1 // SPDX-License-Identifier: GPL-2.0+
2 /* Copyright (c) 2020 Intel Corporation. */
3 
4 #include <linux/clk.h>
5 #include <linux/completion.h>
6 #include <linux/dmaengine.h>
7 #include <linux/dma-direction.h>
8 #include <linux/dma-mapping.h>
9 #include <linux/err.h>
10 #include <linux/init.h>
11 #include <linux/iopoll.h>
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 
15 #include <linux/mtd/mtd.h>
16 #include <linux/mtd/rawnand.h>
17 #include <linux/mtd/nand.h>
18 
19 #include <linux/platform_device.h>
20 #include <linux/sched.h>
21 #include <linux/slab.h>
22 #include <linux/types.h>
23 #include <linux/units.h>
24 #include <asm/unaligned.h>
25 
26 #define EBU_CLC			0x000
27 #define EBU_CLC_RST		0x00000000u
28 
29 #define EBU_ADDR_SEL(n)		(0x020 + (n) * 4)
30 /* 5 bits 26:22 included for comparison in the ADDR_SELx */
31 #define EBU_ADDR_MASK(x)	((x) << 4)
32 #define EBU_ADDR_SEL_REGEN	0x1
33 
34 #define EBU_BUSCON(n)		(0x060 + (n) * 4)
35 #define EBU_BUSCON_CMULT_V4	0x1
36 #define EBU_BUSCON_RECOVC(n)	((n) << 2)
37 #define EBU_BUSCON_HOLDC(n)	((n) << 4)
38 #define EBU_BUSCON_WAITRDC(n)	((n) << 6)
39 #define EBU_BUSCON_WAITWRC(n)	((n) << 8)
40 #define EBU_BUSCON_BCGEN_CS	0x0
41 #define EBU_BUSCON_SETUP_EN	BIT(22)
42 #define EBU_BUSCON_ALEC		0xC000
43 
44 #define EBU_CON			0x0B0
45 #define EBU_CON_NANDM_EN	BIT(0)
46 #define EBU_CON_NANDM_DIS	0x0
47 #define EBU_CON_CSMUX_E_EN	BIT(1)
48 #define EBU_CON_ALE_P_LOW	BIT(2)
49 #define EBU_CON_CLE_P_LOW	BIT(3)
50 #define EBU_CON_CS_P_LOW	BIT(4)
51 #define EBU_CON_SE_P_LOW	BIT(5)
52 #define EBU_CON_WP_P_LOW	BIT(6)
53 #define EBU_CON_PRE_P_LOW	BIT(7)
54 #define EBU_CON_IN_CS_S(n)	((n) << 8)
55 #define EBU_CON_OUT_CS_S(n)	((n) << 10)
56 #define EBU_CON_LAT_EN_CS_P	((0x3D) << 18)
57 
58 #define EBU_WAIT		0x0B4
59 #define EBU_WAIT_RDBY		BIT(0)
60 #define EBU_WAIT_WR_C		BIT(3)
61 
62 #define HSNAND_CTL1		0x110
63 #define HSNAND_CTL1_ADDR_SHIFT	24
64 
65 #define HSNAND_CTL2		0x114
66 #define HSNAND_CTL2_ADDR_SHIFT	8
67 #define HSNAND_CTL2_CYC_N_V5	(0x2 << 16)
68 
69 #define HSNAND_INT_MSK_CTL	0x124
70 #define HSNAND_INT_MSK_CTL_WR_C	BIT(4)
71 
72 #define HSNAND_INT_STA		0x128
73 #define HSNAND_INT_STA_WR_C	BIT(4)
74 
75 #define HSNAND_CTL		0x130
76 #define HSNAND_CTL_ENABLE_ECC	BIT(0)
77 #define HSNAND_CTL_GO		BIT(2)
78 #define HSNAND_CTL_CE_SEL_CS(n)	BIT(3 + (n))
79 #define HSNAND_CTL_RW_READ	0x0
80 #define HSNAND_CTL_RW_WRITE	BIT(10)
81 #define HSNAND_CTL_ECC_OFF_V8TH	BIT(11)
82 #define HSNAND_CTL_CKFF_EN	0x0
83 #define HSNAND_CTL_MSG_EN	BIT(17)
84 
85 #define HSNAND_PARA0		0x13c
86 #define HSNAND_PARA0_PAGE_V8192	0x3
87 #define HSNAND_PARA0_PIB_V256	(0x3 << 4)
88 #define HSNAND_PARA0_BYP_EN_NP	0x0
89 #define HSNAND_PARA0_BYP_DEC_NP	0x0
