libjaylink/transport.c

   1 /*
   2  * This file is part of the libjaylink project.
   3  *
   4  * Copyright (C) 2014-2015 Marc Schink <jaylink-dev@marcschink.de>
   5  *
   6  * This program is free software: you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation, either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <stdlib.h>
  21 #include <stdint.h>
  22 #include <stdbool.h>
  23 #include <string.h>
  24
  25 #ifdef HAVE_CONFIG_H
  26 #include "config.h"
  27 #endif
  28 #include "libjaylink.h"
  29 #include "libjaylink-internal.h"
  30
  31 /**
  32  * @file
  33  *
  34  * Transport abstraction layer.
  35  */
  36
  37 /**
  38  * Open a device.
  39  *
  40  * This function must be called before any other function of the transport
  41  * abstraction layer for the given device handle is called.
  42  *
  43  * @param[in,out] devh Device handle.
  44  *
  45  * @retval JAYLINK_OK Success.
  46  * @retval JAYLINK_ERR_IO Input/output error.
  47  * @retval JAYLINK_ERR Other error conditions.
  48  */
  49 JAYLINK_PRIV int transport_open(struct jaylink_device_handle *devh)
  50 {
  51         int ret;
  52
  53         switch (devh->dev->iface) {
  54 #ifdef HAVE_LIBUSB
  55         case JAYLINK_HIF_USB:
  56                 ret = transport_usb_open(devh);
  57                 break;
  58 #endif
  59         case JAYLINK_HIF_TCP:
  60                 ret = transport_tcp_open(devh);
  61                 break;
  62         default:
  63                 log_err(devh->dev->ctx, "BUG: Invalid host interface: %u.",
  64                         devh->dev->iface);
  65                 return JAYLINK_ERR;
  66         }
  67
  68         return ret;
  69 }
  70
  71 /**
  72  * Close a device.
  73  *
  74  * After this function has been called no other function of the transport
  75  * abstraction layer for the given device handle must be called.
  76  *
  77  * @param[in,out] devh Device handle.
  78  *
  79  * @retval JAYLINK_OK Success.
  80  * @retval JAYLINK_ERR Other error conditions.
  81  */
  82 JAYLINK_PRIV int transport_close(struct jaylink_device_handle *devh)
  83 {
  84         int ret;
  85
  86         switch (devh->dev->iface) {
  87 #ifdef HAVE_LIBUSB
  88         case JAYLINK_HIF_USB:
  89                 ret = transport_usb_close(devh);
  90                 break;
  91 #endif
  92         case JAYLINK_HIF_TCP:
  93                 ret = transport_tcp_close(devh);
  94                 break;
  95         default:
  96                 log_err(devh->dev->ctx, "BUG: Invalid host interface: %u.",
  97                         devh->dev->iface);
  98                 return JAYLINK_ERR;
  99         }
 100
 101         return ret;
 102 }
 103
 104 /**
 105  * Start a write operation for a device.
 106  *
 107  * The data of a write operation must be written with at least one call of
 108  * transport_write(). It is required that all data of a write operation is
 109  * written before an other write and/or read operation is started.
 110  *
 111  * @param[in,out] devh Device handle.
 112  * @param[in] length Number of bytes of the write operation.
 113  * @param[in] has_command Determines whether the data of the write operation
 114  *                        contains the protocol command.
 115  *
 116  * @retval JAYLINK_OK Success.
 117  * @retval JAYLINK_ERR_ARG Invalid arguments.
 118  */
 119 JAYLINK_PRIV int transport_start_write(struct jaylink_device_handle *devh,
 120                 size_t length, bool has_command)
 121 {
 122         int ret;
 123
 124         switch (devh->dev->iface) {
 125 #ifdef HAVE_LIBUSB
 126         case JAYLINK_HIF_USB:
 127                 ret = transport_usb_start_write(devh, length, has_command);
 128                 break;
 129 #endif
 130         case JAYLINK_HIF_TCP:
 131                 ret = transport_tcp_start_write(devh, length, has_command);
 132                 break;
 133         default:
 134                 log_err(devh->dev->ctx, "BUG: Invalid host interface: %u.",
 135                         devh->dev->iface);
 136                 return JAYLINK_ERR;
 137         }
 138
 139         return ret;
 140 }
 141
 142 /**
 143  * Start a read operation for a device.
 144  *
 145  * The data of a read operation must be read with at least one call of
 146  * transport_read(). It is required that all data of a read operation is read
 147  * before an other write and/or read operation is started.
 148  *
 149  * @param[in,out] devh Device handle.
 150  * @param[in] length Number of bytes of the read operation.
 151  *
 152  * @retval JAYLINK_OK Success.
 153  * @retval JAYLINK_ERR_ARG Invalid arguments.
 154  */
 155 JAYLINK_PRIV int transport_start_read(struct jaylink_device_handle *devh,
 156                 size_t length)
 157 {
 158         int ret;
 159
 160         switch (devh->dev->iface) {
 161 #ifdef HAVE_LIBUSB
 162         case JAYLINK_HIF_USB:
 163                 ret = transport_usb_start_read(devh, length);
 164                 break;
 165 #endif
 166         case JAYLINK_HIF_TCP:
 167                 ret = transport_tcp_start_read(devh, length);
 168                 break;
 169         default:
 170                 log_err(devh->dev->ctx, "BUG: Invalid host interface: %u.",
 171                         devh->dev->iface);
 172                 return JAYLINK_ERR;
 173         }
 174
 175         return ret;
 176 }
 177
 178 /**
 179  * Start a write and read operation for a device.
