text: // SPDX-License-Identifier: GPL-2.0
  /*
    USB Driver for Sierra Wireless
  
    Copyright (C) 2006, 2007, 2008  Kevin Lloyd <klloyd@sierrawireless.com>,
  
    Copyright (C) 2008, 2009  Elina Pasheva, Matthew Safar, Rory Filer
  			<linux@sierrawireless.com>
  
    IMPORTANT DISCLAIMER: This driver is not commercially supported by
    Sierra Wireless. Use at your own risk.
  
    Portions based on the option driver by Matthias Urlichs <smurf@smurf.noris.de>
    Whom based his on the Keyspan driver by Hugh Blemings <hugh@blemings.org>
  */
  /* Uncomment to log function calls */
  /* #define DEBUG */
  
  #define DRIVER_AUTHOR "Kevin Lloyd, Elina Pasheva, Matthew Safar, Rory Filer"
  #define DRIVER_DESC "USB Driver for Sierra Wireless USB modems"
  
  #include <linux/kernel.h>
  #include <linux/jiffies.h>
  #include <linux/errno.h>
  #include <linux/tty.h>
  #include <linux/slab.h>
  #include <linux/tty_flip.h>
  #include <linux/module.h>
  #include <linux/usb.h>
  #include <linux/usb/serial.h>
  
  #define SWIMS_USB_REQUEST_SetPower	0x00
  #define SWIMS_USB_REQUEST_SetNmea	0x07
  
  #define N_IN_URB_HM	8
  #define N_OUT_URB_HM	64
  #define N_IN_URB	4
  #define N_OUT_URB	4
  #define IN_BUFLEN	4096
  
  #define MAX_TRANSFER		(PAGE_SIZE - 512)
  /* MAX_TRANSFER is chosen so that the VM is not stressed by
     allocations > PAGE_SIZE and the number of packets in a page
     is an integer 512 is the largest possible packet on EHCI */
  
  static bool nmea;
  
  /* Used in interface blacklisting */
  struct sierra_iface_info {
  	const u32 infolen;	/* number of interface numbers on blacklist */
  	const u8  *ifaceinfo;	/* pointer to the array holding the numbers */
  };
  
  struct sierra_intf_private {
  	spinlock_t susp_lock;
  	unsigned int suspended:1;
  	int in_flight;
  	unsigned int open_ports;
  };
  
  static int sierra_set_power_state(struct usb_device *udev, __u16 swiState)
  {
  	return usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
  			SWIMS_USB_REQUEST_SetPower,	/* __u8 request      */
  			USB_TYPE_VENDOR,		/* __u8 request type */
  			swiState,			/* __u16 value       */
  			0,				/* __u16 index       */
  			NULL,				/* void *data        */
  			0,				/* __u16 size 	     */
  			USB_CTRL_SET_TIMEOUT);		/* int timeout 	     */
  }
  
  static int sierra_vsc_set_nmea(struct usb_device *udev, __u16 enable)
  {
  	return usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
  			SWIMS_USB_REQUEST_SetNmea,	/* __u8 request      */
  			USB_TYPE_VENDOR,		/* __u8 request type */
  			enable,				/* __u16 value       */
  			0x0000,				/* __u16 index       */
  			NULL,				/* void *data        */
  			0,				/* __u16 size 	     */
  			USB_CTRL_SET_TIMEOUT);		/* int timeout       */
  }
  
  static int sierra_calc_num_ports(struct usb_serial *serial,
  					struct usb_serial_endpoints *epds)
  {
  	int num_ports = 0;
  	u8 ifnum, numendpoints;
  
  	ifnum = serial->interface->cur_altsetting->desc.bInterfaceNumber;
  	numendpoints = serial->interface->cur_altsetting->desc.bNumEndpoints;
  
  	/* Dummy interface present on some SKUs should be ignored */
  	if (ifnum == 0x99)
  		num_ports = 0;
  	else if (numendpoints <= 3)
  		num_ports = 1;
  	else
  		num_ports = (numendpoints-1)/2;
  	return num_ports;
  }
  
  static int is_blacklisted(const u8 ifnum,
  				const struct sierra_iface_info *blacklist)
  {
  	const u8  *info;
  	int i;
  
  	if (blacklist) {
  		info = blacklist->ifaceinfo;
  
  		for (i = 0; i < blacklist->infolen; i++) {
  			if (info[i] == ifnum)
  				return 1;
  		}
  	}
  	return 0;
  }
  
  static int is_himemory(const u8 ifnum,
  				const struct sierra_iface_info *himemorylist)
  {
  	const u8  *info;
  	int i;
  
  	if (himemorylist) {
  		info = himemorylist->ifaceinfo;
  
  		for (i=0; i < himemorylist->infolen; i++) {
  			if (info[i] == ifnum)
  				return 1;
  		}
  	}
  	return 0;
  }
  
  static u8 sierra_interface_num(struct usb_serial *serial)
  {
  	return serial->interface->cur_altsetting->desc.bInterfaceNumber;
  }
  
  static int sierra_probe(struct usb_serial *serial,
  			const struct usb_device_id *id)
  {
  	int result = 0;
  	struct usb_device *udev;
  	u8 ifnum;
  
  	udev = serial->dev;
  	ifnum = sierra_interface_num(serial);
  
