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[PATCH] can: m_can: support transmit frame in CAN FD format

Started byWenyou Yang <wenyou.yang@atmel.com>
First post2017-03-03 07:00 +0100
Last post2017-03-06 03:30 +0100
Articles 3 — 3 participants

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  [PATCH] can: m_can: support transmit frame in CAN FD format Wenyou Yang <wenyou.yang@atmel.com> - 2017-03-03 07:00 +0100
    Re: [PATCH] can: m_can: support transmit frame in CAN FD format Oliver Hartkopp <socketcan@hartkopp.net> - 2017-03-05 20:50 +0100
      RE: [PATCH] can: m_can: support transmit frame in CAN FD format <Wenyou.Yang@microchip.com> - 2017-03-06 03:30 +0100

#1591673 — [PATCH] can: m_can: support transmit frame in CAN FD format

FromWenyou Yang <wenyou.yang@atmel.com>
Date2017-03-03 07:00 +0100
Subject[PATCH] can: m_can: support transmit frame in CAN FD format
Message-ID<tgOpY-538-3@gated-at.bofh.it>
Add support to transmit the frame in the CAN FD format and with
the bit rate switching.

Tested on SAMA5D2 Xplained board.

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
---
The testing is based on
[RESEND PATCH 1/1] can: m_can: fix bitrate setup on latest silicon
http://lkml.iu.edu/hypermail/linux/kernel/1702.1/05347.html

 drivers/net/can/m_can/m_can.c | 21 +++++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)

diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
index 195f15edb32e..9ef9b337d25b 100644
--- a/drivers/net/can/m_can/m_can.c
+++ b/drivers/net/can/m_can/m_can.c
@@ -266,8 +266,12 @@ enum m_can_mram_cfg {
 
 /* Tx Buffer Element */
 /* R0 */
+#define TX_BUF_ESI		BIT(31)
 #define TX_BUF_XTD		BIT(30)
 #define TX_BUF_RTR		BIT(29)
+#define TX_BUF_EFC		BIT(23)
+#define TX_BUF_EDL		BIT(21)
+#define TX_BUF_BRS		BIT(20)
 
 /* address offset and element number for each FIFO/Buffer in the Message RAM */
 struct mram_cfg {
@@ -884,7 +888,7 @@ static void m_can_chip_config(struct net_device *dev)
 	}
 
 	if (priv->can.ctrlmode & CAN_CTRLMODE_FD)
-		cccr |= CCCR_CME_CANFD_BRS << CCCR_CME_SHIFT;
+		cccr |= (CCCR_CME_CANFD_BRS | CCCR_CME_CANFD) << CCCR_CME_SHIFT;
 
 	m_can_write(priv, M_CAN_CCCR, cccr);
 	m_can_write(priv, M_CAN_TEST, test);
@@ -1047,6 +1051,7 @@ static netdev_tx_t m_can_start_xmit(struct sk_buff *skb,
 	struct canfd_frame *cf = (struct canfd_frame *)skb->data;
 	u32 id, cccr;
 	int i;
+	u32 dlc;
 
 	if (can_dropped_invalid_skb(dev, skb))
 		return NETDEV_TX_OK;
@@ -1065,7 +1070,6 @@ static netdev_tx_t m_can_start_xmit(struct sk_buff *skb,
 
 	/* message ram configuration */
 	m_can_fifo_write(priv, 0, M_CAN_FIFO_ID, id);
-	m_can_fifo_write(priv, 0, M_CAN_FIFO_DLC, can_len2dlc(cf->len) << 16);
 
 	for (i = 0; i < cf->len; i += 4)
 		m_can_fifo_write(priv, 0, M_CAN_FIFO_DATA(i / 4),
@@ -1073,20 +1077,29 @@ static netdev_tx_t m_can_start_xmit(struct sk_buff *skb,
 
 	can_put_echo_skb(skb, dev, 0);
 