 180  *
 181  * This function starts a write and read operation as the consecutive call of
 182  * transport_start_write() and transport_start_read() but has a different
 183  * meaning from the protocol perspective and can therefore not be replaced by
 184  * these functions and vice versa.
 185  *
 186  * @note The write operation must be completed first before the read operation
 187  *       must be processed.
 188  *
 189  * @param[in,out] devh Device handle.
 190  * @param[in] write_length Number of bytes of the write operation.
 191  * @param[in] read_length Number of bytes of the read operation.
 192  * @param[in] has_command Determines whether the data of the write operation
 193  *                        contains the protocol command.
 194  *
 195  * @retval JAYLINK_OK Success.
 196  * @retval JAYLINK_ERR_ARG Invalid arguments.
 197  */
 198 JAYLINK_PRIV int transport_start_write_read(struct jaylink_device_handle *devh,
 199                 size_t write_length, size_t read_length, bool has_command)
 200 {
 201         int ret;
 202
 203         switch (devh->dev->iface) {
 204 #ifdef HAVE_LIBUSB
 205         case JAYLINK_HIF_USB:
 206                 ret = transport_usb_start_write_read(devh, write_length,
 207                         read_length, has_command);
 208                 break;
 209 #endif
 210         case JAYLINK_HIF_TCP:
 211                 ret = transport_tcp_start_write_read(devh, write_length,
 212                         read_length, has_command);
 213                 break;
 214         default:
 215                 log_err(devh->dev->ctx, "BUG: Invalid host interface: %u.",
 216                         devh->dev->iface);
 217                 return JAYLINK_ERR;
 218         }
 219
 220         return ret;
 221 }
 222
 223 /**
 224  * Write data to a device.
 225  *
 226  * Before this function is used transport_start_write() or
 227  * transport_start_write_read() must be called to start a write operation. The
 228  * total number of written bytes must not exceed the number of bytes of the
 229  * write operation.
 230  *
 231  * @note A write operation will be performed and the data will be sent to the
 232  *       device when the number of written bytes reaches the number of bytes of
 233  *       the write operation. Before that the data will be written into a
 234  *       buffer.
 235  *
 236  * @param[in,out] devh Device handle.
 237  * @param[in] buffer Buffer to write data from.
 238  * @param[in] length Number of bytes to write.
 239  *
 240  * @retval JAYLINK_OK Success.
 241  * @retval JAYLINK_ERR_ARG Invalid arguments.
 242  * @retval JAYLINK_ERR_TIMEOUT A timeout occurred.
 243  * @retval JAYLINK_ERR_IO Input/output error.
 244  * @retval JAYLINK_ERR Other error conditions.
 245  */
 246 JAYLINK_PRIV int transport_write(struct jaylink_device_handle *devh,
 247                 const uint8_t *buffer, size_t length)
 248 {
 249         int ret;
 250
 251         switch (devh->dev->iface) {
 252 #ifdef HAVE_LIBUSB
 253         case JAYLINK_HIF_USB:
 254                 ret = transport_usb_write(devh, buffer, length);
 255                 break;
 256 #endif
 257         case JAYLINK_HIF_TCP:
 258                 ret = transport_tcp_write(devh, buffer, length);
 259                 break;
 260         default:
 261                 log_err(devh->dev->ctx, "BUG: Invalid host interface: %u.",
 262                         devh->dev->iface);
 263                 return JAYLINK_ERR;
 264         }
 265
 266         return ret;
 267 }
 268
 269 /**
 270  * Read data from a device.
 271  *
 272  * Before this function is used transport_start_read() or
 273  * transport_start_write_read() must be called to start a read operation. The
 274  * total number of read bytes must not exceed the number of bytes of the read
 275  * operation.
 276  *
 277  * @param[in,out] devh Device handle.
 278  * @param[out] buffer Buffer to read data into on success. Its content is
 279  *                    undefined on failure.
 280  * @param[in] length Number of bytes to read.
 281  *
 282  * @retval JAYLINK_OK Success.
 283  * @retval JAYLINK_ERR_ARG Invalid arguments.
 284  * @retval JAYLINK_ERR_TIMEOUT A timeout occurred.
 285  * @retval JAYLINK_ERR_IO Input/output error.
 286  * @retval JAYLINK_ERR Other error conditions.
 287  */
 288 JAYLINK_PRIV int transport_read(struct jaylink_device_handle *devh,
 289                 uint8_t *buffer, size_t length)
 290 {
 291         int ret;
 292
 293         switch (devh->dev->iface) {
 294 #ifdef HAVE_LIBUSB
 295         case JAYLINK_HIF_USB:
 296                 ret = transport_usb_read(devh, buffer, length);
 297                 break;
 298 #endif
 299         case JAYLINK_HIF_TCP:
 300                 ret = transport_tcp_read(devh, buffer, length);
 301                 break;
 302         default:
 303                 log_err(devh->dev->ctx, "BUG: Invalid host interface: %u.",
 304                         devh->dev->iface);
 305                 return JAYLINK_ERR;
 306         }
 307
 308         return ret;
 309 }