1 files changed, 118 insertions, 88 deletions

diff --git a/drivers/net/can/xilinx_can.c b/drivers/net/can/xilinx_can.c
index 9bce846acfcc..204a7890dc9c 100644
--- a/drivers/net/can/xilinx_can.c
+++ b/drivers/net/can/xilinx_can.c
@@ -51,16 +51,15 @@ enum xcan_reg {
 	XCAN_ISR_OFFSET		= 0x1C, /* Interrupt status */
 	XCAN_IER_OFFSET		= 0x20, /* Interrupt enable */
 	XCAN_ICR_OFFSET		= 0x24, /* Interrupt clear */
-	XCAN_TXFIFO_ID_OFFSET	= 0x30,/* TX FIFO ID */
-	XCAN_TXFIFO_DLC_OFFSET	= 0x34, /* TX FIFO DLC */
-	XCAN_TXFIFO_DW1_OFFSET	= 0x38, /* TX FIFO Data Word 1 */
-	XCAN_TXFIFO_DW2_OFFSET	= 0x3C, /* TX FIFO Data Word 2 */
-	XCAN_RXFIFO_ID_OFFSET	= 0x50, /* RX FIFO ID */
-	XCAN_RXFIFO_DLC_OFFSET	= 0x54, /* RX FIFO DLC */
-	XCAN_RXFIFO_DW1_OFFSET	= 0x58, /* RX FIFO Data Word 1 */
-	XCAN_RXFIFO_DW2_OFFSET	= 0x5C, /* RX FIFO Data Word 2 */
+	XCAN_TXFIFO_OFFSET	= 0x30, /* TX FIFO base */
+	XCAN_RXFIFO_OFFSET	= 0x50, /* RX FIFO base */
 };
 
+#define XCAN_FRAME_ID_OFFSET(frame_base)	((frame_base) + 0x00)
+#define XCAN_FRAME_DLC_OFFSET(frame_base)	((frame_base) + 0x04)
+#define XCAN_FRAME_DW1_OFFSET(frame_base)	((frame_base) + 0x08)
+#define XCAN_FRAME_DW2_OFFSET(frame_base)	((frame_base) + 0x0C)
+
 /* CAN register bit masks - XCAN_<REG>_<BIT>_MASK */
 #define XCAN_SRR_CEN_MASK		0x00000002 /* CAN enable */
 #define XCAN_SRR_RESET_MASK		0x00000001 /* Soft Reset the CAN core */
@@ -101,11 +100,6 @@ enum xcan_reg {
 #define XCAN_IDR_RTR_MASK		0x00000001 /* Remote TX request */
 #define XCAN_DLCR_DLC_MASK		0xF0000000 /* Data length code */
 
-#define XCAN_INTR_ALL		(XCAN_IXR_TXOK_MASK | XCAN_IXR_BSOFF_MASK |\
-				 XCAN_IXR_WKUP_MASK | XCAN_IXR_SLP_MASK | \
-				 XCAN_IXR_RXNEMP_MASK | XCAN_IXR_ERROR_MASK | \
-				 XCAN_IXR_RXOFLW_MASK | XCAN_IXR_ARBLST_MASK)
-
 /* CAN register bit shift - XCAN_<REG>_<BIT>_SHIFT */
 #define XCAN_BTR_SJW_SHIFT		7  /* Synchronous jump width */
 #define XCAN_BTR_TS2_SHIFT		4  /* Time segment 2 */
@@ -118,6 +112,15 @@ enum xcan_reg {
 #define XCAN_FRAME_MAX_DATA_LEN		8
 #define XCAN_TIMEOUT			(1 * HZ)
 
