[PATCH 0/3] can: flexcan: add imx8qm support

[PATCH 0/3] can: flexcan: add imx8qm support

[Joakim Zhang]

This patch set intends to add Flexcan support for i.MX8QM platform which
defaultly supports CAN FD protocol. Although BRS enabled by system reset
when the driver sets CAN FD mode, now this patch serial does not support
BRS in the driver. And then I will send patch to enable BRS by changing the
register to set bit timing.

Dong Aisheng (3):
  can: rx-offload: add CANFD support based on offload
  can: flexcan: add CAN FD mode support
  can: flexcan: add imx8qm support

 drivers/net/can/flexcan.c      | 114 ++++++++++++++++++++++++++++++---
 drivers/net/can/rx-offload.c   |  16 +++--
 include/linux/can/rx-offload.h |   4 +-
 3 files changed, 117 insertions(+), 17 deletions(-)

-- 
2.17.1

[PATCH 1/3] can: rx-offload: add CANFD support based on offload

[Joakim Zhang]

From: Dong Aisheng <aisheng.dong@nxp.com>

Using struct canfd_frame instead of can_frame to add support for CAN FD
mode in offload. FlexCAN controller will set the is_canfd variable when
it supports CAN FD mode.

Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
---
 drivers/net/can/rx-offload.c   | 16 ++++++++++------
 include/linux/can/rx-offload.h |  4 +++-
 2 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/drivers/net/can/rx-offload.c b/drivers/net/can/rx-offload.c
index 2ce4fa8698c7..131fe600deb3 100644
--- a/drivers/net/can/rx-offload.c
+++ b/drivers/net/can/rx-offload.c
@@ -55,11 +55,11 @@ static int can_rx_offload_napi_poll(struct napi_struct *napi, int quota)
 
 	while ((work_done < quota) &&
 	       (skb = skb_dequeue(&offload->skb_queue))) {
-		struct can_frame *cf = (struct can_frame *)skb->data;
+		struct canfd_frame *cf = (struct canfd_frame *)skb->data;
 
 		work_done++;
 		stats->rx_packets++;
-		stats->rx_bytes += cf->can_dlc;
+		stats->rx_bytes += cf->len;
 		netif_receive_skb(skb);
 	}
 
@@ -122,16 +122,20 @@ static struct sk_buff *can_rx_offload_offload_one(struct can_rx_offload *offload
 {
 	struct sk_buff *skb = NULL;
 	struct can_rx_offload_cb *cb;
-	struct can_frame *cf;
+	struct canfd_frame *cf;
 	int ret;
 
 	/* If queue is full or skb not available, read to discard mailbox */
 	if (likely(skb_queue_len(&offload->skb_queue) <=
-		   offload->skb_queue_len_max))
-		skb = alloc_can_skb(offload->dev, &cf);
+		   offload->skb_queue_len_max)) {
+		if (offload->is_canfd)
+			skb = alloc_canfd_skb(offload->dev, &cf);
+		else
+			skb = alloc_can_skb(offload->dev, (struct can_frame **)&cf);
+	}
 
 	if (!skb) {
-		struct can_frame cf_overflow;
+		struct canfd_frame cf_overflow;
 		u32 timestamp;
 
 		ret = offload->mailbox_read(offload, &cf_overflow,
diff --git a/include/linux/can/rx-offload.h b/include/linux/can/rx-offload.h
index 8268811a697e..6448e7dfc170 100644
--- a/include/linux/can/rx-offload.h
+++ b/include/linux/can/rx-offload.h
@@ -23,7 +23,7 @@
 struct can_rx_offload {
 	struct net_device *dev;
 
-	unsigned int (*mailbox_read)(struct can_rx_offload *offload, struct can_frame *cf,
+	unsigned int (*mailbox_read)(struct can_rx_offload *offload, struct canfd_frame *cf,
 				     u32 *timestamp, unsigned int mb);
 
 	struct sk_buff_head skb_queue;
@@ -35,6 +35,8 @@ struct can_rx_offload {
 	struct napi_struct napi;
 
 	bool inc;
+
+	bool is_canfd;
 };
 
 int can_rx_offload_add_timestamp(struct net_device *dev, struct can_rx_offload *offload);
-- 
2.17.1

[PATCH 2/3] can: flexcan: add CAN FD mode support

[Joakim Zhang]

From: Dong Aisheng <aisheng.dong@nxp.com>

This patch intends to add CAN FD mode support in driver, it means that
payload size can extend up to 64 bytes.

