xref: /openbmc/linux/drivers/mtd/nand/raw/sm_common.h (revision 842ed298)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright © 2009 - Maxim Levitsky
4  * Common routines & support for SmartMedia/xD format
5  */
6 #include <linux/bitops.h>
7 #include <linux/mtd/mtd.h>
8 
9 /* Full oob structure as written on the flash */
10 struct sm_oob {
11 	uint32_t reserved;
12 	uint8_t data_status;
13 	uint8_t block_status;
14 	uint8_t lba_copy1[2];
15 	uint8_t ecc2[3];
16 	uint8_t lba_copy2[2];
17 	uint8_t ecc1[3];
18 } __packed;
19 
20 
21 /* one sector is always 512 bytes, but it can consist of two nand pages */
22 #define SM_SECTOR_SIZE		512
23 
24 /* oob area is also 16 bytes, but might be from two pages */
25 #define SM_OOB_SIZE		16
26 
27 /* This is maximum zone size, and all devices that have more that one zone
28    have this size */
29 #define SM_MAX_ZONE_SIZE 	1024
30 
31 /* support for small page nand */
32 #define SM_SMALL_PAGE 		256
33 #define SM_SMALL_OOB_SIZE	8
34 
35 
36 int sm_register_device(struct mtd_info *mtd, int smartmedia);
37 
38 
39 static inline int sm_sector_valid(struct sm_oob *oob)
40 {
41 	return hweight16(oob->data_status) >= 5;
42 }
43 
44 static inline int sm_block_valid(struct sm_oob *oob)
45 {
46 	return hweight16(oob->block_status) >= 7;
47 }
48 
49 static inline int sm_block_erased(struct sm_oob *oob)
50 {
51 	static const uint32_t erased_pattern[4] = {
52 		0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF };
53 
54 	/* First test for erased block */
55 	if (!memcmp(oob, erased_pattern, sizeof(*oob)))
56 		return 1;
57 	return 0;
58 }
59