xref: /openbmc/linux/drivers/mtd/nand/raw/lpc32xx_mlc.c (revision 3213486f)
1 /*
2  * Driver for NAND MLC Controller in LPC32xx
3  *
4  * Author: Roland Stigge <stigge@antcom.de>
5  *
6  * Copyright © 2011 WORK Microwave GmbH
7  * Copyright © 2011, 2012 Roland Stigge
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation; either version 2 of the License, or
12  * (at your option) any later version.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  *
19  *
20  * NAND Flash Controller Operation:
21  * - Read: Auto Decode
22  * - Write: Auto Encode
23  * - Tested Page Sizes: 2048, 4096
24  */
25 
26 #include <linux/slab.h>
27 #include <linux/module.h>
28 #include <linux/platform_device.h>
29 #include <linux/mtd/mtd.h>
30 #include <linux/mtd/rawnand.h>
31 #include <linux/mtd/partitions.h>
32 #include <linux/clk.h>
33 #include <linux/err.h>
34 #include <linux/delay.h>
35 #include <linux/completion.h>
36 #include <linux/interrupt.h>
37 #include <linux/of.h>
38 #include <linux/of_gpio.h>
39 #include <linux/mtd/lpc32xx_mlc.h>
40 #include <linux/io.h>
41 #include <linux/mm.h>
42 #include <linux/dma-mapping.h>
43 #include <linux/dmaengine.h>
44 #include <linux/mtd/nand_ecc.h>
45 
46 #define DRV_NAME "lpc32xx_mlc"
47 
48 /**********************************************************************
49 * MLC NAND controller register offsets
50 **********************************************************************/
51 
52 #define MLC_BUFF(x)			(x + 0x00000)
53 #define MLC_DATA(x)			(x + 0x08000)
54 #define MLC_CMD(x)			(x + 0x10000)
55 #define MLC_ADDR(x)			(x + 0x10004)
56 #define MLC_ECC_ENC_REG(x)		(x + 0x10008)
57 #define MLC_ECC_DEC_REG(x)		(x + 0x1000C)
58 #define MLC_ECC_AUTO_ENC_REG(x)		(x + 0x10010)
59 #define MLC_ECC_AUTO_DEC_REG(x)		(x + 0x10014)
60 #define MLC_RPR(x)			(x + 0x10018)
61 #define MLC_WPR(x)			(x + 0x1001C)
62 #define MLC_RUBP(x)			(x + 0x10020)
63 #define MLC_ROBP(x)			(x + 0x10024)
64 #define MLC_SW_WP_ADD_LOW(x)		(x + 0x10028)
65 #define MLC_SW_WP_ADD_HIG(x)		(x + 0x1002C)
66 #define MLC_ICR(x)			(x + 0x10030)
67 #define MLC_TIME_REG(x)			(x + 0x10034)
68 #define MLC_IRQ_MR(x)			(x + 0x10038)
69 #define MLC_IRQ_SR(x)			(x + 0x1003C)
70 #define MLC_LOCK_PR(x)			(x + 0x10044)
71 #define MLC_ISR(x)			(x + 0x10048)
72 #define MLC_CEH(x)			(x + 0x1004C)
73 
74 /**********************************************************************
75 * MLC_CMD bit definitions
76 **********************************************************************/
77 #define MLCCMD_RESET			0xFF
78 
79 /**********************************************************************
80 * MLC_ICR bit definitions
81 **********************************************************************/
82 #define MLCICR_WPROT			(1 << 3)
83 #define MLCICR_LARGEBLOCK		(1 << 2)
84 #define MLCICR_LONGADDR			(1 << 1)
85 #define MLCICR_16BIT			(1 << 0)  /* unsupported by LPC32x0! */
86 
87 /**********************************************************************
88 * MLC_TIME_REG bit definitions
89 **********************************************************************/
90 #define MLCTIMEREG_TCEA_DELAY(n)	(((n) & 0x03) << 24)
91 #define MLCTIMEREG_BUSY_DELAY(n)	(((n) & 0x1F) << 19)
92 #define MLCTIMEREG_NAND_TA(n)		(((n) & 0x07) << 16)
93 #define MLCTIMEREG_RD_HIGH(n)		(((n) & 0x0F) << 12)
94 #define MLCTIMEREG_RD_LOW(n)		(((n) & 0x0F) << 8)
95 #define MLCTIMEREG_WR_HIGH(n)		(((n) & 0x0F) << 4)
96 #define MLCTIMEREG_WR_LOW(n)		(((n) & 0x0F) << 0)
97 
98 /**********************************************************************
99 * MLC_IRQ_MR and MLC_IRQ_SR bit definitions
100 **********************************************************************/
101 #define MLCIRQ_NAND_READY		(1 << 5)
102 #define MLCIRQ_CONTROLLER_READY		(1 << 4)
103 #define MLCIRQ_DECODE_FAILURE		(1 << 3)
