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/* * USB Serial Converter Generic functions * * Copyright (C) 2010 - 2013 Johan Hovold (jhovold@gmail.com) * Copyright (C) 1999 - 2002 Greg Kroah-Hartman (greg@kroah.com) * *	This program is free software; you can redistribute it and/or *	modify it under the terms of the GNU General Public License version *	2 as published by the Free Software Foundation. */ #include <linux/kernel.h>#include <linux/errno.h>#include <linux/slab.h>#include <linux/sysrq.h>#include <linux/tty.h>#include <linux/tty_flip.h>#include <linux/module.h>#include <linux/moduleparam.h>#include <linux/usb.h>#include <linux/usb/serial.h>#include <linux/uaccess.h>#include <linux/kfifo.h>#include <linux/serial.h> #ifdef CONFIG_USB_SERIAL_GENERIC static __u16 vendor  = 0x05f9;static __u16 product = 0xffff; module_param(vendor, ushort, 0);MODULE_PARM_DESC(vendor, "User specified USB idVendor"); module_param(product, ushort, 0);MODULE_PARM_DESC(product, "User specified USB idProduct"); static struct usb_device_id generic_device_ids[2]; /* Initially all zeroes. */ struct usb_serial_driver usb_serial_generic_device = {	.driver = {		.owner =	THIS_MODULE,		.name =		"generic",	},	.id_table =		generic_device_ids,	.num_ports =		1,	.throttle =		usb_serial_generic_throttle,	.unthrottle =		usb_serial_generic_unthrottle,	.resume =		usb_serial_generic_resume,}; static struct usb_serial_driver * const serial_drivers[] = {	&usb_serial_generic_device, NULL}; #endif int usb_serial_generic_register(void){	int retval = 0; #ifdef CONFIG_USB_SERIAL_GENERIC	generic_device_ids[0].idVendor = vendor;	generic_device_ids[0].idProduct = product;	generic_device_ids[0].match_flags =		USB_DEVICE_ID_MATCH_VENDOR | USB_DEVICE_ID_MATCH_PRODUCT; 	retval = usb_serial_register_drivers(serial_drivers,			"usbserial_generic", generic_device_ids);#endif	return retval;} void usb_serial_generic_deregister(void){#ifdef CONFIG_USB_SERIAL_GENERIC	usb_serial_deregister_drivers(serial_drivers);#endif} int usb_serial_generic_open(struct tty_struct *tty, struct usb_serial_port *port){	int result = 0;	unsigned long flags; 	spin_lock_irqsave(&port->lock, flags);	port->throttled = 0;	port->throttle_req = 0;	spin_unlock_irqrestore(&port->lock, flags); 	if (port->bulk_in_size)		result = usb_serial_generic_submit_read_urbs(port, GFP_KERNEL); 	return result;}EXPORT_SYMBOL_GPL(usb_serial_generic_open); void usb_serial_generic_close(struct usb_serial_port *port){	unsigned long flags;	int i; 	if (port->bulk_out_size) {		for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i)			usb_kill_urb(port->write_urbs[i]); 		spin_lock_irqsave(&port->lock, flags);		kfifo_reset_out(&port->write_fifo);		spin_unlock_irqrestore(&port->lock, flags);	}	if (port->bulk_in_size) {		for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i)			usb_kill_urb(port->read_urbs[i]);	}}EXPORT_SYMBOL_GPL(usb_serial_generic_close); int usb_serial_generic_prepare_write_buffer(struct usb_serial_port *port,						void *dest, size_t size){	return kfifo_out_locked(&port->write_fifo, dest, size, &port->lock);} /** * usb_serial_generic_write_start - start writing buffered data * @port: usb-serial port * @mem_flags: flags to use for memory allocations * * Serialised using USB_SERIAL_WRITE_BUSY flag. * * Return: Zero on success or if busy, otherwise a negative errno value. */int usb_serial_generic_write_start(struct usb_serial_port *port,							gfp_t mem_flags){	struct urb *urb;	int count, result;	unsigned long flags;	int i; 	if (test_and_set_bit_lock(USB_SERIAL_WRITE_BUSY, &port->flags))		return 0;retry:	spin_lock_irqsave(&port->lock, flags);	if (!port->write_urbs_free || !kfifo_len(&port->write_fifo)) {		clear_bit_unlock(USB_SERIAL_WRITE_BUSY, &port->flags);		spin_unlock_irqrestore(&port->lock, flags);		return 0;	}	i = (int)find_first_bit(&port->write_urbs_free,						ARRAY_SIZE(port->write_urbs));	spin_unlock_irqrestore(&port->lock, flags); 	urb = port->write_urbs[i];	count = port->serial->type->prepare_write_buffer(port,						urb->transfer_buffer,						port->bulk_out_size);	urb->transfer_buffer_length = count;	usb_serial_debug_data(&port->dev, __func__, count, urb->transfer_buffer);	spin_lock_irqsave(&port->lock, flags);	port->tx_bytes += count;	spin_unlock_irqrestore(&port->lock, flags); 	clear_bit(i, &port->write_urbs_free);	