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 #define ONFI_PARAM_PAGES 3
20 
onfi_crc16(u16 crc,u8 const * p,size_t len)21 u16 onfi_crc16(u16 crc, u8 const *p, size_t len)
22 {
23 	int i;
24 	while (len--) {
25 		crc ^= *p++ << 8;
26 		for (i = 0; i < 8; i++)
27 			crc = (crc << 1) ^ ((crc & 0x8000) ? 0x8005 : 0);
28 	}
29 
30 	return crc;
31 }
32 
33 /* Parse the Extended Parameter Page. */
nand_flash_detect_ext_param_page(struct nand_chip * chip,struct nand_onfi_params * p)34 static int nand_flash_detect_ext_param_page(struct nand_chip *chip,
35 					    struct nand_onfi_params *p)
36 {
37 	struct nand_device *base = &chip->base;
38 	struct nand_ecc_props requirements;
39 	struct onfi_ext_param_page *ep;
40 	struct onfi_ext_section *s;
41 	struct onfi_ext_ecc_info *ecc;
42 	uint8_t *cursor;
43 	int ret;
44 	int len;
45 	int i;
46 
47 	len = le16_to_cpu(p->ext_param_page_length) * 16;
48 	ep = kmalloc(len, GFP_KERNEL);
49 	if (!ep)
50 		return -ENOMEM;
51 
52 	/*
53 	 * Use the Change Read Column command to skip the ONFI param pages and
54 	 * ensure we read at the right location.
55 	 */
56 	ret = nand_change_read_column_op(chip,
57 					 sizeof(*p) * p->num_of_param_pages,
58 					 ep, len, true);
59 	if (ret)
60 		goto ext_out;
61 
62 	ret = -EINVAL;
63 	if ((onfi_crc16(ONFI_CRC_BASE, ((uint8_t *)ep) + 2, len - 2)
64 		!= le16_to_cpu(ep->crc))) {
65 		pr_debug("fail in the CRC.\n");
66 		goto ext_out;
67 	}
68 
69 	/*
70 	 * Check the signature.
71 	 * Do not strictly follow the ONFI spec, maybe changed in future.
72 	 */
73 	if (strncmp(ep->sig, "EPPS", 4)) {
74 		pr_debug("The signature is invalid.\n");
75 		goto ext_out;
76 	}
77 
78 	/* find the ECC section. */
79 	cursor = (uint8_t *)(ep + 1);
80 	for (i = 0; i < ONFI_EXT_SECTION_MAX; i++) {
81 		s = ep->sections + i;
82 		if (s->type == ONFI_SECTION_TYPE_2)
83 			break;
84 		cursor += s->length * 16;
85 	}
86 	if (i == ONFI_EXT_SECTION_MAX) {
87 		pr_debug("We can not find the ECC section.\n");
88 		goto ext_out;
89 	}
90 
91 	/* get the info we want. */
92 	ecc = (struct onfi_ext_ecc_info *)cursor;
93 
94 	if (!ecc->codeword_size) {
95 		pr_debug("Invalid codeword size\n");
96 		goto ext_out;
97 	}
98 
99 	requirements.strength = ecc->ecc_bits;
100 	requirements.step_size = 1 << ecc->codeword_size;
101 	nanddev_set_ecc_requirements(base, &requirements);
102 
103 	ret = 0;
104 
105 ext_out:
106 	kfree(ep);
107 	return ret;
108 }
109 
110 /*
111  * Recover data with bit-wise majority
112  */
nand_bit_wise_majority(const void ** srcbufs,unsigned int nsrcbufs,void * dstbuf,unsigned int bufsize)113 static void nand_bit_wise_majority(const void **srcbufs,
114 				   unsigned int nsrcbufs,
115 				   void *dstbuf,
116 				   unsigned int bufsize)
117 {
118 	int i, j, k;
119 
120 	for (i = 0; i < bufsize; i++) {
121 		u8 val = 0;
122 
123 		for (j = 0; j < 8; j++) {
124 			unsigned int cnt = 0;
125 
126 			for (k = 0; k < nsrcbufs; k++) {
127 				const u8 *srcbuf = srcbufs[k];
128 
129 				if (srcbuf[i] & BIT(j))
130 					cnt++;
131 			}
132 
133 			if (cnt > nsrcbufs / 2)
134 				val |= BIT(j);
135 		}
136 
137 		((u8 *)dstbuf)[i] = val;
138 	}
139 }
140 
141 /*
142  * Check if the NAND chip is ONFI compliant, returns 1 if it is, 0 otherwise.