NOTE: Bit rate switch (BRS) enabled by system reset when it enables CAN
FD mode. So CAN hardware has support BRS, but now driver has not support
it due to bit timing must set in CBT register other than CTRL1 register.

Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
---
 drivers/net/can/flexcan.c | 107 ++++++++++++++++++++++++++++++++++----
 1 file changed, 97 insertions(+), 10 deletions(-)

diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
index 0f36eafe3ac1..0fc77d4e8ade 100644
--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c
@@ -51,6 +51,7 @@
 #define FLEXCAN_MCR_IRMQ		BIT(16)
 #define FLEXCAN_MCR_LPRIO_EN		BIT(13)
 #define FLEXCAN_MCR_AEN			BIT(12)
+#define FLEXCAN_MCR_FDEN		BIT(11)
 /* MCR_MAXMB: maximum used MBs is MAXMB + 1 */
 #define FLEXCAN_MCR_MAXMB(x)		((x) & 0x7f)
 #define FLEXCAN_MCR_IDAM_A		(0x0 << 8)
@@ -136,6 +137,19 @@
 	 FLEXCAN_ESR_BOFF_INT | FLEXCAN_ESR_ERR_INT | \
 	 FLEXCAN_ESR_WAK_INT)
 
+/* FLEXCAN FD control register (FDCTRL) bits */
+#define FLEXCAN_FDCTRL_MBDSR3(x)	(((x) & 0x3) << 25)
+#define FLEXCAN_FDCTRL_MBDSR2(x)	(((x) & 0x3) << 22)
+#define FLEXCAN_FDCTRL_MBDSR1(x)	(((x) & 0x3) << 19)
+#define FLEXCAN_FDCTRL_MBDSR0(x)	(((x) & 0x3) << 16)
+
+/* FLEXCAN FD Bit Timing register (FDCBT) bits */
+#define FLEXCAN_FDCBT_FPRESDIV(x)	(((x) & 0x3ff) << 20)
+#define FLEXCAN_FDCBT_FRJW(x)		(((x) & 0x07) << 16)
+#define FLEXCAN_FDCBT_FPROPSEG(x)	(((x) & 0x1f) << 10)
+#define FLEXCAN_FDCBT_FPSEG1(x)		(((x) & 0x07) << 5)
+#define FLEXCAN_FDCBT_FPSEG2(x)		((x) & 0x07)
+
 /* FLEXCAN interrupt flag register (IFLAG) bits */
 /* Errata ERR005829 step7: Reserve first valid MB */
 #define FLEXCAN_TX_MB_RESERVED_OFF_FIFO		8
@@ -147,6 +161,10 @@
 #define FLEXCAN_IFLAG_RX_FIFO_AVAILABLE	BIT(5)
 
 /* FLEXCAN message buffers */
+#define FLEXCAN_MB_CNT_EDL		BIT(31)
+#define FLEXCAN_MB_CNT_BRS		BIT(30)
+#define FLEXCAN_MB_CNT_ESI		BIT(29)
+
 #define FLEXCAN_MB_CODE_MASK		(0xf << 24)
 #define FLEXCAN_MB_CODE_RX_BUSY_BIT	(0x1 << 24)
 #define FLEXCAN_MB_CODE_RX_INACTIVE	(0x0 << 24)
@@ -191,6 +209,7 @@
 #define FLEXCAN_QUIRK_BROKEN_PERR_STATE	BIT(6) /* No interrupt for error passive */
 #define FLEXCAN_QUIRK_DEFAULT_BIG_ENDIAN	BIT(7) /* default to BE register access */
 #define FLEXCAN_QUIRK_SETUP_STOP_MODE		BIT(8) /* Setup stop mode to support wakeup */
+#define FLEXCAN_QUIRK_TIMESTAMP_SUPPORT_FD	BIT(9) /* Use timestamp then support can fd mode */
 
