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[3/6] can: sja1000: Add Quirks for RZ/N1 SJA1000 CAN controller

Message ID 20220702140130.218409-4-biju.das.jz@bp.renesas.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series Add support for RZ/N1 SJA1000 CAN controller | expand

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Commit Message

Biju Das July 2, 2022, 2:01 p.m. UTC
Chapter 6.5.16 of the RZ/N1 Peripheral Manual mentions the below
differences compared to the reference Philips SJA1000 device.

Handling of Transmitted Messages:
 * The CAN controller does not copy transmitted messages to the receive
   buffer, unlike the reference device.

Clock Divider Register:
 * This register is not supported

This patch adds device quirks to handle these differences.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
---
 drivers/net/can/sja1000/sja1000.c | 17 +++++++++++------
 drivers/net/can/sja1000/sja1000.h |  4 +++-
 2 files changed, 14 insertions(+), 7 deletions(-)

Comments

Marc Kleine-Budde July 2, 2022, 4:16 p.m. UTC | #1
On 02.07.2022 15:01:27, Biju Das wrote:
> Chapter 6.5.16 of the RZ/N1 Peripheral Manual mentions the below
> differences compared to the reference Philips SJA1000 device.
> 
> Handling of Transmitted Messages:
>  * The CAN controller does not copy transmitted messages to the receive
>    buffer, unlike the reference device.
> 
> Clock Divider Register:
>  * This register is not supported
> 
> This patch adds device quirks to handle these differences.
> 
> Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
> ---
>  drivers/net/can/sja1000/sja1000.c | 17 +++++++++++------
>  drivers/net/can/sja1000/sja1000.h |  4 +++-
>  2 files changed, 14 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/net/can/sja1000/sja1000.c b/drivers/net/can/sja1000/sja1000.c
> index 2e7638f98cf1..49cf4fc4d896 100644
> --- a/drivers/net/can/sja1000/sja1000.c
> +++ b/drivers/net/can/sja1000/sja1000.c
> @@ -183,8 +183,9 @@ static void chipset_init(struct net_device *dev)
>  {
>  	struct sja1000_priv *priv = netdev_priv(dev);
>  
> -	/* set clock divider and output control register */
> -	priv->write_reg(priv, SJA1000_CDR, priv->cdr | CDR_PELICAN);
> +	if (!(priv->flags & SJA1000_NO_CDR_REG_QUIRK))
> +		/* set clock divider and output control register */
> +		priv->write_reg(priv, SJA1000_CDR, priv->cdr | CDR_PELICAN);
>  
>  	/* set acceptance filter (accept all) */
>  	priv->write_reg(priv, SJA1000_ACCC0, 0x00);
> @@ -208,9 +209,11 @@ static void sja1000_start(struct net_device *dev)
>  	if (priv->can.state != CAN_STATE_STOPPED)
>  		set_reset_mode(dev);
>  
> -	/* Initialize chip if uninitialized at this stage */
> -	if (!(priv->read_reg(priv, SJA1000_CDR) & CDR_PELICAN))
> -		chipset_init(dev);
> +	if (!(priv->flags & SJA1000_NO_CDR_REG_QUIRK)) {
> +		/* Initialize chip if uninitialized at this stage */
> +		if (!(priv->read_reg(priv, SJA1000_CDR) & CDR_PELICAN))
> +			chipset_init(dev);
> +	}
>  
>  	/* Clear error counters and error code capture */
>  	priv->write_reg(priv, SJA1000_TXERR, 0x0);
> @@ -652,12 +655,14 @@ static const struct net_device_ops sja1000_netdev_ops = {
>  
>  int register_sja1000dev(struct net_device *dev)
>  {
> +	struct sja1000_priv *priv = netdev_priv(dev);
>  	int ret;
>  
>  	if (!sja1000_probe_chip(dev))
>  		return -ENODEV;
>  
> -	dev->flags |= IFF_ECHO;	/* we support local echo */
> +	if (!(priv->flags & SJA1000_NO_HW_LOOPBACK_QUIRK))
> +		dev->flags |= IFF_ECHO;	/* we support local echo */
>  	dev->netdev_ops = &sja1000_netdev_ops;
>  
>  	set_reset_mode(dev);
> diff --git a/drivers/net/can/sja1000/sja1000.h b/drivers/net/can/sja1000/sja1000.h
> index 9d46398f8154..d0b8ce3f70ec 100644
> --- a/drivers/net/can/sja1000/sja1000.h
> +++ b/drivers/net/can/sja1000/sja1000.h
> @@ -145,7 +145,9 @@
>  /*
>   * Flags for sja1000priv.flags
>   */
> -#define SJA1000_CUSTOM_IRQ_HANDLER 0x1
> +#define SJA1000_CUSTOM_IRQ_HANDLER	BIT(0)
> +#define SJA1000_NO_CDR_REG_QUIRK	BIT(1)
> +#define SJA1000_NO_HW_LOOPBACK_QUIRK	BIT(2)

