[Linux-kernel] Advanced Sector Protectionの機能がついてるNORフラッシュのロック・アンロック対応

しょっぱなからマニアックな誰得投稿です。

LinuxでAdvanced Sector Protectionの機能がついてるNORフラッシュのロック・アンロック対応してないっぽいので最近のU-bootを見ながら書きました。

NORフラッシュにはいろいろロック形式はありますが、とりあえずSPBだけ対応してます。
これを当てるとmtd-utilsでNORのセクタロック・アンロックが出来るようになります。
つまり、U-boot上でロックされたセクタをアンロックしたり、その逆がLinux上のコマンドで出来るようになります。

もしかしたら最近のカーネルではすでに対応しているかもしれません。

（この記事は私が書いた https://gist.github.com/chromabox/5370360 の転載です。glistだと埋もれて自分が困るので、、、）

cfi_ppb_lock.h

#ifndef PPB_LOCK_H
#define PPB_LOCK_H

#define AMD_CMD_SET_PPB_ENTRY           0xC0
#define AMD_CMD_SET_PPB_EXIT_BC1        0x90
#define AMD_CMD_SET_PPB_EXIT_BC2        0x00
#define AMD_CMD_PPB_UNLOCK_BC1          0x80
#define AMD_CMD_PPB_UNLOCK_BC2          0x30
#define AMD_CMD_PPB_LOCK_BC1            0xA0
#define AMD_CMD_PPB_LOCK_BC2            0x00

enum ppb_lock_state {
    PPB_LOCK = 0,
    PPB_UNLOCK = 1,
};

struct ppb_lock_thunk {
    enum ppb_lock_state val;
};

#define PPB_LOCK_ONEBLOCK_LOCK   ((struct ppb_lock_thunk){ PPB_LOCK })
#define PPB_LOCK_ONEBLOCK_UNLOCK ((struct ppb_lock_thunk){ PPB_UNLOCK })

static int __xipram chip_ready(struct map_info *map, unsigned long addr);

static int do_cfi_ppb_lock_oneblock(struct map_info *map, struct flchip *chip,
    unsigned long adr, int len, void *thunk)
{
    struct cfi_private *cfi = map->fldrv_priv;
    struct ppb_lock_thunk *th = (struct ppb_lock_thunk *)thunk;

    unsigned long timeo;
    int ret = 0;
    uint16_t lock_flag;

    DEBUG(MTD_DEBUG_LEVEL1,
        "do_cfi_ppb_lock_oneblock: start %08lX adr %08lX \n",chip->start,adr);
    adr += chip->start;

    mutex_lock(&chip->mutex);
    ret = get_chip(map, chip, adr, FL_LOCKING);
    if (ret) {
        mutex_unlock(&chip->mutex);
        return ret;
    }
    chip->oldstate = chip->state;
    chip->state = FL_LOCKING;

    DEBUG(MTD_DEBUG_LEVEL1,
        "do_cfi_ppb_lock_oneblock: adr %08lX\n",adr);

    // enter PPB mode
    cfi_send_gen_cmd(0xAA,                  cfi->addr_unlock1, chip->start, map, cfi, cfi->device_type, NULL);
    cfi_send_gen_cmd(0x55,                  cfi->addr_unlock2, chip->start, map, cfi, cfi->device_type, NULL);  
    cfi_send_gen_cmd(AMD_CMD_SET_PPB_ENTRY, cfi->addr_unlock1, chip->start, map, cfi, cfi->device_type, NULL);

    lock_flag = cfi_read_query16(map,adr);
    DEBUG(MTD_DEBUG_LEVEL1,
        "do_cfi_ppb_lock_oneblock: lockflg=%d,%s\n",lock_flag,(lock_flag == PPB_UNLOCK) ? "Unlocked":"Locked");

