d9e,
715 	0x259f, 0x38b7, 0x64fb, 0x3094, 0x4693, 0x6ddd, 0x29bb, 0x0bc8,
716 	0x3f47, 0x490e, 0x0c0e, 0x7933, 0x3c9e, 0x5840, 0x398d, 0x3e68,
717 	0x4af1, 0x71f5, 0x57cf, 0x1121, 0x64eb, 0x3579, 0x15ac, 0x584d,
718 	0x5f2a, 0x47e2, 0x6528, 0x6eac, 0x196e, 0x6b96, 0x0450, 0x0179,
719 	0x609c, 0x06e1, 0x4626, 0x42c7, 0x273e, 0x486f, 0x0705, 0x1601,
720 	0x145b, 0x407e, 0x062b, 0x57a5, 0x53f9, 0x5659, 0x4410, 0x3ccd,
721 };
722 
723 static u16 sunxi_nfc_randomizer_step(u16 state, int count)
724 {
725 	state &= 0x7fff;
726 
727 	/*
728 	 * This loop is just a simple implementation of a Fibonacci LFSR using
729 	 * the x16 + x15 + 1 polynomial.
730 	 */
731 	while (count--)
732 		state = ((state >> 1) |
733 			 (((state ^ (state >> 1)) & 1) << 14)) & 0x7fff;
734 
735 	return state;
736 }
737 
738 static u16 sunxi_nfc_randomizer_state(struct mtd_info *mtd, int page, bool ecc)
739 {
740 	const u16 *seeds = sunxi_nfc_randomizer_page_seeds;
741 	int mod = mtd_div_by_ws(mtd->erasesize, mtd);
742 
743 	if (mod > ARRAY_SIZE(sunxi_nfc_randomizer_page_seeds))
744 		mod = ARRAY_SIZE(sunxi_nfc_randomizer_page_seeds);
745 
746 	if (ecc) {
747 		if (mtd->ecc_step_size == 512)
748 			seeds = sunxi_nfc_randomizer_ecc512_seeds;
749 		else
750 			seeds = sunxi_nfc_randomizer_ecc1024_seeds;
751 	}
752 
753 	return seeds[page % mod];
754 }
755 
756 static void sunxi_nfc_randomizer_config(struct mtd_info *mtd,
757 					int page, bool ecc)
758 {
759 	struct nand_chip *nand = mtd_to_nand(mtd);
760 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
761 	u32 ecc_ctl = readl(nfc->regs + NFC_REG_ECC_CTL);
762 	u16 state;
763 
764 	if (!(nand->options & NAND_NEED_SCRAMBLING))
765 		return;
766 
767 	ecc_ctl = readl(nfc->regs + NFC_REG_ECC_CTL);
768 	state = sunxi_nfc_randomizer_state(mtd, page, ecc);
769 	ecc_ctl = readl(nfc->regs + NFC_REG_ECC_CTL) & ~NFC_RANDOM_SEED_MSK;
770 	writel(ecc_ctl | NFC_RANDOM_SEED(state), nfc->regs + NFC_REG_ECC_CTL);
771 }
772 
773 static void sunxi_nfc_randomizer_enable(struct mtd_info *mtd)
774 {
775 	struct nand_chip *nand = mtd_to_nand(mtd);
776 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
777 
778 	if (!(nand->options & NAND_NEED_SCRAMBLING))
779 		return;
780 
781 	writel(readl(nfc->regs + NFC_REG_ECC_CTL) | NFC_RANDOM_EN,
782 	       nfc->regs + NFC_REG_ECC_CTL);
783 }
784 
785 static void sunxi_nfc_randomizer_disable(struct mtd_info *mtd)
786 {
787 	struct nand_chip *nand = mtd_to_nand(mtd);
788 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
789 
790 	if (!(nand->options & NAND_NEED_SCRAMBLING))
791 		return;
792 
793 	writel(readl(nfc->regs + NFC_REG_ECC_CTL) & ~NFC_RANDOM_EN,
794 	       nfc->regs + NFC_REG_ECC_CTL);
795 }
796 
797 static void sunxi_nfc_randomize_bbm(struct mtd_info *mtd, int page, u8 *bbm)
798 {
799 	u16 state = sunxi_nfc_randomizer_state(mtd, page, true);
800 
801 	bbm[0] ^= state;
802 	bbm[1] ^= sunxi_nfc_randomizer_step(state, 8);
803 }
804 
805 static void sunxi_nfc_randomizer_write_buf(struct mtd_info *mtd,
806 					   const uint8_t *buf, int len,
807 					   bool ecc, int page)
808 {
809 	sunxi_nfc_randomizer_config(mtd, page, ecc);
810 	sunxi_nfc_randomizer_enable(mtd);
811 	sunxi_nfc_write_buf(mtd, buf, len);
812 	sunxi_nfc_randomizer_disable(mtd);
813 }
814 
815 static void sunxi_nfc_randomizer_read_buf(struct mtd_info *mtd, uint8_t *buf,
816 					  int len, bool ecc, int page)
817 {
818 	sunxi_nfc_randomizer_config(mtd, page, ecc);
819 	sunxi_nfc_randomizer_enable(mtd);
820 	sunxi_nfc_read_buf(mtd, buf, len);
821 	sunxi_nfc_randomizer_disable(mtd);
822 }
823 
824 static void sunxi_nfc_hw_ecc_enable(struct mtd_info *mtd)
825 {
826 	struct nand_chip *nand = mtd_to_nand(mtd);
827 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
828 	struct sunxi_nand_hw_ecc *data = nand->ecc.priv;
829 	u32 ecc_ctl;
830 
831 	ecc_ctl = readl(nfc->regs + NFC_REG_ECC_CTL);
832 	ecc_ctl &= ~(NFC_ECC_MODE_MSK | NFC_ECC_PIPELINE |
833 		     NFC_ECC_BLOCK_SIZE_MSK);
834 	ecc_ctl |= NFC_ECC_EN | NFC_ECC_MODE(data->mode) | NFC_ECC_EXCEPTION |
835 		   NFC_ECC_PIPELINE;
836 
837 	if (nand->ecc.size == 512)
838 		ecc_ctl |= NFC_ECC_BLOCK_512;
839 
840 	writel(ecc_ctl, nfc->regs + NFC_REG_ECC_CTL);
841 }
842 
843 static void sunxi_nfc_hw_ecc_disable(struct mtd_info *mtd)
844 {
845 	struct nand_chip *nand = mtd_to_nand(mtd);
846 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
847 
848 	writel(readl(nfc->regs + NFC_REG_ECC_CTL) & ~NFC_ECC_EN,
849 	       nfc->regs + NFC_REG_ECC_CTL);
850 }
851 
852 static inline void sunxi_nfc_user_data_to_buf(u32 user_data, u8 *buf)
853 {
854 	buf[0] = user_data;
855 	buf[1] = user_data >> 8;
856 	buf[2] = user_data >> 16;
857 	buf[3] = user_data >> 24;
858 }
859 
860 static inline u32 sunxi_nfc_buf_to_user_data(const u8 *buf)
861 {
862 	return buf[0] | (buf[1] << 8) | (buf[2] << 16) | (buf[3] << 24);
863 }
864 
865 static void sunxi_nfc_hw_ecc_get_prot_oob_bytes(struct mtd_info *mtd, u8 *oob,
866 						int step, bool bbm, int page)
867 {
868 	struct nand_chip *nand = mtd_to_nand(mtd);
869 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
870 
871 	sunxi_nfc_user_data_to_buf(readl(nfc->regs + NFC_REG_USER_DATA(step)),
872 				   oob);
873 
874 	/* De-randomize the Bad Block Marker. */
875 	if (bbm && (nand->options & NAND_NEED_SCRAMBLING))
876 		sunxi_nfc_randomize_bbm(mtd, page, oob);
877 }
878 
879 static void sunxi_nfc_hw_ecc_set_prot_oob_bytes(struct mtd_info *mtd,
880 						const u8 *oob, int step,
881 						bool bbm, int page)
882 {
883 	struct nand_chip *nand = mtd_to_nand(mtd);
884 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
885 	u8 user_data[4];
886 
887 	/* Randomize the Bad Block Marker. */