Please name these defines SJA1000_QUIRK_*

Marc
Marc Kleine-Budde July 2, 2022, 4:33 p.m. UTC | #2
On 02.07.2022 15:01:27, Biju Das wrote:
> Chapter 6.5.16 of the RZ/N1 Peripheral Manual mentions the below
> differences compared to the reference Philips SJA1000 device.
> 
> Handling of Transmitted Messages:
>  * The CAN controller does not copy transmitted messages to the receive
>    buffer, unlike the reference device.

This is something different than....

>  int register_sja1000dev(struct net_device *dev)
>  {
> +	struct sja1000_priv *priv = netdev_priv(dev);
>  	int ret;
>  
>  	if (!sja1000_probe_chip(dev))
>  		return -ENODEV;
>  
> -	dev->flags |= IFF_ECHO;	/* we support local echo */
> +	if (!(priv->flags & SJA1000_NO_HW_LOOPBACK_QUIRK))
> +		dev->flags |= IFF_ECHO;	/* we support local echo */

... the IFF_ECHO.

IFF_ECHO set means the driver cals can_put_echo_skb() before TX and
can_get_echo_skb() after TX complete interrupt.

| irqreturn_t sja1000_interrupt(int irq, void *dev_id)
[...]
| 	while ((isrc = priv->read_reg(priv, SJA1000_IR)) &&
| 	       (n < SJA1000_MAX_IRQ)) {
| 
| 		status = priv->read_reg(priv, SJA1000_SR);
| 		/* check for absent controller due to hw unplug */
| 		if (status == 0xFF && sja1000_is_absent(priv))
| 			goto out;
| 
| 		if (isrc & IRQ_WUI)
| 			netdev_warn(dev, "wakeup interrupt\n");
| 
| 		if (isrc & IRQ_TI) {
| 			/* transmission buffer released */
| 			if (priv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT &&
| 			    !(status & SR_TCS)) {
| 				stats->tx_errors++;
| 				can_free_echo_skb(dev, 0, NULL);
| 			} else {

Please add a netdev_info() for debugging and verify that you get a TX
complete IRQ.

| 				/* transmission complete */
| 				stats->tx_bytes += can_get_echo_skb(dev, 0, NULL);
| 				stats->tx_packets++;
| 			}
| 			netif_wake_queue(dev);
| 		}


If your hardware doesn't support hardware loopback (configured via
CMD_SRR):

| 	if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
| 		cmd_reg_val |= CMD_SRR;
| 	else
| 		cmd_reg_val |= CMD_TR;

then don't set CAN_CTRLMODE_LOOPBACK in priv->can.ctrlmode_supported.

Marc
Biju Das July 2, 2022, 5:05 p.m. UTC | #3
Hi Marc,

Thanks for the feedback.

