1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * LPC32xx SLC NAND flash controller driver
4  *
5  * (C) Copyright 2015-2018 Vladimir Zapolskiy <vz@mleia.com>
6  * Copyright (c) 2015 Tyco Fire Protection Products.
7  *
8  * Hardware ECC support original source code
9  * Copyright (C) 2008 by NXP Semiconductors
10  * Author: Kevin Wells
11  */
12 
13 #include <common.h>
14 #include <nand.h>
15 #include <linux/mtd/nand_ecc.h>
16 #include <linux/errno.h>
17 #include <asm/io.h>
18 #include <asm/arch/config.h>
19 #include <asm/arch/clk.h>
20 #include <asm/arch/sys_proto.h>
21 #include <asm/arch/dma.h>
22 #include <asm/arch/cpu.h>
23 
24 struct lpc32xx_nand_slc_regs {
25 	u32 data;
26 	u32 addr;
27 	u32 cmd;
28 	u32 stop;
29 	u32 ctrl;
30 	u32 cfg;
31 	u32 stat;
32 	u32 int_stat;
33 	u32 ien;
34 	u32 isr;
35 	u32 icr;
36 	u32 tac;
37 	u32 tc;
38 	u32 ecc;
39 	u32 dma_data;
40 };
41 
42 /* CFG register */
43 #define CFG_CE_LOW		(1 << 5)
44 #define CFG_DMA_ECC		(1 << 4) /* Enable DMA ECC bit */
45 #define CFG_ECC_EN		(1 << 3) /* ECC enable bit */
46 #define CFG_DMA_BURST		(1 << 2) /* DMA burst bit */
47 #define CFG_DMA_DIR		(1 << 1) /* DMA write(0)/read(1) bit */
48 
49 /* CTRL register */
50 #define CTRL_SW_RESET		(1 << 2)
51 #define CTRL_ECC_CLEAR		(1 << 1) /* Reset ECC bit */
52 #define CTRL_DMA_START		(1 << 0) /* Start DMA channel bit */
53 
54 /* STAT register */
55 #define STAT_DMA_FIFO		(1 << 2) /* DMA FIFO has data bit */
56 #define STAT_NAND_READY		(1 << 0)
57 
58 /* INT_STAT register */
59 #define INT_STAT_TC		(1 << 1)
60 #define INT_STAT_RDY		(1 << 0)
61 
62 /* TAC register bits, be aware of overflows */
63 #define TAC_W_RDY(n)		(max_t(uint32_t, (n), 0xF) << 28)
64 #define TAC_W_WIDTH(n)		(max_t(uint32_t, (n), 0xF) << 24)
65 #define TAC_W_HOLD(n)		(max_t(uint32_t, (n), 0xF) << 20)
66 #define TAC_W_SETUP(n)		(max_t(uint32_t, (n), 0xF) << 16)
67 #define TAC_R_RDY(n)		(max_t(uint32_t, (n), 0xF) << 12)
68 #define TAC_R_WIDTH(n)		(max_t(uint32_t, (n), 0xF) << 8)
69 #define TAC_R_HOLD(n)		(max_t(uint32_t, (n), 0xF) << 4)
70 #define TAC_R_SETUP(n)		(max_t(uint32_t, (n), 0xF) << 0)
71 
72 /* NAND ECC Layout for small page NAND devices
73  * Note: For large page devices, the default layouts are used. */
74 static struct nand_ecclayout lpc32xx_nand_oob_16 = {
75 	.eccbytes = 6,
76 	.eccpos = { 10, 11, 12, 13, 14, 15, },
77 	.oobfree = {
78 		{ .offset = 0, .length = 4, },
79 		{ .offset = 6, .length = 4, },
80 	}
81 };
82 
83 #if defined(CONFIG_DMA_LPC32XX) && !defined(CONFIG_SPL_BUILD)
84 #define ECCSTEPS	(CONFIG_SYS_NAND_PAGE_SIZE / CONFIG_SYS_NAND_ECCSIZE)
85 
86 /*
87  * DMA Descriptors
88  * For Large Block: 17 descriptors = ((16 Data and ECC Read) + 1 Spare Area)
89  * For Small Block: 5 descriptors = ((4 Data and ECC Read) + 1 Spare Area)
90  */
91 static struct lpc32xx_dmac_ll dmalist[ECCSTEPS * 2 + 1];
92 static u32 ecc_buffer[8]; /* MAX ECC size */
93 static unsigned int dmachan = (unsigned int)-1; /* Invalid channel */
94 
95 /*
96  * Helper macro for the DMA client (i.e. NAND SLC):
97  * - to write the next DMA linked list item address
98  *   (see arch/include/asm/arch-lpc32xx/dma.h).
