xref: /openbmc/linux/drivers/mtd/nand/raw/lpc32xx_mlc.c (revision f79e4d5f)
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 nand_chip	nand_chip;
188 	struct lpc32xx_mlc_platform_data *pdata;
189 	struct clk		*clk;
190 	void __iomem		*io_base;
191 	int			irq;
192 	struct lpc32xx_nand_cfg_mlc	*ncfg;
193 	struct completion       comp_nand;
194 	struct completion       comp_controller;
195 	uint32_t llptr;
196 	/*
197 	 * Physical addresses of ECC buffer, DMA data buffers, OOB data buffer
198 	 */
199 	dma_addr_t		oob_buf_phy;
200 	/*
201 	 * Virtual addresses of ECC buffer, DMA data buffers, OOB data buffer
202 	 */
203 	uint8_t			*oob_buf;
204 	/* Physical address of DMA base address */
205 	dma_addr_t		io_base_phy;
206 
207 	struct completion	comp_dma;
208 	struct dma_chan		*dma_chan;
209 	struct dma_slave_config	dma_slave_config;
210 	struct scatterlist	sgl;
211 	uint8_t			*dma_buf;
212 	uint8_t			*dummy_buf;
213 	int			mlcsubpages; /* number of 512bytes-subpages */
214 };
215 
216 /*
217  * Activate/Deactivate DMA Operation:
218  *
219  * Using the PL080 DMA Controller for transferring the 512 byte subpages
220  * instead of doing readl() / writel() in a loop slows it down significantly.
221  * Measurements via getnstimeofday() upon 512 byte subpage reads reveal:
222  *
223  * - readl() of 128 x 32 bits in a loop: ~20us
224  * - DMA read of 512 bytes (32 bit, 4...128 words bursts): ~60us
225  * - DMA read of 512 bytes (32 bit, no bursts): ~100us
226  *
227  * This applies to the transfer itself. In the DMA case: only the
228  * wait_for_completion() (DMA setup _not_ included).
229  *
230  * Note that the 512 bytes subpage transfer is done directly from/to a
231  * FIFO/buffer inside the NAND controller. Most of the time (~400-800us for a
232  * 2048 bytes page) is spent waiting for the NAND IRQ, anyway. (The NAND
233  * controller transferring data between its internal buffer to/from the NAND
234  * chip.)
235  *
236  * Therefore, using the PL080 DMA is disabled by default, for now.
237  *
238  */
239 static int use_dma;
240 
241 static void lpc32xx_nand_setup(struct lpc32xx_nand_host *host)
242 {
243 	uint32_t clkrate, tmp;
244 
245 	/* Reset MLC controller */
246 	writel(MLCCMD_RESET, MLC_CMD(host->io_base));
247 	udelay(1000);
248 
249 	/* Get base clock for MLC block */
250 	clkrate = clk_get_rate(host->clk);
251 	if (clkrate == 0)
252 		clkrate = 104000000;
253 
254 	/* Unlock MLC_ICR
255 	 * (among others, will be locked again automatically) */
256 	writew(MLCLOCKPR_MAGIC, MLC_LOCK_PR(host->io_base));
257 
258 	/* Configure MLC Controller: Large Block, 5 Byte Address */
259 	tmp = MLCICR_LARGEBLOCK | MLCICR_LONGADDR;
260 	writel(tmp, MLC_ICR(host->io_base));
261 
262 	/* Unlock MLC_TIME_REG
263 	 * (among others, will be locked again automatically) */
264 	writew(MLCLOCKPR_MAGIC, MLC_LOCK_PR(host->io_base));
265 
266 	/* Compute clock setup values, see LPC and NAND manual */
267 	tmp = 0;
268 	tmp |= MLCTIMEREG_TCEA_DELAY(clkrate / host->ncfg->tcea_delay + 1);
269 	tmp |= MLCTIMEREG_BUSY_DELAY(clkrate / host->ncfg->busy_delay + 1);
270 	tmp |= MLCTIMEREG_NAND_TA(clkrate / host->ncfg->nand_ta + 1);
271 	tmp |= MLCTIMEREG_RD_HIGH(clkrate / host->ncfg->rd_high + 1);
272 	tmp |= MLCTIMEREG_RD_LOW(clkrate / host->ncfg->rd_low);
