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can: slcan: extend the protocol with CAN state info

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It extends the protocol to receive the adapter CAN state changes
(warning, busoff, etc.) and forward them to the netdev upper levels.

Link: https://lore.kernel.org/all/20220628163137.413025-13-dario.binacchi@amarulasolutions.com
Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This commit is contained in:
Dario Binacchi 2022-06-28 18:31:36 +02:00 committed by Marc Kleine-Budde
parent b32ff46685
commit 0a9cdcf098
1 changed files with 73 additions and 1 deletions
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74
drivers/net/can/slcan/slcan-core.c
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@ -78,7 +78,11 @@ MODULE_PARM_DESC(maxdev, "Maximum number of slcan interfaces");
#define SLC_CMD_LEN 1
#define SLC_SFF_ID_LEN 3
#define SLC_EFF_ID_LEN 8
#define SLC_STATE_LEN 1
#define SLC_STATE_BE_RXCNT_LEN 3
#define SLC_STATE_BE_TXCNT_LEN 3
#define SLC_STATE_FRAME_LEN (1 + SLC_CMD_LEN + SLC_STATE_BE_RXCNT_LEN + \
SLC_STATE_BE_TXCNT_LEN)
struct slcan {
struct can_priv can;
int magic;
@ -254,6 +258,72 @@ decode_failed:
dev_kfree_skb(skb);
}
/* A change state frame must contain state info and receive and transmit
* error counters.
*
* Examples:
*
* sb256256 : state bus-off: rx counter 256, tx counter 256
* sa057033 : state active, rx counter 57, tx counter 33
*/
static void slc_bump_state(struct slcan *sl)
{
struct net_device *dev = sl->dev;
struct sk_buff *skb;
struct can_frame *cf;
char *cmd = sl->rbuff;
u32 rxerr, txerr;
enum can_state state, rx_state, tx_state;
switch (cmd[1]) {
case 'a':
state = CAN_STATE_ERROR_ACTIVE;
break;
case 'w':
state = CAN_STATE_ERROR_WARNING;
break;
case 'p':
state = CAN_STATE_ERROR_PASSIVE;
break;
case 'b':
state = CAN_STATE_BUS_OFF;
break;
default:
return;
}
if (state == sl->can.state || sl->rcount < SLC_STATE_FRAME_LEN)
return;
cmd += SLC_STATE_BE_RXCNT_LEN + SLC_CMD_LEN + 1;
cmd[SLC_STATE_BE_TXCNT_LEN] = 0;
if (kstrtou32(cmd, 10, &txerr))
return;
*cmd = 0;
cmd -= SLC_STATE_BE_RXCNT_LEN;
if (kstrtou32(cmd, 10, &rxerr))
return;
skb = alloc_can_err_skb(dev, &cf);
if (skb) {
cf->data[6] = txerr;
cf->data[7] = rxerr;
} else {
cf = NULL;
}
tx_state = txerr >= rxerr ? state : 0;
rx_state = txerr <= rxerr ? state : 0;
can_change_state(dev, cf, tx_state, rx_state);
if (state == CAN_STATE_BUS_OFF)
can_bus_off(dev);
if (skb)
netif_rx(skb);
}
/* An error frame can contain more than one type of error.
*
* Examples:
@ -387,6 +457,8 @@ static void slc_bump(struct slcan *sl)
return slc_bump_frame(sl);
case 'e':
return slc_bump_err(sl);
case 's':
return slc_bump_state(sl);
default:
return;
}