888 	if (bbm && (nand->options & NAND_NEED_SCRAMBLING)) {
889 		memcpy(user_data, oob, sizeof(user_data));
890 		sunxi_nfc_randomize_bbm(mtd, page, user_data);
891 		oob = user_data;
892 	}
893 
894 	writel(sunxi_nfc_buf_to_user_data(oob),
895 	       nfc->regs + NFC_REG_USER_DATA(step));
896 }
897 
898 static void sunxi_nfc_hw_ecc_update_stats(struct mtd_info *mtd,
899 					  unsigned int *max_bitflips, int ret)
900 {
901 	if (ret < 0) {
902 		mtd->ecc_stats.failed++;
903 	} else {
904 		mtd->ecc_stats.corrected += ret;
905 		*max_bitflips = max_t(unsigned int, *max_bitflips, ret);
906 	}
907 }
908 
909 static int sunxi_nfc_hw_ecc_correct(struct mtd_info *mtd, u8 *data, u8 *oob,
910 				    int step, u32 status, bool *erased)
911 {
912 	struct nand_chip *nand = mtd_to_nand(mtd);
913 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
914 	struct nand_ecc_ctrl *ecc = &nand->ecc;
915 	u32 tmp;
916 
917 	*erased = false;
918 
919 	if (status & NFC_ECC_ERR(step))
920 		return -EBADMSG;
921 
922 	if (status & NFC_ECC_PAT_FOUND(step)) {
923 		u8 pattern;
924 
925 		if (unlikely(!(readl(nfc->regs + NFC_REG_PAT_ID) & 0x1))) {
926 			pattern = 0x0;
927 		} else {
928 			pattern = 0xff;
929 			*erased = true;
930 		}
931 
932 		if (data)
933 			memset(data, pattern, ecc->size);
934 
935 		if (oob)
936 			memset(oob, pattern, ecc->bytes + 4);
937 
938 		return 0;
939 	}
940 
941 	tmp = readl(nfc->regs + NFC_REG_ECC_ERR_CNT(step));
942 
943 	return NFC_ECC_ERR_CNT(step, tmp);
944 }
945 
946 static int sunxi_nfc_hw_ecc_read_chunk(struct mtd_info *mtd,
947 				       u8 *data, int data_off,
948 				       u8 *oob, int oob_off,
949 				       int *cur_off,
950 				       unsigned int *max_bitflips,
951 				       bool bbm, bool oob_required, int page)
952 {
953 	struct nand_chip *nand = mtd_to_nand(mtd);
954 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
955 	struct nand_ecc_ctrl *ecc = &nand->ecc;
956 	int raw_mode = 0;
957 	bool erased;
958 	int ret;
959 
960 	if (*cur_off != data_off)
961 		nand_change_read_column_op(nand, data_off, NULL, 0, false);
962 
963 	sunxi_nfc_randomizer_read_buf(mtd, NULL, ecc->size, false, page);
964 
965 	if (data_off + ecc->size != oob_off)
966 		nand_change_read_column_op(nand, oob_off, NULL, 0, false);
967 
968 	ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
969 	if (ret)
970 		return ret;
971 
972 	sunxi_nfc_randomizer_enable(mtd);
973 	writel(NFC_DATA_TRANS | NFC_DATA_SWAP_METHOD | NFC_ECC_OP,
974 	       nfc->regs + NFC_REG_CMD);
975 
976 	ret = sunxi_nfc_wait_events(nfc, NFC_CMD_INT_FLAG, false, 0);
977 	sunxi_nfc_randomizer_disable(mtd);
978 	if (ret)
979 		return ret;
980 
981 	*cur_off = oob_off + ecc->bytes + 4;
982 
983 	ret = sunxi_nfc_hw_ecc_correct(mtd, data, oob_required ? oob : NULL, 0,
984 				       readl(nfc->regs + NFC_REG_ECC_ST),
985 				       &erased);
986 	if (erased)
987 		return 1;
988 
989 	if (ret < 0) {
990 		/*
991 		 * Re-read the data with the randomizer disabled to identify
992 		 * bitflips in erased pages.
993 		 */
994 		if (nand->options & NAND_NEED_SCRAMBLING)
995 			nand_change_read_column_op(nand, data_off, data,
996 						   ecc->size, false);
997 		else
998 			memcpy_fromio(data, nfc->regs + NFC_RAM0_BASE,
999 				      ecc->size);
1000 
1001 		nand_change_read_column_op(nand, oob_off, oob, ecc->bytes + 4,
1002 					   false);
1003 
1004 		ret = nand_check_erased_ecc_chunk(data,	ecc->size,
1005 						  oob, ecc->bytes + 4,
1006 						  NULL, 0, ecc->strength);
1007 		if (ret >= 0)
1008 			raw_mode = 1;
1009 	} else {
1010 		memcpy_fromio(data, nfc->regs + NFC_RAM0_BASE, ecc->size);
1011 
1012 		if (oob_required) {
1013 			nand_change_read_column_op(nand, oob_off, NULL, 0,
1014 						   false);
1015 			sunxi_nfc_randomizer_read_buf(mtd, oob, ecc->bytes + 4,
1016 						      true, page);
1017 
1018 			sunxi_nfc_hw_ecc_get_prot_oob_bytes(mtd, oob, 0,
1019 							    bbm, page);
1020 		}
1021 	}
1022 
1023 	sunxi_nfc_hw_ecc_update_stats(mtd, max_bitflips, ret);
1024 
1025 	return raw_mode;
1026 }
1027 
1028 static void sunxi_nfc_hw_ecc_read_extra_oob(struct mtd_info *mtd,
1029 					    u8 *oob, int *cur_off,
1030 					    bool randomize, int page)
1031 {
1032 	struct nand_chip *nand = mtd_to_nand(mtd);
1033 	struct nand_ecc_ctrl *ecc = &nand->ecc;
1034 	int offset = ((ecc->bytes + 4) * ecc->steps);
1035 	int len = mtd->oobsize - offset;
1036 
1037 	if (len <= 0)
1038 		return;
1039 
1040 	if (!cur_off || *cur_off != offset)
1041 		nand_change_read_column_op(nand, mtd->writesize, NULL, 0,
1042 					   false);
1043 
1044 	if (!randomize)
1045 		sunxi_nfc_read_buf(mtd, oob + offset, len);
1046 	else
1047 		sunxi_nfc_randomizer_read_buf(mtd, oob + offset, len,
1048 					      false, page);
1049 
1050 	if (cur_off)
1051 		*cur_off = mtd->oobsize + mtd->writesize;
1052 }
1053 
1054 static int sunxi_nfc_hw_ecc_read_chunks_dma(struct mtd_info *mtd, uint8_t *buf,
1055 					    int oob_required, int page,
1056 					    int nchunks)
1057 {
1058 	struct nand_chip *nand = mtd_to_nand(mtd);
1059 	bool randomized = nand->options & NAND_NEED_SCRAMBLING;
1060 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
1061 	struct nand_ecc_ctrl *ecc = &nand->ecc;
1062 	unsigned int max_bitflips = 0;
1063 	int ret, i, raw_mode = 0;
1064 	struct scatterlist sg;
1065 	u32 status;
1066 
1067 	ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
1068 	if (ret)
1069 		return ret;
1070 
1071 	ret = sunxi_nfc_dma_op_prepare(mtd, buf, ecc->size, nchunks,
1072 				       DMA_FROM_DEVICE, &sg);
1073 	if (ret)
1074 		return ret;
1075 
1076 	sunxi_nfc_hw_ecc_enable(mtd);
1077 	sunxi_nfc_randomizer_config(mtd, page, false);
1078 	sunxi_nfc_randomizer_enable(mtd);
1079 