90 #define HSNAND_PARA0_TYPE_ONFI	BIT(18)
91 #define HSNAND_PARA0_ADEP_EN	BIT(21)
92 
93 #define HSNAND_CMSG_0		0x150
94 #define HSNAND_CMSG_1		0x154
95 
96 #define HSNAND_ALE_OFFS		BIT(2)
97 #define HSNAND_CLE_OFFS		BIT(3)
98 #define HSNAND_CS_OFFS		BIT(4)
99 
100 #define HSNAND_ECC_OFFSET	0x008
101 
102 #define NAND_DATA_IFACE_CHECK_ONLY	-1
103 
104 #define MAX_CS	2
105 
106 #define USEC_PER_SEC	1000000L
107 
108 struct ebu_nand_cs {
109 	void __iomem *chipaddr;
110 	dma_addr_t nand_pa;
111 	u32 addr_sel;
112 };
113 
114 struct ebu_nand_controller {
115 	struct nand_controller controller;
116 	struct nand_chip chip;
117 	struct device *dev;
118 	void __iomem *ebu;
119 	void __iomem *hsnand;
120 	struct dma_chan *dma_tx;
121 	struct dma_chan *dma_rx;
122 	struct completion dma_access_complete;
123 	unsigned long clk_rate;
124 	struct clk *clk;
125 	u32 nd_para0;
126 	u8 cs_num;
127 	struct ebu_nand_cs cs[MAX_CS];
128 };
129 
130 static inline struct ebu_nand_controller *nand_to_ebu(struct nand_chip *chip)
131 {
132 	return container_of(chip, struct ebu_nand_controller, chip);
133 }
134 
135 static int ebu_nand_waitrdy(struct nand_chip *chip, int timeout_ms)
136 {
137 	struct ebu_nand_controller *ctrl = nand_to_ebu(chip);
138 	u32 status;
139 
140 	return readl_poll_timeout(ctrl->ebu + EBU_WAIT, status,
141 				  (status & EBU_WAIT_RDBY) ||
142 				  (status & EBU_WAIT_WR_C), 20, timeout_ms);
143 }
144 
145 static u8 ebu_nand_readb(struct nand_chip *chip)
146 {
147 	struct ebu_nand_controller *ebu_host = nand_get_controller_data(chip);
148 	u8 cs_num = ebu_host->cs_num;
149 	u8 val;
150 
151 	val = readb(ebu_host->cs[cs_num].chipaddr + HSNAND_CS_OFFS);
152 	ebu_nand_waitrdy(chip, 1000);
153 	return val;
154 }
155 
156 static void ebu_nand_writeb(struct nand_chip *chip, u32 offset, u8 value)
157 {
158 	struct ebu_nand_controller *ebu_host = nand_get_controller_data(chip);
159 	u8 cs_num = ebu_host->cs_num;
160 
161 	writeb(value, ebu_host->cs[cs_num].chipaddr + offset);
162 	ebu_nand_waitrdy(chip, 1000);
163 }
164 
165 static void ebu_read_buf(struct nand_chip *chip, u_char *buf, unsigned int len)
166 {
167 	int i;
168 
169 	for (i = 0; i < len; i++)
170 		buf[i] = ebu_nand_readb(chip);
171 }
172 
173 static void ebu_write_buf(struct nand_chip *chip, const u_char *buf, int len)
174 {
175 	int i;
176 
177 	for (i = 0; i < len; i++)
178 		ebu_nand_writeb(chip, HSNAND_CS_OFFS, buf[i]);
179 }
180 
181 static void ebu_nand_disable(struct nand_chip *chip)
182 {
183 	struct ebu_nand_controller *ebu_host = nand_get_controller_data(chip);
184 
185 	writel(0, ebu_host->ebu + EBU_CON);
186 }
187 
188 static void ebu_select_chip(struct nand_chip *chip)
189 {
190 	struct ebu_nand_controller *ebu_host = nand_get_controller_data(chip);
