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 JEDEC_PARAM_PAGES 3
20 
21 /*
22  * Check if the NAND chip is JEDEC compliant, returns 1 if it is, 0 otherwise.
23  */
nand_jedec_detect(struct nand_chip * chip)24 int nand_jedec_detect(struct nand_chip *chip)
25 {
26 	struct nand_device *base = &chip->base;
27 	struct mtd_info *mtd = nand_to_mtd(chip);
28 	struct nand_memory_organization *memorg;
29 	struct nand_jedec_params *p;
30 	struct jedec_ecc_info *ecc;
31 	bool use_datain = false;
32 	int jedec_version = 0;
33 	char id[5];
34 	int i, val, ret;
35 	u16 crc;
36 
37 	memorg = nanddev_get_memorg(&chip->base);
38 
39 	/* Try JEDEC for unknown chip or LP */
40 	ret = nand_readid_op(chip, 0x40, id, sizeof(id));
41 	if (ret || strncmp(id, "JEDEC", sizeof(id)))
42 		return 0;
43 
44 	/* JEDEC chip: allocate a buffer to hold its parameter page */
45 	p = kzalloc(sizeof(*p), GFP_KERNEL);
46 	if (!p)
47 		return -ENOMEM;
48 
49 	if (!nand_has_exec_op(chip) ||
50 	    !nand_read_data_op(chip, p, sizeof(*p), true, true))
51 		use_datain = true;
52 
53 	for (i = 0; i < JEDEC_PARAM_PAGES; i++) {
54 		if (!i)
55 			ret = nand_read_param_page_op(chip, 0x40, p,
56 						      sizeof(*p));
57 		else if (use_datain)
58 			ret = nand_read_data_op(chip, p, sizeof(*p), true,
59 						false);
60 		else
61 			ret = nand_change_read_column_op(chip, sizeof(*p) * i,
62 							 p, sizeof(*p), true);
63 		if (ret) {
64 			ret = 0;
65 			goto free_jedec_param_page;
66 		}
67 
68 		crc = onfi_crc16(ONFI_CRC_BASE, (u8 *)p, 510);
69 		if (crc == le16_to_cpu(p->crc))
70 			break;
71 	}
72 
73 	if (i == JEDEC_PARAM_PAGES) {
74 		pr_err("Could not find valid JEDEC parameter page; aborting\n");
75 		goto free_jedec_param_page;
76 	}
77 
78 	/* Check version */
79 	val = le16_to_cpu(p->revision);
80 	if (val & (1 << 2))
81 		jedec_version = 10;
82 	else if (val & (1 << 1))
83 		jedec_version = 1; /* vendor specific version */
84 
85 	if (!jedec_version) {
86 		pr_info("unsupported JEDEC version: %d\n", val);
87 		goto free_jedec_param_page;
88 	}
89 
90 	sanitize_string(p->manufacturer, sizeof(p->manufacturer));
91 	sanitize_string(p->model, sizeof(p->model));
92 	chip->parameters.model = kstrdup(p->model, GFP_KERNEL);
93 	if (!chip->parameters.model) {
94 		ret = -ENOMEM;
95 		goto free_jedec_param_page;
96 	}
97 
98 	memorg->pagesize = le32_to_cpu(p->byte_per_page);
99 	mtd->writesize = memorg->pagesize;
100 
101 	/* Please reference to the comment for nand_flash_detect_onfi. */
102 	memorg->pages_per_eraseblock =
103 			1 << (fls(le32_to_cpu(p->pages_per_block)) - 1);
104 	mtd->erasesize = memorg->pages_per_eraseblock * memorg->pagesize;
105 
106 	memorg->oobsize = le16_to_cpu(p->spare_bytes_per_page);
107 	mtd->oobsize = memorg->oobsize;
108 
109 	memorg->luns_per_target = p->lun_count;
110 	memorg->planes_per_lun = 1 << p->multi_plane_addr;
111 
112 	/* Please reference to the comment for nand_flash_detect_onfi. */
113 	memorg->eraseblocks_per_lun =
114 		1 << (fls(le32_to_cpu(p->blocks_per_lun)) - 1);
115 	memorg->bits_per_cell = p->bits_per_cell;
116 
117 	if (le16_to_cpu(p->features) & JEDEC_FEATURE_16_BIT_BUS)
118 		chip->options |= NAND_BUSWIDTH_16;
119 
120 	/* ECC info */
121 	ecc = &p->ecc_info[0];
122 
123 	if (ecc->codeword_size >= 9) {
124 		struct nand_ecc_props requirements = {
125 			.strength = ecc->ecc_bits,
126 			.step_size = 1 << ecc->codeword_size,
127 		};
128 
129 		nanddev_set_ecc_requirements(base, &requirements);
130 	} else {
131 		pr_warn("Invalid codeword size\n");
132 	}
133 
134 	ret = 1;
135 
136 free_jedec_param_page:
137 	kfree(p);
138 	return ret;
139 }
140