[v3,07/13] can: slcan: set bitrate by CAN device driver API
diff mbox series

Message ID 20220612213927.3004444-8-dario.binacchi@amarulasolutions.com
State New
Headers show
Series
  • can: slcan: extend supported features
Related show

Commit Message

Dario Binacchi June 12, 2022, 9:39 p.m. UTC 
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@amarulasolutions.com>

---

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 | 39 ++++++++++++++++++++++++++++++++++++---
 1 file changed, 36 insertions(+), 3 deletions(-)

Comments

Marc Kleine-Budde June 13, 2022, 7:17 a.m. UTC | #1 
On 12.06.2022 23:39:21, Dario Binacchi wrote:
> 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@amarulasolutions.com>
> 
> ---
> 
> 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 | 39 ++++++++++++++++++++++++++++++++++++---
>  1 file changed, 36 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/can/slcan.c b/drivers/net/can/slcan.c
> index 4639a63c3af8..be3f7e5c685b 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 +445,7 @@ static int slc_close(struct net_device *dev)
>  	netif_stop_queue(dev);
>  	close_candev(dev);
>  	sl->can.state = CAN_STATE_STOPPED;
> +	sl->can.bittiming.bitrate = 0;

If the bitrate is configured, please keep that value.

Marc

Patch
diff mbox series 

diff --git a/drivers/net/can/slcan.c b/drivers/net/can/slcan.c
index 4639a63c3af8..be3f7e5c685b 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 +445,7 @@  static int slc_close(struct net_device *dev)
 	netif_stop_queue(dev);
 	close_candev(dev);
 	sl->can.state = CAN_STATE_STOPPED;
+	sl->can.bittiming.bitrate = 0;
 	sl->rcount   = 0;
 	sl->xleft    = 0;
 	spin_unlock_bh(&sl->lock);
@@ -451,7 +457,8 @@  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 +468,39 @@  static int slc_open(struct net_device *dev)
 	 * can.bittiming.bitrate is 0, causing open_candev() to fail.
 	 * So let's set to a fake value.
 	 */
-	sl->can.bittiming.bitrate = -1;
+	if (sl->can.bittiming.bitrate == 0)
+		sl->can.bittiming.bitrate = -1U;
+
 	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 != -1U) {
+		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;
 }
@@ -583,6 +614,8 @@  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);