Add support for Xilinx CAN FD core.
The major difference from the previously supported cores is that there
are TX mailboxes instead of a TX FIFO and the RX FIFO access method is
different.
We only transmit one frame at a time to prevent the HW from reordering
frames (it uses CAN ID priority order).
Support for CAN FD protocol is not added yet.
Signed-off-by: Anssi Hannula <anssi.hannula@xxxxxxxxxx>
Cc: Michal Simek <michal.simek@xxxxxxxxxx>
---
drivers/net/can/xilinx_can.c | 314 +++++++++++++++++++++++++++++++++++++------
1 file changed, 274 insertions(+), 40 deletions(-)
diff --git a/drivers/net/can/xilinx_can.c b/drivers/net/can/xilinx_can.c
index 615223b..e07a2f8 100644
--- a/drivers/net/can/xilinx_can.c
+++ b/drivers/net/can/xilinx_can.c
@@ -2,7 +2,7 @@
*
* Copyright (C) 2012 - 2014 Xilinx, Inc.
* Copyright (C) 2009 PetaLogix. All rights reserved.
- * Copyright (C) 2017 Sandvik Mining and Construction Oy
+ * Copyright (C) 2017 - 2018 Sandvik Mining and Construction Oy
*
* Description:
* This driver is developed for Axi CAN IP and for Zynq CANPS Controller.
@@ -51,8 +51,18 @@ enum xcan_reg {
XCAN_ISR_OFFSET = 0x1C, /* Interrupt status */
XCAN_IER_OFFSET = 0x20, /* Interrupt enable */
XCAN_ICR_OFFSET = 0x24, /* Interrupt clear */
+
+ /* not on CAN FD cores */
XCAN_TXFIFO_OFFSET = 0x30, /* TX FIFO base */
XCAN_RXFIFO_OFFSET = 0x50, /* RX FIFO base */
+ XCAN_AFR_OFFSET = 0x60, /* Acceptance Filter */
+
+ /* only on CAN FD cores */
+ XCAN_TRR_OFFSET = 0x0090, /* TX Buffer Ready Request */
+ XCAN_AFR_EXT_OFFSET = 0x00E0, /* Acceptance Filter */
+ XCAN_FSR_OFFSET = 0x00E8, /* RX FIFO Status */
+ XCAN_TXMSG_BASE_OFFSET = 0x0100, /* TX Message Space */
+ XCAN_RXMSG_BASE_OFFSET = 0x1100, /* RX Message Space */
};
#define XCAN_FRAME_ID_OFFSET(frame_base) ((frame_base) + 0x00)
@@ -60,6 +70,13 @@ enum xcan_reg {
#define XCAN_FRAME_DW1_OFFSET(frame_base) ((frame_base) + 0x08)
#define XCAN_FRAME_DW2_OFFSET(frame_base) ((frame_base) + 0x0C)
+#define XCAN_CANFD_FRAME_SIZE 0x48
+#define XCAN_TXMSG_FRAME_OFFSET(n) (XCAN_TXMSG_BASE_OFFSET + XCAN_CANFD_FRAME_SIZE * (n))
+#define XCAN_RXMSG_FRAME_OFFSET(n) (XCAN_RXMSG_BASE_OFFSET + XCAN_CANFD_FRAME_SIZE * (n))
+
+/* the single TX mailbox used by this driver on CAN FD HW */
+#define XCAN_TX_MAILBOX_IDX 0
+
/* 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 */
@@ -69,6 +86,9 @@ enum xcan_reg {
#define XCAN_BTR_SJW_MASK 0x00000180 /* Synchronous jump width */
#define XCAN_BTR_TS2_MASK 0x00000070 /* Time segment 2 */
#define XCAN_BTR_TS1_MASK 0x0000000F /* Time segment 1 */
+#define XCAN_BTR_SJW_MASK_CANFD 0x000F0000 /* Synchronous jump width */
+#define XCAN_BTR_TS2_MASK_CANFD 0x00000F00 /* Time segment 2 */
+#define XCAN_BTR_TS1_MASK_CANFD 0x0000003F /* Time segment 1 */
#define XCAN_ECR_REC_MASK 0x0000FF00 /* Receive error counter */
#define XCAN_ECR_TEC_MASK 0x000000FF /* Transmit error counter */
#define XCAN_ESR_ACKER_MASK 0x00000010 /* ACK error */
@@ -82,6 +102,7 @@ enum xcan_reg {
#define XCAN_SR_NORMAL_MASK 0x00000008 /* Normal mode */
#define XCAN_SR_LBACK_MASK 0x00000002 /* Loop back mode */
