Revise SCPI read API to allow backend-independent data handling.

[libsigrok.git] / hardware / common / scpi_serial.c

diff --git a/hardware/common/scpi_serial.c b/hardware/common/scpi_serial.c
index dc0996349937a181aef67b71012ed23abe61fddc..0ee5894742629833e20fbe4526afa53460cb6b41 100644 (file)
--- a/hardware/common/scpi_serial.c
+++ b/hardware/common/scpi_serial.c
@@ -29,9 +29,15 @@
 #define SCPI_READ_RETRIES 100
 #define SCPI_READ_RETRY_TIMEOUT 10000
 
+struct scpi_serial {
+       struct sr_serial_dev_inst *serial;
+       char last_character;
+};
+
 SR_PRIV int scpi_serial_open(void *priv)
 {
-       struct sr_serial_dev_inst *serial = priv;
+       struct scpi_serial *sscpi = priv;
+       struct sr_serial_dev_inst *serial = sscpi->serial;
 
        if (serial_open(serial, SERIAL_RDWR | SERIAL_NONBLOCK) != SR_OK)
                return SR_ERR;
@@ -45,14 +51,16 @@ SR_PRIV int scpi_serial_open(void *priv)
 SR_PRIV int scpi_serial_source_add(void *priv, int events, int timeout,
                        sr_receive_data_callback_t cb, void *cb_data)
 {
-       struct sr_serial_dev_inst *serial = priv;
+       struct scpi_serial *sscpi = priv;
+       struct sr_serial_dev_inst *serial = sscpi->serial;
 
        return serial_source_add(serial, events, timeout, cb, cb_data);
 }
 
 SR_PRIV int scpi_serial_source_remove(void *priv)
 {
-       struct sr_serial_dev_inst *serial = priv;
+       struct scpi_serial *sscpi = priv;
+       struct sr_serial_dev_inst *serial = sscpi->serial;
 
        return serial_source_remove(serial);
 }
@@ -61,7 +69,8 @@ SR_PRIV int scpi_serial_send(void *priv, const char *command)
 {
        int len, result, written;
        gchar *terminated_command;
-       struct sr_serial_dev_inst *serial = priv;
+       struct scpi_serial *sscpi = priv;
+       struct sr_serial_dev_inst *serial = sscpi->serial;
 
        terminated_command = g_strconcat(command, "\n", NULL);
        len = strlen(terminated_command);
@@ -89,7 +98,8 @@ SR_PRIV int scpi_serial_receive(void *priv, char **scpi_response)
        char buf[256];
        unsigned int i;
        GString *response;
-       struct sr_serial_dev_inst *serial = priv;
+       struct scpi_serial *sscpi = priv;
+       struct sr_serial_dev_inst *serial = sscpi->serial;
 
        response = g_string_sized_new(1024);
 
@@ -136,43 +146,84 @@ SR_PRIV int scpi_serial_receive(void *priv, char **scpi_response)
        return ret;
 }
 
-/* Some stubs to keep the compiler from whining. */
-static int scpi_serial_read(void *priv, char *buf, int maxlen)
+SR_PRIV int scpi_serial_read_begin(void *priv)
+{
+       struct scpi_serial *sscpi = priv;
+
+       sscpi->last_character = '\0';
+
+       return SR_OK;
+}
+
+SR_PRIV int scpi_serial_read_data(void *priv, char *buf, int maxlen)
 {
-       return serial_read(priv, buf, maxlen);
+       struct scpi_serial *sscpi = priv;
+       int ret;
+
+       ret = serial_read(sscpi->serial, buf, maxlen);
+
+       if (ret < 0)
+               return ret;
+
+       if (ret > 0) {
+               sscpi->last_character = buf[ret - 1];
+               if (sscpi->last_character == '\n')
+                       ret--;
+       }
+
+       return ret;
 }
+
+SR_PRIV int scpi_serial_read_complete(void *priv)
+{
+       struct scpi_serial *sscpi = priv;
+
+       return (sscpi->last_character == '\n');
+}
+
 static int scpi_serial_close(void *priv)
 {
-       return serial_close(priv);
+       struct scpi_serial *sscpi = priv;
+       struct sr_serial_dev_inst *serial = sscpi->serial;
+
+       return serial_close(serial);
 }
+
 static void scpi_serial_free(void *priv)
 {
-       return sr_serial_dev_inst_free(priv);
+       struct scpi_serial *sscpi = priv;
+       struct sr_serial_dev_inst *serial = sscpi->serial;
+
+       sr_serial_dev_inst_free(serial);
+       g_free(sscpi);
 }
 
 SR_PRIV struct sr_scpi_dev_inst *scpi_serial_dev_inst_new(const char *port,
                const char *serialcomm)
 {
        struct sr_scpi_dev_inst *scpi;
+       struct scpi_serial *sscpi;
        struct sr_serial_dev_inst *serial;
 
-       scpi = g_try_malloc(sizeof(struct sr_scpi_dev_inst));
-
        if (!(serial = sr_serial_dev_inst_new(port, serialcomm)))
-       {
-               g_free(scpi);
                return NULL;
-       }
+
+       sscpi = g_malloc(sizeof(struct scpi_serial));
+
+       sscpi->serial = serial;
+
+       scpi = g_malloc(sizeof(struct sr_scpi_dev_inst));
 
        scpi->open = scpi_serial_open;
        scpi->source_add = scpi_serial_source_add;
        scpi->source_remove = scpi_serial_source_remove;
        scpi->send = scpi_serial_send;
-       scpi->receive = scpi_serial_receive;
-       scpi->read = scpi_serial_read;
+       scpi->read_begin = scpi_serial_read_begin;
+       scpi->read_data = scpi_serial_read_data;
+       scpi->read_complete = scpi_serial_read_complete;
        scpi->close = scpi_serial_close;
        scpi->free = scpi_serial_free;
-       scpi->priv = serial;
+       scpi->priv = sscpi;
 
        return scpi;
 }