xref: /openbmc/linux/drivers/mtd/nand/raw/lpc32xx_mlc.c (revision 715f23b6)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Driver for NAND MLC Controller in LPC32xx
4  *
5  * Author: Roland Stigge <stigge@antcom.de>
6  *
7  * Copyright © 2011 WORK Microwave GmbH
8  * Copyright © 2011, 2012 Roland Stigge
9  *
10  * NAND Flash Controller Operation:
11  * - Read: Auto Decode
12  * - Write: Auto Encode
13  * - Tested Page Sizes: 2048, 4096
14  */
15 
16 #include <linux/slab.h>
17 #include <linux/module.h>
18 #include <linux/platform_device.h>
19 #include <linux/mtd/mtd.h>
20 #include <linux/mtd/rawnand.h>
21 #include <linux/mtd/partitions.h>
22 #include <linux/clk.h>
23 #include <linux/err.h>
24 #include <linux/delay.h>
25 #include <linux/completion.h>
26 #include <linux/interrupt.h>
27 #include <linux/of.h>
28 #include <linux/of_gpio.h>
29 #include <linux/mtd/lpc32xx_mlc.h>
30 #include <linux/io.h>
31 #include <linux/mm.h>
32 #include <linux/dma-mapping.h>
33 #include <linux/dmaengine.h>
34 #include <linux/mtd/nand_ecc.h>
35 
36 #define DRV_NAME "lpc32xx_mlc"
37 
38 /**********************************************************************
39 * MLC NAND controller register offsets
40 **********************************************************************/
41 
42 #define MLC_BUFF(x)			(x + 0x00000)
43 #define MLC_DATA(x)			(x + 0x08000)
44 #define MLC_CMD(x)			(x + 0x10000)
45 #define MLC_ADDR(x)			(x + 0x10004)
46 #define MLC_ECC_ENC_REG(x)		(x + 0x10008)
47 #define MLC_ECC_DEC_REG(x)		(x + 0x1000C)
48 #define MLC_ECC_AUTO_ENC_REG(x)		(x + 0x10010)
49 #define MLC_ECC_AUTO_DEC_REG(x)		(x + 0x10014)
50 #define MLC_RPR(x)			(x + 0x10018)
51 #define MLC_WPR(x)			(x + 0x1001C)
52 #define MLC_RUBP(x)			(x + 0x10020)
53 #define MLC_ROBP(x)			(x + 0x10024)
54 #define MLC_SW_WP_ADD_LOW(x)		(x + 0x10028)
55 #define MLC_SW_WP_ADD_HIG(x)		(x + 0x1002C)
56 #define MLC_ICR(x)			(x + 0x10030)
57 #define MLC_TIME_REG(x)			(x + 0x10034)
58 #define MLC_IRQ_MR(x)			(x + 0x10038)
59 #define MLC_IRQ_SR(x)			(x + 0x1003C)
60 #define MLC_LOCK_PR(x)			(x + 0x10044)
61 #define MLC_ISR(x)			(x + 0x10048)
62 #define MLC_CEH(x)			(x + 0x1004C)
63 
64 /**********************************************************************
65 * MLC_CMD bit definitions
66 **********************************************************************/
67 #define MLCCMD_RESET			0xFF
68 
69 /**********************************************************************
70 * MLC_ICR bit definitions
71 **********************************************************************/
72 #define MLCICR_WPROT			(1 << 3)
73 #define MLCICR_LARGEBLOCK		(1 << 2)
74 #define MLCICR_LONGADDR			(1 << 1)
75 #define MLCICR_16BIT			(1 << 0)  /* unsupported by LPC32x0! */
76 
77 /**********************************************************************
78 * MLC_TIME_REG bit definitions
79 **********************************************************************/
80 #define MLCTIMEREG_TCEA_DELAY(n)	(((n) & 0x03) << 24)
81 #define MLCTIMEREG_BUSY_DELAY(n)	(((n) & 0x1F) << 19)
82 #define MLCTIMEREG_NAND_TA(n)		(((n) & 0x07) << 16)
83 #define MLCTIMEREG_RD_HIGH(n)		(((n) & 0x0F) << 12)
84 #define MLCTIMEREG_RD_LOW(n)		(((n) & 0x0F) << 8)
85 #define MLCTIMEREG_WR_HIGH(n)		(((n) & 0x0F) << 4)
86 #define MLCTIMEREG_WR_LOW(n)		(((n) & 0x0F) << 0)
87 
88 /**********************************************************************
89 * MLC_IRQ_MR and MLC_IRQ_SR bit definitions
90 **********************************************************************/
91 #define MLCIRQ_NAND_READY		(1 << 5)
92 #define MLCIRQ_CONTROLLER_READY		(1 << 4)
93 #define MLCIRQ_DECODE_FAILURE		(1 << 3)
94 #define MLCIRQ_DECODE_ERROR		(1 << 2)
95 #define MLCIRQ_ECC_READY		(1 << 1)
