diff options
Diffstat (limited to 'drivers/usb/serial/safe_serial.c')
| -rw-r--r-- | drivers/usb/serial/safe_serial.c | 451 |
1 files changed, 451 insertions, 0 deletions
diff --git a/drivers/usb/serial/safe_serial.c b/drivers/usb/serial/safe_serial.c new file mode 100644 index 000000000000..0e85ed6c6c19 --- /dev/null +++ b/drivers/usb/serial/safe_serial.c @@ -0,0 +1,451 @@ +/* + * Safe Encapsulated USB Serial Driver + * + * Copyright (C) 2001 Lineo + * Copyright (C) 2001 Hewlett-Packard + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * By: + * Stuart Lynne <sl@lineo.com>, Tom Rushworth <tbr@lineo.com> + */ + +/* + * The encapsultaion is designed to overcome difficulties with some USB hardware. + * + * While the USB protocol has a CRC over the data while in transit, i.e. while + * being carried over the bus, there is no end to end protection. If the hardware + * has any problems getting the data into or out of the USB transmit and receive + * FIFO's then data can be lost. + * + * This protocol adds a two byte trailer to each USB packet to specify the number + * of bytes of valid data and a 10 bit CRC that will allow the receiver to verify + * that the entire USB packet was received without error. + * + * Because in this case the sender and receiver are the class and function drivers + * there is now end to end protection. + * + * There is an additional option that can be used to force all transmitted packets + * to be padded to the maximum packet size. This provides a work around for some + * devices which have problems with small USB packets. + * + * Assuming a packetsize of N: + * + * 0..N-2 data and optional padding + * + * N-2 bits 7-2 - number of bytes of valid data + * bits 1-0 top two bits of 10 bit CRC + * N-1 bottom 8 bits of 10 bit CRC + * + * + * | Data Length | 10 bit CRC | + * + 7 . 6 . 5 . 4 . 3 . 2 . 1 . 0 | 7 . 6 . 5 . 4 . 3 . 2 . 1 . 0 + + * + * The 10 bit CRC is computed across the sent data, followed by the trailer with + * the length set and the CRC set to zero. The CRC is then OR'd into the trailer. + * + * When received a 10 bit CRC is computed over the entire frame including the trailer + * and should be equal to zero. + * + * Two module parameters are used to control the encapsulation, if both are + * turned of the module works as a simple serial device with NO + * encapsulation. + * + * See linux/drivers/usbd/serial_fd for a device function driver + * implementation of this. + * + */ + + +#include <linux/config.h> +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/init.h> +#include <linux/slab.h> +#include <linux/tty.h> +#include <linux/tty_driver.h> +#include <linux/tty_flip.h> +#include <linux/module.h> +#include <linux/spinlock.h> +#include <asm/uaccess.h> +#include <linux/usb.h> +#include "usb-serial.h" + + +#ifndef CONFIG_USB_SAFE_PADDED +#define CONFIG_USB_SAFE_PADDED 0 +#endif + +static int debug; +static int safe = 1; +static int padded = CONFIG_USB_SAFE_PADDED; + +#define