> Subject: Re: [PATCH 3/6] can: sja1000: Add Quirks for RZ/N1 SJA1000 CAN
> controller
> 
> On 02.07.2022 15:01:27, Biju Das wrote:
> > Chapter 6.5.16 of the RZ/N1 Peripheral Manual mentions the below
> > differences compared to the reference Philips SJA1000 device.
> >
> > Handling of Transmitted Messages:
> >  * The CAN controller does not copy transmitted messages to the
> receive
> >    buffer, unlike the reference device.
> 
> This is something different than....
> 
> >  int register_sja1000dev(struct net_device *dev)  {
> > +	struct sja1000_priv *priv = netdev_priv(dev);
> >  	int ret;
> >
> >  	if (!sja1000_probe_chip(dev))
> >  		return -ENODEV;
> >
> > -	dev->flags |= IFF_ECHO;	/* we support local echo */
> > +	if (!(priv->flags & SJA1000_NO_HW_LOOPBACK_QUIRK))
> > +		dev->flags |= IFF_ECHO;	/* we support local echo */
> 
> ... the IFF_ECHO.
> 
> IFF_ECHO set means the driver cals can_put_echo_skb() before TX and
> can_get_echo_skb() after TX complete interrupt.

OK.

> 
> | irqreturn_t sja1000_interrupt(int irq, void *dev_id)
> [...]
> | 	while ((isrc = priv->read_reg(priv, SJA1000_IR)) &&
> | 	       (n < SJA1000_MAX_IRQ)) {
> |
> | 		status = priv->read_reg(priv, SJA1000_SR);
> | 		/* check for absent controller due to hw unplug */
> | 		if (status == 0xFF && sja1000_is_absent(priv))
> | 			goto out;
> |
> | 		if (isrc & IRQ_WUI)
> | 			netdev_warn(dev, "wakeup interrupt\n");
> |
> | 		if (isrc & IRQ_TI) {
> | 			/* transmission buffer released */
> | 			if (priv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT &&
> | 			    !(status & SR_TCS)) {
> | 				stats->tx_errors++;
> | 				can_free_echo_skb(dev, 0, NULL);
> | 			} else {
> 
> Please add a netdev_info() for debugging and verify that you get a TX
> complete IRQ.

I have put prints and I confirm I get Tx complete IRQ.

--- a/drivers/net/can/sja1000/sja1000.c
+++ b/drivers/net/can/sja1000/sja1000.c
@@ -526,6 +526,7 @@ irqreturn_t sja1000_interrupt(int irq, void *dev_id)
                                stats->tx_errors++;
                                can_free_echo_skb(dev, 0, NULL);
                        } else {
+                               netdev_info(dev,"#### Completed message in IRQ");
                                /* transmission complete */