    // Lock or Unlock
    if(th->val == PPB_LOCK){
        map_write(map, CMD(AMD_CMD_PPB_LOCK_BC1), adr);
        map_write(map, CMD(AMD_CMD_PPB_LOCK_BC2), adr);
    }else{
        // unlock is no sector spec
        cfi_send_gen_cmd(AMD_CMD_PPB_UNLOCK_BC1,0, chip->start, map, cfi, cfi->device_type, NULL);
        cfi_send_gen_cmd(AMD_CMD_PPB_UNLOCK_BC2,0, chip->start, map, cfi, cfi->device_type, NULL);
    }

    // wait...
    timeo = jiffies + (HZ*20);

    for(;;){
        if(chip_ready(map,adr)) break;

        if (time_after(jiffies, timeo)) {
            printk(KERN_WARNING "MTD %s(): software timeout\n",
                __func__ );
            break;
        }
        mutex_unlock(&chip->mutex);
        cfi_udelay(1000000/HZ);
        mutex_lock(&chip->mutex);
    }
    // exit PPB mode
    cfi_send_gen_cmd(AMD_CMD_SET_PPB_EXIT_BC1,0, chip->start, map, cfi, cfi->device_type, NULL);
    cfi_send_gen_cmd(AMD_CMD_SET_PPB_EXIT_BC2,0, chip->start, map, cfi, cfi->device_type, NULL);    

    chip->state = chip->oldstate;
    put_chip(map, chip, adr);
    mutex_unlock(&chip->mutex);
    return ret;
}


static int cfi_ppb_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
{
    int ret;

    ret = cfi_varsize_frob(mtd, do_cfi_ppb_lock_oneblock, ofs, len,
        (void *)&PPB_LOCK_ONEBLOCK_LOCK);

    return ret;
}


static int cfi_ppb_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
{
    int ret;

    ret = cfi_varsize_frob(mtd, do_cfi_ppb_lock_oneblock, ofs, len,
        (void *)&PPB_LOCK_ONEBLOCK_UNLOCK);

    return ret;
}


/* PBB fixup*/
static void cfi_fixup_ppb_unlock(struct cfi_pri_amdstd *extp,struct mtd_info *mtd)
{
    /* read sector protect/unprotect scheme is 0x08 to old scheme */
    if(extp->BlkProtUnprot != 8) return;

    printk(KERN_INFO "Advanced Sector Protection (PPB) enabled\n");
    printk(KERN_INFO "Use PPB lock/unlock method \n");
    mtd->lock   = cfi_ppb_lock;
    mtd->unlock = cfi_ppb_unlock;
}

#endif /* PPB_LOCK_H */

cfi_cmdset_0002.patch

diff --git a/drivers/mtd/chips/cfi_cmdset_0002.c b/drivers/mtd/chips/cfi_cmdset_0002
old mode 100644
new mode 100755
index d81079e..7ba6a65
--- a/drivers/mtd/chips/cfi_cmdset_0002.c
+++ b/drivers/mtd/chips/cfi_cmdset_0002.c
@@ -68,6 +68,7 @@ static struct mtd_info *cfi_amdstd_setup (struct mtd_info *);
 static int get_chip(struct map_info *map, struct flchip *chip, unsigned long adr, i
 static void put_chip(struct map_info *map, struct flchip *chip, unsigned long adr);
 #include "fwh_lock.h"
+#include "cfi_ppb_lock.h"

 static int cfi_atmel_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len);
 static int cfi_atmel_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len);
@@ -461,6 +462,9 @@ struct mtd_info *cfi_cmdset_0002(struct map_info *map, int prima
                        /* Set the default CFI lock/unlock addresses */
                        cfi->addr_unlock1 = 0x555;
                        cfi->addr_unlock2 = 0x2aa;
+                                               
+                       /* read sector protect/unprotect scheme is 0x08 to old schem
+                       cfi_fixup_ppb_unlock(extp,mtd);
                }
                cfi_fixup(mtd, cfi_nopri_fixup_table);