xref: /openbmc/linux/drivers/mtd/nand/raw/nand_onfi.c (revision 8f8d5745bb520c76b81abef4a2cb3023d0313bfd)
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->ecc_strength_ds = ecc->ecc_bits;
98 	chip->ecc_step_ds = 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_onfi_params *p;
144 	struct onfi_params *onfi;
145 	int onfi_version = 0;
146 	char id[4];
147 	int i, ret, val;
148 
149 	/* Try ONFI for unknown chip or LP */
150 	ret = nand_readid_op(chip, 0x20, id, sizeof(id));
151 	if (ret || strncmp(id, "ONFI", 4))
152 		return 0;
153 
154 	/* ONFI chip: allocate a buffer to hold its parameter page */
155 	p = kzalloc((sizeof(*p) * 3), GFP_KERNEL);
156 	if (!p)
157 		return -ENOMEM;
158 
159 	ret = nand_read_param_page_op(chip, 0, NULL, 0);
160 	if (ret) {
161 		ret = 0;
162 		goto free_onfi_param_page;
163 	}
164 
165 	for (i = 0; i < 3; i++) {
166 		ret = nand_read_data_op(chip, &p[i], sizeof(*p), true);
167 		if (ret) {
168 			ret = 0;
169 			goto free_onfi_param_page;
170 		}
171 
172 		if (onfi_crc16(ONFI_CRC_BASE, (u8 *)&p[i], 254) ==
173 				le16_to_cpu(p->crc)) {
174 			if (i)
175 				memcpy(p, &p[i], sizeof(*p));
176 			break;
177 		}
178 	}
179 
180 	if (i == 3) {
181 		const void *srcbufs[3] = {p, p + 1, p + 2};
182 
183 		pr_warn("Could not find a valid ONFI parameter page, trying bit-wise majority to recover it\n");
184 		nand_bit_wise_majority(srcbufs, ARRAY_SIZE(srcbufs), p,
185 				       sizeof(*p));
186 
187 		if (onfi_crc16(ONFI_CRC_BASE, (u8 *)p, 254) !=
188 				le16_to_cpu(p->crc)) {
189 			pr_err("ONFI parameter recovery failed, aborting\n");
190 			goto free_onfi_param_page;
191 		}
192 	}
193 
194 	if (chip->manufacturer.desc && chip->manufacturer.desc->ops &&
195 	    chip->manufacturer.desc->ops->fixup_onfi_param_page)
196 		chip->manufacturer.desc->ops->fixup_onfi_param_page(chip, p);
197 
198 	/* Check version */
199 	val = le16_to_cpu(p->revision);
200 	if (val & ONFI_VERSION_2_3)
201 		onfi_version = 23;
202 	else if (val & ONFI_VERSION_2_2)
203 		onfi_version = 22;
204 	else if (val & ONFI_VERSION_2_1)
205 		onfi_version = 21;
206 	else if (val & ONFI_VERSION_2_0)
207 		onfi_version = 20;
208 	else if (val & ONFI_VERSION_1_0)
209 		onfi_version = 10;
210 
211 	if (!onfi_version) {
212 		pr_info("unsupported ONFI version: %d\n", val);
213 		goto free_onfi_param_page;
214 	}
215 
216 	sanitize_string(p->manufacturer, sizeof(p->manufacturer));
217 	sanitize_string(p->model, sizeof(p->model));
218 	chip->parameters.model = kstrdup(p->model, GFP_KERNEL);
219 	if (!chip->parameters.model) {
220 		ret = -ENOMEM;
221 		goto free_onfi_param_page;
222 	}
223 
224 	mtd->writesize = le32_to_cpu(p->byte_per_page);
225 
226 	/*
227 	 * pages_per_block and blocks_per_lun may not be a power-of-2 size
228 	 * (don't ask me who thought of this...). MTD assumes that these
229 	 * dimensions will be power-of-2, so just truncate the remaining area.
230 	 */
231 	mtd->erasesize = 1 << (fls(le32_to_cpu(p->pages_per_block)) - 1);
232 	mtd->erasesize *= mtd->writesize;
233 
234 	mtd->oobsize = le16_to_cpu(p->spare_bytes_per_page);
235 
236 	/* See erasesize comment */
237 	chip->chipsize = 1 << (fls(le32_to_cpu(p->blocks_per_lun)) - 1);
238 	chip->chipsize *= (uint64_t)mtd->erasesize * p->lun_count;
239 	chip->bits_per_cell = p->bits_per_cell;
240 
241 	chip->max_bb_per_die = le16_to_cpu(p->bb_per_lun);
242 	chip->blocks_per_die = le32_to_cpu(p->blocks_per_lun);
243 
244 	if (le16_to_cpu(p->features) & ONFI_FEATURE_16_BIT_BUS)
245 		chip->options |= NAND_BUSWIDTH_16;
246 
247 	if (p->ecc_bits != 0xff) {
248 		chip->ecc_strength_ds = p->ecc_bits;
249 		chip->ecc_step_ds = 512;
250 	} else if (onfi_version >= 21 &&
251 		(le16_to_cpu(p->features) & ONFI_FEATURE_EXT_PARAM_PAGE)) {
252 
253 		/*
254 		 * The nand_flash_detect_ext_param_page() uses the
255 		 * Change Read Column command which maybe not supported
256 		 * by the chip->legacy.cmdfunc. So try to update the
257 		 * chip->legacy.cmdfunc now. We do not replace user supplied
258 		 * command function.
259 		 */
260 		nand_legacy_adjust_cmdfunc(chip);
261 
262 		/* The Extended Parameter Page is supported since ONFI 2.1. */
263 		if (nand_flash_detect_ext_param_page(chip, p))
264 			pr_warn("Failed to detect ONFI extended param page\n");
265 	} else {
266 		pr_warn("Could not retrieve ONFI ECC requirements\n");
267 	}
268 
269 	/* Save some parameters from the parameter page for future use */
270 	if (le16_to_cpu(p->opt_cmd) & ONFI_OPT_CMD_SET_GET_FEATURES) {
271 		chip->parameters.supports_set_get_features = true;
272 		bitmap_set(chip->parameters.get_feature_list,
273 			   ONFI_FEATURE_ADDR_TIMING_MODE, 1);
274 		bitmap_set(chip->parameters.set_feature_list,
275 			   ONFI_FEATURE_ADDR_TIMING_MODE, 1);
276 	}
277 
278 	onfi = kzalloc(sizeof(*onfi), GFP_KERNEL);
279 	if (!onfi) {
280 		ret = -ENOMEM;
281 		goto free_model;
282 	}
283 
284 	onfi->version = onfi_version;
285 	onfi->tPROG = le16_to_cpu(p->t_prog);
286 	onfi->tBERS = le16_to_cpu(p->t_bers);
287 	onfi->tR = le16_to_cpu(p->t_r);
288 	onfi->tCCS = le16_to_cpu(p->t_ccs);
289 	onfi->async_timing_mode = le16_to_cpu(p->async_timing_mode);
290 	onfi->vendor_revision = le16_to_cpu(p->vendor_revision);
291 	memcpy(onfi->vendor, p->vendor, sizeof(p->vendor));
292 	chip->parameters.onfi = onfi;
293 
294 	/* Identification done, free the full ONFI parameter page and exit */
295 	kfree(p);
296 
297 	return 1;
298 
299 free_model:
300 	kfree(chip->parameters.model);
301 free_onfi_param_page:
302 	kfree(p);
303 
304 	return ret;
305 }
306