99  * - to assign the DMA data register to DMA source or destination address.
100  * - to assign the ECC register to DMA source or destination address.
101  */
102 #define lpc32xx_dmac_next_lli(x)	((u32)x)
103 #define lpc32xx_dmac_set_dma_data()	((u32)&lpc32xx_nand_slc_regs->dma_data)
104 #define lpc32xx_dmac_set_ecc()		((u32)&lpc32xx_nand_slc_regs->ecc)
105 #endif
106 
107 static struct lpc32xx_nand_slc_regs __iomem *lpc32xx_nand_slc_regs
108 	= (struct lpc32xx_nand_slc_regs __iomem *)SLC_NAND_BASE;
109 
110 static void lpc32xx_nand_init(void)
111 {
112 	uint32_t hclk = get_hclk_clk_rate();
113 
114 	/* Reset SLC NAND controller */
115 	writel(CTRL_SW_RESET, &lpc32xx_nand_slc_regs->ctrl);
116 
117 	/* 8-bit bus, no DMA, no ECC, ordinary CE signal */
118 	writel(0, &lpc32xx_nand_slc_regs->cfg);
119 
120 	/* Interrupts disabled and cleared */
121 	writel(0, &lpc32xx_nand_slc_regs->ien);
122 	writel(INT_STAT_TC | INT_STAT_RDY,
123 	       &lpc32xx_nand_slc_regs->icr);
124 
125 	/* Configure NAND flash timings */
126 	writel(TAC_W_RDY(CONFIG_LPC32XX_NAND_SLC_WDR_CLKS) |
127 	       TAC_W_WIDTH(hclk / CONFIG_LPC32XX_NAND_SLC_WWIDTH) |
128 	       TAC_W_HOLD(hclk / CONFIG_LPC32XX_NAND_SLC_WHOLD) |
129 	       TAC_W_SETUP(hclk / CONFIG_LPC32XX_NAND_SLC_WSETUP) |
130 	       TAC_R_RDY(CONFIG_LPC32XX_NAND_SLC_RDR_CLKS) |
131 	       TAC_R_WIDTH(hclk / CONFIG_LPC32XX_NAND_SLC_RWIDTH) |
132 	       TAC_R_HOLD(hclk / CONFIG_LPC32XX_NAND_SLC_RHOLD) |
133 	       TAC_R_SETUP(hclk / CONFIG_LPC32XX_NAND_SLC_RSETUP),
134 	       &lpc32xx_nand_slc_regs->tac);
135 }
136 
137 static void lpc32xx_nand_cmd_ctrl(struct mtd_info *mtd,
138 				  int cmd, unsigned int ctrl)
139 {
140 	debug("ctrl: 0x%08x, cmd: 0x%08x\n", ctrl, cmd);
141 
142 	if (ctrl & NAND_NCE)
143 		setbits_le32(&lpc32xx_nand_slc_regs->cfg, CFG_CE_LOW);
144 	else
145 		clrbits_le32(&lpc32xx_nand_slc_regs->cfg, CFG_CE_LOW);
146 
147 	if (cmd == NAND_CMD_NONE)
148 		return;
149 
150 	if (ctrl & NAND_CLE)
151 		writel(cmd & 0xFF, &lpc32xx_nand_slc_regs->cmd);
152 	else if (ctrl & NAND_ALE)
153 		writel(cmd & 0xFF, &lpc32xx_nand_slc_regs->addr);
154 }
155 
156 static int lpc32xx_nand_dev_ready(struct mtd_info *mtd)
157 {
158 	return readl(&lpc32xx_nand_slc_regs->stat) & STAT_NAND_READY;
159 }
160 
161 #if defined(CONFIG_DMA_LPC32XX) && !defined(CONFIG_SPL_BUILD)
162 /*
163  * Prepares DMA descriptors for NAND RD/WR operations
164  * If the size is < 256 Bytes then it is assumed to be
165  * an OOB transfer
166  */
167 static void lpc32xx_nand_dma_configure(struct nand_chip *chip,
168 				       const u8 *buffer, int size,
169 				       int read)
170 {
171 	u32 i, dmasrc, ctrl, ecc_ctrl, oob_ctrl, dmadst;
