1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2012-2014 Daniel Schwierzeck, daniel.schwierzeck@gmail.com
4  */
5 
6 #include <malloc.h>
7 #include <linux/errno.h>
8 #include <linux/mtd/mtd.h>
9 #include <spi_flash.h>
10 
11 #if CONFIG_IS_ENABLED(DM_SPI_FLASH)
12 
spi_flash_mtd_register(struct spi_flash * flash)13 int spi_flash_mtd_register(struct spi_flash *flash)
14 {
15 	return add_mtd_device(&flash->mtd);
16 }
17 
spi_flash_mtd_unregister(struct spi_flash * flash)18 void spi_flash_mtd_unregister(struct spi_flash *flash)
19 {
20 	del_mtd_device(&flash->mtd);
21 }
22 
23 #else /* !CONFIG_IS_ENABLED(DM_SPI_FLASH) */
24 
25 static struct mtd_info sf_mtd_info;
26 static bool sf_mtd_registered;
27 static char sf_mtd_name[8];
28 
spi_flash_mtd_erase(struct mtd_info * mtd,struct erase_info * instr)29 static int spi_flash_mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
30 {
31 	struct spi_flash *flash = mtd->priv;
32 	int err;
33 
34 	if (!flash)
35 		return -ENODEV;
36 
37 	instr->state = MTD_ERASING;
38 
39 	err = spi_flash_erase(flash, instr->addr, instr->len);
40 	if (err) {
41 		instr->state = MTD_ERASE_FAILED;
42 		instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
43 		return -EIO;
44 	}
45 
46 	instr->state = MTD_ERASE_DONE;
47 
48 	return 0;
49 }
50 
spi_flash_mtd_read(struct mtd_info * mtd,loff_t from,size_t len,size_t * retlen,u_char * buf)51 static int spi_flash_mtd_read(struct mtd_info *mtd, loff_t from, size_t len,
52 	size_t *retlen, u_char *buf)
53 {
54 	struct spi_flash *flash = mtd->priv;
55 	int err;
56 
57 	if (!flash)
58 		return -ENODEV;
59 
60 	err = spi_flash_read(flash, from, len, buf);
61 	if (!err)
62 		*retlen = len;
63 
64 	return err;
65 }
66 
spi_flash_mtd_write(struct mtd_info * mtd,loff_t to,size_t len,size_t * retlen,const u_char * buf)67 static int spi_flash_mtd_write(struct mtd_info *mtd, loff_t to, size_t len,
68 	size_t *retlen, const u_char *buf)
69 {
70 	struct spi_flash *flash = mtd->priv;
71 	int err;
72 
73 	if (!flash)
74 		return -ENODEV;
75 
76 	err = spi_flash_write(flash, to, len, buf);
77 	if (!err)
78 		*retlen = len;
79 
80 	return err;
81 }
82 
spi_flash_mtd_sync(struct mtd_info * mtd)83 static void spi_flash_mtd_sync(struct mtd_info *mtd)
84 {
85 }
86 
spi_flash_mtd_number(void)87 static int spi_flash_mtd_number(void)
88 {
89 #ifdef CONFIG_SYS_MAX_FLASH_BANKS
90 	return CONFIG_SYS_MAX_FLASH_BANKS;
91 #else
92 	return 0;
93 #endif
94 }
95 
spi_flash_mtd_register(struct spi_flash * flash)96 int spi_flash_mtd_register(struct spi_flash *flash)
97 {
98 	int ret;
99 
100 	if (sf_mtd_registered) {
101 		ret = del_mtd_device(&sf_mtd_info);
102 		if (ret)
103 			return ret;
104 
105 		sf_mtd_registered = false;
106 	}
107 
108 	sf_mtd_registered = false;
109 	memset(&sf_mtd_info, 0, sizeof(sf_mtd_info));
110 	sprintf(sf_mtd_name, "nor%d", spi_flash_mtd_number());
111 
112 	sf_mtd_info.name = sf_mtd_name;
113 	sf_mtd_info.type = MTD_NORFLASH;
114 	sf_mtd_info.flags = MTD_CAP_NORFLASH;
115 	sf_mtd_info.writesize = 1;
116 	sf_mtd_info.writebufsize = flash->page_size;
117 
118 	sf_mtd_info._erase = spi_flash_mtd_erase;
119 	sf_mtd_info._read = spi_flash_mtd_read;
120 	sf_mtd_info._write = spi_flash_mtd_write;
121 	sf_mtd_info._sync = spi_flash_mtd_sync;
122 
123 	sf_mtd_info.size = flash->size;
124 	sf_mtd_info.priv = flash;
125 	sf_mtd_info.dev = flash->dev;
126 
127 	/* Only uniform flash devices for now */
128 	sf_mtd_info.numeraseregions = 0;
129 	sf_mtd_info.erasesize = flash->sector_size;
130 
131 	ret = add_mtd_device(&sf_mtd_info);
132 	if (!ret)
133 		sf_mtd_registered = true;
134 
135 	return ret;
136 }
137 
spi_flash_mtd_unregister(struct spi_flash * flash)138 void spi_flash_mtd_unregister(struct spi_flash *flash)
139 {
140 	int ret;
141 
142 	if (!sf_mtd_registered)
143 		return;
144 
145 	ret = del_mtd_device(&sf_mtd_info);
146 	if (!ret) {
147 		sf_mtd_registered = false;
148 		return;
149 	}
150 
151 	/*
152 	 * Setting mtd->priv to NULL is the best we can do. Thanks to that,
153 	 * the MTD layer can still call mtd hooks without risking a
154 	 * use-after-free bug. Still, things should be fixed to prevent the
155 	 * spi_flash object from being destroyed when del_mtd_device() fails.
156 	 */
157 	sf_mtd_info.priv = NULL;
158 	printf("Failed to unregister MTD %s and the spi_flash object is going away: you're in deep trouble!",
159 	       sf_mtd_info.name);
160 }
161 
162 #endif /* !CONFIG_IS_ENABLED(DM_SPI_FLASH) */
163