Enables the transmission of CAN FD frames on M_CAN IP core >= v3.1.x
and with the bit rate switching.
Tested on M_CAN IP 3.1.0 (CREL = 0x31040730) of SAMA5D2 SoC.
Signed-off-by: Wenyou Yang <[email protected]>
---
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
Changes in v2:
- Rename TX_BUF_EDL with TX_BUF_FDF.
- Improve the commit log to avoid misleading.
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 246584ed89b6..c2dd2550de40 100644
--- a/drivers/net/can/m_can/m_can.c
+++ b/drivers/net/can/m_can/m_can.c
@@ -283,8 +283,12 @@ 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_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 {
@@ -916,7 +920,7 @@ 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);
@@ -1079,6 +1083,7 @@ 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;
@@ -1097,7 +1102,6 @@ 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),
@@ -1105,20 +1109,29 @@ 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_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);
--
2.11.0
On 03/06/2017 03:21 AM, Wenyou Yang wrote:
> Enables the transmission of CAN FD frames on M_CAN IP core >= v3.1.x
> and with the bit rate switching.
>
> Tested on M_CAN IP 3.1.0 (CREL = 0x31040730) of SAMA5D2 SoC.
Does this patch work still with the old version of the silicon?
Marc
--
Pengutronix e.K. | Marc Kleine-Budde |
Industrial Linux Solutions | Phone: +49-231-2826-924 |
Vertretung West/Dortmund | Fax: +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de |
Hi Marc,
On 03/06/2017 11:53 AM, Marc Kleine-Budde wrote:
> On 03/06/2017 03:21 AM, Wenyou Yang wrote:
>> Enables the transmission of CAN FD frames on M_CAN IP core >= v3.1.x
>> and with the bit rate switching.
>>
>> Tested on M_CAN IP 3.1.0 (CREL = 0x31040730) of SAMA5D2 SoC.
>
> Does this patch work still with the old version of the silicon?
The bits that were added in the TX FIFO element are 'reserved' in the
old silicon - so it should not harm.
This code enables
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;
the CAN FD support in the new silicon.
This register is set for the old silicon EVERY time a CAN frame is sent.
So this change should not harm the old silicon either.
In fact I was told that the v3.0.x IP core is rather seldom in the wild.
Although I don't have a v3.0.x to test it should work from the
documentation side of view.
Reviewed-by: Oliver Hartkopp <[email protected]>
If we would like to make it really better, the code in
m_can_start_xmit() should only fiddle with the M_CAN_CCCR register when
working with the v3.0.x silicon.
In fact I would suggest to use the
if (m_can_read_core_rev(priv) < M_CAN_COREREL_3_1_0)
method from
http://marc.info/?l=linux-can&m=148716783119090&w=2
to split the code in m_can_start_xmit() accordingly.
@Wenyou Yang: Can you please send a v3 which splits the tx function?
Regards,
Oliver
@Wenyou Yang: Can you please test the two patches posted here:
[PATCH 1/2] can: m_can: handle bitrate setup on IP core >= 3.1.x
http://marc.info/?l=linux-can&m=148883529927720&w=2
[PATCH 2/2] can: m_can: handle frame transmission on IP core >= 3.1.x
http://marc.info/?l=linux-can&m=148883529927718&w=2
Tnx & regards,
Oliver
HI Oliver,
> -----Original Message-----
> From: Oliver Hartkopp [mailto:[email protected]]
> Sent: 2017年3月7日 5:26
> To: Marc Kleine-Budde <[email protected]>; Wenyou Yang - A41535
> <[email protected]>; Wolfgang Grandegger <[email protected]>
> Cc: Alexandre Belloni <[email protected]>; Florian Fainelli
> <[email protected]>; Quentin Schulz <[email protected]>;
> Wenyou Yang - A41535 <[email protected]>; Nicolas Ferre
> <[email protected]>; [email protected]; [email protected];
> [email protected]
> Subject: Re: [PATCH v2] can: m_can: enable transmission of FD frame on latest
> version
>
> @Wenyou Yang: Can you please test the two patches posted here:
Tested on SAMA5D2 SoC, It works.
>
> [PATCH 1/2] can: m_can: handle bitrate setup on IP core >= 3.1.x
> http://marc.info/?l=linux-can&m=148883529927720&w=2
>
> [PATCH 2/2] can: m_can: handle frame transmission on IP core >= 3.1.x
> http://marc.info/?l=linux-can&m=148883529927718&w=2
>
> Tnx & regards,
> Oliver
Thank you.
Best Regards,
Wenyou Yang
Hi Oliver and Marc,
On 07/03/2017 02:03, [email protected] wrote:
> HI Oliver,
>
>> -----Original Message-----
>> From: Oliver Hartkopp [mailto:[email protected]]
>> Sent: 2017年3月7日 5:26
>> To: Marc Kleine-Budde <[email protected]>; Wenyou Yang - A41535
>> <[email protected]>; Wolfgang Grandegger <[email protected]>
>> Cc: Alexandre Belloni <[email protected]>; Florian Fainelli
>> <[email protected]>; Quentin Schulz <[email protected]>;
>> Wenyou Yang - A41535 <[email protected]>; Nicolas Ferre
>> <[email protected]>; [email protected]; [email protected];
>> [email protected]
>> Subject: Re: [PATCH v2] can: m_can: enable transmission of FD frame on latest
>> version
>>
>> @Wenyou Yang: Can you please test the two patches posted here:
>
> Tested on SAMA5D2 SoC, It works.
>
>>
>> [PATCH 1/2] can: m_can: handle bitrate setup on IP core >= 3.1.x
>> http://marc.info/?l=linux-can&m=148883529927720&w=2
>>
>> [PATCH 2/2] can: m_can: handle frame transmission on IP core >= 3.1.x
>> http://marc.info/?l=linux-can&m=148883529927718&w=2
>>
Sorry, never received those mails so didn't know I had to do something.
I forgot to add my Signed-off-by when resending it so of course you can
add it to your next version:
Signed-off-by: Quentin Schulz <[email protected]>
That gives me the opportunity to relaunch the discussion on it. What's
the status?
Quentin
>> Tnx & regards,
>> Oliver
>
> Thank you.
>
> Best Regards,
> Wenyou Yang
>
--
Quentin Schulz, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com