/*
* Copyright (C) 2021 The LineageOS Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef XIAOMI_FINGERPRINT_H
#define XIAOMI_FINGERPRINT_H
#include <hardware/hardware.h>
#include <hardware/fingerprint.h>
typedef struct xiaomi_fingerprint_device {
/**
* Common methods of the fingerprint device. This *must* be the first member
* of fingerprint_device as users of this structure will cast a hw_device_t
* to fingerprint_device pointer in contexts where it's known
* the hw_device_t references a fingerprint_device.
*/
struct hw_device_t common;
/*
* Client provided callback function to receive notifications.
* Do not set by hand, use the function above instead.
*/
fingerprint_notify_t notify;
/*
* Set notification callback:
* Registers a user function that would receive notifications from the HAL
* The call will block if the HAL state machine is in busy state until HAL
* leaves the busy state.
*
* Function return: 0 if callback function is successfuly registered
* or a negative number in case of error, generally from the errno.h set.
*/
int (*set_notify)(struct xiaomi_fingerprint_device *dev, fingerprint_notify_t notify);
/*
* Fingerprint pre-enroll enroll request:
* Generates a unique token to upper layers to indicate the start of an enrollment transaction.
* This token will be wrapped by security for verification and passed to enroll() for
* verification before enrollment will be allowed. This is to ensure adding a new fingerprint
* template was preceded by some kind of credential confirmation (e.g. device password).
*
* Function return: 0 if function failed
* otherwise, a uint64_t of token
*/
uint64_t (*pre_enroll)(struct xiaomi_fingerprint_device *dev);
/*
* Fingerprint enroll request:
* Switches the HAL state machine to collect and store a new fingerprint
* template. Switches back as soon as enroll is complete
* (fingerprint_msg.type == FINGERPRINT_TEMPLATE_ENROLLING &&
* fingerprint_msg.data.enroll.samples_remaining == 0)
* or after timeout_sec seconds.
* The fingerprint template will be assigned to the group gid. User has a choice
* to supply the gid or set it to 0 in which case a unique group id will be generated.
*
* Function return: 0 if enrollment process can be successfully started
* or a negative number in case of error, generally from the errno.h set.
* A notify() function may be called indicating the error condition.
*/
int (*enroll)(struct xiaomi_fingerprint_device *dev, const hw_auth_token_t *hat,
uint32_t gid, uint32_t timeout_sec);
/*
* Finishes the enroll operation and invalidates the pre_enroll() generated challenge.
* This will be called at the end of a multi-finger enrollment session to indicate
* that no more fingers will be added.
*
* Function return: 0 if the request is accepted
* or a negative number in case of error, generally from the errno.h set.
*/
int (*post_enroll)(struct xiaomi_fingerprint_device *dev);
/*
* get_authenticator_id:
* Returns a token associated with the current fingerprint set. This value will
* change whenever a new fingerprint is enrolled, thus creating a new fingerprint
* set.
*
* Function return: current authenticator id or 0 if function failed.
*/
uint64_t (*get_authenticator_id)(struct xiaomi_fingerprint_device *dev);
/*
* Cancel pending enroll or authenticate, sending FINGERPRINT_ERROR_CANCELED
* to all running clients. Switches the HAL state machine back to the idle state.
* Unlike enroll_done() doesn't invalidate the pre_enroll() challenge.
*
* Function return: 0 if cancel request is accepted
* or a negative number in case of error, generally from the errno.h set.
*/
int (*cancel)(struct xiaomi_fingerprint_device *dev);
/*
* Enumerate all the fingerprint templates found in the directory set by
* set_active_group()
* For each template found a notify() will be called with:
* fingerprint_msg.type == FINGERPRINT_TEMPLATE_ENUMERATED
* fingerprint_msg.data.enumerated.finger indicating a template id
* fingerprint_msg.data.enumerated.remaining_templates indicating how many more
* enumeration messages to expect.
* Note: If there are no fingerprints, then this should return 0 and the first fingerprint
* enumerated should have fingerid=0 and remaining=0
* Function return: 0 if enumerate request is accepted
* or a negative number in case of error, generally from the errno.h set.
*/
int (*enumerate)(struct xiaomi_fingerprint_device *dev);
/*
* Fingerprint remove request:
* Deletes a fingerprint template.
* Works only within the path set by set_active_group().
* The fid parameter can be used as a widcard:
* * fid == 0 -- delete all the templates in the group.
* * fid != 0 -- delete this specific template from the group.
* For each template found a notify() will be called with:
* fingerprint_msg.type == FINGERPRINT_TEMPLATE_REMOVED
* fingerprint_msg.data.removed.finger indicating a template id deleted
* fingerprint_msg.data.removed.remaining_templates indicating how many more
* templates will be deleted by this operation.
*
* Function return: 0 if fingerprint template(s) can be successfully deleted
* or a negative number in case of error, generally from the errno.h set.
*/
int (*remove)(struct xiaomi_fingerprint_device *dev, uint32_t gid, uint32_t fid);
/*
* Restricts the HAL operation to a set of fingerprints belonging to a
* group provided.
* The caller must provide a path to a storage location within the user's
* data directory.
*
* Function return: 0 on success
* or a negative number in case of error, generally from the errno.h set.
*/
int (*set_active_group)(struct xiaomi_fingerprint_device *dev, uint32_t gid,
const char *store_path);
/*
* Authenticates an operation identifed by operation_id
*
* Function return: 0 on success
* or a negative number in case of error, generally from the errno.h set.
*/
int (*authenticate)(struct xiaomi_fingerprint_device *dev, uint64_t operation_id, uint32_t gid);
/*
* Call a Xiaomi fingerprint extension command.
*/
int (*extCmd)(struct xiaomi_fingerprint_device *dev, int32_t cmd, int32_t param);
/*
* Reserved for backward binary compatibility
*/
void *reserved[4];
} xiaomi_fingerprint_device_t;
#endif // XIAOMI_FINGERPRINT_H
