Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) // SPDX-License-Identifier: GPL-2.0+
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3)  * Safe Encapsulated USB Serial Driver
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5)  *      Copyright (C) 2010 Johan Hovold <jhovold@gmail.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6)  *      Copyright (C) 2001 Lineo
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7)  *      Copyright (C) 2001 Hewlett-Packard
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9)  * By:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10)  *      Stuart Lynne <sl@lineo.com>, Tom Rushworth <tbr@lineo.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14)  * The encapsultaion is designed to overcome difficulties with some USB
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15)  * hardware.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17)  * While the USB protocol has a CRC over the data while in transit, i.e. while
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18)  * being carried over the bus, there is no end to end protection. If the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19)  * hardware has any problems getting the data into or out of the USB transmit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20)  * and receive FIFO's then data can be lost.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22)  * This protocol adds a two byte trailer to each USB packet to specify the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23)  * number of bytes of valid data and a 10 bit CRC that will allow the receiver
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24)  * to verify that the entire USB packet was received without error.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26)  * Because in this case the sender and receiver are the class and function
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27)  * drivers there is now end to end protection.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29)  * There is an additional option that can be used to force all transmitted
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30)  * packets to be padded to the maximum packet size. This provides a work
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31)  * around for some devices which have problems with small USB packets.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33)  * Assuming a packetsize of N:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35)  *      0..N-2  data and optional padding
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37)  *      N-2     bits 7-2 - number of bytes of valid data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38)  *              bits 1-0 top two bits of 10 bit CRC
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39)  *      N-1     bottom 8 bits of 10 bit CRC
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42)  *      | Data Length       | 10 bit CRC                                |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43)  *      + 7 . 6 . 5 . 4 . 3 . 2 . 1 . 0 | 7 . 6 . 5 . 4 . 3 . 2 . 1 . 0 +
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45)  * The 10 bit CRC is computed across the sent data, followed by the trailer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46)  * with the length set and the CRC set to zero. The CRC is then OR'd into
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47)  * the trailer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49)  * When received a 10 bit CRC is computed over the entire frame including
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50)  * the trailer and should be equal to zero.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52)  * Two module parameters are used to control the encapsulation, if both are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53)  * turned of the module works as a simple serial device with NO
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54)  * encapsulation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56)  * See linux/drivers/usbd/serial_fd for a device function driver
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57)  * implementation of this.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) #include <linux/errno.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) #include <linux/gfp.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) #include <linux/tty.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) #include <linux/tty_driver.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) #include <linux/tty_flip.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) #include <linux/spinlock.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) #include <linux/uaccess.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) #include <linux/usb.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) #include <linux/usb/serial.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) static bool safe = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) static bool padded = IS_ENABLED(CONFIG_USB_SERIAL_SAFE_PADDED);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) #define DRIVER_AUTHOR "sl@lineo.com, tbr@lineo.com, Johan Hovold <jhovold@gmail.com>"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) #define DRIVER_DESC "USB Safe Encapsulated Serial"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) MODULE_AUTHOR(DRIVER_AUTHOR);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) MODULE_DESCRIPTION(DRIVER_DESC);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) MODULE_LICENSE("GPL");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) module_param(safe, bool, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) MODULE_PARM_DESC(safe, "Turn Safe Encapsulation On/Off");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) module_param(padded, bool, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) MODULE_PARM_DESC(padded, "Pad to full wMaxPacketSize On/Off");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) #define CDC_DEVICE_CLASS                        0x02
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) #define CDC_INTERFACE_CLASS                     0x02
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) #define CDC_INTERFACE_SUBCLASS                  0x06
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) #define LINEO_INTERFACE_CLASS                   0xff
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) #define LINEO_INTERFACE_SUBCLASS_SAFENET        0x01
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) #define LINEO_SAFENET_CRC                       0x01
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) #define LINEO_SAFENET_CRC_PADDED                0x02
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) #define LINEO_INTERFACE_SUBCLASS_SAFESERIAL     0x02
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) #define LINEO_SAFESERIAL_CRC                    0x01
