[PATCH v5 2/3] can: xilinx_can: Add ECC support
From: Srinivas Goud
Date: Fri Nov 17 2023 - 04:30:42 EST
Add ECC support for Xilinx CAN Controller, so this driver reports
1bit/2bit ECC errors for FIFO's based on ECC error interrupt.
ECC feature for Xilinx CAN Controller selected through 'xlnx,has-ecc'
DT property
Signed-off-by: Srinivas Goud <srinivas.goud@xxxxxxx>
---
Changes in v5:
Address review comments
Change the sequence of updates the stats
Use u64 stats helper function
Changes in v4:
None
Changes in v3:
None
Changes in v2:
Address review comments
drivers/net/can/xilinx_can.c | 105 +++++++++++++++++++++++++++++++++++++++++--
1 file changed, 101 insertions(+), 4 deletions(-)
diff --git a/drivers/net/can/xilinx_can.c b/drivers/net/can/xilinx_can.c
index abe58f1..c8691a1 100644
--- a/drivers/net/can/xilinx_can.c
+++ b/drivers/net/can/xilinx_can.c
@@ -31,6 +31,7 @@
#include <linux/phy/phy.h>
#include <linux/pm_runtime.h>
#include <linux/reset.h>
+#include <linux/u64_stats_sync.h>
#define DRIVER_NAME "xilinx_can"
@@ -58,6 +59,13 @@ enum xcan_reg {
*/
XCAN_F_BTR_OFFSET = 0x08C, /* Data Phase Bit Timing */
XCAN_TRR_OFFSET = 0x0090, /* TX Buffer Ready Request */
+
+ /* only on AXI CAN cores */
+ XCAN_ECC_CFG_OFFSET = 0xC8, /* ECC Configuration */
+ XCAN_TXTLFIFO_ECC_OFFSET = 0xCC, /* TXTL FIFO ECC error counter */
+ XCAN_TXOLFIFO_ECC_OFFSET = 0xD0, /* TXOL FIFO ECC error counter */
+ XCAN_RXFIFO_ECC_OFFSET = 0xD4, /* RX FIFO ECC error counter */
+
XCAN_AFR_EXT_OFFSET = 0x00E0, /* Acceptance Filter */
XCAN_FSR_OFFSET = 0x00E8, /* RX FIFO Status */
XCAN_TXMSG_BASE_OFFSET = 0x0100, /* TX Message Space */
@@ -124,6 +132,18 @@ enum xcan_reg {
#define XCAN_IXR_TXFLL_MASK 0x00000004 /* Tx FIFO Full intr */
#define XCAN_IXR_TXOK_MASK 0x00000002 /* TX successful intr */
#define XCAN_IXR_ARBLST_MASK 0x00000001 /* Arbitration lost intr */
+#define XCAN_IXR_E2BERX_MASK BIT(23) /* RX FIFO two bit ECC error */
+#define XCAN_IXR_E1BERX_MASK BIT(22) /* RX FIFO one bit ECC error */
+#define XCAN_IXR_E2BETXOL_MASK BIT(21) /* TXOL FIFO two bit ECC error */
+#define XCAN_IXR_E1BETXOL_MASK BIT(20) /* TXOL FIFO One bit ECC error */
+#define XCAN_IXR_E2BETXTL_MASK BIT(19) /* TXTL FIFO Two bit ECC error */
+#define XCAN_IXR_E1BETXTL_MASK BIT(18) /* TXTL FIFO One bit ECC error */
+#define XCAN_IXR_ECC_MASK (XCAN_IXR_E2BERX_MASK | \
+ XCAN_IXR_E1BERX_MASK | \
+ XCAN_IXR_E2BETXOL_MASK | \
+ XCAN_IXR_E1BETXOL_MASK | \
+ XCAN_IXR_E2BETXTL_MASK | \
+ XCAN_IXR_E1BETXTL_MASK)
#define XCAN_IDR_ID1_MASK 0xFFE00000 /* Standard msg identifier */
#define XCAN_IDR_SRR_MASK 0x00100000 /* Substitute remote TXreq */
