serial.c

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/*
 * serial.c -- USB gadget serial driver
 *
 * Copyright (C) 2003 Al Borchers ([email protected])
 * 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/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

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

/*
 * 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_acm.c"
#include "f_obex.c"
#include "f_serial.c"
#include "u_serial.c"

/*-------------------------------------------------------------------------*/
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,
};

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 int __init serial_bind_config(struct usb_configuration *c)
{
    unsigned i;
    int status = 0;

    for (i = 0; i < n_ports && status == 0; i++) {
        if (use_acm)
            status = acm_bind_config(c, i);
        else if (use_obex)
            status = obex_bind_config(c, i);
        else
            status = gser_bind_config(c, i);
    }
    return status;
}

static struct usb_configuration serial_config_driver = {
    /* .label = f(use_acm) */
    /* .bConfigurationValue = f(use_acm) */
    /* .iConfiguration = DYNAMIC */
    .bmAttributes   = USB_CONFIG_ATT_SELFPOWER,
};

static int __init gs_bind(struct usb_composite_dev *cdev)
{
    int         status;

    status = gserial_setup(cdev->gadget, n_ports);
    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)
        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 */
    status = usb_add_config(cdev, &serial_config_driver,
            serial_bind_config);
    if (status < 0)
        goto fail;

    usb_composite_overwrite_options(cdev, &coverwrite);
    INFO(cdev, "%s\n", GS_VERSION_NAME);

    return 0;

fail:
    gserial_cleanup();
    return status;
}

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,
};

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);
}
module_init(init);

static void __exit cleanup(void)
{
    usb_composite_unregister(&gserial_driver);
    gserial_cleanup();
}
module_exit(cleanup);