xref: /openbmc/linux/drivers/mtd/nand/raw/nand_onfi.c (revision 1a59d1b8)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  Copyright (C) 2000 Steven J. Hill (sjhill@realitydiluted.com)
4  *		  2002-2006 Thomas Gleixner (tglx@linutronix.de)
5  *
6  *  Credits:
7  *	David Woodhouse for adding multichip support
8  *
9  *	Aleph One Ltd. and Toby Churchill Ltd. for supporting the
10  *	rework for 2K page size chips
11  *
12  * This file contains all ONFI helpers.
13  */
14 
15 #include <linux/slab.h>
16 
17 #include "internals.h"
18 
19 u16 onfi_crc16(u16 crc, u8 const *p, size_t len)
20 {
21 	int i;
22 	while (len--) {
23 		crc ^= *p++ << 8;
24 		for (i = 0; i < 8; i++)
25 			crc = (crc << 1) ^ ((crc & 0x8000) ? 0x8005 : 0);
26 	}
27 
28 	return crc;
29 }
30 
31 /* Parse the Extended Parameter Page. */
32 static int nand_flash_detect_ext_param_page(struct nand_chip *chip,
33 					    struct nand_onfi_params *p)
34 {
35 	struct onfi_ext_param_page *ep;
36 	struct onfi_ext_section *s;
37 	struct onfi_ext_ecc_info *ecc;
38 	uint8_t *cursor;
39 	int ret;
40 	int len;
41 	int i;
42 
43 	len = le16_to_cpu(p->ext_param_page_length) * 16;
44 	ep = kmalloc(len, GFP_KERNEL);
45 	if (!ep)
46 		return -ENOMEM;
47 
48 	/* Send our own NAND_CMD_PARAM. */
49 	ret = nand_read_param_page_op(chip, 0, NULL, 0);
50 	if (ret)
51 		goto ext_out;
52 
53 	/* Use the Change Read Column command to skip the ONFI param pages. */
54 	ret = nand_change_read_column_op(chip,
55 					 sizeof(*p) * p->num_of_param_pages,
56 					 ep, len, true);
57 	if (ret)
58 		goto ext_out;
59 
60 	ret = -EINVAL;
61 	if ((onfi_crc16(ONFI_CRC_BASE, ((uint8_t *)ep) + 2, len - 2)
62 		!= le16_to_cpu(ep->crc))) {
63 		pr_debug("fail in the CRC.\n");
64 		goto ext_out;
65 	}
66 
67 	/*
68 	 * Check the signature.
69 	 * Do not strictly follow the ONFI spec, maybe changed in future.
70 	 */
71 	if (strncmp(ep->sig, "EPPS", 4)) {
72 		pr_debug("The signature is invalid.\n");
73 		goto ext_out;
74 	}
75 
76 	/* find the ECC section. */
77 	cursor = (uint8_t *)(ep + 1);
78 	for (i = 0; i < ONFI_EXT_SECTION_MAX; i++) {
79 		s = ep->sections + i;
80 		if (s->type == ONFI_SECTION_TYPE_2)
81 			break;
82 		cursor += s->length * 16;
83 	}
84 	if (i == ONFI_EXT_SECTION_MAX) {
85 		pr_debug("We can not find the ECC section.\n");
86 		goto ext_out;
87 	}
88 
89 	/* get the info we want. */
90 	ecc = (struct onfi_ext_ecc_info *)cursor;
91 
92 	if (!ecc->codeword_size) {
93 		pr_debug("Invalid codeword size\n");
94 		goto ext_out;
95 	}
96 
97 	chip->base.eccreq.strength = ecc->ecc_bits;
98 	chip->base.eccreq.step_size = 1 << ecc->codeword_size;
99 	ret = 0;
100 
101 ext_out:
102 	kfree(ep);
103 	return ret;
104 }
105 
106 /*
107  * Recover data with bit-wise majority
108  */
109 static void nand_bit_wise_majority(const void **srcbufs,
110 				   unsigned int nsrcbufs,
111 				   void *dstbuf,
112 				   unsigned int bufsize)
113 {
114 	int i, j, k;
115 
116 	for (i = 0; i < bufsize; i++) {
117 		u8 val = 0;
118 
119 		for (j = 0; j < 8; j++) {
120 			unsigned int cnt = 0;
121 
122 			for (k = 0; k < nsrcbufs; k++) {
123 				const u8 *srcbuf = srcbufs[k];
124 
125 				if (srcbuf[i] & BIT(j))
126 					cnt++;
127 			}
128 
129 			if (cnt > nsrcbufs / 2)
130 				val |= BIT(j);
131 		}
132 
133 		((u8 *)dstbuf)[i] = val;
134 	}
135 }
136 
137 /*
138  * Check if the NAND chip is ONFI compliant, returns 1 if it is, 0 otherwise.
