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 * See Documentation/usb/usb-serial.txt for more information on using this 8 * driver 9 * 10 * Please report both successes and troubles to the author at omninet@kroah.com 11 */ 12 13 #include <linux/kernel.h> 14 #include <linux/errno.h> 15 #include <linux/slab.h> 16 #include <linux/tty.h> 17 #include <linux/tty_driver.h> 18 #include <linux/tty_flip.h> 19 #include <linux/module.h> 20 #include <linux/uaccess.h> 21 #include <linux/usb.h> 22 #include <linux/usb/serial.h> 23 24 #define DRIVER_AUTHOR "Alessandro Zummo" 25 #define DRIVER_DESC "USB ZyXEL omni.net LCD PLUS Driver" 26 27 #define ZYXEL_VENDOR_ID 0x0586 28 #define ZYXEL_OMNINET_ID 0x1000 29 /* This one seems to be a re-branded ZyXEL device */ 30 #define BT_IGNITIONPRO_ID 0x2000 31 32 /* function prototypes */ 33 static void omninet_process_read_urb(struct urb *urb); 34 static int omninet_prepare_write_buffer(struct usb_serial_port *port, 35 void *buf, size_t count); 36 static int omninet_calc_num_ports(struct usb_serial *serial, 37 struct usb_serial_endpoints *epds); 38 static int omninet_port_probe(struct usb_serial_port *port); 39 static int omninet_port_remove(struct usb_serial_port *port); 40 41 static const struct usb_device_id id_table[] = { 42 { USB_DEVICE(ZYXEL_VENDOR_ID, ZYXEL_OMNINET_ID) }, 43 { USB_DEVICE(ZYXEL_VENDOR_ID, BT_IGNITIONPRO_ID) }, 44 { } /* Terminating entry */ 45 }; 46 MODULE_DEVICE_TABLE(usb, id_table); 47 48 static struct usb_serial_driver zyxel_omninet_device = { 49 .driver = { 50 .owner = THIS_MODULE, 51 .name = "omninet", 52 }, 53 .description = "ZyXEL - omni.net lcd plus usb", 54 .id_table = id_table, 55 .num_bulk_out = 2, 56 .calc_num_ports = omninet_calc_num_ports, 57 .port_probe = omninet_port_probe, 58 .port_remove = omninet_port_remove, 59 .process_read_urb = omninet_process_read_urb, 60 .prepare_write_buffer = omninet_prepare_write_buffer, 61 }; 62 63 static struct usb_serial_driver * const serial_drivers[] = { 64 &zyxel_omninet_device, NULL 65 }; 66 67 68 /* 69 * The protocol. 70 * 71 * The omni.net always exchange 64 bytes of data with the host. The first 72 * four bytes are the control header. 73 * 74 * oh_seq is a sequence number. Don't know if/how it's used. 75 * oh_len is the length of the data bytes in the packet. 76 * oh_xxx Bit-mapped, related to handshaking and status info. 77 * I normally set it to 0x03 in transmitted frames. 78 * 7: Active when the TA is in a CONNECTed state. 79 * 6: unknown 80 * 5: handshaking, unknown 81 * 4: handshaking, unknown 82 * 3: unknown, usually 0 83 * 2: unknown, usually 0 84 * 1: handshaking, unknown, usually set to 1 in transmitted frames 85 * 0: handshaking, unknown, usually set to 1 in transmitted frames 86 * oh_pad Probably a pad byte. 87 * 88 * After the header you will find data bytes if oh_len was greater than zero. 89 */ 90 struct omninet_header { 91 __u8 oh_seq; 92 __u8 oh_len; 93 __u8 oh_xxx; 94 __u8 oh_pad; 95 }; 96 97 struct omninet_data { 98 __u8 od_outseq; /* Sequence number for bulk_out URBs */ 99 }; 100 101 static int omninet_calc_num_ports(struct usb_serial *serial, 102 struct usb_serial_endpoints *epds) 103 { 104 /* We need only the second bulk-out for our single-port device. */ 105 epds->bulk_out[0] = epds->bulk_out[1]; 106 epds->num_bulk_out = 1; 107 108 return 1; 109 } 110 111 static int omninet_port_probe(struct usb_serial_port *port) 112 { 113 struct omninet_data *od; 114 115 od = kzalloc(sizeof(*od), GFP_KERNEL); 116 if (!od) 117 return -ENOMEM; 118 119 usb_set_serial_port_data(port, od); 120 121 return 0; 122 } 123 124 static int omninet_port_remove(struct usb_serial_port *port) 125 { 126 struct omninet_data *od; 127 128 od = usb_get_serial_port_data(port); 129 kfree(od); 130 131 return 0; 132 } 133 134 #define OMNINET_HEADERLEN 4 135 #define OMNINET_BULKOUTSIZE 64 136 #define OMNINET_PAYLOADSIZE (OMNINET_BULKOUTSIZE - OMNINET_HEADERLEN) 137 138 static void omninet_process_read_urb(struct urb *urb) 139 { 140 struct usb_serial_port *port = urb->context; 141 const struct omninet_header *hdr = urb->transfer_buffer; 142 const unsigned char *data; 143 size_t data_len; 144 145 if (urb->actual_length <= OMNINET_HEADERLEN || !hdr->oh_len) 146 return; 147 148 data = (char *)urb->transfer_buffer + OMNINET_HEADERLEN; 149 data_len = min_t(size_t, urb->actual_length - OMNINET_HEADERLEN, 150 hdr->oh_len); 151 tty_insert_flip_string(&port->port, data, data_len); 152 tty_flip_buffer_push(&port->port); 153 } 154 155 static int omninet_prepare_write_buffer(struct usb_serial_port *port, 156 void *buf, size_t count) 157 { 158 struct omninet_data *od = usb_get_serial_port_data(port); 159 struct omninet_header *header = buf; 160 161 count = min_t(size_t, count, OMNINET_PAYLOADSIZE); 162 163 count = kfifo_out_locked(&port->write_fifo, buf + OMNINET_HEADERLEN, 164 count, &port->lock); 165 166 header->oh_seq = od->od_outseq++; 167 header->oh_len = count; 168 header->oh_xxx = 0x03; 169 header->oh_pad = 0x00; 170 171 /* always 64 bytes */ 172 return OMNINET_BULKOUTSIZE; 173 } 174 175 module_usb_serial_driver(serial_drivers, id_table); 176 177 MODULE_AUTHOR(DRIVER_AUTHOR); 178 MODULE_DESCRIPTION(DRIVER_DESC); 179 MODULE_LICENSE("GPL v2"); 180