hid.c

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/*
 * hid.c -- HID Composite driver
 *
 * Based on multi.c
 *
 * Copyright (C) 2010 Fabien Chouteau <[email protected]>
 *
 * 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>
#include <linux/module.h>
#include <linux/usb/composite.h>

#include "gadget_chips.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 "f_hid.c"


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

static LIST_HEAD(hidg_func_list);

/*-------------------------------------------------------------------------*/
USB_GADGET_COMPOSITE_OPTIONS();

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 */
static struct usb_string strings_dev[] = {
    [USB_GADGET_MANUFACTURER_IDX].s = "",
    [USB_GADGET_PRODUCT_IDX].s = DRIVER_DESC,
    [USB_GADGET_SERIAL_IDX].s = "",
    {  } /* 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, 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;

    /* 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)
        return status;
    device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id;
    device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id;

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

    usb_composite_overwrite_options(cdev, &coverwrite);
    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 __refdata struct usb_composite_driver hidg_driver = {
    .name       = "g_hid",
    .dev        = &device_desc,
    .strings    = dev_strings,
    .max_speed  = USB_SPEED_HIGH,
    .bind       = hid_bind,
    .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);
    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);