Update upstream source from tag 'upstream/2.0'

[tio] / src / rs485.c

diff --git a/src/rs485.c b/src/rs485.c
new file mode 100644 (file)
index 0000000..e364b13
--- /dev/null
+++ b/src/rs485.c
@@ -0,0 +1,200 @@
+/*
+ * tio - a simple serial device I/O tool
+ *
+ * Copyright (c) 2022  Martin Lund
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <sys/ioctl.h>
+#include <stdbool.h>
+#include "options.h"
+#include "print.h"
+#include "error.h"
+
+#ifdef HAVE_RS485
+
+#include <linux/serial.h>
+
+static struct serial_rs485 rs485_config_saved;
+static struct serial_rs485 rs485_config;
+static bool rs485_config_written = false;
+
+void rs485_parse_config(const char *arg)
+{
+    bool token_found = true;
+    char *token = NULL;
+    char *buffer = strdup(arg);
+
+    while (token_found == true)
+    {
+        if (token == NULL)
+        {
+            token = strtok(buffer,",");
+        }
+        else
+        {
+            token = strtok(NULL, ",");
+        }
+
+        if (token != NULL)
+        {
+            char keyname[31];
+            unsigned int value;
+            sscanf(token, "%30[^=]=%d", keyname, &value);
+
+            if (!strcmp(keyname, "RTS_ON_SEND"))
+            {
+                if (value)
+                {
+
+                    /* Set logical level for RTS pin equal to 1 when sending */
+                    option.rs485_config_flags |= SER_RS485_RTS_ON_SEND;
+                }
+                else
+                {
+                    /* Set logical level for RTS pin equal to 0 when sending */
+                    option.rs485_config_flags &= ~(SER_RS485_RTS_ON_SEND);
+                }
+            }
+            else if (!strcmp(keyname, "RTS_AFTER_SEND"))
+            {
+                if (value)
+                {
+                    /* Set logical level for RTS pin equal to 1 after sending */
+                    option.rs485_config_flags |= SER_RS485_RTS_AFTER_SEND;
+                }
+                else
+                {
+                    /* Set logical level for RTS pin equal to 0 after sending */
+                    option.rs485_config_flags &= ~(SER_RS485_RTS_AFTER_SEND);
+                }
+            }
+            else if (!strcmp(keyname, "RTS_DELAY_BEFORE_SEND"))
+            {
+                /* Set RTS delay before send */
+                option.rs485_delay_rts_before_send = value;
+            }
+            else if (!strcmp(keyname, "RTS_DELAY_AFTER_SEND"))
+            {
+                /* Set RTS delay after send */
+                option.rs485_delay_rts_after_send = value;
+            }
+            else if (!strcmp(keyname, "RX_DURING_TX"))
+            {
+                /* Receive data even while sending data */
+                option.rs485_config_flags |= SER_RS485_RX_DURING_TX;
+            }
+        }
+        else
+        {
+            token_found = false;
+        }
+    }
+    free(buffer);
+}
+
+void rs485_print_config(void)
+{
+    tio_printf(" RS-485 Configuration:");
+    tio_printf("  RTS_ON_SEND: %s", (rs485_config.flags & SER_RS485_RTS_ON_SEND) ? "high" : "low");
+    tio_printf("  RTS_AFTER_SEND: %s", (rs485_config.flags & SER_RS485_RTS_AFTER_SEND) ? "high" : "low");
+    tio_printf("  RTS_DELAY_BEFORE_SEND = %d", rs485_config.delay_rts_before_send);
+    tio_printf("  RTS_DELAY_AFTER_SEND = %d", rs485_config.delay_rts_after_send);
+    tio_printf("  RX_DURING_TX: %s", (rs485_config.flags & SER_RS485_RX_DURING_TX) ? "enabled" : "disabled");
+}
+
+int rs485_mode_enable(int fd)
+{
+    /* Save existing RS-485 configuration */
+    ioctl (fd, TIOCGRS485, &rs485_config_saved);
+
+    /* Prepare new RS-485 configuration */
+    rs485_config.flags = SER_RS485_ENABLED;
+    rs485_config.flags |= option.rs485_config_flags;
+
+    if (option.rs485_delay_rts_before_send > 0)
+    {
+        rs485_config.delay_rts_before_send = option.rs485_delay_rts_before_send;
+    }
+    else
+    {
+        rs485_config.delay_rts_before_send = rs485_config_saved.delay_rts_before_send;
+    }
+
+    if (option.rs485_delay_rts_after_send > 0)
+    {
+        rs485_config.delay_rts_after_send = option.rs485_delay_rts_after_send;
+    }
+    else
+    {
+        rs485_config.delay_rts_after_send = rs485_config_saved.delay_rts_after_send;
+    }
+
+    /* Write new RS-485 configuration */
+    if (ioctl(fd, TIOCSRS485, &rs485_config) < 0)
+    {
+        tio_warning_printf("RS-485 mode is not supported by your device (%s)", strerror(errno));
+        return -1;
+    }
+
+    rs485_config_written = true;
+
+    return 0;
+}
+
+void rs485_mode_restore(int fd)
+{
+    if (rs485_config_written)
+    {
+        /* Write saved RS-485 configuration */
+        if (ioctl(fd, TIOCSRS485, &rs485_config_saved) < 0)
+        {
+            tio_warning_printf("TIOCGRS485 ioctl failed (%s)", strerror(errno));
+        }
+    }
+}
+
+#else
+
+void rs485_parse_config(const char *arg)
+{
+    UNUSED(arg);
+    return;
+}
+
+void rs485_print_config(void)
+{
+    return;
+}
+
+int rs485_mode_enable(int fd)
+{
+    UNUSED(fd);
+    tio_error_printf("RS485 mode is not supported on your system");
+    exit(EXIT_FAILURE);
+}
+
+void rs485_mode_restore(int fd)
+{
+    UNUSED(fd);
+    return;
+}
+
+#endif