| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <20220607085654.4178-3-srinivas.neeli@xilinx.com>
Date: Tue, 7 Jun 2022 14:26:54 +0530
From: Srinivas Neeli <srinivas.neeli@...inx.com>
To: <wg@...ndegger.com>, <mkl@...gutronix.de>, <davem@...emloft.net>,
<edumazet@...gle.com>, <appana.durga.rao@...inx.com>,
<sgoud@...inx.com>, <michal.simek@...inx.com>
CC: <kuba@...nel.org>, <pabeni@...hat.com>,
<linux-can@...r.kernel.org>, <netdev@...r.kernel.org>,
<linux-arm-kernel@...ts.infradead.org>,
<linux-kernel@...r.kernel.org>, <git@...inx.com>,
Srinivas Neeli <srinivas.neeli@...inx.com>
Subject: [PATCH V2 2/2] can: xilinx_can: Add Transmitter delay compensation (TDC) feature support
Added Transmitter delay compensation (TDC) feature support.
In the case of higher measured loop delay with higher baud rates,
observed bit stuff errors. By enabling the TDC feature in a controller,
will compensate for the measure loop delay in the receive path.
Signed-off-by: Srinivas Neeli <srinivas.neeli@...inx.com>
---
drivers/net/can/xilinx_can.c | 46 +++++++++++++++++++++++++++++++++---
1 file changed, 43 insertions(+), 3 deletions(-)
diff --git a/drivers/net/can/xilinx_can.c b/drivers/net/can/xilinx_can.c
index e179d311aa28..d0edd1bca33c 100644
--- a/drivers/net/can/xilinx_can.c
+++ b/drivers/net/can/xilinx_can.c
@@ -1,7 +1,7 @@
// SPDX-License-Identifier: GPL-2.0-or-later
/* Xilinx CAN device driver
*
- * Copyright (C) 2012 - 2014 Xilinx, Inc.
+ * Copyright (C) 2012 - 2022 Xilinx, Inc.
* Copyright (C) 2009 PetaLogix. All rights reserved.
* Copyright (C) 2017 - 2018 Sandvik Mining and Construction Oy
*
@@ -99,6 +99,7 @@ enum xcan_reg {
#define XCAN_ESR_STER_MASK 0x00000004 /* Stuff error */
#define XCAN_ESR_FMER_MASK 0x00000002 /* Form error */
#define XCAN_ESR_CRCER_MASK 0x00000001 /* CRC error */
+#define XCAN_SR_TDCV_MASK 0x007F0000 /* TDCV Value */
#define XCAN_SR_TXFLL_MASK 0x00000400 /* TX FIFO is full */
#define XCAN_SR_ESTAT_MASK 0x00000180 /* Error status */
#define XCAN_SR_ERRWRN_MASK 0x00000040 /* Error warning */
@@ -132,6 +133,8 @@ enum xcan_reg {
#define XCAN_DLCR_BRS_MASK 0x04000000 /* BRS Mask in DLC */
/* CAN register bit shift - XCAN_<REG>_<BIT>_SHIFT */
+#define XCAN_BRPR_TDCO_SHIFT 8 /* Transmitter Delay Compensation Offset */
+#define XCAN_BRPR_TDC_ENABLE BIT(16) /* Transmitter Delay Compensation (TDC) Enable */
#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 */
@@ -140,6 +143,7 @@ enum xcan_reg {
#define XCAN_IDR_ID2_SHIFT 1 /* Extended Message Identifier */
#define XCAN_DLCR_DLC_SHIFT 28 /* Data length code */
#define XCAN_ESR_REC_SHIFT 8 /* Rx Error Count */
+#define XCAN_SR_TDCV_SHIFT 16 /* TDCV Value */
/* CAN frame length constants */
#define XCAN_FRAME_MAX_DATA_LEN 8
@@ -276,6 +280,16 @@ static const struct can_bittiming_const xcan_data_bittiming_const_canfd2 = {
.brp_inc = 1,
};
+/* Transmission Delay Compensation constants for CANFD2.0 and Versal */
+static const struct can_tdc_const xcan_tdc_const = {
+ .tdcv_min = 0,
+ .tdcv_max = 0, /* Manual mode not supported. */
+ .tdco_min = 0,
+ .tdco_max = 64,
+ .tdcf_min = 0, /* Filter window not supported */
+ .tdcf_max = 0,
+};
+
/**
* xcan_write_reg_le - Write a value to the device register little endian
* @priv: Driver private data structure
@@ -424,6 +438,11 @@ static int xcan_set_bittiming(struct net_device *ndev)
priv->devtype.cantype == XAXI_CANFD_2_0) {
/* Setting Baud Rate prescalar value in F_BRPR Register */
btr0 = dbt->brp - 1;
+ if (can_tdc_is_enabled(&priv->can)) {
+ btr0 = btr0 |
+ priv->can.tdc.tdco << XCAN_BRPR_TDCO_SHIFT |
+ XCAN_BRPR_TDC_ENABLE;
+ }
/* Setting Time Segment 1 in BTR Register */
btr1 = dbt->prop_seg + dbt->phase_seg1 - 1;
@@ -1483,6 +1502,23 @@ static int xcan_get_berr_counter(const struct net_device *ndev,
return 0;
}
+/**
+ * xcan_get_auto_tdcv - Get Transmitter Delay Compensation Value
+ * @ndev: Pointer to net_device structure
+ * @tdcv: Pointer to TDCV value
+ *
+ * Return: 0 on success
+ */
+static int xcan_get_auto_tdcv(const struct net_device *ndev, u32 *tdcv)
+{
+ struct xcan_priv *priv = netdev_priv(ndev);
+
+ *tdcv = (priv->read_reg(priv, XCAN_SR_OFFSET) & XCAN_SR_TDCV_MASK) >>
+ XCAN_SR_TDCV_SHIFT;
+
+ return 0;
+}
+
static const struct net_device_ops xcan_netdev_ops = {
.ndo_open = xcan_open,
.ndo_stop = xcan_close,
@@ -1734,18 +1770,22 @@ static int xcan_probe(struct platform_device *pdev)
priv->can.do_get_berr_counter = xcan_get_berr_counter;
priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
CAN_CTRLMODE_BERR_REPORTING;
+ priv->can.do_get_auto_tdcv = xcan_get_auto_tdcv;
if (devtype->cantype == XAXI_CANFD)
priv->can.data_bittiming_const =
&xcan_data_bittiming_const_canfd;
- if (devtype->cantype == XAXI_CANFD_2_0)
+ if (devtype->cantype == XAXI_CANFD_2_0) {
priv->can.data_bittiming_const =
&xcan_data_bittiming_const_canfd2;
+ priv->can.tdc_const = &xcan_tdc_const;
+ }
if (devtype->cantype == XAXI_CANFD ||
devtype->cantype == XAXI_CANFD_2_0)
- priv->can.ctrlmode_supported |= CAN_CTRLMODE_FD;
+ priv->can.ctrlmode_supported |= CAN_CTRLMODE_FD |
+ CAN_CTRLMODE_TDC_AUTO;
priv->reg_base = addr;
priv->tx_max = tx_max;
--
2.25.1
Powered by blists - more mailing lists