1080 	writel((NAND_CMD_RNDOUTSTART << 16) | (NAND_CMD_RNDOUT << 8) |
1081 	       NAND_CMD_READSTART, nfc->regs + NFC_REG_RCMD_SET);
1082 
1083 	dma_async_issue_pending(nfc->dmac);
1084 
1085 	writel(NFC_PAGE_OP | NFC_DATA_SWAP_METHOD | NFC_DATA_TRANS,
1086 	       nfc->regs + NFC_REG_CMD);
1087 
1088 	ret = sunxi_nfc_wait_events(nfc, NFC_CMD_INT_FLAG, false, 0);
1089 	if (ret)
1090 		dmaengine_terminate_all(nfc->dmac);
1091 
1092 	sunxi_nfc_randomizer_disable(mtd);
1093 	sunxi_nfc_hw_ecc_disable(mtd);
1094 
1095 	sunxi_nfc_dma_op_cleanup(mtd, DMA_FROM_DEVICE, &sg);
1096 
1097 	if (ret)
1098 		return ret;
1099 
1100 	status = readl(nfc->regs + NFC_REG_ECC_ST);
1101 
1102 	for (i = 0; i < nchunks; 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 		bool erased;
1108 
1109 		ret = sunxi_nfc_hw_ecc_correct(mtd, randomized ? data : NULL,
1110 					       oob_required ? oob : NULL,
1111 					       i, status, &erased);
1112 
1113 		/* ECC errors are handled in the second loop. */
1114 		if (ret < 0)
1115 			continue;
1116 
1117 		if (oob_required && !erased) {
1118 			/* TODO: use DMA to retrieve OOB */
1119 			nand_change_read_column_op(nand,
1120 						   mtd->writesize + oob_off,
1121 						   oob, ecc->bytes + 4, false);
1122 
1123 			sunxi_nfc_hw_ecc_get_prot_oob_bytes(mtd, oob, i,
1124 							    !i, page);
1125 		}
1126 
1127 		if (erased)
1128 			raw_mode = 1;
1129 
1130 		sunxi_nfc_hw_ecc_update_stats(mtd, &max_bitflips, ret);
1131 	}
1132 
1133 	if (status & NFC_ECC_ERR_MSK) {
1134 		for (i = 0; i < nchunks; i++) {
1135 			int data_off = i * ecc->size;
1136 			int oob_off = i * (ecc->bytes + 4);
1137 			u8 *data = buf + data_off;
1138 			u8 *oob = nand->oob_poi + oob_off;
1139 
1140 			if (!(status & NFC_ECC_ERR(i)))
1141 				continue;
1142 
1143 			/*
1144 			 * Re-read the data with the randomizer disabled to
1145 			 * identify bitflips in erased pages.
1146 			 * TODO: use DMA to read page in raw mode
1147 			 */
1148 			if (randomized)
1149 				nand_change_read_column_op(nand, data_off,
1150 							   data, ecc->size,
1151 							   false);
1152 
1153 			/* TODO: use DMA to retrieve OOB */
1154 			nand_change_read_column_op(nand,
1155 						   mtd->writesize + oob_off,
1156 						   oob, ecc->bytes + 4, false);
1157 
1158 			ret = nand_check_erased_ecc_chunk(data,	ecc->size,
1159 							  oob, ecc->bytes + 4,
1160 							  NULL, 0,
1161 							  ecc->strength);
1162 			if (ret >= 0)
1163 				raw_mode = 1;
1164 
1165 			sunxi_nfc_hw_ecc_update_stats(mtd, &max_bitflips, ret);
1166 		}
1167 	}
1168 
1169 	if (oob_required)
1170 		sunxi_nfc_hw_ecc_read_extra_oob(mtd, nand->oob_poi,
1171 						NULL, !raw_mode,
1172 						page);
1173 
1174 	return max_bitflips;
1175 }
1176 
1177 static int sunxi_nfc_hw_ecc_write_chunk(struct mtd_info *mtd,
1178 					const u8 *data, int data_off,
1179 					const u8 *oob, int oob_off,
1180 					int *cur_off, bool bbm,
1181 					int page)
1182 {
1183 	struct nand_chip *nand = mtd_to_nand(mtd);
1184 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
1185 	struct nand_ecc_ctrl *ecc = &nand->ecc;
1186 	int ret;
1187 
1188 	if (data_off != *cur_off)
1189 		nand_change_write_column_op(nand, data_off, NULL, 0, false);
1190 
1191 	sunxi_nfc_randomizer_write_buf(mtd, data, ecc->size, false, page);
1192 
1193 	if (data_off + ecc->size != oob_off)
1194 		nand_change_write_column_op(nand, oob_off, NULL, 0, false);
1195 
1196 	ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
1197 	if (ret)
1198 		return ret;
1199 
1200 	sunxi_nfc_randomizer_enable(mtd);
1201 	sunxi_nfc_hw_ecc_set_prot_oob_bytes(mtd, oob, 0, bbm, page);
1202 
1203 	writel(NFC_DATA_TRANS | NFC_DATA_SWAP_METHOD |
1204 	       NFC_ACCESS_DIR | NFC_ECC_OP,
1205 	       nfc->regs + NFC_REG_CMD);
1206 
1207 	ret = sunxi_nfc_wait_events(nfc, NFC_CMD_INT_FLAG, false, 0);
1208 	sunxi_nfc_randomizer_disable(mtd);
1209 	if (ret)
1210 		return ret;
1211 
1212 	*cur_off = oob_off + ecc->bytes + 4;
1213 
1214 	return 0;
1215 }
1216 
1217 static void sunxi_nfc_hw_ecc_write_extra_oob(struct mtd_info *mtd,
1218 					     u8 *oob, int *cur_off,
1219 					     int page)
1220 {
1221 	struct nand_chip *nand = mtd_to_nand(mtd);
1222 	struct nand_ecc_ctrl *ecc = &nand->ecc;
1223 	int offset = ((ecc->bytes + 4) * ecc->steps);
1224 	int len = mtd->oobsize - offset;
1225 
1226 	if (len <= 0)
1227 		return;
1228 
1229 	if (!cur_off || *cur_off != offset)
1230 		nand_change_write_column_op(nand, offset + mtd->writesize,
1231 					    NULL, 0, false);
1232 
1233 	sunxi_nfc_randomizer_write_buf(mtd, oob + offset, len, false, page);
1234 
1235 	if (cur_off)
1236 		*cur_off = mtd->oobsize + mtd->writesize;
1237 }
1238 
1239 static int sunxi_nfc_hw_ecc_read_page(struct mtd_info *mtd,
1240 				      struct nand_chip *chip, uint8_t *buf,
1241 				      int oob_required, int page)
1242 {
1243 	struct nand_ecc_ctrl *ecc = &chip->ecc;
1244 	unsigned int max_bitflips = 0;
1245 	int ret, i, cur_off = 0;
1246 	bool raw_mode = false;
1247 
1248 	nand_read_page_op(chip, page, 0, NULL, 0);
1249 
1250 	sunxi_nfc_hw_ecc_enable(mtd);
1251 
1252 	for (i = 0; i < ecc->steps; i++) {
1253 		int data_off = i * ecc->size;
1254 		int oob_off = i * (ecc->bytes + 4);
1255 		u8 *data = buf + data_off;
1256 		u8 *oob = chip->oob_poi + oob_off;
1257 
1258 		ret = sunxi_nfc_hw_ecc_read_chunk(mtd, data, data_off, oob,
1259 						  oob_off + mtd->writesize,
1260 						  &cur_off, &max_bitflips,
1261 						  !i, oob_required, page);
1262 		if (ret < 0)
1263 			return ret;
1264 		else if (ret)
1265 			raw_mode = true;
1266 	}
1267 
1268 	if (oob_required)
1269 		sunxi_nfc_hw_ecc_read_extra_oob(mtd, chip->oob_poi, &cur_off,
1270 						!raw_mode, page);
1271 
