PERM_READ
(pinfo->capability & PERM_READ) != PERM_READ)
perm |= PERM_READ;
if (perm & PERM_READ) {
mdev->opened |= PERM_READ;
if (mdev->opened & PERM_READ) {
if (mdev->opened & PERM_READ)
if (!(mdev->opened & PERM_READ))
val &= PERM_READ|PERM_WRITE;
if (val == (PERM_READ|PERM_WRITE))
else if (val == PERM_READ)