104 #define MLCIRQ_DECODE_ERROR		(1 << 2)
105 #define MLCIRQ_ECC_READY		(1 << 1)
106 #define MLCIRQ_WRPROT_FAULT		(1 << 0)
107 
108 /**********************************************************************
109 * MLC_LOCK_PR bit definitions
110 **********************************************************************/
111 #define MLCLOCKPR_MAGIC			0xA25E
112 
113 /**********************************************************************
114 * MLC_ISR bit definitions
115 **********************************************************************/
116 #define MLCISR_DECODER_FAILURE		(1 << 6)
117 #define MLCISR_ERRORS			((1 << 4) | (1 << 5))
118 #define MLCISR_ERRORS_DETECTED		(1 << 3)
119 #define MLCISR_ECC_READY		(1 << 2)
120 #define MLCISR_CONTROLLER_READY		(1 << 1)
121 #define MLCISR_NAND_READY		(1 << 0)
122 
123 /**********************************************************************
124 * MLC_CEH bit definitions
125 **********************************************************************/
126 #define MLCCEH_NORMAL			(1 << 0)
127 
128 struct lpc32xx_nand_cfg_mlc {
129 	uint32_t tcea_delay;
130 	uint32_t busy_delay;
131 	uint32_t nand_ta;
132 	uint32_t rd_high;
133 	uint32_t rd_low;
134 	uint32_t wr_high;
135 	uint32_t wr_low;
136 	int wp_gpio;
137 	struct mtd_partition *parts;
138 	unsigned num_parts;
139 };
140 
141 static int lpc32xx_ooblayout_ecc(struct mtd_info *mtd, int section,
142 				 struct mtd_oob_region *oobregion)
143 {
144 	struct nand_chip *nand_chip = mtd_to_nand(mtd);
145 
146 	if (section >= nand_chip->ecc.steps)
147 		return -ERANGE;
148 
149 	oobregion->offset = ((section + 1) * 16) - nand_chip->ecc.bytes;
150 	oobregion->length = nand_chip->ecc.bytes;
151 
152 	return 0;
153 }
154 
155 static int lpc32xx_ooblayout_free(struct mtd_info *mtd, int section,
156 				  struct mtd_oob_region *oobregion)
157 {
158 	struct nand_chip *nand_chip = mtd_to_nand(mtd);
159 
160 	if (section >= nand_chip->ecc.steps)
161 		return -ERANGE;
162 
163 	oobregion->offset = 16 * section;
164 	oobregion->length = 16 - nand_chip->ecc.bytes;
165 
166 	return 0;
167 }
168 
169 static const struct mtd_ooblayout_ops lpc32xx_ooblayout_ops = {
170 	.ecc = lpc32xx_ooblayout_ecc,
171 	.free = lpc32xx_ooblayout_free,
172 };
173 
174 static struct nand_bbt_descr lpc32xx_nand_bbt = {
175 	.options = NAND_BBT_ABSPAGE | NAND_BBT_2BIT | NAND_BBT_NO_OOB |
176 		   NAND_BBT_WRITE,
177 	.pages = { 524224, 0, 0, 0, 0, 0, 0, 0 },
178 };
179 
180 static struct nand_bbt_descr lpc32xx_nand_bbt_mirror = {
181 	.options = NAND_BBT_ABSPAGE | NAND_BBT_2BIT | NAND_BBT_NO_OOB |
182 		   NAND_BBT_WRITE,
183 	.pages = { 524160, 0, 0, 0, 0, 0, 0, 0 },
184 };
185 
186 struct lpc32xx_nand_host {
187 	struct platform_device	*pdev;
188 	struct nand_chip	nand_chip;
189 	struct lpc32xx_mlc_platform_data *pdata;
190 	struct clk		*clk;
191 	void __iomem		*io_base;
192 	int			irq;
193 	struct lpc32xx_nand_cfg_mlc	*ncfg;
194 	struct completion       comp_nand;
195 	struct completion       comp_controller;
196 	uint32_t llptr;
197 	/*
198 	 * Physical addresses of ECC buffer, DMA data buffers, OOB data buffer
199 	 */
200 	dma_addr_t		oob_buf_phy;
201 	/*
202 	 * Virtual addresses of ECC buffer, DMA data buffers, OOB data buffer
203 	 */
204 	uint8_t			*oob_buf;
205 	/* Physical address of DMA base address */
206 	dma_addr_t		io_base_phy;
207 
208 	struct completion	comp_dma;
209 	struct dma_chan		*dma_chan;
210 	struct dma_slave_config	dma_slave_config;
211 	struct scatterlist	sgl;
212 	uint8_t			*dma_buf;
213 	uint8_t			*dummy_buf;
214 	int			mlcsubpages; /* number of 512bytes-subpages */
215 };
216 
217 /*
218  * Activate/Deactivate DMA Operation:
219  *
220  * Using the PL080 DMA Controller for transferring the 512 byte subpages
221  * instead of doing readl() / writel() in a loop slows it down significantly.
