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1 | /* | |
2 | * This file is part of the libsigrok project. | |
3 | * | |
4 | * Copyright (C) 2013 Martin Ling <martin-sigrok@earth.li> | |
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 3 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 "libsigrok.h" | |
21 | #include "libsigrok-internal.h" | |
22 | ||
23 | #include <glib.h> | |
24 | #include <string.h> | |
25 | #include <unistd.h> | |
26 | #include <fcntl.h> | |
27 | #include <errno.h> | |
28 | ||
29 | #define LOG_PREFIX "scpi_usbtmc" | |
30 | ||
31 | #define MAX_READ_LENGTH 2048 | |
32 | ||
33 | struct usbtmc_scpi { | |
34 | struct sr_usbtmc_dev_inst *usbtmc; | |
35 | char response_buffer[MAX_READ_LENGTH]; | |
36 | int response_length; | |
37 | int response_bytes_read; | |
38 | }; | |
39 | ||
40 | static GSList *scpi_usbtmc_scan(struct drv_context *drvc) | |
41 | { | |
42 | GSList *resources = NULL; | |
43 | GDir *dir; | |
44 | const char *dev_name; | |
45 | char *resource; | |
46 | ||
47 | (void)drvc; | |
48 | ||
49 | if (!(dir = g_dir_open("/sys/class/usbmisc/", 0, NULL))) | |
50 | if (!(dir = g_dir_open("/sys/class/usb/", 0, NULL))) | |
51 | return NULL; | |
52 | while ((dev_name = g_dir_read_name(dir))) { | |
53 | if (strncmp(dev_name, "usbtmc", 6)) | |
54 | continue; | |
55 | resource = g_strconcat("/dev/", dev_name, NULL); | |
56 | resources = g_slist_append(resources, resource); | |
57 | } | |
58 | g_dir_close(dir); | |
59 | ||
60 | return resources; | |
61 | } | |
62 | ||
63 | static int scpi_usbtmc_dev_inst_new(void *priv, struct drv_context *drvc, | |
64 | const char *resource, char **params, const char *serialcomm) | |
65 | { | |
66 | struct usbtmc_scpi *uscpi = priv; | |
67 | ||
68 | (void)drvc; | |
69 | (void)params; | |
70 | (void)serialcomm; | |
71 | ||
72 | if (!(uscpi->usbtmc = sr_usbtmc_dev_inst_new(resource))) | |
73 | return SR_ERR; | |
74 | ||
75 | return SR_OK; | |
76 | } | |
77 | ||
78 | static int scpi_usbtmc_open(void *priv) | |
79 | { | |
80 | struct usbtmc_scpi *uscpi = priv; | |
81 | struct sr_usbtmc_dev_inst *usbtmc = uscpi->usbtmc; | |
82 | ||
83 | if ((usbtmc->fd = open(usbtmc->device, O_RDWR)) < 0) | |
84 | return SR_ERR; | |
85 | ||
86 | return SR_OK; | |
87 | } | |
88 | ||
89 | static int scpi_usbtmc_source_add(void *priv, int events, int timeout, | |
90 | sr_receive_data_callback_t cb, void *cb_data) | |
91 | { | |
92 | struct usbtmc_scpi *uscpi = priv; | |
93 | struct sr_usbtmc_dev_inst *usbtmc = uscpi->usbtmc; | |
94 | ||
95 | return sr_source_add(usbtmc->fd, events, timeout, cb, cb_data); | |
96 | } | |
97 | ||
98 | static int scpi_usbtmc_source_remove(void *priv) | |
99 | { | |
100 | struct usbtmc_scpi *uscpi = priv; | |
101 | struct sr_usbtmc_dev_inst *usbtmc = uscpi->usbtmc; | |
102 | ||
103 | return sr_source_remove(usbtmc->fd); | |
104 | } | |
105 | ||
106 | static int scpi_usbtmc_send(void *priv, const char *command) | |
107 | { | |
108 | struct usbtmc_scpi *uscpi = priv; | |