172 	struct lpc32xx_dmac_ll *dmalist_cur;
173 	struct lpc32xx_dmac_ll *dmalist_cur_ecc;
174 
175 	/*
176 	 * CTRL descriptor entry for reading ECC
177 	 * Copy Multiple times to sync DMA with Flash Controller
178 	 */
179 	ecc_ctrl = 0x5 |
180 			DMAC_CHAN_SRC_BURST_1 |
181 			DMAC_CHAN_DEST_BURST_1 |
182 			DMAC_CHAN_SRC_WIDTH_32 |
183 			DMAC_CHAN_DEST_WIDTH_32 |
184 			DMAC_CHAN_DEST_AHB1;
185 
186 	/* CTRL descriptor entry for reading/writing Data */
187 	ctrl = (CONFIG_SYS_NAND_ECCSIZE / 4) |
188 			DMAC_CHAN_SRC_BURST_4 |
189 			DMAC_CHAN_DEST_BURST_4 |
190 			DMAC_CHAN_SRC_WIDTH_32 |
191 			DMAC_CHAN_DEST_WIDTH_32 |
192 			DMAC_CHAN_DEST_AHB1;
193 
194 	/* CTRL descriptor entry for reading/writing Spare Area */
195 	oob_ctrl = (CONFIG_SYS_NAND_OOBSIZE / 4) |
196 			DMAC_CHAN_SRC_BURST_4 |
197 			DMAC_CHAN_DEST_BURST_4 |
198 			DMAC_CHAN_SRC_WIDTH_32 |
199 			DMAC_CHAN_DEST_WIDTH_32 |
200 			DMAC_CHAN_DEST_AHB1;
201 
202 	if (read) {
203 		dmasrc = lpc32xx_dmac_set_dma_data();
204 		dmadst = (u32)buffer;
205 		ctrl |= DMAC_CHAN_DEST_AUTOINC;
206 	} else {
207 		dmadst = lpc32xx_dmac_set_dma_data();
208 		dmasrc = (u32)buffer;
209 		ctrl |= DMAC_CHAN_SRC_AUTOINC;
210 	}
211 
212 	/*
213 	 * Write Operation Sequence for Small Block NAND
214 	 * ----------------------------------------------------------
215 	 * 1. X'fer 256 bytes of data from Memory to Flash.
216 	 * 2. Copy generated ECC data from Register to Spare Area
217 	 * 3. X'fer next 256 bytes of data from Memory to Flash.
218 	 * 4. Copy generated ECC data from Register to Spare Area.
219 	 * 5. X'fer 16 byets of Spare area from Memory to Flash.
220 	 * Read Operation Sequence for Small Block NAND
221 	 * ----------------------------------------------------------
222 	 * 1. X'fer 256 bytes of data from Flash to Memory.
223 	 * 2. Copy generated ECC data from Register to ECC calc Buffer.
224 	 * 3. X'fer next 256 bytes of data from Flash to Memory.
225 	 * 4. Copy generated ECC data from Register to ECC calc Buffer.
226 	 * 5. X'fer 16 bytes of Spare area from Flash to Memory.
227 	 * Write Operation Sequence for Large Block NAND
228 	 * ----------------------------------------------------------
229 	 * 1. Steps(1-4) of Write Operations repeate for four times
230 	 * which generates 16 DMA descriptors to X'fer 2048 bytes of
231 	 * data & 32 bytes of ECC data.
232 	 * 2. X'fer 64 bytes of Spare area from Memory to Flash.
233 	 * Read Operation Sequence for Large Block NAND
234 	 * ----------------------------------------------------------
235 	 * 1. Steps(1-4) of Read Operations repeate for four times
236 	 * which generates 16 DMA descriptors to X'fer 2048 bytes of
237 	 * data & 32 bytes of ECC data.
