Nico Huber merged this change.
serial: Support custom baud rates on linux
The function to do this is contained in custom_baud.c because
of broken include stuff.
Change-Id: I2a20f9182cb85e7bce5d6654a2caf20e6202b195
Signed-off-by: Urja Rannikko <urjaman@gmail.com>
Reviewed-on: https://review.coreboot.org/20224
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
---
M Makefile
A custom_baud.c
A custom_baud.h
M serial.c
4 files changed, 136 insertions(+), 11 deletions(-)
diff --git a/Makefile b/Makefile
index 5573127..52f6c98 100644
--- a/Makefile
+++ b/Makefile
@@ -921,7 +921,7 @@
endif
ifneq ($(NEED_SERIAL), )
-LIB_OBJS += serial.o
+LIB_OBJS += serial.o custom_baud.o
endif
ifneq ($(NEED_POSIX_SOCKETS), )
diff --git a/custom_baud.c b/custom_baud.c
new file mode 100644
index 0000000..0caca80
--- /dev/null
+++ b/custom_baud.c
@@ -0,0 +1,78 @@
+/*
+ * This file is part of the flashrom project.
+ *
+ * Copyright (C) 2017 Urja Rannikko <urjaman@gmail.com>
+ *
+ * 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 St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "platform.h"
+#include "custom_baud.h"
+
+#if IS_LINUX
+#include <sys/ioctl.h>
+#include <fcntl.h>
+#include <asm-generic/termbits.h>
+#include <asm-generic/ioctls.h>
+
+/*
+ * This include hell above is why this is in a separate source file. See eg.
+ * https://www.downtowndougbrown.com/2013/11/linux-custom-serial-baud-rates/
+ * https://stackoverflow.com/questions/12646324/how-to-set-a-custom-baud-rate-on-linux
+ * https://github.com/jbkim/Linux-custom-baud-rate
+ * for more info.
+ */
+
+int set_custom_baudrate(int fd, unsigned int baud)
+{
+ struct termios2 tio;
+ if (ioctl(fd, TCGETS2, &tio)) {
+ return -1;
+ }
+ tio.c_cflag &= ~CBAUD;
+ tio.c_cflag |= BOTHER;
+ tio.c_ispeed = baud;
+ tio.c_ospeed = baud;
+ return ioctl(fd, TCSETS2, &tio);
+}
+
+int use_custom_baud(unsigned int baud, const struct baudentry *baudtable)
+{
+ int i;
+ for (i = 0; baudtable[i].baud; i++) {
+ if (baudtable[i].baud == baud)
+ return 0;
+
+ if (baudtable[i].baud > baud)
+ return 1;
+ }
+ return 1;
+}
+
+#else
+#include <errno.h>
+
+/* Stub, should not get called. */
+int set_custom_baudrate(int fd, unsigned int baud)
+{
+ errno = ENOSYS; /* Hoping "Function not supported" will make you look here. */
+ return -1;
+}
+
+int use_custom_baud(unsigned int baud, const struct baudentry *baudtable)
+{
+ return 0;
+}
+#endif
diff --git a/custom_baud.h b/custom_baud.h
new file mode 100644
index 0000000..ae286f5
--- /dev/null
+++ b/custom_baud.h
@@ -0,0 +1,35 @@
+/*
+ * This file is part of the flashrom project.
+ *
+ * Copyright (C) 2017 Urja Rannikko <urjaman@gmail.com>
+ *
+ * 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 St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef __CUSTOM_BAUD_H__
+#define __CUSTOM_BAUD_H__ 1
+
+struct baudentry {
+ int flag;
+ unsigned int baud;
+};
+
+int set_custom_baudrate(int fd, unsigned int baud);
+
+/* Returns 1 if non-exact rate would be used, and setting a custom rate is supported.
+ The baudtable must be in ascending order and terminated with a 0-baud entry. */
+int use_custom_baud(unsigned int baud, const struct baudentry *baudtable);
+
+#endif
diff --git a/serial.c b/serial.c
index a64a51d..608464b 100644
--- a/serial.c
+++ b/serial.c
@@ -40,6 +40,7 @@
#endif
#include "flash.h"
#include "programmer.h"
+#include "custom_baud.h"
fdtype sp_fd = SER_INV_FD;
@@ -49,18 +50,14 @@
* The code below creates a mapping in sp_baudtable between these macros and the numerical baud rates to deal
* with numerical user input.
*
- * On Linux there is a non-standard way to use arbitrary baud rates that flashrom does not support (yet), cf.
- * http://www.downtowndougbrown.com/2013/11/linux-custom-serial-baud-rates/
+ * On Linux there is a non-standard way to use arbitrary baud rates that we use if there is no
+ * matching standard rate, see custom_baud.c
*
* On Windows there exist similar macros (starting with CBR_ instead of B) but they are only defined for
* backwards compatibility and the API supports arbitrary baud rates in the same manner as the macros, see
* http://msdn.microsoft.com/en-us/library/windows/desktop/aa363214(v=vs.85).aspx
*/
#if !IS_WINDOWS
-struct baudentry {
- int flag;
- unsigned int baud;
-};
#define BAUDENTRY(baud) { B##baud, baud },
static const struct baudentry sp_baudtable[] = {
@@ -195,10 +192,25 @@
}
wanted = observed;
if (baud >= 0) {
- const struct baudentry *entry = round_baud(baud);
- if (cfsetispeed(&wanted, entry->flag) != 0 || cfsetospeed(&wanted, entry->flag) != 0) {
- msg_perr_strerror("Could not set serial baud rate: ");
- return 1;
+ if (use_custom_baud(baud, sp_baudtable)) {
+ if (set_custom_baudrate(fd, baud)) {
+ msg_perr_strerror("Could not set custom baudrate: ");
+ return 1;
+ }
+ /* We want whatever the termios looks like now, so the rest of the
+ setup doesnt mess up the custom rate. */
+ if (tcgetattr(fd, &wanted) != 0) {
+ /* This should pretty much never happen (see above), but.. */
+ msg_perr_strerror("Could not fetch serial port configuration: ");
+ return 1;
+ }
+ msg_pdbg("Using custom baud rate.\n");
+ } else {
+ const struct baudentry *entry = round_baud(baud);
+ if (cfsetispeed(&wanted, entry->flag) != 0 || cfsetospeed(&wanted, entry->flag) != 0) {
+ msg_perr_strerror("Could not set serial baud rate: ");
+ return 1;
+ }
}
}
wanted.c_cflag &= ~(PARENB | CSTOPB | CSIZE | CRTSCTS);
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