  	/*
  	 * If this interface supports more than 1 alternate
  	 * select the 2nd one
  	 */
  	if (serial->interface->num_altsetting == 2) {
  		dev_dbg(&udev->dev, "Selecting alt setting for interface %d\n",
  			ifnum);
  		/* We know the alternate setting is 1 for the MC8785 */
  		usb_set_interface(udev, ifnum, 1);
  	}
  
  	if (is_blacklisted(ifnum,
  				(struct sierra_iface_info *)id->driver_info)) {
  		dev_dbg(&serial->dev->dev,
  			"Ignoring blacklisted interface #%d\n", ifnum);
  		return -ENODEV;
  	}
  
  	return result;
  }
  
  /* interfaces with higher memory requirements */
  static const u8 hi_memory_typeA_ifaces[] = { 0, 2 };
  static const struct sierra_iface_info typeA_interface_list = {
  	.infolen = ARRAY_SIZE(hi_memory_typeA_ifaces),
  	.ifaceinfo = hi_memory_typeA_ifaces,
  };
  
  static const u8 hi_memory_typeB_ifaces[] = { 3, 4, 5, 6 };
  static const struct sierra_iface_info typeB_interface_list = {
  	.infolen = ARRAY_SIZE(hi_memory_typeB_ifaces),
  	.ifaceinfo = hi_memory_typeB_ifaces,
  };
  
  /* 'blacklist' of interfaces not served by this driver */
  static const u8 direct_ip_non_serial_ifaces[] = { 7, 8, 9, 10, 11, 19, 20 };
  static const struct sierra_iface_info direct_ip_interface_blacklist = {
  	.infolen = ARRAY_SIZE(direct_ip_non_serial_ifaces),
  	.ifaceinfo = direct_ip_non_serial_ifaces,
  };
  
  static const struct usb_device_id id_table[] = {
  	{ USB_DEVICE(0x0F3D, 0x0112) }, /* Airprime/Sierra PC 5220 */
  	{ USB_DEVICE(0x03F0, 0x1B1D) },	/* HP ev2200 a.k.a MC5720 */
  	{ USB_DEVICE(0x03F0, 0x211D) }, /* HP ev2210 a.k.a MC5725 */
  	{ USB_DEVICE(0x03F0, 0x1E1D) },	/* HP hs2300 a.k.a MC8775 */
  
  	{ USB_DEVICE(0x1199, 0x0017) },	/* Sierra Wireless EM5625 */
  	{ USB_DEVICE(0x1199, 0x0018) },	/* Sierra Wireless MC5720 */
  	{ USB_DEVICE(0x1199, 0x0218) },	/* Sierra Wireless MC5720 */
  	{ USB_DEVICE(0x1199, 0x0020) },	/* Sierra Wireless MC5725 */
  	{ USB_DEVICE(0x1199, 0x0220) },	/* Sierra Wireless MC5725 */
  	{ USB_DEVICE(0x1199, 0x0022) },	/* Sierra Wireless EM5725 */
  	{ USB_DEVICE(0x1199, 0x0024) },	/* Sierra Wireless MC5727 */
  	{ USB_DEVICE(0x1199, 0x0224) },	/* Sierra Wireless MC5727 */
  	{ USB_DEVICE(0x1199, 0x0019) },	/* Sierra Wireless AirCard 595 */
  	{ USB_DEVICE(0x1199, 0x0021) },	/* Sierra Wireless AirCard 597E */
  	{ USB_DEVICE(0x1199, 0x0112) }, /* Sierra Wireless AirCard 580 */
  	{ USB_DEVICE(0x1199, 0x0120) },	/* Sierra Wireless USB Dongle 595U */
  	{ USB_DEVICE(0x1199, 0x0301) },	/* Sierra Wireless USB Dongle 250U */
  	/* Sierra Wireless C597 */
  	{ USB_DEVICE_AND_INTERFACE_INFO(0x1199, 0x0023, 0xFF, 0xFF, 0xFF) },
  	/* Sierra Wireless T598 */
  	{ USB_DEVICE_AND_INTERFACE_INFO(0x1199, 0x0025, 0xFF, 0xFF, 0xFF) },
  	{ USB_DEVICE(0x1199, 0x0026) }, /* Sierra Wireless T11 */
  	{ USB_DEVICE(0x1199, 0x0027) }, /* Sierra Wireless AC402 */
  	{ USB_DEVICE(0x1199, 0x0028) }, /* Sierra Wireless MC5728 */
  	{ USB_DEVICE(0x1199, 0x0029) }, /* Sierra Wireless Device */
  