238 	 * 2. X'fer 64 bytes of Spare area from Flash to Memory.
239 	 */
240 
241 	for (i = 0; i < size/CONFIG_SYS_NAND_ECCSIZE; i++) {
242 		dmalist_cur = &dmalist[i * 2];
243 		dmalist_cur_ecc = &dmalist[(i * 2) + 1];
244 
245 		dmalist_cur->dma_src = (read ? (dmasrc) : (dmasrc + (i*256)));
246 		dmalist_cur->dma_dest = (read ? (dmadst + (i*256)) : dmadst);
247 		dmalist_cur->next_lli = lpc32xx_dmac_next_lli(dmalist_cur_ecc);
248 		dmalist_cur->next_ctrl = ctrl;
249 
250 		dmalist_cur_ecc->dma_src = lpc32xx_dmac_set_ecc();
251 		dmalist_cur_ecc->dma_dest = (u32)&ecc_buffer[i];
252 		dmalist_cur_ecc->next_lli =
253 			lpc32xx_dmac_next_lli(&dmalist[(i * 2) + 2]);
254 		dmalist_cur_ecc->next_ctrl = ecc_ctrl;
255 	}
256 
257 	if (i) { /* Data only transfer */
258 		dmalist_cur_ecc = &dmalist[(i * 2) - 1];
259 		dmalist_cur_ecc->next_lli = 0;
260 		dmalist_cur_ecc->next_ctrl |= DMAC_CHAN_INT_TC_EN;
261 		return;
262 	}
263 
264 	/* OOB only transfer */
265 	if (read) {
266 		dmasrc = lpc32xx_dmac_set_dma_data();
267 		dmadst = (u32)buffer;
268 		oob_ctrl |= DMAC_CHAN_DEST_AUTOINC;
269 	} else {
270 		dmadst = lpc32xx_dmac_set_dma_data();
271 		dmasrc = (u32)buffer;
272 		oob_ctrl |= DMAC_CHAN_SRC_AUTOINC;
273 	}
274 
275 	/* Read/ Write Spare Area Data To/From Flash */
276 	dmalist_cur = &dmalist[i * 2];
277 	dmalist_cur->dma_src = dmasrc;
278 	dmalist_cur->dma_dest = dmadst;
279 	dmalist_cur->next_lli = 0;
280 	dmalist_cur->next_ctrl = (oob_ctrl | DMAC_CHAN_INT_TC_EN);
281 }
282 
283 static void lpc32xx_nand_xfer(struct mtd_info *mtd, const u8 *buf,
284 			      int len, int read)
285 {
286 	struct nand_chip *chip = mtd_to_nand(mtd);
287 	u32 config;
288 	int ret;
289 
290 	/* DMA Channel Configuration */
291 	config = (read ? DMAC_CHAN_FLOW_D_P2M : DMAC_CHAN_FLOW_D_M2P) |
292 		(read ? DMAC_DEST_PERIP(0) : DMAC_DEST_PERIP(DMA_PERID_NAND1)) |
293 		(read ? DMAC_SRC_PERIP(DMA_PERID_NAND1) : DMAC_SRC_PERIP(0)) |
294 		DMAC_CHAN_ENABLE;
295 
296 	/* Prepare DMA descriptors */
297 	lpc32xx_nand_dma_configure(chip, buf, len, read);
298 
299 	/* Setup SLC controller and start transfer */
300 	if (read)
301 		setbits_le32(&lpc32xx_nand_slc_regs->cfg, CFG_DMA_DIR);
302 	else  /* NAND_ECC_WRITE */
303 		clrbits_le32(&lpc32xx_nand_slc_regs->cfg, CFG_DMA_DIR);
304 	setbits_le32(&lpc32xx_nand_slc_regs->cfg, CFG_DMA_BURST);
305 
306 	/* Write length for new transfers */
307 	if (!((readl(&lpc32xx_nand_slc_regs->stat) & STAT_DMA_FIFO) |
308 	      readl(&lpc32xx_nand_slc_regs->tc))) {
309 		int tmp = (len != mtd->oobsize) ? mtd->oobsize : 0;
310 		writel(len + tmp, &lpc32xx_nand_slc_regs->tc);
311 	}
312 
313 	setbits_le32(&lpc32xx_nand_slc_regs->ctrl, CTRL_DMA_START);
314 
315 	/* Start DMA transfers */
316 	ret = lpc32xx_dma_start_xfer(dmachan, dmalist, config);
317 	if (unlikely(ret < 0))
318 		BUG();
319 
320 	/* Wait for NAND to be ready */
321 	while (!lpc32xx_nand_dev_ready(mtd))
322 		;
323 
324 	/* Wait till DMA transfer is DONE */
325 	if (lpc32xx_dma_wait_status(dmachan))
326 		pr_err("NAND DMA transfer error!\r\n");
327 
328 	/* Stop DMA & HW ECC */
329 	clrbits_le32(&lpc32xx_nand_slc_regs->ctrl, CTRL_DMA_START);
