From aae3666f514af7606db0fe34c601bfdafa4cb7dc Mon Sep 17 00:00:00 2001
From: John Tsiombikas <nuclear@member.fsf.org>
Date: Sat, 31 Oct 2020 23:01:55 -0400
Subject: [PATCH] detection works

---
 Makefile    |    2 +-
 src/main.c  |    6 +--
 src/sball.c |  118 +++++++++++++++++++++++++++++++++++++++++++++++++++++------
 3 files changed, 111 insertions(+), 15 deletions(-)

diff --git a/Makefile b/Makefile
index a41c55c..b6b4c63 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
 src = $(wildcard src/*.c)
 obj = $(src:.c=.o)
 dep = $(obj:.o=.d)
-bin = sball
+bin = test
 
 CFLAGS = -pedantic -Wall -g -MMD
 
diff --git a/src/main.c b/src/main.c
index 7fe32c5..04b0ace 100644
--- a/src/main.c
+++ b/src/main.c
@@ -2,15 +2,15 @@
 #include <stdlib.h>
 #include "sball.h"
 
-static int fd;
+static struct sball *sb;
 
 int main(int argc, char **argv)
 {
-	if(!(fd = sball_open(argv[1] ? argv[1] : "/dev/ttyS0"))) {
+	if(!(sb = sball_open(argv[1] ? argv[1] : "/dev/ttyS0"))) {
 		fprintf(stderr, "Failed to open spaceball at %s\n", argv[1] ? argv[1] : "/dev/ttyS0");
 		return 1;
 	}
 
-	sball_close(fd);
+	sball_close(sb);
 	return 0;
 }
diff --git a/src/sball.c b/src/sball.c
index 7e5101a..2de1403 100644
--- a/src/sball.c
+++ b/src/sball.c
@@ -1,24 +1,36 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <time.h>
 #include <errno.h>
 #include <unistd.h>
 #include <fcntl.h>
 #include <termios.h>
+#include <sys/select.h>
+#include <sys/time.h>
 
 struct sball {
 	int fd;
+
+	int (*decode)(struct sball *sb, char *line);
 };
 
 static int stty_sball(int fd);
 static int stty_mag(int fd);
 
+static int decode_sball(struct sball *sb, char *line);
+static int decode_mag(struct sball *sb, char *line);
+
+static void make_printable(char *buf, int len);
+static int read_timeout(int fd, char *buf, int bufsz, long tm_usec);
+
 struct sball *sball_open(const char *dev)
 {
-	int fd;
+	int fd, sz;
+	char buf[128];
 	struct sball *sb = 0;
 
-	if((fd = open(dev, O_RDWR | | O_NOCTTY | O_NONBLOCK)) == -1) {
+	if((fd = open(dev, O_RDWR | O_NOCTTY)) == -1) {
 		fprintf(stderr, "sball_open: failed to open device: %s: %s\n", dev, strerror(errno));
 		return 0;
 	}
@@ -33,9 +45,29 @@ struct sball *sball_open(const char *dev)
 		goto err;
 	}
 
-	/* set detect receiver function pointer */
+	if((sz = read_timeout(fd, buf, sizeof buf - 1, 2000000)) > 0) {
+		/* we got a response, so it's a spaceball */
+		make_printable(buf, sz);
+		printf("Spaceball detected: %s\n", buf);
+
+		sb->decode = decode_sball;
+		return sb;
+	}
+
+	/* try as a magellan spacemouse */
+	if(stty_mag(fd) == -1) {
+		goto err;
+	}
+	write(fd, "vQ\r", 3);
+
+	if((sz = read_timeout(fd, buf, sizeof buf - 1, 250000)) > 0) {
+		/* we got a response, it's a magellan spacemouse */
+		make_printable(buf, sz);
+		printf("Magellan SpaceMouse detected: %s\n", buf);
 
-	return sb;
+		sb->decode = decode_mag;
+		return sb;
+	}
 
 err:
 	close(fd);
@@ -63,13 +95,13 @@ static int stty_sball(int fd)
 	term.c_oflag = 0;
 	term.c_lflag = 0;
 	term.c_cc[VMIN] = 0;
-	term.c_cc[VTIME] = 0;
+	term.c_cc[VTIME] = 1;
 
 	term.c_cflag = CLOCAL | CREAD | CS8 | HUPCL;
 	term.c_iflag = IGNBRK | IGNPAR | IXON | IXOFF;
 
-	csetispeed(&term, B9600);
-	csetospeed(&term, B9600);
+	cfsetispeed(&term, B9600);
+	cfsetospeed(&term, B9600);
 
 	if(tcsetattr(fd, TCSANOW, &term) == -1) {
 		perror("sball_open: tcsetattr");
@@ -92,13 +124,13 @@ static int stty_mag(int fd)
 	term.c_oflag = 0;
 	term.c_lflag = 0;
 	term.c_cc[VMIN] = 0;
-	term.c_cc[VTIME] = 0;
+	term.c_cc[VTIME] = 1;
 
 	term.c_cflag = CLOCAL | CREAD | CS8 | CSTOPB | HUPCL | CRTSCTS;
-	term.c_iflag = IGNBRK | IGNPAR |;
+	term.c_iflag = IGNBRK | IGNPAR | ICRNL;
 
-	csetispeed(&term, B9600);
-	csetospeed(&term, B9600);
+	cfsetispeed(&term, B9600);
+	cfsetospeed(&term, B9600);
 
 	if(tcsetattr(fd, TCSANOW, &term) == -1) {
 		perror("sball_open: tcsetattr");
@@ -107,3 +139,67 @@ static int stty_mag(int fd)
 
 	return 0;
 }
+
+
+static int decode_sball(struct sball *sb, char *line)
+{
+	return -1;
+}
+
+static int decode_mag(struct sball *sb, char *line)
+{
+	return -1;
+}
+
+static void make_printable(char *buf, int len)
+{
+	int i, c;
+	char *wr = buf;
+
+	for(i=0; i<len; i++) {
+		c = *buf++;
+		if(c == '\r') {
+			*wr++ = '\n';
+			if(*buf == '\n') buf++;
+		} else {
+			*wr++ = c;
+		}
+	}
+	*wr = 0;
+}
+
+static int read_timeout(int fd, char *buf, int bufsz, long tm_usec)
+{
+	int res;
+	long usec, sz = 0;
+	struct timeval tv0, tv;
+	fd_set rdset;
+
+	if(!buf || bufsz <= 0) return -1;
+
+	usec = tm_usec;
+	gettimeofday(&tv0, 0);
+
+	while(sz < bufsz && usec > 0) {
+		tv.tv_sec = usec / 1000000;
+		tv.tv_usec = usec % 1000000;
+
+		FD_ZERO(&rdset);
+		FD_SET(fd, &rdset);
+		if((res = select(fd + 1, &rdset, 0, 0, &tv)) > 0 && FD_ISSET(fd, &rdset)) {
+			sz += read(fd, buf + sz, bufsz - sz);
+			buf[sz] = 0;
+			tm_usec = usec = 128000;	/* wait 128ms for the rest of the message to appear */
+			gettimeofday(&tv0, 0);
+			continue;
+		}
+		if(res == -1 && (errno == EWOULDBLOCK || errno == EAGAIN)) {
+			break;
+		}
+		gettimeofday(&tv, 0);
+		usec = tm_usec - ((tv.tv_sec - tv0.tv_sec) * 1000000 + (tv.tv_usec - tv0.tv_usec));
+	}
+
+	return sz > 0 ? sz : -1;
+}
+
-- 
1.7.10.4