1272 	sunxi_nfc_hw_ecc_disable(mtd);
1273 
1274 	return max_bitflips;
1275 }
1276 
1277 static int sunxi_nfc_hw_ecc_read_page_dma(struct mtd_info *mtd,
1278 					  struct nand_chip *chip, u8 *buf,
1279 					  int oob_required, int page)
1280 {
1281 	int ret;
1282 
1283 	nand_read_page_op(chip, page, 0, NULL, 0);
1284 
1285 	ret = sunxi_nfc_hw_ecc_read_chunks_dma(mtd, buf, oob_required, page,
1286 					       chip->ecc.steps);
1287 	if (ret >= 0)
1288 		return ret;
1289 
1290 	/* Fallback to PIO mode */
1291 	return sunxi_nfc_hw_ecc_read_page(mtd, chip, buf, oob_required, page);
1292 }
1293 
1294 static int sunxi_nfc_hw_ecc_read_subpage(struct mtd_info *mtd,
1295 					 struct nand_chip *chip,
1296 					 u32 data_offs, u32 readlen,
1297 					 u8 *bufpoi, int page)
1298 {
1299 	struct nand_ecc_ctrl *ecc = &chip->ecc;
1300 	int ret, i, cur_off = 0;
1301 	unsigned int max_bitflips = 0;
1302 
1303 	nand_read_page_op(chip, page, 0, NULL, 0);
1304 
1305 	sunxi_nfc_hw_ecc_enable(mtd);
1306 
1307 	for (i = data_offs / ecc->size;
1308 	     i < DIV_ROUND_UP(data_offs + readlen, ecc->size); i++) {
1309 		int data_off = i * ecc->size;
1310 		int oob_off = i * (ecc->bytes + 4);
1311 		u8 *data = bufpoi + data_off;
1312 		u8 *oob = chip->oob_poi + oob_off;
1313 
1314 		ret = sunxi_nfc_hw_ecc_read_chunk(mtd, data, data_off,
1315 						  oob,
1316 						  oob_off + mtd->writesize,
1317 						  &cur_off, &max_bitflips, !i,
1318 						  false, page);
1319 		if (ret < 0)
1320 			return ret;
1321 	}
1322 
1323 	sunxi_nfc_hw_ecc_disable(mtd);
1324 
1325 	return max_bitflips;
1326 }
1327 
1328 static int sunxi_nfc_hw_ecc_read_subpage_dma(struct mtd_info *mtd,
1329 					     struct nand_chip *chip,
1330 					     u32 data_offs, u32 readlen,
1331 					     u8 *buf, int page)
1332 {
1333 	int nchunks = DIV_ROUND_UP(data_offs + readlen, chip->ecc.size);
1334 	int ret;
1335 
1336 	nand_read_page_op(chip, page, 0, NULL, 0);
1337 
1338 	ret = sunxi_nfc_hw_ecc_read_chunks_dma(mtd, buf, false, page, nchunks);
1339 	if (ret >= 0)
1340 		return ret;
1341 
1342 	/* Fallback to PIO mode */
1343 	return sunxi_nfc_hw_ecc_read_subpage(mtd, chip, data_offs, readlen,
1344 					     buf, page);
1345 }
1346 
1347 static int sunxi_nfc_hw_ecc_write_page(struct mtd_info *mtd,
1348 				       struct nand_chip *chip,
1349 				       const uint8_t *buf, int oob_required,
1350 				       int page)
1351 {
1352 	struct nand_ecc_ctrl *ecc = &chip->ecc;
1353 	int ret, i, cur_off = 0;
1354 
1355 	nand_prog_page_begin_op(chip, page, 0, NULL, 0);
1356 
1357 	sunxi_nfc_hw_ecc_enable(mtd);
1358 
1359 	for (i = 0; i < ecc->steps; i++) {
1360 		int data_off = i * ecc->size;
1361 		int oob_off = i * (ecc->bytes + 4);
1362 		const u8 *data = buf + data_off;
1363 		const u8 *oob = chip->oob_poi + oob_off;
1364 
1365 		ret = sunxi_nfc_hw_ecc_write_chunk(mtd, data, data_off, oob,
1366 						   oob_off + mtd->writesize,
1367 						   &cur_off, !i, page);
1368 		if (ret)
1369 			return ret;
1370 	}
1371 
1372 	if (oob_required || (chip->options & NAND_NEED_SCRAMBLING))
1373 		sunxi_nfc_hw_ecc_write_extra_oob(mtd, chip->oob_poi,
1374 						 &cur_off, page);
1375 
1376 	sunxi_nfc_hw_ecc_disable(mtd);
1377 
1378 	return nand_prog_page_end_op(chip);
1379 }
1380 
1381 static int sunxi_nfc_hw_ecc_write_subpage(struct mtd_info *mtd,
1382 					  struct nand_chip *chip,
1383 					  u32 data_offs, u32 data_len,
1384 					  const u8 *buf, int oob_required,
1385 					  int page)
1386 {
1387 	struct nand_ecc_ctrl *ecc = &chip->ecc;
1388 	int ret, i, cur_off = 0;
1389 
1390 	nand_prog_page_begin_op(chip, page, 0, NULL, 0);
1391 
1392 	sunxi_nfc_hw_ecc_enable(mtd);
1393 
1394 	for (i = data_offs / ecc->size;
1395 	     i < DIV_ROUND_UP(data_offs + data_len, ecc->size); i++) {
1396 		int data_off = i * ecc->size;
1397 		int oob_off = i * (ecc->bytes + 4);
1398 		const u8 *data = buf + data_off;
1399 		const u8 *oob = chip->oob_poi + oob_off;
1400 
1401 		ret = sunxi_nfc_hw_ecc_write_chunk(mtd, data, data_off, oob,
1402 						   oob_off + mtd->writesize,
1403 						   &cur_off, !i, page);
1404 		if (ret)
1405 			return ret;
1406 	}
1407 
1408 	sunxi_nfc_hw_ecc_disable(mtd);
1409 
1410 	return nand_prog_page_end_op(chip);
1411 }
1412 
1413 static int sunxi_nfc_hw_ecc_write_page_dma(struct mtd_info *mtd,
1414 					   struct nand_chip *chip,
1415 					   const u8 *buf,
1416 					   int oob_required,
1417 					   int page)
1418 {
1419 	struct nand_chip *nand = mtd_to_nand(mtd);
1420 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
1421 	struct nand_ecc_ctrl *ecc = &nand->ecc;
1422 	struct scatterlist sg;
1423 	int ret, i;
1424 
1425 	ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
1426 	if (ret)
1427 		return ret;
1428 
1429 	ret = sunxi_nfc_dma_op_prepare(mtd, buf, ecc->size, ecc->steps,
1430 				       DMA_TO_DEVICE, &sg);
1431 	if (ret)
1432 		goto pio_fallback;
1433 
1434 	for (i = 0; i < ecc->steps; i++) {
1435 		const u8 *oob = nand->oob_poi + (i * (ecc->bytes + 4));
1436 
1437 		sunxi_nfc_hw_ecc_set_prot_oob_bytes(mtd, oob, i, !i, page);
1438 	}
1439 
1440 	nand_prog_page_begin_op(chip, page, 0, NULL, 0);
1441 
1442 	sunxi_nfc_hw_ecc_enable(mtd);
1443 	sunxi_nfc_randomizer_config(mtd, page, false);
1444 	sunxi_nfc_randomizer_enable(mtd);
1445 
1446 	writel((NAND_CMD_RNDIN << 8) | NAND_CMD_PAGEPROG,
1447 	       nfc->regs + NFC_REG_RCMD_SET);
1448 
1449 	dma_async_issue_pending(nfc->dmac);
1450 
1451 	writel(NFC_PAGE_OP | NFC_DATA_SWAP_METHOD |
1452 	       NFC_DATA_TRANS | NFC_ACCESS_DIR,
1453 	       nfc->regs + NFC_REG_CMD);
1454 
1455 	ret = sunxi_nfc_wait_events(nfc, NFC_CMD_INT_FLAG, false, 0);
1456 	if (ret)
1457 		dmaengine_terminate_all(nfc->dmac);
1458 