  	{ USB_DEVICE(0x1199, 0x6802) },	/* Sierra Wireless MC8755 */
  	{ USB_DEVICE(0x1199, 0x6803) },	/* Sierra Wireless MC8765 */
  	{ USB_DEVICE(0x1199, 0x6804) },	/* Sierra Wireless MC8755 */
  	{ USB_DEVICE(0x1199, 0x6805) },	/* Sierra Wireless MC8765 */
  	{ USB_DEVICE(0x1199, 0x6808) },	/* Sierra Wireless MC8755 */
  	{ USB_DEVICE(0x1199, 0x6809) },	/* Sierra Wireless MC8765 */
  	{ USB_DEVICE(0x1199, 0x6812) },	/* Sierra Wireless MC8775 & AC 875U */
  	{ USB_DEVICE(0x1199, 0x6813) },	/* Sierra Wireless MC8775 */
  	{ USB_DEVICE(0x1199, 0x6815) },	/* Sierra Wireless MC8775 */
  	{ USB_DEVICE(0x1199, 0x6816) },	/* Sierra Wireless MC8775 */
  	{ USB_DEVICE(0x1199, 0x6820) },	/* Sierra Wireless AirCard 875 */
  	{ USB_DEVICE(0x1199, 0x6821) },	/* Sierra Wireless AirCard 875U */
  	{ USB_DEVICE(0x1199, 0x6822) },	/* Sierra Wireless AirCard 875E */
  	{ USB_DEVICE(0x1199, 0x6832) },	/* Sierra Wireless MC8780 */
  	{ USB_DEVICE(0x1199, 0x6833) },	/* Sierra Wireless MC8781 */
  	{ USB_DEVICE(0x1199, 0x6834) },	/* Sierra Wireless MC8780 */
  	{ USB_DEVICE(0x1199, 0x6835) },	/* Sierra Wireless MC8781 */
  	{ USB_DEVICE(0x1199, 0x6838) },	/* Sierra Wireless MC8780 */
  	{ USB_DEVICE(0x1199, 0x6839) },	/* Sierra Wireless MC8781 */
  	{ USB_DEVICE(0x1199, 0x683A) },	/* Sierra Wireless MC8785 */
  	{ USB_DEVICE(0x1199, 0x683B) },	/* Sierra Wireless MC8785 Composite */
  	/* Sierra Wireless MC8790, MC8791, MC8792 Composite */
  	{ USB_DEVICE(0x1199, 0x683C) },
  	{ USB_DEVICE(0x1199, 0x683D) },	/* Sierra Wireless MC8791 Composite */
  	/* Sierra Wireless MC8790, MC8791, MC8792 */
  	{ USB_DEVICE(0x1199, 0x683E) },
  	{ USB_DEVICE(0x1199, 0x6850) },	/* Sierra Wireless AirCard 880 */
  	{ USB_DEVICE(0x1199, 0x6851) },	/* Sierra Wireless AirCard 881 */
  	{ USB_DEVICE(0x1199, 0x6852) },	/* Sierra Wireless AirCard 880 E */
  	{ USB_DEVICE(0x1199, 0x6853) },	/* Sierra Wireless AirCard 881 E */
  	{ USB_DEVICE(0x1199, 0x6855) },	/* Sierra Wireless AirCard 880 U */
  	{ USB_DEVICE(0x1199, 0x6856) },	/* Sierra Wireless AirCard 881 U */
  	{ USB_DEVICE(0x1199, 0x6859) },	/* Sierra Wireless AirCard 885 E */
  	{ USB_DEVICE(0x1199, 0x685A) },	/* Sierra Wireless AirCard 885 E */
  	/* Sierra Wireless C885 */
  	{ USB_DEVICE_AND_INTERFACE_INFO(0x1199, 0x6880, 0xFF, 0xFF, 0xFF)},
  	/* Sierra Wireless C888, Air Card 501, USB 303, USB 304 */
  	{ USB_DEVICE_AND_INTERFACE_INFO(0x1199, 0x6890, 0xFF, 0xFF, 0xFF)},
  	/* Sierra Wireless C22/C33 */
  	{ USB_DEVICE_AND_INTERFACE_INFO(0x1199, 0x6891, 0xFF, 0xFF, 0xFF)},
  	/* Sierra Wireless HSPA Non-Composite Device */
  	{ USB_DEVICE_AND_INTERFACE_INFO(0x1199, 0x6892, 0xFF, 0xFF, 0xFF)},
  	{ USB_DEVICE(0x1199, 0x6893) },	/* Sierra Wireless Device */
  	/* Sierra Wireless Direct IP modems */
  	{ USB_DEVICE_AND_INTERFACE_INFO(0x1199, 0x68A3, 0xFF, 0xFF, 0xFF),
  	  .driver_info = (kernel_ulong_t)&direct_ip_interface_blacklist
  	},
  	{ USB_DEVICE_AND_INTERFACE_INFO(0x1199, 0x68AA, 0xFF, 0xFF, 0xFF),
  	  .driver_info = (kernel_ulong_t)&direct_ip_interface_blacklist
  	},
  	{ USB_DEVICE(0x1199, 0x68AB) }, /* Sierra Wireless AR8550 */
  	/* AT&T Direct IP LTE modems */
  	{ USB_DEVICE_AND_INTERFACE_INFO(0x0F3D, 0x68AA, 0xFF, 0xFF, 0xFF),
  	  .driver_info = (kernel_ulong_t)&direct_ip_interface_blacklist
  	},
  	/* Airprime/Sierra Wireless Direct IP modems */
  	{ USB_DEVICE_AND_INTERFACE_INFO(0x0F3D, 0x68A3, 0xFF, 0xFF, 0xFF),
  	  .driver_info = (kernel_ulong_t)&direct_ip_interface_blacklist
  	},
  
  	{ }
  };
  MODULE_DEVICE_TABLE(usb, id_table);
  
  
  struct sierra_port_private {
  	spinlock_t lock;	/* lock the structure */
  	int outstanding_urbs;	/* number of out urbs in flight */
  	struct usb_anchor active;
  	struct usb_anchor delayed;
  
  	int num_out_urbs;
  	int num_in_urbs;
  	/* Input endpoints and buffers for this port */
  	struct urb *in_urbs[N_IN_URB_HM];
  