273 	tmp |= MLCTIMEREG_WR_HIGH(clkrate / host->ncfg->wr_high + 1);
274 	tmp |= MLCTIMEREG_WR_LOW(clkrate / host->ncfg->wr_low);
275 	writel(tmp, MLC_TIME_REG(host->io_base));
276 
277 	/* Enable IRQ for CONTROLLER_READY and NAND_READY */
278 	writeb(MLCIRQ_CONTROLLER_READY | MLCIRQ_NAND_READY,
279 			MLC_IRQ_MR(host->io_base));
280 
281 	/* Normal nCE operation: nCE controlled by controller */
282 	writel(MLCCEH_NORMAL, MLC_CEH(host->io_base));
283 }
284 
285 /*
286  * Hardware specific access to control lines
287  */
288 static void lpc32xx_nand_cmd_ctrl(struct mtd_info *mtd, int cmd,
289 				  unsigned int ctrl)
290 {
291 	struct nand_chip *nand_chip = mtd_to_nand(mtd);
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 mtd_info *mtd)
306 {
307 	struct nand_chip *nand_chip = mtd_to_nand(mtd);
308 	struct lpc32xx_nand_host *host = nand_get_controller_data(nand_chip);
309 
310 	if ((readb(MLC_ISR(host->io_base)) &
311 	     (MLCISR_CONTROLLER_READY | MLCISR_NAND_READY)) ==
312 	    (MLCISR_CONTROLLER_READY | MLCISR_NAND_READY))
313 		return  1;
314 
315 	return 0;
316 }
317 
318 static irqreturn_t lpc3xxx_nand_irq(int irq, struct lpc32xx_nand_host *host)
319 {
320 	uint8_t sr;
321 
322 	/* Clear interrupt flag by reading status */
323 	sr = readb(MLC_IRQ_SR(host->io_base));
324 	if (sr & MLCIRQ_NAND_READY)
325 		complete(&host->comp_nand);
326 	if (sr & MLCIRQ_CONTROLLER_READY)
327 		complete(&host->comp_controller);
328 
329 	return IRQ_HANDLED;
330 }
331 
332 static int lpc32xx_waitfunc_nand(struct mtd_info *mtd, struct nand_chip *chip)
333 {
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 mtd_info *mtd,
352 				       struct nand_chip *chip)
353 {
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 mtd_info *mtd, struct nand_chip *chip)
372 {
373 	lpc32xx_waitfunc_nand(mtd, chip);
374 	lpc32xx_waitfunc_controller(mtd, 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 mtd_info *mtd, struct nand_chip *chip,
445 			     uint8_t *buf, int oob_required, int page)
446 {
447 	struct lpc32xx_nand_host *host = nand_get_controller_data(chip);
448 	int i, j;
449 	uint8_t *oobbuf = chip->oob_poi;
450 	uint32_t mlc_isr;
451 	int res;
452 	uint8_t *dma_buf;
453 	bool dma_mapped;
454 
455 	if ((void *)buf <= high_memory) {
456 		dma_buf = buf;
457 		dma_mapped = true;
458 	} else {
459 		dma_buf = host->dma_buf;
460 		dma_mapped = false;
461 	}
462 
463 	/* Writing Command and Address */
464 	nand_read_page_op(chip, page, 0, NULL, 0);
465 
466 	/* For all sub-pages */
467 	for (i = 0; i < host->mlcsubpages; i++) {
468 		/* Start Auto Decode Command */
469 		writeb(0x00, MLC_ECC_AUTO_DEC_REG(host->io_base));
470 
471 		/* Wait for Controller Ready */
472 		lpc32xx_waitfunc_controller(mtd, chip);
473 
474 		/* Check ECC Error status */
475 		mlc_isr = readl(MLC_ISR(host->io_base));
476 		if (mlc_isr & MLCISR_DECODER_FAILURE) {
477 			mtd->ecc_stats.failed++;
478 			dev_warn(&mtd->dev, "%s: DECODER_FAILURE\n", __func__);
479 		} else if (mlc_isr & MLCISR_ERRORS_DETECTED) {
480 			mtd->ecc_stats.corrected += ((mlc_isr >> 4) & 0x3) + 1;
481 		}
482 
483 		/* Read 512 + 16 Bytes */
484 		if (use_dma) {
485 			res = lpc32xx_xmit_dma(mtd, dma_buf + i * 512, 512,
486 					       DMA_DEV_TO_MEM);
487 			if (res)
488 				return res;
489 		} else {
490 			for (j = 0; j < (512 >> 2); j++) {
