Re: [PATCH] can: m_can: support transmit frame in CAN FD format
From: Oliver Hartkopp <socketcan@hartkopp.net>
Date: 2017-03-05 19:40:32
Also in:
linux-can, lkml
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.
quoted hunk ↗ jump to hunk
Signed-off-by: Wenyou Yang <redacted> --- 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)
quoted hunk ↗ jump to hunk
+#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