can: peak_usb: allow flashing of the CAN channel ID

This patch adds callbacks that allow the user to set a new self-defined
CAN channel ID to all USB - CAN/CANFD interfaces of PEAK-System managed by
this driver, namely:
- PCAN-USB
- PCAN-USB FD
- PCAN-USB Pro FD
- PCAN-USB X6
- PCAN-Chip USB
- PCAN-USB Pro

The callback functions write the CAN channel ID to the non-volatile
memory of the devices.
Signed-off-by: Stephane Grosjean <s.grosjean@peak-system.com>
Signed-off-by: Lukas Magel <lukas.magel@posteo.net>
Link: https://lore.kernel.org/all/20230116200932.157769-4-lukas.magel@posteo.netSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/usb/peak_usb/pcan_usb.c

@@ -398,6 +398,25 @@ static int pcan_usb_get_can_channel_id(struct peak_usb_device *dev, u32 *can_ch_
 	return err;
 }
 
+/* set a new CAN channel id in the flash memory of the device */
+static int pcan_usb_set_can_channel_id(struct peak_usb_device *dev, u32 can_ch_id)
+{
+	u8 args[PCAN_USB_CMD_ARGS_LEN];
+
+	/* this kind of device supports 8-bit values only */
+	if (can_ch_id > U8_MAX)
+		return -EINVAL;
+
+	/* during the flash process the device disconnects during ~1.25 s.:
+	 * prohibit access when interface is UP
+	 */
+	if (dev->netdev->flags & IFF_UP)
+		return -EBUSY;
+
+	args[0] = can_ch_id;
+	return pcan_usb_send_cmd(dev, PCAN_USB_CMD_DEVID, PCAN_USB_SET, args);
+}
+
 /*
  * update current time ref with received timestamp
  */
@@ -1018,6 +1037,7 @@ const struct peak_usb_adapter pcan_usb = {
 	.dev_set_bus = pcan_usb_write_mode,
 	.dev_set_bittiming = pcan_usb_set_bittiming,
 	.dev_get_can_channel_id = pcan_usb_get_can_channel_id,
+	.dev_set_can_channel_id = pcan_usb_set_can_channel_id,
 	.dev_decode_buf = pcan_usb_decode_buf,
 	.dev_encode_msg = pcan_usb_encode_msg,
 	.dev_start = pcan_usb_start,

drivers/net/can/usb/peak_usb/pcan_usb_core.h

@@ -61,6 +61,7 @@ struct peak_usb_adapter {
 				      struct can_bittiming *bt);
 	int (*dev_set_bus)(struct peak_usb_device *dev, u8 onoff);
 	int (*dev_get_can_channel_id)(struct peak_usb_device *dev, u32 *can_ch_id);
+	int (*dev_set_can_channel_id)(struct peak_usb_device *dev, u32 can_ch_id);
 	int (*dev_decode_buf)(struct peak_usb_device *dev, struct urb *urb);
 	int (*dev_encode_msg)(struct peak_usb_device *dev, struct sk_buff *skb,
 					u8 *obuf, size_t *size);

drivers/net/can/usb/peak_usb/pcan_usb_fd.c

@@ -147,6 +147,15 @@ struct __packed pcan_ufd_ovr_msg {
 	u8	unused[3];
 };
 
+#define PCAN_UFD_CMD_DEVID_SET		0x81
+
+struct __packed pcan_ufd_device_id {
+	__le16	opcode_channel;
+
+	u16	unused;
+	__le32	device_id;
+};
+
 static inline int pufd_omsg_get_channel(struct pcan_ufd_ovr_msg *om)
 {
 	return om->channel & 0xf;
@@ -458,6 +467,19 @@ static int pcan_usb_fd_get_can_channel_id(struct peak_usb_device *dev,
 	return err;
 }
 