#define XCAN_SR_CONFIG_MASK 0x00000001 /* Configuration mode */
+#define XCAN_IXR_RXMNF_MASK 0x00020000 /* RX match not finished */
#define XCAN_IXR_TXFEMP_MASK 0x00004000 /* TX FIFO Empty */
#define XCAN_IXR_WKUP_MASK 0x00000800 /* Wake up interrupt */
#define XCAN_IXR_SLP_MASK 0x00000400 /* Sleep interrupt */
@@ -99,10 +120,15 @@ enum xcan_reg {
#define XCAN_IDR_ID2_MASK 0x0007FFFE /* Extended message ident */
#define XCAN_IDR_RTR_MASK 0x00000001 /* Remote TX request */
#define XCAN_DLCR_DLC_MASK 0xF0000000 /* Data length code */
+#define XCAN_FSR_FL_MASK 0x00003F00 /* RX Fill Level */
+#define XCAN_FSR_IRI_MASK 0x00000080 /* RX Increment Read Index */
+#define XCAN_FSR_RI_MASK 0x0000001F /* RX Read Index */
/* 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 */
+#define XCAN_BTR_SJW_SHIFT_CANFD 16 /* Synchronous jump width */
+#define XCAN_BTR_TS2_SHIFT_CANFD 8 /* Time segment 2 */
#define XCAN_IDR_ID1_SHIFT 21 /* Standard Messg Identifier */
#define XCAN_IDR_ID2_SHIFT 1 /* Extended Message Identifier */
#define XCAN_DLCR_DLC_SHIFT 28 /* Data length code */
@@ -112,13 +138,31 @@ enum xcan_reg {
#define XCAN_FRAME_MAX_DATA_LEN 8
#define XCAN_TIMEOUT (1 * HZ)
+enum xcan_rx_mode {
+ RX_MODE_SEQUENTIAL,
+ RX_MODE_MAILBOX,
+ RX_MODE_UNKNOWN,
+};
+
/* TX-FIFO-empty interrupt available */
#define XCAN_FLAG_TXFEMP 0x0001
+/* RX Match Not Finished interrupt available */
+#define XCAN_FLAG_RXMNF 0x0002
+/* Extended acceptance filters with control at 0xE0 */
+#define XCAN_FLAG_EXT_FILTERS 0x0004
+/* TX mailboxes instead of TX FIFO */
+#define XCAN_FLAG_TX_MAILBOXES 0x0008
+/* RX FIFO with each buffer in separate registers at 0x1100
+ * instead of the regular FIFO at 0x50
+ */
+#define XCAN_FLAG_RX_FIFO_MULTI 0x0010
struct xcan_devtype_data {
unsigned int flags;
const struct can_bittiming_const *bittiming_const;
const char *bus_clk_name;
+ unsigned int btr_ts2_shift;
+ unsigned int btr_sjw_shift;
};
/**
@@ -169,6 +213,18 @@ static const struct can_bittiming_const xcan_bittiming_const = {
.brp_inc = 1,
};
+static const struct can_bittiming_const xcan_bittiming_const_canfd = {
+ .name = DRIVER_NAME,
+ .tseg1_min = 1,
+ .tseg1_max = 64,
+ .tseg2_min = 1,
+ .tseg2_max = 16,
+ .sjw_max = 16,
+ .brp_min = 1,
+ .brp_max = 256,
+ .brp_inc = 1,
+};
+
/**
* xcan_write_reg_le - Write a value to the device register little endian
* @priv: Driver private data structure
@@ -224,6 +280,23 @@ static u32 xcan_read_reg_be(const struct xcan_priv *priv, enum xcan_reg reg)
}
/**
+ * xcan_rx_int_mask - Get the mask for the receive interrupt
+ * @priv: Driver private data structure
+ *
+ * Return: The receive interrupt mask used by the driver on this HW
+ */
+static u32 xcan_rx_int_mask(const struct xcan_priv *priv)
+{
+ /* RXNEMP is better suited for our use case as it cannot be cleared
+ * while the FIFO is non-empty, but CAN FD HW does not have it
+ */
+ if (priv->devtype.flags & XCAN_FLAG_RX_FIFO_MULTI)
+ return XCAN_IXR_RXOK_MASK;
+ else
+ return XCAN_IXR_RXNEMP_MASK;
+}
+
+/**
* set_reset_mode - Resets the CAN device mode
* @ndev: Pointer to net_device structure
*