+/* TX-FIFO-empty interrupt available */
+#define XCAN_FLAG_TXFEMP	0x0001
+
+struct xcan_devtype_data {
+	unsigned int flags;
+	const struct can_bittiming_const *bittiming_const;
+	const char *bus_clk_name;
+};
+
 /**
  * struct xcan_priv - This definition define CAN driver instance
  * @can:			CAN private data structure.
@@ -133,6 +136,7 @@ enum xcan_reg {
  * @irq_flags:			For request_irq()
  * @bus_clk:			Pointer to struct clk
  * @can_clk:			Pointer to struct clk
+ * @devtype:			Device type specific constants
  */
 struct xcan_priv {
 	struct can_priv can;
@@ -149,6 +153,7 @@ struct xcan_priv {
 	unsigned long irq_flags;
 	struct clk *bus_clk;
 	struct clk *can_clk;
+	struct xcan_devtype_data devtype;
 };
 
 /* CAN Bittiming constants as per Xilinx CAN specs */
@@ -164,11 +169,6 @@ static const struct can_bittiming_const xcan_bittiming_const = {
 	.brp_inc = 1,
 };
 
-#define XCAN_CAP_WATERMARK	0x0001
-struct xcan_devtype_data {
-	unsigned int caps;
-};
-
 /**
  * xcan_write_reg_le - Write a value to the device register little endian
  * @priv:	Driver private data structure
@@ -329,7 +329,11 @@ static int xcan_chip_start(struct net_device *ndev)
 		return err;
 
 	/* Enable interrupts */
-	priv->write_reg(priv, XCAN_IER_OFFSET, XCAN_INTR_ALL);
+	priv->write_reg(priv, XCAN_IER_OFFSET,
+			XCAN_IXR_TXOK_MASK | XCAN_IXR_BSOFF_MASK |
+			XCAN_IXR_WKUP_MASK | XCAN_IXR_SLP_MASK |
+			XCAN_IXR_RXNEMP_MASK | XCAN_IXR_ERROR_MASK |
+			XCAN_IXR_RXOFLW_MASK | XCAN_IXR_ARBLST_MASK);
 
 	/* Check whether it is loopback mode or normal mode  */
 	if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) {
@@ -390,33 +394,15 @@ static int xcan_do_set_mode(struct net_device *ndev, enum can_mode mode)
 }
 
 /**
- * xcan_start_xmit - Starts the transmission
- * @skb:	sk_buff pointer that contains data to be Txed
- * @ndev:	Pointer to net_device structure
- *
- * This function is invoked from upper layers to initiate transmission. This
- * function uses the next available free txbuff and populates their fields to
- * start the transmission.
- *
- * Return: NETDEV_TX_OK on success and NETDEV_TX_BUSY when the tx queue is full
+ * xcan_write_frame - Write a frame to HW
+ * @skb:		sk_buff pointer that contains data to be Txed
+ * @frame_offset:	Register offset to write the frame to
  */
-static netdev_tx_t xcan_start_xmit(struct sk_buff *skb, struct net_device *ndev)
+static void xcan_write_frame(struct xcan_priv *priv, struct sk_buff *skb,
+			     int frame_offset)
 {
-	struct xcan_priv *priv = netdev_priv(ndev);
-	struct can_frame *cf = (struct can_frame *)skb->data;
 	u32 id, dlc, data[2] = {0, 0};
-	unsigned long flags;
-
-	if (can_dropped_invalid_skb(ndev, skb))
-		return NETDEV_TX_OK;
-
-	/* Check if the TX buffer is full */
-	if (unlikely(priv->read_reg(priv, XCAN_SR_OFFSET) &
-			XCAN_SR_TXFLL_MASK)) {
-		netif_stop_queue(ndev);
-		netdev_err(ndev, "BUG!, TX FIFO full when queue awake!\n");
-		return NETDEV_TX_BUSY;
-	}
+	struct can_frame *cf = (struct can_frame *)skb->data;
 
 	/* Watch carefully on the bit sequence */
 	if (cf->can_id & CAN_EFF_FLAG) {
@@ -452,23 +438,42 @@ static netdev_tx_t xcan_start_xmit(struct sk_buff *skb, struct net_device *ndev)
 	if (cf->can_dlc > 4)
 		data[1] = be32_to_cpup((__be32 *)(cf->data + 4));
 