222  * Measurements via getnstimeofday() upon 512 byte subpage reads reveal:
223  *
224  * - readl() of 128 x 32 bits in a loop: ~20us
225  * - DMA read of 512 bytes (32 bit, 4...128 words bursts): ~60us
226  * - DMA read of 512 bytes (32 bit, no bursts): ~100us
227  *
228  * This applies to the transfer itself. In the DMA case: only the
229  * wait_for_completion() (DMA setup _not_ included).
230  *
231  * Note that the 512 bytes subpage transfer is done directly from/to a
232  * FIFO/buffer inside the NAND controller. Most of the time (~400-800us for a
233  * 2048 bytes page) is spent waiting for the NAND IRQ, anyway. (The NAND
234  * controller transferring data between its internal buffer to/from the NAND
235  * chip.)
236  *
237  * Therefore, using the PL080 DMA is disabled by default, for now.
238  *
239  */
240 static int use_dma;
241 
242 static void lpc32xx_nand_setup(struct lpc32xx_nand_host *host)
243 {
244 	uint32_t clkrate, tmp;
245 
246 	/* Reset MLC controller */
247 	writel(MLCCMD_RESET, MLC_CMD(host->io_base));
248 	udelay(1000);
249 
250 	/* Get base clock for MLC block */
251 	clkrate = clk_get_rate(host->clk);
252 	if (clkrate == 0)
253 		clkrate = 104000000;
254 
255 	/* Unlock MLC_ICR
256 	 * (among others, will be locked again automatically) */
257 	writew(MLCLOCKPR_MAGIC, MLC_LOCK_PR(host->io_base));
258 
259 	/* Configure MLC Controller: Large Block, 5 Byte Address */
260 	tmp = MLCICR_LARGEBLOCK | MLCICR_LONGADDR;
261 	writel(tmp, MLC_ICR(host->io_base));
262 
263 	/* Unlock MLC_TIME_REG
264 	 * (among others, will be locked again automatically) */
265 	writew(MLCLOCKPR_MAGIC, MLC_LOCK_PR(host->io_base));
266 
267 	/* Compute clock setup values, see LPC and NAND manual */
268 	tmp = 0;
269 	tmp |= MLCTIMEREG_TCEA_DELAY(clkrate / host->ncfg->tcea_delay + 1);
270 	tmp |= MLCTIMEREG_BUSY_DELAY(clkrate / host->ncfg->busy_delay + 1);
271 	tmp |= MLCTIMEREG_NAND_TA(clkrate / host->ncfg->nand_ta + 1);
272 	tmp |= MLCTIMEREG_RD_HIGH(clkrate / host->ncfg->rd_high + 1);
273 	tmp |= MLCTIMEREG_RD_LOW(clkrate / host->ncfg->rd_low);
274 	tmp |= MLCTIMEREG_WR_HIGH(clkrate / host->ncfg->wr_high + 1);
275 	tmp |= MLCTIMEREG_WR_LOW(clkrate / host->ncfg->wr_low);
276 	writel(tmp, MLC_TIME_REG(host->io_base));
277 
278 	/* Enable IRQ for CONTROLLER_READY and NAND_READY */
279 	writeb(MLCIRQ_CONTROLLER_READY | MLCIRQ_NAND_READY,
280 			MLC_IRQ_MR(host->io_base));
281 
282 	/* Normal nCE operation: nCE controlled by controller */
283 	writel(MLCCEH_NORMAL, MLC_CEH(host->io_base));
284 }
285 
286 /*
287  * Hardware specific access to control lines
288  */
289 static void lpc32xx_nand_cmd_ctrl(struct nand_chip *nand_chip, int cmd,
290 				  unsigned int ctrl)
291 {
292 	struct lpc32xx_nand_host *host = nand_get_controller_data(nand_chip);
293 
294 	if (cmd != NAND_CMD_NONE) {
295 		if (ctrl & NAND_CLE)
296 			writel(cmd, MLC_CMD(host->io_base));
297 		else
298 			writel(cmd, MLC_ADDR(host->io_base));
299 	}
300 }
301 
302 /*
303  * Read Device Ready (NAND device _and_ controller ready)
304  */
305 static int lpc32xx_nand_device_ready(struct nand_chip *nand_chip)
306 {
307 	struct lpc32xx_nand_host *host = nand_get_controller_data(nand_chip);
308 
309 	if ((readb(MLC_ISR(host->io_base)) &
310 	     (MLCISR_CONTROLLER_READY | MLCISR_NAND_READY)) ==
311 	    (MLCISR_CONTROLLER_READY | MLCISR_NAND_READY))
312 		return  1;
313 
314 	return 0;
315 }
316 
317 static irqreturn_t lpc3xxx_nand_irq(int irq, struct lpc32xx_nand_host *host)
318 {
319 	uint8_t sr;
320 
321 	/* Clear interrupt flag by reading status */
322 	sr = readb(MLC_IRQ_SR(host->io_base));
323 	if (sr & MLCIRQ_NAND_READY)
324 		complete(&host->comp_nand);