330 	clrbits_le32(&lpc32xx_nand_slc_regs->cfg,
331 		     CFG_DMA_DIR | CFG_DMA_BURST | CFG_ECC_EN | CFG_DMA_ECC);
332 }
333 
334 static u32 slc_ecc_copy_to_buffer(u8 *spare, const u32 *ecc, int count)
335 {
336 	int i;
337 	for (i = 0; i < (count * CONFIG_SYS_NAND_ECCBYTES);
338 	     i += CONFIG_SYS_NAND_ECCBYTES) {
339 		u32 ce = ecc[i / CONFIG_SYS_NAND_ECCBYTES];
340 		ce = ~(ce << 2) & 0xFFFFFF;
341 		spare[i+2] = (u8)(ce & 0xFF); ce >>= 8;
342 		spare[i+1] = (u8)(ce & 0xFF); ce >>= 8;
343 		spare[i]   = (u8)(ce & 0xFF);
344 	}
345 	return 0;
346 }
347 
348 static int lpc32xx_ecc_calculate(struct mtd_info *mtd, const uint8_t *dat,
349 				 uint8_t *ecc_code)
350 {
351 	return slc_ecc_copy_to_buffer(ecc_code, ecc_buffer, ECCSTEPS);
352 }
353 
354 /*
355  * Enables and prepares SLC NAND controller
356  * for doing data transfers with H/W ECC enabled.
357  */
358 static void lpc32xx_hwecc_enable(struct mtd_info *mtd, int mode)
359 {
360 	/* Clear ECC */
361 	writel(CTRL_ECC_CLEAR, &lpc32xx_nand_slc_regs->ctrl);
362 
363 	/* Setup SLC controller for H/W ECC operations */
364 	setbits_le32(&lpc32xx_nand_slc_regs->cfg, CFG_ECC_EN | CFG_DMA_ECC);
365 }
366 
367 /*
368  * lpc32xx_correct_data - [NAND Interface] Detect and correct bit error(s)
369  * mtd:	MTD block structure
370  * dat:	raw data read from the chip
371  * read_ecc:	ECC from the chip
372  * calc_ecc:	the ECC calculated from raw data
373  *
374  * Detect and correct a 1 bit error for 256 byte block
375  */
376 int lpc32xx_correct_data(struct mtd_info *mtd, u_char *dat,
377 			 u_char *read_ecc, u_char *calc_ecc)
378 {
379 	unsigned int i;
380 	int ret1, ret2 = 0;
381 	u_char *r = read_ecc;
382 	u_char *c = calc_ecc;
383 	u16 data_offset = 0;
384 
385 	for (i = 0 ; i < ECCSTEPS ; i++) {
386 		r += CONFIG_SYS_NAND_ECCBYTES;
387 		c += CONFIG_SYS_NAND_ECCBYTES;
388 		data_offset += CONFIG_SYS_NAND_ECCSIZE;
389 
390 		ret1 = nand_correct_data(mtd, dat + data_offset, r, c);
391 		if (ret1 < 0)
392 			return -EBADMSG;
393 		else
394 			ret2 += ret1;
395 	}
396 
397 	return ret2;
398 }
399 
400 static void lpc32xx_dma_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
401 {
402 	lpc32xx_nand_xfer(mtd, buf, len, 1);
403 }
404 
405 static void lpc32xx_dma_write_buf(struct mtd_info *mtd, const uint8_t *buf,
406 				  int len)
407 {
408 	lpc32xx_nand_xfer(mtd, buf, len, 0);
409 }
410 
411 /* Reuse the logic from "nand_read_page_hwecc()" */
412 static int lpc32xx_read_page_hwecc(struct mtd_info *mtd, struct nand_chip *chip,
413 				uint8_t *buf, int oob_required, int page)
414 {
415 	int i;
416 	int stat;
417 	uint8_t *p = buf;
418 	uint8_t *ecc_calc = chip->buffers->ecccalc;
419 	uint8_t *ecc_code = chip->buffers->ecccode;
420 	uint32_t *eccpos = chip->ecc.layout->eccpos;
421 	unsigned int max_bitflips = 0;
422 
423 	/*
424 	 * As per the "LPC32x0 and LPC32x0/01 User manual" table 173 notes
425 	 * and section 9.7, the NAND SLC & DMA allowed single DMA transaction
426 	 * of a page size using DMA controller scatter/gather mode through
427 	 * linked list; the ECC read is done without any software intervention.
