// SPDX-License-Identifier: GPL-2.0+
/*
 * acm_ms.c -- Composite driver, with ACM and mass storage support
 *
 * Copyright (C) 2008 David Brownell
 * Copyright (C) 2008 Nokia Corporation
 * Author: David Brownell
 * Modified: Klaus Schwarzkopf <schwarzkopf@sensortherm.de>
 *
 * Heavily based on multi.c and cdc2.c
 */

#include <linux/kernel.h>
#include <linux/module.h>

#include "u_serial.h"

#define DRIVER_DESC             "Composite Gadget (ACM + MS)"
#define DRIVER_VERSION          "2011/10/10"

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

/*
 * DO NOT REUSE THESE IDs with a protocol-incompatible driver!!  Ever!!
 * Instead:  allocate your own, using normal USB-IF procedures.
 */
#define ACM_MS_VENDOR_NUM       0x1d6b  /* Linux Foundation */
#define ACM_MS_PRODUCT_NUM      0x0106  /* Composite Gadget: ACM + MS*/

#include "f_mass_storage.h"

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

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

        /* .bcdUSB = DYNAMIC */

        .bDeviceClass =         USB_CLASS_MISC /* 0xEF */,
        .bDeviceSubClass =      2,
        .bDeviceProtocol =      1,

        /* .bMaxPacketSize0 = f(hardware) */

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

static const struct usb_descriptor_header *otg_desc[2];

/* 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 struct fsg_module_parameters fsg_mod_data = { .stall = 1 };
#ifdef CONFIG_USB_GADGET_DEBUG_FILES

static unsigned int fsg_num_buffers = CONFIG_USB_GADGET_STORAGE_NUM_BUFFERS;

#else

/*
 * Number of buffers we will use.
 * 2 is usually enough for good buffering pipeline
 */
#define fsg_num_buffers CONFIG_USB_GADGET_STORAGE_NUM_BUFFERS

#endif /* CONFIG_USB_GADGET_DEBUG_FILES */

FSG_MODULE_PARAMETERS(/* no prefix */, fsg_mod_data);

/*-------------------------------------------------------------------------*/
static struct usb_function *f_acm;
static struct usb_function_instance *f_acm_inst;

static struct usb_function_instance *fi_msg;
static struct usb_function *f_msg;

/*
 * We _always_ have both ACM and mass storage functions.
 */
static int acm_ms_do_config(struct usb_configuration *c)
{
        struct fsg_opts *opts;
        int     status;

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

        opts = fsg_opts_from_func_inst(fi_msg);

        f_acm = usb_get_function(f_acm_inst);
        if (IS_ERR(f_acm))
                return PTR_ERR(f_acm);

        f_msg = usb_get_function(fi_msg);
        if (IS_ERR(f_msg)) {
                status = PTR_ERR(f_msg);
                goto put_acm;
        }

        status = usb_add_function(c, f_acm);
        if (status < 0)
                goto put_msg;

        status = usb_add_function(c, f_msg);
        if (status)
                goto remove_acm;

        return 0;
remove_acm:
        usb_remove_function(c, f_acm);
put_msg:
        usb_put_function(f_msg);
put_acm:
        usb_put_function(f_acm);
        return status;
}

static struct usb_configuration acm_ms_config_driver = {
        .label                  = DRIVER_DESC,
        .bConfigurationValue    = 1,
        /* .iConfiguration = DYNAMIC */
        .bmAttributes           = USB_CONFIG_ATT_SELFPOWER,
};

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

static int acm_ms_bind(struct usb_composite_dev *cdev)
{
        struct usb_gadget       *gadget = cdev->gadget;
        struct fsg_opts         *opts;
        struct fsg_config       config;
        int                     status;

        f_acm_inst = usb_get_function_instance("acm");
        if (IS_ERR(f_acm_inst))
                return PTR_ERR(f_acm_inst);

        fi_msg = usb_get_function_instance("mass_storage");
        if (IS_ERR(fi_msg)) {
                status = PTR_ERR(fi_msg);
                goto fail_get_msg;
        }

        /* set up mass storage function */
        fsg_config_from_params(&config, &fsg_mod_data, fsg_num_buffers);
        opts = fsg_opts_from_func_inst(fi_msg);

        opts->no_configfs = true;
        status = fsg_common_set_num_buffers(opts->common, fsg_num_buffers);
        if (status)
                goto fail;

        status = fsg_common_set_cdev(opts->common, cdev, config.can_stall);
        if (status)
                goto fail_set_cdev;

        fsg_common_set_sysfs(opts->common, true);
        status = fsg_common_create_luns(opts->common, &config);
        if (status)
                goto fail_set_cdev;

        fsg_common_set_inquiry_string(opts->common, config.vendor_name,
                                      config.product_name);
        /*
         * 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_string_ids;
        device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id;
        device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id;

        if (gadget_is_otg(gadget) && !otg_desc[0]) {
                struct usb_descriptor_header *usb_desc;

                usb_desc = usb_otg_descriptor_alloc(gadget);
                if (!usb_desc)
                        goto fail_string_ids;
                usb_otg_descriptor_init(gadget, usb_desc);
                otg_desc[0] = usb_desc;
                otg_desc[1] = NULL;
        }

        /* register our configuration */
        status = usb_add_config(cdev, &acm_ms_config_driver, acm_ms_do_config);
        if (status < 0)
                goto fail_otg_desc;

        usb_composite_overwrite_options(cdev, &coverwrite);
        dev_info(&gadget->dev, "%s, version: " DRIVER_VERSION "\n",
                        DRIVER_DESC);
        return 0;

        /* error recovery */
fail_otg_desc:
        kfree(otg_desc[0]);
        otg_desc[0] = NULL;
fail_string_ids:
        fsg_common_remove_luns(opts->common);
fail_set_cdev:
        fsg_common_free_buffers(opts->common);
fail:
        usb_put_function_instance(fi_msg);
fail_get_msg:
        usb_put_function_instance(f_acm_inst);
        return status;
}

static int acm_ms_unbind(struct usb_composite_dev *cdev)
{
        usb_put_function(f_msg);
        usb_put_function_instance(fi_msg);
        usb_put_function(f_acm);
        usb_put_function_instance(f_acm_inst);
        kfree(otg_desc[0]);
        otg_desc[0] = NULL;

        return 0;
}

static struct usb_composite_driver acm_ms_driver = {
        .name           = "g_acm_ms",
        .dev            = &device_desc,
        .max_speed      = USB_SPEED_SUPER,
        .strings        = dev_strings,
        .bind           = acm_ms_bind,
        .unbind         = acm_ms_unbind,
};

module_usb_composite_driver(acm_ms_driver);

MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_AUTHOR("Klaus Schwarzkopf <schwarzkopf@sensortherm.de>");
MODULE_LICENSE("GPL v2");