2 * This file is part of the libjaylink project.
4 * Copyright (C) 2015 Marc Schink <jaylink-dev@marcschink.de>
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.
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.
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/>.
22 #include "libjaylink.h"
23 #include "libjaylink-internal.h"
28 * Emulator communication (EMUCOM).
32 #define CMD_EMUCOM 0xee
34 #define EMUCOM_CMD_WRITE 0x01
37 * Error code indicating that the EMUCOM channel is not supported by the
40 #define EMUCOM_ERR_NOT_SUPPORTED 0x80000001
44 * Write to an EMUCOM channel.
46 * @note This function must only be used if the device has the
47 * #JAYLINK_DEV_CAP_EMUCOM capability.
49 * @param[in,out] devh Device handle.
50 * @param[in] channel Channel to write data to.
51 * @param[in] buffer Buffer to write data from.
52 * @param[in,out] length Number of bytes to write. On success, the value gets
53 * updated with the actual number of bytes written. The
54 * value is undefined on failure.
56 * @retval JAYLINK_OK Success.
57 * @retval JAYLINK_ERR_ARG Invalid arguments.
58 * @retval JAYLINK_ERR_TIMEOUT A timeout occurred.
59 * @retval JAYLINK_ERR_PROTO Protocol violation.
60 * @retval JAYLINK_ERR_DEV Unspecified device error.
61 * @retval JAYLINK_ERR_DEV_NOT_SUPPORTED Channel is not supported by the device.
62 * @retval JAYLINK_ERR Other error conditions.
64 JAYLINK_API
int jaylink_emucom_write(struct jaylink_device_handle
*devh
,
65 uint32_t channel
, const uint8_t *buffer
, uint32_t *length
)
68 struct jaylink_context
*ctx
;
73 if (!devh
|| !buffer
|| !length
)
74 return JAYLINK_ERR_ARG
;
77 return JAYLINK_ERR_ARG
;
80 ret
= transport_start_write(devh
, 10, 1);
82 if (ret
!= JAYLINK_OK
) {
83 log_err(ctx
, "transport_start_write() failed: %i.", ret
);
88 buf
[1] = EMUCOM_CMD_WRITE
;
90 buffer_set_u32(buf
, channel
, 2);
91 buffer_set_u32(buf
, *length
, 6);
93 ret
= transport_write(devh
, buf
, 10);
95 if (ret
!= JAYLINK_OK
) {
96 log_err(ctx
, "transport_write() failed: %i.", ret
);
100 ret
= transport_start_write_read(devh
, *length
, 4, 0);
102 if (ret
!= JAYLINK_OK
) {
103 log_err(ctx
, "transport_start_write_read() failed: %i.", ret
);
107 ret
= transport_write(devh
, buffer
, *length
);
109 if (ret
!= JAYLINK_OK
) {
110 log_err(ctx
, "transport_write() failed: %i.", ret
);
114 ret
= transport_read(devh
, buf
, 4);
116 if (ret
!= JAYLINK_OK
) {
117 log_err(ctx
, "transport_read() failed: %i.", ret
);
121 tmp
= buffer_get_u32(buf
, 0);
123 if (tmp
== EMUCOM_ERR_NOT_SUPPORTED
) {
124 log_err(ctx
, "Channel 0x%x is not supported by the device.",
126 return JAYLINK_ERR_DEV_NOT_SUPPORTED
;
132 log_err(ctx
, "Failed to write to channel 0x%x.", channel
);
133 return JAYLINK_ERR_DEV
;
137 log_err(ctx
, "Only %u bytes were supposed to be written, but "
138 "the device reported %u written bytes.", *length
, tmp
);
139 return JAYLINK_ERR_PROTO
;