/*
 * hid.c -- HID Composite driver
 *
 * Based on multi.c
 *
 * Copyright (C) 2010 Fabien Chouteau <fabien.chouteau@barco.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */


#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/list.h>

#define DRIVER_DESC             "HID Gadget"
#define DRIVER_VERSION          "2010/03/16"

/*-------------------------------------------------------------------------*/

#define HIDG_VENDOR_NUM         0x0525  /* XXX NetChip */
#define HIDG_PRODUCT_NUM        0xa4ac  /* Linux-USB HID gadget */

/*-------------------------------------------------------------------------*/

/*
 * kbuild is not very cooperative with respect to linking separately
 * compiled library objects into one module.  So for now we won't use
 * separate compilation ... ensuring init/exit sections work to shrink
 * the runtime footprint, and giving us at least some parts of what
 * a "gcc --combine ... part1.c part2.c part3.c ... " build would.
 */

#include "composite.c"
#include "usbstring.c"
#include "config.c"
#include "epautoconf.c"

#include "f_hid.c"


struct hidg_func_node {
        struct list_head node;
        struct hidg_func_descriptor *func;
};

static LIST_HEAD(hidg_func_list);

/*-------------------------------------------------------------------------*/

static struct usb_device_descriptor device_desc = {
        .bLength =              sizeof device_desc,
        .bDescriptorType =      USB_DT_DEVICE,

        .bcdUSB =               cpu_to_le16(0x0200),

        /* .bDeviceClass =              USB_CLASS_COMM, */
        /* .bDeviceSubClass =   0, */
        /* .bDeviceProtocol =   0, */
        .bDeviceClass =         USB_CLASS_PER_INTERFACE,
        .bDeviceSubClass =      0,
        .bDeviceProtocol =      0,
        /* .bMaxPacketSize0 = f(hardware) */

        /* Vendor and product id can be overridden by module parameters.  */
        .idVendor =             cpu_to_le16(HIDG_VENDOR_NUM),
        .idProduct =            cpu_to_le16(HIDG_PRODUCT_NUM),
        /* .bcdDevice = f(hardware) */
        /* .iManufacturer = DYNAMIC */
        /* .iProduct = DYNAMIC */
        /* NO SERIAL NUMBER */
        .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,
};

static const struct usb_descriptor_header *otg_desc[] = {
        (struct usb_descriptor_header *) &otg_descriptor,
        NULL,
};


/* string IDs are assigned dynamically */

#define STRING_MANUFACTURER_IDX         0
#define STRING_PRODUCT_IDX              1

static char manufacturer[50];

static struct usb_string strings_dev[] = {
        [STRING_MANUFACTURER_IDX].s = manufacturer,
        [STRING_PRODUCT_IDX].s = DRIVER_DESC,
        {  } /* 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,
};



/****************************** Configurations ******************************/

static int __init do_config(struct usb_configuration *c)
{
        struct hidg_func_node *e;
        int func = 0, status = 0;

        if (gadget_is_otg(c->cdev->gadget)) {
                c->descriptors = otg_desc;
                c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
        }

        list_for_each_entry(e, &hidg_func_list, node) {
                status = hidg_bind_config(c, e->func, func++);
                if (status)
                        break;
        }

        return status;
}

static struct usb_configuration config_driver = {
        .label                  = "HID Gadget",
        .bConfigurationValue    = 1,
        /* .iConfiguration = DYNAMIC */
        .bmAttributes           = USB_CONFIG_ATT_SELFPOWER,
};

/****************************** Gadget Bind ******************************/

static int __init hid_bind(struct usb_composite_dev *cdev)
{
        struct usb_gadget *gadget = cdev->gadget;
        struct list_head *tmp;
        int status, gcnum, funcs = 0;

        list_for_each(tmp, &hidg_func_list)
                funcs++;

        if (!funcs)
                return -ENODEV;

        /* set up HID */
        status = ghid_setup(cdev->gadget, funcs);
        if (status < 0)
                return status;

        gcnum = usb_gadget_controller_number(gadget);
        if (gcnum >= 0)
                device_desc.bcdDevice = cpu_to_le16(0x0300 | gcnum);
        else
                device_desc.bcdDevice = cpu_to_le16(0x0300 | 0x0099);


        /* Allocate string descriptor numbers ... note that string
         * contents can be overridden by the composite_dev glue.
         */

        /* device descriptor strings: manufacturer, product */
        snprintf(manufacturer, sizeof manufacturer, "%s %s with %s",
                init_utsname()->sysname, init_utsname()->release,
                gadget->name);
        status = usb_string_id(cdev);
        if (status < 0)
                return status;
        strings_dev[STRING_MANUFACTURER_IDX].id = status;
        device_desc.iManufacturer = status;

        status = usb_string_id(cdev);
        if (status < 0)
                return status;
        strings_dev[STRING_PRODUCT_IDX].id = status;
        device_desc.iProduct = status;

        /* register our configuration */
        status = usb_add_config(cdev, &config_driver, do_config);
        if (status < 0)
                return status;

        dev_info(&gadget->dev, DRIVER_DESC ", version: " DRIVER_VERSION "\n");

        return 0;
}

static int __exit hid_unbind(struct usb_composite_dev *cdev)
{
        ghid_cleanup();
        return 0;
}

static int __init hidg_plat_driver_probe(struct platform_device *pdev)
{
        struct hidg_func_descriptor *func = pdev->dev.platform_data;
        struct hidg_func_node *entry;

        if (!func) {
                dev_err(&pdev->dev, "Platform data missing\n");
                return -ENODEV;
        }

        entry = kzalloc(sizeof(*entry), GFP_KERNEL);
        if (!entry)
                return -ENOMEM;

        entry->func = func;
        list_add_tail(&entry->node, &hidg_func_list);

        return 0;
}

static int __devexit hidg_plat_driver_remove(struct platform_device *pdev)
{
        struct hidg_func_node *e, *n;

        list_for_each_entry_safe(e, n, &hidg_func_list, node) {
                list_del(&e->node);
                kfree(e);
        }

        return 0;
}


/****************************** Some noise ******************************/


static struct usb_composite_driver hidg_driver = {
        .name           = "g_hid",
        .dev            = &device_desc,
        .strings        = dev_strings,
        .max_speed      = USB_SPEED_HIGH,
        .unbind         = __exit_p(hid_unbind),
};

static struct platform_driver hidg_plat_driver = {
        .remove         = __devexit_p(hidg_plat_driver_remove),
        .driver         = {
                .owner  = THIS_MODULE,
                .name   = "hidg",
        },
};


MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_AUTHOR("Fabien Chouteau, Peter Korsgaard");
MODULE_LICENSE("GPL");

static int __init hidg_init(void)
{
        int status;

        status = platform_driver_probe(&hidg_plat_driver,
                                hidg_plat_driver_probe);
        if (status < 0)
                return status;

        status = usb_composite_probe(&hidg_driver, hid_bind);
        if (status < 0)
                platform_driver_unregister(&hidg_plat_driver);

        return status;
}
module_init(hidg_init);

static void __exit hidg_cleanup(void)
{
        platform_driver_unregister(&hidg_plat_driver);
        usb_composite_unregister(&hidg_driver);
}
module_exit(hidg_cleanup);