From: Bert Vermeulen <redacted>
Date: Mon, 6 Oct 2014 10:10:25 +0000 (+0200)
Subject: serial: Add serial_timeout().
X-Git-Tag: libsigrok-0.4.0~885
X-Git-Url: https://sigrok.org/gitaction?a=commitdiff_plain;h=c5cfc735e50adc53e073355e5521b1c79266441e;p=libsigrok.git

serial: Add serial_timeout().

This calculates a proper timeout value for blocking writes on the
given serial port, for the given number of bytes. Timeout is based
on a fixed 10ms OS overhead, baud rate, data bits and stop bits.
---

diff --git a/src/libsigrok-internal.h b/src/libsigrok-internal.h
index ccf75598..bed08e4c 100644
--- a/src/libsigrok-internal.h
+++ b/src/libsigrok-internal.h
@@ -656,6 +656,7 @@ SR_PRIV int serial_source_add(struct sr_session *session,
 SR_PRIV int serial_source_remove(struct sr_session *session,
 		struct sr_serial_dev_inst *serial);
 SR_PRIV GSList *sr_serial_find_usb(uint16_t vendor_id, uint16_t product_id);
+SR_PRIV int serial_timeout(struct sr_serial_dev_inst *port, int num_bytes);
 #endif
 
 /*--- hardware/common/ezusb.c -----------------------------------------------*/
diff --git a/src/serial.c b/src/serial.c
index 63ffbe22..37463573 100644
--- a/src/serial.c
+++ b/src/serial.c
@@ -798,3 +798,43 @@ SR_PRIV GSList *sr_serial_find_usb(uint16_t vendor_id, uint16_t product_id)
 	sp_free_port_list(ports);
 	return tty_devs;
 }
+
+SR_PRIV int serial_timeout(struct sr_serial_dev_inst *port, int num_bytes)
+{
+	struct sp_port_config *config;
+	int timeout_ms, bits, baud, tmp;
+
+	/* Default to 1s. */
+	timeout_ms = 1000;
+
+	if (sp_new_config(&config) < 0)
+		return timeout_ms;
+
+	bits = baud = 0;
+	do {
+		if (sp_get_config(port->data, config) < 0)
+			break;
+
+		/* Start bit. */
+		bits = 1;
+		if (sp_get_config_bits(config, &tmp) < 0)
+			break;
+		bits += tmp;
+		if (sp_get_config_stopbits(config, &tmp) < 0)
+			break;
+		bits += tmp;
+		if (sp_get_config_baudrate(config, &tmp) < 0)
+			break;
+		baud = tmp;
+	} while (FALSE);
+
+	if (bits && baud) {
+		/* Throw in 10ms for misc OS overhead. */
+		timeout_ms = 10;
+		timeout_ms += ((1000.0 / baud) * bits) * num_bytes;
+	}
+
+	sp_free_config(config);
+
+	return timeout_ms;
+}