+	priv->write_reg(priv, XCAN_FRAME_ID_OFFSET(frame_offset), id);
+	/* If the CAN frame is RTR frame this write triggers transmission */
+	priv->write_reg(priv, XCAN_FRAME_DLC_OFFSET(frame_offset), dlc);
+	if (!(cf->can_id & CAN_RTR_FLAG)) {
+		priv->write_reg(priv, XCAN_FRAME_DW1_OFFSET(frame_offset),
+				data[0]);
+		/* If the CAN frame is Standard/Extended frame this
+		 * write triggers transmission
+		 */
+		priv->write_reg(priv, XCAN_FRAME_DW2_OFFSET(frame_offset),
+				data[1]);
+	}
+}
+
+/**
+ * xcan_start_xmit_fifo - Starts the transmission (FIFO mode)
+ *
+ * Return: 0 on success, -ENOSPC if FIFO is full.
+ */
+static int xcan_start_xmit_fifo(struct sk_buff *skb, struct net_device *ndev)
+{
+	struct xcan_priv *priv = netdev_priv(ndev);
+	unsigned long flags;
+
+	/* Check if the TX buffer is full */
+	if (unlikely(priv->read_reg(priv, XCAN_SR_OFFSET) &
+			XCAN_SR_TXFLL_MASK))
+		return -ENOSPC;
+
 	can_put_echo_skb(skb, ndev, priv->tx_head % priv->tx_max);
 
 	spin_lock_irqsave(&priv->tx_lock, flags);
 
 	priv->tx_head++;
 
-	/* Write the Frame to Xilinx CAN TX FIFO */
-	priv->write_reg(priv, XCAN_TXFIFO_ID_OFFSET, id);
-	/* If the CAN frame is RTR frame this write triggers tranmission */
-	priv->write_reg(priv, XCAN_TXFIFO_DLC_OFFSET, dlc);
-	if (!(cf->can_id & CAN_RTR_FLAG)) {
-		priv->write_reg(priv, XCAN_TXFIFO_DW1_OFFSET, data[0]);
-		/* If the CAN frame is Standard/Extended frame this
-		 * write triggers tranmission
-		 */
-		priv->write_reg(priv, XCAN_TXFIFO_DW2_OFFSET, data[1]);
-	}
+	xcan_write_frame(priv, skb, XCAN_TXFIFO_OFFSET);
 
 	/* Clear TX-FIFO-empty interrupt for xcan_tx_interrupt() */
 	if (priv->tx_max > 1)
@@ -480,6 +485,35 @@ static netdev_tx_t xcan_start_xmit(struct sk_buff *skb, struct net_device *ndev)
 
 	spin_unlock_irqrestore(&priv->tx_lock, flags);
 
+	return 0;
+}
+
+/**
+ * xcan_start_xmit - Starts the transmission
+ * @skb:	sk_buff pointer that contains data to be Txed
+ * @ndev:	Pointer to net_device structure
+ *
+ * This function is invoked from upper layers to initiate transmission. This
+ * function uses the next available free txbuff and populates their fields to
+ * start the transmission.
+ *
+ * Return: NETDEV_TX_OK on success and NETDEV_TX_BUSY when the tx queue is full
+ */
+static int xcan_start_xmit(struct sk_buff *skb, struct net_device *ndev)
+{
+	int ret;
+
+	if (can_dropped_invalid_skb(ndev, skb))
+		return NETDEV_TX_OK;
+
+	ret = xcan_start_xmit_fifo(skb, ndev);
+
+	if (ret < 0) {
+		netdev_err(ndev, "BUG!, TX full when queue awake!\n");
+		netif_stop_queue(ndev);
+		return NETDEV_TX_BUSY;
+	}
+
 	return NETDEV_TX_OK;
 }
 