root@rzn1d400-db:/rzn1_tests/linux# ./test-can.sh
Testing sending from can0 to can1 at 100000 bps
[   30.032757] sja1000_platform 52105000.can can1: setting BTR0=0x0e BTR1=0x1c
[   30.062123] IPv6: ADDRCONF(NETDEV_CHANGE): can1: link becomes ready
[   30.128729] sja1000_platform 52104000.can can0: setting BTR0=0x0e BTR1=0x1c
[   31.130232] IPv6: ADDRCONF(NETDEV_CHANGE): can0: link becomes ready
[   32.237998] sja1000_platform 52104000.can can0: #### Completed message in IRQ
[   32.246774] sja1000_platform 52104000.can can0: #### Completed message in IRQ
....
.....
[   33.210809] sja1000_platform 52104000.can can0: #### Completed message in IRQ
[   33.221272] sja1000_platform 52104000.can can0: #### Completed message in IRQ
Testing sending from can0 to can1 at 500000 bps
[   33.366862] sja1000_platform 52105000.can can1: setting BTR0=0x02 BTR1=0x1c
[   33.455829] sja1000_platform 52104000.can can0: setting BTR0=0x02 BTR1=0x1c
[   35.546544] sja1000_platform 52104000.can can0: #### Completed message in IRQ
[   35.554487] sja1000_platform 52104000.can can0: #### Completed message in IRQ
[   35.562322] sja1000_platform 52104000.can can0: #### Completed message in IRQ
.....
[   36.520433] sja1000_platform 52104000.can can0: #### Completed message in IRQ
[   36.530376] sja1000_platform 52104000.can can0: #### Completed message in IRQ
Testing sending from can0 to can1 at 1000000 bps
[   36.667887] sja1000_platform 52105000.can can1: setting BTR0=0x01 BTR1=0x27
[   36.759561] sja1000_platform 52104000.can can0: setting BTR0=0x01 BTR1=0x27
[   38.849459] sja1000_platform 52104000.can can0: #### Completed message in IRQ
[   38.857118] sja1000_platform 52104000.can can0: #### Completed message in IRQ
[   38.864611] sja1000_platform 52104000.can can0: #### Completed message in IRQ
....
[   39.830284] sja1000_platform 52104000.can can0: #### Completed message in IRQ
root@rzn1d400-db:/rzn1_tests/linux# cat /proc/interrupts | grep can
 35:        300          0 GIC-0 127 Level     can0
 36:        300          0 GIC-0 128 Level     can1
root@rzn1d400-db:/rzn1_tests/linux# ./test-can.sh can1 can0
Testing sending from can1 to can0 at 100000 bps
[  111.972815] sja1000_platform 52104000.can can0: setting BTR0=0x0e BTR1=0x1c
[  112.064622] sja1000_platform 52105000.can can1: setting BTR0=0x0e BTR1=0x1c
[  114.159798] sja1000_platform 52105000.can can1: #### Completed message in IRQ
[  114.168361] sja1000_platform 52105000.can can1: #### Completed message in IRQ
.....
[  115.141437] sja1000_platform 52105000.can can1: #### Completed message in IRQ
Testing sending from can1 to can0 at 500000 bps
[  115.272323] sja1000_platform 52104000.can can0: setting BTR0=0x02 BTR1=0x1c
[  115.365008] sja1000_platform 52105000.can can1: setting BTR0=0x02 BTR1=0x1c
[  117.445187] sja1000_platform 52105000.can can1: #### Completed message in IRQ
[  117.460489] sja1000_platform 52105000.can can1: #### Completed message in IRQ
[  117.470574] sja1000_platform 52105000.can can1: #### Completed message in IRQ
....
[  118.430442] sja1000_platform 52105000.can can1: #### Completed message in IRQ
[  118.440381] sja1000_platform 52105000.can can1: #### Completed message in IRQ
Testing sending from can1 to can0 at 1000000 bps
[  118.564981] sja1000_platform 52104000.can can0: setting BTR0=0x01 BTR1=0x27
[  118.655100] sja1000_platform 52105000.can can1: setting BTR0=0x01 BTR1=0x27
[  120.731882] sja1000_platform 52105000.can can1: #### Completed message in IRQ
[  120.740605] sja1000_platform 52105000.can can1: #### Completed message in IRQ
...
[  121.710274] sja1000_platform 52105000.can can1: #### Completed message in IRQ
[  121.720370] sja1000_platform 52105000.can can1: #### Completed message in IRQ
root@rzn1d400-db:/rzn1_tests/linux#root@rzn1d400-db:/rzn1_tests/linux# cat /proc/interrupts | grep can
 35:        600          0 GIC-0 127 Level     can0
 36:        600          0 GIC-0 128 Level     can1


> 
> | 				/* transmission complete */
> | 				stats->tx_bytes += can_get_echo_skb(dev, 0,
> NULL);
> | 				stats->tx_packets++;
> | 			}
> | 			netif_wake_queue(dev);
> | 		}
> 
> 
> If your hardware doesn't support hardware loopback (configured via
> CMD_SRR):

But our HW supports, CMD_SRR.

b4 bCan_SRR Self Reception Request
1: Set when a message is to be transmitted and received simultaneously
[Condition of “Cleared to 0”]
● Software Reset (Set “1” in bCan_RM)
● Switch to “Bus Off” (Set “1” in bCan_BS)

Cheers,
Biju

> 
> | 	if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
> | 		cmd_reg_val |= CMD_SRR;
> | 	else
> | 		cmd_reg_val |= CMD_TR;
> 
> then don't set CAN_CTRLMODE_LOOPBACK in priv->can.ctrlmode_supported.
Biju Das July 2, 2022, 6:09 p.m. UTC | #4
Hi Marc,

Thanks for the feedback.

