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* [PATCH V3 0/2] xilinx_can: Update on xilinx can
@ 2022-06-09  8:24 Srinivas Neeli
  2022-06-09  8:24 ` [PATCH V3 1/2] Revert "can: xilinx_can: Limit CANFD brp to 2" Srinivas Neeli
                   ` (2 more replies)
  0 siblings, 3 replies; 6+ messages in thread
From: Srinivas Neeli @ 2022-06-09  8:24 UTC (permalink / raw)
  To: wg, mkl, davem, edumazet, srinivas.neeli, neelisrinivas18,
	appana.durga.rao, sgoud, michal.simek
  Cc: kuba, pabeni, linux-can, netdev, linux-arm-kernel, linux-kernel,
	git, Srinivas Neeli

This patch series addresses
1) Reverts the limiting CANFD brp_min to 2.
2) Adds TDC support for Xilinx can driver.

Hi Marc,
Please apply PATCH V3 1/2 on stable branch.
Due to some mailing issue i didn't receive your mail.

Changes in V3:
-Implemented GENMASK,FIELD_PERP & FIELD_GET Calls.
-Implemented TDC feature for all Xilinx CANFD controllers.
-corrected prescalar to prescaler(typo).

Changes in V2:
- Created two patches one for revert another for TDC support.

Srinivas Neeli (2):
  Revert "can: xilinx_can: Limit CANFD brp to 2"
  can: xilinx_can: Add Transmitter delay compensation (TDC) feature
    support

 drivers/net/can/xilinx_can.c | 52 +++++++++++++++++++++++++++++++-----
 1 file changed, 45 insertions(+), 7 deletions(-)

-- 
2.25.1


^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCH V3 1/2] Revert "can: xilinx_can: Limit CANFD brp to 2"
  2022-06-09  8:24 [PATCH V3 0/2] xilinx_can: Update on xilinx can Srinivas Neeli
@ 2022-06-09  8:24 ` Srinivas Neeli
  2022-06-09  8:24 ` [PATCH V3 2/2] can: xilinx_can: Add Transmitter delay compensation (TDC) feature support Srinivas Neeli
  2022-06-09  8:34 ` [PATCH V3 0/2] xilinx_can: Update on xilinx can Marc Kleine-Budde
  2 siblings, 0 replies; 6+ messages in thread
From: Srinivas Neeli @ 2022-06-09  8:24 UTC (permalink / raw)
  To: wg, mkl, davem, edumazet, srinivas.neeli, neelisrinivas18,
	appana.durga.rao, sgoud, michal.simek
  Cc: kuba, pabeni, linux-can, netdev, linux-arm-kernel, linux-kernel,
	git, Srinivas Neeli

This reverts commit 05ca14fdb6fe65614e0652d03e44b02748d25af7.

On early silicon engineering samples observed
bit shrinking issue when we use brp as 1.
Hence updated brp_min as 2. As in production
silicon this issue is fixed,so reverting the patch.

Signed-off-by: Srinivas Neeli <srinivas.neeli@xilinx.com>
---
Changes in V3:
-None
Changes in V2:
-New patch
---
 drivers/net/can/xilinx_can.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/can/xilinx_can.c b/drivers/net/can/xilinx_can.c
index 8a3b7b103ca4..e179d311aa28 100644
--- a/drivers/net/can/xilinx_can.c
+++ b/drivers/net/can/xilinx_can.c
@@ -258,7 +258,7 @@ static const struct can_bittiming_const xcan_bittiming_const_canfd2 = {
 	.tseg2_min = 1,
 	.tseg2_max = 128,
 	.sjw_max = 128,
-	.brp_min = 2,
+	.brp_min = 1,
 	.brp_max = 256,
 	.brp_inc = 1,
 };
@@ -271,7 +271,7 @@ static const struct can_bittiming_const xcan_data_bittiming_const_canfd2 = {
 	.tseg2_min = 1,
 	.tseg2_max = 16,
 	.sjw_max = 16,
-	.brp_min = 2,
+	.brp_min = 1,
 	.brp_max = 256,
 	.brp_inc = 1,
 };
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* [PATCH V3 2/2] can: xilinx_can: Add Transmitter delay compensation (TDC) feature support
  2022-06-09  8:24 [PATCH V3 0/2] xilinx_can: Update on xilinx can Srinivas Neeli
  2022-06-09  8:24 ` [PATCH V3 1/2] Revert "can: xilinx_can: Limit CANFD brp to 2" Srinivas Neeli
@ 2022-06-09  8:24 ` Srinivas Neeli
  2022-06-09  8:31   ` Marc Kleine-Budde
  2022-06-09  8:34 ` [PATCH V3 0/2] xilinx_can: Update on xilinx can Marc Kleine-Budde
  2 siblings, 1 reply; 6+ messages in thread
From: Srinivas Neeli @ 2022-06-09  8:24 UTC (permalink / raw)
  To: wg, mkl, davem, edumazet, srinivas.neeli, neelisrinivas18,
	appana.durga.rao, sgoud, michal.simek
  Cc: kuba, pabeni, linux-can, netdev, linux-arm-kernel, linux-kernel,
	git, Srinivas Neeli