491 				*((uint32_t *)(buf)) =
492 					readl(MLC_BUFF(host->io_base));
493 				buf += 4;
494 			}
495 		}
496 		for (j = 0; j < (16 >> 2); j++) {
497 			*((uint32_t *)(oobbuf)) =
498 				readl(MLC_BUFF(host->io_base));
499 			oobbuf += 4;
500 		}
501 	}
502 
503 	if (use_dma && !dma_mapped)
504 		memcpy(buf, dma_buf, mtd->writesize);
505 
506 	return 0;
507 }
508 
509 static int lpc32xx_write_page_lowlevel(struct mtd_info *mtd,
510 				       struct nand_chip *chip,
511 				       const uint8_t *buf, int oob_required,
512 				       int page)
513 {
514 	struct lpc32xx_nand_host *host = nand_get_controller_data(chip);
515 	const uint8_t *oobbuf = chip->oob_poi;
516 	uint8_t *dma_buf = (uint8_t *)buf;
517 	int res;
518 	int i, j;
519 
520 	if (use_dma && (void *)buf >= high_memory) {
521 		dma_buf = host->dma_buf;
522 		memcpy(dma_buf, buf, mtd->writesize);
523 	}
524 
525 	nand_prog_page_begin_op(chip, page, 0, NULL, 0);
526 
527 	for (i = 0; i < host->mlcsubpages; i++) {
528 		/* Start Encode */
529 		writeb(0x00, MLC_ECC_ENC_REG(host->io_base));
530 
531 		/* Write 512 + 6 Bytes to Buffer */
532 		if (use_dma) {
533 			res = lpc32xx_xmit_dma(mtd, dma_buf + i * 512, 512,
534 					       DMA_MEM_TO_DEV);
535 			if (res)
536 				return res;
537 		} else {
538 			for (j = 0; j < (512 >> 2); j++) {
539 				writel(*((uint32_t *)(buf)),
540 				       MLC_BUFF(host->io_base));
541 				buf += 4;
542 			}
543 		}
544 		writel(*((uint32_t *)(oobbuf)), MLC_BUFF(host->io_base));
545 		oobbuf += 4;
546 		writew(*((uint16_t *)(oobbuf)), MLC_BUFF(host->io_base));
547 		oobbuf += 12;
548 
549 		/* Auto Encode w/ Bit 8 = 0 (see LPC MLC Controller manual) */
550 		writeb(0x00, MLC_ECC_AUTO_ENC_REG(host->io_base));
551 
552 		/* Wait for Controller Ready */
553 		lpc32xx_waitfunc_controller(mtd, chip);
554 	}
555 
556 	return nand_prog_page_end_op(chip);
557 }
558 
559 static int lpc32xx_read_oob(struct mtd_info *mtd, struct nand_chip *chip,
560 			    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(mtd, chip, host->dummy_buf, 1, page);
566 
567 	return 0;
568 }
569 
570 static int lpc32xx_write_oob(struct mtd_info *mtd, struct nand_chip *chip,
571 			      int page)
572 {
573 	/* None, write_oob conflicts with the automatic LPC MLC ECC decoder! */
574 	return 0;
575 }
576 
577 /* Prepares MLC for transfers with H/W ECC enabled: always enabled anyway */
578 static void lpc32xx_ecc_enable(struct mtd_info *mtd, int mode)
579 {
580 	/* Always enabled! */
581 }
582 
583 static int lpc32xx_dma_setup(struct lpc32xx_nand_host *host)
584 {
585 	struct mtd_info *mtd = nand_to_mtd(&host->nand_chip);
586 	dma_cap_mask_t mask;
587 
588 	if (!host->pdata || !host->pdata->dma_filter) {
589 		dev_err(mtd->dev.parent, "no DMA platform data\n");
590 		return -ENOENT;
591 	}
592 
593 	dma_cap_zero(mask);
594 	dma_cap_set(DMA_SLAVE, mask);
595 	host->dma_chan = dma_request_channel(mask, host->pdata->dma_filter,
596 					     "nand-mlc");
597 	if (!host->dma_chan) {
598 		dev_err(mtd->dev.parent, "Failed to request DMA channel\n");
599 		return -EBUSY;
600 	}
601 
602 	/*
603 	 * Set direction to a sensible value even if the dmaengine driver
604 	 * should ignore it. With the default (DMA_MEM_TO_MEM), the amba-pl08x
605 	 * driver criticizes it as "alien transfer direction".