> Subject: Re: [PATCH 3/6] can: sja1000: Add Quirks for RZ/N1 SJA1000 CAN
> controller
> 
> On 02.07.2022 15:01:27, Biju Das wrote:
> > Chapter 6.5.16 of the RZ/N1 Peripheral Manual mentions the below
> > differences compared to the reference Philips SJA1000 device.
> >
> > Handling of Transmitted Messages:
> >  * The CAN controller does not copy transmitted messages to the
> receive
> >    buffer, unlike the reference device.
> >
> > Clock Divider Register:
> >  * This register is not supported
> >
> > This patch adds device quirks to handle these differences.
> >
> > Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
> > ---
> >  drivers/net/can/sja1000/sja1000.c | 17 +++++++++++------
> > drivers/net/can/sja1000/sja1000.h |  4 +++-
> >  2 files changed, 14 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/net/can/sja1000/sja1000.c
> > b/drivers/net/can/sja1000/sja1000.c
> > index 2e7638f98cf1..49cf4fc4d896 100644
> > --- a/drivers/net/can/sja1000/sja1000.c
> > +++ b/drivers/net/can/sja1000/sja1000.c
> > @@ -183,8 +183,9 @@ static void chipset_init(struct net_device *dev)
> > {
> >  	struct sja1000_priv *priv = netdev_priv(dev);
> >
> > -	/* set clock divider and output control register */
> > -	priv->write_reg(priv, SJA1000_CDR, priv->cdr | CDR_PELICAN);
> > +	if (!(priv->flags & SJA1000_NO_CDR_REG_QUIRK))
> > +		/* set clock divider and output control register */
> > +		priv->write_reg(priv, SJA1000_CDR, priv->cdr | CDR_PELICAN);
> >
> >  	/* set acceptance filter (accept all) */
> >  	priv->write_reg(priv, SJA1000_ACCC0, 0x00); @@ -208,9 +209,11 @@
> > static void sja1000_start(struct net_device *dev)
> >  	if (priv->can.state != CAN_STATE_STOPPED)
> >  		set_reset_mode(dev);
> >
> > -	/* Initialize chip if uninitialized at this stage */
> > -	if (!(priv->read_reg(priv, SJA1000_CDR) & CDR_PELICAN))
> > -		chipset_init(dev);
> > +	if (!(priv->flags & SJA1000_NO_CDR_REG_QUIRK)) {
> > +		/* Initialize chip if uninitialized at this stage */
> > +		if (!(priv->read_reg(priv, SJA1000_CDR) & CDR_PELICAN))
> > +			chipset_init(dev);
> > +	}
> >
> >  	/* Clear error counters and error code capture */
> >  	priv->write_reg(priv, SJA1000_TXERR, 0x0); @@ -652,12 +655,14 @@
> > static const struct net_device_ops sja1000_netdev_ops = {
> >
> >  int register_sja1000dev(struct net_device *dev)  {
> > +	struct sja1000_priv *priv = netdev_priv(dev);
> >  	int ret;
> >
> >  	if (!sja1000_probe_chip(dev))
> >  		return -ENODEV;
> >
> > -	dev->flags |= IFF_ECHO;	/* we support local echo */
> > +	if (!(priv->flags & SJA1000_NO_HW_LOOPBACK_QUIRK))
> > +		dev->flags |= IFF_ECHO;	/* we support local echo */
> >  	dev->netdev_ops = &sja1000_netdev_ops;
> >
> >  	set_reset_mode(dev);
> > diff --git a/drivers/net/can/sja1000/sja1000.h
> > b/drivers/net/can/sja1000/sja1000.h
> > index 9d46398f8154..d0b8ce3f70ec 100644
> > --- a/drivers/net/can/sja1000/sja1000.h
> > +++ b/drivers/net/can/sja1000/sja1000.h
> > @@ -145,7 +145,9 @@
> >  /*
> >   * Flags for sja1000priv.flags
> >   */
> > -#define SJA1000_CUSTOM_IRQ_HANDLER 0x1
> > +#define SJA1000_CUSTOM_IRQ_HANDLER	BIT(0)
> > +#define SJA1000_NO_CDR_REG_QUIRK	BIT(1)
> > +#define SJA1000_NO_HW_LOOPBACK_QUIRK	BIT(2)
> 
> Please name these defines SJA1000_QUIRK_*

