1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * USB ZyXEL omni.net LCD PLUS driver 4 * 5 * Copyright (C) 2013,2017 Johan Hovold <johan@kernel.org> 6 * 7 * This program is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU General Public License version 9 * 2 as published by the Free Software Foundation. 10 * 11 * See Documentation/usb/usb-serial.txt for more information on using this 12 * driver 13 * 14 * Please report both successes and troubles to the author at omninet@kroah.com 15 */ 16 17 #include <linux/kernel.h> 18 #include <linux/errno.h> 19 #include <linux/slab.h> 20 #include <linux/tty.h> 21 #include <linux/tty_driver.h> 22 #include <linux/tty_flip.h> 23 #include <linux/module.h> 24 #include <linux/uaccess.h> 25 #include <linux/usb.h> 26 #include <linux/usb/serial.h> 27 28 #define DRIVER_AUTHOR "Alessandro Zummo" 29 #define DRIVER_DESC "USB ZyXEL omni.net LCD PLUS Driver" 30 31 #define ZYXEL_VENDOR_ID 0x0586 32 #define ZYXEL_OMNINET_ID 0x1000 33 /* This one seems to be a re-branded ZyXEL device */ 34 #define BT_IGNITIONPRO_ID 0x2000 35 36 /* function prototypes */ 37 static void omninet_process_read_urb(struct urb *urb); 38 static int omninet_prepare_write_buffer(struct usb_serial_port *port, 39 void *buf, size_t count); 40 static int omninet_calc_num_ports(struct usb_serial *serial, 41 struct usb_serial_endpoints *epds); 42 static int omninet_port_probe(struct usb_serial_port *port); 43 static int omninet_port_remove(struct usb_serial_port *port); 44 45 static const struct usb_device_id id_table[] = { 46 { USB_DEVICE(ZYXEL_VENDOR_ID, ZYXEL_OMNINET_ID) }, 47 { USB_DEVICE(ZYXEL_VENDOR_ID, BT_IGNITIONPRO_ID) }, 48 { } /* Terminating entry */ 49 }; 50 MODULE_DEVICE_TABLE(usb, id_table); 51 52 static struct usb_serial_driver zyxel_omninet_device = { 53 .driver = { 54 .owner = THIS_MODULE, 55 .name = "omninet", 56 }, 57 .description = "ZyXEL - omni.net lcd plus usb", 58 .id_table = id_table, 59 .num_bulk_out = 2, 60 .calc_num_ports = omninet_calc_num_ports, 61 .port_probe = omninet_port_probe, 62 .port_remove = omninet_port_remove, 63 .process_read_urb = omninet_process_read_urb, 64 .prepare_write_buffer = omninet_prepare_write_buffer, 65 }; 66 67 static struct usb_serial_driver * const serial_drivers[] = { 68 &zyxel_omninet_device, NULL 69 }; 70 71 72 /* 73 * The protocol. 74 * 75 * The omni.net always exchange 64 bytes of data with the host. The first 76 * four bytes are the control header. 77 * 78 * oh_seq is a sequence number. Don't know if/how it's used. 79 * oh_len is the length of the data bytes in the packet. 80 * oh_xxx Bit-mapped, related to handshaking and status info. 81 * I normally set it to 0x03 in transmitted frames. 82 * 7: Active when the TA is in a CONNECTed state. 83 * 6: unknown 84 * 5: handshaking, unknown 85 * 4: handshaking, unknown 86 * 3: unknown, usually 0 87 * 2: unknown, usually 0 88 * 1: handshaking, unknown, usually set to 1 in transmitted frames 89 * 0: handshaking, unknown, usually set to 1 in transmitted frames 90 * oh_pad Probably a pad byte. 91 * 92 * After the header you will find data bytes if oh_len was greater than zero. 93 */ 94 struct omninet_header { 95 __u8 oh_seq; 96 __u8 oh_len; 97 __u8 oh_xxx; 98 __u8 oh_pad; 99 }; 100 101 struct omninet_data { 102 __u8 od_outseq; /* Sequence number for bulk_out URBs */ 103 }; 104 105 static int omninet_calc_num_ports(struct usb_serial *serial, 106 struct usb_serial_endpoints *epds) 107 { 108 /* We need only the second bulk-out for our single-port device. */ 109 epds->bulk_out[0] = epds->bulk_out[1]; 110 epds->num_bulk_out = 1; 111 112 return 1; 113 } 114 115 static int omninet_port_probe(struct usb_serial_port *port) 116 { 117 struct omninet_data *od; 118 119 od = kzalloc(sizeof(*od), GFP_KERNEL); 120 if (!od) 121 return -ENOMEM; 122 123 usb_set_serial_port_data(port, od); 124 125 return 0; 126 } 127 128 static int omninet_port_remove(struct usb_serial_port *port) 129 { 130 struct omninet_data *od; 131 132 od = usb_get_serial_port_data(port); 133 kfree(od); 134 135 return 0; 136 } 137 138 #define OMNINET_HEADERLEN 4 139 #define OMNINET_BULKOUTSIZE 64 140 #define OMNINET_PAYLOADSIZE (OMNINET_BULKOUTSIZE - OMNINET_HEADERLEN) 141 142 static void omninet_process_read_urb(struct urb *urb) 143 { 144 struct usb_serial_port *port = urb->context; 145 const struct omninet_header *hdr = urb->transfer_buffer; 146 const unsigned char *data; 147 size_t data_len; 148 149 if (urb->actual_length <= OMNINET_HEADERLEN || !hdr->oh_len) 150 return; 151 152 data = (char *)urb->transfer_buffer + OMNINET_HEADERLEN; 153 data_len = min_t(size_t, urb->actual_length - OMNINET_HEADERLEN, 154 hdr->oh_len); 155 tty_insert_flip_string(&port->port, data, data_len); 156 tty_flip_buffer_push(&port->port); 157 } 158 159 static int omninet_prepare_write_buffer(struct usb_serial_port *port, 160 void *buf, size_t count) 161 { 162 struct omninet_data *od = usb_get_serial_port_data(port); 163 struct omninet_header *header = buf; 164 165 count = min_t(size_t, count, OMNINET_PAYLOADSIZE); 166 167 count = kfifo_out_locked(&port->write_fifo, buf + OMNINET_HEADERLEN, 168 count, &port->lock); 169 170 header->oh_seq = od->od_outseq++; 171 header->oh_len = count; 172 header->oh_xxx = 0x03; 173 header->oh_pad = 0x00; 174 175 /* always 64 bytes */ 176 return OMNINET_BULKOUTSIZE; 177 } 178 179 module_usb_serial_driver(serial_drivers, id_table); 180 181 MODULE_AUTHOR(DRIVER_AUTHOR); 182 MODULE_DESCRIPTION(DRIVER_DESC); 183 MODULE_LICENSE("GPL"); 184