606 	 */
607 	host->dma_slave_config.direction = DMA_DEV_TO_MEM;
608 	host->dma_slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
609 	host->dma_slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
610 	host->dma_slave_config.src_maxburst = 128;
611 	host->dma_slave_config.dst_maxburst = 128;
612 	/* DMA controller does flow control: */
613 	host->dma_slave_config.device_fc = false;
614 	host->dma_slave_config.src_addr = MLC_BUFF(host->io_base_phy);
615 	host->dma_slave_config.dst_addr = MLC_BUFF(host->io_base_phy);
616 	if (dmaengine_slave_config(host->dma_chan, &host->dma_slave_config)) {
617 		dev_err(mtd->dev.parent, "Failed to setup DMA slave\n");
618 		goto out1;
619 	}
620 
621 	return 0;
622 out1:
623 	dma_release_channel(host->dma_chan);
624 	return -ENXIO;
625 }
626 
627 static struct lpc32xx_nand_cfg_mlc *lpc32xx_parse_dt(struct device *dev)
628 {
629 	struct lpc32xx_nand_cfg_mlc *ncfg;
630 	struct device_node *np = dev->of_node;
631 
632 	ncfg = devm_kzalloc(dev, sizeof(*ncfg), GFP_KERNEL);
633 	if (!ncfg)
634 		return NULL;
635 
636 	of_property_read_u32(np, "nxp,tcea-delay", &ncfg->tcea_delay);
637 	of_property_read_u32(np, "nxp,busy-delay", &ncfg->busy_delay);
638 	of_property_read_u32(np, "nxp,nand-ta", &ncfg->nand_ta);
639 	of_property_read_u32(np, "nxp,rd-high", &ncfg->rd_high);
640 	of_property_read_u32(np, "nxp,rd-low", &ncfg->rd_low);
641 	of_property_read_u32(np, "nxp,wr-high", &ncfg->wr_high);
642 	of_property_read_u32(np, "nxp,wr-low", &ncfg->wr_low);
643 
644 	if (!ncfg->tcea_delay || !ncfg->busy_delay || !ncfg->nand_ta ||
645 	    !ncfg->rd_high || !ncfg->rd_low || !ncfg->wr_high ||
646 	    !ncfg->wr_low) {
647 		dev_err(dev, "chip parameters not specified correctly\n");
648 		return NULL;
649 	}
650 
651 	ncfg->wp_gpio = of_get_named_gpio(np, "gpios", 0);
652 
653 	return ncfg;
654 }
655 
656 /*
657  * Probe for NAND controller
658  */
659 static int lpc32xx_nand_probe(struct platform_device *pdev)
660 {
661 	struct lpc32xx_nand_host *host;
662 	struct mtd_info *mtd;
663 	struct nand_chip *nand_chip;
664 	struct resource *rc;
665 	int res;
666 
667 	/* Allocate memory for the device structure (and zero it) */
668 	host = devm_kzalloc(&pdev->dev, sizeof(*host), GFP_KERNEL);
669 	if (!host)
670 		return -ENOMEM;
671 
672 	rc = platform_get_resource(pdev, IORESOURCE_MEM, 0);
673 	host->io_base = devm_ioremap_resource(&pdev->dev, rc);
674 	if (IS_ERR(host->io_base))
675 		return PTR_ERR(host->io_base);
676 
677 	host->io_base_phy = rc->start;
678 
679 	nand_chip = &host->nand_chip;
680 	mtd = nand_to_mtd(nand_chip);
681 	if (pdev->dev.of_node)
682 		host->ncfg = lpc32xx_parse_dt(&pdev->dev);
683 	if (!host->ncfg) {
684 		dev_err(&pdev->dev,
685 			"Missing or bad NAND config from device tree\n");
686 		return -ENOENT;
687 	}
688 	if (host->ncfg->wp_gpio == -EPROBE_DEFER)
689 		return -EPROBE_DEFER;
690 	if (gpio_is_valid(host->ncfg->wp_gpio) &&
691 			gpio_request(host->ncfg->wp_gpio, "NAND WP")) {
692 		dev_err(&pdev->dev, "GPIO not available\n");
693 		return -EBUSY;
694 	}
695 	lpc32xx_wp_disable(host);
696 
697 	host->pdata = dev_get_platdata(&pdev->dev);
698 
699 	/* link the private data structures */
