drivers/mtd/spi/sf_mtd.c

   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
  14 int spi_flash_mtd_register(struct spi_flash *flash)
  15 {
  16         return add_mtd_device(&flash->mtd);
  17 }
  18
  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
  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
  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
  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
  84 static void spi_flash_mtd_sync(struct mtd_info *mtd)
  85 {
  86 }
  87
  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
  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
 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) */