lib: added fdelay_read and fdelay_fread

5593ebfb · Alessandro Rubini · 465ea0ad · 5593ebfb · 5593ebfb
Commit 5593ebfb authored May 03, 2012 by Alessandro Rubini
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fdelay-lib.h lib/fdelay-lib.h +6 -0

fdelay-tdc.c lib/fdelay-tdc.c +84 -0

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--- a/lib/fdelay-lib.h
+++ b/lib/fdelay-lib.h
@@ -42,6 +42,12 @@ extern int fdelay_set_host_time(struct fdelay_board *b);
 extern int fdelay_set_config_tdc(struct fdelay_board *b, int flags);
 extern int fdelay_get_config_tdc(struct fdelay_board *b);

+extern int fdelay_fread(struct fdelay_board *b, struct fdelay_time *t, int n);
+extern int fdelay_fileno_tdc(struct fdelay_board *b);
+extern int fdelay_read(struct fdelay_board *b, struct fdelay_time *t, int n,
+		       int flags);
+
+

 #ifdef FDELAY_INTERNAL /* Libray users should ignore what follows */


--- a/lib/fdelay-tdc.c
+++ b/lib/fdelay-tdc.c
@@ -15,6 +15,7 @@
 #include <unistd.h>
 #include <errno.h>
 #include <fcntl.h>
+#include <sys/select.h>

 #include <linux/zio.h>
 #include <linux/zio-user.h>
@@ -51,3 +52,86 @@ int fdelay_get_config_tdc(struct fdelay_board *userb)
 	if (ret) return ret;
 	return val;
 }
+
+static int __fdelay_open_tdc(struct __fdelay_board *b)
+{
+	char fname[128];
+	if (b->fd[0] <= 0) {
+		sprintf(fname, "%s-0-0-ctrl", b->devbase);
+		b->fd[0] = open(fname, O_RDONLY | O_NONBLOCK);
+	}
+	return b->fd[0];
+}
+
+int fdelay_fileno_tdc(struct fdelay_board *userb)
+{
+	__define_board(b, userb);
+	return __fdelay_open_tdc(b);
+}
+
+
+/* "read" behaves like the system call and obeys O_NONBLOCK */
+int fdelay_read(struct fdelay_board *userb, struct fdelay_time *t, int n,
+		       int flags)
+{
+	__define_board(b, userb);
+	struct zio_control ctrl;
+	uint32_t *attrs;
+	int i, j, fd;
+	fd_set set;
+
+	fd = __fdelay_open_tdc(b);
+	if (fd < 0)
+		return fd; /* errno already set */
+
+	for (i = 0; i < n;) {
+		j = read(fd, &ctrl, sizeof(ctrl));
+		if (j < 0 && errno != EAGAIN)
+			return -1;
+		if (j == sizeof(ctrl)) {
+			/* one sample: pick it */
+			attrs = ctrl.attr_channel.ext_val;
+			t->utc = (uint64_t)attrs[FD_ATTR_TDC_UTC_H] << 32
+				| attrs[FD_ATTR_TDC_UTC_L];
+			t->coarse = attrs[FD_ATTR_TDC_COARSE];
+			t->frac = attrs[FD_ATTR_TDC_FRAC];
+			t->seq_id = attrs[FD_ATTR_TDC_SEQ];
+			t->channel = attrs[FD_ATTR_TDC_CHAN];
+
+			i++;
+			continue;
+		}
+		if (j > 0) {
+			errno = EIO;
+			return -1;
+		}
+		/* so, it's EAGAIN: if we already got something, we are done */
+		if (i)
+			return i;
+		/* EAGAIN at first sample */
+		if (j < 0 && flags == O_NONBLOCK)
+			return -1;
+
+		/* So, first sample and blocking read. Wait.. */
+		FD_ZERO(&set);
+		FD_SET(fd, &set);
+		if (select(fd+1, &set, NULL, NULL, NULL) < 0)
+			return -1;
+		continue;
+	}
+	return i;
+}
+
+/* "fread" behaves like stdio: it reads all the samples */
+int fdelay_fread(struct fdelay_board *userb, struct fdelay_time *t, int n)
+{
+	int i, loop;
+
+	for (i = 0; i < n; ) {
+		loop = fdelay_read(userb, t, n - i, 0);
+		if (loop < 0)
+			return -1;
+		i += loop;
+	}
+	return i;
+}