  	/* Settings for the port */
  	int rts_state;	/* Handshaking pins (outputs) */
  	int dtr_state;
  	int cts_state;	/* Handshaking pins (inputs) */
  	int dsr_state;
  	int dcd_state;
  	int ri_state;
  };
  
  static int sierra_send_setup(struct usb_serial_port *port)
  {
  	struct usb_serial *serial = port->serial;
  	struct sierra_port_private *portdata;
  	__u16 interface = 0;
  	int val = 0;
  	int do_send = 0;
  	int retval;
  
  	portdata = usb_get_serial_port_data(port);
  
  	if (portdata->dtr_state)
  		val |= 0x01;
  	if (portdata->rts_state)
  		val |= 0x02;
  
  	/* If composite device then properly report interface */
  	if (serial->num_ports == 1) {
  		interface = sierra_interface_num(serial);
  		/* Control message is sent only to interfaces with
  		 * interrupt_in endpoints
  		 */
  		if (port->interrupt_in_urb) {
  			/* send control message */
  			do_send = 1;
  		}
  	}
  
  	/* Otherwise the need to do non-composite mapping */
  	else {
  		if (port->bulk_out_endpointAddress == 2)
  			interface = 0;
  		else if (port->bulk_out_endpointAddress == 4)
  			interface = 1;
  		else if (port->bulk_out_endpointAddress == 5)
  			interface = 2;
  
  		do_send = 1;
  	}
  	if (!do_send)
  		return 0;
  
  	retval = usb_autopm_get_interface(serial->interface);
  	if (retval < 0)
  		return retval;
  
  	retval = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
  		0x22, 0x21, val, interface, NULL, 0, USB_CTRL_SET_TIMEOUT);
  	usb_autopm_put_interface(serial->interface);
  
  	return retval;
  }
  
  static int sierra_tiocmget(struct tty_struct *tty)
  {
  	struct usb_serial_port *port = tty->driver_data;
  	unsigned int value;
  	struct sierra_port_private *portdata;
  
  	portdata = usb_get_serial_port_data(port);
  
  	value = ((portdata->rts_state) ? TIOCM_RTS : 0) |
  		((portdata->dtr_state) ? TIOCM_DTR : 0) |
  		((portdata->cts_state) ? TIOCM_CTS : 0) |
  		((portdata->dsr_state) ? TIOCM_DSR : 0) |
  		((portdata->dcd_state) ? TIOCM_CAR : 0) |
  		((portdata->ri_state) ? TIOCM_RNG : 0);
  
  	return value;
  }
  
  static int sierra_tiocmset(struct tty_struct *tty,
  			unsigned int set, unsigned int clear)
  {
  	struct usb_serial_port *port = tty->driver_data;
  	struct sierra_port_private *portdata;
  
  	portdata = usb_get_serial_port_data(port);
  
  	if (set & TIOCM_RTS)
  		portdata->rts_state = 1;
  	if (set & TIOCM_DTR)
  		portdata->dtr_state = 1;
  
  	if (clear & TIOCM_RTS)
  		portdata->rts_state = 0;
  	if (clear & TIOCM_DTR)
  		portdata->dtr_state = 0;
  	return sierra_send_setup(port);
  }
  
  static void sierra_release_urb(struct urb *urb)
  {
  	if (urb) {
  		kfree(urb->transfer_buffer);
  		usb_free_urb(urb);
  	}
  }
  
  static void sierra_outdat_callback(struct urb *urb)
  {
  	struct usb_serial_port *port = urb->context;
  	struct sierra_port_private *portdata = usb_get_serial_port_data(port);
  	struct sierra_intf_private *intfdata;
  	int status = urb->status;
  
  	intfdata = usb_get_serial_data(port->serial);
  
  	/* free up the transfer buffer, as usb_free_urb() does not do this */
  	kfree(urb->transfer_buffer);
  	usb_autopm_put_interface_async(port->serial->interface);
  	if (status)
  		dev_dbg(&port->dev, "%s - nonzero write bulk status "
  		    "received: %d\n", __func__, status);
  
  	spin_lock(&portdata->lock);
  	--portdata->outstanding_urbs;
  	spin_unlock(&portdata->lock);
  	spin_lock(&intfdata->susp_lock);
  	--intfdata->in_flight;
  	spin_unlock(&intfdata->susp_lock);
  
  	usb_serial_port_softint(port);
  }
  
  /* Write */
  static int sierra_write(struct tty_struct *tty, struct usb_serial_port *port,
  					const unsigned char *buf, int count)
  {
  	struct sierra_port_private *portdata;
  	struct sierra_intf_private *intfdata;
  	struct usb_serial *serial = port->serial;
  	unsigned long flags;
  	unsigned char *buffer;
  	struct urb *urb;
  	size_t writesize = min((size_t)count, (size_t)MAX_TRANSFER);
  	int retval = 0;
  