191 	void __iomem *nand_con = ebu_host->ebu + EBU_CON;
192 	u32 cs = ebu_host->cs_num;
193 
194 	writel(EBU_CON_NANDM_EN | EBU_CON_CSMUX_E_EN | EBU_CON_CS_P_LOW |
195 	       EBU_CON_SE_P_LOW | EBU_CON_WP_P_LOW | EBU_CON_PRE_P_LOW |
196 	       EBU_CON_IN_CS_S(cs) | EBU_CON_OUT_CS_S(cs) |
197 	       EBU_CON_LAT_EN_CS_P, nand_con);
198 }
199 
200 static int ebu_nand_set_timings(struct nand_chip *chip, int csline,
201 				const struct nand_interface_config *conf)
202 {
203 	struct ebu_nand_controller *ctrl = nand_to_ebu(chip);
204 	unsigned int rate = clk_get_rate(ctrl->clk) / HZ_PER_MHZ;
205 	unsigned int period = DIV_ROUND_UP(USEC_PER_SEC, rate);
206 	const struct nand_sdr_timings *timings;
207 	u32 trecov, thold, twrwait, trdwait;
208 	u32 reg = 0;
209 
210 	timings = nand_get_sdr_timings(conf);
211 	if (IS_ERR(timings))
212 		return PTR_ERR(timings);
213 
214 	if (csline == NAND_DATA_IFACE_CHECK_ONLY)
215 		return 0;
216 
217 	trecov = DIV_ROUND_UP(max(timings->tREA_max, timings->tREH_min),
218 			      period);
219 	reg |= EBU_BUSCON_RECOVC(trecov);
220 
221 	thold = DIV_ROUND_UP(max(timings->tDH_min, timings->tDS_min), period);
222 	reg |= EBU_BUSCON_HOLDC(thold);
223 
224 	trdwait = DIV_ROUND_UP(max(timings->tRC_min, timings->tREH_min),
225 			       period);
226 	reg |= EBU_BUSCON_WAITRDC(trdwait);
227 
228 	twrwait = DIV_ROUND_UP(max(timings->tWC_min, timings->tWH_min), period);
229 	reg |= EBU_BUSCON_WAITWRC(twrwait);
230 
231 	reg |= EBU_BUSCON_CMULT_V4 | EBU_BUSCON_BCGEN_CS | EBU_BUSCON_ALEC |
232 		EBU_BUSCON_SETUP_EN;
233 
234 	writel(reg, ctrl->ebu + EBU_BUSCON(ctrl->cs_num));
235 
236 	return 0;
237 }
238 
239 static int ebu_nand_ooblayout_ecc(struct mtd_info *mtd, int section,
240 				  struct mtd_oob_region *oobregion)
241 {
242 	struct nand_chip *chip = mtd_to_nand(mtd);
243 
244 	if (section)
245 		return -ERANGE;
246 
247 	oobregion->offset = HSNAND_ECC_OFFSET;
248 	oobregion->length = chip->ecc.total;
249 
250 	return 0;
251 }
252 
253 static int ebu_nand_ooblayout_free(struct mtd_info *mtd, int section,
254 				   struct mtd_oob_region *oobregion)
255 {
256 	struct nand_chip *chip = mtd_to_nand(mtd);
257 
258 	if (section)
259 		return -ERANGE;
260 
261 	oobregion->offset = chip->ecc.total + HSNAND_ECC_OFFSET;
262 	oobregion->length = mtd->oobsize - oobregion->offset;
263 
264 	return 0;
265 }
266 
267 static const struct mtd_ooblayout_ops ebu_nand_ooblayout_ops = {
268 	.ecc = ebu_nand_ooblayout_ecc,
269 	.free = ebu_nand_ooblayout_free,
270 };
271 
272 static void ebu_dma_rx_callback(void *cookie)
273 {
274 	struct ebu_nand_controller *ebu_host = cookie;
275 
276 	dmaengine_terminate_async(ebu_host->dma_rx);
277 
278 	complete(&ebu_host->dma_access_complete);
279 }
280 