1459 	sunxi_nfc_randomizer_disable(mtd);
1460 	sunxi_nfc_hw_ecc_disable(mtd);
1461 
1462 	sunxi_nfc_dma_op_cleanup(mtd, DMA_TO_DEVICE, &sg);
1463 
1464 	if (ret)
1465 		return ret;
1466 
1467 	if (oob_required || (chip->options & NAND_NEED_SCRAMBLING))
1468 		/* TODO: use DMA to transfer extra OOB bytes ? */
1469 		sunxi_nfc_hw_ecc_write_extra_oob(mtd, chip->oob_poi,
1470 						 NULL, page);
1471 
1472 	return nand_prog_page_end_op(chip);
1473 
1474 pio_fallback:
1475 	return sunxi_nfc_hw_ecc_write_page(mtd, chip, buf, oob_required, page);
1476 }
1477 
1478 static int sunxi_nfc_hw_ecc_read_oob(struct mtd_info *mtd,
1479 				     struct nand_chip *chip,
1480 				     int page)
1481 {
1482 	chip->pagebuf = -1;
1483 
1484 	return chip->ecc.read_page(mtd, chip, chip->data_buf, 1, page);
1485 }
1486 
1487 static int sunxi_nfc_hw_ecc_write_oob(struct mtd_info *mtd,
1488 				      struct nand_chip *chip,
1489 				      int page)
1490 {
1491 	int ret;
1492 
1493 	chip->pagebuf = -1;
1494 
1495 	memset(chip->data_buf, 0xff, mtd->writesize);
1496 	ret = chip->ecc.write_page(mtd, chip, chip->data_buf, 1, page);
1497 	if (ret)
1498 		return ret;
1499 
1500 	/* Send command to program the OOB data */
1501 	return nand_prog_page_end_op(chip);
1502 }
1503 
1504 static const s32 tWB_lut[] = {6, 12, 16, 20};
1505 static const s32 tRHW_lut[] = {4, 8, 12, 20};
1506 
1507 static int _sunxi_nand_lookup_timing(const s32 *lut, int lut_size, u32 duration,
1508 		u32 clk_period)
1509 {
1510 	u32 clk_cycles = DIV_ROUND_UP(duration, clk_period);
1511 	int i;
1512 
1513 	for (i = 0; i < lut_size; i++) {
1514 		if (clk_cycles <= lut[i])
1515 			return i;
1516 	}
1517 
1518 	/* Doesn't fit */
1519 	return -EINVAL;
1520 }
1521 
1522 #define sunxi_nand_lookup_timing(l, p, c) \
1523 			_sunxi_nand_lookup_timing(l, ARRAY_SIZE(l), p, c)
1524 
1525 static int sunxi_nfc_setup_data_interface(struct mtd_info *mtd, int csline,
1526 					const struct nand_data_interface *conf)
1527 {
1528 	struct nand_chip *nand = mtd_to_nand(mtd);
1529 	struct sunxi_nand_chip *chip = to_sunxi_nand(nand);
1530 	struct sunxi_nfc *nfc = to_sunxi_nfc(chip->nand.controller);
1531 	const struct nand_sdr_timings *timings;
1532 	u32 min_clk_period = 0;
1533 	s32 tWB, tADL, tWHR, tRHW, tCAD;
1534 	long real_clk_rate;
1535 
1536 	timings = nand_get_sdr_timings(conf);
1537 	if (IS_ERR(timings))
1538 		return -ENOTSUPP;
1539 
1540 	/* T1 <=> tCLS */
1541 	if (timings->tCLS_min > min_clk_period)
1542 		min_clk_period = timings->tCLS_min;
1543 
1544 	/* T2 <=> tCLH */
1545 	if (timings->tCLH_min > min_clk_period)
1546 		min_clk_period = timings->tCLH_min;
1547 
1548 	/* T3 <=> tCS */
1549 	if (timings->tCS_min > min_clk_period)
1550 		min_clk_period = timings->tCS_min;
1551 
1552 	/* T4 <=> tCH */
1553 	if (timings->tCH_min > min_clk_period)
1554 		min_clk_period = timings->tCH_min;
1555 
1556 	/* T5 <=> tWP */
1557 	if (timings->tWP_min > min_clk_period)
1558 		min_clk_period = timings->tWP_min;
1559 
1560 	/* T6 <=> tWH */
1561 	if (timings->tWH_min > min_clk_period)
1562 		min_clk_period = timings->tWH_min;
1563 
1564 	/* T7 <=> tALS */
1565 	if (timings->tALS_min > min_clk_period)
1566 		min_clk_period = timings->tALS_min;
1567 
1568 	/* T8 <=> tDS */
1569 	if (timings->tDS_min > min_clk_period)
1570 		min_clk_period = timings->tDS_min;
1571 
1572 	/* T9 <=> tDH */
1573 	if (timings->tDH_min > min_clk_period)
1574 		min_clk_period = timings->tDH_min;
1575 
1576 	/* T10 <=> tRR */
1577 	if (timings->tRR_min > (min_clk_period * 3))
1578 		min_clk_period = DIV_ROUND_UP(timings->tRR_min, 3);
1579 
1580 	/* T11 <=> tALH */
1581 	if (timings->tALH_min > min_clk_period)
1582 		min_clk_period = timings->tALH_min;
1583 
1584 	/* T12 <=> tRP */
1585 	if (timings->tRP_min > min_clk_period)
1586 		min_clk_period = timings->tRP_min;
1587 
1588 	/* T13 <=> tREH */
1589 	if (timings->tREH_min > min_clk_period)
1590 		min_clk_period = timings->tREH_min;
1591 
1592 	/* T14 <=> tRC */
1593 	if (timings->tRC_min > (min_clk_period * 2))
1594 		min_clk_period = DIV_ROUND_UP(timings->tRC_min, 2);
1595 
1596 	/* T15 <=> tWC */
1597 	if (timings->tWC_min > (min_clk_period * 2))
1598 		min_clk_period = DIV_ROUND_UP(timings->tWC_min, 2);
1599 
1600 	/* T16 - T19 + tCAD */
1601 	if (timings->tWB_max > (min_clk_period * 20))
1602 		min_clk_period = DIV_ROUND_UP(timings->tWB_max, 20);
1603 
1604 	if (timings->tADL_min > (min_clk_period * 32))
1605 		min_clk_period = DIV_ROUND_UP(timings->tADL_min, 32);
1606 
1607 	if (timings->tWHR_min > (min_clk_period * 32))
1608 		min_clk_period = DIV_ROUND_UP(timings->tWHR_min, 32);
1609 
1610 	if (timings->tRHW_min > (min_clk_period * 20))
1611 		min_clk_period = DIV_ROUND_UP(timings->tRHW_min, 20);
1612 
1613 	tWB  = sunxi_nand_lookup_timing(tWB_lut, timings->tWB_max,
1614 					min_clk_period);
1615 	if (tWB < 0) {
1616 		dev_err(nfc->dev, "unsupported tWB\n");
1617 		return tWB;
1618 	}
1619 
1620 	tADL = DIV_ROUND_UP(timings->tADL_min, min_clk_period) >> 3;
1621 	if (tADL > 3) {
1622 		dev_err(nfc->dev, "unsupported tADL\n");
1623 		return -EINVAL;
1624 	}
1625 
1626 	tWHR = DIV_ROUND_UP(timings->tWHR_min, min_clk_period) >> 3;
1627 	if (tWHR > 3) {
1628 		dev_err(nfc->dev, "unsupported tWHR\n");
1629 		return -EINVAL;
1630 	}
1631 
1632 	tRHW = sunxi_nand_lookup_timing(tRHW_lut, timings->tRHW_min,
1633 					min_clk_period);
1634 	if (tRHW < 0) {
1635 		dev_err(nfc->dev, "unsupported tRHW\n");
1636 		return tRHW;
1637 	}
1638 
1639 	if (csline == NAND_DATA_IFACE_CHECK_ONLY)
1640 		return 0;
1641 
1642 	/*
1643 	 * TODO: according to ONFI specs this value only applies for DDR NAND,
1644 	 * but Allwinner seems to set this to 0x7. Mimic them for now.
