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* [PATCH v3] can: mcba_usb: Add support for Microchip CAN BUS Analyzer
@ 2017-01-25 13:02 Remigiusz Kołłątaj
  2017-02-20 10:22 ` Kołłątaj, Remigiusz
  2017-04-13 15:56 ` Marc Kleine-Budde
  0 siblings, 2 replies; 8+ messages in thread
From: Remigiusz Kołłątaj @ 2017-01-25 13:02 UTC (permalink / raw)
  To: linux-can; +Cc: remigiusz.kollataj

SocketCAN driver for Microchip CAN BUS Analyzer
(http://www.microchip.com/development-tools/)

Changes since v2:
- improved/simplified CAN ID conversion
- functions for transmission of skb and cmd separated
- fixed/improved netif_stop_queue handling
- style/cosmetic corrections

Changes since v1:
- Termination handling reimplemented to fit new netlink API
(IFLA_CAN_TERMINATION)
- Bitrate handling reimplemented to fit new netlink API
(IFLA_CAN_BITRATE)
- CAN ID conversion refactored (changed from macro to inline functions)
- CAN DLC handling using get_can_dlc()
- Endianness handling for can_speed introduced
- Debugging removed
- Redundant error prints removed
- Style/cosmetic corrections (i.e. macro names, redefs, inits etc.)

Signed-off-by: Remigiusz Kołłątaj <remigiusz.kollataj@mobica.com>
---
 drivers/net/can/usb/Kconfig    |   6 +
 drivers/net/can/usb/Makefile   |   1 +
 drivers/net/can/usb/mcba_usb.c | 894 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 901 insertions(+)
 create mode 100644 drivers/net/can/usb/mcba_usb.c

diff --git a/drivers/net/can/usb/Kconfig b/drivers/net/can/usb/Kconfig
index 8483a40e7e9e..2d0313eb31c0 100644
--- a/drivers/net/can/usb/Kconfig
+++ b/drivers/net/can/usb/Kconfig
@@ -81,4 +81,10 @@ config CAN_8DEV_USB
 	  This driver supports the USB2CAN interface
 	  from 8 devices (http://www.8devices.com).
 
+config CAN_MCBA_USB
+	tristate "Microchip CAN BUS Analyzer interface"
+	---help---
+	  This driver supports the CAN BUS Analyzer interface
+	  from Microchip (http://www.microchip.com/development-tools/).
+
 endmenu
diff --git a/drivers/net/can/usb/Makefile b/drivers/net/can/usb/Makefile
index a64cf983fb87..164453fd55d0 100644
--- a/drivers/net/can/usb/Makefile
+++ b/drivers/net/can/usb/Makefile
@@ -8,3 +8,4 @@ obj-$(CONFIG_CAN_GS_USB) += gs_usb.o
 obj-$(CONFIG_CAN_KVASER_USB) += kvaser_usb.o
 obj-$(CONFIG_CAN_PEAK_USB) += peak_usb/
 obj-$(CONFIG_CAN_8DEV_USB) += usb_8dev.o
+obj-$(CONFIG_CAN_MCBA_USB) += mcba_usb.o
diff --git a/drivers/net/can/usb/mcba_usb.c b/drivers/net/can/usb/mcba_usb.c
new file mode 100644
index 000000000000..2c92f3903034
--- /dev/null
+++ b/drivers/net/can/usb/mcba_usb.c
@@ -0,0 +1,894 @@
+/* SocketCAN driver for Microchip CAN BUS Analyzer Tool
+ *
+ * Copyright (C) 2017 Mobica Limited
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published
+ * by the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program.
+ *
+ * This driver is inspired by the 4.6.2 version of net/can/usb/usb_8dev.c
+ */
+
+#include <asm/unaligned.h>
+#include <linux/can.h>
+#include <linux/can/dev.h>
+#include <linux/can/error.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/signal.h>
+#include <linux/slab.h>
+#include <linux/usb.h>
+
+/* vendor and product id */
+#define MCBA_MODULE_NAME "mcba_usb"
+#define MCBA_VENDOR_ID 0x04d8
+#define MCBA_PRODUCT_ID 0x0a30
+
+/* driver constants */
+#define MCBA_MAX_RX_URBS 20
+#define MCBA_MAX_TX_URBS 20
+#define MCBA_CTX_FREE MCBA_MAX_TX_URBS
+
+/* RX buffer must be bigger than msg size since at the
+ * beggining USB messages are stacked.
+ */
+#define MCBA_USB_RX_BUFF_SIZE 64
+#define MCBA_USB_TX_BUFF_SIZE (sizeof(struct mcba_usb_msg))
+
+/* MCBA endpoint numbers */
+#define MCBA_USB_EP_IN 1
+#define MCBA_USB_EP_OUT 1
+
+/* Microchip command id */
+#define MBCA_CMD_RECEIVE_MESSAGE 0xE3
+#define MBCA_CMD_I_AM_ALIVE_FROM_CAN 0xF5
+#define MBCA_CMD_I_AM_ALIVE_FROM_USB 0xF7
+#define MBCA_CMD_CHANGE_BIT_RATE 0xA1
+#define MBCA_CMD_TRANSMIT_MESSAGE_EV 0xA3
+#define MBCA_CMD_SETUP_TERMINATION_RESISTANCE 0xA8
+#define MBCA_CMD_READ_FW_VERSION 0xA9
+#define MBCA_CMD_NOTHING_TO_SEND 0xFF
+#define MBCA_CMD_TRANSMIT_MESSAGE_RSP 0xE2
+
+#define MCBA_VER_REQ_USB 1
+#define MCBA_VER_REQ_CAN 2
+
+#define MCBA_SIDL_EXID_MASK 0x8
+#define MCBA_DLC_MASK 0xf
+#define MCBA_DLC_RTR_MASK 0x40
+
+#define MCBA_CAN_STATE_WRN_TH 95
+#define MCBA_CAN_STATE_ERR_PSV_TH 127
+
+#define MCBA_TERMINATION_DISABLED CAN_TERMINATION_DISABLED
+#define MCBA_TERMINATION_ENABLED 120
+
+struct mcba_usb_ctx {
+	struct mcba_priv *priv;
+	u32 ndx;
+	u8 dlc;
+	bool can;
+};
+
+/* Structure to hold all of our device specific stuff */
+struct mcba_priv {
+	struct can_priv can; /* must be the first member */
+	struct sk_buff *echo_skb[MCBA_MAX_TX_URBS];
+	struct mcba_usb_ctx tx_context[MCBA_MAX_TX_URBS];
+	struct usb_device *udev;
+	struct net_device *netdev;
+	struct usb_anchor tx_submitted;
+	struct usb_anchor rx_submitted;
+	struct can_berr_counter bec;
+	bool usb_ka_first_pass;
+	bool can_ka_first_pass;
+	bool can_speed_check;
+	atomic_t free_ctx_cnt;
+};
+
+/* CAN frame */
+struct __packed mcba_usb_msg_can {
+	u8 cmd_id;
+	__be16 eid;
+	__be16 sid;
+	u8 dlc;
+	u8 data[8];
+	u8 timestamp[4];
+	u8 checksum;
+};
+
+/* command frame */
+struct __packed mcba_usb_msg {
+	u8 cmd_id;
+	u8 unused[18];
+};
+
+struct __packed mcba_usb_msg_ka_usb {
+	u8 cmd_id;
+	u8 termination_state;
+	u8 soft_ver_major;
+	u8 soft_ver_minor;
+	u8 unused[15];
+};
+
+struct __packed mcba_usb_msg_ka_can {
+	u8 cmd_id;
+	u8 tx_err_cnt;
+	u8 rx_err_cnt;
+	u8 rx_buff_ovfl;
+	u8 tx_bus_off;
+	__be16 can_bitrate;
+	__le16 rx_lost;
+	u8 can_stat;
+	u8 soft_ver_major;
+	u8 soft_ver_minor;
+	u8 debug_mode;
+	u8 test_complete;
+	u8 test_result;
+	u8 unused[4];
+};
+
+struct __packed mcba_usb_msg_change_bitrate {
+	u8 cmd_id;
+	__be16 bitrate;
+	u8 unused[16];
+};
+
+struct __packed mcba_usb_msg_termination {
+	u8 cmd_id;
+	u8 termination;
+	u8 unused[17];
+};
+
+struct __packed mcba_usb_msg_fw_ver {
+	u8 cmd_id;
+	u8 pic;
+	u8 unused[17];
+};
+
+static const struct usb_device_id mcba_usb_table[] = {
+	{ USB_DEVICE(MCBA_VENDOR_ID, MCBA_PRODUCT_ID) },
+	{} /* Terminating entry */
+};
+
+MODULE_DEVICE_TABLE(usb, mcba_usb_table);
+
+static const u16 mcba_termination[] = { MCBA_TERMINATION_DISABLED,
+					MCBA_TERMINATION_ENABLED };
+
+static const u32 mcba_bitrate[] = { 20000,  33333,  50000,  80000,  83333,
+				    100000, 125000, 150000, 175000, 200000,
+				    225000, 250000, 275000, 300000, 500000,
+				    625000, 800000, 1000000 };
+
+static inline void mcba_init_ctx(struct mcba_priv *priv)
+{
+	int i = 0;
+
+	for (i = 0; i < MCBA_MAX_TX_URBS; i++) {
+		priv->tx_context[i].ndx = MCBA_CTX_FREE;
+		priv->tx_context[i].priv = priv;
+	}
+
+	atomic_set(&priv->free_ctx_cnt, ARRAY_SIZE(priv->tx_context));
+}
+
+static inline struct mcba_usb_ctx *mcba_usb_get_free_ctx(struct mcba_priv *priv,
+							 struct can_frame *cf)
+{
+	int i = 0;
+	struct mcba_usb_ctx *ctx = NULL;
+
+	for (i = 0; i < MCBA_MAX_TX_URBS; i++) {
+		if (priv->tx_context[i].ndx == MCBA_CTX_FREE) {
+			ctx = &priv->tx_context[i];
+			ctx->ndx = i;
+
+			if (cf) {
+				ctx->can = true;
+				ctx->dlc = cf->can_dlc;
+			} else {
+				ctx->can = false;
+				ctx->dlc = 0;
+			}
+
+			atomic_dec(&priv->free_ctx_cnt);
+			break;
+		}
+	}
+
+	if (!atomic_read(&priv->free_ctx_cnt))
+		/* That was the last free ctx. Slow down tx path */
+		netif_stop_queue(priv->netdev);
+
+	return ctx;
+}
+
+/* mcba_usb_free_ctx and mcba_usb_get_free_ctx are executed by different
+ * threads. The order of execution in below function is important.
+ */
+static inline void mcba_usb_free_ctx(struct mcba_usb_ctx *ctx)
+{
+	/* Increase number of free ctxs before freeing ctx */
+	atomic_inc(&ctx->priv->free_ctx_cnt);
+
+	ctx->ndx = MCBA_CTX_FREE;
+
+	/* Wake up the queue once ctx is marked free */
+	netif_wake_queue(ctx->priv->netdev);
+}
+
+static void mcba_usb_write_bulk_callback(struct urb *urb)
+{
+	struct mcba_usb_ctx *ctx = urb->context;
+	struct net_device *netdev;
+
+	WARN_ON(!ctx);
+
+	netdev = ctx->priv->netdev;
+
+	if (ctx->can) {
+		if (!netif_device_present(netdev))
+			return;
+
+		netdev->stats.tx_packets++;
+		netdev->stats.tx_bytes += ctx->dlc;
+
+		can_get_echo_skb(netdev, ctx->ndx);
+	}
+
+	/* free up our allocated buffer */
+	usb_free_coherent(urb->dev, urb->transfer_buffer_length,
+			  urb->transfer_buffer, urb->transfer_dma);
+
+	if (urb->status)
+		netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status);
+
+	/* Release the context */
+	mcba_usb_free_ctx(ctx);
+}
+
+/* Send data to device */
+static netdev_tx_t mcba_usb_xmit(struct mcba_priv *priv,
+				 struct mcba_usb_msg *usb_msg,
+				 struct mcba_usb_ctx *ctx)
+{
+	struct urb *urb;
+	u8 *buf;
+	int err;
+
+	/* create a URB, and a buffer for it, and copy the data to the URB */
+	urb = usb_alloc_urb(0, GFP_ATOMIC);
+	if (!urb)
+		return -ENOMEM;
+
+	buf = usb_alloc_coherent(priv->udev, MCBA_USB_TX_BUFF_SIZE, GFP_ATOMIC,
+				 &urb->transfer_dma);
+	if (!buf) {
+		err = -ENOMEM;
+		goto nomembuf;
+	}
+
+	memcpy(buf, usb_msg, MCBA_USB_TX_BUFF_SIZE);
+
+	usb_fill_bulk_urb(urb, priv->udev,
+			  usb_sndbulkpipe(priv->udev, MCBA_USB_EP_OUT), buf,
+			  MCBA_USB_TX_BUFF_SIZE, mcba_usb_write_bulk_callback,
+			  ctx);
+
+	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
+	usb_anchor_urb(urb, &priv->tx_submitted);
+
+	err = usb_submit_urb(urb, GFP_ATOMIC);
+	if (unlikely(err))
+		goto failed;
+
+	/* Release our reference to this URB, the USB core will eventually free
+	 * it entirely.
+	 */
+	usb_free_urb(urb);
+
+	return 0;
+
+failed:
+	usb_unanchor_urb(urb);
+	usb_free_coherent(priv->udev, MCBA_USB_TX_BUFF_SIZE, buf,
+			  urb->transfer_dma);
+
+	if (err == -ENODEV)
+		netif_device_detach(priv->netdev);
+	else
+		netdev_warn(priv->netdev, "failed tx_urb %d\n", err);
+
+nomembuf:
+	usb_free_urb(urb);
+
+	return err;
+}
+
+/* Send data to device */
+static netdev_tx_t mcba_usb_start_xmit(struct sk_buff *skb,
+				       struct net_device *netdev)
+{
+	struct mcba_priv *priv = netdev_priv(netdev);
+	struct can_frame *cf = (struct can_frame *)skb->data;
+	struct mcba_usb_msg_can usb_msg;
+	struct mcba_usb_ctx *ctx = NULL;
+	struct net_device_stats *stats = &priv->netdev->stats;
+	u16 sid;
+	int err;
+
+	if (can_dropped_invalid_skb(netdev, skb))
+		return NETDEV_TX_OK;
+
+	ctx = mcba_usb_get_free_ctx(priv, cf);
+	if (!ctx)
+		return NETDEV_TX_BUSY;
+
+	can_put_echo_skb(skb, priv->netdev, ctx->ndx);
+
+	usb_msg.cmd_id = MBCA_CMD_TRANSMIT_MESSAGE_EV;
+	if (cf->can_id & CAN_EFF_FLAG) {
+		/* SIDH    | SIDL                 | EIDH   | EIDL
+		 * 28 - 21 | 20 19 18 x x x 17 16 | 15 - 8 | 7 - 0
+		 */
+		sid = MCBA_SIDL_EXID_MASK;
+		/* store 28-18 bits */
+		sid |= (cf->can_id & 0x1ffc0000) >> 13;
+		/* store 17-16 bits */
+		sid |= (cf->can_id & 0x30000) >> 16;
+		put_unaligned_be16(sid, &usb_msg.sid);
+
+		/* store 15-0 bits */
+		put_unaligned_be16(cf->can_id & 0xffff, &usb_msg.eid);
+	} else {
+		/* SIDH   | SIDL
+		 * 10 - 3 | 2 1 0 x x x x x
+		 */
+		put_unaligned_be16((cf->can_id & CAN_SFF_MASK) << 5,
+				   &usb_msg.sid);
+		usb_msg.eid = 0;
+	}
+
+	usb_msg.dlc = cf->can_dlc;
+
+	memcpy(usb_msg.data, cf->data, usb_msg.dlc);
+
+	if (cf->can_id & CAN_RTR_FLAG)
+		usb_msg.dlc |= MCBA_DLC_RTR_MASK;
+
+	err = mcba_usb_xmit(priv, (struct mcba_usb_msg *)&usb_msg, ctx);
+	if (err)
+		goto xmit_failed;
+
+	return NETDEV_TX_OK;
+
+xmit_failed:
+	can_free_echo_skb(priv->netdev, ctx->ndx);
+	mcba_usb_free_ctx(ctx);
+	dev_kfree_skb(skb);
+	stats->tx_dropped++;
+
+	return NETDEV_TX_OK;
+}
+
+/* Send cmd to device */
+static void mcba_usb_xmit_cmd(struct mcba_priv *priv,
+			      struct mcba_usb_msg *usb_msg)
+{
+	struct mcba_usb_ctx *ctx = NULL;
+	int err;
+
+	ctx = mcba_usb_get_free_ctx(priv, NULL);
+	if (!ctx) {
+		netdev_err(priv->netdev,
+			   "Lack of free ctx. Sending (%d) cmd aborted",
+			   usb_msg->cmd_id);
+
+		return;
+	}
+
+	err = mcba_usb_xmit(priv, usb_msg, ctx);
+	if (err)
+		netdev_err(priv->netdev, "Failed to send cmd (%d)",
+			   usb_msg->cmd_id);
+}
+
+static void mcba_usb_xmit_change_bitrate(struct mcba_priv *priv, u16 bitrate)
+{
+	struct mcba_usb_msg_change_bitrate usb_msg;
+
+	usb_msg.cmd_id = MBCA_CMD_CHANGE_BIT_RATE;
+	put_unaligned_be16(bitrate, &usb_msg.bitrate);
+
+	mcba_usb_xmit_cmd(priv, (struct mcba_usb_msg *)&usb_msg);
+}
+
+static void mcba_usb_xmit_read_fw_ver(struct mcba_priv *priv, u8 pic)
+{
+	struct mcba_usb_msg_fw_ver usb_msg;
+
+	usb_msg.cmd_id = MBCA_CMD_READ_FW_VERSION;
+	usb_msg.pic = pic;
+
+	mcba_usb_xmit_cmd(priv, (struct mcba_usb_msg *)&usb_msg);
+}
+
+static void mcba_usb_process_can(struct mcba_priv *priv,
+				 struct mcba_usb_msg_can *msg)
+{
+	struct can_frame *cf;
+	struct sk_buff *skb;
+	struct net_device_stats *stats = &priv->netdev->stats;
+	u16 sid;
+
+	skb = alloc_can_skb(priv->netdev, &cf);
+	if (!skb)
+		return;
+
+	sid = get_unaligned_be16(&msg->sid);
+
+	if (sid & MCBA_SIDL_EXID_MASK) {
+		/* SIDH    | SIDL                 | EIDH   | EIDL
+		 * 28 - 21 | 20 19 18 x x x 17 16 | 15 - 8 | 7 - 0
+		 */
+		cf->can_id = CAN_EFF_FLAG;
+
+		/* store 28-18 bits */
+		cf->can_id |= (sid & 0xffe0) << 13;
+		/* store 17-16 bits */
+		cf->can_id |= (sid & 3) << 16;
+		/* store 15-0 bits */
+		cf->can_id |= get_unaligned_be16(&msg->eid);
+	} else {
+		/* SIDH   | SIDL
+		 * 10 - 3 | 2 1 0 x x x x x
+		 */
+		cf->can_id = (sid & 0xffe0) >> 5;
+	}
+
+	if (msg->dlc & MCBA_DLC_RTR_MASK)
+		cf->can_id |= CAN_RTR_FLAG;
+
+	cf->can_dlc = get_can_dlc(msg->dlc & MCBA_DLC_MASK);
+
+	memcpy(cf->data, msg->data, cf->can_dlc);
+
+	stats->rx_packets++;
+	stats->rx_bytes += cf->can_dlc;
+
+	netif_rx(skb);
+}
+
+static void mcba_usb_process_ka_usb(struct mcba_priv *priv,
+				    struct mcba_usb_msg_ka_usb *msg)
+{
+	if (unlikely(priv->usb_ka_first_pass)) {
+		netdev_info(priv->netdev, "PIC USB version %hhu.%hhu\n",
+			    msg->soft_ver_major, msg->soft_ver_minor);
+
+		priv->usb_ka_first_pass = false;
+	}
+
+	if (msg->termination_state)
+		priv->can.termination = MCBA_TERMINATION_ENABLED;
+	else
+		priv->can.termination = MCBA_TERMINATION_DISABLED;
+}
+
+static u32 convert_can2host_bitrate(struct mcba_usb_msg_ka_can *msg)
+{
+	const u32 bitrate = get_unaligned_be16(&msg->can_bitrate);
+
+	if ((bitrate == 33) || (bitrate == 83))
+		return bitrate * 1000 + 333;
+	else
+		return bitrate * 1000;
+}
+
+static void mcba_usb_process_ka_can(struct mcba_priv *priv,
+				    struct mcba_usb_msg_ka_can *msg)
+{
+	if (unlikely(priv->can_ka_first_pass)) {
+		netdev_info(priv->netdev, "PIC CAN version %hhu.%hhu\n",
+			    msg->soft_ver_major, msg->soft_ver_minor);
+
+		priv->can_ka_first_pass = false;
+	}
+
+	if (unlikely(priv->can_speed_check)) {
+		const u32 bitrate = convert_can2host_bitrate(msg);
+
+		priv->can_speed_check = false;
+
+		if (bitrate != priv->can.bittiming.bitrate)
+			netdev_err(
+			    priv->netdev,
+			    "Wrong bitrate reported by the device (%u). Expected %u",
+			    bitrate, priv->can.bittiming.bitrate);
+	}
+
+	priv->bec.txerr = msg->tx_err_cnt;
+	priv->bec.rxerr = msg->rx_err_cnt;
+
+	if (msg->tx_bus_off)
+		priv->can.state = CAN_STATE_BUS_OFF;
+
+	else if ((priv->bec.txerr > MCBA_CAN_STATE_ERR_PSV_TH) ||
+		 (priv->bec.rxerr > MCBA_CAN_STATE_ERR_PSV_TH))
+		priv->can.state = CAN_STATE_ERROR_PASSIVE;
+
+	else if ((priv->bec.txerr > MCBA_CAN_STATE_WRN_TH) ||
+		 (priv->bec.rxerr > MCBA_CAN_STATE_WRN_TH))
+		priv->can.state = CAN_STATE_ERROR_WARNING;
+}
+
+static void mcba_usb_process_rx(struct mcba_priv *priv,
+				struct mcba_usb_msg *msg)
+{
+	switch (msg->cmd_id) {
+	case MBCA_CMD_I_AM_ALIVE_FROM_CAN:
+		mcba_usb_process_ka_can(priv,
+					(struct mcba_usb_msg_ka_can *)msg);
+		break;
+
+	case MBCA_CMD_I_AM_ALIVE_FROM_USB:
+		mcba_usb_process_ka_usb(priv,
+					(struct mcba_usb_msg_ka_usb *)msg);
+		break;
+
+	case MBCA_CMD_RECEIVE_MESSAGE:
+		mcba_usb_process_can(priv, (struct mcba_usb_msg_can *)msg);
+		break;
+
+	case MBCA_CMD_NOTHING_TO_SEND:
+		/* Side effect of communication between PIC_USB and PIC_CAN.
+		 * PIC_CAN is telling us that it has nothing to send
+		 */
+		break;
+
+	case MBCA_CMD_TRANSMIT_MESSAGE_RSP:
+		/* Transmission response from the device containing timestamp */
+		break;
+
+	default:
+		netdev_warn(priv->netdev, "Unsupported msg (0x%hhX)",
+			    msg->cmd_id);
+		break;
+	}
+}
+
+/* Callback for reading data from device
+ *
+ * Check urb status, call read function and resubmit urb read operation.
+ */
+static void mcba_usb_read_bulk_callback(struct urb *urb)
+{
+	struct mcba_priv *priv = urb->context;
+	struct net_device *netdev;
+	int retval;
+	int pos = 0;
+
+	netdev = priv->netdev;
+
+	if (!netif_device_present(netdev))
+		return;
+
+	switch (urb->status) {
+	case 0: /* success */
+		break;
+
+	case -ENOENT:
+	case -ESHUTDOWN:
+		return;
+
+	default:
+		netdev_info(netdev, "Rx URB aborted (%d)\n", urb->status);
+
+		goto resubmit_urb;
+	}
+
+	while (pos < urb->actual_length) {
+		struct mcba_usb_msg *msg;
+
+		if (pos + sizeof(struct mcba_usb_msg) > urb->actual_length) {
+			netdev_err(priv->netdev, "format error\n");
+			break;
+		}
+
+		msg = (struct mcba_usb_msg *)(urb->transfer_buffer + pos);
+		mcba_usb_process_rx(priv, msg);
+
+		pos += sizeof(struct mcba_usb_msg);
+	}
+
+resubmit_urb:
+
+	usb_fill_bulk_urb(urb, priv->udev,
+			  usb_rcvbulkpipe(priv->udev, MCBA_USB_EP_OUT),
+			  urb->transfer_buffer, MCBA_USB_RX_BUFF_SIZE,
+			  mcba_usb_read_bulk_callback, priv);
+
+	retval = usb_submit_urb(urb, GFP_ATOMIC);
+
+	if (retval == -ENODEV)
+		netif_device_detach(netdev);
+	else if (retval)
+		netdev_err(netdev, "failed resubmitting read bulk urb: %d\n",
+			   retval);
+}
+
+/* Start USB device */
+static int mcba_usb_start(struct mcba_priv *priv)
+{
+	struct net_device *netdev = priv->netdev;
+	int err, i;
+
+	mcba_init_ctx(priv);
+
+	for (i = 0; i < MCBA_MAX_RX_URBS; i++) {
+		struct urb *urb = NULL;
+		u8 *buf;
+
+		/* create a URB, and a buffer for it */
+		urb = usb_alloc_urb(0, GFP_KERNEL);
+		if (!urb) {
+			err = -ENOMEM;
+			break;
+		}
+
+		buf = usb_alloc_coherent(priv->udev, MCBA_USB_RX_BUFF_SIZE,
+					 GFP_KERNEL, &urb->transfer_dma);
+		if (!buf) {
+			netdev_err(netdev, "No memory left for USB buffer\n");
+			usb_free_urb(urb);
+			err = -ENOMEM;
+			break;
+		}
+
+		usb_fill_bulk_urb(urb, priv->udev,
+				  usb_rcvbulkpipe(priv->udev, MCBA_USB_EP_IN),
+				  buf, MCBA_USB_RX_BUFF_SIZE,
+				  mcba_usb_read_bulk_callback, priv);
+		urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
+		usb_anchor_urb(urb, &priv->rx_submitted);
+
+		err = usb_submit_urb(urb, GFP_KERNEL);
+		if (err) {
+			usb_unanchor_urb(urb);
+			usb_free_coherent(priv->udev, MCBA_USB_RX_BUFF_SIZE,
+					  buf, urb->transfer_dma);
+			usb_free_urb(urb);
+			break;
+		}
+
+		/* Drop reference, USB core will take care of freeing it */
+		usb_free_urb(urb);
+	}
+
+	/* Did we submit any URBs */
+	if (i == 0) {
+		netdev_warn(netdev, "couldn't setup read URBs\n");
+		return err;
+	}
+
+	/* Warn if we've couldn't transmit all the URBs */
+	if (i < MCBA_MAX_RX_URBS)
+		netdev_warn(netdev, "rx performance may be slow\n");
+
+	mcba_usb_xmit_read_fw_ver(priv, MCBA_VER_REQ_USB);
+	mcba_usb_xmit_read_fw_ver(priv, MCBA_VER_REQ_CAN);
+
+	return err;
+}
+
+/* Open USB device */
+static int mcba_usb_open(struct net_device *netdev)
+{
+	struct mcba_priv *priv = netdev_priv(netdev);
+	int err;
+
+	/* common open */
+	err = open_candev(netdev);
+	if (err)
+		return err;
+
+	priv->can_speed_check = true;
+	priv->can.state = CAN_STATE_ERROR_ACTIVE;
+
+	netif_start_queue(netdev);
+
+	return 0;
+}
+
+static void mcba_urb_unlink(struct mcba_priv *priv)
+{
+	usb_kill_anchored_urbs(&priv->rx_submitted);
+	usb_kill_anchored_urbs(&priv->tx_submitted);
+}
+
+/* Close USB device */
+static int mcba_usb_close(struct net_device *netdev)
+{
+	struct mcba_priv *priv = netdev_priv(netdev);
+
+	priv->can.state = CAN_STATE_STOPPED;
+
+	netif_stop_queue(netdev);
+
+	/* Stop polling */
+	mcba_urb_unlink(priv);
+
+	close_candev(netdev);
+
+	return 0;
+}
+
+/* Set network device mode
+ *
+ * Maybe we should leave this function empty, because the device
+ * set mode variable with open command.
+ */
+static int mcba_net_set_mode(struct net_device *netdev, enum can_mode mode)
+{
+	return 0;
+}
+
+static int mcba_net_get_berr_counter(const struct net_device *netdev,
+				     struct can_berr_counter *bec)
+{
+	struct mcba_priv *priv = netdev_priv(netdev);
+
+	bec->txerr = priv->bec.txerr;
+	bec->rxerr = priv->bec.rxerr;
+
+	return 0;
+}
+
+static const struct net_device_ops mcba_netdev_ops = {
+	.ndo_open = mcba_usb_open,
+	.ndo_stop = mcba_usb_close,
+	.ndo_start_xmit = mcba_usb_start_xmit,
+};
+
+/* Microchip CANBUS has hardcoded bittiming values by default.
+ * This function sends request via USB to change the speed and align bittiming
+ * values for presentation purposes only
+ */
+static int mcba_net_set_bittiming(struct net_device *netdev)
+{
+	struct mcba_priv *priv = netdev_priv(netdev);
+	const u16 bitrate_kbps = priv->can.bittiming.bitrate / 1000;
+
+	mcba_usb_xmit_change_bitrate(priv, bitrate_kbps);
+
+	return 0;
+}
+
+static int mcba_set_termination(struct net_device *netdev, u16 term)
+{
+	struct mcba_priv *priv = netdev_priv(netdev);
+	struct mcba_usb_msg_termination usb_msg;
+
+	usb_msg.cmd_id = MBCA_CMD_SETUP_TERMINATION_RESISTANCE;
+
+	if (term == MCBA_TERMINATION_ENABLED)
+		usb_msg.termination = 1;
+	else
+		usb_msg.termination = 0;
+
+	mcba_usb_xmit_cmd(priv, (struct mcba_usb_msg *)&usb_msg);
+
+	return 0;
+}
+
+static int mcba_usb_probe(struct usb_interface *intf,
+			  const struct usb_device_id *id)
+{
+	struct net_device *netdev;
+	struct mcba_priv *priv;
+	int err = -ENOMEM;
+	struct usb_device *usbdev = interface_to_usbdev(intf);
+
+	netdev = alloc_candev(sizeof(struct mcba_priv), MCBA_MAX_TX_URBS);
+	if (!netdev) {
+		dev_err(&intf->dev, "Couldn't alloc candev\n");
+		return -ENOMEM;
+	}
+
+	priv = netdev_priv(netdev);
+
+	priv->udev = usbdev;
+	priv->netdev = netdev;
+	priv->usb_ka_first_pass = true;
+	priv->can_ka_first_pass = true;
+	priv->can_speed_check = false;
+
+	init_usb_anchor(&priv->rx_submitted);
+	init_usb_anchor(&priv->tx_submitted);
+
+	usb_set_intfdata(intf, priv);
+
+	/* Init CAN device */
+	priv->can.state = CAN_STATE_STOPPED;
+	priv->can.termination_const = mcba_termination;
+	priv->can.termination_const_cnt = ARRAY_SIZE(mcba_termination);
+	priv->can.bitrate_const = mcba_bitrate;
+	priv->can.bitrate_const_cnt = ARRAY_SIZE(mcba_bitrate);
+
+	priv->can.do_set_termination = mcba_set_termination;
+	priv->can.do_set_mode = mcba_net_set_mode;
+	priv->can.do_get_berr_counter = mcba_net_get_berr_counter;
+	priv->can.do_set_bittiming = mcba_net_set_bittiming;
+
+	netdev->netdev_ops = &mcba_netdev_ops;
+
+	netdev->flags |= IFF_ECHO; /* we support local echo */
+
+	SET_NETDEV_DEV(netdev, &intf->dev);
+
+	err = register_candev(netdev);
+	if (err) {
+		netdev_err(netdev, "couldn't register CAN device: %d\n", err);
+
+		netif_device_detach(priv->netdev);
+
+		goto cleanup_candev;
+	}
+
+	/* Start USB device only if we have successfuly registered CAN device */
+	err = mcba_usb_start(priv);
+	if (err) {
+		if (err == -ENODEV)
+			netif_device_detach(priv->netdev);
+
+		netdev_warn(netdev, "couldn't start device: %d\n", err);
+
+		goto cleanup_candev;
+	}
+
+	dev_info(&intf->dev, "Microchip CAN BUS analizer connected\n");
+
+	return err;
+
+cleanup_candev:
+	free_candev(netdev);
+
+	return err;
+}
+
+/* Called by the usb core when driver is unloaded or device is removed */
+static void mcba_usb_disconnect(struct usb_interface *intf)
+{
+	struct mcba_priv *priv = usb_get_intfdata(intf);
+
+	usb_set_intfdata(intf, NULL);
+
+	netdev_info(priv->netdev, "device disconnected\n");
+
+	unregister_candev(priv->netdev);
+	free_candev(priv->netdev);
+
+	mcba_urb_unlink(priv);
+}
+
+static struct usb_driver mcba_usb_driver = {
+	.name = MCBA_MODULE_NAME,
+	.probe = mcba_usb_probe,
+	.disconnect = mcba_usb_disconnect,
+	.id_table = mcba_usb_table,
+};
+
+module_usb_driver(mcba_usb_driver);
+
+MODULE_AUTHOR("Remigiusz Kołłątaj <remigiusz.kollataj@mobica.com>");
+MODULE_DESCRIPTION("SocketCAN driver for Microchip CAN BUS Analyzer Tool");
+MODULE_LICENSE("GPL v2");
-- 
2.11.0