428 	 */
429 
430 	lpc32xx_hwecc_enable(mtd, NAND_ECC_READ);
431 	lpc32xx_dma_read_buf(mtd, p, chip->ecc.size * chip->ecc.steps);
432 	lpc32xx_ecc_calculate(mtd, p, &ecc_calc[0]);
433 	lpc32xx_dma_read_buf(mtd, chip->oob_poi, mtd->oobsize);
434 
435 	for (i = 0; i < chip->ecc.total; i++)
436 		ecc_code[i] = chip->oob_poi[eccpos[i]];
437 
438 	stat = chip->ecc.correct(mtd, p, &ecc_code[0], &ecc_calc[0]);
439 	if (stat < 0)
440 		mtd->ecc_stats.failed++;
441 	else {
442 		mtd->ecc_stats.corrected += stat;
443 		max_bitflips = max_t(unsigned int, max_bitflips, stat);
444 	}
445 
446 	return max_bitflips;
447 }
448 
449 /* Reuse the logic from "nand_write_page_hwecc()" */
450 static int lpc32xx_write_page_hwecc(struct mtd_info *mtd,
451 				    struct nand_chip *chip,
452 				    const uint8_t *buf, int oob_required,
453 				    int page)
454 {
455 	int i;
456 	uint8_t *ecc_calc = chip->buffers->ecccalc;
457 	const uint8_t *p = buf;
458 	uint32_t *eccpos = chip->ecc.layout->eccpos;
459 
460 	/*
461 	 * As per the "LPC32x0 and LPC32x0/01 User manual" table 173 notes
462 	 * and section 9.7, the NAND SLC & DMA allowed single DMA transaction
463 	 * of a page size using DMA controller scatter/gather mode through
464 	 * linked list; the ECC read is done without any software intervention.
465 	 */
466 
467 	lpc32xx_hwecc_enable(mtd, NAND_ECC_WRITE);
468 	lpc32xx_dma_write_buf(mtd, p, chip->ecc.size * chip->ecc.steps);
469 	lpc32xx_ecc_calculate(mtd, p, &ecc_calc[0]);
470 
471 	for (i = 0; i < chip->ecc.total; i++)
472 		chip->oob_poi[eccpos[i]] = ecc_calc[i];
473 
474 	lpc32xx_dma_write_buf(mtd, chip->oob_poi, mtd->oobsize);
475 
476 	return 0;
477 }
478 #else
479 static void lpc32xx_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
480 {
481 	while (len-- > 0)
482 		*buf++ = readl(&lpc32xx_nand_slc_regs->data);
483 }
484 
485 static void lpc32xx_write_buf(struct mtd_info *mtd, const uint8_t *buf, int len)
486 {
487 	while (len-- > 0)
488 		writel(*buf++, &lpc32xx_nand_slc_regs->data);
489 }
490 #endif
491 
492 static uint8_t lpc32xx_read_byte(struct mtd_info *mtd)
493 {
494 	return readl(&lpc32xx_nand_slc_regs->data);
495 }
496 
497 static void lpc32xx_write_byte(struct mtd_info *mtd, uint8_t byte)
498 {
499 	writel(byte, &lpc32xx_nand_slc_regs->data);
500 }
501 
502 /*
503  * LPC32xx has only one SLC NAND controller, don't utilize
504  * CONFIG_SYS_NAND_SELF_INIT to be able to reuse this function
505  * both in SPL NAND and U-Boot images.