1645 	 */
1646 	tCAD = 0x7;
1647 
1648 	/* TODO: A83 has some more bits for CDQSS, CS, CLHZ, CCS, WC */
1649 	chip->timing_cfg = NFC_TIMING_CFG(tWB, tADL, tWHR, tRHW, tCAD);
1650 
1651 	/* Convert min_clk_period from picoseconds to nanoseconds */
1652 	min_clk_period = DIV_ROUND_UP(min_clk_period, 1000);
1653 
1654 	/*
1655 	 * Unlike what is stated in Allwinner datasheet, the clk_rate should
1656 	 * be set to (1 / min_clk_period), and not (2 / min_clk_period).
1657 	 * This new formula was verified with a scope and validated by
1658 	 * Allwinner engineers.
1659 	 */
1660 	chip->clk_rate = NSEC_PER_SEC / min_clk_period;
1661 	real_clk_rate = clk_round_rate(nfc->mod_clk, chip->clk_rate);
1662 	if (real_clk_rate <= 0) {
1663 		dev_err(nfc->dev, "Unable to round clk %lu\n", chip->clk_rate);
1664 		return -EINVAL;
1665 	}
1666 
1667 	/*
1668 	 * ONFI specification 3.1, paragraph 4.15.2 dictates that EDO data
1669 	 * output cycle timings shall be used if the host drives tRC less than
1670 	 * 30 ns.
1671 	 */
1672 	min_clk_period = NSEC_PER_SEC / real_clk_rate;
1673 	chip->timing_ctl = ((min_clk_period * 2) < 30) ?
1674 			   NFC_TIMING_CTL_EDO : 0;
1675 
1676 	return 0;
1677 }
1678 
1679 static int sunxi_nand_ooblayout_ecc(struct mtd_info *mtd, int section,
1680 				    struct mtd_oob_region *oobregion)
1681 {
1682 	struct nand_chip *nand = mtd_to_nand(mtd);
1683 	struct nand_ecc_ctrl *ecc = &nand->ecc;
1684 
1685 	if (section >= ecc->steps)
1686 		return -ERANGE;
1687 
1688 	oobregion->offset = section * (ecc->bytes + 4) + 4;
1689 	oobregion->length = ecc->bytes;
1690 
1691 	return 0;
1692 }
1693 
1694 static int sunxi_nand_ooblayout_free(struct mtd_info *mtd, int section,
1695 				     struct mtd_oob_region *oobregion)
1696 {
1697 	struct nand_chip *nand = mtd_to_nand(mtd);
1698 	struct nand_ecc_ctrl *ecc = &nand->ecc;
1699 
1700 	if (section > ecc->steps)
1701 		return -ERANGE;
1702 
1703 	/*
1704 	 * The first 2 bytes are used for BB markers, hence we
1705 	 * only have 2 bytes available in the first user data
1706 	 * section.
1707 	 */
1708 	if (!section && ecc->mode == NAND_ECC_HW) {
1709 		oobregion->offset = 2;
1710 		oobregion->length = 2;
1711 
1712 		return 0;
1713 	}
1714 
1715 	oobregion->offset = section * (ecc->bytes + 4);
1716 
1717 	if (section < ecc->steps)
1718 		oobregion->length = 4;
1719 	else
1720 		oobregion->offset = mtd->oobsize - oobregion->offset;
1721 
1722 	return 0;
1723 }
1724 
1725 static const struct mtd_ooblayout_ops sunxi_nand_ooblayout_ops = {
1726 	.ecc = sunxi_nand_ooblayout_ecc,
1727 	.free = sunxi_nand_ooblayout_free,
1728 };
1729 
1730 static void sunxi_nand_hw_ecc_ctrl_cleanup(struct nand_ecc_ctrl *ecc)
1731 {
1732 	kfree(ecc->priv);
1733 }
1734 
1735 static int sunxi_nand_hw_ecc_ctrl_init(struct mtd_info *mtd,
1736 				       struct nand_ecc_ctrl *ecc,
1737 				       struct device_node *np)
1738 {
1739 	static const u8 strengths[] = { 16, 24, 28, 32, 40, 48, 56, 60, 64 };
1740 	struct nand_chip *nand = mtd_to_nand(mtd);
1741 	struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
1742 	struct sunxi_nfc *nfc = to_sunxi_nfc(sunxi_nand->nand.controller);
1743 	struct sunxi_nand_hw_ecc *data;
1744 	int nsectors;
1745 	int ret;
1746 	int i;
1747 
1748 	if (ecc->options & NAND_ECC_MAXIMIZE) {
1749 		int bytes;
1750 
1751 		ecc->size = 1024;
1752 		nsectors = mtd->writesize / ecc->size;
1753 
1754 		/* Reserve 2 bytes for the BBM */
1755 		bytes = (mtd->oobsize - 2) / nsectors;
1756 
1757 		/* 4 non-ECC bytes are added before each ECC bytes section */
1758 		bytes -= 4;
1759 
1760 		/* and bytes has to be even. */
1761 		if (bytes % 2)
1762 			bytes--;
1763 
1764 		ecc->strength = bytes * 8 / fls(8 * ecc->size);
1765 
1766 		for (i = 0; i < ARRAY_SIZE(strengths); i++) {
1767 			if (strengths[i] > ecc->strength)
1768 				break;
1769 		}
1770 
1771 		if (!i)
1772 			ecc->strength = 0;
1773 		else
1774 			ecc->strength = strengths[i - 1];
1775 	}
1776 
1777 	if (ecc->size != 512 && ecc->size != 1024)
1778 		return -EINVAL;
1779 
1780 	data = kzalloc(sizeof(*data), GFP_KERNEL);
1781 	if (!data)
1782 		return -ENOMEM;
1783 
1784 	/* Prefer 1k ECC chunk over 512 ones */
1785 	if (ecc->size == 512 && mtd->writesize > 512) {
1786 		ecc->size = 1024;
1787 		ecc->strength *= 2;
1788 	}
1789 
1790 	/* Add ECC info retrieval from DT */
1791 	for (i = 0; i < ARRAY_SIZE(strengths); i++) {
1792 		if (ecc->strength <= strengths[i]) {
1793 			/*
1794 			 * Update ecc->strength value with the actual strength
1795 			 * that will be used by the ECC engine.
