1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright 2007, Frank A Kingswood <frank@kingswood-consulting.co.uk>
4 * Copyright 2007, Werner Cornelius <werner@cornelius-consult.de>
5 * Copyright 2009, Boris Hajduk <boris@hajduk.org>
7 * ch341.c implements a serial port driver for the Winchiphead CH341.
9 * The CH341 device can be used to implement an RS232 asynchronous
10 * serial port, an IEEE-1284 parallel printer port or a memory-like
11 * interface. In all cases the CH341 supports an I2C interface as well.
12 * This driver only supports the asynchronous serial interface.
15 #include <linux/kernel.h>
16 #include <linux/tty.h>
17 #include <linux/module.h>
18 #include <linux/slab.h>
19 #include <linux/usb.h>
20 #include <linux/usb/serial.h>
21 #include <linux/serial.h>
22 #include <asm/unaligned.h>
24 #define DEFAULT_BAUD_RATE 9600
25 #define DEFAULT_TIMEOUT 1000
27 /* flags for IO-Bits */
28 #define CH341_BIT_RTS (1 << 6)
29 #define CH341_BIT_DTR (1 << 5)
31 /******************************/
32 /* interrupt pipe definitions */
33 /******************************/
34 /* always 4 interrupt bytes */
35 /* first irq byte normally 0x08 */
36 /* second irq byte base 0x7d + below */
37 /* third irq byte base 0x94 + below */
38 /* fourth irq byte normally 0xee */
40 /* second interrupt byte */
41 #define CH341_MULT_STAT 0x04 /* multiple status since last interrupt event */
43 /* status returned in third interrupt answer byte, inverted in data
45 #define CH341_BIT_CTS 0x01
46 #define CH341_BIT_DSR 0x02
47 #define CH341_BIT_RI 0x04
48 #define CH341_BIT_DCD 0x08
49 #define CH341_BITS_MODEM_STAT 0x0f /* all bits */
51 /* Break support - the information used to implement this was gleaned from
52 * the Net/FreeBSD uchcom.c driver by Takanori Watanabe. Domo arigato.
55 #define CH341_REQ_READ_VERSION 0x5F
56 #define CH341_REQ_WRITE_REG 0x9A
57 #define CH341_REQ_READ_REG 0x95
58 #define CH341_REQ_SERIAL_INIT 0xA1
59 #define CH341_REQ_MODEM_CTRL 0xA4
61 #define CH341_REG_BREAK 0x05
62 #define CH341_REG_PRESCALER 0x12
63 #define CH341_REG_DIVISOR 0x13
64 #define CH341_REG_LCR 0x18
65 #define CH341_REG_LCR2 0x25
67 #define CH341_NBREAK_BITS 0x01
69 #define CH341_LCR_ENABLE_RX 0x80
70 #define CH341_LCR_ENABLE_TX 0x40
71 #define CH341_LCR_MARK_SPACE 0x20
72 #define CH341_LCR_PAR_EVEN 0x10
73 #define CH341_LCR_ENABLE_PAR 0x08
74 #define CH341_LCR_STOP_BITS_2 0x04
75 #define CH341_LCR_CS8 0x03
76 #define CH341_LCR_CS7 0x02
77 #define CH341_LCR_CS6 0x01
78 #define CH341_LCR_CS5 0x00
80 #define CH341_QUIRK_LIMITED_PRESCALER BIT(0)
81 #define CH341_QUIRK_SIMULATE_BREAK BIT(1)
83 static const struct usb_device_id id_table[] = {
84 { USB_DEVICE(0x1a86, 0x5512) },
85 { USB_DEVICE(0x1a86, 0x5523) },
86 { USB_DEVICE(0x1a86, 0x7522) },
87 { USB_DEVICE(0x1a86, 0x7523) },
88 { USB_DEVICE(0x4348, 0x5523) },
89 { USB_DEVICE(0x9986, 0x7523) },
92 MODULE_DEVICE_TABLE(usb, id_table);
94 struct ch341_private {
95 spinlock_t lock; /* access lock */
96 unsigned baud_rate; /* set baud rate */
100 unsigned long quirks;
101 unsigned long break_end;
104 static void ch341_set_termios(struct tty_struct *tty,
105 struct usb_serial_port *port,
106 struct ktermios *old_termios);
108 static int ch341_control_out(struct usb_device *dev, u8 request,
109 u16 value, u16 index)
113 dev_dbg(&dev->dev, "%s - (%02x,%04x,%04x)\n", __func__,
114 request, value, index);