+	dlc = can_len2dlc(cf->len) << 16;
+
 	if (priv->can.ctrlmode & CAN_CTRLMODE_FD) {
 		cccr = m_can_read(priv, M_CAN_CCCR);
 		cccr &= ~(CCCR_CMR_MASK << CCCR_CMR_SHIFT);
 		if (can_is_canfd_skb(skb)) {
-			if (cf->flags & CANFD_BRS)
+			dlc |= TX_BUF_EDL;
+			if (cf->flags & CANFD_ESI)
+				dlc |= TX_BUF_ESI;
+			if (cf->flags & CANFD_BRS) {
+				dlc |= TX_BUF_BRS;
 				cccr |= CCCR_CMR_CANFD_BRS << CCCR_CMR_SHIFT;
-			else
+			} else {
 				cccr |= CCCR_CMR_CANFD << CCCR_CMR_SHIFT;
+			}
 		} else {
 			cccr |= CCCR_CMR_CAN << CCCR_CMR_SHIFT;
 		}
 		m_can_write(priv, M_CAN_CCCR, cccr);
 	}
 
+	m_can_fifo_write(priv, 0, M_CAN_FIFO_DLC, dlc);
+
 	/* enable first TX buffer to start transfer  */
 	m_can_write(priv, M_CAN_TXBTIE, 0x1);
 	m_can_write(priv, M_CAN_TXBAR, 0x1);
-- 
2.11.0

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#1592832

FromOliver Hartkopp <socketcan@hartkopp.net>
Date2017-03-05 20:50 +0100
Message-ID<thKkh-51v-9@gated-at.bofh.it>
In reply to#1591673
The patch has some issues:

On 03/03/2017 06:33 AM, Wenyou Yang wrote:
> Add support to transmit the frame in the CAN FD format and with
> the bit rate switching.

This is a misleading comment.

"can: m_can: support transmit frame in CAN FD format"
is misleading too. You were able to send CAN FD frames before.

This patch enables the transmission of CAN FD frames on M_CAN IP cores 
 >= v3.1.x, right?

So this should be mentioned properly.

> Tested on SAMA5D2 Xplained board.

Tested on which M_CAN IP core revision would be useful here.

> Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
> ---
> The testing is based on
> [RESEND PATCH 1/1] can: m_can: fix bitrate setup on latest silicon
> http://lkml.iu.edu/hypermail/linux/kernel/1702.1/05347.html
>
>  drivers/net/can/m_can/m_can.c | 21 +++++++++++++++++----
>  1 file changed, 17 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
> index 195f15edb32e..9ef9b337d25b 100644
> --- a/drivers/net/can/m_can/m_can.c
> +++ b/drivers/net/can/m_can/m_can.c
> @@ -266,8 +266,12 @@ enum m_can_mram_cfg {
>
>  /* Tx Buffer Element */
>  /* R0 */
> +#define TX_BUF_ESI		BIT(31)
>  #define TX_BUF_XTD		BIT(30)
>  #define TX_BUF_RTR		BIT(29)
> +#define TX_BUF_EFC		BIT(23)
> +#define TX_BUF_EDL		BIT(21)

This bit is named FDF (FD Format bit).

It has to be:

#define TX_BUF_FDF		BIT(21)

> +#define TX_BUF_BRS		BIT(20)
>
>  /* address offset and element number for each FIFO/Buffer in the Message RAM */
>  struct mram_cfg {
> @@ -884,7 +888,7 @@ static void m_can_chip_config(struct net_device *dev)
>  	}
>
>  	if (priv->can.ctrlmode & CAN_CTRLMODE_FD)
> -		cccr |= CCCR_CME_CANFD_BRS << CCCR_CME_SHIFT;
> +		cccr |= (CCCR_CME_CANFD_BRS | CCCR_CME_CANFD) << CCCR_CME_SHIFT;
>
>  	m_can_write(priv, M_CAN_CCCR, cccr);
>  	m_can_write(priv, M_CAN_TEST, test);
> @@ -1047,6 +1051,7 @@ static netdev_tx_t m_can_start_xmit(struct sk_buff *skb,
>  	struct canfd_frame *cf = (struct canfd_frame *)skb->data;
>  	u32 id, cccr;
>  	int i;
> +	u32 dlc;
>
>  	if (can_dropped_invalid_skb(dev, skb))
>  		return NETDEV_TX_OK;
> @@ -1065,7 +1070,6 @@ static netdev_tx_t m_can_start_xmit(struct sk_buff *skb,
>
>  	/* message ram configuration */
>  	m_can_fifo_write(priv, 0, M_CAN_FIFO_ID, id);
> -	m_can_fifo_write(priv, 0, M_CAN_FIFO_DLC, can_len2dlc(cf->len) << 16);
>
>  	for (i = 0; i < cf->len; i += 4)
>  		m_can_fifo_write(priv, 0, M_CAN_FIFO_DATA(i / 4),
> @@ -1073,20 +1077,29 @@ static netdev_tx_t m_can_start_xmit(struct sk_buff *skb,
>
>  	can_put_echo_skb(skb, dev, 0);
>
> +	dlc = can_len2dlc(cf->len) << 16;
> +
>  	if (priv->can.ctrlmode & CAN_CTRLMODE_FD) {
>  		cccr = m_can_read(priv, M_CAN_CCCR);
>  		cccr &= ~(CCCR_CMR_MASK << CCCR_CMR_SHIFT);
>  		if (can_is_canfd_skb(skb)) {
> -			if (cf->flags & CANFD_BRS)
> +			dlc |= TX_BUF_EDL;