281 static void ebu_dma_tx_callback(void *cookie)
282 {
283 	struct ebu_nand_controller *ebu_host = cookie;
284 
285 	dmaengine_terminate_async(ebu_host->dma_tx);
286 
287 	complete(&ebu_host->dma_access_complete);
288 }
289 
290 static int ebu_dma_start(struct ebu_nand_controller *ebu_host, u32 dir,
291 			 const u8 *buf, u32 len)
292 {
293 	struct dma_async_tx_descriptor *tx;
294 	struct completion *dma_completion;
295 	dma_async_tx_callback callback;
296 	struct dma_chan *chan;
297 	dma_cookie_t cookie;
298 	unsigned long flags = DMA_CTRL_ACK | DMA_PREP_INTERRUPT;
299 	dma_addr_t buf_dma;
300 	int ret;
301 	u32 timeout;
302 
303 	if (dir == DMA_DEV_TO_MEM) {
304 		chan = ebu_host->dma_rx;
305 		dma_completion = &ebu_host->dma_access_complete;
306 		callback = ebu_dma_rx_callback;
307 	} else {
308 		chan = ebu_host->dma_tx;
309 		dma_completion = &ebu_host->dma_access_complete;
310 		callback = ebu_dma_tx_callback;
311 	}
312 
313 	buf_dma = dma_map_single(chan->device->dev, (void *)buf, len, dir);
314 	if (dma_mapping_error(chan->device->dev, buf_dma)) {
315 		dev_err(ebu_host->dev, "Failed to map DMA buffer\n");
316 		ret = -EIO;
317 		goto err_unmap;
318 	}
319 
320 	tx = dmaengine_prep_slave_single(chan, buf_dma, len, dir, flags);
321 	if (!tx) {
322 		ret = -ENXIO;
323 		goto err_unmap;
324 	}
325 
326 	tx->callback = callback;
327 	tx->callback_param = ebu_host;
328 	cookie = tx->tx_submit(tx);
329 
330 	ret = dma_submit_error(cookie);
331 	if (ret) {
332 		dev_err(ebu_host->dev, "dma_submit_error %d\n", cookie);
333 		ret = -EIO;
334 		goto err_unmap;
335 	}
336 
337 	init_completion(dma_completion);
338 	dma_async_issue_pending(chan);
339 
340 	/* Wait DMA to finish the data transfer.*/
341 	timeout = wait_for_completion_timeout(dma_completion, msecs_to_jiffies(1000));
342 	if (!timeout) {
343 		dev_err(ebu_host->dev, "I/O Error in DMA RX (status %d)\n",
344 			dmaengine_tx_status(chan, cookie, NULL));
345 		dmaengine_terminate_sync(chan);
346 		ret = -ETIMEDOUT;
347 		goto err_unmap;
348 	}
349 
350 	return 0;
351 
352 err_unmap:
353 	dma_unmap_single(ebu_host->dev, buf_dma, len, dir);
354 
355 	return ret;
356 }
357 
358 static void ebu_nand_trigger(struct ebu_nand_controller *ebu_host,
359 			     int page, u32 cmd)
360 {
361 	unsigned int val;
362 
363 	val = cmd | (page & 0xFF) << HSNAND_CTL1_ADDR_SHIFT;
364 	writel(val, ebu_host->hsnand + HSNAND_CTL1);
365 	val = (page & 0xFFFF00) >> 8 | HSNAND_CTL2_CYC_N_V5;
366 	writel(val, ebu_host->hsnand + HSNAND_CTL2);
367 
368 	writel(ebu_host->nd_para0, ebu_host->hsnand + HSNAND_PARA0);
369 
370 	/* clear first, will update later */
371 	writel(0xFFFFFFFF, ebu_host->hsnand + HSNAND_CMSG_0);
372 	writel(0xFFFFFFFF, ebu_host->hsnand + HSNAND_CMSG_1);