116 r = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), request,
117 USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
118 value, index, NULL, 0, DEFAULT_TIMEOUT);
120 dev_err(&dev->dev, "failed to send control message: %d\n", r);
125 static int ch341_control_in(struct usb_device *dev,
126 u8 request, u16 value, u16 index,
127 char *buf, unsigned bufsize)
131 dev_dbg(&dev->dev, "%s - (%02x,%04x,%04x,%u)\n", __func__,
132 request, value, index, bufsize);
134 r = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), request,
135 USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
136 value, index, buf, bufsize, DEFAULT_TIMEOUT);
137 if (r < (int)bufsize) {
140 "short control message received (%d < %u)\n",
145 dev_err(&dev->dev, "failed to receive control message: %d\n",
153 #define CH341_CLKRATE 48000000
154 #define CH341_CLK_DIV(ps, fact) (1 << (12 - 3 * (ps) - (fact)))
155 #define CH341_MIN_RATE(ps) (CH341_CLKRATE / (CH341_CLK_DIV((ps), 1) * 512))
157 static const speed_t ch341_min_rates[] = {
164 /* Supported range is 46 to 3000000 bps. */
165 #define CH341_MIN_BPS DIV_ROUND_UP(CH341_CLKRATE, CH341_CLK_DIV(0, 0) * 256)
166 #define CH341_MAX_BPS (CH341_CLKRATE / (CH341_CLK_DIV(3, 0) * 2))
169 * The device line speed is given by the following equation:
171 * baudrate = 48000000 / (2^(12 - 3 * ps - fact) * div), where
175 * 2 <= div <= 256 if fact = 0, or
176 * 9 <= div <= 256 if fact = 1
178 static int ch341_get_divisor(struct ch341_private *priv, speed_t speed)
180 unsigned int fact, div, clk_div;
181 bool force_fact0 = false;
185 * Clamp to supported range, this makes the (ps < 0) and (div < 2)
186 * sanity checks below redundant.
188 speed = clamp_val(speed, CH341_MIN_BPS, CH341_MAX_BPS);
191 * Start with highest possible base clock (fact = 1) that will give a
192 * divisor strictly less than 512.
195 for (ps = 3; ps >= 0; ps--) {
196 if (speed > ch341_min_rates[ps])
203 /* Determine corresponding divisor, rounding down. */
204 clk_div = CH341_CLK_DIV(ps, fact);
205 div = CH341_CLKRATE / (clk_div * speed);
207 /* Some devices require a lower base clock if ps < 3. */
208 if (ps < 3 && (priv->quirks & CH341_QUIRK_LIMITED_PRESCALER))
211 /* Halve base clock (fact = 0) if required. */
212 if (div < 9 || div > 255 || force_fact0) {
222 * Pick next divisor if resulting rate is closer to the requested one,
223 * scale up to avoid rounding errors on low rates.
225 if (16 * CH341_CLKRATE / (clk_div * div) - 16 * speed >=
226 16 * speed - 16 * CH341_CLKRATE / (clk_div * (div + 1)))
230 * Prefer lower base clock (fact = 0) if even divisor.
232 * Note that this makes the receiver more tolerant to errors.
234 if (fact == 1 && div % 2 == 0) {
239 return (0x100 - div) << 8 | fact << 2 | ps;
242 static int ch341_set_baudrate_lcr(struct usb_device *dev,
243 struct ch341_private *priv,
244 speed_t baud_rate, u8 lcr)
252 val = ch341_get_divisor(priv, baud_rate);
257 * CH341A buffers data until a full endpoint-size packet (32 bytes)
258 * has been received unless bit 7 is set.
262 r = ch341_control_out(dev, CH341_REQ_WRITE_REG,
263 CH341_REG_DIVISOR << 8 | CH341_REG_PRESCALER,
269 * Chip versions before version 0x30 as read using
270 * CH341_REQ_READ_VERSION used separate registers for line control
271 * (stop bits, parity and word length). Version 0x30 and above use
272 * CH341_REG_LCR only and CH341_REG_LCR2 is always set to zero.