#define XCAN_IDR_IDE_MASK 0x00080000 /* Identifier extension */
@@ -137,6 +157,11 @@ enum xcan_reg {
#define XCAN_2_FSR_RI_MASK 0x0000003F /* RX Read Index */
#define XCAN_DLCR_EDL_MASK 0x08000000 /* EDL Mask in DLC */
#define XCAN_DLCR_BRS_MASK 0x04000000 /* BRS Mask in DLC */
+#define XCAN_ECC_CFG_REECRX_MASK BIT(2) /* Reset RX FIFO ECC error counters */
+#define XCAN_ECC_CFG_REECTXOL_MASK BIT(1) /* Reset TXOL FIFO ECC error counters */
+#define XCAN_ECC_CFG_REECTXTL_MASK BIT(0) /* Reset TXTL FIFO ECC error counters */
+#define XCAN_ECC_1BIT_CNT_MASK GENMASK(15, 0) /* FIFO ECC 1bit count mask */
+#define XCAN_ECC_2BIT_CNT_MASK GENMASK(31, 16) /* FIFO ECC 2bit count mask */
/* CAN register bit shift - XCAN_<REG>_<BIT>_SHIFT */
#define XCAN_BRPR_TDC_ENABLE BIT(16) /* Transmitter Delay Compensation (TDC) Enable */
@@ -202,6 +227,13 @@ struct xcan_devtype_data {
* @devtype: Device type specific constants
* @transceiver: Optional pointer to associated CAN transceiver
* @rstc: Pointer to reset control
+ * @ecc_enable: ECC enable flag
+ * @ecc_2bit_rxfifo_cnt: RXFIFO 2bit ECC count
+ * @ecc_1bit_rxfifo_cnt: RXFIFO 1bit ECC count
+ * @ecc_2bit_txolfifo_cnt: TXOLFIFO 2bit ECC count
+ * @ecc_1bit_txolfifo_cnt: TXOLFIFO 1bit ECC count
+ * @ecc_2bit_txtlfifo_cnt: TXTLFIFO 2bit ECC count
+ * @ecc_1bit_txtlfifo_cnt: TXTLFIFO 1bit ECC count
*/
struct xcan_priv {
struct can_priv can;
@@ -221,6 +253,13 @@ struct xcan_priv {
struct xcan_devtype_data devtype;
struct phy *transceiver;
struct reset_control *rstc;
+ bool ecc_enable;
+ u64_stats_t ecc_2bit_rxfifo_cnt;
+ u64_stats_t ecc_1bit_rxfifo_cnt;
+ u64_stats_t ecc_2bit_txolfifo_cnt;
+ u64_stats_t ecc_1bit_txolfifo_cnt;
+ u64_stats_t ecc_2bit_txtlfifo_cnt;
+ u64_stats_t ecc_1bit_txtlfifo_cnt;
};
/* CAN Bittiming constants as per Xilinx CAN specs */
@@ -523,6 +562,9 @@ static int xcan_chip_start(struct net_device *ndev)
XCAN_IXR_ERROR_MASK | XCAN_IXR_RXOFLW_MASK |
XCAN_IXR_ARBLST_MASK | xcan_rx_int_mask(priv);
+ if (priv->ecc_enable)
+ ier |= XCAN_IXR_ECC_MASK;
+
if (priv->devtype.flags & XCAN_FLAG_RXMNF)
ier |= XCAN_IXR_RXMNF_MASK;
@@ -1127,6 +1169,50 @@ static void xcan_err_interrupt(struct net_device *ndev, u32 isr)
priv->can.can_stats.bus_error++;
}
+ if (priv->ecc_enable && isr & XCAN_IXR_ECC_MASK) {
+ u32 reg_rx_ecc, reg_txol_ecc, reg_txtl_ecc;
+
+ reg_rx_ecc = priv->read_reg(priv, XCAN_RXFIFO_ECC_OFFSET);
+ reg_txol_ecc = priv->read_reg(priv, XCAN_TXOLFIFO_ECC_OFFSET);
+ reg_txtl_ecc = priv->read_reg(priv, XCAN_TXTLFIFO_ECC_OFFSET);
+
+ /* The counter reaches its maximum at 0xffff and does not overflow.
+ * Accept the small race window between reading and resetting ECC counters.