^ permalink raw reply related	[flat|nested] 8+ messages in thread

* Re: [PATCH v3] can: mcba_usb: Add support for Microchip CAN BUS Analyzer
  2017-01-25 13:02 [PATCH v3] can: mcba_usb: Add support for Microchip CAN BUS Analyzer Remigiusz Kołłątaj
@ 2017-02-20 10:22 ` Kołłątaj, Remigiusz
  2017-04-13 15:56 ` Marc Kleine-Budde
  1 sibling, 0 replies; 8+ messages in thread
From: Kołłątaj, Remigiusz @ 2017-02-20 10:22 UTC (permalink / raw)
  To: linux-can

Hi Marc,

Did you get a chance to take a look at mcba_usb v3 patch?


Regards,
Remik

On 25 January 2017 at 14:02, Remigiusz Kołłątaj
<remigiusz.kollataj@mobica.com> wrote:
>
> SocketCAN driver for Microchip CAN BUS Analyzer
> (http://www.microchip.com/development-tools/)
>
> Changes since v2:
> - improved/simplified CAN ID conversion
> - functions for transmission of skb and cmd separated
> - fixed/improved netif_stop_queue handling
> - style/cosmetic corrections
>
> Changes since v1:
> - Termination handling reimplemented to fit new netlink API
> (IFLA_CAN_TERMINATION)
> - Bitrate handling reimplemented to fit new netlink API
> (IFLA_CAN_BITRATE)
> - CAN ID conversion refactored (changed from macro to inline functions)
> - CAN DLC handling using get_can_dlc()
> - Endianness handling for can_speed introduced
> - Debugging removed
> - Redundant error prints removed
> - Style/cosmetic corrections (i.e. macro names, redefs, inits etc.)
>
> Signed-off-by: Remigiusz Kołłątaj <remigiusz.kollataj@mobica.com>
> ---
>  drivers/net/can/usb/Kconfig    |   6 +
>  drivers/net/can/usb/Makefile   |   1 +
>  drivers/net/can/usb/mcba_usb.c | 894 +++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 901 insertions(+)
>  create mode 100644 drivers/net/can/usb/mcba_usb.c
>
> diff --git a/drivers/net/can/usb/Kconfig b/drivers/net/can/usb/Kconfig
> index 8483a40e7e9e..2d0313eb31c0 100644
> --- a/drivers/net/can/usb/Kconfig
> +++ b/drivers/net/can/usb/Kconfig
> @@ -81,4 +81,10 @@ config CAN_8DEV_USB
>           This driver supports the USB2CAN interface
>           from 8 devices (http://www.8devices.com).
>
> +config CAN_MCBA_USB
> +       tristate "Microchip CAN BUS Analyzer interface"
> +       ---help---
> +         This driver supports the CAN BUS Analyzer interface
> +         from Microchip (http://www.microchip.com/development-tools/).
> +
>  endmenu
> diff --git a/drivers/net/can/usb/Makefile b/drivers/net/can/usb/Makefile
> index a64cf983fb87..164453fd55d0 100644
> --- a/drivers/net/can/usb/Makefile
> +++ b/drivers/net/can/usb/Makefile
> @@ -8,3 +8,4 @@ obj-$(CONFIG_CAN_GS_USB) += gs_usb.o
>  obj-$(CONFIG_CAN_KVASER_USB) += kvaser_usb.o
>  obj-$(CONFIG_CAN_PEAK_USB) += peak_usb/
>  obj-$(CONFIG_CAN_8DEV_USB) += usb_8dev.o
> +obj-$(CONFIG_CAN_MCBA_USB) += mcba_usb.o
> diff --git a/drivers/net/can/usb/mcba_usb.c b/drivers/net/can/usb/mcba_usb.c
> new file mode 100644
> index 000000000000..2c92f3903034
> --- /dev/null
> +++ b/drivers/net/can/usb/mcba_usb.c
> @@ -0,0 +1,894 @@
> +/* SocketCAN driver for Microchip CAN BUS Analyzer Tool
> + *
> + * Copyright (C) 2017 Mobica Limited
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License as published
> + * by the Free Software Foundation; version 2 of the License.
> + *
> + * This program is distributed in the hope that it will be useful, but
> + * WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + * General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License along
> + * with this program.
> + *
> + * This driver is inspired by the 4.6.2 version of net/can/usb/usb_8dev.c
> + */
> +
> +#include <asm/unaligned.h>
> +#include <linux/can.h>
> +#include <linux/can/dev.h>
> +#include <linux/can/error.h>
> +#include <linux/module.h>
> +#include <linux/netdevice.h>
> +#include <linux/signal.h>
> +#include <linux/slab.h>
> +#include <linux/usb.h>
> +
> +/* vendor and product id */
> +#define MCBA_MODULE_NAME "mcba_usb"
> +#define MCBA_VENDOR_ID 0x04d8
> +#define MCBA_PRODUCT_ID 0x0a30
> +
> +/* driver constants */
> +#define MCBA_MAX_RX_URBS 20
> +#define MCBA_MAX_TX_URBS 20
> +#define MCBA_CTX_FREE MCBA_MAX_TX_URBS
> +
> +/* RX buffer must be bigger than msg size since at the
> + * beggining USB messages are stacked.
> + */
> +#define MCBA_USB_RX_BUFF_SIZE 64
> +#define MCBA_USB_TX_BUFF_SIZE (sizeof(struct mcba_usb_msg))
> +
> +/* MCBA endpoint numbers */
> +#define MCBA_USB_EP_IN 1
> +#define MCBA_USB_EP_OUT 1
> +
> +/* Microchip command id */
> +#define MBCA_CMD_RECEIVE_MESSAGE 0xE3
> +#define MBCA_CMD_I_AM_ALIVE_FROM_CAN 0xF5
> +#define MBCA_CMD_I_AM_ALIVE_FROM_USB 0xF7
> +#define MBCA_CMD_CHANGE_BIT_RATE 0xA1
> +#define MBCA_CMD_TRANSMIT_MESSAGE_EV 0xA3
> +#define MBCA_CMD_SETUP_TERMINATION_RESISTANCE 0xA8
> +#define MBCA_CMD_READ_FW_VERSION 0xA9
> +#define MBCA_CMD_NOTHING_TO_SEND 0xFF
> +#define MBCA_CMD_TRANSMIT_MESSAGE_RSP 0xE2
> +
> +#define MCBA_VER_REQ_USB 1
> +#define MCBA_VER_REQ_CAN 2
> +
> +#define MCBA_SIDL_EXID_MASK 0x8
> +#define MCBA_DLC_MASK 0xf
> +#define MCBA_DLC_RTR_MASK 0x40
> +
> +#define MCBA_CAN_STATE_WRN_TH 95
> +#define MCBA_CAN_STATE_ERR_PSV_TH 127
> +
> +#define MCBA_TERMINATION_DISABLED CAN_TERMINATION_DISABLED
> +#define MCBA_TERMINATION_ENABLED 120
> +
> +struct mcba_usb_ctx {
> +       struct mcba_priv *priv;
> +       u32 ndx;
> +       u8 dlc;
> +       bool can;
> +};
> +
> +/* Structure to hold all of our device specific stuff */
> +struct mcba_priv {
> +       struct can_priv can; /* must be the first member */
> +       struct sk_buff *echo_skb[MCBA_MAX_TX_URBS];
> +       struct mcba_usb_ctx tx_context[MCBA_MAX_TX_URBS];
> +       struct usb_device *udev;
> +       struct net_device *netdev;
> +       struct usb_anchor tx_submitted;
> +       struct usb_anchor rx_submitted;
> +       struct can_berr_counter bec;
> +       bool usb_ka_first_pass;
> +       bool can_ka_first_pass;
> +       bool can_speed_check;
> +       atomic_t free_ctx_cnt;
> +};
> +
> +/* CAN frame */
> +struct __packed mcba_usb_msg_can {
> +       u8 cmd_id;
> +       __be16 eid;
> +       __be16 sid;
> +       u8 dlc;
> +       u8 data[8];
> +       u8 timestamp[4];
> +       u8 checksum;
> +};
> +
> +/* command frame */
> +struct __packed mcba_usb_msg {
> +       u8 cmd_id;
> +       u8 unused[18];
> +};
> +
> +struct __packed mcba_usb_msg_ka_usb {
> +       u8 cmd_id;
> +       u8 termination_state;
> +       u8 soft_ver_major;
> +       u8 soft_ver_minor;
> +       u8 unused[15];
> +};
> +
> +struct __packed mcba_usb_msg_ka_can {
> +       u8 cmd_id;
> +       u8 tx_err_cnt;
> +       u8 rx_err_cnt;
> +       u8 rx_buff_ovfl;
> +       u8 tx_bus_off;
> +       __be16 can_bitrate;
> +       __le16 rx_lost;
> +       u8 can_stat;
> +       u8 soft_ver_major;
> +       u8 soft_ver_minor;
> +       u8 debug_mode;
> +       u8 test_complete;
> +       u8 test_result;
> +       u8 unused[4];
> +};
> +
> +struct __packed mcba_usb_msg_change_bitrate {
> +       u8 cmd_id;
> +       __be16 bitrate;
> +       u8 unused[16];
> +};
> +
> +struct __packed mcba_usb_msg_termination {
> +       u8 cmd_id;
> +       u8 termination;
> +       u8 unused[17];
> +};
> +
> +struct __packed mcba_usb_msg_fw_ver {
> +       u8 cmd_id;
> +       u8 pic;
> +       u8 unused[17];
> +};
> +
> +static const struct usb_device_id mcba_usb_table[] = {
> +       { USB_DEVICE(MCBA_VENDOR_ID, MCBA_PRODUCT_ID) },
> +       {} /* Terminating entry */
> +};
> +
> +MODULE_DEVICE_TABLE(usb, mcba_usb_table);
> +
> +static const u16 mcba_termination[] = { MCBA_TERMINATION_DISABLED,
> +                                       MCBA_TERMINATION_ENABLED };
> +
> +static const u32 mcba_bitrate[] = { 20000,  33333,  50000,  80000,  83333,
> +                                   100000, 125000, 150000, 175000, 200000,
> +                                   225000, 250000, 275000, 300000, 500000,
> +                                   625000, 800000, 1000000 };
> +
> +static inline void mcba_init_ctx(struct mcba_priv *priv)
> +{
> +       int i = 0;
> +
> +       for (i = 0; i < MCBA_MAX_TX_URBS; i++) {
> +               priv->tx_context[i].ndx = MCBA_CTX_FREE;
> +               priv->tx_context[i].priv = priv;
> +       }
> +
> +       atomic_set(&priv->free_ctx_cnt, ARRAY_SIZE(priv->tx_context));
> +}
> +
> +static inline struct mcba_usb_ctx *mcba_usb_get_free_ctx(struct mcba_priv *priv,
> +                                                        struct can_frame *cf)
> +{
> +       int i = 0;
> +       struct mcba_usb_ctx *ctx = NULL;
> +
> +       for (i = 0; i < MCBA_MAX_TX_URBS; i++) {
> +               if (priv->tx_context[i].ndx == MCBA_CTX_FREE) {
> +                       ctx = &priv->tx_context[i];
> +                       ctx->ndx = i;
> +
> +                       if (cf) {
> +                               ctx->can = true;
> +                               ctx->dlc = cf->can_dlc;
> +                       } else {
> +                               ctx->can = false;
> +                               ctx->dlc = 0;
> +                       }
> +
> +                       atomic_dec(&priv->free_ctx_cnt);
> +                       break;
> +               }
> +       }
> +
> +       if (!atomic_read(&priv->free_ctx_cnt))
> +               /* That was the last free ctx. Slow down tx path */
> +               netif_stop_queue(priv->netdev);
> +
> +       return ctx;
> +}
> +
> +/* mcba_usb_free_ctx and mcba_usb_get_free_ctx are executed by different
> + * threads. The order of execution in below function is important.
> + */
> +static inline void mcba_usb_free_ctx(struct mcba_usb_ctx *ctx)
> +{
> +       /* Increase number of free ctxs before freeing ctx */
> +       atomic_inc(&ctx->priv->free_ctx_cnt);
> +
> +       ctx->ndx = MCBA_CTX_FREE;
> +
> +       /* Wake up the queue once ctx is marked free */
> +       netif_wake_queue(ctx->priv->netdev);
> +}
> +
> +static void mcba_usb_write_bulk_callback(struct urb *urb)
> +{
> +       struct mcba_usb_ctx *ctx = urb->context;
> +       struct net_device *netdev;
> +
> +       WARN_ON(!ctx);
> +
> +       netdev = ctx->priv->netdev;
> +
> +       if (ctx->can) {
> +               if (!netif_device_present(netdev))
> +                       return;
> +
> +               netdev->stats.tx_packets++;
> +               netdev->stats.tx_bytes += ctx->dlc;
> +
> +               can_get_echo_skb(netdev, ctx->ndx);
> +       }
> +
> +       /* free up our allocated buffer */
> +       usb_free_coherent(urb->dev, urb->transfer_buffer_length,
> +                         urb->transfer_buffer, urb->transfer_dma);
> +
> +       if (urb->status)
> +               netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status);
> +
> +       /* Release the context */
> +       mcba_usb_free_ctx(ctx);
> +}
> +
> +/* Send data to device */
> +static netdev_tx_t mcba_usb_xmit(struct mcba_priv *priv,
> +                                struct mcba_usb_msg *usb_msg,
> +                                struct mcba_usb_ctx *ctx)
> +{
> +       struct urb *urb;
> +       u8 *buf;
> +       int err;
> +
> +       /* create a URB, and a buffer for it, and copy the data to the URB */
> +       urb = usb_alloc_urb(0, GFP_ATOMIC);
> +       if (!urb)
> +               return -ENOMEM;
> +
> +       buf = usb_alloc_coherent(priv->udev, MCBA_USB_TX_BUFF_SIZE, GFP_ATOMIC,
> +                                &urb->transfer_dma);
> +       if (!buf) {
> +               err = -ENOMEM;
> +               goto nomembuf;
> +       }
> +
> +       memcpy(buf, usb_msg, MCBA_USB_TX_BUFF_SIZE);
> +
> +       usb_fill_bulk_urb(urb, priv->udev,
> +                         usb_sndbulkpipe(priv->udev, MCBA_USB_EP_OUT), buf,
> +                         MCBA_USB_TX_BUFF_SIZE, mcba_usb_write_bulk_callback,
> +                         ctx);
> +
> +       urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
> +       usb_anchor_urb(urb, &priv->tx_submitted);
> +
> +       err = usb_submit_urb(urb, GFP_ATOMIC);
> +       if (unlikely(err))
> +               goto failed;
> +
> +       /* Release our reference to this URB, the USB core will eventually free
> +        * it entirely.
> +        */
> +       usb_free_urb(urb);
> +
> +       return 0;
> +
> +failed:
> +       usb_unanchor_urb(urb);
> +       usb_free_coherent(priv->udev, MCBA_USB_TX_BUFF_SIZE, buf,
> +                         urb->transfer_dma);
> +
> +       if (err == -ENODEV)
> +               netif_device_detach(priv->netdev);
> +       else
> +               netdev_warn(priv->netdev, "failed tx_urb %d\n", err);
> +
> +nomembuf:
> +       usb_free_urb(urb);
> +
> +       return err;
> +}
> +
> +/* Send data to device */
> +static netdev_tx_t mcba_usb_start_xmit(struct sk_buff *skb,
> +                                      struct net_device *netdev)
> +{
> +       struct mcba_priv *priv = netdev_priv(netdev);
> +       struct can_frame *cf = (struct can_frame *)skb->data;
> +       struct mcba_usb_msg_can usb_msg;
> +       struct mcba_usb_ctx *ctx = NULL;
> +       struct net_device_stats *stats = &priv->netdev->stats;
> +       u16 sid;
> +       int err;
> +
> +       if (can_dropped_invalid_skb(netdev, skb))
> +               return NETDEV_TX_OK;
> +
> +       ctx = mcba_usb_get_free_ctx(priv, cf);
> +       if (!ctx)
> +               return NETDEV_TX_BUSY;
> +
> +       can_put_echo_skb(skb, priv->netdev, ctx->ndx);
> +
> +       usb_msg.cmd_id = MBCA_CMD_TRANSMIT_MESSAGE_EV;
> +       if (cf->can_id & CAN_EFF_FLAG) {
> +               /* SIDH    | SIDL                 | EIDH   | EIDL
> +                * 28 - 21 | 20 19 18 x x x 17 16 | 15 - 8 | 7 - 0
> +                */
> +               sid = MCBA_SIDL_EXID_MASK;
> +               /* store 28-18 bits */
> +               sid |= (cf->can_id & 0x1ffc0000) >> 13;
> +               /* store 17-16 bits */
> +               sid |= (cf->can_id & 0x30000) >> 16;
> +               put_unaligned_be16(sid, &usb_msg.sid);
> +
> +               /* store 15-0 bits */
> +               put_unaligned_be16(cf->can_id & 0xffff, &usb_msg.eid);
> +       } else {
> +               /* SIDH   | SIDL
> +                * 10 - 3 | 2 1 0 x x x x x
> +                */
> +               put_unaligned_be16((cf->can_id & CAN_SFF_MASK) << 5,
> +                                  &usb_msg.sid);
> +               usb_msg.eid = 0;
> +       }
> +
> +       usb_msg.dlc = cf->can_dlc;
> +
> +       memcpy(usb_msg.data, cf->data, usb_msg.dlc);
> +
> +       if (cf->can_id & CAN_RTR_FLAG)
> +               usb_msg.dlc |= MCBA_DLC_RTR_MASK;
> +
> +       err = mcba_usb_xmit(priv, (struct mcba_usb_msg *)&usb_msg, ctx);
> +       if (err)
> +               goto xmit_failed;
> +
> +       return NETDEV_TX_OK;
> +
> +xmit_failed:
> +       can_free_echo_skb(priv->netdev, ctx->ndx);
> +       mcba_usb_free_ctx(ctx);
> +       dev_kfree_skb(skb);
> +       stats->tx_dropped++;
> +
> +       return NETDEV_TX_OK;
> +}
> +
> +/* Send cmd to device */
> +static void mcba_usb_xmit_cmd(struct mcba_priv *priv,
> +                             struct mcba_usb_msg *usb_msg)
> +{
> +       struct mcba_usb_ctx *ctx = NULL;
> +       int err;
> +
> +       ctx = mcba_usb_get_free_ctx(priv, NULL);
> +       if (!ctx) {
> +               netdev_err(priv->netdev,
> +                          "Lack of free ctx. Sending (%d) cmd aborted",
> +                          usb_msg->cmd_id);
> +
> +               return;
> +       }
> +
> +       err = mcba_usb_xmit(priv, usb_msg, ctx);
> +       if (err)
> +               netdev_err(priv->netdev, "Failed to send cmd (%d)",
> +                          usb_msg->cmd_id);
> +}
> +
> +static void mcba_usb_xmit_change_bitrate(struct mcba_priv *priv, u16 bitrate)
> +{
> +       struct mcba_usb_msg_change_bitrate usb_msg;
> +
> +       usb_msg.cmd_id = MBCA_CMD_CHANGE_BIT_RATE;
> +       put_unaligned_be16(bitrate, &usb_msg.bitrate);
> +
> +       mcba_usb_xmit_cmd(priv, (struct mcba_usb_msg *)&usb_msg);
