/*
   * serial.c -- USB gadget serial driver
   *
   * Copyright (C) 2003 Al Borchers (alborchers@steinerpoint.com)
   * Copyright (C) 2008 by David Brownell
   * Copyright (C) 2008 by Nokia Corporation
   *
   * This software is distributed under the terms of the GNU General
   * Public License ("GPL") as published by the Free Software Foundation,
   * either version 2 of that License or (at your option) any later version.
   */
  
  #include <linux/kernel.h>
  #include <linux/device.h>
  #include <linux/module.h>
  #include <linux/tty.h>
  #include <linux/tty_flip.h>
  
  #include "u_serial.h"
  #include "gadget_chips.h"
  
  
  /* Defines */
  
  #define GS_VERSION_STR			"v2.4"
  #define GS_VERSION_NUM			0x2400
  
  #define GS_LONG_NAME			"Gadget Serial"
  #define GS_VERSION_NAME			GS_LONG_NAME " " GS_VERSION_STR
  
  /*-------------------------------------------------------------------------*/
  USB_GADGET_COMPOSITE_OPTIONS();
  
  /* Thanks to NetChip Technologies for donating this product ID.
  *
  * DO NOT REUSE THESE IDs with a protocol-incompatible driver!!  Ever!!
  * Instead:  allocate your own, using normal USB-IF procedures.
  */
  #define GS_VENDOR_ID			0x0525	/* NetChip */
  #define GS_PRODUCT_ID			0xa4a6	/* Linux-USB Serial Gadget */
  #define GS_CDC_PRODUCT_ID		0xa4a7	/* ... as CDC-ACM */
  #define GS_CDC_OBEX_PRODUCT_ID		0xa4a9	/* ... as CDC-OBEX */
  
  /* string IDs are assigned dynamically */
  
  #define STRING_DESCRIPTION_IDX		USB_GADGET_FIRST_AVAIL_IDX
  
  static struct usb_string strings_dev[] = {
  	[USB_GADGET_MANUFACTURER_IDX].s = "",
  	[USB_GADGET_PRODUCT_IDX].s = GS_VERSION_NAME,
  	[USB_GADGET_SERIAL_IDX].s = "",
  	[STRING_DESCRIPTION_IDX].s = NULL /* updated; f(use_acm) */,
  	{  } /* end of list */
  };
  
  static struct usb_gadget_strings stringtab_dev = {
  	.language	= 0x0409,	/* en-us */
  	.strings	= strings_dev,
  };
  
  static struct usb_gadget_strings *dev_strings[] = {
  	&stringtab_dev,
  	NULL,
  };
  
  static struct usb_device_descriptor device_desc = {
  	.bLength =		USB_DT_DEVICE_SIZE,
  	.bDescriptorType =	USB_DT_DEVICE,
  	.bcdUSB =		cpu_to_le16(0x0200),
  	/* .bDeviceClass = f(use_acm) */
  	.bDeviceSubClass =	0,
  	.bDeviceProtocol =	0,
  	/* .bMaxPacketSize0 = f(hardware) */
  	.idVendor =		cpu_to_le16(GS_VENDOR_ID),
  	/* .idProduct =	f(use_acm) */
  	.bcdDevice = cpu_to_le16(GS_VERSION_NUM),
  	/* .iManufacturer = DYNAMIC */
  	/* .iProduct = DYNAMIC */
  	.bNumConfigurations =	1,
  };
  
  static struct usb_otg_descriptor otg_descriptor = {
  	.bLength =		sizeof otg_descriptor,
  	.bDescriptorType =	USB_DT_OTG,
  
  	/* REVISIT SRP-only hardware is possible, although
  	 * it would not be called "OTG" ...
  	 */
  	.bmAttributes =		USB_OTG_SRP | USB_OTG_HNP,
  	.bcdOTG =		cpu_to_le16(0x0200),
  };
  
  static const struct usb_descriptor_header *otg_desc[] = {
  	(struct usb_descriptor_header *) &otg_descriptor,
  	NULL,
  };
  
  /*-------------------------------------------------------------------------*/
  
  /* Module */
  MODULE_DESCRIPTION(GS_VERSION_NAME);
  MODULE_AUTHOR("Al Borchers");
  MODULE_AUTHOR("David Brownell");
  MODULE_LICENSE("GPL");
  
  static bool use_acm = true;
  module_param(use_acm, bool, 0);
  MODULE_PARM_DESC(use_acm, "Use CDC ACM, default=yes");
  
  static bool use_obex = false;
  module_param(use_obex, bool, 0);
  MODULE_PARM_DESC(use_obex, "Use CDC OBEX, default=no");
  
  static unsigned n_ports = 1;
  module_param(n_ports, uint, 0);
  MODULE_PARM_DESC(n_ports, "number of ports to create, default=1");
  
