From db76143dfff9aa69318273010fe2922c1e60ea4c Mon Sep 17 00:00:00 2001
From: cbdev <cb@cbcdn.com>
Date: Sun, 16 May 2021 17:09:23 +0200
Subject: Fix VISCA serial output (Fixes #91)

---
 backends/visca.c  | 57 ++++++++++++++++++++++++++++++++++++++++++++++++++++---
 backends/visca.h  |  1 +
 backends/visca.md |  2 +-
 3 files changed, 56 insertions(+), 4 deletions(-)

diff --git a/backends/visca.c b/backends/visca.c
index ba81f8d..611d142 100644
--- a/backends/visca.c
+++ b/backends/visca.c
@@ -2,7 +2,10 @@
 #define DEBUG
 
 #include <string.h>
-#include <math.h>	
+#include <math.h>
+#include <sys/ioctl.h>
+#include <asm/termbits.h>
+
 #include "visca.h"
 #include "libmmbackend.h"
 
@@ -81,11 +84,41 @@ static int ptz_configure_instance(instance* inst, char* option, char* value){
 		LOG("Direct device connections are not possible on Windows");
 		return 1;
 		#else
-		data->fd = open(value, O_NONBLOCK);
+
+		struct termios2 device_config;
+
+		options = strchr(value, ' ');
+		if(options){
+			//terminate port name
+			*options = 0;
+			options++;
+		}
+
+		data->fd = open(value, O_RDWR | O_NONBLOCK);
 		if(data->fd < 0){
 			LOGPF("Failed to connect instance %s to device %s", inst->name, value);
 			return 1;
 		}
+		data->direct_device = 1;
+
+		//configure baudrate
+		if(options){
+			//get current port config
+			if(ioctl(data->fd, TCGETS2, &device_config)){
+				LOGPF("Failed to get port configuration data for %s: %s", value, strerror(errno));
+				return 0;
+			}
+
+			device_config.c_cflag &= ~CBAUD;
+			device_config.c_cflag |= BOTHER;
+			device_config.c_ispeed = strtoul(options, NULL, 10);
+			device_config.c_ospeed = strtoul(options, NULL, 10);
+
+			//set updated config
+			if(ioctl(data->fd, TCSETS2, &device_config)){
+				LOGPF("Failed to set port configuration data for %s: %s", value, strerror(errno));
+			}
+		}
 		return 0;
 		#endif
 	}
@@ -315,6 +348,21 @@ static size_t ptz_set_memory_store(instance* inst, channel* c, channel_value* v,
 	return ptz_channels[store].bytes;
 }
 
+static int ptz_write_serial(int fd, uint8_t* data, size_t bytes){
+	ssize_t total = 0, sent;
+
+	while(total < bytes){
+		sent = write(fd, data + total, bytes - total);
+		if(sent < 0){
+			LOGPF("Failed to write to serial port: %s", strerror(errno));
+			return 1;
+		}
+		total += sent;
+	}
+
+	return 0;
+}
+
 static int ptz_set(instance* inst, size_t num, channel** c, channel_value* v){
 	ptz_instance_data* data = (ptz_instance_data*) inst->impl;
 	size_t n = 0, bytes = 0;
@@ -336,7 +384,10 @@ static int ptz_set(instance* inst, size_t num, channel** c, channel_value* v){
 			bytes = ptz_channels[command].set(inst, c[n], v + n, tx);
 		}
 
-		if(bytes && mmbackend_send(data->fd, tx, bytes)){
+		if(data->direct_device && bytes && ptz_write_serial(data->fd, tx, bytes)){
+			LOGPF("Failed to write %s command on instance %s", ptz_channels[command].name, inst->name);	
+		}
+		else if(!data->direct_device && bytes && mmbackend_send(data->fd, tx, bytes)){
 			LOGPF("Failed to push %s command on instance %s", ptz_channels[command].name, inst->name);
 		}
 	}
diff --git a/backends/visca.h b/backends/visca.h
index 1004076..1b8c0e5 100644
--- a/backends/visca.h
+++ b/backends/visca.h
@@ -30,6 +30,7 @@ typedef struct /*_ptz_instance_data*/ {
 	uint8_t tiltspeed;
 	uint8_t relative_movement;
 	double deadzone;
+	uint8_t direct_device;
 } ptz_instance_data;
 
 enum /*ptz_channels*/ {
diff --git a/backends/visca.md b/backends/visca.md
index cf5906d..101aa20 100644
--- a/backends/visca.md
+++ b/backends/visca.md
@@ -18,7 +18,7 @@ The `visca` backend does not take any global configuration.
 |---------------|-----------------------|-----------------------|---------------------------------------------------------------|
 | `id`		| `5`			| `1`			| VISCA Camera address (normally 1 for network communication	|
 | `connect`	| `10.10.10.1 5678`	| none			| Camera network address and port. Default connection is TCP, when optionally suffixed with the `udp` keyword, connection will be UDP |
-| `device`	| `/dev/ttyUSB0`	| none			| (Linux only) Device node for a serial port adapter connecting to the camera |
+| `device`	| `/dev/ttyUSB0 115200`	| none			| (Linux only) Device node for a serial port adapter connecting to the camera, optionally followed by the baudrate |
 | `deadzone`	| `0.1`			| `0.1`			| Amount of event value variation to be ignored for relative movement commands |
 
 #### Channel specification
-- 
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