can: janz-ican3: add support for one shot mode

The Janz VMOD-ICAN3 hardware has support for one shot packet
transmission. This means that a packet will be attempted to be sent
once, with no automatic retries.

The SocketCAN core has a controller-wide setting for this mode:
CAN_CTRLMODE_ONE_SHOT. The Janz VMOD-ICAN3 hardware supports this flag
on a per-packet level, but the SocketCAN core does not.

Signed-off-by: Ira W. Snyder <iws@ovro.caltech.edu>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

diff --git a/drivers/net/can/janz-ican3.c b/drivers/net/can/janz-ican3.c
index e06ec40..98ee438 100644 (file)
--- a/drivers/net/can/janz-ican3.c
+++ b/drivers/net/can/janz-ican3.c
@@ -116,6 +116,7 @@
 #define ICAN3_BUSERR_QUOTA_MAX 255
 
 /* Janz ICAN3 CAN Frame Conversion */
+#define ICAN3_SNGL     0x02
 #define ICAN3_ECHO     0x10
 #define ICAN3_EFF_RTR  0x40
 #define ICAN3_SFF_RTR  0x10
@@ -848,6 +849,10 @@ static void can_frame_to_ican3(struct ican3_dev *mod,
        desc->data[0] |= cf->can_dlc;
        desc->data[1] |= ICAN3_ECHO;
 
+       /* support single transmission (no retries) mode */
+       if (mod->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT)
+               desc->data[1] |= ICAN3_SNGL;
+
        if (cf->can_id & CAN_RTR_FLAG)
                desc->data[0] |= ICAN3_EFF_RTR;
 
@@ -1810,7 +1815,8 @@ static int __devinit ican3_probe(struct platform_device *pdev)
        mod->can.do_set_mode = ican3_set_mode;
        mod->can.do_get_berr_counter = ican3_get_berr_counter;
        mod->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES
-                                   | CAN_CTRLMODE_BERR_REPORTING;
+                                   | CAN_CTRLMODE_BERR_REPORTING
+                                   | CAN_CTRLMODE_ONE_SHOT;
 
        /* find our IRQ number */
        mod->irq = platform_get_irq(pdev, 0);