  	/* verify that we actually have some data to write */
  	if (count == 0)
  		return 0;
  
  	portdata = usb_get_serial_port_data(port);
  	intfdata = usb_get_serial_data(serial);
  
  	dev_dbg(&port->dev, "%s: write (%zd bytes)\n", __func__, writesize);
  	spin_lock_irqsave(&portdata->lock, flags);
  	dev_dbg(&port->dev, "%s - outstanding_urbs: %d\n", __func__,
  		portdata->outstanding_urbs);
  	if (portdata->outstanding_urbs > portdata->num_out_urbs) {
  		spin_unlock_irqrestore(&portdata->lock, flags);
  		dev_dbg(&port->dev, "%s - write limit hit\n", __func__);
  		return 0;
  	}
  	portdata->outstanding_urbs++;
  	dev_dbg(&port->dev, "%s - 1, outstanding_urbs: %d\n", __func__,
  		portdata->outstanding_urbs);
  	spin_unlock_irqrestore(&portdata->lock, flags);
  
  	retval = usb_autopm_get_interface_async(serial->interface);
  	if (retval < 0) {
  		spin_lock_irqsave(&portdata->lock, flags);
  		portdata->outstanding_urbs--;
  		spin_unlock_irqrestore(&portdata->lock, flags);
  		goto error_simple;
  	}
  
  	buffer = kmalloc(writesize, GFP_ATOMIC);
  	if (!buffer) {
  		retval = -ENOMEM;
  		goto error_no_buffer;
  	}
  
  	urb = usb_alloc_urb(0, GFP_ATOMIC);
  	if (!urb) {
  		retval = -ENOMEM;
  		goto error_no_urb;
  	}
  
  	memcpy(buffer, buf, writesize);
  
  	usb_serial_debug_data(&port->dev, __func__, writesize, buffer);
  
  	usb_fill_bulk_urb(urb, serial->dev,
  			  usb_sndbulkpipe(serial->dev,
  					  port->bulk_out_endpointAddress),
  			  buffer, writesize, sierra_outdat_callback, port);
  
  	/* Handle the need to send a zero length packet */
  	urb->transfer_flags |= URB_ZERO_PACKET;
  
  	spin_lock_irqsave(&intfdata->susp_lock, flags);
  
  	if (intfdata->suspended) {
  		usb_anchor_urb(urb, &portdata->delayed);
  		spin_unlock_irqrestore(&intfdata->susp_lock, flags);
  		goto skip_power;
  	} else {
  		usb_anchor_urb(urb, &portdata->active);
  	}
  	/* send it down the pipe */
  	retval = usb_submit_urb(urb, GFP_ATOMIC);
  	if (retval) {
  		usb_unanchor_urb(urb);
  		spin_unlock_irqrestore(&intfdata->susp_lock, flags);
  		dev_err(&port->dev, "%s - usb_submit_urb(write bulk) failed "
  			"with status = %d\n", __func__, retval);
  		goto error;
  	} else {
  		intfdata->in_flight++;
  		spin_unlock_irqrestore(&intfdata->susp_lock, flags);
  	}
  
  skip_power:
  	/* we are done with this urb, so let the host driver
  	 * really free it when it is finished with it */
  	usb_free_urb(urb);
  
  	return writesize;
  error:
  	usb_free_urb(urb);
  error_no_urb:
  	kfree(buffer);
  error_no_buffer:
  	spin_lock_irqsave(&portdata->lock, flags);
  	--portdata->outstanding_urbs;
  	dev_dbg(&port->dev, "%s - 2. outstanding_urbs: %d\n", __func__,
  		portdata->outstanding_urbs);
  	spin_unlock_irqrestore(&portdata->lock, flags);
  	usb_autopm_put_interface_async(serial->interface);
  error_simple:
  	return retval;
  }
  
  static void sierra_indat_callback(struct urb *urb)
  {
  	int err;
  	int endpoint;
  	struct usb_serial_port *port;
  	unsigned char *data = urb->transfer_buffer;
  	int status = urb->status;
  
  	endpoint = usb_pipeendpoint(urb->pipe);
  	port = urb->context;
  
  	if (status) {
  		dev_dbg(&port->dev, "%s: nonzero status: %d on"
  			" endpoint %02x\n", __func__, status, endpoint);
  	} else {
  		if (urb->actual_length) {
  			tty_insert_flip_string(&port->port, data,
  				urb->actual_length);
  			tty_flip_buffer_push(&port->port);
  
  			usb_serial_debug_data(&port->dev, __func__,
  					      urb->actual_length, data);
  		} else {
  			dev_dbg(&port->dev, "%s: empty read urb"
  				" received\n", __func__);
  		}
  	}
  
  	/* Resubmit urb so we continue receiving */
  	if (status != -ESHUTDOWN && status != -EPERM) {
  		usb_mark_last_busy(port->serial->dev);
  		err = usb_submit_urb(urb, GFP_ATOMIC);
  		if (err && err != -EPERM)
  			dev_err(&port->dev, "resubmit read urb failed."
  				"(%d)\n", err);
  	}
  }
  
  static void sierra_instat_callback(struct urb *urb)
  {
  	int err;
  	int status = urb->status;
  	struct usb_serial_port *port =  urb->context;
  	struct sierra_port_private *portdata = usb_get_serial_port_data(port);
  	struct usb_serial *serial = port->serial;
  
  	dev_dbg(&port->dev, "%s: urb %p port %p has data %p\n", __func__,
  		urb, port, portdata);
  
  	if (status == 0) {
  		struct usb_ctrlrequest *req_pkt =
  				(struct usb_ctrlrequest *)urb->transfer_buffer;
  
  		if (!req_pkt) {
  			dev_dbg(&port->dev, "%s: NULL req_pkt\n",
  				__func__);
  			return;
  		}
  		if ((req_pkt->bRequestType == 0xA1) &&
  				(req_pkt->bRequest == 0x20)) {
  			int old_dcd_state;
  			unsigned char signals = *((unsigned char *)
  					urb->transfer_buffer +
  					sizeof(struct usb_ctrlrequest));
  
