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path: root/drivers/net/can/c_can/c_can.c
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Diffstat (limited to 'drivers/net/can/c_can/c_can.c')
-rw-r--r--drivers/net/can/c_can/c_can.c51
1 files changed, 46 insertions, 5 deletions
diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
index e3dccd3200d5..4ead5a18b794 100644
--- a/drivers/net/can/c_can/c_can.c
+++ b/drivers/net/can/c_can/c_can.c
@@ -52,6 +52,7 @@
#define CONTROL_EX_PDR BIT(8)
/* control register */
+#define CONTROL_SWR BIT(15)
#define CONTROL_TEST BIT(7)
#define CONTROL_CCE BIT(6)
#define CONTROL_DISABLE_AR BIT(5)
@@ -97,6 +98,9 @@
#define BTR_TSEG2_SHIFT 12
#define BTR_TSEG2_MASK (0x7 << BTR_TSEG2_SHIFT)
+/* interrupt register */
+#define INT_STS_PENDING 0x8000
+
/* brp extension register */
#define BRP_EXT_BRPE_MASK 0x0f
#define BRP_EXT_BRPE_SHIFT 0
@@ -569,6 +573,26 @@ static void c_can_configure_msg_objects(struct net_device *dev)
IF_MCONT_RCV_EOB);
}
+static int c_can_software_reset(struct net_device *dev)
+{
+ struct c_can_priv *priv = netdev_priv(dev);
+ int retry = 0;
+
+ if (priv->type != BOSCH_D_CAN)
+ return 0;
+
+ priv->write_reg(priv, C_CAN_CTRL_REG, CONTROL_SWR | CONTROL_INIT);
+ while (priv->read_reg(priv, C_CAN_CTRL_REG) & CONTROL_SWR) {
+ msleep(20);
+ if (retry++ > 100) {
+ netdev_err(dev, "CCTRL: software reset failed\n");
+ return -EIO;
+ }
+ }
+
+ return 0;
+}
+
/*
* Configure C_CAN chip:
* - enable/disable auto-retransmission
@@ -578,6 +602,11 @@ static void c_can_configure_msg_objects(struct net_device *dev)
static int c_can_chip_config(struct net_device *dev)
{
struct c_can_priv *priv = netdev_priv(dev);
+ int err;
+
+ err = c_can_software_reset(dev);
+ if (err)
+ return err;
/* enable automatic retransmission */
priv->write_reg(priv, C_CAN_CTRL_REG, CONTROL_ENABLE_AR);
@@ -1029,10 +1058,16 @@ static int c_can_poll(struct napi_struct *napi, int quota)
u16 curr, last = priv->last_status;
int work_done = 0;
- priv->last_status = curr = priv->read_reg(priv, C_CAN_STS_REG);
- /* Ack status on C_CAN. D_CAN is self clearing */
- if (priv->type != BOSCH_D_CAN)
- priv->write_reg(priv, C_CAN_STS_REG, LEC_UNUSED);
+ /* Only read the status register if a status interrupt was pending */
+ if (atomic_xchg(&priv->sie_pending, 0)) {
+ priv->last_status = curr = priv->read_reg(priv, C_CAN_STS_REG);
+ /* Ack status on C_CAN. D_CAN is self clearing */
+ if (priv->type != BOSCH_D_CAN)
+ priv->write_reg(priv, C_CAN_STS_REG, LEC_UNUSED);
+ } else {
+ /* no change detected ... */
+ curr = last;
+ }
/* handle state changes */
if ((curr & STATUS_EWARN) && (!(last & STATUS_EWARN))) {
@@ -1083,10 +1118,16 @@ static irqreturn_t c_can_isr(int irq, void *dev_id)
{
struct net_device *dev = (struct net_device *)dev_id;
struct c_can_priv *priv = netdev_priv(dev);
+ int reg_int;
- if (!priv->read_reg(priv, C_CAN_INT_REG))
+ reg_int = priv->read_reg(priv, C_CAN_INT_REG);
+ if (!reg_int)
return IRQ_NONE;
+ /* save for later use */
+ if (reg_int & INT_STS_PENDING)
+ atomic_set(&priv->sie_pending, 1);
+
/* disable all interrupts and schedule the NAPI */
c_can_irq_control(priv, false);
napi_schedule(&priv->napi);