373 
374 	writel(HSNAND_INT_MSK_CTL_WR_C,
375 	       ebu_host->hsnand + HSNAND_INT_MSK_CTL);
376 
377 	if (!cmd)
378 		val = HSNAND_CTL_RW_READ;
379 	else
380 		val = HSNAND_CTL_RW_WRITE;
381 
382 	writel(HSNAND_CTL_MSG_EN | HSNAND_CTL_CKFF_EN |
383 	       HSNAND_CTL_ECC_OFF_V8TH | HSNAND_CTL_CE_SEL_CS(ebu_host->cs_num) |
384 	       HSNAND_CTL_ENABLE_ECC | HSNAND_CTL_GO | val,
385 	       ebu_host->hsnand + HSNAND_CTL);
386 }
387 
388 static int ebu_nand_read_page_hwecc(struct nand_chip *chip, u8 *buf,
389 				    int oob_required, int page)
390 {
391 	struct mtd_info *mtd = nand_to_mtd(chip);
392 	struct ebu_nand_controller *ebu_host = nand_get_controller_data(chip);
393 	int ret, reg_data;
394 
395 	ebu_nand_trigger(ebu_host, page, NAND_CMD_READ0);
396 
397 	ret = ebu_dma_start(ebu_host, DMA_DEV_TO_MEM, buf, mtd->writesize);
398 	if (ret)
399 		return ret;
400 
401 	if (oob_required)
402 		chip->ecc.read_oob(chip, page);
403 
404 	reg_data = readl(ebu_host->hsnand + HSNAND_CTL);
405 	reg_data &= ~HSNAND_CTL_GO;
406 	writel(reg_data, ebu_host->hsnand + HSNAND_CTL);
407 
408 	return 0;
409 }
410 
411 static int ebu_nand_write_page_hwecc(struct nand_chip *chip, const u8 *buf,
412 				     int oob_required, int page)
413 {
414 	struct mtd_info *mtd = nand_to_mtd(chip);
415 	struct ebu_nand_controller *ebu_host = nand_get_controller_data(chip);
416 	void __iomem *int_sta = ebu_host->hsnand + HSNAND_INT_STA;
417 	int reg_data, ret, val;
418 	u32 reg;
419 
420 	ebu_nand_trigger(ebu_host, page, NAND_CMD_SEQIN);
421 
422 	ret = ebu_dma_start(ebu_host, DMA_MEM_TO_DEV, buf, mtd->writesize);
423 	if (ret)
424 		return ret;
425 
426 	if (oob_required) {
427 		reg = get_unaligned_le32(chip->oob_poi);
428 		writel(reg, ebu_host->hsnand + HSNAND_CMSG_0);
429 
430 		reg = get_unaligned_le32(chip->oob_poi + 4);
431 		writel(reg, ebu_host->hsnand + HSNAND_CMSG_1);
432 	}
433 
434 	ret = readl_poll_timeout_atomic(int_sta, val, !(val & HSNAND_INT_STA_WR_C),
435 					10, 1000);
436 	if (ret)
437 		return ret;
438 
439 	reg_data = readl(ebu_host->hsnand + HSNAND_CTL);
440 	reg_data &= ~HSNAND_CTL_GO;
441 	writel(reg_data, ebu_host->hsnand + HSNAND_CTL);
442 
443 	return 0;
444 }
445 
446 static const u8 ecc_strength[] = { 1, 1, 4, 8, 24, 32, 40, 60, };
447 
448 static int ebu_nand_attach_chip(struct nand_chip *chip)
449 {
450 	struct mtd_info *mtd = nand_to_mtd(chip);
451 	struct ebu_nand_controller *ebu_host = nand_get_controller_data(chip);
452 	u32 ecc_steps, ecc_bytes, ecc_total, pagesize, pg_per_blk;
453 	u32 ecc_strength_ds = chip->ecc.strength;
454 	u32 ecc_size = chip->ecc.size;
455 	u32 writesize = mtd->writesize;
456 	u32 blocksize = mtd->erasesize;
457 	int bch_algo, start, val;
458 