143  */
nand_onfi_detect(struct nand_chip * chip)144 int nand_onfi_detect(struct nand_chip *chip)
145 {
146 	struct nand_device *base = &chip->base;
147 	struct mtd_info *mtd = nand_to_mtd(chip);
148 	struct nand_memory_organization *memorg;
149 	struct nand_onfi_params *p = NULL, *pbuf;
150 	struct onfi_params *onfi;
151 	bool use_datain = false;
152 	int onfi_version = 0;
153 	char id[4];
154 	int i, ret, val;
155 	u16 crc;
156 
157 	memorg = nanddev_get_memorg(&chip->base);
158 
159 	/* Try ONFI for unknown chip or LP */
160 	ret = nand_readid_op(chip, 0x20, id, sizeof(id));
161 	if (ret || strncmp(id, "ONFI", 4))
162 		return 0;
163 
164 	/* ONFI chip: allocate a buffer to hold its parameter page */
165 	pbuf = kzalloc((sizeof(*pbuf) * ONFI_PARAM_PAGES), GFP_KERNEL);
166 	if (!pbuf)
167 		return -ENOMEM;
168 
169 	if (!nand_has_exec_op(chip) ||
170 	    !nand_read_data_op(chip, &pbuf[0], sizeof(*pbuf), true, true))
171 		use_datain = true;
172 
173 	for (i = 0; i < ONFI_PARAM_PAGES; i++) {
174 		if (!i)
175 			ret = nand_read_param_page_op(chip, 0, &pbuf[i],
176 						      sizeof(*pbuf));
177 		else if (use_datain)
178 			ret = nand_read_data_op(chip, &pbuf[i], sizeof(*pbuf),
179 						true, false);
180 		else
181 			ret = nand_change_read_column_op(chip, sizeof(*pbuf) * i,
182 							 &pbuf[i], sizeof(*pbuf),
183 							 true);
184 		if (ret) {
185 			ret = 0;
186 			goto free_onfi_param_page;
187 		}
188 
189 		crc = onfi_crc16(ONFI_CRC_BASE, (u8 *)&pbuf[i], 254);
190 		if (crc == le16_to_cpu(pbuf[i].crc)) {
191 			p = &pbuf[i];
192 			break;
193 		}
194 	}
195 
196 	if (i == ONFI_PARAM_PAGES) {
197 		const void *srcbufs[ONFI_PARAM_PAGES];
198 		unsigned int j;
199 
200 		for (j = 0; j < ONFI_PARAM_PAGES; j++)
201 			srcbufs[j] = pbuf + j;
202 
203 		pr_warn("Could not find a valid ONFI parameter page, trying bit-wise majority to recover it\n");
204 		nand_bit_wise_majority(srcbufs, ONFI_PARAM_PAGES, pbuf,
205 				       sizeof(*pbuf));
206 
207 		crc = onfi_crc16(ONFI_CRC_BASE, (u8 *)pbuf, 254);
208 		if (crc != le16_to_cpu(pbuf->crc)) {
209 			pr_err("ONFI parameter recovery failed, aborting\n");
210 			goto free_onfi_param_page;
211 		}
212 		p = pbuf;
213 	}
214 
215 	if (chip->manufacturer.desc && chip->manufacturer.desc->ops &&
216 	    chip->manufacturer.desc->ops->fixup_onfi_param_page)
217 		chip->manufacturer.desc->ops->fixup_onfi_param_page(chip, p);
218 
219 	/* Check version */
220 	val = le16_to_cpu(p->revision);
221 	if (val & ONFI_VERSION_2_3)
222 		onfi_version = 23;
223 	else if (val & ONFI_VERSION_2_2)
224 		onfi_version = 22;
225 	else if (val & ONFI_VERSION_2_1)
226 		onfi_version = 21;
227 	else if (val & ONFI_VERSION_2_0)
228 		onfi_version = 20;
229 	else if (val & ONFI_VERSION_1_0)
230 		onfi_version = 10;
231 
232 	if (!onfi_version) {
233 		pr_info("unsupported ONFI version: %d\n", val);
234 		goto free_onfi_param_page;
235 	}
236 
237 	sanitize_string(p->manufacturer, sizeof(p->manufacturer));
238 	sanitize_string(p->model, sizeof(p->model));
239 	chip->parameters.model = kstrdup(p->model, GFP_KERNEL);
240 	if (!chip->parameters.model) {
241 		ret = -ENOMEM;
242 		goto free_onfi_param_page;
243 	}
244 
245 	memorg->pagesize = le32_to_cpu(p->byte_per_page);
246 	mtd->writesize = memorg->pagesize;
247 
248 	/*
249 	 * pages_per_block and blocks_per_lun may not be a power-of-2 size
250 	 * (don't ask me who thought of this...). MTD assumes that these
251 	 * dimensions will be power-of-2, so just truncate the remaining area.