+/* set a new CAN channel id in the flash memory of the device */
+static int pcan_usb_fd_set_can_channel_id(struct peak_usb_device *dev, u32 can_ch_id)
+{
+	struct pcan_ufd_device_id *cmd = pcan_usb_fd_cmd_buffer(dev);
+
+	cmd->opcode_channel = pucan_cmd_opcode_channel(dev->ctrl_idx,
+						       PCAN_UFD_CMD_DEVID_SET);
+	cmd->device_id = cpu_to_le32(can_ch_id);
+
+	/* send the command */
+	return pcan_usb_fd_send_cmd(dev, ++cmd);
+}
+
 /* handle restart but in asynchronously way
  * (uses PCAN-USB Pro code to complete asynchronous request)
  */
@@ -1170,6 +1192,7 @@ const struct peak_usb_adapter pcan_usb_fd = {
 	.dev_set_bittiming = pcan_usb_fd_set_bittiming_slow,
 	.dev_set_data_bittiming = pcan_usb_fd_set_bittiming_fast,
 	.dev_get_can_channel_id = pcan_usb_fd_get_can_channel_id,
+	.dev_set_can_channel_id = pcan_usb_fd_set_can_channel_id,
 	.dev_decode_buf = pcan_usb_fd_decode_buf,
 	.dev_start = pcan_usb_fd_start,
 	.dev_stop = pcan_usb_fd_stop,
@@ -1245,6 +1268,7 @@ const struct peak_usb_adapter pcan_usb_chip = {
 	.dev_set_bittiming = pcan_usb_fd_set_bittiming_slow,
 	.dev_set_data_bittiming = pcan_usb_fd_set_bittiming_fast,
 	.dev_get_can_channel_id = pcan_usb_fd_get_can_channel_id,
+	.dev_set_can_channel_id = pcan_usb_fd_set_can_channel_id,
 	.dev_decode_buf = pcan_usb_fd_decode_buf,
 	.dev_start = pcan_usb_fd_start,
 	.dev_stop = pcan_usb_fd_stop,
@@ -1320,6 +1344,7 @@ const struct peak_usb_adapter pcan_usb_pro_fd = {
 	.dev_set_bittiming = pcan_usb_fd_set_bittiming_slow,
 	.dev_set_data_bittiming = pcan_usb_fd_set_bittiming_fast,
 	.dev_get_can_channel_id = pcan_usb_fd_get_can_channel_id,
+	.dev_set_can_channel_id = pcan_usb_fd_set_can_channel_id,
 	.dev_decode_buf = pcan_usb_fd_decode_buf,
 	.dev_start = pcan_usb_fd_start,
 	.dev_stop = pcan_usb_fd_stop,
@@ -1395,6 +1420,7 @@ const struct peak_usb_adapter pcan_usb_x6 = {
 	.dev_set_bittiming = pcan_usb_fd_set_bittiming_slow,
 	.dev_set_data_bittiming = pcan_usb_fd_set_bittiming_fast,
 	.dev_get_can_channel_id = pcan_usb_fd_get_can_channel_id,
+	.dev_set_can_channel_id = pcan_usb_fd_set_can_channel_id,
 	.dev_decode_buf = pcan_usb_fd_decode_buf,
 	.dev_start = pcan_usb_fd_start,
 	.dev_stop = pcan_usb_fd_stop,

drivers/net/can/usb/peak_usb/pcan_usb_pro.c

@@ -76,6 +76,7 @@ static u16 pcan_usb_pro_sizeof_rec[256] = {
 	[PCAN_USBPRO_SETFILTR] = sizeof(struct pcan_usb_pro_filter),
 	[PCAN_USBPRO_SETTS] = sizeof(struct pcan_usb_pro_setts),
 	[PCAN_USBPRO_GETDEVID] = sizeof(struct pcan_usb_pro_devid),
+	[PCAN_USBPRO_SETDEVID] = sizeof(struct pcan_usb_pro_devid),
 	[PCAN_USBPRO_SETLED] = sizeof(struct pcan_usb_pro_setled),
 	[PCAN_USBPRO_RXMSG8] = sizeof(struct pcan_usb_pro_rxmsg),
 	[PCAN_USBPRO_RXMSG4] = sizeof(struct pcan_usb_pro_rxmsg) - 4,
@@ -149,6 +150,7 @@ static int pcan_msg_add_rec(struct pcan_usb_pro_msg *pm, int id, ...)
 
 	case PCAN_USBPRO_SETBTR:
 	case PCAN_USBPRO_GETDEVID:
+	case PCAN_USBPRO_SETDEVID:
 		*pc++ = va_arg(ap, int);
 		pc += 2;
 		*(__le32 *)pc = cpu_to_le32(va_arg(ap, u32));
@@ -444,6 +446,18 @@ static int pcan_usb_pro_get_can_channel_id(struct peak_usb_device *dev,
 	return err;
 }
 
+static int pcan_usb_pro_set_can_channel_id(struct peak_usb_device *dev,
+					   u32 can_ch_id)
+{
+	struct pcan_usb_pro_msg um;
+
+	pcan_msg_init_empty(&um, dev->cmd_buf, PCAN_USB_MAX_CMD_LEN);
+	pcan_msg_add_rec(&um, PCAN_USBPRO_SETDEVID, dev->ctrl_idx,
+			 can_ch_id);
+
+	return pcan_usb_pro_send_cmd(dev, &um);
+}
+
 static int pcan_usb_pro_set_bittiming(struct peak_usb_device *dev,
 				      struct can_bittiming *bt)
 {
@@ -1077,6 +1091,7 @@ const struct peak_usb_adapter pcan_usb_pro = {
 	.dev_set_bus = pcan_usb_pro_set_bus,
 	.dev_set_bittiming = pcan_usb_pro_set_bittiming,
 	.dev_get_can_channel_id = pcan_usb_pro_get_can_channel_id,
+	.dev_set_can_channel_id = pcan_usb_pro_set_can_channel_id,
 	.dev_decode_buf = pcan_usb_pro_decode_buf,
 	.dev_encode_msg = pcan_usb_pro_encode_msg,
 	.dev_start = pcan_usb_pro_start,

drivers/net/can/usb/peak_usb/pcan_usb_pro.h

@@ -62,6 +62,7 @@ struct __packed pcan_usb_pro_fwinfo {
 #define PCAN_USBPRO_SETBTR	0x02
 #define PCAN_USBPRO_SETBUSACT	0x04
 #define PCAN_USBPRO_SETSILENT	0x05
+#define PCAN_USBPRO_SETDEVID	0x06
 #define PCAN_USBPRO_SETFILTR	0x0a
 #define PCAN_USBPRO_SETTS	0x10
 #define PCAN_USBPRO_GETDEVID	0x12