325 	if (sr & MLCIRQ_CONTROLLER_READY)
326 		complete(&host->comp_controller);
327 
328 	return IRQ_HANDLED;
329 }
330 
331 static int lpc32xx_waitfunc_nand(struct nand_chip *chip)
332 {
333 	struct mtd_info *mtd = nand_to_mtd(chip);
334 	struct lpc32xx_nand_host *host = nand_get_controller_data(chip);
335 
336 	if (readb(MLC_ISR(host->io_base)) & MLCISR_NAND_READY)
337 		goto exit;
338 
339 	wait_for_completion(&host->comp_nand);
340 
341 	while (!(readb(MLC_ISR(host->io_base)) & MLCISR_NAND_READY)) {
342 		/* Seems to be delayed sometimes by controller */
343 		dev_dbg(&mtd->dev, "Warning: NAND not ready.\n");
344 		cpu_relax();
345 	}
346 
347 exit:
348 	return NAND_STATUS_READY;
349 }
350 
351 static int lpc32xx_waitfunc_controller(struct nand_chip *chip)
352 {
353 	struct mtd_info *mtd = nand_to_mtd(chip);
354 	struct lpc32xx_nand_host *host = nand_get_controller_data(chip);
355 
356 	if (readb(MLC_ISR(host->io_base)) & MLCISR_CONTROLLER_READY)
357 		goto exit;
358 
359 	wait_for_completion(&host->comp_controller);
360 
361 	while (!(readb(MLC_ISR(host->io_base)) &
362 		 MLCISR_CONTROLLER_READY)) {
363 		dev_dbg(&mtd->dev, "Warning: Controller not ready.\n");
364 		cpu_relax();
365 	}
366 
367 exit:
368 	return NAND_STATUS_READY;
369 }
370 
371 static int lpc32xx_waitfunc(struct nand_chip *chip)
372 {
373 	lpc32xx_waitfunc_nand(chip);
374 	lpc32xx_waitfunc_controller(chip);
375 
376 	return NAND_STATUS_READY;
377 }
378 
379 /*
380  * Enable NAND write protect
381  */
382 static void lpc32xx_wp_enable(struct lpc32xx_nand_host *host)
383 {
384 	if (gpio_is_valid(host->ncfg->wp_gpio))
385 		gpio_set_value(host->ncfg->wp_gpio, 0);
386 }
387 
388 /*
389  * Disable NAND write protect
390  */
391 static void lpc32xx_wp_disable(struct lpc32xx_nand_host *host)
392 {
393 	if (gpio_is_valid(host->ncfg->wp_gpio))
394 		gpio_set_value(host->ncfg->wp_gpio, 1);
395 }
396 
397 static void lpc32xx_dma_complete_func(void *completion)
398 {
399 	complete(completion);
400 }
401 
402 static int lpc32xx_xmit_dma(struct mtd_info *mtd, void *mem, int len,
403 			    enum dma_transfer_direction dir)
404 {
405 	struct nand_chip *chip = mtd_to_nand(mtd);
406 	struct lpc32xx_nand_host *host = nand_get_controller_data(chip);
407 	struct dma_async_tx_descriptor *desc;
408 	int flags = DMA_CTRL_ACK | DMA_PREP_INTERRUPT;
409 	int res;
410 
411 	sg_init_one(&host->sgl, mem, len);
412 
413 	res = dma_map_sg(host->dma_chan->device->dev, &host->sgl, 1,
414 			 DMA_BIDIRECTIONAL);
415 	if (res != 1) {
416 		dev_err(mtd->dev.parent, "Failed to map sg list\n");
417 		return -ENXIO;
418 	}
419 	desc = dmaengine_prep_slave_sg(host->dma_chan, &host->sgl, 1, dir,
420 				       flags);
421 	if (!desc) {
422 		dev_err(mtd->dev.parent, "Failed to prepare slave sg\n");
423 		goto out1;
424 	}
425 
426 	init_completion(&host->comp_dma);
427 	desc->callback = lpc32xx_dma_complete_func;
428 	desc->callback_param = &host->comp_dma;
429 
430 	dmaengine_submit(desc);
431 	dma_async_issue_pending(host->dma_chan);
432 
433 	wait_for_completion_timeout(&host->comp_dma, msecs_to_jiffies(1000));
434 
435 	dma_unmap_sg(host->dma_chan->device->dev, &host->sgl, 1,
436 		     DMA_BIDIRECTIONAL);
437 	return 0;
438 out1:
439 	dma_unmap_sg(host->dma_chan->device->dev, &host->sgl, 1,
440 		     DMA_BIDIRECTIONAL);
441 	return -ENXIO;
442 }
443 
444 static int lpc32xx_read_page(struct nand_chip *chip, uint8_t *buf,
445 			     int oob_required, int page)
446 {
447 	struct mtd_info *mtd = nand_to_mtd(chip);
448 	struct lpc32xx_nand_host *host = nand_get_controller_data(chip);
449 	int i, j;
450 	uint8_t *oobbuf = chip->oob_poi;
451 	uint32_t mlc_isr;