252 	 */
253 	memorg->pages_per_eraseblock =
254 			1 << (fls(le32_to_cpu(p->pages_per_block)) - 1);
255 	mtd->erasesize = memorg->pages_per_eraseblock * memorg->pagesize;
256 
257 	memorg->oobsize = le16_to_cpu(p->spare_bytes_per_page);
258 	mtd->oobsize = memorg->oobsize;
259 
260 	memorg->luns_per_target = p->lun_count;
261 	memorg->planes_per_lun = 1 << p->interleaved_bits;
262 
263 	/* See erasesize comment */
264 	memorg->eraseblocks_per_lun =
265 		1 << (fls(le32_to_cpu(p->blocks_per_lun)) - 1);
266 	memorg->max_bad_eraseblocks_per_lun = le32_to_cpu(p->blocks_per_lun);
267 	memorg->bits_per_cell = p->bits_per_cell;
268 
269 	if (le16_to_cpu(p->features) & ONFI_FEATURE_16_BIT_BUS)
270 		chip->options |= NAND_BUSWIDTH_16;
271 
272 	if (p->ecc_bits != 0xff) {
273 		struct nand_ecc_props requirements = {
274 			.strength = p->ecc_bits,
275 			.step_size = 512,
276 		};
277 
278 		nanddev_set_ecc_requirements(base, &requirements);
279 	} else if (onfi_version >= 21 &&
280 		(le16_to_cpu(p->features) & ONFI_FEATURE_EXT_PARAM_PAGE)) {
281 
282 		/*
283 		 * The nand_flash_detect_ext_param_page() uses the
284 		 * Change Read Column command which maybe not supported
285 		 * by the chip->legacy.cmdfunc. So try to update the
286 		 * chip->legacy.cmdfunc now. We do not replace user supplied
287 		 * command function.
288 		 */
289 		nand_legacy_adjust_cmdfunc(chip);
290 
291 		/* The Extended Parameter Page is supported since ONFI 2.1. */
292 		if (nand_flash_detect_ext_param_page(chip, p))
293 			pr_warn("Failed to detect ONFI extended param page\n");
294 	} else {
295 		pr_warn("Could not retrieve ONFI ECC requirements\n");
296 	}
297 
298 	/* Save some parameters from the parameter page for future use */
299 	if (le16_to_cpu(p->opt_cmd) & ONFI_OPT_CMD_SET_GET_FEATURES) {
300 		chip->parameters.supports_set_get_features = true;
301 		bitmap_set(chip->parameters.get_feature_list,
302 			   ONFI_FEATURE_ADDR_TIMING_MODE, 1);
303 		bitmap_set(chip->parameters.set_feature_list,
304 			   ONFI_FEATURE_ADDR_TIMING_MODE, 1);
305 	}
306 
307 	onfi = kzalloc(sizeof(*onfi), GFP_KERNEL);
308 	if (!onfi) {
309 		ret = -ENOMEM;
310 		goto free_model;
311 	}
312 
313 	onfi->version = onfi_version;
314 	onfi->tPROG = le16_to_cpu(p->t_prog);
315 	onfi->tBERS = le16_to_cpu(p->t_bers);
316 	onfi->tR = le16_to_cpu(p->t_r);
317 	onfi->tCCS = le16_to_cpu(p->t_ccs);
318 	onfi->fast_tCAD = le16_to_cpu(p->nvddr_nvddr2_features) & BIT(0);
319 	onfi->sdr_timing_modes = le16_to_cpu(p->sdr_timing_modes);
320 	if (le16_to_cpu(p->features) & ONFI_FEATURE_NV_DDR)
321 		onfi->nvddr_timing_modes = le16_to_cpu(p->nvddr_timing_modes);
322 	onfi->vendor_revision = le16_to_cpu(p->vendor_revision);
323 	memcpy(onfi->vendor, p->vendor, sizeof(p->vendor));
324 	chip->parameters.onfi = onfi;
325 
326 	/* Identification done, free the full ONFI parameter page and exit */
327 	kfree(pbuf);
328 
329 	return 1;
330 
331 free_model:
332 	kfree(chip->parameters.model);
333 free_onfi_param_page:
334 	kfree(pbuf);
335 
336 	return ret;
337 }
338