274 r = ch341_control_out(dev, CH341_REQ_WRITE_REG,
275 CH341_REG_LCR2 << 8 | CH341_REG_LCR, lcr);
282 static int ch341_set_handshake(struct usb_device *dev, u8 control)
284 return ch341_control_out(dev, CH341_REQ_MODEM_CTRL, ~control, 0);
287 static int ch341_get_status(struct usb_device *dev, struct ch341_private *priv)
289 const unsigned int size = 2;
294 buffer = kmalloc(size, GFP_KERNEL);
298 r = ch341_control_in(dev, CH341_REQ_READ_REG, 0x0706, 0, buffer, size);
302 spin_lock_irqsave(&priv->lock, flags);
303 priv->msr = (~(*buffer)) & CH341_BITS_MODEM_STAT;
304 spin_unlock_irqrestore(&priv->lock, flags);
310 /* -------------------------------------------------------------------------- */
312 static int ch341_configure(struct usb_device *dev, struct ch341_private *priv)
314 const unsigned int size = 2;
318 buffer = kmalloc(size, GFP_KERNEL);
322 /* expect two bytes 0x27 0x00 */
323 r = ch341_control_in(dev, CH341_REQ_READ_VERSION, 0, 0, buffer, size);
326 dev_dbg(&dev->dev, "Chip version: 0x%02x\n", buffer[0]);
328 r = ch341_control_out(dev, CH341_REQ_SERIAL_INIT, 0, 0);
332 r = ch341_set_baudrate_lcr(dev, priv, priv->baud_rate, priv->lcr);
336 r = ch341_set_handshake(dev, priv->mcr);
342 static int ch341_detect_quirks(struct usb_serial_port *port)
344 struct ch341_private *priv = usb_get_serial_port_data(port);
345 struct usb_device *udev = port->serial->dev;
346 const unsigned int size = 2;
347 unsigned long quirks = 0;
351 buffer = kmalloc(size, GFP_KERNEL);
356 * A subset of CH34x devices does not support all features. The
357 * prescaler is limited and there is no support for sending a RS232
358 * break condition. A read failure when trying to set up the latter is
359 * used to detect these devices.
361 r = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0), CH341_REQ_READ_REG,
362 USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
363 CH341_REG_BREAK, 0, buffer, size, DEFAULT_TIMEOUT);
365 dev_info(&port->dev, "break control not supported, using simulated break\n");
366 quirks = CH341_QUIRK_LIMITED_PRESCALER | CH341_QUIRK_SIMULATE_BREAK;
374 dev_err(&port->dev, "failed to read break control: %d\n", r);
383 dev_dbg(&port->dev, "enabling quirk flags: 0x%02lx\n", quirks);
384 priv->quirks |= quirks;
390 static int ch341_port_probe(struct usb_serial_port *port)
392 struct ch341_private *priv;
395 priv = kzalloc(sizeof(struct ch341_private), GFP_KERNEL);
399 spin_lock_init(&priv->lock);
400 priv->baud_rate = DEFAULT_BAUD_RATE;
402 * Some CH340 devices appear unable to change the initial LCR
403 * settings, so set a sane 8N1 default.
