// SPDX-License-Identifier: GPL-2.0+
/*
 * multi.c -- Multifunction Composite driver
 *
 * Copyright (C) 2008 David Brownell
 * Copyright (C) 2008 Nokia Corporation
 * Copyright (C) 2009 Samsung Electronics
 * Author: Michal Nazarewicz (mina86@mina86.com)
 */


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

#include "u_serial.h"
#if defined USB_ETH_RNDIS
#  undef USB_ETH_RNDIS
#endif
#ifdef CONFIG_USB_G_MULTI_RNDIS
#  define USB_ETH_RNDIS y
#endif


#define DRIVER_DESC             "Multifunction Composite Gadget"

MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_AUTHOR("Michal Nazarewicz");
MODULE_LICENSE("GPL");


#include "f_mass_storage.h"

#include "u_ecm.h"
#ifdef USB_ETH_RNDIS
#  include "u_rndis.h"
#  include "rndis.h"
#endif
#include "u_ether.h"

USB_GADGET_COMPOSITE_OPTIONS();

USB_ETHERNET_MODULE_PARAMETERS();

/***************************** Device Descriptor ****************************/

#define MULTI_VENDOR_NUM        0x1d6b  /* Linux Foundation */
#define MULTI_PRODUCT_NUM       0x0104  /* Multifunction Composite Gadget */


enum {
        __MULTI_NO_CONFIG,
#ifdef CONFIG_USB_G_MULTI_RNDIS
        MULTI_RNDIS_CONFIG_NUM,
#endif
#ifdef CONFIG_USB_G_MULTI_CDC
        MULTI_CDC_CONFIG_NUM,
#endif
};


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,

        /* Vendor and product id can be overridden by module parameters.  */
        .idVendor =             cpu_to_le16(MULTI_VENDOR_NUM),
        .idProduct =            cpu_to_le16(MULTI_PRODUCT_NUM),
};

static const struct usb_descriptor_header *otg_desc[2];

enum {
        MULTI_STRING_RNDIS_CONFIG_IDX = USB_GADGET_FIRST_AVAIL_IDX,
        MULTI_STRING_CDC_CONFIG_IDX,
};

static struct usb_string strings_dev[] = {
        [USB_GADGET_MANUFACTURER_IDX].s = "",
        [USB_GADGET_PRODUCT_IDX].s = DRIVER_DESC,
        [USB_GADGET_SERIAL_IDX].s = "",
        [MULTI_STRING_RNDIS_CONFIG_IDX].s = "Multifunction with RNDIS",
        [MULTI_STRING_CDC_CONFIG_IDX].s   = "Multifunction with CDC ECM",
        {  } /* end of list */
};

static struct usb_gadget_strings *dev_strings[] = {
        &(struct usb_gadget_strings){
                .language       = 0x0409,       /* en-us */
                .strings        = strings_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_instance *fi_acm;
static struct usb_function_instance *fi_msg;

/********** RNDIS **********/

#ifdef USB_ETH_RNDIS
static struct usb_function_instance *fi_rndis;
static struct usb_function *f_acm_rndis;
static struct usb_function *f_rndis;
static struct usb_function *f_msg_rndis;

static int rndis_do_config(struct usb_configuration *c)
{
        int ret;

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

        f_rndis = usb_get_function(fi_rndis);
        if (IS_ERR(f_rndis))
                return PTR_ERR(f_rndis);

        ret = usb_add_function(c, f_rndis);
        if (ret < 0)
                goto err_func_rndis;

        f_acm_rndis = usb_get_function(fi_acm);
        if (IS_ERR(f_acm_rndis)) {
                ret = PTR_ERR(f_acm_rndis);
                goto err_func_acm;
        }

        ret = usb_add_function(c, f_acm_rndis);
        if (ret)
                goto err_conf;

        f_msg_rndis = usb_get_function(fi_msg);
        if (IS_ERR(f_msg_rndis)) {
                ret = PTR_ERR(f_msg_rndis);
                goto err_fsg;
        }

        ret = usb_add_function(c, f_msg_rndis);
        if (ret)
                goto err_run;

        return 0;
err_run:
        usb_put_function(f_msg_rndis);
err_fsg:
        usb_remove_function(c, f_acm_rndis);
err_conf:
        usb_put_function(f_acm_rndis);
err_func_acm:
        usb_remove_function(c, f_rndis);
err_func_rndis:
        usb_put_function(f_rndis);
        return ret;
}

static int rndis_config_register(struct usb_composite_dev *cdev)
{
        static struct usb_configuration config = {
                .bConfigurationValue    = MULTI_RNDIS_CONFIG_NUM,
                .bmAttributes           = USB_CONFIG_ATT_SELFPOWER,
        };

        config.label          = strings_dev[MULTI_STRING_RNDIS_CONFIG_IDX].s;
        config.iConfiguration = strings_dev[MULTI_STRING_RNDIS_CONFIG_IDX].id;

        return usb_add_config(cdev, &config, rndis_do_config);
}

#else

static int rndis_config_register(struct usb_composite_dev *cdev)
{
        return 0;
}

