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
21u16 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. */
34static 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 offset_in_page: sizeof(*p) * p->num_of_param_pages,
58 buf: ep, len, force_8bit: true);
59 if (ret)
60 goto ext_out;
61
62 ret = -EINVAL;
63 if ((onfi_crc16(ONFI_CRC_BASE, p: ((uint8_t *)ep) + 2, len: 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(nand: base, reqs: &requirements);
102
103 ret = 0;
104
105ext_out:
106 kfree(objp: ep);
107 return ret;
108}
109
110/*
111 * Recover data with bit-wise majority
112 */
113static 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 */
144int 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(nand: &chip->base);
158
159 /* Try ONFI for unknown chip or LP */
160 ret = nand_readid_op(chip, addr: 0x20, buf: id, len: 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) || chip->controller->supported_op.data_only_read)
170 use_datain = true;
171
172 for (i = 0; i < ONFI_PARAM_PAGES; i++) {
173 if (!i)
174 ret = nand_read_param_page_op(chip, page: 0, buf: &pbuf[i],
175 len: sizeof(*pbuf));
176 else if (use_datain)
177 ret = nand_read_data_op(chip, buf: &pbuf[i], len: sizeof(*pbuf),
178 force_8bit: true, check_only: false);
179 else
180 ret = nand_change_read_column_op(chip, offset_in_page: sizeof(*pbuf) * i,
181 buf: &pbuf[i], len: sizeof(*pbuf),
182 force_8bit: true);
183 if (ret) {
184 ret = 0;
185 goto free_onfi_param_page;
186 }
187
188 crc = onfi_crc16(ONFI_CRC_BASE, p: (u8 *)&pbuf[i], len: 254);
189 if (crc == le16_to_cpu(pbuf[i].crc)) {
190 p = &pbuf[i];
191 break;
192 }
193 }
194
195 if (i == ONFI_PARAM_PAGES) {
196 const void *srcbufs[ONFI_PARAM_PAGES];
197 unsigned int j;
198
199 for (j = 0; j < ONFI_PARAM_PAGES; j++)
200 srcbufs[j] = pbuf + j;
201
202 pr_warn("Could not find a valid ONFI parameter page, trying bit-wise majority to recover it\n");
203 nand_bit_wise_majority(srcbufs, ONFI_PARAM_PAGES, dstbuf: pbuf,
204 bufsize: sizeof(*pbuf));
205
206 crc = onfi_crc16(ONFI_CRC_BASE, p: (u8 *)pbuf, len: 254);
207 if (crc != le16_to_cpu(pbuf->crc)) {
208 pr_err("ONFI parameter recovery failed, aborting\n");
209 goto free_onfi_param_page;
210 }
211 p = pbuf;
212 }
213
214 if (chip->manufacturer.desc && chip->manufacturer.desc->ops &&
215 chip->manufacturer.desc->ops->fixup_onfi_param_page)
216 chip->manufacturer.desc->ops->fixup_onfi_param_page(chip, p);
217
218 /* Check version */
219 val = le16_to_cpu(p->revision);
220 if (val & ONFI_VERSION_2_3)
221 onfi_version = 23;
222 else if (val & ONFI_VERSION_2_2)
223 onfi_version = 22;
224 else if (val & ONFI_VERSION_2_1)
225 onfi_version = 21;
226 else if (val & ONFI_VERSION_2_0)
227 onfi_version = 20;
228 else if (val & ONFI_VERSION_1_0)
229 onfi_version = 10;
230
231 if (!onfi_version) {
232 pr_info("unsupported ONFI version: %d\n", val);
233 goto free_onfi_param_page;
234 }
235
236 sanitize_string(s: p->manufacturer, len: sizeof(p->manufacturer));
237 sanitize_string(s: p->model, len: sizeof(p->model));
238 chip->parameters.model = kstrdup(s: p->model, GFP_KERNEL);
239 if (!chip->parameters.model) {
240 ret = -ENOMEM;
241 goto free_onfi_param_page;
242 }
243
244 memorg->pagesize = le32_to_cpu(p->byte_per_page);
245 mtd->writesize = memorg->pagesize;
246
247 /*
248 * pages_per_block and blocks_per_lun may not be a power-of-2 size
249 * (don't ask me who thought of this...). MTD assumes that these
250 * dimensions will be power-of-2, so just truncate the remaining area.