506  */
507 int board_nand_init(struct nand_chip *lpc32xx_chip)
508 {
509 #if defined(CONFIG_DMA_LPC32XX) && !defined(CONFIG_SPL_BUILD)
510 	int ret;
511 
512 	/* Acquire a channel for our use */
513 	ret = lpc32xx_dma_get_channel();
514 	if (unlikely(ret < 0)) {
515 		pr_info("Unable to get free DMA channel for NAND transfers\n");
516 		return -1;
517 	}
518 	dmachan = (unsigned int)ret;
519 #endif
520 
521 	lpc32xx_chip->cmd_ctrl  = lpc32xx_nand_cmd_ctrl;
522 	lpc32xx_chip->dev_ready = lpc32xx_nand_dev_ready;
523 
524 	/*
525 	 * The implementation of these functions is quite common, but
526 	 * they MUST be defined, because access to data register
527 	 * is strictly 32-bit aligned.
528 	 */
529 	lpc32xx_chip->read_byte  = lpc32xx_read_byte;
530 	lpc32xx_chip->write_byte = lpc32xx_write_byte;
531 
532 #if defined(CONFIG_DMA_LPC32XX) && !defined(CONFIG_SPL_BUILD)
533 	/* Hardware ECC calculation is supported when DMA driver is selected */
534 	lpc32xx_chip->ecc.mode		= NAND_ECC_HW;
535 
536 	lpc32xx_chip->read_buf		= lpc32xx_dma_read_buf;
537 	lpc32xx_chip->write_buf		= lpc32xx_dma_write_buf;
538 
539 	lpc32xx_chip->ecc.calculate	= lpc32xx_ecc_calculate;
540 	lpc32xx_chip->ecc.correct	= lpc32xx_correct_data;
541 	lpc32xx_chip->ecc.hwctl		= lpc32xx_hwecc_enable;
542 	lpc32xx_chip->chip_delay	= 2000;
543 
544 	lpc32xx_chip->ecc.read_page	= lpc32xx_read_page_hwecc;
545 	lpc32xx_chip->ecc.write_page	= lpc32xx_write_page_hwecc;
546 	lpc32xx_chip->options		|= NAND_NO_SUBPAGE_WRITE;
547 #else
548 	/*
549 	 * Hardware ECC calculation is not supported by the driver,
550 	 * because it requires DMA support, see LPC32x0 User Manual,
551 	 * note after SLC_ECC register description (UM10326, p.198)
552 	 */
553 	lpc32xx_chip->ecc.mode = NAND_ECC_SOFT;
554 
555 	/*
556 	 * The implementation of these functions is quite common, but
557 	 * they MUST be defined, because access to data register
558 	 * is strictly 32-bit aligned.
559 	 */
560 	lpc32xx_chip->read_buf   = lpc32xx_read_buf;
561 	lpc32xx_chip->write_buf  = lpc32xx_write_buf;
562 #endif
563 
564 	/*
565 	 * These values are predefined
566 	 * for both small and large page NAND flash devices.
567 	 */
568 	lpc32xx_chip->ecc.size     = CONFIG_SYS_NAND_ECCSIZE;
569 	lpc32xx_chip->ecc.bytes    = CONFIG_SYS_NAND_ECCBYTES;
570 	lpc32xx_chip->ecc.strength = 1;
571 
572 	if (CONFIG_SYS_NAND_PAGE_SIZE != NAND_LARGE_BLOCK_PAGE_SIZE)
573 		lpc32xx_chip->ecc.layout = &lpc32xx_nand_oob_16;
574 
575 #if defined(CONFIG_SYS_NAND_USE_FLASH_BBT)
576 	lpc32xx_chip->bbt_options |= NAND_BBT_USE_FLASH;
577 #endif
578 
579 	/* Initialize NAND interface */
580 	lpc32xx_nand_init();
581 
582 	return 0;
583 }
584