libusbgx: Add example to show how to create ffs functions.

Add example which demonstartes two ways of creating ffs
based usb functions.

How to set-up gadget using this example:
1) Run gadget-ffs

2) Mount both instances:
 $ mount my_dev_name -t functionfs /path/to/mount/dir1
 $ mount my_awesome_dev_name -t functionfs /path/to/mount/dir2

3) Run ffs daemons for both instances:
 $ my-ffs-daemon /path/to/mount/dir1
 $ my-ffs-daemon /path/to/mount/dir2

4) Enable your gadget:
 $ echo "my_udc_name" > /sys/kernel/config/usb_gadget/g1/UDC

Signed-off-by: Krzysztof Opasiak <k.opasiak@samsung.com>
[Port from libusbg and update description]
Signed-off-by: Krzysztof Opasiak <k.opasiak@samsung.com>

diff --git a/examples/Makefile.am b/examples/Makefile.am
index 9bb25fd..4080d02 100644 (file)
--- a/examples/Makefile.am
+++ b/examples/Makefile.am
@@ -1,6 +1,7 @@
-bin_PROGRAMS = show-gadgets gadget-acm-ecm gadget-vid-pid-remove
+bin_PROGRAMS = show-gadgets gadget-acm-ecm gadget-vid-pid-remove gadget-ffs
 gadget_acm_ecm_SOURCES = gadget-acm-ecm.c
 show_gadgets_SOURCES = show-gadgets.c
 gadget_vid_pid_remove_SOURCES = gadget-vid-pid-remove.c
+gadget_ffs_SOURCES = gadget-ffs.c
 AM_CPPFLAGS=-I../include/
 AM_LDFLAGS=-L../src/ -lusbgx

diff --git a/examples/gadget-ffs.c b/examples/gadget-ffs.c
new file mode 100644 (file)
index 0000000..062780e
--- /dev/null
+++ b/examples/gadget-ffs.c
@@ -0,0 +1,154 @@
+/*
+ * 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 <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;
+       usbg_function_attrs f_attrs = {
+               .ffs = {
+                       .dev_name = "my_awesome_dev_name",
+               },
+       };
+
+       usbg_gadget_attrs g_attrs = {
+                       0x0200, /* bcdUSB */
+                       0x00, /* Defined at interface level */
+                       0x00, /* subclass */
+                       0x00, /* device protocol */
+                       0x0040, /* Max allowed packet size */
+                       VENDOR,
+                       PRODUCT,
+                       0x0001, /* Verson of device */
+       };
+
+       usbg_gadget_strs g_strs = {
+                       "0123456789", /* Serial number */
+                       "Foo Inc.", /* Manufacturer */
+                       "Bar Gadget" /* Product string */
+       };
+
+       usbg_config_strs c_strs = {
+                       "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, 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;
+       }
+
+       /* When NULL is passed as instance name, dev_name take from f_attrs
+          is used as instance name for this function */
+       usbg_ret = usbg_create_function(g, F_FFS, NULL, &f_attrs, &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;
+}