700 	nand_set_controller_data(nand_chip, host);
701 	nand_set_flash_node(nand_chip, pdev->dev.of_node);
702 	mtd->dev.parent = &pdev->dev;
703 
704 	/* Get NAND clock */
705 	host->clk = clk_get(&pdev->dev, NULL);
706 	if (IS_ERR(host->clk)) {
707 		dev_err(&pdev->dev, "Clock initialization failure\n");
708 		res = -ENOENT;
709 		goto free_gpio;
710 	}
711 	res = clk_prepare_enable(host->clk);
712 	if (res)
713 		goto put_clk;
714 
715 	nand_chip->cmd_ctrl = lpc32xx_nand_cmd_ctrl;
716 	nand_chip->dev_ready = lpc32xx_nand_device_ready;
717 	nand_chip->chip_delay = 25; /* us */
718 	nand_chip->IO_ADDR_R = MLC_DATA(host->io_base);
719 	nand_chip->IO_ADDR_W = MLC_DATA(host->io_base);
720 
721 	/* Init NAND controller */
722 	lpc32xx_nand_setup(host);
723 
724 	platform_set_drvdata(pdev, host);
725 
726 	/* Initialize function pointers */
727 	nand_chip->ecc.hwctl = lpc32xx_ecc_enable;
728 	nand_chip->ecc.read_page_raw = lpc32xx_read_page;
729 	nand_chip->ecc.read_page = lpc32xx_read_page;
730 	nand_chip->ecc.write_page_raw = lpc32xx_write_page_lowlevel;
731 	nand_chip->ecc.write_page = lpc32xx_write_page_lowlevel;
732 	nand_chip->ecc.write_oob = lpc32xx_write_oob;
733 	nand_chip->ecc.read_oob = lpc32xx_read_oob;
734 	nand_chip->ecc.strength = 4;
735 	nand_chip->ecc.bytes = 10;
736 	nand_chip->waitfunc = lpc32xx_waitfunc;
737 
738 	nand_chip->options = NAND_NO_SUBPAGE_WRITE;
739 	nand_chip->bbt_options = NAND_BBT_USE_FLASH | NAND_BBT_NO_OOB;
740 	nand_chip->bbt_td = &lpc32xx_nand_bbt;
741 	nand_chip->bbt_md = &lpc32xx_nand_bbt_mirror;
742 
743 	if (use_dma) {
744 		res = lpc32xx_dma_setup(host);
745 		if (res) {
746 			res = -EIO;
747 			goto unprepare_clk;
748 		}
749 	}
750 
751 	/*
752 	 * Scan to find existance of the device and
753 	 * Get the type of NAND device SMALL block or LARGE block
754 	 */
755 	res = nand_scan_ident(mtd, 1, NULL);
756 	if (res)
757 		goto release_dma_chan;
758 
759 	host->dma_buf = devm_kzalloc(&pdev->dev, mtd->writesize, GFP_KERNEL);
760 	if (!host->dma_buf) {
761 		res = -ENOMEM;
762 		goto release_dma_chan;
763 	}
764 
765 	host->dummy_buf = devm_kzalloc(&pdev->dev, mtd->writesize, GFP_KERNEL);
766 	if (!host->dummy_buf) {
767 		res = -ENOMEM;
768 		goto release_dma_chan;
769 	}
770 
771 	nand_chip->ecc.mode = NAND_ECC_HW;
772 	nand_chip->ecc.size = 512;
773 	mtd_set_ooblayout(mtd, &lpc32xx_ooblayout_ops);
774 	host->mlcsubpages = mtd->writesize / 512;
775 
776 	/* initially clear interrupt status */
777 	readb(MLC_IRQ_SR(host->io_base));
778 
779 	init_completion(&host->comp_nand);
780 	init_completion(&host->comp_controller);
781 
782 	host->irq = platform_get_irq(pdev, 0);
783 	if (host->irq < 0) {
784 		dev_err(&pdev->dev, "failed to get platform irq\n");
785 		res = -EINVAL;
786 		goto release_dma_chan;
787 	}
788 
789 	if (request_irq(host->irq, (irq_handler_t)&lpc3xxx_nand_irq,
790 			IRQF_TRIGGER_HIGH, DRV_NAME, host)) {
791 		dev_err(&pdev->dev, "Error requesting NAND IRQ\n");
792 		res = -ENXIO;
793 		goto release_dma_chan;
794 	}
795 
796 	/*
797 	 * Fills out all the uninitialized function pointers with the defaults
798 	 * And scans for a bad block table if appropriate.
