1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2012-2014 Daniel Schwierzeck, daniel.schwierzeck@gmail.com
4  */
5 
6 #include <common.h>
7 #include <malloc.h>
8 #include <linux/errno.h>
9 #include <linux/mtd/mtd.h>
10 #include <spi_flash.h>
11 
12 #if CONFIG_IS_ENABLED(DM_SPI_FLASH)
13 
spi_flash_mtd_register(struct spi_flash * flash)14 int spi_flash_mtd_register(struct spi_flash *flash)
15 {
16 	return add_mtd_device(&flash->mtd);
17 }
18 
spi_flash_mtd_unregister(struct spi_flash * flash)19 void spi_flash_mtd_unregister(struct spi_flash *flash)
20 {
21 	del_mtd_device(&flash->mtd);
22 }
23 
24 #else /* !CONFIG_IS_ENABLED(DM_SPI_FLASH) */
25 
26 static struct mtd_info sf_mtd_info;
27 static bool sf_mtd_registered;
28 static char sf_mtd_name[8];
29 
spi_flash_mtd_erase(struct mtd_info * mtd,struct erase_info * instr)30 static int spi_flash_mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
31 {
32 	struct spi_flash *flash = mtd->priv;
33 	int err;
34 
35 	if (!flash)
36 		return -ENODEV;
37 
38 	instr->state = MTD_ERASING;
39 
40 	err = spi_flash_erase(flash, instr->addr, instr->len);
41 	if (err) {
42 		instr->state = MTD_ERASE_FAILED;
43 		instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
44 		return -EIO;
45 	}
46 
47 	instr->state = MTD_ERASE_DONE;
48 
49 	return 0;
50 }
51 
spi_flash_mtd_read(struct mtd_info * mtd,loff_t from,size_t len,size_t * retlen,u_char * buf)52 static int spi_flash_mtd_read(struct mtd_info *mtd, loff_t from, size_t len,
53 	size_t *retlen, u_char *buf)
54 {
55 	struct spi_flash *flash = mtd->priv;
56 	int err;
57 
58 	if (!flash)
59 		return -ENODEV;
60 
61 	err = spi_flash_read(flash, from, len, buf);
62 	if (!err)
63 		*retlen = len;
64 
65 	return err;
66 }
67 
spi_flash_mtd_write(struct mtd_info * mtd,loff_t to,size_t len,size_t * retlen,const u_char * buf)68 static int spi_flash_mtd_write(struct mtd_info *mtd, loff_t to, size_t len,
69 	size_t *retlen, const u_char *buf)
70 {
71 	struct spi_flash *flash = mtd->priv;
72 	int err;
73 
74 	if (!flash)
75 		return -ENODEV;
76 
77 	err = spi_flash_write(flash, to, len, buf);
78 	if (!err)
79 		*retlen = len;
80 
81 	return err;
82 }
83 
spi_flash_mtd_sync(struct mtd_info * mtd)84 static void spi_flash_mtd_sync(struct mtd_info *mtd)
85 {
86 }
87 
spi_flash_mtd_number(void)88 static int spi_flash_mtd_number(void)
89 {
90 #ifdef CONFIG_SYS_MAX_FLASH_BANKS
91 	return CONFIG_SYS_MAX_FLASH_BANKS;
92 #else
93 	return 0;
94 #endif
95 }
96 
spi_flash_mtd_register(struct spi_flash * flash)97 int spi_flash_mtd_register(struct spi_flash *flash)
98 {
99 	int ret;
100 
101 	if (sf_mtd_registered) {
102 		ret = del_mtd_device(&sf_mtd_info);
103 		if (ret)
104 			return ret;
105 
106 		sf_mtd_registered = false;
107 	}
108 
109 	sf_mtd_registered = false;
110 	memset(&sf_mtd_info, 0, sizeof(sf_mtd_info));
111 	sprintf(sf_mtd_name, "nor%d", spi_flash_mtd_number());
112 
113 	sf_mtd_info.name = sf_mtd_name;
114 	sf_mtd_info.type = MTD_NORFLASH;
115 	sf_mtd_info.flags = MTD_CAP_NORFLASH;
116 	sf_mtd_info.writesize = 1;
117 	sf_mtd_info.writebufsize = flash->page_size;
118 
119 	sf_mtd_info._erase = spi_flash_mtd_erase;
120 	sf_mtd_info._read = spi_flash_mtd_read;
121 	sf_mtd_info._write = spi_flash_mtd_write;
122 	sf_mtd_info._sync = spi_flash_mtd_sync;
123 
124 	sf_mtd_info.size = flash->size;
125 	sf_mtd_info.priv = flash;
126 	sf_mtd_info.dev = flash->dev;
127 
128 	/* Only uniform flash devices for now */
129 	sf_mtd_info.numeraseregions = 0;
130 	sf_mtd_info.erasesize = flash->sector_size;
131 
132 	ret = add_mtd_device(&sf_mtd_info);
133 	if (!ret)
134 		sf_mtd_registered = true;
135 
136 	return ret;
137 }
138 
spi_flash_mtd_unregister(struct spi_flash * flash)139 void spi_flash_mtd_unregister(struct spi_flash *flash)
140 {
141 	int ret;
142 
143 	if (!sf_mtd_registered)
144 		return;
145 
146 	ret = del_mtd_device(&sf_mtd_info);
147 	if (!ret) {
148 		sf_mtd_registered = false;
149 		return;
150 	}
151 
152 	/*
153 	 * Setting mtd->priv to NULL is the best we can do. Thanks to that,
154 	 * the MTD layer can still call mtd hooks without risking a
155 	 * use-after-free bug. Still, things should be fixed to prevent the
156 	 * spi_flash object from being destroyed when del_mtd_device() fails.
157 	 */
158 	sf_mtd_info.priv = NULL;
159 	printf("Failed to unregister MTD %s and the spi_flash object is going away: you're in deep trouble!",
160 	       sf_mtd_info.name);
161 }
162 
163 #endif /* !CONFIG_IS_ENABLED(DM_SPI_FLASH) */
164