 /* Structure of the message buffer */
 struct flexcan_mb {
@@ -249,6 +268,9 @@ struct flexcan_regs {
 	u32 rerrdr;		/* 0xaf4 */
 	u32 rerrsynr;		/* 0xaf8 */
 	u32 errsr;		/* 0xafc */
+	u32 _reserved7[64];     /* 0xb00 */
+	u32 fdctrl;             /* 0xc00 */
+	u32 fdcbt;              /* 0xc04 */
 };
 
 struct flexcan_devtype_data {
@@ -333,6 +355,18 @@ static const struct can_bittiming_const flexcan_bittiming_const = {
 	.brp_inc = 1,
 };
 
+static const struct can_bittiming_const flexcan_fd_data_bittiming_const = {
+	.name = DRV_NAME,
+	.tseg1_min = 1,
+	.tseg1_max = 39,
+	.tseg2_min = 1,
+	.tseg2_max = 8,
+	.sjw_max = 8,
+	.brp_min = 1,
+	.brp_max = 1024,
+	.brp_inc = 1,
+};
+
 /* FlexCAN module is essentially modelled as a little-endian IP in most
  * SoCs, i.e the registers as well as the message buffer areas are
  * implemented in a little-endian fashion.
@@ -590,10 +624,10 @@ static int flexcan_get_berr_counter(const struct net_device *dev,
 static netdev_tx_t flexcan_start_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	const struct flexcan_priv *priv = netdev_priv(dev);
-	struct can_frame *cf = (struct can_frame *)skb->data;
+	struct canfd_frame *cf = (struct canfd_frame *)skb->data;
 	u32 can_id;
 	u32 data;
-	u32 ctrl = FLEXCAN_MB_CODE_TX_DATA | (cf->can_dlc << 16);
+	u32 ctrl = FLEXCAN_MB_CODE_TX_DATA | ((can_len2dlc(cf->len)) << 16);
 	int i;
 
 	if (can_dropped_invalid_skb(dev, skb))
@@ -611,7 +645,10 @@ static netdev_tx_t flexcan_start_xmit(struct sk_buff *skb, struct net_device *de
 	if (cf->can_id & CAN_RTR_FLAG)
 		ctrl |= FLEXCAN_MB_CNT_RTR;
 
-	for (i = 0; i < cf->can_dlc; i += sizeof(u32)) {
+	if (can_is_canfd_skb(skb))
+		ctrl |= FLEXCAN_MB_CNT_EDL;
+
+	for (i = 0; i < cf->len; i += sizeof(u32)) {
 		data = be32_to_cpup((__be32 *)&cf->data[i]);
 		priv->write(data, &priv->tx_mb->data[i / sizeof(u32)]);
 	}
@@ -741,7 +778,7 @@ static inline struct flexcan_priv *rx_offload_to_priv(struct can_rx_offload *off
 }
 
 static unsigned int flexcan_mailbox_read(struct can_rx_offload *offload,
-					 struct can_frame *cf,
+					 struct canfd_frame *cf,
 					 u32 *timestamp, unsigned int n)
 {
 	struct flexcan_priv *priv = rx_offload_to_priv(offload);
@@ -787,11 +824,21 @@ static unsigned int flexcan_mailbox_read(struct can_rx_offload *offload,
 	else
 		cf->can_id = (reg_id >> 18) & CAN_SFF_MASK;
 
