From: Al Cooper <acooper@xxxxxxxxxxxx> Create a sysfs interface that allows a user to manage an inserted cards lock state. The sysfs attribute "lock" will be added to the device's sysfs directory. The following commands are supported: "setpw" - Set the cards password "clearpw" - Clear the cards password "lock" - Lock the card "unlock" - Unlock the card "erase" - Force erase the card, clear the password and unlock it Commands that require a password will request the password through the kernels KEYS subsystem. refs #SWLINUX-2545 Signed-off-by: Al Cooper <acooper@xxxxxxxxxxxx> --- drivers/mmc/core/mmc.c | 82 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 82 insertions(+) diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c index 6d02012..1ad33ca 100644 --- a/drivers/mmc/core/mmc.c +++ b/drivers/mmc/core/mmc.c @@ -654,6 +654,85 @@ out: return err; } +#ifdef CONFIG_MMC_LOCK + +ssize_t mmc_lock_show(struct device *dev, struct device_attribute *att, + char *buf) +{ + struct mmc_card *card = mmc_dev_to_card(dev); + + if (!mmc_card_lockable(card)) + return sprintf(buf, "unsupported\n"); + else + return sprintf(buf, "%slocked\n", mmc_card_locked(card) ? + "" : "un"); +} + + +struct lock_cmd { + const char *name; + int io_cmd; + int locked_required; + int need_pw; +} lock_cmds[] = { + { "erase" , MMC_LOCK_MODE_ERASE, true, false }, + { "clrpw", MMC_LOCK_MODE_CLR_PWD, false, true }, + { "setpw", MMC_LOCK_MODE_SET_PWD, false, true }, + { "lock", MMC_LOCK_MODE_LOCK, false, true }, + { "unlock", MMC_LOCK_MODE_UNLOCK, true, true }, +}; + +#define LOCK_CMD_CNT (sizeof(lock_cmds) / sizeof(struct lock_cmd)) + +/* + * implement MMC password functions: force erase, set password, + * clear password, lock and unlock. + */ +ssize_t mmc_lock_store(struct device *dev, struct device_attribute *att, + const char *data, size_t len) +{ + struct mmc_card *card = mmc_dev_to_card(dev); + int res = -EINVAL; + int x; + struct mmc_password password; + + mmc_claim_host(card->host); + if (!mmc_card_lockable(card)) + goto out; + for (x = 0; x < LOCK_CMD_CNT; x++) { + if (sysfs_streq(data, lock_cmds[x].name)) + break; + } + if (x >= LOCK_CMD_CNT) + goto out; + if (lock_cmds[x].locked_required ^ + (mmc_card_locked(card) ? true : false)) { + pr_warning("%s requires %slocked card\n", + lock_cmds[x].name, + lock_cmds[x].locked_required ? "" : "un"); + goto out; + } + if (lock_cmds[x].need_pw) { + res = mmc_get_password(card, &password); + if (res) + goto out; + } + res = mmc_lock_unlock(card, &password, lock_cmds[x].io_cmd); +out: + mmc_release_host(card->host); + if (res == 0) + return len; + else + return res; +} + +static DEVICE_ATTR(lock, S_IWUSR | S_IRUGO, + mmc_lock_show, mmc_lock_store); + + +#endif /* CONFIG_MMC_LOCK */ + + MMC_DEV_ATTR(cid, "%08x%08x%08x%08x\n", card->raw_cid[0], card->raw_cid[1], card->raw_cid[2], card->raw_cid[3]); MMC_DEV_ATTR(csd, "%08x%08x%08x%08x\n", card->raw_csd[0], card->raw_csd[1], @@ -691,6 +770,9 @@ static struct attribute *mmc_std_attrs[] = { &dev_attr_enhanced_area_size.attr, &dev_attr_raw_rpmb_size_mult.attr, &dev_attr_rel_sectors.attr, +#ifdef CONFIG_MMC_LOCK + &dev_attr_lock.attr, +#endif /* CONFIG_MMC_LOCK */ NULL, }; -- 1.8.1.3 -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html