459 	/* Default to an ECC size of 512 */
460 	if (!chip->ecc.size)
461 		chip->ecc.size = 512;
462 
463 	switch (ecc_size) {
464 	case 512:
465 		start = 1;
466 		if (!ecc_strength_ds)
467 			ecc_strength_ds = 4;
468 		break;
469 	case 1024:
470 		start = 4;
471 		if (!ecc_strength_ds)
472 			ecc_strength_ds = 32;
473 		break;
474 	default:
475 		return -EINVAL;
476 	}
477 
478 	/* BCH ECC algorithm Settings for number of bits per 512B/1024B */
479 	bch_algo = round_up(start + 1, 4);
480 	for (val = start; val < bch_algo; val++) {
481 		if (ecc_strength_ds == ecc_strength[val])
482 			break;
483 	}
484 	if (val == bch_algo)
485 		return -EINVAL;
486 
487 	if (ecc_strength_ds == 8)
488 		ecc_bytes = 14;
489 	else
490 		ecc_bytes = DIV_ROUND_UP(ecc_strength_ds * fls(8 * ecc_size), 8);
491 
492 	ecc_steps = writesize / ecc_size;
493 	ecc_total = ecc_steps * ecc_bytes;
494 	if ((ecc_total + 8) > mtd->oobsize)
495 		return -ERANGE;
496 
497 	chip->ecc.total = ecc_total;
498 	pagesize = fls(writesize >> 11);
499 	if (pagesize > HSNAND_PARA0_PAGE_V8192)
500 		return -ERANGE;
501 
502 	pg_per_blk = fls((blocksize / writesize) >> 6) / 8;
503 	if (pg_per_blk > HSNAND_PARA0_PIB_V256)
504 		return -ERANGE;
505 
506 	ebu_host->nd_para0 = pagesize | pg_per_blk | HSNAND_PARA0_BYP_EN_NP |
507 			     HSNAND_PARA0_BYP_DEC_NP | HSNAND_PARA0_ADEP_EN |
508 			     HSNAND_PARA0_TYPE_ONFI | (val << 29);
509 
510 	mtd_set_ooblayout(mtd, &ebu_nand_ooblayout_ops);
511 	chip->ecc.read_page = ebu_nand_read_page_hwecc;
512 	chip->ecc.write_page = ebu_nand_write_page_hwecc;
513 
514 	return 0;
515 }
516 
517 static int ebu_nand_exec_op(struct nand_chip *chip,
518 			    const struct nand_operation *op, bool check_only)
519 {
520 	const struct nand_op_instr *instr = NULL;
521 	unsigned int op_id;
522 	int i, timeout_ms, ret = 0;
523 
524 	if (check_only)
525 		return 0;
526 
527 	ebu_select_chip(chip);
528 	for (op_id = 0; op_id < op->ninstrs; op_id++) {
529 		instr = &op->instrs[op_id];
530 
531 		switch (instr->type) {
532 		case NAND_OP_CMD_INSTR:
533 			ebu_nand_writeb(chip, HSNAND_CLE_OFFS | HSNAND_CS_OFFS,
534 					instr->ctx.cmd.opcode);
535 			break;
536 
537 		case NAND_OP_ADDR_INSTR:
538 			for (i = 0; i < instr->ctx.addr.naddrs; i++)
539 				ebu_nand_writeb(chip,
540 						HSNAND_ALE_OFFS | HSNAND_CS_OFFS,
541 						instr->ctx.addr.addrs[i]);
542 			break;
543 
544 		case NAND_OP_DATA_IN_INSTR:
545 			ebu_read_buf(chip, instr->ctx.data.buf.in,
546 				     instr->ctx.data.len);
547 			break;
548 
549 		case NAND_OP_DATA_OUT_INSTR:
550 			ebu_write_buf(chip, instr->ctx.data.buf.out,
551 				      instr->ctx.data.len);
552 			break;
553 
554 		case NAND_OP_WAITRDY_INSTR:
555 			timeout_ms = instr->ctx.waitrdy.timeout_ms * 1000;
