1 files changed, 13 insertions, 3 deletions

diff --git a/drivers/staging/poch/poch.c b/drivers/staging/poch/poch.c
index 1637c281ea3..babd881809a 100644
--- a/drivers/staging/poch/poch.c
+++ b/drivers/staging/poch/poch.c
@@ -252,6 +252,11 @@ module_param(synth_rx, bool, 0600);
 MODULE_PARM_DESC(synth_rx,
                 "Synthesize received values using a counter. Default: No");
 
+static int loopback;
+module_param(loopback, bool, 0600);
+MODULE_PARM_DESC(loopback,
+                "Enable hardware loopback of trasnmitted data. Default: No");
+
 static dev_t poch_first_dev;
 static struct class *poch_cls;
 static DEFINE_IDR(poch_ids);
@@ -830,9 +835,14 @@ static int poch_open(struct inode *inode, struct file *filp)
 
         if (channel->dir == CHANNEL_DIR_TX) {
                 /* Flush TX FIFO and output data from cardbus. */
-                iowrite32(FPGA_TX_CTL_FIFO_FLUSH
-                          | FPGA_TX_CTL_OUTPUT_CARDBUS,
-                          fpga + FPGA_TX_CTL_REG);
+                u32 ctl_val = 0;
+
+                ctl_val |= FPGA_TX_CTL_FIFO_FLUSH;
+                ctl_val |= FPGA_TX_CTL_OUTPUT_CARDBUS;
+                if (loopback)
+                        ctl_val |= FPGA_TX_CTL_LOOPBACK;
+
+                iowrite32(ctl_val, fpga + FPGA_TX_CTL_REG);
         } else {
                 /* Flush RX FIFO and output data to cardbus. */
                 u32 ctl_val = FPGA_RX_CTL_CONT_CAP | FPGA_RX_CTL_FIFO_FLUSH;