libfprint/libfprint/fpi-spi-transfer.h
Benjamin Berg 7fcce7891a spi-transfer: Add SPI transfer helper routines
These routines assume that any messages is composed of a write and/or
read part. While the API allows sending and receiving as part of one
messages/transfer, it does not permit full duplex operation where data is
both send and received at the same time.
2021-04-08 16:52:20 +00:00

113 lines
4 KiB
C

/*
* FPrint spidev transfer handling
* Copyright (C) 2019-2020 Benjamin Berg <bberg@redhat.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#pragma once
#include "fpi-compat.h"
#include "fpi-device.h"
G_BEGIN_DECLS
#define FPI_TYPE_SPI_TRANSFER (fpi_spi_transfer_get_type ())
typedef struct _FpiSpiTransfer FpiSpiTransfer;
typedef struct _FpiSsm FpiSsm;
typedef void (*FpiSpiTransferCallback)(FpiSpiTransfer *transfer,
FpDevice *dev,
gpointer user_data,
GError *error);
/**
* FpiSpiTransfer:
* @device: The #FpDevice that the transfer belongs to.
* @ssm: Storage slot to associate the transfer with a state machine.
* Used by fpi_ssm_spi_transfer_cb() to modify the given state machine.
* @length_wr: The length of the write buffer
* @length_rd: The length of the read buffer
* @buffer_wr: The write buffer.
* @buffer_rd: The read buffer.
*
* Helper for handling SPI transfers. Currently transfers can either be pure
* write/read transfers or a write followed by a read (full duplex support
* can easily be added if desired).
*/
struct _FpiSpiTransfer
{
/*< public >*/
FpDevice *device;
FpiSsm *ssm;
gssize length_wr;
gssize length_rd;
guchar *buffer_wr;
guchar *buffer_rd;
/*< private >*/
guint ref_count;
int spidev_fd;
/* Callbacks */
gpointer user_data;
FpiSpiTransferCallback callback;
/* Data free function */
GDestroyNotify free_buffer_wr;
GDestroyNotify free_buffer_rd;
};
GType fpi_spi_transfer_get_type (void) G_GNUC_CONST;
FpiSpiTransfer *fpi_spi_transfer_new (FpDevice *device,
int spidev_fd);
FpiSpiTransfer *fpi_spi_transfer_ref (FpiSpiTransfer *self);
void fpi_spi_transfer_unref (FpiSpiTransfer *self);
void fpi_spi_transfer_write (FpiSpiTransfer *transfer,
gsize length);
FP_GNUC_ACCESS (read_only, 2, 3)
void fpi_spi_transfer_write_full (FpiSpiTransfer *transfer,
guint8 *buffer,
gsize length,
GDestroyNotify free_func);
void fpi_spi_transfer_read (FpiSpiTransfer *transfer,
gsize length);
FP_GNUC_ACCESS (write_only, 2, 3)
void fpi_spi_transfer_read_full (FpiSpiTransfer *transfer,
guint8 *buffer,
gsize length,
GDestroyNotify free_func);
void fpi_spi_transfer_submit (FpiSpiTransfer *transfer,
GCancellable *cancellable,
FpiSpiTransferCallback callback,
gpointer user_data);
gboolean fpi_spi_transfer_submit_sync (FpiSpiTransfer *transfer,
GError **error);
G_DEFINE_AUTOPTR_CLEANUP_FUNC (FpiSpiTransfer, fpi_spi_transfer_unref)
G_END_DECLS