1796 			 */
1797 			ecc->strength = strengths[i];
1798 			break;
1799 		}
1800 	}
1801 
1802 	if (i >= ARRAY_SIZE(strengths)) {
1803 		dev_err(nfc->dev, "unsupported strength\n");
1804 		ret = -ENOTSUPP;
1805 		goto err;
1806 	}
1807 
1808 	data->mode = i;
1809 
1810 	/* HW ECC always request ECC bytes for 1024 bytes blocks */
1811 	ecc->bytes = DIV_ROUND_UP(ecc->strength * fls(8 * 1024), 8);
1812 
1813 	/* HW ECC always work with even numbers of ECC bytes */
1814 	ecc->bytes = ALIGN(ecc->bytes, 2);
1815 
1816 	nsectors = mtd->writesize / ecc->size;
1817 
1818 	if (mtd->oobsize < ((ecc->bytes + 4) * nsectors)) {
1819 		ret = -EINVAL;
1820 		goto err;
1821 	}
1822 
1823 	ecc->read_oob = sunxi_nfc_hw_ecc_read_oob;
1824 	ecc->write_oob = sunxi_nfc_hw_ecc_write_oob;
1825 	mtd_set_ooblayout(mtd, &sunxi_nand_ooblayout_ops);
1826 	ecc->priv = data;
1827 
1828 	if (nfc->dmac) {
1829 		ecc->read_page = sunxi_nfc_hw_ecc_read_page_dma;
1830 		ecc->read_subpage = sunxi_nfc_hw_ecc_read_subpage_dma;
1831 		ecc->write_page = sunxi_nfc_hw_ecc_write_page_dma;
1832 		nand->options |= NAND_USE_BOUNCE_BUFFER;
1833 	} else {
1834 		ecc->read_page = sunxi_nfc_hw_ecc_read_page;
1835 		ecc->read_subpage = sunxi_nfc_hw_ecc_read_subpage;
1836 		ecc->write_page = sunxi_nfc_hw_ecc_write_page;
1837 	}
1838 
1839 	/* TODO: support DMA for raw accesses and subpage write */
1840 	ecc->write_subpage = sunxi_nfc_hw_ecc_write_subpage;
1841 	ecc->read_oob_raw = nand_read_oob_std;
1842 	ecc->write_oob_raw = nand_write_oob_std;
1843 
1844 	return 0;
1845 
1846 err:
1847 	kfree(data);
1848 
1849 	return ret;
1850 }
1851 
1852 static void sunxi_nand_ecc_cleanup(struct nand_ecc_ctrl *ecc)
1853 {
1854 	switch (ecc->mode) {
1855 	case NAND_ECC_HW:
1856 		sunxi_nand_hw_ecc_ctrl_cleanup(ecc);
1857 		break;
1858 	case NAND_ECC_NONE:
1859 	default:
1860 		break;
1861 	}
1862 }
1863 
1864 static int sunxi_nand_ecc_init(struct mtd_info *mtd, struct nand_ecc_ctrl *ecc,
1865 			       struct device_node *np)
1866 {
1867 	struct nand_chip *nand = mtd_to_nand(mtd);
1868 	int ret;
1869 
1870 	if (!ecc->size) {
1871 		ecc->size = nand->ecc_step_ds;
1872 		ecc->strength = nand->ecc_strength_ds;
1873 	}
1874 
1875 	if (!ecc->size || !ecc->strength)
1876 		return -EINVAL;
1877 
1878 	switch (ecc->mode) {
1879 	case NAND_ECC_HW:
1880 		ret = sunxi_nand_hw_ecc_ctrl_init(mtd, ecc, np);
1881 		if (ret)
1882 			return ret;
1883 		break;
1884 	case NAND_ECC_NONE:
1885 	case NAND_ECC_SOFT:
1886 		break;
1887 	default:
1888 		return -EINVAL;
1889 	}
1890 
1891 	return 0;
1892 }
1893 
1894 static int sunxi_nand_chip_init(struct device *dev, struct sunxi_nfc *nfc,
1895 				struct device_node *np)
1896 {
1897 	struct sunxi_nand_chip *chip;
1898 	struct mtd_info *mtd;
1899 	struct nand_chip *nand;
1900 	int nsels;
1901 	int ret;
1902 	int i;
1903 	u32 tmp;
1904 
1905 	if (!of_get_property(np, "reg", &nsels))
1906 		return -EINVAL;
1907 
1908 	nsels /= sizeof(u32);
1909 	if (!nsels) {
1910 		dev_err(dev, "invalid reg property size\n");
1911 		return -EINVAL;
1912 	}
1913 
1914 	chip = devm_kzalloc(dev,
1915 			    sizeof(*chip) +
1916 			    (nsels * sizeof(struct sunxi_nand_chip_sel)),
1917 			    GFP_KERNEL);
1918 	if (!chip) {
1919 		dev_err(dev, "could not allocate chip\n");
1920 		return -ENOMEM;
1921 	}
1922 
1923 	chip->nsels = nsels;
1924 	chip->selected = -1;
1925 
1926 	for (i = 0; i < nsels; i++) {
1927 		ret = of_property_read_u32_index(np, "reg", i, &tmp);
1928 		if (ret) {
1929 			dev_err(dev, "could not retrieve reg property: %d\n",
1930 				ret);
1931 			return ret;
1932 		}
1933 
1934 		if (tmp > NFC_MAX_CS) {
1935 			dev_err(dev,
1936 				"invalid reg value: %u (max CS = 7)\n",
1937 				tmp);
1938 			return -EINVAL;
1939 		}
1940 
1941 		if (test_and_set_bit(tmp, &nfc->assigned_cs)) {
1942 			dev_err(dev, "CS %d already assigned\n", tmp);
1943 			return -EINVAL;
1944 		}
1945 
1946 		chip->sels[i].cs = tmp;
1947 
1948 		if (!of_property_read_u32_index(np, "allwinner,rb", i, &tmp) &&
1949 		    tmp < 2) {
1950 			chip->sels[i].rb.type = RB_NATIVE;
1951 			chip->sels[i].rb.info.nativeid = tmp;
1952 		} else {
1953 			ret = of_get_named_gpio(np, "rb-gpios", i);
1954 			if (ret >= 0) {
1955 				tmp = ret;
1956 				chip->sels[i].rb.type = RB_GPIO;
1957 				chip->sels[i].rb.info.gpio = tmp;
1958 				ret = devm_gpio_request(dev, tmp, "nand-rb");
1959 				if (ret)
1960 					return ret;
1961 
1962 				ret = gpio_direction_input(tmp);
1963 				if (ret)
1964 					return ret;
1965 			} else {
1966 				chip->sels[i].rb.type = RB_NONE;
1967 			}
1968 		}
1969 	}
1970 
1971 	nand = &chip->nand;
1972 	/* Default tR value specified in the ONFI spec (chapter 4.15.1) */
1973 	nand->chip_delay = 200;
1974 	nand->controller = &nfc->controller;
1975 	/*
1976 	 * Set the ECC mode to the default value in case nothing is specified
1977 	 * in the DT.
