Refactor scan options check.

[libsigrok.git] / src / serial.c

diff --git a/src/serial.c b/src/serial.c
index 4fe9b88fc0805e43b7716a4cdd1ace37501620a4..192b18a7245a4caffa17eb3a23ab3801bd16c33e 100644 (file)
--- a/src/serial.c
+++ b/src/serial.c
@@ -4,6 +4,7 @@
  * Copyright (C) 2010-2012 Bert Vermeulen <bert@biot.com>
  * Copyright (C) 2010-2012 Uwe Hermann <uwe@hermann-uwe.de>
  * Copyright (C) 2012 Alexandru Gagniuc <mr.nuke.me@gmail.com>
+ * Copyright (C) 2014 Uffe Jakobsen <uffe@uffe.org>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -169,8 +170,46 @@ SR_PRIV int serial_flush(struct sr_serial_dev_inst *serial)
        return SR_OK;
 }
 
+/**
+ * Drain serial port buffers.
+ *
+ * @param serial Previously initialized serial port structure.
+ *
+ * @retval SR_OK Success.
+ * @retval SR_ERR Failure.
+ */
+SR_PRIV int serial_drain(struct sr_serial_dev_inst *serial)
+{
+       int ret;
+       char *error;
+
+       if (!serial) {
+               sr_dbg("Invalid serial port.");
+               return SR_ERR;
+       }
+
+       if (!serial->data) {
+               sr_dbg("Cannot drain unopened serial port %s.", serial->port);
+               return SR_ERR;
+       }
+
+       sr_spew("Draining serial port %s.", serial->port);
+
+       ret = sp_drain(serial->data);
+
+       if (ret == SP_ERR_FAIL) {
+               error = sp_last_error_message();
+               sr_err("Error draining port (%d): %s.",
+                       sp_last_error_code(), error);
+               sp_free_error_message(error);
+               return SR_ERR;
+       }
+
+       return SR_OK;
+}
+
 static int _serial_write(struct sr_serial_dev_inst *serial,
-               const void *buf, size_t count, int nonblocking)
+               const void *buf, size_t count, int nonblocking, unsigned int timeout_ms)
 {
        ssize_t ret;
        char *error;
@@ -188,7 +227,7 @@ static int _serial_write(struct sr_serial_dev_inst *serial,
        if (nonblocking)
                ret = sp_nonblocking_write(serial->data, buf, count);
        else
-               ret = sp_blocking_write(serial->data, buf, count, 0);
+               ret = sp_blocking_write(serial->data, buf, count, timeout_ms);
 
        switch (ret) {
        case SP_ERR_ARG:
@@ -212,15 +251,17 @@ static int _serial_write(struct sr_serial_dev_inst *serial,
  * @param serial Previously initialized serial port structure.
  * @param[in] buf Buffer containing the bytes to write.
  * @param[in] count Number of bytes to write.
+ * @param[in] timeout_ms Timeout in ms, or 0 for no timeout.
  *
  * @retval SR_ERR_ARG Invalid argument.
  * @retval SR_ERR Other error.
- * @retval other The number of bytes written.
+ * @retval other The number of bytes written. If this is less than the number
+ * specified in the call, the timeout was reached.
  */
 SR_PRIV int serial_write_blocking(struct sr_serial_dev_inst *serial,
-               const void *buf, size_t count)
+               const void *buf, size_t count, unsigned int timeout_ms)
 {
-       return _serial_write(serial, buf, count, 0);
+       return _serial_write(serial, buf, count, 0, timeout_ms);
 }
 
 /**
@@ -237,11 +278,11 @@ SR_PRIV int serial_write_blocking(struct sr_serial_dev_inst *serial,
 SR_PRIV int serial_write_nonblocking(struct sr_serial_dev_inst *serial,
                const void *buf, size_t count)
 {
-       return _serial_write(serial, buf, count, 1);
+       return _serial_write(serial, buf, count, 1, 0);
 }
 
 static int _serial_read(struct sr_serial_dev_inst *serial, void *buf,
-               size_t count, int nonblocking)
+               size_t count, int nonblocking, unsigned int timeout_ms)
 {
        ssize_t ret;
        char *error;
@@ -259,7 +300,7 @@ static int _serial_read(struct sr_serial_dev_inst *serial, void *buf,
        if (nonblocking)
                ret = sp_nonblocking_read(serial->data, buf, count);
        else
-               ret = sp_blocking_read(serial->data, buf, count, 0);
+               ret = sp_blocking_read(serial->data, buf, count, timeout_ms);
 
        switch (ret) {
        case SP_ERR_ARG:
@@ -284,15 +325,17 @@ static int _serial_read(struct sr_serial_dev_inst *serial, void *buf,
  * @param serial Previously initialized serial port structure.
  * @param buf Buffer where to store the bytes that are read.
  * @param[in] count The number of bytes to read.
+ * @param[in] timeout_ms Timeout in ms, or 0 for no timeout.
  *
  * @retval SR_ERR_ARG Invalid argument.
  * @retval SR_ERR     Other error.
- * @retval other      The number of bytes read.
+ * @retval other      The number of bytes read. If this is less than the number
+ * requested, the timeout was reached.
  */
 SR_PRIV int serial_read_blocking(struct sr_serial_dev_inst *serial, void *buf,
-               size_t count)
+               size_t count, unsigned int timeout_ms)
 {
-       return _serial_read(serial, buf, count, 0);
+       return _serial_read(serial, buf, count, 0, timeout_ms);
 }
 
 /**
@@ -310,7 +353,7 @@ SR_PRIV int serial_read_blocking(struct sr_serial_dev_inst *serial, void *buf,
 SR_PRIV int serial_read_nonblocking(struct sr_serial_dev_inst *serial, void *buf,
                size_t count)
 {
-       return _serial_read(serial, buf, count, 1);
+       return _serial_read(serial, buf, count, 1, 0);
 }
 
 /**
@@ -794,3 +837,43 @@ 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;
+}