@@ -487,13 +521,14 @@ static netdev_tx_t xcan_start_xmit(struct sk_buff *skb, struct net_device *ndev)
  * xcan_rx -  Is called from CAN isr to complete the received
  *		frame  processing
  * @ndev:	Pointer to net_device structure
+ * @frame_base:	Register offset to the frame to be read
  *
  * This function is invoked from the CAN isr(poll) to process the Rx frames. It
  * does minimal processing and invokes "netif_receive_skb" to complete further
  * processing.
  * Return: 1 on success and 0 on failure.
  */
-static int xcan_rx(struct net_device *ndev)
+static int xcan_rx(struct net_device *ndev, int frame_base)
 {
 	struct xcan_priv *priv = netdev_priv(ndev);
 	struct net_device_stats *stats = &ndev->stats;
@@ -508,9 +543,9 @@ static int xcan_rx(struct net_device *ndev)
 	}
 
 	/* Read a frame from Xilinx zynq CANPS */
-	id_xcan = priv->read_reg(priv, XCAN_RXFIFO_ID_OFFSET);
-	dlc = priv->read_reg(priv, XCAN_RXFIFO_DLC_OFFSET) >>
-				XCAN_DLCR_DLC_SHIFT;
+	id_xcan = priv->read_reg(priv, XCAN_FRAME_ID_OFFSET(frame_base));
+	dlc = priv->read_reg(priv, XCAN_FRAME_DLC_OFFSET(frame_base)) >>
+				   XCAN_DLCR_DLC_SHIFT;
 
 	/* Change Xilinx CAN data length format to socketCAN data format */
 	cf->can_dlc = get_can_dlc(dlc);
@@ -533,8 +568,8 @@ static int xcan_rx(struct net_device *ndev)
 	}
 
 	/* DW1/DW2 must always be read to remove message from RXFIFO */
-	data[0] = priv->read_reg(priv, XCAN_RXFIFO_DW1_OFFSET);
-	data[1] = priv->read_reg(priv, XCAN_RXFIFO_DW2_OFFSET);
+	data[0] = priv->read_reg(priv, XCAN_FRAME_DW1_OFFSET(frame_base));
+	data[1] = priv->read_reg(priv, XCAN_FRAME_DW2_OFFSET(frame_base));
 
 	if (!(cf->can_id & CAN_RTR_FLAG)) {
 		/* Change Xilinx CAN data format to socketCAN data format */
@@ -806,7 +841,7 @@ static int xcan_rx_poll(struct napi_struct *napi, int quota)
 
 	isr = priv->read_reg(priv, XCAN_ISR_OFFSET);
 	while ((isr & XCAN_IXR_RXNEMP_MASK) && (work_done < quota)) {
-		work_done += xcan_rx(ndev);
+		work_done += xcan_rx(ndev, XCAN_RXFIFO_OFFSET);
 		priv->write_reg(priv, XCAN_ICR_OFFSET, XCAN_IXR_RXNEMP_MASK);
 		isr = priv->read_reg(priv, XCAN_ISR_OFFSET);
 	}
@@ -1193,13 +1228,21 @@ static const struct dev_pm_ops xcan_dev_pm_ops = {
 };
 
 static const struct xcan_devtype_data xcan_zynq_data = {
-	.caps = XCAN_CAP_WATERMARK,
+	.flags = XCAN_FLAG_TXFEMP,
+	.bittiming_const = &xcan_bittiming_const,
+	.bus_clk_name = "pclk",
+};
+
+static const struct xcan_devtype_data xcan_axi_data = {
+	.flags = 0,
+	.bittiming_const = &xcan_bittiming_const,
+	.bus_clk_name = "s_axi_aclk",
 };
 