  			dev_dbg(&port->dev, "%s: signal x%x\n", __func__,
  				signals);
  
  			old_dcd_state = portdata->dcd_state;
  			portdata->cts_state = 1;
  			portdata->dcd_state = ((signals & 0x01) ? 1 : 0);
  			portdata->dsr_state = ((signals & 0x02) ? 1 : 0);
  			portdata->ri_state = ((signals & 0x08) ? 1 : 0);
  
  			if (old_dcd_state && !portdata->dcd_state)
  				tty_port_tty_hangup(&port->port, true);
  		} else {
  			dev_dbg(&port->dev, "%s: type %x req %x\n",
  				__func__, req_pkt->bRequestType,
  				req_pkt->bRequest);
  		}
  	} else
  		dev_dbg(&port->dev, "%s: error %d\n", __func__, status);
  
  	/* Resubmit urb so we continue receiving IRQ data */
  	if (status != -ESHUTDOWN && status != -ENOENT) {
  		usb_mark_last_busy(serial->dev);
  		err = usb_submit_urb(urb, GFP_ATOMIC);
  		if (err && err != -EPERM)
  			dev_err(&port->dev, "%s: resubmit intr urb "
  				"failed. (%d)\n", __func__, err);
  	}
  }
  
  static int sierra_write_room(struct tty_struct *tty)
  {
  	struct usb_serial_port *port = tty->driver_data;
  	struct sierra_port_private *portdata = usb_get_serial_port_data(port);
  	unsigned long flags;
  
  	/* try to give a good number back based on if we have any free urbs at
  	 * this point in time */
  	spin_lock_irqsave(&portdata->lock, flags);
  	if (portdata->outstanding_urbs > (portdata->num_out_urbs * 2) / 3) {
  		spin_unlock_irqrestore(&portdata->lock, flags);
  		dev_dbg(&port->dev, "%s - write limit hit\n", __func__);
  		return 0;
  	}
  	spin_unlock_irqrestore(&portdata->lock, flags);
  
  	return 2048;
  }
  
  static int sierra_chars_in_buffer(struct tty_struct *tty)
  {
  	struct usb_serial_port *port = tty->driver_data;
  	struct sierra_port_private *portdata = usb_get_serial_port_data(port);
  	unsigned long flags;
  	int chars;
  
  	/* NOTE: This overcounts somewhat. */
  	spin_lock_irqsave(&portdata->lock, flags);
  	chars = portdata->outstanding_urbs * MAX_TRANSFER;
  	spin_unlock_irqrestore(&portdata->lock, flags);
  
  	dev_dbg(&port->dev, "%s - %d\n", __func__, chars);
  
  	return chars;
  }
  
  static void sierra_stop_rx_urbs(struct usb_serial_port *port)
  {
  	int i;
  	struct sierra_port_private *portdata = usb_get_serial_port_data(port);
  
  	for (i = 0; i < portdata->num_in_urbs; i++)
  		usb_kill_urb(portdata->in_urbs[i]);
  
  	usb_kill_urb(port->interrupt_in_urb);
  }
  
  static int sierra_submit_rx_urbs(struct usb_serial_port *port, gfp_t mem_flags)
  {
  	int ok_cnt;
  	int err = -EINVAL;
  	int i;
  	struct urb *urb;
  	struct sierra_port_private *portdata = usb_get_serial_port_data(port);
  
  	ok_cnt = 0;
  	for (i = 0; i < portdata->num_in_urbs; i++) {
  		urb = portdata->in_urbs[i];
  		if (!urb)
  			continue;
  		err = usb_submit_urb(urb, mem_flags);
  		if (err) {
  			dev_err(&port->dev, "%s: submit urb failed: %d\n",
  				__func__, err);
  		} else {
  			ok_cnt++;
  		}
  	}
  
  	if (ok_cnt && port->interrupt_in_urb) {
  		err = usb_submit_urb(port->interrupt_in_urb, mem_flags);
  		if (err) {
  			dev_err(&port->dev, "%s: submit intr urb failed: %d\n",
  				__func__, err);
  		}
  	}
  
  	if (ok_cnt > 0) /* at least one rx urb submitted */
  		return 0;
  	else
  		return err;
  }
  
  static struct urb *sierra_setup_urb(struct usb_serial *serial, int endpoint,
  					int dir, void *ctx, int len,
  					gfp_t mem_flags,
  					usb_complete_t callback)
  {
  	struct urb	*urb;
  	u8		*buf;
  
  	urb = usb_alloc_urb(0, mem_flags);
  	if (!urb)
  		return NULL;
  
  	buf = kmalloc(len, mem_flags);
  	if (buf) {
  		/* Fill URB using supplied data */
  		usb_fill_bulk_urb(urb, serial->dev,
  			usb_sndbulkpipe(serial->dev, endpoint) | dir,
  			buf, len, callback, ctx);
  
  		dev_dbg(&serial->dev->dev, "%s %c u : %p d:%p\n", __func__,
  				dir == USB_DIR_IN ? 'i' : 'o', urb, buf);
  	} else {
  		sierra_release_urb(urb);
  		urb = NULL;
  	}
  
  	return urb;
  }
  
  static void sierra_close(struct usb_serial_port *port)
  {
  	int i;
  	struct usb_serial *serial = port->serial;
  	struct sierra_port_private *portdata;
  	struct sierra_intf_private *intfdata = usb_get_serial_data(serial);
  	struct urb *urb;
  
  	portdata = usb_get_serial_port_data(port);
  
