1 // SPDX-License-Identifier: GPL-2.0-or-later
3  * USB network interface driver for Samsung Kalmia based LTE USB modem like the
4  * Samsung GT-B3730 and GT-B3710.
27  * The Samsung Kalmia based LTE USB modems have a CDC ACM port for modem control
31  * The stick must first be switched into modem mode by usb_modeswitch
32  * or similar tool. Then the modem gets sent two initialization packets by
34  * connect the modem using AT commands through the ACM port and then use
36  * sent to and from the modem in a proprietary format discovered after watching
37  * the behavior of the windows driver for the modem.
39  * More information about the use of the modem is available in usb_modeswitch
43  * https://github.com/mkotsbak/Samsung-GT-B3730-linux-driver
53 /*-------------------------------------------------------------------------*/
62 	netdev_dbg(dev->net, "Sending init packet");  in kalmia_send_init_packet()
64 	status = usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 0x02),  in kalmia_send_init_packet()
67 		netdev_err(dev->net,  in kalmia_send_init_packet()
68 			"Error sending init packet. Status %i, length %i\n",  in kalmia_send_init_packet()
73 		netdev_err(dev->net,  in kalmia_send_init_packet()
74 			"Did not send all of init packet. Bytes sent: %i",  in kalmia_send_init_packet()
78 		netdev_dbg(dev->net, "Successfully sent init packet.");  in kalmia_send_init_packet()
81 	status = usb_bulk_msg(dev->udev, usb_rcvbulkpipe(dev->udev, 0x81),  in kalmia_send_init_packet()
85 		netdev_err(dev->net,  in kalmia_send_init_packet()
86 			"Error receiving init result. Status %i, length %i\n",  in kalmia_send_init_packet()
89 		netdev_err(dev->net, "Unexpected init result length: %i\n",  in kalmia_send_init_packet()
110 		return -ENOMEM;  in kalmia_init_and_get_ethernet_addr()
137 	if (intf->cur_altsetting->desc.bInterfaceClass != USB_CLASS_VENDOR_SPEC)  in kalmia_bind()
138 		return -EINVAL;  in kalmia_bind()
140 	dev->in = usb_rcvbulkpipe(dev->udev, 0x81 & USB_ENDPOINT_NUMBER_MASK);  in kalmia_bind()
141 	dev->out = usb_sndbulkpipe(dev->udev, 0x02 & USB_ENDPOINT_NUMBER_MASK);  in kalmia_bind()
142 	dev->status = NULL;  in kalmia_bind()
144 	dev->net->hard_header_len += KALMIA_HEADER_LENGTH;  in kalmia_bind()
145 	dev->hard_mtu = 1400;  in kalmia_bind()
146 	dev->rx_urb_size = dev->hard_mtu * 10; // Found as optimal after testing  in kalmia_bind()
152 	memcpy(dev->net->dev_addr, ethernet_addr, ETH_ALEN);  in kalmia_bind()
176 			skb->data = memmove(skb->head + KALMIA_HEADER_LENGTH,  in kalmia_tx_fixup()
177 				skb->data, skb->len);  in kalmia_tx_fixup()
178 			skb_set_tail_pointer(skb, skb->len);  in kalmia_tx_fixup()
196 	netdev_dbg(dev->net, "Sending etherType: %02x%02x", ether_type_1,  in kalmia_tx_fixup()
202 	content_len = skb->len - KALMIA_HEADER_LENGTH;  in kalmia_tx_fixup()
209 	remainder = skb->len % KALMIA_ALIGN_SIZE;  in kalmia_tx_fixup()
211 		padlen = KALMIA_ALIGN_SIZE - remainder;  in kalmia_tx_fixup()
215 	netdev_dbg(dev->net,  in kalmia_tx_fixup()
238 	if (skb->len < KALMIA_HEADER_LENGTH)  in kalmia_rx_fixup()
247 		header_start = skb->data;  in kalmia_rx_fixup()
254 				netdev_dbg(dev->net,  in kalmia_rx_fixup()
257 					skb->len - KALMIA_HEADER_LENGTH);  in kalmia_rx_fixup()
260 				netdev_err(dev->net,  in kalmia_rx_fixup()
263 					skb->len - KALMIA_HEADER_LENGTH);  in kalmia_rx_fixup()
268 			netdev_dbg(dev->net,  in kalmia_rx_fixup()
270 				header_start, skb->len - KALMIA_HEADER_LENGTH);  in kalmia_rx_fixup()
273 		usb_packet_length = skb->len - (2 * KALMIA_HEADER_LENGTH);  in kalmia_rx_fixup()
284 			netdev_dbg(dev->net, "Correct package length #%i", i  in kalmia_rx_fixup()
287 			is_last = (memcmp(skb->data + ether_packet_length,  in kalmia_rx_fixup()
291 				header_start = skb->data + ether_packet_length;  in kalmia_rx_fixup()
292 				netdev_dbg(dev->net,  in kalmia_rx_fixup()
295 					skb->len - KALMIA_HEADER_LENGTH);  in kalmia_rx_fixup()
320 	while (skb->len);  in kalmia_rx_fixup()
333 /*-------------------------------------------------------------------------*/
338 	/* The stick switched into modem (by e.g. usb_modeswitch): */