#endif


/********** CDC ECM **********/

#ifdef CONFIG_USB_G_MULTI_CDC
static struct usb_function_instance *fi_ecm;
static struct usb_function *f_acm_multi;
static struct usb_function *f_ecm;
static struct usb_function *f_msg_multi;

static int cdc_do_config(struct usb_configuration *c)
{
        int ret;

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

        f_ecm = usb_get_function(fi_ecm);
        if (IS_ERR(f_ecm))
                return PTR_ERR(f_ecm);

        ret = usb_add_function(c, f_ecm);
        if (ret < 0)
                goto err_func_ecm;

        /* implicit port_num is zero */
        f_acm_multi = usb_get_function(fi_acm);
        if (IS_ERR(f_acm_multi)) {
                ret = PTR_ERR(f_acm_multi);
                goto err_func_acm;
        }

        ret = usb_add_function(c, f_acm_multi);
        if (ret)
                goto err_conf;

        f_msg_multi = usb_get_function(fi_msg);
        if (IS_ERR(f_msg_multi)) {
                ret = PTR_ERR(f_msg_multi);
                goto err_fsg;
        }

        ret = usb_add_function(c, f_msg_multi);
        if (ret)
                goto err_run;

        return 0;
err_run:
        usb_put_function(f_msg_multi);
err_fsg:
        usb_remove_function(c, f_acm_multi);
err_conf:
        usb_put_function(f_acm_multi);
err_func_acm:
        usb_remove_function(c, f_ecm);
err_func_ecm:
        usb_put_function(f_ecm);
        return ret;
}

static int cdc_config_register(struct usb_composite_dev *cdev)
{
        static struct usb_configuration config = {
                .bConfigurationValue    = MULTI_CDC_CONFIG_NUM,
                .bmAttributes           = USB_CONFIG_ATT_SELFPOWER,
        };

        config.label          = strings_dev[MULTI_STRING_CDC_CONFIG_IDX].s;
        config.iConfiguration = strings_dev[MULTI_STRING_CDC_CONFIG_IDX].id;

        return usb_add_config(cdev, &config, cdc_do_config);
}

#else

static int cdc_config_register(struct usb_composite_dev *cdev)
{
        return 0;
}

#endif



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

static int multi_bind(struct usb_composite_dev *cdev)
{
        struct usb_gadget *gadget = cdev->gadget;
#ifdef CONFIG_USB_G_MULTI_CDC
        struct f_ecm_opts *ecm_opts;
#endif
#ifdef USB_ETH_RNDIS
        struct f_rndis_opts *rndis_opts;
#endif
        struct fsg_opts *fsg_opts;
        struct fsg_config config;
        int status;

        if (!can_support_ecm(cdev->gadget)) {
                dev_err(&gadget->dev, "controller '%s' not usable\n",
                        gadget->name);
                return -EINVAL;
        }

#ifdef CONFIG_USB_G_MULTI_CDC
        fi_ecm = usb_get_function_instance("ecm");
        if (IS_ERR(fi_ecm))
                return PTR_ERR(fi_ecm);

        ecm_opts = container_of(fi_ecm, struct f_ecm_opts, func_inst);

        gether_set_qmult(ecm_opts->net, qmult);
        if (!gether_set_host_addr(ecm_opts->net, host_addr))
                pr_info("using host ethernet address: %s", host_addr);
        if (!gether_set_dev_addr(ecm_opts->net, dev_addr))
                pr_info("using self ethernet address: %s", dev_addr);
#endif

#ifdef USB_ETH_RNDIS
        fi_rndis = usb_get_function_instance("rndis");
        if (IS_ERR(fi_rndis)) {
                status = PTR_ERR(fi_rndis);
                goto fail;
        }

        rndis_opts = container_of(fi_rndis, struct f_rndis_opts, func_inst);

        gether_set_qmult(rndis_opts->net, qmult);
        if (!gether_set_host_addr(rndis_opts->net, host_addr))
                pr_info("using host ethernet address: %s", host_addr);
        if (!gether_set_dev_addr(rndis_opts->net, dev_addr))
                pr_info("using self ethernet address: %s", dev_addr);
#endif

