It allows to set the bitrate via ip tool, as it happens for the other
CAN device drivers. It still remains possible to set the bitrate via
slcand or slcan_attach utilities. In case the ip tool is used, the
driver will send the serial command to the adapter.
Signed-off-by: Dario Binacchi <dario.binacchi@xxxxxxxxxxxxxxxxxxxx>
---
Changes in v4:
- Use CAN_BITRATE_UNSET (0) and CAN_BITRATE_UNKNOWN (-1U) macros.
- Don't reset the bitrate in ndo_stop() if it has been configured.
Changes in v3:
- Remove the slc_do_set_bittiming().
- Set the bitrate in the ndo_open().
- Replace -1UL with -1U in setting a fake value for the bitrate.
Changes in v2:
- Use the CAN framework support for setting fixed bit rates.
drivers/net/can/slcan.c | 41 ++++++++++++++++++++++++++++++++++++++---
1 file changed, 38 insertions(+), 3 deletions(-)
diff --git a/drivers/net/can/slcan.c b/drivers/net/can/slcan.c
index 2afddaf62586..bd3cf53246c7 100644
--- a/drivers/net/can/slcan.c
+++ b/drivers/net/can/slcan.c
@@ -105,6 +105,11 @@ struct slcan {
static struct net_device **slcan_devs;
static DEFINE_SPINLOCK(slcan_lock);
+static const u32 slcan_bitrate_const[] = {
+ 10000, 20000, 50000, 100000, 125000,
+ 250000, 500000, 800000, 1000000
+};
+
/************************************************************************
* SLCAN ENCAPSULATION FORMAT *
************************************************************************/
@@ -440,6 +445,9 @@ static int slc_close(struct net_device *dev)
netif_stop_queue(dev);
close_candev(dev);
sl->can.state = CAN_STATE_STOPPED;
+ if (sl->can.bittiming.bitrate == CAN_BITRATE_UNKNOWN)
+ sl->can.bittiming.bitrate = CAN_BITRATE_UNSET;
+
sl->rcount = 0;
sl->xleft = 0;
spin_unlock_bh(&sl->lock);
@@ -451,7 +459,8 @@ static int slc_close(struct net_device *dev)
static int slc_open(struct net_device *dev)
{
struct slcan *sl = netdev_priv(dev);
- int err;
+ unsigned char cmd[SLC_MTU];
+ int err, s;
if (sl->tty == NULL)
return -ENODEV;
@@ -461,15 +470,39 @@ static int slc_open(struct net_device *dev)
* can.bittiming.bitrate is CAN_BITRATE_UNSET (0), causing
* open_candev() to fail. So let's set to a fake value.
*/
- sl->can.bittiming.bitrate = CAN_BITRATE_UNKNOWN;
+ if (sl->can.bittiming.bitrate == CAN_BITRATE_UNSET)
+ sl->can.bittiming.bitrate = CAN_BITRATE_UNKNOWN;
+
err = open_candev(dev);
if (err) {
netdev_err(dev, "failed to open can device\n");
return err;
}
- sl->can.state = CAN_STATE_ERROR_ACTIVE;
sl->flags &= BIT(SLF_INUSE);
+
+ if (sl->can.bittiming.bitrate != CAN_BITRATE_UNKNOWN) {
+ for (s = 0; s < ARRAY_SIZE(slcan_bitrate_const); s++) {
+ if (sl->can.bittiming.bitrate == slcan_bitrate_const[s])
+ break;
+ }
+
+ /* The CAN framework has already validate the bitrate value,
+ * so we can avoid to check if `s' has been properly set.
+ */
+
+ snprintf(cmd, sizeof(cmd), "C\rS%d\r", s);
+ err = slcan_transmit_cmd(sl, cmd);
+ if (err) {
+ netdev_err(dev,
+ "failed to send bitrate command 'C\\rS%d\\r'\n",
+ s);
+ close_candev(dev);
+ return err;
+ }
+ }
+
+ sl->can.state = CAN_STATE_ERROR_ACTIVE;
netif_start_queue(dev);
return 0;
}
@@ -582,6 +615,8 @@ static struct slcan *slc_alloc(void)
/* Initialize channel control data */
sl->magic = SLCAN_MAGIC;
sl->dev = dev;
+ sl->can.bitrate_const = slcan_bitrate_const;
+ sl->can.bitrate_const_cnt = ARRAY_SIZE(slcan_bitrate_const);
spin_lock_init(&sl->lock);
INIT_WORK(&sl->tx_work, slcan_transmit);
init_waitqueue_head(&sl->xcmd_wait);
--
2.32.0