251 */
252 memorg->pages_per_eraseblock =
253 1 << (fls(le32_to_cpu(p->pages_per_block)) - 1);
254 mtd->erasesize = memorg->pages_per_eraseblock * memorg->pagesize;
255
256 memorg->oobsize = le16_to_cpu(p->spare_bytes_per_page);
257 mtd->oobsize = memorg->oobsize;
258
259 memorg->luns_per_target = p->lun_count;
260 memorg->planes_per_lun = 1 << p->interleaved_bits;
261
262 /* See erasesize comment */
263 memorg->eraseblocks_per_lun =
264 1 << (fls(le32_to_cpu(p->blocks_per_lun)) - 1);
265 memorg->max_bad_eraseblocks_per_lun = le32_to_cpu(p->blocks_per_lun);
266 memorg->bits_per_cell = p->bits_per_cell;
267
268 if (le16_to_cpu(p->features) & ONFI_FEATURE_16_BIT_BUS)
269 chip->options |= NAND_BUSWIDTH_16;
270
271 if (p->ecc_bits != 0xff) {
272 struct nand_ecc_props requirements = {
273 .strength = p->ecc_bits,
274 .step_size = 512,
275 };
276
277 nanddev_set_ecc_requirements(nand: base, reqs: &requirements);
278 } else if (onfi_version >= 21 &&
279 (le16_to_cpu(p->features) & ONFI_FEATURE_EXT_PARAM_PAGE)) {
280
281 /*
282 * The nand_flash_detect_ext_param_page() uses the
283 * Change Read Column command which maybe not supported
284 * by the chip->legacy.cmdfunc. So try to update the
285 * chip->legacy.cmdfunc now. We do not replace user supplied
286 * command function.
287 */
288 nand_legacy_adjust_cmdfunc(chip);
289
290 /* The Extended Parameter Page is supported since ONFI 2.1. */
291 if (nand_flash_detect_ext_param_page(chip, p))
292 pr_warn("Failed to detect ONFI extended param page\n");
293 } else {
294 pr_warn("Could not retrieve ONFI ECC requirements\n");
295 }
296
297 /* Save some parameters from the parameter page for future use */
298 if (le16_to_cpu(p->opt_cmd) & ONFI_OPT_CMD_SET_GET_FEATURES) {
299 chip->parameters.supports_set_get_features = true;
300 bitmap_set(map: chip->parameters.get_feature_list,
301 ONFI_FEATURE_ADDR_TIMING_MODE, nbits: 1);
302 bitmap_set(map: chip->parameters.set_feature_list,
303 ONFI_FEATURE_ADDR_TIMING_MODE, nbits: 1);
304 }
305
306 if (le16_to_cpu(p->opt_cmd) & ONFI_OPT_CMD_READ_CACHE)
307 chip->parameters.supports_read_cache = true;
308
309 onfi = kzalloc(sizeof(*onfi), GFP_KERNEL);
310 if (!onfi) {
311 ret = -ENOMEM;
312 goto free_model;
313 }
314
315 onfi->version = onfi_version;
316 onfi->tPROG = le16_to_cpu(p->t_prog);
317 onfi->tBERS = le16_to_cpu(p->t_bers);
318 onfi->tR = le16_to_cpu(p->t_r);
319 onfi->tCCS = le16_to_cpu(p->t_ccs);
320 onfi->fast_tCAD = le16_to_cpu(p->nvddr_nvddr2_features) & BIT(0);
321 onfi->sdr_timing_modes = le16_to_cpu(p->sdr_timing_modes);
322 if (le16_to_cpu(p->features) & ONFI_FEATURE_NV_DDR)
323 onfi->nvddr_timing_modes = le16_to_cpu(p->nvddr_timing_modes);
324 onfi->vendor_revision = le16_to_cpu(p->vendor_revision);
325 memcpy(onfi->vendor, p->vendor, sizeof(p->vendor));
326 chip->parameters.onfi = onfi;
327
328 /* Identification done, free the full ONFI parameter page and exit */
329 kfree(objp: pbuf);
330
331 return 1;
332
333free_model:
334 kfree(objp: chip->parameters.model);
335free_onfi_param_page:
336 kfree(objp: pbuf);
337
338 return ret;
339}
340

source code of linux/drivers/mtd/nand/raw/nand_onfi.c