452 	int res;
453 	uint8_t *dma_buf;
454 	bool dma_mapped;
455 
456 	if ((void *)buf <= high_memory) {
457 		dma_buf = buf;
458 		dma_mapped = true;
459 	} else {
460 		dma_buf = host->dma_buf;
461 		dma_mapped = false;
462 	}
463 
464 	/* Writing Command and Address */
465 	nand_read_page_op(chip, page, 0, NULL, 0);
466 
467 	/* For all sub-pages */
468 	for (i = 0; i < host->mlcsubpages; i++) {
469 		/* Start Auto Decode Command */
470 		writeb(0x00, MLC_ECC_AUTO_DEC_REG(host->io_base));
471 
472 		/* Wait for Controller Ready */
473 		lpc32xx_waitfunc_controller(chip);
474 
475 		/* Check ECC Error status */
476 		mlc_isr = readl(MLC_ISR(host->io_base));
477 		if (mlc_isr & MLCISR_DECODER_FAILURE) {
478 			mtd->ecc_stats.failed++;
479 			dev_warn(&mtd->dev, "%s: DECODER_FAILURE\n", __func__);
480 		} else if (mlc_isr & MLCISR_ERRORS_DETECTED) {
481 			mtd->ecc_stats.corrected += ((mlc_isr >> 4) & 0x3) + 1;
482 		}
483 
484 		/* Read 512 + 16 Bytes */
485 		if (use_dma) {
486 			res = lpc32xx_xmit_dma(mtd, dma_buf + i * 512, 512,
487 					       DMA_DEV_TO_MEM);
488 			if (res)
489 				return res;
490 		} else {
491 			for (j = 0; j < (512 >> 2); j++) {
492 				*((uint32_t *)(buf)) =
493 					readl(MLC_BUFF(host->io_base));
494 				buf += 4;
495 			}
496 		}
497 		for (j = 0; j < (16 >> 2); j++) {
498 			*((uint32_t *)(oobbuf)) =
499 				readl(MLC_BUFF(host->io_base));
500 			oobbuf += 4;
501 		}
502 	}
503 
504 	if (use_dma && !dma_mapped)
505 		memcpy(buf, dma_buf, mtd->writesize);
506 
507 	return 0;
508 }
509 
510 static int lpc32xx_write_page_lowlevel(struct nand_chip *chip,
511 				       const uint8_t *buf, int oob_required,
512 				       int page)
513 {
514 	struct mtd_info *mtd = nand_to_mtd(chip);
515 	struct lpc32xx_nand_host *host = nand_get_controller_data(chip);
516 	const uint8_t *oobbuf = chip->oob_poi;
517 	uint8_t *dma_buf = (uint8_t *)buf;
518 	int res;
519 	int i, j;
520 
521 	if (use_dma && (void *)buf >= high_memory) {
522 		dma_buf = host->dma_buf;
523 		memcpy(dma_buf, buf, mtd->writesize);
524 	}
525 
526 	nand_prog_page_begin_op(chip, page, 0, NULL, 0);
527 
528 	for (i = 0; i < host->mlcsubpages; i++) {
529 		/* Start Encode */
530 		writeb(0x00, MLC_ECC_ENC_REG(host->io_base));
531 
532 		/* Write 512 + 6 Bytes to Buffer */
533 		if (use_dma) {
534 			res = lpc32xx_xmit_dma(mtd, dma_buf + i * 512, 512,
535 					       DMA_MEM_TO_DEV);
536 			if (res)
537 				return res;
538 		} else {
539 			for (j = 0; j < (512 >> 2); j++) {
540 				writel(*((uint32_t *)(buf)),
541 				       MLC_BUFF(host->io_base));
542 				buf += 4;
543 			}
544 		}
545 		writel(*((uint32_t *)(oobbuf)), MLC_BUFF(host->io_base));
546 		oobbuf += 4;
547 		writew(*((uint16_t *)(oobbuf)), MLC_BUFF(host->io_base));
548 		oobbuf += 12;
549 
550 		/* Auto Encode w/ Bit 8 = 0 (see LPC MLC Controller manual) */
551 		writeb(0x00, MLC_ECC_AUTO_ENC_REG(host->io_base));
552 
553 		/* Wait for Controller Ready */
554 		lpc32xx_waitfunc_controller(chip);
555 	}
556 
557 	return nand_prog_page_end_op(chip);
558 }
559 
560 static int lpc32xx_read_oob(struct nand_chip *chip, int page)
561 {
562 	struct lpc32xx_nand_host *host = nand_get_controller_data(chip);
563 
564 	/* Read whole page - necessary with MLC controller! */
565 	lpc32xx_read_page(chip, host->dummy_buf, 1, page);
566 
567 	return 0;
568 }
569 
570 static int lpc32xx_write_oob(struct nand_chip *chip, int page)
571 {
572 	/* None, write_oob conflicts with the automatic LPC MLC ECC decoder! */
573 	return 0;
574 }
575 
576 /* Prepares MLC for transfers with H/W ECC enabled: always enabled anyway */
577 static void lpc32xx_ecc_enable(struct nand_chip *chip, int mode)