  	/*
  	 * Need to take susp_lock to make sure port is not already being
  	 * resumed, but no need to hold it due to initialized
  	 */
  	spin_lock_irq(&intfdata->susp_lock);
  	if (--intfdata->open_ports == 0)
  		serial->interface->needs_remote_wakeup = 0;
  	spin_unlock_irq(&intfdata->susp_lock);
  
  	for (;;) {
  		urb = usb_get_from_anchor(&portdata->delayed);
  		if (!urb)
  			break;
  		kfree(urb->transfer_buffer);
  		usb_free_urb(urb);
  		usb_autopm_put_interface_async(serial->interface);
  		spin_lock(&portdata->lock);
  		portdata->outstanding_urbs--;
  		spin_unlock(&portdata->lock);
  	}
  
  	sierra_stop_rx_urbs(port);
  	usb_kill_anchored_urbs(&portdata->active);
  
  	for (i = 0; i < portdata->num_in_urbs; i++) {
  		sierra_release_urb(portdata->in_urbs[i]);
  		portdata->in_urbs[i] = NULL;
  	}
  
  	usb_autopm_get_interface_no_resume(serial->interface);
  }
  
  static int sierra_open(struct tty_struct *tty, struct usb_serial_port *port)
  {
  	struct sierra_port_private *portdata;
  	struct usb_serial *serial = port->serial;
  	struct sierra_intf_private *intfdata = usb_get_serial_data(serial);
  	int i;
  	int err;
  	int endpoint;
  	struct urb *urb;
  
  	portdata = usb_get_serial_port_data(port);
  
  	endpoint = port->bulk_in_endpointAddress;
  	for (i = 0; i < portdata->num_in_urbs; i++) {
  		urb = sierra_setup_urb(serial, endpoint, USB_DIR_IN, port,
  					IN_BUFLEN, GFP_KERNEL,
  					sierra_indat_callback);
  		portdata->in_urbs[i] = urb;
  	}
  	/* clear halt condition */
  	usb_clear_halt(serial->dev,
  			usb_sndbulkpipe(serial->dev, endpoint) | USB_DIR_IN);
  
  	err = sierra_submit_rx_urbs(port, GFP_KERNEL);
  	if (err)
  		goto err_submit;
  
  	spin_lock_irq(&intfdata->susp_lock);
  	if (++intfdata->open_ports == 1)
  		serial->interface->needs_remote_wakeup = 1;
  	spin_unlock_irq(&intfdata->susp_lock);
  	usb_autopm_put_interface(serial->interface);
  
  	return 0;
  
  err_submit:
  	sierra_stop_rx_urbs(port);
  
  	for (i = 0; i < portdata->num_in_urbs; i++) {
  		sierra_release_urb(portdata->in_urbs[i]);
  		portdata->in_urbs[i] = NULL;
  	}
  
  	return err;
  }
  
  
  static void sierra_dtr_rts(struct usb_serial_port *port, int on)
  {
  	struct sierra_port_private *portdata;
  
  	portdata = usb_get_serial_port_data(port);
  	portdata->rts_state = on;
  	portdata->dtr_state = on;
  
  	sierra_send_setup(port);
  }
  
  static int sierra_startup(struct usb_serial *serial)
  {
  	struct sierra_intf_private *intfdata;
  
  	intfdata = kzalloc(sizeof(*intfdata), GFP_KERNEL);
  	if (!intfdata)
  		return -ENOMEM;
  
  	spin_lock_init(&intfdata->susp_lock);
  
  	usb_set_serial_data(serial, intfdata);
  
  	/* Set Device mode to D0 */
  	sierra_set_power_state(serial->dev, 0x0000);
  
  	/* Check NMEA and set */
  	if (nmea)
  		sierra_vsc_set_nmea(serial->dev, 1);
  
  	return 0;
  }
  
  static void sierra_release(struct usb_serial *serial)
  {
  	struct sierra_intf_private *intfdata;
  
  	intfdata = usb_get_serial_data(serial);
  	kfree(intfdata);
  }
  
  static int sierra_port_probe(struct usb_serial_port *port)
  {
  	struct usb_serial *serial = port->serial;
  	struct sierra_port_private *portdata;
  	const struct sierra_iface_info *himemoryp;
  	u8 ifnum;
  
  	portdata = kzalloc(sizeof(*portdata), GFP_KERNEL);
  	if (!portdata)
  		return -ENOMEM;
  
  	spin_lock_init(&portdata->lock);
  	init_usb_anchor(&portdata->active);
  	init_usb_anchor(&portdata->delayed);
  
  	/* Assume low memory requirements */
  	portdata->num_out_urbs = N_OUT_URB;
  	portdata->num_in_urbs  = N_IN_URB;
  