405 priv->lcr = CH341_LCR_ENABLE_RX | CH341_LCR_ENABLE_TX | CH341_LCR_CS8;
407 r = ch341_configure(port->serial->dev, priv);
411 usb_set_serial_port_data(port, priv);
413 r = ch341_detect_quirks(port);
423 static void ch341_port_remove(struct usb_serial_port *port)
425 struct ch341_private *priv;
427 priv = usb_get_serial_port_data(port);
431 static int ch341_carrier_raised(struct usb_serial_port *port)
433 struct ch341_private *priv = usb_get_serial_port_data(port);
434 if (priv->msr & CH341_BIT_DCD)
439 static void ch341_dtr_rts(struct usb_serial_port *port, int on)
441 struct ch341_private *priv = usb_get_serial_port_data(port);
444 /* drop DTR and RTS */
445 spin_lock_irqsave(&priv->lock, flags);
447 priv->mcr |= CH341_BIT_RTS | CH341_BIT_DTR;
449 priv->mcr &= ~(CH341_BIT_RTS | CH341_BIT_DTR);
450 spin_unlock_irqrestore(&priv->lock, flags);
451 ch341_set_handshake(port->serial->dev, priv->mcr);
454 static void ch341_close(struct usb_serial_port *port)
456 usb_serial_generic_close(port);
457 usb_kill_urb(port->interrupt_in_urb);
461 /* open this device, set default parameters */
462 static int ch341_open(struct tty_struct *tty, struct usb_serial_port *port)
464 struct ch341_private *priv = usb_get_serial_port_data(port);
468 ch341_set_termios(tty, port, NULL);
470 dev_dbg(&port->dev, "%s - submitting interrupt urb\n", __func__);
471 r = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
473 dev_err(&port->dev, "%s - failed to submit interrupt urb: %d\n",
478 r = ch341_get_status(port->serial->dev, priv);
480 dev_err(&port->dev, "failed to read modem status: %d\n", r);
481 goto err_kill_interrupt_urb;
484 r = usb_serial_generic_open(tty, port);
486 goto err_kill_interrupt_urb;
490 err_kill_interrupt_urb:
491 usb_kill_urb(port->interrupt_in_urb);
496 /* Old_termios contains the original termios settings and
497 * tty->termios contains the new setting to be used.
499 static void ch341_set_termios(struct tty_struct *tty,
500 struct usb_serial_port *port, struct ktermios *old_termios)
502 struct ch341_private *priv = usb_get_serial_port_data(port);
508 /* redundant changes may cause the chip to lose bytes */
509 if (old_termios && !tty_termios_hw_change(&tty->termios, old_termios))
512 baud_rate = tty_get_baud_rate(tty);
514 lcr = CH341_LCR_ENABLE_RX | CH341_LCR_ENABLE_TX;
516 switch (C_CSIZE(tty)) {
518 lcr |= CH341_LCR_CS5;
521 lcr |= CH341_LCR_CS6;
524 lcr |= CH341_LCR_CS7;
527 lcr |= CH341_LCR_CS8;
532 lcr |= CH341_LCR_ENABLE_PAR;
533 if (C_PARODD(tty) == 0)
534 lcr |= CH341_LCR_PAR_EVEN;
536 lcr |= CH341_LCR_MARK_SPACE;
540 lcr |= CH341_LCR_STOP_BITS_2;
543 priv->baud_rate = baud_rate;
545 r = ch341_set_baudrate_lcr(port->serial->dev, priv,
546 priv->baud_rate, lcr);
547 if (r < 0 && old_termios) {
548 priv->baud_rate = tty_termios_baud_rate(old_termios);
549 tty_termios_copy_hw(&tty->termios, old_termios);
555 spin_lock_irqsave(&priv->lock, flags);
556 if (C_BAUD(tty) == B0)
557 priv->mcr &= ~(CH341_BIT_DTR | CH341_BIT_RTS);
558 else if (old_termios && (old_termios->c_cflag & CBAUD) == B0)
559 priv->mcr |= (CH341_BIT_DTR | CH341_BIT_RTS);
560 spin_unlock_irqrestore(&priv->lock, flags);
562 ch341_set_handshake(port->serial->dev, priv->mcr);
566 * A subset of all CH34x devices don't support a real break condition and
567 * reading CH341_REG_BREAK fails (see also ch341_detect_quirks). This function
568 * simulates a break condition by lowering the baud rate to the minimum
569 * supported by the hardware upon enabling the break condition and sending
572 * Incoming data is corrupted while the break condition is being simulated.
574 * Normally the duration of the break condition can be controlled individually
575 * by userspace using TIOCSBRK and TIOCCBRK or by passing an argument to
576 * TCSBRKP. Due to how the simulation is implemented the duration can't be
577 * controlled. The duration is always about (1s / 46bd * 9bit) = 196ms.