578 {
579 	/* Always enabled! */
580 }
581 
582 static int lpc32xx_dma_setup(struct lpc32xx_nand_host *host)
583 {
584 	struct mtd_info *mtd = nand_to_mtd(&host->nand_chip);
585 	dma_cap_mask_t mask;
586 
587 	if (!host->pdata || !host->pdata->dma_filter) {
588 		dev_err(mtd->dev.parent, "no DMA platform data\n");
589 		return -ENOENT;
590 	}
591 
592 	dma_cap_zero(mask);
593 	dma_cap_set(DMA_SLAVE, mask);
594 	host->dma_chan = dma_request_channel(mask, host->pdata->dma_filter,
595 					     "nand-mlc");
596 	if (!host->dma_chan) {
597 		dev_err(mtd->dev.parent, "Failed to request DMA channel\n");
598 		return -EBUSY;
599 	}
600 
601 	/*
602 	 * Set direction to a sensible value even if the dmaengine driver
603 	 * should ignore it. With the default (DMA_MEM_TO_MEM), the amba-pl08x
604 	 * driver criticizes it as "alien transfer direction".
605 	 */
606 	host->dma_slave_config.direction = DMA_DEV_TO_MEM;
607 	host->dma_slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
608 	host->dma_slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
609 	host->dma_slave_config.src_maxburst = 128;
610 	host->dma_slave_config.dst_maxburst = 128;
611 	/* DMA controller does flow control: */
612 	host->dma_slave_config.device_fc = false;
613 	host->dma_slave_config.src_addr = MLC_BUFF(host->io_base_phy);
614 	host->dma_slave_config.dst_addr = MLC_BUFF(host->io_base_phy);
615 	if (dmaengine_slave_config(host->dma_chan, &host->dma_slave_config)) {
616 		dev_err(mtd->dev.parent, "Failed to setup DMA slave\n");
617 		goto out1;
618 	}
619 
620 	return 0;
621 out1:
622 	dma_release_channel(host->dma_chan);
623 	return -ENXIO;
624 }
625 
626 static struct lpc32xx_nand_cfg_mlc *lpc32xx_parse_dt(struct device *dev)
627 {
628 	struct lpc32xx_nand_cfg_mlc *ncfg;
629 	struct device_node *np = dev->of_node;
630 
631 	ncfg = devm_kzalloc(dev, sizeof(*ncfg), GFP_KERNEL);
632 	if (!ncfg)
633 		return NULL;
634 
635 	of_property_read_u32(np, "nxp,tcea-delay", &ncfg->tcea_delay);
636 	of_property_read_u32(np, "nxp,busy-delay", &ncfg->busy_delay);
637 	of_property_read_u32(np, "nxp,nand-ta", &ncfg->nand_ta);
638 	of_property_read_u32(np, "nxp,rd-high", &ncfg->rd_high);
639 	of_property_read_u32(np, "nxp,rd-low", &ncfg->rd_low);
640 	of_property_read_u32(np, "nxp,wr-high", &ncfg->wr_high);
641 	of_property_read_u32(np, "nxp,wr-low", &ncfg->wr_low);
642 
643 	if (!ncfg->tcea_delay || !ncfg->busy_delay || !ncfg->nand_ta ||
644 	    !ncfg->rd_high || !ncfg->rd_low || !ncfg->wr_high ||
645 	    !ncfg->wr_low) {
646 		dev_err(dev, "chip parameters not specified correctly\n");
647 		return NULL;
648 	}
649 
650 	ncfg->wp_gpio = of_get_named_gpio(np, "gpios", 0);
651 
652 	return ncfg;
653 }
654 
655 static int lpc32xx_nand_attach_chip(struct nand_chip *chip)
656 {
657 	struct mtd_info *mtd = nand_to_mtd(chip);
658 	struct lpc32xx_nand_host *host = nand_get_controller_data(chip);
659 	struct device *dev = &host->pdev->dev;
660 
661 	host->dma_buf = devm_kzalloc(dev, mtd->writesize, GFP_KERNEL);
662 	if (!host->dma_buf)
663 		return -ENOMEM;
664 
665 	host->dummy_buf = devm_kzalloc(dev, mtd->writesize, GFP_KERNEL);
666 	if (!host->dummy_buf)
667 		return -ENOMEM;
668 
669 	chip->ecc.mode = NAND_ECC_HW;
670 	chip->ecc.size = 512;
671 	mtd_set_ooblayout(mtd, &lpc32xx_ooblayout_ops);
672 	host->mlcsubpages = mtd->writesize / 512;
673 
674 	return 0;
675 }
676 
677 static const struct nand_controller_ops lpc32xx_nand_controller_ops = {
678 	.attach_chip = lpc32xx_nand_attach_chip,
679 };
680 
681 /*
682  * Probe for NAND controller
683  */
684 static int lpc32xx_nand_probe(struct platform_device *pdev)
685 {
686 	struct lpc32xx_nand_host *host;