dito FDF

> +			if (cf->flags & CANFD_ESI)
> +				dlc |= TX_BUF_ESI;
> +			if (cf->flags & CANFD_BRS) {
> +				dlc |= TX_BUF_BRS;
>  				cccr |= CCCR_CMR_CANFD_BRS << CCCR_CMR_SHIFT;
> -			else
> +			} else {
>  				cccr |= CCCR_CMR_CANFD << CCCR_CMR_SHIFT;
> +			}
>  		} else {
>  			cccr |= CCCR_CMR_CAN << CCCR_CMR_SHIFT;
>  		}
>  		m_can_write(priv, M_CAN_CCCR, cccr);
>  	}
>
> +	m_can_fifo_write(priv, 0, M_CAN_FIFO_DLC, dlc);
> +
>  	/* enable first TX buffer to start transfer  */
>  	m_can_write(priv, M_CAN_TXBTIE, 0x1);
>  	m_can_write(priv, M_CAN_TXBAR, 0x1);
>

Beside the documentation and the wrong bit naming the patch looks ok.
Please resend.

Regards,
Oliver

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#1592894

From<Wenyou.Yang@microchip.com>
Date2017-03-06 03:30 +0100
Message-ID<thQzn-15B-3@gated-at.bofh.it>
In reply to#1592832
Hi Oliver,

Thank you for your review.

> -----Original Message-----
> From: Oliver Hartkopp [mailto:socketcan@hartkopp.net]
> Sent: 2017年3月6日 3:34
> To: Wenyou Yang - A41535 <Wenyou.Yang@microchip.com>; Wolfgang
> Grandegger <wg@grandegger.com>; Marc Kleine-Budde <mkl@pengutronix.de>
> Cc: Alexandre Belloni <alexandre.belloni@free-electrons.com>; Florian Fainelli
> <f.fainelli@gmail.com>; Quentin Schulz <quentin.schulz@free-electrons.com>;
> Wenyou Yang - A41535 <Wenyou.Yang@microchip.com>; Nicolas Ferre
> <nicolas.ferre@atmel.com>; linux-can@vger.kernel.org; netdev@vger.kernel.org;
> linux-kernel@vger.kernel.org
> Subject: Re: [PATCH] can: m_can: support transmit frame in CAN FD format
> 
> The patch has some issues:
> 
> On 03/03/2017 06:33 AM, Wenyou Yang wrote:
> > Add support to transmit the frame in the CAN FD format and with the
> > bit rate switching.
> 
> This is a misleading comment.
> 
> "can: m_can: support transmit frame in CAN FD format"
> is misleading too. You were able to send CAN FD frames before.
> 
> This patch enables the transmission of CAN FD frames on M_CAN IP cores  >=
> v3.1.x, right?

The revision of M_CAN IP on SAMA5D2 is 3.1.0 (CREL = 0x31040730).

