1 files changed, 272 insertions, 0 deletions
diff --git a/src/rs232.c b/src/rs232.c
new file mode 100644
index 0000000..70aff46
--- /dev/null
+++ b/src/rs232.c
@@ -0,0 +1,272 @@
+/* T-Link interface using POSIX serial port */
+
+/* (C) 2008-2011 by Harald Welte <laforge@gnumonks.org>
+ *
+ * All Rights Reserved
+ *
+ * Authors:	Harald Welte <laforge@gnumonks.org>
+ *		Pablo Neira Ayuso <pablo@gnumonks.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation; either version 3 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+#include <termios.h>
+#include <fcntl.h>
+#include <limits.h>
+
+#include <osmocom/core/select.h>
+#include <osmocom/core/msgb.h>
+#include <osmocom/core/logging.h>
+#include <osmocom/core/talloc.h>
+#include <osmocom/abis/e1_input.h>
+
+struct osmo_rs232 {
+	struct osmo_fd		ofd;
+	struct llist_head	tx_queue;
+
+	struct {
+		int (*read)(struct osmo_rs232 *);
+	} cb;
+
+	/* sometimes we want to delay the transmission. */
+	struct osmo_timer_list	tx_timer;
+
+	struct {
+		char		serial_port[PATH_MAX];
+		int		baudrate;
+		unsigned int	delay_us;
+	} cfg;
+};
+
+void rs232_tx_timer_cb(void *ptr)
+{
+	struct osmo_rs232 *r = ptr;
+
+	/* we're again ready to transmit. */
+	r->ofd.when |= BSC_FD_WRITE;
+}
+
+static int handle_ser_write(struct osmo_fd *bfd)
+{
+	struct osmo_rs232 *r = bfd->data;
+	struct llist_head *lh;
+	struct msgb *msg;
+	int written;
+
+        LOGP(DLINP, LOGL_DEBUG, "writing data to rs232\n");
+
+        if (llist_empty(&r->tx_queue)) {
+                r->ofd.when &= ~BSC_FD_WRITE;
+                return 0;
+        }
+        lh = r->tx_queue.next;
+        llist_del(lh);
+        msg = llist_entry(lh, struct msgb, list);
+
+	written = write(bfd->fd, msg->data, msg->len);
+	if (written < msg->len) {
+		LOGP(DLINP, LOGL_ERROR, "rs232: short write\n");
+		msgb_free(msg);
+		return -1;
+	}
+	msgb_free(msg);
+
+	/* We've got more data to write, but we have to wait to make it. */
+	if (!llist_empty(&r->tx_queue) && r->cfg.delay_us) {
+		r->ofd.when &= ~BSC_FD_WRITE;
+		osmo_timer_schedule(&r->tx_timer, 0, r->cfg.delay_us);
+	}
+	return 0;
+}
+
+static int handle_ser_read(struct osmo_fd *bfd)
+{
+	struct osmo_rs232 *r = bfd->data;
+
+	LOGP(DLINP, LOGL_DEBUG, "data to be read in rs232\n");
+
+	if (r->cb.read)
+		r->cb.read(r);
+
+	return 0;
+}
+
+static int serial_fd_cb(struct osmo_fd *bfd, unsigned int what)
+{
+	int rc = 0;
+
+	if (what & BSC_FD_READ)
+		rc = handle_ser_read(bfd);
+
+	if (rc < 0)
+		return rc;
+
+	if (what & BSC_FD_WRITE)
+		rc = handle_ser_write(bfd);
+
+	return rc;
+}
+
+struct osmo_rs232 *osmo_rs232_create(void *ctx)
+{
+	struct osmo_rs232 *r;
+
+	r = talloc_zero(ctx, struct osmo_rs232);
+	if (r == NULL)
+		return NULL;
+
+	INIT_LLIST_HEAD(&r->tx_queue);
+
+	return r;
+}
+
+void osmo_rs232_set_serial_port(struct osmo_rs232 *r, char *serial_port)
+{
+	strncpy(r->cfg.serial_port, serial_port, PATH_MAX);