-	if (reg_ctrl & FLEXCAN_MB_CNT_RTR)
-		cf->can_id |= CAN_RTR_FLAG;
-	cf->can_dlc = get_can_dlc((reg_ctrl >> 16) & 0xf);
+	if (reg_ctrl & FLEXCAN_MB_CNT_EDL) {
+		cf->len = can_dlc2len((reg_ctrl >> 16) & 0x0F);
+	} else {
+		cf->len = get_can_dlc((reg_ctrl >> 16) & 0x0F);
+
+		if (reg_ctrl & FLEXCAN_MB_CNT_RTR)
+			cf->can_id |= CAN_RTR_FLAG;
+	}
+
+	if (reg_ctrl & FLEXCAN_MB_CNT_ESI) {
+		cf->flags |= CANFD_ESI;
+		netdev_warn(priv->can.dev, "ESI Error\n");
+	}
 
-	for (i = 0; i < cf->can_dlc; i += sizeof(u32)) {
+	for (i = 0; i < cf->len; i += sizeof(u32)) {
 		__be32 data = cpu_to_be32(priv->read(&mb->data[i / sizeof(u32)]));
 		*(__be32 *)(cf->data + i) = data;
 	}
@@ -953,6 +1000,7 @@ static void flexcan_set_bittiming(struct net_device *dev)
 {
 	const struct flexcan_priv *priv = netdev_priv(dev);
 	const struct can_bittiming *bt = &priv->can.bittiming;
+	const struct can_bittiming *dbt = &priv->can.data_bittiming;
 	struct flexcan_regs __iomem *regs = priv->regs;
 	u32 reg;
 
@@ -982,6 +1030,15 @@ static void flexcan_set_bittiming(struct net_device *dev)
 	netdev_dbg(dev, "writing ctrl=0x%08x\n", reg);
 	priv->write(reg, &regs->ctrl);
 
+	if (priv->can.ctrlmode & CAN_CTRLMODE_FD) {
+		reg = FLEXCAN_FDCBT_FPRESDIV(dbt->brp - 1) |
+			FLEXCAN_FDCBT_FPSEG1(dbt->phase_seg1 - 1) |
+			FLEXCAN_FDCBT_FPSEG2(dbt->phase_seg2 - 1) |
+			FLEXCAN_FDCBT_FRJW(dbt->sjw - 1) |
+			FLEXCAN_FDCBT_FPROPSEG(dbt->prop_seg);
+		priv->write(reg, &regs->fdcbt);
+	}
+
 	/* print chip status */
 	netdev_dbg(dev, "%s: mcr=0x%08x ctrl=0x%08x\n", __func__,
 		   priv->read(&regs->mcr), priv->read(&regs->ctrl));
@@ -996,7 +1053,7 @@ static int flexcan_chip_start(struct net_device *dev)
 {
 	struct flexcan_priv *priv = netdev_priv(dev);
 	struct flexcan_regs __iomem *regs = priv->regs;
-	u32 reg_mcr, reg_ctrl, reg_ctrl2, reg_mecr;
+	u32 reg_mcr, reg_ctrl, reg_ctrl2, reg_mecr, reg_fdctrl;
 	int err, i;
 	struct flexcan_mb __iomem *mb;
 
@@ -1092,6 +1149,21 @@ static int flexcan_chip_start(struct net_device *dev)
 	netdev_dbg(dev, "%s: writing ctrl=0x%08x", __func__, reg_ctrl);
 	priv->write(reg_ctrl, &regs->ctrl);
 