> +}
> +
> +static void mcba_usb_xmit_read_fw_ver(struct mcba_priv *priv, u8 pic)
> +{
> +       struct mcba_usb_msg_fw_ver usb_msg;
> +
> +       usb_msg.cmd_id = MBCA_CMD_READ_FW_VERSION;
> +       usb_msg.pic = pic;
> +
> +       mcba_usb_xmit_cmd(priv, (struct mcba_usb_msg *)&usb_msg);
> +}
> +
> +static void mcba_usb_process_can(struct mcba_priv *priv,
> +                                struct mcba_usb_msg_can *msg)
> +{
> +       struct can_frame *cf;
> +       struct sk_buff *skb;
> +       struct net_device_stats *stats = &priv->netdev->stats;
> +       u16 sid;
> +
> +       skb = alloc_can_skb(priv->netdev, &cf);
> +       if (!skb)
> +               return;
> +
> +       sid = get_unaligned_be16(&msg->sid);
> +
> +       if (sid & MCBA_SIDL_EXID_MASK) {
> +               /* SIDH    | SIDL                 | EIDH   | EIDL
> +                * 28 - 21 | 20 19 18 x x x 17 16 | 15 - 8 | 7 - 0
> +                */
> +               cf->can_id = CAN_EFF_FLAG;
> +
> +               /* store 28-18 bits */
> +               cf->can_id |= (sid & 0xffe0) << 13;
> +               /* store 17-16 bits */
> +               cf->can_id |= (sid & 3) << 16;
> +               /* store 15-0 bits */
> +               cf->can_id |= get_unaligned_be16(&msg->eid);
> +       } else {
> +               /* SIDH   | SIDL
> +                * 10 - 3 | 2 1 0 x x x x x
> +                */
> +               cf->can_id = (sid & 0xffe0) >> 5;
> +       }
> +
> +       if (msg->dlc & MCBA_DLC_RTR_MASK)
> +               cf->can_id |= CAN_RTR_FLAG;
> +
> +       cf->can_dlc = get_can_dlc(msg->dlc & MCBA_DLC_MASK);
> +
> +       memcpy(cf->data, msg->data, cf->can_dlc);
> +
> +       stats->rx_packets++;
> +       stats->rx_bytes += cf->can_dlc;
> +
> +       netif_rx(skb);
> +}
> +
> +static void mcba_usb_process_ka_usb(struct mcba_priv *priv,
> +                                   struct mcba_usb_msg_ka_usb *msg)
> +{
> +       if (unlikely(priv->usb_ka_first_pass)) {
> +               netdev_info(priv->netdev, "PIC USB version %hhu.%hhu\n",
> +                           msg->soft_ver_major, msg->soft_ver_minor);
> +
> +               priv->usb_ka_first_pass = false;
> +       }
> +
> +       if (msg->termination_state)
> +               priv->can.termination = MCBA_TERMINATION_ENABLED;
> +       else
> +               priv->can.termination = MCBA_TERMINATION_DISABLED;
> +}
> +
> +static u32 convert_can2host_bitrate(struct mcba_usb_msg_ka_can *msg)
> +{
> +       const u32 bitrate = get_unaligned_be16(&msg->can_bitrate);
> +
> +       if ((bitrate == 33) || (bitrate == 83))
> +               return bitrate * 1000 + 333;
> +       else
> +               return bitrate * 1000;
> +}
> +
> +static void mcba_usb_process_ka_can(struct mcba_priv *priv,
> +                                   struct mcba_usb_msg_ka_can *msg)
> +{
> +       if (unlikely(priv->can_ka_first_pass)) {
> +               netdev_info(priv->netdev, "PIC CAN version %hhu.%hhu\n",
> +                           msg->soft_ver_major, msg->soft_ver_minor);
> +
> +               priv->can_ka_first_pass = false;
> +       }
> +
> +       if (unlikely(priv->can_speed_check)) {
> +               const u32 bitrate = convert_can2host_bitrate(msg);
> +
> +               priv->can_speed_check = false;
> +
> +               if (bitrate != priv->can.bittiming.bitrate)
> +                       netdev_err(
> +                           priv->netdev,
> +                           "Wrong bitrate reported by the device (%u). Expected %u",
> +                           bitrate, priv->can.bittiming.bitrate);
> +       }
> +
> +       priv->bec.txerr = msg->tx_err_cnt;
> +       priv->bec.rxerr = msg->rx_err_cnt;
> +
> +       if (msg->tx_bus_off)
> +               priv->can.state = CAN_STATE_BUS_OFF;
> +
> +       else if ((priv->bec.txerr > MCBA_CAN_STATE_ERR_PSV_TH) ||
> +                (priv->bec.rxerr > MCBA_CAN_STATE_ERR_PSV_TH))
> +               priv->can.state = CAN_STATE_ERROR_PASSIVE;
> +
> +       else if ((priv->bec.txerr > MCBA_CAN_STATE_WRN_TH) ||
> +                (priv->bec.rxerr > MCBA_CAN_STATE_WRN_TH))
> +               priv->can.state = CAN_STATE_ERROR_WARNING;
> +}
> +
> +static void mcba_usb_process_rx(struct mcba_priv *priv,
> +                               struct mcba_usb_msg *msg)
> +{
> +       switch (msg->cmd_id) {
> +       case MBCA_CMD_I_AM_ALIVE_FROM_CAN:
> +               mcba_usb_process_ka_can(priv,
> +                                       (struct mcba_usb_msg_ka_can *)msg);
> +               break;
> +
> +       case MBCA_CMD_I_AM_ALIVE_FROM_USB:
> +               mcba_usb_process_ka_usb(priv,
> +                                       (struct mcba_usb_msg_ka_usb *)msg);
> +               break;
> +
> +       case MBCA_CMD_RECEIVE_MESSAGE:
> +               mcba_usb_process_can(priv, (struct mcba_usb_msg_can *)msg);
> +               break;
> +
> +       case MBCA_CMD_NOTHING_TO_SEND:
> +               /* Side effect of communication between PIC_USB and PIC_CAN.
> +                * PIC_CAN is telling us that it has nothing to send
> +                */
> +               break;
> +
> +       case MBCA_CMD_TRANSMIT_MESSAGE_RSP:
> +               /* Transmission response from the device containing timestamp */
> +               break;
> +
> +       default:
> +               netdev_warn(priv->netdev, "Unsupported msg (0x%hhX)",
> +                           msg->cmd_id);
> +               break;
> +       }
> +}
> +
> +/* Callback for reading data from device
> + *
> + * Check urb status, call read function and resubmit urb read operation.
> + */
> +static void mcba_usb_read_bulk_callback(struct urb *urb)
> +{
> +       struct mcba_priv *priv = urb->context;
> +       struct net_device *netdev;
> +       int retval;
> +       int pos = 0;
> +
> +       netdev = priv->netdev;
> +
> +       if (!netif_device_present(netdev))
> +               return;
> +
> +       switch (urb->status) {
> +       case 0: /* success */
> +               break;
> +
> +       case -ENOENT:
> +       case -ESHUTDOWN:
> +               return;
> +
> +       default:
> +               netdev_info(netdev, "Rx URB aborted (%d)\n", urb->status);
> +
> +               goto resubmit_urb;
> +       }
> +
> +       while (pos < urb->actual_length) {
> +               struct mcba_usb_msg *msg;
> +
> +               if (pos + sizeof(struct mcba_usb_msg) > urb->actual_length) {
> +                       netdev_err(priv->netdev, "format error\n");
> +                       break;
> +               }
> +
> +               msg = (struct mcba_usb_msg *)(urb->transfer_buffer + pos);
> +               mcba_usb_process_rx(priv, msg);
> +
> +               pos += sizeof(struct mcba_usb_msg);
> +       }
> +
> +resubmit_urb:
> +
> +       usb_fill_bulk_urb(urb, priv->udev,
> +                         usb_rcvbulkpipe(priv->udev, MCBA_USB_EP_OUT),
> +                         urb->transfer_buffer, MCBA_USB_RX_BUFF_SIZE,
> +                         mcba_usb_read_bulk_callback, priv);
> +
> +       retval = usb_submit_urb(urb, GFP_ATOMIC);
> +
> +       if (retval == -ENODEV)
> +               netif_device_detach(netdev);
> +       else if (retval)
> +               netdev_err(netdev, "failed resubmitting read bulk urb: %d\n",
> +                          retval);
> +}
> +
> +/* Start USB device */
> +static int mcba_usb_start(struct mcba_priv *priv)
> +{
> +       struct net_device *netdev = priv->netdev;
> +       int err, i;
> +
> +       mcba_init_ctx(priv);
> +
> +       for (i = 0; i < MCBA_MAX_RX_URBS; i++) {
> +               struct urb *urb = NULL;
> +               u8 *buf;
> +
> +               /* create a URB, and a buffer for it */
> +               urb = usb_alloc_urb(0, GFP_KERNEL);
> +               if (!urb) {
> +                       err = -ENOMEM;
> +                       break;
> +               }
> +
> +               buf = usb_alloc_coherent(priv->udev, MCBA_USB_RX_BUFF_SIZE,
> +                                        GFP_KERNEL, &urb->transfer_dma);
> +               if (!buf) {
> +                       netdev_err(netdev, "No memory left for USB buffer\n");
> +                       usb_free_urb(urb);
> +                       err = -ENOMEM;
> +                       break;
> +               }
> +
> +               usb_fill_bulk_urb(urb, priv->udev,
> +                                 usb_rcvbulkpipe(priv->udev, MCBA_USB_EP_IN),
> +                                 buf, MCBA_USB_RX_BUFF_SIZE,
> +                                 mcba_usb_read_bulk_callback, priv);
> +               urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
> +               usb_anchor_urb(urb, &priv->rx_submitted);
> +
> +               err = usb_submit_urb(urb, GFP_KERNEL);
> +               if (err) {
> +                       usb_unanchor_urb(urb);
> +                       usb_free_coherent(priv->udev, MCBA_USB_RX_BUFF_SIZE,
> +                                         buf, urb->transfer_dma);
> +                       usb_free_urb(urb);
> +                       break;
> +               }
> +
> +               /* Drop reference, USB core will take care of freeing it */
> +               usb_free_urb(urb);
> +       }
> +
> +       /* Did we submit any URBs */
> +       if (i == 0) {
> +               netdev_warn(netdev, "couldn't setup read URBs\n");
> +               return err;
> +       }
> +
> +       /* Warn if we've couldn't transmit all the URBs */
> +       if (i < MCBA_MAX_RX_URBS)
> +               netdev_warn(netdev, "rx performance may be slow\n");
> +
> +       mcba_usb_xmit_read_fw_ver(priv, MCBA_VER_REQ_USB);
> +       mcba_usb_xmit_read_fw_ver(priv, MCBA_VER_REQ_CAN);
> +
> +       return err;
> +}
> +
> +/* Open USB device */
> +static int mcba_usb_open(struct net_device *netdev)
> +{
> +       struct mcba_priv *priv = netdev_priv(netdev);
> +       int err;
> +
> +       /* common open */
> +       err = open_candev(netdev);
> +       if (err)
> +               return err;
> +
> +       priv->can_speed_check = true;
> +       priv->can.state = CAN_STATE_ERROR_ACTIVE;
> +
> +       netif_start_queue(netdev);
> +
> +       return 0;
> +}
> +
> +static void mcba_urb_unlink(struct mcba_priv *priv)
> +{
> +       usb_kill_anchored_urbs(&priv->rx_submitted);
> +       usb_kill_anchored_urbs(&priv->tx_submitted);
> +}
> +
> +/* Close USB device */
> +static int mcba_usb_close(struct net_device *netdev)
> +{
> +       struct mcba_priv *priv = netdev_priv(netdev);
> +
> +       priv->can.state = CAN_STATE_STOPPED;
> +
> +       netif_stop_queue(netdev);
> +
> +       /* Stop polling */
> +       mcba_urb_unlink(priv);
> +
> +       close_candev(netdev);
> +
> +       return 0;
> +}
> +
> +/* Set network device mode
> + *
> + * Maybe we should leave this function empty, because the device
> + * set mode variable with open command.
> + */
> +static int mcba_net_set_mode(struct net_device *netdev, enum can_mode mode)
> +{
> +       return 0;
> +}
> +
> +static int mcba_net_get_berr_counter(const struct net_device *netdev,
> +                                    struct can_berr_counter *bec)
> +{
> +       struct mcba_priv *priv = netdev_priv(netdev);
> +
> +       bec->txerr = priv->bec.txerr;
> +       bec->rxerr = priv->bec.rxerr;
> +
> +       return 0;
> +}
> +
> +static const struct net_device_ops mcba_netdev_ops = {
> +       .ndo_open = mcba_usb_open,
> +       .ndo_stop = mcba_usb_close,
> +       .ndo_start_xmit = mcba_usb_start_xmit,
> +};
> +
> +/* Microchip CANBUS has hardcoded bittiming values by default.
> + * This function sends request via USB to change the speed and align bittiming
> + * values for presentation purposes only
> + */
> +static int mcba_net_set_bittiming(struct net_device *netdev)
> +{
> +       struct mcba_priv *priv = netdev_priv(netdev);
> +       const u16 bitrate_kbps = priv->can.bittiming.bitrate / 1000;
> +
> +       mcba_usb_xmit_change_bitrate(priv, bitrate_kbps);
> +
> +       return 0;
> +}
> +
> +static int mcba_set_termination(struct net_device *netdev, u16 term)
> +{
> +       struct mcba_priv *priv = netdev_priv(netdev);
> +       struct mcba_usb_msg_termination usb_msg;
> +
> +       usb_msg.cmd_id = MBCA_CMD_SETUP_TERMINATION_RESISTANCE;
> +
> +       if (term == MCBA_TERMINATION_ENABLED)
> +               usb_msg.termination = 1;
> +       else
> +               usb_msg.termination = 0;
> +
> +       mcba_usb_xmit_cmd(priv, (struct mcba_usb_msg *)&usb_msg);
> +
> +       return 0;
> +}
> +
> +static int mcba_usb_probe(struct usb_interface *intf,
> +                         const struct usb_device_id *id)
> +{
> +       struct net_device *netdev;
> +       struct mcba_priv *priv;
> +       int err = -ENOMEM;
> +       struct usb_device *usbdev = interface_to_usbdev(intf);
> +
> +       netdev = alloc_candev(sizeof(struct mcba_priv), MCBA_MAX_TX_URBS);
> +       if (!netdev) {
> +               dev_err(&intf->dev, "Couldn't alloc candev\n");
> +               return -ENOMEM;
> +       }
> +
> +       priv = netdev_priv(netdev);
> +
> +       priv->udev = usbdev;
> +       priv->netdev = netdev;
> +       priv->usb_ka_first_pass = true;
> +       priv->can_ka_first_pass = true;
> +       priv->can_speed_check = false;
> +
> +       init_usb_anchor(&priv->rx_submitted);
> +       init_usb_anchor(&priv->tx_submitted);
> +
> +       usb_set_intfdata(intf, priv);
> +
> +       /* Init CAN device */
> +       priv->can.state = CAN_STATE_STOPPED;
> +       priv->can.termination_const = mcba_termination;
> +       priv->can.termination_const_cnt = ARRAY_SIZE(mcba_termination);
> +       priv->can.bitrate_const = mcba_bitrate;
> +       priv->can.bitrate_const_cnt = ARRAY_SIZE(mcba_bitrate);
> +
> +       priv->can.do_set_termination = mcba_set_termination;
> +       priv->can.do_set_mode = mcba_net_set_mode;
> +       priv->can.do_get_berr_counter = mcba_net_get_berr_counter;
> +       priv->can.do_set_bittiming = mcba_net_set_bittiming;
> +
> +       netdev->netdev_ops = &mcba_netdev_ops;
> +
> +       netdev->flags |= IFF_ECHO; /* we support local echo */
> +
> +       SET_NETDEV_DEV(netdev, &intf->dev);
> +
> +       err = register_candev(netdev);
> +       if (err) {
> +               netdev_err(netdev, "couldn't register CAN device: %d\n", err);
> +
> +               netif_device_detach(priv->netdev);
> +
> +               goto cleanup_candev;
> +       }
> +
> +       /* Start USB device only if we have successfuly registered CAN device */
> +       err = mcba_usb_start(priv);
> +       if (err) {
> +               if (err == -ENODEV)
> +                       netif_device_detach(priv->netdev);
> +
> +               netdev_warn(netdev, "couldn't start device: %d\n", err);
> +
> +               goto cleanup_candev;
> +       }
> +
> +       dev_info(&intf->dev, "Microchip CAN BUS analizer connected\n");
> +
> +       return err;
> +
> +cleanup_candev:
> +       free_candev(netdev);
> +
> +       return err;
> +}
> +
> +/* Called by the usb core when driver is unloaded or device is removed */
> +static void mcba_usb_disconnect(struct usb_interface *intf)
> +{
> +       struct mcba_priv *priv = usb_get_intfdata(intf);
> +
> +       usb_set_intfdata(intf, NULL);
> +
> +       netdev_info(priv->netdev, "device disconnected\n");
> +
> +       unregister_candev(priv->netdev);
> +       free_candev(priv->netdev);
> +
> +       mcba_urb_unlink(priv);
> +}
> +
> +static struct usb_driver mcba_usb_driver = {
> +       .name = MCBA_MODULE_NAME,
> +       .probe = mcba_usb_probe,
> +       .disconnect = mcba_usb_disconnect,
> +       .id_table = mcba_usb_table,
> +};
> +
> +module_usb_driver(mcba_usb_driver);
> +
> +MODULE_AUTHOR("Remigiusz Kołłątaj <remigiusz.kollataj@mobica.com>");
> +MODULE_DESCRIPTION("SocketCAN driver for Microchip CAN BUS Analyzer Tool");
> +MODULE_LICENSE("GPL v2");
> --
> 2.11.0
>