 /* Match table for OF platform binding */
 static const struct of_device_id xcan_of_match[] = {
 	{ .compatible = "xlnx,zynq-can-1.0", .data = &xcan_zynq_data },
-	{ .compatible = "xlnx,axi-can-1.00.a", },
+	{ .compatible = "xlnx,axi-can-1.00.a", .data = &xcan_axi_data },
 	{ /* end of list */ },
 };
 MODULE_DEVICE_TABLE(of, xcan_of_match);
@@ -1219,7 +1262,7 @@ static int xcan_probe(struct platform_device *pdev)
 	struct net_device *ndev;
 	struct xcan_priv *priv;
 	const struct of_device_id *of_id;
-	int caps = 0;
+	const struct xcan_devtype_data *devtype = &xcan_axi_data;
 	void __iomem *addr;
 	int ret, rx_max, tx_max, tx_fifo_depth;
 
@@ -1241,12 +1284,8 @@ static int xcan_probe(struct platform_device *pdev)
 		goto err;
 
 	of_id = of_match_device(xcan_of_match, &pdev->dev);
-	if (of_id) {
-		const struct xcan_devtype_data *devtype_data = of_id->data;
-
-		if (devtype_data)
-			caps = devtype_data->caps;
-	}
+	if (of_id && of_id->data)
+		devtype = of_id->data;
 
 	/* There is no way to directly figure out how many frames have been
 	 * sent when the TXOK interrupt is processed. If watermark programming
@@ -1259,7 +1298,7 @@ static int xcan_probe(struct platform_device *pdev)
 	 * sent), which is not a sensible state - possibly TXFWMEMP is not
 	 * completely synchronized with the rest of the bits?
 	 */
-	if (caps & XCAN_CAP_WATERMARK)
+	if (devtype->flags & XCAN_FLAG_TXFEMP)
 		tx_max = min(tx_fifo_depth, 2);
 	else
 		tx_max = 1;
@@ -1271,13 +1310,14 @@ static int xcan_probe(struct platform_device *pdev)
 
 	priv = netdev_priv(ndev);
 	priv->dev = &pdev->dev;
-	priv->can.bittiming_const = &xcan_bittiming_const;
+	priv->can.bittiming_const = devtype->bittiming_const;
 	priv->can.do_set_mode = xcan_do_set_mode;
 	priv->can.do_get_berr_counter = xcan_get_berr_counter;
 	priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
 					CAN_CTRLMODE_BERR_REPORTING;
 	priv->reg_base = addr;
 	priv->tx_max = tx_max;
+	priv->devtype = *devtype;
 	spin_lock_init(&priv->tx_lock);
 
 	/* Get IRQ for the device */
@@ -1295,22 +1335,12 @@ static int xcan_probe(struct platform_device *pdev)
 		ret = PTR_ERR(priv->can_clk);
 		goto err_free;
 	}
-	/* Check for type of CAN device */
-	if (of_device_is_compatible(pdev->dev.of_node,
-				    "xlnx,zynq-can-1.0")) {
-		priv->bus_clk = devm_clk_get(&pdev->dev, "pclk");
-		if (IS_ERR(priv->bus_clk)) {
-			dev_err(&pdev->dev, "bus clock not found\n");
-			ret = PTR_ERR(priv->bus_clk);
-			goto err_free;
-		}
-	} else {
-		priv->bus_clk = devm_clk_get(&pdev->dev, "s_axi_aclk");
-		if (IS_ERR(priv->bus_clk)) {
-			dev_err(&pdev->dev, "bus clock not found\n");
-			ret = PTR_ERR(priv->bus_clk);
-			goto err_free;
-		}
+
+	priv->bus_clk = devm_clk_get(&pdev->dev, devtype->bus_clk_name);
+	if (IS_ERR(priv->bus_clk)) {
+		dev_err(&pdev->dev, "bus clock not found\n");
+		ret = PTR_ERR(priv->bus_clk);
+		goto err_free;
 	}
 
 	priv->write_reg = xcan_write_reg_le;