96 #define MLCIRQ_WRPROT_FAULT		(1 << 0)
97 
98 /**********************************************************************
99 * MLC_LOCK_PR bit definitions
100 **********************************************************************/
101 #define MLCLOCKPR_MAGIC			0xA25E
102 
103 /**********************************************************************
104 * MLC_ISR bit definitions
105 **********************************************************************/
106 #define MLCISR_DECODER_FAILURE		(1 << 6)
107 #define MLCISR_ERRORS			((1 << 4) | (1 << 5))
108 #define MLCISR_ERRORS_DETECTED		(1 << 3)
109 #define MLCISR_ECC_READY		(1 << 2)
110 #define MLCISR_CONTROLLER_READY		(1 << 1)
111 #define MLCISR_NAND_READY		(1 << 0)
112 
113 /**********************************************************************
114 * MLC_CEH bit definitions
115 **********************************************************************/
116 #define MLCCEH_NORMAL			(1 << 0)
117 
118 struct lpc32xx_nand_cfg_mlc {
119 	uint32_t tcea_delay;
120 	uint32_t busy_delay;
121 	uint32_t nand_ta;
122 	uint32_t rd_high;
123 	uint32_t rd_low;
124 	uint32_t wr_high;
125 	uint32_t wr_low;
126 	int wp_gpio;
127 	struct mtd_partition *parts;
128 	unsigned num_parts;
129 };
130 
131 static int lpc32xx_ooblayout_ecc(struct mtd_info *mtd, int section,
132 				 struct mtd_oob_region *oobregion)
133 {
134 	struct nand_chip *nand_chip = mtd_to_nand(mtd);
135 
136 	if (section >= nand_chip->ecc.steps)
137 		return -ERANGE;
138 
139 	oobregion->offset = ((section + 1) * 16) - nand_chip->ecc.bytes;
140 	oobregion->length = nand_chip->ecc.bytes;
141 
142 	return 0;
143 }
144 
145 static int lpc32xx_ooblayout_free(struct mtd_info *mtd, int section,
146 				  struct mtd_oob_region *oobregion)
147 {
148 	struct nand_chip *nand_chip = mtd_to_nand(mtd);
149 
150 	if (section >= nand_chip->ecc.steps)
151 		return -ERANGE;
152 
153 	oobregion->offset = 16 * section;
154 	oobregion->length = 16 - nand_chip->ecc.bytes;
155 
156 	return 0;
157 }
158 
159 static const struct mtd_ooblayout_ops lpc32xx_ooblayout_ops = {
160 	.ecc = lpc32xx_ooblayout_ecc,
161 	.free = lpc32xx_ooblayout_free,
162 };
163 
164 static struct nand_bbt_descr lpc32xx_nand_bbt = {
165 	.options = NAND_BBT_ABSPAGE | NAND_BBT_2BIT | NAND_BBT_NO_OOB |
166 		   NAND_BBT_WRITE,
167 	.pages = { 524224, 0, 0, 0, 0, 0, 0, 0 },
168 };
169 
170 static struct nand_bbt_descr lpc32xx_nand_bbt_mirror = {
171 	.options = NAND_BBT_ABSPAGE | NAND_BBT_2BIT | NAND_BBT_NO_OOB |
172 		   NAND_BBT_WRITE,
173 	.pages = { 524160, 0, 0, 0, 0, 0, 0, 0 },
174 };
175 
176 struct lpc32xx_nand_host {
177 	struct platform_device	*pdev;
178 	struct nand_chip	nand_chip;
179 	struct lpc32xx_mlc_platform_data *pdata;
180 	struct clk		*clk;
181 	void __iomem		*io_base;
182 	int			irq;
183 	struct lpc32xx_nand_cfg_mlc	*ncfg;
184 	struct completion       comp_nand;
185 	struct completion       comp_controller;
186 	uint32_t llptr;
187 	/*
188 	 * Physical addresses of ECC buffer, DMA data buffers, OOB data buffer
189 	 */
190 	dma_addr_t		oob_buf_phy;
191 	/*
192 	 * Virtual addresses of ECC buffer, DMA data buffers, OOB data buffer
193 	 */
194 	uint8_t			*oob_buf;
195 	/* Physical address of DMA base address */
196 	dma_addr_t		io_base_phy;
197 
198 	struct completion	comp_dma;
199 	struct dma_chan		*dma_chan;
200 	struct dma_slave_config	dma_slave_config;
201 	struct scatterlist	sgl;
202 	uint8_t			*dma_buf;
203 	uint8_t			*dummy_buf;
204 	int			mlcsubpages; /* number of 512bytes-subpages */
205 };
206 
207 /*
208  * Activate/Deactivate DMA Operation:
209  *
210  * Using the PL080 DMA Controller for transferring the 512 byte subpages
211  * instead of doing readl() / writel() in a loop slows it down significantly.