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) #define LINEO_SAFESERIAL_CRC_PADDED             0x02
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) #define MY_USB_DEVICE(vend, prod, dc, ic, isc) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 	.match_flags = USB_DEVICE_ID_MATCH_DEVICE | \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 		       USB_DEVICE_ID_MATCH_DEV_CLASS | \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) 		       USB_DEVICE_ID_MATCH_INT_CLASS | \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 		       USB_DEVICE_ID_MATCH_INT_SUBCLASS, \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 	.idVendor = (vend), \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 	.idProduct = (prod),\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 	.bDeviceClass = (dc),\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) 	.bInterfaceClass = (ic), \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) 	.bInterfaceSubClass = (isc),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) static const struct usb_device_id id_table[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) 	{MY_USB_DEVICE(0x49f, 0xffff, CDC_DEVICE_CLASS, LINEO_INTERFACE_CLASS, LINEO_INTERFACE_SUBCLASS_SAFESERIAL)},	/* Itsy */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) 	{MY_USB_DEVICE(0x3f0, 0x2101, CDC_DEVICE_CLASS, LINEO_INTERFACE_CLASS, LINEO_INTERFACE_SUBCLASS_SAFESERIAL)},	/* Calypso */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) 	{MY_USB_DEVICE(0x4dd, 0x8001, CDC_DEVICE_CLASS, LINEO_INTERFACE_CLASS, LINEO_INTERFACE_SUBCLASS_SAFESERIAL)},	/* Iris */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) 	{MY_USB_DEVICE(0x4dd, 0x8002, CDC_DEVICE_CLASS, LINEO_INTERFACE_CLASS, LINEO_INTERFACE_SUBCLASS_SAFESERIAL)},	/* Collie */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) 	{MY_USB_DEVICE(0x4dd, 0x8003, CDC_DEVICE_CLASS, LINEO_INTERFACE_CLASS, LINEO_INTERFACE_SUBCLASS_SAFESERIAL)},	/* Collie */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) 	{MY_USB_DEVICE(0x4dd, 0x8004, CDC_DEVICE_CLASS, LINEO_INTERFACE_CLASS, LINEO_INTERFACE_SUBCLASS_SAFESERIAL)},	/* Collie */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) 	{MY_USB_DEVICE(0x5f9, 0xffff, CDC_DEVICE_CLASS, LINEO_INTERFACE_CLASS, LINEO_INTERFACE_SUBCLASS_SAFESERIAL)},	/* Sharp tmp */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 	{}			/* terminating entry  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) MODULE_DEVICE_TABLE(usb, id_table);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) static const __u16 crc10_table[256] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 	0x000, 0x233, 0x255, 0x066, 0x299, 0x0aa, 0x0cc, 0x2ff,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) 	0x301, 0x132, 0x154, 0x367, 0x198, 0x3ab, 0x3cd, 0x1fe,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 	0x031, 0x202, 0x264, 0x057, 0x2a8, 0x09b, 0x0fd, 0x2ce,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) 	0x330, 0x103, 0x165, 0x356, 0x1a9, 0x39a, 0x3fc, 0x1cf,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) 	0x062, 0x251, 0x237, 0x004, 0x2fb, 0x0c8, 0x0ae, 0x29d,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) 	0x363, 0x150, 0x136, 0x305, 0x1fa, 0x3c9, 0x3af, 0x19c,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 	0x053, 0x260, 0x206, 0x035, 0x2ca, 0x0f9, 0x09f, 0x2ac,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) 	0x352, 0x161, 0x107, 0x334, 0x1cb, 0x3f8, 0x39e, 0x1ad,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) 	0x0c4, 0x2f7, 0x291, 0x0a2, 0x25d, 0x06e, 0x008, 0x23b,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) 	0x3c5, 0x1f6, 0x190, 0x3a3, 0x15c, 0x36f, 0x309, 0x13a,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) 	0x0f5, 0x2c6, 0x2a0, 0x093, 0x26c, 0x05f, 0x039, 0x20a,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) 	0x3f4, 0x1c7, 0x1a1, 0x392, 0x16d, 0x35e, 0x338, 0x10b,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) 	0x0a6, 0x295, 0x2f3, 0x0c0, 0x23f, 0x00c, 0x06a, 0x259,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 	0x3a7, 0x194, 0x1f2, 0x3c1, 0x13e, 0x30d, 0x36b, 0x158,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 	0x097, 0x2a4, 0x2c2, 0x0f1, 0x20e, 0x03d, 0x05b, 0x268,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 	0x396, 0x1a5, 0x1c3, 0x3f0, 0x10f, 0x33c, 0x35a, 0x169,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 	0x188, 0x3bb, 0x3dd, 0x1ee, 0x311, 0x122, 0x144, 0x377,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) 	0x289, 0x0ba, 0x0dc, 0x2ef, 0x010, 0x223, 0x245, 0x076,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 	0x1b9, 0x38a, 0x3ec, 0x1df, 0x320, 0x113, 0x175, 0x346,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) 	0x2b8, 0x08b, 0x0ed, 0x2de, 0x021, 0x212, 0x274, 0x047,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) 	0x1ea, 0x3d9, 0x3bf, 0x18c, 0x373, 0x140, 0x126, 0x315,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) 	0x2eb, 0x0d8, 0x0be, 0x28d, 0x072, 0x241, 0x227, 0x014,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) 	0x1db, 0x3e8, 0x38e, 0x1bd, 0x342, 0x171, 0x117, 0x324,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) 	0x2da, 0x0e9, 0x08f, 0x2bc, 0x043, 0x270, 0x216, 0x025,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 	0x14c, 0x37f, 0x319, 0x12a, 0x3d5, 0x1e6, 0x180, 0x3b3,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 	0x24d, 0x07e, 0x018, 0x22b, 0x0d4, 0x2e7, 0x281, 0x0b2,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 	0x17d, 0x34e, 0x328, 0x11b, 0x3e4, 0x1d7, 0x1b1, 0x382,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 	0x27c, 0x04f, 0x029, 0x21a, 0x0e5, 0x2d6, 0x2b0, 0x083,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 	0x12e, 0x31d, 0x37b, 0x148, 0x3b7, 0x184, 0x1e2, 0x3d1,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 	0x22f, 0x01c, 0x07a, 0x249, 0x0b6, 0x285, 0x2e3, 0x0d0,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 	0x11f, 0x32c, 0x34a, 0x179, 0x386, 0x1b5, 0x1d3, 0x3e0,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 	0x21e, 0x02d, 0x04b, 0x278, 0x087, 0x2b4, 0x2d2, 0x0e1,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) #define CRC10_INITFCS     0x000	/* Initial FCS value */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) #define CRC10_GOODFCS     0x000	/* Good final FCS value */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) #define CRC10_FCS(fcs, c) ((((fcs) << 8) & 0x3ff) ^ crc10_table[((fcs) >> 2) & 0xff] ^ (c))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171)  * fcs_compute10 - memcpy and calculate 10 bit CRC across buffer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172)  * @sp: pointer to buffer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173)  * @len: number of bytes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174)  * @fcs: starting FCS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176)  * Perform a memcpy and calculate fcs using ppp 10bit CRC algorithm. Return
