2 * This file is part of the libsigrok project.
4 * Copyright (C) 2013 Martin Ling <martin-sigrok@earth.li>
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 3 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/>.
20 #include "libsigrok.h"
21 #include "libsigrok-internal.h"
29 #define LOG_PREFIX "scpi_usbtmc"
31 #define MAX_READ_LENGTH 2048
34 struct sr_usbtmc_dev_inst *usbtmc;
35 char response_buffer[MAX_READ_LENGTH];
37 int response_bytes_read;
40 static GSList *scpi_usbtmc_scan(struct drv_context *drvc)
42 GSList *resources = NULL;
49 if (!(dir = g_dir_open("/sys/class/usbmisc/", 0, NULL)))
50 if (!(dir = g_dir_open("/sys/class/usb/", 0, NULL)))
52 while ((dev_name = g_dir_read_name(dir))) {
53 if (strncmp(dev_name, "usbtmc", 6))
55 resource = g_strconcat("/dev/", dev_name, NULL);
56 resources = g_slist_append(resources, resource);
63 static int scpi_usbtmc_dev_inst_new(void *priv, struct drv_context *drvc,
64 const char *resource, char **params, const char *serialcomm)
66 struct usbtmc_scpi *uscpi = priv;
72 if (!(uscpi->usbtmc = sr_usbtmc_dev_inst_new(resource)))
78 static int scpi_usbtmc_open(void *priv)
80 struct usbtmc_scpi *uscpi = priv;
81 struct sr_usbtmc_dev_inst *usbtmc = uscpi->usbtmc;
83 if ((usbtmc->fd = open(usbtmc->device, O_RDWR)) < 0)
89 static int scpi_usbtmc_source_add(void *priv, int events, int timeout,
90 sr_receive_data_callback cb, void *cb_data)
92 struct usbtmc_scpi *uscpi = priv;
93 struct sr_usbtmc_dev_inst *usbtmc = uscpi->usbtmc;
95 return sr_source_add(usbtmc->fd, events, timeout, cb, cb_data);
98 static int scpi_usbtmc_source_remove(void *priv)
100 struct usbtmc_scpi *uscpi = priv;
101 struct sr_usbtmc_dev_inst *usbtmc = uscpi->usbtmc;
103 return sr_source_remove(usbtmc->fd);
106 static int scpi_usbtmc_send(void *priv, const char *command)
108 struct usbtmc_scpi *uscpi = priv;
109 struct sr_usbtmc_dev_inst *usbtmc = uscpi->usbtmc;
112 len = strlen(command);
113 out = write(usbtmc->fd, command, len);
116 sr_err("Write error: %s", strerror(errno));
121 sr_dbg("Only sent %d/%d bytes of SCPI command: '%s'.", out,
125 sr_spew("Successfully sent SCPI command: '%s'.", command);
130 static int scpi_usbtmc_read_begin(void *priv)
132 struct usbtmc_scpi *uscpi = priv;
133 struct sr_usbtmc_dev_inst *usbtmc = uscpi->usbtmc;
136 len = read(usbtmc->fd, uscpi->response_buffer, MAX_READ_LENGTH);
139 sr_err("Read error: %s", strerror(errno));
143 uscpi->response_length = len;
144 uscpi->response_bytes_read = 0;
146 sr_spew("Read %d bytes from device into buffer", len);
151 static int scpi_usbtmc_read_data(void *priv, char *buf, int maxlen)
153 struct usbtmc_scpi *uscpi = priv;
156 sr_spew("%d bytes requested", maxlen);
158 if (uscpi->response_bytes_read == uscpi->response_length) {
159 sr_spew("Buffer is empty.");
160 if (uscpi->response_length == MAX_READ_LENGTH) {
161 sr_spew("Previous read was of maximum length, reading again.");
162 if (scpi_usbtmc_read_begin(uscpi) != SR_OK)
169 read_length = uscpi->response_length - uscpi->response_bytes_read;
171 if (read_length > maxlen)
172 read_length = maxlen;
174 memcpy(buf, uscpi->response_buffer + uscpi->response_bytes_read, read_length);
176 uscpi->response_bytes_read += read_length;
178 sr_spew("Returned %d bytes from buffer, %d/%d bytes of buffer now read",
179 read_length, uscpi->response_bytes_read, uscpi->response_length);
184 static int scpi_usbtmc_read_complete(void *priv)
186 struct usbtmc_scpi *uscpi = priv;
188 if (uscpi->response_length == MAX_READ_LENGTH
189 && uscpi->response_bytes_read == uscpi->response_length)
190 scpi_usbtmc_read_begin(uscpi);
192 return (uscpi->response_bytes_read >= uscpi->response_length);
195 static int scpi_usbtmc_close(void *priv)
197 struct usbtmc_scpi *uscpi = priv;
199 if (close(uscpi->usbtmc->fd) < 0)
205 static void scpi_usbtmc_free(void *priv)
207 struct usbtmc_scpi *uscpi = priv;
209 sr_usbtmc_dev_inst_free(uscpi->usbtmc);
212 SR_PRIV const struct sr_scpi_dev_inst scpi_usbtmc_dev = {
214 .prefix = "/dev/usbtmc",
215 .priv_size = sizeof(struct usbtmc_scpi),
216 .scan = scpi_usbtmc_scan,
217 .dev_inst_new = scpi_usbtmc_dev_inst_new,
218 .open = scpi_usbtmc_open,
219 .source_add = scpi_usbtmc_source_add,
220 .source_remove = scpi_usbtmc_source_remove,
221 .send = scpi_usbtmc_send,
222 .read_begin = scpi_usbtmc_read_begin,
223 .read_data = scpi_usbtmc_read_data,
224 .read_complete = scpi_usbtmc_read_complete,
225 .close = scpi_usbtmc_close,
226 .free = scpi_usbtmc_free,