212  * Measurements via getnstimeofday() upon 512 byte subpage reads reveal:
213  *
214  * - readl() of 128 x 32 bits in a loop: ~20us
215  * - DMA read of 512 bytes (32 bit, 4...128 words bursts): ~60us
216  * - DMA read of 512 bytes (32 bit, no bursts): ~100us
217  *
218  * This applies to the transfer itself. In the DMA case: only the
219  * wait_for_completion() (DMA setup _not_ included).
220  *
221  * Note that the 512 bytes subpage transfer is done directly from/to a
222  * FIFO/buffer inside the NAND controller. Most of the time (~400-800us for a
223  * 2048 bytes page) is spent waiting for the NAND IRQ, anyway. (The NAND
224  * controller transferring data between its internal buffer to/from the NAND
225  * chip.)
226  *
227  * Therefore, using the PL080 DMA is disabled by default, for now.
228  *
229  */
230 static int use_dma;
231 
232 static void lpc32xx_nand_setup(struct lpc32xx_nand_host *host)
233 {
234 	uint32_t clkrate, tmp;
235 
236 	/* Reset MLC controller */
237 	writel(MLCCMD_RESET, MLC_CMD(host->io_base));
238 	udelay(1000);
239 
240 	/* Get base clock for MLC block */
241 	clkrate = clk_get_rate(host->clk);
242 	if (clkrate == 0)
243 		clkrate = 104000000;
244 
245 	/* Unlock MLC_ICR
246 	 * (among others, will be locked again automatically) */
247 	writew(MLCLOCKPR_MAGIC, MLC_LOCK_PR(host->io_base));
248 
249 	/* Configure MLC Controller: Large Block, 5 Byte Address */
250 	tmp = MLCICR_LARGEBLOCK | MLCICR_LONGADDR;
251 	writel(tmp, MLC_ICR(host->io_base));
252 
253 	/* Unlock MLC_TIME_REG
254 	 * (among others, will be locked again automatically) */
255 	writew(MLCLOCKPR_MAGIC, MLC_LOCK_PR(host->io_base));
256 
257 	/* Compute clock setup values, see LPC and NAND manual */
258 	tmp = 0;
259 	tmp |= MLCTIMEREG_TCEA_DELAY(clkrate / host->ncfg->tcea_delay + 1);
260 	tmp |= MLCTIMEREG_BUSY_DELAY(clkrate / host->ncfg->busy_delay + 1);
261 	tmp |= MLCTIMEREG_NAND_TA(clkrate / host->ncfg->nand_ta + 1);
262 	tmp |= MLCTIMEREG_RD_HIGH(clkrate / host->ncfg->rd_high + 1);
263 	tmp |= MLCTIMEREG_RD_LOW(clkrate / host->ncfg->rd_low);
264 	tmp |= MLCTIMEREG_WR_HIGH(clkrate / host->ncfg->wr_high + 1);
265 	tmp |= MLCTIMEREG_WR_LOW(clkrate / host->ncfg->wr_low);
266 	writel(tmp, MLC_TIME_REG(host->io_base));
267 
268 	/* Enable IRQ for CONTROLLER_READY and NAND_READY */
269 	writeb(MLCIRQ_CONTROLLER_READY | MLCIRQ_NAND_READY,
270 			MLC_IRQ_MR(host->io_base));
271 
272 	/* Normal nCE operation: nCE controlled by controller */
273 	writel(MLCCEH_NORMAL, MLC_CEH(host->io_base));
274 }
275 
276 /*
277  * Hardware specific access to control lines
278  */
279 static void lpc32xx_nand_cmd_ctrl(struct nand_chip *nand_chip, int cmd,
280 				  unsigned int ctrl)
281 {
282 	struct lpc32xx_nand_host *host = nand_get_controller_data(nand_chip);
283 
284 	if (cmd != NAND_CMD_NONE) {
285 		if (ctrl & NAND_CLE)
286 			writel(cmd, MLC_CMD(host->io_base));
287 		else
288 			writel(cmd, MLC_ADDR(host->io_base));
289 	}
290 }
291 
292 /*
293  * Read Device Ready (NAND device _and_ controller ready)
294  */
295 static int lpc32xx_nand_device_ready(struct nand_chip *nand_chip)
296 {
297 	struct lpc32xx_nand_host *host = nand_get_controller_data(nand_chip);
298 
299 	if ((readb(MLC_ISR(host->io_base)) &
300 	     (MLCISR_CONTROLLER_READY | MLCISR_NAND_READY)) ==
301 	    (MLCISR_CONTROLLER_READY | MLCISR_NAND_READY))
302 		return  1;
303 
304 	return 0;
305 }
306 
307 static irqreturn_t lpc3xxx_nand_irq(int irq, struct lpc32xx_nand_host *host)
308 {
309 	uint8_t sr;
310 
311 	/* Clear interrupt flag by reading status */
312 	sr = readb(MLC_IRQ_SR(host->io_base));
313 	if (sr & MLCIRQ_NAND_READY)