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
CANFD controllers, will compensate for the measure loop delay in
the receive path.

Signed-off-by: Srinivas Neeli <srinivas.neeli@xilinx.com>
---
Changes in V3:
-Implemented GENMASK,FIELD_PERP & FIELD_GET Calls.
-Implemented TDC feature for all Xilinx CANFD controllers.
-corrected prescalar to prescaler(typo).
Changes in V2:
-Created two patchs one for revert another for TDC support.
---
 drivers/net/can/xilinx_can.c | 48 ++++++++++++++++++++++++++++++++----
 1 file changed, 43 insertions(+), 5 deletions(-)

diff --git a/drivers/net/can/xilinx_can.c b/drivers/net/can/xilinx_can.c
index e179d311aa28..288be69c0aed 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
  *
@@ -9,6 +9,7 @@
  * This driver is developed for Axi CAN IP and for Zynq CANPS Controller.
  */
 
+#include <linux/bitfield.h>
 #include <linux/clk.h>
 #include <linux/errno.h>
 #include <linux/init.h>
@@ -99,6 +100,7 @@ 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		GENMASK(22, 16) /* 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 +134,8 @@ 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		GENMASK(13, 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 */
@@ -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
@@ -405,7 +419,7 @@ static int xcan_set_bittiming(struct net_device *ndev)
 		return -EPERM;
 	}
 
-	/* Setting Baud Rate prescalar value in BRPR Register */
+	/* Setting Baud Rate prescaler value in BRPR Register */
 	btr0 = (bt->brp - 1);
 
 	/* Setting Time Segment 1 in BTR Register */
@@ -422,8 +436,12 @@ static int xcan_set_bittiming(struct net_device *ndev)
 
 	if (priv->devtype.cantype == XAXI_CANFD ||
 	    priv->devtype.cantype == XAXI_CANFD_2_0) {
-		/* Setting Baud Rate prescalar value in F_BRPR Register */
+		/* Setting Baud Rate prescaler value in F_BRPR Register */
 		btr0 = dbt->brp - 1;
+		if (can_tdc_is_enabled(&priv->can))
+			btr0 |=
+			FIELD_PREP(XCAN_BRPR_TDCO_SHIFT, priv->can.tdc.tdco) |
+			XCAN_BRPR_TDC_ENABLE;
 
 		/* Setting Time Segment 1 in BTR Register */
 		btr1 = dbt->prop_seg + dbt->phase_seg1 - 1;
@@ -1483,6 +1501,22 @@ 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 = FIELD_GET(XCAN_SR_TDCV_MASK, priv->read_reg(priv, XCAN_SR_OFFSET));
+
+	return 0;
+}
+
 static const struct net_device_ops xcan_netdev_ops = {
 	.ndo_open	= xcan_open,
 	.ndo_stop	= xcan_close,
@@ -1744,8 +1778,12 @@ static int xcan_probe(struct platform_device *pdev)
 			&xcan_data_bittiming_const_canfd2;
 
 	if (devtype->cantype == XAXI_CANFD ||
-	    devtype->cantype == XAXI_CANFD_2_0)
-		priv->can.ctrlmode_supported |= CAN_CTRLMODE_FD;
+	    devtype->cantype == XAXI_CANFD_2_0) {
+		priv->can.ctrlmode_supported |= CAN_CTRLMODE_FD |
+						CAN_CTRLMODE_TDC_AUTO;
+		priv->can.do_get_auto_tdcv = xcan_get_auto_tdcv;
+		priv->can.tdc_const = &xcan_tdc_const;
+	}
 