+	r->cfg.serial_port[PATH_MAX-1] = '\0';
+}
+
+void osmo_rs232_set_baudrate(struct osmo_rs232 *r, int baudrate)
+{
+	r->cfg.baudrate = baudrate;
+}
+
+void osmo_rs232_set_delay_us(struct osmo_rs232 *r, int delay_us)
+{
+	r->cfg.delay_us = delay_us;
+}
+
+void osmo_rs232_set_read_cb(struct osmo_rs232 *r,
+			    int (*read_cb)(struct osmo_rs232 *r))
+{
+	r->cb.read = read_cb;
+}
+
+/* XXX: Better use TIOCGSERIAL / TIOCSSERIAL to allow setting non-standard. */
+static struct baudrate2termbits {
+	int rate;
+	int def;
+} baudrate2termbits[] = {
+	{ 9600, B9600 },
+	{ 19200, B19200 },
+	{ 38400, B38400 },
+	{ 115200, B1152000 },
+	{ -1, -1 },
+};
+
+int osmo_rs232_open(struct osmo_rs232 *r)
+{
+	int rc, i, speed = 0;
+	struct osmo_fd *bfd = &r->ofd;
+	struct termios tio;
+
+	rc = open(r->cfg.serial_port, O_RDWR);
+	if (rc < 0) {
+		LOGP(DLINP, LOGL_ERROR, "rs232: cannot open serial port: %s",
+			strerror(errno));
+		return rc;
+	}
+	bfd->fd = rc;
+
+	/* set baudrate */
+	rc = tcgetattr(bfd->fd, &tio);
+	if (rc < 0) {
+		LOGP(DLINP, LOGL_ERROR, "rs232: tcgetattr says: %s",
+			strerror(errno));
+		return rc;
+	}
+	for (i=0; i<baudrate2termbits[i].rate; i++) {
+		if (baudrate2termbits[i].rate == -1)
+			break;
+
+		if (baudrate2termbits[i].rate == r->cfg.baudrate) {
+			speed = baudrate2termbits[i].def;
+			break;
+		}
+	}
+	if (speed == 0) {
+		close(rc);
+		bfd->fd = -1;
+		return -1;
+	}
+
+	cfsetispeed(&tio, speed);
+	cfsetospeed(&tio, speed);
+	tio.c_cflag |=  (CREAD | CLOCAL | CS8);
+	tio.c_cflag &= ~(PARENB | CSTOPB | CSIZE | CRTSCTS);
+	tio.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG);
+	tio.c_iflag |=  (INPCK | ISTRIP);
+	tio.c_iflag &= ~(ISTRIP | IXON | IXOFF | IGNBRK | INLCR | ICRNL | IGNCR);
+	tio.c_oflag &= ~(OPOST);
+	rc = tcsetattr(bfd->fd, TCSADRAIN, &tio);
+	if (rc < 0) {
+		LOGP(DLINP, LOGL_ERROR, "rs232: tcsetattr says: %s",
+			strerror(errno));
+		return rc;
+	}
+
+	bfd->when = BSC_FD_READ;
+	bfd->cb = serial_fd_cb;
+	bfd->data = r;
+
+	rc = osmo_fd_register(bfd);
+	if (rc < 0) {
+		close(bfd->fd);
+		LOGP(DLINP, LOGL_ERROR, "rs232: could not register FD: %s\n",
+			strerror(rc));
+		return rc;
+	}
+
+	if (r->cfg.delay_us) {
+		r->tx_timer.cb = rs232_tx_timer_cb;
+		r->tx_timer.data = r;
+	}
+	return 0;
+}
+
+int osmo_rs232_read(struct osmo_rs232 *r, struct msgb *msg)
+{
+	int ret;
+
+	ret = read(r->ofd.fd, msg->data, msg->data_len);
+	if (ret < 0) {
+		LOGP(DLINP, LOGL_ERROR, "read error: %s\n", strerror(errno));
+		return -EIO;
+	}
+	msgb_put(msg, ret);
+	return ret;
+}
+
+void osmo_rs232_write(struct osmo_rs232 *r, struct msgb *msg)
+{
+        msgb_enqueue(&r->tx_queue, msg);
+        r->ofd.when |= BSC_FD_WRITE;
+}
+
+void osmo_rs232_close(struct osmo_rs232 *r)
+{
+	close(r->ofd.fd);
+	r->ofd.fd = -1;
+}
+
+void osmo_rs232_destroy(struct osmo_rs232 *r)
+{
+	talloc_free(r);
+}