@@ -287,10 +360,10 @@ static int xcan_set_bittiming(struct net_device *ndev)
btr1 = (bt->prop_seg + bt->phase_seg1 - 1);
/* Setting Time Segment 2 in BTR Register */
- btr1 |= (bt->phase_seg2 - 1) << XCAN_BTR_TS2_SHIFT;
+ btr1 |= (bt->phase_seg2 - 1) << priv->devtype.btr_ts2_shift;
/* Setting Synchronous jump width in BTR Register */
- btr1 |= (bt->sjw - 1) << XCAN_BTR_SJW_SHIFT;
+ btr1 |= (bt->sjw - 1) << priv->devtype.btr_sjw_shift;
priv->write_reg(priv, XCAN_BRPR_OFFSET, btr0);
priv->write_reg(priv, XCAN_BTR_OFFSET, btr1);
@@ -318,6 +391,7 @@ static int xcan_chip_start(struct net_device *ndev)
u32 reg_msr, reg_sr_mask;
int err;
unsigned long timeout;
+ u32 ier;
/* Check if it is in reset mode */
err = set_reset_mode(ndev);
@@ -329,11 +403,15 @@ static int xcan_chip_start(struct net_device *ndev)
return err;
/* Enable interrupts */
- 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);
+ ier = XCAN_IXR_TXOK_MASK | XCAN_IXR_BSOFF_MASK |
+ XCAN_IXR_WKUP_MASK | XCAN_IXR_SLP_MASK |
+ XCAN_IXR_ERROR_MASK | XCAN_IXR_RXOFLW_MASK |
+ XCAN_IXR_ARBLST_MASK | xcan_rx_int_mask(priv);
+
+ if (priv->devtype.flags & XCAN_FLAG_RXMNF)
+ ier |= XCAN_IXR_RXMNF_MASK;
+
+ priv->write_reg(priv, XCAN_IER_OFFSET, ier);
/* Check whether it is loopback mode or normal mode */
if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) {
@@ -344,6 +422,12 @@ static int xcan_chip_start(struct net_device *ndev)
reg_sr_mask = XCAN_SR_NORMAL_MASK;
}
+ /* enable the first extended filter, if any, as cores with extended
+ * filtering default to non-receipt if all filters are disabled
+ */
+ if (priv->devtype.flags & XCAN_FLAG_EXT_FILTERS)
+ priv->write_reg(priv, XCAN_AFR_EXT_OFFSET, 0x00000001);
+
priv->write_reg(priv, XCAN_MSR_OFFSET, reg_msr);
priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_CEN_MASK);
@@ -439,12 +523,14 @@ static void xcan_write_frame(struct xcan_priv *priv, struct sk_buff *skb,
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 */
+ /* If the CAN frame is RTR frame this write triggers transmission
+ * (not on CAN FD)
+ */
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
+ * write triggers transmission (not on CAN FD)
*/
priv->write_reg(priv, XCAN_FRAME_DW2_OFFSET(frame_offset), data[1]);
}
@@ -487,24 +573,57 @@ static int xcan_start_xmit_fifo(struct sk_buff *skb, struct net_device *ndev)
}
/**
+ * xcan_start_xmit_mailbox - Starts the transmission (mailbox mode)
+ *
+ * Return: 0 on success, -ENOSPC if there is no space
+ */
+static int xcan_start_xmit_mailbox(struct sk_buff *skb, struct net_device *ndev)
+{
+ struct xcan_priv *priv = netdev_priv(ndev);
+ unsigned long flags;
+
+ if (unlikely(priv->read_reg(priv, XCAN_TRR_OFFSET) & BIT(XCAN_TX_MAILBOX_IDX)))
+ return -ENOSPC;
+
+ can_put_echo_skb(skb, ndev, 0);
+
+ spin_lock_irqsave(&priv->tx_lock, flags);
+
+ priv->tx_head++;
+
+ xcan_write_frame(priv, skb, XCAN_TXMSG_FRAME_OFFSET(XCAN_TX_MAILBOX_IDX));
+
+ /* Mark buffer as ready for transmit */
+ priv->write_reg(priv, XCAN_TRR_OFFSET, BIT(XCAN_TX_MAILBOX_IDX));
+
+ netif_stop_queue(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.
