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