 	priv->reg_base = addr;
 	priv->tx_max = tx_max;
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [PATCH V3 2/2] can: xilinx_can: Add Transmitter delay compensation (TDC) feature support
  2022-06-09  8:24 ` [PATCH V3 2/2] can: xilinx_can: Add Transmitter delay compensation (TDC) feature support Srinivas Neeli
@ 2022-06-09  8:31   ` Marc Kleine-Budde
  2022-06-09  8:55     ` Vincent Mailhol
  0 siblings, 1 reply; 6+ messages in thread
From: Marc Kleine-Budde @ 2022-06-09  8:31 UTC (permalink / raw)
  To: Srinivas Neeli
  Cc: wg, davem, edumazet, srinivas.neeli, neelisrinivas18,
	appana.durga.rao, sgoud, michal.simek, kuba, pabeni, linux-can,
	netdev, linux-arm-kernel, linux-kernel, git

[-- Attachment #1: Type: text/plain, Size: 5776 bytes --]

On 09.06.2022 13:54:33, Srinivas Neeli wrote:
> 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
> CANFD controllers, will compensate for the measure loop delay in
> the receive path.
> 
> Signed-off-by: Srinivas Neeli <srinivas.neeli@xilinx.com>
> ---
> Changes in V3:
> -Implemented GENMASK,FIELD_PERP & FIELD_GET Calls.
> -Implemented TDC feature for all Xilinx CANFD controllers.
> -corrected prescalar to prescaler(typo).
> Changes in V2:
> -Created two patchs one for revert another for TDC support.
> ---
>  drivers/net/can/xilinx_can.c | 48 ++++++++++++++++++++++++++++++++----
>  1 file changed, 43 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/net/can/xilinx_can.c b/drivers/net/can/xilinx_can.c
> index e179d311aa28..288be69c0aed 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
>   *
> @@ -9,6 +9,7 @@
>   * This driver is developed for Axi CAN IP and for Zynq CANPS Controller.
>   */
>  
> +#include <linux/bitfield.h>
>  #include <linux/clk.h>
>  #include <linux/errno.h>
>  #include <linux/init.h>
> @@ -99,6 +100,7 @@ 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		GENMASK(22, 16) /* 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 +134,8 @@ 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		GENMASK(13, 8)  /* Transmitter Delay Compensation Offset */
                          ^^^^^
This is a MASK.

> +#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 */
> @@ -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
> @@ -405,7 +419,7 @@ static int xcan_set_bittiming(struct net_device *ndev)
>  		return -EPERM;
>  	}
>  
> -	/* Setting Baud Rate prescalar value in BRPR Register */
> +	/* Setting Baud Rate prescaler value in BRPR Register */

unrelated change, please make it a separate patch

>  	btr0 = (bt->brp - 1);
>  
>  	/* Setting Time Segment 1 in BTR Register */
> @@ -422,8 +436,12 @@ static int xcan_set_bittiming(struct net_device *ndev)
>  
>  	if (priv->devtype.cantype == XAXI_CANFD ||
>  	    priv->devtype.cantype == XAXI_CANFD_2_0) {
> -		/* Setting Baud Rate prescalar value in F_BRPR Register */
> +		/* Setting Baud Rate prescaler value in F_BRPR Register */

same

>  		btr0 = dbt->brp - 1;
> +		if (can_tdc_is_enabled(&priv->can))
> +			btr0 |=
> +			FIELD_PREP(XCAN_BRPR_TDCO_SHIFT, priv->can.tdc.tdco) |
> +			XCAN_BRPR_TDC_ENABLE;
>  
>  		/* Setting Time Segment 1 in BTR Register */
>  		btr1 = dbt->prop_seg + dbt->phase_seg1 - 1;
> @@ -1483,6 +1501,22 @@ 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 = FIELD_GET(XCAN_SR_TDCV_MASK, priv->read_reg(priv, XCAN_SR_OFFSET));
> +
> +	return 0;
> +}
> +
>  static const struct net_device_ops xcan_netdev_ops = {
>  	.ndo_open	= xcan_open,
>  	.ndo_stop	= xcan_close,
> @@ -1744,8 +1778,12 @@ static int xcan_probe(struct platform_device *pdev)
>  			&xcan_data_bittiming_const_canfd2;
>  
>  	if (devtype->cantype == XAXI_CANFD ||
> -	    devtype->cantype == XAXI_CANFD_2_0)
> -		priv->can.ctrlmode_supported |= CAN_CTRLMODE_FD;
> +	    devtype->cantype == XAXI_CANFD_2_0) {
> +		priv->can.ctrlmode_supported |= CAN_CTRLMODE_FD |
> +						CAN_CTRLMODE_TDC_AUTO;
> +		priv->can.do_get_auto_tdcv = xcan_get_auto_tdcv;
> +		priv->can.tdc_const = &xcan_tdc_const;
> +	}
>  
>  	priv->reg_base = addr;
>  	priv->tx_max = tx_max;
> -- 
> 2.25.1
> 
> 

Otherwise looks good.

Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde           |
Embedded Linux                   | https://www.pengutronix.de  |
Vertretung West/Dortmund         | Phone: +49-231-2826-924     |
Amtsgericht Hildesheim, HRA 2686 | Fax:   +49-5121-206917-5555 |

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^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH V3 0/2] xilinx_can: Update on xilinx can
  2022-06-09  8:24 [PATCH V3 0/2] xilinx_can: Update on xilinx can Srinivas Neeli
  2022-06-09  8:24 ` [PATCH V3 1/2] Revert "can: xilinx_can: Limit CANFD brp to 2" Srinivas Neeli
  2022-06-09  8:24 ` [PATCH V3 2/2] can: xilinx_can: Add Transmitter delay compensation (TDC) feature support Srinivas Neeli
@ 2022-06-09  8:34 ` Marc Kleine-Budde
  2 siblings, 0 replies; 6+ messages in thread
From: Marc Kleine-Budde @ 2022-06-09  8:34 UTC (permalink / raw)
  To: Srinivas Neeli
  Cc: wg, davem, edumazet, srinivas.neeli, neelisrinivas18,
	appana.durga.rao, sgoud, michal.simek, kuba, pabeni, linux-can,
	netdev, linux-arm-kernel, linux-kernel, git

[-- Attachment #1: Type: text/plain, Size: 925 bytes --]

On 09.06.2022 13:54:31, Srinivas Neeli wrote:
> This patch series addresses
> 1) Reverts the limiting CANFD brp_min to 2.
> 2) Adds TDC support for Xilinx can driver.

Thanks for your patches!

> Hi Marc,
> Please apply PATCH V3 1/2 on stable branch.
> Due to some mailing issue i didn't receive your mail.

Applied to can/testing, please don't mix patches for can and can-next in
on series in the future.

> Changes in V3:
> -Implemented GENMASK,FIELD_PERP & FIELD_GET Calls.
> -Implemented TDC feature for all Xilinx CANFD controllers.
> -corrected prescalar to prescaler(typo).

Pleas make this a separate patch.

regards,
Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde           |
Embedded Linux                   | https://www.pengutronix.de  |
Vertretung West/Dortmund         | Phone: +49-231-2826-924     |
Amtsgericht Hildesheim, HRA 2686 | Fax:   +49-5121-206917-5555 |

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH V3 2/2] can: xilinx_can: Add Transmitter delay compensation (TDC) feature support
  2022-06-09  8:31   ` Marc Kleine-Budde
@ 2022-06-09  8:55     ` Vincent Mailhol
  0 siblings, 0 replies; 6+ messages in thread
From: Vincent Mailhol @ 2022-06-09  8:55 UTC (permalink / raw)
  To: Marc Kleine-Budde
  Cc: Srinivas Neeli, wg, davem, edumazet, srinivas.neeli,
	neelisrinivas18, appana.durga.rao, sgoud, michal.simek, kuba,
	pabeni, linux-can, netdev, linux-arm-kernel, linux-kernel, git