DRIVER_VERSION "v0.0b" +#define DRIVER_AUTHOR "sl@lineo.com, tbr@lineo.com" +#define DRIVER_DESC "USB Safe Encapsulated Serial" + +MODULE_AUTHOR (DRIVER_AUTHOR); +MODULE_DESCRIPTION (DRIVER_DESC); +MODULE_LICENSE("GPL"); + +#if defined(CONFIG_USBD_SAFE_SERIAL_VENDOR) && !defined(CONFIG_USBD_SAFE_SERIAL_PRODUCT) +#abort "SAFE_SERIAL_VENDOR defined without SAFE_SERIAL_PRODUCT" +#endif + +#if ! defined(CONFIG_USBD_SAFE_SERIAL_VENDOR) +static __u16 vendor; // no default +static __u16 product; // no default +module_param(vendor, ushort, 0); +MODULE_PARM_DESC(vendor, "User specified USB idVendor (required)"); +module_param(product, ushort, 0); +MODULE_PARM_DESC(product, "User specified USB idProduct (required)"); +#endif + +module_param(debug, bool, S_IRUGO | S_IWUSR); +MODULE_PARM_DESC(debug, "Debug enabled or not"); + +module_param(safe, bool, 0); +MODULE_PARM_DESC(safe, "Turn Safe Encapsulation On/Off"); + +module_param(padded, bool, 0); +MODULE_PARM_DESC(padded, "Pad to full wMaxPacketSize On/Off"); + +#define CDC_DEVICE_CLASS 0x02 + +#define CDC_INTERFACE_CLASS 0x02 +#define CDC_INTERFACE_SUBCLASS 0x06 + +#define LINEO_INTERFACE_CLASS 0xff + +#define LINEO_INTERFACE_SUBCLASS_SAFENET 0x01 +#define LINEO_SAFENET_CRC 0x01 +#define LINEO_SAFENET_CRC_PADDED 0x02 + +#define LINEO_INTERFACE_SUBCLASS_SAFESERIAL 0x02 +#define LINEO_SAFESERIAL_CRC 0x01 +#define LINEO_SAFESERIAL_CRC_PADDED 0x02 + + +#define MY_USB_DEVICE(vend,prod,dc,ic,isc) \ + .match_flags = USB_DEVICE_ID_MATCH_DEVICE | USB_DEVICE_ID_MATCH_DEV_CLASS | \ + USB_DEVICE_ID_MATCH_INT_CLASS | USB_DEVICE_ID_MATCH_INT_SUBCLASS, \ + .idVendor = (vend), \ + .idProduct = (prod),\ + .bDeviceClass = (dc),\ + .bInterfaceClass = (ic), \ + .bInterfaceSubClass = (isc), + +static struct usb_device_id id_table[] = { + {MY_USB_DEVICE (0x49f, 0xffff, CDC_DEVICE_CLASS, LINEO_INTERFACE_CLASS, LINEO_INTERFACE_SUBCLASS_SAFESERIAL)}, // Itsy + {MY_USB_DEVICE (0x3f0, 0x2101, CDC_DEVICE_CLASS, LINEO_INTERFACE_CLASS, LINEO_INTERFACE_SUBCLASS_SAFESERIAL)}, // Calypso + {MY_USB_DEVICE (0x4dd, 0x8001, CDC_DEVICE_CLASS, LINEO_INTERFACE_CLASS, LINEO_INTERFACE_SUBCLASS_SAFESERIAL)}, // Iris + {MY_USB_DEVICE (0x4dd, 0x8002, CDC_DEVICE_CLASS, LINEO_INTERFACE_CLASS, LINEO_INTERFACE_SUBCLASS_SAFESERIAL)}, // Collie + {MY_USB_DEVICE (0x4dd, 0x8003, CDC_DEVICE_CLASS, LINEO_INTERFACE_CLASS, LINEO_INTERFACE_SUBCLASS_SAFESERIAL)}, // Collie + {MY_USB_DEVICE (0x4dd, 0x8004, CDC_DEVICE_CLASS, LINEO_INTERFACE_CLASS, LINEO_INTERFACE_SUBCLASS_SAFESERIAL)}, // Collie + {MY_USB_DEVICE (0x5f9, 0xffff, CDC_DEVICE_CLASS, LINEO_INTERFACE_CLASS, LINEO_INTERFACE_SUBCLASS_SAFESERIAL)}, // Sharp tmp +#if defined(CONFIG_USB_SAFE_SERIAL_VENDOR) + {MY_USB_DEVICE + (CONFIG_USB_SAFE_SERIAL_VENDOR, CONFIG_USB_SAFE_SERIAL_PRODUCT, CDC_DEVICE_CLASS, + LINEO_INTERFACE_CLASS, LINEO_INTERFACE_SUBCLASS_SAFESERIAL)}, +#endif + // extra null entry for module + // vendor/produc parameters + {MY_USB_DEVICE (0, 