commit bf3af54732bea5894ccc2cbde3ab566f0af7da56
author Wolfgang Grandegger <wg@denx.de> Thu Jan 07 09:43:07 2010 +0000
committer David S. Miller <davem@davemloft.net> Fri Jan 08 01:02:18 2010 -0800
tree e8e6681168c9f695006962cacfb937d3dc1bbb06
parent 2d4b6faf7d1818e9a52ae9f068ab4ffd9c3be923

can: mscan-mpc5xxx: add support for the MPC512x processor

The main differences compared to the MSCAN on the MPC5200 are:

- More flexibility in choosing the CAN source clock and frequency:

  Three different clock sources can be selected: "ip", "ref" or "sys".
  For the latter two, a clock divider can be defined as well. If the
  clock source is not specified by the device tree, we first try to
  find an optimal CAN source clock based on the system clock. If that
  is not possible, the reference clock will be used.

- The behavior of bus-off recovery is configurable:

  To comply with the usual handling of Socket-CAN bus-off recovery,
  "recovery on request" is selected (instead of automatic recovery).

Note that only MPC5121 Rev. 2 and later is supported.

Signed-off-by: Wolfgang Grandegger <wg@denx.de>
Reviewed-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/can/mscan/mscan.c

diff --git a/drivers/net/can/mscan/mscan.c b/drivers/net/can/mscan/mscan.c
index 0dcbe8c..500d189 100644
--- a/drivers/net/can/mscan/mscan.c
+++ b/drivers/net/can/mscan/mscan.c
@@ -152,6 +152,12 @@
 	priv->shadow_canrier = 0;
 	priv->flags = 0;
 
+	if (priv->type == MSCAN_TYPE_MPC5121) {
+		/* Clear pending bus-off condition */
+		if (in_8(&regs->canmisc) & MSCAN_BOHOLD)
+			out_8(&regs->canmisc, MSCAN_BOHOLD);
+	}
+
 	err = mscan_set_mode(dev, MSCAN_NORMAL_MODE);
 	if (err)
 		return err;
@@ -163,8 +169,29 @@
 	out_8(&regs->cantier, 0);
 
 	/* Enable receive interrupts. */
-	out_8(&regs->canrier, MSCAN_OVRIE | MSCAN_RXFIE | MSCAN_CSCIE |
-	      MSCAN_RSTATE1 | MSCAN_RSTATE0 | MSCAN_TSTATE1 | MSCAN_TSTATE0);
+	out_8(&regs->canrier, MSCAN_RX_INTS_ENABLE);
+
+	return 0;
+}
+
+static int mscan_restart(struct net_device *dev)
+{
+	struct mscan_priv *priv = netdev_priv(dev);
+
+	if (priv->type == MSCAN_TYPE_MPC5121) {
+		struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
+
+		priv->can.state = CAN_STATE_ERROR_ACTIVE;
+		WARN(!(in_8(&regs->canmisc) & MSCAN_BOHOLD),
+		     "bus-off state expected");
+		out_8(&regs->canmisc, MSCAN_BOHOLD);
+		/* Re-enable receive interrupts. */
+		out_8(&regs->canrier, MSCAN_RX_INTS_ENABLE);
+	} else {
+		if (priv->can.state <= CAN_STATE_BUS_OFF)
+			mscan_set_mode(dev, MSCAN_INIT_MODE);
+		return mscan_start(dev);
+	}
 
 	return 0;
 }
@@ -362,9 +389,12 @@
 			 * automatically. To avoid that we stop the chip doing
 			 * a light-weight stop (we are in irq-context).
 			 */
-			out_8(&regs->cantier, 0);
-			out_8(&regs->canrier, 0);
-			setbits8(&regs->canctl0, MSCAN_SLPRQ | MSCAN_INITRQ);
+			if (priv->type != MSCAN_TYPE_MPC5121) {
+				out_8(&regs->cantier, 0);
+				out_8(&regs->canrier, 0);
+				setbits8(&regs->canctl0,
+					 MSCAN_SLPRQ | MSCAN_INITRQ);
+			}
 			can_bus_off(dev);
 			break;
 		default:
@@ -494,9 +524,7 @@
 
 	switch (mode) {
 	case CAN_MODE_START:
-		if (priv->can.state <= CAN_STATE_BUS_OFF)
-			mscan_set_mode(dev, MSCAN_INIT_MODE);
-		ret = mscan_start(dev);
+		ret = mscan_restart(dev);
 		if (ret)
 			break;
 		if (netif_queue_stopped(dev))
@@ -595,18 +623,21 @@
        .ndo_start_xmit         = mscan_start_xmit,
 };
 
-int register_mscandev(struct net_device *dev, int clock_src)
+int register_mscandev(struct net_device *dev, int mscan_clksrc)
 {
 	struct mscan_priv *priv = netdev_priv(dev);
 	struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
 	u8 ctl1;
 
 	ctl1 = in_8(&regs->canctl1);
-	if (clock_src)
+	if (mscan_clksrc)
 		ctl1 |= MSCAN_CLKSRC;
 	else
 		ctl1 &= ~MSCAN_CLKSRC;
 
+	if (priv->type == MSCAN_TYPE_MPC5121)
+		ctl1 |= MSCAN_BORM; /* bus-off recovery upon request */
+
 	ctl1 |= MSCAN_CANE;
 	out_8(&regs->canctl1, ctl1);
 	udelay(100);