314 		complete(&host->comp_nand);
315 	if (sr & MLCIRQ_CONTROLLER_READY)
316 		complete(&host->comp_controller);
317 
318 	return IRQ_HANDLED;
319 }
320 
321 static int lpc32xx_waitfunc_nand(struct nand_chip *chip)
322 {
323 	struct mtd_info *mtd = nand_to_mtd(chip);
324 	struct lpc32xx_nand_host *host = nand_get_controller_data(chip);
325 
326 	if (readb(MLC_ISR(host->io_base)) & MLCISR_NAND_READY)
327 		goto exit;
328 
329 	wait_for_completion(&host->comp_nand);
330 
331 	while (!(readb(MLC_ISR(host->io_base)) & MLCISR_NAND_READY)) {
332 		/* Seems to be delayed sometimes by controller */
333 		dev_dbg(&mtd->dev, "Warning: NAND not ready.\n");
334 		cpu_relax();
335 	}
336 
337 exit:
338 	return NAND_STATUS_READY;
339 }
340 
341 static int lpc32xx_waitfunc_controller(struct nand_chip *chip)
342 {
343 	struct mtd_info *mtd = nand_to_mtd(chip);
344 	struct lpc32xx_nand_host *host = nand_get_controller_data(chip);
345 
346 	if (readb(MLC_ISR(host->io_base)) & MLCISR_CONTROLLER_READY)
347 		goto exit;
348 
349 	wait_for_completion(&host->comp_controller);
350 
351 	while (!(readb(MLC_ISR(host->io_base)) &
352 		 MLCISR_CONTROLLER_READY)) {
353 		dev_dbg(&mtd->dev, "Warning: Controller not ready.\n");
354 		cpu_relax();
355 	}
356 
357 exit:
358 	return NAND_STATUS_READY;
359 }
360 
361 static int lpc32xx_waitfunc(struct nand_chip *chip)
362 {
363 	lpc32xx_waitfunc_nand(chip);
364 	lpc32xx_waitfunc_controller(chip);
365 
366 	return NAND_STATUS_READY;
367 }
368 
369 /*
370  * Enable NAND write protect
371  */
372 static void lpc32xx_wp_enable(struct lpc32xx_nand_host *host)
373 {
374 	if (gpio_is_valid(host->ncfg->wp_gpio))
375 		gpio_set_value(host->ncfg->wp_gpio, 0);
376 }
377 
378 /*
379  * Disable NAND write protect
380  */
381 static void lpc32xx_wp_disable(struct lpc32xx_nand_host *host)
382 {
383 	if (gpio_is_valid(host->ncfg->wp_gpio))
384 		gpio_set_value(host->ncfg->wp_gpio, 1);
385 }
386 
387 static void lpc32xx_dma_complete_func(void *completion)
388 {
389 	complete(completion);
390 }
391 
392 static int lpc32xx_xmit_dma(struct mtd_info *mtd, void *mem, int len,
393 			    enum dma_transfer_direction dir)
394 {
395 	struct nand_chip *chip = mtd_to_nand(mtd);
396 	struct lpc32xx_nand_host *host = nand_get_controller_data(chip);
397 	struct dma_async_tx_descriptor *desc;
398 	int flags = DMA_CTRL_ACK | DMA_PREP_INTERRUPT;
399 	int res;
400 
401 	sg_init_one(&host->sgl, mem, len);
402 
403 	res = dma_map_sg(host->dma_chan->device->dev, &host->sgl, 1,
404 			 DMA_BIDIRECTIONAL);
405 	if (res != 1) {
406 		dev_err(mtd->dev.parent, "Failed to map sg list\n");
407 		return -ENXIO;
408 	}
409 	desc = dmaengine_prep_slave_sg(host->dma_chan, &host->sgl, 1, dir,
410 				       flags);
411 	if (!desc) {
412 		dev_err(mtd->dev.parent, "Failed to prepare slave sg\n");
413 		goto out1;
414 	}
415 
416 	init_completion(&host->comp_dma);
417 	desc->callback = lpc32xx_dma_complete_func;
418 	desc->callback_param = &host->comp_dma;
419 
420 	dmaengine_submit(desc);
421 	dma_async_issue_pending(host->dma_chan);
422 
423 	wait_for_completion_timeout(&host->comp_dma, msecs_to_jiffies(1000));
424 
425 	dma_unmap_sg(host->dma_chan->device->dev, &host->sgl, 1,
426 		     DMA_BIDIRECTIONAL);
427 	return 0;
428 out1:
429 	dma_unmap_sg(host->dma_chan->device->dev, &host->sgl, 1,
430 		     DMA_BIDIRECTIONAL);
431 	return -ENXIO;
432 }
433 
434 static int lpc32xx_read_page(struct nand_chip *chip, uint8_t *buf,
435 			     int oob_required, int page)
436 {
437 	struct mtd_info *mtd = nand_to_mtd(chip);
438 	struct lpc32xx_nand_host *host = nand_get_controller_data(chip);
439 	int i, j;
440 	uint8_t *oobbuf = chip->oob_poi;