139  */
140 int nand_onfi_detect(struct nand_chip *chip)
141 {
142 	struct mtd_info *mtd = nand_to_mtd(chip);
143 	struct nand_memory_organization *memorg;
144 	struct nand_onfi_params *p;
145 	struct onfi_params *onfi;
146 	int onfi_version = 0;
147 	char id[4];
148 	int i, ret, val;
149 
150 	memorg = nanddev_get_memorg(&chip->base);
151 
152 	/* Try ONFI for unknown chip or LP */
153 	ret = nand_readid_op(chip, 0x20, id, sizeof(id));
154 	if (ret || strncmp(id, "ONFI", 4))
155 		return 0;
156 
157 	/* ONFI chip: allocate a buffer to hold its parameter page */
158 	p = kzalloc((sizeof(*p) * 3), GFP_KERNEL);
159 	if (!p)
160 		return -ENOMEM;
161 
162 	ret = nand_read_param_page_op(chip, 0, NULL, 0);
163 	if (ret) {
164 		ret = 0;
165 		goto free_onfi_param_page;
166 	}
167 
168 	for (i = 0; i < 3; i++) {
169 		ret = nand_read_data_op(chip, &p[i], sizeof(*p), true);
170 		if (ret) {
171 			ret = 0;
172 			goto free_onfi_param_page;
173 		}
174 
175 		if (onfi_crc16(ONFI_CRC_BASE, (u8 *)&p[i], 254) ==
176 				le16_to_cpu(p->crc)) {
177 			if (i)
178 				memcpy(p, &p[i], sizeof(*p));
179 			break;
180 		}
181 	}
182 
183 	if (i == 3) {
184 		const void *srcbufs[3] = {p, p + 1, p + 2};
185 
186 		pr_warn("Could not find a valid ONFI parameter page, trying bit-wise majority to recover it\n");
187 		nand_bit_wise_majority(srcbufs, ARRAY_SIZE(srcbufs), p,
188 				       sizeof(*p));
189 
190 		if (onfi_crc16(ONFI_CRC_BASE, (u8 *)p, 254) !=
191 				le16_to_cpu(p->crc)) {
192 			pr_err("ONFI parameter recovery failed, aborting\n");
193 			goto free_onfi_param_page;
194 		}
195 	}
196 
197 	if (chip->manufacturer.desc && chip->manufacturer.desc->ops &&
198 	    chip->manufacturer.desc->ops->fixup_onfi_param_page)
199 		chip->manufacturer.desc->ops->fixup_onfi_param_page(chip, p);
200 
201 	/* Check version */
202 	val = le16_to_cpu(p->revision);
203 	if (val & ONFI_VERSION_2_3)
204 		onfi_version = 23;
205 	else if (val & ONFI_VERSION_2_2)
206 		onfi_version = 22;
207 	else if (val & ONFI_VERSION_2_1)
208 		onfi_version = 21;
209 	else if (val & ONFI_VERSION_2_0)
210 		onfi_version = 20;
211 	else if (val & ONFI_VERSION_1_0)
212 		onfi_version = 10;
213 
214 	if (!onfi_version) {
215 		pr_info("unsupported ONFI version: %d\n", val);
216 		goto free_onfi_param_page;
217 	}
218 
219 	sanitize_string(p->manufacturer, sizeof(p->manufacturer));
220 	sanitize_string(p->model, sizeof(p->model));
221 	chip->parameters.model = kstrdup(p->model, GFP_KERNEL);
222 	if (!chip->parameters.model) {
223 		ret = -ENOMEM;
224 		goto free_onfi_param_page;
225 	}
226 
227 	memorg->pagesize = le32_to_cpu(p->byte_per_page);
228 	mtd->writesize = memorg->pagesize;
229 
230 	/*
231 	 * pages_per_block and blocks_per_lun may not be a power-of-2 size
232 	 * (don't ask me who thought of this...). MTD assumes that these
233 	 * dimensions will be power-of-2, so just truncate the remaining area.
