libsi24: recv mode fifo read changes

- recv does not clear RX_DR bit when user buffer is full, but
not all of RX FIFO
- returns bytes_read instead of err code

diff --git a/libsi24.c b/libsi24.c
index 250dd03..f85326c 100644 (file)
--- a/libsi24.c
+++ b/libsi24.c
@@ -237,7 +237,7 @@ size_t si24_recv(si24_t* si, unsigned char * buf, size_t size)
        if (!(flags & (1 << RX_DR))) {
                ev.type = EV_RX_EMPTY;
                si->eh(si, &ev);
-               return -1;
+               return bytes_read;
        }
 
        /* do not accept any new incoming data */
@@ -249,17 +249,21 @@ size_t si24_recv(si24_t* si, unsigned char * buf, size_t size)
                
                int m_size = (size - bytes_read) > p_size ? p_size : (size - bytes_read);
                _reg_read(si, SI24_R_RX_PAYLOAD, tmpbuf, m_size);
+
                memcpy(buf + bytes_read, tmpbuf, m_size);
                bytes_read += m_size;
-               
-               ev.type = EV_RX_COMPLETE;
-               si->eh(si, &ev);
 
                _reg_read(si, SI24_REG_FIFO_SATUS, &fifo_flags, 1);
        }
 
-       flags |= (1 << RX_DR);
-       _reg_write(si, SI24_REG_STATUS, &flags, 1);
+       /* only clear data ready flag when FIFO is empty */
+       if (fifo_flags & (1 << RX_EMPTY)) {
+               flags |= (1 << RX_DR);
+               _reg_write(si, SI24_REG_STATUS, &flags, 1);
+       }
+       
+       ev.type = EV_RX_COMPLETE;
+       si->eh(si, &ev);
 
        si->opts->ioctl->chip_enable(1);