can: Proper ctrlmode handling for CAN devices

This patch adds error checking of ctrlmode values for CAN devices. As
an example all availabe bits are implemented in the mcp251x driver.

Signed-off-by: Christian Pellegrin <chripell@fsfe.org>
Acked-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Author: Christian Pellegrin

drivers/net/can/at91_can.c

@@ -1073,6 +1073,7 @@ static int __init at91_can_probe(struct platform_device *pdev)
 	priv->can.bittiming_const = &at91_bittiming_const;
 	priv->can.do_set_bittiming = at91_set_bittiming;
 	priv->can.do_set_mode = at91_set_mode;
+	priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
 	priv->reg_base = addr;
 	priv->dev = dev;
 	priv->clk = clk;

drivers/net/can/bfin_can.c

@@ -603,6 +603,7 @@ struct net_device *alloc_bfin_candev(void)
 	priv->can.bittiming_const = &bfin_can_bittiming_const;
 	priv->can.do_set_bittiming = bfin_can_set_bittiming;
 	priv->can.do_set_mode = bfin_can_set_mode;
+	priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
 
 	return dev;
 }

drivers/net/can/dev.c

@@ -592,6 +592,8 @@ static int can_changelink(struct net_device *dev,
 		if (dev->flags & IFF_UP)
 			return -EBUSY;
 		cm = nla_data(data[IFLA_CAN_CTRLMODE]);
+		if (cm->flags & ~priv->ctrlmode_supported)
+			return -EOPNOTSUPP;
 		priv->ctrlmode &= ~cm->mask;
 		priv->ctrlmode |= cm->flags;
 	}

drivers/net/can/mcp251x.c

@@ -539,9 +539,14 @@ static void mcp251x_set_normal_mode(struct spi_device *spi)
 	if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) {
 		/* Put device into loopback mode */
 		mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_LOOPBACK);
+	} else if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY) {
+		/* Put device into listen-only mode */
+		mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_LISTEN_ONLY);
 	} else {
 		/* Put device into normal mode */
-		mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_NORMAL);
+		mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_NORMAL |
+				  (priv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT ?
+				   CANCTRL_OSM : 0));
 
 		/* Wait for the device to enter normal mode */
 		timeout = jiffies + HZ;
@@ -948,6 +953,10 @@ static int __devinit mcp251x_can_probe(struct spi_device *spi)
 	priv->can.bittiming_const = &mcp251x_bittiming_const;
 	priv->can.do_set_mode = mcp251x_do_set_mode;
 	priv->can.clock.freq = pdata->oscillator_frequency / 2;
+	priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES |
+		CAN_CTRLMODE_LOOPBACK | CAN_CTRLMODE_LISTENONLY;
+	if (pdata->model == CAN_MCP251X_MCP2515)
+		priv->can.ctrlmode_supported |= CAN_CTRLMODE_ONE_SHOT;
 	priv->net = net;
 	dev_set_drvdata(&spi->dev, priv);
 

drivers/net/can/mscan/mscan.c

@@ -686,6 +686,7 @@ struct net_device *alloc_mscandev(void)
 	priv->can.bittiming_const = &mscan_bittiming_const;
 	priv->can.do_set_bittiming = mscan_do_set_bittiming;
 	priv->can.do_set_mode = mscan_do_set_mode;
+	priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
 
 	for (i = 0; i < TX_QUEUE_SIZE; i++) {
 		priv->tx_queue[i].id = i;

drivers/net/can/sja1000/sja1000.c

@@ -567,6 +567,7 @@ struct net_device *alloc_sja1000dev(int sizeof_priv)
 	priv->can.bittiming_const = &sja1000_bittiming_const;
 	priv->can.do_set_bittiming = sja1000_set_bittiming;
 	priv->can.do_set_mode = sja1000_set_mode;
+	priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
 
 	if (sizeof_priv)
 		priv->priv = (void *)priv + sizeof(struct sja1000_priv);

drivers/net/can/ti_hecc.c

@@ -909,6 +909,7 @@ static int ti_hecc_probe(struct platform_device *pdev)
 	priv->can.bittiming_const = &ti_hecc_bittiming_const;
 	priv->can.do_set_mode = ti_hecc_do_set_mode;
 	priv->can.do_get_state = ti_hecc_get_state;
+	priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
 
 	ndev->irq = irq->start;
 	ndev->flags |= IFF_ECHO;

drivers/net/can/usb/ems_usb.c

@@ -1022,6 +1022,7 @@ static int ems_usb_probe(struct usb_interface *intf,
 	dev->can.bittiming_const = &ems_usb_bittiming_const;
 	dev->can.do_set_bittiming = ems_usb_set_bittiming;
 	dev->can.do_set_mode = ems_usb_set_mode;
+	dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
 
 	netdev->flags |= IFF_ECHO; /* we support local echo */
 

include/linux/can/dev.h

@@ -38,6 +38,7 @@ struct can_priv {
 
 	enum can_state state;
 	u32 ctrlmode;
+	u32 ctrlmode_supported;
 
 	int restart_ms;
 	struct timer_list restart_timer;