+ * This function is invoked from upper layers to initiate transmission.
*
* Return: 0 on success and failure value on error
*/
static int xcan_start_xmit(struct sk_buff *skb, struct net_device *ndev)
{
+ struct xcan_priv *priv = netdev_priv(ndev);
int ret;
if (can_dropped_invalid_skb(ndev, skb))
return NETDEV_TX_OK;
- ret = xcan_start_xmit_fifo(skb, ndev);
+ if (priv->devtype.flags & XCAN_FLAG_TX_MAILBOXES)
+ ret = xcan_start_xmit_mailbox(skb, ndev);
+ else
+ ret = xcan_start_xmit_fifo(skb, ndev);
if (ret < 0) {
netdev_err(ndev, "BUG!, TX full when queue awake!\n");
@@ -737,6 +856,17 @@ static void xcan_err_interrupt(struct net_device *ndev, u32 isr)
}
}
+ /* Check for RX Match Not Finished interrupt */
+ if (isr & XCAN_IXR_RXMNF_MASK) {
+ stats->rx_dropped++;
+ stats->rx_errors++;
+ netdev_err(ndev, "RX match not finished, frame discarded\n");
+ if (skb) {
+ cf->can_id |= CAN_ERR_CRTL;
+ cf->data[1] |= CAN_ERR_CRTL_UNSPEC;
+ }
+ }
+
/* Check for error interrupt */
if (isr & XCAN_IXR_ERROR_MASK) {
if (skb)
@@ -821,6 +951,43 @@ static void xcan_state_interrupt(struct net_device *ndev, u32 isr)
}
/**
+ * xcan_rx_fifo_get_next_frame - Get register offset of next RX frame
+ *
+ * Return: Register offset of the next frame in RX FIFO.
+ */
+static int xcan_rx_fifo_get_next_frame(struct xcan_priv *priv)
+{
+ int offset;
+
+ if (priv->devtype.flags & XCAN_FLAG_RX_FIFO_MULTI) {
+ u32 fsr;
+
+ /* clear RXOK before the is-empty check so that any newly received
+ * frame will reassert it without a race
+ */
+ priv->write_reg(priv, XCAN_ICR_OFFSET, XCAN_IXR_RXOK_MASK);
+
+ fsr = priv->read_reg(priv, XCAN_FSR_OFFSET);
+
+ /* check if RX FIFO is empty */
+ if (!(fsr & XCAN_FSR_FL_MASK))
+ return -ENOENT;
+
+ offset = XCAN_RXMSG_FRAME_OFFSET(fsr & XCAN_FSR_RI_MASK);
+
+ } else {
+ /* check if RX FIFO is empty */
+ if (!(priv->read_reg(priv, XCAN_ISR_OFFSET) & XCAN_IXR_RXNEMP_MASK))
+ return -ENOENT;
+
+ /* frames are read from a static offset */
+ offset = XCAN_RXFIFO_OFFSET;
+ }
+
+ return offset;
+}
+
+/**
* xcan_rx_poll - Poll routine for rx packets (NAPI)
* @napi: napi structure pointer
* @quota: Max number of rx packets to be processed.