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH v3] can: mcba_usb: Add support for Microchip CAN BUS Analyzer
  2017-01-25 13:02 [PATCH v3] can: mcba_usb: Add support for Microchip CAN BUS Analyzer Remigiusz Kołłątaj
  2017-02-20 10:22 ` Kołłątaj, Remigiusz
@ 2017-04-13 15:56 ` Marc Kleine-Budde
  2017-04-14  8:25   ` Kołłątaj, Remigiusz
  1 sibling, 1 reply; 8+ messages in thread
From: Marc Kleine-Budde @ 2017-04-13 15:56 UTC (permalink / raw)
  To: Remigiusz Kołłątaj, linux-can


[-- Attachment #1.1: Type: text/plain, Size: 28249 bytes --]

On 01/25/2017 02:02 PM, Remigiusz Kołłątaj wrote:
> SocketCAN driver for Microchip CAN BUS Analyzer
> (http://www.microchip.com/development-tools/)
> 
> Changes since v2:
> - improved/simplified CAN ID conversion
> - functions for transmission of skb and cmd separated
> - fixed/improved netif_stop_queue handling
> - style/cosmetic corrections
> 
> Changes since v1:
> - Termination handling reimplemented to fit new netlink API
> (IFLA_CAN_TERMINATION)
> - Bitrate handling reimplemented to fit new netlink API
> (IFLA_CAN_BITRATE)
> - CAN ID conversion refactored (changed from macro to inline functions)
> - CAN DLC handling using get_can_dlc()
> - Endianness handling for can_speed introduced
> - Debugging removed
> - Redundant error prints removed
> - Style/cosmetic corrections (i.e. macro names, redefs, inits etc.)
> 
> Signed-off-by: Remigiusz Kołłątaj <remigiusz.kollataj@mobica.com>

Can you pleeas add LED support, see commit:

    adccadb92f05 can: flexcan: add LED trigger support

as an example. More comments inline.

> ---
>  drivers/net/can/usb/Kconfig    |   6 +
>  drivers/net/can/usb/Makefile   |   1 +
>  drivers/net/can/usb/mcba_usb.c | 894 +++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 901 insertions(+)
>  create mode 100644 drivers/net/can/usb/mcba_usb.c
> 
> diff --git a/drivers/net/can/usb/Kconfig b/drivers/net/can/usb/Kconfig
> index 8483a40e7e9e..2d0313eb31c0 100644
> --- a/drivers/net/can/usb/Kconfig
> +++ b/drivers/net/can/usb/Kconfig
> @@ -81,4 +81,10 @@ config CAN_8DEV_USB
>  	  This driver supports the USB2CAN interface
>  	  from 8 devices (http://www.8devices.com).
>  
> +config CAN_MCBA_USB
> +	tristate "Microchip CAN BUS Analyzer interface"
> +	---help---
> +	  This driver supports the CAN BUS Analyzer interface
> +	  from Microchip (http://www.microchip.com/development-tools/).
> +
>  endmenu
> diff --git a/drivers/net/can/usb/Makefile b/drivers/net/can/usb/Makefile
> index a64cf983fb87..164453fd55d0 100644
> --- a/drivers/net/can/usb/Makefile
> +++ b/drivers/net/can/usb/Makefile
> @@ -8,3 +8,4 @@ obj-$(CONFIG_CAN_GS_USB) += gs_usb.o
>  obj-$(CONFIG_CAN_KVASER_USB) += kvaser_usb.o
>  obj-$(CONFIG_CAN_PEAK_USB) += peak_usb/
>  obj-$(CONFIG_CAN_8DEV_USB) += usb_8dev.o
> +obj-$(CONFIG_CAN_MCBA_USB) += mcba_usb.o
> diff --git a/drivers/net/can/usb/mcba_usb.c b/drivers/net/can/usb/mcba_usb.c
> new file mode 100644
> index 000000000000..2c92f3903034
> --- /dev/null
> +++ b/drivers/net/can/usb/mcba_usb.c
> @@ -0,0 +1,894 @@
> +/* SocketCAN driver for Microchip CAN BUS Analyzer Tool
> + *
> + * Copyright (C) 2017 Mobica Limited
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License as published
> + * by the Free Software Foundation; version 2 of the License.
> + *
> + * This program is distributed in the hope that it will be useful, but
> + * WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + * General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License along
> + * with this program.
> + *
> + * This driver is inspired by the 4.6.2 version of net/can/usb/usb_8dev.c
> + */
> +
> +#include <asm/unaligned.h>
> +#include <linux/can.h>
> +#include <linux/can/dev.h>
> +#include <linux/can/error.h>
> +#include <linux/module.h>
> +#include <linux/netdevice.h>
> +#include <linux/signal.h>
> +#include <linux/slab.h>
> +#include <linux/usb.h>
> +
> +/* vendor and product id */
> +#define MCBA_MODULE_NAME "mcba_usb"
> +#define MCBA_VENDOR_ID 0x04d8
> +#define MCBA_PRODUCT_ID 0x0a30
> +
> +/* driver constants */
> +#define MCBA_MAX_RX_URBS 20
> +#define MCBA_MAX_TX_URBS 20
> +#define MCBA_CTX_FREE MCBA_MAX_TX_URBS
> +
> +/* RX buffer must be bigger than msg size since at the
> + * beggining USB messages are stacked.
> + */
> +#define MCBA_USB_RX_BUFF_SIZE 64
> +#define MCBA_USB_TX_BUFF_SIZE (sizeof(struct mcba_usb_msg))
> +
> +/* MCBA endpoint numbers */
> +#define MCBA_USB_EP_IN 1
> +#define MCBA_USB_EP_OUT 1
> +
> +/* Microchip command id */
> +#define MBCA_CMD_RECEIVE_MESSAGE 0xE3
> +#define MBCA_CMD_I_AM_ALIVE_FROM_CAN 0xF5
> +#define MBCA_CMD_I_AM_ALIVE_FROM_USB 0xF7
> +#define MBCA_CMD_CHANGE_BIT_RATE 0xA1
> +#define MBCA_CMD_TRANSMIT_MESSAGE_EV 0xA3
> +#define MBCA_CMD_SETUP_TERMINATION_RESISTANCE 0xA8
> +#define MBCA_CMD_READ_FW_VERSION 0xA9
> +#define MBCA_CMD_NOTHING_TO_SEND 0xFF
> +#define MBCA_CMD_TRANSMIT_MESSAGE_RSP 0xE2
> +
> +#define MCBA_VER_REQ_USB 1
> +#define MCBA_VER_REQ_CAN 2
> +
> +#define MCBA_SIDL_EXID_MASK 0x8
> +#define MCBA_DLC_MASK 0xf
> +#define MCBA_DLC_RTR_MASK 0x40
> +
> +#define MCBA_CAN_STATE_WRN_TH 95
> +#define MCBA_CAN_STATE_ERR_PSV_TH 127
> +
> +#define MCBA_TERMINATION_DISABLED CAN_TERMINATION_DISABLED
> +#define MCBA_TERMINATION_ENABLED 120
> +
> +struct mcba_usb_ctx {
> +	struct mcba_priv *priv;
> +	u32 ndx;
> +	u8 dlc;
> +	bool can;
> +};
> +
> +/* Structure to hold all of our device specific stuff */
> +struct mcba_priv {
> +	struct can_priv can; /* must be the first member */
> +	struct sk_buff *echo_skb[MCBA_MAX_TX_URBS];
> +	struct mcba_usb_ctx tx_context[MCBA_MAX_TX_URBS];
> +	struct usb_device *udev;
> +	struct net_device *netdev;
> +	struct usb_anchor tx_submitted;
> +	struct usb_anchor rx_submitted;
> +	struct can_berr_counter bec;
> +	bool usb_ka_first_pass;
> +	bool can_ka_first_pass;
> +	bool can_speed_check;
> +	atomic_t free_ctx_cnt;
> +};
> +
> +/* CAN frame */
> +struct __packed mcba_usb_msg_can {
> +	u8 cmd_id;
> +	__be16 eid;
> +	__be16 sid;
> +	u8 dlc;
> +	u8 data[8];
> +	u8 timestamp[4];
> +	u8 checksum;
> +};
> +
> +/* command frame */
> +struct __packed mcba_usb_msg {
> +	u8 cmd_id;
> +	u8 unused[18];
> +};
> +
> +struct __packed mcba_usb_msg_ka_usb {
> +	u8 cmd_id;
> +	u8 termination_state;
> +	u8 soft_ver_major;
> +	u8 soft_ver_minor;
> +	u8 unused[15];
> +};
> +
> +struct __packed mcba_usb_msg_ka_can {
> +	u8 cmd_id;
> +	u8 tx_err_cnt;
> +	u8 rx_err_cnt;
> +	u8 rx_buff_ovfl;
> +	u8 tx_bus_off;
> +	__be16 can_bitrate;
> +	__le16 rx_lost;
> +	u8 can_stat;
> +	u8 soft_ver_major;
> +	u8 soft_ver_minor;
> +	u8 debug_mode;
> +	u8 test_complete;
> +	u8 test_result;
> +	u8 unused[4];
> +};
> +
> +struct __packed mcba_usb_msg_change_bitrate {
> +	u8 cmd_id;
> +	__be16 bitrate;
> +	u8 unused[16];
> +};
> +
> +struct __packed mcba_usb_msg_termination {
> +	u8 cmd_id;
> +	u8 termination;
> +	u8 unused[17];
> +};
> +
> +struct __packed mcba_usb_msg_fw_ver {
> +	u8 cmd_id;
> +	u8 pic;
> +	u8 unused[17];
> +};
> +
> +static const struct usb_device_id mcba_usb_table[] = {
> +	{ USB_DEVICE(MCBA_VENDOR_ID, MCBA_PRODUCT_ID) },
> +	{} /* Terminating entry */
> +};
> +
> +MODULE_DEVICE_TABLE(usb, mcba_usb_table);
> +
> +static const u16 mcba_termination[] = { MCBA_TERMINATION_DISABLED,
> +					MCBA_TERMINATION_ENABLED };
> +
> +static const u32 mcba_bitrate[] = { 20000,  33333,  50000,  80000,  83333,
> +				    100000, 125000, 150000, 175000, 200000,
> +				    225000, 250000, 275000, 300000, 500000,
> +				    625000, 800000, 1000000 };
> +
> +static inline void mcba_init_ctx(struct mcba_priv *priv)
> +{
> +	int i = 0;
> +
> +	for (i = 0; i < MCBA_MAX_TX_URBS; i++) {
> +		priv->tx_context[i].ndx = MCBA_CTX_FREE;
> +		priv->tx_context[i].priv = priv;
> +	}
> +
> +	atomic_set(&priv->free_ctx_cnt, ARRAY_SIZE(priv->tx_context));
> +}
> +
> +static inline struct mcba_usb_ctx *mcba_usb_get_free_ctx(struct mcba_priv *priv,
> +							 struct can_frame *cf)
> +{
> +	int i = 0;
> +	struct mcba_usb_ctx *ctx = NULL;
> +
> +	for (i = 0; i < MCBA_MAX_TX_URBS; i++) {
> +		if (priv->tx_context[i].ndx == MCBA_CTX_FREE) {
> +			ctx = &priv->tx_context[i];
> +			ctx->ndx = i;
> +
> +			if (cf) {
> +				ctx->can = true;
> +				ctx->dlc = cf->can_dlc;
> +			} else {
> +				ctx->can = false;
> +				ctx->dlc = 0;
> +			}
> +
> +			atomic_dec(&priv->free_ctx_cnt);
> +			break;
> +		}
> +	}
> +
> +	if (!atomic_read(&priv->free_ctx_cnt))
> +		/* That was the last free ctx. Slow down tx path */
> +		netif_stop_queue(priv->netdev);
> +
> +	return ctx;
> +}
> +
> +/* mcba_usb_free_ctx and mcba_usb_get_free_ctx are executed by different
> + * threads. The order of execution in below function is important.
> + */
> +static inline void mcba_usb_free_ctx(struct mcba_usb_ctx *ctx)
> +{
> +	/* Increase number of free ctxs before freeing ctx */
> +	atomic_inc(&ctx->priv->free_ctx_cnt);
> +
> +	ctx->ndx = MCBA_CTX_FREE;
> +
> +	/* Wake up the queue once ctx is marked free */
> +	netif_wake_queue(ctx->priv->netdev);
> +}
> +
> +static void mcba_usb_write_bulk_callback(struct urb *urb)
> +{
> +	struct mcba_usb_ctx *ctx = urb->context;
> +	struct net_device *netdev;
> +
> +	WARN_ON(!ctx);
> +
> +	netdev = ctx->priv->netdev;
> +
> +	if (ctx->can) {
> +		if (!netif_device_present(netdev))
> +			return;