441 	uint32_t mlc_isr;
442 	int res;
443 	uint8_t *dma_buf;
444 	bool dma_mapped;
445 
446 	if ((void *)buf <= high_memory) {
447 		dma_buf = buf;
448 		dma_mapped = true;
449 	} else {
450 		dma_buf = host->dma_buf;
451 		dma_mapped = false;
452 	}
453 
454 	/* Writing Command and Address */
455 	nand_read_page_op(chip, page, 0, NULL, 0);
456 
457 	/* For all sub-pages */
458 	for (i = 0; i < host->mlcsubpages; i++) {
459 		/* Start Auto Decode Command */
460 		writeb(0x00, MLC_ECC_AUTO_DEC_REG(host->io_base));
461 
462 		/* Wait for Controller Ready */
463 		lpc32xx_waitfunc_controller(chip);
464 
465 		/* Check ECC Error status */
466 		mlc_isr = readl(MLC_ISR(host->io_base));
467 		if (mlc_isr & MLCISR_DECODER_FAILURE) {
468 			mtd->ecc_stats.failed++;
469 			dev_warn(&mtd->dev, "%s: DECODER_FAILURE\n", __func__);
470 		} else if (mlc_isr & MLCISR_ERRORS_DETECTED) {
471 			mtd->ecc_stats.corrected += ((mlc_isr >> 4) & 0x3) + 1;
472 		}
473 
474 		/* Read 512 + 16 Bytes */
475 		if (use_dma) {
476 			res = lpc32xx_xmit_dma(mtd, dma_buf + i * 512, 512,
477 					       DMA_DEV_TO_MEM);
478 			if (res)
479 				return res;
480 		} else {
481 			for (j = 0; j < (512 >> 2); j++) {
482 				*((uint32_t *)(buf)) =
483 					readl(MLC_BUFF(host->io_base));
484 				buf += 4;
485 			}
486 		}
487 		for (j = 0; j < (16 >> 2); j++) {
488 			*((uint32_t *)(oobbuf)) =
489 				readl(MLC_BUFF(host->io_base));
490 			oobbuf += 4;
491 		}
492 	}
493 
494 	if (use_dma && !dma_mapped)
495 		memcpy(buf, dma_buf, mtd->writesize);
496 
497 	return 0;
498 }
499 
500 static int lpc32xx_write_page_lowlevel(struct nand_chip *chip,
501 				       const uint8_t *buf, int oob_required,
502 				       int page)
503 {
504 	struct mtd_info *mtd = nand_to_mtd(chip);
505 	struct lpc32xx_nand_host *host = nand_get_controller_data(chip);
506 	const uint8_t *oobbuf = chip->oob_poi;
507 	uint8_t *dma_buf = (uint8_t *)buf;
508 	int res;
509 	int i, j;
510 
511 	if (use_dma && (void *)buf >= high_memory) {
512 		dma_buf = host->dma_buf;
513 		memcpy(dma_buf, buf, mtd->writesize);
514 	}
515 
516 	nand_prog_page_begin_op(chip, page, 0, NULL, 0);
517 
518 	for (i = 0; i < host->mlcsubpages; i++) {
519 		/* Start Encode */
520 		writeb(0x00, MLC_ECC_ENC_REG(host->io_base));
521 
522 		/* Write 512 + 6 Bytes to Buffer */
523 		if (use_dma) {
524 			res = lpc32xx_xmit_dma(mtd, dma_buf + i * 512, 512,
525 					       DMA_MEM_TO_DEV);
526 			if (res)
527 				return res;
528 		} else {
529 			for (j = 0; j < (512 >> 2); j++) {
530 				writel(*((uint32_t *)(buf)),
531 				       MLC_BUFF(host->io_base));
532 				buf += 4;
533 			}
534 		}
535 		writel(*((uint32_t *)(oobbuf)), MLC_BUFF(host->io_base));
536 		oobbuf += 4;
537 		writew(*((uint16_t *)(oobbuf)), MLC_BUFF(host->io_base));
538 		oobbuf += 12;
539 
540 		/* Auto Encode w/ Bit 8 = 0 (see LPC MLC Controller manual) */
541 		writeb(0x00, MLC_ECC_AUTO_ENC_REG(host->io_base));
542 
543 		/* Wait for Controller Ready */
544 		lpc32xx_waitfunc_controller(chip);
545 	}
546 
547 	return nand_prog_page_end_op(chip);
548 }
549 
550 static int lpc32xx_read_oob(struct nand_chip *chip, int page)
551 {
552 	struct lpc32xx_nand_host *host = nand_get_controller_data(chip);
553 
554 	/* Read whole page - necessary with MLC controller! */
555 	lpc32xx_read_page(chip, host->dummy_buf, 1, page);
556 
557 	return 0;
558 }
559 
560 static int lpc32xx_write_oob(struct nand_chip *chip, int page)
561 {
562 	/* None, write_oob conflicts with the automatic LPC MLC ECC decoder! */
563 	return 0;
564 }
565 
566 /* Prepares MLC for transfers with H/W ECC enabled: always enabled anyway */
567 static void lpc32xx_ecc_enable(struct nand_chip *chip, int mode)
