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