xref: /openbmc/linux/drivers/mtd/nand/raw/sm_common.h (revision 0c874100)
1 /*
2  * Copyright © 2009 - Maxim Levitsky
3  * Common routines & support for SmartMedia/xD format
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License version 2 as
7  * published by the Free Software Foundation.
8  */
9 #include <linux/bitops.h>
10 #include <linux/mtd/mtd.h>
11 
12 /* Full oob structure as written on the flash */
13 struct sm_oob {
14 	uint32_t reserved;
15 	uint8_t data_status;
16 	uint8_t block_status;
17 	uint8_t lba_copy1[2];
18 	uint8_t ecc2[3];
19 	uint8_t lba_copy2[2];
20 	uint8_t ecc1[3];
21 } __packed;
22 
23 
24 /* one sector is always 512 bytes, but it can consist of two nand pages */
25 #define SM_SECTOR_SIZE		512
26 
27 /* oob area is also 16 bytes, but might be from two pages */
28 #define SM_OOB_SIZE		16
29 
30 /* This is maximum zone size, and all devices that have more that one zone
31    have this size */
32 #define SM_MAX_ZONE_SIZE 	1024
33 
34 /* support for small page nand */
35 #define SM_SMALL_PAGE 		256
36 #define SM_SMALL_OOB_SIZE	8
37 
38 
39 int sm_register_device(struct mtd_info *mtd, int smartmedia);
40 
41 
42 static inline int sm_sector_valid(struct sm_oob *oob)
43 {
44 	return hweight16(oob->data_status) >= 5;
45 }
46 
47 static inline int sm_block_valid(struct sm_oob *oob)
48 {
49 	return hweight16(oob->block_status) >= 7;
50 }
51 
52 static inline int sm_block_erased(struct sm_oob *oob)
53 {
54 	static const uint32_t erased_pattern[4] = {
55 		0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF };
56 
57 	/* First test for erased block */
58 	if (!memcmp(oob, erased_pattern, sizeof(*oob)))
59 		return 1;
60 	return 0;
61 }
62