> 
> So this should be mentioned properly.
> 
> > Tested on SAMA5D2 Xplained board.
> 
> Tested on which M_CAN IP core revision would be useful here.
> 
> > Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
> > ---
> > The testing is based on
> > [RESEND PATCH 1/1] can: m_can: fix bitrate setup on latest silicon
> > http://lkml.iu.edu/hypermail/linux/kernel/1702.1/05347.html
> >
> >  drivers/net/can/m_can/m_can.c | 21 +++++++++++++++++----
> >  1 file changed, 17 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/net/can/m_can/m_can.c
> > b/drivers/net/can/m_can/m_can.c index 195f15edb32e..9ef9b337d25b
> > 100644
> > --- a/drivers/net/can/m_can/m_can.c
> > +++ b/drivers/net/can/m_can/m_can.c
> > @@ -266,8 +266,12 @@ enum m_can_mram_cfg {
> >
> >  /* Tx Buffer Element */
> >  /* R0 */
> > +#define TX_BUF_ESI		BIT(31)
> >  #define TX_BUF_XTD		BIT(30)
> >  #define TX_BUF_RTR		BIT(29)
> > +#define TX_BUF_EFC		BIT(23)
> > +#define TX_BUF_EDL		BIT(21)
> 
> This bit is named FDF (FD Format bit).
> 
> It has to be:
> 
> #define TX_BUF_FDF		BIT(21)
> 
> > +#define TX_BUF_BRS		BIT(20)
> >
> >  /* address offset and element number for each FIFO/Buffer in the
> > Message RAM */  struct mram_cfg { @@ -884,7 +888,7 @@ static void
> > m_can_chip_config(struct net_device *dev)
> >  	}
> >
> >  	if (priv->can.ctrlmode & CAN_CTRLMODE_FD)
> > -		cccr |= CCCR_CME_CANFD_BRS << CCCR_CME_SHIFT;
> > +		cccr |= (CCCR_CME_CANFD_BRS | CCCR_CME_CANFD) <<
> CCCR_CME_SHIFT;
> >
> >  	m_can_write(priv, M_CAN_CCCR, cccr);
> >  	m_can_write(priv, M_CAN_TEST, test); @@ -1047,6 +1051,7 @@ static
> > netdev_tx_t m_can_start_xmit(struct sk_buff *skb,
> >  	struct canfd_frame *cf = (struct canfd_frame *)skb->data;
> >  	u32 id, cccr;
> >  	int i;
> > +	u32 dlc;
> >
> >  	if (can_dropped_invalid_skb(dev, skb))
> >  		return NETDEV_TX_OK;
> > @@ -1065,7 +1070,6 @@ static netdev_tx_t m_can_start_xmit(struct
> > sk_buff *skb,
> >
> >  	/* message ram configuration */
> >  	m_can_fifo_write(priv, 0, M_CAN_FIFO_ID, id);
> > -	m_can_fifo_write(priv, 0, M_CAN_FIFO_DLC, can_len2dlc(cf->len) << 16);
> >
> >  	for (i = 0; i < cf->len; i += 4)
> >  		m_can_fifo_write(priv, 0, M_CAN_FIFO_DATA(i / 4), @@ -
> 1073,20
> > +1077,29 @@ static netdev_tx_t m_can_start_xmit(struct sk_buff *skb,
> >
> >  	can_put_echo_skb(skb, dev, 0);
> >
> > +	dlc = can_len2dlc(cf->len) << 16;
> > +
> >  	if (priv->can.ctrlmode & CAN_CTRLMODE_FD) {
> >  		cccr = m_can_read(priv, M_CAN_CCCR);
> >  		cccr &= ~(CCCR_CMR_MASK << CCCR_CMR_SHIFT);
> >  		if (can_is_canfd_skb(skb)) {
> > -			if (cf->flags & CANFD_BRS)
> > +			dlc |= TX_BUF_EDL;
> 
> dito FDF
> 
> > +			if (cf->flags & CANFD_ESI)
> > +				dlc |= TX_BUF_ESI;
> > +			if (cf->flags & CANFD_BRS) {
> > +				dlc |= TX_BUF_BRS;
> >  				cccr |= CCCR_CMR_CANFD_BRS <<
> CCCR_CMR_SHIFT;
> > -			else
> > +			} else {
> >  				cccr |= CCCR_CMR_CANFD <<
> CCCR_CMR_SHIFT;
> > +			}
> >  		} else {
> >  			cccr |= CCCR_CMR_CAN << CCCR_CMR_SHIFT;
> >  		}
> >  		m_can_write(priv, M_CAN_CCCR, cccr);
> >  	}
> >
> > +	m_can_fifo_write(priv, 0, M_CAN_FIFO_DLC, dlc);
> > +
> >  	/* enable first TX buffer to start transfer  */
> >  	m_can_write(priv, M_CAN_TXBTIE, 0x1);
> >  	m_can_write(priv, M_CAN_TXBAR, 0x1);
> >
> 
> Beside the documentation and the wrong bit naming the patch looks ok.
> Please resend.

I will send a version 2. Thanks

> 
> Regards,
> Oliver


Best Regards,
Wenyou Yang

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