579 static void ch341_simulate_break(struct tty_struct *tty, int break_state)
581 struct usb_serial_port *port = tty->driver_data;
582 struct ch341_private *priv = usb_get_serial_port_data(port);
583 unsigned long now, delay;
586 if (break_state != 0) {
587 dev_dbg(&port->dev, "enter break state requested\n");
589 r = ch341_set_baudrate_lcr(port->serial->dev, priv,
591 CH341_LCR_ENABLE_RX | CH341_LCR_ENABLE_TX | CH341_LCR_CS8);
594 "failed to change baud rate to %u: %d\n",
599 r = tty_put_char(tty, '\0');
602 "failed to write NUL byte for simulated break condition: %d\n",
608 * Compute expected transmission duration including safety
609 * margin. The original baud rate is only restored after the
610 * computed point in time.
612 * 11 bits = 1 start, 8 data, 1 stop, 1 margin
614 priv->break_end = jiffies + (11 * HZ / CH341_MIN_BPS);
619 dev_dbg(&port->dev, "leave break state requested\n");
623 if (time_before(now, priv->break_end)) {
624 /* Wait until NUL byte is written */
625 delay = priv->break_end - now;
627 "wait %d ms while transmitting NUL byte at %u baud\n",
628 jiffies_to_msecs(delay), CH341_MIN_BPS);
629 schedule_timeout_interruptible(delay);
633 /* Restore original baud rate */
634 r = ch341_set_baudrate_lcr(port->serial->dev, priv, priv->baud_rate,
638 "restoring original baud rate of %u failed: %d\n",
642 static void ch341_break_ctl(struct tty_struct *tty, int break_state)
644 const uint16_t ch341_break_reg =
645 ((uint16_t) CH341_REG_LCR << 8) | CH341_REG_BREAK;
646 struct usb_serial_port *port = tty->driver_data;
647 struct ch341_private *priv = usb_get_serial_port_data(port);
649 uint16_t reg_contents;
652 if (priv->quirks & CH341_QUIRK_SIMULATE_BREAK) {
653 ch341_simulate_break(tty, break_state);
657 break_reg = kmalloc(2, GFP_KERNEL);
661 r = ch341_control_in(port->serial->dev, CH341_REQ_READ_REG,
662 ch341_break_reg, 0, break_reg, 2);
664 dev_err(&port->dev, "%s - USB control read error (%d)\n",
668 dev_dbg(&port->dev, "%s - initial ch341 break register contents - reg1: %x, reg2: %x\n",
669 __func__, break_reg[0], break_reg[1]);
670 if (break_state != 0) {
671 dev_dbg(&port->dev, "%s - Enter break state requested\n", __func__);
672 break_reg[0] &= ~CH341_NBREAK_BITS;
673 break_reg[1] &= ~CH341_LCR_ENABLE_TX;
675 dev_dbg(&port->dev, "%s - Leave break state requested\n", __func__);
676 break_reg[0] |= CH341_NBREAK_BITS;
677 break_reg[1] |= CH341_LCR_ENABLE_TX;
679 dev_dbg(&port->dev, "%s - New ch341 break register contents - reg1: %x, reg2: %x\n",
680 __func__, break_reg[0], break_reg[1]);
681 reg_contents = get_unaligned_le16(break_reg);
682 r = ch341_control_out(port->serial->dev, CH341_REQ_WRITE_REG,
683 ch341_break_reg, reg_contents);
685 dev_err(&port->dev, "%s - USB control write error (%d)\n",
691 static int ch341_tiocmset(struct tty_struct *tty,
692 unsigned int set, unsigned int clear)
694 struct usb_serial_port *port = tty->driver_data;
695 struct ch341_private *priv = usb_get_serial_port_data(port);
699 spin_lock_irqsave(&priv->lock, flags);
701 priv->mcr |= CH341_BIT_RTS;
703 priv->mcr |= CH341_BIT_DTR;
704 if (clear & TIOCM_RTS)
705 priv->mcr &= ~CH341_BIT_RTS;
706 if (clear & TIOCM_DTR)
707 priv->mcr &= ~CH341_BIT_DTR;
709 spin_unlock_irqrestore(&priv->lock, flags);
711 return ch341_set_handshake(port->serial->dev, control);
714 static void ch341_update_status(struct usb_serial_port *port,