Have a look at the 8dev driver, the call to usb_free_coherent() is done
always. I think you're leaking memory here.

> +
> +		netdev->stats.tx_packets++;
> +		netdev->stats.tx_bytes += ctx->dlc;
> +
> +		can_get_echo_skb(netdev, ctx->ndx);
> +	}
> +
> +	/* free up our allocated buffer */
> +	usb_free_coherent(urb->dev, urb->transfer_buffer_length,
> +			  urb->transfer_buffer, urb->transfer_dma);
> +
> +	if (urb->status)
> +		netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status);
> +
> +	/* Release the context */
> +	mcba_usb_free_ctx(ctx);
> +}
> +
> +/* Send data to device */
> +static netdev_tx_t mcba_usb_xmit(struct mcba_priv *priv,
> +				 struct mcba_usb_msg *usb_msg,
> +				 struct mcba_usb_ctx *ctx)
> +{
> +	struct urb *urb;
> +	u8 *buf;
> +	int err;
> +
> +	/* create a URB, and a buffer for it, and copy the data to the URB */
> +	urb = usb_alloc_urb(0, GFP_ATOMIC);
> +	if (!urb)
> +		return -ENOMEM;
> +
> +	buf = usb_alloc_coherent(priv->udev, MCBA_USB_TX_BUFF_SIZE, GFP_ATOMIC,
> +				 &urb->transfer_dma);
> +	if (!buf) {
> +		err = -ENOMEM;
> +		goto nomembuf;
> +	}
> +
> +	memcpy(buf, usb_msg, MCBA_USB_TX_BUFF_SIZE);
> +
> +	usb_fill_bulk_urb(urb, priv->udev,
> +			  usb_sndbulkpipe(priv->udev, MCBA_USB_EP_OUT), buf,
> +			  MCBA_USB_TX_BUFF_SIZE, mcba_usb_write_bulk_callback,
> +			  ctx);
> +
> +	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
> +	usb_anchor_urb(urb, &priv->tx_submitted);
> +
> +	err = usb_submit_urb(urb, GFP_ATOMIC);
> +	if (unlikely(err))
> +		goto failed;
> +
> +	/* Release our reference to this URB, the USB core will eventually free
> +	 * it entirely.
> +	 */
> +	usb_free_urb(urb);
> +
> +	return 0;
> +
> +failed:
> +	usb_unanchor_urb(urb);
> +	usb_free_coherent(priv->udev, MCBA_USB_TX_BUFF_SIZE, buf,
> +			  urb->transfer_dma);
> +
> +	if (err == -ENODEV)
> +		netif_device_detach(priv->netdev);
> +	else
> +		netdev_warn(priv->netdev, "failed tx_urb %d\n", err);
> +
> +nomembuf:
> +	usb_free_urb(urb);
> +
> +	return err;
> +}
> +
> +/* Send data to device */
> +static netdev_tx_t mcba_usb_start_xmit(struct sk_buff *skb,
> +				       struct net_device *netdev)
> +{
> +	struct mcba_priv *priv = netdev_priv(netdev);
> +	struct can_frame *cf = (struct can_frame *)skb->data;
> +	struct mcba_usb_msg_can usb_msg;
> +	struct mcba_usb_ctx *ctx = NULL;
> +	struct net_device_stats *stats = &priv->netdev->stats;
> +	u16 sid;
> +	int err;
> +
> +	if (can_dropped_invalid_skb(netdev, skb))
> +		return NETDEV_TX_OK;
> +
> +	ctx = mcba_usb_get_free_ctx(priv, cf);
> +	if (!ctx)
> +		return NETDEV_TX_BUSY;
> +
> +	can_put_echo_skb(skb, priv->netdev, ctx->ndx);
> +
> +	usb_msg.cmd_id = MBCA_CMD_TRANSMIT_MESSAGE_EV;
> +	if (cf->can_id & CAN_EFF_FLAG) {
> +		/* SIDH    | SIDL                 | EIDH   | EIDL
> +		 * 28 - 21 | 20 19 18 x x x 17 16 | 15 - 8 | 7 - 0
> +		 */
> +		sid = MCBA_SIDL_EXID_MASK;
> +		/* store 28-18 bits */
> +		sid |= (cf->can_id & 0x1ffc0000) >> 13;
> +		/* store 17-16 bits */
> +		sid |= (cf->can_id & 0x30000) >> 16;
> +		put_unaligned_be16(sid, &usb_msg.sid);
> +
> +		/* store 15-0 bits */
> +		put_unaligned_be16(cf->can_id & 0xffff, &usb_msg.eid);
> +	} else {
> +		/* SIDH   | SIDL
> +		 * 10 - 3 | 2 1 0 x x x x x
> +		 */
> +		put_unaligned_be16((cf->can_id & CAN_SFF_MASK) << 5,
> +				   &usb_msg.sid);
> +		usb_msg.eid = 0;
> +	}
> +
> +	usb_msg.dlc = cf->can_dlc;
> +
> +	memcpy(usb_msg.data, cf->data, usb_msg.dlc);
> +
> +	if (cf->can_id & CAN_RTR_FLAG)
> +		usb_msg.dlc |= MCBA_DLC_RTR_MASK;
> +
> +	err = mcba_usb_xmit(priv, (struct mcba_usb_msg *)&usb_msg, ctx);
> +	if (err)
> +		goto xmit_failed;
> +
> +	return NETDEV_TX_OK;
> +
> +xmit_failed:
> +	can_free_echo_skb(priv->netdev, ctx->ndx);
> +	mcba_usb_free_ctx(ctx);
> +	dev_kfree_skb(skb);
> +	stats->tx_dropped++;
> +
> +	return NETDEV_TX_OK;
> +}
> +
> +/* Send cmd to device */
> +static void mcba_usb_xmit_cmd(struct mcba_priv *priv,
> +			      struct mcba_usb_msg *usb_msg)
> +{
> +	struct mcba_usb_ctx *ctx = NULL;
> +	int err;
> +
> +	ctx = mcba_usb_get_free_ctx(priv, NULL);
> +	if (!ctx) {
> +		netdev_err(priv->netdev,
> +			   "Lack of free ctx. Sending (%d) cmd aborted",
> +			   usb_msg->cmd_id);
> +
> +		return;
> +	}
> +
> +	err = mcba_usb_xmit(priv, usb_msg, ctx);
> +	if (err)
> +		netdev_err(priv->netdev, "Failed to send cmd (%d)",
> +			   usb_msg->cmd_id);
> +}
> +
> +static void mcba_usb_xmit_change_bitrate(struct mcba_priv *priv, u16 bitrate)
> +{
> +	struct mcba_usb_msg_change_bitrate usb_msg;
> +
> +	usb_msg.cmd_id = MBCA_CMD_CHANGE_BIT_RATE;

use C99 initializers please.

> +	put_unaligned_be16(bitrate, &usb_msg.bitrate);
> +
> +	mcba_usb_xmit_cmd(priv, (struct mcba_usb_msg *)&usb_msg);
> +}
> +
> +static void mcba_usb_xmit_read_fw_ver(struct mcba_priv *priv, u8 pic)
> +{
> +	struct mcba_usb_msg_fw_ver usb_msg;
> +
> +	usb_msg.cmd_id = MBCA_CMD_READ_FW_VERSION;
> +	usb_msg.pic = pic;
>
use C99 initializers please.

> +	mcba_usb_xmit_cmd(priv, (struct mcba_usb_msg *)&usb_msg);
> +}
> +
> +static void mcba_usb_process_can(struct mcba_priv *priv,
> +				 struct mcba_usb_msg_can *msg)
> +{
> +	struct can_frame *cf;
> +	struct sk_buff *skb;
> +	struct net_device_stats *stats = &priv->netdev->stats;
> +	u16 sid;
> +
> +	skb = alloc_can_skb(priv->netdev, &cf);
> +	if (!skb)
> +		return;
> +
> +	sid = get_unaligned_be16(&msg->sid);
> +
> +	if (sid & MCBA_SIDL_EXID_MASK) {
> +		/* SIDH    | SIDL                 | EIDH   | EIDL
> +		 * 28 - 21 | 20 19 18 x x x 17 16 | 15 - 8 | 7 - 0
> +		 */
> +		cf->can_id = CAN_EFF_FLAG;
> +
> +		/* store 28-18 bits */
> +		cf->can_id |= (sid & 0xffe0) << 13;
> +		/* store 17-16 bits */
> +		cf->can_id |= (sid & 3) << 16;
> +		/* store 15-0 bits */
> +		cf->can_id |= get_unaligned_be16(&msg->eid);
> +	} else {
> +		/* SIDH   | SIDL
> +		 * 10 - 3 | 2 1 0 x x x x x
> +		 */
> +		cf->can_id = (sid & 0xffe0) >> 5;
> +	}
> +
> +	if (msg->dlc & MCBA_DLC_RTR_MASK)
> +		cf->can_id |= CAN_RTR_FLAG;
> +
> +	cf->can_dlc = get_can_dlc(msg->dlc & MCBA_DLC_MASK);
> +
> +	memcpy(cf->data, msg->data, cf->can_dlc);
> +
> +	stats->rx_packets++;
> +	stats->rx_bytes += cf->can_dlc;
> +
> +	netif_rx(skb);
> +}
> +
> +static void mcba_usb_process_ka_usb(struct mcba_priv *priv,
> +				    struct mcba_usb_msg_ka_usb *msg)
> +{
> +	if (unlikely(priv->usb_ka_first_pass)) {
> +		netdev_info(priv->netdev, "PIC USB version %hhu.%hhu\n",
> +			    msg->soft_ver_major, msg->soft_ver_minor);
> +
> +		priv->usb_ka_first_pass = false;
> +	}
> +
> +	if (msg->termination_state)
> +		priv->can.termination = MCBA_TERMINATION_ENABLED;
> +	else
> +		priv->can.termination = MCBA_TERMINATION_DISABLED;
> +}
> +
> +static u32 convert_can2host_bitrate(struct mcba_usb_msg_ka_can *msg)
> +{
> +	const u32 bitrate = get_unaligned_be16(&msg->can_bitrate);
> +
> +	if ((bitrate == 33) || (bitrate == 83))
> +		return bitrate * 1000 + 333;
> +	else
> +		return bitrate * 1000;
> +}
> +
> +static void mcba_usb_process_ka_can(struct mcba_priv *priv,
> +				    struct mcba_usb_msg_ka_can *msg)
> +{
> +	if (unlikely(priv->can_ka_first_pass)) {
> +		netdev_info(priv->netdev, "PIC CAN version %hhu.%hhu\n",
> +			    msg->soft_ver_major, msg->soft_ver_minor);
> +
> +		priv->can_ka_first_pass = false;
> +	}
> +
> +	if (unlikely(priv->can_speed_check)) {
> +		const u32 bitrate = convert_can2host_bitrate(msg);
> +
> +		priv->can_speed_check = false;
> +
> +		if (bitrate != priv->can.bittiming.bitrate)
> +			netdev_err(
> +			    priv->netdev,
> +			    "Wrong bitrate reported by the device (%u). Expected %u",
> +			    bitrate, priv->can.bittiming.bitrate);
> +	}
> +
> +	priv->bec.txerr = msg->tx_err_cnt;
> +	priv->bec.rxerr = msg->rx_err_cnt;
> +
> +	if (msg->tx_bus_off)
> +		priv->can.state = CAN_STATE_BUS_OFF;
> +
> +	else if ((priv->bec.txerr > MCBA_CAN_STATE_ERR_PSV_TH) ||
> +		 (priv->bec.rxerr > MCBA_CAN_STATE_ERR_PSV_TH))
> +		priv->can.state = CAN_STATE_ERROR_PASSIVE;
> +
> +	else if ((priv->bec.txerr > MCBA_CAN_STATE_WRN_TH) ||
> +		 (priv->bec.rxerr > MCBA_CAN_STATE_WRN_TH))
> +		priv->can.state = CAN_STATE_ERROR_WARNING;
> +}
> +
> +static void mcba_usb_process_rx(struct mcba_priv *priv,
> +				struct mcba_usb_msg *msg)
> +{
> +	switch (msg->cmd_id) {
> +	case MBCA_CMD_I_AM_ALIVE_FROM_CAN:
> +		mcba_usb_process_ka_can(priv,
> +					(struct mcba_usb_msg_ka_can *)msg);
> +		break;
> +
> +	case MBCA_CMD_I_AM_ALIVE_FROM_USB:
> +		mcba_usb_process_ka_usb(priv,
> +					(struct mcba_usb_msg_ka_usb *)msg);
> +		break;
> +
> +	case MBCA_CMD_RECEIVE_MESSAGE:
> +		mcba_usb_process_can(priv, (struct mcba_usb_msg_can *)msg);
> +		break;
> +
> +	case MBCA_CMD_NOTHING_TO_SEND:
> +		/* Side effect of communication between PIC_USB and PIC_CAN.
> +		 * PIC_CAN is telling us that it has nothing to send
> +		 */
> +		break;
> +
> +	case MBCA_CMD_TRANSMIT_MESSAGE_RSP:
> +		/* Transmission response from the device containing timestamp */
> +		break;
> +
> +	default:
> +		netdev_warn(priv->netdev, "Unsupported msg (0x%hhX)",
> +			    msg->cmd_id);
> +		break;
> +	}
> +}
> +
> +/* Callback for reading data from device
> + *
> + * Check urb status, call read function and resubmit urb read operation.
> + */
> +static void mcba_usb_read_bulk_callback(struct urb *urb)
> +{
> +	struct mcba_priv *priv = urb->context;
> +	struct net_device *netdev;
> +	int retval;
> +	int pos = 0;
> +
> +	netdev = priv->netdev;
> +
> +	if (!netif_device_present(netdev))
> +		return;
> +
> +	switch (urb->status) {
> +	case 0: /* success */
> +		break;
> +
> +	case -ENOENT:
> +	case -ESHUTDOWN:
> +		return;
> +
> +	default:
> +		netdev_info(netdev, "Rx URB aborted (%d)\n", urb->status);
> +
> +		goto resubmit_urb;
> +	}
> +
> +	while (pos < urb->actual_length) {
> +		struct mcba_usb_msg *msg;
> +
> +		if (pos + sizeof(struct mcba_usb_msg) > urb->actual_length) {
> +			netdev_err(priv->netdev, "format error\n");
> +			break;
> +		}
> +
> +		msg = (struct mcba_usb_msg *)(urb->transfer_buffer + pos);
> +		mcba_usb_process_rx(priv, msg);
> +
> +		pos += sizeof(struct mcba_usb_msg);
> +	}
> +
> +resubmit_urb:
> +
> +	usb_fill_bulk_urb(urb, priv->udev,
> +			  usb_rcvbulkpipe(priv->udev, MCBA_USB_EP_OUT),
> +			  urb->transfer_buffer, MCBA_USB_RX_BUFF_SIZE,
> +			  mcba_usb_read_bulk_callback, priv);
> +
> +	retval = usb_submit_urb(urb, GFP_ATOMIC);
> +
> +	if (retval == -ENODEV)
> +		netif_device_detach(netdev);
> +	else if (retval)
> +		netdev_err(netdev, "failed resubmitting read bulk urb: %d\n",
> +			   retval);
> +}
> +
> +/* Start USB device */
> +static int mcba_usb_start(struct mcba_priv *priv)
> +{
> +	struct net_device *netdev = priv->netdev;
> +	int err, i;
> +
> +	mcba_init_ctx(priv);
> +
> +	for (i = 0; i < MCBA_MAX_RX_URBS; i++) {
> +		struct urb *urb = NULL;
> +		u8 *buf;
> +
> +		/* create a URB, and a buffer for it */
> +		urb = usb_alloc_urb(0, GFP_KERNEL);
> +		if (!urb) {
> +			err = -ENOMEM;
> +			break;
> +		}
> +
> +		buf = usb_alloc_coherent(priv->udev, MCBA_USB_RX_BUFF_SIZE,
> +					 GFP_KERNEL, &urb->transfer_dma);
> +		if (!buf) {
> +			netdev_err(netdev, "No memory left for USB buffer\n");
> +			usb_free_urb(urb);
> +			err = -ENOMEM;
> +			break;
> +		}
> +
> +		usb_fill_bulk_urb(urb, priv->udev,
> +				  usb_rcvbulkpipe(priv->udev, MCBA_USB_EP_IN),
> +				  buf, MCBA_USB_RX_BUFF_SIZE,
> +				  mcba_usb_read_bulk_callback, priv);
> +		urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
> +		usb_anchor_urb(urb, &priv->rx_submitted);
> +
> +		err = usb_submit_urb(urb, GFP_KERNEL);
> +		if (err) {
> +			usb_unanchor_urb(urb);
> +			usb_free_coherent(priv->udev, MCBA_USB_RX_BUFF_SIZE,
> +					  buf, urb->transfer_dma);
> +			usb_free_urb(urb);
> +			break;
> +		}
> +
> +		/* Drop reference, USB core will take care of freeing it */
> +		usb_free_urb(urb);
> +	}
> +
> +	/* Did we submit any URBs */
> +	if (i == 0) {
> +		netdev_warn(netdev, "couldn't setup read URBs\n");
> +		return err;
> +	}
> +
> +	/* Warn if we've couldn't transmit all the URBs */
> +	if (i < MCBA_MAX_RX_URBS)
> +		netdev_warn(netdev, "rx performance may be slow\n");
> +
> +	mcba_usb_xmit_read_fw_ver(priv, MCBA_VER_REQ_USB);
> +	mcba_usb_xmit_read_fw_ver(priv, MCBA_VER_REQ_CAN);
> +
> +	return err;

return 0;