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177)  * new 10 bit FCS.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) static inline __u16 fcs_compute10(unsigned char *sp, int len, __u16 fcs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) 	for (; len-- > 0; fcs = CRC10_FCS(fcs, *sp++));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) 	return fcs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) static void safe_process_read_urb(struct urb *urb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) 	struct usb_serial_port *port = urb->context;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 	unsigned char *data = urb->transfer_buffer;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) 	unsigned char length = urb->actual_length;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) 	int actual_length;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 	__u16 fcs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) 	if (!length)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) 	if (!safe)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) 		goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) 	if (length < 2) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) 		dev_err(&port->dev, "malformed packet\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) 	fcs = fcs_compute10(data, length, CRC10_INITFCS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) 	if (fcs) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) 		dev_err(&port->dev, "%s - bad CRC %x\n", __func__, fcs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) 	actual_length = data[length - 2] >> 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) 	if (actual_length > (length - 2)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) 		dev_err(&port->dev, "%s - inconsistent lengths %d:%d\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) 				__func__, actual_length, length);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) 	dev_info(&urb->dev->dev, "%s - actual: %d\n", __func__, actual_length);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) 	length = actual_length;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) 	tty_insert_flip_string(&port->port, data, length);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) 	tty_flip_buffer_push(&port->port);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) static int safe_prepare_write_buffer(struct usb_serial_port *port,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) 						void *dest, size_t size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) 	unsigned char *buf = dest;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) 	int count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) 	int trailer_len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) 	int pkt_len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) 	__u16 fcs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) 	trailer_len = safe ? 2 : 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) 	count = kfifo_out_locked(&port->write_fifo, buf, size - trailer_len,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) 								&port->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) 	if (!safe)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) 		return count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) 	/* pad if necessary */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) 	if (padded) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) 		pkt_len = size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) 		memset(buf + count, '0', pkt_len - count - trailer_len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) 	} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) 		pkt_len = count + trailer_len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) 	/* set count */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) 	buf[pkt_len - 2] = count << 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) 	buf[pkt_len - 1] = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) 	/* compute fcs and insert into trailer */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) 	fcs = fcs_compute10(buf, pkt_len, CRC10_INITFCS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) 	buf[pkt_len - 2] |= fcs >> 8;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) 	buf[pkt_len - 1] |= fcs & 0xff;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) 	return pkt_len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) static int safe_startup(struct usb_serial *serial)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) 	struct usb_interface_descriptor	*desc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) 	if (serial->dev->descriptor.bDeviceClass != CDC_DEVICE_CLASS)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) 		return -ENODEV;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) 	desc = &serial->interface->cur_altsetting->desc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) 	if (desc->bInterfaceClass != LINEO_INTERFACE_CLASS)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) 		return -ENODEV;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) 	if (desc->bInterfaceSubClass != LINEO_INTERFACE_SUBCLASS_SAFESERIAL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) 		return -ENODEV;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) 	switch (desc->bInterfaceProtocol) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) 	case LINEO_SAFESERIAL_CRC:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) 	case LINEO_SAFESERIAL_CRC_PADDED:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) 		padded = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) 	default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) 		return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) static struct usb_serial_driver safe_device = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) 	.driver = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) 		.owner =	THIS_MODULE,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) 		.name =		"safe_serial",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) 	},
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) 	.id_table =		id_table,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) 	.num_ports =		1,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) 	.process_read_urb =	safe_process_read_urb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) 	.prepare_write_buffer =	safe_prepare_write_buffer,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) 	.attach =		safe_startup,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) static struct usb_serial_driver * const serial_drivers[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) 	&safe_device, NULL
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) module_usb_serial_driver(serial_drivers, id_table);