Agreed, Will fix this in V2.

Cheers,
Biju
diff mbox series

Patch

diff --git a/drivers/net/can/sja1000/sja1000.c b/drivers/net/can/sja1000/sja1000.c
index 2e7638f98cf1..49cf4fc4d896 100644
--- a/drivers/net/can/sja1000/sja1000.c
+++ b/drivers/net/can/sja1000/sja1000.c
@@ -183,8 +183,9 @@  static void chipset_init(struct net_device *dev)
 {
 	struct sja1000_priv *priv = netdev_priv(dev);
 
-	/* set clock divider and output control register */
-	priv->write_reg(priv, SJA1000_CDR, priv->cdr | CDR_PELICAN);
+	if (!(priv->flags & SJA1000_NO_CDR_REG_QUIRK))
+		/* set clock divider and output control register */
+		priv->write_reg(priv, SJA1000_CDR, priv->cdr | CDR_PELICAN);
 
 	/* set acceptance filter (accept all) */
 	priv->write_reg(priv, SJA1000_ACCC0, 0x00);
@@ -208,9 +209,11 @@  static void sja1000_start(struct net_device *dev)
 	if (priv->can.state != CAN_STATE_STOPPED)
 		set_reset_mode(dev);
 
-	/* Initialize chip if uninitialized at this stage */
-	if (!(priv->read_reg(priv, SJA1000_CDR) & CDR_PELICAN))
-		chipset_init(dev);
+	if (!(priv->flags & SJA1000_NO_CDR_REG_QUIRK)) {
+		/* Initialize chip if uninitialized at this stage */
+		if (!(priv->read_reg(priv, SJA1000_CDR) & CDR_PELICAN))
+			chipset_init(dev);
+	}
 
 	/* Clear error counters and error code capture */
 	priv->write_reg(priv, SJA1000_TXERR, 0x0);
@@ -652,12 +655,14 @@  static const struct net_device_ops sja1000_netdev_ops = {
 
 int register_sja1000dev(struct net_device *dev)
 {
+	struct sja1000_priv *priv = netdev_priv(dev);
 	int ret;
 
 	if (!sja1000_probe_chip(dev))
 		return -ENODEV;
 
-	dev->flags |= IFF_ECHO;	/* we support local echo */
+	if (!(priv->flags & SJA1000_NO_HW_LOOPBACK_QUIRK))
+		dev->flags |= IFF_ECHO;	/* we support local echo */
 	dev->netdev_ops = &sja1000_netdev_ops;
 
 	set_reset_mode(dev);
diff --git a/drivers/net/can/sja1000/sja1000.h b/drivers/net/can/sja1000/sja1000.h
index 9d46398f8154..d0b8ce3f70ec 100644
--- a/drivers/net/can/sja1000/sja1000.h
+++ b/drivers/net/can/sja1000/sja1000.h
@@ -145,7 +145,9 @@ 
 /*
  * Flags for sja1000priv.flags
  */
-#define SJA1000_CUSTOM_IRQ_HANDLER 0x1
+#define SJA1000_CUSTOM_IRQ_HANDLER	BIT(0)
+#define SJA1000_NO_CDR_REG_QUIRK	BIT(1)
+#define SJA1000_NO_HW_LOOPBACK_QUIRK	BIT(2)
 
 /*
  * SJA1000 private data structure