  	/* Determine actual memory requirements */
  	if (serial->num_ports == 1) {
  		/* Get interface number for composite device */
  		ifnum = sierra_interface_num(serial);
  		himemoryp = &typeB_interface_list;
  	} else {
  		/* This is really the usb-serial port number of the interface
  		 * rather than the interface number.
  		 */
  		ifnum = port->port_number;
  		himemoryp = &typeA_interface_list;
  	}
  
  	if (is_himemory(ifnum, himemoryp)) {
  		portdata->num_out_urbs = N_OUT_URB_HM;
  		portdata->num_in_urbs  = N_IN_URB_HM;
  	}
  
  	dev_dbg(&port->dev,
  			"Memory usage (urbs) interface #%d, in=%d, out=%d\n",
  			ifnum, portdata->num_in_urbs, portdata->num_out_urbs);
  
  	usb_set_serial_port_data(port, portdata);
  
  	return 0;
  }
  
  static int sierra_port_remove(struct usb_serial_port *port)
  {
  	struct sierra_port_private *portdata;
  
  	portdata = usb_get_serial_port_data(port);
  	usb_set_serial_port_data(port, NULL);
  	kfree(portdata);
  
  	return 0;
  }
  
  #ifdef CONFIG_PM
  static void stop_read_write_urbs(struct usb_serial *serial)
  {
  	int i;
  	struct usb_serial_port *port;
  	struct sierra_port_private *portdata;
  
  	/* Stop reading/writing urbs */
  	for (i = 0; i < serial->num_ports; ++i) {
  		port = serial->port[i];
  		portdata = usb_get_serial_port_data(port);
  		if (!portdata)
  			continue;
  		sierra_stop_rx_urbs(port);
  		usb_kill_anchored_urbs(&portdata->active);
  	}
  }
  
  static int sierra_suspend(struct usb_serial *serial, pm_message_t message)
  {
  	struct sierra_intf_private *intfdata = usb_get_serial_data(serial);
  
  	spin_lock_irq(&intfdata->susp_lock);
  	if (PMSG_IS_AUTO(message)) {
  		if (intfdata->in_flight) {
  			spin_unlock_irq(&intfdata->susp_lock);
  			return -EBUSY;
  		}
  	}
  	intfdata->suspended = 1;
  	spin_unlock_irq(&intfdata->susp_lock);
  
  	stop_read_write_urbs(serial);
  
  	return 0;
  }
  
  /* Caller must hold susp_lock. */
  static int sierra_submit_delayed_urbs(struct usb_serial_port *port)
  {
  	struct sierra_port_private *portdata = usb_get_serial_port_data(port);
  	struct sierra_intf_private *intfdata;
  	struct urb *urb;
  	int ec = 0;
  	int err;
  
  	intfdata = usb_get_serial_data(port->serial);
  
  	for (;;) {
  		urb = usb_get_from_anchor(&portdata->delayed);
  		if (!urb)
  			break;
  
  		usb_anchor_urb(urb, &portdata->active);
  		intfdata->in_flight++;
  		err = usb_submit_urb(urb, GFP_ATOMIC);
  		if (err) {
  			dev_err(&port->dev, "%s - submit urb failed: %d",
  					__func__, err);
  			ec++;
  			intfdata->in_flight--;
  			usb_unanchor_urb(urb);
  			kfree(urb->transfer_buffer);
  			usb_free_urb(urb);
  
  			spin_lock(&portdata->lock);
  			portdata->outstanding_urbs--;
  			spin_unlock(&portdata->lock);
  		}
  	}
  
  	if (ec)
  		return -EIO;
  
  	return 0;
  }
  
  static int sierra_resume(struct usb_serial *serial)
  {
  	struct usb_serial_port *port;
  	struct sierra_intf_private *intfdata = usb_get_serial_data(serial);
  	int ec = 0;
  	int i, err;
  
  	spin_lock_irq(&intfdata->susp_lock);
  	for (i = 0; i < serial->num_ports; i++) {
  		port = serial->port[i];
  
  		if (!tty_port_initialized(&port->port))
  			continue;
  
  		err = sierra_submit_delayed_urbs(port);
  		if (err)
  			ec++;
  
  		err = sierra_submit_rx_urbs(port, GFP_ATOMIC);
  		if (err)
  			ec++;
  	}
  	intfdata->suspended = 0;
  	spin_unlock_irq(&intfdata->susp_lock);
  
  	return ec ? -EIO : 0;
  }
  
  #else
  #define sierra_suspend NULL
  #define sierra_resume NULL
  #endif
  
  static struct usb_serial_driver sierra_device = {
  	.driver = {
  		.owner =	THIS_MODULE,
  		.name =		"sierra",
  	},
  	.description       = "Sierra USB modem",
  	.id_table          = id_table,
  	.calc_num_ports	   = sierra_calc_num_ports,
  	.probe		   = sierra_probe,
  	.open              = sierra_open,
  	.close             = sierra_close,
  	.dtr_rts	   = sierra_dtr_rts,
  	.write             = sierra_write,
  	.write_room        = sierra_write_room,
  	.chars_in_buffer   = sierra_chars_in_buffer,
  	.tiocmget          = sierra_tiocmget,
  	.tiocmset          = sierra_tiocmset,
  	.attach            = sierra_startup,
  	.release           = sierra_release,
  	.port_probe        = sierra_port_probe,
  	.port_remove       = sierra_port_remove,
  	.suspend	   = sierra_suspend,
  	.resume		   = sierra_resume,
  	.read_int_callback = sierra_instat_callback,
  };
  
  static struct usb_serial_driver * const serial_drivers[] = {
  	&sierra_device, NULL
  };
  
  module_usb_serial_driver(serial_drivers, id_table);
  
  MODULE_AUTHOR(DRIVER_AUTHOR);
  MODULE_DESCRIPTION(DRIVER_DESC);
  MODULE_LICENSE("GPL v2");
  
  module_param(nmea, bool, S_IRUGO | S_IWUSR);
  MODULE_PARM_DESC(nmea, "NMEA streaming");
  