1978 	 */
1979 	nand->ecc.mode = NAND_ECC_HW;
1980 	nand_set_flash_node(nand, np);
1981 	nand->select_chip = sunxi_nfc_select_chip;
1982 	nand->cmd_ctrl = sunxi_nfc_cmd_ctrl;
1983 	nand->read_buf = sunxi_nfc_read_buf;
1984 	nand->write_buf = sunxi_nfc_write_buf;
1985 	nand->read_byte = sunxi_nfc_read_byte;
1986 	nand->setup_data_interface = sunxi_nfc_setup_data_interface;
1987 
1988 	mtd = nand_to_mtd(nand);
1989 	mtd->dev.parent = dev;
1990 
1991 	ret = nand_scan_ident(mtd, nsels, NULL);
1992 	if (ret)
1993 		return ret;
1994 
1995 	if (nand->bbt_options & NAND_BBT_USE_FLASH)
1996 		nand->bbt_options |= NAND_BBT_NO_OOB;
1997 
1998 	if (nand->options & NAND_NEED_SCRAMBLING)
1999 		nand->options |= NAND_NO_SUBPAGE_WRITE;
2000 
2001 	nand->options |= NAND_SUBPAGE_READ;
2002 
2003 	ret = sunxi_nand_ecc_init(mtd, &nand->ecc, np);
2004 	if (ret) {
2005 		dev_err(dev, "ECC init failed: %d\n", ret);
2006 		return ret;
2007 	}
2008 
2009 	ret = nand_scan_tail(mtd);
2010 	if (ret) {
2011 		dev_err(dev, "nand_scan_tail failed: %d\n", ret);
2012 		return ret;
2013 	}
2014 
2015 	ret = mtd_device_register(mtd, NULL, 0);
2016 	if (ret) {
2017 		dev_err(dev, "failed to register mtd device: %d\n", ret);
2018 		nand_release(mtd);
2019 		return ret;
2020 	}
2021 
2022 	list_add_tail(&chip->node, &nfc->chips);
2023 
2024 	return 0;
2025 }
2026 
2027 static int sunxi_nand_chips_init(struct device *dev, struct sunxi_nfc *nfc)
2028 {
2029 	struct device_node *np = dev->of_node;
2030 	struct device_node *nand_np;
2031 	int nchips = of_get_child_count(np);
2032 	int ret;
2033 
2034 	if (nchips > 8) {
2035 		dev_err(dev, "too many NAND chips: %d (max = 8)\n", nchips);
2036 		return -EINVAL;
2037 	}
2038 
2039 	for_each_child_of_node(np, nand_np) {
2040 		ret = sunxi_nand_chip_init(dev, nfc, nand_np);
2041 		if (ret) {
2042 			of_node_put(nand_np);
2043 			return ret;
2044 		}
2045 	}
2046 
2047 	return 0;
2048 }
2049 
2050 static void sunxi_nand_chips_cleanup(struct sunxi_nfc *nfc)
2051 {
2052 	struct sunxi_nand_chip *chip;
2053 
2054 	while (!list_empty(&nfc->chips)) {
2055 		chip = list_first_entry(&nfc->chips, struct sunxi_nand_chip,
2056 					node);
2057 		nand_release(nand_to_mtd(&chip->nand));
2058 		sunxi_nand_ecc_cleanup(&chip->nand.ecc);
2059 		list_del(&chip->node);
2060 	}
2061 }
2062 
2063 static int sunxi_nfc_probe(struct platform_device *pdev)
2064 {
2065 	struct device *dev = &pdev->dev;
2066 	struct resource *r;
2067 	struct sunxi_nfc *nfc;
2068 	int irq;
2069 	int ret;
2070 
2071 	nfc = devm_kzalloc(dev, sizeof(*nfc), GFP_KERNEL);
2072 	if (!nfc)
2073 		return -ENOMEM;
2074 
2075 	nfc->dev = dev;
2076 	nand_hw_control_init(&nfc->controller);
2077 	INIT_LIST_HEAD(&nfc->chips);
2078 
2079 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
2080 	nfc->regs = devm_ioremap_resource(dev, r);
2081 	if (IS_ERR(nfc->regs))
2082 		return PTR_ERR(nfc->regs);
2083 
2084 	irq = platform_get_irq(pdev, 0);
2085 	if (irq < 0) {
2086 		dev_err(dev, "failed to retrieve irq\n");
2087 		return irq;
2088 	}
2089 
2090 	nfc->ahb_clk = devm_clk_get(dev, "ahb");
2091 	if (IS_ERR(nfc->ahb_clk)) {
2092 		dev_err(dev, "failed to retrieve ahb clk\n");
2093 		return PTR_ERR(nfc->ahb_clk);
2094 	}
2095 
2096 	ret = clk_prepare_enable(nfc->ahb_clk);
2097 	if (ret)
2098 		return ret;
2099 
2100 	nfc->mod_clk = devm_clk_get(dev, "mod");
2101 	if (IS_ERR(nfc->mod_clk)) {
2102 		dev_err(dev, "failed to retrieve mod clk\n");
2103 		ret = PTR_ERR(nfc->mod_clk);
2104 		goto out_ahb_clk_unprepare;
2105 	}
2106 
2107 	ret = clk_prepare_enable(nfc->mod_clk);
2108 	if (ret)
2109 		goto out_ahb_clk_unprepare;
2110 
2111 	nfc->reset = devm_reset_control_get_optional_exclusive(dev, "ahb");
2112 	if (IS_ERR(nfc->reset)) {
2113 		ret = PTR_ERR(nfc->reset);
2114 		goto out_mod_clk_unprepare;
2115 	}
2116 
2117 	ret = reset_control_deassert(nfc->reset);
2118 	if (ret) {
2119 		dev_err(dev, "reset err %d\n", ret);
2120 		goto out_mod_clk_unprepare;
2121 	}
2122 
2123 	ret = sunxi_nfc_rst(nfc);
2124 	if (ret)
2125 		goto out_ahb_reset_reassert;
2126 
2127 	writel(0, nfc->regs + NFC_REG_INT);
2128 	ret = devm_request_irq(dev, irq, sunxi_nfc_interrupt,
2129 			       0, "sunxi-nand", nfc);
2130 	if (ret)
2131 		goto out_ahb_reset_reassert;
2132 
2133 	nfc->dmac = dma_request_slave_channel(dev, "rxtx");
2134 	if (nfc->dmac) {
2135 		struct dma_slave_config dmac_cfg = { };
2136 
2137 		dmac_cfg.src_addr = r->start + NFC_REG_IO_DATA;
2138 		dmac_cfg.dst_addr = dmac_cfg.src_addr;
2139 		dmac_cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
2140 		dmac_cfg.dst_addr_width = dmac_cfg.src_addr_width;
2141 		dmac_cfg.src_maxburst = 4;
2142 		dmac_cfg.dst_maxburst = 4;
2143 		dmaengine_slave_config(nfc->dmac, &dmac_cfg);
2144 	} else {
2145 		dev_warn(dev, "failed to request rxtx DMA channel\n");
2146 	}
2147 
2148 	platform_set_drvdata(pdev, nfc);
2149 
2150 	ret = sunxi_nand_chips_init(dev, nfc);
2151 	if (ret) {
2152 		dev_err(dev, "failed to init nand chips\n");
2153 		goto out_release_dmac;
2154 	}
2155 
2156 	return 0;
2157 
2158 out_release_dmac:
2159 	if (nfc->dmac)
2160 		dma_release_channel(nfc->dmac);
2161 out_ahb_reset_reassert:
2162 	reset_control_assert(nfc->reset);
2163 out_mod_clk_unprepare:
2164 	clk_disable_unprepare(nfc->mod_clk);
2165 out_ahb_clk_unprepare:
2166 	clk_disable_unprepare(nfc->ahb_clk);
2167 
2168 	return ret;
2169 }
2170 
2171 static int sunxi_nfc_remove(struct platform_device *pdev)
2172 {
2173 	struct sunxi_nfc *nfc = platform_get_drvdata(pdev);
2174 
2175 	sunxi_nand_chips_cleanup(nfc);
2176 
2177 	reset_control_assert(nfc->reset);
2178 
2179 	if (nfc->dmac)
2180 		dma_release_channel(nfc->dmac);
2181 	clk_disable_unprepare(nfc->mod_clk);
2182 	clk_disable_unprepare(nfc->ahb_clk);
2183 
2184 	return 0;
2185 }
2186 
2187 static const struct of_device_id sunxi_nfc_ids[] = {
2188 	{ .compatible = "allwinner,sun4i-a10-nand" },
2189 	{ /* sentinel */ }
2190 };
2191 MODULE_DEVICE_TABLE(of, sunxi_nfc_ids);
2192 
2193 static struct platform_driver sunxi_nfc_driver = {
2194 	.driver = {
2195 		.name = "sunxi_nand",
2196 		.of_match_table = sunxi_nfc_ids,
2197 	},
2198 	.probe = sunxi_nfc_probe,
2199 	.remove = sunxi_nfc_remove,
2200 };
2201 module_platform_driver(sunxi_nfc_driver);
2202 
2203 MODULE_LICENSE("GPL v2");
2204 MODULE_AUTHOR("Boris BREZILLON");
2205 MODULE_DESCRIPTION("Allwinner NAND Flash Controller driver");
2206 MODULE_ALIAS("platform:sunxi_nand");
2207