234 	 */
235 	memorg->pages_per_eraseblock =
236 			1 << (fls(le32_to_cpu(p->pages_per_block)) - 1);
237 	mtd->erasesize = memorg->pages_per_eraseblock * memorg->pagesize;
238 
239 	memorg->oobsize = le16_to_cpu(p->spare_bytes_per_page);
240 	mtd->oobsize = memorg->oobsize;
241 
242 	memorg->luns_per_target = p->lun_count;
243 	memorg->planes_per_lun = 1 << p->interleaved_bits;
244 
245 	/* See erasesize comment */
246 	memorg->eraseblocks_per_lun =
247 		1 << (fls(le32_to_cpu(p->blocks_per_lun)) - 1);
248 	memorg->max_bad_eraseblocks_per_lun = le32_to_cpu(p->blocks_per_lun);
249 	memorg->bits_per_cell = p->bits_per_cell;
250 
251 	if (le16_to_cpu(p->features) & ONFI_FEATURE_16_BIT_BUS)
252 		chip->options |= NAND_BUSWIDTH_16;
253 
254 	if (p->ecc_bits != 0xff) {
255 		chip->base.eccreq.strength = p->ecc_bits;
256 		chip->base.eccreq.step_size = 512;
257 	} else if (onfi_version >= 21 &&
258 		(le16_to_cpu(p->features) & ONFI_FEATURE_EXT_PARAM_PAGE)) {
259 
260 		/*
261 		 * The nand_flash_detect_ext_param_page() uses the
262 		 * Change Read Column command which maybe not supported
263 		 * by the chip->legacy.cmdfunc. So try to update the
264 		 * chip->legacy.cmdfunc now. We do not replace user supplied
265 		 * command function.
266 		 */
267 		nand_legacy_adjust_cmdfunc(chip);
268 
269 		/* The Extended Parameter Page is supported since ONFI 2.1. */
270 		if (nand_flash_detect_ext_param_page(chip, p))
271 			pr_warn("Failed to detect ONFI extended param page\n");
272 	} else {
273 		pr_warn("Could not retrieve ONFI ECC requirements\n");
274 	}
275 
276 	/* Save some parameters from the parameter page for future use */
277 	if (le16_to_cpu(p->opt_cmd) & ONFI_OPT_CMD_SET_GET_FEATURES) {
278 		chip->parameters.supports_set_get_features = true;
279 		bitmap_set(chip->parameters.get_feature_list,
280 			   ONFI_FEATURE_ADDR_TIMING_MODE, 1);
281 		bitmap_set(chip->parameters.set_feature_list,
282 			   ONFI_FEATURE_ADDR_TIMING_MODE, 1);
283 	}
284 
285 	onfi = kzalloc(sizeof(*onfi), GFP_KERNEL);
286 	if (!onfi) {
287 		ret = -ENOMEM;
288 		goto free_model;
289 	}
290 
291 	onfi->version = onfi_version;
292 	onfi->tPROG = le16_to_cpu(p->t_prog);
293 	onfi->tBERS = le16_to_cpu(p->t_bers);
294 	onfi->tR = le16_to_cpu(p->t_r);
295 	onfi->tCCS = le16_to_cpu(p->t_ccs);
296 	onfi->async_timing_mode = le16_to_cpu(p->async_timing_mode);
297 	onfi->vendor_revision = le16_to_cpu(p->vendor_revision);
298 	memcpy(onfi->vendor, p->vendor, sizeof(p->vendor));
299 	chip->parameters.onfi = onfi;
300 
301 	/* Identification done, free the full ONFI parameter page and exit */
302 	kfree(p);
303 
304 	return 1;
305 
306 free_model:
307 	kfree(chip->parameters.model);
308 free_onfi_param_page:
309 	kfree(p);
310 
311 	return ret;
312 }
313