@@ -834,14 +1001,20 @@ static int xcan_rx_poll(struct napi_struct *napi, int quota)
{
struct net_device *ndev = napi->dev;
struct xcan_priv *priv = netdev_priv(ndev);
- u32 isr, ier;
+ u32 ier;
int work_done = 0;
-
- isr = priv->read_reg(priv, XCAN_ISR_OFFSET);
- while ((isr & XCAN_IXR_RXNEMP_MASK) && (work_done < quota)) {
- 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);
+ int frame_offset;
+
+ while ((frame_offset = xcan_rx_fifo_get_next_frame(priv)) >= 0
+ && (work_done < quota)) {
+ work_done += xcan_rx(ndev, frame_offset);
+
+ if (priv->devtype.flags & XCAN_FLAG_RX_FIFO_MULTI)
+ /* increment read index */
+ priv->write_reg(priv, XCAN_FSR_OFFSET, XCAN_FSR_IRI_MASK);
+ else
+ /* clear rx-not-empty (will actually clear only if empty) */
+ priv->write_reg(priv, XCAN_ICR_OFFSET, XCAN_IXR_RXNEMP_MASK);
}
if (work_done) {
@@ -852,7 +1025,7 @@ static int xcan_rx_poll(struct napi_struct *napi, int quota)
if (work_done < quota) {
napi_complete_done(napi, work_done);
ier = priv->read_reg(priv, XCAN_IER_OFFSET);
- ier |= XCAN_IXR_RXNEMP_MASK;
+ ier |= xcan_rx_int_mask(priv);
priv->write_reg(priv, XCAN_IER_OFFSET, ier);
}
return work_done;
@@ -951,6 +1124,7 @@ static irqreturn_t xcan_interrupt(int irq, void *dev_id)
struct xcan_priv *priv = netdev_priv(ndev);
u32 isr, ier;
u32 isr_errors;
+ u32 rx_int_mask = xcan_rx_int_mask(priv);
/* Get the interrupt status from Xilinx CAN */
isr = priv->read_reg(priv, XCAN_ISR_OFFSET);
@@ -970,16 +1144,17 @@ static irqreturn_t xcan_interrupt(int irq, void *dev_id)
/* Check for the type of error interrupt and Processing it */
isr_errors = isr & (XCAN_IXR_ERROR_MASK | XCAN_IXR_RXOFLW_MASK |
- XCAN_IXR_BSOFF_MASK | XCAN_IXR_ARBLST_MASK);
+ XCAN_IXR_BSOFF_MASK | XCAN_IXR_ARBLST_MASK |
+ XCAN_IXR_RXMNF_MASK);
if (isr_errors) {
priv->write_reg(priv, XCAN_ICR_OFFSET, isr_errors);
xcan_err_interrupt(ndev, isr);
}
/* Check for the type of receive interrupt and Processing it */
- if (isr & XCAN_IXR_RXNEMP_MASK) {
+ if (isr & rx_int_mask) {
ier = priv->read_reg(priv, XCAN_IER_OFFSET);
- ier &= ~XCAN_IXR_RXNEMP_MASK;
+ ier &= ~rx_int_mask;
priv->write_reg(priv, XCAN_IER_OFFSET, ier);
napi_schedule(&priv->napi);
}
@@ -1226,14 +1401,27 @@ static const struct dev_pm_ops xcan_dev_pm_ops = {
};
static const struct xcan_devtype_data xcan_zynq_data = {
- .flags = XCAN_FLAG_TXFEMP,
.bittiming_const = &xcan_bittiming_const,
+ .btr_ts2_shift = XCAN_BTR_TS2_SHIFT,
+ .btr_sjw_shift = XCAN_BTR_SJW_SHIFT,
.bus_clk_name = "pclk",
};
static const struct xcan_devtype_data xcan_axi_data = {
- .flags = 0,
.bittiming_const = &xcan_bittiming_const,
+ .btr_ts2_shift = XCAN_BTR_TS2_SHIFT,
+ .btr_sjw_shift = XCAN_BTR_SJW_SHIFT,
+ .bus_clk_name = "s_axi_aclk",
+};
+
+static const struct xcan_devtype_data xcan_canfd_data = {
+ .flags = XCAN_FLAG_EXT_FILTERS |
+ XCAN_FLAG_RXMNF |
+ XCAN_FLAG_TX_MAILBOXES |
+ XCAN_FLAG_RX_FIFO_MULTI,
+ .bittiming_const = &xcan_bittiming_const,
+ .btr_ts2_shift = XCAN_BTR_TS2_SHIFT_CANFD,
+ .btr_sjw_shift = XCAN_BTR_SJW_SHIFT_CANFD,
.bus_clk_name = "s_axi_aclk",
};
@@ -1241,10 +1429,27 @@ static const struct xcan_devtype_data xcan_axi_data = {
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", .data = &xcan_axi_data },
+ { .compatible = "xlnx,canfd-1.0", .data = &xcan_canfd_data },
{ /* end of list */ },
};
MODULE_DEVICE_TABLE(of, xcan_of_match);
+static enum xcan_rx_mode xcan_read_rx_mode(struct platform_device *pdev)
+{
+ const char *rx_mode_str;
+