799 	 */
800 	res = nand_scan_tail(mtd);
801 	if (res)
802 		goto free_irq;
803 
804 	mtd->name = DRV_NAME;
805 
806 	res = mtd_device_register(mtd, host->ncfg->parts,
807 				  host->ncfg->num_parts);
808 	if (res)
809 		goto cleanup_nand;
810 
811 	return 0;
812 
813 cleanup_nand:
814 	nand_cleanup(nand_chip);
815 free_irq:
816 	free_irq(host->irq, host);
817 release_dma_chan:
818 	if (use_dma)
819 		dma_release_channel(host->dma_chan);
820 unprepare_clk:
821 	clk_disable_unprepare(host->clk);
822 put_clk:
823 	clk_put(host->clk);
824 free_gpio:
825 	lpc32xx_wp_enable(host);
826 	gpio_free(host->ncfg->wp_gpio);
827 
828 	return res;
829 }
830 
831 /*
832  * Remove NAND device
833  */
834 static int lpc32xx_nand_remove(struct platform_device *pdev)
835 {
836 	struct lpc32xx_nand_host *host = platform_get_drvdata(pdev);
837 	struct mtd_info *mtd = nand_to_mtd(&host->nand_chip);
838 
839 	nand_release(mtd);
840 	free_irq(host->irq, host);
841 	if (use_dma)
842 		dma_release_channel(host->dma_chan);
843 
844 	clk_disable_unprepare(host->clk);
845 	clk_put(host->clk);
846 
847 	lpc32xx_wp_enable(host);
848 	gpio_free(host->ncfg->wp_gpio);
849 
850 	return 0;
851 }
852 
853 #ifdef CONFIG_PM
854 static int lpc32xx_nand_resume(struct platform_device *pdev)
855 {
856 	struct lpc32xx_nand_host *host = platform_get_drvdata(pdev);
857 	int ret;
858 
859 	/* Re-enable NAND clock */
860 	ret = clk_prepare_enable(host->clk);
861 	if (ret)
862 		return ret;
863 
864 	/* Fresh init of NAND controller */
865 	lpc32xx_nand_setup(host);
866 
867 	/* Disable write protect */
868 	lpc32xx_wp_disable(host);
869 
870 	return 0;
871 }
872 
873 static int lpc32xx_nand_suspend(struct platform_device *pdev, pm_message_t pm)
874 {
875 	struct lpc32xx_nand_host *host = platform_get_drvdata(pdev);
876 
877 	/* Enable write protect for safety */
878 	lpc32xx_wp_enable(host);
879 
880 	/* Disable clock */
881 	clk_disable_unprepare(host->clk);
882 	return 0;
883 }
884 
885 #else
886 #define lpc32xx_nand_resume NULL
887 #define lpc32xx_nand_suspend NULL
888 #endif
889 
890 static const struct of_device_id lpc32xx_nand_match[] = {
891 	{ .compatible = "nxp,lpc3220-mlc" },
892 	{ /* sentinel */ },
893 };
894 MODULE_DEVICE_TABLE(of, lpc32xx_nand_match);
895 
896 static struct platform_driver lpc32xx_nand_driver = {
897 	.probe		= lpc32xx_nand_probe,
898 	.remove		= lpc32xx_nand_remove,
899 	.resume		= lpc32xx_nand_resume,
900 	.suspend	= lpc32xx_nand_suspend,
901 	.driver		= {
902 		.name	= DRV_NAME,
903 		.of_match_table = lpc32xx_nand_match,
904 	},
905 };
906 
907 module_platform_driver(lpc32xx_nand_driver);
908 
909 MODULE_LICENSE("GPL");
910 MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
911 MODULE_DESCRIPTION("NAND driver for the NXP LPC32XX MLC controller");
912