1 files changed, 279 insertions, 0 deletions
diff --git a/cethcan/ttydmx.c b/cethcan/ttydmx.c
new file mode 100644
index 0000000..6165ed7
--- /dev/null
+++ b/cethcan/ttydmx.c
@@ -0,0 +1,279 @@
+#include "cethcan.h"
+
+#include <limits.h>
+#include <sys/types.h>
+#include <sys/ioctl.h>
+#include <termio.h>
+#include <linux/serial.h>
+#include <pthread.h>
+#include <stdatomic.h>
+
+struct ttydmx_device;
+
+struct ttydmx_data {
+	size_t len;
+	uint8_t data[];
+};
+
+struct ttydmx_sink {
+	struct ttydmx_sink *next;
+
+	struct can_user *u;
+	int fd;
+	char *ttydev;
+	size_t maxaddr;
+
+	pthread_t pusher;
+	struct ttydmx_data * _Atomic nextdata;
+
+	struct ttydmx_device *devs;
+};
+
+struct ttydmx_device {
+	struct ttydmx_device *next;
+	struct ttydmx_sink *sink;
+
+	char *name;
+	unsigned baseaddr;
+	uint8_t r, g, b;
+};
+
+static struct ttydmx_sink *sinks = NULL, **psinks = &sinks;
+
+struct ttydmx_device *ttydmx_find(const char *name)
+{
+	for (struct ttydmx_sink *sink = sinks; sink; sink = sink->next)
+		for (struct ttydmx_device *d = sink->devs; d; d = d->next)
+			if (!strcmp(d->name, name))
+				return d;
+	return NULL;
+}
+
+int ttydmx_set(struct ttydmx_device *dev, unsigned r, unsigned g, unsigned b)
+{
+	struct ttydmx_sink *sink = dev->sink;
+	struct ttydmx_data *newdata, *prevdata;
+	struct ttydmx_device *walk;
+	bool bump = dev->r != r || dev->g != g || dev->b != b;
+
+	dev->r = r;
+	dev->g = g;
+	dev->b = b;
+
+	newdata = calloc(offsetof(struct ttydmx_data, data[sink->maxaddr]), 1);
+	newdata->len = sink->maxaddr;
+	for (walk = sink->devs; walk; walk = walk->next) {
+		newdata->data[walk->baseaddr + 0] = walk->r;
+		newdata->data[walk->baseaddr + 1] = walk->g;
+		newdata->data[walk->baseaddr + 2] = walk->b;
+	}
+	prevdata = atomic_exchange(&sink->nextdata, newdata);
+	if (prevdata)
+		free(prevdata);
+
+	if (bump)
+		json_bump_longpoll();
+	return 0;
+}
+
+void ttydmx_get(struct ttydmx_device *dev,
+		unsigned *r, unsigned *g, unsigned *b)
+{
+	*r = dev->r;
+	*g = dev->g;
+	*b = dev->b;
+}
+
+static void ttydmx_json_one(struct ttydmx_sink *sink,
+		struct ttydmx_device *dev,
+		json_t *json, enum json_subtype type)
+{
+	json_t *lobj = json_object();
+
+	json_object_set_new(lobj, "klass", json_string("dmxrgb"));
+	json_object_set_new(lobj, "dmxaddr", json_integer(dev->baseaddr));
+
+	json_object_set_new(lobj, "r", json_integer(dev->r));
+	json_object_set_new(lobj, "g", json_integer(dev->g));
+	json_object_set_new(lobj, "b", json_integer(dev->b));
+
+	json_object_set_new(json, dev->name, lobj);
+}
+
+static void ttydmx_json_handler(void *arg, json_t *json,
+		enum json_subtype type)
+{
+	struct ttydmx_sink *sink = arg;
+	for (struct ttydmx_device *d = sink->devs; d; d = d->next)
+		ttydmx_json_one(sink, d, json, type);
+}
+
+static void ttydmx_can_handler(void *arg, struct can_message *msg)
+{
+}
+
+static struct ttydmx_device *ttydmx_add_dev(struct ttydmx_sink *sink,
+		json_t *config)
+{
+	struct ttydmx_device *d;
+
+	if (!json_is_object(config)) {
+		lprintf("ttyDMX device config must be an object/dictionary");
+		return NULL;
+	}
+	if (!json_is_string(json_object_get(config, "name"))) {
+		lprintf("ttyDMX device config must specify str 'name'");
+		return NULL;
+	}
+	if (!json_is_integer(json_object_get(config, "baseaddr"))) {
+		lprintf("ttyDMX device config must specify int 'baseaddr'");
+		return NULL;
+	}
+
+	d = calloc(sizeof(*d), 1);
+	d->sink = sink;
+	d->baseaddr = json_integer_value(json_object_get(config, "baseaddr"));
+	d->name = strdup(json_string_value(json_object_get(config, "name")));
+
+	if (d->baseaddr + 4 > sink->maxaddr)