568 {
569 	/* Always enabled! */
570 }
571 
572 static int lpc32xx_dma_setup(struct lpc32xx_nand_host *host)
573 {
574 	struct mtd_info *mtd = nand_to_mtd(&host->nand_chip);
575 	dma_cap_mask_t mask;
576 
577 	if (!host->pdata || !host->pdata->dma_filter) {
578 		dev_err(mtd->dev.parent, "no DMA platform data\n");
579 		return -ENOENT;
580 	}
581 
582 	dma_cap_zero(mask);
583 	dma_cap_set(DMA_SLAVE, mask);
584 	host->dma_chan = dma_request_channel(mask, host->pdata->dma_filter,
585 					     "nand-mlc");
586 	if (!host->dma_chan) {
587 		dev_err(mtd->dev.parent, "Failed to request DMA channel\n");
588 		return -EBUSY;
589 	}
590 
591 	/*
592 	 * Set direction to a sensible value even if the dmaengine driver
593 	 * should ignore it. With the default (DMA_MEM_TO_MEM), the amba-pl08x
594 	 * driver criticizes it as "alien transfer direction".
595 	 */
596 	host->dma_slave_config.direction = DMA_DEV_TO_MEM;
597 	host->dma_slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
598 	host->dma_slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
599 	host->dma_slave_config.src_maxburst = 128;
600 	host->dma_slave_config.dst_maxburst = 128;
601 	/* DMA controller does flow control: */
602 	host->dma_slave_config.device_fc = false;
603 	host->dma_slave_config.src_addr = MLC_BUFF(host->io_base_phy);
604 	host->dma_slave_config.dst_addr = MLC_BUFF(host->io_base_phy);
605 	if (dmaengine_slave_config(host->dma_chan, &host->dma_slave_config)) {
606 		dev_err(mtd->dev.parent, "Failed to setup DMA slave\n");
607 		goto out1;
608 	}
609 
610 	return 0;
611 out1:
612 	dma_release_channel(host->dma_chan);
613 	return -ENXIO;
614 }
615 
616 static struct lpc32xx_nand_cfg_mlc *lpc32xx_parse_dt(struct device *dev)
617 {
618 	struct lpc32xx_nand_cfg_mlc *ncfg;
619 	struct device_node *np = dev->of_node;
620 
621 	ncfg = devm_kzalloc(dev, sizeof(*ncfg), GFP_KERNEL);
622 	if (!ncfg)
623 		return NULL;
624 
625 	of_property_read_u32(np, "nxp,tcea-delay", &ncfg->tcea_delay);
626 	of_property_read_u32(np, "nxp,busy-delay", &ncfg->busy_delay);
627 	of_property_read_u32(np, "nxp,nand-ta", &ncfg->nand_ta);
628 	of_property_read_u32(np, "nxp,rd-high", &ncfg->rd_high);
629 	of_property_read_u32(np, "nxp,rd-low", &ncfg->rd_low);
630 	of_property_read_u32(np, "nxp,wr-high", &ncfg->wr_high);
631 	of_property_read_u32(np, "nxp,wr-low", &ncfg->wr_low);
632 
633 	if (!ncfg->tcea_delay || !ncfg->busy_delay || !ncfg->nand_ta ||
634 	    !ncfg->rd_high || !ncfg->rd_low || !ncfg->wr_high ||
635 	    !ncfg->wr_low) {
636 		dev_err(dev, "chip parameters not specified correctly\n");
637 		return NULL;
638 	}
639 
640 	ncfg->wp_gpio = of_get_named_gpio(np, "gpios", 0);
641 
642 	return ncfg;
643 }
644 
645 static int lpc32xx_nand_attach_chip(struct nand_chip *chip)
646 {
647 	struct mtd_info *mtd = nand_to_mtd(chip);
648 	struct lpc32xx_nand_host *host = nand_get_controller_data(chip);
649 	struct device *dev = &host->pdev->dev;
650 
651 	host->dma_buf = devm_kzalloc(dev, mtd->writesize, GFP_KERNEL);
652 	if (!host->dma_buf)
653 		return -ENOMEM;
654 
655 	host->dummy_buf = devm_kzalloc(dev, mtd->writesize, GFP_KERNEL);
656 	if (!host->dummy_buf)
657 		return -ENOMEM;
658 
659 	chip->ecc.mode = NAND_ECC_HW;
660 	chip->ecc.size = 512;
661 	mtd_set_ooblayout(mtd, &lpc32xx_ooblayout_ops);
662 	host->mlcsubpages = mtd->writesize / 512;
663 
664 	return 0;
665 }
666 
667 static const struct nand_controller_ops lpc32xx_nand_controller_ops = {
668 	.attach_chip = lpc32xx_nand_attach_chip,
669 };
670 
671 /*
672  * Probe for NAND controller
673  */
674 static int lpc32xx_nand_probe(struct platform_device *pdev)