556 			ret = ebu_nand_waitrdy(chip, timeout_ms);
557 			break;
558 		}
559 	}
560 
561 	return ret;
562 }
563 
564 static const struct nand_controller_ops ebu_nand_controller_ops = {
565 	.attach_chip = ebu_nand_attach_chip,
566 	.setup_interface = ebu_nand_set_timings,
567 	.exec_op = ebu_nand_exec_op,
568 };
569 
570 static void ebu_dma_cleanup(struct ebu_nand_controller *ebu_host)
571 {
572 	if (ebu_host->dma_rx)
573 		dma_release_channel(ebu_host->dma_rx);
574 
575 	if (ebu_host->dma_tx)
576 		dma_release_channel(ebu_host->dma_tx);
577 }
578 
579 static int ebu_nand_probe(struct platform_device *pdev)
580 {
581 	struct device *dev = &pdev->dev;
582 	struct ebu_nand_controller *ebu_host;
583 	struct nand_chip *nand;
584 	struct mtd_info *mtd;
585 	struct resource *res;
586 	char *resname;
587 	int ret;
588 	u32 cs;
589 
590 	ebu_host = devm_kzalloc(dev, sizeof(*ebu_host), GFP_KERNEL);
591 	if (!ebu_host)
592 		return -ENOMEM;
593 
594 	ebu_host->dev = dev;
595 	nand_controller_init(&ebu_host->controller);
596 
597 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "ebunand");
598 	ebu_host->ebu = devm_ioremap_resource(&pdev->dev, res);
599 	if (IS_ERR(ebu_host->ebu))
600 		return PTR_ERR(ebu_host->ebu);
601 
602 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "hsnand");
603 	ebu_host->hsnand = devm_ioremap_resource(&pdev->dev, res);
604 	if (IS_ERR(ebu_host->hsnand))
605 		return PTR_ERR(ebu_host->hsnand);
606 
607 	ret = device_property_read_u32(dev, "reg", &cs);
608 	if (ret) {
609 		dev_err(dev, "failed to get chip select: %d\n", ret);
610 		return ret;
611 	}
612 	if (cs >= MAX_CS) {
613 		dev_err(dev, "got invalid chip select: %d\n", cs);
614 		return -EINVAL;
615 	}
616 
617 	ebu_host->cs_num = cs;
618 
619 	resname = devm_kasprintf(dev, GFP_KERNEL, "nand_cs%d", cs);
620 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, resname);
621 	ebu_host->cs[cs].chipaddr = devm_ioremap_resource(dev, res);
622 	ebu_host->cs[cs].nand_pa = res->start;
623 	if (IS_ERR(ebu_host->cs[cs].chipaddr))
624 		return PTR_ERR(ebu_host->cs[cs].chipaddr);
625 
626 	ebu_host->clk = devm_clk_get(dev, NULL);
627 	if (IS_ERR(ebu_host->clk))
628 		return dev_err_probe(dev, PTR_ERR(ebu_host->clk),
629 				     "failed to get clock\n");
630 
631 	ret = clk_prepare_enable(ebu_host->clk);
632 	if (ret) {
633 		dev_err(dev, "failed to enable clock: %d\n", ret);
634 		return ret;
635 	}
636 	ebu_host->clk_rate = clk_get_rate(ebu_host->clk);
637 
638 	ebu_host->dma_tx = dma_request_chan(dev, "tx");
639 	if (IS_ERR(ebu_host->dma_tx)) {
640 		ret = dev_err_probe(dev, PTR_ERR(ebu_host->dma_tx),
641 				    "failed to request DMA tx chan!.\n");
642 		goto err_disable_unprepare_clk;
643 	}
644 
645 	ebu_host->dma_rx = dma_request_chan(dev, "rx");