+		sink->maxaddr = d->baseaddr + 4;
+	return d;
+}
+
+static void *ttydmx_thread(void *arg)
+{
+	struct ttydmx_sink *sink = arg;
+	struct ttydmx_data *data = NULL, *newdata;
+	uint8_t dummy = 0;
+
+	while (1) {
+		newdata = atomic_exchange(&sink->nextdata, NULL);
+		if (newdata) {
+			free(data);
+			data = newdata;
+		}
+
+		ioctl(sink->fd, TIOCSBRK, 0);
+		usleep(100);
+		ioctl(sink->fd, TIOCCBRK, 0);
+		usleep(12);
+		write(sink->fd, data ? data->data : &dummy,
+				data ? data->len : 1);
+		tcdrain(sink->fd);
+	}
+	return NULL;
+}
+
+int ttydmx_init_conf(json_t *config)
+{
+	struct ttydmx_sink *sink;
+	struct ttydmx_device **devp;
+	const char *ttydev;
+	char ttydevfull[PATH_MAX];
+	struct stat st;
+	struct termios termios;
+	struct serial_struct serial;
+
+	if (!json_is_object(config)) {
+		lprintf("ttyDMX config must be an object/dictionary");
+		return 1;
+	}
+	if (!json_is_string(json_object_get(config, "ttydev"))) {
+		lprintf("ttyDMX config must have a string 'ttydev' key");
+		return 1;
+	}
+	if (!json_is_array(json_object_get(config, "devices"))) {
+		lprintf("ttyDMX config must have an array 'devices' key");
+		return 1;
+	}
+
+	ttydev = json_string_value(json_object_get(config, "ttydev"));
+	if (strchr(ttydev, '/'))
+		snprintf(ttydevfull, sizeof(ttydevfull), "%s", ttydev);
+	else
+		snprintf(ttydevfull, sizeof(ttydevfull), "/dev/%s", ttydev);
+
+	if (stat(ttydevfull, &st)) {
+		lprintf("ttyDMX: stat(\"%s\") failed: %s",
+			ttydevfull, strerror(errno));
+		return 1;
+	}
+	if (!S_ISCHR(st.st_mode)) {
+		lprintf("ttyDMX: \"%s\" needs to be a character device!",
+			ttydevfull);
+		return 1;
+	}
+
+	sink = calloc(sizeof(*sink), 1);
+	sink->ttydev = strdup(ttydevfull);
+	sink->fd = open(ttydevfull, O_RDWR | O_NOCTTY);
+	if (sink->fd < 0) {
+		lprintf("ttyDMX: failed to open \"%s\": %s",
+			ttydevfull, strerror(errno));
+		free(sink->ttydev);
+		free(sink);
+		return 1;
+	}
+
+	memset(&serial, 0, sizeof(serial));
+	if (ioctl(sink->fd, TIOCGSERIAL, &serial))
+		goto out_setup_err;
+
+	serial.flags &= ~ASYNC_SPD_MASK;
+	serial.flags |= ASYNC_SPD_CUST;
+	serial.custom_divisor = serial.baud_base / 250000;
+
+	if (ioctl(sink->fd, TIOCSSERIAL, &serial))
+		goto out_setup_err;
+	if (ioctl(sink->fd, TIOCGSERIAL, &serial))
+		goto out_setup_err;
+	lprintf("ttyDMX: \"%s\": divisor: %d, result rate: %d\n",
+		ttydevfull,
+		(int)serial.custom_divisor,
+		(int)serial.baud_base / serial.custom_divisor);
+
+	if (tcgetattr(sink->fd, &termios))
+		goto out_setup_err;
+	cfsetispeed(&termios, B38400);
+	cfsetospeed(&termios, B38400);
+	cfmakeraw(&termios);
+	termios.c_cflag |= CLOCAL | CREAD | CSTOPB;
+	termios.c_cflag &= ~CRTSCTS;
+	if (tcsetattr(sink->fd, TCSANOW, &termios))
+		goto out_setup_err;
+
+	json_t *devcfg = json_object_get(config, "devices");
+	devp = &sink->devs;
+	for (size_t i = 0; i < json_array_size(devcfg); i++) {
+		struct ttydmx_device *dev;
+		json_t *c = json_array_get(devcfg, i);
+		dev = ttydmx_add_dev(sink, c);
+		if (!dev) {
+			close(sink->fd);
+			free(sink->ttydev);
+			free(sink);
+			return 1;
+		}
+		*devp = dev;
+		devp = &dev->next;
+	}
+
+	sink->u = can_register_alloc(sink, ttydmx_can_handler,
+		"ttyDMX[%s]", sink->ttydev);
+	sink->u->json = ttydmx_json_handler;
+
+	if (pthread_create(&sink->pusher, NULL, ttydmx_thread, sink))
+		lprintf("ttyDMX[%s]: failed to start thread!", sink->ttydev);
+
+	*psinks = sink;
+	psinks = &sink->next;
+	return 0;
+
+out_setup_err:
+	lprintf("ttyDMX: setup error on \"%s\": %s",
+		ttydevfull, strerror(errno));
+	close(sink->fd);
+	free(sink->ttydev);
+	free(sink);
+	return 1;
+}