+ if (of_property_read_string(pdev->dev.of_node, "rx-mode",
+ &rx_mode_str) < 0)
+ return RX_MODE_SEQUENTIAL;
+ if (strcmp(rx_mode_str, "sequential") == 0)
+ return RX_MODE_SEQUENTIAL;
+ if (strcmp(rx_mode_str, "mailbox") == 0)
+ return RX_MODE_MAILBOX;
+
+ dev_err(&pdev->dev, "unknown RX mode \"%s\"\n", rx_mode_str);
+ return RX_MODE_UNKNOWN;
+}
+
/**
* xcan_probe - Platform registration call
* @pdev: Handle to the platform device structure
@@ -1262,7 +1467,11 @@ static int xcan_probe(struct platform_device *pdev)
const struct of_device_id *of_id;
const struct xcan_devtype_data *devtype = &xcan_axi_data;
void __iomem *addr;
- int ret, rx_max, tx_max, tx_fifo_depth;
+ int ret;
+ int rx_max, tx_max;
+ int hw_tx_max, hw_rx_max;
+ enum xcan_rx_mode rx_mode;
+ const char *hw_tx_max_property;
/* Get the virtual base address for the device */
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@@ -1272,21 +1481,38 @@ static int xcan_probe(struct platform_device *pdev)
goto err;
}
- ret = of_property_read_u32(pdev->dev.of_node, "tx-fifo-depth",
- &tx_fifo_depth);
- if (ret < 0)
+ rx_mode = xcan_read_rx_mode(pdev);
+ if (rx_mode == RX_MODE_UNKNOWN) {
+ ret = -EINVAL;
goto err;
-
- ret = of_property_read_u32(pdev->dev.of_node, "rx-fifo-depth", &rx_max);
- if (ret < 0)
+ } else if (rx_mode == RX_MODE_MAILBOX) {
+ dev_err(&pdev->dev, "mailbox RX mode is not supported\n");
+ ret = -ENOSYS;
goto err;
+ }
of_id = of_match_device(xcan_of_match, &pdev->dev);
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
+ hw_tx_max_property = devtype->flags & XCAN_FLAG_TX_MAILBOXES ?
+ "tx-mailbox-count" : "tx-fifo-depth";
+
+ ret = of_property_read_u32(pdev->dev.of_node, hw_tx_max_property,
+ &hw_tx_max);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "missing %s property\n", hw_tx_max_property);
+ goto err;
+ }
+
+ ret = of_property_read_u32(pdev->dev.of_node, "rx-fifo-depth", &hw_rx_max);
+ if (ret < 0)
+ goto err;
+
+ /* With TX FIFO:
+ *
+ * There is no way to directly figure out how many frames have been
+ * sent when the TXOK interrupt is processed. If TXFEMP
* is supported, we can have 2 frames in the FIFO and use TXFEMP
* to determine if 1 or 2 frames have been sent.
* Theoretically we should be able to use TXFWMEMP to determine up
@@ -1295,12 +1521,20 @@ static int xcan_probe(struct platform_device *pdev)
* than 2 frames in FIFO) is set anyway with no TXOK (a frame was
* sent), which is not a sensible state - possibly TXFWMEMP is not
* completely synchronized with the rest of the bits?
+ *
+ * With TX mailboxes:
+ *
+ * HW sends frames in CAN ID priority order. To preserve FIFO ordering
+ * we submit frames one at a time.
*/
- if (devtype->flags & XCAN_FLAG_TXFEMP)
- tx_max = min(tx_fifo_depth, 2);
+ if (!(devtype->flags & XCAN_FLAG_TX_MAILBOXES) &&
+ (devtype->flags & XCAN_FLAG_TXFEMP))
+ tx_max = min(hw_tx_max, 2);
else
tx_max = 1;
+ rx_max = hw_rx_max;
+
/* Create a CAN device instance */
ndev = alloc_candev(sizeof(struct xcan_priv), tx_max);
if (!ndev)
@@ -1371,9 +1605,9 @@ static int xcan_probe(struct platform_device *pdev)
pm_runtime_put(&pdev->dev);
- netdev_dbg(ndev, "reg_base=0x%p irq=%d clock=%d, tx fifo depth: actual %d, using %d\n",
+ netdev_dbg(ndev, "reg_base=0x%p irq=%d clock=%d, tx buffers: actual %d, using %d\n",
priv->reg_base, ndev->irq, priv->can.clock.freq,
- tx_fifo_depth, priv->tx_max);
+ hw_tx_max, priv->tx_max);
return 0;
--
2.8.3
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