#if (defined CONFIG_USB_G_MULTI_CDC && defined USB_ETH_RNDIS)
        /*
         * If both ecm and rndis are selected then:
         *      1) rndis borrows the net interface from ecm
         *      2) since the interface is shared it must not be bound
         *      twice - in ecm's _and_ rndis' binds, so do it here.
         */
        gether_set_gadget(ecm_opts->net, cdev->gadget);
        status = gether_register_netdev(ecm_opts->net);
        if (status)
                goto fail0;

        rndis_borrow_net(fi_rndis, ecm_opts->net);
        ecm_opts->bound = true;
#endif

        /* set up serial link layer */
        fi_acm = usb_get_function_instance("acm");
        if (IS_ERR(fi_acm)) {
                status = PTR_ERR(fi_acm);
                goto fail0;
        }

        /* set up mass storage function */
        fi_msg = usb_get_function_instance("mass_storage");
        if (IS_ERR(fi_msg)) {
                status = PTR_ERR(fi_msg);
                goto fail1;
        }
        fsg_config_from_params(&config, &fsg_mod_data, fsg_num_buffers);
        fsg_opts = fsg_opts_from_func_inst(fi_msg);

        fsg_opts->no_configfs = true;
        status = fsg_common_set_num_buffers(fsg_opts->common, fsg_num_buffers);
        if (status)
                goto fail2;

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

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

        fsg_common_set_inquiry_string(fsg_opts->common, config.vendor_name,
                                      config.product_name);

        /* allocate string IDs */
        status = usb_string_ids_tab(cdev, strings_dev);
        if (unlikely(status < 0))
                goto fail_string_ids;
        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) {
                        status = -ENOMEM;
                        goto fail_string_ids;
                }
                usb_otg_descriptor_init(gadget, usb_desc);
                otg_desc[0] = usb_desc;
                otg_desc[1] = NULL;
        }

        /* register configurations */
        status = rndis_config_register(cdev);
        if (unlikely(status < 0))
                goto fail_otg_desc;

        status = cdc_config_register(cdev);
        if (unlikely(status < 0))
                goto fail_otg_desc;
        usb_composite_overwrite_options(cdev, &coverwrite);

        /* we're done */
        dev_info(&gadget->dev, DRIVER_DESC "\n");
        return 0;


        /* error recovery */
fail_otg_desc:
        kfree(otg_desc[0]);
        otg_desc[0] = NULL;
fail_string_ids:
        fsg_common_remove_luns(fsg_opts->common);
fail_set_cdev:
        fsg_common_free_buffers(fsg_opts->common);
fail2:
        usb_put_function_instance(fi_msg);
fail1:
        usb_put_function_instance(fi_acm);
fail0:
#ifdef USB_ETH_RNDIS
        usb_put_function_instance(fi_rndis);
fail:
#endif
#ifdef CONFIG_USB_G_MULTI_CDC
        usb_put_function_instance(fi_ecm);
#endif
        return status;
}

static int multi_unbind(struct usb_composite_dev *cdev)
{
#ifdef CONFIG_USB_G_MULTI_CDC
        usb_put_function(f_msg_multi);
#endif
#ifdef USB_ETH_RNDIS
        usb_put_function(f_msg_rndis);
#endif
        usb_put_function_instance(fi_msg);
#ifdef CONFIG_USB_G_MULTI_CDC
        usb_put_function(f_acm_multi);
#endif
#ifdef USB_ETH_RNDIS
        usb_put_function(f_acm_rndis);
#endif
        usb_put_function_instance(fi_acm);
#ifdef USB_ETH_RNDIS
        usb_put_function(f_rndis);
        usb_put_function_instance(fi_rndis);
#endif
#ifdef CONFIG_USB_G_MULTI_CDC
        usb_put_function(f_ecm);
        usb_put_function_instance(fi_ecm);
#endif
        kfree(otg_desc[0]);
        otg_desc[0] = NULL;

        return 0;
}


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


static struct usb_composite_driver multi_driver = {
        .name           = "g_multi",
        .dev            = &device_desc,
        .strings        = dev_strings,
        .max_speed      = USB_SPEED_SUPER,
        .bind           = multi_bind,
        .unbind         = multi_unbind,
        .needs_serial   = 1,
};

module_usb_composite_driver(multi_driver);