0, CDC_DEVICE_CLASS, LINEO_INTERFACE_CLASS, LINEO_INTERFACE_SUBCLASS_SAFESERIAL)}, + {} // terminating entry +}; + +MODULE_DEVICE_TABLE (usb, id_table); + +static struct usb_driver safe_driver = { + .owner = THIS_MODULE, + .name = "safe_serial", + .probe = usb_serial_probe, + .disconnect = usb_serial_disconnect, + .id_table = id_table, +}; + +static __u16 crc10_table[256] = { + 0x000, 0x233, 0x255, 0x066, 0x299, 0x0aa, 0x0cc, 0x2ff, 0x301, 0x132, 0x154, 0x367, 0x198, 0x3ab, 0x3cd, 0x1fe, + 0x031, 0x202, 0x264, 0x057, 0x2a8, 0x09b, 0x0fd, 0x2ce, 0x330, 0x103, 0x165, 0x356, 0x1a9, 0x39a, 0x3fc, 0x1cf, + 0x062, 0x251, 0x237, 0x004, 0x2fb, 0x0c8, 0x0ae, 0x29d, 0x363, 0x150, 0x136, 0x305, 0x1fa, 0x3c9, 0x3af, 0x19c, + 0x053, 0x260, 0x206, 0x035, 0x2ca, 0x0f9, 0x09f, 0x2ac, 0x352, 0x161, 0x107, 0x334, 0x1cb, 0x3f8, 0x39e, 0x1ad, + 0x0c4, 0x2f7, 0x291, 0x0a2, 0x25d, 0x06e, 0x008, 0x23b, 0x3c5, 0x1f6, 0x190, 0x3a3, 0x15c, 0x36f, 0x309, 0x13a, + 0x0f5, 0x2c6, 0x2a0, 0x093, 0x26c, 0x05f, 0x039, 0x20a, 0x3f4, 0x1c7, 0x1a1, 0x392, 0x16d, 0x35e, 0x338, 0x10b, + 0x0a6, 0x295, 0x2f3, 0x0c0, 0x23f, 0x00c, 0x06a, 0x259, 0x3a7, 0x194, 0x1f2, 0x3c1, 0x13e, 0x30d, 0x36b, 0x158, + 0x097, 0x2a4, 0x2c2, 0x0f1, 0x20e, 0x03d, 0x05b, 0x268, 0x396, 0x1a5, 0x1c3, 0x3f0, 0x10f, 0x33c, 0x35a, 0x169, + 0x188, 0x3bb, 0x3dd, 0x1ee, 0x311, 0x122, 0x144, 0x377, 0x289, 0x0ba, 0x0dc, 0x2ef, 0x010, 0x223, 0x245, 0x076, + 0x1b9, 0x38a, 0x3ec, 0x1df, 0x320, 0x113, 0x175, 0x346, 0x2b8, 0x08b, 0x0ed, 0x2de, 0x021, 0x212, 0x274, 0x047, + 0x1ea, 0x3d9, 0x3bf, 0x18c, 0x373, 0x140, 0x126, 0x315, 0x2eb, 0x0d8, 0x0be, 0x28d, 0x072, 0x241, 0x227, 0x014, + 0x1db, 0x3e8, 0x38e, 0x1bd, 0x342, 0x171, 0x117, 0x324, 0x2da, 0x0e9, 0x08f, 0x2bc, 0x043, 0x270, 0x216, 0x025, + 0x14c, 0x37f, 0x319, 0x12a, 0x3d5, 0x1e6, 0x180, 0x3b3, 0x24d, 0x07e, 0x018, 0x22b, 0x0d4, 0x2e7, 0x281, 0x0b2, + 0x17d, 0x34e, 0x328, 0x11b, 0x3e4, 0x1d7, 0x1b1, 0x382, 0x27c, 0x04f, 0x029, 0x21a, 0x0e5, 0x2d6, 0x2b0, 0x083, + 0x12e, 0x31d, 0x37b, 0x148, 0x3b7, 0x184, 0x1e2, 0x3d1, 0x22f, 0x01c, 0x07a, 0x249, 0x0b6, 0x285, 0x2e3, 0x0d0, + 0x11f, 0x32c, 0x34a, 0x179, 0x386, 0x1b5, 0x1d3, 0x3e0, 0x21e, 0x02d, 0x04b, 0x278, 0x087, 0x2b4, 0x2d2, 0x0e1, +}; + +#define CRC10_INITFCS 0x000 // Initial FCS value +#define CRC10_GOODFCS 0x000 // Good final FCS value +#define CRC10_FCS(fcs, c) ( (((fcs) << 8) & 0x3ff) ^ crc10_table[((fcs) >> 2) & 0xff] ^ (c)) + +/** + * fcs_compute10 - memcpy and calculate 10 bit CRC across buffer + * @sp: pointer to buffer + * @len: number of bytes + * @fcs: starting FCS + * + * Perform a memcpy and calculate fcs using ppp 10bit CRC algorithm. Return + * new 10 bit FCS. + */ +static __u16 __inline__ fcs_compute10 (unsigned char *sp, int len, __u16 fcs) +{ + for (; len-- > 0; fcs = CRC10_FCS (fcs, *sp++)); + return fcs; +} + +static void safe_read_bulk_callback (struct urb *urb, struct pt_regs *regs) +{ + struct usb_serial_port *port = (struct usb_serial_port *) urb->context; + unsigned char *data = urb->transfer_buffer; + unsigned char length = urb->actual_length; + int i; + int result; + + dbg ("%s", __FUNCTION__); + + if (urb->status) { + dbg ("%s - nonzero read bulk status received: %d", __FUNCTION__, urb->status); + return; + } + + dbg ("safe_read_bulk_callback length: %d", port->read_urb->actual_length); +#ifdef ECHO_RCV + { + int i; + unsigned char *cp = port->read_urb->transfer_buffer; + for (i = 0; i < port->read_urb->actual_length; i++) { + if ((i % 32) == 0) { + printk ("\nru[%02x] ", i); + } + printk ("%02x ", *cp++); + } + printk ("\n"); + } +#endif + if (safe) { + __u16 fcs; + if (!(fcs = fcs_compute10 (data, length, CRC10_INITFCS))) { + + int actual_length = data[length - 2] >> 2; + + if (actual_length <= (length - 2)) { + + info ("%s - actual: %d", __FUNCTION__, actual_length); + + for (i = 0; i < actual_length; i++) { + tty_insert_flip_char (port->tty, data[i], 0); + } + tty_flip_buffer_push (port->tty); + } else { + err ("%s - inconsistent lengths %d:%d", __FUNCTION__, + actual_length, length); + } + } else { + err ("%s - bad CRC %x", __FUNCTION__, fcs); + } + } else { + for (i = 0; i < length; i++) { + tty_insert_flip_char (port->tty, data[i], 0); + } + tty_flip_buffer_push (port->tty); + } + + /* Continue trying to always read */ + usb_fill_bulk_urb (urb, port->serial->dev, + usb_rcvbulkpipe (port->serial->dev, port->bulk_in_endpointAddress), + urb->transfer_buffer, urb->transfer_buffer_length, + safe_read_bulk_callback, port); + + if ((result = usb_submit_urb (urb, GFP_ATOMIC))) { + err ("%s - failed resubmitting read urb, error %d", __FUNCTION__, result); + } +} + +static int safe_write (struct usb_serial_port *port, const unsigned char *buf, int count) +{ + unsigned char *data; + int result; + int i; + int packet_length; + + dbg ("safe_write port: %p %d urb: %p count: %d", port, port->number, port->write_urb, + count); + + if (!port->write_urb) { + dbg ("%s - write urb NULL", __FUNCTION__); + return (0); + } + + dbg ("safe_write write_urb: %d transfer_buffer_length", + port->write_urb->transfer_buffer_length); + + if (!port->write_urb->transfer_buffer_length) { + dbg ("%s - write urb transfer_buffer_length zero", __FUNCTION__); + return (0); + } + if (count == 0) { + dbg ("%s - write request of 0 bytes", __FUNCTION__); + return (0); + } + if (port->write_urb->status == -EINPROGRESS) { + dbg ("%s - already writing", __FUNCTION__); + return (0); + } + + packet_length = port->bulk_out_size; // get max packetsize + + i = packet_length - (safe ? 2 : 0); // get bytes to send + count = (count > i) ? i : count; + + + // get the data into the transfer buffer + data = port->write_urb->transfer_buffer; + memset (data, '0', packet_length); + + memcpy (data, buf, count); + + if (safe) { + __u16 fcs; + + // pad if necessary + if (!padded) { + packet_length = count + 2; + } + // set count + data[packet_length - 2] = count << 2; + data[packet_length - 1] = 0; + + // compute fcs and insert into trailer + fcs = fcs_compute10 (data, packet_length, CRC10_INITFCS); + data[packet_length - 2] |= fcs >> 8; + data[packet_length - 1] |= fcs & 0xff; + + // set length to send + port->write_urb->transfer_buffer_length = packet_length; + } else { + port->write_urb->transfer_buffer_length = count; + } + + usb_serial_debug_data(debug, &port->dev, __FUNCTION__, count, port->write_urb->transfer_buffer); +#ifdef ECHO_TX + { + int i; + unsigned char *cp = port->write_urb->transfer_buffer; + for (i = 0; i < port->write_urb->transfer_buffer_length; i++) { + if ((i % 32) == 0) { + printk ("\nsu[%02x] ", i); + } + printk ("%02x ", *cp++); + } + printk ("\n"); + } +#endif + port->write_urb->dev = port->serial->dev; + if ((result = usb_submit_urb (port->write_urb, GFP_KERNEL))) { + err ("%s - failed submitting write urb, error %d", __FUNCTION__, result); + return 0; + } + dbg ("%s urb: %p submitted", __FUNCTION__, port->write_urb); + + return (count); +} + +static int safe_write_room (struct usb_serial_port *port) +{ + int room = 0; // Default: no room + + dbg ("%s", __FUNCTION__); + + if (port->write_urb->status != -EINPROGRESS) + room = port->bulk_out_size - (safe ? 2 : 0); + + if (room) { + dbg ("safe_write_room returns %d", room); + } + + return (room); +} + +static int safe_startup (struct usb_serial *serial) +{ + switch (serial->interface->cur_altsetting->desc.bInterfaceProtocol) { + case LINEO_SAFESERIAL_CRC: + break; + case LINEO_SAFESERIAL_CRC_PADDED: + padded = 1; + break; + default: + return -EINVAL; + } + return 0; +} + +static struct usb_serial_device_type safe_device = { + .owner = THIS_MODULE, + .name = "Safe", + .id_table = id_table, + .num_interrupt_in = NUM_DONT_CARE, + .num_bulk_in = NUM_DONT_CARE, + .num_bulk_out = NUM_DONT_CARE, + .num_ports = 1, + .write = safe_write, + .write_room = safe_write_room, + .read_bulk_callback = safe_read_bulk_callback, + .attach = safe_startup, +}; + +static int __init safe_init (void) +{ + int i, retval; + + info (DRIVER_VERSION " " DRIVER_AUTHOR); + info (DRIVER_DESC); + info ("vendor: %x product: %x safe: %d padded: %d\n", vendor, product, safe, padded); + + // if we have vendor / product parameters patch them into id list + if (vendor || product) { + info ("vendor: %x product: %x\n", vendor, product); + + for (i = 0; i < (sizeof (id_table) / sizeof (struct usb_device_id)); i++) { + if (!id_table[i].idVendor && !id_table[i].idProduct) { + id_table[i].idVendor = vendor; + id_table[i].idProduct = product; + break; + } + } + } + + retval = usb_serial_register(&safe_device); + if (retval) + goto failed_usb_serial_register; + retval = usb_register(&safe_driver); + if (retval) + goto failed_usb_register; + + return 0; +failed_usb_register: + usb_serial_deregister(&safe_device); +failed_usb_serial_register: + return retval; +} + +static void __exit safe_exit (void) +{ + usb_deregister (&safe_driver); + usb_serial_deregister (&safe_device); +} + +module_init (safe_init); +module_exit (safe_exit); |