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