646 	if (IS_ERR(ebu_host->dma_rx)) {
647 		ret = dev_err_probe(dev, PTR_ERR(ebu_host->dma_rx),
648 				    "failed to request DMA rx chan!.\n");
649 		ebu_host->dma_rx = NULL;
650 		goto err_cleanup_dma;
651 	}
652 
653 	resname = devm_kasprintf(dev, GFP_KERNEL, "addr_sel%d", cs);
654 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, resname);
655 	if (!res) {
656 		ret = -EINVAL;
657 		goto err_cleanup_dma;
658 	}
659 	ebu_host->cs[cs].addr_sel = res->start;
660 	writel(ebu_host->cs[cs].addr_sel | EBU_ADDR_MASK(5) | EBU_ADDR_SEL_REGEN,
661 	       ebu_host->ebu + EBU_ADDR_SEL(cs));
662 
663 	nand_set_flash_node(&ebu_host->chip, dev->of_node);
664 
665 	mtd = nand_to_mtd(&ebu_host->chip);
666 	if (!mtd->name) {
667 		dev_err(ebu_host->dev, "NAND label property is mandatory\n");
668 		ret = -EINVAL;
669 		goto err_cleanup_dma;
670 	}
671 
672 	mtd->dev.parent = dev;
673 	ebu_host->dev = dev;
674 
675 	platform_set_drvdata(pdev, ebu_host);
676 	nand_set_controller_data(&ebu_host->chip, ebu_host);
677 
678 	nand = &ebu_host->chip;
679 	nand->controller = &ebu_host->controller;
680 	nand->controller->ops = &ebu_nand_controller_ops;
681 
682 	/* Scan to find existence of the device */
683 	ret = nand_scan(&ebu_host->chip, 1);
684 	if (ret)
685 		goto err_cleanup_dma;
686 
687 	ret = mtd_device_register(mtd, NULL, 0);
688 	if (ret)
689 		goto err_clean_nand;
690 
691 	return 0;
692 
693 err_clean_nand:
694 	nand_cleanup(&ebu_host->chip);
695 err_cleanup_dma:
696 	ebu_dma_cleanup(ebu_host);
697 err_disable_unprepare_clk:
698 	clk_disable_unprepare(ebu_host->clk);
699 
700 	return ret;
701 }
702 
703 static int ebu_nand_remove(struct platform_device *pdev)
704 {
705 	struct ebu_nand_controller *ebu_host = platform_get_drvdata(pdev);
706 	int ret;
707 
708 	ret = mtd_device_unregister(nand_to_mtd(&ebu_host->chip));
709 	WARN_ON(ret);
710 	nand_cleanup(&ebu_host->chip);
711 	ebu_nand_disable(&ebu_host->chip);
712 	ebu_dma_cleanup(ebu_host);
713 	clk_disable_unprepare(ebu_host->clk);
714 
715 	return 0;
716 }
717 
718 static const struct of_device_id ebu_nand_match[] = {
719 	{ .compatible = "intel,nand-controller" },
720 	{ .compatible = "intel,lgm-ebunand" },
721 	{}
722 };
723 MODULE_DEVICE_TABLE(of, ebu_nand_match);
724 
725 static struct platform_driver ebu_nand_driver = {
726 	.probe = ebu_nand_probe,
727 	.remove = ebu_nand_remove,
728 	.driver = {
729 		.name = "intel-nand-controller",
730 		.of_match_table = ebu_nand_match,
731 	},
732 
733 };
734 module_platform_driver(ebu_nand_driver);
735 
736 MODULE_LICENSE("GPL v2");
737 MODULE_AUTHOR("Vadivel Murugan R <vadivel.muruganx.ramuthevar@intel.com>");
738 MODULE_DESCRIPTION("Intel's LGM External Bus NAND Controller driver");
739