> +}
> +
> +/* Open USB device */
> +static int mcba_usb_open(struct net_device *netdev)
> +{
> +	struct mcba_priv *priv = netdev_priv(netdev);
> +	int err;
> +
> +	/* common open */
> +	err = open_candev(netdev);
> +	if (err)
> +		return err;
> +
> +	priv->can_speed_check = true;
> +	priv->can.state = CAN_STATE_ERROR_ACTIVE;
> +
> +	netif_start_queue(netdev);
> +
> +	return 0;
> +}
> +
> +static void mcba_urb_unlink(struct mcba_priv *priv)
> +{
> +	usb_kill_anchored_urbs(&priv->rx_submitted);
> +	usb_kill_anchored_urbs(&priv->tx_submitted);
> +}
> +
> +/* Close USB device */
> +static int mcba_usb_close(struct net_device *netdev)
> +{
> +	struct mcba_priv *priv = netdev_priv(netdev);
> +
> +	priv->can.state = CAN_STATE_STOPPED;
> +
> +	netif_stop_queue(netdev);
> +
> +	/* Stop polling */
> +	mcba_urb_unlink(priv);
> +
> +	close_candev(netdev);
> +
> +	return 0;
> +}
> +
> +/* Set network device mode
> + *
> + * Maybe we should leave this function empty, because the device
> + * set mode variable with open command.
> + */
> +static int mcba_net_set_mode(struct net_device *netdev, enum can_mode mode)
> +{
> +	return 0;
> +}
> +
> +static int mcba_net_get_berr_counter(const struct net_device *netdev,
> +				     struct can_berr_counter *bec)
> +{
> +	struct mcba_priv *priv = netdev_priv(netdev);
> +
> +	bec->txerr = priv->bec.txerr;
> +	bec->rxerr = priv->bec.rxerr;
> +
> +	return 0;
> +}
> +
> +static const struct net_device_ops mcba_netdev_ops = {
> +	.ndo_open = mcba_usb_open,
> +	.ndo_stop = mcba_usb_close,
> +	.ndo_start_xmit = mcba_usb_start_xmit,
> +};
> +
> +/* Microchip CANBUS has hardcoded bittiming values by default.
> + * This function sends request via USB to change the speed and align bittiming
> + * values for presentation purposes only
> + */
> +static int mcba_net_set_bittiming(struct net_device *netdev)
> +{
> +	struct mcba_priv *priv = netdev_priv(netdev);
> +	const u16 bitrate_kbps = priv->can.bittiming.bitrate / 1000;
> +
> +	mcba_usb_xmit_change_bitrate(priv, bitrate_kbps);
> +
> +	return 0;
> +}
> +
> +static int mcba_set_termination(struct net_device *netdev, u16 term)
> +{
> +	struct mcba_priv *priv = netdev_priv(netdev);
> +	struct mcba_usb_msg_termination usb_msg;
> +
> +	usb_msg.cmd_id = MBCA_CMD_SETUP_TERMINATION_RESISTANCE;

use C99 initializers please:

	struct mcba_usb_msg_termination usb_msg = {
		.cmd_id = MBCA_CMD_SETUP_TERMINATION_RESISTANCE;
	};

Then all the other struct members are automatically nulled.

> +
> +	if (term == MCBA_TERMINATION_ENABLED)
> +		usb_msg.termination = 1;
> +	else
> +		usb_msg.termination = 0;
> +
> +	mcba_usb_xmit_cmd(priv, (struct mcba_usb_msg *)&usb_msg);
> +
> +	return 0;
> +}
> +
> +static int mcba_usb_probe(struct usb_interface *intf,
> +			  const struct usb_device_id *id)
> +{
> +	struct net_device *netdev;
> +	struct mcba_priv *priv;
> +	int err = -ENOMEM;
> +	struct usb_device *usbdev = interface_to_usbdev(intf);
> +
> +	netdev = alloc_candev(sizeof(struct mcba_priv), MCBA_MAX_TX_URBS);
> +	if (!netdev) {
> +		dev_err(&intf->dev, "Couldn't alloc candev\n");
> +		return -ENOMEM;
> +	}
> +
> +	priv = netdev_priv(netdev);
> +
> +	priv->udev = usbdev;
> +	priv->netdev = netdev;
> +	priv->usb_ka_first_pass = true;
> +	priv->can_ka_first_pass = true;
> +	priv->can_speed_check = false;
> +
> +	init_usb_anchor(&priv->rx_submitted);
> +	init_usb_anchor(&priv->tx_submitted);
> +
> +	usb_set_intfdata(intf, priv);
> +
> +	/* Init CAN device */
> +	priv->can.state = CAN_STATE_STOPPED;
> +	priv->can.termination_const = mcba_termination;
> +	priv->can.termination_const_cnt = ARRAY_SIZE(mcba_termination);
> +	priv->can.bitrate_const = mcba_bitrate;
> +	priv->can.bitrate_const_cnt = ARRAY_SIZE(mcba_bitrate);
> +
> +	priv->can.do_set_termination = mcba_set_termination;
> +	priv->can.do_set_mode = mcba_net_set_mode;
> +	priv->can.do_get_berr_counter = mcba_net_get_berr_counter;
> +	priv->can.do_set_bittiming = mcba_net_set_bittiming;
> +
> +	netdev->netdev_ops = &mcba_netdev_ops;
> +
> +	netdev->flags |= IFF_ECHO; /* we support local echo */
> +
> +	SET_NETDEV_DEV(netdev, &intf->dev);
> +
> +	err = register_candev(netdev);
> +	if (err) {
> +		netdev_err(netdev, "couldn't register CAN device: %d\n", err);
> +
> +		netif_device_detach(priv->netdev);

Why detach here, it's has not been regeistered.

> +
> +		goto cleanup_candev;

better rename to cleanup_free_candev

> +	}
> +
> +	/* Start USB device only if we have successfuly registered CAN device */
> +	err = mcba_usb_start(priv);
> +	if (err) {
> +		if (err == -ENODEV)
> +			netif_device_detach(priv->netdev);

You have to call unregister_candev(). Do this via a "goto
cleanup_unregister_candev;"

> +
> +		netdev_warn(netdev, "couldn't start device: %d\n", err);
> +
> +		goto cleanup_candev;
> +	}
> +
> +	dev_info(&intf->dev, "Microchip CAN BUS analizer connected\n");
> +
> +	return err;
	return 0;

cleanup_unregister_candev:
	unregister_candev();

> +
> +cleanup_candev:
cleanup_free_candev:
> +	free_candev(netdev);
> +
> +	return err;
> +}
> +
> +/* Called by the usb core when driver is unloaded or device is removed */
> +static void mcba_usb_disconnect(struct usb_interface *intf)
> +{
> +	struct mcba_priv *priv = usb_get_intfdata(intf);
> +
> +	usb_set_intfdata(intf, NULL);
> +
> +	netdev_info(priv->netdev, "device disconnected\n");
> +
> +	unregister_candev(priv->netdev);
> +	free_candev(priv->netdev);
> +
> +	mcba_urb_unlink(priv);
> +}
> +
> +static struct usb_driver mcba_usb_driver = {
> +	.name = MCBA_MODULE_NAME,
> +	.probe = mcba_usb_probe,
> +	.disconnect = mcba_usb_disconnect,
> +	.id_table = mcba_usb_table,
> +};
> +
> +module_usb_driver(mcba_usb_driver);
> +
> +MODULE_AUTHOR("Remigiusz Kołłątaj <remigiusz.kollataj@mobica.com>");
> +MODULE_DESCRIPTION("SocketCAN driver for Microchip CAN BUS Analyzer Tool");
> +MODULE_LICENSE("GPL v2");
> 

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   |


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^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH v3] can: mcba_usb: Add support for Microchip CAN BUS Analyzer
  2017-04-13 15:56 ` Marc Kleine-Budde
@ 2017-04-14  8:25   ` Kołłątaj, Remigiusz
  2017-04-14 12:24     ` Marc Kleine-Budde
  0 siblings, 1 reply; 8+ messages in thread
From: Kołłątaj, Remigiusz @ 2017-04-14  8:25 UTC (permalink / raw)
  To: Marc Kleine-Budde; +Cc: linux-can

Hi Marc,

Thanks for the review. My answers/comments inline.

On 13 April 2017 at 17:56, Marc Kleine-Budde <mkl@pengutronix.de> wrote:
>
> On 01/25/2017 02:02 PM, Remigiusz Kołłątaj wrote:
> > SocketCAN driver for Microchip CAN BUS Analyzer
> > (http://www.microchip.com/development-tools/)
> >
> > Changes since v2:
> > - improved/simplified CAN ID conversion
> > - functions for transmission of skb and cmd separated
> > - fixed/improved netif_stop_queue handling
> > - style/cosmetic corrections
> >
> > Changes since v1:
> > - Termination handling reimplemented to fit new netlink API
> > (IFLA_CAN_TERMINATION)
> > - Bitrate handling reimplemented to fit new netlink API
> > (IFLA_CAN_BITRATE)
> > - CAN ID conversion refactored (changed from macro to inline functions)
> > - CAN DLC handling using get_can_dlc()
> > - Endianness handling for can_speed introduced
> > - Debugging removed
> > - Redundant error prints removed
> > - Style/cosmetic corrections (i.e. macro names, redefs, inits etc.)
> >
> > Signed-off-by: Remigiusz Kołłątaj <remigiusz.kollataj@mobica.com>
>
> Can you pleeas add LED support, see commit:
>
>     adccadb92f05 can: flexcan: add LED trigger support
>
> as an example. More comments inline.
>

In MBCA leds are controlled by device itself - CAN status leds are
connected directly CANTX and CANRX pins of PIC controller and CAN
Error led is driven by firmware.

> > ---
> >  drivers/net/can/usb/Kconfig    |   6 +
> >  drivers/net/can/usb/Makefile   |   1 +
> >  drivers/net/can/usb/mcba_usb.c | 894 +++++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 901 insertions(+)
> >  create mode 100644 drivers/net/can/usb/mcba_usb.c
> >
> > diff --git a/drivers/net/can/usb/Kconfig b/drivers/net/can/usb/Kconfig
> > index 8483a40e7e9e..2d0313eb31c0 100644
> > --- a/drivers/net/can/usb/Kconfig
> > +++ b/drivers/net/can/usb/Kconfig
> > @@ -81,4 +81,10 @@ config CAN_8DEV_USB
> >         This driver supports the USB2CAN interface
> >         from 8 devices (http://www.8devices.com).
> >
> > +config CAN_MCBA_USB
> > +     tristate "Microchip CAN BUS Analyzer interface"
> > +     ---help---
> > +       This driver supports the CAN BUS Analyzer interface
> > +       from Microchip (http://www.microchip.com/development-tools/).
> > +
> >  endmenu
> > diff --git a/drivers/net/can/usb/Makefile b/drivers/net/can/usb/Makefile
> > index a64cf983fb87..164453fd55d0 100644
> > --- a/drivers/net/can/usb/Makefile
> > +++ b/drivers/net/can/usb/Makefile
> > @@ -8,3 +8,4 @@ obj-$(CONFIG_CAN_GS_USB) += gs_usb.o
> >  obj-$(CONFIG_CAN_KVASER_USB) += kvaser_usb.o
> >  obj-$(CONFIG_CAN_PEAK_USB) += peak_usb/
> >  obj-$(CONFIG_CAN_8DEV_USB) += usb_8dev.o
> > +obj-$(CONFIG_CAN_MCBA_USB) += mcba_usb.o
> > diff --git a/drivers/net/can/usb/mcba_usb.c b/drivers/net/can/usb/mcba_usb.c
> > new file mode 100644
> > index 000000000000..2c92f3903034
> > --- /dev/null
> > +++ b/drivers/net/can/usb/mcba_usb.c
> > @@ -0,0 +1,894 @@
> > +/* SocketCAN driver for Microchip CAN BUS Analyzer Tool
> > + *
> > + * Copyright (C) 2017 Mobica Limited
> > + *
> > + * This program is free software; you can redistribute it and/or modify it
> > + * under the terms of the GNU General Public License as published
> > + * by the Free Software Foundation; version 2 of the License.
> > + *
> > + * This program is distributed in the hope that it will be useful, but
> > + * WITHOUT ANY WARRANTY; without even the implied warranty of
> > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> > + * General Public License for more details.
> > + *
> > + * You should have received a copy of the GNU General Public License along
> > + * with this program.
> > + *
> > + * This driver is inspired by the 4.6.2 version of net/can/usb/usb_8dev.c
> > + */
> > +
> > +#include <asm/unaligned.h>
> > +#include <linux/can.h>
> > +#include <linux/can/dev.h>
> > +#include <linux/can/error.h>
> > +#include <linux/module.h>
> > +#include <linux/netdevice.h>
> > +#include <linux/signal.h>
> > +#include <linux/slab.h>
> > +#include <linux/usb.h>
> > +
> > +/* vendor and product id */
> > +#define MCBA_MODULE_NAME "mcba_usb"
> > +#define MCBA_VENDOR_ID 0x04d8
> > +#define MCBA_PRODUCT_ID 0x0a30
> > +
> > +/* driver constants */
> > +#define MCBA_MAX_RX_URBS 20
> > +#define MCBA_MAX_TX_URBS 20
> > +#define MCBA_CTX_FREE MCBA_MAX_TX_URBS
> > +
> > +/* RX buffer must be bigger than msg size since at the
> > + * beggining USB messages are stacked.
> > + */
> > +#define MCBA_USB_RX_BUFF_SIZE 64
> > +#define MCBA_USB_TX_BUFF_SIZE (sizeof(struct mcba_usb_msg))
> > +
> > +/* MCBA endpoint numbers */
> > +#define MCBA_USB_EP_IN 1
> > +#define MCBA_USB_EP_OUT 1
> > +
> > +/* Microchip command id */
> > +#define MBCA_CMD_RECEIVE_MESSAGE 0xE3
> > +#define MBCA_CMD_I_AM_ALIVE_FROM_CAN 0xF5
> > +#define MBCA_CMD_I_AM_ALIVE_FROM_USB 0xF7
> > +#define MBCA_CMD_CHANGE_BIT_RATE 0xA1
> > +#define MBCA_CMD_TRANSMIT_MESSAGE_EV 0xA3
> > +#define MBCA_CMD_SETUP_TERMINATION_RESISTANCE 0xA8
> > +#define MBCA_CMD_READ_FW_VERSION 0xA9
> > +#define MBCA_CMD_NOTHING_TO_SEND 0xFF
> > +#define MBCA_CMD_TRANSMIT_MESSAGE_RSP 0xE2
> > +
> > +#define MCBA_VER_REQ_USB 1
> > +#define MCBA_VER_REQ_CAN 2
> > +
> > +#define MCBA_SIDL_EXID_MASK 0x8
> > +#define MCBA_DLC_MASK 0xf
> > +#define MCBA_DLC_RTR_MASK 0x40
> > +
> > +#define MCBA_CAN_STATE_WRN_TH 95
> > +#define MCBA_CAN_STATE_ERR_PSV_TH 127
> > +
> > +#define MCBA_TERMINATION_DISABLED CAN_TERMINATION_DISABLED
> > +#define MCBA_TERMINATION_ENABLED 120
> > +
> > +struct mcba_usb_ctx {
> > +     struct mcba_priv *priv;
> > +     u32 ndx;
> > +     u8 dlc;
> > +     bool can;
> > +};
> > +
> > +/* Structure to hold all of our device specific stuff */
> > +struct mcba_priv {
> > +     struct can_priv can; /* must be the first member */
> > +     struct sk_buff *echo_skb[MCBA_MAX_TX_URBS];
> > +     struct mcba_usb_ctx tx_context[MCBA_MAX_TX_URBS];
> > +     struct usb_device *udev;
> > +     struct net_device *netdev;
> > +     struct usb_anchor tx_submitted;
> > +     struct usb_anchor rx_submitted;
> > +     struct can_berr_counter bec;
> > +     bool usb_ka_first_pass;
> > +     bool can_ka_first_pass;
> > +     bool can_speed_check;
> > +     atomic_t free_ctx_cnt;
> > +};
> > +
> > +/* CAN frame */
> > +struct __packed mcba_usb_msg_can {
> > +     u8 cmd_id;
> > +     __be16 eid;
> > +     __be16 sid;
> > +     u8 dlc;
> > +     u8 data[8];
> > +     u8 timestamp[4];
> > +     u8 checksum;
> > +};
> > +
> > +/* command frame */
> > +struct __packed mcba_usb_msg {
> > +     u8 cmd_id;
> > +     u8 unused[18];
> > +};
> > +
> > +struct __packed mcba_usb_msg_ka_usb {
> > +     u8 cmd_id;
> > +     u8 termination_state;
> > +     u8 soft_ver_major;
> > +     u8 soft_ver_minor;
> > +     u8 unused[15];
> > +};
> > +
> > +struct __packed mcba_usb_msg_ka_can {
> > +     u8 cmd_id;
> > +     u8 tx_err_cnt;
> > +     u8 rx_err_cnt;
> > +     u8 rx_buff_ovfl;
> > +     u8 tx_bus_off;
> > +     __be16 can_bitrate;
> > +     __le16 rx_lost;
> > +     u8 can_stat;
> > +     u8 soft_ver_major;
> > +     u8 soft_ver_minor;
> > +     u8 debug_mode;
> > +     u8 test_complete;
> > +     u8 test_result;
> > +     u8 unused[4];
> > +};
> > +
> > +struct __packed mcba_usb_msg_change_bitrate {
> > +     u8 cmd_id;
> > +     __be16 bitrate;
> > +     u8 unused[16];
> > +};
> > +
> > +struct __packed mcba_usb_msg_termination {
> > +     u8 cmd_id;
> > +     u8 termination;
> > +     u8 unused[17];
> > +};
> > +
> > +struct __packed mcba_usb_msg_fw_ver {
> > +     u8 cmd_id;
> > +     u8 pic;
> > +     u8 unused[17];
> > +};
> > +
> > +static const struct usb_device_id mcba_usb_table[] = {
> > +     { USB_DEVICE(MCBA_VENDOR_ID, MCBA_PRODUCT_ID) },
> > +     {} /* Terminating entry */
> > +};
> > +
> > +MODULE_DEVICE_TABLE(usb, mcba_usb_table);
> > +
> > +static const u16 mcba_termination[] = { MCBA_TERMINATION_DISABLED,
> > +                                     MCBA_TERMINATION_ENABLED };
> > +
> > +static const u32 mcba_bitrate[] = { 20000,  33333,  50000,  80000,  83333,
> > +                                 100000, 125000, 150000, 175000, 200000,
> > +                                 225000, 250000, 275000, 300000, 500000,
> > +                                 625000, 800000, 1000000 };
> > +
> > +static inline void mcba_init_ctx(struct mcba_priv *priv)
> > +{
> > +     int i = 0;
> > +
> > +     for (i = 0; i < MCBA_MAX_TX_URBS; i++) {
> > +             priv->tx_context[i].ndx = MCBA_CTX_FREE;
> > +             priv->tx_context[i].priv = priv;
> > +     }
> > +
> > +     atomic_set(&priv->free_ctx_cnt, ARRAY_SIZE(priv->tx_context));
> > +}
> > +
> > +static inline struct mcba_usb_ctx *mcba_usb_get_free_ctx(struct mcba_priv *priv,
> > +                                                      struct can_frame *cf)
> > +{
> > +     int i = 0;
> > +     struct mcba_usb_ctx *ctx = NULL;
> > +
> > +     for (i = 0; i < MCBA_MAX_TX_URBS; i++) {
> > +             if (priv->tx_context[i].ndx == MCBA_CTX_FREE) {
> > +                     ctx = &priv->tx_context[i];
> > +                     ctx->ndx = i;
> > +
> > +                     if (cf) {
> > +                             ctx->can = true;
> > +                             ctx->dlc = cf->can_dlc;
> > +                     } else {
> > +                             ctx->can = false;
> > +                             ctx->dlc = 0;
> > +                     }
> > +
> > +                     atomic_dec(&priv->free_ctx_cnt);
> > +                     break;
> > +             }
> > +     }
> > +
> > +     if (!atomic_read(&priv->free_ctx_cnt))
> > +             /* That was the last free ctx. Slow down tx path */
> > +             netif_stop_queue(priv->netdev);
> > +
> > +     return ctx;
> > +}
> > +
> > +/* mcba_usb_free_ctx and mcba_usb_get_free_ctx are executed by different
> > + * threads. The order of execution in below function is important.
> > + */
> > +static inline void mcba_usb_free_ctx(struct mcba_usb_ctx *ctx)
> > +{
> > +     /* Increase number of free ctxs before freeing ctx */
> > +     atomic_inc(&ctx->priv->free_ctx_cnt);
> > +
> > +     ctx->ndx = MCBA_CTX_FREE;
> > +
> > +     /* Wake up the queue once ctx is marked free */
> > +     netif_wake_queue(ctx->priv->netdev);
> > +}
> > +
> > +static void mcba_usb_write_bulk_callback(struct urb *urb)
> > +{
> > +     struct mcba_usb_ctx *ctx = urb->context;
> > +     struct net_device *netdev;
> > +
> > +     WARN_ON(!ctx);
> > +
> > +     netdev = ctx->priv->netdev;
> > +
> > +     if (ctx->can) {
> > +             if (!netif_device_present(netdev))
> > +                     return;
>
> Have a look at the 8dev driver, the call to usb_free_coherent() is done
> always. I think you're leaking memory here.