715 unsigned char *data, size_t len)
717 struct ch341_private *priv = usb_get_serial_port_data(port);
718 struct tty_struct *tty;
726 status = ~data[2] & CH341_BITS_MODEM_STAT;
728 spin_lock_irqsave(&priv->lock, flags);
729 delta = status ^ priv->msr;
731 spin_unlock_irqrestore(&priv->lock, flags);
733 if (data[1] & CH341_MULT_STAT)
734 dev_dbg(&port->dev, "%s - multiple status change\n", __func__);
739 if (delta & CH341_BIT_CTS)
741 if (delta & CH341_BIT_DSR)
743 if (delta & CH341_BIT_RI)
745 if (delta & CH341_BIT_DCD) {
747 tty = tty_port_tty_get(&port->port);
749 usb_serial_handle_dcd_change(port, tty,
750 status & CH341_BIT_DCD);
755 wake_up_interruptible(&port->port.delta_msr_wait);
758 static void ch341_read_int_callback(struct urb *urb)
760 struct usb_serial_port *port = urb->context;
761 unsigned char *data = urb->transfer_buffer;
762 unsigned int len = urb->actual_length;
765 switch (urb->status) {
772 /* this urb is terminated, clean up */
773 dev_dbg(&urb->dev->dev, "%s - urb shutting down: %d\n",
774 __func__, urb->status);
777 dev_dbg(&urb->dev->dev, "%s - nonzero urb status: %d\n",
778 __func__, urb->status);
782 usb_serial_debug_data(&port->dev, __func__, len, data);
783 ch341_update_status(port, data, len);
785 status = usb_submit_urb(urb, GFP_ATOMIC);
787 dev_err(&urb->dev->dev, "%s - usb_submit_urb failed: %d\n",
792 static int ch341_tiocmget(struct tty_struct *tty)
794 struct usb_serial_port *port = tty->driver_data;
795 struct ch341_private *priv = usb_get_serial_port_data(port);
801 spin_lock_irqsave(&priv->lock, flags);
804 spin_unlock_irqrestore(&priv->lock, flags);
806 result = ((mcr & CH341_BIT_DTR) ? TIOCM_DTR : 0)
807 | ((mcr & CH341_BIT_RTS) ? TIOCM_RTS : 0)
808 | ((status & CH341_BIT_CTS) ? TIOCM_CTS : 0)
809 | ((status & CH341_BIT_DSR) ? TIOCM_DSR : 0)
810 | ((status & CH341_BIT_RI) ? TIOCM_RI : 0)
811 | ((status & CH341_BIT_DCD) ? TIOCM_CD : 0);
813 dev_dbg(&port->dev, "%s - result = %x\n", __func__, result);
818 static int ch341_reset_resume(struct usb_serial *serial)
820 struct usb_serial_port *port = serial->port[0];
821 struct ch341_private *priv;
824 priv = usb_get_serial_port_data(port);
828 /* reconfigure ch341 serial port after bus-reset */
829 ch341_configure(serial->dev, priv);
831 if (tty_port_initialized(&port->port)) {
832 ret = usb_submit_urb(port->interrupt_in_urb, GFP_NOIO);
834 dev_err(&port->dev, "failed to submit interrupt urb: %d\n",
839 ret = ch341_get_status(port->serial->dev, priv);
841 dev_err(&port->dev, "failed to read modem status: %d\n",
846 return usb_serial_generic_resume(serial);
849 static struct usb_serial_driver ch341_device = {
851 .owner = THIS_MODULE,
852 .name = "ch341-uart",
854 .id_table = id_table,
857 .dtr_rts = ch341_dtr_rts,
858 .carrier_raised = ch341_carrier_raised,
859 .close = ch341_close,
860 .set_termios = ch341_set_termios,
861 .break_ctl = ch341_break_ctl,
862 .tiocmget = ch341_tiocmget,
863 .tiocmset = ch341_tiocmset,
864 .tiocmiwait = usb_serial_generic_tiocmiwait,
865 .read_int_callback = ch341_read_int_callback,
866 .port_probe = ch341_port_probe,
867 .port_remove = ch341_port_remove,
868 .reset_resume = ch341_reset_resume,
871 static struct usb_serial_driver * const serial_drivers[] = {
875 module_usb_serial_driver(serial_drivers, id_table);
877 MODULE_LICENSE("GPL v2");