]> git.karo-electronics.de Git - karo-tx-linux.git/blobdiff - drivers/mtd/chips/cfi_cmdset_0002.c
mtd: cfi_cmdset_0002: Support Persistent Protection Bits (PPB) locking
[karo-tx-linux.git] / drivers / mtd / chips / cfi_cmdset_0002.c
index b86197286f2406d4c419736a4252ab59e0403c11..fff665d59a0dba759f63854bb95e25bbb998b64f 100644 (file)
@@ -33,6 +33,8 @@
 #include <linux/delay.h>
 #include <linux/interrupt.h>
 #include <linux/reboot.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
 #include <linux/mtd/map.h>
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/cfi.h>
@@ -74,6 +76,10 @@ static void put_chip(struct map_info *map, struct flchip *chip, unsigned long ad
 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);
 
+static int cfi_ppb_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len);
+static int cfi_ppb_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len);
+static int cfi_ppb_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len);
+
 static struct mtd_chip_driver cfi_amdstd_chipdrv = {
        .probe          = NULL, /* Not usable directly */
        .destroy        = cfi_amdstd_destroy,
@@ -496,6 +502,7 @@ static void cfi_fixup_m29ew_delay_after_resume(struct cfi_private *cfi)
 struct mtd_info *cfi_cmdset_0002(struct map_info *map, int primary)
 {
        struct cfi_private *cfi = map->fldrv_priv;
+       struct device_node __maybe_unused *np = map->device_node;
        struct mtd_info *mtd;
        int i;
 
@@ -570,6 +577,17 @@ struct mtd_info *cfi_cmdset_0002(struct map_info *map, int primary)
                        cfi_tell_features(extp);
 #endif
 
+#ifdef CONFIG_OF
+                       if (np && of_property_read_bool(
+                                   np, "use-advanced-sector-protection")
+                           && extp->BlkProtUnprot == 8) {
+                               printk(KERN_INFO "  Advanced Sector Protection (PPB Locking) supported\n");
+                               mtd->_lock = cfi_ppb_lock;
+                               mtd->_unlock = cfi_ppb_unlock;
+                               mtd->_is_locked = cfi_ppb_is_locked;
+                       }
+#endif
+
                        bootloc = extp->TopBottom;
                        if ((bootloc < 2) || (bootloc > 5)) {
                                printk(KERN_WARNING "%s: CFI contains unrecognised boot "
@@ -2172,6 +2190,205 @@ static int cfi_atmel_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
        return cfi_varsize_frob(mtd, do_atmel_unlock, ofs, len, NULL);
 }
 