+	/* FDCTRL
+	 *
+	 * BRS enabled by system reset when enable CAN FD mode
+	 * 64 bytes payload per MB and 7 MBs per RAM block by default
+	 * enable CAN FD mode
+	 */
+	if (priv->can.ctrlmode & CAN_CTRLMODE_FD) {
+		reg_fdctrl = priv->read(&regs->fdctrl);
+		reg_fdctrl |= FLEXCAN_FDCTRL_MBDSR3(3) | FLEXCAN_FDCTRL_MBDSR2(3) |
+				FLEXCAN_FDCTRL_MBDSR1(3) | FLEXCAN_FDCTRL_MBDSR0(3);
+		priv->write(reg_fdctrl, &regs->fdctrl);
+		reg_mcr = priv->read(&regs->mcr);
+		priv->write(reg_mcr | FLEXCAN_MCR_FDEN, &regs->mcr);
+	}
+
 	if ((priv->devtype_data->quirks & FLEXCAN_QUIRK_ENABLE_EACEN_RRS)) {
 		reg_ctrl2 = priv->read(&regs->ctrl2);
 		reg_ctrl2 |= FLEXCAN_CTRL2_EACEN | FLEXCAN_CTRL2_RRS;
@@ -1231,7 +1303,10 @@ static int flexcan_open(struct net_device *dev)
 	if (err)
 		goto out_close;
 
-	priv->mb_size = sizeof(struct flexcan_mb) + CAN_MAX_DLEN;
+	if (priv->can.ctrlmode & CAN_CTRLMODE_FD)
+		priv->mb_size = sizeof(struct flexcan_mb) + CANFD_MAX_DLEN;
+	else
+		priv->mb_size = sizeof(struct flexcan_mb) + CAN_MAX_DLEN;
 	priv->mb_count = (sizeof(priv->regs->mb[0]) / priv->mb_size) +
 			 (sizeof(priv->regs->mb[1]) / priv->mb_size);
 
@@ -1568,6 +1643,18 @@ static int flexcan_probe(struct platform_device *pdev)
 	priv->clk_per = clk_per;
 	priv->devtype_data = devtype_data;
 	priv->reg_xceiver = reg_xceiver;
+	priv->offload.is_canfd = false;
+
+	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_TIMESTAMP_SUPPORT_FD) {
+		if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
+			priv->offload.is_canfd = true;
+			priv->can.ctrlmode_supported |= CAN_CTRLMODE_FD;
+			priv->can.data_bittiming_const = &flexcan_fd_data_bittiming_const;
+		} else {
+			dev_err(&pdev->dev, "canfd mode can't work on fifo mode\n");
+			err = -EINVAL;
+		}
+	}
 
 	err = register_flexcandev(dev);
 	if (err) {
-- 
2.17.1

[PATCH 3/3] can: flexcan: add imx8qm support

[Joakim Zhang]

From: Dong Aisheng <aisheng.dong@nxp.com>

The Flexcan on i.MX8QM supports CAN FD protocol.

Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
---
 drivers/net/can/flexcan.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
index 0fc77d4e8ade..b7ab6ed87344 100644
--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c
@@ -331,6 +331,12 @@ static const struct flexcan_devtype_data fsl_imx6q_devtype_data = {
 		FLEXCAN_QUIRK_SETUP_STOP_MODE,
 };
 
+static struct flexcan_devtype_data fsl_imx8qm_devtype_data = {
+	.quirks = FLEXCAN_QUIRK_DISABLE_RXFG | FLEXCAN_QUIRK_ENABLE_EACEN_RRS |
+		FLEXCAN_QUIRK_USE_OFF_TIMESTAMP | FLEXCAN_QUIRK_BROKEN_PERR_STATE |
+		FLEXCAN_QUIRK_TIMESTAMP_SUPPORT_FD,
+};
+
 static const struct flexcan_devtype_data fsl_vf610_devtype_data = {
 	.quirks = FLEXCAN_QUIRK_DISABLE_RXFG | FLEXCAN_QUIRK_ENABLE_EACEN_RRS |
 		FLEXCAN_QUIRK_DISABLE_MECR | FLEXCAN_QUIRK_USE_OFF_TIMESTAMP |
@@ -1534,6 +1540,7 @@ static int flexcan_setup_stop_mode(struct platform_device *pdev)
 }
 
 static const struct of_device_id flexcan_of_match[] = {
+	{ .compatible = "fsl,imx8qm-flexcan", .data = &fsl_imx8qm_devtype_data, },
 	{ .compatible = "fsl,imx6q-flexcan", .data = &fsl_imx6q_devtype_data, },
 	{ .compatible = "fsl,imx28-flexcan", .data = &fsl_imx28_devtype_data, },
 	{ .compatible = "fsl,imx53-flexcan", .data = &fsl_imx25_devtype_data, },
-- 
2.17.1

RE: [PATCH 0/3] can: flexcan: add imx8qm support

[Joakim Zhang]

Kindly Ping...

