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/*
* Copyright (C) 2014 Samsung Electronics
*
* Krzysztof Opasiak <k.opasiak@samsung.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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
/**
* @file gadget-ffs.c
* @example gadget-ffs.c
* This is an example of how to create gadget with FunctionFS based functions
* in two ways. After executing this program gadget will not be enabled
* because ffs instances should be mounted and both descriptors and strings
* should be written to ep0.
* For more details about FunctionFS please refer to FunctionFS documentation
* in linux kernel repository.
*/
#include <errno.h>
#include <stdio.h>
#include <linux/usb/ch9.h>
#include <usbg/usbg.h>
#define VENDOR 0x1d6b
#define PRODUCT 0x0104
int main(void)
{
usbg_state *s;
usbg_gadget *g;
usbg_config *c;
usbg_function *f_ffs1, *f_ffs2;
int ret = -EINVAL;
int usbg_ret;
struct usbg_gadget_attrs g_attrs = {
.bcdUSB = 0x0200,
.bDeviceClass = USB_CLASS_PER_INTERFACE,
.bDeviceSubClass = 0x00,
.bDeviceProtocol = 0x00,
.bMaxPacketSize0 = 64, /* Max allowed ep0 packet size */
.idVendor = VENDOR,
.idProduct = PRODUCT,
.bcdDevice = 0x0001, /* Verson of device */
};
struct usbg_gadget_strs g_strs = {
.serial = "0123456789", /* Serial number */
.manufacturer = "Foo Inc.", /* Manufacturer */
.product = "Bar Gadget" /* Product string */
};
struct usbg_config_strs c_strs = {
.configuration = "2xFFS"
};
usbg_ret = usbg_init("/sys/kernel/config", &s);
if (usbg_ret != USBG_SUCCESS) {
fprintf(stderr, "Error on USB gadget init\n");
fprintf(stderr, "Error: %s : %s\n", usbg_error_name(usbg_ret),
usbg_strerror(usbg_ret));
goto out1;
}
usbg_ret = usbg_create_gadget(s, "g1", &g_attrs, &g_strs, &g);
if (usbg_ret != USBG_SUCCESS) {
fprintf(stderr, "Error on create gadget\n");
fprintf(stderr, "Error: %s : %s\n", usbg_error_name(usbg_ret),
usbg_strerror(usbg_ret));
goto out2;
}
usbg_ret = usbg_create_function(g, USBG_F_FFS, "my_dev_name", NULL, &f_ffs1);
if (usbg_ret != USBG_SUCCESS) {
fprintf(stderr, "Error creating ffs1 function\n");
fprintf(stderr, "Error: %s : %s\n", usbg_error_name(usbg_ret),
usbg_strerror(usbg_ret));
goto out2;
}
usbg_ret = usbg_create_function(g, USBG_F_FFS, "my_other_dev_name",
NULL, &f_ffs2);
if (usbg_ret != USBG_SUCCESS) {
fprintf(stderr, "Error creating ffs2 function\n");
fprintf(stderr, "Error: %s : %s\n", usbg_error_name(usbg_ret),
usbg_strerror(usbg_ret));
goto out2;
}
/* NULL can be passed to use kernel defaults */
usbg_ret = usbg_create_config(g, 1, "The only one", NULL, &c_strs, &c);
if (usbg_ret != USBG_SUCCESS) {
fprintf(stderr, "Error creating config\n");
fprintf(stderr, "Error: %s : %s\n", usbg_error_name(usbg_ret),
usbg_strerror(usbg_ret));
goto out2;
}
usbg_ret = usbg_add_config_function(c, "some_name_here", f_ffs1);
if (usbg_ret != USBG_SUCCESS) {
fprintf(stderr, "Error adding ffs1\n");
fprintf(stderr, "Error: %s : %s\n", usbg_error_name(usbg_ret),
usbg_strerror(usbg_ret));
goto out2;
}
usbg_ret = usbg_add_config_function(c, "some_name_here_too", f_ffs2);
if (usbg_ret != USBG_SUCCESS) {
fprintf(stderr, "Error adding ffs2\n");
fprintf(stderr, "Error: %s : %s\n", usbg_error_name(usbg_ret),
usbg_strerror(usbg_ret));
goto out2;
}
fprintf(stdout, "2xFFS gadget has been created.\n"
"Enable it after preparing your functions.\n");
/*
* Here we end up with two created ffs instances but they are not
* fully operational. Now we have to do step by step:
* 1) Mount both instances:
* $ mount my_dev_name -t functionfs /path/to/mount/dir1
* $ mount my_awesome_dev_name -t functionfs /path/to/mount/dir2
*
* 2) Run ffs daemons for both instances:
* $ my-ffs-daemon /path/to/mount/dir1
* $ my-ffs-daemon /path/to/mount/dir2
*
* 3) Enable your gadget:
* $ echo "my_udc_name" > /sys/kernel/config/usb_gadget/g1/UDC
*/
ret = 0;
out2:
usbg_cleanup(s);
out1:
return ret;
}
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