687 	struct mtd_info *mtd;
688 	struct nand_chip *nand_chip;
689 	struct resource *rc;
690 	int res;
691 
692 	/* Allocate memory for the device structure (and zero it) */
693 	host = devm_kzalloc(&pdev->dev, sizeof(*host), GFP_KERNEL);
694 	if (!host)
695 		return -ENOMEM;
696 
697 	host->pdev = pdev;
698 
699 	rc = platform_get_resource(pdev, IORESOURCE_MEM, 0);
700 	host->io_base = devm_ioremap_resource(&pdev->dev, rc);
701 	if (IS_ERR(host->io_base))
702 		return PTR_ERR(host->io_base);
703 
704 	host->io_base_phy = rc->start;
705 
706 	nand_chip = &host->nand_chip;
707 	mtd = nand_to_mtd(nand_chip);
708 	if (pdev->dev.of_node)
709 		host->ncfg = lpc32xx_parse_dt(&pdev->dev);
710 	if (!host->ncfg) {
711 		dev_err(&pdev->dev,
712 			"Missing or bad NAND config from device tree\n");
713 		return -ENOENT;
714 	}
715 	if (host->ncfg->wp_gpio == -EPROBE_DEFER)
716 		return -EPROBE_DEFER;
717 	if (gpio_is_valid(host->ncfg->wp_gpio) &&
718 			gpio_request(host->ncfg->wp_gpio, "NAND WP")) {
719 		dev_err(&pdev->dev, "GPIO not available\n");
720 		return -EBUSY;
721 	}
722 	lpc32xx_wp_disable(host);
723 
724 	host->pdata = dev_get_platdata(&pdev->dev);
725 
726 	/* link the private data structures */
727 	nand_set_controller_data(nand_chip, host);
728 	nand_set_flash_node(nand_chip, pdev->dev.of_node);
729 	mtd->dev.parent = &pdev->dev;
730 
731 	/* Get NAND clock */
732 	host->clk = clk_get(&pdev->dev, NULL);
733 	if (IS_ERR(host->clk)) {
734 		dev_err(&pdev->dev, "Clock initialization failure\n");
735 		res = -ENOENT;
736 		goto free_gpio;
737 	}
738 	res = clk_prepare_enable(host->clk);
739 	if (res)
740 		goto put_clk;
741 
742 	nand_chip->legacy.cmd_ctrl = lpc32xx_nand_cmd_ctrl;
743 	nand_chip->legacy.dev_ready = lpc32xx_nand_device_ready;
744 	nand_chip->legacy.chip_delay = 25; /* us */
745 	nand_chip->legacy.IO_ADDR_R = MLC_DATA(host->io_base);
746 	nand_chip->legacy.IO_ADDR_W = MLC_DATA(host->io_base);
747 
748 	/* Init NAND controller */
749 	lpc32xx_nand_setup(host);
750 
751 	platform_set_drvdata(pdev, host);
752 
753 	/* Initialize function pointers */
754 	nand_chip->ecc.hwctl = lpc32xx_ecc_enable;
755 	nand_chip->ecc.read_page_raw = lpc32xx_read_page;
756 	nand_chip->ecc.read_page = lpc32xx_read_page;
757 	nand_chip->ecc.write_page_raw = lpc32xx_write_page_lowlevel;
758 	nand_chip->ecc.write_page = lpc32xx_write_page_lowlevel;
759 	nand_chip->ecc.write_oob = lpc32xx_write_oob;
760 	nand_chip->ecc.read_oob = lpc32xx_read_oob;
761 	nand_chip->ecc.strength = 4;
762 	nand_chip->ecc.bytes = 10;
763 	nand_chip->legacy.waitfunc = lpc32xx_waitfunc;
764 
765 	nand_chip->options = NAND_NO_SUBPAGE_WRITE;
766 	nand_chip->bbt_options = NAND_BBT_USE_FLASH | NAND_BBT_NO_OOB;
767 	nand_chip->bbt_td = &lpc32xx_nand_bbt;
768 	nand_chip->bbt_md = &lpc32xx_nand_bbt_mirror;
769 
770 	if (use_dma) {
771 		res = lpc32xx_dma_setup(host);
772 		if (res) {
773 			res = -EIO;
774 			goto unprepare_clk;
775 		}
776 	}
777 
778 	/* initially clear interrupt status */
779 	readb(MLC_IRQ_SR(host->io_base));
780 
781 	init_completion(&host->comp_nand);
782 	init_completion(&host->comp_controller);
783 
784 	host->irq = platform_get_irq(pdev, 0);
785 	if (host->irq < 0) {
786 		dev_err(&pdev->dev, "failed to get platform irq\n");
787 		res = -EINVAL;
788 		goto release_dma_chan;
789 	}
790 
791 	if (request_irq(host->irq, (irq_handler_t)&lpc3xxx_nand_irq,
792 			IRQF_TRIGGER_HIGH, DRV_NAME, host)) {
793 		dev_err(&pdev->dev, "Error requesting NAND IRQ\n");
794 		res = -ENXIO;
795 		goto release_dma_chan;
796 	}
797 
798 	/*
799 	 * Scan to find existence of the device and get the type of NAND device:
800 	 * SMALL block or LARGE block.