result = usb_submit_urb(urb, mem_flags);	if (result) {		dev_err_console(port, "%s - error submitting urb: %d\n",						__func__, result);		set_bit(i, &port->write_urbs_free);		spin_lock_irqsave(&port->lock, flags);		port->tx_bytes -= count;		spin_unlock_irqrestore(&port->lock, flags); 		clear_bit_unlock(USB_SERIAL_WRITE_BUSY, &port->flags);		return result;	} 	goto retry;	/* try sending off another urb */}EXPORT_SYMBOL_GPL(usb_serial_generic_write_start); /** * usb_serial_generic_write - generic write function * @tty: tty for the port * @port: usb-serial port * @buf: data to write * @count: number of bytes to write * * Return: The number of characters buffered, which may be anything from * zero to @count, or a negative errno value. */int usb_serial_generic_write(struct tty_struct *tty,	struct usb_serial_port *port, const unsigned char *buf, int count){	int result; 	if (!port->bulk_out_size)		return -ENODEV; 	if (!count)		return 0; 	count = kfifo_in_locked(&port->write_fifo, buf, count, &port->lock);	result = usb_serial_generic_write_start(port, GFP_ATOMIC);	if (result)		return result; 	return count;}EXPORT_SYMBOL_GPL(usb_serial_generic_write); int usb_serial_generic_write_room(struct tty_struct *tty){	struct usb_serial_port *port = tty->driver_data;	unsigned long flags;	int room; 	if (!port->bulk_out_size)		return 0; 	spin_lock_irqsave(&port->lock, flags);	room = kfifo_avail(&port->write_fifo);	spin_unlock_irqrestore(&port->lock, flags); 	dev_dbg(&port->dev, "%s - returns %d\n", __func__, room);	return room;} int usb_serial_generic_chars_in_buffer(struct tty_struct *tty){	struct usb_serial_port *port = tty->driver_data;	unsigned long flags;	int chars; 	if (!port->bulk_out_size)		return 0; 	spin_lock_irqsave(&port->lock, flags);	chars = kfifo_len(&port->write_fifo) + port->tx_bytes;	spin_unlock_irqrestore(&port->lock, flags); 	dev_dbg(&port->dev, "%s - returns %d\n", __func__, chars);	return chars;}EXPORT_SYMBOL_GPL(usb_serial_generic_chars_in_buffer); void usb_serial_generic_wait_until_sent(struct tty_struct *tty, long timeout){	struct usb_serial_port *port = tty->driver_data;	unsigned int bps;	unsigned long period;	unsigned long expire; 	bps = tty_get_baud_rate(tty);	if (!bps)		bps = 9600;	/* B0 */	/*	 * Use a poll-period of roughly the time it takes to send one	 * character or at least one jiffy.	 */	period = max_t(unsigned long, (10 * HZ / bps), 1);	period = min_t(unsigned long, period, timeout); 	dev_dbg(&port->dev, "%s - timeout = %u ms, period = %u ms\n",					__func__, jiffies_to_msecs(timeout),					jiffies_to_msecs(period));	expire = jiffies + timeout;	while (!port->serial->type->tx_empty(port)) {		schedule_timeout_interruptible(period);		if (signal_pending(current))			break;		if (time_after(jiffies, expire))			break;	}}EXPORT_SYMBOL_GPL(usb_serial_generic_wait_until_sent); static int usb_serial_generic_submit_read_urb(struct usb_serial_port *port,						int index, gfp_t mem_flags){	int res; 	if (!test_and_clear_bit(index, &port->read_urbs_free))		return 0; 	dev_dbg(&port->dev, "%s - urb %d\n", __func__, index); 	res = usb_submit_urb(port->read_urbs[index], mem_flags);	if (res) {		if (res != -EPERM) {			dev_err(&port->dev,					"%s - usb_submit_urb failed: %d\n",					__func__, res);		}		set_bit(index, &port->read_urbs_free);		return res;	} 	return 0;} int usb_serial_generic_submit_read_urbs(struct usb_serial_port *port,					gfp_t mem_flags){	int res;	int i; 	for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i) {		res = usb_serial_generic_submit_read_urb(port, i, mem_flags);		if (res)			goto err;	} 	return 0;err:	for (; i >= 0; --i)		usb_kill_urb(port->read_urbs[i]); 	return res;}EXPORT_SYMBOL_GPL(usb_serial_generic_submit_read_urbs); void usb_serial_generic_process_read_urb(struct urb *urb){	struct usb_serial_port *port = urb->context;	char *ch = (char *)urb->transfer_buffer;	int i; 	if (!urb->actual_length)		return;	/*	 * The per character mucking around with sysrq path it too slow for	 * stuff like 3G modems, so shortcircuit it in the 99.9999999% of	 * cases where the USB serial is not a console anyway.	 */	if (!port->port.console || !port->sysrq)		tty_insert_flip_string(&port->port, ch, urb->actual_length);	else {		for (i = 0; i < urb->actual_length; i++, ch++) {			if (!usb_serial_handle_sysrq_char(port, *ch))				tty_insert_flip_char(&port->port, *ch, TTY_NORMAL);		}	}	tty_flip_buffer_push(&port->port);}EXPORT_SYMBOL_GPL(usb_serial_generic_process_read_urb); void usb_serial_generic_read_bulk_callback(struct urb *urb){	struct usb_serial_port *port = urb->context;	unsigned char *data = urb->transfer_buffer;	unsigned long flags;	int i; 	for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i) {		if (urb == port->read_urbs[i])			break;	}	set_bit(i, &port->read_urbs_free); 	dev_dbg(&port->dev, "%s - urb %d, len %d\n", __func__, i,							urb->actual_length); 	if (urb->status) {		dev_dbg(&port->dev, "%s - non-zero urb status: %d\n",			__func__, urb->status);		return;	} 	usb_serial_debug_data(&port->dev, __func__, urb->actual_length, data);	port->serial->type->process_read_urb(urb); 	/* Throttle the device if requested by tty */	spin_lock_irqsave(&port->lock, flags);	port->throttled = port->throttle_req;	if (!port->throttled) {		spin_unlock_irqrestore(&port->lock, flags);		usb_serial_generic_submit_read_urb(port, i, GFP_ATOMIC);	} else		spin_unlock_irqrestore(&port->lock, flags);}EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback); void usb_serial_generic_write_bulk_callback(struct urb *urb){	unsigned long flags;	struct usb_serial_port *port = urb->context;	int status = urb->status;	int i; 	for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i)		if (port->write_urbs[i] == urb)			break; 	spin_lock_irqsave(&port->lock, flags);	port->tx_bytes -= urb->transfer_buffer_length;	set_bit(i, &port->write_urbs_free);	spin_unlock_irqrestore(&port->lock, flags); 	if (status) {		dev_dbg(&port->dev, "%s - non-zero urb status: %d\n",			__func__, status); 		spin_lock_irqsave(&port->lock, flags);		kfifo_reset_out(&port->write_fifo);		spin_unlock_irqrestore(&port->lock, flags);	} else {		usb_serial_generic_write_start(port, GFP_ATOMIC);	} 	usb_serial_port_softint(port);}EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback); void usb_serial_generic_throttle(struct tty_struct *tty){	struct usb_serial_port *port = tty->driver_data;	unsigned long flags; 	spin_lock_irqsave(&port->lock, flags);	port->throttle_req = 1;	spin_unlock_irqrestore(&port->lock, flags);}EXPORT_SYMBOL_GPL(usb_serial_generic_throttle); void usb_serial_generic_unthrottle(struct tty_struct *tty){	struct usb_serial_port *port = tty->driver_data;	int was_throttled; 	spin_lock_irq(&port->lock);	was_throttled = port->throttled;	port->throttled = port->throttle_req = 0;	spin_unlock_irq(&port->lock); 	if (was_throttled)		usb_serial_generic_submit_read_urbs(port, GFP_KERNEL);}EXPORT_SYMBOL_GPL(usb_serial_generic_unthrottle); static bool usb_serial_generic_msr_changed(struct tty_struct *tty,				unsigned long arg, struct async_icount *cprev){	struct usb_serial_port *port = tty->driver_data;	struct async_icount cnow;	unsigned long flags;	bool ret; 	/*	 * Use tty-port initialised flag to detect all hangups including the	 * one generated at USB-device disconnect.	 */	if (!test_bit(ASYNCB_INITIALIZED, &port->port.flags))		return true; 	spin_lock_irqsave(&port->lock, flags);	cnow = port->icount;				/* atomic copy*/	spin_unlock_irqrestore(&port->lock, flags); 	ret =	((arg & TIOCM_RNG) && (cnow.rng != cprev->rng)) ||		((arg & TIOCM_DSR) && (cnow.dsr != cprev->dsr)) ||		((arg & TIOCM_CD)  && (cnow.dcd != cprev->dcd)) ||		((arg & TIOCM_CTS) && (cnow.cts != cprev->cts)); 	*cprev = cnow; 	return ret;} int usb_serial_generic_tiocmiwait(struct tty_struct *tty, unsigned long arg){	struct usb_serial_port *port = tty->driver_data;	struct async_icount cnow;	unsigned long flags;	int ret; 	spin_lock_irqsave(&port->lock, flags);	cnow = port->icount;				/* atomic copy */	spin_unlock_irqrestore(&port->lock, flags); 	ret = wait_event_interruptible(port->port.delta_msr_wait,			usb_serial_generic_msr_changed(tty, arg, &cnow));	if (!ret && !test_bit(ASYNCB_INITIALIZED, &port->port.flags))		ret = -EIO; 	return ret;}EXPORT_SYMBOL_GPL(usb_serial_generic_tiocmiwait); int usb_serial_generic_get_icount(struct tty_struct *tty,					struct serial_icounter_struct *icount){	struct usb_serial_port *port = tty->driver_data;	struct async_icount cnow;	unsigned long flags; 	spin_lock_irqsave(&port->lock, flags);	cnow = port->icount;				/* atomic copy */	spin_unlock_irqrestore(&port->lock, flags); 	icount->cts = cnow.cts;

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