  /*-------------------------------------------------------------------------*/
  
  static struct usb_configuration serial_config_driver = {
  	/* .label = f(use_acm) */
  	/* .bConfigurationValue = f(use_acm) */
  	/* .iConfiguration = DYNAMIC */
  	.bmAttributes	= USB_CONFIG_ATT_SELFPOWER,
  };
  
  static struct usb_function_instance *fi_serial[MAX_U_SERIAL_PORTS];
  static struct usb_function *f_serial[MAX_U_SERIAL_PORTS];
  
  static int serial_register_ports(struct usb_composite_dev *cdev,
  		struct usb_configuration *c, const char *f_name)
  {
  	int i;
  	int ret;
  
  	ret = usb_add_config_only(cdev, c);
  	if (ret)
  		goto out;
  
  	for (i = 0; i < n_ports; i++) {
  
  		fi_serial[i] = usb_get_function_instance(f_name);
  		if (IS_ERR(fi_serial[i])) {
  			ret = PTR_ERR(fi_serial[i]);
  			goto fail;
  		}
  
  		f_serial[i] = usb_get_function(fi_serial[i]);
  		if (IS_ERR(f_serial[i])) {
  			ret = PTR_ERR(f_serial[i]);
  			goto err_get_func;
  		}
  
  		ret = usb_add_function(c, f_serial[i]);
  		if (ret)
  			goto err_add_func;
  	}
  
  	return 0;
  
  err_add_func:
  	usb_put_function(f_serial[i]);
  err_get_func:
  	usb_put_function_instance(fi_serial[i]);
  
  fail:
  	i--;
  	while (i >= 0) {
  		usb_remove_function(c, f_serial[i]);
  		usb_put_function(f_serial[i]);
  		usb_put_function_instance(fi_serial[i]);
  		i--;
  	}
  out:
  	return ret;
  }
  
  static int __init gs_bind(struct usb_composite_dev *cdev)
  {
  	int			status;
  
  	/* Allocate string descriptor numbers ... note that string
  	 * contents can be overridden by the composite_dev glue.
  	 */
  
  	status = usb_string_ids_tab(cdev, strings_dev);
  	if (status < 0)
  		goto fail;
  	device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id;
  	device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id;
  	status = strings_dev[STRING_DESCRIPTION_IDX].id;
  	serial_config_driver.iConfiguration = status;
  
  	if (gadget_is_otg(cdev->gadget)) {
  		serial_config_driver.descriptors = otg_desc;
  		serial_config_driver.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
  	}
  
  	/* register our configuration */
  	if (use_acm) {
  		status  = serial_register_ports(cdev, &serial_config_driver,
  				"acm");
  		usb_ep_autoconfig_reset(cdev->gadget);
  	} else if (use_obex)
  		status = serial_register_ports(cdev, &serial_config_driver,
  				"obex");
  	else {
  		status = serial_register_ports(cdev, &serial_config_driver,
  				"gser");
  	}
  	if (status < 0)
  		goto fail;
  
  	usb_composite_overwrite_options(cdev, &coverwrite);
  	INFO(cdev, "%s
  ", GS_VERSION_NAME);
  
  	return 0;
  
  fail:
  	return status;
  }
  
  static int gs_unbind(struct usb_composite_dev *cdev)
  {
  	int i;
  
  	for (i = 0; i < n_ports; i++) {
  		usb_put_function(f_serial[i]);
  		usb_put_function_instance(fi_serial[i]);
  	}
  	return 0;
  }
  
  static __refdata struct usb_composite_driver gserial_driver = {
  	.name		= "g_serial",
  	.dev		= &device_desc,
  	.strings	= dev_strings,
  	.max_speed	= USB_SPEED_SUPER,
  	.bind		= gs_bind,
  	.unbind		= gs_unbind,
  };
  
  static int __init init(void)
  {
  	/* We *could* export two configs; that'd be much cleaner...
  	 * but neither of these product IDs was defined that way.
  	 */
  	if (use_acm) {
  		serial_config_driver.label = "CDC ACM config";
  		serial_config_driver.bConfigurationValue = 2;
  		device_desc.bDeviceClass = USB_CLASS_COMM;
  		device_desc.idProduct =
  				cpu_to_le16(GS_CDC_PRODUCT_ID);
  	} else if (use_obex) {
  		serial_config_driver.label = "CDC OBEX config";
  		serial_config_driver.bConfigurationValue = 3;
  		device_desc.bDeviceClass = USB_CLASS_COMM;
  		device_desc.idProduct =
  			cpu_to_le16(GS_CDC_OBEX_PRODUCT_ID);
  	} else {
  		serial_config_driver.label = "Generic Serial config";
  		serial_config_driver.bConfigurationValue = 1;
  		device_desc.bDeviceClass = USB_CLASS_VENDOR_SPEC;
  		device_desc.idProduct =
  				cpu_to_le16(GS_PRODUCT_ID);
  	}
  	strings_dev[STRING_DESCRIPTION_IDX].s = serial_config_driver.label;
  
  	return usb_composite_probe(&gserial_driver);
  }
  late_initcall(init);
  
  static void __exit cleanup(void)
  {
  	usb_composite_unregister(&gserial_driver);
  }
  module_exit(cleanup);