801 	 */
802 	nand_chip->legacy.dummy_controller.ops = &lpc32xx_nand_controller_ops;
803 	res = nand_scan(nand_chip, 1);
804 	if (res)
805 		goto free_irq;
806 
807 	mtd->name = DRV_NAME;
808 
809 	res = mtd_device_register(mtd, host->ncfg->parts,
810 				  host->ncfg->num_parts);
811 	if (res)
812 		goto cleanup_nand;
813 
814 	return 0;
815 
816 cleanup_nand:
817 	nand_cleanup(nand_chip);
818 free_irq:
819 	free_irq(host->irq, host);
820 release_dma_chan:
821 	if (use_dma)
822 		dma_release_channel(host->dma_chan);
823 unprepare_clk:
824 	clk_disable_unprepare(host->clk);
825 put_clk:
826 	clk_put(host->clk);
827 free_gpio:
828 	lpc32xx_wp_enable(host);
829 	gpio_free(host->ncfg->wp_gpio);
830 
831 	return res;
832 }
833 
834 /*
835  * Remove NAND device
836  */
837 static int lpc32xx_nand_remove(struct platform_device *pdev)
838 {
839 	struct lpc32xx_nand_host *host = platform_get_drvdata(pdev);
840 
841 	nand_release(&host->nand_chip);
842 	free_irq(host->irq, host);
843 	if (use_dma)
844 		dma_release_channel(host->dma_chan);
845 
846 	clk_disable_unprepare(host->clk);
847 	clk_put(host->clk);
848 
849 	lpc32xx_wp_enable(host);
850 	gpio_free(host->ncfg->wp_gpio);
851 
852 	return 0;
853 }
854 
855 #ifdef CONFIG_PM
856 static int lpc32xx_nand_resume(struct platform_device *pdev)
857 {
858 	struct lpc32xx_nand_host *host = platform_get_drvdata(pdev);
859 	int ret;
860 
861 	/* Re-enable NAND clock */
862 	ret = clk_prepare_enable(host->clk);
863 	if (ret)
864 		return ret;
865 
866 	/* Fresh init of NAND controller */
867 	lpc32xx_nand_setup(host);
868 
869 	/* Disable write protect */
870 	lpc32xx_wp_disable(host);
871 
872 	return 0;
873 }
874 
875 static int lpc32xx_nand_suspend(struct platform_device *pdev, pm_message_t pm)
876 {
877 	struct lpc32xx_nand_host *host = platform_get_drvdata(pdev);
878 
879 	/* Enable write protect for safety */
880 	lpc32xx_wp_enable(host);
881 
882 	/* Disable clock */
883 	clk_disable_unprepare(host->clk);
884 	return 0;
885 }
886 
887 #else
888 #define lpc32xx_nand_resume NULL
889 #define lpc32xx_nand_suspend NULL
890 #endif
891 
892 static const struct of_device_id lpc32xx_nand_match[] = {
893 	{ .compatible = "nxp,lpc3220-mlc" },
894 	{ /* sentinel */ },
895 };
896 MODULE_DEVICE_TABLE(of, lpc32xx_nand_match);
897 
898 static struct platform_driver lpc32xx_nand_driver = {
899 	.probe		= lpc32xx_nand_probe,
900 	.remove		= lpc32xx_nand_remove,
901 	.resume		= lpc32xx_nand_resume,
902 	.suspend	= lpc32xx_nand_suspend,
903 	.driver		= {
904 		.name	= DRV_NAME,
905 		.of_match_table = lpc32xx_nand_match,
906 	},
907 };
908 
909 module_platform_driver(lpc32xx_nand_driver);
910 
911 MODULE_LICENSE("GPL");
912 MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
913 MODULE_DESCRIPTION("NAND driver for the NXP LPC32XX MLC controller");
914