You are right. I will fix that.

>
> > +
> > +             netdev->stats.tx_packets++;
> > +             netdev->stats.tx_bytes += ctx->dlc;
> > +
> > +             can_get_echo_skb(netdev, ctx->ndx);
> > +     }
> > +
> > +     /* free up our allocated buffer */
> > +     usb_free_coherent(urb->dev, urb->transfer_buffer_length,
> > +                       urb->transfer_buffer, urb->transfer_dma);
> > +
> > +     if (urb->status)
> > +             netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status);
> > +
> > +     /* Release the context */
> > +     mcba_usb_free_ctx(ctx);
> > +}
> > +
> > +/* Send data to device */
> > +static netdev_tx_t mcba_usb_xmit(struct mcba_priv *priv,
> > +                              struct mcba_usb_msg *usb_msg,
> > +                              struct mcba_usb_ctx *ctx)
> > +{
> > +     struct urb *urb;
> > +     u8 *buf;
> > +     int err;
> > +
> > +     /* create a URB, and a buffer for it, and copy the data to the URB */
> > +     urb = usb_alloc_urb(0, GFP_ATOMIC);
> > +     if (!urb)
> > +             return -ENOMEM;
> > +
> > +     buf = usb_alloc_coherent(priv->udev, MCBA_USB_TX_BUFF_SIZE, GFP_ATOMIC,
> > +                              &urb->transfer_dma);
> > +     if (!buf) {
> > +             err = -ENOMEM;
> > +             goto nomembuf;
> > +     }
> > +
> > +     memcpy(buf, usb_msg, MCBA_USB_TX_BUFF_SIZE);
> > +
> > +     usb_fill_bulk_urb(urb, priv->udev,
> > +                       usb_sndbulkpipe(priv->udev, MCBA_USB_EP_OUT), buf,
> > +                       MCBA_USB_TX_BUFF_SIZE, mcba_usb_write_bulk_callback,
> > +                       ctx);
> > +
> > +     urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
> > +     usb_anchor_urb(urb, &priv->tx_submitted);
> > +
> > +     err = usb_submit_urb(urb, GFP_ATOMIC);
> > +     if (unlikely(err))
> > +             goto failed;
> > +
> > +     /* Release our reference to this URB, the USB core will eventually free
> > +      * it entirely.
> > +      */
> > +     usb_free_urb(urb);
> > +
> > +     return 0;
> > +
> > +failed:
> > +     usb_unanchor_urb(urb);
> > +     usb_free_coherent(priv->udev, MCBA_USB_TX_BUFF_SIZE, buf,
> > +                       urb->transfer_dma);
> > +
> > +     if (err == -ENODEV)
> > +             netif_device_detach(priv->netdev);
> > +     else
> > +             netdev_warn(priv->netdev, "failed tx_urb %d\n", err);
> > +
> > +nomembuf:
> > +     usb_free_urb(urb);
> > +
> > +     return err;
> > +}
> > +
> > +/* Send data to device */
> > +static netdev_tx_t mcba_usb_start_xmit(struct sk_buff *skb,
> > +                                    struct net_device *netdev)
> > +{
> > +     struct mcba_priv *priv = netdev_priv(netdev);
> > +     struct can_frame *cf = (struct can_frame *)skb->data;
> > +     struct mcba_usb_msg_can usb_msg;
> > +     struct mcba_usb_ctx *ctx = NULL;
> > +     struct net_device_stats *stats = &priv->netdev->stats;
> > +     u16 sid;
> > +     int err;
> > +
> > +     if (can_dropped_invalid_skb(netdev, skb))
> > +             return NETDEV_TX_OK;
> > +
> > +     ctx = mcba_usb_get_free_ctx(priv, cf);
> > +     if (!ctx)
> > +             return NETDEV_TX_BUSY;
> > +
> > +     can_put_echo_skb(skb, priv->netdev, ctx->ndx);
> > +
> > +     usb_msg.cmd_id = MBCA_CMD_TRANSMIT_MESSAGE_EV;
> > +     if (cf->can_id & CAN_EFF_FLAG) {
> > +             /* SIDH    | SIDL                 | EIDH   | EIDL
> > +              * 28 - 21 | 20 19 18 x x x 17 16 | 15 - 8 | 7 - 0
> > +              */
> > +             sid = MCBA_SIDL_EXID_MASK;
> > +             /* store 28-18 bits */
> > +             sid |= (cf->can_id & 0x1ffc0000) >> 13;
> > +             /* store 17-16 bits */
> > +             sid |= (cf->can_id & 0x30000) >> 16;
> > +             put_unaligned_be16(sid, &usb_msg.sid);
> > +
> > +             /* store 15-0 bits */
> > +             put_unaligned_be16(cf->can_id & 0xffff, &usb_msg.eid);
> > +     } else {
> > +             /* SIDH   | SIDL
> > +              * 10 - 3 | 2 1 0 x x x x x
> > +              */
> > +             put_unaligned_be16((cf->can_id & CAN_SFF_MASK) << 5,
> > +                                &usb_msg.sid);
> > +             usb_msg.eid = 0;
> > +     }
> > +
> > +     usb_msg.dlc = cf->can_dlc;
> > +
> > +     memcpy(usb_msg.data, cf->data, usb_msg.dlc);
> > +
> > +     if (cf->can_id & CAN_RTR_FLAG)
> > +             usb_msg.dlc |= MCBA_DLC_RTR_MASK;
> > +
> > +     err = mcba_usb_xmit(priv, (struct mcba_usb_msg *)&usb_msg, ctx);
> > +     if (err)
> > +             goto xmit_failed;
> > +
> > +     return NETDEV_TX_OK;
> > +
> > +xmit_failed:
> > +     can_free_echo_skb(priv->netdev, ctx->ndx);
> > +     mcba_usb_free_ctx(ctx);
> > +     dev_kfree_skb(skb);
> > +     stats->tx_dropped++;
> > +
> > +     return NETDEV_TX_OK;
> > +}
> > +
> > +/* Send cmd to device */
> > +static void mcba_usb_xmit_cmd(struct mcba_priv *priv,
> > +                           struct mcba_usb_msg *usb_msg)
> > +{
> > +     struct mcba_usb_ctx *ctx = NULL;
> > +     int err;
> > +
> > +     ctx = mcba_usb_get_free_ctx(priv, NULL);
> > +     if (!ctx) {
> > +             netdev_err(priv->netdev,
> > +                        "Lack of free ctx. Sending (%d) cmd aborted",
> > +                        usb_msg->cmd_id);
> > +
> > +             return;
> > +     }
> > +
> > +     err = mcba_usb_xmit(priv, usb_msg, ctx);
> > +     if (err)
> > +             netdev_err(priv->netdev, "Failed to send cmd (%d)",
> > +                        usb_msg->cmd_id);
> > +}
> > +
> > +static void mcba_usb_xmit_change_bitrate(struct mcba_priv *priv, u16 bitrate)
> > +{
> > +     struct mcba_usb_msg_change_bitrate usb_msg;
> > +
> > +     usb_msg.cmd_id = MBCA_CMD_CHANGE_BIT_RATE;
>
> use C99 initializers please.
>

ok

> > +     put_unaligned_be16(bitrate, &usb_msg.bitrate);
> > +
> > +     mcba_usb_xmit_cmd(priv, (struct mcba_usb_msg *)&usb_msg);
> > +}
> > +
> > +static void mcba_usb_xmit_read_fw_ver(struct mcba_priv *priv, u8 pic)
> > +{
> > +     struct mcba_usb_msg_fw_ver usb_msg;
> > +
> > +     usb_msg.cmd_id = MBCA_CMD_READ_FW_VERSION;
> > +     usb_msg.pic = pic;
> >
> use C99 initializers please.

ok

>
> > +     mcba_usb_xmit_cmd(priv, (struct mcba_usb_msg *)&usb_msg);
> > +}
> > +
> > +static void mcba_usb_process_can(struct mcba_priv *priv,
> > +                              struct mcba_usb_msg_can *msg)
> > +{
> > +     struct can_frame *cf;
> > +     struct sk_buff *skb;
> > +     struct net_device_stats *stats = &priv->netdev->stats;
> > +     u16 sid;
> > +
> > +     skb = alloc_can_skb(priv->netdev, &cf);
> > +     if (!skb)
> > +             return;
> > +
> > +     sid = get_unaligned_be16(&msg->sid);
> > +
> > +     if (sid & MCBA_SIDL_EXID_MASK) {
> > +             /* SIDH    | SIDL                 | EIDH   | EIDL
> > +              * 28 - 21 | 20 19 18 x x x 17 16 | 15 - 8 | 7 - 0
> > +              */
> > +             cf->can_id = CAN_EFF_FLAG;
> > +
> > +             /* store 28-18 bits */
> > +             cf->can_id |= (sid & 0xffe0) << 13;
> > +             /* store 17-16 bits */
> > +             cf->can_id |= (sid & 3) << 16;
> > +             /* store 15-0 bits */
> > +             cf->can_id |= get_unaligned_be16(&msg->eid);
> > +     } else {
> > +             /* SIDH   | SIDL
> > +              * 10 - 3 | 2 1 0 x x x x x
> > +              */
> > +             cf->can_id = (sid & 0xffe0) >> 5;
> > +     }
> > +
> > +     if (msg->dlc & MCBA_DLC_RTR_MASK)
> > +             cf->can_id |= CAN_RTR_FLAG;
> > +
> > +     cf->can_dlc = get_can_dlc(msg->dlc & MCBA_DLC_MASK);
> > +
> > +     memcpy(cf->data, msg->data, cf->can_dlc);
> > +
> > +     stats->rx_packets++;
> > +     stats->rx_bytes += cf->can_dlc;
> > +
> > +     netif_rx(skb);
> > +}
> > +
> > +static void mcba_usb_process_ka_usb(struct mcba_priv *priv,
> > +                                 struct mcba_usb_msg_ka_usb *msg)
> > +{
> > +     if (unlikely(priv->usb_ka_first_pass)) {
> > +             netdev_info(priv->netdev, "PIC USB version %hhu.%hhu\n",
> > +                         msg->soft_ver_major, msg->soft_ver_minor);
> > +
> > +             priv->usb_ka_first_pass = false;
> > +     }
> > +
> > +     if (msg->termination_state)
> > +             priv->can.termination = MCBA_TERMINATION_ENABLED;
> > +     else
> > +             priv->can.termination = MCBA_TERMINATION_DISABLED;
> > +}
> > +
> > +static u32 convert_can2host_bitrate(struct mcba_usb_msg_ka_can *msg)
> > +{
> > +     const u32 bitrate = get_unaligned_be16(&msg->can_bitrate);
> > +
> > +     if ((bitrate == 33) || (bitrate == 83))
> > +             return bitrate * 1000 + 333;
> > +     else
> > +             return bitrate * 1000;
> > +}
> > +
> > +static void mcba_usb_process_ka_can(struct mcba_priv *priv,
> > +                                 struct mcba_usb_msg_ka_can *msg)
> > +{
> > +     if (unlikely(priv->can_ka_first_pass)) {
> > +             netdev_info(priv->netdev, "PIC CAN version %hhu.%hhu\n",
> > +                         msg->soft_ver_major, msg->soft_ver_minor);
> > +
> > +             priv->can_ka_first_pass = false;
> > +     }
> > +
> > +     if (unlikely(priv->can_speed_check)) {
> > +             const u32 bitrate = convert_can2host_bitrate(msg);
> > +
> > +             priv->can_speed_check = false;
> > +
> > +             if (bitrate != priv->can.bittiming.bitrate)
> > +                     netdev_err(
> > +                         priv->netdev,
> > +                         "Wrong bitrate reported by the device (%u). Expected %u",
> > +                         bitrate, priv->can.bittiming.bitrate);
> > +     }
> > +
> > +     priv->bec.txerr = msg->tx_err_cnt;
> > +     priv->bec.rxerr = msg->rx_err_cnt;
> > +
> > +     if (msg->tx_bus_off)
> > +             priv->can.state = CAN_STATE_BUS_OFF;
> > +
> > +     else if ((priv->bec.txerr > MCBA_CAN_STATE_ERR_PSV_TH) ||
> > +              (priv->bec.rxerr > MCBA_CAN_STATE_ERR_PSV_TH))
> > +             priv->can.state = CAN_STATE_ERROR_PASSIVE;
> > +
> > +     else if ((priv->bec.txerr > MCBA_CAN_STATE_WRN_TH) ||
> > +              (priv->bec.rxerr > MCBA_CAN_STATE_WRN_TH))
> > +             priv->can.state = CAN_STATE_ERROR_WARNING;
> > +}
> > +
> > +static void mcba_usb_process_rx(struct mcba_priv *priv,
> > +                             struct mcba_usb_msg *msg)
> > +{
> > +     switch (msg->cmd_id) {
> > +     case MBCA_CMD_I_AM_ALIVE_FROM_CAN:
> > +             mcba_usb_process_ka_can(priv,
> > +                                     (struct mcba_usb_msg_ka_can *)msg);
> > +             break;
> > +
> > +     case MBCA_CMD_I_AM_ALIVE_FROM_USB:
> > +             mcba_usb_process_ka_usb(priv,
> > +                                     (struct mcba_usb_msg_ka_usb *)msg);
> > +             break;
> > +
> > +     case MBCA_CMD_RECEIVE_MESSAGE:
> > +             mcba_usb_process_can(priv, (struct mcba_usb_msg_can *)msg);
> > +             break;
> > +
> > +     case MBCA_CMD_NOTHING_TO_SEND:
> > +             /* Side effect of communication between PIC_USB and PIC_CAN.
> > +              * PIC_CAN is telling us that it has nothing to send
> > +              */
> > +             break;
> > +
> > +     case MBCA_CMD_TRANSMIT_MESSAGE_RSP:
> > +             /* Transmission response from the device containing timestamp */
> > +             break;
> > +
> > +     default:
> > +             netdev_warn(priv->netdev, "Unsupported msg (0x%hhX)",
> > +                         msg->cmd_id);
> > +             break;
> > +     }
> > +}
> > +
> > +/* Callback for reading data from device
> > + *
> > + * Check urb status, call read function and resubmit urb read operation.
> > + */
> > +static void mcba_usb_read_bulk_callback(struct urb *urb)
> > +{
> > +     struct mcba_priv *priv = urb->context;
> > +     struct net_device *netdev;
> > +     int retval;
> > +     int pos = 0;
> > +
> > +     netdev = priv->netdev;
> > +
> > +     if (!netif_device_present(netdev))
> > +             return;
> > +
> > +     switch (urb->status) {
> > +     case 0: /* success */
> > +             break;
> > +
> > +     case -ENOENT:
> > +     case -ESHUTDOWN:
> > +             return;
> > +
> > +     default:
> > +             netdev_info(netdev, "Rx URB aborted (%d)\n", urb->status);
> > +
> > +             goto resubmit_urb;
> > +     }
> > +
> > +     while (pos < urb->actual_length) {
> > +             struct mcba_usb_msg *msg;
> > +
> > +             if (pos + sizeof(struct mcba_usb_msg) > urb->actual_length) {
> > +                     netdev_err(priv->netdev, "format error\n");
> > +                     break;
> > +             }
> > +
> > +             msg = (struct mcba_usb_msg *)(urb->transfer_buffer + pos);
> > +             mcba_usb_process_rx(priv, msg);
> > +
> > +             pos += sizeof(struct mcba_usb_msg);
> > +     }
> > +
> > +resubmit_urb:
> > +
> > +     usb_fill_bulk_urb(urb, priv->udev,
> > +                       usb_rcvbulkpipe(priv->udev, MCBA_USB_EP_OUT),
> > +                       urb->transfer_buffer, MCBA_USB_RX_BUFF_SIZE,
> > +                       mcba_usb_read_bulk_callback, priv);
> > +
> > +     retval = usb_submit_urb(urb, GFP_ATOMIC);
> > +
> > +     if (retval == -ENODEV)
> > +             netif_device_detach(netdev);
> > +     else if (retval)
> > +             netdev_err(netdev, "failed resubmitting read bulk urb: %d\n",
> > +                        retval);
> > +}
> > +
> > +/* Start USB device */
> > +static int mcba_usb_start(struct mcba_priv *priv)
> > +{
> > +     struct net_device *netdev = priv->netdev;
> > +     int err, i;
> > +
> > +     mcba_init_ctx(priv);
> > +
> > +     for (i = 0; i < MCBA_MAX_RX_URBS; i++) {
> > +             struct urb *urb = NULL;
> > +             u8 *buf;
> > +
> > +             /* create a URB, and a buffer for it */
> > +             urb = usb_alloc_urb(0, GFP_KERNEL);
> > +             if (!urb) {
> > +                     err = -ENOMEM;
> > +                     break;
> > +             }
> > +
> > +             buf = usb_alloc_coherent(priv->udev, MCBA_USB_RX_BUFF_SIZE,
> > +                                      GFP_KERNEL, &urb->transfer_dma);
> > +             if (!buf) {
> > +                     netdev_err(netdev, "No memory left for USB buffer\n");
> > +                     usb_free_urb(urb);
> > +                     err = -ENOMEM;
> > +                     break;
> > +             }
> > +
> > +             usb_fill_bulk_urb(urb, priv->udev,
> > +                               usb_rcvbulkpipe(priv->udev, MCBA_USB_EP_IN),
> > +                               buf, MCBA_USB_RX_BUFF_SIZE,
> > +                               mcba_usb_read_bulk_callback, priv);
> > +             urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
> > +             usb_anchor_urb(urb, &priv->rx_submitted);
> > +
> > +             err = usb_submit_urb(urb, GFP_KERNEL);
> > +             if (err) {
> > +                     usb_unanchor_urb(urb);
> > +                     usb_free_coherent(priv->udev, MCBA_USB_RX_BUFF_SIZE,
> > +                                       buf, urb->transfer_dma);
> > +                     usb_free_urb(urb);
> > +                     break;
> > +             }
> > +
> > +             /* Drop reference, USB core will take care of freeing it */
> > +             usb_free_urb(urb);
> > +     }
> > +
> > +     /* Did we submit any URBs */
> > +     if (i == 0) {
> > +             netdev_warn(netdev, "couldn't setup read URBs\n");
> > +             return err;
> > +     }
> > +
> > +     /* Warn if we've couldn't transmit all the URBs */
> > +     if (i < MCBA_MAX_RX_URBS)
> > +             netdev_warn(netdev, "rx performance may be slow\n");
> > +
> > +     mcba_usb_xmit_read_fw_ver(priv, MCBA_VER_REQ_USB);
> > +     mcba_usb_xmit_read_fw_ver(priv, MCBA_VER_REQ_CAN);
> > +
> > +     return err;
>
> return 0;