675 {
676 	struct lpc32xx_nand_host *host;
677 	struct mtd_info *mtd;
678 	struct nand_chip *nand_chip;
679 	struct resource *rc;
680 	int res;
681 
682 	/* Allocate memory for the device structure (and zero it) */
683 	host = devm_kzalloc(&pdev->dev, sizeof(*host), GFP_KERNEL);
684 	if (!host)
685 		return -ENOMEM;
686 
687 	host->pdev = pdev;
688 
689 	rc = platform_get_resource(pdev, IORESOURCE_MEM, 0);
690 	host->io_base = devm_ioremap_resource(&pdev->dev, rc);
691 	if (IS_ERR(host->io_base))
692 		return PTR_ERR(host->io_base);
693 
694 	host->io_base_phy = rc->start;
695 
696 	nand_chip = &host->nand_chip;
697 	mtd = nand_to_mtd(nand_chip);
698 	if (pdev->dev.of_node)
699 		host->ncfg = lpc32xx_parse_dt(&pdev->dev);
700 	if (!host->ncfg) {
701 		dev_err(&pdev->dev,
702 			"Missing or bad NAND config from device tree\n");
703 		return -ENOENT;
704 	}
705 	if (host->ncfg->wp_gpio == -EPROBE_DEFER)
706 		return -EPROBE_DEFER;
707 	if (gpio_is_valid(host->ncfg->wp_gpio) &&
708 			gpio_request(host->ncfg->wp_gpio, "NAND WP")) {
709 		dev_err(&pdev->dev, "GPIO not available\n");
710 		return -EBUSY;
711 	}
712 	lpc32xx_wp_disable(host);
713 
714 	host->pdata = dev_get_platdata(&pdev->dev);
715 
716 	/* link the private data structures */
717 	nand_set_controller_data(nand_chip, host);
718 	nand_set_flash_node(nand_chip, pdev->dev.of_node);
719 	mtd->dev.parent = &pdev->dev;
720 
721 	/* Get NAND clock */
722 	host->clk = clk_get(&pdev->dev, NULL);
723 	if (IS_ERR(host->clk)) {
724 		dev_err(&pdev->dev, "Clock initialization failure\n");
725 		res = -ENOENT;
726 		goto free_gpio;
727 	}
728 	res = clk_prepare_enable(host->clk);
729 	if (res)
730 		goto put_clk;
731 
732 	nand_chip->legacy.cmd_ctrl = lpc32xx_nand_cmd_ctrl;
733 	nand_chip->legacy.dev_ready = lpc32xx_nand_device_ready;
734 	nand_chip->legacy.chip_delay = 25; /* us */
735 	nand_chip->legacy.IO_ADDR_R = MLC_DATA(host->io_base);
736 	nand_chip->legacy.IO_ADDR_W = MLC_DATA(host->io_base);
737 
738 	/* Init NAND controller */
739 	lpc32xx_nand_setup(host);
740 
741 	platform_set_drvdata(pdev, host);
742 
743 	/* Initialize function pointers */
744 	nand_chip->ecc.hwctl = lpc32xx_ecc_enable;
745 	nand_chip->ecc.read_page_raw = lpc32xx_read_page;
746 	nand_chip->ecc.read_page = lpc32xx_read_page;
747 	nand_chip->ecc.write_page_raw = lpc32xx_write_page_lowlevel;
748 	nand_chip->ecc.write_page = lpc32xx_write_page_lowlevel;
749 	nand_chip->ecc.write_oob = lpc32xx_write_oob;
750 	nand_chip->ecc.read_oob = lpc32xx_read_oob;
751 	nand_chip->ecc.strength = 4;
752 	nand_chip->ecc.bytes = 10;
753 	nand_chip->legacy.waitfunc = lpc32xx_waitfunc;
754 
755 	nand_chip->options = NAND_NO_SUBPAGE_WRITE;
756 	nand_chip->bbt_options = NAND_BBT_USE_FLASH | NAND_BBT_NO_OOB;
757 	nand_chip->bbt_td = &lpc32xx_nand_bbt;
758 	nand_chip->bbt_md = &lpc32xx_nand_bbt_mirror;
759 
760 	if (use_dma) {
761 		res = lpc32xx_dma_setup(host);
762 		if (res) {
763 			res = -EIO;
764 			goto unprepare_clk;
765 		}
766 	}
767 
768 	/* initially clear interrupt status */
769 	readb(MLC_IRQ_SR(host->io_base));
770 
771 	init_completion(&host->comp_nand);
772 	init_completion(&host->comp_controller);
773 
774 	host->irq = platform_get_irq(pdev, 0);
775 	if (host->irq < 0) {
776 		res = -EINVAL;
777 		goto release_dma_chan;
778 	}
779 
780 	if (request_irq(host->irq, (irq_handler_t)&lpc3xxx_nand_irq,
781 			IRQF_TRIGGER_HIGH, DRV_NAME, host)) {
782 		dev_err(&pdev->dev, "Error requesting NAND IRQ\n");
783 		res = -ENXIO;
784 		goto release_dma_chan;
785 	}
786 
787 	/*
788 	 * Scan to find existence of the device and get the type of NAND device:
789 	 * SMALL block or LARGE block.