On Thu. 9 juin 2022 at 17:34, Marc Kleine-Budde <mkl@pengutronix.de> wrote:
> On 09.06.2022 13:54:33, Srinivas Neeli wrote:
> > 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
> > CANFD controllers, will compensate for the measure loop delay in
> > the receive path.
> >
> > Signed-off-by: Srinivas Neeli <srinivas.neeli@xilinx.com>
> > ---
> > Changes in V3:
> > -Implemented GENMASK,FIELD_PERP & FIELD_GET Calls.
> > -Implemented TDC feature for all Xilinx CANFD controllers.
> > -corrected prescalar to prescaler(typo).
> > Changes in V2:
> > -Created two patchs one for revert another for TDC support.
> > ---
> >  drivers/net/can/xilinx_can.c | 48 ++++++++++++++++++++++++++++++++----
> >  1 file changed, 43 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/net/can/xilinx_can.c b/drivers/net/can/xilinx_can.c
> > index e179d311aa28..288be69c0aed 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
> >   *
> > @@ -9,6 +9,7 @@
> >   * This driver is developed for Axi CAN IP and for Zynq CANPS Controller.
> >   */
> >
> > +#include <linux/bitfield.h>
> >  #include <linux/clk.h>
> >  #include <linux/errno.h>
> >  #include <linux/init.h>
> > @@ -99,6 +100,7 @@ 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            GENMASK(22, 16) /* 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 +134,8 @@ 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         GENMASK(13, 8)  /* Transmitter Delay Compensation Offset */
>                           ^^^^^
> This is a MASK.
>
> > +#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 */
> > @@ -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
> > @@ -405,7 +419,7 @@ static int xcan_set_bittiming(struct net_device *ndev)
> >               return -EPERM;
> >       }
> >
> > -     /* Setting Baud Rate prescalar value in BRPR Register */
> > +     /* Setting Baud Rate prescaler value in BRPR Register */
>
> unrelated change, please make it a separate patch
>
> >       btr0 = (bt->brp - 1);
> >
> >       /* Setting Time Segment 1 in BTR Register */
> > @@ -422,8 +436,12 @@ static int xcan_set_bittiming(struct net_device *ndev)
> >
> >       if (priv->devtype.cantype == XAXI_CANFD ||
> >           priv->devtype.cantype == XAXI_CANFD_2_0) {
> > -             /* Setting Baud Rate prescalar value in F_BRPR Register */
> > +             /* Setting Baud Rate prescaler value in F_BRPR Register */
>
> same
>
> >               btr0 = dbt->brp - 1;
> > +             if (can_tdc_is_enabled(&priv->can))
> > +                     btr0 |=
> > +                     FIELD_PREP(XCAN_BRPR_TDCO_SHIFT, priv->can.tdc.tdco) |
> > +                     XCAN_BRPR_TDC_ENABLE;
> >
> >               /* Setting Time Segment 1 in BTR Register */
> >               btr1 = dbt->prop_seg + dbt->phase_seg1 - 1;
> > @@ -1483,6 +1501,22 @@ 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 = FIELD_GET(XCAN_SR_TDCV_MASK, priv->read_reg(priv, XCAN_SR_OFFSET));
> > +
> > +     return 0;
> > +}
> > +
> >  static const struct net_device_ops xcan_netdev_ops = {
> >       .ndo_open       = xcan_open,
> >       .ndo_stop       = xcan_close,
> > @@ -1744,8 +1778,12 @@ static int xcan_probe(struct platform_device *pdev)
> >                       &xcan_data_bittiming_const_canfd2;
> >
> >       if (devtype->cantype == XAXI_CANFD ||
> > -         devtype->cantype == XAXI_CANFD_2_0)
> > -             priv->can.ctrlmode_supported |= CAN_CTRLMODE_FD;
> > +         devtype->cantype == XAXI_CANFD_2_0) {
> > +             priv->can.ctrlmode_supported |= CAN_CTRLMODE_FD |
> > +                                             CAN_CTRLMODE_TDC_AUTO;
> > +             priv->can.do_get_auto_tdcv = xcan_get_auto_tdcv;
> > +             priv->can.tdc_const = &xcan_tdc_const;
> > +     }
> >
> >       priv->reg_base = addr;
> >       priv->tx_max = tx_max;
> > --
> > 2.25.1
> >
> >
>
> Otherwise looks good.

Same for me. Also, thanks for using the TDC framework. You are the
first one to use it after I created it!

Assuming you address all of Marc’s comment, please add this in your v4:
Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>


Yours sincerely,
Vincent Mailhol

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2022-06-09  8:56 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-06-09  8:24 [PATCH V3 0/2] xilinx_can: Update on xilinx can Srinivas Neeli
2022-06-09  8:24 ` [PATCH V3 1/2] Revert "can: xilinx_can: Limit CANFD brp to 2" Srinivas Neeli
2022-06-09  8:24 ` [PATCH V3 2/2] can: xilinx_can: Add Transmitter delay compensation (TDC) feature support Srinivas Neeli
2022-06-09  8:31   ` Marc Kleine-Budde
2022-06-09  8:55     ` Vincent Mailhol
2022-06-09  8:34 ` [PATCH V3 0/2] xilinx_can: Update on xilinx can Marc Kleine-Budde

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