RE: [PATCH] can: flexcan: add TX support for variable payload size

[Joakim Zhang]

Kindly Ping...

Best Regards,
Joakim Zhang

> -----Original Message-----
> From: Joakim Zhang
> Sent: 2018年12月12日 14:47
> To: m...@pengutronix.de; linux-...@vger.kernel.org
> Cc: w...@grandegger.com; netdev@vger.kernel.org;
> linux-ker...@vger.kernel.org; dl-linux-imx <linux-...@nxp.com>; Joakim
> Zhang <qiangqing.zh...@nxp.com>
> Subject: [PATCH] can: flexcan: add TX support for variable payload size
> 
> Now the FlexCAN driver always use last mailbox for TX, it will work well when
> MB payload size is 8/16 bytes.
> TX mailbox would change to 13 when MB payload size is 64 bytes to support
> CANFD. So we may need to set iflag register to add support for variable
> payload size.
> 
> Signed-off-by: Joakim Zhang <qiangqing.zh...@nxp.com>
> ---
>  drivers/net/can/flexcan.c | 42 +++++++++++++++++++++++++++++----------
>  1 file changed, 32 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c index
> 0f36eafe3ac1..13fd085fcf84 100644
> --- a/drivers/net/can/flexcan.c
> +++ b/drivers/net/can/flexcan.c
> @@ -141,7 +141,9 @@
>  #define FLEXCAN_TX_MB_RESERVED_OFF_FIFO              8
>  #define FLEXCAN_TX_MB_RESERVED_OFF_TIMESTAMP 0
>  #define FLEXCAN_RX_MB_OFF_TIMESTAMP_FIRST
>       (FLEXCAN_TX_MB_RESERVED_OFF_TIMESTAMP + 1)
> -#define FLEXCAN_IFLAG_MB(x)          BIT((x) & 0x1f)
> +#define FLEXCAN_IFLAG1_MB_NUM                32
> +#define FLEXCAN_IFLAG1_MB(x)         BIT(x)
> +#define FLEXCAN_IFLAG2_MB(x)         BIT((x) & 0x1f)
>  #define FLEXCAN_IFLAG_RX_FIFO_OVERFLOW       BIT(7)
>  #define FLEXCAN_IFLAG_RX_FIFO_WARN   BIT(6)
>  #define FLEXCAN_IFLAG_RX_FIFO_AVAILABLE      BIT(5)
> @@ -822,9 +824,15 @@ static inline u64 flexcan_read_reg_iflag_rx(struct
> flexcan_priv *priv)
>       struct flexcan_regs __iomem *regs = priv->regs;
>       u32 iflag1, iflag2;
> 
> -     iflag2 = priv->read(&regs->iflag2) & priv->reg_imask2_default &
> -             ~FLEXCAN_IFLAG_MB(priv->tx_mb_idx);
> -     iflag1 = priv->read(&regs->iflag1) & priv->reg_imask1_default;
> +     if (priv->tx_mb_idx >= FLEXCAN_IFLAG1_MB_NUM) {
> +             iflag2 = priv->read(&regs->iflag2) & priv->reg_imask2_default &
> +                     ~FLEXCAN_IFLAG2_MB(priv->tx_mb_idx);
> +             iflag1 = priv->read(&regs->iflag1) & priv->reg_imask1_default;
> +     } else {
> +             iflag2 = priv->read(&regs->iflag2) & priv->reg_imask2_default;
> +             iflag1 = priv->read(&regs->iflag1) & priv->reg_imask1_default &
> +                     ~FLEXCAN_IFLAG1_MB(priv->tx_mb_idx);
> +     }
> 
>       return (u64)iflag2 << 32 | iflag1;
>  }
> @@ -836,7 +844,8 @@ static irqreturn_t flexcan_irq(int irq, void *dev_id)
>       struct flexcan_priv *priv = netdev_priv(dev);
>       struct flexcan_regs __iomem *regs = priv->regs;
>       irqreturn_t handled = IRQ_NONE;
> -     u32 reg_iflag2, reg_esr;
> +     u32 reg_tx_iflag, tx_iflag_idx, reg_esr;
> +     void __iomem *reg_iflag;
>       enum can_state last_state = priv->can.state;
> 
>       /* reception interrupt */
> @@ -870,10 +879,18 @@ static irqreturn_t flexcan_irq(int irq, void *dev_id)
>               }
>       }
> 
> -     reg_iflag2 = priv->read(&regs->iflag2);
> +     if (priv->tx_mb_idx >= FLEXCAN_IFLAG1_MB_NUM) {
> +             reg_tx_iflag = priv->read(&regs->iflag2);
> +             tx_iflag_idx = FLEXCAN_IFLAG2_MB(priv->tx_mb_idx);
> +             reg_iflag = &regs->iflag2;
> +     } else {
> +             reg_tx_iflag = priv->read(&regs->iflag1);
> +             tx_iflag_idx = FLEXCAN_IFLAG1_MB(priv->tx_mb_idx);
> +             reg_iflag = &regs->iflag1;
> +     }
> 
>       /* transmission complete interrupt */
> -     if (reg_iflag2 & FLEXCAN_IFLAG_MB(priv->tx_mb_idx)) {
> +     if (reg_tx_iflag & tx_iflag_idx) {
>               u32 reg_ctrl = priv->read(&priv->tx_mb->can_ctrl);
> 
>               handled = IRQ_HANDLED;
> @@ -885,7 +902,7 @@ static irqreturn_t flexcan_irq(int irq, void *dev_id)
>               /* after sending a RTR frame MB is in RX mode */
>               priv->write(FLEXCAN_MB_CODE_TX_INACTIVE,
>                           &priv->tx_mb->can_ctrl);
> -             priv->write(FLEXCAN_IFLAG_MB(priv->tx_mb_idx), &regs->iflag2);
> +             priv->write(tx_iflag_idx, reg_iflag);
>               netif_wake_queue(dev);
>       }
> 
> @@ -1244,8 +1261,13 @@ static int flexcan_open(struct net_device *dev)
>       priv->tx_mb_idx = priv->mb_count - 1;
>       priv->tx_mb = flexcan_get_mb(priv, priv->tx_mb_idx);
> 
> -     priv->reg_imask1_default = 0;
> -     priv->reg_imask2_default = FLEXCAN_IFLAG_MB(priv->tx_mb_idx);
> +     if (priv->tx_mb_idx >= FLEXCAN_IFLAG1_MB_NUM) {
> +             priv->reg_imask1_default = 0;
> +             priv->reg_imask2_default = FLEXCAN_IFLAG2_MB(priv->tx_mb_idx);
> +     } else {
> +             priv->reg_imask1_default = FLEXCAN_IFLAG1_MB(priv->tx_mb_idx);
> +             priv->reg_imask2_default = 0;
> +     }
> 
>       priv->offload.mailbox_read = flexcan_mailbox_read;
> 
> --
> 2.17.1