ok

>
> > +}
> > +
> > +/* Open USB device */
> > +static int mcba_usb_open(struct net_device *netdev)
> > +{
> > +     struct mcba_priv *priv = netdev_priv(netdev);
> > +     int err;
> > +
> > +     /* common open */
> > +     err = open_candev(netdev);
> > +     if (err)
> > +             return err;
> > +
> > +     priv->can_speed_check = true;
> > +     priv->can.state = CAN_STATE_ERROR_ACTIVE;
> > +
> > +     netif_start_queue(netdev);
> > +
> > +     return 0;
> > +}
> > +
> > +static void mcba_urb_unlink(struct mcba_priv *priv)
> > +{
> > +     usb_kill_anchored_urbs(&priv->rx_submitted);
> > +     usb_kill_anchored_urbs(&priv->tx_submitted);
> > +}
> > +
> > +/* Close USB device */
> > +static int mcba_usb_close(struct net_device *netdev)
> > +{
> > +     struct mcba_priv *priv = netdev_priv(netdev);
> > +
> > +     priv->can.state = CAN_STATE_STOPPED;
> > +
> > +     netif_stop_queue(netdev);
> > +
> > +     /* Stop polling */
> > +     mcba_urb_unlink(priv);
> > +
> > +     close_candev(netdev);
> > +
> > +     return 0;
> > +}
> > +
> > +/* Set network device mode
> > + *
> > + * Maybe we should leave this function empty, because the device
> > + * set mode variable with open command.
> > + */
> > +static int mcba_net_set_mode(struct net_device *netdev, enum can_mode mode)
> > +{
> > +     return 0;
> > +}
> > +
> > +static int mcba_net_get_berr_counter(const struct net_device *netdev,
> > +                                  struct can_berr_counter *bec)
> > +{
> > +     struct mcba_priv *priv = netdev_priv(netdev);
> > +
> > +     bec->txerr = priv->bec.txerr;
> > +     bec->rxerr = priv->bec.rxerr;
> > +
> > +     return 0;
> > +}
> > +
> > +static const struct net_device_ops mcba_netdev_ops = {
> > +     .ndo_open = mcba_usb_open,
> > +     .ndo_stop = mcba_usb_close,
> > +     .ndo_start_xmit = mcba_usb_start_xmit,
> > +};
> > +
> > +/* Microchip CANBUS has hardcoded bittiming values by default.
> > + * This function sends request via USB to change the speed and align bittiming
> > + * values for presentation purposes only
> > + */
> > +static int mcba_net_set_bittiming(struct net_device *netdev)
> > +{
> > +     struct mcba_priv *priv = netdev_priv(netdev);
> > +     const u16 bitrate_kbps = priv->can.bittiming.bitrate / 1000;
> > +
> > +     mcba_usb_xmit_change_bitrate(priv, bitrate_kbps);
> > +
> > +     return 0;
> > +}
> > +
> > +static int mcba_set_termination(struct net_device *netdev, u16 term)
> > +{
> > +     struct mcba_priv *priv = netdev_priv(netdev);
> > +     struct mcba_usb_msg_termination usb_msg;
> > +
> > +     usb_msg.cmd_id = MBCA_CMD_SETUP_TERMINATION_RESISTANCE;
>
> use C99 initializers please:
>
>         struct mcba_usb_msg_termination usb_msg = {
>                 .cmd_id = MBCA_CMD_SETUP_TERMINATION_RESISTANCE;
>         };
>
> Then all the other struct members are automatically nulled.
>

ok

> > +
> > +     if (term == MCBA_TERMINATION_ENABLED)
> > +             usb_msg.termination = 1;
> > +     else
> > +             usb_msg.termination = 0;
> > +
> > +     mcba_usb_xmit_cmd(priv, (struct mcba_usb_msg *)&usb_msg);
> > +
> > +     return 0;
> > +}
> > +
> > +static int mcba_usb_probe(struct usb_interface *intf,
> > +                       const struct usb_device_id *id)
> > +{
> > +     struct net_device *netdev;
> > +     struct mcba_priv *priv;
> > +     int err = -ENOMEM;
> > +     struct usb_device *usbdev = interface_to_usbdev(intf);
> > +
> > +     netdev = alloc_candev(sizeof(struct mcba_priv), MCBA_MAX_TX_URBS);
> > +     if (!netdev) {
> > +             dev_err(&intf->dev, "Couldn't alloc candev\n");
> > +             return -ENOMEM;
> > +     }
> > +
> > +     priv = netdev_priv(netdev);
> > +
> > +     priv->udev = usbdev;
> > +     priv->netdev = netdev;
> > +     priv->usb_ka_first_pass = true;
> > +     priv->can_ka_first_pass = true;
> > +     priv->can_speed_check = false;
> > +
> > +     init_usb_anchor(&priv->rx_submitted);
> > +     init_usb_anchor(&priv->tx_submitted);
> > +
> > +     usb_set_intfdata(intf, priv);
> > +
> > +     /* Init CAN device */
> > +     priv->can.state = CAN_STATE_STOPPED;
> > +     priv->can.termination_const = mcba_termination;
> > +     priv->can.termination_const_cnt = ARRAY_SIZE(mcba_termination);
> > +     priv->can.bitrate_const = mcba_bitrate;
> > +     priv->can.bitrate_const_cnt = ARRAY_SIZE(mcba_bitrate);
> > +
> > +     priv->can.do_set_termination = mcba_set_termination;
> > +     priv->can.do_set_mode = mcba_net_set_mode;
> > +     priv->can.do_get_berr_counter = mcba_net_get_berr_counter;
> > +     priv->can.do_set_bittiming = mcba_net_set_bittiming;
> > +
> > +     netdev->netdev_ops = &mcba_netdev_ops;
> > +
> > +     netdev->flags |= IFF_ECHO; /* we support local echo */
> > +
> > +     SET_NETDEV_DEV(netdev, &intf->dev);
> > +
> > +     err = register_candev(netdev);
> > +     if (err) {
> > +             netdev_err(netdev, "couldn't register CAN device: %d\n", err);
> > +
> > +             netif_device_detach(priv->netdev);
>
> Why detach here, it's has not been regeistered.

I will remove that.

>
> > +
> > +             goto cleanup_candev;
>
> better rename to cleanup_free_candev

ok

>
> > +     }
> > +
> > +     /* Start USB device only if we have successfuly registered CAN device */
> > +     err = mcba_usb_start(priv);
> > +     if (err) {
> > +             if (err == -ENODEV)
> > +                     netif_device_detach(priv->netdev);
>
> You have to call unregister_candev(). Do this via a "goto
> cleanup_unregister_candev;"

ok

>
> > +
> > +             netdev_warn(netdev, "couldn't start device: %d\n", err);
> > +
> > +             goto cleanup_candev;
> > +     }
> > +
> > +     dev_info(&intf->dev, "Microchip CAN BUS analizer connected\n");
> > +
> > +     return err;
>         return 0;
>
> cleanup_unregister_candev:
>         unregister_candev();

ok

>
> > +
> > +cleanup_candev:
> cleanup_free_candev:
> > +     free_candev(netdev);
> > +
> > +     return err;
> > +}
> > +
> > +/* Called by the usb core when driver is unloaded or device is removed */
> > +static void mcba_usb_disconnect(struct usb_interface *intf)
> > +{
> > +     struct mcba_priv *priv = usb_get_intfdata(intf);
> > +
> > +     usb_set_intfdata(intf, NULL);
> > +
> > +     netdev_info(priv->netdev, "device disconnected\n");
> > +
> > +     unregister_candev(priv->netdev);
> > +     free_candev(priv->netdev);
> > +
> > +     mcba_urb_unlink(priv);
> > +}
> > +
> > +static struct usb_driver mcba_usb_driver = {
> > +     .name = MCBA_MODULE_NAME,
> > +     .probe = mcba_usb_probe,
> > +     .disconnect = mcba_usb_disconnect,
> > +     .id_table = mcba_usb_table,
> > +};
> > +
> > +module_usb_driver(mcba_usb_driver);
> > +
> > +MODULE_AUTHOR("Remigiusz Kołłątaj <remigiusz.kollataj@mobica.com>");
> > +MODULE_DESCRIPTION("SocketCAN driver for Microchip CAN BUS Analyzer Tool");
> > +MODULE_LICENSE("GPL v2");
> >
>
> 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   |
>



-- 
____________________
Remigiusz Kołłątaj
Mobica Ltd
Technology Consultant
Skype: remigiusz.kollataj
www.mobica.com

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH v3] can: mcba_usb: Add support for Microchip CAN BUS Analyzer
  2017-04-14  8:25   ` Kołłątaj, Remigiusz
@ 2017-04-14 12:24     ` Marc Kleine-Budde
  2017-04-14 13:19       ` Kołłątaj, Remigiusz
  0 siblings, 1 reply; 8+ messages in thread
From: Marc Kleine-Budde @ 2017-04-14 12:24 UTC (permalink / raw)
  To: Kołłątaj, Remigiusz; +Cc: linux-can


[-- Attachment #1.1: Type: text/plain, Size: 1901 bytes --]

On 04/14/2017 10:25 AM, Kołłątaj, Remigiusz wrote:
> Hi Marc,
> 
> Thanks for the review. My answers/comments inline.
> 
> On 13 April 2017 at 17:56, Marc Kleine-Budde <mkl@pengutronix.de> wrote:
>>
>> On 01/25/2017 02:02 PM, Remigiusz Kołłątaj wrote:
>>> SocketCAN driver for Microchip CAN BUS Analyzer
>>> (http://www.microchip.com/development-tools/)
>>>
>>> Changes since v2:
>>> - improved/simplified CAN ID conversion
>>> - functions for transmission of skb and cmd separated
>>> - fixed/improved netif_stop_queue handling
>>> - style/cosmetic corrections
>>>
>>> Changes since v1:
>>> - Termination handling reimplemented to fit new netlink API
>>> (IFLA_CAN_TERMINATION)
>>> - Bitrate handling reimplemented to fit new netlink API
>>> (IFLA_CAN_BITRATE)
>>> - CAN ID conversion refactored (changed from macro to inline functions)
>>> - CAN DLC handling using get_can_dlc()
>>> - Endianness handling for can_speed introduced
>>> - Debugging removed
>>> - Redundant error prints removed
>>> - Style/cosmetic corrections (i.e. macro names, redefs, inits etc.)
>>>
>>> Signed-off-by: Remigiusz Kołłątaj <remigiusz.kollataj@mobica.com>
>>
>> Can you pleeas add LED support, see commit:
>>
>>     adccadb92f05 can: flexcan: add LED trigger support
>>
>> as an example. More comments inline.
>>
> 
> In MBCA leds are controlled by device itself - CAN status leds are
> connected directly CANTX and CANRX pins of PIC controller and CAN
> Error led is driven by firmware.

With LED support in the driver, you can use CAN RX and/or TX events to
drive generic LEDs.

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   |


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^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH v3] can: mcba_usb: Add support for Microchip CAN BUS Analyzer
  2017-04-14 12:24     ` Marc Kleine-Budde
@ 2017-04-14 13:19       ` Kołłątaj, Remigiusz
  2017-04-14 14:34         ` Marc Kleine-Budde
  0 siblings, 1 reply; 8+ messages in thread
From: Kołłątaj, Remigiusz @ 2017-04-14 13:19 UTC (permalink / raw)
  To: Marc Kleine-Budde; +Cc: linux-can

On 14 April 2017 at 14:24, Marc Kleine-Budde <mkl@pengutronix.de> wrote:
> On 04/14/2017 10:25 AM, Kołłątaj, Remigiusz wrote:
>> Hi Marc,
>>
>> Thanks for the review. My answers/comments inline.
>>
>> On 13 April 2017 at 17:56, Marc Kleine-Budde <mkl@pengutronix.de> wrote:
>>>
>>> On 01/25/2017 02:02 PM, Remigiusz Kołłątaj wrote:
>>>> SocketCAN driver for Microchip CAN BUS Analyzer
>>>> (http://www.microchip.com/development-tools/)
>>>>
>>>> Changes since v2:
>>>> - improved/simplified CAN ID conversion
>>>> - functions for transmission of skb and cmd separated
>>>> - fixed/improved netif_stop_queue handling
>>>> - style/cosmetic corrections
>>>>
>>>> Changes since v1:
>>>> - Termination handling reimplemented to fit new netlink API
>>>> (IFLA_CAN_TERMINATION)
>>>> - Bitrate handling reimplemented to fit new netlink API
>>>> (IFLA_CAN_BITRATE)
>>>> - CAN ID conversion refactored (changed from macro to inline functions)
>>>> - CAN DLC handling using get_can_dlc()
>>>> - Endianness handling for can_speed introduced
>>>> - Debugging removed
>>>> - Redundant error prints removed
>>>> - Style/cosmetic corrections (i.e. macro names, redefs, inits etc.)
>>>>
>>>> Signed-off-by: Remigiusz Kołłątaj <remigiusz.kollataj@mobica.com>
>>>
>>> Can you pleeas add LED support, see commit:
>>>
>>>     adccadb92f05 can: flexcan: add LED trigger support
>>>
>>> as an example. More comments inline.
>>>
>>
>> In MBCA leds are controlled by device itself - CAN status leds are
>> connected directly CANTX and CANRX pins of PIC controller and CAN
>> Error led is driven by firmware.
>
> With LED support in the driver, you can use CAN RX and/or TX events to
> drive generic LEDs.
>

I am ok with adding it to the driver however I don't know if I
understand the idea. Will addition of generic LEDs expose device TX
and RX status via SYSFS?

Regards,
Remik

-- 
____________________
Remigiusz Kołłątaj
Mobica Ltd
Technology Consultant
Skype: remigiusz.kollataj
www.mobica.com

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH v3] can: mcba_usb: Add support for Microchip CAN BUS Analyzer
  2017-04-14 13:19       ` Kołłątaj, Remigiusz
@ 2017-04-14 14:34         ` Marc Kleine-Budde
  2017-04-14 17:16           ` Kołłątaj, Remigiusz
  0 siblings, 1 reply; 8+ messages in thread
From: Marc Kleine-Budde @ 2017-04-14 14:34 UTC (permalink / raw)
  To: Kołłątaj, Remigiusz; +Cc: linux-can


[-- Attachment #1.1: Type: text/plain, Size: 977 bytes --]

On 04/14/2017 03:19 PM, Kołłątaj, Remigiusz wrote:>>> In MBCA leds are
controlled by device itself - CAN status leds are
>>> connected directly CANTX and CANRX pins of PIC controller and CAN
>>> Error led is driven by firmware.
>>
>> With LED support in the driver, you can use CAN RX and/or TX events to
>> drive generic LEDs.
> 
> I am ok with adding it to the driver however I don't know if I
> understand the idea. Will addition of generic LEDs expose device TX
> and RX status via SYSFS?

No. If your System has a generic LED, you can use the CAN RX/TX trigger
to blink the LED - in a total generic way, see:

https://fabiobaltieri.com/2011/09/21/linux-led-subsystem/

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   |


[-- Attachment #2: OpenPGP digital signature --]
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^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH v3] can: mcba_usb: Add support for Microchip CAN BUS Analyzer
  2017-04-14 14:34         ` Marc Kleine-Budde
@ 2017-04-14 17:16           ` Kołłątaj, Remigiusz
  0 siblings, 0 replies; 8+ messages in thread
From: Kołłątaj, Remigiusz @ 2017-04-14 17:16 UTC (permalink / raw)
  To: Marc Kleine-Budde; +Cc: linux-can

On 14 April 2017 at 16:34, Marc Kleine-Budde <mkl@pengutronix.de> wrote:
> On 04/14/2017 03:19 PM, Kołłątaj, Remigiusz wrote:>>> In MBCA leds are
> controlled by device itself - CAN status leds are
>>>> connected directly CANTX and CANRX pins of PIC controller and CAN
>>>> Error led is driven by firmware.
>>>
>>> With LED support in the driver, you can use CAN RX and/or TX events to
>>> drive generic LEDs.
>>
>> I am ok with adding it to the driver however I don't know if I
>> understand the idea. Will addition of generic LEDs expose device TX
>> and RX status via SYSFS?
>
> No. If your System has a generic LED, you can use the CAN RX/TX trigger
> to blink the LED - in a total generic way, see:
>
> https://fabiobaltieri.com/2011/09/21/linux-led-subsystem/

Got it now. Thanks!

Regards,
Remik

-- 
____________________
Remigiusz Kołłątaj
Mobica Ltd
Technology Consultant
Skype: remigiusz.kollataj
www.mobica.com

^ permalink raw reply	[flat|nested] 8+ messages in thread

end of thread, other threads:[~2017-04-14 17:16 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-01-25 13:02 [PATCH v3] can: mcba_usb: Add support for Microchip CAN BUS Analyzer Remigiusz Kołłątaj
2017-02-20 10:22 ` Kołłątaj, Remigiusz
2017-04-13 15:56 ` Marc Kleine-Budde
2017-04-14  8:25   ` Kołłątaj, Remigiusz
2017-04-14 12:24     ` Marc Kleine-Budde
2017-04-14 13:19       ` Kołłątaj, Remigiusz
2017-04-14 14:34         ` Marc Kleine-Budde
2017-04-14 17:16           ` Kołłątaj, Remigiusz

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