109 | struct sr_usbtmc_dev_inst *usbtmc = uscpi->usbtmc; | |
110 | int len, out; | |
111 | ||
112 | len = strlen(command); | |
113 | out = write(usbtmc->fd, command, len); | |
114 | ||
115 | if (out < 0) { | |
116 | sr_err("Write error: %s", strerror(errno)); | |
117 | return SR_ERR; | |
118 | } | |
119 | ||
120 | if (out < len) { | |
121 | sr_dbg("Only sent %d/%d bytes of SCPI command: '%s'.", out, | |
122 | len, command); | |
123 | } | |
124 | ||
125 | sr_spew("Successfully sent SCPI command: '%s'.", command); | |
126 | ||
127 | return SR_OK; | |
128 | } | |
129 | ||
130 | static int scpi_usbtmc_read_begin(void *priv) | |
131 | { | |
132 | struct usbtmc_scpi *uscpi = priv; | |
133 | struct sr_usbtmc_dev_inst *usbtmc = uscpi->usbtmc; | |
134 | int len; | |
135 | ||
136 | len = read(usbtmc->fd, uscpi->response_buffer, MAX_READ_LENGTH); | |
137 | ||
138 | if (len < 0) { | |
139 | sr_err("Read error: %s", strerror(errno)); | |
140 | return SR_ERR; | |
141 | } | |
142 | ||
143 | uscpi->response_length = len; | |
144 | uscpi->response_bytes_read = 0; | |
145 | ||
146 | sr_spew("Read %d bytes from device into buffer", len); | |
147 | ||
148 | return SR_OK; | |
149 | } | |
150 | ||
151 | static int scpi_usbtmc_read_data(void *priv, char *buf, int maxlen) | |
152 | { | |
153 | struct usbtmc_scpi *uscpi = priv; | |
154 | int read_length; | |
155 | ||
156 | sr_spew("%d bytes requested", maxlen); | |
157 | ||
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) | |
163 | return SR_ERR; | |
164 | } else { | |
165 | return SR_ERR; | |
166 | } | |
167 | } | |
168 | ||
169 | read_length = uscpi->response_length - uscpi->response_bytes_read; | |
170 | ||
171 | if (read_length > maxlen) | |
172 | read_length = maxlen; | |
173 | ||
174 | memcpy(buf, uscpi->response_buffer + uscpi->response_bytes_read, read_length); | |
175 | ||
176 | uscpi->response_bytes_read += read_length; | |
177 | ||
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); | |
180 | ||
181 | return read_length; | |
182 | } | |
183 | ||
184 | static int scpi_usbtmc_read_complete(void *priv) | |
185 | { | |
186 | struct usbtmc_scpi *uscpi = priv; | |
187 | ||
188 | if (uscpi->response_length == MAX_READ_LENGTH | |
189 | && uscpi->response_bytes_read == uscpi->response_length) | |
190 | scpi_usbtmc_read_begin(uscpi); | |
191 | ||
192 | return (uscpi->response_bytes_read >= uscpi->response_length); | |
193 | } | |
194 | ||
195 | static int scpi_usbtmc_close(void *priv) | |
196 | { | |
197 | struct usbtmc_scpi *uscpi = priv; | |
198 | ||
199 | if (close(uscpi->usbtmc->fd) < 0) | |
200 | return SR_ERR; | |
201 | ||
202 | return SR_OK; | |
203 | } | |
204 | ||
205 | static void scpi_usbtmc_free(void *priv) | |
206 | { | |
207 | struct usbtmc_scpi *uscpi = priv; | |
208 | ||
209 | sr_usbtmc_dev_inst_free(uscpi->usbtmc); | |
210 | } | |
211 | ||
212 | SR_PRIV const struct sr_scpi_dev_inst scpi_usbtmc_dev = { | |
213 | .name = "USBTMC", | |
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, | |
227 | }; |