Best Regards,
Joakim Zhang

> -----Original Message-----
> From: Joakim Zhang
> Sent: 2018年12月19日 16:39
> To: mkl@pengutronix.de; linux-can@vger.kernel.org
> Cc: wg@grandegger.com; netdev@vger.kernel.org;
> linux-kernel@vger.kernel.org; dl-linux-imx <linux-imx@nxp.com>; Joakim
> Zhang <qiangqing.zhang@nxp.com>
> Subject: [PATCH 0/3] can: flexcan: add imx8qm support
> 
> This patch set intends to add Flexcan support for i.MX8QM platform which
> defaultly supports CAN FD protocol. Although BRS enabled by system reset
> when the driver sets CAN FD mode, now this patch serial does not support BRS
> in the driver. And then I will send patch to enable BRS by changing the register
> to set bit timing.
> 
> Dong Aisheng (3):
>   can: rx-offload: add CANFD support based on offload
>   can: flexcan: add CAN FD mode support
>   can: flexcan: add imx8qm support
> 
>  drivers/net/can/flexcan.c      | 114 ++++++++++++++++++++++++++++++---
>  drivers/net/can/rx-offload.c   |  16 +++--
>  include/linux/can/rx-offload.h |   4 +-
>  3 files changed, 117 insertions(+), 17 deletions(-)
> 
> --
> 2.17.1

RE: [PATCH 0/3] can: flexcan: add imx8qm support

[Joakim Zhang]

Kindly Ping...

Best Regards,
Joakim Zhang

> -----Original Message-----
> From: Joakim Zhang
> Sent: 2019年1月17日 14:28
> To: mkl@pengutronix.de; linux-can@vger.kernel.org
> Cc: wg@grandegger.com; netdev@vger.kernel.org;
> linux-kernel@vger.kernel.org; dl-linux-imx <linux-imx@nxp.com>
> Subject: RE: [PATCH 0/3] can: flexcan: add imx8qm support
> 
> 
> Kindly Ping...
> 
> Best Regards,
> Joakim Zhang
> 
> > -----Original Message-----
> > From: Joakim Zhang
> > Sent: 2018年12月19日 16:39
> > To: mkl@pengutronix.de; linux-can@vger.kernel.org
> > Cc: wg@grandegger.com; netdev@vger.kernel.org;
> > linux-kernel@vger.kernel.org; dl-linux-imx <linux-imx@nxp.com>; Joakim
> > Zhang <qiangqing.zhang@nxp.com>
> > Subject: [PATCH 0/3] can: flexcan: add imx8qm support
> >
> > This patch set intends to add Flexcan support for i.MX8QM platform
> > which defaultly supports CAN FD protocol. Although BRS enabled by
> > system reset when the driver sets CAN FD mode, now this patch serial
> > does not support BRS in the driver. And then I will send patch to
> > enable BRS by changing the register to set bit timing.
> >
> > Dong Aisheng (3):
> >   can: rx-offload: add CANFD support based on offload
> >   can: flexcan: add CAN FD mode support
> >   can: flexcan: add imx8qm support
> >
> >  drivers/net/can/flexcan.c      | 114
> ++++++++++++++++++++++++++++++---
> >  drivers/net/can/rx-offload.c   |  16 +++--
> >  include/linux/can/rx-offload.h |   4 +-
> >  3 files changed, 117 insertions(+), 17 deletions(-)
> >
> > --
> > 2.17.1