790 	 */
791 	nand_chip->legacy.dummy_controller.ops = &lpc32xx_nand_controller_ops;
792 	res = nand_scan(nand_chip, 1);
793 	if (res)
794 		goto free_irq;
795 
796 	mtd->name = DRV_NAME;
797 
798 	res = mtd_device_register(mtd, host->ncfg->parts,
799 				  host->ncfg->num_parts);
800 	if (res)
801 		goto cleanup_nand;
802 
803 	return 0;
804 
805 cleanup_nand:
806 	nand_cleanup(nand_chip);
807 free_irq:
808 	free_irq(host->irq, host);
809 release_dma_chan:
810 	if (use_dma)
811 		dma_release_channel(host->dma_chan);
812 unprepare_clk:
813 	clk_disable_unprepare(host->clk);
814 put_clk:
815 	clk_put(host->clk);
816 free_gpio:
817 	lpc32xx_wp_enable(host);
818 	gpio_free(host->ncfg->wp_gpio);
819 
820 	return res;
821 }
822 
823 /*
824  * Remove NAND device
825  */
826 static int lpc32xx_nand_remove(struct platform_device *pdev)
827 {
828 	struct lpc32xx_nand_host *host = platform_get_drvdata(pdev);
829 
830 	nand_release(&host->nand_chip);
831 	free_irq(host->irq, host);
832 	if (use_dma)
833 		dma_release_channel(host->dma_chan);
834 
835 	clk_disable_unprepare(host->clk);
836 	clk_put(host->clk);
837 
838 	lpc32xx_wp_enable(host);
839 	gpio_free(host->ncfg->wp_gpio);
840 
841 	return 0;
842 }
843 
844 #ifdef CONFIG_PM
845 static int lpc32xx_nand_resume(struct platform_device *pdev)
846 {
847 	struct lpc32xx_nand_host *host = platform_get_drvdata(pdev);
848 	int ret;
849 
850 	/* Re-enable NAND clock */
851 	ret = clk_prepare_enable(host->clk);
852 	if (ret)
853 		return ret;
854 
855 	/* Fresh init of NAND controller */
856 	lpc32xx_nand_setup(host);
857 
858 	/* Disable write protect */
859 	lpc32xx_wp_disable(host);
860 
861 	return 0;
862 }
863 
864 static int lpc32xx_nand_suspend(struct platform_device *pdev, pm_message_t pm)
865 {
866 	struct lpc32xx_nand_host *host = platform_get_drvdata(pdev);
867 
868 	/* Enable write protect for safety */
869 	lpc32xx_wp_enable(host);
870 
871 	/* Disable clock */
872 	clk_disable_unprepare(host->clk);
873 	return 0;
874 }
875 
876 #else
877 #define lpc32xx_nand_resume NULL
878 #define lpc32xx_nand_suspend NULL
879 #endif
880 
881 static const struct of_device_id lpc32xx_nand_match[] = {
882 	{ .compatible = "nxp,lpc3220-mlc" },
883 	{ /* sentinel */ },
884 };
885 MODULE_DEVICE_TABLE(of, lpc32xx_nand_match);
886 
887 static struct platform_driver lpc32xx_nand_driver = {
888 	.probe		= lpc32xx_nand_probe,
889 	.remove		= lpc32xx_nand_remove,
890 	.resume		= lpc32xx_nand_resume,
891 	.suspend	= lpc32xx_nand_suspend,
892 	.driver		= {
893 		.name	= DRV_NAME,
894 		.of_match_table = lpc32xx_nand_match,
895 	},
896 };
897 
898 module_platform_driver(lpc32xx_nand_driver);
899 
900 MODULE_LICENSE("GPL");
901 MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
902 MODULE_DESCRIPTION("NAND driver for the NXP LPC32XX MLC controller");
903