+ */
+ priv->write_reg(priv, XCAN_ECC_CFG_OFFSET, XCAN_ECC_CFG_REECRX_MASK |
+ XCAN_ECC_CFG_REECTXOL_MASK | XCAN_ECC_CFG_REECTXTL_MASK);
+
+ if (isr & XCAN_IXR_E2BERX_MASK) {
+ u64_stats_add(&priv->ecc_2bit_rxfifo_cnt,
+ FIELD_GET(XCAN_ECC_2BIT_CNT_MASK, reg_rx_ecc));
+ }
+
+ if (isr & XCAN_IXR_E1BERX_MASK) {
+ u64_stats_add(&priv->ecc_1bit_rxfifo_cnt,
+ FIELD_GET(XCAN_ECC_1BIT_CNT_MASK, reg_rx_ecc));
+ }
+
+ if (isr & XCAN_IXR_E2BETXOL_MASK) {
+ u64_stats_add(&priv->ecc_2bit_txolfifo_cnt,
+ FIELD_GET(XCAN_ECC_2BIT_CNT_MASK, reg_txol_ecc));
+ }
+
+ if (isr & XCAN_IXR_E1BETXOL_MASK) {
+ u64_stats_add(&priv->ecc_1bit_txolfifo_cnt,
+ FIELD_GET(XCAN_ECC_1BIT_CNT_MASK, reg_txol_ecc));
+ }
+
+ if (isr & XCAN_IXR_E2BETXTL_MASK) {
+ u64_stats_add(&priv->ecc_2bit_txtlfifo_cnt,
+ FIELD_GET(XCAN_ECC_2BIT_CNT_MASK, reg_txtl_ecc));
+ }
+
+ if (isr & XCAN_IXR_E1BETXTL_MASK) {
+ u64_stats_add(&priv->ecc_1bit_txtlfifo_cnt,
+ FIELD_GET(XCAN_ECC_1BIT_CNT_MASK, reg_txtl_ecc));
+ }
+ }
+
if (cf.can_id) {
struct can_frame *skb_cf;
struct sk_buff *skb = alloc_can_err_skb(ndev, &skb_cf);
@@ -1355,7 +1441,7 @@ static irqreturn_t xcan_interrupt(int irq, void *dev_id)
struct net_device *ndev = (struct net_device *)dev_id;
struct xcan_priv *priv = netdev_priv(ndev);
u32 isr, ier;
- u32 isr_errors;
+ u32 isr_errors, mask;
u32 rx_int_mask = xcan_rx_int_mask(priv);
/* Get the interrupt status from Xilinx CAN */
@@ -1374,10 +1460,15 @@ static irqreturn_t xcan_interrupt(int irq, void *dev_id)
if (isr & XCAN_IXR_TXOK_MASK)
xcan_tx_interrupt(ndev, isr);
+ mask = XCAN_IXR_ERROR_MASK | XCAN_IXR_RXOFLW_MASK |
+ XCAN_IXR_BSOFF_MASK | XCAN_IXR_ARBLST_MASK |
+ XCAN_IXR_RXMNF_MASK;
+
+ if (priv->ecc_enable)
+ mask |= XCAN_IXR_ECC_MASK;
+
/* 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_RXMNF_MASK);
+ isr_errors = isr & mask;
if (isr_errors) {
priv->write_reg(priv, XCAN_ICR_OFFSET, isr_errors);
xcan_err_interrupt(ndev, isr);
@@ -1796,6 +1887,7 @@ static int xcan_probe(struct platform_device *pdev)
return -ENOMEM;
priv = netdev_priv(ndev);
+ priv->ecc_enable = of_property_read_bool(pdev->dev.of_node, "xlnx,has-ecc");
priv->dev = &pdev->dev;
priv->can.bittiming_const = devtype->bittiming_const;
priv->can.do_set_mode = xcan_do_set_mode;
@@ -1912,6 +2004,11 @@ static int xcan_probe(struct platform_device *pdev)
priv->reg_base, ndev->irq, priv->can.clock.freq,
hw_tx_max, priv->tx_max);
+ if (priv->ecc_enable) {
+ /* Reset FIFO ECC counters */
+ priv->write_reg(priv, XCAN_ECC_CFG_OFFSET, XCAN_ECC_CFG_REECRX_MASK |
+ XCAN_ECC_CFG_REECTXOL_MASK | XCAN_ECC_CFG_REECTXTL_MASK);
+ }
return 0;
err_disableclks:
--
2.1.1