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