+/*
+ * Advanced Sector Protection - PPB (Persistent Protection Bit) locking
+ */
+
+struct ppb_lock {
+       struct flchip *chip;
+       loff_t offset;
+       int locked;
+};
+
+#define MAX_SECTORS                    512
+
+#define DO_XXLOCK_ONEBLOCK_LOCK                ((void *)1)
+#define DO_XXLOCK_ONEBLOCK_UNLOCK      ((void *)2)
+#define DO_XXLOCK_ONEBLOCK_GETLOCK     ((void *)3)
+
+static int __maybe_unused do_ppb_xxlock(struct map_info *map,
+                                       struct flchip *chip,
+                                       unsigned long adr, int len, void *thunk)
+{
+       struct cfi_private *cfi = map->fldrv_priv;
+       unsigned long timeo;
+       int ret;
+
+       mutex_lock(&chip->mutex);
+       ret = get_chip(map, chip, adr + chip->start, FL_LOCKING);
+       if (ret) {
+               mutex_unlock(&chip->mutex);
+               return ret;
+       }
+
+       pr_debug("MTD %s(): XXLOCK 0x%08lx len %d\n", __func__, adr, len);
+
+       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);
+       /* PPB entry command */
+       cfi_send_gen_cmd(0xC0, cfi->addr_unlock1, chip->start, map, cfi,
+                        cfi->device_type, NULL);
+
+       if (thunk == DO_XXLOCK_ONEBLOCK_LOCK) {
+               chip->state = FL_LOCKING;
+               map_write(map, CMD(0xA0), chip->start + adr);
+               map_write(map, CMD(0x00), chip->start + adr);
+       } else if (thunk == DO_XXLOCK_ONEBLOCK_UNLOCK) {
+               /*
+                * Unlocking of one specific sector is not supported, so we
+                * have to unlock all sectors of this device instead
+                */
+               chip->state = FL_UNLOCKING;
+               map_write(map, CMD(0x80), chip->start);
+               map_write(map, CMD(0x30), chip->start);
+       } else if (thunk == DO_XXLOCK_ONEBLOCK_GETLOCK) {
+               chip->state = FL_JEDEC_QUERY;
+               /* Return locked status: 0->locked, 1->unlocked */
+               ret = !cfi_read_query(map, adr);
+       } else
+               BUG();
+
+       /*
+        * Wait for some time as unlocking of all sectors takes quite long
+        */
+       timeo = jiffies + msecs_to_jiffies(2000);       /* 2s max (un)locking */
+       for (;;) {
+               if (chip_ready(map, adr))
+                       break;
+
+               if (time_after(jiffies, timeo)) {
+                       printk(KERN_ERR "Waiting for chip to be ready timed out.\n");
+                       ret = -EIO;
+                       break;
+               }
+
+               UDELAY(map, chip, adr, 1);
+       }
+
+       /* Exit BC commands */
+       map_write(map, CMD(0x90), chip->start);
+       map_write(map, CMD(0x00), chip->start);
+
+       chip->state = FL_READY;
+       put_chip(map, chip, adr + chip->start);
+       mutex_unlock(&chip->mutex);
+
+       return ret;
+}
+
+static int __maybe_unused cfi_ppb_lock(struct mtd_info *mtd, loff_t ofs,
+                                      uint64_t len)
+{
+       return cfi_varsize_frob(mtd, do_ppb_xxlock, ofs, len,
+                               DO_XXLOCK_ONEBLOCK_LOCK);
+}
+
+static int __maybe_unused cfi_ppb_unlock(struct mtd_info *mtd, loff_t ofs,
+                                        uint64_t len)
+{
+       struct mtd_erase_region_info *regions = mtd->eraseregions;
+       struct map_info *map = mtd->priv;
+       struct cfi_private *cfi = map->fldrv_priv;
+       struct ppb_lock *sect;
+       unsigned long adr;
+       loff_t offset;
+       uint64_t length;
+       int chipnum;
+       int i;
+       int sectors;
+       int ret;
+
+       /*
+        * PPB unlocking always unlocks all sectors of the flash chip.
+        * We need to re-lock all previously locked sectors. So lets
+        * first check the locking status of all sectors and save
+        * it for future use.
+        */
+       sect = kzalloc(MAX_SECTORS * sizeof(struct ppb_lock), GFP_KERNEL);
+       if (!sect)
+               return -ENOMEM;
+
+       /*
+        * This code to walk all sectors is a slightly modified version
+        * of the cfi_varsize_frob() code.
+        */
+       i = 0;
+       chipnum = 0;
+       adr = 0;
+       sectors = 0;
+       offset = 0;
+       length = mtd->size;
+
+       while (length) {
+               int size = regions[i].erasesize;
+
+               /*
+                * Only test sectors that shall not be unlocked. The other
+                * sectors shall be unlocked, so lets keep their locking
+                * status at "unlocked" (locked=0) for the final re-locking.
+                */
+               if ((adr < ofs) || (adr >= (ofs + len))) {
+                       sect[sectors].chip = &cfi->chips[chipnum];
+                       sect[sectors].offset = offset;
+                       sect[sectors].locked = do_ppb_xxlock(
+                               map, &cfi->chips[chipnum], adr, 0,
+                               DO_XXLOCK_ONEBLOCK_GETLOCK);
+               }
+
+               adr += size;
+               offset += size;
+               length -= size;
+
+               if (offset == regions[i].offset + size * regions[i].numblocks)
+                       i++;
+
+               if (adr >> cfi->chipshift) {
+                       adr = 0;
+                       chipnum++;
+
+                       if (chipnum >= cfi->numchips)
+                               break;
+               }
+
+               sectors++;
+               if (sectors >= MAX_SECTORS) {
+                       printk(KERN_ERR "Only %d sectors for PPB locking supported!\n",
+                              MAX_SECTORS);
+                       kfree(sect);
+                       return -EINVAL;
+               }
+       }
+
+       /* Now unlock the whole chip */
+       ret = cfi_varsize_frob(mtd, do_ppb_xxlock, ofs, len,
+                              DO_XXLOCK_ONEBLOCK_UNLOCK);
+       if (ret) {
+               kfree(sect);
+               return ret;
+       }
+
+       /*
+        * PPB unlocking always unlocks all sectors of the flash chip.
+        * We need to re-lock all previously locked sectors.
+        */
+       for (i = 0; i < sectors; i++) {
+               if (sect[i].locked)
+                       do_ppb_xxlock(map, sect[i].chip, sect[i].offset, 0,
+                                     DO_XXLOCK_ONEBLOCK_LOCK);
+       }
+
+       kfree(sect);
+       return ret;
+}
+
+static int __maybe_unused cfi_ppb_is_locked(struct mtd_info *mtd, loff_t ofs,
+                                           uint64_t len)
+{
+       return cfi_varsize_frob(mtd, do_ppb_xxlock, ofs, len,
+                               DO_XXLOCK_ONEBLOCK_GETLOCK) ? 1 : 0;
+}
 
 static void cfi_amdstd_sync (struct mtd_info *mtd)
 {